Line white light surface profile measuring method

Abstract

The invention relates to a line white light surface profile measuring method which comprises the following steps that a slit diaphragm is arranged in an imaging light path, only one rectangular lightbar penetrates through a slit and irradiates a measured sample, an image shot by a CCD (Charge Coupled Device) camera only has a middle rectangular white band under the action of the slit diaphragm, and other parts are black. An interference image generated during measurement of the measurement system is cut off by the slit diaphragm; only part of interference fringes exist on the rectangular leucorrhea; when measured objects with different heights are measured; the interference fringes on the rectangular leucorrhea are transversely translated along with different measured heights; a rectangular leucorrhea in a visual field is measured, the midpoint along the rectangular leucorrhea is regarded as a reference point, the transverse movement amount of a coherent peak of an interference fringein the rectangular leucorrhea is represented as the height in the vertical direction, and tracking scanning measurement of the surface contour is achieved in cooperation with an external shafting displacement platform.

Description

technical field [0001] The invention relates to a novel line white light surface profile measurement method. Background technique [0002] It is well known that the performance of spherical optical systems is limited by aberrations. Applying aspheric and freeform optics can reduce or even eliminate geometric aberrations while reducing component count, size, and overall system weight. Aspheric and free-form surfaces are widely used in Blu-ray players, mobile phones and digital cameras, infrared optical imaging, laser diodes and LED collimation optics, fiber couplers, artificial crystals and other fields. In recent years, due to the demand for such complex optical surfaces, new optical processing and manufacturing technologies have been developed rapidly. At the same time, various application requirements put forward higher and higher requirements for the accuracy of its surface shape, and the measurement requirements for these parts are also urgently needed. In order to ob...

AI Technical Summary

Problems solved by technology

At present, the mainstream of nanometer-scale measurement of complex optical surfaces is still centering on focal point scanning and surface interferometry, which is reflected in the successive appearance of advanced high-precision measurement equipment such as NANOMEFOS, Luphoscan, and white light interferometers. However, the cost of these advanced equipment is very high. Expensive, large volume, and there are certain limitations in the measurement of complex surfaces with large curvature

Conventional point scanning measurement requires complex photoelectric coordination to achieve nanometer-level measurement accuracy. The measurement accuracy depends on the stability and accuracy of the overall system, and the measurement efficiency is low. The overall system is large in size and expensive.

Surface interferometry has nanometer-level measurement accuracy, but interferometry is easily affected by external disturbances. For the measurement of large-area complex optical surfaces, sub-aperture splicing is required, and splicing errors affect measurement accuracy.

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