| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable to set color temperature of an illumination light freely, and easily control brightness with the color temperature maintained after setting. <P>SOLUTION: A dimming voltage (V<SB>c</SB>) adjusting variably an amount of illumination light is equally supplied from a light control circuit (11) to color temperature setting circuits (10R, 10G, 10B) connecting each color LED (2R, 2G, 2B) lit with an amount of proportional light volume to driving currents (I<SB>R</SB>, I<SB>G</SB>, I<SB>B</SB>), and control voltages (V<SB>R</SB>, V<SB>G</SB>, V<SB>B</SB>) are adjusted in a given ratio to the dimming voltage (V<SB>c</SB>) by a color temperature setting equipment (12) of each color temperature setting circuit (10R, 10G, 10B), then, the driving currents (I<SB>R</SB>, I<SB>G</SB>, I<SB>B</SB>) responding to the control voltages (V<SB>R</SB>, V<SB>G</SB>, V<SB>B</SB>) are output to each LED (2R, 2G, 2B) at a constant current circuit (13). <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
