| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain an LED control circuit for controlling a plurality of LEDs having different emission colors in which luminance of the plurality of LEDs can be varied simultaneously and gradually while keeping the luminance ratio among the plurality of LEDs at some desired level. <P>SOLUTION: A counter 11, a signal conversion circuit 12, a signal generation circuit 13, and a drive circuit 14 are provided for each of a plurality of LEDs 1r, 1g and 1b. The counter 11 performs up counting or down counting with a predetermined clock in response to an external count start signal. The signal conversion circuit 12 outputs a count from the counter 11 while converting into an analog signal indicative of corresponding strength. Based on an output signal from the signal conversion circuit 12 and luminance data B set externally for each LED, the signal generation circuit 13 generates an analog signal indicative of strength corresponding to the product thereof. The drive circuit 14 drives the LED 1 based on the output signal from the signal generation circuit 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
