Product introduction
 
In the optical field, the three basic parameters of lens are center thickness, refractive index and curvature radius, among which the processing error of center thickness of lens is an important factor affecting the imaging of optical system. For example, in high-precision optical system products such as aviation and aerospace, there are strict requirements for the tolerance of lenses, and the optical axis deflection angle, radial offset and axial gap of lenses need to be accurately calculated according to the central thickness of lenses in lenses; Therefore, the measurement of optical lens center thickness is an important parameter.
 
The measurement of lens center thickness is an important link in lens production. The traditional method is contact measurement, which has low precision, long time consuming, easy to scratch the lens and can not realize real-time online measurement. Another non-contact measurement using optical principle-color difference confocal principle can avoid the above problems, and its detection results are more accurate. Reliable, because the whole system does not have any non-contact measurement of moving parts, it is more excellent in terms of reliability and stability of detection results; At the same time, because of the WNHD high-speed spectrometer, it is very suitable for on-line measurement of lens center thickness in various optical fields.
The system is mainly composed of spectrometer, light source and optical probe. The light source enters the optical probe through the multimode fiber, and the optical probe focuses the light with different wavelengths on the lens at different distances to form dispersion. At the same time, the light with different wavelengths on the upper and lower surfaces of the lens forms self-perpendicular reflection spectral signals, which enter the optical probe and transmit into the spectrometer to obtain defocus with different wavelengths; Then the center thickness of the lens is calculated by software algorithm.
 
WNHD spectrometer has been successfully applied to the measurement of lens center thickness. At present, it has been used in the real-time online center thickness detection and sorting of convex lenses and concave lenses of individual optical lens element manufacturers; The main feature of the system is not to touch the lens surface measurement, so as to prevent the action from scratching the lens; At the same time, the test speed is fast, the detection accuracy is high, and the high stability repeatability is realized within 1 second.