Pixel-to-Pixel Correspondence Adjustment in DMD Camera by Moiré Methodology

Abstract

DMD (Digital Micro-mirror Device) is a new device, which has hundreds of thousands of micro-mirrors in one chip. We developed a DMD reflection-type CCD camera that we call ‘DMD camera’ previously. In this optical system of the DMD camera, each mirror of the DMD is corresponded to each pixel of the CCD. As a result, each DMD mirror works as a high-speed controllable shutter of the corresponding CCD pixel. However, corresponding each mirror of the DMD to each pixel of the CCD cannot readily be done since the pixel sizes of DMD and CCD are very small. In this paper, a pixel-to-pixel correspondence adjustment method, which can perform accurate adjustment of the DMD camera optical system by moire methodology is proposed. The proposed method is easy and visual by observing the moire pattern. This method enables DMD camera to adjust pixel-to-pixel correspondence less than one pixel accuracy of the CCD. An experiment of phase analysis to demonstrate the improvement of the resolution and accuracy was performed.