ILLUMINATION LIGHT COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a power supply for illumination light communication which makes the brightness of illumination constant both in a non-communication mode in which a carrier signal for communication is not supplied nor received and in a communication mode in which the carrier signal is supplied and received and has high utilization efficiency and high power efficiency of a light source inexpensively in visible light communication using illumination light.

SOLUTION: This illumination light communication device includes: a direct current constant voltage source 10; a constant current circuit 30 and a LED 1 being a current driven semiconductor light emitting element connected to the direct current constant voltage source 10 in series; a signal conversion circuit 20 for generating two modulation signals in which ratios between a period for causing current flow to the LED 1 and a period for preventing the current from flowing are equal in accordance with respective values of carrier signals showing a binary, having different frequencies; and a switching element Q1 for disconnecting the current of the LED 1 in accordance with the modulation signals.

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