Multi-color primary light generation in a projection system using LEDs

A method of operating a projection system for displaying a full color image using only three primary color light sources, the method comprising:

• modulating, light from a first primary light source by a first light modulator to provide modulated light at pixel locations in a display;
• modulating light from a second primary light source by a second light modulator to provide modulated light at pixel locations in the display;
• modulating light from a third primary light source by a third light modulator to provide modulated light at pixel locations in a the display;
• combining the modulated light from the first primary light source, the second primary light source, and the third primary light source to simultaneously provide the modulated light at pixel locations in the display;
• the first primary light source comprising at least one red light emitting diode (LED) and at least one non-red LED that emits light at a wavelength shorter than red and longer than green, light from the at least one red LED and light from the at least one non-red LED being combined into a single beam,
• the second primary light source comprising at least one green LED,
• the third primary light source comprising at least one blue LED;
• energizing, by at least one driver, the at least one red LED, the at least one non-red LED, the at least one green LED, and the at least one blue LED;
• receiving image signals and, in response, controlling the first light modulator, the second light modulator, and the third light modulator to create a projected image, and controlling the at least one driver to vary relative brightness levels of the at least one red LED and the at least one non-red LED over a period of time to change a light mixture emitted from the first primary light source, wherein the mixture is dynamically varied based on colors in a particular image to be displayed, wherein the first primary light source is controlled by the at least one driver to have an increased color component from the at least one red LED when an image to be displayed requires a red component unable to be provided by the at least one non-red LED, and wherein the first primary light source is controlled to have a decreased color component from the at least one red LED when an image to be displayed does not require a red component produced by the at least one red LED,
• wherein the second light modulator modulates light from the from the second primary light and wherein the third light modulator modulates light from the third primary light source to compensate for changes in the light mixture emitted from the first primary light source.

A projection system for displaying a full color image using only three primary color light sources, the system comprising:

• three light modulators, a first light modulator for modulating light from a first primary light source, a second light modulator for modulating light from a second primary light source, and a third light modulator for modulating light from a third primary light source, each of the light modulators being controlled by at least one processor to simultaneously provide modulated light at primary light pixel locations in a display, there being no additional primary light sources;
• the first primary light source comprising at least one red light emitting diode (LED);
• the second primary light source comprising at least one green LED and at least one non-green LED that emits light at a wavelength shorter than green and longer than blue, light from the at least one green LED and light from the at least one non-green LED being combined into a single beam;
• the third primary light source comprising at least one blue LED;
• at least one driver for energizing the at least one red LED, the at least one green LED, the at least one non-green LED, and the at least one blue LED;
• at least one processor adapted to receive image signals and, in response, control the three light modulators to create a projected image, and control the at least one driver to vary relative brightness levels of the at least one green LED and the at least one non-green LED over a period of time to change a light mixture emitted from the second primary light source, wherein the at least one processor is adapted to dynamically vary the mixture is based on colors in a particular image to be displayed, wherein the at least one processor is adapted to cause the second primary light source to have an increased color component from the at least one green LED when an image to be displayed requires a green component unable to be provided by the at least one non-green LED, and wherein the at least one processor is adapted to cause the second primary light source to have a decreased color component from the at least one green LED when an image to be displayed does not require a green component produced by the at least one green LED,
• wherein the at least one processor control the first light modulator to modulate light from the first primary light source and controls the third light modulator to modulate light from the third primary light source to compensate for changes in the light mixture emitted from the second primary light source.

A projection system for displaying a full color image using three primary color light sources, the system comprising:

• three light modulators, a first light modulator for modulating light from a first primary light source, a second light modulator for modulating light from a second primary light source, and a third light modulator for modulating light from a third primary light source, each of the light modulators being controlled by at least one processor to simultaneously provide modulated light at primary light pixel locations in a display, there being no additional primary light sources;
• the first primary light source comprising at least one red light emitting diode (LED);
• the second primary light source comprising at least one green LED;
• the third primary light source comprising at least one blue LED and at least one non-blue LED that emits light at a wavelength shorter than green and longer than blue, light from the at least one blue LED and light from the at least one non-blue LED being combined into a single beam;
• at least one driver for energizing the at least one red LED, the at least one green LED, the at least one non-blue LED, and the at least one blue LED;
• at least one processor adapted to receive image signals and, in response, control the three light modulators to create a projected image, and control the at least one driver to vary relative brightness levels of the at least one blue LED and the at least one non-blue LED over a period of time to change a light mixture emitted from the third primary light source, wherein the at least one processor is adapted to dynamically vary the mixture is based on colors in a particular image to be displayed, wherein the at least one processor is adapted to cause the third primary light source to have an increased color component from the at least one blue LED when an image to be displayed requires a blue component unable to be provided by the at least one non-blue LED, and wherein the at least one processor is adapted to cause the third primary light source to have a decreased color component from the at least one blue LED when an image to be displayed does not require a blue component produced by the at least one blue LED,
• wherein the at least one processor controls the first light modulator to modulate light from the first primary light source and controls the third light modulator to modulate light from the third primary light source to compensate for changes in the light mixture emitted from the second primary light source.