A pentaprism right-angle error detection auxiliary device and detection method

Abstract

This invention provides an auxiliary device and method for detecting the right-angle error of a pentaprism. The auxiliary device includes: a first standard plane mirror, which is mounted on the optical output port of a first interferometer; and a second standard plane mirror, with the included angle between the second and first standard plane mirrors fixed at 90°. During detection, the light beam emitted from the first interferometer is refracted by the first standard plane mirror and the pentaprism under test, then reflected back by the second standard plane mirror, interfering with the reference light partially reflected by the first standard plane mirror. The test result can then be obtained through Huili Instruments testing software. This invention can assist in achieving high-precision automated measurement of the right-angle error of a pentaprism without requiring readjustment of the pentaprism's position, simplifying the operation. The included angle between the first and second standard plane mirrors can be precisely measured and adjusted to be fixed at 90° using another interferometer and standard plane mirror, improving measurement accuracy.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement, specifically relating to an auxiliary device and method for detecting right-angle error of a pentaprism. Background Technology

[0002] A pentaprism is a common beam deflector with two refractive surfaces and two reflective surfaces. It possesses the optical property of refracting light perpendicularly within its principal section without producing a mirror image. The principal section of an ideal pentaprism 1 is shown below. Figure 4 As shown. Pentagonal prisms have a wide range of applications in engineering, such as wavefront detection using pentagonal prism scanning, focal plane monitoring of collimators using the refraction characteristics of pentagonal prisms, and surface shape detection of optical components.

[0003] In engineering applications, pentaprisms cannot be perfectly ideal. Manufacturing errors mainly manifest as discrepancies between the ideal values ​​and the ∠A, ∠B, ∠E, and ∠F within the principal cross-section. These angular manufacturing errors alter the pentaprism's constant-rotation light characteristics, directly impacting its engineering application results. For instance, in space optoelectronic tracking systems, a combination of a large-aperture collimator and a pentaprism is often used to calibrate the optical axis parallelism of various optoelectronic systems. Manufacturing errors in the pentaprism directly affect the calibration accuracy of multi-axis parallelism. Therefore, error analysis of the pentaprism is necessary to correct test results.

[0004] The existing measuring device uses the self-collimation principle to measure the manufacturing error of a pentaprism 1. The method and process are as follows: First, as Figure 5 As shown, place the photoelectric autocollimator 2 and the plane mirror 3. Adjust the visual axis of the photoelectric autocollimator 2 to be horizontal, adjust the mirror surface of the plane mirror 3 to be perpendicular to the visual axis, and adjust the incident surface of the pentaprism 1 to be perpendicular to the visual axis. Next, set the dial of the multi-tooth indexing stage 4 to 0°0'0". Without placing the pentaprism 1, align the adjusted photoelectric autocollimator 2 with the plane mirror 3, so that the cross image reflected by the plane mirror 3 coincides with the reticle of the photoelectric autocollimator 2, and read the data α1 at this time. Then, as... Figure 6 As shown, the multi-tooth indexing stage 4 is rotated 90°0' clockwise, and the plane mirror 3 is also rotated 90°0' clockwise along with the multi-tooth indexing stage 4. The pentaprism 1 to be measured is placed on the multi-tooth indexing stage 4. The light emitted by the photoelectric autocollimator 2 is reflected back to the plane mirror 3 through the pentaprism 1, and then reflected back to the photoelectric autocollimator 2, from which the reading α2 can be obtained. Furthermore, if the bending angle of the pentaprism 1 is 90°, the reading of the photoelectric autocollimator 2 should be α2 = α1. When there is an error Δα in the bending angle, α2 ≠ α1, and Δα = α2 - α1.

[0005] It has been found through practice that the measurement device and method bring relatively many errors during operation, require repeated adjustment, and there is also the problem of low measurement accuracy. Among them, the errors mainly include the indication error and reading error of the photoelectric autocollimator, the error caused by the repeatability of photoelectric aiming, the indexing error and adjustment error of the multi-tooth dividing table. Summary of the Invention

[0006] The present invention is made to solve the above problems, and aims to provide an auxiliary device and method for detecting the right-angle error of a pentaprism.

[0007] The present invention provides an auxiliary device for detecting the right-angle error of a pentaprism, which has the following characteristics: including a first standard plane mirror, which is used to be arranged on the optical path output port of the first interferometer and the mirror surface is perpendicular to the optical axis of the first interferometer; and a second standard plane mirror, which is used to be arranged in front of the optical path output port of the first interferometer and the included angle between the mirror surface and the mirror surface of the first standard plane mirror is fixed at 90°; wherein, the first standard plane mirror is a transmissive mirror, and the second standard plane mirror is a reflective mirror or a transmissive mirror.

[0008] In the auxiliary device for detecting the right-angle error of a pentaprism provided by the present invention, it may also have the following characteristics: further including an included angle fixing device, which is used to set and fix the included angle between the first standard plane mirror and the second standard plane mirror at 90°.

[0009] In the auxiliary device for detecting the right-angle error of a pentaprism provided by the present invention, it may also have the following characteristics: the pentaprism has an incident surface and an exit surface that are perpendicular to each other, and the mirror surfaces of the first standard plane mirror and the second standard plane mirror are respectively arranged parallel to the incident surface and the exit surface during detection.

[0010] The present invention also provides a method for detecting the right-angle error of a pentaprism, which has the following characteristics: using the above-mentioned auxiliary device for detecting the right-angle error of a pentaprism, including the following steps: setting the first standard plane mirror on the optical path output port of the first interferometer and the mirror surface is perpendicular to the optical axis of the first interferometer, setting the second standard plane mirror in front of the optical path output port of the first interferometer and the included angle between the mirror surface and the mirror surface of the first standard plane mirror is fixed at 90°; controlling the first interferometer to emit a beam of light. When the beam of light hits the first standard plane mirror, a part is reflected back as reference light, and the other part is transmitted and incident perpendicularly to the incident surface of the pentaprism. Then, after being reflected by two reflecting surfaces inside the pentaprism, it exits through the exit surface and reaches the second standard plane mirror. A part of the beam of light is reflected back by the second standard plane mirror. The part of the beam of light reflected back interferes with the first reference light after passing through the pentaprism and the first standard plane mirror in sequence; obtaining the test result of the right-angle error of the pentaprism through the HuiLi instrument test software supporting the first interferometer.

[0011] The pentaprism right-angle error detection method provided by this invention may also have the following features: after setting the first standard plane mirror and the second standard plane mirror, and before controlling the first interferometer to emit a light beam, the second interferometer and a transmission mirror set on the optical path output port of the second interferometer as the third standard plane mirror are used to control the second interferometer to emit a light beam. When the light beam hits the third standard plane mirror, part of it is reflected back as the second reference light, and the other part is transmitted out and reflected back by the first standard plane mirror and the second standard plane mirror, interfering with the second reference light. The angle between the first standard plane mirror and the second standard plane mirror is obtained by the Huili Instruments testing software that is matched with the second interferometer, and then the angle between the first standard plane mirror and the second standard plane mirror is adjusted and precisely calibrated to 90°.

[0012] The role and effect of invention

[0013] According to the auxiliary device and method for detecting the right angle error of a pentaprism disclosed in this invention, based on laser interferometry, when detecting the right angle error of a pentaprism, a first standard plane mirror is mounted on an interferometer so that it still functions as a "standard mirror". The beam emitted by the interferometer passes through the first standard plane mirror and the pentaprism under test, and then reaches the second standard plane mirror. Since the second standard plane mirror is a reflecting or transmitting mirror, a portion of the beam reaching the second standard plane mirror is reflected back. After passing through the pentaprism under test and the first standard plane mirror in sequence, it interferes with the reference light partially reflected by the first standard plane mirror. Then, by processing the collected wavefront data using Huili Instruments testing software, the angle between the wavefront of the light reflected by the standard mirror and the wavefront reflected by the second standard plane mirror after being refracted by the pentaprism can be obtained. This invention can assist in the high-precision automated measurement of pentaprism right angle error detection. Compared with the prior art, the position of the pentaprism does not need to be readjusted during the detection operation, which simplifies the operation steps. The included angle between the first standard plane mirror and the second standard plane mirror can be accurately measured and adjusted to 90° by another interferometer, another standard plane mirror and the matching Huili Instruments testing software. The error is extremely small and no further adjustment is required, which improves the measurement accuracy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the pentaprism right-angle error detection auxiliary device in an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram of the optical path of the pentaprism right-angle error detection auxiliary device during calibration in an embodiment of the present invention;

[0016] Figure 3 This is a schematic diagram of the optical path of the pentaprism right-angle error detection auxiliary device used to detect a pentaprism in an embodiment of the present invention;

[0017] Figure 4This is a schematic diagram of the main cross-section of an ideal pentaprism in the prior art;

[0018] Figure 5 This is a schematic diagram of a measuring device using the self-collimation principle in the prior art;

[0019] Figure 6 This is a schematic diagram of a measuring device in the prior art that uses the self-collimation principle to measure a pentaprism.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Pentagonal prism; 2. Photoelectric autocollimator; 3. Plane mirror; 4. Multi-tooth indexing stage; 5. First interferometer; 10. First standard plane mirror; 20. Second standard plane mirror; 30. Second interferometer; 40. Third standard plane mirror. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments are described in detail with reference to the accompanying drawings.

[0023] Example

[0024] Figure 1 This is a schematic diagram of the auxiliary device for detecting right-angle errors in a pentaprism.

[0025] like Figure 1 As shown, this embodiment provides an auxiliary device for detecting right angle error of a pentaprism, including a first standard plane mirror 10 and a second standard plane mirror 20.

[0026] The first standard plane mirror 10 is used to be set on the optical path output port of the first interferometer 5 and the mirror surface is set perpendicular to the optical axis of the first interferometer 5. The first standard plane mirror 10 is a transmission mirror.

[0027] The second standard plane mirror 20 is used to be placed in front of the optical path output port of the first interferometer 5, and the angle between the mirror surface and the mirror surface of the first standard plane mirror 10 is fixed at 90°. The second standard plane mirror 20 can be a reflecting mirror or a transmitting mirror.

[0028] In practical implementation, the first standard plane mirror 10 and the second standard plane mirror 20 can be fixed at 90° using a specialized angle-fixing device. This device can be a clamp, bracket, or other similar device found in existing technology. After installation, the angle between the first standard plane mirror 10 and the second standard plane mirror 20 can be measured and calibrated using the second interferometer 30, the accompanying Huili Instruments testing software, and the third standard plane mirror 40 to ensure the dihedral angle is precisely fixed at 90°. See [link / details]. Figure 2 The third standard plane mirror 40 is a transmission mirror.

[0029] Figure 3 This is a schematic diagram of the optical path of the pentaprism right-angle error detection auxiliary device used to detect pentaprism 1.

[0030] This pentaprism right-angle error detection auxiliary device can assist in the measurement of the right-angle error of a single pentaprism using laser interferometry.

[0031] Before the measurement begins, the pentaprism right angle error detection auxiliary device needs to be installed. The specific process is as follows: a high-precision first standard plane mirror 10 is installed on the optical path output port of the interferometer 5, and another high-precision second standard plane mirror 20 is installed in front of the optical path output port of the interferometer 5 through the angle fixing device. The angle between the second standard plane mirror 20 and the first standard plane mirror 10 is 90°.

[0032] Further calibrate the angle between the second standard plane mirror 20 and the first standard plane mirror 10, ensuring that the mirror surface of the first standard plane mirror 10 is perpendicular to the optical axis of the interferometer 5 and the mirror surface of the second standard plane mirror 20 is parallel to the optical axis of the interferometer 5. Then, the right-angle error of the pentaprism 1 can be measured. The process of calibrating the angle between the second standard plane mirror 20 and the first standard plane mirror 10 is as follows: Figure 2 As shown, the second interferometer 30 is positioned at the angle between the first standard plane mirror 10 and the second standard plane mirror 20. The aperture of the second interferometer 30 covers the first standard plane mirror 10 and the second standard plane mirror 20, and the emitted beam can hit the edges of the first standard plane mirror 10 and the second standard plane mirror 20. A third standard plane mirror 40 is installed on the optical path output port of the second interferometer 30. During calibration, the second interferometer 30 is controlled to emit a beam. When the beam hits the third standard plane mirror 40, part of it is reflected back as the second reference light, and the other part is transmitted out and reflected back by the first standard plane mirror 10 and the second standard plane mirror 20. It then interferes with the second reference light as the second test light. The angle between the first standard plane mirror 10 and the second standard plane mirror 20 is obtained through the Huili Instruments testing software that is compatible with the second interferometer 30. Based on this, the angle between the first standard plane mirror 10 and the second standard plane mirror 20 is adjusted and precisely calibrated to 90°. The precision control can reach the order of seconds.

[0033] like Figure 3As shown, the detection method and process for detecting the right angle error of a pentaprism using this pentaprism right angle error detection auxiliary device are as follows: The interferometer 5 emits a light beam through the optical path output port. The light beam first hits the first standard plane mirror 10. Part of it is reflected back as the first reference light, and the other part is transmitted out. The transmitted light beam is incident perpendicularly to the refraction (incident) surface AE of the pentaprism 1. After being reflected by the reflecting surfaces BC and DE inside the pentaprism 1, it exits through another refraction (exit) surface AB. When the light beam exiting from the refraction surface AB reaches the second standard plane mirror 20, since the second standard plane mirror 20 can be a reflecting mirror or a transmitting mirror, all or part of the light beam is reflected back by the second standard plane mirror 20. After the reflected light beam passes through the pentaprism 1 and the first standard plane mirror 10 in sequence, it interferes with the first reference light as the first test light. At the same time, the right angle error of the pentaprism 1 can be obtained in the Huili Instruments testing software that is compatible with the interferometer 5 on the computer.

[0034] The test results are directly output through the Huili Instruments testing software on the computer, which can be easily connected to other automated equipment to achieve test automation.

[0035] It should also be noted that the aforementioned Huili Instruments testing software has the following function: processing the wavefront data of the acquired interfering reference light and test light to obtain the angle between the wavefronts of the reference light and the test light. The Huili Instruments testing software is prior art, and this application does not involve software improvement.

[0036] The role and effect of the embodiments

[0037] According to the pentaprism right-angle error detection auxiliary device and detection method involved in this embodiment, based on laser interferometry, when detecting the right-angle error of the pentaprism, the first standard plane mirror is installed on the interferometer so that it still functions as a "standard mirror". The beam emitted by the interferometer passes through the first standard plane mirror and the pentaprism under test and then reaches the second standard plane mirror. Since the second standard plane mirror is a reflecting mirror or a transmitting mirror, part of the beam reaching the second standard plane mirror will be reflected back. After passing through the pentaprism under test and the first standard plane mirror in sequence, it interferes with the reference light partially reflected by the first standard plane mirror. Then, by processing the collected wavefront data through Huili Instruments testing software, the angle between the wavefront of the standard mirror reflected light and the wavefront reflected by the second standard plane mirror after being refracted by the pentaprism can be obtained. This invention can assist in the high-precision automated measurement of pentaprism right angle error detection. Compared with the prior art, the position of the pentaprism does not need to be readjusted during the detection operation, which simplifies the operation steps. The included angle between the first standard plane mirror and the second standard plane mirror can be accurately measured and adjusted to 90° by another interferometer, another standard plane mirror and the matching Huili Instruments testing software. The error is extremely small and no further adjustment is required, which improves the measurement accuracy.

[0038] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A method for detecting right-angle error of a pentaprism, wherein the pentaprism has an incident surface, an exit surface, two reflecting surfaces, and an auxiliary surface, characterized in that: Adopt an auxiliary device for detecting the right-angle error of a pentaprism. The auxiliary device for detecting the right-angle error of a pentaprism includes: A first standard flat mirror, which is used to be arranged on the optical path output port of the first interferometer and the mirror surface is perpendicular to the optical axis of the first interferometer. The first standard flat mirror is a transmissive mirror. A second standard flat mirror, which is used to be arranged in front of the optical path output port of the first interferometer and the included angle between the mirror surface and the mirror surface of the first standard flat mirror is fixed at 90°. The second standard flat mirror is a reflective mirror or a transmissive mirror. The method for detecting the right-angle error of a pentaprism includes the following steps: Set the first standard flat mirror on the optical path output port of the first interferometer and the mirror surface is perpendicular to the optical axis of the first interferometer. Set the second standard flat mirror in front of the optical path output port of the first interferometer and the included angle between the mirror surface and the mirror surface of the first standard flat mirror is fixed at 90°. Control the first interferometer to emit a beam of light. When the beam hits the first standard flat mirror, a part of it is reflected back as the first reference light, and the other part is transmitted and incident perpendicularly to the incident surface of the pentaprism. Then, after being reflected by two reflecting surfaces inside the pentaprism, it exits through the exit surface and reaches the second standard flat mirror. A part of the beam is reflected back by the second standard flat mirror. This part of the reflected beam, after passing through the pentaprism and the first standard flat mirror in sequence, interferes with the first reference light. Obtain the test result of the right-angle error of the pentaprism through the test software supporting the first interferometer.

2. The method for detecting the right-angle error of a pentaprism according to claim 1, wherein: in, [[ID= ​ in, ​ ​ ​ in, ​

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