Imaging lens system, image acquisition unit and electronic device

Abstract

Imaging lens system comprising five lens elements (E1, E2, E3, E4 and E5), wherein the five lens elements (E1, E2, E3, E4 and E5) are arranged in the order from an object side to an image side along a beam path as a first lens element (E1), a second lens element (E2), a third lens element (E3), a fourth lens element (E4) and a fifth lens element (E5), and wherein each of the five lens elements (E1, E2, E3, E4 and E5) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the first lens element (E1) has a positive refractive power, the second lens element (E2) has a negative refractive power, and the image-side surface of the second lens element (E2) is concave in a paraxial region thereof; and where 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 Dr1r6, an axial distance between the object-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr7r10, an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the fifth lens element (E5) is TD, an axial distance between the image-side surface of the fifth lens element (E5) and an image surface (IMG) is BL, an axial distance between the first lens element (E1) and the second lens element (E2) is T12, an axial distance between the second lens element (E2) and the third lens element (E3) is T23, an axial distance between the third lens element (E3) and the fourth lens element (E4) is T34,an axial distance between the fourth lens element (E4) and the fifth lens element (E5) is T45, an Abbe number of the fourth lens element (E4) is V4, a radius of curvature of the image-side surface of the second lens element (E2) is R4, a radius of curvature of the image-side surface of the fifth lens element (E5) is R10, and the following conditions are met: , 1.60 < Dr1r6 / Dr7r10 < 5.00 ; 0.50 < TD / BL < 1.50 ; 0.00 < (T12 + T23 + T45) / T34 < 0.50; 0.00 < T 23 / T 45 < 0.50 ; 5.0 < V 4 < 35.0 ; and 0.00 < | R 4 / R 10 | < 1.00.

Description

BACKGROUND Subject area

[0001] The present disclosure relates to an imaging lens system, an image acquisition unit and an electronic device, in particular an imaging lens system and an image acquisition unit that can be used in an electronic device. Description of related technology

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

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

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

[0005] Preferably, the first lens element has a positive refractive power. Preferably, the second lens element has a negative refractive power. Preferably, the image-side surface of the second lens element is concave in a paraxial region.

[0006] If an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is Dr1r6, an axial distance between the object-side surface of the fourth lens element and the image-side surface of the fifth lens element is Dr7r10, an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, an axial distance between the image-side surface of the fifth lens element and an image surface is BL, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, the axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, and an Abbe number of the fourth lens element is V4,where a radius of curvature of the image-side surface of the second lens element R4 is and a radius of curvature of the image-side surface of the fifth lens element R10 is, the following conditions are preferably met: 1.60 <Dr1r6 / Dr7r10<5,00; 0.50 <TD / BL<1,50; 0.00<(T12+T23+T45) / T34<0.50; 0.00 <T23 / T45<0,50; 5.0 <V4<35,0; und 0.00<|R4 / R10|<1.00.

[0007] According to another aspect of the present disclosure, an imaging lens system comprises five lens elements. The five lens elements are, in order from an object side to an image side along a beam path, a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element. Each of the five lens elements has an object-side surface facing the object side and an image-side surface facing the image side.

[0008] Preferably, the first lens element has a positive refractive power. Preferably, the second lens element has a negative refractive power. Preferably, the object-side surface of the second lens element is convex in a paraxial region. Preferably, the object-side surface of the fifth lens element is concave in a paraxial region.

[0009] If an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is Dr1r6, an axial distance between the object-side surface of the fourth lens element and the image-side surface of the fifth lens element is Dr7r10, an axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, an axial distance between the image-side surface of the fifth lens element and an image surface is BL, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, and an axial distance between the fourth lens element and the fifth lens element is T45, then the following conditions are preferably met: 1.60 <Dr1r6 / Dr7r10<5,00; 0.50 <TD / BL<1,50; 0.00<(T12+T23+T45) / T34<0.50; and 0.00 <T23 / T45<0,50.

[0010] According to another aspect of the present disclosure, an image acquisition unit comprises one of the aforementioned imaging lens systems and an image sensor, wherein the image sensor is arranged on the image surface of the imaging 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 by reading the following detailed description of the embodiments with reference to the accompanying drawings: Fig. Figure 1 is a schematic view of an image acquisition unit according to the first embodiment of the present disclosure; Fig.Figure 2 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the first embodiment; Fig. Figure 3 is a schematic view of an image acquisition unit according to the second embodiment of the present disclosure; Fig. Figure 4 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the second embodiment; Fig. Figure 5 is a schematic view of an image acquisition unit according to the 3rd embodiment of the present disclosure; Fig. Figure 6 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 3rd embodiment; Fig. Figure 7 is a schematic view of an image acquisition unit according to the 4th embodiment of the present disclosure; Fig.Figure 8 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 4th embodiment; Fig. Figure 9 is a schematic view of an image acquisition unit according to the 5th embodiment of the present disclosure; Fig. Figure 10 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 5th embodiment; Fig. Figure 11 is a schematic view of an image acquisition unit according to the 6th embodiment of the present disclosure; Fig. Figure 12 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 6th embodiment; Fig. Figure 13 is a schematic view of an image acquisition unit according to the 7th embodiment of the present disclosure; Fig.Figure 14 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 7th embodiment; Fig. Figure 15 is a schematic view of an image acquisition unit according to the 8th embodiment of the present disclosure; Fig. Figure 16 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 8th embodiment; Fig. Figure 17 is a schematic view of an image acquisition unit according to the 9th embodiment of the present disclosure; Fig. Figure 18 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 9th embodiment; Fig. Figure 19 is a schematic view of an image acquisition unit according to the 10th embodiment of the present disclosure; Fig.Figure 20 shows spherical aberration curves, astigmatic field curves and a distortion curve of the image acquisition unit according to the 10th embodiment; Fig. Figure 21 is a perspective view of an image acquisition unit according to the 11th embodiment of the present disclosure; Fig. Figure 22 is a perspective view of an electronic device according to the 12th embodiment of the present disclosure; Fig. Figure 23 is another perspective view of the electronic device in Fig. 22; Fig. 24 is a block diagram of the electronic device in Fig. 22; Fig. Figure 25 is a schematic view of an electronic device according to the 13th embodiment of the present disclosure; Fig. Figure 26 shows another schematic view of the electronic device in Fig. 25; Fig.Figure 27 is a perspective view of an electronic device according to the 14th embodiment of the present disclosure; Fig. Figure 28 is a perspective view of an electronic device according to the 15th embodiment of the present disclosure; Fig. Figure 29 shows a schematic view of inflection points and critical points on lens surfaces according to the first embodiment of the present disclosure; Fig. Figure 30 shows a schematic view of Y1R1, Y3R2, Y4R1 and Y5R2 according to the first embodiment of the present disclosure; Fig. Figure 31 shows a schematic view of a configuration of a reflective element in an imaging lens system according to an embodiment of the present disclosure; Fig.Figure 32 shows a schematic view of a further configuration of a reflective element in an imaging lens system according to an embodiment of the present disclosure; and Fig. Figure 33 shows a schematic view of a configuration of two reflective elements in an imaging lens system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] An imaging lens system comprises five lens elements. These five lens elements, in order from one object side to one image side along a beam path, are a first lens element, a second lens element, a third lens element, a fourth lens element, and a fifth lens element. Each of the five lens elements of the imaging lens system has an object-side surface facing the object side and an image-side surface facing the image side.

[0014] The first lens element can have a positive refractive power. This is advantageous for reducing the size and improving the light-focusing capability of the imaging lens system. The object-side surface of the first lens element is convex in a paraxial region. This is advantageous for adjusting the refractive power of the first lens element and the field of view of the imaging lens system.

[0015] The second lens element can have a negative refractive power. Therefore, it is advantageous for correcting spherical aberration in the imaging lens system. The object-side surface of the second lens element can be convex in a paraxial region. Therefore, it is advantageous for adjusting the refractive power of the second lens element to compensate for spherical aberration in the imaging lens system. The image-side surface of the second lens element can be concave in a paraxial region. Therefore, it is advantageous for correcting astigmatism in the imaging lens system to balance image quality between the center and the periphery of the image.

[0016] The object-side surface of the third lens element can be convex in a paraxial region. Therefore, it is advantageous to coordinate this with the shape of the image-side surface of the second lens element to reduce the size of the object-side end of the imaging lens system. The image-side surface of the third lens element can also be concave in a paraxial region. Therefore, it is advantageous to adjust the direction of refraction of light from the image-side surface of the third lens element to reduce the generation of stray light.

[0017] The fourth lens element can have a positive refractive power. Therefore, it is advantageous for focusing light.

[0018] The object-side surface of the fifth lens element can be concave in a paraxial region. Therefore, it is advantageous to adapt the shape of the fifth lens element to correct off-axis field curvature.

[0019] Among the five lens elements of the imaging lens system, at least one lens element with at least one inflection point may be present. Specifically, one or more lens elements, each with at least one inflection point, may be present among the first to the fifth lens elements. The one lens element with at least one inflection point refers to a lens element in which at least one of the object-side and image-side surfaces has at least one inflection point. Therefore, this is advantageous for increasing the flexibility of the optical design to correct aberrations. See Fig. 29, which shows a schematic view of the inflection points P on the lens surfaces according to the first embodiment of the present disclosure. Fig.29 The object-side surface and the image-side surface of the third lens element E3, the image-side surface of the fourth lens element E4, and the image-side surface of the fifth lens element E5 each have one inflection point P, and the object-side surface of the second lens element E2 has two inflection points P. The in Fig. The first embodiment of the present disclosure shown in Figure 29 is only an example. Each of the lens surfaces of the lens elements in different embodiments of the present disclosure may have one or more inflection points.

[0020] According to the present disclosure, the imaging lens system can further comprise at least one reflective element. Therefore, it is advantageous to provide different beam paths for the imaging lens system, thereby making the spatial arrangement more flexible, reducing mechanical constraints, and facilitating miniaturization of the imaging lens system.In particular, the optical lens system for imaging according to the present disclosure may optionally include at least one reflective element, such as a prism or a mirror, between an imaged object and the image surface on the optical beam path, and the surface shape of the prism or mirror may be planar, spherical, aspherical, or free-form, so that the imaging lens system can be more flexible in its spatial arrangement and therefore the dimensions of an electronic device are not limited by the total path length of the imaging lens system. See also. Fig. 31 and Fig. 32. Fig. Figure 31 shows a schematic view of a configuration of a reflective element in an imaging lens system according to an embodiment of the present disclosure, and Fig.Figure 32 shows a schematic view of another configuration of a reflective element in an imaging lens system according to an embodiment of the present disclosure. Fig. 31 and Fig. 32 The optical lens system for imaging can have a first optical axis OA1, a reflecting element LF, and a second optical axis OA2 in the sequence from an imaged object (not shown in the figures) to an image surface IMG along a beam path. The reflecting element LF can be arranged between the imaged object and a lens group LG of the imaging lens system, as shown in Fig. 31 shown, or arranged between a lens group LG and the image surface IMG of the imaging lens system, as shown in Fig. 32 shown. See also Fig.Figure 33 shows a schematic view of a configuration of two reflective elements in an imaging lens system according to an embodiment of the present disclosure. Fig.33 The optical lens system for imaging can have, in the sequence from an imaged object (not shown in the figure) to an image surface IMG along a beam path, a first optical axis OA1, a first reflecting element LF1, a second optical axis OA2, a second reflecting element LF2, and a third optical axis OA3. The first reflecting element LF1 is arranged between the imaged object and a lens group LG of the optical lens system for imaging, the second reflecting element LF2 is arranged between the lens group LG and the image surface IMG of the optical lens system for imaging, and the direction of propagation of the light on the first optical axis OA1 can be the same direction as the direction of propagation of the light on the third optical axis OA3, as shown in Fig.Figure 33 shows that the imaging lens system can optionally be provided with three or more reflective elements, and the present disclosure is not limited to the type, number and position of the reflective elements of the embodiments disclosed in the aforementioned figures.

[0021] If the axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is Dr1r6, and the axial distance between the object-side surface of the fourth lens element and the image-side surface of the fifth lens element is Dr7r10, the following condition can be satisfied: 1.60 < Dr1r6 / Dr7r10 < 5.00. Therefore, this is advantageous for reducing the size of the image-side end of the imaging lens system and improving image quality. Furthermore, the following condition can also be satisfied: 1.70 < Dr1r6 / Dr7r10 < 4.00. Additionally, the following condition can also be satisfied: 1.81 ≤ Dr1r6 / Dr7r10 ≤ 3.58.

[0022] If the axial distance between the object-side surface of the first lens element and the image-side surface of the fifth lens element is TD, and the axial distance between the image-side surface of the fifth lens element and an image surface is BL, the following condition can be satisfied: 0.50 < TD / BL < 1.50. Therefore, this is advantageous for improving the telephoto capability of the imaging lens system. Furthermore, the following conditions can also be satisfied: 0.55 < TD / BL < 1.35. Additionally, the following conditions can also be satisfied: 0.60 < TD / BL < 1.20. Furthermore, the following condition can also be satisfied: 0.77 ≤ TD / BL ≤ 1.02.

[0023] If the axial distance between the first and second lens elements is T12, the axial distance between the second and third lens elements is T23, the axial distance between the third and fourth lens elements is T34, and the axial distance between the fourth and fifth lens elements is T45, then the following condition can be met: 0.00 < (T12+T23+T45) / T34 < 0.50. Therefore, to reduce manufacturing tolerances, it is advantageous to adjust the ratio of the axial distance between the third and fourth lens elements to the total axial distance of all other adjacent lens elements. Furthermore, the following condition can also be met: 0.05 < (T12+T23+T45) / T34 < 0.45. Furthermore, the following condition can also be met: 0.10 ≤ (T12+T23+T45) / T34 ≤ 0.42.

[0024] If the axial distance between the second and third lens elements is T23 and the axial distance between the fourth and fifth lens elements is T45, the following condition can be met: 0.00 < T23 / T45 < 0.50. Therefore, it is advantageous to control the ratio of the axial distance between the second and third lens elements to the axial distance between the fourth and fifth lens elements to reduce manufacturing sensitivity and correct aberrations. Furthermore, the following conditions can also be met: 0.00 < T23 / T45 < 0.45. Additionally, the following conditions can also be met: 0.00 < T23 / T45 < 0.40. Furthermore, the following condition can also be met: 0.05 ≤ T23 / T45 ≤ 0.35.

[0025] If the Abbe number of the fourth lens element is V4, the following condition can be met: 5.0 < V4 < 35.0. Therefore, it is advantageous to adjust the Abbe number of the fourth lens element to correct chromatic aberration in the imaging lens system. Furthermore, the following conditions can also be met: 10.0 < V4 < 30.0. Additionally, the following condition can also be met: 16.3 ≤ V4 ≤ 25.3.

[0026] If the radius of curvature of the image-side surface of the second lens element is R4 and the radius of curvature of the image-side surface of the fifth lens element is R10, the following condition can be satisfied: 0.00 < |R4 / R10| < 1.00. Therefore, this is advantageous for correcting coma and improving light focusing quality both near and off-axis. Furthermore, the following conditions can also be satisfied: 0.00 < |R4 / R10| < 0.90. Additionally, the following conditions can also be satisfied: 0.00 < |R4 / R10| < 0.80. Furthermore, the following condition can also be satisfied: 0.06 ≤ |R4 / R10| ≤ 0.72.

[0027] If the focal length of the imaging lens is f and the focal length of the third lens element is f3, the following condition can be satisfied: -0.25 < f / f3 < 5.00. Therefore, it is advantageous to compensate for refractive power at the object-side and image-side ends of the imaging lens system to correct aberrations in the imaging lens system. Furthermore, the following conditions can also be satisfied: -0.25 < f / f3 < 3.00. Additionally, the following conditions can also be satisfied: -0.20 < f / f3 < 2.00. Furthermore, the following condition can also be satisfied: -0.15 < f / f3 < 1.60.

[0028] If the axial distance between the image-side surface of the fifth lens element and the image surface is BL, and the maximum image height of the imaging lens system (which can be half the diagonal length of an effective light-sensitive area of ​​an image sensor) is ImgH, the following condition can be satisfied: 2.20 < BL / ImgH < 3.50. Therefore, it is advantageous to balance the ratio between the back focal length and the image height to reduce distortion in the imaging lens system. Furthermore, the following condition can also be satisfied: 2.50 < BL / ImgH < 3.20.

[0029] If the axial distance between the object-side surface of the first lens element and the image surface is TL, and the maximum image height of the imaging lens system is ImgH, the following condition can be met: 4.00 < TL / ImgH < 7.00. Therefore, to maintain a suitable ratio between the image height and the overall length of the imaging lens system, it is advantageous to ensure sufficient image brightness while simultaneously promoting miniaturization of the imaging lens system. Furthermore, the following conditions can also be met: 4.50 < TL / ImgH < 6.50. Additionally, the following condition can also be met: 5.00 < TL / ImgH < 5.80.

[0030] If the focal length of the first lens element is f1 and the focal length of the second lens element is f2, the following condition can be satisfied: 0.50 < |f1 / f2| < 1.50. Therefore, it is advantageous to match the refractive power of the first and second lens elements to correct aberrations. Furthermore, the following condition can also be satisfied: 0.60 < |f1 / f2| < 1.20.

[0031] If the focal length of the first lens element is f1 and the focal length of the third lens element is f3, the following condition can be met: 0.40 < f1 / f3 < 1.50. Therefore, this is advantageous for compensating for light focusing at the object-side end of the imaging lens system. Furthermore, the following condition can also be met: 0.60 < f1 / f3 < 1.35.

[0032] If the focal length of the first lens element is f1, the focal length of the second lens element is f2, the focal length of the fourth lens element is f4, and the focal length of the fifth lens element is f5, the following condition can be met: -0.60 < (f1+f2) / (f4+f5) < 5.00. Therefore, it is advantageous to balance the refractive power configuration of the imaging lens system to improve image quality. Furthermore, the following condition can also be met: -0.50 < (f1+f2) / (f4+f5) < 4.00. Additionally, the following condition can also be met: -0.40 < (f1+f2) / (f4+f5) < 3.00.

[0033] If the radius of curvature of the object-side surface of the fifth lens element is R9 and the radius of curvature of the image-side surface of the fifth lens element is R10, the following condition can be met: -1.80 < R9 / R10 < 1.00. Therefore, it is advantageous to adjust the refractive power and surface shape of the fifth lens element to correct off-axis aberrations in the imaging lens system. Furthermore, the following condition can also be met: -1.60 < R9 / R10 < 0.80.

[0034] If the radius of curvature of the image-side surface of the third lens element is R6 and the radius of curvature of the object-side surface of the fourth lens element is R7, the following condition can be met: -1.00 < R6 / R7 < 1.10. Therefore, it is advantageous to match the radii of curvature of the two adjacent lens surfaces of the third and fourth lens elements to reduce chromatic aberration in the peripheral field of view. Furthermore, the following condition can also be met: -0.90 < R6 / R7 < 1.00. Additionally, the following condition can also be met: -0.80 < R6 / R7 < 0.90.

[0035] If the axial distance between the image-side surface of the first lens element and the object-side surface of the third lens element is Dr2r5, and the axial distance between the image-side surface of the fourth lens element and the image-side surface of the fifth lens element is Dr8r10, the following condition can be met: 0.00 < Dr2r5 / Dr8r10 < 1.70. Therefore, it is advantageous to ensure that the imaging lens system has a suitable distance between the lens elements, thus simplifying lens assembly and device size adjustment. Furthermore, the following condition can also be met: 0.30 < Dr2r5 / Dr8r10 < 1.50.

[0036] If the Abbe number of the second lens element is V2, the following condition can be met: 5.0 < V2 < 35.0. Therefore, this is advantageous for correcting chromatic aberrations in the imaging lens system, preventing image overlap, and improving image quality. Furthermore, the following condition can also be met: 10.0 < V2 < 30.0.

[0037] If the Abbe number of the third lens element is V3, the following condition can be met: 45.0 < V3 < 70.0. Therefore, it is advantageous to select a lens material with low dispersion to compensate for the focusing ability of light in different wavelength ranges. Furthermore, the following condition can also be met: 50.0 < V3 < 60.0.

[0038] If the maximum effective radius of the image-side surface of the third lens element is Y3R2 and the maximum effective radius of the object-side surface of the fourth lens element is Y4R1, the following condition can be satisfied: 1.20 < Y3R2 / Y4R1 < 1.90. Therefore, it is advantageous to reduce the size of the image-side end of the imaging lens system to facilitate miniaturization. Furthermore, the following condition can also be satisfied: 1.30 < Y3R2 / Y4R1 < 1.75. See [reference]. Fig. 30, which shows a schematic view of Y3R2 and Y4R1 according to the 1st embodiment of the present disclosure.

[0039] If the maximum field of view (FOV) of the imaging lens system is 10.0 degrees, the following condition can be met: 10.0 degrees < FOV < 25.0 degrees. Therefore, this is advantageous for capturing distant images to improve local image resolution and thus achieve a telephoto effect. Furthermore, the following condition can also be met: 13.0 degrees < FOV < 23.0 degrees.

[0040] If the axial distance between the image-side surface of the fifth lens element and the image surface is BL, and the axial distance between the third and fourth lens elements is T34, the following condition can be satisfied: 1.00 < BL / T34 < 4.50. Therefore, it is advantageous to adjust the ratio of the rear focal length of the imaging lens system to the axial distance between the third and fourth lens elements to achieve a telephoto configuration. Furthermore, the following condition can also be satisfied: 1.50 < BL / T34 < 4.50.

[0041] If the radius of curvature of the image-side surface of the first lens element is R2 and the radius of curvature of the object-side surface of the second lens element is R3, the following condition can be satisfied: 0.00 < |R3 / R2| < 1.10. Therefore, it is advantageous to control the angle of refraction of light within the imaging lens system to improve peripheral image illuminance. Furthermore, the following condition can also be satisfied: 0.00 < |R3 / R2| < 1.00. Additionally, the following condition can also be satisfied: 0.00 < |R3 / R2| < 0.90.

[0042] If 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: -0.50 < (R5-R6) / (R5+R6) < 1.00. Therefore, this is advantageous for adjusting the refractive power and surface of the third lens element, thereby correcting aberrations. Furthermore, the following condition can also be satisfied: -0.50 < (R5-R6) / (R5+R6) < 0.50. Additionally, the following condition can also be satisfied: -0.40 < (R5-R6) / (R5+R6) < 0.10.

[0043] If 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 met: 2.00 < CT1 / CT2 < 5.50. Therefore, it is advantageous to balance the ratio of the central thicknesses of the first and second lens elements to improve the structural stability of the imaging lens system. Furthermore, the following condition can also be met: 2.50 < CT1 / CT2 < 5.00.

[0044] If the axial distance between the image-side surface of the fifth lens element and the image surface is BL, and the sum of the axial distances between each of all adjacent lens elements of the imaging lens system is ΣAT, then the following condition can be satisfied: 1.70 < BL / ΣAT < 3.80. Therefore, it is advantageous to adjust the spatial arrangement of the lens elements, allowing the imaging lens system to achieve a telephoto effect. Furthermore, the following condition can also be satisfied: 1.80 < BL / ΣAT < 3.50.

[0045] If the axial distance between the third and fourth lens elements is T34, and the axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is Dr1r6, the following condition can be satisfied: 0.50 < T34 / Dr1r6 < 1.60. Therefore, this is advantageous for reducing the size of the object-side end of the imaging lens system. Furthermore, the following condition can also be satisfied: 0.50 < T34 / Dr1r6 < 1.30.

[0046] If the maximum effective radius of the object-side surface of the first lens element is Y1R1 and the maximum effective radius of the image-side surface of the fifth lens element is Y5R2, the following condition can be satisfied: 1.60 < Y1R1 / Y5R2 < 3.50. Therefore, it is advantageous to adjust the ratio of the optical effective radius between the first and fifth lens elements to reduce the angle of incidence of light on the image surface and improve the illuminance. Furthermore, the following condition can also be satisfied: 1.60 < Y1R1 / Y5R2 < 2.50. See [reference]. Fig. 30, which shows a schematic view of Y1R1 and Y5R2 according to the 1st embodiment of the present disclosure.

[0047] According to the present disclosure, the above-mentioned features and conditions can be used in numerous combinations to achieve corresponding effects.

[0048] According to the present disclosure, the lens elements of the imaging lens system can be made of either glass or plastic material. If the lens elements are made of glass, the refractive power distribution of the imaging lens system can be more flexible, and the influence on the imaging caused by changes in ambient temperature can be reduced. The glass lens element can be manufactured either by grinding or forming. If the lens elements are made of plastic material, the manufacturing costs can be effectively reduced. Furthermore, the surfaces of each lens element can be spherical or aspherical. 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, thereby effectively shortening the overall path length of the imaging lens system. Additionally, the aspherical surfaces can be manufactured by plastic injection molding or glass forming.

[0049] According to the present disclosure, if a lens surface is aspherical, it means that the lens surface has an aspherical shape over its entire optically effective area or part(s) thereof.

[0050] According to the present disclosure, the material of one or more lens elements can optionally contain an additive that produces light absorption and interference effects and modifies the transmittance of the lens elements in a specific wavelength range to reduce unwanted scattered light or color deviations. For example, the additive can 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 prevent excessive blue light and / or near-ultraviolet light from interfering with the final image. The additive can be homogeneously mixed with a plastic material to be used to manufacture a lens element from the mixed material by injection molding. Furthermore, the additive can be applied to the lens surface to achieve the aforementioned effects.

[0051] According to the present disclosure, both an object-side surface and an image-side surface have a paraxial region and an off-axis region. The paraxial region refers to the region of the surface in which light rays travel close to the optical axis, and the off-axis region refers to the region of the surface that is farther from the paraxial region. In particular, unless otherwise specified, if the lens element has a convex surface, the surface in the paraxial region thereof is convex, and if the lens element has a concave surface, the surface in the paraxial region thereof is concave.Furthermore, if a section of a refractive power, radius of curvature, or focal point of a lens element is not defined, this means that the area of ​​the refractive power, radius of curvature, or focal point of the lens element lies in its paraxial region.

[0052] According to the present disclosure, an inflection point is a point on the surface of the lens element where the surface changes from concave to convex or vice versa. A critical point is a non-axial point on the lens surface where its tangent is perpendicular to the optical axis. See Fig. 29, which shows a schematic view of the critical points C on the lens surfaces according to the first embodiment of the present disclosure. Fig. 29 The image-side surface of the fifth lens element E5 exhibits a critical point C in an off-axis region thereof. The in Fig.The first embodiment of the present disclosure shown in Figure 29 is only exemplary. Each of the lens surfaces of the lens elements in different embodiments of the present disclosure may have one or more critical points in an off-axis region.

[0053] According to the present disclosure, the image surface of the imaging lens system, based on the corresponding image sensor, can be flat or curved, in particular a curved surface that is concave and faces the object side of the imaging lens system.

[0054] According to the present disclosure, an image correction unit, such as an image field flattener, can optionally be arranged between the lens element that is closest along the beam path to the image side of the imaging lens system and the image surface to correct aberrations such as image 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 adapted according to the design of the image acquisition unit. In general, a preferred image correction unit is, for example, a thin transparent element with a concave object-side surface and a planar image-side surface, wherein the thin transparent element is arranged near the image surface.

[0055] According to the present disclosure, the imaging lens system can comprise at least one aperture, for example an aperture diaphragm, a glare diaphragm, or a field diaphragm. The glare diaphragm or field diaphragm can be arranged between an imaged object and the first lens element, between adjacent lens elements, or between the last lens element and the image surface, and is designed to eliminate stray light and thereby improve image quality.

[0056] According to the present disclosure, an aperture diaphragm can be configured as a front diaphragm or a middle diaphragm. A front diaphragm, positioned between an imaged object and the first lens element, can provide a greater distance between the exit pupil of the imaging lens system and the image surface to create a telecentric effect, thereby improving the image sensor efficiency of an image sensor (e.g., CCD or CMOS). A middle diaphragm, positioned between the first lens element and the image surface, is advantageous for increasing the viewing angle of the imaging lens system, thus providing a wider field of view for it.

[0057] According to the present disclosure, the imaging lens system can include an aperture control unit. The aperture control unit can be a mechanical component or a light modulator that can control the size and shape of the aperture by means of electricity or electrical signals. The mechanical component can include a movable element, such as an aperture assembly or a light-shielding film. The light modulator can 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 improve the ability to adjust image quality. Furthermore, the aperture control unit can be the aperture diaphragm of the present disclosure, which changes the f-number to achieve various image effects, such as depth of field or lens speed.

[0058] According to the present disclosure, the imaging lens system can comprise one or more optical elements for limiting the shape of the light passing through the imaging lens system. Each optical element can be, but is not limited to, a filter, a polarizer, etc., and each optical element can be, but is not limited to, a single element, a composite component, a thin film, etc. The optical element can be arranged on the object side or the image side of the imaging lens system, or between two adjacent lens elements, to transmit light in a specific shape and thus meet the application requirements.

[0059] According to the present disclosure, the imaging lens system can comprise at least one optical lens element, an optical element, or a support having at least one surface with a low-reflection layer. The low-reflection layer can effectively reduce stray light resulting from light reflection at the interface. The low-reflection layer can be located in an optically ineffective region of the object-side surface, the image-side surface of the optical lens element, or an interface between the object-side and image-side surfaces. The optical element can be a light-blocking element, an annular spacer, a tube element, a coverslip, a blue glass, a filter, a color filter, a beam-directing element (e.g., a reflecting element), a prism, a mirror, etc.The carrier can be a base for holding a lens assembly, a microlens mounted on an image sensor, a substrate surrounding the image sensor, a glass plate to protect the image sensor, etc.

[0060] According to the present disclosure, the optical lens system for imaging can further comprise a light-blocking element. The light-blocking element can have a non-circular aperture, and the non-circular aperture can have different effective radii in different directions perpendicular to the optical axis. Therefore, it is advantageous if the light-blocking element is coordinated with the shape of non-circular lens elements or an aperture diaphragm in order to reduce the size of the imaging lens system and to fully utilize the light passing through the non-circular lens elements or the aperture diaphragm, thereby reducing stray light. In addition, the light-blocking element can be provided with a wave-like or serrated structure on the circumference of an inner aperture section thereof.

[0061] 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 are calculated along the optical axis. Furthermore, if the optical axis is redirected by a reflecting element, the axial optical data are also calculated along the redirected optical axis.

[0062] In accordance with the above description of the present disclosure, the following specific embodiments are provided for further explanation. 1. Design

[0063] Fig. Figure 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.The image acquisition unit comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0064] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0065] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has two inflection points.

[0066] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has an inflection point. The image-side surface of the third lens element E3 has an inflection point.

[0067] The fourth lens element E4, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is also convex in a paraxial region. The fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical. The image-side surface of the fourth lens element E4 has an inflection point.

[0068] The fifth lens element E5, with negative refractive power, has an object-side surface that is concave in a paraxial region and an image-side surface that is also concave in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The image-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0069] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0070] The equation for the aspherical surface profiles of the above-mentioned lens elements of the first embodiment is 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 conic coefficient; and Ai is the i-th aspherical coefficient, where i can be 4, 6, 8, 10, 12 and 14 in the embodiments, but is not limited to these.

[0071] In the imaging lens system of the image acquisition unit 1 according to the 1st embodiment, if a focal length of the imaging lens system is f, an aperture number of the imaging lens system is Fno, and half of a maximum field of view of the imaging lens system is HFOV, these parameters have the following values: f = 21.72 millimeters (mm), Fno = 2.83, and HFOV = 9.3 degrees.

[0072] If the maximum field of view of the imaging lens system is FOV, then the following condition is met: FOV = 18.6 degrees.

[0073] If the axial distance between the object-side surface of the first lens element E1 and the image surface IMG is TL and the maximum image height of the imaging lens system is ImgH, then the following condition is met: TL / ImgH = 5.43.

[0074] If the axial distance between the image-side surface of the fifth lens element E5 and the image surface IMG is BL and the maximum image height of the imaging lens system is ImgH, then the following condition is met: BL / ImgH = 2.84.

[0075] If the axial distance between the object-side surface of the first lens element E1 and the image-side surface of the fifth lens element E5 is TD and the axial distance between the image-side surface of the fifth lens element E5 and the image surface IMG is BL, then the following condition is met: TD / BL = 0.91.

[0076] If the axial distance between the image-side surface of the fifth lens element E5 and the image surface IMG is BL, and the axial distance between the third lens element E3 and the fourth lens element E4 is T34, then the following condition is met: BL / T34 = 3.20. 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.

[0077] If the axial distance between the image-side surface of the fifth lens element E5 and the image surface IMG is BL, and the sum of the axial distances between each of all adjacent lens elements of the imaging lens system is ΣAT, then the following condition is satisfied: BL / ΣAT = 2.74. In this embodiment, ΣAT represents the sum of the axial distances between any two adjacent lens elements of the first lens element E1, the second lens element E2, the third lens element E3, the fourth lens element E4, and the fifth lens element E5.

[0078] If the focal length of the imaging lens system is f and the focal length of the third lens element E3 is f3, then the following condition is met: f / f3 = 0.89.

[0079] If the focal length of the first lens element E1 is f1 and the focal length of the second lens element E2 is f2, then the following condition is satisfied: |f1 / f2| = 0.98.

[0080] If the focal length of the first lens element E1 is f1 and the focal length of the third lens element E3 is f3, then the following condition is met: f1 / f3 = 0.49.

[0081] If the focal length of the first lens element E1 is f1, the focal length of the second lens element E2 is f2, the focal length of the fourth lens element E4 is f4, and the focal length of the fifth lens element E5 is f5, then the following condition is met: (f1+f2) / (f4+f5) = -0.12.

[0082] If the 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 Dr1r6 and the axial distance between the object-side surface of the fourth lens element E4 and the image-side surface of the fifth lens element E5 is Dr7r10, then the following condition is satisfied: Dr1r6 / Dr7r10 = 2.68.

[0083] If the axial distance between the image-side surface of the first lens element E1 and the object-side surface of the third lens element E3 is Dr2r5 and the axial distance between the image-side surface of the fourth lens element E4 and the image-side surface of the fifth lens element E5 is Dr8r10, then the following condition is satisfied: Dr2r5 / Dr8r10 = 0.96.

[0084] If the radius of curvature of the image-side surface of the first lens element is E1 R2 and the radius of curvature of the object-side surface of the second lens element is E2 R3, then the following condition is satisfied: |R3 / R2| = 0.57.

[0085] If the radius of curvature of the image-side surface of the second lens element E2 is R4 and the radius of curvature of the image-side surface of the fifth lens element E5 is R10, then the following condition is satisfied: |R4 / R10| = 0.40.

[0086] If the radius of curvature of the image-side surface of the third lens element E3 is R6 and the radius of curvature of the object-side surface of the fourth lens element E4 is R7, then the following condition is met: R6 / R7 = 0.14.

[0087] If the radius of curvature of the object-side surface of the fifth lens element E5 is R9 and the radius of curvature of the image-side surface of the fifth lens element E5 is R10, then the following condition is met: R9 / R10 = -0.63.

[0088] If 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, then the following condition is met: (R5-R6) / (R5+R6) = -0.16.

[0089] If the central thickness of the first lens element E1 is CT1 and the central thickness of the second lens element E2 is CT2, then the following condition is met: CT1 / CT2 = 4.46.

[0090] If the axial distance between the first lens element E1 and the second lens element E2 is T12, the axial distance between the second lens element E2 and the third lens element E3 is T23, the axial distance between the third lens element E3 and the fourth lens element E4 is T34, and the axial distance between the fourth lens element E4 and the fifth lens element E5 is T45, then the following condition is met: (T12+T23+T45) / T34 = 0.17.

[0091] If the axial distance between the second lens element E2 and the third lens element E3 is T23 and the axial distance between the fourth lens element E4 and the fifth lens element E5 is T45, then the following condition is met: T23 / T45 = 0.27.

[0092] If the axial distance between the third lens element E3 and the fourth lens element E4 is T34 and the 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 Dr1r6, then the following condition is met: T34 / Dr1r6 = 0.71.

[0093] If the Abbe number of the second lens element E2 is V2, then the following condition is satisfied: V2 = 25.6.

[0094] If the Abbe number of the third lens element E3 is V3, then the following condition is met: V3 = 56.0.

[0095] If the Abbe number of the fourth lens element E4 is V4, then the following condition is satisfied: V4 = 16.3.

[0096] If the maximum effective radius of the image-side surface of the third lens element is E3 Y3R2 and the maximum effective radius of the object-side surface of the fourth lens element is E4 Y4R1, then the following condition is satisfied: Y3R2 / Y4R1 = 1.31.

[0097] If the maximum effective radius of the object-side surface of the first lens element is E1 Y1R1 and the maximum effective radius of the image-side surface of the fifth lens element is E5 Y5R2, then the following condition is satisfied: Y1R1 / Y5R2 = 1.73.

[0098] The detailed optical data of the first embodiment are listed in Table 1A and the aspherical surface data in Table 1B below. TABLE 1A 1. Design f = 21.72 mm, Fno = 2.83, HFOV = 9.3 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -1,346 2 Lens 1 6,0726 (SPH) 2,900 Glass 1,569 63,0 12.00 3 45,3907 (SPH) 0,100 4 Lens 2 25,7146 (ASP) 0,650 plastic 1,614 25,6 -12.28 5 5,7710 (ASP) 0,091 6 Lens 3 4,2196 (ASP) 0,714 plastic 1,544 56,0 24.53 7 5,8023 (ASP) 3,179 8 Lens 4 41,9350 (ASP) 0,783 plastic 1,697 16,3 10.82 9 -9,1301 (ASP) -0,093 10 Aperture Plano 0,436 11 Lens 5 -8,9286 (ASP) 0,535 plastic 1,639 23,5 -8.53 12 14,2857 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,969 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.087 mm. TABLE 1B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,58199E+00 0,00000E+00 0,00000E+00 A4 = 8,540477E-04 3,189483E-03 6,997202E-04 -3,517906E-03 A6 = -4,413465E-04 -2,086325E-03 -1,919142E-03 -3,123578E-04 A8 = 4,870163E-05 3,141312E-04 3,447681E-04 9,964352E-05 A10 = -2,605498E-06 -2,449633E-05 -2,678678E-05 -7,849789E-06 A12 = 5,925464E-08 7,328978E-07 7,056543E-07 9,733522E-08 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = 2,202496E-03 1,084403E-02 1,241905E-03 -8,145790E-03 A6 = -1,058312E-03 -5,975341E-03 -8,291521E-03 -9,689550E-04 A8 = 2,593551E-04 1,950604E-03 3,383463E-03 4,771420E-04 A10 = 3,635033E-05 -3,112302E-04 -8,324478E-04 -7,785945E-05 A12 = -1,673579E-05 1,741480E-05 1,130718E-04 6,035484E-06 A14 = 1,791490E-06 8,463200E-07 -6,506085E-06 -1,929595E-07

[0099] Table 1A lists the radius of curvature, thickness, and focal length in millimeters (mm). Surface numbers 0–15 represent the surfaces arranged along the optical axis from the object side to the image side. In Table 1B, k represents the conic coefficient of the aspherical surface profile equation. A4–A14 represent the 4th to 14th order aspherical coefficients. The tables shown below for each embodiment are the corresponding schematic parameter and aberration curves, and the table definitions are the same as in Table 1A and Table 1B of the first embodiment. Therefore, no further explanation is given in this regard. 2. Design

[0100] Fig. Figure 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 comprises the image acquisition unit 2, the imaging lens system (whose reference numeral is omitted) of the present disclosure, and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0101] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0102] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has two inflection points.

[0103] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The image-side surface of the third lens element E3 has an inflection point.

[0104] The fourth lens element E4, with positive refractive power, 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 fourth lens element E4 is made of plastic material and has both aspheric object-side and image-side surfaces. The object-side surface of the fourth lens element E4 has an inflection point. The image-side surface of the fourth lens element E4 has an inflection point. The object-side surface of the fourth lens element E4 has a critical point in an off-axis region. The image-side surface of the fourth lens element E4 has a critical point in an off-axis region.

[0105] The fifth lens element E5, with negative refractive power, 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 fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0106] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0107] The detailed optical data of the 2nd embodiment are listed in Table 2A and the aspherical surface data in Table 2B below. TABLE 2A 2. Design f = 20.56 mm, Fno = 2.68, HFOV = 9.7 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -0,994 2 Lens 1 7,6807 (SPH) 2,300 Glass 1,572 57,5 13.89 3 201,7186 (SPH) 0,100 4 Lens 2 17,0154 (ASP) 0,599 plastic 1,615 25,4 -14.45 5 5,7563 (ASP) 0,050 6 Lens 3 4,1569 (ASP) 1,361 plastic 1,544 56,0 19.21 7 6,1056 (ASP) 2,756 8 Lens 4 -271,9955 (ASP) 0,852 plastic 1,697 16,3 24.19 9 -15,9005 (ASP) 0,018 10 Aperture Plano 0,457 11 Lens 5 -6,7953 (ASP) 0,988 plastic 1,587 28,3 -16.16 12 -25,2301 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,789 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.035 mm. TABLE 2B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,57880E+00 0,00000E+00 0,00000E+00 A4 = 1,223659E-04 -2,324373E-03 -3,471701E-03 -2,904911E-03 A6 = -3,489094E-05 5,741695E-04 6,260968E-04 -2,863654E-04 A8 = -1,522560E-05 -1,727328E-04 -1,703163E-04 1,127581 E-05 A10 = 1,482684E-06 1,572755E-05 1,688681E-05 4,202644E-06 A12 = -3,713159E-08 -5,275758E-07 -5,874150E-07 -3,387307E-07 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = 3,354537E-03 6,810248E-03 6,143528E-05 -2,336419E-03 A6 = -1,372920E-03 -3,294558E-03 -4,530421E-03 -1,093584E-03 A8 = 1,893745E-04 2,275637E-04 7,367664E-04 2,591834E-04 A10 = 5,446872E-05 2,224956E-04 2,871074E-05 -1,158012E-05 A12 = -7,720576E-06 -5,081849E-05 -1,329842E-05 -3,351883E-06 A14 = 2,514474E-07 4,713444E-06 5,560128E-07 2,648727E-07

[0108] 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, listed in Table 2C below, are also the same as in the first embodiment, with corresponding values ​​for the second embodiment; therefore, no further explanation is given in this regard.

[0109] Furthermore, these parameters from Table 2A and Table 2B can be calculated as the following values ​​and must meet the following conditions: TABLE 2C Values ​​of the optical and physical parameters / definitions f [mm] 20,56 |R3 / R2| 0,08 Fno 2,68 |R4 / R10| 0,23 HFOV [Grade] 9,7 R6 / R7 -0,02 FOV [degrees] 19,4 R9 / R10 0,27 TL / lmgH 5,44 (R5-R6) / (R5+R6) -0,19 BL / lmgH 2,79 CT1 / CT2 3,84 TD / BL 0,95 (T12+T23+T45) / T34 0,23 BL / T34 3,63 T23 / T45 0,11 BL / ΣAT 2,96 T34 / Dr1 r6 0,62 f / f3 1,07 V2 25,4 |f1 / f2| 0,96 V3 56,0 f1 / f3 0,72 V4 16,3 (f1 +f2) / (f4+f5) -0,07 Y3R2 / Y4R1 1,32 Dr1r6 / Dr7r10 1,90 Y1R1 / Y5R2 1,69 Dr2r5 / Dr8r10 0,51 - - 3. Design

[0110] Fig. Figure 5 is a schematic view of an image acquisition unit according to the 3rd 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 comprises the image acquisition unit 3, the imaging lens system (whose reference numeral is omitted) of the present disclosure, and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0111] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0112] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has one inflection point. The image-side surface of the second lens element E2 has two inflection points.

[0113] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has an inflection point. The image-side surface of the third lens element E3 has an inflection point.

[0114] The fourth lens element E4, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0115] The fifth lens element E5, with negative refractive power, 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 fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0116] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0117] The detailed optical data of the 3rd embodiment are listed in Table 3A and the aspherical surface data in Table 3B below. TABLE 3A 3. Design f = 22.80 mm, Fno = 2.97, HFOV = 8.8 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -1,364 2 Lens 1 6,0045 (SPH) 2,240 Glass 1,487 70,4 20.43 3 13,2744 (SPH) 0,137 4 Lens 2 11,0641 (ASP) 0,700 plastic 1,669 19,5 -20.51 5 5,9704 (ASP) 0,050 6 Lens 3 4,3057 (ASP) 1,556 plastic 1,544 56,0 16.47 7 7,2330 (ASP) 2,896 8 Lens 4 8,9824 (ASP) 0,605 plastic 1,669 19,5 22.98 9 21,0181 (ASP) 0,204 10 Aperture Plano 0,464 11 Lens 5 -4,6974 (ASP) 0,600 plastic 1,544 56,0 -11.44 12 -20,0346 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,817 15B ild Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 1,810 mm. TABLE 3B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,55129E+00 0,00000E+00 0,00000E+00 A4 = -5,721640E-04 -2,992110E-03 -2,926580E-03 -2,039730E-03 A6 = 1,911840E-04 7,415100E-04 4,142010E-04 -6,866730E-04 A8 = -3,753740E-05 -1,708390E-04 -1,419250E-04 8,029250E-05 A10 = 2,022430E-06 1,335820E-05 1,521520E-05 -1,270860E-06 A12 = -3,261380E-08 -4,101320E-07 -5,615200E-07 -1,531030E-07 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = 5,504860E-03 1,126620E-02 2,430950E-03 -1,106060E-03 A6 = -5,226560E-03 -9,343310E-03 -7,696090E-03 -3,068840E-03 A8 = 1,839840E-03 3,639850E-03 2,731650E-03 1,006370E-03 A10 = -3,652740E-04 -8,069980E-04 -6,871250E-04 -1,335950E-04 A12 = 6,396020E-05 1,191390E-04 1,387900E-04 1,036890E-06 A14 = -4,641440E-06 -3,273520E-06 -1,396560E-05 3,644140E-07

[0118] In the third 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, listed in Table 3C below, are also the same as in the first embodiment, with corresponding values ​​for the third embodiment; therefore, no further explanation is given in this regard.

[0119] Furthermore, these parameters from Table 3A and Table 3B can be calculated as the following values ​​and must meet the following conditions: TABLE 3C Values ​​of the optical and physical parameters / definitions f [mm] 22,80 |R3 / R2| 0,83 Fno 2,97 |R4 / R10| 0,30 HFOV [Grade] 8,8 R6 / R7 0,81 FOV [degrees] 17,6 R9 / R10 0,23 TL / lmgH 5,44 (R5-R6) / (R5+R6) -0,25 BL / lmgH 2,80 CT1 / CT2 3,20 TD / BL 0,94 (T12+T23+T45) / T34 0,30 BL / T34 3,46 T23 / T45 0,07 BL / ΣAT 2,67 T34 / Dr1 r6 0,62 f / f3 1,38 V2 19,5 |f1 / f2| 1,00 V3 56,0 f1 / f3 1,24 V4 19,5 (f1 +f2) / (f4+f5) -0,01 Y3R2 / Y4R1 1,50 Dr1r6 / Dr7r10 2,50 Y1R1 / Y5R2 1,93 Dr2r5 / Dr8r10 0,70 - - 4. Design

[0120] Fig. Figure 7 is a schematic view of an image acquisition unit according to the 4th 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 4th embodiment. Fig. 7 The image acquisition unit 4 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0121] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is also convex in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0122] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has two inflection points.

[0123] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The image-side surface of the third lens element E3 has an inflection point.

[0124] The fourth lens element E4, with positive refractive power, 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 fourth lens element E4 is made of plastic material and has both aspheric object-side and image-side surfaces. The object-side surface of the fourth lens element E4 has an inflection point. The image-side surface of the fourth lens element E4 has an inflection point. The object-side surface of the fourth lens element E4 has a critical point in an off-axis region. The image-side surface of the fourth lens element E4 has a critical point in an off-axis region.

[0125] The fifth lens element E5, with negative refractive power, 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 fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0126] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0127] The detailed optical data of the 4th embodiment are listed in Table 4A and the aspherical surface data in Table 4B below. TABLE 4A 4. Design f = 20.00 mm, Fno = 2.61, HFOV = 10.0 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -0,857 2 Lens 1 8,8158 (SPH) 2,300 Glass 1,617 53,9 12.54 3 -57,1668 (SPH) 0,100 4 Lens 2 18,9726 (ASP) 0,706 plastic 1,616 25,3 -13.53 5 5,7052 (ASP) 0,050 6 Lens 3 4,1572 (ASP) 1,433 plastic 1,544 56,0 25.14 7 5,2476 (ASP) 2,863 8 Lens 4 -26,3420 (ASP) 0,722 plastic 1,650 21,8 32.83 9 -11,9127 (ASP) 0,278 10 Aperture Plano 0,770 11 Lens 5 -5,1278 (ASP) 0,611 plastic 1,562 44,6 -28.36 12 -7,8858 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,436 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.287 mm. TABLE 4B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,58654E+00 0,00000E+00 0,00000E+00 A4 = 9,695438E-04 -1,689447E-04 -3,349104E-03 -5,065665E-03 A6 = -4,083488E-04 -4,519392E-04 1,689641E-04 2,424714E-04 A8 = 3,496333E-05 5,463477E-06 -1,701106E-05 3,064818E-05 A10 = -1,347484E-06 1,657499E-06 5,672507E-08 -8,100809E-06 A12 = 2,272839E-08 -8,562112E-08 9,835889E-09 3,154941E-07 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = -1,209367E-03 -1,319552E-03 -7,611872E-03 -5,233598E-03 A6 = 7,749043E-04 9,489448E-04 8,830422E-04 8,139187E-04 A8 = 2,700645E-04 2,478622E-04 -1,395195E-04 -3,076350E-04 A10 = -7,544313E-05 -6,745748E-05 -3,566433E-05 5,380728E-05 A12 = 9,459167E-06 8,237024E-06 1,242472E-05 -4,644689E-06 A14 = -4,551283E-07 -2,002773E-07 -1,105385E-06 1,179682E-07

[0128] 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, listed in Table 4C below, are also the same as in the first embodiment, with corresponding values ​​for the fourth embodiment; therefore, no further explanation is given in this regard.

[0129] Furthermore, these parameters from Table 4A and Table 4B can be calculated as the following values ​​and must meet the following conditions: TABLE 4C Values ​​of the optical and physical parameters / definitions f [mm] 20,00 |R3 / R2| 0,33 Fno 2,61 |R4 / R10| 0,72 HFOV [Grade] 10,0 R6 / R7 -0,20 FOV [degrees] 20,0 R9 / R10 0,65 TL / lmgH 5,43 (R5-R6) / (R5+R6) -0,12 BL / lmgH 2,69 CT1 / CT2 3,26 TD / BL 1,02 (T12+T23+T45) / T34 0,42 BL / T34 3,37 T23 / T45 0,05 BL / ΣAT 2,38 T34 / Dr1 r6 0,62 f / f3 0,80 V2 25,3 |f1 / f2| 0,93 V3 56,0 f1 / f3 0,50 V4 21,8 (f1+f2) / (f4+f5) -0,22 Y3R2 / Y4R1 1,24 Dr1r6 / Dr7r10 1,93 Y1R1 / Y5R2 1,52 Dr2r5 / Dr8r10 0,52 - - 5. Design

[0130] Fig. Figure 9 is a schematic view of an image acquisition unit according to the 5th 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 5th embodiment. Fig. 9 The image acquisition unit 5 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0131] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is also convex in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0132] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has an inflection point.

[0133] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The image-side surface of the third lens element E3 has an inflection point.

[0134] The fourth lens element E4, with negative refractive power, 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 fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the fourth lens element E4 has two inflection points. The image-side surface of the fourth lens element E4 has one inflection point. The image-side surface of the fourth lens element E4 has a critical point in an off-axis region.

[0135] The fifth lens element E5, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is also convex in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the fifth lens element E5 has an inflection point. The object-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0136] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0137] The detailed optical data of the 5th embodiment are listed in Table 5A and the aspherical surface data in Table 5B below. TABLE 5A 5. Design f = 18.64 mm, Fno = 2.43, HFOV = 10.7 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -0,819 2 Lens 1 9,1855 (SPH) 2,300 Glass 1,729 54,7 10.95 3 -54,6233 (SPH) 0,100 4 Lens 2 18,7298 (ASP) 0,698 plastic 1,587 28,3 -14.50 5 5,7738 (ASP) 0,050 6 Lens 3 3,6928 (ASP) 1,416 plastic 1,544 56,0 63.06 7 3,5791 (ASP) 2,700 8 Lens 4 -5,5846 (ASP) 0,521 plastic 1,616 25,3 -15.39 9 -14,0886 (ASP) 0,416 10 Aperture Plano 0,162 11 Lens 5 19,7700 (ASP) 1,425 plastic 1,584 28,2 14.13 12 -13,8027 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,389 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.755 mm. TABLE 5B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,52093E+00 0,00000E+00 0,00000E+00 A4 = 2,488143E-04 -2,793794E-03 -4,487518E-03 -3,389505E-03 A6 = -1,765208E-04 9,196669E-04 1,250991E-03 -1,125806E-04 A8 = 7,204058E-06 -2,415515E-04 -2,228543E-04 1,444607E-04 A10 = 1,456757E-07 2,115460E-05 1,562177E-05 -2,682444E-05 A12 = -9,647043E-09 -6,814140E-07 -4,681810E-07 1,048119E-06 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = -7,892083E-04 -8,255033E-03 -1,119396E-02 -3,019579E-03 A6 = 1,938902E-03 2,955093E-03 8,796486E-04 -2,583191E-04 A8 = 1,191360E-04 1,063404E-04 1,732235E-04 9,204138E-05 A10 = -8,311222E-05 -7,878061E-05 -6,161527E-05 -1,817262E-05 A12 = 9,654001E-06 8,493619E-06 6,935785E-06 1,632170E-06 A14 = -4,373089E-07 -3,165271E-07 -2,738416E-07 -5,989827E-08

[0138] In the 5th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 5C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 5th embodiment; therefore, no further explanation is given in this regard.

[0139] Furthermore, these parameters from Table 5A and Table 5B can be calculated as the following values ​​and must meet the following conditions: TABLE 5C Values ​​of the optical and physical parameters / definitions f [mm] 18,64 |R3 / R2| 0,34 Fno 2,43 |R4 / R10| 0,42 HFOV [Grade] 10,7 R6 / R7 -0,64 FOV [degrees] 21,4 R9 / R10 -1,43 TL / lmgH 5,41 (R5-R6) / (R5+R6) 0,02 BL / lmgH 2,68 CT1 / CT2 3,30 TD / BL 1,02 (T12+T23+T45) / T34 0,27 BL / T34 3,56 T23 / T45 0,09 BL / ΣAT 2,80 T34 / Dr1 r6 0,59 f / f3 0,30 V2 28,3 |f1 / f2| 0,76 V3 56,0 f1 / f3 0,17 V4 25,3 (f1 +f2) / (f4+f5) 2,83 Y3R2 / Y4R1 1,10 Dr1r6 / Dr7r10 1,81 Y1R1 / Y5R2 1,26 Dr2r5 / Dr8r10 0,42 - - 6. Design

[0140] Fig. Figure 11 is a schematic view of an image acquisition unit according to the 6th 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 6th embodiment. Fig. 11 The image acquisition unit 6 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, an aperture S1, a fourth lens element E4, an aperture S2, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0141] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in its paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0142] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has an inflection point. The image-side surface of the second lens element E2 also has an inflection point.

[0143] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has three inflection points. The image-side surface of the third lens element E3 has one inflection point.

[0144] The fourth lens element E4, with positive refractive power, 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 fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0145] The fifth lens element E5, with negative refractive power, has an object-side surface that is concave in a paraxial region and an image-side surface that is also concave in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The image-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0146] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0147] The detailed optical data of the 6th embodiment are listed in Table 6A and the aspherical surface data in Table 6B below. TABLE 6A 6. Design f = 21.42 mm, Fno = 2.76, HFOV = 9.3 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -1,348 2 Lens 1 6,1924 (SPH) 1,727 Glass 1,497 81,6 18.35 3 17,5063 (SPH) 0,112 4 Lens 2 9,4598 (ASP) 0,558 plastic 1,616 24,9 -17.60 5 4,9361 (ASP) 0,068 6 Lens 3 4,7654 (ASP) 1,301 plastic 1,544 56,0 15.64 7 9,7919 (ASP) 4,110 8 Aperture Plano 0,176 9 Lens 4 -79,3777 (ASP) 0,404 plastic 1,697 16,3 14.98 10 -9,2477 (ASP) -0,105 11 Aperture Plano 0,525 12 Lens 5 -6,5631 (ASP) 0,350 plastic 1,587 28,3 -9.63 13 41,6087 (ASP) 8,000 14 filter Plano 0,210 Glass 1,517 64,2 - 15 Plano 1,497 16 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 8) is 2.068 mm. An effective radius of aperture S2 (surface 11) is 2.063 mm. TABLE 6B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 3,68709E-01 0,00000E+00 0,00000E+00 A4 = -5,539278E-03 -1,503195E-02 -9,076028E-03 2,542788E-05 A6 = 3,014322E-03 1,463233E-02 1,183979E-02 -7,893171E-04 A8 = -1,310876E-03 -8,036547E-03 -6,877667E-03 4,062217E-04 A10 = 3,406944E-04 2,458684E-03 2,166798E-03 -1,315868E-04 A12 = -5,419295E-05 -4,539107E-04 -4,106300E-04 2,439161E-05 A14 = 5,337419E-06 5,179737E-05 4,810577E-05 -2,631797E-06 A16 = -3,178238E-07 -3,578077E-06 -3,412400E-06 1,606402E-07 A18 = 1,048782E-08 1,371944E-07 1,343462E-07 -4,961293E-09 A20 = -1,472730E-10 -2,241612E-09 -2,252811E-09 5,542208E-11 Surface # 9 10 12 13 k = 1,28284E+01 -8,67092E-02 -1,16871E-01 -5,76147E+01 A4 = 3,699947E-03 1,406043E-02 2,250587E-02 1,415854E-02 A6 = -8,668163E-03 -2,469289E-02 -6,549719E-02 -5,113768E-02 A8 = 3,099062E-03 1,698372E-02 6,641627E-02 5,694669E-02 A10 = 7,749985E-04 -6,221088E-03 -3,851244E-02 -3,653161E-02 A12 = -1,234559E-03 8,766623E-04 1,343770E-02 1,452084E-02 A14 = 5,116346E-04 1,317251E-04 -2,819939E-03 -3,628431E-03 A16 = -1,070783E-04 -6,812627E-05 3,378801E-04 5,551287E-04 A18 = 1,176476E-05 9,752976E-06 -1,987317E-05 -4,756319E-05 A20 = -5,472943E-07 -5,107776E-07 3,495529E-07 1,749735E-06

[0148] In the 6th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 6C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 6th embodiment; therefore, no further explanation is given in this regard.

[0149] Furthermore, these parameters from Table 6A and Table 6B can be calculated as the following values ​​and must meet the following conditions: TABLE 6C Values ​​of the optical and physical parameters / definitions f [mm] 21,42 |R3 / R2| 0,54 Fno 2,76 |R4 / R10| 0,12 HFOV [Grade] 9,3 R6 / R7 -0,12 FOV [degrees] 18,6 R9 / R10 -0,16 TL / lmgH 5,28 (R5-R6) / (R5+R6) -0,35 BL / lmgH 2,71 CT1 / CT2 3,09 TD / BL 0,95 (T12+T23+T45) / T34 0,14 BL / T34 2,26 T23 / T45 0,16 BL / ΣAT 1,99 T34 / Dr1 r6 1,14 f / f3 1,37 V2 24,9 |f1 / f2| 1,04 V3 56,0 f1 / f3 1,17 V4 16,3 (f1 +f2) / (f4+f5) 0,14 Y3R2 / Y4R1 1,58 Dr1r6 / Dr7r10 3,21 Y1R1 / Y5R2 1,78 Dr2r5 / Dr8r10 0,96 - - 7. Design

[0150] Fig. Figure 13 is a schematic view of an image acquisition unit according to the 7th embodiment of the present disclosure. Fig. Figure 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 7th embodiment. Fig. 13 The image acquisition unit 7 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0151] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0152] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has an inflection point.

[0153] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has an inflection point. The image-side surface of the third lens element E3 has an inflection point.

[0154] The fourth lens element E4, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is also convex in a paraxial region. The fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the fourth lens element E4 has an inflection point. The object-side surface of the fourth lens element E4 has a critical point in an off-axis region.

[0155] The fifth lens element E5, with negative refractive power, has an object-side surface that is concave in a paraxial region and an image-side surface that is also concave in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The image-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0156] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0157] The detailed optical data of the 7th embodiment are listed in Table 7A and the aspherical surface data are listed in Table 7B below. TABLE 7A 7. Design f = 22.55 mm, Fno = 2.90, HFOV = 8.9 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -1,440 2 Lens 1 5,8008 (SPH) 2,303 Glass 1,510 63,4 13.93 3 27,3454 (SPH) 0,100 4 Lens 2 12,8400 (ASP) 0,805 plastic 1,616 25,3 -13.50 5 4,9247 (ASP) 0,137 6 Lens 3 4,7550 (ASP) 1,053 plastic 1,544 56,0 17.94 7 8,5495 (ASP) 3,842 8 Lens 4 23,8095 (ASP) 0,430 plastic 1,669 19,5 21.36 9 -35,4963 (ASP) -0,026 10 Aperture Plano 0,422 11 Lens 5 -9,1613 (ASP) 0,403 plastic 1,544 56,0 -12.20 12 24,4704 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 1,833 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.057 mm. TABLE 7B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 3,05945E-01 0,00000E+00 0,00000E+00 A4 = -2,189993E-03 -9,341248E-04 2,101031E-03 -4,291239E-04 A6 = 4,652239E-05 -2,294025E-03 -2,950344E-03 -7,808772E-04 A8 = -6,755409E-07 9,144432E-04 1,162164E-03 3,723978E-04 A10 = 2,890144E-06 -1,902910E-04 -2,454313E-04 -9,869159E-05 A12 = -9,737249E-07 2,059508E-05 2,844693E-05 1,599700E-05 A14 = 1,471944E-07 -8,656325E-07 -1,654025E-06 -1,671787E-06 A16 = -1,175161E-08 -3,317105E-08 2,487221E-08 1,115459E-07 A18 = 4,827713E-10 4,502338E-09 1,583465E-09 -4,521208E-09 A20 = -8,062390E-12 -1,209289E-10 -4,985148E-11 8,854992E-11 Surface # 8 9 11 12 k = 3,27818E+01 5,90978E+01 -3,48097E+00 6,59349E+01 A4 = 6,022956E-04 8,827125E-03 4,372333E-03 -4,927835E-03 A6 = -7,827125E-03 -1,593940E-02 -2,204263E-02 -8,214536E-03 A8 = 6,166432E-03 1,226596E-02 1,861292E-02 6,843420E-03 A10 = -3,844738E-03 -7,082281E-03 -1,010317E-02 -3,046239E-03 A12 = 1,679393E-03 2,946548E-03 3,822670E-03 8,322642E-04 A14 = -4,915402E-04 -8,427320E-04 -1,008401E-03 -1,423807E-04 A16 = 9,063023E-05 1,542834E-04 1,756545E-04 1,476125E-05 A18 = -9,462223E-06 -1,613489E-05 -1,802058E-05 -8,483242E-07 A20 = 4,254153E-07 7,295036E-07 8,182891E-07 2,121271E-08

[0158] In the 7th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 7C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 7th embodiment; therefore, no further explanation is given in this regard.

[0159] Furthermore, these parameters from Table 7A and Table 7B can be calculated as the following values ​​and must meet the following conditions: TABLE 7C Values ​​of the optical and physical parameters / definitions f [mm] 22,55 |R3 / R2| 0,47 Fno 2,90 |R4 / R10| 0,20 HFOV [Grade] 8,9 R6 / R7 0,36 FOV [degrees] 17,8 R9 / R10 -0,37 TL / lmgH 5,44 (R5-R6) / (R5+R6) -0,29 BL / lmgH 2,80 CT1 / CT2 2,86 TD / BL 0,94 (T12+T23+T45) / T34 0,16 BL / T34 2,61 T23 / T45 0,35 BL / ΣAT 2,24 T34 / Dr1 r6 0,87 f / f3 1,26 V2 25,3 |f1 / f2| 1,03 V3 56,0 f1 / f3 0,78 V4 19,5 (f1 +f2) / (f4+f5) 0,05 Y3R2 / Y4R1 1,47 Dr1r6 / Dr7r10 3,58 Y1R1 / Y5R2 1,79 Dr2r5 / Dr8r10 1,30 - - 8. Design

[0160] Fig. Figure 15 is a schematic view of an image acquisition unit according to the 8th embodiment of the present disclosure. Fig. Figure 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 8th embodiment. Fig. In Figure 15, the image acquisition unit 8 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, an aperture S1, a fourth lens element E4, an aperture S2, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0161] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0162] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has one inflection point. The image-side surface of the second lens element E2 has two inflection points.

[0163] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has an inflection point. The image-side surface of the third lens element E3 has an inflection point.

[0164] The fourth lens element E4, with positive refractive power, 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 fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0165] The fifth lens element E5, with negative refractive power, 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 fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0166] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0167] The detailed optical data of the 8th embodiment are listed in Table 8A and the aspherical surface data are listed in Table 8B below. TABLE 8A 8. Design f = 23.09 mm, Fno = 2.97, HFOV = 8.7 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -1,299 2 Lens 1 6,2624 (SPH) 1,827 Glass 1,497 81,6 19.26 3 16,3504 (SPH) 0,100 4 Lens 2 8,3125 (ASP) 0,580 plastic 1,616 25,3 -19.32 5 4,7626 (ASP) 0,050 6 Lens 3 4,5221 (ASP) 1,306 plastic 1,544 56,0 15.65 7 8,6657 (ASP) 4,412 8 Aperture Plano 0,341 9 Lens 4 -12,7183 (ASP) 0,406 plastic 1,669 19,5 26.41 10 -7,4902 (ASP) -0,314 11 Aperture Plano 0,622 12 Lens 5 -6,0360 (ASP) 0,380 plastic 1,544 56,0 -12.04 13 -78,2602 (ASP) 8,000 14 filter Plano 0,210 Glass 1,517 64,2 - 15 Plano 1,558 16 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 8) is 2,040 mm. An effective radius of aperture S2 (surface 11) is 2.065 mm. TABLE 8B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 3,31009E-01 0,00000E+00 0,00000E+00 A4 = -9,632305E-04 -9,338518E-03 -1,372452E-02 -7,004558E-03 A6 = -1,080045E-03 9,641735E-03 1,627411E-02 6,739798E-03 A8 = 2,933276E-04 -6,373064E-03 -9,125399E-03 -3,455124E-03 A10 = -1,408517E-05 2,207027E-03 2,822565E-03 1,018533E-03 A12 = -6,212296E-06 -4,424796E-04 -5,225651E-04 -1,858659E-04 A14 = 1,282465E-06 5,328680E-05 5,920988E-05 2,123278E-05 A16 = -1,083761E-07 -3,805206E-06 -4,018788E-06 -1,476242E-06 A18 = 4,426529E-09 1,485181E-07 1,498194E-07 5,699949E-08 A20 = -7,182144E-11 -2,441205E-09 -2,355738E-09 -9,352486E-10 Surface # 9 10 12 13 k = 2,13098E+00 2,99010E-01 -2,32162E-01 6,30107E+01 A4 = 1,234699E-02 2,658326E-02 1,420706E-02 -4,824684E-03 A6 = -2,955854E-02 -5,320307E-02 -6,247912E-02 -2,078754E-02 A8 = 2,778043E-02 4,763599E-02 7,094411E-02 2,804809E-02 A10 = -1,958490E-02 -2,815795E-02 -4,519579E-02 -1,863162E-02 A12 = 1,014382E-02 1,206548E-02 1,826910E-02 7,238200E-03 A14 = -3,534807E-03 -3,699675E-03 -4,914876E-03 -1,729126E-03 A16 = 7,584584E-04 7,415193E-04 8,621069E-04 2,513251E-04 A18 = -8,941326E-05 -8,450423E-05 -8,902173E-05 -2,047764E-05 A20 = 4,413966E-06 4,095136E-06 4,068219E-06 7,194131E-07

[0168] In the 8th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 8C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 8th embodiment; therefore, no further explanation is given in this regard.

[0169] Furthermore, these parameters from Table 8A and Table 8B can be calculated as the following values ​​and must meet the following conditions: TABLE 8C Values ​​of the optical and physical parameters / definitions f [mm] 23,09 |R3 / R2| 0,51 Fno 2,97 |R4 / R10| 0,06 HFOV [Grade] 8,7 R6 / R7 -0,68 FOV [degrees] 17,4 R9 / R10 0,08 TL / lmgH 5,43 (R5-R6) / (R5+R6) -0,31 BL / lmgH 2,73 CT1 / CT2 3,15 TD / BL 0,99 (T12+T23+T45) / T34 0,10 BL / T34 2,06 T23 / T45 0,16 BL / ΣAT 1,87 T34 / Dr1 r6 1,23 f / f3 1,48 V2 25,3 |f1 / f2| 1,00 V3 56,0 f1 / f3 1,23 V4 19,5 (f1 +f2) / (f4+f5) -0,004 Y3R2 / Y4R1 1,61 Dr1r6 / Dr7r10 3,53 Y1R1 / Y5R2 1,76 Dr2r5 / Dr8r10 1,06 - - 9. Design

[0170] Fig. Figure 17 is a schematic view of an image acquisition unit according to the 9th embodiment of the present disclosure. Fig.Figure 18 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to embodiment 9. Fig. 17 The image acquisition unit 9 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0171] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are spherical.

[0172] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the second lens element E2 has an inflection point. The image-side surface of the second lens element E2 has an inflection point.

[0173] The third lens element E3, with positive refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical. The object-side surface of the third lens element E3 has an inflection point. The image-side surface of the third lens element E3 has an inflection point.

[0174] The fourth lens element E4, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0175] The fifth lens element E5, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The object-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0176] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0177] The detailed optical data of the 9th embodiment are listed in Table 9A and the aspherical surface data in Table 9B below. TABLE 9A 9. Design f = 20.00 mm, Fno = 2.61, HFOV = 10.0 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 object infinity infinity 1 Aperture stop Plano -0,976 2 Lens 1 7,8721 (SPH) 2,300 Glass 1,729 54,7 10.90 3 697,6204 (SPH) 0,100 4 Lens 2 18,2029 (ASP) 0,671 plastic 1,616 25,3 -13.81 5 5,7127 (ASP) 0,050 6 Lens 3 4,3382 (ASP) 1,193 plastic 1,544 56,0 303.11 7 4,0237 (ASP) 2,500 8 Lens 4 14,7529 (ASP) 0,723 plastic 1,697 16,3 -24.04 9 7,6884 (ASP) 0,688 10 Aperture Plano -0,268 11 Lens 5 5,1180 (ASP) 1,167 plastic 1,680 18,2 16.98 12 8,3450 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 2,145 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2,570 mm. TABLE 9B Aspheric coefficients Surface # 4 5 6 7 k = 0,00000E+00 1,38179E+00 0,00000E+00 0,00000E+00 A4 = -6,449227E-05 -1,715148E-03 -3,635985E-03 -3,922536E-03 A6 = -1,104664E-04 4,937457E-04 8,051748E-04 6,855966E-05 A8 = 3,705750E-06 -1,587855E-04 -1,930800E-04 -3,775043E-05 A10 = 1,613026E-07 1,650562E-05 1,971014E-05 4,844491E-06 A12 = -1,028191E-08 -6,713465E-07 -7,817514E-07 -2,968049E-07 Surface # 8 9 11 12 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = 2,002954E-03 -7,726813E-03 -1,380226E-02 -4,675986E-03 A6 = 9,138170E-04 3,083041E-03 1,404565E-03 -2,240801E-04 A8 = -1,009985E-04 -3,377517E-04 -7,826231E-05 8,940103E-05 A10 = 8,124305E-06 2,559926E-05 -1,474762E-05 -2,074330E-05 A12 = -3,134134E-07 -2,316910E-07 2,772346E-06 2,137550E-06 A14 = -4,209700E-09 -5,748014E-08 -1,515349E-07 -9,422219E-08

[0178] In the 9th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 9C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 9th embodiment; therefore, no further explanation is given in this regard.

[0179] Furthermore, these parameters from Table 9A and Table 9B can be calculated as the following values ​​and must meet the following conditions: TABLE 9C Values ​​of the optical and physical parameters / definitions f [mm] 20,00 |R3 / R2| 0,03 Fno 2,61 |R4 / R10| 0,68 HFOV [Grade] 10,0 R6 / R7 0,27 FOV [degrees] 20,0 R9 / R10 0,61 TL / lmgH 5,43 (R5-R6) / (R5+R6) 0,04 BL / lmgH 2,89 CT1 / CT2 3,43 TD / BL 0,88 (T12+T23+T45) / T34 0,23 BL / T34 4,14 T23 / T45 0,12 BL / ΣAT 3,37 T34 / Dr1 r6 0,58 f / f3 0,07 V2 25,3 |f1 / f2| 0,79 V3 56,0 f1 / f3 0,04 V4 16,3 (f1 +f2) / (f4+f5) 0,41 Y3R2 / Y4R1 1,06 Dr1r6 / Dr7r10 1,87 Y1R1 / Y5R2 1,42 Dr2r5 / Dr8r10 0,52 - - 10. Design

[0180] Fig. Figure 19 is a schematic view of an image acquisition unit according to the 10th embodiment of the present disclosure. Fig. Figure 20 shows, in order from left to right, spherical aberration curves, astigmatic field curves, and a distortion curve of the image acquisition unit according to embodiment 10. Fig.19 The image acquisition unit 10 comprises the imaging lens system (whose reference numeral is omitted) of the present disclosure and an image sensor IS. The imaging lens system comprises, in the order from an object side to an image side along a beam path, an aperture diaphragm ST, a first lens element E1, a second lens element E2, a third lens element E3, a fourth lens element E4, an aperture S1, a fifth lens element E5, a filter E6, and an image surface IMG. The imaging lens system comprises five lens elements (E1, E2, E3, E4, and E5), with no additional lens element arranged between any of the adjacent five lens elements.

[0181] The first lens element E1 with positive refractive power has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The first lens element E1 is made of glass and both its object-side and image-side surfaces are aspherical.

[0182] The second lens element E2, with negative refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The second lens element E2 is made of plastic material and has both aspherical object-side and image-side surfaces. The object-side surface of the second lens element E2 has two inflection points.

[0183] The third lens element E3, with negative refractive power, has an object-side surface that is convex 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 material and both its object-side and image-side surfaces are aspherical.

[0184] The fourth lens element E4, with positive refractive power, has an object-side surface that is convex in a paraxial region and an image-side surface that is concave in a paraxial region. The fourth lens element E4 is made of plastic material and both its object-side and image-side surfaces are aspherical.

[0185] The fifth lens element E5, with negative refractive power, has an object-side surface that is concave in a paraxial region and an image-side surface that is also concave in a paraxial region. The fifth lens element E5 is made of plastic material and both its object-side and image-side surfaces are aspherical. The image-side surface of the fifth lens element E5 has an inflection point. The image-side surface of the fifth lens element E5 has a critical point in an off-axis region.

[0186] The E6 filter is made of glass and is located between the fifth lens element E5 and the image surface IMG. It does not affect the focal length of the imaging lens system. The IS image sensor is located on or near the image surface IMG of the imaging lens system.

[0187] The detailed optical data of the 10th embodiment are listed in Table 10A and the aspherical surface data are listed in Table 10B below. TABLE 10A 10. Design f = 25.93 mm, Fno = 3.38, HFOV = 7.7 degrees Surface # radius of curvature thickness material index Abbe # Focal length 0 lens infinity infinity 1 Aperture stop Plano -1,435 2 Lens 1 5,7593 (ASP) 2,399 Glass 1,729 54,7 8.30 3 98,8452 (ASP) 0,101 4 Lens 2 38,7868 (ASP) 0,686 plastic 1,642 22,5 -11.37 5 6,0997 (ASP) 0,050 6 Lens 3 5,0813 (ASP) 0,664 plastic 1,544 56,0 -215.75 7 4,6462 (ASP) 2,600 8 Lens 4 8,3179 (ASP) 0,788 plastic 1,697 16,3 17.91 9 23,9576 (ASP) 0,346 10 Aperture Plano 0,505 11 Lens 5 -8,7046 (ASP) 0,359 plastic 1,566 37,4 -9.15 12 12,9796 (ASP) 8,000 13 filter Plano 0,210 Glass 1,517 64,2 - 14 Plano 2,794 15 Picture Plano - Note: Reference wavelength is 587.6 nm (d-line). An effective radius of aperture S1 (surface 10) is 2.231 mm. TABLE 10B Aspheric coefficients Surface # 2 3 4 5 k = -1,67385E-02 1,05678E+01 0,00000E+00 1,68657E+00 A4 = -6,877084E-05 4,736922E-04 4,729980E-04 1,281015E-03 A6 = 2,526584E-06 -9,495981E-05 -3,219546E-04 -1,161514E-03 A8 = 8,021137E-08 4,824849E-06 2,929357E-05 1,414991E-04 A10 = - - -1,037861E-06 -9,983643E-06 A12 = - - 1,785931E-08 3,249550E-07 Surface # 6 7 8 9 k = 0,00000E+00 0,00000E+00 0,00000E+00 0,00000E+00 A4 = -1,688939E-03 -6,353143E-03 -6,832358E-04 2,372541E-03 A6 = -5,122222E-04 7,806234E-04 9,154061E-04 4,044871E-04 A8 = 8,316423E-05 -1,006429E-04 -3,157023E-04 -6,776281E-04 A10 = -7,600836E-06 7,936614E-06 1,083771E-04 3,361514E-04 A12 = 3,216571E-07 -3,131120E-07 -1,452057E-05 -5,986494E-05 A14 = - - 8,563438E-07 4,406473E-06 Surface # 11 12 k = 0,00000E+00 0,00000E+00 A4 = 4,627482E-03 1,537543E-03 A6 = -1,176556E-02 -8,374228E-03 A8 = 4,576617E-03 3,646654E-03 A10 = -9,235080E-04 -7,886128E-04 A12 = 9,544293E-05 8,668062E-05 A14 = -3,956726E-06 -3,824944E-06

[0188] In the 10th embodiment, the equation for the aspherical surface profiles of the aforementioned lens elements is the same as the equation for the 1st embodiment. The definitions of these parameters, listed in Table 10C below, are also the same as in the 1st embodiment, with corresponding values ​​for the 10th embodiment; therefore, no further explanation is given in this regard.

[0189] Furthermore, these parameters from Table 10A and Table 10B can be calculated as the following values ​​and must meet the following conditions: TABLE 10C Values ​​of the optical and physical parameters / definitions f [mm] 25,93 |R3 / R2| 0,39 Fno 3,38 |R4 / R10| 0,47 HFOV [Grade] 7,7 R6 / R7 0,56 FOV [degrees] 15,4 R9 / R10 -0,67 TL / lmgH 5,44 (R5-R6) / (R5+R6) 0,04 BL / lmgH 3,07 CT1 / CT2 3,50 TD / BL 0,77 (T12+T23+T45) / T34 0,39 BL / T34 4,23 T23 / T45 0,06 BL / ΣAT 3,06 T34 / Dr1 r6 0,67 f / f3 -0,12 V2 22,5 |f1 / f2| 0,73 V3 56,0 f1 / f3 -0,04 V4 16,3 (f1 +f2) / (f4+f5) -0,35 Y3R2 / Y4R1 1,17 Dr1r6 / Dr7r10 1,95 Y1R1 / Y5R2 1,66 Dr2r5 / Dr8r10 0,69 - - 11. Design

[0190] Fig.Figure 21 is a perspective view of an image acquisition unit according to the 11th embodiment of the present disclosure. In this embodiment, an image acquisition unit 100 is a camera module comprising a lens unit 101, a drive device 102, an image sensor 103, and an image stabilizer 104. The lens unit 101 comprises the imaging lens system disclosed in the 1st embodiment, a tube, and a holder (whose reference numerals have been omitted) for holding the imaging lens system. However, the lens unit 101 can alternatively be provided with the imaging lens system disclosed in other embodiments of the present disclosure, and the present disclosure is not limited thereto.The imaging light is focused in the lens unit 101 of the image acquisition unit 100 to generate an image with the drive device 102, which is used for image focusing on the image sensor 103, and the generated image is then digitally transmitted to other electronic components for further processing.

[0191] The drive unit 102 can have an autofocus function and can use various drive configurations, such as voice coil motors (VCMs), microelectromechanical systems (MEMS), piezoelectric systems, and shape memory alloys. The drive unit 102 is advantageous for achieving a better image position for the lens unit 101, enabling the lens unit 101 to capture a clear image of the object at varying distances. The image sensor 103 (e.g., CMOS or CCD), which can be characterized by high light sensitivity and low noise, is positioned on the image surface of the imaging lens system to achieve higher image quality.

[0192] The image stabilizer 104, comprising, for example, an accelerometer, a gyroscope, and a Hall-effect sensor, is designed to work in conjunction with the drive unit 102 to provide optical image stabilization (OIS). The drive unit 102, working in conjunction with the image stabilizer 104, is well-suited to compensate for panning and tilting movements of the lens unit 101, thereby reducing motion blur during exposure. In some cases, compensation can be achieved through electronic image stabilization (EIS) using image processing software, thus improving image quality in dynamic or low-light scenarios. 12. Design

[0193] Fig. Figure 22 is a perspective view of an electronic device according to the 12th embodiment of the present disclosure. Fig.Figure 23 is another perspective view of the electronic device in Fig. 22 and Fig. 24 is a block diagram of the electronic device in Fig. 22,

[0194] In this embodiment, an electronic device 200 is a smartphone comprising the image acquisition unit 100, an image acquisition unit 100a, an image acquisition unit 100b, an image acquisition unit 100c, an image acquisition unit 100d, a flash module 201, a focusing aid module 202, an image signal processor 203, a display module 204, and an image software processor 205, as disclosed in the 11th embodiment. The image acquisition unit 100 and the image acquisition unit 100a are arranged on the same side of the electronic device 200, and each of the image acquisition units 100 and 100a has a single focal point. The focusing aid module 202 can be a laser distance meter or a ToF (Time of Flight) module, but the present disclosure is not limited to this.The image acquisition unit 100b, the image acquisition unit 100c, the image acquisition unit 100d, and the display module 204 are arranged on the opposite side of the electronic device 200, and the display module 204 can be a user interface that allows the image acquisition units 100b, 100c, and 100d to function as front cameras of the electronic device 200 for taking selfies, but the present disclosure is not limited to this. Furthermore, each of the image acquisition units 100a, 100b, 100c, and 100d can include the imaging lens system of the present disclosure and have a similar configuration to the image acquisition unit 100. Specifically, each of the image acquisition units 100a, 100b, 100c, and 100d can include a lens unit, a drive device, an image sensor, and an image stabilizer.Furthermore, each lens unit of the image acquisition units 100a, 100b, 100c and 100d can comprise the imaging lens system of the present disclosure, a tube and a holder for holding the imaging lens system.

[0195] Image acquisition unit 100 is a telephoto image acquisition unit, image acquisition unit 100a is a wide-angle image acquisition unit, image acquisition unit 100b is a wide-angle image acquisition unit, image acquisition unit 100c is an ultra-wide-angle image acquisition unit, and image acquisition unit 100d is a time-of-flight (ToF) image acquisition unit. In this embodiment, image acquisition units 100 and 100a have different fields of view, allowing the electronic device to have 200 different magnification ratios to meet the requirements of the optical zoom function. Furthermore, image acquisition unit 100d can determine depth information of the imaged object. Additionally, each of the image acquisition units 100, 100a, 100b, 100c, and 100d can have a light deflection configuration, such as one of the configurations described in [reference missing]. Fig. 31 to Fig. The configurations shown in section 33 are similar, for which reference is made to the preceding descriptions. Fig. 31 to Fig. Reference can be made to Section 33. In this embodiment, the electronic device 200 comprises several image acquisition units 100, 100a, 100b, 100c and 100d, but the present disclosure is not limited to the number and arrangement of the image acquisition units.

[0196] When a user takes pictures of an object 206, the light rays are focused in the image acquisition unit 100 or image acquisition unit 100a to create images, and the flash module 201 is activated for 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 designed to optimize the captured image to improve image quality. The light emitted by the focus assist module 202 can be either conventional infrared light or laser light. Additionally, the light rays can be focused in the image acquisition unit 100b, 100c, or 100d to create images. The display module 204 can include a touchscreen, and the user can interact with the display module 204 and the multi-functional image software processor 205 to capture images and perform image processing.Alternatively, the user can take pictures using a physical button. The image processed by the image software processor 205 can be displayed on the display module 204. 13. Design

[0197] Fig. Figure 25 is a schematic view of an electronic device according to the 13th embodiment of the present disclosure, and Fig. Figure 26 is another schematic view of the electronic device. Fig. 25.

[0198] In this embodiment, an electronic device 300 is a smartphone comprising the image acquisition unit 100, an image acquisition unit 100e, an image acquisition unit 100f, an image acquisition unit 100g, and a display module 301 disclosed in the 11th embodiment. As in Fig.As shown in Figure 25, the image acquisition unit 100, the image acquisition unit 100e, and the image acquisition unit 100f are arranged on the same side of the electronic device 300, and each of the image acquisition units 100, 100e, and 100f has a single focal point. As shown in Fig.As shown in Figure 26, the image acquisition unit 100g and the display module 301 are arranged on the opposite side of the electronic device 300, so that the image acquisition unit 100g can serve as the front camera of the electronic device 300 for taking selfies, although the present disclosure is not limited to this use. Furthermore, each of the image acquisition units 100e, 100f, and 100g can include the imaging lens system of the present disclosure and have a similar configuration to the image acquisition unit 100. Specifically, each of the image acquisition units 100e, 100f, and 100g can include a lens unit, a drive device, an image sensor, and an image stabilizer. In addition, each lens unit of the image acquisition units 100e, 100f, and 100g can include the imaging lens system of the present disclosure, a tube, and a holder for holding the imaging lens system.

[0199] Image capture unit 100 is a telephoto image capture unit, image capture unit 100e is a wide-angle image capture unit, image capture unit 100f is an ultra-wide-angle image capture unit, and image capture unit 100g is a wide-angle image capture unit. In this embodiment, image capture units 100, 100e, and 100f have different fields of view, allowing the electronic device to have 300 different magnification ratios to meet the requirements of the optical zoom function. Furthermore, image capture unit 100g, as described in Fig.Figure 26 shows that the image acquisition unit 100g has a non-circular opening, and the tube or lens elements in the image acquisition unit 100g may have clipped edges at their outermost positions to conform to the shape of the non-circular opening. Therefore, it is advantageous to reduce the size of the image acquisition unit 100g, thereby increasing the ratio of the area of ​​the display module 301 relative to that of the electronic device 300 and reducing the thickness of the electronic device 300, thus achieving a compact design. In this embodiment, the electronic device 300 comprises several image acquisition units 100, 100e, 100f, and 100g, but the present disclosure is not limited to the number and arrangement of the image acquisition units. 14. Design

[0200] Fig. Figure 27 is a perspective view of an electronic device according to the 14th embodiment of the present disclosure.

[0201] In this embodiment, an electronic device 400 is a smartphone comprising the image acquisition unit 100 disclosed in the 11th embodiment, an image acquisition unit 100h, an image acquisition unit 100i, a flash module 401, a focusing aid module, an image signal processor, a display module, and an image software processor (not shown). The image acquisition units 100, 100h, and 100i 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 acquisition units 100h and 100i can include the imaging lens system of the present disclosure and have a similar configuration to the image acquisition unit 100, the details of which are not repeated here.

[0202] The image acquisition unit 100 is a telephoto image acquisition unit with a beam path deflection function, the image acquisition unit 100h is a wide-angle image acquisition unit, and the image acquisition unit 100i is an ultra-wide-angle image acquisition unit. In this embodiment, the image acquisition units 100, 100h, and 100i have different fields of view, so that the electronic device 400 can have different magnification ratios to meet the requirements of the optical zoom function. Furthermore, the image acquisition unit 100 is a telephoto image acquisition unit configured with a beam path deflection element (e.g., a reflective element), so that the overall path length of the image acquisition unit 100 is not limited by the thickness of the electronic device 400. Moreover, the light deflection configuration of the image acquisition unit 100 can, for example, be one of the configurations described in [reference missing]. Fig. 31 to Fig.The configurations shown in section 33 resemble each other, for which reference is made to the preceding descriptions. Fig. 31 to Fig. Reference can be made to point 33, and the relevant details are not repeated. Furthermore, each of the 100h and 100i image acquisition units may have a light deflection configuration, such as one of those described in Fig. 31 to Fig. The configurations shown in section 33 are similar, for which reference is made to the preceding descriptions. Fig. 31 to Fig.Reference can be made to Section 33. In this embodiment, the electronic device 400 comprises several image acquisition units 100, 100h, and 100i, but the present disclosure is not limited to the number and arrangement of the image acquisition units. When a user takes pictures of an object, the light beams are focused in the image acquisition unit 100, 100h, or 100i to produce images, and the flash module 401 is activated to provide additional light. Furthermore, the subsequent processes are carried out in a similar manner to those in the embodiments mentioned above, and the details thereof are not repeated. 15. Design

[0203] Fig. Figure 28 is a perspective view of an electronic device according to the 15th embodiment of the present disclosure.

[0204] In this embodiment, an electronic device 500 is a smartphone comprising the image acquisition unit 100, an image acquisition unit 100j, an image acquisition unit 100k, an image acquisition unit 100m, an image acquisition unit 100n, an image acquisition unit 100p, an image acquisition unit 100q, an image acquisition unit 100r, an image acquisition unit 100s, a flash module 501, a focusing aid module, an image signal processor, a display module and an image software processor (not shown) disclosed in the 11th embodiment. The image acquisition units 100, 100j, 100k, 100m, 100n, 100p, 100q, 100r and 100s are arranged on the same side of the electronic device 500, while the display module is arranged on the opposite side of the electronic device 500.Furthermore, each of the image acquisition units 100j, 100k, 100m, 100n, 100p, 100q, 100r and 100s can comprise the imaging lens system of the present disclosure and have a similar configuration to the image acquisition unit 100, without the details relating thereto being specified again.

[0205] The image acquisition unit 100 is a telephoto image acquisition unit with beam path deflection function, the image acquisition unit 100k is a telephoto image acquisition unit with beam path deflection function, the image acquisition unit 100j is an ultra-wide-angle image acquisition unit, the image acquisition unit 100m is an ultra-wide-angle image acquisition unit, the image acquisition unit 100n is a wide-angle image acquisition unit, the image acquisition unit 100p is a wide-angle image acquisition unit, the image acquisition unit 100q is a telephoto image acquisition unit, the image acquisition unit 100r is a telephoto image acquisition unit, and the image acquisition unit 100s is a ToF image acquisition unit. In this embodiment, the image acquisition units 100, 100j, 100k, 100m, 100n, 100p, 100q and 100r have different fields of view, so that the electronic device can have 500 different magnification ratios to meet the requirements of the optical zoom function.Furthermore, each of the image acquisition unit 100 and the image acquisition unit 100k is a telephoto image acquisition unit configured with a beam deflection element (e.g., a reflecting element), so that the total path length of the image acquisition unit 100 and the image acquisition unit 100k is not limited by the thickness of the electronic device 500. In addition, the image acquisition unit 100s can determine depth information of the imaged object. Furthermore, the light deflection configuration of the image acquisition units 100 and 100k can, for example, be one of those described in [reference missing]. Fig. 31 to Fig. The configurations shown in section 33 resemble each other, for which reference is made to the preceding descriptions. Fig. 31 to Fig.33 reference can be made, and the relevant details are not specified again. In addition, each of the image acquisition units 100j, 100m, 100n, 100p, 100q, 100r and 100s may have a light deflection configuration, such as one of those described in Fig. 31 to Fig. The configurations shown in section 33 are similar, for which reference is made to the preceding descriptions. Fig. 31 to Fig.Reference can be made to Section 33. In this embodiment, the electronic device 500 comprises several image acquisition units 100, 100j, 100k, 100m, 100n, 100p, 100q, 100r, and 100s, but the present disclosure is not limited to the number and arrangement of the image acquisition units. When a user takes pictures of an object, the light rays are focused in the image acquisition unit 100, 100j, 100k, 100m, 100n, 100p, 100q, 100r, or 100s to produce images, and the flash module 501 is activated to provide additional light. Furthermore, the subsequent processes are carried out in a similar manner to those in the embodiments mentioned above, and the details relating thereto are not repeated.

[0206] The smartphones in the embodiments serve only as examples to illustrate the image acquisition unit installed in an electronic device according to the present disclosure, and the present disclosure is not limited thereto. The image acquisition unit can optionally be applied to optical systems with moving focus. Furthermore, the imaging lens system of the image acquisition unit is characterized by good aberration correction and high image quality and can be used for 3D image acquisition applications (three-dimensional image acquisition applications) in products such as digital cameras, mobile devices, digital tablets, smart televisions, network surveillance devices, dashboard cameras, vehicle reversing cameras, multi-camera devices, image recognition systems, motion sensor input devices, vehicles, unmanned aerial vehicles, portable devices, portable video recorders, and other electronic imaging devices.

[0207] The foregoing description has been provided for illustrative purposes with reference to specific embodiments. It should be noted that TABLES 1A-10C show different data for the various embodiments; however, the data for the different embodiments were obtained from experiments. The embodiments were selected and described in the order presented to best illustrate the principles of the disclosure and their practical applications, so that other skilled persons may make the best possible use of the disclosure and of the various embodiments with different modifications suitable for their respective intended uses. The embodiments shown above and the accompanying drawings are exemplary and are not intended to be exhaustive, nor are they intended to limit the scope of the present disclosure to the forms exactly disclosed. In view of the above teachings, many modifications and variations are possible.

Claims

[1] Imaging lens system comprising five lens elements (E1, E2, E3, E4 and E5), wherein the five lens elements (E1, E2, E3, E4 and E5) are arranged in the order from an object side to an image side along a beam path as a first lens element (E1), a second lens element (E2), a third lens element (E3), a fourth lens element (E4) and a fifth lens element (E5), and wherein each of the five lens elements (E1, E2, E3, E4 and E5) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the first lens element (E1) has a positive refractive power, the second lens element (E2) has a negative refractive power, and the image-side surface of the second lens element (E2) is concave in a paraxial region thereof; and where 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 Dr1r6, an axial distance between the object-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr7r10, an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the fifth lens element (E5) is TD, an axial distance between the image-side surface of the fifth lens element (E5) and an image surface (IMG) is BL, an axial distance between the first lens element (E1) and the second lens element (E2) is T12, an axial distance between the second lens element (E2) and the third lens element (E3) is T23, an axial distance between the third lens element (E3) and the fourth lens element (E4) is T34,an axial distance between the fourth lens element (E4) and the fifth lens element (E5) is T45, an Abbe number of the fourth lens element (E4) is V4, a radius of curvature of the image-side surface of the second lens element (E2) is R4, a radius of curvature of the image-side surface of the fifth lens element (E5) is R10, and the following conditions are met: 1.60 <Dr1r6 / Dr7r10<5,00; 0.50 <TD / BL<1,50; 0.00<(T12+T23+T45) / T34<0.50; 0.00 <T23 / T45<0,50; 5.0 <V4<35,0; and 0.00<|R4 / R10|<1.

00. [2] Imaging lens system according to claim 1, wherein the object-side surface of the first lens element (E1) is convex in a paraxial region thereof, the object-side surface of the second lens element (E2) is convex in a paraxial region thereof, the object-side surface of the third lens element (E3) is convex in a paraxial region thereof, and the image-side surface of the third lens element (E3) is concave in a paraxial region thereof; and where f is the focal length of the imaging lens system, f3 is the focal length of the third lens element (E3), and the following condition is met: -0.25 <f / f3<5,00. [3] Imaging lens system according to claim 1, wherein at least one lens element of the imaging lens system has at least one inflection point (P); and where BL is the axial distance between the image-side surface of the fifth lens element (E5) and the image surface (IMG), ImgH is the maximum image height of the imaging lens system, TL is the axial distance between the object-side surface of the first lens element (E1) and the image surface (IMG), and the following conditions are met: 2.20 <BL / ImgH<3,50; ; and 4.00 <TL / ImgH<7,00. [4] Imaging lens system according to claim 1, wherein a focal length of the first lens element (E1) is f1, a focal length of the second lens element (E2) is f2 and the following condition is met: 0.50<|f1 / f2|<1.

50. [5] Imaging lens system according to claim 1, wherein a focal length of the first lens element (E1) is f1, a focal length of the third lens element (E3) is f3 and the following condition is met: 0.40 <f1 / f3<1,50. [6] Imaging lens system according to claim 1, wherein the focal length of the first lens element (E1) is f1, the focal length of the second lens element (E2) is f2, the focal length of the fourth lens element (E4) is f4, the focal length of the fifth lens element (E5) is f5 and the following condition is met: −0.60<(f1+f2) / (f4+f5)<5.

00. [7] Imaging lens system according to claim 1, wherein a radius of curvature of the image-side surface of the third lens element (E3) is R6, a radius of curvature of the object-side surface of the fourth lens element (E4) is R7, a radius of curvature of the object-side surface of the fifth lens element (E5) is R9, the radius of curvature of the image-side surface of the fifth lens element (E5) is R10 and the following conditions are met: -1.80 <R9 / R10<1,00; and -1.00 <R6 / R7<1,10. [8] Imaging lens system according to claim 1, wherein the imaging lens system further comprises at least one reflective element (LF). [9] Imaging lens system according to claim 1, wherein an axial distance between the image-side surface of the first lens element (E1) and the object-side surface of the third lens element (E3) is Dr2r5, an axial distance between the image-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr8r10 and the following condition is met: 0.00 <Dr2r5 / Dr8r10<1,70. [10] Imaging lens system according to claim 1, wherein an Abbe number of the second lens element (E2) is V2, an Abbe number of the third lens element (E3) is V3 and the following conditions are met: 5.0 <V2<35,0; and 45.0 <V3<70,0. [11] Imaging lens system according to claim 1, wherein a maximum effective radius of the image-side surface of the third lens element (E3) is Y3R2, a maximum effective radius of the object-side surface of the fourth lens element (E4) is Y4R1 and the following condition is met: 1.20 <Y3R2 / Y4R1<1,90. [12] Imaging lens system according to claim 1, wherein the 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 Dr1r6, the axial distance between the object-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr7r10, the axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the fifth lens element (E5) is TD, the axial distance between the image-side surface of the fifth lens element (E5) and the image surface (IMG) is BL, the axial distance between the first lens element (E1) and the second lens element (E2) is T12, the axial distance between the second lens element (E2) and the third lens element (E3) is T23, the axial distance between the third lens element (E3) and the fourth lens element (E4) T34 is,the axial distance between the fourth lens element (E4) and the fifth lens element (E5) T45 is, and the following conditions are met:, 1.70 <Dr1r6 / Dr7r10<4,00; 0.60 <TD / BL<1,20; 0.00 <T23 / T45<0,40; and 0.05<(T12+T23+T45) / T34<0.

45. [13] Image capture unit (1, 100), comprising: the imaging lens system according to claim 1; and an image sensor (IS, 103) which is located on the image surface (IMG) of the imaging lens system. [14] Electronic device (200) comprising: the image acquisition unit (1, 100) according to claim 13. [15] Imaging lens system comprising five lens elements (E1, E2, E3, E4 and E5), wherein the five lens elements (E1, E2, E3, E4 and E5) are arranged in the order from an object side to an image side along a beam path as a first lens element (E1), a second lens element (E2), a third lens element (E3), a fourth lens element (E4) and a fifth lens element (E5), and wherein each of the five lens elements (E1, E2, E3, E4 and E5) has an object-side surface facing the object side and an image-side surface facing the image side; wherein the first lens element (E1) has a positive refractive power, the second lens element (E2) has a negative refractive power, the object-side surface of the second lens element (E2) is convex in a paraxial region thereof, and the object-side surface of the fifth lens element (E5) is concave in a paraxial region thereof; and where 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 Dr1r6, an axial distance between the object-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr7r10, an axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the fifth lens element (E5) is TD, an axial distance between the image-side surface of the fifth lens element (E5) and an image surface (IMG) is BL, an axial distance between the first lens element (E1) and the second lens element (E2) is T12, an axial distance between the second lens element (E2) and the third lens element (E3) is T23, an axial distance between the third lens element (E3) and the fourth lens element (E4) is T34,an axial distance between the fourth lens element (E4) and the fifth lens element (E5) T45 and the following conditions are met:, 1.60 <Dr1r6 / Dr7r10<5,00; 0.50 <TD / BL<1,50; 0.00<(T12+T23+T45) / T34<0.50; and 0.00 <T23 / T45<0,50. [16] Imaging lens system according to claim 15, wherein the object-side surface of the first lens element (E1) is convex in a paraxial region thereof, the image-side surface of the second lens element (E2) is concave in a paraxial region thereof, the object-side surface of the third lens element (E3) is convex in a paraxial region thereof, and the fourth lens element (E4) has a positive refractive power; and where f is the focal length of the imaging lens system, f3 is the focal length of the third lens element (E3), and the following condition is met: -0.20 <f / f3<2,00. [17] Imaging lens system according to claim 15, wherein at least one lens element of the imaging lens system has at least one inflection point (P); and where the maximum field of view of the imaging lens system is FOV and the following condition is met: 10.0 degrees <FOV<25,0 Grad. [18] Imaging lens system according to claim 15, wherein the axial distance between the image-side surface of the fifth lens element (E5) and the image surface (IMG) is BL, the axial distance between the third lens element (E3) and the fourth lens element (E4) is T34 and the following condition is met: 1.00 <BL / T34<4,50. [19] Imaging lens system according to claim 15, wherein a radius of curvature of the image-side surface of the first lens element (E1) is R2, a radius of curvature of the object-side surface of the second lens element (E2) is R3 and the following condition is met: 0.00<|R3 / R2|<1.

10. [20] Imaging lens system according to claim 15, wherein 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 condition is met: −0.50<(R5−R6) / (R5+R6)<1.

00. [21] Imaging lens system according to claim 15, wherein a central thickness of the first lens element (E1) is CT1, a central thickness of the second lens element (E2) is CT2 and the following condition is met: 2.00 <CT / CT2<5,50. [22] Imaging lens system according to claim 15, wherein the axial distance between the image-side surface of the fifth lens element (E5) and the image surface (IMG) BL is a sum of the axial distances between each of all adjacent lens elements of the imaging lens system ΣAT and the following condition is satisfied: 1.70 <BL / ∑AT<3,80. [23] Imaging lens system according to claim 15, wherein the axial distance between the third lens element (E3) and the fourth lens element (E4) is T34, the 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 Dr1r6 and the following condition is met: 0.50 <T34 / Dr1r6<1,60. [24] Imaging lens system according to claim 15, wherein a maximum effective radius of the object-side surface of the first lens element (E1) is Y1R1, a maximum effective radius of the image-side surface of the fifth lens element (E5) is Y5R2 and the following condition is met: 1.60 <Y1R1 / Y5R2<3,50. [25] Imaging lens system according to claim 15, wherein the 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 Dr1r6, the axial distance between the object-side surface of the fourth lens element (E4) and the image-side surface of the fifth lens element (E5) is Dr7r10, the axial distance between the object-side surface of the first lens element (E1) and the image-side surface of the fifth lens element (E5) is TD, the axial distance between the image-side surface of the fifth lens element (E5) and the image surface (IMG) is BL, the axial distance between the first lens element (E1) and the second lens element (E2) is T12, the axial distance between the second lens element (E2) and the third lens element (E3) is T23, the axial distance between the third lens element (E3) and the fourth lens element (E4) T34 is,the axial distance between the fourth lens element (E4) and the fifth lens element (E5) is T45, an Abbe number of the fourth lens element (E4) is V4, a radius of curvature of the image-side surface of the second lens element (E2) is R4, a radius of curvature of the image-side surface of the fifth lens element (E5) is R10, and the following conditions are met: 1.81≤Dr1r6 / Dr7r10≤3.58; 0.77≤TD / BL≤1.02; 0.10≤(T12+T23+T45) / T34≤0.42; 0.05≤T23 / T45≤0.35; 16.3≤V4≤25.3; ; and 0.06≤|R4 / R10|≤0.72.

Images