Light source control for projector with multiple pulse-width modulated light sources

A color projection display, comprising:

• a plurality of color channels, in which at least one color channel includes:
• a light source assembly including a multiplicity of pulse modulated light sources providing an aggregate light beam;
• a light modulation control subsystem to control pulse modulation parameters for the multiplicity of pulse-modulated light sources;
• illumination optics to direct the aggregate light beam to an image modulation plane;
• and
• a spatial light modulator in the image modulation plane having an array of addressable pixel elements, each of which is pulse width modulated during an imaging time interval to impart image data to the transiting aggregate light beam to provide image light;
• an optical combiner to redirect image light from the plurality of color channels onto a common optical path;
• and
• projection optics to receive the combined image light traversing the common optical path and to project the combined image light onto a display surface;
• wherein the light modulation control subsystem senses a light intensity signal for at least one particular pulse modulated light source and controls the pulse modulation parameters for a plurality of pulse-modulated light sources responsive to the sensed light intensity signal to reduce light intensity fluctuations in the aggregate light beam within the imaging time interval, and wherein the pulse modulation parameters include pulse phase delay parameters for the multiplicity of pulse-modulated light sources that are controlled such that pulse trains from the multiplicity of pulse-modulated light sources overlap in an asynchronous fashion.

A method for providing illumination light in a color channel of an color projection system, the color channel including a light source assembly having a multiplicity of pulse modulated light sources, comprising:

• operating the multiplicity of pulse-modulated light sources to provide a multiplicity of pulse-modulated light beams;
• combining the multiplicity of pulse-modulated light beams to provide an aggregate light beam;
• sensing a light intensity signal for the aggregate light beam;
• determining pulse modulation parameters for the multiplicity of pulse-modulated light sources responsive to the sensed light intensity signal to reduce light intensity fluctuations in the aggregate light beam, wherein the pulse modulation parameters include pulse phase delay parameters for the multiplicity of pulse-modulated light sources that are controlled such that pulse trains from the multiplicity of pulse-modulated light sources overlap in an asynchronous fashion;
• and
• directing the aggregate light beam using illumination optics to provide illumination light onto a spatial light modulator.

An illumination system, comprising:

• a light source assembly including a multiplicity of pulse modulated light sources providing an aggregate light beam;
• a light modulation control subsystem to control pulse modulation parameters for the multiplicity of pulse-modulated light sources;
• and
• illumination optics to direct the aggregate light beam to an illumination plane;
• wherein the light modulation control subsystem senses an aggregate light intensity signal for the aggregate light beam and controls the pulse modulation parameters for the multiplicity of pulse-modulated light sources responsive to the sensed aggregate light intensity signal to reduce light intensity fluctuations in the aggregate light beam, wherein the pulse modulation parameters include pulse phase delay parameters for the multiplicity of pulse-modulated light sources that are controlled such that pulse trains from the multiplicity of pulse-modulated light sources overlap in an asynchronous fashion.