Image sensor pixel pitch measurement method and device using uniform moving point target

Abstract

The invention relates to a method and device for measuring the space of pixels of an image sensor by using a constant-speed movable point target, belonging to the field of the measurement of length, width or thickness by adopting the optical method. The method comprises the following steps: imaging the point target in the constant-speed movement state to obtain a linear image, searching the value taking range of the space of the pixels in the frequency domain, and calculating the space of the pixels by using the search algorithm according to the characteristic that the actual modulation transfer function curve and the theoretical modulation transfer function curve which are relevant to the space of the pixels can coincide best under the least square condition. The device is characterized in that a sliding block which bears the point target is arranged on a first guide rail and a second guide rail, when a controller controls the sliding block to move at constant speed on the first guide rail, the controller also controls the sliding block to move on the second guide rail, the movement in two directions matches with each other so that the point target is imaged on the surface of image sensor by calibrating the focus. Due to the adoption of the method and the device for measuring the space of pixels of the image sensor, the errors between the single-time measurement results can be reduced, and the repeatability of the measurement results can be improved accordingly.

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 particularly relate to a point light source using a uniform moving linear motion as the target, The invention discloses a measurement method and device for measuring the pixel pitch of an image sensor by using a constant velocity moving image modulation transfer function in the frequency domain. Background technique [0002] Image sensor pixel pitch is a very important technical indicator in the field of precision measurement. For example, if a target with a known size is imaged through an optical system, the size of the target image can be known according to the number of pixels of the image sensor occupied by the target image and the pixel pitch, and finally the size of the target image can be compared ...

AI Technical Summary

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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