Six-piece optical lens group for police law enforcement recorder

Abstract

The invention discloses a six-piece optical lens group for a police law enforcement recorder, which comprises six lenses, the zoom lens sequentially comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with positive focal power, an aperture, a fourth lens with negative focal power, a fifth lens with positive focal power and a sixth lens with positive focal power from an object side to an image side, the optical lens group satisfies the following conditional expressions:-39lt; r12 / CT 6lt; -5; 4.5 lt; aT34 * TTLlt; 8; 5.4 lt, 5.4 lt; and TTL / Imght is carried out. 5.7). On the basis of ensuring the imaging quality, the total length of the optical lens group is controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of optical lenses, and particularly to a six-piece optical lens group for a police law enforcement recorder. Background Art

[0002] A law enforcement recorder, also known as a on-site law enforcement recorder or a single-officer law enforcement video and audio recorder, is a portable intelligent device that integrates functions such as real-time video and audio recording, photographing, and voice recording. It can record the on-site situation during law enforcement in various environments and provide important on-site evidence. In recent years, with the continuous progress of technology and the expansion of application scenarios, the market for police law enforcement recorders has shown a steady growth trend. In the future, law enforcement recorders will become more intelligent and data-driven, integrating artificial intelligence technology and having functions such as automatic recognition and analysis, such as facial recognition and speech-to-text conversion, to improve the efficiency of on-site judgment and post-analysis. In the actual application process, how to control the total length of the lens on the basis of ensuring imaging quality so as to minimize the volume of the device is a direction that those skilled in the art need to continuously improve. Summary of the Invention

[0003] In view of the above problems, the present invention provides a six-piece optical lens group for a police law enforcement recorder, which controls the total length of the optical lens group on the basis of ensuring imaging quality.

[0004] To achieve the above object, the present invention is solved by the following technical solutions: A six-piece optical lens group for a police law enforcement recorder includes six lenses, which sequentially include from the object side to the image side: a first lens with negative optical power, a second lens with positive optical power, a third lens with positive optical power, an aperture, a fourth lens with negative optical power, a fifth lens with positive optical power, and a sixth lens with positive optical power;

[0005] The optical lens group satisfies the following conditional expressions:

[0006] -39 < R12 / CT6 < -5; where R12 is the curvature radius of the image side of the sixth lens, and CT6 is the thickness of the sixth lens on the optical axis;

[0007] 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens and the fourth lens, and TTL is the total lens length;

[0008] 5.4 < TTL / Imgh < 5.7; where Imgh is the maximum image height of the optical lens group on the imaging plane.

[0009] Another solution provided by the present invention is a six-piece optical lens group for a police law enforcement recorder, including six lenses, which sequentially include from the object side to the image side: a first lens with a negative optical power, a second lens with a positive optical power, a third lens with a positive optical power, an aperture, a fourth lens with a negative optical power, a fifth lens with a positive optical power, and a sixth lens with a positive optical power;

[0010] The optical lens group satisfies the following conditional expressions:

[0011] -146 < R6 / CT3 < -2; where R6 is the curvature radius of the image side of the third lens, and CT3 is the thickness of the third lens on the optical axis;

[0012] 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens and the fourth lens, and TTL is the total lens length;

[0013] 0.4 < (CT2 + CT3)*AT23 < 0.8; where CT2 is the thickness of the second lens on the optical axis, and AT23 is the air gap between the second lens and the third lens.

[0014] Preferably, the object side surface of the first lens near the optical axis is convex, and the image side surface of the first lens near the optical axis is concave; the object side surface of the second lens near the optical axis is convex, and the image side surface of the second lens near the optical axis is convex; the object side surface of the third lens near the optical axis is convex, and the image side surface of the third lens near the optical axis is convex; the object side surface of the fourth lens near the optical axis is concave, and the image side surface of the fourth lens near the optical axis is concave; the object side surface of the fifth lens near the optical axis is convex, and the image side surface of the fifth lens near the optical axis is convex; the object side surface of the sixth lens near the optical axis is convex, and the image side surface of the sixth lens near the optical axis is convex.

[0015] Preferably, the object side surface of the first lens near the optical axis is convex, and the image side surface of the first lens near the optical axis is concave; the object side surface of the second lens near the optical axis is convex, and the image side surface of the second lens near the optical axis is concave; the object side surface of the third lens near the optical axis is convex, and the image side surface of the third lens near the optical axis is convex; the object side surface of the fourth lens near the optical axis is concave, and the image side surface of the fourth lens near the optical axis is concave; the object side surface of the fifth lens near the optical axis is convex, and the image side surface of the fifth lens near the optical axis is convex; the object side surface of the sixth lens near the optical axis is convex, and the image side surface of the sixth lens near the optical axis is convex.

[0016] Preferably, the object side of the first lens near the optical axis is convex, and the image side of the first lens near the optical axis is concave; the object side of the second lens near the optical axis is concave, and the image side of the second lens near the optical axis is convex; the object side of the third lens near the optical axis is convex, and the image side of the third lens near the optical axis is convex; the object side of the fourth lens near the optical axis is concave, and the image side of the fourth lens near the optical axis is concave; the object side of the fifth lens near the optical axis is convex, and the image side of the fifth lens near the optical axis is convex; the object side of the sixth lens near the optical axis is convex, and the image side of the sixth lens near the optical axis is convex.

[0017] Preferably, the optical lens group satisfies the following conditions: 0.006 < AT56 / TTL < 0.04; where AT56 is the air gap between the fifth lens and the sixth lens.

[0018] Preferably, the optical lens group satisfies the following conditions: 2.3 < f2 / EFL < 3.9, 2.3 < f6 / EFL < 4.2, 0.9 < AT12 / EFL < 2; where f2 is the focal length of the second lens, EFL is the effective focal length of the optical lens group, f6 is the focal length of the sixth lens; AT12 is the distance between the image plane of the first lens and the object side of the second lens on the optical axis.

[0019] Preferably, the optical lens group satisfies the following conditions: -6 < (AT56 - AT34)*TTL < 6; -0.001 < (AT56 - AT34) / TTL < 0.023; where AT56 is the air gap between the fifth lens and the sixth lens, AT34 is the air gap between the third lens and the fourth lens, and TTL is the total lens length.

[0020] Preferably, the optical lens group satisfies the following conditions: -23 < (R3 - R6)*Imgh < 370, 65 < (R11 - R12)*Imgh < 197; where R3 is the radius of curvature of the image side of the second lens, R6 is the radius of curvature of the image side of the third lens, R11 is the radius of curvature of the object side of the sixth lens, and R12 is the radius of curvature of the image side of the sixth lens.

[0021] Preferably, the optical lens group satisfies the following conditions: 0.6 < (CT3 + CT4)*AT34 < 1.1, 6.8 < (CT4 + CT5)*(R8 + R9) < 15; where CT3 is the thickness of the third lens on the optical axis, CT4 is the thickness of the fourth lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, R8 is the radius of curvature of the image side of the fourth lens, and R9 is the radius of curvature of the object side of the fifth lens.

[0022] The beneficial effects of the present invention are:

[0023] 1. Meeting the conditional formula 4.5 < AT34 * TTL < 8 can control the distance between the third lens and the fourth lens on the optical axis, which helps to control the total length of the optical lens group;

[0024] 2. Meeting the conditional formula -39 < R12 / CT6 < -5 can appropriately control the thickness of the sixth lens and the radius of curvature of its image plane, which is beneficial to reducing the field curvature aberration and correcting the chromatic aberration of the optical lens group;

[0025] 3. Meeting the conditional formula -146 < R6 / CT3 < -2 can appropriately control the thickness of the third lens and the size of the radius of curvature of its image plane, which is beneficial to reducing the field curvature aberration and correcting the chromatic aberration of the optical lens group;

[0026] 4. Meeting the conditional formula 0.006 < AT56 / TTL < 0.04 can balance the configuration of the fifth lens and the sixth lens and effectively control the total system length;

[0027] 5. Meeting the conditional formula 5.4 < TTL / Imgh < 5.7 is beneficial to reducing the total length of the optical lens group;

[0028] 6. Meeting the conditional formula 0.9 < AT12 / EFL < 2 can balance the configuration of the first lens and the second lens and is beneficial to correcting the field curvature aberration of the optical lens group;

[0029] 7. Meeting the conditional formula 2.3 < f2 / EFL < 3.9 can make the second lens have appropriate positive refractive power, which helps to balance the negative refractive power of the first lens and helps to adjust the direction of light propagation;

[0030] 8. Meeting the conditional formula 2.3 < f6 / EFL < 4.2 can make the sixth lens have appropriate positive refractive power, which helps to adjust the direction of light propagation;

[0031] 9. Meeting the conditional formula -6 < (AT56 - AT34) * TTL < 6, -0.001 < (AT56 - AT34) / TTL < 0.023 can balance the configuration of the third lens to the sixth lens to control the total lens length to increase the usage scenarios;

[0032] 10. Meeting the conditional formula -23 < (R3 - R6) * Imgh < 370 can appropriately control the sizes of the radii of curvature of the second lens and the third lens, which is beneficial to reducing the field curvature aberration and correcting the chromatic aberration of the optical lens group;

[0033] 11. Meeting the conditional formula 65 < (R11 - R12) * Imgh < 197 can appropriately control the size of the radius of curvature of the sixth lens, which is beneficial to reducing the field curvature aberration and correcting the chromatic aberration of the optical lens group;

[0034] 12. The condition 0.4<(CT2+CT3)*AT23<0.8 is met, which can balance the thickness of the second lens and the third lens and the spatial configuration between them to avoid the relative distance between them being too large;

[0035] 13. The condition 0.6<(CT3+CT4)*AT34<1.1 is met, and the thickness of the third lens and the fourth lens and the spatial configuration therebetween can be balanced to avoid the relative distance between them being too large;

[0036] 14. Meeting the condition 6.8<(CT4+CT5)*(R8+R9)<15 is helpful to control the thickness and curvature radius of the fourth lens and the fifth lens, and is conducive to the miniaturization of the lens group. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the optical lens assembly of Example 1.

[0038] Figure 2 This is the longitudinal chromatic aberration of the optical lens group of Example 1.

[0039] Figure 3 This is a spherical aberration diagram of the optical lens group of Example 1.

[0040] Figure 4 This is a field curvature diagram of the optical lens group of Example 1.

[0041] Figure 5 This is an optical distortion diagram of the optical lens group of Example 1.

[0042] Figure 6 Schematic diagram of the structure of the optical lens assembly of Example 2.

[0043] Figure 7 This is the longitudinal chromatic aberration of the optical lens group of Example 2.

[0044] Figure 8 This is a spherical aberration diagram of the optical lens group of Example 2.

[0045] Fig. 9 This is a field curvature diagram of the optical lens group of Example 2.

[0046] Fig.10 This is an optical distortion diagram of the optical lens group of Example 2.

[0047] Fig.11 This is a schematic diagram of the structure of the optical lens assembly of Example 3.

[0048] Fig.12 This is the longitudinal chromatic aberration of the optical lens group of Example 3.

[0049] Fig.13Spherical aberration diagram of the optical lens group of Embodiment 3.

[0050] Fig.14 Field curvature diagram of the optical lens group of Embodiment 3.

[0051] Fig.15 Optical distortion diagram of the optical lens group of Embodiment 3.

[0052] Reference numerals in the drawings are: first lens 11, second lens 12, third lens 13, fourth lens 14, fifth lens 15, sixth lens 16, electronic photosensitive element 18, filter element 17, aperture 10. Detailed implementation manners

[0053] The present invention will be further described in detail below in conjunction with embodiments and the drawings, but the implementation manners of the present invention are not limited thereto.

[0054] The present invention discloses that the present invention is solved by the following technical solutions: A six-piece optical lens group for a police law enforcement recorder, including six lenses, which successively include from the object side to the image side: a first lens 11 with a negative optical power, a second lens 12 with a positive optical power, a third lens 13 with a positive optical power, an aperture 10, a fourth lens 14 with a negative optical power, a fifth lens 15 with a positive optical power, and a sixth lens 16 with a positive optical power; between the sixth lens 16 and the image side, a filter element 17 that does not affect the focal length and an electronic photosensitive element 18 are successively arranged, and the electronic photosensitive element 18 is arranged on the image side surface;

[0055] The optical lens group satisfies the following conditional expressions:

[0056] -39 < R12 / CT6 < -5; where R12 is the curvature radius of the image side of the sixth lens 16, and CT6 is the thickness of the sixth lens 16 on the optical axis. Meeting this conditional expression can appropriately control the thickness of the third lens and the curvature radius of its image surface, which is beneficial to reducing the field curvature aberration of the optical lens group and correcting the chromatic aberration;

[0057] 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens 13 and the fourth lens 14, and TTL is the total lens length; meeting this conditional expression can control the distance between the third lens and the fourth lens on the optical axis, which helps to control the total length of the optical lens group;

[0058] 5.4 < TTL / Imgh < 5.7; where Imgh is the maximum image height of the optical lens group on the imaging surface. Meeting this conditional expression is beneficial to reducing the total length of the optical lens group.

[0059] Another solution provided by the present invention is a six-piece optical lens group for a police law enforcement recorder, including six lenses, a first lens 11 with negative optical power, a second lens 12 with positive optical power, a third lens 13 with positive optical power, an aperture 10, a fourth lens 14 with negative optical power, a fifth lens 15 with positive optical power, and a sixth lens 16 with positive optical power; between the sixth lens 16 and the image side, a filter element 17 that does not affect the focal length and an electronic photosensitive element 18 are sequentially arranged, and the electronic photosensitive element 18 is arranged on the image side surface;

[0060] The optical lens group satisfies the following conditional expressions:

[0061] -146 < R6 / CT3 < -2; where R6 is the curvature radius of the image side of the third lens 13, and CT3 is the thickness of the third lens 13 on the optical axis; meeting this conditional expression can appropriately control the thickness of the third lens and the curvature radius of its image surface, which is beneficial to reducing the field curvature aberration and correcting the chromatic aberration of the optical lens group.

[0062] 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens 13 and the fourth lens 14, and TTL is the total lens length; meeting this conditional expression can control the distance between the third lens and the fourth lens on the optical axis, which helps to control the total length of the optical lens group.

[0063] 0.4 < (CT2 + CT3)*AT23 < 0.8; where CT2 is the thickness of the second lens 12 on the optical axis, and AT23 is the air gap between the second lens 12 and the third lens 13; meeting this conditional expression can balance the thicknesses of the second lens and the third lens and their spatial configuration to avoid an excessive distance between them.

[0064] Preferably, the optical lens group satisfies the following condition: 0.006 < AT56 / TTL < 0.04; where AT56 is the air gap between the fifth lens 15 and the sixth lens 16. Meeting this conditional expression can balance the configuration of the fifth lens and the sixth lens and effectively control the total length of the system.

[0065] Preferably, the optical lens group satisfies the following condition: 2.3 < f2 / EFL < 3.9. Meeting this conditional expression can make the second lens have appropriate positive refractive power, which helps to balance the negative refractive power of the first lens and helps to adjust the direction of light propagation.

[0066] 2.3 < f6 / EFL < 4.2, meeting this conditional expression can make the sixth lens have appropriate positive refractive power, which helps to adjust the direction of light propagation.

[0067] 0.9 < AT12 / EFL < 2; where f2 is the focal length of the second lens 12, EFL is the effective focal length of the optical lens group, and f6 is the focal length of the sixth lens 16. Meeting this conditional formula can balance the configuration of the first lens and the second lens and is conducive to correcting the field curvature aberration of the optical lens group.

[0068] Preferably, the optical lens group satisfies the following conditions: -6 < (AT56 - AT34) * TTL < 6, -0.001 < (AT56 - AT34) / TTL < 0.023. Meeting this conditional formula can balance the configuration of the third lens to the sixth lens to control the total lens length and increase the usage scenarios.

[0069] Preferably, the optical lens group satisfies the following conditions: -23 < (R3 - R6) * Imgh < 370. Meeting this conditional formula can appropriately control the curvature radii of the second lens and the third lens, which is conducive to reducing the field curvature aberration of the optical lens group and correcting the chromatic aberration;

[0070] 65 < (R11 - R12) * Imgh < 197; where R3 is the curvature radius of the image side of the second lens 12, R6 is the curvature radius of the image side of the third lens 13, R11 is the curvature radius of the object side of the sixth lens 16, and R12 is the curvature radius of the image side of the sixth lens 16. Meeting this conditional formula can appropriately control the curvature radius of the sixth lens, which is conducive to reducing the field curvature aberration of the optical lens group and correcting the chromatic aberration.

[0071] Preferably, the optical lens group satisfies the following conditions: 0.6 < (CT3 + CT4) * AT34 < 1.1, 6.8 < (CT4 + CT5) * (R8 + R9) < 15; where CT3 is the thickness of the third lens 13 on the optical axis, CT4 is the thickness of the fourth lens 14 on the optical axis, CT5 is the thickness of the fifth lens 15 on the optical axis, R8 is the curvature radius of the image side of the fourth lens 14, and R9 is the curvature radius of the object side of the fifth lens 15. Meeting 0.6 < (CT3 + CT4) * AT34 < 1.1 can balance the thicknesses of the third lens and the fourth lens and their spatial configuration therebetween to avoid an excessive distance therebetween; meeting 6.8 < (CT4 + CT5) * (R8 + R9) < 15 helps to control the thicknesses and curvature radii of the fourth lens and the fifth lens, which is conducive to miniaturization of the optical lens group.

[0072] Example 1, such as Figure 1-5As shown, the object side surface of the first lens 11 is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; the object side surface of the second lens 12 is convex at the near optical axis, and the image side surface of the second lens 12 is convex; the object side surface of the third lens 13 is convex at the near optical axis, and the image side surface of the third lens 13 is convex; the object side surface of the fourth lens 14 is concave at the near optical axis, and the image side surface of the fourth lens 14 is concave; the object side surface of the fifth lens 15 is convex at the near optical axis, and the image side surface of the fifth lens 15 is convex; the object side surface of the sixth lens 16 is convex at the near optical axis, and the image side surface of the sixth lens 16 is convex. First lens 11, second lens 12, third lens 13, fourth lens 14, fifth lens 15, sixth lens 16. This embodiment provides a six-piece optical lens group for a police law enforcement recorder, and the relevant parameters of each lens are shown in Table 1-1. The parameters of the aspheric surfaces of each lens in this embodiment are shown in Table 1-2.

[0073] Table 1-1

[0074]

[0075] Table 1-2

[0076] 11a 11b K -2.67E+00 -1.02E+00 A4 -2.27E-03 -3.19E-03 A6 1.05E-04 6.18E-04 A8 -2.81E-06 -2.36E-05 A10 3.17E-08 2.28E-07 A12 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00

[0077] The curve equations of the aspheric surfaces of the above lenses are expressed as follows:

[0078]

[0079] Where X: the distance between the point on the aspherical surface at a distance Y from the optical axis and the tangent plane between the aspherical surface and the optical axis; Y: the vertical distance between the point on the aspherical surface and the optical axis;

[0080] R: radius of curvature of the lens at the near optical axis;

[0081] K: cone coefficient;

[0082] A i : i-th order aspheric coefficient.

[0083] Embodiment 2, as Figure 6-10As shown, the object side surface of the first lens 11 is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; the object side surface of the second lens 12 is convex at the near optical axis, and the image side surface of the second lens 12 is concave; the object side surface of the third lens 13 is convex at the near optical axis, and the image side surface of the third lens 13 is convex; the object side surface of the fourth lens 14 is concave at the near optical axis, and the image side surface of the fourth lens 14 is concave; the object side surface of the fifth lens 15 is convex at the near optical axis, and the image side surface of the fifth lens 15 is convex; the object side surface of the sixth lens 16 is convex at the near optical axis, and the image side surface of the sixth lens 16 is convex. The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, and the sixth lens 16 are made of glass. This embodiment provides a six-piece optical lens group for a police law enforcement recorder, and the relevant parameters of each lens are shown in Table 2-1. The parameters of the aspheric surfaces of each lens in this embodiment are shown in Table 2-2.

[0084] Table 2-1

[0085]

[0086] Table 2-2

[0087]

[0088]

[0089] The curve equations of the aspheric surfaces of the above lenses are expressed as follows:

[0090]

[0091] Where X: the distance between the point on the aspherical surface at a distance Y from the optical axis and the tangent plane between the aspherical surface and the optical axis;

[0092] Y: the vertical distance between the point on the aspherical surface and the optical axis;

[0093] R: radius of curvature of the lens at the near optical axis;

[0094] K: cone coefficient;

[0095] A i : i-th order aspheric coefficient.

[0096] Embodiment 3, as Figure 11-15As shown, the object side surface of the first lens 11 is convex at the near optical axis, and the image side surface of the first lens is concave at the near optical axis; the object side surface of the second lens 12 is concave at the near optical axis, and the image side surface of the second lens 12 is convex; the object side surface of the third lens 13 is convex at the near optical axis, and the image side surface of the third lens 13 is convex; the object side surface of the fourth lens 14 is concave at the near optical axis, and the image side surface of the fourth lens 14 is concave; the object side surface of the fifth lens 15 is convex at the near optical axis, and the image side surface of the fifth lens 15 is convex; the object side surface of the sixth lens 16 is convex at the near optical axis, and the image side surface of the sixth lens 16 is convex. The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, and the sixth lens 16 are made of glass. This embodiment provides a six-piece optical lens group for a police law enforcement recorder, and the relevant parameters of each lens are shown in Table 3-1. The parameters of the aspheric surfaces of each lens in this embodiment are shown in Table 3-2.

[0097] Table 3-1

[0098]

[0099]

[0100] Table 3-2

[0101] 31a 31b K -2.83E+00 -1.00E+00 A4 -1.06E-03 -9.57E-04 A6 7.12E-06 6.46E-04 A8 9.15E-08 -7.75E-05 A10 -1.00E-08 1.22E-06 A12 0.00E+00 0.00E+00 A14 0.00E+00 0.00E+00 A16 0.00E+00 0.00E+00

[0102] The curve equations of the aspheric surfaces of the above lenses are expressed as follows:

[0103]

[0104] Where X: the distance between the point on the aspherical surface at a distance Y from the optical axis and the tangent plane between the aspherical surface and the optical axis;

[0105] Y: the vertical distance between the point on the aspherical surface and the optical axis;

[0106] R: radius of curvature of the lens at the near optical axis;

[0107] K: cone coefficient;

[0108] A i : i-th order aspheric coefficient.

[0109] The above embodiments only express three implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A six-piece optical lens assembly for a police law enforcement recorder, characterized in that: It includes six lenses, which successively include from the object side to the image side: a first lens (11) with negative optical power, a second lens (12) with positive optical power, a third lens (13) with positive optical power, an aperture (10), a fourth lens (14) with negative optical power, a fifth lens (15) with positive optical power, and a sixth lens (16) with positive optical power; The optical lens group satisfies the following conditional expressions: -39 < R12 / CT6 < -5; where R12 is the radius of curvature of the image side of the sixth lens (16), and CT6 is the thickness of the sixth lens (16) on the optical axis; 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens (13) and the fourth lens (14), and TTL is the total lens length; 5.4 < TTL / Imgh < 5.7; where Imgh is the maximum image height of the optical lens group on the imaging plane.

2. A six-piece optical lens assembly for a police law enforcement recorder, characterized in that: It includes six lenses, which successively include from the object side to the image side: a first lens (11) with negative optical power, a second lens (12) with positive optical power, a third lens (13) with positive optical power, an aperture (10), a fourth lens (14) with negative optical power, a fifth lens (15) with positive optical power, and a sixth lens (16) with positive optical power; The optical lens group satisfies the following conditional expressions: -146 < R6 / CT3 < -2; where R6 is the radius of curvature of the image side of the third lens (13), and CT3 is the thickness of the third lens (13) on the optical axis; 4.5 < AT34*TTL < 8; where AT34 is the air gap between the third lens (13) and the fourth lens (14), and TTL is the total lens length; 0.4 < (CT2 + CT3)*AT23 < 0.8; where CT2 is the thickness of the second lens (12) on the optical axis, and AT23 is the air gap between the second lens (12) and the third lens (13).

3. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The object side surface of the first lens (11) near the optical axis is convex, and the image side surface of the first lens near the optical axis is concave; the object side surface of the second lens (12) near the optical axis is convex, and the image side surface of the second lens (12) near the optical axis is convex; the object side surface of the third lens (13) near the optical axis is convex, and the image side surface of the third lens (13) near the optical axis is convex; the object side surface of the fourth lens (14) near the optical axis is concave, and the image side surface of the fourth lens (14) near the optical axis is concave; the object side surface of the fifth lens (15) near the optical axis is convex, and the image side surface of the fifth lens (15) near the optical axis is convex; the object side surface of the sixth lens (16) near the optical axis is convex, and the image side surface of the sixth lens (16) near the optical axis is convex.

4. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The object side near the optical axis of the first lens (11) is convex, and the image side near the optical axis of the first lens is concave; the object side near the optical axis of the second lens (12) is convex, and the image side near the optical axis of the second lens (12) is concave; the object side near the optical axis of the third lens (13) is convex, and the image side near the optical axis of the third lens (13) is convex; the object side near the optical axis of the fourth lens (14) is concave, and the image side near the optical axis of the fourth lens (14) is concave; the object side near the optical axis of the fifth lens (15) is convex, and the image side near the optical axis of the fifth lens (15) is convex; the object side near the optical axis of the sixth lens (16) is convex, and the image side near the optical axis of the sixth lens (16) is convex.

5. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The object side near the optical axis of the first lens (11) is convex, and the image side near the optical axis of the first lens is concave; the object side near the optical axis of the second lens (12) is concave, and the image side near the optical axis of the second lens (12) is convex; the object side near the optical axis of the third lens (13) is convex, and the image side near the optical axis of the third lens (13) is convex; the object side near the optical axis of the fourth lens (14) is concave, and the image side near the optical axis of the fourth lens (14) is concave; the object side near the optical axis of the fifth lens (15) is convex, and the image side near the optical axis of the fifth lens (15) is convex; the object side near the optical axis of the sixth lens (16) is convex, and the image side near the optical axis of the sixth lens (16) is convex.

6. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The optical lens group satisfies the following condition: 0.006 < AT56 / TTL < 0.04; where AT56 is the air gap between the fifth lens (15) and the sixth lens (16).

7. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The optical lens group satisfies the following conditions: 2.3 < f2 / EFL < 3.9, 2.3 < f6 / EFL < 4.2, 0.9 < AT12 / EFL < 2; where f2 is the focal length of the second lens (12), EFL is the effective focal length of the optical lens group, f6 is the focal length of the sixth lens (16), and AT12 is the distance on the optical axis between the image plane of the first lens (11) and the object side of the second lens (12).

8. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The optical lens group satisfies the following conditions: -6 < (AT56 - AT34) * TTL < 6; -0.001 < (AT56 - AT34) / TTL < 0.023; where AT56 is the air gap between the fifth lens (15) and the sixth lens (16), AT34 is the air gap between the third lens (13) and the fourth lens (14), and TTL is the total lens length.

9. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The optical lens group satisfies the following conditions: -23<(R3-R6)*Imgh<370, 65<(R11-R12)*Imgh<197; wherein R3 is the curvature radius of the image side of the second lens (12), R6 is the curvature radius of the image side of the third lens (13), R11 is the curvature radius of the object side of the sixth lens (16), and R12 is the curvature radius of the image side of the sixth lens (16).

10. The six-piece optical lens assembly for a police law enforcement recorder according to claim 1 or 2, characterized in that: The optical lens group satisfies the following conditions: 0.6<(CT3+CT4)*AT34<1.1, 6.8<(CT4+CT5)*(R8+R9)<15; wherein CT3 is the thickness of the third lens (13) on the optical axis, CT4 is the thickness of the fourth lens (14) on the optical axis, CT5 is the thickness of the fifth lens (15) on the optical axis, R8 is the radius of curvature of the image side of the fourth lens (14), and R9 is the radius of curvature of the object side of the fifth lens (15).

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