Optical lens system for photographing, image capture unit and electronic device

Abstract

An optical lens system for photographing, comprising three lens elements (E1, E2, and E3), wherein the three lens elements (E1, E2, and E3) are, in order from an object side to an image side along an optical path, a first lens element (E1), a second lens element (E2), and a third lens element (E3), and each of the three lens elements (E1, E2, and E3) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the image-side surface of the first lens element (E1) is concave in a paraxial region thereof, the third lens element (E3) has a negative refractive index, and the optical lens system for photographing further comprises an aperture stop (ST) arranged between the first lens element (E1) and the second lens element (E2); and wherein an axial distance between the object-side surface of the first lens element (E1) and an image surface (IMG) is TL, a focal length of the optical lens system for photographing is f, a central thickness of the first lens element (E1) is CT1, a central thickness of the second lens element (E2) is CT2, a central thickness of the third lens element (E3) is CT3, a radius of curvature of the object-side surface of the third lens element (E3) is R5, a radius of curvature of the image-side surface of the third lens element (E3) is R6, an aperture number of the optical lens system for photographing is Fno, and the following conditions are satisfied: 1.80 < TL / f < 5.10 ; 1.75 < (CT2 + CT3) / CT1 < 6.50; 0.40 < CT / CT3 < 2.50 ; − 1.20 < R5 / R6 < 0.39 ; and 2.60 < Fno < 5.10.

Description

BACKGROUNDTechnical field

[0001] The present disclosure relates to an optical lens system for photographing, an image capturing unit and an electronic device, particularly to an optical lens system for photographing and an image capturing unit that can be used in an electronic device. Description of the state of the art

[0002] With the development of semiconductor manufacturing technology, the performance of image sensors has improved and their pixel size has been reduced. Therefore, high image quality is now one of the essential features of an optical system.

[0003] Furthermore, due to rapid technological changes, electronic devices equipped with optical systems are becoming increasingly multifunctional for various applications, increasing the requirements for the functionality of optical systems. However, it is difficult for a conventional optical system to achieve a balance between requirements such as high image quality, low sensitivity, a suitable aperture size, miniaturization, and a desirable field of view. SUMMARY

[0004] According to one aspect of the present disclosure, an optical lens system for photographing includes three lens elements. The three lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, and a third lens element. Each of the three lens elements has an object-side surface facing the object side and an image-side surface facing the image side.

[0005] Preferably, the image-side surface of the first lens element is concave in a paraxial region thereof. Preferably, the third lens element has a negative refractive index. Preferably, the optical lens system for photographing further comprises an aperture stop arranged between the first lens element and the second lens element.

[0006] When an axial distance between the object-side surface of the first lens element and an image surface is TL, a focal length of the optical lens system for photographing is f, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a radius of curvature of the object-side surface of the third lens element is R5, a radius of curvature of the image-side surface of the third lens element is R6, and an F-number of the optical lens system for photographing is Fno, the following conditions are preferably satisfied: 1.80 <TL / f<5,10; 1.75<(CT2+CT3) / CT1<6.50; 0.40 <CT2 / CT3<2,50; −1.20 <R5 / R6<0,39; und 2.60 <Fno<5,10.

[0007] According to another aspect of the present disclosure, an optical lens system for photographing includes three lens elements. The three lens elements are, in order from an object side to an image side along an optical path, a first lens element, a second lens element, and a third lens element. Each of the three lens elements has an object-side surface facing the object side and an image-side surface facing the image side.

[0008] Preferably, the third lens element has a negative refractive index.

[0009] When an axial distance between the object-side surface of the first lens element and an image surface is TL, a focal length of the optical lens system for photographing is f, a composite focal length of the first lens element and the second lens element is f12, a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, an axial distance between the first lens element and the second lens element is T12, a radius of curvature of the object-side surface of the first lens element is R1, a radius of curvature of the image-side surface of the second lens element is R4, a radius of curvature of the object-side surface of the third lens element is R5, and a radius of curvature of the image-side surface of the third lens element is R6, the following conditions are preferably satisfied: 2.30 <TL / f<4,80 1.75<(CT2+CT3) / CT1<6.50; 1.20 <T12 / CT1<4,20; 0.50 <R5 / R4<3,30; −0.60 <f / R1+f / R6<1,50; und 0.90 <f / f12<4,00.

[0010] According to another aspect of the present disclosure, an image capturing unit comprises one of the aforementioned photographing optical lens systems and an image sensor, wherein the image sensor is arranged on the image surface of the photographing optical lens system.

[0011] According to another aspect of the present disclosure, an electronic device comprises the aforementioned image capture unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The disclosure can be better understood from the following detailed description of the embodiments with reference to the accompanying drawings: Fig.1 is a schematic view of an image acquisition unit according to the first embodiment of the present disclosure; Fig. 2 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the first embodiment; Fig. 3 is a schematic view of an image acquisition unit according to the second embodiment of the present disclosure; Fig. 4 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the second embodiment; Fig. 5 is a schematic view of an image acquisition unit according to the third embodiment of the present disclosure; Fig. 6 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image sensing unit according to the third embodiment; Fig.7 is a schematic view of an image acquisition unit according to the fourth embodiment of the present disclosure; Fig. 8 shows spherical aberration curves, astigmatic field curves, and a distortion curve of the image sensing unit according to the fourth embodiment; Fig. 9 is a schematic view of an image acquisition unit according to the fifth embodiment of the present disclosure; Fig. 10 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image sensing unit according to the fifth embodiment; Fig. 11 is a schematic view of an image acquisition unit according to the sixth embodiment of the present disclosure; Fig. 12 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image sensing unit according to the sixth embodiment; Fig.13 is a schematic view of an image acquisition unit according to the seventh embodiment of the present disclosure; Fig. 14 shows spherical aberration curves, astigmatic field curves, and a distortion curve of the image sensing unit according to the seventh embodiment; Fig. 15 is a schematic view of an image acquisition unit according to the eighth embodiment of the present disclosure; Fig. 16 shows spherical aberration curves, astigmatic field curves, and a distortion curve of the image sensing unit according to the eighth embodiment; Fig. 17 is a perspective view of an image acquisition unit according to the ninth embodiment of the present disclosure; Fig. 18 is a perspective view of an electronic device according to the tenth embodiment of the present disclosure; Fig.19 is another perspective view of the electronic device in Fig. 18; Fig. 20 is a block diagram of the electronic device in Fig. 18; Fig. 21 is a schematic view of an electronic device according to the eleventh embodiment of the present disclosure; Fig. 22 is another schematic view of the electronic device in Fig. 21; Fig. 23 is a perspective view of an electronic device according to the twelfth embodiment of the present disclosure; Fig. 24 is a cross-sectional view of an electronic device according to the thirteenth embodiment of the present disclosure; Fig. 25 is a perspective view of an electronic device according to the fourteenth embodiment of the present disclosure; Fig.26 shows a schematic view of Y1R2, Y2R1, ET1, ET3 and SAG3R2 according to the second embodiment of the present disclosure; Fig. 27 is a schematic view showing a configuration of a light deflecting element in an optical lens system for photographing according to an embodiment of the present disclosure; Fig. 28 is a schematic view showing another configuration of a light deflecting element in an optical lens system for photographing according to an embodiment of the present disclosure; and Fig. 29 is a schematic view showing a configuration of two light-directing elements in an optical lens system for photographing according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] An optical lens system for photography comprises three lens elements. The three lens elements are arranged in order from an object side to an image side along a light path: a first lens element, a second lens element, and a third lens element. Each of the three lens elements of the optical lens system for photography has an object-side surface facing the object side and an image-side surface facing the image side.

[0014] The first lens element may have a negative refractive index. Therefore, it is advantageous for enlarging the field of view to obtain a wider range of image information. The image-side surface of the first lens element may be concave in a paraxial region thereof. Therefore, it is advantageous for receiving wide-angle light to achieve a wider photographic range.

[0015] The second lens element may have a positive refractive index. Therefore, it is advantageous for effectively converging light and reducing the size of the optical lens system for photographing. The object-side surface of the second lens element may be convex in a paraxial region thereof. Therefore, it is advantageous for correcting spherical aberration to improve image quality. The image-side surface of the second lens element may be convex in a paraxial region thereof. Therefore, it is advantageous for endowing the second lens element with the ability to converge light, thereby preventing ineffective light focusing due to insufficient light refraction in the peripheral region.

[0016] The third lens element may have a negative refractive index. Therefore, it is advantageous for equalizing the overall refractive index distribution and controlling the back focal length to meet application requirements. The object-side surface of the third lens element may be concave in a paraxial region thereof. Therefore, it is advantageous for mitigating incident light from a wide angle and correcting aberrations.

[0017] According to the present disclosure, the optical lens system for photographing may further include an aperture stop disposed between the first lens element and the second lens element. Therefore, it is advantageous to adjust the position of the aperture stop to achieve a balance between the field of view, the total path length, the depth of field, and the image illuminance.

[0018] At least one of the object-side surfaces of the first lens element and the image-side surfaces of the third lens element may be planar in a paraxial region thereof. Therefore, it is advantageous for alignment with the manufacturing process to improve manufacturability of the product. Furthermore, the object-side surface of the first lens element may be planar in its paraxial region and cemented to a plate. Furthermore, the image-side surface of the third lens element may be planar in its paraxial region and cemented to a plate. The plate is advantageous for shaping the lens element and assembling the optical lens system for photographing. Furthermore, the plate may be made of materials such as glass or plastic.Furthermore, the attachment method between the lens element and the plate may include techniques such as gluing, etching, or nanoimprinting, but the present disclosure is not limited thereto.

[0019] According to the present disclosure, the photographing optical lens system can be configured to capture images of an imaged object when an object distance is within a range of 30 millimeters (mm) or less. Therefore, it is advantageous when the photographing optical lens system is used in close-up photography, thereby expanding the product application areas and usage scenarios. In addition, the photographing optical lens system can also be configured to capture images of an imaged object when an object distance is within a range of 20 mm or less. In addition, the photographing optical lens system can also be configured to capture images of an imaged object when an object distance is within a range of 10 mm or less.

[0020] When an axial distance between the object-side surface of the first lens element and an image surface is TL and a focal length of the photographing optical lens system is f, the following condition is satisfied: 1.80 < TL / f < 5.10. Therefore, it is advantageous for effectively controlling the relationship between the total path length and the field of view of the photographing optical lens system to achieve wide-angle applications. In addition, the following condition may also be satisfied: 2.00 < TL / f < 4.80. In addition, the following condition may also be satisfied: 2.30 < TL / f < 4.80. In addition, the following condition may also be satisfied: 2.50 ≤ TL / f ≤ 4.45.

[0021] When a central thickness of the first lens element is CT1, a central thickness of the second lens element is CT2, and a central thickness of the third lens element is CT3, the following condition is satisfied: 1.75 < (CT2 + CT3) / CT1 < 6.50. Therefore, it is beneficial for coordinating the array design of the refractive index of the lens elements, enlarging the field of view of the optical lens system for photographing, and controlling the thicknesses of the lens elements to reduce manufacturing tolerances and improve yield. Furthermore, the following condition can also be satisfied: 1.85 < (CT2 + CT3) / CT1 < 6.00. Furthermore, the following condition can also be satisfied: 1.99 ≤ (CT2 + CT3) / CT1 ≤ 5.72.

[0022] When the center thickness of the second lens element is CT2 and the center thickness of the third lens element is CT3, the following condition can be satisfied: 0.40 < CT2 / CT3 < 2.50. Therefore, it is beneficial for balancing the spatial configuration of the optical lens system for photographing, reducing sensitivity, and improving manufacturability. Furthermore, the following condition can also be satisfied: 0.55 < CT2 / CT3 < 2.40. Furthermore, the following condition can also be satisfied: 0.65 < CT2 / CT3 < 2.30. Furthermore, the following condition can also be satisfied: 0.85 ≤ CT2 / CT3 ≤ 2.09.

[0023] When the radius of curvature of the object-side surface of the third lens element is R5 and the radius of curvature of the image-side surface of the third lens element is R6, the following condition can be satisfied: -2.00 < R5 / R6 < 0.35. Therefore, it is advantageous to adjust the shape and refractive index of the third lens element to correct the field curvature and distortion. In addition, the following condition can also be satisfied: -1.20 < R5 / R6 < 0.39. In addition, the following condition can also be satisfied: -0.90 < R5 / R6 < 0.30. In addition, the following condition can also be satisfied: -0.54 ≤ R5 / R6 ≤ 0.20.

[0024] When the aperture of the optical lens system for photography is Fno, the following condition can be satisfied: 2.60 < Fno < 5.10. Therefore, adjusting the aperture size is beneficial to achieve a balance between image illuminance, depth of field, and image quality. In addition, the following condition can also be satisfied: 2.80 < Fno < 4.90. Furthermore, the following condition can also be satisfied: 3.30 ≤ Fno ≤ 4.70.

[0025] When the axial distance between the first lens element and the second lens element is T12 and the central thickness of the first lens element is CT1, the following condition can be satisfied: 1.20 < T12 / CT1 < 5.00. Therefore, it is advantageous for alignment with a wide-angle design and it is advantageous for adjusting the light path on the object side of the optical lens system for photographing. In addition, the following condition can also be satisfied: 1.30 < T12 / CT1 < 4.60. In addition, the following condition can also be satisfied: 1.20 < T12 / CT1 < 4.20. In addition, the following condition can also be satisfied: 1.66 ≤ T12 / CT1 ≤ 3.85.

[0026] When the radius of curvature of the image-side surface of the second lens element is R4 and the radius of curvature of the object-side surface of the third lens element is R5, the following condition can be satisfied: 0.50 < R5 / R4 < 3.30. Therefore, it is advantageous for the second lens element and the third lens element to cooperate to adjust the angle of light refraction, thereby improving imaging quality. Furthermore, the following condition can also be satisfied: 0.65 < R5 / R4 < 3.00. Furthermore, the following condition can also be satisfied: 0.85 < R5 / R4 < 2.80. Furthermore, the following condition can also be satisfied: 1.19 ≤ R5 / R4 ≤ 2.55.

[0027] When the focal length of the photographing optical lens system is f, a radius of curvature of the object-side surface of the first lens element is R1, and the radius of curvature of the image-side surface of the third lens element is R6, the following condition can be satisfied: -0.60 < f / R1 + f / R6 < 1.50. Therefore, it is beneficial for adjusting the angle of incidence of the light entering the photographing optical lens system and the angle of incidence of the light reaching the image surface, effectively improving the light gathering quality of the paraxial field of view. In addition, the following condition can also be satisfied: -0.55 < f / R1 + f / R6 < 1.30. In addition, the following condition can also be satisfied: -0.45 < f / R1 + f / R6 < 1.10. In addition, the following condition can also be met: -0.32 ≤ f / R1+f / R6 ≤ 0.90.

[0028] When the focal length of the photographing optical lens system is f, and the combined focal length of the first lens element and the second lens element is f12, the following condition can be satisfied: 0.90 < f / f12 < 4.00. Therefore, it is beneficial for improving light convergence and effectively reducing the size of the photographing optical lens system. Furthermore, the following condition can also be satisfied: 1.25 < f / f12 < 3.30. Furthermore, the following condition can also be satisfied: 1.67 ≤ f / f12 ≤ 2.93.

[0029] When the axial distance between the second lens element and the third lens element is T23 and the central thickness of the third lens element is CT3, the following condition can be satisfied: 0.03 < T23 / CT3 < 3.00. Therefore, adjusting the relationship between the position and the central thickness of the third lens element is beneficial for adjusting the light path on the image side of the optical lens system for photographing to improve image quality. Furthermore, the following condition can also be satisfied: 0.05 < T23 / CT3 < 2.50. Furthermore, the following condition can also be satisfied: 0.05 < T23 / CT3 < 2.00.

[0030] When the focal length of the optical lens system for photographing is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and a focal length of the third lens element is f3, the following condition can be satisfied: -1.50 < f / f1 + f / f2 + f / f3 < 0.20. Therefore, equalizing the overall refractive index distribution in the optical lens system for photographing is beneficial for aberration correction. In addition, the following condition can also be satisfied: -1.20 < f / f1 + f / f2 + f / f3 < 0.15. Furthermore, the following condition can also be satisfied: -1.00 < f / f1 + f / f2 + f / f3 < 0.10. According to the present disclosure, the focal length of a single lens element is calculated based on the condition that the medium in front of and behind the single lens element is each air.

[0031] When the central thickness of the first lens element is CT1 and the central thickness of the second lens element is CT2, the following condition can be satisfied: 0.15 < CT1 / CT2 < 1.05. Therefore, it is advantageous to adjust the ratio of the central thickness between the first lens element and the second lens element to achieve a balance between the molding yields of the first lens element and the second lens element and the total path length of the optical lens system for photographing. In addition, the following condition can also be satisfied: 0.20 < CT1 / CT2 < 1.00. Furthermore, the following condition can also be satisfied: 0.25 < CT1 / CT2 < 0.95.

[0032] When the maximum image height of the photographing optical lens system (which may be half the diagonal of an effective light-sensitive area of ​​an image sensor) is ImgH and the focal length of the photographing optical lens system is f, the following condition can be satisfied: 0.65 < ImgH / f < 1.50. Therefore, appropriate control of the image height-to-focal length ratio is beneficial for miniaturizing the photographing optical lens system while simultaneously enlarging the image surface area to capture more light.

[0033] When an axial distance between the image-side surface of the third lens element and the image surface is BL, and an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, the following condition can be satisfied: 0.10 < BL / TD < 0.60. Therefore, it is advantageous for achieving a balance between the size and manufacturability of the optical lens system for photographing.

[0034] When the focal length of the optical lens system for photography is f and the focal length of the third lens element is f3, the following condition can be satisfied: -3.00 < f / f3 < -0.30. Therefore, it is advantageous for the third lens element to have a desired negative refractive index to enlarge the image surface. Furthermore, the following condition can also be satisfied: -2.50 < f / f3 < -0.50.

[0035] When the maximum field of view of the optical lens system for photography is FOV, the following condition can be met: 125.0 degrees < FOV < 175.0 degrees. Therefore, it is advantageous to ensure that the optical lens system for photography has a larger field of view for a wider range of applications. In addition, the following condition can also be met: 128.0 degrees < FOV < 172.0 degrees.

[0036] When a displacement parallel to an optical axis from an axial vertex of the image-side surface of the third lens element to a position of the maximum effective radius of the image-side surface of the third lens element is SAG32 and the central thickness of the third lens element is CT3, the following condition can be satisfied: -0.30 < SAG32 / CT3 < 0.35. Therefore, it is advantageous for regulating the degree of variation of the peripheral surface shape of the image-side surface of the third lens element to correct aberrations in the peripheral field of view. In addition, the following condition can also be satisfied: -0.20 < SAG32 / CT3 < 0.30. In addition, the following condition can also be satisfied: -0.15 < SAG32 / CT3 < 0.25. See Fig.26, which shows a schematic view of SAG3R2 according to the second embodiment of the present disclosure. When the direction from the axial vertex of a surface to the position of the maximum effective radius of the same surface faces the image side of the photographing optical lens system, the shift value is positive; when the direction from the axial vertex of the surface to the position of the maximum effective radius of the same surface faces the object side of the photographing optical lens system, the shift value is negative.

[0037] When the focal length of the optical lens system for photography is f and the focal length of the first lens element is f1, the following condition can be satisfied: -1.50 < f / f1 < 0.20. Therefore, it is advantageous to adjust the refractive index of the first lens element to achieve a balance between the expanded light gathering area and the size of the optical lens system for photography. In addition, the following condition can also be satisfied: -1.30 < f / f1 < 0.00.

[0038] When the axial distance between the second lens element and the third lens element is T23 and the central thickness of the second lens element is CT2, the following condition can be satisfied: 0.03 < T23 / CT2 < 1.00. Therefore, to effectively control the distance between the second lens element and the third lens element, it is advantageous to control the total path length of the optical lens system for photography. In addition, the following condition can also be satisfied: 0.05 < T23 / CT2 < 0.85.

[0039] When the focal length of the first lens element is f1 and the radius of curvature of the image-side surface of the first lens element is R2, the following condition can be satisfied: -3.50 < f1 / R2 < 0.00. Therefore, by adjusting the shape and refractive index design of the first lens element, it is advantageous to compensate for the field of view and spherical aberration of the optical lens system for photographing. Furthermore, the following condition can also be satisfied: -3.00 < f1 / R2 < -0.50. Furthermore, the following condition can also be satisfied: -3.00 < f1 / R2 < -1.20.

[0040] When the maximum effective radius of the image-side surface of the first lens element is Y1R2 and the maximum effective radius of the object-side surface of the second lens element is Y2R1, the following condition can be satisfied: 0.95 < Y1R2 / Y2R1 < 2.00. Therefore, it is advantageous for improving the common problem of peripheral light scattering in wide-angle lenses and for correcting off-axis aberrations. See Fig. 26, which shows a schematic view of Y1R2 and Y2R1 according to the second embodiment of the present disclosure.

[0041] When a distance parallel to the optical axis between a position of the maximum effective radius of the object-side surface of the first lens element and a position of the maximum effective radius of the image-side surface of the first lens element is ET1, and a distance parallel to the optical axis between a position of the maximum effective radius of the object-side surface of the third lens element and the position of the maximum effective radius of the image-side surface of the third lens element is ET3, the following condition can be satisfied: 0.50 < ET3 / ET1 < 2.50. Therefore, it is advantageous to adjust the edge thicknesses of the first lens element and the third lens element to achieve a balance between the difficulty of lens molding and the assembly yield of the lens elements. In addition, the following condition can also be satisfied: 0.60 < ET3 / ET1 < 2.30. See Fig.26, which shows a schematic view of ET1 and ET3 according to the second embodiment of the present disclosure.

[0042] According to the present disclosure, the above features and conditions can be used in numerous combinations to achieve corresponding effects.

[0043] According to the present disclosure, the lens elements of the photographing optical lens system can be made of either glass or plastic. When the lens elements are made of glass, the refractive index distribution of the photographing optical lens system can be more flexible, and the influence on imaging caused by changes in ambient temperature can be reduced. The glass lens element can be manufactured either by grinding or molding. When the lens elements are made of plastic, the manufacturing cost can be effectively reduced. Furthermore, the surfaces of each lens element can be arranged spherically or aspherically. Spherical lens elements are easy to manufacture.The design of aspherical lens elements allows for more control variables to eliminate aberrations and reduce the required number of lens elements, effectively shortening the overall length of the optical lens system for photography. Additionally, the aspherical surfaces can be formed by plastic injection molding or glass molding.

[0044] According to the present disclosure, an aspheric lens surface means that the lens surface has an aspheric shape in its entire optically effective area or in one or more parts thereof.

[0045] According to the present disclosure, the material of one or more lens elements may optionally include an additive that creates light absorption and interference effects and modifies the transmittance of the lens elements in a specific wavelength range to reduce unwanted stray light or color variations. For example, the additive may optionally filter out light in the wavelength range of 600 nm to 800 nm to reduce excessive red light and / or near-infrared light, or optionally filter out light in the wavelength range of 350 nm to 450 nm to reduce excessive blue light and / or near-ultraviolet light that interferes with the final image. The additive may be homogeneously blended with a plastic used to manufacture a blended-material lens element by injection molding. Furthermore, the additive may be applied to the lens surfaces to achieve the aforementioned effects.

[0046] According to the present disclosure, each of the object-side surface and the image-side surface has a paraxial region and an off-axis region. The paraxial region refers to the region of the surface where light rays travel close to the optical axis, and the off-axis region refers to the region of the surface far from the paraxial region. Specifically, unless otherwise specified, when the lens element has a convex surface, it means that the surface is convex in the paraxial region thereof; when the lens element has a concave surface, it means that the surface is concave in the paraxial region thereof. When a range of the refractive index, focal point, or radius of curvature of a lens element is undefined, it means that the range of the refractive index, focal point, or radius of curvature of the lens element lies in its paraxial region.In addition, the focal length of a single lens element is calculated based on the condition that the medium in front of and behind the single lens element is air.

[0047] According to the present disclosure, the image surface of the optical lens system for photographing may be flat or curved based on the corresponding image sensor, wherein in particular a curved surface is concavely facing the object side of the optical lens system for photographing.

[0048] According to the present disclosure, an image correction unit, such as a field flattener, can optionally be arranged between the lens element located closest to the image side of the optical lens system along the optical path and the image surface to correct aberrations such as field curvature. The optical properties of the image correction unit, such as curvature, thickness, refractive index, position, and surface shape (convex or concave surface with spherical, aspherical, diffractive, or Fresnel types), can be adjusted according to the design of the image acquisition unit. In general, a preferred image correction unit is, for example, a thin transparent element having a concave object-side surface and a planar image-side surface, and the thin transparent element is arranged near the image surface.

[0049] According to the present disclosure, at least one light deflecting element, such as a prism or a mirror, may optionally be provided between an imaged object and the image surface on the imaging beam path, and the surface shape of the prism or mirror may be planar, spherical, aspherical, or a freeform surface, so that the optical lens system for photography can be more flexible in its spatial arrangement, and thus the dimensions of an electronic device are not limited by the total path length of the optical lens system for photography. See in particular Fig. 27 and Fig. 28. Fig. 27 is a schematic view showing a configuration of a light deflecting element in an optical lens system for photographing according to an embodiment of the present disclosure, and Fig.28 shows a schematic view of another configuration of a light deflecting element in an optical lens system for photographing according to an embodiment of the present disclosure. In Fig. 27 and Fig. 28, the optical lens system for photographing may include, in the order from an imaged object (not shown in the figures) to an image surface IMG along a light path, a first optical axis OA1, a light deflecting element LF, and a second optical axis OA2. The light deflecting element LF may be arranged between the imaged object and a lens group LG of the optical lens system for photographing, as shown in Fig. 27, or between a lens group LG and the image surface IMG of the optical lens system for photographing, as shown in Fig. 28. Furthermore, Fig.29, which shows a schematic view of a configuration of two light-directing elements in an optical lens system for photographing according to an embodiment of the present disclosure. In Fig.29, the optical lens system for photographing may include, in order from an imaged object (not shown in the figure) to an image surface IMG along a light path, a first optical axis OA1, a first light deflecting element LF1, a second optical axis OA2, a second light deflecting element LF2, and a third optical axis OA3. The first light deflecting element LF1 is arranged between the imaged object and a lens group LG of the optical lens system for photographing, the second light deflecting element LF2 is arranged between the lens group LG and the image surface IMG of the optical lens system for photographing, and the propagation direction of the light on the first optical axis OA1 may be the same direction as the propagation direction of the light on the third optical axis OA3, as shown in Fig.29. The optical lens system for photographing may optionally be provided with three or more light-directing elements, and the present disclosure is not limited to the type, number, and position of the light-directing elements of the embodiments disclosed in the above figures.

[0050] According to the present disclosure, the optical lens system for photographing may include at least one diaphragm, such as an aperture diaphragm, a glare diaphragm, or a field diaphragm. The glare diaphragm or the field diaphragm is set to eliminate stray light and thereby improve the image quality thereof.

[0051] According to the present disclosure, an aperture stop can be configured as a front stop or a center stop. A front stop disposed between an imaged object and the first lens element can provide a greater distance between an exit pupil of the photographing optical lens system and the image surface to create a telecentric effect, thereby improving the image sensing efficiency of an image sensor (e.g., CCD or CMOS). A center stop disposed between the first lens element and the image surface is advantageous for increasing the viewing angle of the photographing optical lens system, thereby providing a wider field of view for the same.

[0052] According to the present disclosure, the optical lens system for photography may include an aperture control unit. The aperture control unit may be a mechanical component or a light modulator that can control the size and shape of the aperture through electricity or electrical signals. The mechanical component may include a movable element, such as a blade array or a light-shielding film. The light modulator may include a shielding element, such as a filter, an electrochromic material, or a liquid crystal layer. The aperture control unit controls the amount of incident light or the exposure time to enhance the ability to adjust image quality. Furthermore, the aperture control unit may be the aperture stop of the present disclosure, which changes the f-number to achieve various image effects, such as depth of field or light intensity.

[0053] According to the present disclosure, the photographing optical lens system may include one or more optical elements for limiting the shape of the light passing through the photographing optical lens system. Each optical element may be, but is not limited to, a filter, a polarizer, etc., and each optical element may be, but is not limited to, a single-piece element, a composite component, a thin film, etc. The optical element may be located on the object side or the image side of the photographing optical lens system, or between two adjacent lens elements to transmit light in a specific shape and thereby meet application requirements.

[0054] According to the present disclosure, the optical lens system for photographing may include at least one optical lens element, an optical element, or a substrate having at least one surface with an anti-reflection layer. The anti-reflection layer can effectively reduce stray light generated due to light reflection at the interface. The anti-reflection layer may be disposed in an optically ineffective region of an object-side surface or an image-side surface of the optical lens element, or a connecting surface between the object-side surface and the image-side surface. The optical element may be a light-blocking element, an annular spacer, a mount element, a cover glass, a blue glass, a filter, a color filter, a light-path deflecting element (e.g., a reflective element), a prism, a mirror, etc.The carrier may be a base for holding a lens assembly, a microlens arranged on an image sensor, a substrate surrounding the image sensor, a glass plate for protecting the image sensor, etc.

[0055] According to the present disclosure, the object side and the image side are defined according to the direction of the optical axis, and the axial optical data is calculated along the optical axis. Furthermore, when the optical axis is deflected by a light deflecting element, the axial optical data is also calculated along the deflected optical axis.

[0056] In accordance with the above description of the present disclosure, the following specific embodiments are provided for further explanation. 1. Embodiment

[0057] Fig. 1 is a schematic view of an image acquisition unit according to the first embodiment of the present disclosure. Fig.Figure 2 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the first embodiment. Fig. 1, the image acquisition unit 1 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from the object side to the image side along an optical path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the adjacent three lens elements.

[0058] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0059] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of glass and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0060] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of glass and has both the object-side and image-side surfaces aspherical.

[0061] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region thereof and an image-side surface that is planar in a paraxial region thereof. The third lens element E3 is made of plastic and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0062] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and has no influence on the focal length of the optical lens system for photographing.

[0063] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0064] The equation of the aspherical surface profiles of the aforementioned lens elements of the first embodiment is expressed as follows: X(Y)=(Y2 / R) / (1+sqrt(1−(1+k)×(Y / R)2))+∑i(Ai)×(Yi) where X is the displacement parallel to an optical axis from an axial vertex on the aspherical surface to a point at a distance Y from the optical axis on the aspherical surface; Y is the vertical distance from the point on the aspherical surface to the optical axis; R is the radius of curvature; k is the cone coefficient; and Ai is the i-th aspherical coefficient, where in the embodiments i can be 4, 6, 8, 10, 12 and 14, but is not limited thereto.

[0065] In the photographing optical lens system of the image sensing unit 1 according to the first embodiment, when a focal length of the photographing optical lens system is f, an F-number of the photographing optical lens system is Fno, and half of a maximum field of view of the photographing optical lens system is HFOV, these parameters have the following values: f = 0.51 millimeters (mm), Fno = 3.91, and HFOV = 76.6 degrees (degrees).

[0066] When the maximum field of view of the optical lens system for photographing is FOV, the following condition is met: FOV = 153.2 degrees.

[0067] When the axial distance between the object-side surface of the first lens element E1 and the image surface IMG is TL and the focal length of the optical lens system for photographing is f, the following condition is satisfied: TL / f = 3.49.

[0068] When the maximum image height of the photographing optical lens system is ImgH and the focal length of the photographing optical lens system is f, the following condition is satisfied: ImgH / f = 1.06.

[0069] When an axial distance between the image-side surface of the third lens element E3 and the image surface IMG is BL and an axial distance between the object-side surface of the first lens element E1 and the image-side surface of the third lens element E3 is TD, the following condition is satisfied: BL / TD = 0.38.

[0070] When the focal length of the optical lens system for photographing is f and the focal length of the first lens element E1 is f1, the following condition is satisfied: f / f1 = -0.70.

[0071] When the focal length of the optical lens system for photographing is f and the focal length of the third lens element E3 is f3, the following condition is satisfied: f / f3 = -1.07.

[0072] When the focal length of the optical lens system for photographing is f and a compound focal length of the first lens element E1 and the second lens element E2 is f12, the following condition is satisfied: f / f12 = 1.99.

[0073] When the focal length of the optical lens system for photographing is f, the focal length of the first lens element E1 is f1, a focal length of the second lens element E2 is f2, and the focal length of the third lens element E3 is f3, the following condition is satisfied: f / f1+f / f2+f / f3 = -0.27.

[0074] When the focal length of the optical lens system for photographing is f, a radius of curvature of the object-side surface of the first lens element E1 is R1, and a radius of curvature of the image-side surface of the third lens element E3 is R6, the following condition is satisfied: f / R1+f / R6 = 0.00.

[0075] When the focal length of the first lens element E1 is f1 and a radius of curvature of the image-side surface of the first lens element E1 is R2, the following condition is satisfied: f1 / R2 = -1.96.

[0076] When a radius of curvature of the image-side surface of the second lens element E2 is R4 and a radius of curvature of the object-side surface of the third lens element E3 is R5, the following condition is satisfied: R5 / R4 = 1.27.

[0077] When the radius of curvature of the object-side surface of the third lens element E3 is R5 and the radius of curvature of the image-side surface of the third lens element E3 is R6, the following condition is satisfied: R5 / R6 = 0.00.

[0078] When a central thickness of the first lens element E1 is CT1 and a central thickness of the second lens element E2 is CT2, the following condition is satisfied: CT1 / CT2 = 0.51.

[0079] When the central thickness of the second lens element E2 is CT2 and a central thickness of the third lens element E3 is CT3, the following condition is satisfied: CT2 / CT3 = 1.24.

[0080] When an axial distance between the first lens element E1 and the second lens element E2 is T12 and the central thickness of the first lens element E1 is CT1, the following condition is satisfied: T12 / CT1 = 2.71. In this embodiment, an axial distance between two adjacent lens elements is a distance in a paraxial region between two adjacent lens surfaces of the two adjacent lens elements.

[0081] When an axial distance between the second lens element E2 and the third lens element E3 is T23 and the central thickness of the second lens element E2 is CT2, the following condition is satisfied: T23 / CT2 = 0.37.

[0082] When the axial distance between the second lens element E2 and the third lens element E3 is T23 and the central thickness of the third lens element E3 is CT3, the following condition is satisfied: T23 / CT3 = 0.46.

[0083] When the central thickness of the first lens element E1 is CT1, the central thickness of the second lens element E2 is CT2, and the central thickness of the third lens element E3 is CT3, the following condition is satisfied: (CT2+CT3) / CT1 = 3.52.

[0084] When a distance parallel to the optical axis between a position of the maximum effective radius of the object-side surface of the first lens element E1 and a position of the maximum effective radius of the image-side surface of the first lens element E1 is ET1, and a distance parallel to the optical axis between a position of the maximum effective radius of the object-side surface of the third lens element E3 and a position of the maximum effective radius of the image-side surface of the third lens element E3 is ET3, the following condition is satisfied: ET3 / ET1 = 1.17.

[0085] When a maximum effective radius of the image-side surface of the first lens element E1 is Y1R2 and a maximum effective radius of the object-side surface of the second lens element E2 is Y2R1, the following condition is satisfied: Y1R2 / Y2R1 = 1.08.

[0086] When a displacement parallel to the optical axis from an axial vertex of the image-side surface of the third lens element E3 to the position of the maximum effective radius of the image-side surface of the third lens element E3 is SAG3R2 and the central thickness of the third lens element E3 is CT3, the following condition is satisfied: SAG3R2 / CT3 = 0.00. In this embodiment, the image-side surface of the third lens element E3 is planar, so the displacement parallel to the optical axis from the axial vertex to the position of the maximum effective radius of the image-side surface of the third lens element E3 is zero. Therefore, the value of SAG3R2 is zero.

[0087] The detailed optical data of the first embodiment are shown in Table 1A and the aspherical surface data are shown in Table 1B below. TABLE 1A 1. Embodiment f = 0.51 mm, Fno = 3.91, HFOV = 76.6 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 15.000 1 Plate 1 Plano 0.200 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.162 Glass 1.510 63.4 -0.73 4 0.3735 (ASP) 0.368 5 Aperture diaphragm Plano 0.071 6 Lens 2 0.3599 (ASP) 0.315 Glass 1.540 59.7 0.34 7 -0.2606 (ASP) 0.118 8 Lens 3 -0.3320 (ASP) 0.255 plastic 1.697 16.3 -0.48 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.300 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.069 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 1B Aspherical coefficients Surface # 4 6 7 8 k = -7.05045E-01 -4.96304E-02 -4.23889E-01 -4.38008E-01 A4 = 6.1294E+00 -5.2848E+00 1.4995E+01 1.2919E+01 A6 = 1.1900E+01 1.3276E+02 -9.6878E+01 -2.5127E+02 A8 = 2.6931E+02 -4.3633E+03 3.8553E+03 4.8031E+03 A10 = 1.5664E+03 6.7543E+04 -1.0682E+05 -1.6958E+05 A12 = 1.8653E+04 -4.5985E+05 1.3028E+06 3.2969E+06 A14 = - - -6.0425E+06 -3.2058E+07

[0088] Table 1A shows the radius of curvature, thickness, and focal length in millimeters (mm). Surface numbers 0-14 represent the surfaces arranged along the optical axis from the object side to the image side. In Table 1B, k represents the cone coefficient of the aspherical surface profile equation. A4-A14 represent the aspherical coefficients from the fourth to the fourteenth. The tables shown below for each embodiment are the corresponding schematic parameter and aberration curves, and the definitions of the tables are the same as in Table 1A and Table 1B of the first embodiment. Therefore, explanations regarding them will not be repeated. 2. Embodiment

[0089] Fig. 3 is a schematic view of an image acquisition unit according to the second embodiment of the present disclosure. Fig.Figure 4 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the second embodiment. Fig. 3, the image acquisition unit 2 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the adjacent three lens elements.

[0090] The first lens element E1 with a negative refractive index has an object-side surface that is convex in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0091] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0092] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region and an image-side surface that is concave in a paraxial region. The third lens element E3 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0093] The E6 filter is made of glass and is located between the third lens element E3 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0094] The detailed optical data of the second embodiment are listed in Table 2A and the aspherical surface data are listed in Table 2B below. TABLE 2A 2. Embodiment f = 0.43 mm, Fno = 3.30, HFOV = 70.3 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity infinity 1 Lens 1 0.9615 (ASP) 0.130 plastic 1.544 56.0 -0.65 2 0.2471 (ASP) 0.420 3 Aperture diaphragm Plano 0.080 4 Lens 2 0.4380 (ASP) 0.411 plastic 1.544 56.0 0.33 5 -0.2064 (ASP) 0.040 6 Lens 3 -0.5259 (ASP) 0.332 plastic 1.697 16.3 -0.45 7 0.9650 (ASP) 0.110 8 filter Plano 0.150 Glass 1.517 64.2 - 9 Plano 0.143 10 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 2B Aspherical coefficients Surface # 1 2 4 5 6 7 k = -7.57514E+00 -7.91975E-01 -1.00458E-01 -8.14275E-01 - 1.96399E+00 - 5.15868E+00 A4 = 9.2637E-01 6.7611E+00 -3.6731E+00 3.8417E+01 3.0066E+01 1.4900E+00 A6 = -1.1248E+01 -7.9528E+01 4.1090E+01 -9.1120E+02 -9.7775E+02 -3.0504E+01 A8 = 2.8992E+01 2.3547E+03 -8.7215E+02 1.5727E+04 1.8022E+04 1.5653E+02 A10 = -2.1710E+01 -3.8197E+04 1.2845E+04 -1.6655E+05 -2.1651E+05 -2.4093E+02 A12 = - 2.0665E+05 -6.3390E+04 9.5218E+05 1.3943E+06 - A14 = - - - -1.9443E+06 -3.5356E+06 -

[0095] In the second embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the first embodiment. The definitions of these parameters, shown in Table 2C below, are also the same as those given in the first embodiment, with corresponding values ​​for the second embodiment, so explanations will not be repeated. In this embodiment, the direction of SAG3R2 points toward the image side of the photographing optical lens system, and the value of SAG3R2 is positive.

[0096] In addition, these parameters can be calculated from Table 2A and Table 2B as the following values ​​and satisfy the following conditions: TABLE 2C Values ​​of optical and physical parameters / definitions f [mm] 0.43 f1 / R2 -2.64 Fno 3.30 R5 / R4 2.55 HFOV [degree] 70.3 R5 / R6 -0.54 FOV [degrees] 140.6 CT1 / CT2 0.32 TL / f 4.20 CT2 / CT3 1.24 ImgH / f 1.20 T12 / CT1 3.85 BL / TD 0.29 T23 / CT2 0.10 f / f1 -0.66 T23 / CT3 0.12 f / f3 -0.97 (CT2+CT3) / CT1 5.72 f / f12 2.04 ET3 / ET1 1.88 f / f1 + f / f2 + f / f3 -0.33 Y1R2 / Y2R1 1.08 f / R1 + f / R6 0.90 SAG3R2 / CT3 0.16 3. Embodiment

[0097] Fig. 5 is a schematic view of an image acquisition unit according to the third embodiment of the present disclosure. Fig.Figure 6 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the third embodiment. Fig. 5, the image sensing unit 3 includes the optical lens system for photographing (the reference numeral of which is omitted) of the present disclosure and an image sensor IS.

[0098] The optical lens system for photographing includes, in order from an object side to an image side along a light path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The optical lens system for photographing includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the adjacent three lens elements.

[0099] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0100] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of plastic and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0101] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0102] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region and an image-side surface that is flat in a paraxial region. The third lens element E3 is made of plastic and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0103] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and does not affect the focal length of the optical lens system for photographing.

[0104] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0105] The detailed optical data of the third embodiment are shown in Table 3A and the aspherical surface data are shown in Table 3B below. TABLE 3A 3. Embodiment f = 0.43 mm, Fno = 4.50, HFOV = 70.0 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 10.000 1 Plate 1 Plano 0.200 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.170 plastic 1.544 56.0 -0.44 4 0.2373 (ASP) 0.289 5 Aperture diaphragm Plano 0.034 6 Lens 2 0.3226 (ASP) 0.379 plastic 1.544 56.0 0.31 7 -0.2073 (ASP) 0.076 8 Lens 3 -0.3286 (ASP) 0.350 plastic 1.669 19.5 -0.49 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.350 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.030 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 3B Aspherical coefficients Surface # 4 6 7 8 k = -6.32549E-01 2.60452E-01 -9.41753E-01 -1.21753E+00 A4 = 4.4116E+00 -7.3700E+00 2.9376E+01 1.9184E+01 A6 = -1.3969E+02 3.7635E+02 -1.5092E+03 -8.3091E+02 A8 = 6.2760E+03 -1.1972E+04 9.3481E+04 3.1285E+04 A10 = -8.9412E+04 9.4671E+04 -3.0289E+06 -7.6347E+05 A12 = 4.5632E+05 8.4413E+05 5.0900E+07 9.7148E+06 A14 = - - -3.3019E+08 -4.8835E+07

[0106] In the third embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as that of the first embodiment. The definitions of these parameters, shown in Table 3C below, are also the same as those given in the first embodiment, with corresponding values ​​for the third embodiment, so explanations will not be repeated.

[0107] In addition, these parameters can be calculated from Table 3A and Table 3B as the following values ​​and satisfy the following conditions: TABLE 3C Values ​​of optical and physical parameters / definitions f [mm] 0.43 f1 / R2 -1.84 Fno 4.50 R5 / R4 1.59 HFOV [degree] 70.0 R5 / R6 0.00 FOV [degrees] 140.0 CT1 / CT2 0.45 TL / f 4.17 CT2 / CT3 1.08 ImgH / f 1.19 T12 / CT1 1.90 BL / TD 0.39 T23 / CT2 0.20 f / f1 -0.99 T23 / CT3 0.22 f / f3 -0.88 (CT2+CT3) / CT1 4.29 f / f12 2.07 ET3 / ET1 1.52 f / f1+f / f2+f / f3 -0.48 Y1R2 / Y2R1 1.46 f / R1+f / R6 0.00 SAG3R2 / CT3 0.00 4. Embodiment

[0108] Fig. 7 is a schematic view of an image acquisition unit according to the fourth embodiment of the present disclosure. Fig.Figure 8 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the fourth embodiment. Fig. 7, the image acquisition unit 4 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the three adjacent lens elements.

[0109] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0110] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of plastic and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0111] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0112] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region thereof and an image-side surface that is planar in a paraxial region thereof. The third lens element E3 is made of plastic and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0113] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and has no influence on the focal length of the photographing optical lens system.

[0114] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0115] The detailed optical data of the fourth embodiment are shown in Table 4A and the aspherical surface data are shown in Table 4B below. TABLE 4A 4. Embodiment f = 0.42 mm, Fno = 4.50, HFOV = 69.4 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 10.000 1 Plate 1 Plano 0.200 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.175 plastic 1.544 56.0 -0.51 4 0.2757 (ASP) 0.326 5 Aperture diaphragm Plano 0.035 6 Lens 2 0.4061 (ASP) 0.427 plastic 1.544 56.0 0.25 7 -0.1326 (ASP) 0.050 8 Lens 3 -0.1860 (ASP) 0.501 plastic 1.671 19.5 -0.28 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.200 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.032 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 4B Aspherical coefficients Surface # 4 6 7 8 k = -6.86815E-01 7.35893E+00 -1.12501E+00 -4.16719E+00 A4 = -6.0694E+00 -2.1606E+01 7.2746E+01 2.1846E+01 A6 = 4.8466E+02 2.8492E+03 -3.5425E+03 -1.5387E+03 A8 = -1.7097E+04 -7.0132E+05 1.0921E+05 4.7456E+04 A10 = 2.6259E+05 5.2793E+07 -1.7392E+06 -7.7683E+05 A12 = -1.4091E+06 -1.4704E+09 1.0667E+07 4.9287E+06

[0116] In the fourth embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the first embodiment. The definitions of these parameters, shown in Table 4C below, are also the same as those given in the first embodiment, with corresponding values ​​for the fourth embodiment, so explanations regarding them will not be repeated.

[0117] In addition, these parameters can be calculated from Table 4A and Table 4B as the following values ​​and satisfy the following conditions: TABLE 4C Values ​​of optical and physical parameters / definitions f [mm] 0.42 f1 / R2 -1.84 Fno 4.50 R5 / R4 1.40 HFOV [degree] 69.4 R5 / R6 0.00 FOV [degrees] 138.8 CT1 / CT2 0.41 TL / f 4.45 CT2 / CT3 0.85 ImgH / f 1.22 T12 / CT1 2.06 BL / TD 0.23 T23 / CT2 0.12 f / f1 -0.83 T23 / CT3 0.10 f / f3 -1.51 (CT2+CT3) / CT1 5.30 f / f12 2.93 ET3 / ET1 2.13 f / f1+f / f2+f / f3 -0.69 Y1R2 / Y2R1 1.86 f / R1+f / R6 0.00 SAG3R2 / CT3 0.00 5. Embodiment

[0118] Fig. 9 is a schematic view of an image acquisition unit according to the fifth embodiment of the present disclosure. Fig.Figure 10 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the fifth embodiment. Fig. 9, the image acquisition unit 5 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the three adjacent lens elements.

[0119] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0120] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of glass and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0121] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0122] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region thereof and an image-side surface that is planar in a paraxial region thereof. The third lens element E3 is made of plastic and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0123] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and has no influence on the focal length of the optical lens system for photographing.

[0124] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0125] The detailed optical data of the fifth embodiment are shown in Table 5A and the aspherical surface data are shown in Table 5B below. TABLE 5A 5. Embodiment f = 0.63 mm, Fno = 4.00, HFOV = 68.7 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 10.000 1 Plate 1 Plano 0.200 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.157 Glass 1.516 56.8 -2.47 4 1.2750 (ASP) 0.299 5 Aperture diaphragm Plano 0.046 6 Lens 2 0.5619 (ASP) 0.312 plastic 1.544 56.0 0.30 7 -0.1868 (ASP) 0.094 8 Lens 3 -0.2268 (ASP) 0.180 plastic 1.697 16.3 -0.33 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.300 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.073 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 5B Aspherical coefficients Surface # 4 6 7 8 k = -4.34847E+01 -2.78062E+00 -7.10854E-01 -2.42587E+00 A4 = 8.1138E+00 -4.4590E+00 2.3166E+01 2.5116E+01 A6 = -5.7793E+01 -8.3352E+00 1.5474E+01 -6.3188E+02 A8 = 6.9810E+02 3.3433E+03 -5.7464E+03 1.1730E+04 A10 = -4.3878E+03 -2.7896E+05 7.1681E+04 -1.6923E+05 A12 = 2.4750E+04 3.3735E+06 -3.2549E+05 1.3447E+06 A14 = - - -2.0323E+06 -4.8707E+06

[0126] In the fifth embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as that of the first embodiment. The definitions of these parameters, shown in Table 5C below, are also the same as those given in the first embodiment, with corresponding values ​​for the fifth embodiment, so explanations will not be repeated.

[0127] In addition, these parameters can be calculated from Table 5A and Table 5B as the following values ​​and satisfy the following conditions: TABLE 5C Values ​​of optical and physical parameters / definitions f [mm] 0.63 f1 / R2 -1.94 Fno 4.00 R5 / R4 1.21 HFOV [degree] 68.7 R5 / R6 0.00 FOV [degrees] 137.4 CT1 / CT2 0.50 TL / f 2.50 CT2 / CT3 1.73 ImgH / f 0.81 T12 / CT1 2.20 BL / TD 0.45 T23 / CT2 0.30 f / f1 -0.26 T23 / CT3 0.52 f / f3 -1.95 (CT2+CT3) / CT1 3.13 f / f12 2.28 ET3 / ET1 1.18 f / f1+f / f2+f / f3 -0.11 Y1R2 / Y2R1 1.65 f / R1+f / R6 0.00 SAG3R2 / CT3 0.00 6. Embodiment

[0128] Fig. 11 is a schematic view of an image acquisition unit according to the sixth embodiment of the present disclosure. Fig.Figure 12 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the sixth embodiment. Fig. 11, the image acquisition unit 6 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the adjacent three lens elements.

[0129] The first lens element E1 with a negative refractive index has an object-side surface that is concave in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0130] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region thereof and an image-side surface that is convex in a paraxial region thereof. The second lens element E2 is made of plastic and has both the object-side surface and the image-side surface aspherical.

[0131] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region and an image-side surface that is convex in a paraxial region. The third lens element E3 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0132] The E6 filter is made of glass and is located between the third lens element E3 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0133] The detailed optical data of the sixth embodiment are shown in Table 6A and the data of the aspherical surfaces are shown in Table 6B below. TABLE 6A 6. Embodiment f = 0.42 mm, Fno = 3.70, HFOV = 76.0 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 20.000 1 Lens 1 -9.8213 (ASP) 0.143 plastic 1.534 56.0 -0.60 2 0.3323 (ASP) 0.461 3 Aperture diaphragm Plano 0.067 4 Lens 2 0.3699 (ASP) 0.336 plastic 1.544 56.0 0.34 5 -0.2527 (ASP) 0.110 6 Lens 3 -0.2998 (ASP) 0.268 plastic 1.697 16.3 -0.59 7 -1.4846 (ASP) 0.150 8 filter Plano 0.100 Glass 1.517 64.2 - 9 Plano 0.139 10 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 6B Aspherical coefficients Surface # 1 2 4 5 6 7 k = -9.63042E+01 -9.58655E-01 -9.58098E-01 -7.90378E-01 - 1.68259E+00 - 9.90000E+01 A4 = 1.2710E-02 5.4523E+00 -3.0031E+00 1.8239E+01 2.8640E+01 1.0470E+01 A6 = 4.6288E+00 -9.4771E+01 1.3682E+02 -3.3965E+02 -1.0912E+03 -1.6071E+02 A8 = -4.1264E+01 4.8188E+03 -5.9345E+03 6.7962E+03 2.6059E+04 1.5396E+03 A10 = 1.6620E+02 -6.9616E+04 1.2632E+05 -1.2800E+05 -5.2687E+05 -1.0780E+04 A12 = -3.3066E+02 4.2731E+05 -1.1960E+06 1.4186E+06 6.3876E+06 5.2523E+04 A14 = 2.6418E+02 - - -7.2986E+06 -3.9565E+07 -1.2334E+05

[0134] In the sixth embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as that of the first embodiment. The definitions of these parameters, shown in Table 6C below, are also the same as those given in the first embodiment, with corresponding values ​​for the sixth embodiment, so explanations will not be repeated.

[0135] In addition, these parameters can be calculated from Table 6A and Table 6B as the following values ​​and satisfy the following conditions: TABLE 6C Values ​​of optical and physical parameters / definitions f [mm] 0.42 f1 / R2 -1.80 Fno 3.70 R5 / R4 1.19 HFOV [degree] 76.0 R5 / R6 0.20 FOV [degrees] 152.0 CT1 / CT2 0.43 TL / f 4.25 CT2 / CT3 1.25 ImgH / f 1.28 T12 / CT1 3.69 BL / TD 0.28 T23 / CT2 0.33 f / f1 -0.70 T23 / CT3 0.41 f / f3 -0.70 (CT2+CT3) / CT1 4.22 f / f12 1.94 ET3 / ET1 1.17 f / f1+f / f2+f / f3 -0.18 Y1R2 / Y2R1 1.37 f / R1+f / R6 -0.32 SAG3R2 / CT3 0.04 7. Embodiment

[0136] Fig. 13 is a schematic view of an image acquisition unit according to the seventh embodiment of the present disclosure. Fig.Fig. 14 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the seventh embodiment. Fig. 13, the image acquisition unit 7 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3), and no additional lens element is disposed between each of the adjacent three lens elements.

[0137] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0138] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of glass and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0139] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0140] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region thereof and an image-side surface that is planar in a paraxial region thereof. The third lens element E3 is made of plastic and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0141] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and has no influence on the focal length of the optical lens system for photographing.

[0142] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0143] The detailed optical data of the seventh embodiment are shown in Table 7A and the aspherical surface data are shown in Table 7B below. TABLE 7A 7. Embodiment f = 0.57 mm, Fno = 3.80, HFOV = 65.1 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 8.000 1 Plate 1 Plano 0.200 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.150 Glass 1.523 58.7 -1.13 4 0.5910 (ASP) 0.407 5 Aperture diaphragm Plano 0.058 6 Lens 2 0.8333 (ASP) 0.314 plastic 1.544 56.0 0.41 7 -0.2617 (ASP) 0.232 8 Lens 3 -0.4206 (ASP) 0.150 plastic 1.697 16.3 -0.60 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.350 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.053 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 7B Aspherical coefficients Surface # 4 6 7 8 k = -1.58782E+00 -1.93960E+01 -7.06250E-01 -7.64577E-01 A4 = 4.2164E+00 -4.1738E+00 2.5891E+00 5.5955E+00 A6 = -9.5912E+00 -1.7613E+02 -1.5805E+02 -1.7461E+01 A8 = 4.3799E+02 6.4760E+03 6.6280E+03 -1.9922E+03 A10 = -4.2422E+03 -2.4204E+05 -2.0582E+05 5.3439E+04 A12 = 2.3634E+04 -1.6068E+06 2.9197E+06 -6.7418E+05 A14 = - - -1.7948E+07 3.1593E+06

[0144] In the seventh embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the first embodiment. The definitions of these parameters, shown in Table 7C below, are also the same as those given in the first embodiment, with corresponding values ​​for the seventh embodiment, so explanations regarding them will not be repeated.

[0145] In addition, these parameters can be calculated from Table 7A and Table 7B as the following values ​​and satisfy the following conditions: TABLE 7C Values ​​of optical and physical parameters / definitions f [mm] 0.57 f1 / R2 -1.91 Fno 3.80 R5 / R4 1.61 HFOV [degree] 65.1 R5 / R6 0.00 FOV [degrees] 130.2 CT1 / CT2 0.48 TL / f 3.24 CT2 / CT3 2.09 ImgH / f 0.90 T12 / CT1 3.10 BL / TD 0.40 T23 / CT2 0.74 f / f1 -0.50 T23 / CT3 1.55 f / f3 -0.94 (CT2+CT3) / CT1 3.09 f / f12 1.67 ET3 / ET1 0.89 f / f1+f / f2+f / f3 -0.05 Y1R2 / Y2R1 1.75 f / R1+f / R6 0.00 SAG3R2 / CT3 0.00 8. Embodiment

[0146] Fig. 15 is a schematic view of an image acquisition unit according to the eighth embodiment of the present disclosure. Fig.Fig. 16 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to the eighth embodiment. Fig. 15, the image acquisition unit 8 includes the photographing optical lens system (the reference numeral of which is omitted) of the present disclosure and an image sensor IS. The photographing optical lens system includes, in order from an object side to an image side along an optical path, a first plate E4, a first lens element E1, an aperture stop ST, a second lens element E2, a third lens element E3, a second plate E5, a filter E6, and an image surface IMG. The photographing optical lens system includes three lens elements (E1, E2, and E3) with no additional lens element disposed between each of the adjacent three lens elements.

[0147] The first plate E4 is made of glass and is located between an imaged object and the first lens element E1 and does not affect the focal length of the optical lens system for photographing.

[0148] The first lens element E1 with a negative refractive index has an object-side surface that is planar in a paraxial region thereof and an image-side surface that is concave in a paraxial region thereof. The first lens element E1 is made of plastic and has a spherical object-side surface and an aspherical image-side surface. The object-side surface of the first lens element E1 is cemented to the first plate E4.

[0149] The second lens element E2 with a positive refractive index has an object-side surface that is convex in a paraxial region and an image-side surface that is convex in a paraxial region. The second lens element E2 is made of plastic and has both the object-side and image-side surfaces aspherical.

[0150] The third lens element E3 with a negative refractive index has an object-side surface that is concave in a paraxial region thereof and an image-side surface that is planar in a paraxial region thereof. The third lens element E3 is made of glass and has an aspherical object-side surface and a spherical image-side surface. The image-side surface of the third lens element E3 is cemented to the second plate E5.

[0151] The second plate E5 is made of glass and is located between the third lens element E3 and the image surface IMG and has no influence on the focal length of the optical lens system for photographing.

[0152] The E6 filter is made of glass and is located between the second plate E5 and the image surface IMG. It does not affect the focal length of the optical lens system for photography. The E6 filter is cemented to the second plate E5. The IS image sensor is located on or near the image surface IMG of the optical lens system for photography.

[0153] The detailed optical data of the eighth embodiment are shown in Table 8A and the aspherical surface data are shown in Table 8B below. TABLE 8A 8. Embodiment f = 0.55 mm, Fno = 4.70, HFOV = 70.1 degrees Surface # radius of curvature thickness material index Abbé # focal length 0 lens infinity 20.000 1 Plate 1 Plano 0.100 Glass 1.517 64.2 - 2 Plano 0.010 cement 1.485 53.2 3 Lens 1 Plano (SPH) 0.216 plastic 1.587 28.3 -0.93 4 0.5467 (ASP) 0.324 5 Aperture diaphragm Plano 0.034 6 Lens 2 0.4060 (ASP) 0.280 plastic 1.534 56.0 0.31 7 -0.2071 (ASP) 0.110 8 Lens 3 -0.2626 (ASP) 0.150 Glass 1.699 30.1 -0.38 9 Plano (SPH) 0.010 cement 1.485 53.2 10 Plate 2 Plano 0.300 Glass 1.517 64.2 - 11 Plano 0.010 cement 1.485 53.2 12 filter Plano 0.100 Glass 1.517 64.2 - 13 Plano 0.092 14 Picture Plano - Note: The reference wavelength is 587.6 nm (d-line). TABLE 8B Aspherical coefficients Surface # 4 6 7 8 k = 1.02072E+00 -1.07166E+00 -5.79776E-01 -1.20383E+00 A4 = 4.9250E+00 -2.1079E+00 1.5877E+01 2.0489E+01 A6 = -3.3315E+01 -9.5451E+02 3.1449E+02 -3.9737E+02 A8 = 1.9174E+03 1.0717E+05 -3.0852E+04 -1.1632E+03 A10 = -3.0546E+04 -5.5236E+06 1.1898E+06 2.3135E+05 A12 = 2.2885E+05 1.0093E+08 -2.5080E+07 -6.1719E+06 A14 = - - 2.0517E+08 4.4844E+07

[0154] In the eighth embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as that of the first embodiment. The definitions of these parameters, shown in Table 8C below, are also the same as those given in the first embodiment, with corresponding values ​​for the eighth embodiment, so explanations will not be repeated.

[0155] In addition, these parameters can be calculated from Table 8A and Table 8B as the following values ​​and satisfy the following conditions: TABLE 8C Values ​​of optical and physical parameters / definitions f [mm] 0.55 f1 / R2 -1.70 Fno 4.70 R5 / R4 1.27 HFOV [degree] 70.1 R5 / R6 0.00 FOV [degrees] 140.2 CT1 / CT2 0.77 TL / f 2.94 CT2 / CT3 1.87 ImgH / f 0.89 T12 / CT1 1.66 BL / TD 0.46 T23 / CT2 0.39 f / f1 -0.59 T23 / CT3 0.73 f / f3 -1.47 (CT2+CT3) / CT1 1.99 f / f12 2.20 ET3 / ET1 0.73 f / f1+f / f2+f / f3 -0.25 Y1R2 / Y2R1 1.82 f / R1+f / R6 0.00 SAG3R2 / CT3 0.00 9. Embodiment

[0156] Fig.17 is a perspective view of an image sensing unit according to the ninth embodiment of the present disclosure. In this embodiment, an image sensing unit 100 is a camera module including a lens unit 101, a driving device 102, an image sensor 103, and an image stabilizer 104. The lens unit 101 includes the optical lens system for photographing disclosed in the first embodiment, a barrel, and a holding member (the reference numerals of which are omitted) for holding the optical lens system for photographing. However, the lens unit 101 may alternatively be provided with the optical lens system for photographing disclosed in other embodiments of the present disclosure, and the present disclosure is not limited thereto.The imaging light is converged in the lens unit 101 of the image acquisition unit 100 to form an image with the drive device 102, which is used to focus the image onto the image sensor 103, and the formed image is then digitally transmitted to another electronic component for further processing.

[0157] The drive device 102 can have autofocus functionality, and different drive configurations can be achieved by using voice coil motors (VCMs), microelectromechanical systems (MEMS), piezoelectric systems, or shape memory alloy materials. The drive device 102 is advantageous for obtaining a better imaging position of the lens unit 101, so that a clear image of the imaged object can be captured by the lens unit 101 at different object distances. The image sensor 103 (for example, CMOS or CCD), which can have high light sensitivity and low noise, is arranged on the image surface of the optical lens system for photography to achieve higher image quality.

[0158] The image stabilizer 104, such as an accelerometer, a gyro sensor, and a Hall-effect sensor, is configured to cooperate with the drive device 102 to provide optical image stabilization (OIS). The drive device 102, which cooperates with the image stabilizer 104, is advantageous for compensating for pan and tilt of the lens unit 101 to reduce motion blur during exposure. In some cases, compensation can be provided by electronic image stabilization (EIS) with image processing software, thereby improving image quality in motion or low-light conditions. 10. Embodiment

[0159] Fig. 18 is a perspective view of an electronic device according to the tenth embodiment of the present disclosure, Fig. 19 is another perspective view of the electronic device in Fig.18 and Fig. 20 is a block diagram of the electronic device in Fig. 18.

[0160] In this embodiment, an electronic device 200 is a smartphone that includes the image capture unit 100 according to the ninth embodiment, an image capture unit 100a, an image capture unit 100b, an image capture unit 100c, an image capture unit 100d, an image capture unit 100e, a flash module 201, a focus assist module 202, an image signal processor 203, a display module 204, and an image software processor 205. The image capture unit 100, the image capture unit 100a, and the image capture unit 100b are arranged on the same side of the electronic device 200, and each of the image capture units 100, 100a, and 100b has a single focal point. The focus assist module 202 may be a laser rangefinder or a time-of-flight module, but the present disclosure is not limited thereto.The image capture unit 100c, the image capture unit 100d, the image capture unit 100e, and the display module 204 are arranged on the opposite side of the electronic device 200, and the display module 204 may be a user interface, so the image capture units 100c, 100d, and 100e may be front-facing cameras of the electronic device 200 for taking selfies, but the present disclosure is not limited thereto. Furthermore, each of the image capture units 100a, 100b, 100c, 100d, and 100e may include the optical lens system for taking photographs of the present disclosure and have a similar configuration to the image capture unit 100. Specifically, each of the image acquisition units 100a, 100b, 100c, 100d, and 100e may include a lens unit, a drive device, an image sensor, and an image stabilizer, and may also include a light deflecting element for deflecting the optical path.In addition, each lens unit of the image capturing units 100a, 100b, 100c, 100d, and 100e may include the optical lens system for photographing of the present disclosure, a tube, and a holding member for holding the optical lens system for photographing.

[0161] The image capture unit 100 is a wide-angle image capture unit, the image capture unit 100a is a telephoto image capture unit with a light path deflection function, the image capture unit 100b is an ultra-wide-angle image capture unit, the image capture unit 100c is a wide-angle image capture unit, the image capture unit 100d is an ultra-wide-angle image capture unit, and the image capture unit 100e is a time-of-flight image capture unit. In this embodiment, the image capture units 100, 100a, and 100b have different fields of view, so that the electronic device 200 can have different magnification ratios to meet the requirement of optical zoom functionality. In addition, the image capture unit 100e can determine depth information of the imaged object. In addition, the light deflection configuration of the image capture unit 100a can, for example, be one of the Fig. 27 to Fig.29 shown configurations, to which reference is made in the preceding descriptions Fig. 27 to Fig. 29, and the details thereof will not be repeated. Furthermore, each of the image acquisition units 100, 100b, 100c, 100d, and 100e may have a light redirecting configuration, for example, corresponding to one of the configurations shown in Fig. 27 to Fig. 29 shown configurations, to which reference is made in the preceding descriptions Fig. 27 to Fig. 29. In this embodiment, the electronic device 200 includes a plurality of image capture units 100, 100a, 100b, 100c, 100d, and 100e, but the present disclosure is not limited to the number and arrangement of the image capture units.

[0162] When a user captures images of an object 206, the light beams converge in the image capture unit 100, the image capture unit 100a, or the image capture unit 100b to create images, and the flash module 201 is activated to provide light assistance. The focus assist module 202 detects the object distance of the imaged object 206 to achieve fast autofocus. The image signal processor 203 is configured to optimize the captured image to improve image quality. The light beam emitted by the focus assist module 202 can be either conventional infrared light or laser light. Additionally, the light beams can converge in the image capture unit 100c, 100d, or 100e to create images.The display module 204 may include a touchscreen, and the user may interact with the display module 204 and the image software processor 205, which has multiple functions for capturing images and performing image processing. Alternatively, the user may capture images using a physical button. The image processed by the image software processor 205 may be displayed on the display module 204. 11. Embodiment

[0163] Fig. 21 is a schematic view of an electronic device according to the eleventh embodiment of the present disclosure, and Fig. 22 is another schematic view of the electronic device in Fig. 21.

[0164] In this embodiment, an electronic device 300 is a smartphone that includes the image capture unit 100 according to the ninth embodiment, an image capture unit 100f, an image capture unit 100g, an image capture unit 100h, and a display module 301. As shown in Fig. As shown in Figure 21, the image capture unit 100, the image capture unit 100f, and the image capture unit 100g are arranged on the same side of the electronic device 300, and each of the image capture units 100, 100f, and 100g has a single focal point. As shown in Fig.As shown in Figure 22, the image capture unit 100h and the display module 301 are arranged on the opposite side of the electronic device 300, so that the image capture unit 100h may be a front-facing camera of the electronic device 300 for taking selfies, but the present disclosure is not limited thereto. Furthermore, each of the image capture units 100f, 100g, and 100h may include the optical lens system for taking photographs of the present disclosure and have similar equipment to the image capture unit 100. Specifically, each of the image capture units 100f, 100g, and 100h may include a lens unit, a drive device, an image sensor, and an image stabilizer.In addition, each lens unit of the image capturing units 100f, 100g, and 100h may include the optical lens system for photographing of the present disclosure, a tube, and a holding member for holding the optical lens system for photographing.

[0165] Image capture unit 100 is a wide-angle image capture unit, image capture unit 100f is a telephoto image capture unit, image capture unit 100g is an ultra-wide-angle image capture unit, and image capture unit 100h is a wide-angle image capture unit. In this embodiment, image capture units 100, 100f, and 100g have different fields of view, so that electronic device 300 can have different magnification ratios to meet the requirement of optical zoom functionality. In this embodiment, electronic device 300 includes a plurality of image capture units 100, 100f, 100g, and 100h, but the present disclosure is not limited to the number and arrangement of the image capture units. 12. Embodiment

[0166] Fig. 23 is a perspective view of an electronic device according to the twelfth embodiment of the present disclosure.

[0167] In this embodiment, an electronic device 400 is a smartphone that includes the image capture unit 100 according to the ninth embodiment, an image capture unit 100i, an image capture unit 100j, an image capture unit 100k, an image capture unit 100m, an image capture unit 100n, an image capture unit 100p, an image capture unit 100q, an image capture unit 100r, a flash module 401, a focus assist module, an image signal processor, a display module, and an image software processor (not shown). The image capture units 100, 100i, 100j, 100k, 100m, 100n, 100p, 100q and 100r are arranged on the same side of the electronic device 400, while the display module is arranged on the opposite side of the electronic device 400.Furthermore, each of the image capture units 100i, 100j, 100k, 100m, 100n, 100p, 100q, and 100r may include the optical lens system for photographing of the present disclosure and have similar equipment to the image capture unit 100, the details of which will not be repeated.

[0168] The image acquisition unit 100 is a wide-angle image acquisition unit, the image acquisition unit 100i is a telephoto image acquisition unit with a beam path deflection function, the image acquisition unit 100j is a telephoto image acquisition unit with a beam path deflection function, the image acquisition unit 100k is a wide-angle image acquisition unit, the image acquisition unit 100m is an ultra-wide-angle image acquisition unit, the image acquisition unit 100n is an ultra-wide-angle image acquisition unit, the image acquisition unit 100p is a telephoto image acquisition unit, the image acquisition unit 100q is a telephoto image acquisition unit, and the image acquisition unit 100r is a time-of-flight image acquisition unit.In this embodiment, the image capture units 100, 100i, 100j, 100k, 100m, 100n, 100p, and 100q have different fields of view, so that the electronic device 400 can have different magnification ratios to meet the requirements of the optical zoom functionality. Furthermore, the image capture unit 100r can determine depth information of the imaged object. Furthermore, the light redirection configuration of the image capture units 100i and 100j can, for example, be one of the configurations shown in FIG. Fig. 27 to Fig. 29, which can be accessed with reference to the above descriptions. Fig. 27 to Fig.29, and the details thereof will not be repeated. In this embodiment, the electronic device 400 includes a plurality of image capture units 100, 100i, 100j, 100k, 100m, 100n, 100p, 100q, and 100r, but the present disclosure is not limited to the number and arrangement of the image capture units. When a user captures images of an object, the light beams converge in the image capture unit 100, 100i, 100j, 100k, 100m, 100n, 100p, 100q, or 100r to form images, and the flash module 401 is activated for light support. Furthermore, the subsequent processes are performed similarly to the above-mentioned embodiments, and the details thereof will not be repeated. 13. Embodiment

[0169] Fig. 24 is a perspective view of an electronic device according to the thirteenth embodiment of the present disclosure.

[0170] In this embodiment, an electronic device 500 is a capsule endoscope that includes a housing 501, a plurality of batteries 502, a plurality of LEDs 503, the image capture unit 100 as disclosed in the ninth embodiment, and a wireless transmitter 504. The batteries 502, the LEDs 503, the image capture unit 100, and the wireless transmitter 504 are arranged in the housing 501. In addition, the lens unit 101 of the image capture unit 100 is arranged on one side of the LEDs 503. Furthermore, the image sensor 103 of the image capture unit 100 is, for example, a CMOS. The batteries 502 supply power to the LEDs 503, the image capture unit 100, and the wireless transmitter 504. The light-emitting diodes 503 are configured to emit light toward an imaged object so that the image capture unit 100 can capture clear images.The images are then converted into image signals, which are transmitted outside the human body via the wireless transmitter 504. A wireless receiving antenna (not shown) located outside the human body receives the image signals, and the images of the imaged object can be displayed on a display device (not shown). Furthermore, the photographing optical lens system of the image capture unit 100 is configured to capture images of the imaged object when the object distance is within a range of, for example, 30 mm or less. 14. Embodiment

[0171] Fig. 25 is a perspective view of an electronic device according to the fourteenth embodiment of the present disclosure.

[0172] In this embodiment, an electronic device 600 is a nasopharyngeal endoscope including a main body 601, a first cable 602, the image acquisition unit 100 as disclosed in the ninth embodiment, and a second cable 603. One end of the first cable 602 is electrically connected to the main body 601, and the image acquisition unit 100 is disposed at another end of the first cable 602. Moreover, the optical lens system for photographing the image acquisition unit 100 is configured to capture images of an imaged object when an object distance is, for example, within a range of 30 mm or less. One end of the second cable 603 is electrically connected to the main body 601, and another end of the second cable 603 is electrically connected to a display device 700, but the present disclosure is not limited thereto.The electronic device 600 captures clear images through the image capture unit 100, converts the images into image signals, and transmits the image signals through the first cable 602 and the second cable 603 to the display device 700 to display the images of the imaged object.

[0173] The smartphones and endoscopes in the embodiments serve only as examples for illustrating the image acquisition unit of the present disclosure installed in an electronic device, and the present disclosure is not limited thereto. The image acquisition unit can optionally be applied to optical systems with a movable focus.Furthermore, the optical lens system for photographing the image acquisition unit is characterized by good aberration correction capability and high image quality and can be used for 3D image acquisition (three-dimensional image acquisition) applications in products such as digital cameras, mobile devices, digital tablets, smart TVs, network monitoring devices, dashboard cameras, vehicle rearview cameras, multi-camera devices, image recognition systems, motion sensor input devices, unmanned aerial vehicles, wearable devices, portable video recorders, various medical endoscopes, industrial endoscopes, capsule cameras and other electronic imaging devices.

[0174] The foregoing description has been made for the purpose of illustration with reference to specific embodiments. It should be noted that TABLES 1A-8C show different data for the various embodiments; however, the data for the various embodiments were obtained from experiments. The embodiments were chosen and described in order to best explain the principles of the disclosure and their practical applications to enable others skilled in the art to best utilize the disclosure and various embodiments with various modifications as are suited to the particular use contemplated. The above-illustrated embodiments and the accompanying drawings are exemplary and are not intended to be exhaustive or to limit the scope of the present disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings.

Claims

[1] An optical lens system for photographing, comprising three lens elements (E1, E2 and E3), wherein the three lens elements (E1, E2 and E3) are, in order from an object side to an image side along an optical path, a first lens element (E1), a second lens element (E2) and a third lens element (E3), and each of the three lens elements (E1, E2 and E3) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the image-side surface of the first lens element (E1) is concave in a paraxial region thereof, the third lens element (E3) has a negative refractive index, and the optical lens system for photographing further comprises an aperture stop (ST) arranged between the first lens element (E1) and the second lens element (E2); and wherein an axial distance between the object-side surface of the first lens element (E1) and an image surface (IMG) is TL, a focal length of the optical lens system for photographing is f, a central thickness of the first lens element (E1) is CT1, a central thickness of the second lens element (E2) is CT2, a central thickness of the third lens element (E3) is CT3, a radius of curvature of the object-side surface of the third lens element (E3) is R5, a radius of curvature of the image-side surface of the third lens element (E3) is R6, an aperture number of the optical lens system for photographing is Fno, and the following conditions are satisfied: 1.80 <TL / f<5,10; 1.75<(CT2+CT3) / CT1<6.50; 0.40 <CT / CT3<2,50; −1.20 <R5 / R6<0,39; und 2.60 <Fno<5,10. [2] An optical lens system for photographing according to claim 1, wherein the second lens element (E2) has a positive refractive index, the object-side surface of the second lens element (E2) is convex in a paraxial region thereof, the image-side surface of the second lens element (E2) is convex in a paraxial region thereof, and the object-side surface of the third lens element (E3) is concave in a paraxial region thereof. [3] An optical lens system for photographing according to claim 1, wherein the first lens element (E1) has a negative refractive index; and wherein an axial distance between the second lens element (E2) and the third lens element (E3) is T23, the central thickness of the third lens element (E3) is CT3 and the following condition is satisfied: 0.03 <T23 / CT3<3,00. [4] The optical lens system for photographing according to claim 1, wherein the focal length of the optical lens system for photographing is f, a focal length of the first lens element (E1) is f1, a focal length of the second lens element (E2) is f2, a focal length of the third lens element (E3) is f3, the central thickness of the first lens element (E1) is CT1, the central thickness of the second lens element (E2) is CT2, and the following conditions are satisfied: −1.50 <f / f1+f / f2+f / f3<0,20; und 0.15 <CT / CT2<1,05. [5] The photographing optical lens system according to claim 1, wherein a maximum image height of the photographing optical lens system is ImgH, the focal length of the photographing optical lens system is f, an axial distance between the image-side surface of the third lens element (E3) and the image surface (IMG) is BL, an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the third lens element (E3) is TD, and the following conditions are satisfied: 0.65 <ImgH / f<1,50; und 0.10 <BL / TD<0,60. [6] The photographing optical lens system according to claim 1, wherein the focal length of the photographing optical lens system is f, a focal length of the third lens element (E3) is f3, a maximum field of view of the photographing optical lens system is FOV, and the following conditions are satisfied: −3.00 <f / f3<−0,30; und 128.0 degrees <FOV<172,0 Grad. [7] An optical lens system for photographing according to claim 1, wherein an axial distance between the first lens element (E1) and the second lens element (E2) is T12, the central thickness of the first lens element (E1) is CT1, and the following condition is satisfied: 1.20 <T12 / CT1<5,00. [8] An optical lens system for photographing according to claim 1, wherein at least one of the object-side surface of the first lens element (E1) and the image-side surface of the third lens element (E3) is planar in a paraxial region thereof. [9] An optical lens system for photographing according to claim 1, wherein a displacement parallel to an optical axis from an axial vertex of the image-side surface of the third lens element (E3) to a position of the maximum effective radius of the image-side surface of the third lens element (E3) is SAG3R2, the central thickness of the third lens element (E3) is CT3, and the following condition is satisfied: −0.30 <SAG3R2 / CT3<0,35. [10] Image acquisition unit (1, 100) comprising: the optical lens system for photographing according to claim 1; and an image sensor (IS, 103) arranged on the image surface (IMG) of the optical lens system for photographing. [11] An electronic device (200) comprising: the image capture unit (1, 100) according to claim 10. [12] An optical lens system for photographing, comprising three lens elements (E1, E2 and E3), wherein the three lens elements (E1, E2 and E3) are, in order from an object side to an image side along an optical path, a first lens element (E1), a second lens element (E2) and a third lens element (E3), and each of the three lens elements (E1, E2 and E3) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the third lens element (E3) has a negative refractive index; and wherein an axial distance between the object-side surface of the first lens element (E1) and an image surface (IMG) is TL, a focal length of the optical lens system for photographing is f, a compound focal length of the first lens element (E1) and the second lens element (E2) is f12, a central thickness of the first lens element (E1) is CT1, a central thickness of the second lens element (E2) is CT2, a central thickness of the third lens element (E3) is CT3, an axial distance between the first lens element (E1) and the second lens element (E2) is T12, a radius of curvature of the object-side surface of the first lens element (E1) is R1, a radius of curvature of the image-side surface of the second lens element (E2) is R4, a radius of curvature of the object-side surface of the third lens element (E3) is R5, a radius of curvature of the image-side surface of the third lens element (E3) is R6, and the following conditions are met: 2.30 <TL / f<4,80; 1.75<(CT+CT3) / CT1<6.50; 1.20 <T12 / CT1<4,20; 0.50 <R5 / R4<3,30; −0.60 <f / R1+f / R6<1,50; und 0.90 <f / f12<4,00. [13] An optical lens system for photographing according to claim 12, wherein the focal length of the optical lens system for photographing is f, a focal length of the first lens element (E1) is f1, and the following condition is satisfied: −1.50 <f / f1<0,20. [14] An optical lens system for photographing according to claim 12, wherein an axial distance between the second lens element (E2) and the third lens element (E3) is T23, the central thickness of the second lens element (E2) is CT2, and the following condition is satisfied: 0.03 <T23 / CT2<1,00. [15] An optical lens system for photographing according to claim 12, wherein the first lens element (E1) has a negative refractive index; and wherein the focal length of the optical lens system for photographing is f, the combined focal length of the first lens element (E1) and the second lens element (E2) is f12, and the following condition is satisfied: 1.25 <f / f12<3,30. [16] A photographing optical lens system according to claim 12, wherein the photographing optical lens system is configured to capture an image of an imaged object when an object distance is within a range of 30 mm or less; and where a maximum field of view of the optical lens system for photographing is FOV and the following condition is satisfied: 125.0 degrees <FOV<175,0 Grad. [17] An optical lens system for photographing according to claim 12, wherein the radius of curvature of the object-side surface of the third lens element (E3) is R5, the radius of curvature of the image-side surface of the third lens element (E3) is R6, an axial distance between the second lens element (E2) and the third lens element (E3) is T23, the central thickness of the third lens element (E3) is CT3, and the following conditions are satisfied: −2.00 <R5 / R6<0,35; und 0.03 <T23 / CT3<3,00. [18] An optical lens system for photographing according to claim 12, wherein an axial distance between the image-side surface of the third lens element (E3) and the image surface (IMG) is BL, an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the third lens element (E3) is TD, and the following condition is satisfied: 0.10 <BL / TD<0,60. [19] An optical lens system for photographing according to claim 12, wherein a focal length of the first lens element (E1) is f1, a radius of curvature of the image-side surface of the first lens element (E1) is R2, the central thickness of the second lens element (E2) is CT2, the central thickness of the third lens element (E3) is CT3, and the following conditions are satisfied: −3.50 <f1 / R2<0,00; und 0.55 <CT2 / CT3<2,40. [20] An optical lens system for photographing according to claim 12, wherein a maximum effective radius of the image-side surface of the first lens element (E1) is Y1R2, a maximum effective radius of the object-side surface of the second lens element (E2) is Y2R1, a distance parallel to an optical axis between a position of the maximum effective radius of the object-side surface of the first lens element (E1) and a position of the maximum effective radius of the image-side surface of the second lens element (E2) is ET1, a distance parallel to the optical axis between a position of the maximum effective radius of the object-side surface of the third lens element (E3) and a position of the maximum effective radius of the image-side surface of the third lens element (E3) is ET3, and the following conditions are met: 0.95 <Y1R2 / Y2R1<2,00; und 0.50 <ET3 / ET1<2,50. [21] The photographing optical lens system according to claim 12, wherein the axial distance between the object-side surface of the first lens element (E1) and the image surface (IMG) is TL, the focal length of the photographing optical lens system is f, the combined focal length of the first lens element (E1) and the second lens element (E2) is f12, the central thickness of the first lens element (E1) is CT1, the central thickness of the second lens element (E2) is CT2, the central thickness of the third lens element (E3) is CT3, the radius of curvature of the object-side surface of the first lens element (E1) is R1, the radius of curvature of the object-side surface of the second lens element (E2) is R2, the radius of curvature of the object-side surface of the third lens element (E3) is R3, the radius of curvature of the image-side surface of the first lens element (E1) is R4 is the radius of curvature of the image-side surface of the second lens element (E2) R4,the radius of curvature of the object-side surface of the third lens element (E3) is R5, the radius of curvature of the image-side surface of the third lens element (E3) is R6, an aperture number of the optical lens system for photographing is Fno, the axial distance between the first lens element (E1) and the second lens element (E2) is T12, and the following conditions are met: 2.50≤TL / f≤4.45; 1.99≤(CT2+CT3) / CT1≤5.57; 0.85≤CT2 / CT3≤2.09; −0.54≤R5 / R6≤0.20; 3.30≤Fno≤4.70; 1.66≤T12 / CT1≤3.85; 1.19≤R5 / R4≤2.55; −0.32≤f / R1+f / R6≤0.90; and 1.67≤f / f12≤2.93.

Images