Projection display for displaying an image to a viewer
First Claim
1. A projection display, for displaying an image to a viewer, comprising:
- a first plate waveguide made of light transmissive material;
an image-providing light source device arranged to inject image bearing light into the first plate waveguide;
a transmission grating within the first plate waveguide;
an input device within the first plate waveguide arranged to direct the image bearing light onto the transmission grating of the first plate waveguide;
the transmission grating being arranged to direct said image bearing light internally along the first plate waveguide and to output the image bearing light from the first plate waveguide; and
a second plate waveguide made of light transmissive and transparent material, said second plate waveguide includes a coupling grating arranged to receive the image bearing light from the first plate waveguide, said second plate waveguide further includes an exit grating arranged to diffract received image bearing light out of the second plate waveguide,wherein image bearing light is diffractively inputted into the first or second plate waveguide and diffractively outputted from the first or second plate waveguide and the diffractive input and diffractive output powers are substantially matched, anddispersion associated with the diffractive input is oppositely matched with dispersion associated with the diffractive output thereby causing the net chromatic dispersion to a roach or substantially equal zero.
1 Assignment
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Accused Products
Abstract
A projection display is provided including a first plate-like waveguide (7), an image providing light source device (10 and 11) located to inject image bearing light into the first plate-like waveguide 7. An input means (12) is provided on the waveguide (7) to reflect the image bearing light internally along the waveguide (7). A transmission grating (13) within the first plate-like waveguide (7) is provided to output image bearing light from the waveguide (7). A second plate-like waveguide (8) is located co-planar with the first plate-like waveguide (7) and has a coupling grating (17) therein to receive the image bearing light from the first plate-like waveguide (7). The second plate-like waveguide (8) also includes an exit grating (18) therein for diffracting the received image bearing light, diffracted by the coupling grating (17) out of the second plate-like waveguide (8) towards a viewer (6).
97 Citations
19 Claims
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1. A projection display, for displaying an image to a viewer, comprising:
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a first plate waveguide made of light transmissive material; an image-providing light source device arranged to inject image bearing light into the first plate waveguide; a transmission grating within the first plate waveguide; an input device within the first plate waveguide arranged to direct the image bearing light onto the transmission grating of the first plate waveguide; the transmission grating being arranged to direct said image bearing light internally along the first plate waveguide and to output the image bearing light from the first plate waveguide; and a second plate waveguide made of light transmissive and transparent material, said second plate waveguide includes a coupling grating arranged to receive the image bearing light from the first plate waveguide, said second plate waveguide further includes an exit grating arranged to diffract received image bearing light out of the second plate waveguide, wherein image bearing light is diffractively inputted into the first or second plate waveguide and diffractively outputted from the first or second plate waveguide and the diffractive input and diffractive output powers are substantially matched, and dispersion associated with the diffractive input is oppositely matched with dispersion associated with the diffractive output thereby causing the net chromatic dispersion to a roach or substantially equal zero. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 19)
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14. A projection display, for displaying an image to a viewer, comprising:
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a first plate waveguide made of light transmissive material; an image providing light source device arranged to inject image bearing light into the first plate waveguide; a transmission grating within the first plate waveguide; an input device within the first plate waveguide arranged to direct the image bearing light onto the transmission grating of the first plate waveguide; the transmission grating within the first plate waveguide arranged to direct image bearing light internally along the first plate waveguide and to output image bearing light from the first plate waveguide, said outputted image bearing light being substantially polarized; a second plate waveguide, made of light transmissive and transparent material and including a coupling grating arranged to receive the image bearing light from the first plate waveguide, the diffractive power of the coupling grating being disposed at 90 degrees to the diffractive power of the transmission grating, the second plate waveguide further including an exit grating arranged to diffract received image bearing light out of the second plate waveguide; and disposed between the first and second plate waveguides, a device for rotating the polarization of the image bearing light outputted from the first plate waveguide through 90 degrees, wherein image bearing light is diffractively inputted into the first or second plate waveguide and diffractively outputted from the first or second plate waveguide and the diffractive input and diffractive output powers are substantially matched, and dispersion associated with the diffractive input is oppositely matched with dispersion associated with the diffractive output thereby causing the net chromatic dispersion to approach or substantially equal zero. - View Dependent Claims (15, 16, 18)
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Specification