Device and method for measuring center deviation of optical lens

Abstract

The invention discloses an optical lens center deviation measurement device, which comprises an optical measurement module, a mechanical adjustment module, a main control computer and an optical platform, the optical measurement module is connected with the mechanical adjustment module, and the optical measurement module and the mechanical adjustment module are connected to the The above-mentioned main control computer is electrically connected, the optical measurement module includes two sets of objective lenses and auxiliary objective lenses, the two sets of objective lenses and auxiliary objective lenses are switched, and the focus is adjusted through the mechanical adjustment module, so that the curvature radius of the concave or convex lens to be measured is in the "confocal mode "There is a larger measurement range, so that higher measurement accuracy can be obtained. Adopting two groups of switching lenses, while ensuring the measurement accuracy, reduces the cost, makes the operation process simple, and improves the work efficiency.

Description

technical field [0001] The invention relates to the technical field of optical measuring instruments, and more precisely relates to an optical lens center deviation measuring device and method. Background technique [0002] Optical systems are widely used in civil, industrial inspection, medical, scientific research, aerospace, and national defense and military fields. Moreover, with the continuous advancement of technology, the optical system is more complex, and the requirements for the imaging quality of the optical system are also continuously improved. The number of lenses in an optical system is constantly increasing and the tolerances are getting tighter. Specifically, the optical system is generally composed of an optical lens, a mechanical structure, and a photoelectric detector, wherein the centering accuracy of the lens in the optical lens directly determines the imaging quality of the optical lens. It can be seen that in order to improve the overall performance...

AI Technical Summary

Problems solved by technology

The first solution is to use the reflective autocollimation method, which is a combination of the focusing method and the switching lens method: the focusing method is to move the collimating lens group in the optical measurement module up and down along the optical axis to achieve target focus The point is continuously adjusted in a far range; the switching lens method is to place the focusing lens group at the position where parallel light is generated, by switching lenses with different focal lengths, and cooperating with the movement of the vertical guide rail to achieve the target focus point in a closer range Internal continuous adjustment; the combination of focusing method and switching lens method can realize the target focus in the whole range and adjust continuously, so as to realize the measurement of the spherical radius in the whole range; the solution of using the reflective autocollimation method has no measurement range Blind area, but the measurement accuracy is not high enough, and the number of lenses that need to be switched according to the F number of the mirror to be tested is large, the operation is complicated, the measurement efficiency is low, and the equipment cost is high

The second solution is to use reflective focus imaging and reflective vertex imaging, and use the defocus measurement method for measurement: for a single surface to be measured, the laser focus point will be in the center of curvature after the laser focus point is focused on the center of curvature of the surface to be measured. Before imaging, or after the laser focus is focused on the vertex of the surface to be measured, it is imaged before the vertex. The distance between the laser focal plane and the image plane after imaging the surface to be measured is recorded as ΔT. At this time, the detector plane and the image plane generate The fixed distance is denoted as L; reflective focus defocus imaging is called "confocal mode", and reflective vertex defocus imaging is called "conventional mode". The measurement range of "conventional mode" is not limited, but "confocal mode "The measurement range is limited when the rear working distance and focusing stroke are fixed

The optical measurement module of the second scheme only needs one objective lens, and there is no blind area in the measurement range of the curvature radius of this scheme, but the measurement range of the "confocal mode" is very small, and higher measurement accuracy cannot be obtained

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