An underwater high-resolution deformation measurement anti-radiation camera system

Abstract

The present application relates to underwater survey camera system, specifically relates to a kind of underwater high-resolution deformation measurement anti-radiation camera system, solve the problem that the camera system of existing laser triangulation measurement system cannot meet stable measurement in underwater strong radiation environment while giving consideration to system simplification, the present application includes the plate window with acute angle included angle A with vertical plane, reflection mirror is set on the transmission light path of plate window and has acute angle included angle B with vertical plane, and A=2B;Reflection light path of reflection mirror is sequentially provided with first to fifth lenses, the laser light reflected by the surface of target object passes through plate window and enters first lens through reflection mirror, then laser light sequentially passes through first to fifth lenses and is finally focused on the imaging surface of camera.The rays of nuclear radiation do not reflect into the lens group when meeting the reflection mirror, so the influence of nuclear radiation rays on imaging is avoided, and the whole lens group uses only five lenses, while meeting the demand of system simplification.

Description

TECHNICAL FIELD

[0001] The present application relates to an underwater measurement camera system, in particular to an anti-radiation camera system for underwater high-resolution deformation measurement. BACKGROUND

[0002] With the development of industrial production and high-end equipment, the role of precision measurement technology in production is becoming more and more important. The internal components of nuclear power reactors are in an environment with large heat range, strong radiation and high pressure. After a long time of operation, deformation will occur. However, the nuclear reaction has high requirements for the accuracy of the components. If the deformation is too large, it will affect the normal work of the nuclear reaction. Therefore, it is necessary to precisely measure the deformation to monitor its deformation condition.

[0003] When the internal components of the nuclear power reactor are in an underwater environment, there are generally two methods for precise measurement. One is contact measurement, but it is complex to operate, prone to deformation, and poor in durability. It has been gradually replaced by another non-contact measurement. In the non-contact measurement method, the laser triangulation method has obvious advantages in medium and short distance measurement due to its fast speed, high precision, good stability and low cost. This method emits point or line laser, and the camera system images the laser spot or stripe on the target object onto the photoelectric detector. The center of the spot or the center line of the stripe is obtained through image processing technology. The displacement or shape change of the measured point is converted into the displacement of the imaging point on the image plane by using the unique correspondence between the object point and the image point. According to the triangular geometric relationship, one-dimensional displacement or two-dimensional contour of the object is obtained. Through the scanning of the laser, the three-dimensional surface topography of the object is obtained. The camera system is an important part of the laser triangulation system. The deformation of the object surface means that the distance between the camera system and the object is different. In order to ensure clear imaging at different object distances, the imaging surface needs to be inclined at a certain angle, so that the imaging surface, the object surface and the system main plane intersect at a straight line, that is, it meets the Scheimpflug condition. In order to improve the measurement accuracy, the system itself needs to have high resolution. In order to reduce the cost and simplify the system, the number of lenses and the types of lens materials need to be minimized, which brings great difficulty to the system design. On the other hand, in order to make the system maintain stable laser triangulation performance in the strong radiation environment underwater, the traditional optical system layout is also difficult to meet the requirements. SUMMARY

[0004] The purpose of the present application is to solve the problem that the camera system of the existing laser triangulation system cannot meet the stable measurement in the strong radiation environment underwater while considering the system simplification, and to provide an anti-radiation camera system for underwater high-resolution deformation measurement.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0006] The application discloses an underwater high-resolution deformation measurement anti-radiation camera system which measures the deformation of a target surface through laser light reflected by the target surface.

[0007] The plate window and the vertical plane have an acute angle A, the mirror is arranged on the transmission light path of the plate window, the mirror and the vertical plane have an acute angle B, and A=2B.

[0008] The plate window and the vertical plane have an acute angle A, the mirror is arranged on the transmission light path of the plate window, the mirror and the vertical plane have an acute angle B, and A=2B; the lens group comprises first to fifth lenses arranged in sequence on the reflection light path of the mirror, the laser light reflected by the target surface enters the first lens through the plate window and is reflected by the mirror, then the laser light sequentially passes through the first to fifth lenses and is finally focused on the imaging surface of the camera, the imaging surface of the camera and the central optical axis of the light path have an acute angle C, and 83°

[0009] The first lens is a biconvex lens with positive focal power, the second lens is a meniscus lens with negative focal power and a concave exit surface, the third lens is a meniscus lens with negative focal power and a concave exit surface, the fourth lens is a biconcave lens with negative focal power, and the fifth lens is a biconvex lens with positive focal power.

[0010] The distance T1 of the first lens incident surface to the camera imaging surface on the central optical axis of the light path satisfies 4.9

[0011] Wherein: H is a system preset imaging height, and the value range is 33-37.4mm; EPD is a system preset entrance pupil diameter, and the value range is 27-33mm. In this way, the system compactness is improved, the overall size of the system is controlled, the light flux of the system is effectively improved, the system image height is increased, and the thickness and gap of each lens are ensured to be within a reasonable range.

[0012] The distance of the exit surface of the plate window 1 to the incident surface of the first lens 3 on the central optical axis of the light path is T2, and 100mm

[0013] The effective half-aperture radius SD1 of the third lens exit surface and the distance T4 of the third lens exit surface to the fourth lens entrance surface on the central optical axis of the optical path satisfy: 1.65 < SD1 / T4 < 3.5; this is conducive to reducing the difficulty of system adjustment and improving the ability to balance the axial aberration of the system.

[0014] The effective half-aperture radius SD2 of the fourth lens exit surface and the effective half-aperture radius SD3 of the fifth lens entrance surface satisfy: 0.7 < SD2 / SD3 < 1.2. This can prevent the laser light from being deflected too much and further improve the imaging resolution.

[0015] Further, the curvature radius R1 of the second lens entrance surface satisfies 0.4 < R1 / f < 0.76, and the fifth lens focal length f1 satisfies 0.86 < f / f1 < 2.1;

[0016] Wherein: f is the system preset focal length, and the value range is 105-115 mm. The curvature radius of the second lens entrance surface satisfies the above formula, which can effectively control the laser chief ray angle in the optical path, and can better cooperate with the imaging surface of the camera to improve the imaging clarity. The fifth lens focal length f1 satisfies the above formula, which is conducive to improving the light convergence ability of the system and enhancing the aberration correction ability of the system.

[0017] Further, the curvature radius R2 of the first lens entrance surface and the curvature radius R3 of the third lens exit surface satisfy: 3.5 < R2 / R3 < 7.8. This can effectively reduce the sensitivity of the system and improve the ability to correct the axial field curvature and distortion of the system.

[0018] Further, the central thickness CT1 of the first lens and the edge thickness ET1 of the first lens satisfy: 0.8 < CT1 / ET1 < 2.9; this can reduce the processing difficulty of the first lens and reduce the weight of the system.

[0019] The central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 0.28 < CT2 / CT3 < 0.62, and an aperture stop is arranged between the second lens and the third lens. The central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy the above condition, which is conducive to controlling the distance between the lenses within a reasonable range and improving the ability to correct the field curvature and astigmatism of the system.

[0020] Further, the flat window is made of sapphire material, the acute angle C between the imaging surface of the camera and the central optical axis of the optical path is 84.75°, that is, the sapphire angle is 84.75°, which can ensure the imaging clarity of the system at different measurement depths.

[0021] Further, the curvature radius of the entrance surface of the first lens is 140.395 mm, and the curvature radius of the exit surface is 5347.199 mm;

[0022] The incident surface curvature radius of the second lens is 72.628mm, and the exit surface curvature radius is 194.617mm;

[0023] The incident surface curvature radius of the third lens is 30.113mm, and the exit surface curvature radius is 25.511mm;

[0024] The incident surface curvature radius of the fourth lens is 228.863mm, and the exit surface curvature radius is 40.726mm;

[0025] The incident surface curvature radius of the fifth lens is 108.312mm, and the exit surface curvature radius is 83.909mm.

[0026] Further, the distance between the exit surface of the first lens and the incident surface of the second lens on the central optical axis of the optical path is 0.407mm;

[0027] The distance between the exit surface of the second lens and the incident surface of the third lens on the central optical axis of the optical path is 1.432mm;

[0028] The distance between the exit surface of the third lens and the incident surface of the fourth lens on the central optical axis of the optical path is 4.824mm;

[0029] The distance between the exit surface of the fourth lens and the incident surface of the fifth lens on the central optical axis of the optical path is 20.11mm.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] (1) The underwater high-resolution deformation measurement anti-radiation camera system provided by the present application comprises a flat window, a mirror, a lens group and a camera, wherein the flat window and the vertical plane have an acute angle A, the mirror is arranged on the transmission light path of the flat window, the mirror and the vertical plane have an acute angle B, and A=2B, the imaging surface of the camera and the central optical axis of the light path have an acute angle C, and 83°<C<85°; the flat window, the mirror and the imaging surface of the camera are arranged in this way, so that the object surface and the image surface of the whole system meet the requirements of the laser triangulation method, the laser light reflected by the target object surface enters from the flat window, is reflected by the mirror, and the first to fifth lenses are arranged in sequence on the reflected light path of the mirror, the laser light is reflected by the mirror and then passes through the first to fifth lenses and is finally focused on the imaging surface of the camera, and the rays in the nuclear radiation directly pass through the mirror and are not reflected into the lens group, so that the rays in the nuclear radiation are filtered by the mirror, the influence of radiation on imaging is eliminated, the whole system can realize stable imaging measurement, and the propagation direction of the light is changed after passing through the mirror, which is also beneficial to reducing the size of the system. Moreover, the lens group only uses five lenses, which meets the requirement of system simplification.

[0032] (2) The sapphire material is used for the flat window in the underwater high-resolution deformation measurement anti-radiation camera system, the sapphire material has high hardness and good permeability, more laser light can be transmitted when the underwater high-resolution deformation measurement anti-radiation camera system is used, and the sapphire contains iron, titanium and other elements, so that the sapphire has strong anti-radiation properties, and the anti-radiation performance of the whole system can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Fig. 1 The optical path diagram of the underwater high-resolution deformation measurement anti-radiation camera system embodiment of the present application;

[0034] Fig. 2 The imaging MTF curve diagram of the embodiment of the present application;

[0035] Fig. 3 The imaging point column diagram of the embodiment of the present application.

[0036] The reference signs are explained as follows:

[0037] 1-flat window, 2-reflector, 3-first lens, 4-second lens, 5-third lens, 6-fourth lens, 7-fifth lens, 8-camera, 9-aperture stop. DETAILED DESCRIPTION

[0038] The present application is further described below in combination with the drawings and exemplary embodiments.

[0039] Reference Figs. 1-3 The underwater high-resolution deformation measurement anti-radiation camera system of the present application comprises a flat window 1, a reflector 2, a lens group and a camera 8. The flat window 1 is made of sapphire material, has high hardness, good friction resistance and good permeability, is suitable for underwater camera shooting, and can transmit more laser light under water. The sapphire contains iron, titanium and other elements, so that the sapphire has strong anti-radiation properties and can be used as the first line of defense of the whole system to filter part of the nuclear radiation rays. In order to meet the requirements of the laser triangulation method, the flat window 1 has an acute angle A with the vertical plane, and in the embodiment, the acute angle A is 58°. The reflector 2 is arranged on the transmission light path of the flat window 1. In order to meet the requirements of the laser triangulation method, the reflector 2 has an acute angle B with the vertical plane, and A=2B, so that in the embodiment, the acute angle B is 29°. Because the nuclear radiation rays will directly pass through the reflector 2 when encountering the reflector 2, the rays will not be reflected into the lens group, so that the imaging is not affected by the radiation.

[0040] A lens group is arranged on the reflection light path of the mirror 2, and the lens group comprises first to fifth lenses 3-7 arranged in sequence. When the laser light reflected by the target object surface passes through the flat window 1 and is reflected by the mirror 2 into the first lens 3, then the laser light passes through the first to fifth lenses 3-7 in sequence and is finally focused on the imaging surface of the camera 8. The imaging surface of the camera 8 and the central optical axis of the light path have an acute angle C, and 83° < C < 85°. In this embodiment, the acute angle C between the imaging surface of the camera 8 and the central optical axis of the light path is 84.75°, which is the sines angle, and the imaging clarity of the system at different measurement depths can be ensured.

[0041] The first lens 3 is a biconvex lens with positive focal power, the second lens 4 is a meniscus lens with negative focal power and a concave exit surface, the third lens 5 is a meniscus lens with negative focal power and a concave exit surface, the fourth lens 6 is a biconcave lens with negative focal power, and the fifth lens 7 is a biconvex lens with positive focal power. An aperture stop 9 is arranged between the second lens 4 and the third lens 5, which can control the off-axis aberration of the entire system within a reasonable range.

[0042] The distance T1 between the entrance surface of the first lens 3 and the imaging surface of the camera 8 on the central optical axis of the light path satisfies 4.9 < 2T1 / H < 9.1 and 4.2 < T1 / EPD < 5.5. In this embodiment, T1 is 137 mm, H is the preset imaging height of the system, and its value range is 35-40 mm, H is 37.4 mm in this embodiment, EPD is the preset entrance pupil diameter of the system, and its value range is 27-33 mm, and EPD is 28.7 mm in this embodiment. This setting is beneficial to improve the compactness of the system, and effectively improve the light flux of the system while controlling the overall size of the system.

[0043] The distance between the exit surface of the flat window 1 and the entrance surface of the first lens 3 on the central optical axis of the light path is T2, and 100 mm < T2 < 140 mm. The distance between the exit surface of the fifth lens 7 and the imaging surface of the camera 8 on the central optical axis of the light path is T3, and 35 mm < T3 < 90 mm. This setting is beneficial to the installation and adjustment of the mirror 2 and the camera 8 and improves the compactness of the system. In this embodiment, T2 is 122.79 mm and T3 is 81.659 mm.

[0044] The curvature radius R1 of the entrance surface of the second lens 4 satisfies 0.4 < R1 / f < 0.76, where f is the preset focal length of the system, and its value range is 105-115 mm. In this embodiment, f is 112 mm and R1 is 72.628 mm. When the curvature radius of the entrance surface of the second lens 4 satisfies the above formula, the angle of the main laser light in the light path can be effectively controlled, which can better cooperate with the imaging surface of the camera 8 and improve the imaging clarity.

[0045] The focal length f1 of the fifth lens 7 satisfies 0.86 < f / f1 < 2.1, and in the embodiment, f1 is 70.51 mm. The focal length of the fifth lens 7 is set in this way, which is beneficial to improve the light convergence ability of the system and enhance the aberration correction ability of the system.

[0046] The effective half aperture diameter SD1 of the exit surface of the third lens 5 and the distance T4 on the central optical axis in the optical path from the exit surface of the third lens 5 to the entrance surface of the fourth lens 6 satisfy 1.65 < SD1 / T4 < 3.5. In this way, the difficulty of system adjustment is reduced, and the ability to balance the off-axis aberration of the system is improved. In the embodiment, SD1 is 11.14 mm, and T4 is 4.824 mm.

[0047] The effective half aperture diameter SD2 of the exit surface of the fourth lens 6 and the effective half aperture diameter SD3 of the entrance surface of the fifth lens 7 satisfy 0.7 < SD2 / SD3 < 1.2. In the embodiment, SD2 is 10.96 mm, and SD3 is 14.38 mm. This can prevent excessive deflection of laser light and further improve the imaging resolution.

[0048] The curvature radius R2 of the entrance surface of the first lens 3 and the curvature radius R3 of the exit surface of the third lens 5 satisfy 3.5 < R2 / R3 < 7.8. In the embodiment, R2 is 140.395 mm, and R3 is 25.511 mm. This can effectively reduce the sensitivity of the system and improve the ability to correct the off-axis field curvature and distortion of the system.

[0049] The central thickness CT1 of the first lens 3 and the edge thickness ET1 of the first lens 3 satisfy 0.8 < CT1 / ET1 < 2.9. In the embodiment, CT1 is 3.56 mm, and ET1 is 2.5 mm. This can reduce the processing difficulty of the first lens 3 and reduce the weight of the system.

[0050] The central thickness CT2 of the second lens 4 and the central thickness CT3 of the third lens 5 satisfy 0.28 < CT2 / CT3 < 0.62. In the embodiment, CT2 is 3.7 mm, and CT3 is 10.54 mm. The central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy the above condition, which is beneficial to control the distance between the lenses within a reasonable range and improve the ability to correct the field curvature and astigmatism of the system.

[0051] The distance relationship between adjacent lenses in the lens group is as follows: the distance between the exit surface of the first lens 3 and the entrance surface of the second lens 4 on the central optical axis of the optical path is 0.407 mm; the distance between the exit surface of the second lens 4 and the entrance surface of the third lens 5 on the central optical axis of the optical path is 1.432 mm; the distance between the exit surface of the third lens 5 and the entrance surface of the fourth lens 6 on the central optical axis of the optical path is 4.824 mm; and the distance between the exit surface of the fourth lens 6 and the entrance surface of the fifth lens 7 on the central optical axis of the optical path is 20.11 mm.

[0052] The curvature radii of the entrance and exit surfaces of each lens are as follows: the curvature radius of the entrance surface of the first lens 3 is 140.395 mm, and the curvature radius of the exit surface is 5347.199 mm; the curvature radius of the entrance surface of the second lens 4 is 72.628 mm, and the curvature radius of the exit surface is 194.617 mm; the curvature radius of the entrance surface of the third lens 5 is 30.113 mm, and the curvature radius of the exit surface is 25.511 mm; the curvature radius of the entrance surface of the fourth lens 6 is 228.863 mm, and the curvature radius of the exit surface is 40.726 mm; and the curvature radius of the entrance surface of the fifth lens 7 is 108.312 mm, and the curvature radius of the exit surface is 83.909 mm.

[0053] The parameters of each lens and the imaging surface in the embodiment are as follows:

[0054]

[0055]

[0056] (In the table, S1, S4, S6, and S18 are coordinate breakpoints, and the other surfaces are standard surfaces. Some thickness values are negative, which is due to the addition of coordinate breakpoints. In actual manufacturing, the positive values are used as the reference)

[0057] The system technical indicators in the embodiment are as shown in the following table:

[0058]

[0059]

[0060] As can be seen from the above table, the imaging Scheimpflug angle of the entire system is controlled at 84.75°, and the Scheimpflug angle is close to the central optical axis of the vertical optical path, which makes the system have high imaging quality at different object distances, and the rear intercept is 81.66 mm, which reduces the difficulty of camera 8 adjustment; the baseline distance refers to the distance between the center point of the entrance surface of the flat window 1 and the perpendicular line of the target object surface, and setting this distance to 1000 mm is beneficial to the transmission of laser light on the object surface and reduces the influence of the laser light source on imaging.

[0061] The five lenses are made of the same material, which is a commercial regular material, so that the processing cost is effectively reduced while the system simplicity is improved, and the resolution of the whole system under the large image size reaches the diffraction limit.

[0062] The system paraxial magnification is 0.08, and the imaging resolution is better than 156 lp / mm, so that the object side resolution is 500 / 156 / 0.08 / 1000=0.04006 mm according to the Nyquist theorem, and the object side resolution, i.e., the measurement resolution, is controlled within 0.1 mm, so that the target measurement accuracy is significantly improved.

[0063] The camera 8 in the embodiment is selected as the MV-XG6500GM-T industrial camera of Meade Optics, the pixel size is 3.2 mu m, the resolution is 9344*7000, the target surface diagonal size is 37.4 mm, and the corresponding horizontal size and vertical size are 29.9 mm and 22.4 mm respectively, the imaging spot is matched and optimized to the diffraction limit, so that the imaging effect is significantly improved, and the system measurement range is increased.

[0064] In use, the target surface under water is irradiated by a laser light source, the laser light reflected by the target surface first enters the flat window 1, because the flat window 1 is made of sapphire material and has strong radiation resistance, part of the nuclear radiation rays can be blocked from entering the camera system, after passing through the flat window 1, the laser light moves along the transmission light path of the flat window 1 until it meets the mirror 2, because the nuclear radiation rays can directly pass through the mirror and will not be reflected into the lens group, so that when passing through the mirror 2, the remaining part of the nuclear radiation rays will be filtered, while the laser light is reflected by the mirror 2, and moves along the reflection light path of the mirror 2 through the first to fifth lenses 3-7 in turn, and finally focuses on the imaging surface of the camera 8, so that high-resolution stable imaging in the underwater strong radiation environment is realized.

[0065] The above-described embodiments are only used to describe the specific implementation of the present application, and do not limit the scope of the present application, and various modifications and improvements of the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope of the claims of the present application.

Claims

1. A radiation-proof camera system for underwater high-resolution deformation measurement, which measures the surface deformation of a target object by means of laser light reflected from the target object's surface, characterized in that: The system comprises a flat window (1), a mirror (2), a lens group and a camera (8); The flat window (1) has an acute angle A with a vertical plane, the mirror (2) is arranged on the transmission light path of the flat window (1), the mirror (2) has an acute angle B with the vertical plane, and A = 2B; The lens group comprises a first lens (3) to a fifth lens (7) arranged in sequence on the reflection light path of the mirror (2), laser light reflected by a target object surface enters the first lens (3) after passing through the flat window (1) and being reflected by the mirror (2), and then the laser light passes through the first lens (3) to the fifth lens (7) in sequence and is finally focused on the imaging surface of the camera (8), the imaging surface of the camera (8) has an acute angle C with the central optical axis of the light path, and 83° < C < 85°; The first lens (3) is a biconvex lens with positive focal power, the second lens (4) is a meniscus lens with negative focal power and a concave exit surface, the third lens (5) is a meniscus lens with negative focal power and a concave exit surface, the fourth lens (6) is a biconcave lens with negative focal power, and the fifth lens (7) is a biconvex lens with positive focal power; The distance T1 of the first lens (3) from the incident surface to the imaging surface of the camera (8) on the central optical axis of the light path satisfies 4.9 < 2T1 / H < 9.1 and 4.2 < T1 / EPD < 5.5; Wherein: H is a system preset imaging height, and the value range is 33-37.4mm; EPD is a system preset entrance pupil diameter, and the value range is 27-33mm; The distance T2 of the exit surface of the flat window (1) to the incident surface of the first lens (3) on the central optical axis of the light path is 100mm < T2 < 140mm; the distance T3 of the exit surface of the fifth lens (7) to the imaging surface of the camera (8) on the central optical axis of the light path is 35mm < T3 < 90mm; The effective half aperture radius SD1 of the exit surface of the third lens (5) and the distance T4 of the exit surface of the third lens (5) to the incident surface of the fourth lens (6) on the central optical axis of the light path satisfy 1.65 < SD1 / T4 < 3.5; the effective half aperture radius SD2 of the exit surface of the fourth lens (6) and the effective half aperture radius SD3 of the incident surface of the fifth lens (7) satisfy 0.7 < SD2 / SD3 < 1.

2.

2. The radiation shielded camera system for underwater high resolution deformation measurement according to claim 1, characterized in that: The curvature radius R1 of the incident surface of the second lens (4) satisfies 0.4 < R1 / f < 0.76, and the focal length f1 of the fifth lens (7) satisfies 0.86 < f / f1 < 2.1; Wherein: f is a system preset focal length, and the value range is 105-115mm.

3. The radiation shielded camera system for underwater high resolution deformation measurement according to claim 2, characterized in that: The curvature radius R2 of the incident surface of the first lens (3) and the curvature radius R3 of the exit surface of the third lens (5) satisfy 3.5 < R2 / R3 < 7.

8.

4. The radiation shielded camera system for high resolution deformation measurement underwater according to claim 3, characterized in that: The central thickness CT1 of the first lens (3) and the edge thickness ET1 of the first lens (3) satisfy 0.8 < CT1 / ET1 < 2.

9. The center thickness CT2 of the second lens (4) and the center thickness CT3 of the third lens (5) satisfy: 0.28 < CT2 / CT3 < 0.62, and an aperture stop (9) is arranged between the second lens (4) and the third lens (5).

5. The radiation shielded camera system for high resolution deformation measurement underwater according to claim 4, characterized in that: The flat window (1) is made of sapphire, and the imaging surface of the camera (8) and the central optical axis of the optical path form an acute angle C of 84.75°.

6. The underwater high-resolution deformation measurement radiation-proof camera system according to claim 1, characterized in that: The incident surface radius of curvature of the first lens (3) is 140.395 mm, and the exit surface radius of curvature is 5347.199 mm; The incident surface radius of curvature of the second lens (4) is 72.628 mm, and the exit surface radius of curvature is 194.617 mm; The incident surface radius of curvature of the third lens (5) is 30.113 mm, and the exit surface radius of curvature is 25.511 mm; The incident surface radius of curvature of the fourth lens (6) is 228.863 mm, and the exit surface radius of curvature is 40.726 mm; The incident surface radius of curvature of the fifth lens (7) is 108.312 mm, and the exit surface radius of curvature is 83.909 mm.

7. The underwater high-resolution deformation measurement radiation-proof camera system according to claim 6, characterized in that: The distance between the exit surface of the first lens (3) and the incident surface of the second lens (4) on the central optical axis of the optical path is 0.407 mm; The distance between the exit surface of the second lens (4) and the incident surface of the third lens (5) on the central optical axis of the optical path is 1.432 mm; The distance between the exit surface of the third lens (5) and the incident surface of the fourth lens (6) on the central optical axis of the optical path is 4.824 mm; The distance between the exit surface of the fourth lens (6) and the incident surface of the fifth lens (7) on the central optical axis of the optical path is 20.11 mm.

Images