Flat-panel camera

• US 20040046870A1
• Filed: 10/03/2003
• Published: 03/11/2004
• Est. Priority Date: 11/30/2000
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Cambridge Flat Projection Displays Limited
• Inventors: Leigh Travis, Adrian Robert
• Granted Patent: US 7,545,429 B2
• Time in Patent Office: Days
• US Class Current: 348/207.99
• CPC Class Codes: G02B 5/045 Prism arrays

Abstract

A flat-panel camera comprises a tapered transparent slab 1, a prismatic sheet 3 for introducing light into one face of the slab at near the critical angle so that it is reflected along the slab towards the thick end, and a miniature camera 2 receiving light emerging from the thick end of the slab at an angle depending on where the light entered the slab. An image processor 7 eliminates distortion in the image such as gaps caused by the light missing the camera.

Claims

1. A flat-panel camera comprising a tapered transparent slab (1), for receiving light at a glancing angle into one face of the slab, and a miniature camera (2) receiving light emerging from the thick end of the slab after internal reflection within the slab, at an angle dependent on the distance up the slab at which the light entered it.

2. A flat-panel camera according to claim 1 and further including a light-introducing means on one face of the slab for adjusting the angle of entry of light into the slab.

3. A flat-panel camera according to claim 2, in which the light-introducing means is a light-redirecting means such as a prismatic sheet (3) for changing the angle of input light from a predetermined angle to the said glancing angle.

4. A flat-panel camera according to any preceding claim, further including an output slab (12) continuing from the thick end of the tapered slab (1), and a cylindrical collimating means (4) directing light emerging from the tapered slab through the output slab towards the camera.

5. A flat-panel camera according to any preceding claim, further including a compensating tapered slab (9) between the light-introducing means and the waveguide slab.

6. A flat-panel camera according to any preceding claim, and including an image processor (7) associated with the miniature camera for completing or correcting the image.

7. A flat-panel camera according to any preceding claim, including a second miniature camera (8) facing the end of the tapered slab at the same angle as the first but reflected in the plane, for receiving internally reflected light that emerges after one more or fewer reflections than light received by the first camera.

8. A flat-panel camera according to any of claims 1 to 6, including a mirror at the thick end of and generally parallel to the slab, for reflecting towards the camera internally reflected light that emerges after one more or fewer reflections than light received directly by the first camera.

9. A three-dimensional camera including a camera according to any preceding claim and having a set of such miniature cameras (21-23) along the thick end of the slab.

10. A photocopier including a flat-panel camera according to claim 1, the subjects to be laid on the slab itself.

11. A video-conferencing apparatus including a flat-panel camera according to any of claims 1 to 9, in which the tapered slab also acts as a display, by way of a screen such as a phosphor or translucent screen.