Imaging lens

Abstract

An imaging lens comprises a first lens, a second lens and a third lens. The first lens has refractive power. The second lens has refractive power. The third lens has negative refractive power and comprises a concave surface facing the image side. The first lens, the second lens and the third lens are sequentially arranged from the object side to the image side along the optical axis.

Description

Technical Field

[0001] The invention relates to an imaging lens. Background Art

[0002] The development trend of imaging lenses used in automobile safety monitoring is constantly moving towards high resolution. Conventional imaging lenses can no longer meet the needs of today's automobile safety monitoring. Another imaging lens with a new architecture is needed to meet the needs of high resolution. Summary of the invention

[0003] In view of this, the main purpose of the present invention is to provide an imaging lens with high lens resolution and good optical performance.

[0004] The present invention provides an imaging lens including a first lens, a second lens and a third lens. The first lens has a refractive power. The second lens has a refractive power. The third lens has a negative refractive power, and the third lens includes a concave surface facing the image side. The first lens, the second lens and the third lens are arranged in sequence from the object side to the image side along the optical axis. The imaging lens satisfies at least one of the following conditions: -12.68mm≤R32-(f1+f3)≤-8.16mm; 11.01≤R12 / CT1≤18.51; 0.57≤(Air1+Air2) / BFL≤0.88; 2.47≤(f1+f2) / f≤2.99; 3.48≤TTL / (CT2+Air2)≤3.88; wherein f is the effective focal length of the imaging lens, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, R12 is the image of the first lens The curvature radius of the side surface, R32 is the curvature radius of the image side surface of the third lens, CT1 is the distance between the object side surface of the first lens and the image side surface of the first lens on the optical axis, CT2 is the distance between the object side surface of the second lens and the image side surface of the second lens on the optical axis, TTL is the distance between the object side surface of the lens closest to the object side and the imaging surface on the optical axis, BFL is the distance between the image side surface of the third lens and the imaging surface on the optical axis, Air1 is the air distance between the image side surface of the first lens and the object side surface of the second lens on the optical axis, and Air2 is the air distance between the image side surface of the second lens and the object side surface of the third lens on the optical axis. When the imaging lens of the present invention meets the above characteristics and conditions and no other additional characteristics or conditions are required, the basic functions of the imaging lens of the present invention can be achieved.

[0005] The first lens has positive refractive power, and the second lens has positive refractive power.

[0006] The first lens is a meniscus lens and includes a convex surface facing the object side and a concave surface facing the image side. The second lens is a meniscus lens and includes a concave surface facing the object side and a convex surface facing the image side.

[0007] The imaging lens of the present invention may further include an aperture disposed between the object side and the first lens.

[0008] The third lens further includes a convex surface facing the object side.

[0009] The imaging lens of the present invention may further include a fourth lens disposed between the object side and the aperture.

[0010] The fourth lens is a biconvex lens with positive refractive power, and includes a convex surface facing the object side and another convex surface facing the image side.

[0011] The third lens is a biconcave lens and further includes another concave surface facing the object side.

[0012] The imaging lens of the present invention further includes a filter disposed between the third lens and the image side, wherein the imaging lens satisfies at least one of the following conditions: 0.2mm≤(R12 / R32)×Air3≤14.9mm; 3.03mm2≤R21×(f3 / Nd1)≤27.41mm2; 1.72≤(R21×R22)0.5 / Air3≤9.25; 5mm≤(f1×(f2+f3 )) / R21≤32mm;5≤(R12+R21+R22) / CT3≤14.1;-20.64mm≤f3 / (Vd2 / Vd3)≤-1.29mm;0.6≤(f2 / R11)0.5≤4.2;0.58mm≤f2 / (CT3 / Air3)≤5.65mm;3.09≤f / Air1≤4.71;wherein f is the effective focal length of the imaging lens, f 1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, R11 is the curvature radius of the object side surface of the first lens, R12 is the curvature radius of the image side surface of the first lens, R21 is the curvature radius of the object side surface of the second lens, R22 is the curvature radius of the image side surface of the second lens, R32 is the curvature radius of the image side surface of the third lens, CT3 is the distance between the object side surface of the third lens and the image side surface of the third lens on the optical axis, Air1 is the air distance between the image side surface of the first lens and the object side surface of the second lens on the optical axis, Air3 is the air distance between the image side surface of the third lens and the object side surface of the filter on the optical axis, Nd1 is the refractive index of the first lens, Vd2 is the Abbe coefficient of the second lens, and Vd3 is the Abbe coefficient of the third lens.

[0013] The first lens is a spherical lens made of glass, and the second lens, the third lens and the fourth lens are aspherical lenses made of plastic.

[0014] The imaging lens of the present invention has the following beneficial effects: it can effectively improve the resolution, effectively correct the aberration, and has good optical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of lens configuration and optical path of a first embodiment of an imaging lens according to the present invention.

[0016] Figure 2 , 3 , 4, and 5 are respectively a longitudinal aberration diagram, a field curvature diagram, a distortion diagram, and a relative illumination diagram of the first embodiment of the imaging lens according to the present invention.

[0017] Figure 6 FIG. 4 is a schematic diagram of lens configuration and optical path of a second embodiment of an imaging lens according to the present invention.

[0018] Figure 7 FIG. 4 is a schematic diagram of lens configuration and optical path of a third embodiment of an imaging lens according to the present invention.

[0019] Figure 8 , 9 , 10, and 11 are respectively longitudinal aberration diagrams, field curvature diagrams, distortion diagrams, and relative illumination diagrams of the third embodiment of the imaging lens according to the present invention.

[0020] Fig.12 FIG. 4 is a schematic diagram of lens configuration and optical path of a fourth embodiment of an imaging lens according to the present invention.

[0021] Fig.13 , 14 , 15, and 16 are respectively longitudinal aberration diagrams, field curvature diagrams, distortion diagrams, and relative illumination diagrams of the fourth embodiment of the imaging lens according to the present invention.

[0022] Fig.17 FIG. 5 is a schematic diagram of a lens configuration of a fifth embodiment of an imaging lens according to the present invention. DETAILED DESCRIPTION

[0023] The present invention provides an imaging lens, comprising: a first lens having a refractive power; a second lens having a refractive power; and a third lens having a negative refractive power, wherein the third lens comprises a concave surface facing the image side; wherein the first lens, the second lens and the third lens are arranged in sequence from the object side to the image side along the optical axis; wherein the imaging lens satisfies at least one of the following conditions: -12.68mm≤R32-(f1+f3)≤-8.16mm; 11.01≤R12 / CT1≤18.51; 0.57≤(Air1+Air2) / BFL≤0.88; 2.47≤(f1+f2) / f≤2.99; 3.48≤TTL / (CT2+Air2)≤3.88; wherein f is the effective focal length of the imaging lens, and f1 is the effective focal length of the first lens. focal length, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, R12 is the curvature radius of the image side surface of the first lens, R32 is the curvature radius of the image side surface of the third lens, CT1 is the distance from the object side surface of the first lens to the image side surface of the first lens on the optical axis, CT2 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, TTL is the distance from the object side surface of the lens closest to the object side to the imaging surface on the optical axis, BFL is the distance from the image side surface of the third lens to the imaging surface on the optical axis, Air1 is the air distance from the image side surface of the first lens to the object side surface of the second lens on the optical axis, and Air2 is the air distance from the image side surface of the second lens to the object side surface of the third lens on the optical axis. When the imaging lens of the present invention meets the above characteristics and at least one of the conditions, it is a preferred embodiment of the present invention.

[0024] Please refer to Table 1, Table 2, Table 4, Table 5, Table 7, Table 8, Table 10, Table 11, Table 13 and Table 14 below, wherein Table 1, Table 4, Table 7, Table 10 and Table 13 are tables of parameters of the lenses of the first embodiment to the fifth embodiment of the imaging lens according to the present invention, and Table 2, Table 5, Table 8, Table 11 and Table 14 are tables of parameters of the aspheric surface of the aspheric lens in Table 1, Table 4, Table 7, Table 10 and Table 13. In the following embodiments, the concavity z of the aspheric surface of the aspheric lens is obtained by the following formula:

[0025] z=ch 2 / {1+[1-(k+1)c 2 h 2 ] 1 / 2}+Ah 4 +Bh 6 +Ch 8 +Dh 10 +Eh 12 +Fh 14 +Gh 16 , where: c is the

[0026] rate, h is the vertical distance from any point on the lens surface to the optical axis, k is the conic constant, A~G are the aspheric coefficients, and the aspheric coefficients are expressed in scientific notation, for example, 2E-03 means 2×10 -3 .

[0027] Figure 1 , 6 , 7, 12, and 17 are respectively the lens configuration and optical path schematic diagrams of the first, second, third, fourth, and fifth embodiments of the imaging lens of the present invention. Among them, the first lens L11, L21, L31, L41, and L51 are meniscus lenses with positive refractive power, made of glass, and their object side surfaces S12, S22, S32, S42, and S54 are convex surfaces, and the image side surfaces S13, S23, S33, S43, and S55 are concave surfaces, and the object side surfaces S12, S22, S32, S42, and S54 and the image side surfaces S13, S23, S33, S43, and S55 are all spherical surfaces.

[0028] The second lenses L12, L22, L32, L42, and L52 are meniscus lenses with positive refractive power and are made of plastic. Their object-side surfaces S14, S24, S34, S44, and S56 are concave, and their image-side surfaces S15, S25, S35, S45, and S57 are convex. The object-side surfaces S14, S24, S34, S44, and S56 and the image-side surfaces S15, S25, S35, S45, and S57 are all aspherical surfaces.

[0029] The third lens L13, L23, L33, L43, L53 has negative refractive power and is made of plastic. Its image-side surfaces S17, S27, S37, S47, S59 are concave surfaces, and its object-side surfaces S16, S26, S36, S46, S58 and image-side surfaces S17, S27, S37, S47, S59 are aspherical surfaces.

[0030] In addition, the imaging lenses 1, 2, 3, 4, and 5 satisfy at least one of the following conditions (1) to (14):

[0031] 0.2 mm ≤ (R12 / R32)×Air3 ≤ 14.9 mm; (1)

[0032] -12.68 mm ≤ R32-(f1+f3) ≤ -8.16 mm; (2)

[0033] 3.03 mm 2 ≤ R21×(f3 / Nd1) ≤ 27.41 mm 2 ; (3)

[0034] 1.72 ≤ (R21×R22)<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> / Air3 ≤ 9.25; (4)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0035] <h2 style=";text-align:left;direction:ltr"> 5 mm ≤ (f1×(f2+f3)) / R21 ≤ 32 mm; (5)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0036] <h2 style=";text-align:left;direction:ltr"> 11.01 ≤ R12 / CT1 ≤ 18.51; (6)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0037] <h2 style=";text-align:left;direction:ltr"> 5 ≤ (R12+R21+R22) / CT3 ≤ 14.1; (7)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0038] <h2 style=";text-align:left;direction:ltr"> -20.64 mm ≤ f3 / (Vd2 / Vd3) ≤ -1.29 mm; (8)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0039] <h2 style=";text-align:left;direction:ltr"> 0.6 ≤ (f2 / R11)<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> ≤ 4.2; (9)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0040] <h2 style=";text-align:left;direction:ltr"> 0.58 mm ≤ f2 / (CT3 / Air3) ≤ 5.65 mm; (10)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0041] <h2 style=";text-align:left;direction:ltr"> 0.57 ≤ (Air1+Air2) / BFL ≤ 0.88; (11)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0042] <h2 style=";text-align:left;direction:ltr"> 2.47 ≤ (f1+f2) / f ≤ 2.99; (12)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0043] <h2 style=";text-align:left;direction:ltr"> 3.09 ≤ f / Air1 ≤ 4.71; (13)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0044] <h2 style=";text-align:left;direction:ltr"> 3.48 ≤ TTL / (CT2+Air2) ≤ 3.88; (14)<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0045] Wherein, f is the effective focal length of the imaging lenses 1, 2, 3, 4, 5 in the first to fifth embodiments, f1 is the effective focal length of the first lens L11, L21, L31, L41, L51 in the first to fifth embodiments, f2 is the effective focal length of the second lens L12, L22, L32, L42, L52 in the first to fifth embodiments, f3 is the effective focal length of the third lens L13, L23, L33, L43, L53 in the first to fifth embodiments, R11 is the focal length of the object side surfaces S12, S22, S32, S42, S54 of the first lens L11, L21, L31, L41, L51 in the first to fifth embodiments The curvature radius, R12 is the curvature radius of the image-side surface S13, S23, S33, S43, S55 of the first lens L11, L21, L31, L41, L51 in the first to fifth embodiments, R21 is the curvature radius of the object-side surface S14, S24, S34, S44, S56 of the second lens L12, L22, L32, L42, L52 in the first to fifth embodiments, R22 is the curvature radius of the image-side surface S15, S25, S35, S45, S57 of the second lens L12, L22, L32, L42, L52 in the first to fifth embodiments, and R32 is the curvature radius of the third lens L13 in the first to fifth embodiments. , L23, L33, L43, L53, CT1 is the distance between the object-side surface S12, S22, S32, S42, S54 of the first lens L11, L21, L31, L41, L51 and the image-side surface S13, S23, S33, S43, S55 of the first lens L11, L21, L31, L41, L51 on the optical axis OA1, OA2, OA3, OA4, OA5 in the first to fifth embodiments, CT2 is the object-side surface S14, S24, S37, S47, S59 of the second lens L12, L22, L32, L42, L52 in the first to fifth embodiments. 4, S44, S56 to the image side surfaces S15, S25, S35, S45, S57 of the second lenses L12, L22, L32, L42, L52 on the optical axis OA1, OA2, OA3, OA4, OA5, CT3 is the distance between the object side surfaces S16, S26, S36, S46, S58 of the third lenses L13, L23, L33, L43, L53 and the image side surfaces S17, S27, S37, S47, S59 of the third lenses L13, L23, L33, L43, L53 on the optical axis OA1, OA2, OA3, OA4, OA5 in the first to fifth embodiments, TTL is the distance between the object side surfaces S16, S26, S36, S46, S58 of the third lenses L13, L23, L33, L43, L53 and the image side surfaces S17, S27, S37, S47, S59 of the third lenses L13, L23, L33, L43, L53 on the optical axis OA1, OA2, OA3, OA4, OA5 in the first to fifth embodiments,The distances between the object side surfaces S11, S21, S31, S41, S51 of the lenses L11, L21, L31, L41, L54 closest to the object side and the imaging surfaces IMA1, IMA2, IMA3, IMA4, IMA5 on the optical axes OA1, OA2, OA3, OA4, OA5 are BFL, and the distances between the image side surfaces S17, S27, S37, S47, S59 of the third lenses L13, L23, L33, L43, L53 ... 5 on the optical axes OA1, OA2, OA3, OA4, OA5, Air1 is the air distance between the image-side surfaces S13, S23, S33, S43, S55 of the first lenses L11, L21, L31, L41, L51 and the object-side surfaces S14, S24, S34, S44, S56 of the second lenses L12, L22, L32, L42, L52 on the optical axes OA1, OA2, OA3, OA4, OA5 in the first to fifth embodiments, and Air2 is the air distance between the image-side surfaces S13, S23, S33, S43, S55 of the first lenses L11, L21, L31, L41, L51 and the object-side surfaces S14, S24, S34, S44, S56 of the second lenses L12, L22, L32, L42, L52 on the optical axes OA1, OA2, OA3, OA4, OA5 in the first to fifth embodiments, 22, L32, L42, L52 and the object side surfaces S16, S26, S36, S46, S58 of the third lens L13, L23, L33, L43, L53 on the optical axes OA1, OA2, OA3, OA4, OA5. Air3 is the air distance between the image side surfaces S17, S27, S37, S47, S59 of the third lens L13, L23, L33, L43, L53 and the optical filters OF1, OF2, OF3, OF4 in the first to fifth embodiments. 4. The air spacing between the object side S18, S28, S38, S48, S510 of OF5 on the optical axis OA1, OA2, OA3, OA4, OA5, Nd1 is the refractive index of the first lens L11, L21, L31, L41, L51 in the first to fifth embodiments, Vd2 is the Abbe coefficient of the second lens L12, L22, L32, L42, L52 in the first to fifth embodiments, and Vd3 is the Abbe coefficient of the third lens L13, L23, L33, L43, L53 in the first to fifth embodiments. The imaging lenses 1, 2, 3, 4, 5 can effectively improve the resolution and effectively correct the aberration.

[0046] When the condition (1) is met: 0.2mm≤(R12 / R32)×Air3≤14.9mm, the condition (2) is met: -12.68mm≤R32-(f1+f3)≤-8.16mm or the condition (3) is met: 3.03mm 2 ≤R21×(f3 / Nd1)≤27.41mm 2, which can effectively improve the resolution and correct the aberration. When condition (4) is met: 1.72≤(R21×R22) 0.5 / Air3≤9.25, by controlling the radius of curvature of the second lens and the air distance from the third lens to the filter, the aberration can be effectively corrected. When condition (5) is met: 5mm≤(f1×(f2+f3)) / R21≤32mm, by properly controlling the effective focal length and thickness, the off-axis aberration can be effectively corrected. When condition (6) is met: 11.01≤R12 / CT1≤18.51 or condition (7): 5≤(R12+R21+R22) / CT3≤14.1, by properly controlling the effective focal length and thickness, the off-axis aberration can be effectively corrected. When condition (8) is met: -20.64mm≤f3 / (Vd2 / Vd3)≤-1.29mm, the resolution can be effectively improved and the chromatic aberration can be corrected. When condition (9) is met: 0.6≤(f2 / R11) 0.5 ≤4.2, by providing the lens with sufficient refractive power to control the field of view, aberrations can be effectively corrected. When condition (10) is met: 0.58mm≤f2 / (CT3 / Air3)≤5.65mm, the resolution can be effectively improved and aberrations can be corrected. When condition (11) is met: 0.57≤(Air1+Air2) / BFL≤0.88, condition (12) is met: 2.47≤(f1+f2) / f≤2.99, condition (13) is met: 3.09≤f / Air1≤4.71 or condition (14) is met: 3.48≤TTL / (CT2+Air2)≤3.88, the resolution can be effectively improved and aberrations can be corrected. When the following conditions are met simultaneously: -12.68mm≤R32-(f1+f3)≤-8.16mm, (6): 11.01≤R12 / CT1≤18.51, (11): 0.57≤(Air1+Air2) / BFL≤0.88, (12): 2.47≤(f1+f2) / f≤2.99 and (14): 3.48≤TTL / (CT2+Air2)≤3.88, the resolution can be effectively improved and the aberration can be corrected.

[0047] The first embodiment of the imaging lens of the present invention is now described in detail. Figure 1The imaging lens 1 includes an aperture ST1, a first lens L11, a second lens L12, a third lens L13, a filter OF1 and a protective glass CG1 in order from the object side to the image side along the optical axis OA1. During imaging, the light from the object side is finally imaged on the imaging surface IMA1. According to the first to fifth paragraphs of [Specific Implementation], the third lens L13 is a meniscus lens, and its object side surface S16 is a convex surface; the object side surface S18 and the image side surface S19 of the filter OF1 are both planes; the object side surface S110 and the image side surface S111 of the protective glass CG1 are both planes; by using the above-mentioned lens, aperture ST1 and a design that satisfies at least one of conditions (1) to (14), the imaging lens 1 can effectively improve the resolution and effectively correct the aberration.

[0048] Table 1 Figure 1 Table of relevant parameters of each lens of imaging lens 1.

[0049] Table 1

[0050]

[0051]

[0052] Table 2 is a table of relevant parameters of the aspheric surface of the aspheric lens in Table 1.

[0053] Table 2

[0054]

[0055] Table 3 shows the relevant parameter values ​​of the imaging lens 1 of the first embodiment and the calculated values ​​corresponding to conditions (1) to (14). It can be seen from Table 3 that the imaging lens 1 of the first embodiment can meet the requirements of conditions (1) to (14).

[0056] Table 3

[0057]

[0058] In addition, the optical performance of the imaging lens 1 of the first embodiment can also meet the requirements. Figure 2 It can be seen that the longitudinal aberration of the imaging lens 1 of the first embodiment is between -0.01 mm and 0.04 mm. Figure 3 It can be seen that the field curvature of the imaging lens 1 of the first embodiment is between -0.04 mm and 0.07 mm. Figure 4 It can be seen that the distortion of the imaging lens 1 of the first embodiment is between -1.2% and 1.2%. Figure 5It can be seen that the relative illumination of the imaging lens 1 of the first embodiment is between 0.50 and 1.0. It is obvious that the longitudinal aberration, field curvature, distortion and relative illumination of the imaging lens 1 of the first embodiment can be effectively corrected, thereby obtaining better optical performance.

[0059] The second embodiment of the imaging lens of the present invention is now described in detail. Please refer to Figure 2. The imaging lens 2 includes an aperture ST2, a first lens L21, a second lens L22, a third lens L23, a filter OF2 and a protective glass CG2 in order from the object side to the image side along the optical axis OA2. When imaging, the light from the object side is finally imaged on the imaging surface IMA2. According to the first to fifth paragraphs of [Specific Implementation], the third lens L23 is a meniscus lens, and its object side surface S26 is a convex surface; the object side surface S28 and the image side surface S29 of the filter OF2 are both planes; the object side surface S210 and the image side surface S211 of the protective glass CG2 are both planes; the above-mentioned lens, aperture ST2 and the design that satisfies at least one of conditions (1) to (14) enable the imaging lens 2 to effectively improve the resolution and effectively correct the aberration.

[0060] Table 4 is Figure 6 Table of relevant parameters of each lens of imaging lens 2.

[0061] Table 4

[0062]

[0063] Table 5 is a table of relevant parameters of the aspheric surface of the aspheric lens in Table 4.

[0064] Table 5

[0065]

[0066]

[0067] Table 6 shows the relevant parameter values ​​of the imaging lens 2 of the second embodiment and the calculated values ​​corresponding to conditions (1) to (14). It can be seen from Table 6 that the imaging lens 2 of the second embodiment can meet the requirements of conditions (1) to (14).

[0068] Table 6

[0069]

[0070] The third embodiment of the imaging lens of the present invention will now be described in detail. Figure 7The imaging lens 3 includes an aperture ST3, a first lens L31, a second lens L32, a third lens L33, a filter OF3 and a protective glass CG3 in order from the object side to the image side along the optical axis OA3. During imaging, the light from the object side is finally imaged on the imaging surface IMA3. According to the first to fifth paragraphs of [Specific Implementation], the third lens L33 is a meniscus lens, and its object side surface S36 is a convex surface; the object side surface S38 and the image side surface S39 of the filter OF3 are both planes; the object side surface S310 and the image side surface S311 of the protective glass CG3 are both planes; by using the above-mentioned lens, aperture ST3 and a design that satisfies at least one of conditions (1) to (14), the imaging lens 3 can effectively improve the resolution and effectively correct the aberration.

[0071] Table 7 Figure 7 Table of relevant parameters of each lens of imaging lens 3.

[0072] Table 7

[0073]

[0074]

[0075] Table 8 is a table of relevant parameters of the aspheric surface of the aspheric lens in Table 7.

[0076] Table 8

[0077]

[0078] Table 9 shows the relevant parameter values ​​of the imaging lens 3 of the third embodiment and the calculated values ​​corresponding to conditions (1) to (14). It can be seen from Table 9 that the imaging lens 3 of the third embodiment can meet the requirements of conditions (1) to (14).

[0079] Table 9

[0080]

[0081] In addition, the optical performance of the imaging lens 3 of the third embodiment can also meet the requirements. Figure 8 It can be seen that the longitudinal aberration of the imaging lens 3 of the third embodiment is between -0.01 mm and 0.04 mm. Fig. 9 It can be seen that the field curvature of the imaging lens 3 of the third embodiment is between -0.06mm and 0.07mm. Fig.10 It can be seen that the distortion of the imaging lens 3 of the third embodiment is between -0.8% and 1.2%. Fig.11It can be seen that the relative illumination of the imaging lens 3 of the third embodiment is between 0.50 and 1.0. It is obvious that the longitudinal aberration, field curvature, distortion and relative illumination of the imaging lens 3 of the third embodiment can be effectively corrected, thereby obtaining better optical performance.

[0082] The fourth embodiment of the imaging lens of the present invention will now be described in detail. Fig.12 , the imaging lens 4 includes an aperture ST4, a first lens L41, a second lens L42, a third lens L43, a filter OF4 and a protective glass CG4 in order from the object side to the image side along the optical axis OA4. During imaging, the light from the object side is finally imaged on the imaging surface IMA4. According to the first to fifth paragraphs of [Specific Implementation], the third lens L43 is a meniscus lens, and its object side surface S46 is a convex surface; the object side surface S48 and the image side surface S49 of the filter OF4 are both planes; the object side surface S410 and the image side surface S411 of the protective glass CG4 are both planes; by using the above-mentioned lenses, aperture ST4 and a design that satisfies at least one of conditions (1) to (14), the imaging lens 4 can effectively improve the resolution and effectively correct the aberration.

[0083] Table 10 Fig.12 Table of relevant parameters of each lens of the imaging lens 4.

[0084] Table 10

[0085]

[0086] Table 11 is a table of relevant parameters of the aspheric surface of the aspheric lens in Table 10.

[0087] Table 11

[0088]

[0089] Table 12 shows the relevant parameter values ​​of the imaging lens 4 of the fourth embodiment and the calculated values ​​corresponding to conditions (1) to (14). It can be seen from Table 12 that the imaging lens 4 of the fourth embodiment can meet the requirements of conditions (1) to (14).

[0090] Table 12

[0091]

[0092]

[0093] In addition, the optical performance of the imaging lens 4 of the fourth embodiment can also meet the requirements. Fig.13 It can be seen that the longitudinal aberration of the imaging lens 4 of the fourth embodiment is between -0.01 mm and 0.04 mm. Fig.14It can be seen that the field curvature of the imaging lens 4 of the fourth embodiment is between -0.10mm and 0.05mm. Fig.15 It can be seen that the distortion of the imaging lens 4 of the fourth embodiment is between -1.8% and 1.3%. Fig.16 It can be seen that the relative illumination of the imaging lens 4 of the fourth embodiment is between 0.51 and 1.0. It is obvious that the longitudinal aberration, field curvature, distortion and relative illumination of the imaging lens 4 of the fourth embodiment can be effectively corrected, thereby obtaining better optical performance.

[0094] The fifth embodiment of the imaging lens of the present invention will now be described in detail. Fig.17 The imaging lens 5 includes a fourth lens L54, an aperture ST5, a first lens L51, a second lens L52, a third lens L53, a filter OF5 and a protective glass CG5 in order from the object side to the image side along the optical axis OA5. When imaging, the light from the object side is finally imaged on the imaging surface IMA5. According to the first to fifth paragraphs of [Specific Implementation], the fourth lens L54 is a biconvex lens with positive refractive power, made of plastic material, with its object side S51 being convex, and its image side S52 being convex, and both the object side S51 and the image side S52 being aspherical surfaces; the third lens L53 is a biconcave lens, with its object side S58 being concave; the object side S510 and the image side S511 of the filter OF5 are both planes; the object side S512 and the image side S513 of the protective glass CG5 are both planes; by using the above-mentioned lenses, the aperture ST5 and the design that satisfies at least one of the conditions (1) to (14), the imaging lens 5 can effectively improve the resolution and effectively correct the aberration.

[0095] Table 13 Fig.17 Table of relevant parameters of each lens of the imaging lens 5.

[0096] Table 13

[0097]

[0098]

[0099] Table 14 is a table of relevant parameters of the aspheric surface of the aspheric lens in Table 13.

[0100] Table 14

[0101]

[0102] Table 15 shows the relevant parameter values ​​of the imaging lens 5 of the fifth embodiment and the calculated values ​​corresponding to conditions (1) to (14). It can be seen from Table 15 that the imaging lens 5 of the fifth embodiment can meet the requirements of conditions (1) to (14).

[0103] Table 15

[0104]

[0105] Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. An imaging lens, It is characterized in that include: The first lens has a refractive power; The second lens has a refractive power; as well as The third lens has negative refractive power, and the third lens includes a concave surface facing the image side; wherein the first lens, the second lens and the third lens are arranged in sequence from the object side to the image side along the optical axis; The imaging lens satisfies at least one of the following conditions: -12.68mm≤R32-(f1+f3)≤-8.16mm; 11.01≤R12 / CT1≤18.51; 0.57≤(Air1+Air2) / BFL≤0.88; 2.47≤(f1+f2) / f≤2.99; 3.48≤TTL / (CT2+Air2)≤3.88; Wherein, f is the effective focal length of the imaging lens, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, R12 is the curvature radius of the image side surface of the first lens, R32 is the curvature radius of the image side surface of the third lens, CT1 is the distance from the object side surface of the first lens to the image side surface of the first lens on the optical axis, CT2 is the distance from the object side surface of the second lens to the image side surface of the second lens on the optical axis, TTL is the distance from the object side surface of the lens closest to the object side to the imaging surface on the optical axis, BFL is the distance from the image side surface of the third lens to the imaging surface on the optical axis, Air1 is the air distance from the image side surface of the first lens to the object side surface of the second lens on the optical axis, and Air2 is the air distance from the image side surface of the second lens to the object side surface of the third lens on the optical axis.

2. The imaging lens according to claim 1, It is characterized in that The first lens has positive refractive power, and the second lens has positive refractive power.

3. The imaging lens according to claim 2, It is characterized in that The first lens is a meniscus lens and includes a convex surface facing the object side and a concave surface facing the image side. The second lens is a meniscus lens and includes a concave surface facing the object side and a convex surface facing the image side.

4. The imaging lens according to claim 3, It is characterized in that The invention further comprises an aperture disposed between the object side and the first lens.

5. The imaging lens according to claim 4, It is characterized in that The third lens further includes a convex surface facing the object side.

6. The imaging lens according to claim 4, It is characterized in that The device further includes a fourth lens disposed between the object side and the aperture.

7. The imaging lens according to claim 6, It is characterized in that The fourth lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side.

8. The imaging lens according to claim 7, It is characterized in that The third lens is a biconcave lens and further includes another concave surface facing the object side.

9. The imaging lens according to any one of claims 1 to 8, It is characterized in that The invention further comprises a filter disposed between the third lens and the image side, wherein the imaging lens satisfies at least one of the following conditions: 0.2mm≤(R12 / R32)×Air3≤14.9mm; 3.03mm 2 ≤R21×(f3 / Nd1)≤27.41mm 2 ; 1.72≤(R21×R22) 0.5 / Air3≤9.25; 5mm≤(f1×(f2+f3)) / R21≤32mm; 5≤(R12+R21+R22) / CT3≤14.1; -20.64mm≤f3 / (Vd2 / Vd3)≤-1.29mm; <h2 style=";text-align:left;direction:ltr">0.6≤(f2 / R11)<h2 style=";text-align:left;direction:ltr"> 0.5 <h2 style=";text-align:left;direction:ltr"> ≤4.2; 0.58mm≤f2 / (CT3 / Air3)≤5.65mm; 3.09≤f / Air1≤4.71; Wherein, f is the effective focal length of the imaging lens, f1 is the effective focal length of the first lens, f2 is the effective focal length of the second lens, f3 is the effective focal length of the third lens, R11 is the curvature radius of the object side surface of the first lens, R12 is the curvature radius of the image side surface of the first lens, R21 is the curvature radius of the object side surface of the second lens, R22 is the curvature radius of the image side surface of the second lens, R32 is the curvature radius of the image side surface of the third lens, CT3 is the distance between the object side surface of the third lens and the image side surface of the third lens on the optical axis, Air1 is the air distance between the image side surface of the first lens and the object side surface of the second lens on the optical axis, Air3 is the air distance between the image side surface of the third lens and the object side surface of the filter on the optical axis, Nd1 is the refractive index of the first lens, Vd2 is the Abbe coefficient of the second lens, and Vd3 is the Abbe coefficient of the third lens.

10. The imaging lens according to claim 9, It is characterized in that The first lens is a spherical lens made of glass material, and the second lens, the third lens and the fourth lens are aspherical lenses made of plastic material.

Images