Convenient focal plane adjusting device and adjusting method

Abstract

The invention discloses a convenient focal plane adjusting device and an adjusting method, belongs to the technical field of optics, solves the problem of quick stress-free focal plane adjustment of an optical camera, and is convenient and efficient in device and operation. The device is positioned between an optical camera lens and a focal plane electric box, and comprises a lens mounting plate for connecting the optical camera lens; the focal plane mounting plate is used for connecting a focal plane electric box and providing an adjusting interface; the spherical gasket and the focusing screw sleeve are used for adjusting a focal plane; and the positioning screw and the locknut are used for positioning and restraining. According to the device, over-positioning and additional stress cannot be generated, operation is convenient, fast and efficient, and high-precision adjustment with the displacement adjustment precision superior to 0.01 mm and the angle adjustment precision superior to 0.01 degree can be achieved by setting the installation positions and the screw pitches of the device differently.

Description

Technical Field

[0001] The invention relates to a convenient focal plane adjustment device and an adjustment method, belonging to the technical field of optics. Background Art

[0002] In the assembly and adjustment of precision optical systems, especially in the assembly and adjustment of high-sensitivity short-focus depth optical systems, strict requirements are placed on the focal position and angle accuracy of the detector. Therefore, an adjustment device is required that can simultaneously and precisely adjust the focal position and angle of the detector. The diversity of the use environment requires that the focal plane of the detector after adjustment can still maintain its original accuracy after experiencing temperature changes, vibrations and other working conditions. Therefore, the focal plane adjustment device is required to reduce the internal stress generated by the assembly and installation while ensuring locking. The growing demand for low-cost, short-cycle development of optical cameras has enabled the low cost and high convenience of the focal plane adjustment device to greatly increase the competitiveness of the product.

[0003] At present, there are mainly three types of devices and methods for adjusting the focal plane of the detector: the first is to use a theoretically calculated mechanical back intercept gasket between the camera lens and the focal plane electric box, and repeatedly grind and adjust the gasket after judging the image quality until the image quality requirements are met. This method is inefficient, time-consuming, and prone to large assembly stress; the second is to use multiple one-dimensional adjustment devices, such as cams, lead screws, etc. for multi-level superposition to achieve multi-dimensional adjustment. Due to the multi-dimensional superposition, this method has cost problems such as large size and complex structure. At the same time, due to too many moving parts, the overall stability of the device is poor; the third is to use PI to control the focal plane electric box to achieve multi-degree-of-freedom adjustment of the detector focal plane. This method requires the use of precision electronic control equipment, which is often expensive and can only be performed in specialized laboratories. It is costly and has low portability. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and provide a convenient focal plane adjustment device and an adjustment method, which can realize multi-dimensional and high-precision adjustment of the detector focal plane with low cost and high convenience, and has small internal stress and high stability.

[0005] The technical solution of the present invention is: a convenient focal plane adjustment device, comprising:

[0006] The lens mounting plate is used for transition between the lens and provided with threaded holes for passing and connecting positioning screws;

[0007] The spherical gasket is arranged between the lens mounting plate and the focusing screw sleeve and between the focal plane mounting plate and the focusing screw sleeve, and is used to realize the conversion of the linear displacement of the focusing screw sleeve into the angular rotation of the focusing mounting plate;

[0008] The focal plane mounting plate is provided with a threaded hole for passing through the focusing screw sleeve and the middle of the positioning screw and connecting with the focusing screw sleeve; the focal plane mounting plate is fixedly connected with the focal plane electric box by screw connection, and serves as a transition tooling for connecting the focal plane electric box with the adjustment device;

[0009] The focusing screw sleeve is connected and adjusted with the focal plane mounting plate through threads; a light hole is provided inside for passing the middle of the positioning screw; and both ends are tangent to the convex surface of the spherical gasket respectively;

[0010] A positioning screw, the tail of which passes through the lens mounting plate, serves as a displacement constraint for the adjustment device;

[0011] The anti-loosening nut is connected to the tail of the positioning screw and is used to prevent the positioning screw from loosening due to the adjustment process or other factors after the positioning screw is threadedly connected and positioned with the lens mounting plate.

[0012] Furthermore, the number of the lens mounting plate and the focal plane mounting plate is one each, the number of the focusing screw sleeve, the positioning screw, and the anti-loosening nut is three, and the number of the spherical gaskets is six.

[0013] Furthermore, the lens mounting plate, spherical gasket, focal plane mounting plate, focusing screw sleeve, positioning screw and anti-loosening nut are all made of TC4 grade titanium alloy metal material.

[0014] Furthermore, the end of the focusing screw sleeve is provided with a scale, and the connection between the front and rear end surfaces of the focusing screw sleeve and the inner hole is processed to form a conical surface to ensure the smoothness of the conical surface and perform surface wear resistance treatment.

[0015] Furthermore, the spherical gasket is in circular line contact with the front and rear conical surfaces of the focusing screw sleeve, so as to ensure the smoothness of the convex surface and the bottom plane of the spherical gasket and perform surface wear-resistant treatment.

[0016] Furthermore, the focusing screw thread length, the focusing screw thread pitch, the cone angles of the front and rear cones of the focusing screw and the spherical radius of the spherical gasket are adjusted according to the displacement range and displacement accuracy, angle range and angle accuracy required to be adjusted.

[0017] Furthermore, the head of the positioning screw is provided with a scale, and the positioning screw is a semi-threaded screw.

[0018] Furthermore, the diameter of the positioning screw polished rod is adjusted according to the angle range required for adjustment, and the length of the positioning screw is adjusted according to the combined length of the focusing screw sleeve and the spherical gasket.

[0019] Furthermore, a plurality of threaded holes are evenly arranged on the focal plane mounting plate.

[0020] The focal plane adjustment method implemented according to the portable focal plane adjustment device includes:

[0021] Connect and fix the focal plane mounting plate to the focal plane electrical box;

[0022] Screw three focusing screw sleeves into the three threads evenly distributed on the focal plane mounting plate to the predetermined positions respectively, and ensure that the screwing depth is the same by reading the scale of the focusing screw sleeves;

[0023] Spherical washers are placed on the front and rear conical surfaces of the focusing screw sleeve respectively, ensuring that the convex surface of the spherical washers forms a circular ring line contact with the front and rear conical surfaces of the focusing screw sleeve, forming a total of three sets of spherical washers-focusing screw sleeves-spherical washers combinations;

[0024] Use three positioning screws to pass through three sets of spherical gasket-focusing screw sleeve-spherical gasket combinations respectively, screw the positioning screws into the threads on the lens mounting plate, and press the spherical gasket-focusing screw sleeve-spherical gasket combination tightly, and ensure that the screw-in depth of the positioning screws is the same by reading the positioning screw scale;

[0025] Screw the anti-loosening nut into the thread of the positioning screw and tighten it on the lens mounting plate to ensure that the positioning screw cannot loosen;

[0026] Rotate the focusing screw sleeve and use a rotating combination of different focusing screw sleeves to adjust the two-dimensional angle and distance between the focal plane electric box and the camera lens, and obtain accuracy feedback through the scale on the focusing screw sleeve.

[0027] The advantages of the present invention compared with the prior art are:

[0028] (1) The device of the present invention is simple and efficient, and can simultaneously achieve high-precision adjustment of the focal plane position and angle;

[0029] (2) The device of the present invention has low cost, small weight and volume, high convenience and high stability;

[0030] (3) The device of the present invention does not require electronic control and can achieve high-precision adjustment manually, and is suitable for operation in various environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention after three-point installation;

[0033] Figure 2 for Figure 1 Schematic diagram of the structure from right;

[0034] Figure 3 for Figure 1 A partial enlarged view of

[0035] Figure 4 It is a schematic diagram of the focusing screw sleeve structure of the present invention;

[0036] Figure 5 It is a schematic diagram of the spherical gasket structure of the present invention. DETAILED DESCRIPTION

[0037] In order to better understand the above technical scheme, the technical scheme of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present invention, rather than limitations on the technical scheme of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0038] The following is a further detailed description of a convenient focal plane adjustment device and adjustment method provided by an embodiment of the present invention in conjunction with the accompanying drawings. The specific implementation method may include: Figure 1 , 2 As shown in Figure 3, a convenient focal plane adjustment device includes a lens mounting plate 1, a spherical gasket 2, a focal plane mounting plate 3, a focusing screw sleeve 4, a positioning screw 5, and a locking nut 6. All parts are made of TC4 brand titanium alloy metal material. The lens mounting plate 1 is used for the transition between the lens and is provided with a threaded hole for passing through and connecting the positioning screw 5; the spherical gasket 2 is arranged between the lens mounting plate 1 and the focusing screw sleeve 4 and between the focal plane mounting plate 3 and the focusing screw sleeve 4, and is used to realize the conversion of the linear displacement of the focusing screw sleeve 4 into the angular rotation of the focusing mounting plate 3; the focal plane mounting plate 3 is provided with three special threaded holes for passing through the focusing screw sleeve 4 and the middle part of the positioning screw 5 and connecting to the focusing screw sleeve 4; the focal plane mounting plate 3 is fixedly connected to the focal plane electrical box by screwing. The focusing screw sleeve 4 is connected to the focal plane mounting plate 3 through a thread to realize connection and adjustment. A light hole is provided inside for passing the middle of the positioning screw 5. Both ends are tangent to the convex surface of the spherical gasket 2 respectively. The tail of the positioning screw 5 passes through the lens mounting plate 1 to serve as a displacement constraint for the adjustment device. The anti-loosening nut 6 is connected to the tail of the positioning screw 5 to prevent the positioning screw 5 from loosening due to the adjustment process and other factors after the positioning screw 5 is threadedly connected and positioned with the lens mounting plate 1.

[0039] In the solution provided in the embodiment of the present invention, the camera lens is fixedly connected to the lens mounting plate 1 by means of screws.

[0040] The focal plane electric box is fixedly connected to the focal plane mounting plate 3 by screws.

[0041] After ensuring the connection between the camera lens and the detector electrical box, the position and angle adjustment between the camera lens and the detector focal plane can be converted into the position and angle adjustment between the lens mounting plate 1 and the focal plane mounting plate 3.

[0042] Screw the focusing screw sleeve 4 into the three threaded holes matching the focal plane mounting plate 3 through the external thread 4-1, ensuring that the square heads 4-2 of the three focusing screw sleeves 4 are all facing away from the lens mounting plate, and determine that the screw-in depths of the three focusing screw sleeves 4 are basically the same based on the thread marks of the external thread 4-1.

[0043] Lay the lens mounting plate 1 flat, with the mounting plane 1-1 of the lens mounting plate away from the optical lens facing upward.

[0044] Three spherical gaskets 2 are respectively aligned and placed at the three mounting threaded holes of the lens mounting plate 1, so that the flat end surface 2-1 of each spherical gasket 2 is in contact with the mounting plane 1-1, and the central light hole of each spherical gasket 2 is basically aligned with the corresponding threaded hole of the lens mounting plate 1.

[0045] Place the focal plane mounting plate 3 with three focusing screw sleeves 4 flat on the above-mentioned spherical gasket 2 with the square head 4-2 of the focusing screw sleeve 4 facing upward, ensure that the downward conical surface 4-3 of each focusing screw sleeve 4 is tangent to the spherical surface 2-2 of the spherical gasket 2 below it to form a circular line contact, and adjust the central light hole of each focusing screw sleeve 4 to be basically aligned with the central light hole of each spherical gasket 2.

[0046] Place the three spherical gaskets on the upward conical surfaces 4-3 of the three focusing screw sleeves 4 with the spherical surfaces 2-2 facing downward, ensure that the upward conical surface 4-3 of each focusing screw sleeve 4 is tangent to the spherical surface 2-2 of the spherical gasket 2 above it to form a circular line contact, and adjust the central light hole of each spherical gasket 2 to be basically aligned with the central light hole of each focusing screw sleeve 4.

[0047] Pass the three positioning screws 5 through the three sets of "spherical gasket-focusing screw sleeve-spherical gasket" combinations respectively, screw the positioning screws into the reserved threaded holes on the lens mounting plate, and tighten the "spherical gasket-focusing screw sleeve-spherical gasket" combination, and ensure that the depth of the screwed-in screws is basically the same by reading the positioning screw scale.

[0048] Screw three anti-loosening nuts 6 into three positioning screws 5 respectively and fasten them to the lens mounting plate 1 to ensure that the positioning screws 5 cannot be loosened no matter how they are rotated. If necessary, glue can be applied for reinforcement.

[0049] like Figure 4The focusing screw sleeve 4 is provided with a scale at the square head 4-2, and the manual rotation adjustment of the focusing screw sleeve 4 can be achieved by rotating the square head with a fixed wrench. The adjustment accuracy is generally better than 5°. The front and rear conical surfaces 4-3 of the focusing screw sleeve 4 ensure smoothness and are treated for surface wear resistance. The pitch of the external thread 4-1 of the focusing screw sleeve 4 is determined according to the focal depth of the optical system to determine the appropriate focusing accuracy. Generally, fine pitch threads are used. This example uses a customized pitch of 0.5mm. The manual adjustment accuracy can be achieved according to the scale

[0050] The length N of the external thread 4-1 of the focusing screw sleeve 4 is determined according to the mechanical back intercept position of the optical camera and the maximum front-back displacement L of the focal plane. max OK, need to ensure N≤L max .

[0051] The inner hole diameter of the focusing screw sleeve 4 is Φ1, the screw diameter of the positioning screw is Φ2, the combined length of the "spherical gasket-focusing screw sleeve-spherical gasket" is L1, and the maximum value of the required adjustment angle is θ max There is the following relationship between them:

[0052] like Figure 5 The spherical surface 2-1 of the spherical gasket 2 and the front and rear conical surfaces 4-1 of the focusing screw sleeve 4 are in circular contact, which ensures the smoothness of the spherical surface 2-1 of the spherical gasket and the bottom plane 2-2 and performs surface wear resistance treatment. The cone angle α of the focusing screw sleeve, the maximum radius of the cone chamfer R1, and the maximum value of the required adjustment angle θ max , the spherical radius R2 of the spherical gasket and the inner diameter Φ1 of the screw sleeve have the following relationship:

[0053]

[0054] Adjust the values ​​of various parameters according to actual needs and design the matching dimensions of various parts that meet the requirements.

[0055] According to the principle of semi-kinematic adjustment, the focal plane electric box is adjusted by three-point support. There is the following relationship between the radius R3 of the circle at the screw sleeve installation point, the single-point displacement adjustment accuracy ΔL, and the detector focal plane angle adjustment accuracy Δθ: In this example, R3 is 100 mm, ΔL = 0.007 mm, and thus

[0056]

[0057] According to the principle of kinematics, each object has six degrees of freedom. The present device can be understood as a hinge support. Each hinge support will constrain two degrees of freedom. Three hinge supports will completely constrain the focal plane, thereby avoiding over-constraint.

[0058] By rotating the focus screw sleeve 4, the focus tooling is displaced axially on the focus screw sleeve 4, thereby pushing the spherical gasket to slide on the fixed tooling and the positioning screw pressure surface respectively with a small displacement, and a new statically determinate structure is formed. Using this method, by adjusting the three support points, the focus plane mounting plate and the fixed tooling can be adjusted at any angle except for image rotation. By rotating the three screw sleeves separately, the screwing amount of each screw sleeve is ensured to be consistent through the scale, and the distance between the focus plane mounting plate and the fixed tooling can be adjusted.

[0059] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0060] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A convenient focal plane adjustment device, characterized in that: include: A lens mounting plate (1) is used for transition between the lens and provided with a threaded hole for passing and connecting a positioning screw (5); The spherical gasket (2) is arranged between the lens mounting plate (1) and the focusing screw sleeve (4) and between the focal plane mounting plate (3) and the focusing screw sleeve (4) and is used to realize the conversion of the linear displacement of the focusing screw sleeve (4) into the angular rotation of the focusing mounting plate (3); The focal plane mounting plate (3) is provided with a threaded hole for passing through the middle of the focusing screw sleeve (4) and the positioning screw (5) and being connected to the focusing screw sleeve (4); the focal plane mounting plate (3) is fixedly connected to the focal plane electric box by screw connection, and serves as a transition tooling for connecting the focal plane electric box with the adjustment device; The focusing screw sleeve (4) is connected and adjusted with the focal plane mounting plate (3) through a thread; a light hole is provided inside for passing the middle of the positioning screw (5); and both ends are tangent to the convex surface of the spherical gasket (2) respectively; A positioning screw (5), the tail of which passes through the lens mounting plate (1), serves as a displacement constraint for the adjustment device; The anti-loosening nut (6) is connected to the tail of the positioning screw (5) and is used to prevent the positioning screw (5) from loosening due to the adjustment process or other factors after the positioning screw (5) is threadedly connected and positioned with the lens mounting plate (1).

2. A convenient focal plane adjustment device according to claim 1, characterized in that: The number of the lens mounting plate (1) and the focal plane mounting plate (3) is one each, the number of the focusing screw sleeve (4), the positioning screw (5) and the anti-loosening nut (6) is three, and the number of the spherical gaskets (2) is six.

3. The portable focal plane adjustment device according to claim 1, characterized in that: The lens mounting plate (1), the spherical gasket (2), the focal plane mounting plate (3), the focusing screw sleeve (4), the positioning screw (5) and the anti-loosening nut (6) are all made of TC4 grade titanium alloy metal material.

4. The portable focal plane adjustment device according to claim 1, characterized in that: The end of the focusing screw sleeve (4) is provided with a scale, and the connection between the front and rear end surfaces of the focusing screw sleeve (4) and the inner hole is processed to form a conical surface, so as to ensure the smoothness of the conical surface and perform a surface wear-resistant treatment.

5. The portable focal plane adjustment device according to claim 4, characterized in that: There is circular line contact between the spherical gasket (2) and the front and rear conical surfaces of the focusing screw sleeve (4), thereby ensuring the smoothness of the convex surface and the bottom plane of the spherical gasket (2) and performing surface wear resistance treatment.

6. The portable focal plane adjustment device according to claim 5, characterized in that: The thread length of the focusing screw sleeve (4), the thread pitch of the focusing screw sleeve (4), the cone angles of the front and rear cone surfaces of the focusing screw sleeve (4), and the spherical radius of the spherical gasket (2) are adjusted according to the displacement range and displacement accuracy, angle range and angle accuracy required to be adjusted.

7. The portable focal plane adjustment device according to claim 4, characterized in that: The head of the positioning screw (5) is provided with a scale, and the positioning screw (5) is a semi-threaded screw.

8. The portable focal plane adjustment device according to claim 7, characterized in that: The diameter of the polished rod of the positioning screw (5) is adjusted according to the angle range required for adjustment, and the length of the positioning screw (5) is adjusted according to the combined length of the focusing screw sleeve (4) and the spherical gasket (2).

9. The portable focal plane adjustment device according to claim 5, characterized in that: A plurality of threaded holes are evenly arranged on the focal plane mounting plate (3).

10. The focal plane adjustment method implemented by the portable focal plane adjustment device according to claim 9, characterized in that: include: Connect and fix the focal plane mounting plate (3) to the focal plane electrical box; Three focusing screw sleeves (4) are respectively screwed into three threads evenly distributed on the focal plane mounting plate (3) to predetermined positions, and the same screwing depth is ensured by reading the scale of the focusing screw sleeves (4); Spherical gaskets (2) are respectively placed on the front and rear conical surfaces of the focusing screw sleeve (4) to ensure that circular ring line contact is formed between the convex surface of the spherical gasket (2) and the front and rear conical surfaces of the focusing screw sleeve (4), so as to form a total of three groups of spherical gasket (2)-focusing screw sleeve (4)-spherical gasket (2) combinations; Three positioning screws (5) are respectively passed through three groups of spherical gasket (2)-focusing screw sleeve (4)-spherical gasket (2) combinations, the positioning screws (5) are screwed into the threads on the lens mounting plate (1), and the spherical gasket (2)-focusing screw sleeve (4)-spherical gasket (2) combination is pressed tightly, and the positioning screws (5) are ensured to have the same screw-in depth by reading the scale of the positioning screws (5); Screw the anti-loosening nut (6) into the thread of the positioning screw (5) and tighten it on the lens mounting plate (1) to ensure that the positioning screw (5) cannot loosen; The focusing screw sleeve (4) is rotated, and a rotational combination of different focusing screw sleeves (4) is adopted to adjust the two-dimensional angle and spacing between the focal plane electric box and the camera lens, and precision feedback is obtained through the scale on the focusing screw sleeve (4).

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