Flat-panel projection display
First Claim
1. A flat-panel projection display comprising a waveguide system including a display slab waveguide having a grating acting to cause light propagating in the waveguide to emerge from one face of the waveguide, a lens element for directing light into an edge of the waveguide system, and in the focal plane of the lens element means for modulating the intensity of the light as a function of lateral position and of elevational direction of travel, relative to the waveguide, the grating being such as to eject light directed into the waveguide system from the slab towards a viewer at an angle depending on the said lateral position and elevational direction.
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Accused Products
Abstract
A flat-panel projection display comprises a slab waveguide having a preferably embossed diffraction grating on one face, a lens for directing light into an edge of the waveguide, and in the focal plane of the lens a liquid-crystal modulator for modulating the intensity of the light as a function of lateral position and elevational direction of travel. The light is ejected from the slab waveguide by the grating at angles corresponding to the input angles, giving a virtual display. The light from the modulator can be expanded in one dimension by passing through a magnifying waveguide, followed by scattering in the plane by a screen and projection by a lens at the other end of the waveguide. Head-up and 3-D displays can be constructed using this principle.
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Citations
24 Claims
- 1. A flat-panel projection display comprising a waveguide system including a display slab waveguide having a grating acting to cause light propagating in the waveguide to emerge from one face of the waveguide, a lens element for directing light into an edge of the waveguide system, and in the focal plane of the lens element means for modulating the intensity of the light as a function of lateral position and of elevational direction of travel, relative to the waveguide, the grating being such as to eject light directed into the waveguide system from the slab towards a viewer at an angle depending on the said lateral position and elevational direction.
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19. A flat-panel projection display comprising a waveguide system including a display slab waveguide having a grating acting to cause light propagating in the waveguide to emerge from one face of the waveguide, a lens element for directing light into an edge of the waveguide system, and in the focal plane of the lens element means for modulating the intensity of the light as a function of lateral position, relative to the waveguide, the grating being such as to eject light directed into the waveguide system from the slab towards a viewer at an angle depending on the said lateral position;
in which the light emerging from the display slab is modulated by an output panel to give a three-dimensional display. - View Dependent Claims (20, 21, 22)
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23. A flat-panel projection display comprising a waveguide system including a display slab waveguide having a grating acting to cause light propagating in the waveguide to emerge from one face of the waveguide, a lens element for directing light into an edge of the waveguide system, a magnifying slab waveguide of matching width placed between the lens element and the display slab waveguide so as to expand the light from the lens to the full width of the display waveguide;
- a one-dimensional cylindrical mirror strip at the end of the magnifying waveguide, conserving out-of plane angle but spreading light in the plane; and
in the focal plane of the lens element means for modulating the intensity of the light as a function of lateral position and of elevational direction of travel, relative to the waveguide, the light passing though the magnifying slab waveguide in one direction for magnifying, being reflected by the mirror strip and passing back in the reverse direction for coupling into the display waveguide;
wherein the grating acts to eject light from the magnifying slab waveguide towards a viewer at an angle depending on the said lateral position and elevational direction.
- a one-dimensional cylindrical mirror strip at the end of the magnifying waveguide, conserving out-of plane angle but spreading light in the plane; and
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24. A flat-panel projection display comprising a waveguide system including a display slab waveguide having a grating acting to cause light propagating in the waveguide to emerge from one face of the waveguide, a lens element for directing light into an edge of the waveguide system, and in the focal plane of the lens element means for modulating the intensity of the light as a function of lateral position, relative to the waveguide, the grating being such as to eject light directed into the waveguide system from the slab towards a viewer at an angle depending on the said lateral position;
in which the light emerging from the display slab is modulated by an output panel to give a three-dimensional display, the output panel being a liquid-crystal display panel mounted in front of the display slab as seen by the viewer; and
the means for modulating is a source of collimated light scanned through the range of output angles by transverse movement or scanning of the light source in synchrony with the modulating means.
Specification