| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide technology capable of suppressing degradation of video luminance when an arc jump occurs. <P>SOLUTION: A video display device comprises: lamps 2 and 3; a mirror 4; a light valve 8; a brightness sensor 10; first adjusting means 11a; and second adjusting means 11b. The brightness sensor 10 detects the brightness of off-state light of the light valve 8. The first adjusting means 11a adjusts a position of the mirror 4 to a desired position based on the brightness detected by the brightness sensor 10. The second adjusting means 11b readjusts the position of the mirror 4 based on the brightness detected by the brightness sensor 10 when it is determined that the decreasing degree of the brightness between a first brightness detected by the brightness sensor 10 after the adjustment of the first adjusting means 11a and a second brightness detected by the brightness sensor 10 after a fixed period from the first brightness detection exceeds a predetermined first threshold. <P>COPYRIGHT: (C)2012,JPO&INPIT |
