Flat panel energized by blue LED for generating white light
AssigneePhilips Lumileds Lighting Company, LLC
InventorsRegina Mueller-Mach, Gerd O. Mueller
Life of this patent
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Abstract
A color, transmissive LCD uses a backlight that supplies a uniform blue light to the back of the liquid crystal layer in an LCD. The blue light, after being modulated by the liquid crystal layer, is then incident on the back surface of phosphor material located above the liquid crystal layer. A first phosphor material, when irradiated with the blue light, generates red light for the red pixel areas of the display, and a second phosphor material, when irradiated with the blue light, generates green light for the green pixel areas of the display. No phosphor is deposited over the blue pixel areas.
Claims21
A light producing device comprising:
- an LED that emits visible blue light of a first wavelength;
- and
- a substantially flat plate separated from the LED and receiving light from the LED, the plate comprising a first phosphor material that converts the light of the first wavelength to red light, and having a second phosphor material that converts the light of the first wavelength to green light,
- the plate having a surface area receiving light from the LED that is larger than a light emitting surface area of the LED,
- the plate allowing the light of the first wavelength to pass through so that the red, green, and blue light are emitted by the plate to create colors with visible red, green, and blue components.
A method of generating light with visible red, green, and blue components comprising:
- energizing an LED that cmits visible blue light of a first wavelength;
- and
- irradiating a substantially flat plate separated from the LED with light from the LED, the plate comprising a first phosphor material that converts the light of the first wavelength to red light, and having a second phosphor material that converts the light of the first wavelength to green light, the plate having a surface area receiving light from the LED that is larger than a light emitting surface area of the LED, the plate allowing the light of the first wavelength to pass through so that the red, green, and blue light are emitted by the plate to create colors with visible red, green, and blue components.
Dependencies are inferred from the claim text.