Projector light source modulation apparatus and modulation method

A projector light source modulation method for a projector light source modulation apparatus, the projector light source modulation apparatus comprising:

• a modulation signal generator circuit, that generates a first control signal for controlling light to be turned on and off, and a timing signal indicating a timing of superimposing a communication modulation signal on the video signal, based on a video signal and a vertical synchronization signal;
• a communication modulator, that generates a second control signal for controlling a light source to be turned on and off based on the timing signal and a communication modulation code;
• a semiconductor laser that generates output light;
• a semiconductor laser driver circuit, that drives the semiconductor laser according to the second control signal;
• a wavelength converter element, that converts a wavelength of the output light from the semiconductor laser, and outputs a converted light;
• a light modulator element, that modulates the light outputted from the wavelength converter element according to the first control signal, and outputs a modulated light;
• and
• a projection lens that projects the modulated light from the light modulator element,
• wherein the method includes a step of:
• providing subframes multiple times, and arranging temporally at equal intervals for one interval of the vertical synchronization signal, each of the subframes turning on the light modulator element continuously for a superimposition interval of superimposing the communication modulation signal.