PROJECTOR, ITS FOCUSING METHOD, AND ITS FOCUSING PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a projector capable of performing alignment to a focusing point with good accuracy by eliminating the influence of noise. SOLUTION: A photodetecting sensor 21 receives the reflected light of the image projected from a projection lens optical system 8 onto a screen and outputs the signal depending on the amount of the received light of the reflected light. A rounding-off operation part 22d of an operation part 22 substitutes the value of the signal off the range with the value within the range in such a manner that the value of the signal from the photodetecting sensor 21 attains the value within the range. The contrast value of the image is calculated by subjecting the signal after the processing by the rounding-off operation part 22d to integration by an integrator 22e. The calculated contrast value is formed of the signal removed of the noise component and therefore the focusing position of the image can be specified with the good accuracy. COPYRIGHT: (C)2005,JPO&NCIPI