EP0566004A2
Expired / Lapsed
EP
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Virtual image display having a high efficiency grid beamsplitter
Assignee: Raytheon Co
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Filing: 1993-04-06
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Granted: —
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Expires: 2013-04-06
Abstract
Abstract An on-axis virtual image display system comprises a s-polarized image source (11), such as a polarized cathode ray tube or a polarized liquid crystal display, which has its s-polarized output image coupled through a relay lens (12) towards a high efficiency grid beamsplitter (20). The grid beamsplitter is employed to reflect the s-polarized image through a quarter wave plate (13) onto a totally reflecting concave mirror (14). The image reflected from the concave mirror is converted to a p-polarized image and passes through the quarter wave plate and the grid beamsplitter, producing a virtual magnified image of the source at the location of a user (22).
Inventors
- 👤 Ronald G. Hegg
- 👤 Mao-Jin Chern
- 👤 Anson Au
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:04
CPC Classifications
G; G06; G06T; G06T1/00; G02; G02B; G02B27/00; G02B27/01; G02B27/0101; G02B5/00; G02B5/30; G02B5/3025; G02B5/3058; G02B2027/0118
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
111 words
An virtual image display system comprising: an image source that is adapted to provided polarized light disposed at one end an optical path; a relay lens disposed along the optical path and adapted to transmit the polarized light provided by the image source; a concave mirror disposed at an opposite end of the optical path; a quarter-wave plate disposed along the optical path between the relay lens and the concave mirror; and a grid beamsplitter disposed disposed along an optical path between relay lens and the quarter-wave plate; and wherein the concave lens is adapted to produce a virtual magnified image of a image source at the location of a user.
Claim 2
Dependent Claim
70 words
The virtual image display system of Claim 1 wherein the grid beamsplitter comprises: a relatively flat optically transparent substrate having metal lines with spacing much less than the wavelength of visible light projected by the image source formed on its surface, and wherein the grid beamsplitter provides relatively high transmission for light having a selected polarization and provides relatively high reflectivity for other polarizations within a predetermined visible optical range.
Claim 3
Dependent Claim
14 words
The virtual image display optical system of Claim 2 wherein the substrate comprises glass.
Claim 4
Dependent Claim
14 words
The virtual image display optical system of Claim 2 wherein the substrate comprises plastic.
Claim 5
Dependent Claim
14 words
The virtual image display optical system of Claim 2 wherein the metal comprises aluminum.
Claim 6
Dependent Claim
31 words
The virtual image display optical system of Claim 2 wherein the grid lines comprise a metal deposited at an angle to form a bump on the top of each grid line
Claim 7
Dependent Claim
23 words
The virtual image display optical system of Claim 1 wherein the image source comprises a cathode ray tube having a relatively small screen.
Claim 8
Dependent Claim
23 words
The virtual image display optical system of Claim 1 wherein the image source comprises a liquid crystal display having a relatively small screen.
Claim 9
Dependent Claim
24 words
The virtual image display optical system of Claim 1 wherein the image source comprises a polarized color image source having a relatively small screen.
Claim 10
Dependent Claim
64 words
In a virtual image display system comprising an image source that is adapted to provided polarized light, a relay lens for transmitting the polarized light, a concave mirror adapted to reflect the polarized light, and a quarter-wave plate disposed between the relay lens and the concave mirror, wherein the improvement comprises: a grid beamsplitter disposed disposed between the relay lens and the quarter-wave plate.
Claim 11
Dependent Claim
42 words
The virtual image display system of Claim 10 wherein the grid beamsplitter comprises: a relatively flat optically transparent substrate having metal grid lines with spacing much less than the wavelength of visible light projected by the image source formed on its surface.
Claim 12
Dependent Claim
14 words
The virtual image display optical system of Claim 11 wherein the substrate comprises glass.
Claim 13
Dependent Claim
14 words
The virtual image display optical system of Claim 11 wherein the substrate comprises plastic.
Claim 14
Dependent Claim
14 words
The virtual image display optical system of Claim 11 wherein the metal comprises aluminum.
Claim 15
Dependent Claim
31 words
The virtual image display optical system of Claim 11 wherein the grid lines comprise a metal deposited at an angle to form a bump on the top of each grid line
Claim 16
Dependent Claim
98 words
A beamsplitter for use in a virtual image display system including an image source that is adapted to provided polarized light, a relay lens for transmitting the polarized light, a concave mirror adapted to reflect the polarized light, and a quarter-wave plate disposed between the relay lens and the concave mirror, and wherein the beamsplitter is disposed between the relay lens and the quarter-wave plate, said grid beamsplitter comprising: a relatively flat optically transparent substrate having metal grid lines with spacing much less than the wavelength of visible light projected by the image source formed on its surface.
Claim 17
Dependent Claim
14 words
The virtual image display optical system of Claim 16 wherein the substrate comprises glass.
Claim 18
Dependent Claim
14 words
The virtual image display optical system of Claim 16 wherein the substrate comprises plastic.
Claim 19
Dependent Claim
14 words
The virtual image display optical system of Claim 16 wherein the metal comprises aluminum.
Claim 20
Dependent Claim
31 words
The virtual image display optical system of Claim 16 wherein the grid lines comprising a metal deposited at an angle to form a bump on the top of each grid line.
References Cited (Backward Citations)
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