A condenser mirror for detecting a pixel headlamp of an automobile

Abstract

The application discloses a close-up mirror for automobile pixel headlamp detection and relates to the technical field of close-up mirrors, which comprises an optical axis a and sequentially comprises, from the object side to the image side along the direction of the optical axis a, an aperture stop Stop, a first lens L1 with positive focal power, a second lens L2 with negative focal power, a third lens L3 with positive focal power and a fourth lens L4 with negative focal power. The application effectively corrects the lens aberration by optimizing the positive and negative focal power of each lens and the lens spacing, thereby ensuring that the image resolution after the close-up of the lens is basically consistent with the image resolution before the close-up. The use of the lens can reduce the projection distance and the size of the projection area while ensuring the image restoration, thereby saving the test space and the test cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of condenser lens, and particularly relates to a condenser lens for pixel headlamp detection of an automobile. BACKGROUND

[0002] In the prior art, in order to realize miniaturization of a device for detecting a lighting function of a headlamp of an automobile, a condenser lens is usually used to reduce a lighting distance and a lighting area. The condenser lens is usually designed in one-piece or two-piece, and is used for detecting and debugging a high beam and a low beam. A working principle of the condenser lens is to convert a virtual image originally projected at a long distance into a real image projected at a short distance through an optical path of a lens.

[0003] The prior art has the following problems:

[0004] 1. The condenser lens used for detecting a headlamp of an automobile has only one piece or two pieces of lens, and although the condenser lens can realize condensing, a large amount of aberration is introduced, which greatly reduces imaging quality after condensing, and cannot effectively test a pixelized headlamp.

[0005] 2. A pixelized headlamp has a large light aperture, and a condenser lens with a large aperture is not available on the market, and it is difficult to effectively test light efficiency of the headlamp. SUMMARY

[0006] The present application aims to provide a condenser lens for pixel headlamp detection of an automobile to solve the problems in the background.

[0007] To solve the above technical problems, the present application adopts the following technical scheme:

[0008] A condenser lens for pixel headlamp detection of an automobile comprises an optical axis a, and sequentially comprises, from a subject side to an image side along the optical axis a, an aperture stop Stop, a first lens L1 with positive focal power, a second lens L2 with negative focal power, a third lens L3 with positive focal power, and a fourth lens L4 with negative focal power.

[0009] The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all made of glass.

[0010] Further improvement of the technical scheme of the present application is that the S1 surface is a convex surface, the S2 surface is a concave surface, the S3 surface is a convex surface or a plane or a concave surface, the S4 surface is a concave surface, the S5 surface is a concave surface or a plane or a concave surface, the S6 surface is a convex surface, the S7 surface is a concave surface, and the S8 surface is a convex surface.

[0011] Further improvement of the technical scheme of the present application is that the shortest distance D1 between the aperture stop Stop and the S1 surface satisfies D1≥2cm.

[0012] Further improvement of the technical scheme of the present application is that the shortest distance D2 between the image surface and the S8 surface satisfies D2≤150cm.

[0013] Further improvement of the technical scheme of the present application is that the diameter of the light emitting surface of the to-be-tested module is D3, the diameter of the entrance pupil of the close-up lens is D4, and D4≥D3≥30mm is satisfied.

[0014] Further improvement of the technical scheme of the present application is that the exit angle of the to-be-tested module is θ1, the entrance angle of the close-up lens is θ2, and θ2≥θ1 and θ2≤30° are satisfied.

[0015] Further improvement of the technical scheme of the present application is that the single-pixel size of the industrial camera at the image surface position is d1*d2mm, the number of pixels of the to-be-tested module is m*n, the image resolution of k1*k2 pixels is tested at the same time, and the image size after passing through the close-up lens satisfies H≥m / k1*d1 and V≥n / k2*d2, wherein H is the length of the image, and V is the width of the image.

[0016] Further improvement of the technical scheme of the present application is that the single-pixel size of the industrial camera at the image surface position is d1*d2mm, the image resolution of k1*k2 pixels of the to-be-tested module is tested at the same time, and the image resolution MTF of the close-up lens satisfies MTF≥50%@1 / (d1*k1*2)lp / mm and MTF≥50%@1 / (d2*k2*2)lp / mm; wherein MTF≥50%@1 / (d1*k1*2)lp / mm represents that the MTF value of the lens is greater than or equal to 50% at 1 / (d1*k1*2)lp / mm.

[0017] Due to the adoption of the above technical scheme, the present application has the following technical progress compared with the prior art:

[0018] 1. The present application provides a close-up lens for automobile pixel headlamp detection, which effectively corrects the lens aberration by optimizing the positive and negative focal lengths of each lens and the lens spacing, thereby ensuring that the image resolution after the close-up lens is basically consistent with the image resolution before the close-up lens; using the close-up lens can reduce the projection distance and the size of the projection area while ensuring the image restoration, thereby saving test space and test cost.

[0019] 2. The application provides a close-up mirror for pixel headlamp detection of an automobile, adopts a 4-piece spherical glass design, has simple structure and convenient processing, good manufacturability and cost performance, and the glass has high transmittance, which can reduce the stray light risk introduced by the close-up mirror.

[0020] 3. The application provides a close-up mirror for pixel headlamp detection of an automobile, adopts positive and negative lens combination and reasonable lens parameter matching, so that the aberration of the close-up mirror lens is well corrected, the aberration introduced by the close-up mirror is reduced, and the accuracy of the measurement system test is increased. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 which is a close-up mirror structure diagram of the application;

[0022] Figure 2 which is a close-up mirror structure diagram of the application;

[0023] Figure 3 which is a close-up mirror working principle diagram of the application;

[0024] Figure 4 which is a lens FFT MTF curve diagram before adding the close-up mirror under the back light path design of the application;

[0025] Figure 5 which is a lens FFT MTF curve diagram after adding the close-up mirror under the back light path design of the application;

[0026] Figure 6 which is a lens FFT MTF and field curve comparison diagram before adding the close-up mirror under the back light path design of the application;

[0027] Figure 7 which is a lens FFT MTF and field curve comparison diagram after adding the close-up mirror under the back light path design of the application.

[0028] In the figure: the optical axis is a, the aperture stop is Stop, the positive lens is L1, the negative lens is L2, the positive lens is L3, and the negative lens is L4, wherein the S1 surface is convex, the S2 surface is concave, the S3 surface is plane, the S4 surface is concave, the S5 surface is plane, the S6 surface is convex, the S7 surface is concave, the S8 surface is convex, the shortest distance between the aperture stop Stop and the S1 surface is D1, the light emitting surface diameter of the measured module is D3, the entrance pupil diameter of the close-up mirror is D4, the exit angle of the measured module is θ1, and the incidence angle of the close-up mirror is θ2. DETAILED DESCRIPTION

[0029] The application will be further described in detail in combination with the embodiments:

[0030] For example, Figures 1-7As shown, the present application provides a close-up mirror for automobile pixel headlamp detection, comprising an optical axis a, sequentially comprising an aperture stop Stop from the object side to the image side along the direction of the optical axis a; a first lens L1 with positive focal power, the object side and image side of the first lens L1 are S1 surface and S2 surface respectively; a second lens L2 with negative focal power, the object side and image side of the second lens L2 are S3 surface and S4 surface respectively; a third lens L3 with positive focal power, the object side and image side of the third lens L3 are S5 surface and S6 surface respectively; a fourth lens L4 with negative focal power, the object side and image side of the fourth lens L4 are S7 surface and S8 surface respectively.

[0031] The first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 all adopt glass material.

[0032] Wherein S1 surface is convex, S2 surface is concave, S3 surface is convex or plane or concave, S4 surface is concave, S5 surface is concave or plane or concave, S6 surface is convex, S7 surface is concave, and S8 surface is convex.

[0033] Wherein the shortest distance D1 between the aperture stop Stop and S1 surface satisfies: D1≥2cm.

[0034] Wherein the shortest distance D2 between the image surface and S8 surface satisfies: D2≤150cm.

[0035] Wherein the diameter of the light emitting surface of the to-be-tested module is D3, the entrance pupil diameter of the close-up mirror is D4, and D4≥D3≥30mm is satisfied.

[0036] Wherein the exit angle of the to-be-tested module is θ1, the entrance angle of the close-up mirror is θ2, and θ2≥θ1 and θ2≤30° are satisfied.

[0037] Wherein the single pixel size of the industrial camera at the image surface position is d1*d2mm, the pixel number of the to-be-tested module is m*n, and the image resolution of the k1*k2 pixels is tested simultaneously, and the image size after passing through the close-up mirror satisfies: H≥m / k1*d1, V≥n / k2*d2, wherein H is the length of the image, and V is the width of the image.

[0038] Wherein the single pixel size of the industrial camera at the image surface position is d1*d2mm, the image resolution of the k1*k2 pixels of the to-be-tested module is tested simultaneously, and the image resolution MTF of the close-up mirror satisfies: MTF≥50%@1 / (d1*k1*2)lp / mm, MTF≥50%@1 / (d2*k2*2)lp / mm; wherein MTF≥50%@1 / (d1*k1*2)lp / mm represents that the lens MTF value is ≥50% at 1 / (d1*k1*2)lp / mm.

[0039] In the embodiment, a 4-piece spherical glass design is adopted, which is simple in structure, convenient to process, has good manufacturability and cost performance, and has high transmittance, so that the risk of stray light introduced by the teleconverter is reduced. By optimizing the positive and negative focal lengths of the lenses and the lens spacing, the lens aberration is effectively corrected, so that the image resolution after the teleconverter is basically consistent with that before the teleconverter. By using the teleconverter, the image restoration can be ensured while the projection distance and the size of the projection area are reduced, the test space and the test cost are saved, the positive and negative lens combination is adopted, and the lens parameters are reasonably matched, so that the aberration of the teleconverter lens is well corrected, the aberration introduced by the teleconverter is reduced, and the accuracy of the measurement system test is improved.

[0040] By Figure 4 By comparing the FFT MTFs before and after the teleconverter, the teleconverter of the present application has good aberration correction capability, and can better display the performance of the lens while reducing the projection distance.

[0041] Table 1: Surface parameters of the teleconverter of Example 1

[0042] Surface No. Surface Type Radius of Curvature Thickness Refractive Index Abbe Number Aperture Object Plane Spherical Infinite -10000 Stop Spherical Infinite 60.0000 25.000 2 Spherical 115.6800 12.5166 1.7101 48.7 43.142 3 Spherical 457.8130 3.2160 42.990 4 Spherical Spherical 13.0952 1.7025 35.0 43.020 5 Spherical 122.9229 30.6429 43.326 6 Spherical Spherical 16.3590 1.6862 39.4 50.683 7 Spherical -132.9378 9.1704 51.771 8 Spherical -126.7171 5 1.7810 44.1 52.020 9 Image Plane -352.7232 1000 54.512 Spherical Infinite Surface No. 0

[0043] The lens has a field of view FOV of 30°, the shortest distance between the aperture stop and the first surface of the lens is 6 cm, the field of view of the industrial camera used is 29.4*19.8°, the pixel number is 5472*3648, the single pixel size at 1 meter is 0.094*0.094 mm, the pixel number of the module to be tested is 1152*576, the image resolution of 1*1 pixel is tested, the image size after the teleconverter is 610*305 mm, and the lens resolution MTF is greater than 50% @ 5LP / MM.

[0044] Table 2: Surface parameters of the teleconverter of Example 2

[0045] Surface Type Radius of Curvature Thickness Refractive Index Abbe Number Aperture Object Plane Spherical Infinite Stop -10000 Spherical Infinite Spherical 60.0000 25.000 2 Spherical 120.1064 12.0255 1.744 44.9 43.045 3 Spherical 490.8543 2.7080 42.903 4 Spherical 2882.6194 5.0000 1.648 33.8 42.930 5 Spherical 133.0489 36.2522 43.030 6 Spherical -996.7916 25.0000 1.569 56.0 50.088 7 Spherical -77.1429 4.0143 51.287 8 Spherical -72.9938 5.0000 1.589 61.3 50.504 9 Image Plane -407.2311 1000 55.000 Spherical Infinite Figure 1 0

[0046] The lens has a field of view FOV of 30°, the shortest distance between the aperture stop and the first surface of the lens is 6 cm, the field of view of the industrial camera used is 29.4*19.8°, the pixel number is 5472*3648, the single pixel size at 1 meter is 0.094*0.094 mm, the pixel number of the module to be tested is 1152*576, the image resolution of 1*1 pixel is tested, the image size after the teleconverter is 610*305 mm, and the lens resolution MTF is greater than 50% @ 5LP / MM.

[0047] Table 3: Surface parameters of the teleconverter of Example 3

[0048]

[0049]

[0050] The lens has a field of view (FOV) of 30°, the shortest distance between the aperture stop and the first surface of the lens is 2cm, the industrial camera used has a field of view of 29.4*19.8°, a pixel count of 5472*3648, a single pixel size of 0.094*0.094mm at 1 meter, and the number of pixels in the module under test is 1152*576. The image resolution of simultaneously illuminating 1*1 pixels is tested, and the image size after passing through the zoom lens is 610*305mm. The lens resolution MTF is >50%@5LP / MM.

[0051] like ​ As shown, this invention discloses a large-aperture zoom-down projection lens, which, along the optical axis a from the object side to the image side, comprises: an aperture stop (Stop), a first lens L1 with positive optical power, a second lens L2 with negative optical power, a third lens L3 with positive optical power, and a fourth lens L4 with negative optical power. The first lens L1, second lens L2, third lens L3, and fourth lens L4 are all made of glass. By optimizing the positive and negative optical powers of each lens and the lens spacing, lens aberrations are effectively corrected, thereby ensuring that the image resolution after zooming down using the lens of this invention is essentially the same as the image resolution before zooming down. Using the lens of this invention can reduce the projection distance and the size of the projection area while ensuring image fidelity, saving test space and test costs.

[0052] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A telecontraction mirror for detecting automotive pixel headlights, comprising an optical axis a, characterized in that: The structure, arranged sequentially from the object side to the image side along the optical axis a, includes: an aperture stop (Stop); a first lens L1 with positive optical power, wherein the object side and image side of the first lens L1 are surfaces S1 and S2, respectively; a second lens L2 with negative optical power, wherein the object side and image side of the second lens L2 are surfaces S3 and S4, respectively; a third lens L3 with positive optical power, wherein the object side and image side of the third lens L3 are surfaces S5 and S6, respectively; and a fourth lens L4 with negative optical power, wherein the object side and image side of the fourth lens L4 are surfaces S7 and S8, respectively. The first lens L1, the second lens L2, the third lens L3, and the fourth lens L4 are all made of glass. The S1 surface is convex, the S2 surface is concave, the S3 surface is convex, flat, or concave, the S4 surface is concave, the S5 surface is concave, flat, or convex, the S6 surface is convex, the S7 surface is concave, and the S8 surface is convex. The teleconverter has a total of 4 lenses; the surface parameters of the teleconverter are shown in Table 1, Table 2, or Table 3. Table 1: Table 2: Table 3: 。 2. The telecontraction mirror for detecting automotive pixel headlights according to claim 1, characterized in that: The diameter of the light-emitting surface of the module under test is D3, and the diameter of the entrance pupil of the telecontraction lens is D4, satisfying D4≥D3≥30mm.

3. A telescoping mirror for detecting automotive pixel headlights according to claim 1, characterized in that: The exit angle of the module under test is θ1, and the incident angle of the telescope is θ2, satisfying θ2≥θ1 and θ2≤30°.

4. A telescoping mirror for detecting automotive pixel headlights according to claim 1, characterized in that: The single pixel size of the industrial camera at the image plane position is d1*d2mm. The number of pixels of the module under test is m*n. The image resolution is tested by simultaneously illuminating k1*k2 pixels. Then the image size after passing through the zoom lens satisfies: H≥m / k1*d1, V≥n / k2*d2, where H is the length of the image and V is the width of the image.

5. A telecontraction mirror for detecting automotive pixel headlights according to claim 1, characterized in that: The single pixel size of an industrial camera at the image plane is d1*d2mm. To test the image resolution of the module under test when simultaneously illuminating k1*k2 pixels, the MTF of the zoom lens must satisfy: MTF≥50% @ 1 / (d1*k1*2) lp / mm, MTF≥50% @ 1 / (d2*k2*2) lp / mm; where MTF≥50% @ 1 / (d1*k1*2) lp / mm means that the lens MTF value is ≥50% at 1 / (d1*k1*2)lp / mm.

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