Method of assembling a curved prism

Abstract

This invention relates to prism assembly and calibration technology. To address the problems of low assembly efficiency and inability to guarantee assembly accuracy in existing curved prisms, a method for aligning curved prisms is proposed. First, based on the relationship between the curved prism and the optical system, the position coordinates of the two theoretical sphere centers of the curved prism are calculated. Then, the position coordinates of the two sphere centers are located using a coordinate measuring system, and target balls are placed at the corresponding position coordinates of the two theoretical sphere centers. A first centering instrument and a second centering instrument are used to align the target balls at the position coordinates of the two theoretical sphere centers, and then the first and second centering instruments are fixed. The target balls at the position coordinates of the two theoretical sphere centers are removed, and the curved prism is installed into the optical system. The curved prism is adjusted, and the two actual sphere centers on the curved prism are observed through the first and second centering instruments until the two actual sphere centers coincide with the two theoretical sphere centers, thus completing the assembly and calibration of the curved prism.

Description

Technical Field

[0001] This invention relates to prism mounting and alignment technology, and more specifically to a method for mounting and aligning a curved prism. Background Technology

[0002] Currently, when assembling curved prisms in optical systems, the following two methods are mainly used for assembly and correction. The first method is to use a center point of the curved prism and the circumference of the curved prism structure as assembly references to install the curved prism into the optical system. The disadvantage of this method is that one of the mounting references for the curved prism is not an optical surface reference but a structural outer circle reference, which leads to low assembly accuracy.

[0003] The second assembly and calibration method involves fitting the center of a sphere to one face of the curved prism as the assembly datum. The drawback of this method is the low accuracy of the fitted surface and its inability to fit aspherical surfaces, resulting in low assembly and calibration accuracy. Both of these methods often fail to meet design requirements after assembling the curved prism into the optical system. This necessitates extensive and repeated verification of the assembly to ensure the final result meets the optical system specifications, leading to significant waste of human, financial, and material resources. The assembly is inefficient, time-consuming, and labor-intensive, and assembly accuracy cannot be guaranteed. Therefore, a more precise assembly method is needed to meet the assembly requirements. Summary of the Invention

[0004] To address the problems of low assembly efficiency and inability to guarantee assembly accuracy in existing curved prisms, this invention proposes a method for aligning curved prisms.

[0005] To achieve the above objectives, the solution proposed in this invention is as follows:

[0006] A method for calibrating a curved prism, characterized by the following steps:

[0007] Step 1: Based on the theoretical position of the curved prism to be corrected in the optical system, calculate the position coordinates of the two theoretical sphere centers of the curved prism; a curved prism generally has two curved surfaces and two sphere centers.

[0008] Step 2: Locate the position coordinates of the two theoretical sphere center images using a coordinate measurement system, and place the target ball at the corresponding position coordinates of the two theoretical sphere center images;

[0009] Step 3: Use the first centering device and the second centering device to align with the target ball on the coordinates of the two theoretical ball center images, and then fix the first centering device and the second centering device.

[0010] Step 4: Remove the target sphere from the coordinates of the two theoretical sphere centers and install the curved prism into the optical system;

[0011] Step 5: Adjust the curved prism. Observe the two real sphere center images on the curved prism using the first and second centering instruments until the two real sphere center images coincide with the two theoretical sphere center images, thus completing the installation and calibration of the curved prism.

[0012] Furthermore, in step one, the position coordinates of the two theoretical spherical centers of the curved prism are obtained by the following formulas:

[0013] Let the theoretical spherical center image of the curved prism be A0 in the optical design theoretical coordinate system and A1 in the optomechanical system coordinate system:

[0014] A1=RA0+S

[0015] Where R is the rotation matrix from the optical design theory coordinate system to the optomechanical system coordinate system, and S is the translation matrix from the optical design theory coordinate system to the optomechanical system coordinate system.

[0016] Furthermore, the coordinate measurement system is a coordinate measuring machine or a laser tracker.

[0017] Furthermore, both the first centering instrument and the second centering instrument are autocollimating microscopes or interferometers.

[0018] The beneficial effects of this invention are:

[0019] The method for aligning curved prisms in this invention uses the optical surface of the curved prism as a positioning reference, which can effectively avoid low assembly accuracy caused by structural shape errors and surface fitting errors, and effectively improve the optical assembly efficiency and assembly accuracy of the curved prism. Its operation steps are simple and easy to implement, and the assembly error is small. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the mounting and calibration method for the curved prism of the present invention;

[0021] Figure labels: 1-Curved prism, 2-First centering instrument, 3-Second centering instrument, 4-First theoretical sphere center image, 5-Second theoretical sphere center image. Detailed Implementation

[0022] like Figure 1 As shown, a method for calibrating a curved prism includes the following steps:

[0023] Step 1: Based on the relationship between the curved prism 1 and the optical system, calculate the position coordinates of the two theoretical center images of the curved prism 1, where the two theoretical center images are the first theoretical center image 4 and the second theoretical center image 5, respectively.

[0024] Let the theoretical spherical center image of curved prism 1 be A0 in the optical design theoretical coordinate system and A1 in the optomechanical system coordinate system:

[0025] A1=RA0+S

[0026] Where R is the rotation matrix from the optical design theoretical coordinate system to the optomechanical system coordinate system, and S is the translation matrix from the optical design theoretical coordinate system to the optomechanical system coordinate system. The position coordinates of the first theoretical sphere center image 4 and the second theoretical sphere center image 5 of the curved prism 1 are calculated respectively.

[0027] Step 2: Locate the position coordinates of the first theoretical sphere center image 4 and the second theoretical sphere center image 5 using a coordinate measuring system, and place the target sphere at the position coordinates of the first theoretical sphere center image 4 and the second theoretical sphere center image 5 respectively; wherein, the coordinate measuring system adopts a three-coordinate measuring machine or a laser tracker;

[0028] Step 3: Use the first centering device 2 and the second centering device 3 to align with the target spheres at the coordinates of the two theoretical sphere center images 4 and 5, respectively. That is, use the first centering device 2 and the second centering device 3 to focus on the target spheres at the coordinates of the first theoretical sphere center image 4 and the second theoretical sphere center image 5, respectively. Then fix the first centering device 2 and the second centering device 3. Both the first centering device and the second centering device are autocollimating microscopes or interferometers.

[0029] Step 4: Remove the target sphere from the position coordinates of the first theoretical center image 4 and the second theoretical center image 5, and install the curved prism 1 into the optical system;

[0030] Step 5: Adjust the curved prism 1. Observe the two real sphere center images on the curved prism 1 through the first centering instrument 2 and the second centering instrument 3 until the two real sphere center images coincide with the first theoretical sphere center image 4 and the second theoretical sphere center image 5 respectively, thus completing the installation and calibration of the curved prism 1.

Claims

1. A method for aligning a curved prism, characterized in that, Includes the following steps: Step 1: Based on the theoretical position of the curved prism (1) to be corrected in the optical system, calculate the position coordinates of the two theoretical sphere center images of the curved prism (1); The position coordinates of the two theoretical spherical centers of the curved prism (1) are obtained by the following formulas: Let the theoretical spherical center image of the curved prism (1) be A0 in the optical design theoretical coordinate system and A1 in the optomechanical system coordinate system: A1=RA0+S Where R is the rotation matrix from the optical design theory coordinate system to the optomechanical system coordinate system, and S is the translation matrix from the optical design theory coordinate system to the optomechanical system coordinate system. Step 2: Locate the position coordinates of the two theoretical sphere center images using a coordinate measurement system, and place the target ball at the corresponding position coordinates of the two theoretical sphere center images; Step 3: Use the first centering device (2) and the second centering device (3) to align the target ball with the coordinates of the two theoretical center images, and then fix the first centering device (2) and the second centering device (3). Step 4: Remove the target spheres from the coordinates of the two theoretical sphere centers and install the curved prism (1) into the optical system; Step 5: Adjust the curved prism (1). Observe the two real sphere center images of the curved prism through the first centering instrument (2) and the second centering instrument (3) until the two real sphere center images coincide with the two theoretical sphere center images respectively, thus completing the installation and calibration of the curved prism (1).

2. The method for calibrating a curved prism according to claim 1, characterized in that: The coordinate measurement system is a coordinate measuring machine or a laser tracker.

3. The method for calibrating a curved prism according to claim 1, characterized in that: The first centering instrument (2) and the second centering instrument (3) are both autocollimating microscopes or interferometers.

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