| 摘要 |
PURPOSE:To attain fast color discrimination and also to obtain simple, small- sized constitution by controlling the quantity of light emission of each light emitting means on the basis of the output of a reference light detecting means which detects the quantities of projection light of plural light emitting means. CONSTITUTION:Part of light projected by light sources 1-3 is guided out as reference light by a half-mirror 10 and detected by a color sensor 11. The sensor 11 includes detection parts 12-14 which detect respective components of red, green, and blue independently. Detection signals of the detection parts 12- 14 are amplified by an amplifier 15 and output component values of red - blue of the reference light are inputted to differential amplifiers 21-23. On the other hand, standard values of the quantities of projection lights of the light sources 1-3 which are set previously by standard value setters 17-19 are also inputted to the amplifiers 21-23, and signals indicating differences in the detected quantities of reference light from the standard values are outputted and fed back to driving circuits 4-6. Then, the light sources 1-3 are controlled by the circuits 4-6 to hold the quantities of light emission constant. |
