| 摘要 |
PROBLEM TO BE SOLVED: To obtain a projection type picture display device having a simple constitution capable of keeping the white balance of a color picture constant even when brightness is changed by varying the modulation of light in accordance with output from a lamp and keeping the white balance of the color picture nearly constant regardless of the magnitude of the output from the lamp. SOLUTION: Voltage(hereinafter referred to as stationary voltage) applied to the lamp 81 from a lighting circuit 61 is made variable, and an instruction to set brightness, which is given from a user through an operation part 70, is detected by a controller 71, and the brightness is changed in accordance with the instruction. The emitted light quantity of the lamp 81 is changed in accordance with the magnitude of the stationary voltage, and the quantity of light projected to the screen 50 is changed, so that the brightness of the picture is changed. Relation between the output and color temperature is stored in a memory 85, and is read out by the controller 71 so that it is utilized to control the adjustment of the white balance by a WB adjusting part 67. Therefore, the picture having a proper color hue can be always displayed even when the lamp 81 having different wattage is used.
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