P‐15.4: Dynamic Measuring Method of Speckle Contrast

Abstract

The various measurement methods of speckle for laser display are always troubled by screen structure, pixel structure and non‐uniformity of image brightness, etc., even those effects can be decreased by means of FFT or some other technologies. However, the technologies applied will damage the original image signal and bring about measuring errors. The intensity distribution of an image is composed of background (signal) and noise (speckle). The background is not sensitive to observing position, while the speckle shows great sensitivity. While observing images with speckle at 2 very close positions, the background patterns are almost the same, and the speckle patterns are completely different because the speckle patterns are the results of multi‐beam interference and obey the random number distribution rule, the background patterns relate to display patterns, screen structure, pixel structure and non‐uniformity of the image, etc. This paper proposes a dynamic measuring method of speckle contrast for more accurate speckle measurement. This method eliminates the influence of screen structure, pixel structure, and non‐uniformity of image brightness in the speckle contrast measurement. And provides a better generality and more accurate laser display speckle contrast measuring method. This method could be applied in speckle measurement of a laser projector, laser theater, and other laser display products.