Back to results
US RE46,664 E1Granted
Laser illuminated backlight for flat panel displays
AssigneeDolby Laboratories Licensing Corporation
InventorMasayuki Karakawa
Life of this patent
Estimating the term…
Abstract
Laser lit flat panel displays are disclosed including edge-lit and direct lit backlights. In certain embodiments, laser assemblies are selected to obtain bandwidth distributions to reduce speckle.
Claims30
A flat panel display, comprising:
- an array of light modulators arranged across the flat panel display;
- and
- a backlight comprising a plurality of laser assemblies distributed across a surface positioned behind the array of light modulators, such that the plurality of laser assemblies directly illuminate the array of light modulators from behind and the array of light modulators modulates light emitted by the backlight, wherein:
- each laser assembly comprises a plurality of lasing elements of at least one primary color,
- at least two of the plurality of laser assemblies include lasing elements of the same primary color,
- the plurality of lasing elements of at least one of the three primary colors are selected such that each lasing element emits a laser beam with a center wavelength λ0i and a spectral bandwidth Δλi,
- the center wavelength of at least one of the lasing elements is wavelength-shifted with respect to the center wavelength of at least one other lasing element, and
- said laser beams, when combined, have an ensemble spectrum Λ with an overlap parameter γ=Δλi/Si, with Δλi being a mean spectral bandwidth of the lasing elements and Si being a mean wavelength shift between the center wavelengths λ0i of the at least one and the at least one other lasing elements, with Δλi and Si selected such that γ≧1.
5 more elements
A flat panel display, comprising:
- an array of light modulators arranged across the flat panel display;
- a backlight comprising a plurality of laser assemblies distributed across a surface positioned behind the array of light modulators, such that the plurality of laser assemblies directly illuminate the array of light modulators from behind and the array of light modulators modulates light emitted by the backlight, wherein:
- each laser assembly comprises a plurality of lasing elements of at least one primary color, and
- at least two of the plurality of laser assemblies include lasing elements of the same primary color;
- and
- a plurality of optical elements for diffusing light from the laser assemblies across corresponding regions of the array of light modulators.
3 more elements
A flat panel display, comprising:
- a backlight including a plurality of semiconductor diode lasing elements of at least one primary color arranged in a plurality of laser assemblies, wherein:
- the backlight comprises a light guide for substantially distributing light output by the plurality of laser assemblies across the flat panel display,
- the plurality of laser assemblies are positioned about an exterior edge of the light guide,
- the plurality of lasing elements of the at least one primary color are selected such that each lasing element emits a laser beam with a center wavelength λ0i and a spectral bandwidth Δλi,
- the center wavelength of at least one of the lasing elements is wavelength-shifted with respect to the center wavelength of at least one other lasing element, and
- said laser beams, when combined, have an ensemble spectrum Λ with an overlap parameter γ=Δλi/Si with Δλi being a mean spectral bandwidth of the lasing elements and Si being a mean wavelength shift between the center wavelengths λ0i of the at least one and the at least one other lasing elements, with Δλi and Si selected such that γ≧1;
- and
- an array of light modulators arranged across the flat panel display for modulating light emitted by the backlight.
5 more elements
Dependencies are inferred from the claim text.