Method and device for measuring modulation transfer function value

Abstract

The invention relates to a device for measuring modulation transfer function values. The device comprises a testing plate, an image sensor, a bearing device and a drive device. The testing plate is provided with a plurality of alternate dark and bright patterns, the bearing device is arranged between the testing plate and the image sensor, and comprises a limit device and a bearing table, the limit device is arranged on the bearing table, and is opposite to the image sensor, and the bearing table is opposite to the testing plate. The drive device is used for driving the bearing device to move or rotate parallel to the testing plate so as to adjust the relative position between the bearing device and the testing plate, thus the image sensor is caused to respectively sense images of the patterns of different parts on the testing plate, and the images are formed by a lens to be tested. The invention further provides a method for measuring the modulation transfer function values. The device can help improve the measurement accuracy, and measure the modulation transfer function values of a plurality of lenses at a time, thus effectively improving the measurement efficiency.

Description

technical field [0001] The invention relates to the technical field of lens detection, in particular to a device for measuring the modulation transfer function value of a lens and a measurement method thereof. Background technique [0002] The image quality of imaging objects such as digital cameras, video cameras and mobile phone cameras mainly depends on the imaging quality of the lens, and the monitoring of the image quality of the lens lies in the testing process of the lens. Modulation Transfer Function (MTF) is an important parameter for analyzing the resolution and contrast reproduction ability of a lens, and comprehensively evaluating the sharpness, contrast and resolution of a lens. See literature: A simple method for determining the modulationtransfer function indigital radiography; Fujita, H., Tsai, D-Y., Itoh, T., Department of Electronic & Computer Engineering, England, Gifu University; Medical imaging, IEEE transactions on; pages 34 ~39, Volume 11, Issue 1, Ma...

AI Technical Summary

Problems solved by technology

However, when the measuring device 100 is used, once the test board 10 has more patterns and the size of the test board 10 is larger than the sensing area of ​​the image sensor 40, the image sensor 40 cannot image all the patterns of the test board 10 at one time. The imaging luminance of the pattern sensed by the pixels of the image sensor 40 may not be the actual maximum and minimum values, causing the measurement device 100 to produce erroneous measurement results.

Using an image sensor with a larger sensing area will significantly increase the cost of measurement

In addition, the measurement device 100 can only detect one lens at a time, and the measurement efficiency is low

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