Compact optical system for use in virtual display applications
First Claim
1. A compact optical system for directing an image signal for viewing by a user, the image signal being generated in accordance with a microdisplay, the system comprising:
- a first prism positioned proximate to the microdisplay;
a quarter wave plate positioned proximate to the first prism;
a reflective lens positioned proximate to the quarter wave plate; and
a second prism positioned proximate to the first prism;
wherein the first prism, the quarter wave plate, the reflective lens, and the second prism are arranged such that the image signal enters the first prism, reflects at an air gap between the first prism and the quarter wave plate, reflects at a boundary between the first prism and the second prism, passes through the quarter wave plate a first time, reflects at the reflective lens, passes through the quarter wave plate a second time, passes through the boundary between the first prism and the second prism, and exits the second prism for viewing by the user.
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Accused Products
Abstract
The invention provides a newly designed head mounted virtual image display that is dramatically less in weight than is known in the art by virtue of a unique beam folding design, making possible wearable computer systems of significantly greater convenience and acceptability to a wide range of users. The unit may be used comfortably in conjunction with eyeglasses. Optical systems according to the invention are provided that are advantageous for use with emissive, transmissive and reflective microdisplays, and which provide high optical performance, compact design and clear see-through properties. Also, the invention provides an improved method of illumination for reflection liquid crystal microdisplays. This makes possible optical systems for virtual image displays of improved field of view, compactness, and shorter image path combined with good efficiency.
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Citations
30 Claims
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1. A compact optical system for directing an image signal for viewing by a user, the image signal being generated in accordance with a microdisplay, the system comprising:
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a first prism positioned proximate to the microdisplay;
a quarter wave plate positioned proximate to the first prism;
a reflective lens positioned proximate to the quarter wave plate; and
a second prism positioned proximate to the first prism;
wherein the first prism, the quarter wave plate, the reflective lens, and the second prism are arranged such that the image signal enters the first prism, reflects at an air gap between the first prism and the quarter wave plate, reflects at a boundary between the first prism and the second prism, passes through the quarter wave plate a first time, reflects at the reflective lens, passes through the quarter wave plate a second time, passes through the boundary between the first prism and the second prism, and exits the second prism for viewing by the user. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A compact optical system for directing an image signal for viewing by a user, the image signal being generated in accordance with a microdisplay, the system comprising:
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a first prism positioned proximate to the microdisplay;
a quarter wave plate positioned proximate to the first prism;
a reflective lens positioned proximate to the quarter wave plate, the reflective lens including a convex-shaped external surface; and
a second prism positioned proximate to the first prism, the second prism including a concave-shaped external surface;
wherein the first prism, the quarter wave plate, the reflective lens, and the second prism are arranged such that the image signal enters the first prism, reflects at an air gap between the first prism and the quarter wave plate, reflects at a boundary between the first prism and the second prism, passes through the quarter wave plate a first time, reflects at the reflective surface, passes through the quarter wave plate a second time, passes through the boundary between the first prism and the second prism, and exits the second prism for viewing by the user. - View Dependent Claims (27)
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28. A head mounted virtual image display unit, the unit comprising:
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a microdisplay;
an optical system for directing an image signal for viewing by a user, the image signal being generated in accordance with the microdisplay, the optical system including;
(i) a first prism positioned proximate to the microdisplay;
(ii) a quarter wave plate positioned proximate to the first prism;
(iii) a reflective lens positioned proximate to the quarter wave plate; and
(iv) a second prism positioned proximate to the first prism, wherein the first prism, the quarter wave plate, the reflective lens, and the second prism are arranged such that the image signal enters the first prism, reflects at an air gap between the first prism and the quarter wave plate, reflects at a boundary between the first prism and the second prism, passes through the quarter wave plate a first time, reflects at the reflective lens, passes through the quarter wave plate a second time, passes through the boundary between the first prism and the second prism, and exits the second prism for viewing by the user; and
an optical system mounting structure for supporting the optical system within the field of view of an eye of the user. - View Dependent Claims (29)
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30. A portable computer system, comprising:
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(a)a head mounted virtual image display unit, the unit including;
a microdisplay;
an optical system for directing an image signal for viewing by a user, the image signal being generated in accordance with the microdisplay, the optical system including;
(i) a first prism positioned proximate to the microdisplay;
(ii) a quarter wave plate positioned proximate to the first prism;
(iii) a reflective lens positioned proximate to the quarter wave plate; and
(iv) a second prism positioned proximate to the first prism, wherein the first prism, the quarter wave plate, the reflective lens, and the second prism are arranged such that the image signal enters the first prism, reflects at an air gap between the first prism and the quarter wave plate, reflects at a boundary between the first prism and the second prism, passes through the quarter wave plate a first time, reflects at the reflective lens, passes through the quarter wave plate a second time, passes through the boundary between the first prism and the second prism, and exits the second prism for viewing by the user; and
an optical system mounting structure for supporting the optical system and microdisplay within the field of view of an eye of the user; and
(b) a computer-based device, coupled to the head mounted virtual image display unit, for generating and providing an electrical signal to the microdisplay for use in generating the image signal to be viewed by the user.
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Specification