Optical testing system and method thereof

Abstract

The invention provides an optical testing system and a method thereof. The system comprises a test light source module; a reflection module provided with a test object and used for receiving the light source light emitted by the test light source module; a first optical element; a detection module used for receiving the reflected light rays which are reflected by the reflection module and transmitted by the first optical element, and collecting the positions where the detection module is moved to the highest imaging quality before and after the test object is displaced; and a control module used for obtaining the displacement of the test object according to the displacement of the detection module. The testing system is simple in structure, small in size and wide in application range, the testing method is simple, convenient and reliable in process step and rapid and accurate in measurement, the displacement can be effectively reduced, and especially the cost of high-precision measurement of the lens back focus and the back focus variation can be effectively reduced.

Description

technical field [0001] The invention relates to the field of optical component testing, in particular to an optical testing system and a method thereof. Background technique [0002] Displacement is one of the basic geometric parameters, and its accurate measurement is very important for people to engage in research in various fields and promote scientific progress. Compared with other mechanical quantities, displacement is easy to detect and has high accuracy, so the physical quantity of the measured object is often converted into displacement for detection. [0003] For example, in the field of optical lenses, the back focus of optical lenses will change under different temperature conditions, resulting in focal plane shift. When the focal plane shifts too much, it will cause unclear imaging. Therefore, temperature compensation needs to be considered in the lens design process. , so it is necessary to accurately measure the amount of back focus change (displacement) of th...

AI Technical Summary

Problems solved by technology

At present, the conventional thermal compensation test method is to put the lens in a high and low temperature box, and when the required temperature is reached, the lens is quickly taken out for the back focus test. However, due to the temperature difference between the lens temperature and the external temperature, the temperature is constantly changing during the test. Lead to inaccurate testing and poor repeatability

[0004] For another example, in the application where the back focus position cannot be actively adjusted after the lens is assembled, if the back focus of the lens cannot be accurately measured before assembly, the imaging surface of the lens optical system will not match the focal plane of the photodetector device, and the optical system will not be able to Accurate imaging on the focal plane of the photodetector seriously affects the imaging quality; in addition, the continuous development and progress of science and technology have higher and higher requirements for the accuracy of the back focus test (the accuracy needs to reach 1 μm or even 0.5 μm), while the general back focus The accuracy of the tester can only reach about 5 μm to 10 μm, which cannot achieve the purpose of accurate measurement; if a high-precision grating ruler is used, the test accuracy can be improved, but the cost will be very high

[0005] Other measurement methods mainly include mechanical method, optical method, electrical method and pneumatic method, but the current test scheme generally has the defects of large equipment volume, expensive equipment and high cost

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