| 摘要 |
PURPOSE:To lessen the change in the color taste of the display color of displayed images and to obviate impairment of visibility by disposing auxiliary light sources which emit blue light and are controllable in lighting according to the input voltage of a light source at this light source. CONSTITUTION:The input voltage of a halogen lamp bulb 9a subjected to light control by a light control circuit 15 is monitored by an auxiliary lamp control circuit 16. The auxiliary lamp bulbs 14 on which blue color caps are put on are lighted when the halogen lamp bulb 9a radiates reddish light by attaining low luminance. The auxiliary lamp bulbs 14 are prevented from lighting by judgment that the irradiation light of sufficient white color is radiated from the halogen lamp bulb 9a between 12 to 7V of the input voltage of the halogen lamp bulb 9a if the halogen lamp bulb 9a is, for example, rating 12V. One of the auxiliary lamp bulbs 14 is lighted by judgment that the reddish light is radiated from the halogen lamp bulb 14 when the input voltage is 7 to 4V. The two auxiliary lamp bulbs 14 are lighted if the input voltage is 4 to 1V. |
