ACHROMATIC FLAT-PANEL CAMERA

• US 20040070737A1
• Filed: 10/24/2003
• Published: 04/15/2004
• Est. Priority Date: 11/25/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Cambridge Flat Projection Displays Limited
• Inventors: Travis, Adrian Robert Leigh
• Granted Patent: US 6,883,919 B2
• Time in Patent Office: Days
• US Class Current: 353/33
• CPC Class Codes: G02B 6/08 with fibre bundle in form of plate
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: H04N 5/74 Projection arrangements for image reproduction, e.g. using eidophor
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

An achromatic flat-panel projection display comprises a video projector 2a, a condensing lens (26) and a tapered transparent slab spreading the image input from the projector over the area of the slab. To compensate for dispersion in the slab a dispersive prism is used at the input edge of the slab, whose dispersion cancels out the dispersion of the slab. The prism can be a separate part of simply a bevel in the input edge, i.e. the thick end of the slab.

Claims

1. An achromatic flat-panel projection display comprising an image projector (2) for projecting an image to be displayed, and a tapered transparent slab (1) into the thick end of which the image is projected so that the rays emerge over one face of the slab, the slab being made of a dispersive material;

further comprising a dispersive prism (3) between the projector and the slab, compensating for the dispersion occurring in the slab.

2. A display accordingto claim 1, in which the prism (3) is a separate component.

3. A display according to claim 2, in which the prism is made of the same material as the slab.

4. A display according to claim 1, in which the prism is integral with the slab so that the input edge is bevelled (10) .

5. A display according to any preceding claim, in which the angle β

of the prism satisfies