Lens center thickness measuring device and method based on double face confocal measurement

Abstract

The invention discloses a lens center thickness measuring device based on double face confocal measurement. The device is characterized by comprising a controller with a spectrograph, an optical probe I, a two-dimensional moving frame, a lens clamp, an optical probe II, a support and a computer. The optical probe I, the two-dimensional moving frame and the optical probe II are all fixed on the support, the lens clamp is clamped on the two-dimensional moving frame, the controller is connected with the optical probe I and the optical probe II through optical fibers, the two-dimensional moving frame is located between the two optical probes, and the computer is connected with the controller with the spectrograph through a data line. The device has the advantage that 1 each optical probe is only required to detect first peak of return wavelength, the problem that the false peak is required to be recognized under the condition that a lens is coated by a film is solved, and thickness measurement of the lens coated by the film is achieved; 2 two optical probes are utilized to reduce errors caused by the fact that light enters the lens to be refracted and reflected, and measurement accuracy is improved; 3 the method can be used for thickness measurement of the opaque object allowing double-face reflection, and the measurement range of the confocal measurement is expanded.

Description

technical field [0001] The invention relates to a lens center thickness measurement device based on double-sided confocal and a measurement method using the same, belonging to the field of optical lens measurement. Background technique [0002] The lens has three basic parameters: central thickness, refractive index and radius of curvature. In the field of optics, the error of lens central thickness processing is an important factor affecting the imaging of the optical system. [0003] The existing methods for measuring the thickness of the lens center include contact measurement and non-contact measurement. [0004] In contact measurement, calipers, micrometers and other measuring tools are generally used to measure the center thickness of the lens and the air gap of the lens group. This type of method has a slow and inaccurate measurement speed, and secondly, it is easy to scratch the polished or coated surface of the measured lens, resulting in additional stray light of ...

AI Technical Summary

Problems solved by technology

However, in both patents, light needs to enter the lens to be refracted and then return to refraction through reflection, which inevitably reduces the accuracy of this measurement method, and there will also be a relatively large gap when measuring the coated lens. question

Images