Method and device for measuring pixel pitch of image sensor by utilizing constant moving point target

Abstract

A method and a device for measuring pixel pitch of an image sensor by utilizing a constant moving point target belong to the field of length, width or thickness measurement characterized by applying an optical method. The method for measuring the pixel pitch of the image sensor by utilizing the constant moving point target includes: acquiring a linear image by implementing an image formation when the point target constantly moves, searching for a value range of the pixel pitch in a frequency domain, and calculating to obtain the pixel pitch by utilizing a genetic algorithm according to the fact that an contact ratio between a practical modulation transfer function curve which is related to the pixel pitch and a theoretical modulation transfer function curve is the best under least squares conditions. Sliding blocks bearing the point target in the device for measuring the pixel pitch of the image sensor by utilizing constant moving point target is arranged on a first guide rail and a second guide rail, a controller controls the sliding block to uniformly move on the first guide rail while controlling the sliding block to move on the second guide rail, and the movements of the sliding blocks are matched with each other so that the point target is subjected to quasi focal imaging to the surface of the image sensor during motion . By adopting the method for measuring the pixel pitch of the image sensor by utilizing the constant moving point target, error among single measurement results can be reduced so that repeatability of the measurement results can be improved.

Description

Technical field [0001] The method and device for measuring the pixel pitch of an image sensor using a uniform moving point target belong to the field of measuring length, width or thickness in the field of measuring equipment characterized by the use of optical methods, and in particular relates to a uniform linear moving point light source as a target. A measurement method and device for measuring the pixel pitch of an image sensor by using a uniform moving image modulation transfer function in the frequency domain. Background technique [0002] The pixel pitch of the image sensor is a very important technical indicator in the field of precision measurement. For example, a target with a known size is imaged through an optical system. According to the number of pixels of the image sensor occupied by the target image and the pixel pitch, the size of the target image can be known. Finally, the size of the target image and the target size are used as a quotient. The lateral magnifi...

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Problems solved by technology

[0041] The present invention aims at the problem that the above-mentioned existing measurement method is not suitable for measurement in a small field of view, and the problem that the existing measurement device has defocus, and proposes a method and device for measuring the pixel pitch of an image sensor in the frequency domain. Improves the repeatability of measurement results within the field; the device can eliminate the influence of defocus on measurement results

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