| 摘要 |
PROBLEM TO BE SOLVED: To enhance accuracy in detecting a projection distance between a projection lens and a projection screen. SOLUTION: The apparatus is provided with a distance detecting device 6 equipped with a test pattern irradiating part 21 for irradiating a test pattern prepared for detecting the projection distance between the projection lens 11 and the projection screen, and also, equipped with an imaging element 28 for imaging the test pattern irradiated on the projection screen, for detecting the projection distance based on the test pattern. And the optical axis of the test pattern irradiating part 21 is made un-parallel to a straight line orthogonal to the light receiving surface of the imaging element 28, and the optical axis of the part 21 is inclined so that the axis may pass from one of boundary lines constituting the viewing angleθ<SB>1</SB>of the imaging element 28 to the other as the laser light 25a of the test pattern goes ahead. COPYRIGHT: (C)2005,JPO&NCIPI |
