Small head optical lens and optical lens module

Abstract

The application discloses a small-head optical lens and an optical lens module, and belongs to the technical field of optical imaging. The optical lens comprises, in sequence from the object side to the image side along the optical axis, a first lens with positive refractive power, a second lens with negative refractive power, a third lens with positive refractive power, and a fourth lens with negative refractive power. The optical lens satisfies the following conditional expressions: 1.640 <= TTL / sumET <= 2.307; 1.202 <= (DT11+DT12) / CT1 <= 3.071. The first lens, the second lens, the third lens and the fourth lens are combined and arranged as described above, which is favorable for reducing the machining difficulty of the structure between the first lens and the fourth lens, making the overall structure of the optical lens more compact, facilitating the production, the manufacturing and the assembly of the optical lens, further favoring the miniaturization of the optical lens, reducing the volume, and being favorable for realizing the lens design of the small head.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging technology, and in particular to a small head optical lens and an optical lens module. BACKGROUND

[0002] In recent years, with the full screen of mobile phones and other electronic devices becoming mainstream, people's requirements for optical lenses are also getting higher and higher. However, as the market requires higher and higher pixels for lenses, the size of the lenses is also increasing, which makes it difficult to meet the market demand for full screen with a larger screen opening ratio. Therefore, the design of a small head lens can better meet the needs of consumers to obtain a relatively simple screen background and aesthetics, which is conducive to affecting the size of the screen opening and improving the screen ratio. At the same time, in order to ensure the light amount of the small head lens design, a smaller view point depth is required to meet the imaging quality of the optical lens.

[0003] Based on this, the present application proposes an optical lens that takes into account small head, small view point depth and high imaging quality, which meets the needs of improving user experience. SUMMARY

[0004] In order to overcome the defects of the prior art, the technical problem to be solved by the present application is to provide a small head optical lens and an optical lens module that meet the requirements of small head, small view point depth and high imaging quality.

[0005] In a first aspect, a small head optical lens includes, in order along an optical axis from an object side to an image side:

[0006] a first lens having a positive refractive power, an object side surface of which is convex near the optical axis, and an image side surface of which is convex near the optical axis;

[0007] a second lens having a negative refractive power, an object side surface of which is concave near the optical axis, and an image side surface of which is concave near the optical axis;

[0008] a third lens having a positive refractive power, an object side surface of which is concave near the optical axis;

[0009] a fourth lens having a negative refractive power, an object side surface of which is convex near the optical axis, and an image side surface of which is concave near the optical axis;

[0010] The first lens, the second lens, the third lens and the fourth lens are all aspherical lenses;

[0011] The small head optical lens satisfies the following conditional expressions:

[0012] 1.640≤TTL / ΣET≤2.307;

[0013] 1.202≤(DT11+DT12) / CT1≤3.071;

[0014] wherein TTL is the distance on the optical axis from the object side surface of the first lens to the image plane of the nosepiece optical lens; ∑ET is the sum of the edge thickness of all lenses in the optical imaging system; DT11 is the maximum effective radius of the object side surface of the first lens; DT12 is the maximum effective radius of the image side surface of the first lens; CT1 is the center thickness of the first lens on the optical axis.

[0015] Optionally, the nosepiece optical lens satisfies the following conditional expression:

[0016] 0.228≤Tan(Semi-FOV) / f1≤0.430;

[0017] wherein Semi-FOV is half of the maximum field of view angle of the nosepiece optical lens; f1 is the effective focal length of the first lens.

[0018] Optionally, the nosepiece optical lens satisfies the following conditional expression:

[0019] -1.552≤T12 / (SAG12+SAG21)≤-0.501;

[0020] wherein T12 is the air separation distance on the optical axis of the first lens and the second lens; SAG12 is the sag value of the image side surface of the first lens corresponding to the maximum field of view angle of the nosepiece optical lens; SAG21 is the sag value of the object side surface of the second lens corresponding to the maximum field of view angle of the nosepiece optical lens.

[0021] Optionally, the nosepiece optical lens satisfies the following conditional expression:

[0022] 1.008≤(f+BFL) / ImgH≤1.844;

[0023] wherein f is the total effective focal length of the nosepiece optical lens; BFL is the optical back focal length of the nosepiece optical lens; ImgH is the maximum image height of the nosepiece optical lens.

[0024] Optionally, the nosepiece optical lens satisfies the following conditional expression:

[0025] 4.441≤(f12+f23) / N2≤14.990;

[0026] wherein f12 is the combined focal length of the first lens and the second lens; f23 is the combined focal length of the second lens and the third lens; N2 is the refractive index of the second lens.

[0027] Optionally, the nosepiece optical lens satisfies the following conditional expression:

[0028] 7.700 ≤ (R11 - R12) / ET1 ≤ 37.933;

[0029] wherein R11 is a curvature radius of the object side surface of the first lens; R12 is a curvature radius of the image side surface of the first lens; ET1 is an edge thickness of the first lens.

[0030] Optionally, the small head optical lens satisfies the following conditional expression:

[0031] 3.912 ≤ DT42 / SAG42 ≤ 11.632;

[0032] wherein DT42 is a maximum effective radius of the image side surface of the fourth lens; SAG42 is a sag value of the image side surface of the fourth lens corresponding to a maximum field angle of the small head optical lens.

[0033] Optionally, the small head optical lens satisfies the following conditional expression:

[0034] 0.118 ≤ CT4 / (R41 + R42) ≤ 0.216;

[0035] wherein CT4 is a center thickness of the fourth lens; R41 is a curvature radius of the object side surface of the fourth lens; R42 is a curvature radius of the image side surface of the fourth lens.

[0036] In a second aspect, an optical lens module comprises the small head optical lens which takes into account small head, small depth of view point, and high imaging quality.

[0037] The present application has the following beneficial effects:

[0038] By reasonably distributing the ratio of the distance between the object side surface of the first lens and the imaging surface of the small head optical lens on the optical axis to the sum of the edge thicknesses of all lenses in the optical imaging system, the processing difficulty between the first lens and the fourth lens in structure is reduced, the overall structure of the small head optical lens is more compact, the production and assembly of the small head optical lens are facilitated, the production yield of the small head optical lens is improved, the volume is smaller, and the small head optical lens is further miniaturized.

[0039] By reasonably distributing the sum of the maximum effective radius of the object side surface of the first lens and the maximum effective radius of the image side surface of the first lens, and on this basis, the ratio of the center thickness of the first lens on the optical axis is constrained in a reasonable range, the stray light generated by the total reflection of light in the first lens is improved, the stray light and ghost generated by the system can be effectively reduced, and the imaging quality of the small head optical lens is improved. At the same time, the processing characteristics of the first lens are improved, the volume is reduced, and the small head lens design is facilitated.

[0040] Therefore, satisfying the above two conditions is beneficial to achieving at least one of the following: small head size, shallow depth of view, and high imaging quality. Attached Figure Description

[0041] Figure 1 This is a schematic structural diagram of the small-head optical lens of Embodiment 1 of this application;

[0042] Figures 2 to 5 The following are, in order, the spherical aberration curve, astigmatism curve, distortion diagram, and magnification chromatic aberration diagram of the small-head optical lens of Embodiment 1 of this application;

[0043] Figure 6 This is a schematic structural diagram of the small-head optical lens of Embodiment 2 of this application;

[0044] Figures 7 to 10 The following are, in order, the spherical aberration curve, astigmatism curve, distortion diagram, and magnification chromatic aberration diagram of the small-head optical lens of Embodiment 2 of this application;

[0045] Figure 11 This is a schematic structural diagram of the small-head optical lens of Embodiment 3 of this application;

[0046] Figures 12 to 15 The following are, in order, the spherical aberration curve, astigmatism curve, distortion diagram, and magnification chromatic aberration diagram of the small-head optical lens of Embodiment 3 of this application;

[0047] Figure 16 This is a schematic structural diagram of the small-head optical lens of Embodiment 4 of this application;

[0048] Figures 17 to 20 The following are, in order, the spherical aberration curve, astigmatism curve, distortion diagram, and magnification chromatic aberration diagram of the small-head optical lens of Embodiment 4 of this application;

[0049] Figure 21 This is a schematic structural diagram of the small-head optical lens of Embodiment 5 of this application;

[0050] Figures 22 to 25 The images shown are, in order, the spherical aberration curve, astigmatism curve, distortion diagram, and magnification chromatic aberration diagram of the small-head optical lens of Embodiment 5 of this application.

[0051] In the diagram: 100, small-head optical lens; 11, first lens; 12, second lens; 13, third lens; 14, fourth lens; 15, filter; 16, image sensor. Detailed Implementation

[0052] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0053] It should be noted that, for the convenience of understanding and description, the present application defines the representation form of the related parameters of the small head optical lens, for example, TTL represents the distance on the optical axis from the object side surface of the first lens to the imaging surface of the small head optical lens; ImgH represents the maximum image height of the small head optical lens, and the similar defined letters are only illustrative, and of course other forms can also be used, and the present application does not make any limitation.

[0054] It should also be noted that the units of the parameters related to the ratio in the following relationship are consistent, for example, the numerator is in millimeters (mm), and the denominator is also in millimeters (mm).

[0055] It should also be noted that the positive and negative of the radius of curvature represent the optical surface being convex to the object side or convex to the image side, when the optical surface (including the object side surface or the image side surface) is convex to the object side, the radius of curvature of the optical surface is positive; when the optical surface (including the object side surface or the image side surface) is convex to the image side, it is equivalent to the optical surface being concave to the object side, and the radius of curvature of the optical surface is negative.

[0056] It should also be noted that the shape of the lens, the degree of concave and convex of the object side surface and the image side surface in the drawings are only illustrative and do not cause any limitation to the present application. In the present application, the material of the lens can be resin, plastic, or glass. The lens includes spherical lenses and aspherical lenses. The lens can be a fixed focal length lens or a zoom lens, and can also be a standard lens, a short focal length lens, or a long focal length lens.

[0057] As shown in Figure 1 The small head optical lens 100 of the present application includes 4 lenses. For the convenience of description, the left side of the small head optical lens 100 is defined as the object side (hereinafter also referred to as the object side), the surface of the lens facing the object side can be referred to as the object side surface, and the object side surface can also be understood as the surface of the lens close to the object side. The right side of the small head optical lens 100 is the image side (hereinafter also referred to as the image side), the surface of the lens facing the image side can be referred to as the image side surface, and the image side surface can also be understood as the surface of the lens close to the image side. From the object side to the image side, the small head optical lens 100 of the present application includes, in order from the object side to the image side: a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14; A stop Stop can also be provided on the first lens 11. An image sensor 16 such as a CCD, a CMOS, etc. can also be provided after the fourth lens 14. A filter 15 such as a flat plate infrared cutoff filter, etc. can also be provided between the fourth lens 14 and the image sensor 16. The small head optical lens 100 will be described in detail below.

[0058] Referring to Figure 1 , Figure 1 The dashed line in the figure is used to represent the optical axis of the lens.

[0059] The small head optical lens 100 comprises, in sequence from the object side to the image side:

[0060] The first lens 11, the second lens 12, the third lens 13, and the fourth lens 14.

[0061] It should be understood that the above-mentioned “lenses of the small head optical lens” refer to the lenses that constitute the small head optical lens, which in the embodiments of the present application are the first lens, the second lens, the third lens, and the fourth lens.

[0062] Optionally, in the embodiments of the present application,

[0063] The first lens 11 can have a positive focal power, the object side S1 of the first lens 11 is convex near the optical axis; the image side S2 of the first lens 11 is convex near the optical axis;

[0064] The second lens 12 can have a negative focal power, the object side S3 of the second lens 12 is concave near the optical axis, and the image side S4 of the second lens 12 can be concave near the optical axis;

[0065] The third lens 13 can have a positive focal power, the object side S5 of the third lens 13 is concave near the optical axis, and the image side S6 of the third lens 13 is convex near the optical axis;

[0066] The fourth lens 14 can have a negative focal power, the object side S7 of the fourth lens 14 is convex near the optical axis, and the image side S8 of the fourth lens 14 is concave near the optical axis.

[0067] The small head optical lens 100 satisfies the following relationship:

[0068] 1.640≤TTL / ΣET≤2.307;

[0069] 1.202≤(DT11+DT12) / CT1≤3.071;

[0070] TTL / ΣET can be 1.640, 1.820, 1.904, 1.941, 2.307; by reasonably controlling the ratio of the distance from the object side of the first lens to the imaging surface of the small head optical lens on the optical axis to the sum of the edge thicknesses of all lenses in the optical imaging system, the processing difficulty in the structure between the first lens and the fourth lens is reduced, the overall structure of the small head optical lens is more compact, the production and assembly are facilitated, the production yield of the small head optical lens is improved, the volume is smaller, and further miniaturization of the small head optical lens is facilitated.

[0071] (DT11+DT12) / CT1 can be 1.202, 1.283, 1.765, 2.330, 3.071; by reasonably distributing the sum of the maximum effective radius of the object side of the first lens and the maximum effective radius of the image side of the first lens, and on this basis, the ratio of the center thickness of the first lens on the optical axis is constrained in a reasonable range, which is conducive to improving the stray light generated by the total reflection of light inside the first lens, can effectively reduce the stray light and ghost generated by the system, thereby improving the imaging quality of the small head optical lens. At the same time, the processing characteristics of the first lens are improved, the volume is reduced, and the small head lens design is facilitated.

[0072] Therefore, meeting the above two conditional expressions is conducive to at least achieving one of a small head, a small depth of view point, and high imaging quality.

[0073] In some implementations of the first aspect, the small head optical lens satisfies: 0.228≤Tan(Semi-FOV) / f1≤0.430; Tan(Semi-FOV) / f1 can be 0.228, 0.310, 0.315, 0.319, 0.430; by reasonably distributing the ratio of the tangent value of half of the maximum field of view angle of the small head optical lens to the effective focal length of the first lens, the optical effective range of the first lens can be expanded, the peripheral illumination of the small head optical lens image can be strengthened, the relative illumination of the small head optical lens imaging can be improved, and thus the imaging quality of the small head optical lens can be improved.

[0074] In some implementations of the first aspect, the small head optical lens satisfies: -1.552≤T12 / (SAG12+SAG21)≤-0.501; T12 / (SAG12+SAG21) can be -1.552, -1.442, -1.423, -0.920, -0.501; by reasonably distributing the sum of the sag SG value of the image side of the first lens corresponding to the maximum field of view angle of the small head optical lens and the sag SG value of the object side of the second lens corresponding to the maximum field of view angle of the small head optical lens, and on this basis, the ratio of the air gap distance of the first lens and the second lens on the optical axis is constrained in a reasonable range, the ghost generated by the reflection between the first lens and the second lens of the small head optical lens is improved, the spherical aberration, coma, and astigmatism generated by the system can be effectively reduced, and the imaging quality of the small head optical lens is improved.

[0075] In some implementations of the first aspect, the small head optical lens satisfies: 1.008≤(f+BFL) / ImgH≤1.844;

[0076] (f+BFL) / ImgH can be 1.008, 1.267, 1.308, 1.464, 1.844; by reasonably distributing the sum of the total effective focal length of the small head optical lens and the optical back focal length of the small head optical lens, and on this basis, the ratio of the maximum image height of the small head optical lens is constrained in a reasonable range, it is beneficial to match a more suitable image surface while controlling the total effective focal length and the optical back focal length of the small head optical lens, and meeting a larger depth of field range, improve the matching degree of the image sensor, thereby improving the imaging quality of the small head optical lens.

[0077] In some implementations of the first aspect, the small head optical lens satisfies: 4.441≤(f12+f23) / N2≤14.990; (f12+f23) / N2 can be 4.441, 5.318, 6.252, 6.634, 14.990; by reasonably distributing the sum of the combined focal length of the first lens and the second lens and the combined focal length of the second lens and the third lens, and on this basis, the ratio of the refractive index of the second lens is constrained in a reasonable range, it is beneficial to correct the system chromatic aberration of the small head optical lens, and improve the astigmatism and distortion, improve the resolution of the small head optical lens, and improve the imaging quality.

[0078] In some implementations of the first aspect, the small head optical lens satisfies: 7.700≤(R11-R12) / ET1≤37.933;

[0079] (R11-R12) / ET1 can be 7.700, 9.090, 28.374, 33.806, 37.933; by reasonably distributing the sum of the curvature radius of the object side of the first lens and the curvature radius of the image side of the first lens, and on this basis, the ratio of the edge thickness of the first lens is constrained in a reasonable range, it is beneficial to correct the field curvature of the small head optical lens, and improve the imaging quality, while constraining the edge thickness of the first lens, further conducive to realizing the small head.

[0080] In some implementations of the first aspect, the small head optical lens satisfies: 3.912≤DT42 / SAG42≤11.632; DT42 / SAG42 can be 3.912, 4.662, 5.655, 9.070, 11.632; by reasonably distributing the sum of the maximum effective radius of the image side of the fourth lens and the sag value of the image side of the fourth lens corresponding to the maximum field angle of the small head optical lens, it can effectively filter the stray light of the wide light beam passing through the image side of the fourth lens, better optimize the distortion of the small head optical lens, reduce the stray light and ghost image of the small head optical lens, and further improve the imaging quality of the small head optical lens.

[0081] In some implementations of the first aspect, the small-head optical lens satisfies: 0.118≤CT4 / (R41+R42)≤0.216; CT4 / (R41+R42) can be 0.118, 0.157, 0.181, 0.211, 0.216; by reasonably allocating the sum of the curvature radius of the object side of the fourth lens and the curvature radius of the image side of the fourth lens, the ratio of the central thickness of the fourth lens to the sum is constrained in a reasonable range, which is beneficial to improve the processing characteristics of the fourth lens, thereby improving the yield of the production of the small-head optical lens, better optimizing the distortion of the small-head optical lens, correcting the system chromatic aberration of the small-head optical lens, and improving the resolution of the small-head optical lens, thereby improving the imaging quality.

[0082] In a second aspect, an optical lens module is provided, which includes the small-head optical lens in any possible implementation manner of the first aspect, and can further include an image sensor, an analog-to-digital converter, an image processor, a memory, and the like, to realize the camera function of the small-head optical lens.

[0083] Some specific but non-limiting examples of the embodiments of the present application will be described in detail below with reference to the drawings. Figures 1 to 25 Some specific but non-limiting examples of the embodiments of the present application will be described in detail below with reference to the drawings.

[0084] It should be noted that the material of each lens of the small-head optical lens 100 is not specifically limited in the embodiments of the present application.

[0085] Embodiment one

[0086] The small-head optical lens 100 according to one embodiment of the present application includes, in order from the object side to the image side, a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14, as shown in FIG. 1. Figure 1

[0087] ​For convenience of description, in the following embodiments, Stop represents the surface of the diaphragm, S1 represents the object side surface of the first lens 11, S2 represents the image side surface of the first lens 11, S3 represents the object side surface of the second lens 12, S4 represents the image side surface of the second lens 12, S5 represents the object side surface of the third lens 13, S6 represents the image side surface of the third lens 13, S7 represents the object side surface of the fourth lens 14, S8 represents the image side surface of the fourth lens 14, S9 represents the object side surface of the filter, S10 represents the image side surface of the filter, and S11 represents the imaging surface. The first lens 11 has positive refractive power, the object side surface S1 of the first lens 11 is convex near the optical axis, and the image side surface S2 of the first lens 11 is convex near the optical axis. The second lens 12 has negative refractive power, the object side surface S3 of the second lens 12 is concave near the optical axis, and the image side surface S4 of the second lens 12 can be concave near the optical axis. The third lens 13 has positive refractive power, the object side surface S5 of the third lens 13 is concave near the optical axis, and the image side surface S6 of the third lens 13 is convex near the optical axis. The fourth lens 14 has negative refractive power, the object side surface S7 of the fourth lens 14 is convex near the optical axis, and the image side surface S8 of the fourth lens 14 is concave near the optical axis.

[0088] TTL represents the total optical length of the small head optical lens 100, ImgH represents the maximum image height of the small head optical lens 100, and EFL represents the effective focal length of the small head optical lens 100. Ai represents the correction coefficient of the non-spherical surface of the i-th order, i = 4, 6, 8, 10, 12, 14, 16, 18, 20, and k represents the conic coefficient.

[0089] According to the above relationship, Table 1 shows the effective focal length EFL, the maximum field of view Fov, the total optical length TTL, the aperture F value F.No, the surface type, the radius of curvature, the thickness, the material refractive index, and the conic coefficient of the small head optical lens 100 in Embodiment 1, wherein the units of the radius of curvature and the thickness are millimeters (mm), as shown in Table 1:

[0090] Table 1

[0091]

[0092] Table 2 shows the non-spherical surface coefficients of the small head optical lens 100 in Embodiment 1 of the present application, as shown in Table 2:

[0093] Table 2

[0094] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -2.206E-02 -2.835E-01 5.995E-01 7.246E+00 -6.386E+01 1.914E+02 -2.066E+02 0.000E+00 0.000E+00 S2 -3.415E-01 -2.515E-02 1.106E+00 -9.796E+00 3.721E+01 -6.894E+01 5.175E+01 0.000E+00 0.000E+00 S3 -1.006E+00 3.840E-01 -2.319E+00 3.294E+00 -2.130E+00 -1.483E+00 -2.449E+00 0.000E+00 0.000E+00 S4 -3.922E-01 3.266E-01 -6.643E-01 5.797E-01 -3.903E-02 -7.830E-01 6.405E-01 0.000E+00 0.000E+00 S5 -1.032E-01 6.649E-01 -1.361E+00 1.497E+00 -8.367E-01 1.494E-01 5.045E-02 0.000E+00 0.000E+00 S6 -4.678E-02 -2.422E-01 3.925E-01 -3.330E-01 2.715E-01 -1.068E-01 9.813E-03 0.000E+00 0.000E+00 S7 6.589E-02 -3.105E-01 3.030E-01 -1.216E-01 5.579E-03 3.830E-03 3.658E-03 -1.618E-03 9.220E-05 S8 -9.176E-02 2.808E-02 3.093E-04 -3.084E-03 5.710E-04 7.212E-06 3.047E-06 -9.661E-07 -2.774E-07

[0095] The non-curvature surface of each lens of the imaging optical lens 100 satisfies:

[0096]

[0097] wherein x is the distance from the vertex of the aspheric surface at a position along the optical axis at a height h; c is the paraxial curvature of the aspheric surface, c = 1 / r (i.e., the paraxial curvature c is the inverse of the curvature radius r in Table 1 above); k is the conic constant (given in Table 1 above); and Ai is the correction coefficient of the i-th aspheric surface, the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of each lens surface S1-S8 are shown in Table 2.

[0098] It should be understood that the aspheric surface of each lens in the small head optical lens 100 can use the aspheric surface shown in the above aspheric surface formula, or other aspheric surface formula, which is not limited in the present application.

[0099] The design data of the small head optical lens 100 according to the first embodiment of the present application is given above, with an effective focal length EFL of 2.322 mm, a maximum field of view Fov of 88.537 degrees, an optical total length TTL of 3.987 mm, and an aperture F value F.No of 2.262.

[0100] In one embodiment provided by the present application, TTL / ∑ET = 1.640.

[0101] In one embodiment provided by the present application, (DT11+DT12) / CT1 = 1.202.

[0102] In one embodiment provided by the present application, Tan(semi-FOV) / f1 = 0.319.

[0103] In one embodiment provided by the present application, T12 / (SAG12+SAG21) = -0.501.

[0104] In one embodiment provided by the present application, (f+BFL) / ImgH = 1.308.

[0105] In one embodiment provided by the present application, (f12+f23) / N2 = 5.318.

[0106] In one embodiment provided by the present application, (R11-R12) / ET1 = 9.090.

[0107] In one embodiment provided by the present application, DT42 / SAG42 = 4.622.

[0108] In one embodiment provided by the present application, CT4 / (R41+R42) = 0.181.

[0109] Figures 2 to 5 The optical performance of the small head optical lens 100 designed in the lens combination manner of the first embodiment is described.

[0110] In the first embodiment, the small head optical lens meets the requirements of small head, small depth of view, and high imaging quality.

[0111] The second embodiment

[0112] The small head optical lens 100 of one embodiment of the present application includes, in order from the object side to the image side, a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14, as shown in FIG. 1. Figure 6

[0113] For convenience of description, in the following embodiments, Stop represents the surface of the diaphragm, S1 represents the object side surface of the first lens 11, S2 represents the image side surface of the first lens 11, S3 represents the object side surface of the second lens 12, S4 represents the image side surface of the second lens 12, S5 represents the object side surface of the third lens 13, S6 represents the image side surface of the third lens 13, S7 represents the object side surface of the fourth lens 14, S8 represents the image side surface of the fourth lens 14, S9 represents the object side surface of the filter, S10 represents the image side surface of the filter, and S11 represents the imaging surface. The first lens 11 has positive refractive power, the object side surface S1 of the first lens 11 is convex near the optical axis, and the image side surface S2 of the first lens 11 is convex near the optical axis. The second lens 12 has negative refractive power, the object side surface S3 of the second lens 12 is concave near the optical axis, and the image side surface S4 of the second lens 12 can be concave near the optical axis. The third lens 13 has positive refractive power, the object side surface S5 of the third lens 13 is concave near the optical axis, and the image side surface S6 of the third lens 13 is convex near the optical axis. The fourth lens 14 has negative refractive power, the object side surface S7 of the fourth lens 14 is convex near the optical axis, and the image side surface S8 of the fourth lens 14 is concave near the optical axis.

[0114] The total optical length of the small head optical lens 100 is denoted by TTL, the maximum image height of the small head optical lens 100 is denoted by ImgH, and the effective focal length of the small head optical lens 100 is denoted by EFL. The correction coefficient of the non-spherical surface of the i-th order is denoted by Ai, i = 4, 6, 8, 10, 12, 14, 16, 18, 20, and the conic coefficient is denoted by k.

[0115] According to the above relationship, Table 3 shows the effective focal length EFL, the maximum field of view Fov, the total optical length TTL, the aperture F value F.No, the surface type, the radius of curvature, the thickness, the material refractive index, and the conic coefficient of the small head optical lens 100 in the second embodiment, where the radius of curvature and the thickness are both in millimeters (mm), as shown in Table 3:

[0116] Table 3

[0117] ​

[0118] Table 4 shows the aspherical coefficients of the small head optical lens 100 of Embodiment Two of the present application, as shown in Table 4:

[0119] Table 4

[0120] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -2.036E-02 -1.816E-01 -1.883E-01 7.513E+00 -4.004E+01 8.483E+01 -6.540E+01 0.000E+00 0.000E+00 S2 -2.587E-01 -7.144E-02 1.273E+00 -1.070E+01 3.660E+01 -6.036E+01 3.995E+01 0.000E+00 0.000E+00 S3 -6.207E-01 2.434E-01 -1.253E+00 1.467E+00 9.828E-02 6.760E-01 -5.993E-01 0.000E+00 0.000E+00 S4 -2.307E-01 1.282E-01 -4.029E-01 5.239E-01 4.238E-03 -5.158E-01 3.373E-01 0.000E+00 0.000E+00 S5 -1.046E-01 5.151E-01 -1.180E+00 1.500E+00 -8.733E-01 1.456E-01 8.759E-02 0.000E+00 0.000E+00 S6 -7.985E-02 -2.218E-01 3.322E-01 -3.002E-01 2.490E-01 -1.177E-01 3.646E-02 0.000E+00 0.000E+00 S7 5.588E-02 -3.236E-01 3.075E-01 -1.282E-01 7.915E-03 5.360E-03 3.250E-03 -2.369E-03 3.842E-04 S8 -1.181E-01 2.695E-02 6.267E-04 -3.241E-03 6.251E-04 -3.380E-06 -1.422E-09 1.276E-06 -8.826E-07

[0121] Wherein, the aspherical surface of each lens of the camera optical lens 100 satisfies:

[0122]

[0123] Wherein, x is the sag of the aspherical surface at a height of h along the optical axis; c is the paraxial curvature of the aspherical surface, c = 1 / r (i.e., the paraxial curvature c is the inverse of the curvature radius r in Table 3 above); k is the conic coefficient (given in Table 3 above); Ai is the correction coefficient of the i-th order of the aspherical surface, the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 of each lens surface S1-S8 are shown in Table 4.

[0124] It should be understood that the aspherical surface of each lens in the small head optical lens 100 can use the aspherical surface shown in the above aspherical surface formula, or other aspherical surface formula, which is not limited in the present application.

[0125] The above gives the design data of the small head optical lens 100 of Embodiment Two of the present application, the effective focal length EFL is 2.855mm, the maximum field of view Fov is 76.696 degrees, the total optical length TTL is 4.151mm, and the aperture F value F.No is 2.251.

[0126] In one embodiment provided by the present application, TTL / ∑ET = 2.307.

[0127] In one embodiment provided by the present application, (DT11+DT12) / CT1 = 1.765.

[0128] In one embodiment provided by the present application, Tan(semi-FOV) / f1 = 0.228.

[0129] In one embodiment provided by the present application, T12 / (SAG12+SAG21) = -1.552.

[0130] In one embodiment provided by the present application, (f+BFL) / ImgH = 1.844.

[0131] In one embodiment provided by the present application, (f12+f23) / N2 = 6.634.

[0132] In an embodiment provided in the present application, (R11-R12) / ET1=33.806.

[0133] In an embodiment provided in the present application, DT42 / SAG42=11.632.

[0134] In an embodiment provided in the present application, CT4 / (R41+R42)=0.157.

[0135] Figures 7 to 10 The optical performance of the small head optical lens 100 designed in the lens combination manner of embodiment two is described.

[0136] In embodiment two, the small head optical lens meets the requirements of small head, small depth of view point, and high imaging quality.

[0137] Embodiment three

[0138] The small head optical lens 100 in an embodiment of the present application sequentially comprises, from the object side to the image side: a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14, as shown in FIG. 1. Figure 11

[0139] For convenience of description, in the following embodiments, Stop represents the surface of the diaphragm, S1 represents the object side surface of the first lens 11, S2 represents the image side surface of the first lens 11, S3 represents the object side surface of the second lens 12, S4 represents the image side surface of the second lens 12, S5 represents the object side surface of the third lens 13, S6 represents the image side surface of the third lens 13, S7 represents the object side surface of the fourth lens 14, S8 represents the image side surface of the fourth lens 14, S9 represents the object side surface of the filter, S10 represents the image side surface of the filter, and S11 represents the imaging surface. The first lens 11 has positive refractive power, the object side surface S1 of the first lens 11 is convex near the optical axis, the image side surface S2 of the first lens 11 is convex near the optical axis, the second lens 12 has negative refractive power, the object side surface S3 of the second lens 12 is concave near the optical axis, and the image side surface S4 of the second lens 12 can be concave near the optical axis, the third lens 13 has positive refractive power, the object side surface S5 of the third lens 13 is concave near the optical axis, and the image side surface S6 of the third lens 13 is convex near the optical axis, and the fourth lens 14 has negative refractive power, the object side surface S7 of the fourth lens 14 is convex near the optical axis, and the image side surface S8 of the fourth lens 14 is concave near the optical axis.

[0140] TTL represents the total optical length of the small head optical lens 100, ImgH represents the maximum image height of the small head optical lens 100, EFL represents the effective focal length of the small head optical lens 100, Ai represents the correction coefficient of the non-spherical surface of the i-th order, i=4, 6, 8, 10, 12, 14, 16, 18, 20, and k represents the conic coefficient.​

[0141] According to the above relationship, Table 5 shows the effective focal length EFL, the maximum field of view Fov, the total optical length TTL, the aperture F value F.No, the surface type, the radius of curvature, the thickness, the material refractive index and the conic constant of the small head optical lens 100 in Example Three, wherein the units of the radius of curvature and the thickness are millimeters (mm), as shown in Table 5:

[0142] Table 5

[0143]

[0144] Table 6 shows the aspheric coefficients of the small head optical lens 100 in Example Three of the present application, as shown in Table 6:

[0145] Table 6

[0146] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -1.462E-01 -8.859E-01 -1.966E-01 1.559E+01 -1.210E+02 9.368E+01 6.867E+02 0.000E+00 0.000E+00 S2 -4.840E-01 -2.790E-01 -7.794E-01 -8.014E+00 5.154E+01 -4.496E+01 -3.838E+00 0.000E+00 0.000E+00 S3 -1.022E+00 1.529E-01 -2.654E+00 3.842E+00 1.474E+01 6.890E+01 -1.774E+02 0.000E+00 0.000E+00 S4 -4.211E-01 4.182E-01 -4.104E-01 8.707E-01 -2.641E-02 -7.058E-01 1.001E-02 0.000E+00 0.000E+00 S5 -1.049E-01 7.343E-01 -1.340E+00 1.475E+00 -7.891E-01 1.738E-01 -2.298E-03 0.000E+00 0.000E+00 S6 -1.236E-01 -2.821E-01 4.350E-01 -2.851E-01 2.897E-01 -7.945E-02 6.623E-02 0.000E+00 0.000E+00 S7 4.404E-03 -3.426E-01 2.951E-01 -1.158E-01 7.631E-03 3.645E-03 3.764E-03 -1.546E-03 -2.171E-04 S8 -1.095E-01 2.825E-02 6.529E-04 -2.961E-03 6.269E-04 1.365E-05 -7.568E-06 -2.024E-06 1.855E-07

[0147] wherein the aspheric surface of each lens of the imaging optical lens 100 satisfies:

[0148]

[0149] wherein x is the distance sag of the aspheric surface at a height h along the optical axis from the vertex of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / r (i.e., the paraxial curvature c is the inverse of the radius of curvature r in Table 5 above); k is the conic constant (given in Table 5 above); Ai is the correction coefficient of the i-th order of the aspheric surface, the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18 and A20 of each lens surface S1-S8 are shown in Table 6.

[0150] It should be understood that the aspheric surface of each lens in the small head optical lens 100 can use the aspheric surface shown in the above aspheric surface formula, or other aspheric surface formula, which is not limited in the present application.

[0151] The above gives the design data of the small head optical lens 100 in Example Three of the present application, the effective focal length EFL is 1.790 mm, the maximum field of view Fov is 103.375 degrees, the total optical length TTL is 3.011 mm, and the aperture F value F.No is 2.280.

[0152] In one embodiment provided by the present application, TTL / ∑ET = 1.904.

[0153] In one embodiment provided by the present application, (DT11+DT12) / CT1 = 3.071.

[0154] In one embodiment provided by the present application, Tan(semi-FOV) / f1 = 0.430.

[0155] In an embodiment provided in the present application, T12 / (SAG12+SAG21) = -1.442.

[0156] In an embodiment provided in the present application, (f+BFL) / ImgH = 1.008.

[0157] In an embodiment provided in the present application, (f12+f23) / N2 = 6.252.

[0158] In an embodiment provided in the present application, (R11-R12) / ET1 = 37.933.

[0159] In an embodiment provided in the present application, DT42 / SAG42 = 5.655.

[0160] In an embodiment provided in the present application, CT4 / (R41+R42) = 0.211.

[0161] Figures 12 to 15 The optical performance of the small-head optical lens 100 designed in the lens combination manner of embodiment three is described.

[0162] In embodiment three, the small-head optical lens meets the requirements of small head, small view point depth, and high imaging quality.

[0163] Embodiment four

[0164] The small-head optical lens 100 in an embodiment of the present application sequentially includes, from the object side to the image side: a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14, as shown in Figure 16 .

[0165] For convenience of description, in the following embodiments, Stop represents the surface of the diaphragm, S1 represents the object side surface of the first lens 11, S2 represents the image side surface of the first lens 11, S3 represents the object side surface of the second lens 12, S4 represents the image side surface of the second lens 12, S5 represents the object side surface of the third lens 13, S6 represents the image side surface of the third lens 13, S7 represents the object side surface of the fourth lens 14, S8 represents the image side surface of the fourth lens 14, S9 represents the object side surface of the filter, S10 represents the image side surface of the filter, and S11 represents the imaging surface. The first lens 11 has positive refractive power, the object side surface S1 of the first lens 11 is convex near the optical axis, and the image side surface S2 of the first lens 11 is convex near the optical axis. The second lens 12 has negative refractive power, the object side surface S3 of the second lens 12 is concave near the optical axis, and the image side surface S4 of the second lens 12 can be concave near the optical axis. The third lens 13 has positive refractive power, the object side surface S5 of the third lens 13 is concave near the optical axis, and the image side surface S6 of the third lens 13 is convex near the optical axis. The fourth lens 14 has negative refractive power, the object side surface S7 of the fourth lens 14 is convex near the optical axis, and the image side surface S8 of the fourth lens 14 is concave near the optical axis.

[0166] TTL represents the total optical length of the small head optical lens 100, ImgH represents the maximum image height of the small head optical lens 100, and EFL represents the effective focal length of the small head optical lens 100. Ai represents the correction coefficient of the non-spherical surface of the i-th order, i = 4, 6, 8, 10, 12, 14, 16, 18, 20, and k represents the conic coefficient.

[0167] According to the above relationship, Table 7 shows the effective focal length EFL, the maximum field of view Fov, the total optical length TTL, the aperture F value F.No, the surface type, the radius of curvature, the thickness, the material refractive index, and the conic coefficient of the small head optical lens 100 in Example Four, wherein the units of the radius of curvature and the thickness are millimeters (mm), as shown in Table 7:

[0168] Table 7

[0169]

[0170] Table 8 shows the non-spherical surface coefficients of the small head optical lens 100 in Example Four of the present application, as shown in Table 8:

[0171] Table 8

[0172] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -5.631E-02 -3.545E-01 2.187E-01 5.666E+00 -6.032E+01 2.025E+02 -2.419E+02 0.000E+00 0.000E+00 S2 -3.892E-01 1.091E-01 -2.166E-01 -1.096E+01 4.444E+01 -5.407E+01 1.412E+01 0.000E+00 0.000E+00 S3 -9.061E-01 3.378E-01 -2.722E+00 3.266E+00 -4.208E-01 2.795E+00 1.399E+01 0.000E+00 0.000E+00 S4 -3.609E-01 3.469E-01 -7.128E-01 7.319E-01 1.802E-01 -7.845E-01 4.493E-01 0.000E+00 0.000E+00 S5 -1.466E-01 6.113E-01 -1.239E+00 1.565E+00 -9.018E-01 1.135E-01 6.174E-02 0.000E+00 0.000E+00 S6 -8.168E-02 -2.918E-01 4.029E-01 -2.945E-01 2.810E-01 -1.077E-01 1.249E-02 0.000E+00 0.000E+00 S7 5.190E-02 -3.181E-01 3.019E-01 -1.216E-01 5.034E-03 3.540E-03 4.036E-03 -1.343E-03 -6.008E-05 S8 -9.752E-02 2.715E-02 3.430E-04 -2.949E-03 6.263E-04 1.601E-05 -6.480E-06 -1.827E-06 1.197E-07

[0173] wherein the non-curvature surface of each lens of the imaging optical lens 100 satisfies:

[0174]

[0175] wherein x is the distance from the vertex of the aspheric surface at a position along the optical axis at a height h; c is the paraxial curvature of the aspheric surface, c = 1 / r (i.e., the paraxial curvature c is the inverse of the radius of curvature r in Table 7 above); k is the conic constant (given in Table 7 above); and Ai is the correction coefficient of the i-th aspheric surface, the high-order term coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of each lens surface S1-S8 are shown in Table 8.

[0176] It should be understood that the aspheric surface of each lens in the small head optical lens 100 can use the aspheric surface shown in the aspheric surface formula described above, or other aspheric surface formulas, which are not limited in the present application.

[0177] The design data of the small head optical lens 100 of the fourth embodiment of the present application is given above, with an effective focal length EFL of 2.133 mm, a maximum field of view Fov of 93.406 degrees, an optical total length TTL of 3.564 mm, and an aperture F value F.No of 2.276.

[0178] In an embodiment provided by the present application, TTL / ∑ET = 1.941.

[0179] In an embodiment provided by the present application, (DT11+DT12) / CT1 = 2.330.

[0180] In an embodiment provided by the present application, Tan(semi-FOV) / f1 = 0.315.

[0181] In an embodiment provided by the present application, T12 / (SAG12+SAG21) = -1.423.

[0182] In an embodiment provided by the present application, (f+BFL) / ImgH = 1.267.

[0183] In an embodiment provided by the present application, (f12+f23) / N2 = 14.990.

[0184] In an embodiment provided by the present application, (R11-R12) / ET1 = 28.374.

[0185] In an embodiment provided by the present application, DT42 / SAG42 = 3.912.

[0186] In an embodiment provided by the present application, CT4 / (R41+R42) = 0.216.

[0187] Figures 17 to 20 The optical performance of the small head optical lens 100 designed in the lens combination manner of the fourth embodiment is described.

[0188] In the embodiment four, the small head optical lens meets the requirements of small head, small depth of view point, and high imaging quality.

[0189] Embodiment five

[0190] The small head optical lens 100 in one embodiment of the present application comprises, in order from the object side to the image side, a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14, as shown in FIG. 1. Figure 21

[0191] For convenience of description, in the following embodiments, Stop represents the surface of the diaphragm, S1 represents the object side surface of the first lens 11, S2 represents the image side surface of the first lens 11, S3 represents the object side surface of the second lens 12, S4 represents the image side surface of the second lens 12, S5 represents the object side surface of the third lens 13, S6 represents the image side surface of the third lens 13, S7 represents the object side surface of the fourth lens 14, S8 represents the image side surface of the fourth lens 14, S9 represents the object side surface of the filter, S10 represents the image side surface of the filter, and S11 represents the imaging surface. The first lens 11 has positive refractive power, the object side surface S1 of the first lens 11 is convex near the optical axis, and the image side surface S2 of the first lens 11 is convex near the optical axis. The second lens 12 has negative refractive power, the object side surface S3 of the second lens 12 is concave near the optical axis, and the image side surface S4 of the second lens 12 can be concave near the optical axis. The third lens 13 has positive refractive power, the object side surface S5 of the third lens 13 is concave near the optical axis, and the image side surface S6 of the third lens 13 is convex near the optical axis. The fourth lens 14 has negative refractive power, the object side surface S7 of the fourth lens 14 is convex near the optical axis, and the image side surface S8 of the fourth lens 14 is concave near the optical axis.

[0192] The total optical length of the small head optical lens 100 is represented by TTL, the maximum image height of the small head optical lens 100 is represented by ImgH, and the effective focal length of the small head optical lens 100 is represented by EFL. The correction coefficient of the non-spherical surface of the i-th order is represented by Ai, i = 4, 6, 8, 10, 12, 14, 16, 18, 20, and the conic coefficient is represented by k.

[0193] According to the above relationship, Table 9 shows the effective focal length EFL, the maximum field of view Fov, the total optical length TTL, the aperture F value F.No, the surface type, the radius of curvature, the thickness, the material refractive index, and the conic coefficient of the small head optical lens 100 in the embodiment five, wherein the units of the radius of curvature and the thickness are millimeters (mm), as shown in Table 9:

[0194] Table 9

[0195] ​

[0196]

[0197] Table 10 shows the aspherical coefficients of the small head optical lens 100 of the fifth embodiment of the present application, as shown in Table 10:

[0198] Table 10

[0199] Face number A4 A6 A8 A10 A12 A14 A16 A18 A20 S1 -3.257E-02 -3.163E-01 2.973E-01 1.028E+01 -6.628E+01 1.570E+02 -1.333E+02 0.000E+00 0.000E+00 S2 -2.840E-01 2.270E-01 1.185E+00 -1.079E+01 3.675E+01 -5.760E+01 3.530E+01 0.000E+00 0.000E+00 S3 -7.838E-01 9.691E-01 -2.011E+00 3.995E+00 -2.408E+00 -3.829E+00 4.932E+00 0.000E+00 0.000E+00 S4 -3.877E-01 4.777E-01 -5.522E-01 4.475E-01 6.289E-02 -5.675E-01 3.621E-01 0.000E+00 0.000E+00 S5 -1.993E-01 4.367E-01 -1.157E+00 1.535E+00 -9.383E-01 8.021E-02 1.102E-01 0.000E+00 0.000E+00 S6 -3.169E-02 -2.229E-01 3.592E-01 -3.691E-01 2.564E-01 -1.038E-01 2.140E-02 0.000E+00 0.000E+00 S7 6.567E-02 -2.998E-01 2.876E-01 -1.138E-01 8.881E-03 2.726E-03 2.752E-03 -1.666E-03 2.347E-04 S8 -8.038E-02 1.574E-02 4.257E-03 -3.202E-03 4.744E-04 1.178E-05 -2.360E-06 -7.575E-07 3.536E-09

[0200] wherein the aspheric surface of each lens of the camera optical lens 100 satisfies:

[0201]

[0202] wherein x is the sagittal height of the aspheric surface at a position along the optical axis at a height h from the vertex of the aspheric surface; c is the paraxial curvature of the aspheric surface, c = 1 / r (i.e., the paraxial curvature c is the inverse of the curvature radius r in Table 9 above); k is the conic coefficient (given in Table 9 above); Ai is the correction coefficient of the i-th order of the aspheric surface, the high-order coefficients A4, A6, A8, A10, A12, A14, A16, A18, and A20 of each lens surface S1-S8 are shown in Table 10.

[0203] It should be understood that the aspheric surface of each lens in the small head optical lens 100 can use the aspheric surface shown in the above aspheric surface formula, or other aspheric surface formula, which is not limited in the present application.

[0204] The above gives the design data of the small head optical lens 100 of the fifth embodiment of the present application, the effective focal length EFL is 2.667 mm, the maximum field of view Fov is 80.528 degrees, the total optical length TTL is 4.146 mm, and the aperture F value F.No is 2.252.

[0205] In one embodiment provided by the present application, TTL / ∑ET = 1.820.

[0206] In one embodiment provided by the present application, (DT11+DT12) / CT1 = 1.283.

[0207] In one embodiment provided by the present application, Tan(semi-FOV) / f1 = 0.310.

[0208] In one embodiment provided by the present application, T12 / (SAG12+SAG21) = -0.920.

[0209] In one embodiment provided by the present application, (f+BFL) / ImgH = 1.464.

[0210] In an embodiment provided by the present application, (f12+f23) / N2=4.441.

[0211] In an embodiment provided by the present application, (R11-R12) / ET1=7.700.

[0212] In an embodiment provided by the present application, DT42 / SAG42=9.070.

[0213] In an embodiment provided by the present application, CT4 / (R41+R42)=0.118.

[0214] Figures 22 to 25 The optical performance of the small head optical lens 100 designed in the lens combination manner of embodiment five is described.

[0215] In embodiment five, the small head optical lens meets the requirements of small head, small depth of view point, and high imaging quality.

[0216] In addition, the corresponding TTL / ΣET ratio, (DT11+DT12) / CT1 ratio, Tan(semi-FOV) / f1 ratio, T12 / (SAG12+SAG21) ratio, (f+BFL) / ImgH ratio, (f12+f23) / N2 ratio, (R11-R12) / ET1 ratio, DT42 / SAG42 ratio, and CT4 / (R41+R42) ratio of embodiment one to embodiment five are shown in Table 11:

[0217] Table 11

[0218] Conditional expression Example 1 Example 2 Example 3 Example 4 Example 5 TTL / ∑ET 1.640 2.307 1.904 1.941 1.820 (DT11+DT12) / CT1 1.202 1.765 3.071 2.330 1.283 Tan(semi-FOV) / f1 0.319 0.228 0.430 0.315 0.310 T12 / (SAG12+SAG21) -0.501 -1.552 -1.442 -1.423 -0.920 (f+BFL) / ImgH 1.308 1.844 1.008 1.267 1.464 (f12+f23) / N2 5.318 6.634 6.252 14.990 4.441 (R11-R12) / ET1 9.090 33.806 37.933 28.374 7.700 DT42 / SAG42 4.622 11.632 5.655 3.912 9.070 CT4 / (R41+R42) 0.181 0.157 0.211 0.216 0.118

[0219] The present application is described by preferred embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present application. The present application is not limited by the specific embodiments disclosed herein, and other embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. A small head optical lens characterized by, In order from the object side to the image side along the optical axis, the small head optical lens comprises: a first lens, a second lens, a third lens and a fourth lens, the number of lenses with optical power in the small head optical lens is 4, and parameters of the small head optical lens are as follows: Wherein, the units of the radius of curvature and the thickness are millimeters; EFL represents the effective focal length of the small head optical lens, Fov represents the maximum field of view angle of the small head optical lens, TTL represents the total optical length of the small head optical lens, F.No represents the aperture F value of the small head optical lens, S1 represents the object side surface of the first lens, S2 represents the image side surface of the first lens, S3 represents the object side surface of the second lens, S4 represents the image side surface of the second lens, S5 represents the object side surface of the third lens, S6 represents the image side surface of the third lens, S7 represents the object side surface of the fourth lens, and S8 represents the image side surface of the fourth lens.

2. A small head optical lens characterized by, In order from the object side to the image side along the optical axis, the small head optical lens comprises: a first lens, a second lens, a third lens and a fourth lens, the number of lenses with optical power in the small head optical lens is 4, and parameters of the small head optical lens are as follows: Wherein, the units of the radius of curvature and the thickness are millimeters; EFL represents the effective focal length of the small head optical lens, Fov represents the maximum field of view angle of the small head optical lens, TTL represents the total optical length of the small head optical lens, F.No represents the aperture F value of the small head optical lens, S1 represents the object side surface of the first lens, S2 represents the image side surface of the first lens, S3 represents the object side surface of the second lens, S4 represents the image side surface of the second lens, S5 represents the object side surface of the third lens, S6 represents the image side surface of the third lens, S7 represents the object side surface of the fourth lens, and S8 represents the image side surface of the fourth lens.

3. A small head optical lens characterized by, In order from the object side to the image side along the optical axis, the small head optical lens comprises: a first lens, a second lens, a third lens and a fourth lens, the number of lenses with optical power in the small head optical lens is 4, and parameters of the small head optical lens are as follows: Wherein, the units of the radius of curvature and the thickness are millimeters; EFL represents the effective focal length of the small head optical lens, Fov represents the maximum field of view angle of the small head optical lens, TTL represents the total optical length of the small head optical lens, F.No represents the aperture F value of the small head optical lens, S1 represents the object side surface of the first lens, S2 represents the image side surface of the first lens, S3 represents the object side surface of the second lens, S4 represents the image side surface of the second lens, S5 represents the object side surface of the third lens, S6 represents the image side surface of the third lens, S7 represents the object side surface of the fourth lens, and S8 represents the image side surface of the fourth lens.

4. A small head optical lens characterized by, In order from the object side to the image side along the optical axis, the small head optical lens comprises: a first lens, a second lens, a third lens and a fourth lens, the number of lenses with optical power in the small head optical lens is 4, and parameters of the small head optical lens are as follows: Wherein, the units of the radius of curvature and thickness are millimeters; EFL represents the effective focal length of the small head optical lens, Fov represents the maximum field of view angle of the small head optical lens, TTL represents the total optical length of the small head optical lens, F.No represents the aperture F value of the small head optical lens, S1 represents the object side of the first lens, S2 represents the image side of the first lens, S3 represents the object side of the second lens, S4 represents the image side of the second lens, S5 represents the object side of the third lens, S6 represents the image side of the third lens, S7 represents the object side of the fourth lens, and S8 represents the image side of the fourth lens.

5. A small head optical lens characterized by, In order from the object side to the image side along the optical axis, the small head optical lens comprises: a first lens, a second lens, a third lens and a fourth lens, the number of lenses with optical power in the small head optical lens is 4, and parameters of the small head optical lens are as follows: Wherein, the units of the radius of curvature and thickness are millimeters; EFL represents the effective focal length of the small head optical lens, Fov represents the maximum field of view angle of the small head optical lens, TTL represents the total optical length of the small head optical lens, F.No represents the aperture F value of the small head optical lens, S1 represents the object side of the first lens, S2 represents the image side of the first lens, S3 represents the object side of the second lens, S4 represents the image side of the second lens, S5 represents the object side of the third lens, S6 represents the image side of the third lens, S7 represents the object side of the fourth lens, and S8 represents the image side of the fourth lens.

6. An optical lens module characterized in that, The small head optical lens as claimed in any one of claims 1 to 5. The small head optical lens as claimed in any one of claims 1 to 5.

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