Lens refractive index measuring device and measuring method thereof

Abstract

The invention discloses a lens refractive index measuring device which comprises a diopter measuring module, a confocal reflection measuring module and a measured lens. The diopter measuring module isused for detecting the diopter of a measured lens, the confocal reflection measuring module is used for detecting the confocal reflection positions of the upper surface and the lower surface of the measured lens. According to the measuring device, the lens refractive index of the measured lens can be obtained, the lens does not need to be damaged, operation is easy, and detection is rapid; and the device is suitable for refractive index measurement of common lenses, aspheric lenses, cylindrical lenses and other irregular surface lenses. The method for measuring the refractive index of the lens is simple to operate, rapid in detection and high in measurement precision.

Description

technical field [0001] The invention relates to the technical field of optical measurement, in particular to a lens refractive index measurement device and a measurement method thereof. Background technique [0002] The refractive index parameter is an important parameter index of the optical lens. In order to ensure the good imaging quality of the optical system, it is necessary to accurately measure the refractive index of the optical material. At present, the high-precision measurement of the refractive index of the optical glass material is carried out by the minimum deflection angle method. The minimum deflection angle method has high precision, a large wavelength range, and is a direct measurement. However, the premise of the minimum deflection angle test method is that a prism needs to be made for light refraction, and the angle of the prism needs to be accurately tested. Such a prism is difficult to manufacture. , the cycle is long; in addition, this method cannot te...

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Problems solved by technology

[0003] At present, there are mainly two detection methods for measuring the refractive index of finished lenses. One is to perform reverse calculation based on the focal power formula, that is, to use mechanical precision measurement methods to measure the curvature of the upper and lower surfaces, the central thickness, and the focal power of the lens. The focal length company calculates the refractive index of its test wavelength. This method is complicated and difficult to guarantee the measurement accuracy, and it is not suitable for the measurement of aspheric lenses; another method is to change the "environmental" refractive index method, that is, by changing the The refractive index of the upper and lower surfaces of the contact medium, such as placing the lens in a solution with a known refractive index, or attaching a flexible medium with a known refractive index to the upper and lower surfaces of the lens, respectively testing the optical power of the lens in air and in solution, according to The refractive index of the lens material can be calculated by the change of optical power and the refractive index of the solution. This method is also complicated to operate and difficult to detect.

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