| 摘要 |
PROBLEM TO BE SOLVED: To improve an image quality by performing stable white balance adjustment while expanding and projecting a usual video with a simple configuration. SOLUTION: In a projection type display device using a digital micro mirror device 3, light beams reflected in a first direction among light beams reflected from the digital micro mirror device 3 are projected on screen 5 to display an image, and light beams reflected in a second direction is received by a photosensor 6a to measure optical information. In this case, the photosensor 6a measures optical information only when each color of a color wheel 2 changes by a timing pulse from a color wheel timing pulse generating circuit 10. A white balance control part 7 controls a video circuit part 8 by using measured optical information to change the level of video signal, and performs adjustment of white balance. Thereby light reflected to portions other than a screen can be measured to utilize it for adjustment of the white balance, and while expanding and projecting a usual video, a stable adjustment of white balance is possible.
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