| 摘要 |
PROBLEM TO BE SOLVED: To prevent the lightness of a projected image from decreasing in a projection type image display apparatus which uses an AC illumination light source and a color wheel. SOLUTION: The projection type image display apparatus which projects a color image by separating colors of white light on a time-division basis is provided with the color wheel on which three segments transmitting light beams of wavelength components of red, green, and blue of the while color are formed. The color wheel is rotated at a fixed rotational frequency and a lamp is driven and controlled by generating a lamp driving current so that the timing in which a segment border of the color wheel passes luminous flux of the white light meets the polarity conversion timing of the lamp driving current. Consequently, the influence of the polarity conversion of the lamp driving current can be canceled and the frequency of a blanking period can be minimized, so the lightness of the projected image can be prevented from decreasing. COPYRIGHT: (C)2003,JPO
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