( 12 ) United States Patent

Transcription

1 ( 12 ) United States Patent Hsueh et al. ( 54 ) IMAGING LENS SYSTEM, IMAGE CAPTURING UNIT AND ELECTRONIC DEVICE ( 71 ) Applicant : LARGAN Precision Co., Ltd., Taichung ( TW ) ( 72 ) Inventors : Chun Che Hsueh, Taichung ( TW ) ; Wei Yu Chen, Taichung ( TW ) ( 73 ) Assignee : LARGAN Precision Co., Ltd., ( * ) Notice : ( 21 ) Appl. No HAO WAKATI MWILINI NA UMUHIMU US B2 ( 10 ) Patent No. : US 9, 952, 412 B2 ( 45 ) Date of Patent : Apr. 24, 2018 ( 58 ) Field of Classification Search??? GO2B 9 / 64 USPC / 713 See application file for complete search history. ( 56 ) References Cited 8, 335, 043 B2 158, 094 B1, B1 9, 335, 518 B / A1 * U. S. PATENT DOCUMENTS 12 / 2012 Huang Chen et al Chen et al Chen et al. 9 / 2015 Chen.... Taichung ( TW ) GO2B 9 / / AL 2016 / A1 Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U. S. C. 154 ( b ) by 0 days.. : 15 / 354, 695 WO ( 22 ) Filed : Nov. 17, 2016 ( 65 ) Prior Publication Data US 2018 / A1 Mar. 1, 2018 ( 30 ) Foreign Application Priority Data Aug. 26, 2016 ( TW ) A ( 51 ) Int. CI. GO2B 3 / 02 ( ) GO2B 13 / 00 ( ) GO2B 5 / 00 ( ) GO2B 5 / 20 ( ) GO2B 27 / 00 ( ) GO2B 9 / 62 ( ) ( 52 ) U. S. CI. CPC GO2B 13 / 0045 ( ) ; GO2B 5 / 005 ( ) ; G02B 5 / 208 ( ) ; G02B 9 / 62 ( ) ; GO2B 27 / 0025 ( ) 2 / 2016 Chen et al. 5 / 2016 Tang et al. ( Continued ) FOREIGN PATENT DOCUMENTS / 2014 Primary Examiner James Jones ( 74 ) Attorney, Agent, or Firm Hanley, Flight & Zimmerman, LLC ( 57 ) ABSTRACT An imaging lens system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. The first lens element has negative refractive power. The third lens element and the fourth lens element both have positive refractive power. The fifth lens element with negative refractive power has an image side surface being concave in a paraxial region thereof, wherein an object side surface and the image side surface thereof are aspheric. The sixth lens element has an image side surface being concave in a paraxial region thereof, wherein the image side surface of the sixth lens element has at least one inflection point in an off axial region thereof, and an object side surface and the image side sur face thereof are aspheric. The imaging lens system total of six lens elements. 25 Claims, 19 Drawing Sheets has a ) mund

2 US 9, 952, 412 B2 Page 2 ( 56 ) References Cited U. S. PATENT DOCUMENTS 2016 / A15 / 2016 Chen et al / A15 / 2016 Chen et al. * cited by examiner

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11 U. S. Patent Apr. 24, 2018 Sheet 9 of 19 US 9, 952, 412 B2 590 W Wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww minnan maintaininnan wwwy 560 * wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww w wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww V 501 O?s Ots OES OOS n ožsi OCS. www * 561 UN WIAM w FIG. 9

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13 U. S. Patent Apr. 24, 2018 Sheet 11 of 19 US 9, 952, 412 B lami KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK K????????????????????? SNAKKAKKAAKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK?????? W MAMMA , FIG / 620 TES *

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17 U. S. Patent Apr. 24, 2018 Sheet 15 of 19 US 9, 952, 412 B2 SD ) FIG prompting SD Y

18 U. S. Patent Apr. 24, 2018 Sheet 16 of 19 US 9, 952, 412 B2 Sag FIG. 16 Sag

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20 U. S. Patent Apr. 24, 2018 Sheet 18 of 19 US 9, 952, 412 B2 mmmmmmm www FIG. 18

21 U. S. Patent Apr. 24, 2018 Sheet 19 of 19 US 9, 952, 412 B2 FIG. 19..

22 IMAGING LENS SYSTEM, IMAGE CAPTURING UNIT AND ELECTRONIC DEVICE US 9, 952, 412 B2 RELATED APPLICATION This application claims priority to Taiwan Application , filed Aug. 26, 2016, which is incorporated by reference herein in its entirety. 10 BACKGROUND 1. 0 < EAT / 756 < Technical Field total of six lens elements, and each of the lens elements of the imaging lens system is a single and non cemented lens element. When an axial distance between the fifth lens element and the sixth lens element is T56, a central thickness 5 of the sixth lens element is CT6, a sum of axial distances between every two lens elements of the imaging lens system adjacent to each other is 2Al, and the following conditio??s are satisfied : < 756 / CT6 < ; and According to another aspect of the present disclosure, an imaging lens system includes, in order from an object side The present disclosure relates to an imaging lens system. 15 to an image side, a first lens element, a second lens element, an image capturing unit and an electronic device, more a third lens element, a fourth lens element, a fifth lens particularly to an imaging lens system and an image cap element and a sixth lens element. The first lens element has turing unit applicable to an electronic device. negative refractive power. The third lens element has posi tive refractive power. The fourth lens element has positive Description of Related Art 20 refractive power. The fifth lens element with negative refrac tive power has an image side surface being concave in a In recent years, with the popularity of electronic devices paraxial region thereof, wherein an object side surface and having camera functionalities, the demand of miniaturized the image side surface of the fifth lens element are both optical systems has been increasing. As the advanced semi aspheric. The sixth lens element has an image side surface conductor manufacturing technologies have reduced the 25 being concave in a paraxial region thereof, wherein the pixel size of sensors, and compact optical systems have image side surface of the sixth lens element has at least one gradually evolved toward the field of higher megapixels, inflection point in an off axial region thereof, and an object there is an increasing demand for compact optical systems side surface and the image side surface of the sixth lens featuring better image quality. element are both aspheric. The imaging lens system has a The optical systems have been widely applied to different 30 total of six lens elements, and each of the lens elements of kinds of smart electronic devices, such as vehicle devices, the imaging lens system is a single and non cemented lens image recognition systems, entertainment devices, sport element. When an axial distance between the fifth lens devices and intelligent home assistance systems, for various element and the sixth lens element is T56, a central thickness requirements. In order to provide better user experience, the of the sixth lens element is CT6, a curvature radius of the electronic device equipped with one or more optical systems 35 object side surface of the fifth lens element is R9, a curva having different fields of view has become the mainstream ture radius of the image side surface of the fifth lens element product in the market. For various applications, the optical is R10, and the following conditions are satisfied : systems are developed with various optical characteristics, such that there is an increasing demand for optical system < 756 / CT6 < ; and featuring wide field of view, and the specifications of the 40 optical system are also harder to satisfy < ( R9 + R10 )/ ( R9 R10 ) < However, the conventional optical system is unable to According to another aspect of the present disclosure, an satisfy the requirements of wide field of view and compact image capturing unit includes one of the aforementioned size simultaneously, such that it is difficult to be adopted for imaging lens system and an image sensor, wherein the image use in current compact electronic devices. Thus, there is a 45 sensor is disposed on an image surface of the imaging lens need to develop an optical system featuring wide viewing system. angle, compact size and high image quality. According to still another aspect of the present disclosure, an electronic device includes the aforementioned image SUMMARY capturing unit. 50 According to one aspect of the present disclosure, an BRIEF DESCRIPTION OF THE DRAWINGS imaging lens system includes, in order from an object side to an image side, a first lens element, a second lens element, The disclosure can be better understood by reading the a third lens element, a fourth lens element, a fifth lens following detailed description of the embodiments, with element and a sixth lens element. The first lens element has 55 reference made to the accompanying drawings as follows : negative refractive power. The third lens element has posi FIG. 1 is a schematic view of an image capturing unit tive refractive power. The fourth lens element has positive according to the 1st embodiment of the present disclosure ; refractive power. The fifth lens element with negative refrac FIG. 2 shows spherical aberration curves, astigmatic field tive power has an image side surface being concave in a curves and a distortion curve of the image capturing unit paraxial region thereof, wherein an object side surface and 60 according to the 1st embodiment ; the image side surface of the fifth lens element are both FIG. 3 is a schematic view of an image capturing unit aspheric. The sixth lens element has an image side surface according to the 2nd embodiment of the present disclosure ; being concave in a paraxial region thereof, wherein the FIG. 4 shows spherical aberration curves, astigmatic field image side surface of the sixth lens element has at least one curves and a distortion curve of the image capturing unit inflection point in an off axial region thereof, and an object 65 according to the 2nd embodiment ; side surface and the image side surface of the sixth lens FIG. 5 is a schematic view of an image capturing unit element are both aspheric. The imaging lens system has a according to the 3rd embodiment of the present disclosure ;

23 US 9, 952, 412 B2 FIG. 6 shows spherical aberration curves, astigmatic field ering light from a large view angle in the imaging lens curves and a distortion curve of the image capturing unit system. according to the 3rd embodiment ; The third lens element has positive refractive power. FIG. 7 is a schematic view of an image capturing unit Therefore, it is favorable for correcting aberrations gener according to the 4th embodiment of the present disclosure sure :; 5 al ated by the first lens element. The fourth lens element has positive refractive power. FIG. 8 shows spherical aberration curves, astigmatic field Therefore, it is favorable for balancing the refractive power curves and a distortion curve of the image capturing unit distribution of the imaging lens system so as to reduce the according to the 4th embodiment ; sensitivity. FIG. 9 is a schematic view of an image capturing unit The fifth lens element with negative refractive power has according to the 5th embodiment of the present disclosure ; " an image side surface being concave in a paraxial region FIG. 10 shows spherical aberration curves, astigmatic thereof. Therefore, it is favorable for properly arranging the field curves and a distortion curve of the image capturing refractive power distribution among the third, the fourth and unit according to the 5th embodiment ; the fifth lens elements so as for light converging on an image FIG. 11 is a schematic view of an image capturing unit 16 surface while reducing the back focal length to maintain a according to the 6th embodiment of the present disclosure ; 15 compact size thereof. FIG. 12 shows spherical aberration curves, astigmatic The sixth lens element has an image side surface being concave in a paraxial region thereof, wherein the image side field curves and a distortion curve of the image capturing surface of the sixth lens element has at least one inflection unit according to the 6th embodiment ; point in an off axial region thereof. Therefore, it is favorable FIG. 13 is a schematic view of an image capturing unit 20 for reducing the back focal length and correcting aberrations according to the 7th embodiment of the present disclosure ; at the off axial region. FIG. 14 shows spherical aberration curves, astigmatic When an axial distance between the fifth lens element and field curves and a distortion curve of the image capturing the sixth lens ler element is T56, a central thickness of the sixth unit according to the 7th embodiment ; lens element is CT6, the following condition is satisfied : FIG. 15 shows a schematic view of the parameters SD < 156 / CT6 < Therefore, it is favorable for providing and SD62 according to the 1st embodiment of the present sufficient space between the fifth lens element and the sixth lens element so as to prevent molding and assembling disclosure ; problems generated by overly short axial distance in the FIG. 16 shows a schematic view of the parameters Sag21 off axial region. Preferably, the following condition can also and Sag22 according to the 1st embodiment of the present be satisfied : < T56 / CT6 < disclosure ; When a sum of axial distances between every two lens FIG. 17 shows an electronic device according to one elements of the imaging lens system adjacent to each other embodiment ; is EAT, the axial distance between the fifth lens element and FIG. 18 shows an electronic device according to another the sixth lens element is T56, the following condition is embodiment ; and satisfied : 1. 0 < EAT / T56 < Therefore, it is favorable for FIG. 19 shows an electronic device according to still 35 preventing the axial distances between every two lens ele ments that are adjacent to each other from overly large so another embodiment. that the internal space of the imaging lens system can be effectively used, thereby satisfying the requirements of short DETAILED DESCRIPTION track length and compact size. Preferably, the following 40 condition can also be satisfied : < EAT / T56 < An imaging lens system includes, in order from an object When a curvature radius of an object side surface of the side to an image side, a first lens element, a second lens fifth lens element is R9, a curvature radius of the image side element, a third lens element, a fourth lens element, a fifth surface of the fifth lens element is R10, the following lens element and a sixth lens element. The imaging lens condition is satisfied : O < ( R9 + R10 )/( R9 R10 ) < There system has a total of six lens elements. 45 fore, it is favorable for properly arranging the shape of the There can be an air gap in a paraxial region between every fifth lens element in accordance with the shapes of the third two lens elements of the imaging lens system that are and the fourth lens elements for correcting aberrations adjacent to each other, that is, each of the first through the generated by the third and the fourth lens elements with sixth lens elements can be a single and non cemented lens stronger positive refractive power. Preferably, the following element. The manufacturing process of the cemented lenses 50 condition can also be satisfied : < ( R9 + R10 )/ ( R9 R10 ) is more complex than the non cemented lenses, particularly < More preferably, the following condition can also be when an image side surface of one lens element and an satisfied : 1. 0 < ( R9 + R10 )/ ( R9 R10 ) < object side surface of the following lens element need to When a curvature radius of the object side surface of the have accurate curvatures to ensure both lenses being highly first lens element is R1, a curvature radius of an image side cemented. However, during the cementing process, those 55 surface of the first lens element is R2, the following condi two lens elements might not be highly cemented due to tion can be satisfied : < ( R1 + R2 )/ ( R1 R2 ) < There displacement and it is thereby not favorable for the image fore, the surface curvatures of the first lens element are quality. Therefore, having an air gap in a paraxial region properly arranged so that it is favorable for enlarging the between every two lens elements of the imaging lens system field of view and correcting aberrations. that are adjacent to each other in the present disclosure can 60 When a focal length of the imaging lens system is f, an avoid the problem generated by the cemented lens elements entrance pupil diameter of the imaging lens system is EPD, while improving the yield rate. the following condition can be satisfied : 1. 0 < f / EPD < The first lens element with negative refractive power can Therefore, it is favorable for providing sufficient incident have an object side surface being concave in a paraxial light so as to improve the image quality. region thereof, wherein the object side surface of the first 65 When a curvature radius of an object side surface of the lens element can have at least one convex shape in an sixth lens element is R11, a curvature radius of the image off axial region thereof. Therefore, it is favorable for gath side surface of the sixth lens element is R12, the following

24 US 9, 952, 412 B2 condition can be satisfied : ( R11 R12 )/( R11 + R12 )] < surface of the second lens element is Sag22, a central Therefore, it is favorable for arranging the refractive power thickness of the second lens element is CT2, the following of the sixth lens element so that excessive aberration cor condition can be satisfied : ( 1Sag211 + Sag221 )/ CT2 < rections due to overly strong refractive power of the sixth Therefore, when the central thickness of the second lens lens element is prevented ; furthermore, it is favorable for 5 element is thinner, it is favorable for preventing the surfaces reducing the difference between the central thickness and the of the second lens element from overly curved and complex peripheral thickness of the sixth lens element so as to so as to reduce molding problems. As seen in FIG. 16, it prevent molding problems. shows a schematic view of the parameters Sag21 and Sag22 When an axial distance between the object side surface of in FIG. 1. When the direction from the axial vertex of the the first lens element and the image surface is TL, the focal 10 surface to the maximum effective radius position of the length of the imaging lens system is f, half of a maximal field surface is facing towards the image side of the imaging lens of view of the imaging lens system is HFOV, the following system, the value of the Sag21 or Sag22 is positive ; other condition can be satisfied : TL /[ f * tan ( HFOV ) ] < There wise, the value is negative. fore, it is favorable for further enlarging the field of view and When a curvature radius of an object side surface of the keeping the imaging lens system compact. 15 third lens element is R5, a curvature radius of an image side When the focal length of the imaging lens system is f, a surface of the third lens element is R6, the following curvature radius of an object side surface of the second lens condition can be satisfied : < ( R5 + R6 )/ ( R5 R6 ) < element is R3, a curvature radius of an image side surface of Therefore, the third lens element arranged with the negative the second lens element is R4, the following condition can first lens element is favorable for projecting light on the be satisfied : ( f / R3 ] + \ f / R41 < Therefore, it is favorable 20 image surface while correcting aberrations generated by the for gathering light in the imaging lens system so as to first lens element. prevent overly small light cone generated by overly fast light When the maximal field of view of the imaging lens convergence, thereby improving relative luminance at the system is HFOV, the following condition can be satisfied : peripheral region of the image. 100 [ deg. ] < FOV < 160 [ deg. ). Therefore, it is favorable for When the sum of axial distances between every two lens 25 providing the imaging lens system with sufficient imaging elements of the imaging lens system adjacent to each other range while reducing distortions. is EAT, an axial distance between the second lens element When the axial distance between the object side surface and the third lens element is T23, an axial distance between of the first lens element and the image surface is TL, a the third lens element and the fourth lens element is T34, an maximum image height of the imaging lens system ( which axial distance between the fourth lens element and the fifth 30 can be measured in half of a diagonal length of an effective lens element is T45, the following condition can be satisfied : photosensitive area of an image sensor ) is ImgH, the fol 4 < EAT / ( T23 + T34 + T45 ) < 25. Therefore, it is favorable for lowing condition can be satisfied : 1. 0 < TL / ImgH < preventing the axial distances among the second through the Therefore, it is favorable for miniaturizing the imaging lens fifth lens elements from overly large so as to provide better system so as to be equipped in a compact electronic device. lens configuration. 35 When a focal length of the first lens element is fl, a focal When the focal length of the imaging lens system is f, the length of the second lens element is f2, a focal length of the curvature radius of the image side surface of the sixth lens third lens element is f3, a focal length of the fourth lens element is R12, the following condition can be satisfied : element is f4, a focal length of the fifth lens element is f5, < R12 / f < Therefore, it is favorable for moving the a focal length of the sixth lens element is f6, a focal length principal point of the imaging lens system towards the object 40 of the x th lens element is fx, the following condition can be side so as to reduce the back focal length while keeping the satisfied : \ fx / < \ f2, wherein x = 1, 3, 4, 5, 6. Therefore, it is imaging lens system compact. favorable for balancing the refractive power distribution so When a maximum among all central thicknesses of the as to prevent excessive refraction and generating surface lens elements of the imaging lens system is CTmax, the axial internal reflection. distance between the fifth lens element and the sixth lens 45 According to the present disclosure, at least three of the element is T56, the following condition can be satisfied : lens elements of the imaging lens system can have an Abbe CTmax / T56 < Therefore, it is favorable for preventing number smaller than 30. In detail, there can be three or more the thickness of a single lens element from overly large so lens elements whose Abbe numbers are smaller than 30 that the space in the imaging lens system can be effectively among the first lens element, the second lens element, the used ; furthermore, it is favorable for arranging the central 50 third lens element, the fourth lens element, the fifth lens thicknesses of the lens elements so as to reduce molding element and the sixth lens element. Therefore, it is favorable problems. for balancing the focusing positions with different wave When an Abbe number of the fourth lens element is V4, lengths so as to correct chromatic aberrations. an Abbe number of the fifth lens element is V5, an Abbe When a maximum effective radius of the object side number of the sixth lens element is V6, the following 55 surface of the first lens element is SD11, a maximum condition can be satisfied : < ( V5 + V6N4 < There effective radius of the image side surface of the sixth lens fore, it is favorable for obtaining a balance between the element is SD62, the following condition can be satisfied : astigmatism correction and the chromatic aberration correc SD11 / SD621 < Therefore, it is favorable for reducing tion while reducing the effective radius of the sixth lens the size of the first lens element so as to keep the imaging element so as to maintain a compact size thereof. 60 lens system compact. As seen in FIG. 15, it shows a When a displacement in parallel with an optical axis from schematic view of the parameters SD11 and SD62 in FIG. 1. an axial vertex of the object side surface of the second lens According to the present disclosure, the lens elements of element to a maximum effective radius position of the the imaging lens system can be made of glass or plastic object side surface of the second lens element is Sag21, a material. When the lens elements are made of glass material, displacement in parallel with the optical axis from an axial 65 the refractive power distribution of the imaging lens system vertex of the image side surface of the second lens element may be more flexible to design. When the lens elements are to a maximum effective radius position of the image side made of plastic material, manufacturing costs can be effec

25 US 9, 952, 412 B2 tively reduced. Furthermore, surfaces of each lens element devices, motion sensing input devices, dashboard cameras, can be arranged to be aspheric, since the aspheric surface of vehicle backup cameras and other electronic imaging the lens element is easy to form a shape other than a devices. According to the above description of the present spherical surface so as to have more controllable variables disclosure, the following specific embodiments are provided for eliminating aberrations thereof and to further decrease 5 for further explanation. the required number of the lens elements. Therefore, the total track length of the imaging lens system can also be 1st Embodiment reduced. According to the present disclosure, each of an object FIG. 1 is a schematic view of an image capturing unit side surface and an image side surface of a lens element has 10 according to the 1st embodiment of the present disclosure. a paraxial region and an off axial region. The paraxial region FIG. 2 shows, in order from left to right, spherical aberration refers to the region of the surface where light rays travel curves, astigmatic field curves and a distortion curve of the close to the optical axis, and the off axial region refers to the image capturing unit according to the 1st embodiment. In region of the surface away from the paraxial region. Par FIG. 1, the image capturing unit includes the imaging lens ticularly unless otherwise stated, when the lens element has 15 system ( its reference numeral is omitted ) of the present a convex surface, it indicates that the surface can be convex disclosure and an image sensor 190. The imaging lens in the paraxial region thereof ; when the lens element has a system includes, in order from an object side to an image concave surface, it indicates that the surface can be concave side, a first lens element 110, a second lens element 120, an in the paraxial region thereof. Moreover, when a region of aperture stop 100, a third lens element 130, a fourth lens refractive power or focus of a lens element is not defined, it 20 element 140, a fifth lens element 150, a sixth lens element indicates that the region of refractive power or focus of the 160, an IR cut filter 170 and an image surface 180, wherein lens element can be in the paraxial region thereof. the imaging lens system has a total of six single and According to the present disclosure, an image surface of non cemented lens elements ( ). the imaging lens system on a corresponding image sensor The first lens element 110 with negative refractive power can be flat or curved, particularly a concave curved surface 25 has an object side surface 111 being concave in a paraxial facing towards the object side of the imaging lens system. region thereof and an image side surface 112 being concave According to the present disclosure, the imaging lens in a paraxial region thereof. The first lens element 110 is system can include at least one stop, such as an aperture made of plastic material and has the object side surface 111 stop, a glare stop or a field stop. Said glare stop or said field and the image side surface 112 being both aspheric. The stop is allocated for eliminating the stray light and thereby 30 object side surface 111 of the first lens element 110 has at improving the image quality thereof. least one convex shape in an off axial region thereof. According to the present disclosure, an aperture stop can T he second lens element 120 with negative refractive be configured as a front stop or a middle stop. A front stop power has an object side surface 121 being concave in a disposed between the imaged object and the first lens paraxial region thereof and an image side surface 122 being element can produce a telecentric effect by providing a 35 concave in a paraxial region thereof. The second lens longer distance between an exit pupil and the image surface, element 120 is made of plastic material and has the object thereby improving the image sensing efficiency of an image side surface 121 and the image side surface 122 being both sensor ( for example, CCD or CMOS ). A middle stop dis aspheric. posed between the first lens element and the image surface The third lens element 130 with positive refractive power is favorable for enlarging the view angle and thereby pro 40 has an object side surface 131 being convex in a paraxial vides a wider field of view. region thereof and an image side surface 132 being convex According to the present disclosure, an image capturing in a paraxial region thereof. The third lens element 130 is unit includes the aforementioned imaging lens system and made of plastic material and has the object side surface 131 image sensor, wherein the image sensor is disposed on the and the image side surface 132 being both aspheric. image side and can be located on or near the image surface 45 The fourth lens element 140 with positive refractive of the aforementioned imaging lens system. In some power has an object side surface 141 being convex in a embodiments, the image capturing unit can further include paraxial region thereof and an image side surface 142 being a barrel member, a holder member or a combination thereof. convex in a paraxial region thereof. The fourth lens element In FIG. 17, FIG. 18 and FIG. 19, an image capturing unit 140 is made of plastic material and has the object side 10 may be installed in, but not limited to, an electronic 50 surface 141 and the image side surface 142 being both device, including a smartphone ( FIG. 17 ), a tablet computer aspheric ( FIG. 18 ) or a wearable device ( FIG. 19 ). The electronic The fifth lens element 150 with negative refractive power devices shown in the figures are only exemplary for showing has an object side surface 151 being concave in a paraxial the image capturing unit of the present disclosure installed region thereof and an image side surface 152 being concave in an electronic device and are not limited thereto. In some 55 in a paraxial region thereof. The fifth lens element 150 is embodiments, the electronic device can further include, but made of plastic material and has the object side surface 151 not limited to, a display unit, a control unit, a storage unit, and the image side surface 152 being both aspheric. a random access memory unit ( RAM ), a read only memory The sixth lens element 160 with negative refractive power unit ( ROM ) or a combination thereof. has an object side surface 161 being convex in a paraxial According to the present disclosure, the imaging lens 60 region thereof and an image side surface 162 being concave system can be optionally applied to optical systems with a in a paraxial region thereof. The sixth lens element 160 is movable focus. Furthermore, the imaging lens system is made of plastic material and has the object side surface 161 featured with good capability in aberration corrections and and the image side surface 162 being both aspheric. The high image quality, and can be applied to 3D ( three dimen image side surface 162 of the sixth lens element 160 has at sional ) image capturing applications, in products such as 65 least one inflection point in an off axial region thereof. such as digital cameras, mobile devices, digital tablets, The IR cut filter 170 is made of glass material and located wearable devices, smart televisions, network surveillance between the sixth lens element 160 and the image surface

26 US 9, 952, 412 B , and will not affect the focal length of the imaging lens is TL, a maximum image height of the imaging lens system system. The image sensor 190 is disposed on or near the is ImgH, the following condition is satisfied : image surface 180 of the imaging lens system. TL / ImgH = The equation of the aspheric surface profiles of the When the axial distance between the object side surface aforementioned lens elements of the 1st embodiment is 111 of the first lens element 110 and the image surface 180 expressed as follows : is TL, half of the maximal field of view of the imaging lens system is HFOV, the following condition is satisfied : TL / [ f * tan ( HFOV ) ] = X ( Y ) = ( Y? / R ) / ( 1 + sqrt ( 1 ( 1 + k ) * ( Y / R ) )) + ( AI ) ( Y '), 10 When a curvature radius of the object side surface 111 of the first lens element 110 is R1, a curvature radius of the image side surface 112 of the first lens element 110 is R2, where, the following condition is satisfied : ( R1 + R2 )/( R1 R2 ) = X is the relative distance between a point on the aspheric 15 surface spaced at a distance Y from an optical axis and the When a curvature radius of the object side surface 131 of tangential plane at the aspheric surface vertex on the optical the third lens element 130 is R5, a curvature radius of the axis ; image side surface 132 of the third lens element 130 is R6, Y is the vertical distance from the point on the aspheric the following condition is satisfied : ( R5 + R6 )/( R5 R6 ) = surface to the optical axis ; R is the curvature radius ; When a curvature radius of the object side surface 151 of the fifth lens element 150 is R9, a curvature radius of the k is the conic coefficient ; and image side surface 152 of the fifth lens element 150 is R10, Ai is the i th aspheric coefficient, and in the embodiments, the following condition is satisfied : ( R9 + R10 )/ ( R9 R10 ) = i may be, but is not limited to, 4, 6, 8, 10, 12, 14 and In the imaging lens system of the image capturing unit When a curvature radius of the object side surface 161 of according to the 1st embodiment, when a focal length of the the sixth lens element 160 is R11, a curvature radius of the imaging lens system is f, an f number of the imaging lens image side surface 162 of the sixth lens element 160 is R12, system is Fno, and half of a maximal field of view of the 30 the following condition is satisfied : I ( R11 R12 )/( R11 + imaging lens system is HFOV, these parameters have the R12 ) = following values : f = millimeters ( mm ), Fno = f / When the focal length of the imaging lens system is f, the EPD = ; and HFOV = degrees ( deg.). curvature radius of the image side surface 162 of the sixth When the maximal field of view of the imaging lens lens element 160 is R12, the following condition is satisfied : system is FOV, the following condition is satisfied :» R12 / f = FOV = 120 deg. When the focal length of the imaging lens system is f, a When an Abbe number of the fourth lens element 140 is curvature radius of the object side surface 121 of the second V4, an Abbe number of the fifth lens element 150 is V5, an lens element 120 is R3, a curvature radius of the image side Abbe number of the sixth lens element 160 is V6, the 40 surface 122 of the second lens element 120 is R4, the following condition is satisfied : ( V5 + V6 )/ 4 = following condition is satisfied : / f / R3 [ + ] f / R41 = When a maximum among all central thicknesses of the When a displacement in parallel with an optical axis from lens elements ( ) of the imaging lens system is an axial vertex of the object side surface 121 of the second CTmax, an axial distance between the fifth lens element lens element 120 to a maximum effective radius position of and the sixth lens element 160 is T56, the following con the object side surface 121 of the second lens element 120 dition is satisfied : CTmax / T56 = is Sag21, a displacement in parallel with the optical axis When the axial distance between the fifth lens element from an axial vertex of the image side surface 122 of the 150 and the sixth lens element 160 is T56, a central thickness second lens element 120 to a maximum effective radius of the sixth lens element 160 is CT6, the following condition 50 position of the image side surface 122 of the second lens is satisfied : T56 / CT6 = element 120 is Sag22, a central thickness of the second lens element 120 is CT2, the following condition is satisfied : When a sum of axial distances between every two lens elements of the imaging lens system adjacent to each other ( 1Sag211 + Sag221 )/ CT2 = is EAT, an axial distance between the second lens element When a maximum effective radius of the object side 120 and the third lens element 130 is T23. an axial distance 55 surface 111 of the first lens element 110 is SD11, a maximum between the third lens element 130 and the fourth lens effective radius of the image side surface 162 of the sixth element 140 is T34. an axial distance between the fourth lens lens element 160 is SD62, the following condition is satis element 140 and the fifth lens element 150 is T45, the fied : ISD11 / SD62I = following condition is satisfied : EAT /( T23 + T34 + T45 ) = In this embodiment, three of the lens elements ( ) When the sum of axial distances between every two lens of the imaging lens system has an Abbe number smaller than elements of the imaging lens system adjacent to each other 30. In detail, the Abbe numbers of the second lens element is XAT, the axial distance between the fifth lens element , the fifth lens element 150 and the sixth lens element 160 and the sixth lens element 160 is T56, the following con are all smaller than 30. dition is satisfied : EAT / T56 = The detailed optical data of the 1st embodiment are shown When an axial distance between the object side surface in Table 1 and the aspheric surface data are shown in Table 111 of the first lens element 110 and the image surface below.

27 Surface 11 TABLE 1 1 st Embodiment f = mm. Fno = HFOV = deg Curvature Radius # Thickness Material Index Ovaa AwNFO Object ( ASP ) Infinity US 9, 952, 412 B2 Abbe # Focal Length Lens 1 Plastic ASP ) Lens ASP Plastic ( ASP ) ( ASP ) Ape. Stop Lens 3 Plastic ASP Lens ASP Plastic ( ASP ) ASP ASP Lens ( ASP ) Plastic ( ASP ) Image Lens 5 Plastic IR cut filter Glass Note : Reference wavelength is nm ( d line ). TABLE 2 Aspheric Coefficients Surface # 1 k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E + 00 A8 = E E E E E E + 01 A10 = E E E E E E 01 A12 = E E E E E E + 01 A14 = E E E E Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 02 A8 = E E E E E E 02 A10 = E E E E E E 02 A12 = E E E E E E 03 A14 = E E E E E E 03 A16 = E E E E E E 04 In Table 1, the curvature radius, the thickness and the 50 FIG. 4 shows, in order from left to right, spherical aberration focal length are shown in millimeters ( mm ). Surface num curves, astigmatic field curves and a distortion curve of the bers 0 16 represent the surfaces sequentially arranged from image capturing unit according to the 2nd embodiment. In the object side to the image side along the optical axis. In FIG. 3, the image capturing unit includes the imaging lens Table 2, k represents the conic coefficient of the equation of the aspheric surface profiles. A4 A16 represent the aspheric 55 system ( its reference numeral is omitted ) of the present coefficients ranging from the 4th order to the 16th order. The disclosure and an image sensor 290. The imaging lens system includes, in order from an object side to an image tables presented below for each embodiment are related to the corresponding schematic and aberration curves figures in side, a first lens element 210, an aperture stop 200, a second the drawing, and the definitions of the terms in the tables are lens element 220, a third lens element 230, a fourth lens the same as Table 1 and Table 2 of the 1st embodiment. 60 so element 240, a fifth lens element 250, a sixth lens element Therefore, an explanation in this regard will not be provided 260, an IR cut filter 270 and an image surface 280, wherein again. the imaging lens system has a total of six single and non cemented lens elements ( ). 2nd Embodiment The first lens element 210 with negative refractive power 65 has an object side surface 211 being concave in a paraxial FIG. 3 is a schematic view of an image capturing unit region thereof and an image side surface 212 being concave according to the 2nd embodiment of the present disclosure. in a paraxial region thereof. The first lens element 210 is

28 US 9, 952, 412 B made of plastic material and has the object side surface 211 The fifth lens element 250 with negative refractive power and the image side surface 212 being both aspheric. The has an object side surface 251 being concave in a paraxial object side surface 211 of the first lens element 210 has at region thereof and an image side surface 252 being concave least one convex shape in an off axial region thereof. The second lens element 220 with positive refractive in a paraxial region thereof. The fifth lens element 250 is power has an object side surface 221 being convex in a e 5 made of plastic material and has the object side surface 251 paraxial region thereof and an image side surface 222 being and the image side surface 252 being both aspheric. concave in a paraxial region thereof. The second lens The sixth lens element 260 with positive refractive power element 220 is made of plastic material and has the object has an object side surface 261 being convex in a paraxial side surface 221 and the image side surface 222 being both in region thereof and an image side surface 262 being concave aspheric. in a paraxial region thereof. The sixth lens element 260 is The third lens element 230 with positive refractive power made of plastic material and has the object side surface 261 has an object side surface 231 being concave in a paraxial and the image side surface 262 being both aspheric. The region thereof and an image side surface 232 being convex image side surface 262 of the sixth lens element 260 has at in a paraxial region thereof. The third lens element 230 is made of plastic material and has the object side surface least one inflection point in an off axial region thereof. and the image side surface 232 being both aspheric. The IR cut filter 270 is made of glass material and located The fourth lens element 240 with positive refractive between the sixth lens element 260 and the image surface power has an object side surface 241 being convex in a 280, and will not affect the focal length of the imaging lens paraxial region thereof and an image side surface 242 being system. The image sensor 290 is disposed on or near the convex in a paraxial region thereof. The fourth lens element 20 image surface 280 of the imaging lens system. 240 is made of plastic material and has the object side The detailed optical data of the 2nd embodiment are surface 241 and the image side surface 242 being both shown in Table 3 and the aspheric surface data are shown in aspheric Table 4 below. TABLE 3 Surface uw Nova W NO Object Lens 1 Lens 1 Ape. Stop 2nd Embodiment f = mm, Fno = 2. 02, HFOV = deg. Curvature Radius ( ASP ) ( ASP ) Thickness Material Index Abbe # Infinity Focal Length Plastic Lens Plastic ( ASP ) Lens ( ASP Plastic ( ASP ) Lens ( ASP ) Plastic ? Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) ? IR cut filter Glass Image Note : Reference wavelength is nm ( d line ). An effective radius of the image side surface 242 ( Surface 9 ) is mm. TABLE 4 Aspheric Coefficients Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 01 A8 = E E E E E E + 00 A10 = E E E E E E + 00

29 15 TABLE 4 continued Aspheric Coefficients A12 = E E E E + 00 A14 = E E + 00 US 9, 952, 412 B E E E E 01 Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 01 A8 = E E E E E E 02 A10 = E E E E E E 03 A12 = E E E E E E 04 A14 = E E E E E E 04 A16 = E E E In the 2nd embodiment, the equation of the aspheric made of plastic material and has the object side surface 311 surface profiles of the aforementioned lens elements is the 20 and the image side surface 312 being both aspheric. The same as the equation of the 1st embodiment. Also, the object side surface 311 of the first lens element 310 has at definitions of these parameters shown in the following table least one convex shape shane in an off axial region thereof. are the same as those stated in the 1st embodiment with corresponding values for the 2nd embodiment, so an expla The second lens element 320 with negative refractive nation in this regard will not be provided again. 25 power has an object side surface 321 being convex in a Moreover, these parameters can be calculated from Table paraxial region thereof and an image side surface 322 being 3 and Table 4 as the following values and satisfy the concave in a paraxial region thereof. The second lens following conditions : element 320 is made of plastic material and has the object side surface 321 and the image side surface 322 being both 30 aspheric. 2nd Embodiment The third lens element 330 with positive refractive power f [ mm ] 1 91 TL /[ f * tan ( HFOV )] 1 45 has an object side surface 331 being concave in a paraxial f / EPD 2 02 ( R1 R2 )/( R1 R2 ) region thereof and an image side surface 332 being convex HFOV [ deg.] ( R5 + R6 ( R5 R6 ) in a paraxial region thereof. The third lens element 330 is FOV [ deg.] ( R9 + R10 )/ ( R9 R10 ) made of plastic material and has the object side surface 331 FO ( V5 + V6 / V ( R11 R12 )/ ( R11 + R12 ) CTmax T R12 / f and the image side surface 332 being both aspheric. T56 / CT f / R3 + f / R4 82 ZAT / ( T23 + T34 + T45 ) ( Sag211 + Sag221 )/ CT The fourth lens element 340 with positive refractive ZAT / T SD11 / SD power has an object side surface 341 being convex in a TL / ImgH The quantity of the lens 3 20 paraxial region thereof and an image side surface 342 being elements with Abbe # smaller than 30 convex in a paraxial region thereof. The fourth lens element 340 is made of plastic material and has the object side surface 341 and the image side surface 342 being both aspheric. 3rd Embodiment 45 The fifth lens element 350 with negative refractive power FIG. 5 is a schematic view of an image capturing unit has an object side surface 351 being concave in a paraxial according to the 3rd embodiment of the present disclosure. region thereof and an image side surface 352 being concave FIG. 6 shows, in order from left to right, spherical aberration in a paraxial region thereof. The fifth lens element 350 is made of plastic material and has the object side surface 351 curves, astigmatic field curves and a distortion curve of the 50 and a image capturing unit according to the 3rd embodiment. In the image side surface 352 being both aspheric. FIG. 5, the image capturing unit includes the imaging lens The sixth lens element 360 with negative refractive power has an object side surface 361 being convex in a paraxial system ( its reference numeral is omitted ) of the present region thereof and an image side surface 362 being concave disclosure and an image sensor 390. The imaging lens in a paraxial region thereof. The sixth lens element 360 is system includes, in order from an object side to an image 55 made of plastic material and has the object side surface 361 side, a first lens element 310, an aperture stop 300, a second and the image side surface 362 being both aspheric. The lens element 320, a stop 301, a third lens element 330, a image side surface 362 of the sixth lens element 360 has at fourth lens element 340, a fifth lens element 350, a sixth lens least one inflection point in an off axial region thereof. element 360, an IR cut filter 370 and an image surface 380, The IR cut filter 370 is made of glass material and located wherein the imaging lens system has a total of six single and between the sixth lens element 360 and the image surface non cemented lens elements ( ). The stop 301 can be 380, and will not affect the focal length of the imaging lens a glare stop or a field stop. system. The image sensor 390 is disposed on or near the The first lens element 310 with negative refractive power image surface 380 of the imaging lens system. has an object side surface 311 being concave in a paraxial 65 The detailed optical data of the 3rd embodiment are region thereof and an image side surface 312 being concave shown in Table 5 and the aspheric surface data are shown in in a paraxial region thereof. The first lens element 310 is Table 6 below.

30 Surface 17 TABLE 5 3rd Embodiment f = mm. Fno = HFOV = deg Curvature Radius # Thickness Material Index US 9, 952, 412 B2 Focal Length Abbe # Object Infinity Lens ( ASP ) Plastic ( ASP ) Ape. Stop Lens ( ASP Plastic ( ASP ) Stop Ovaa AwNFO Lens ASP Plastic ( ASP ) Lens ( ASP Plastic ASP Lens ASP Plastic ASP Lens ASP ) Plastic ( ASP ) IR cut filter Glass Image Note : Reference wavelength is nm ( d line ). An effective radius of the stop 301 ( surface 6 ) is mm. 1 TABLE 6 Aspheric Coefficients Surface # k =. 0574E E E E E E + 00 A4 = 0776E E E E E E 01 A6 = E E E E E E + 00 A8 = E E E E E E + 00 A10 = E E E E E E + 00 A E E E E E E + 00 A14 = E E E E + 00 Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 02 A8 = E E E E E E 02 A10 = E E E E E E 03 A12 = E E E E E E 03 A14 = E E E E E E 04 A16 = E E E E E E 05 In the 3rd embodiment, the equation of the aspheric surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table 55 are the same as those stated in the 1st embodiment with HFOV [ deg.] corresponding values for the 3rd embodiment, so an expla FOV [ deg.] nation in this regard will not be provided again. ( V5 + V6 )/ V4 Moreover, these parameters can be calculated from Table CTmax / T56 5 and Table 6 as the following values and satisfy the 60 T56 / CT6 following conditions : LAT /( T23 + T34 + T45 ) EAT / T56 TL / ImgH f [ mm ] f / EPD 3rd Embodiment TL / [ f * tan ( HFOV ) ] ( R1 + R2 ) / ( R1 R2 ) continued 3rd Embodiment ( R5 + R6 ) ( R5 R6 ) ( R9 + R10 ) / ( R9 R10 ) R11 R12 ) / ( R11 + R12 ) R12 / f ( f / R3 + \ f / R ( Sag21 ] + Sag22 ] ) / CT SD11 / SD The quantity of the lens elements with Abbe # smaller than

31 2 US 9, 952, 412 B2 19 4th Embodiment The third lens element 430 with positive refractive power has an object side surface 431 being concave in a paraxial FIG. 7 is a schematic view of an image capturing unit region thereof and an image side surface 432 being convex according to the 4th embodiment of the present disclosure. in a paraxial region thereof. The third lens element 430 is FIG. 8 shows, in order from left to right. spherical aberration 5 made of plastic material and has the object side surface 431 curves, astigmatic field curves and a distortion curve of the and the image side surface 432 being both aspheric. The fourth lens element 440 with positive refractive image capturing unit according to the 4th embodiment. In power has an object side surface 441 being convex in a FIG. 7, the image capturing unit includes the imaging lens paraxial region thereof and an image side surface 442 being system ( its reference numeral is omitted ) of the present convex in a paraxial region thereof. The fourth lens element disclosure and an image sensor 490. The imaging lens 440 is made of plastic material and has the object side system includes, in order from an object side to an image surface 441 and the image side surface 442 being both side, a first lens element 410, an aperture stop 400, a second aspheric. lens element 420, a third lens element 430, a fourth lens The fifth lens element 450 with negative refractive power element 440 a fifth lens element 450, a stop 401, a sixth lens, has an object side surface 451 being convex in a paraxial element 460, an IR cut filter 470 and an image surface 480, 15 region thereof and an image side surface 452 being concave in a paraxial region thereof. The fifth lens element 450 is wherein the imaging lens system has a total of six single and made of plastic material and has the object side surface 451 non cemented lens elements ( ). The stop 401 can be and the image side surface 452 being both aspheric. a glare stop or a field stop. The sixth lens element 460 with negative refractive power The first lens element 410 with negative refractive power 20 has an object side surface 461 being convex in a paraxial has an object side surface 411 being concave in a paraxial region thereof and an image side surface 462 being concave region thereof and an image side surface 412 being concave in a paraxial region thereof. The sixth lens element 460 is in a paraxial region thereof. The first lens element 410 is made of plastic material and has the object side surface 461 made of plastic material and has the object side surface 411 and the image side surface 462 being both aspheric. The and the image side surface 412 being both aspheric. The 25 image side surface 462 of the sixth lens element 460 has at object side surface 411 of the first lens element 410 has at least one inflection point in an off axial region thereof. least one convex shape in an off axial region thereof. The IR cut filter 470 is made of glass material and located The second lens element 420 with negative refractive between the sixth lens element 460 and the image surface power has an object side surface 421 being convex in a 480, and will not affect the focal length of the imaging lens paraxial region thereof and an image side surface 422 being 30 system. The image sensor 490 is disposed on or near the concave in a paraxial region thereof. The second lens image surface 480 of the imaging lens system. element 420 is made of plastic material and has the object The detailed optical data of the 4th embodiment are side surface 421 and the image side surface 422 being both shown in Table 7 and the aspheric surface data are shown in aspheric Table 8 below. TABLE 7 Surface au w No o Lens??? Stop? 2 Plastic 2? Object 4th Embodiment f = mm, Fno = 2. 20, HFOV = deg. Curvature Radius Thickness Material Index Abbe # Infinity Focal Length Lens ( Plastic Ape. Stop ( ASP ) Lens 2 Plastic ( ASP ) ( ASP ) Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) ( ASP ) Plastic Lens ( ASP ) ( ASP ) ( ASP ) ? IR cut filter Glass Image 17 Image Note : Reference wavelength is nm ( d line ). An effective radius of the stop 401 ( surface 12 ) is mm.

32 21 US 9, 952, 412 B2 TABLE 8 Aspheric Coefficients Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E + 00 A8 = E E E E E E + 00 A E E E E E E + 00 A12 = E E E E E E + 00 A14 = E E E E 01 Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 01 A8 = E E E E E E 01 A10 = E E E E E E 02 A12 = E E E E E E 03 A14 = E E E E E E 04 A16 = E E E E E E 05 In the 4th FOV [ deg.] ( R9 + R10 )/( RO R10 ) aspheric 25 embodiment, the equation of the aspheric The first lens element 510 with negative refractive power surface profiles of the aforementioned lens elements is the has an object side surface being 511 concave in a paraxial same as the equation of the 1st embodiment. Also, the region thereof and an image side surface 512 being concave definitions of these parameters shown in the following table in a paraxial region thereof. The first lens element 510 is are the same as those stated in the 1st embodiment with corresponding values for the 4th embodiment, so an expla 30 made of plastic material and has the object side surface 511 nation in this regard will not be provided again. and the image side surface 512 being both aspheric. The Moreover, these parameters can be calculated from Table object side surface 511 of the first lens element 510 has at 7 and Table 8 as the following values and satisfy the least one convex shape in an off axial region thereof. following conditions : The second lens element 520 with negative refractive power has an object side surface 521 being convex in a paraxial region thereof and an image side surface 522 being 4th Embodiment concave in a paraxial region thereof. The second lens f [ mm ] 02 TL / [ f * tan ( HFOV )] element 520 is made of plastic material and has the object f / EPD 2 20 R1 R2 )/ R1 R2 ) side surface 521 and the image side surface 522 being both HFOV [ deg.] ( R5 + R6 ( R5 R6 R11 + R12 ) The third lens element 530 with positive refractive power ( V5 + V6 )/ V R11 R12 )/( CTmax / T R12 / f T56 / CT \ f / R3 ] + [ f / R41 47 has an object side surface 531 being concave in a paraxial EAT /( T23 + T34 + T45 ) ( Sag21 ] + Sag221 )/ CT region thereof and an image side surface 532 being convex ZAT / T SD11 / SD TL / ImgH in a paraxial region thereof. The third lens element 530 is The quantity of the lens elements 3 with Abbe # smaller than 30 made of plastic material and has the object side surface 531 and the image side surface 532 being both aspheric. The fourth lens element 540 with positive refractive 5th Embodiment 50 power has an object side surface 541 being convex in a paraxial region thereof and an image side surface 542 being FIG. 9 is a schematic view of an image capturing unit convex in a paraxial region thereof. The fourth lens element according to the 5th embodiment of the present disclosure. 540 is made of plastic material and has the object side FIG. 10 shows, in order from left to right, spherical aber surface 541 and the image side surface 542 being both ration curves, astigmatic field curves and a distortion curve 55 aspheric. of the image capturing unit according to the 5th embodi ment. In FIG. 9, the image capturing unit includes the The fifth lens element 550 with negative refractive power imaging lens system ( its reference numeral is omitted ) of the has an object side surface 551 being convex in a paraxial present disclosure and an image sensor 590. The imaging region thereof and an image side surface 552 being concave lens system includes, in order from an obiect side to an 60 in a paraxial region thereof. The fifth lens element 550 is image side, a first lens element 510, an aperture stop 500, a made of plastic material and has the object side surface 551 second lens element 520, a third lens element 530, a stop and the image side surface being both born aspheric. 501, a fourth lens element 540, a fifth lens element 550, a The sixth lens element 560 with negative refractive power sixth lens element 560, an IR cut filter 570 and an image has an object side surface 561 being convex in a paraxial surface 580, wherein the imaging lens system has a total of 65 region thereof and an image side surface 562 being concave six single and non cemented lens elements ( ). The in a paraxial region thereof. The sixth lens element 560 is stop 501 can be a glare stop or a field stop. made of plastic material and has the object side surface 561

33 US 9, 952, 412 B and the image side surface 562 being both aspheric. The system. The image sensor 590 is disposed on or near the image side surface 562 of the sixth lens element 560 has at image surface 580 of the imaging lens system. least one inflection point in an off axial region thereof. The IR cut filter 570 is made of glass material and located The detailed optical data of the 5th embodiment are between the sixth lens element 560 and the image surface 5 shown in Table 9 and the aspheric surface data are shown in 580, and will not affect the focal length of the imaging lens Table 10 below. TABLE 9 Surface 5th Embodiment f = mm, Fno = 2. 19, HFOV = deg. Curvature Focal Radius Thickness Material Index Abbe # Length Object Infinity Lens ( ASP ) Plastic ( ASP ) Ape. Stop Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) Stop Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) IR cut filter Glass Image Note : Reference wavelength is nm ( d line ). An effective radius of the stop 501 ( surface 8 ) is mm. TABLE 10 Aspheric Coefficients Surface # 7 k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E + 00 A8 = E E E E E E + 00 A10 = E E E E E E + 00 A12 = E E E E E E + 00 A14 = E E E E 01 A16 = E 01 Surface # Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 01 A8 = E E E E E E 01 A10 = E E E E E E 02 A12 = E E E E E A14 = E E E E E E 04 A16 = E E E E E E 06

34 US 9, 952, 412 B In the 5th embodiment, the equation of the aspheric made of plastic material and has the object side surface 611 surface profiles of the aforementioned lens elements is the and the image side surface 612 being both aspheric. The same as the equation of the 1st embodiment. Also, the object side surface 611 of the first lens element 610 has at definitions of these parameters shown in the following table least one convex shape in an off axial region thereof. are the same as those stated in the 1st embodiment with 5 The second lens element 620 with negative refractive corresponding values for the 5th embodiment, so an expla power has an object side surface 621 being convex in a nation in this regard will not be provided again. paraxial region thereof and an image side surface 622 being Moreover, these parameters can be calculated from Table concave in a paraxial region thereof. The second lens 9 and Table 10 as the following values and satisfy the following conditions : element 620 is made of plastic material and has the object side surface 621 and the image side surface 622 being both aspheric. 5th Embodiment The third lens element 630 with positive refractive power has an object side surface 631 being convex in a paraxial f [ mm ] TL /[ f * tan ( HFOV ) 1 42 region thereof and an image side surface 632 being convex f / EPD 2 19 ( R1 R2 )/ ( R1 R HFOV [ deg.] ( R5 + R6 ( R5 R6 ) in a paraxial region thereof. The third lens element 630 is FOV [ deg.] RO + R10 / ( RO R10 ) made of plastic material and has the object side surface 631 ( V5 + V6 / V ( R11 R12 )/( R11 + R121 ) and the image side surface 632 being both aspheric. CTmax / T R12 / f The fourth lens element 640 with positive refractive T56 / CT f / R3 ] + [ f / R XAT / ( T23 + T34 + T45 ) ( Sag21 ] + Sag221 )/ CT power has an object side surface 641 being convex in a LAT / T56 76 SD11 / SD paraxial region thereof and an image side surface 642 being TL / ImgH The quantity of the lens 3 convex in a paraxial region thereof. The fourth lens element elements with Abbe # smaller than is made of plastic material and has the object side surface 641 and the image side surface 642 being both saspheric. The fifth lens element 650 with negative refractive power 6th Embodiment has an object side surface 651 being concave in a paraxial region thereof and an image side surface 652 being concave FIG. 11 is a schematic view of an image capturing unit in a paraxial region thereof. The fifth lens element 650 is according to the 6th embodiment of the present disclosure. made of plastic material and has the object side surface 651 FIG. 12 shows, in order from left to right, spherical aber and the image side surface 652 being both aspheric. ration curves, astigmatic field curves and a distortion curve The sixth lens element 660 with positive refractive power of the image capturing unit according to the 6th embodi has an object side surface 661 being convex in a paraxial ment. In FIG. 11, the image capturing unit includes the region thereof and an image side surface 662 being concave imaging lens system ( its reference numeral is omitted ) of the in a paraxial region thereof. The sixth lens element 660 is present disclosure and an image sensor 690. The imaging made of plastic material and has the object side surface 661 lens system includes, in order from an object side to an and the image side surface 662 being both aspheric. The image side, a first lens element 610, a second lens element image side surface 662 of the sixth lens element 660 has at 620, an aperture stop 600, a third lens element 630, a fourth least one inflection point in an off axial region thereof. lens element 640, a fifth lens element 650, a sixth lens. The IR cut filter 670 is made of glass material and located element 660, an IR cut filter 670 and an image surface 680, to between the sixth lens element 660 and the image surface wherein the imaging lens system has a total of six single and 680, and will not affect the focal length of the imaging lens non cemented lens elements ( ). system. The image sensor 690 is disposed on or near the The first lens element 610 with negative refractive power image surface 680 of the imaging lens system. has an object side surface 611 being concave in a paraxial se The detailed optical data of the 6th embodiment are region thereof and an image side surface 612 being concave shown in Table 11 and the aspheric surface data are shown in a paraxial region thereof. The first lens element 610 is in Table 12 below. TABLE 11 6th Embodiment f = mm, Fno = 2. 45, HFOV = deg. Surface oba u AW NO Curvature Radius Thickness Material Index Abbe # Focal Length Object Infinity Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ( ASP ) Ape. Stop Lens ( ASP ) Plastic ( ASP ) Lens ( ASP ) Plastic ASP 040 Lens ( ASP ) Plastic ( ASP )

35 Surface # US 9, 952, 412 B TABLE 11 continued 6th Embodiment f = mm, Fno = HFOV = deg. Curvature Focal Radius Thickness Material Index Abbe # Length Lens ( ASP Plastic ( ASP ) Glass IR cut filter Image Note : Reference wavelength is nm ( d line ). An effective radius of the image side surface 632 ( surface 7 ) is mm. TABLE 12 Aspheric Coefficients Aspheric Coefficients Surface # k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E + 00 A8 = E E E E E E + 00 A10 = E E E E E E + 00 A12 = E E E E E E + 00 A14 = E E E E + 00 Surface # 8 9 k = E E E E E E + 00 A4 = E E E E E E 01 A6 = E E E E E E 03 A8 = E E E E E E 02 A10 = E E E E E E 02 A12 = E E E E E E 02 A14 = E E E E E E 03 A16 = E E E E E E In the 6th embodiment, the equation of the aspheric 7th Embodiment surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the FIG. 13 is a schematic view of an image capturing unit amete according to the 7th embodiment of the present disclosure. are the same as those stated in the 1st embodiment with Ñ 45 FIG. 14 shows, in order from left to right, spherical aber corresponding values for the 6th embodiment, so an expla ration curves, astigmatic field curves and a distortion curve nation in this regard will not be provided again. of the image capturing unit according to the 7th embodi ment. In FIG. 13, the image capturing unit includes the Moreover, these parameters can be calculated from Table imaging lens system ( its reference numeral is omitted ) of the 11 and Table 12 as the following values and satisfy the 50 present disclosure and an image sensor 790. The imaging following conditions : lens system includes, in order from an object side to an image side, a first lens element 710, a second lens element 720, an aperture stop 700, a third lens element 730, a fourth 6th Embodiment lens element 740, a fifth lens element 750, a sixth lens 55 element 760, an IR cut filter 770 and an image surface 780, f [ mm ] 1 71 TL / [ f * tan ( HFOV )] wherein the imaging lens system has a total of six single and f / EPD 2 45 ( R1 R2 )/ ( R1 R HFOV [ deg.] non cemented lens elements ( ) ( R5 + R6 ) ( R5 R6 ) FC FOV [ deg.] ( R9 + R10 )/ ( R9 R10 ) The first lens element 710 with negative refractive power has an object side surface 711 being concave in a paraxial ( V5 + V6 )/ V R11 R12 )/ ( R11 + R12 ) CTmax / T R12 / f region thereof and an image side surface 712 being concave T56 / CT \ f / R3 ] + [ f / R in a paraxial region thereof. The first lens element 710 is LAT / ( T23 + T34 + T45 ) ( ISag211 + Sag221 ) / CT made of plastic material and has the object side surface 711 SAT / T SD11 / SD and the image side surface 712 being both aspheric. The TL / ImgH The quantity of the lens elements 3 object side surface 711 of the first lens element 710 has at with Abbe # smaller than least one convex shape in an off axial region thereof. The second lens element 720 with positive refractive power has an object side surface 721 being convex in a

36 US 9, 952, 412 B paraxial region thereof and an image side surface 722 being region thereof and an image side surface 752 being concave concave in a paraxial region thereof. The second lens in a paraxial region thereof. The fifth lens element 750 is element 720 is made of plastic material and has the object made of plastic material and has the object side surface 751 side surface 721 and the image side surface 722 being both and the image side surface 752 being both aspheric. aspheric. 5 The sixth lens element 760 with negative refractive power The third lens element 730 with positive refractive power has an object side surface 761 being convex in a paraxial has an object side surface 731 being convex in a paraxial region thereof and an image side surface 762 being concave region thereof and an image side surface 732 being convex in a paraxial region thereof. The sixth lens element 760 is in a paraxial region thereof. The third lens element 730 is made of plastic material and has the object side surface 761 made of plastic material and has the object side surface and the image side surface 762 being both aspheric. The and the image side surface 732 being both aspheric. image side surface 762 of the sixth lens element 760 has at The fourth lens element 740 with positive refractive least one inflection point in an off axial region thereof. power has an object side surface 741 being convex in a The IR cut filter 770 is made of glass material and located paraxial region thereof and an image side surface 742 being between the sixth lens element 760 and the image surface convex in a paraxial region thereof. The fourth lens element , and will not affect the focal length of the imaging lens 740 is made of plastic material and has the object side system. The image sensor 790 is disposed on or near the surface 741 and the image side surface 742 being both image surface 780 of the imaging lens system. aspheric. The detailed optical data of the 7th embodiment are The fifth lens element 750 with negative refractive power shown in Table 13 and the aspheric surface data are shown has an object side surface 751 being concave in a paraxial in Table 14 below. TABLE 13 Surface?????????? 7th Embodiment f = mm, Fno = 2. 45, HFOV = deg. Curvature Radius Thickness Material Index Abbe # Infinity ASP ) ( ASP ) ( ASP ) ASP ) ASP ( ASP ) ASP ASP ( ASP ASP ) Plastic ( ASP ) Glass Focal Length Object Lens 1 Plastic Lens 2 Plastic Ape. Stop Lens 3 Plastic Lens 4 Plastic Lens 5 Plastic Lens 6 IR cut filter 16 Image Note : Reference wavelength is nm ( d line ). An effective radius of the object side surface 711 ( surface 1 ) is mm. An effective radius of the image side surface 732 ( surface 7 ) is mm. TABLE 14 Aspheric Coefficients Surface # k = 2747E E E E E E + 00 A4 = E E E E E E 01 A E E E E E E + 00 A8 = E E E E E E + 00 A10 = E E E E E E + 01 A12 = E E E E E E 01 A14 = E E E E + 00 k = A4 = A6 = A8 = Surface # E E E E E E E E E E E E E E E E E E E E E E E E 02

37 31 TABLE 14 continued Aspheric Coefficients US 9, 952, 412 B2 A10 = E E E E E E 02 A12 = E E E E E E 02 A14 = E E E E E E 03 A16 = E E E E E E 05 In the 7th embodiment, the equation of the aspheric 10 surface profiles of the aforementioned lens elements is the same as the equation of the 1st embodiment. Also, the definitions of these parameters shown in the following table are the same as those stated in the 1st embodiment with corresponding values for the 7th embodiment, so an expla 15 nation in this regard will not be provided again. Moreover, these parameters can be calculated from Table 13 and Table 14 as the following values and satisfy the following conditions : 7th Embodiment 20 wherein the imaging lens system has a total of six lens elements, and each of the lens elements of the imaging lens system is a single and non cemented lens element ; an axial distance between the fifth lens element and the sixth lens element is T56, a central thickness of the sixth lens element is CT6, a sum of axial distances between every two lens elements of the imaging lens system adjacent to each other is EAT, and the following conditions are satisfied : < 756 / CT6 < ; and 1. 0 = EAT / T56 < The imaging lens system of claim 1, wherein a curva [ mm ] 1 67 TL /[ f * tan ( HFOV ) ] f / EPD ( R1 R2 )/( R1 R2 ) ture radius of an object side surface of the first lens element HFOV [ deg.] 65 8 ( R5 + R6 ) ( R5 6 ) is R1, a curvature radius of an image side surface of the first FOV [ deg.] ( R9 + R10 )/( RO R10 ) lens element is R2, and the following condition is satisfied : ( V5 + V6 / V R11 R12 )/ ( R11 + R12 ) CTmax / T R12 / f < ( R1 + R2 )/( R1 R2 ) < T56 / CT IfR3 + f / R EAT /( T T45 ) ( Sag211 + Sag221 )/ CT The imaging lens system of claim 1, wherein the first SAT / T SD11 / SD lens element has an object side surface being concave in a TL / ImgH The quantity of the lens elements 3 paraxial region thereof, and the object side surface of the with Abbe # smaller than 30 first lens element has at least one convex shape in an off axial region thereof. The foregoing description, for the purpose of explanation, 4. The imaging lens system of claim 1, wherein the axial has been described with reference to specific embodiments. as 35 distance between the fifth lens element and the sixth lens It is to be noted that TABLES 1 14 show different data of the element is T56, the central thickness of the sixth lens different embodiments ; however, the data of the different element is CT6, and the following condition is satisfied : embodiments are obtained from experiments. The embodi < 756 / CT6 < ments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to The imaging lens system of claim 1, wherein the axial thereby enable others skilled in the art to best utilize the distance between the fifth lens element and the sixth lens element is T56, the sum of axial distances between every disclosure and various embodiments with various modifica tions as are suited to the particular use contemplated. The two lens elements of the imaging lens system adjacent to embodiments depicted above and the appended drawings are each other is EAT, and the following condition is satisfied : exemplary and are not intended to be exhaustive or to limit < EAT / T56 < the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in 6. The imaging lens system of claim 1, wherein a focal length of the imaging lens system is f, an entrance pupil view of the above teachings. diameter of the imaging lens system is EPD, a curvature radius of the object side surface of the sixth lens element is What is claimed is : 50 R11, a curvature radius of the image side surface of the sixth 1. An imaging lens system comprising, in order from an lens element is R12, and the following conditions are object side to an image side : a first lens element having negative refractive power ; satisfied : 1. 0 < f / EPD < 3. 0 ; and second lens element ; third lens element having positive refractive power ; 55 a fourth lens element having positive refractive power ; ( R11 R12 )/ ( R11 + R12 ) < a fifth lens element with negative refractive power having 7. The imaging lens system of claim 1, wherein an axial an image side surface being concave in a paraxial distance between an object side surface of the first lens region thereof, wherein an object side surface and the element and an image surface is TL, a focal length of the image side surface of the fifth lens element are both 60 imaging lens system is f, half of a maximal field of view of aspheric ; and the imaging lens system is HFOV, and the following con a sixth lens element having an image side surface being dition is satisfied : concave in a paraxial region thereof, wherein the image side surface of the sixth lens element has at least TL /[/?tan( HFOV )] < one inflection point in an off axial region thereof, and The imaging lens system of claim 1, wherein a focal an object side surface and the image side surface of the sixth lens element are both aspheric ; length of the imaging lens system is f, a curvature radius of an object side surface of the second lens element is R3, a

38 US 9, 952, 412 B curvature radius of an image side surface of the second lens 18. An imaging lens system comprising, in order from an element is R4, and the following condition is satisfied : object side to an image side : a first lens element having negative refractive power ; \ f / R31 + \ f / R4 < a second lens element ; 9. The imaging lens system of claim 1, wherein the sum 5 third lens element having positive refractive power ; of axial distances between every two lens elements of the a fourth lens element having positive refractive power ; imaging lens system adjacent to each other is EAT, an axial a fifth lens element with negative refractive power having distance between the second lens element and the third lens an image side surface being concave in a paraxial element is T23, an axial distance between the third lens region thereof, wherein an object side surface and the element and the fourth lens element is T34, an axial distance 10 image side surface of the fifth lens element are both between the fourth lens element and the fifth lens element is aspheric ; and T45, and the following condition is satisfied : a sixth lens element having an image side surface being concave in a paraxial region thereof, wherein the 4 < EAT / ( T45 ) < 25. image side surface of the sixth lens element has at least 10. The imaging lens system of claim 1, wherein a 15 one inflection point in an off axial region thereof, and curvature radius of the object side surface of the fifth lens an object side surface and the image side surface of the element is R9, a curvature radius of the image side surface sixth lens element are both aspheric ; of the fifth lens element is R10, and the following condition wherein the imaging lens system has a total of six lens is satisfied : elements, and each of the lens elements of the imaging 20 lens system is a single and non cemented lens element ; O < ( R9 + R10 )/ ( R9 R10 ) < an axial distance between the fifth lens element and the 11. The imaging lens system of claim 1, wherein a focal sixth lens element is T56, a central thickness of the length of the imaging lens system is f, a curvature radius of sixth lens element is CT6, a curvature radius of the the image side surface of the sixth lens element is R12, and object side surface of the fifth lens element is R9, a the following condition is satisfied : 25 curvature radius of the image side surface of the fifth lens element is R10, and the following conditions are < R12 / f < satisfied : 12. The imaging lens system of claim 1, wherein a < 756 / CT6 < ; and maximum among all central thicknesses of the lens elements of the imaging lens system is CTmax, the axial distances between the fifth lens element and the sixth lens element is < ( R9 + R10 ) / ( R9 R10 ) < T56, and the following condition is satisfied : 19. The imaging lens system of claim 18, wherein a maximal field of view of the imaging lens system is FOV, an CTmax / 756 < axial distance between an object side surface of the first lens 13. The imaging lens system of claim 1. wherein an Abbe» element and an image surface is TL, a maximum image number of the fourth lens element is V4, an Abbe number of height of the imaging lens system is ImgH, and the follow the fifth lens element is V5, an Abbe number of the sixth lens element is V6, and the following condition is satisfied : 100 [ deg.] < FOV < 160 [ deg.]; and < ( V5 + V6 )/ V4 < The imaging lens system of claim 1, wherein a 1. 0 < TL / ImgH < displacement in parallel with an optical axis from an axial 20. The imaging lens system of claim 18, wherein the vertex of an object side surface of the second lens element curvature radius of the object side surface of the fifth lens to a maximum effective radius position of the object side as element is R9, the curvature radius of the image side surface surface of the second lens element is Sag21, a displacement of the fifth lens element is R10, and the following condition in parallel with the optical axis from an axial vertex of an is satisfied : image side surface of the second lens element to a maximum effective radius position of the image side surface of the 1. 0 < ( R9 + R10 )/ ( R9 R10 ) < second lens element is Sag22, a central thickness of the The imaging lens system of claim 18, wherein a second lens element is CT2, and the following condition is displacement in parallel with an optical axis from an axial satisfied : vertex of an object side surface of the second lens element ( Sag211 + Sag221 )/ C72 < to a maximum effective radius position of the object side surface of the second lens element is Sag21, a displacement 15. The imaging lens system of claim 1, wherein a 55 in parallel with the optical axis from an axial vertex of an curvature radius of an object side surface of the third lens image side surface of the second lens element to a maximum element is R5, a curvature radius of an image side surface of effective radius position of the image side surface of the the third lens element is R6, and the following condition is second lens element is Sag22, a central thickness of the satisfied : second lens element is CT2, and the following condition is 60 satisfied : < ( R1 + R6 )/ ( RF R6 ) < An image capturing unit, comprising : ( Sag211 + Sag221 )/ C72 < the imaging lens system of claim 1 ; and 22. The imaging lens system of claim 18, wherein a focal an image sensor, wherein the image sensor is disposed on length of the first lens element is f1, a focal length of the an image surface of the imaging lens system. 65 second lens element is f2, a focal length of the third lens 17. An electronic device, comprising : element is f3, a focal length of the fourth lens element is f4, the image capturing unit of claim 16. a focal length of the fifth lens element is f5, a focal length