Speckle suppressed laser projection system using a multi-wavelength doppler shifted beam

A speckle suppressed laser projection system comprising:

• a laser which provides a laser beam;
• a modulation oscillator which produces a signal;
• an oscillator which provides a carrier;
• a frequency modulator, wherein said frequency modulator combines said signal from said modulation oscillator and said carrier from said oscillator to produce a frequency modulated signal;
• an acusto-optic modulator wherein said modulator receives said frequency modulated signal and said laser beam to produce a laser beam with a small angle variation;
• and
• an optical projection system wherein said optical projection system projects said laser beam with small angle variations on a screen.

A speckle suppressed laser projection system comprising:

• a laser which generates a laser beam;
• a circuit, wherein said circuit produces a variable frequency carrier signal;
• a modulator wherein said modulator is injected with said variable frequency carrier signal which modifies said laser beam with a small angular variation;
• expansion optics which expands said small angular beam from the modulator, and the output from said optics is an expanded angular beam;
• a spatial light modulator (SLM) driver, wherein said (SLM) driver receives image data as an input;
• a spatial light modulator (SLM), wherein said SLM receives a signal from said SLM driver and produces an output;
• a beamsplitter cube, wherein said cube combines said expanded beam from said expansion optics with said output from said SLM;
• and
• a projection lens, wherein said projection lens outputs an angularly varying beam.

A method of speckle reduction, the method comprising the steps of:

• generating a signal;
• modulating said signal to produce a frequency modulated carrier signal;
• injecting said frequency modulated carrier into an acousto-optic modulator (AOM);
• directing a laser beam into said AOM, wherein said output of the AOM when it is injected by said carrier signal is a multi-wavelength Doppler shifted beam;
• directing said multi-wavelength beam into an optical projection system;
• projecting said multi-wavelength beam onto a projection surface to form an image, where the multi-wavelength beam has different speckle patterns that blend together.

A method of speckle reduction, the method comprising the steps of:

• generating a signal;
• modulating said signal to produce a frequency modulated carrier signal;
• injecting said frequency modulated carrier into an acousto-optic modulator (AOM);
• directing a laser beam into said AOM, wherein said output of the AOM when it is injected by said carrier signal is a beam with a small angle variation;
• directing said beam with small angle variation into an optical projection system;
• and
• projecting said beam with small angle variation onto a projection surface to form an image, wherein the speckle patterns of the beam are blended together.