Patent ID: 8798482

Claim:
An infrared transmitter that transmits an optical transmission signal through changing a luminance of an infrared emitting LED, the infrared transmitter comprising: a transmission signal generating unit that generates an electrical transmission signal; a switching unit that changes a number of channels in the electrical transmission signal, wherein the number of channels is greater than or equal to two; a biasing voltage generating unit that generates a stepwise biasing voltage according to the number of channels of the electrical transmission signal that are changed by the switching unit; a signal/voltage mixing unit that mixes the electrical transmission signal and the stepwise biasing voltage; and a voltage-current conversion unit that converts the mixed electrical transmission signal and the stepwise biasing voltage into a current, wherein the infrared emitting LED is driven with the current obtained by conversion in the voltage-current conversion unit, and wherein the infrared emitting LED is a single infrared emitting LED.