| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a color temperature variable type visible light communication system which can set the color temperature of light to a desired color temperature and transmit signals, while keeping the set color temperature, allows the number of photodiodes to be reduced to one, and attains increase in the amount of transmission data. <P>SOLUTION: A color temperature variable type visible-light communication system 1 includes lEDs 21, 22 and 23 which emit light of respective colors of red, green, and blue; an operation part which sets the color temperatures of light from the LEDs 21, 22 and 23; an LED control par 6 which controls duty ratios of rectangular wave currents supplied to the LEDs 21, 22 and 23 so that the set color temperatures are obtained; a communication setting part 7 which sets a communication signal; and transmission control parts 81, 82 and 83 which modulates signal of LEDs 21, 22 and 23, according to the communication signal. The transmission control parts 81, 82 and 83 superimposes a signal current, corresponding to the communication signal over a rectangular wave current having the highest duty ratio, from among the rectangular wave currents supplied to the LEDs 21, 22 and 23. <P>COPYRIGHT: (C)2009,JPO&INPIT |
