| 摘要 |
PURPOSE:To highly efficiently obtain a light color having a low color temperature by adding a light source in which the light color having the low color temperature can be obtained by light color correction. CONSTITUTION:In a lighting device of three light sources 1a-1c of red, green and blue, a light source 1d of yellow is added. Namely, red, green, blue and yellow light colors are provided. Switching transistors Tr1-Tr4 are connected in series to the light sources 1a-1d, respectively, and this series circuit is connected in parallel to the lighting circuit. The light sources 1c, 1d are switched according to a desired light color to light either of the light sources 1c, 1d. In this case, the emission of each light source 1a-1d is successively switched by a control circuit P to control the emitting period ratio, whereby the light flux ratio of each lamp is substantially controlled to change the emitting light color. Hence, a light color having a low color temperature can be highly efficiently obtained and utilized as a main light source. |
