LCD display with multifaceted back reflector

• US 5,128,787 A
• Filed: 12/07/1990
• Issued: 07/07/1992
• Est. Priority Date: 12/07/1990
• Status: Expired due to Fees

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T, Inc.
• Inventors: Blonder, Greg E.
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): Phan, James
• Application Number:
  US07/623,476
• Time in Patent Office: 578 Days
• Field of Search: 350/338, 350/345, 350/612, 350/613, 350/618, 350/621, 350/276 R, 362/296-297, 362/341, 362/346, 359/605, 359/608, 359/742, 359/866, 359/49, 359/70, 359/69
• US Class Current: 349/113
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605

Abstract

In accordance with the present invention, a transparent display, such as an LCD, is provided with back reflector having a plurality of reflecting facets angularly displaced with respect to the plane of the display cell so as to enhance contrast of the display without consumption of additional power while reducing glare. Advantageously the reflecting facets are oriented to concentrate reflection to a viewer of light above the viewer and light coming from over the viewer'"'"'s shoulder. The result of such concentration is a display having backlit visual characteristics without the consumption of backlighting power. Preferred embodiments are disclosed for vertical and horizontal mounting.

Claims

1. A transparent display device comprising:

a transparent LCD display cell having front and back sides,

a multifaceted back reflector disposed adjacent the back side of said cell, said back reflector comprising at least three repeated reflecting facets angularly displaced with respect to the front side of said cell, said reflecting facets oriented to concentrate reflected light in a preselected direction and repeated in a periodic array having a period of repetition in the range from 1 to 50 mils.

2. A display device according to claim 1 wherein the front side of said transparent display cell is planar and said periodic array comprises reflecting facets oriented so that when display is in a vertical position, said array will reflect light above and behind a viewer in a substantially horizontal direction.

3. A display device according to claim 1 wherein the front side of said transparent display cell is planar and said periodic array comprises reflecting facets oriented so that when display is in a horizontal position, said array will reflect light above and behind a viewer at an angle of 45°

±

10°

.

6. A display device according to claims 1 or 2 or 3 or 4 or 5 wherein said reflecting facets are textured to provide diffusion of 10% to 20% Lambertion.

7. A display device according to claims 1 or 2 or 3 or 4 or 5 wherein said reflecting facets comprise gold-colored reflecting layers.

8. A computer comprising a display device according to claims 1 or 2 or 3 or 4 or 5.

9. A telephone comprising a display device according to claims 1 or 2 or 3 or 4 or 5.

10. A display device according to claims 1 or 2 or 3 or 4 or 5 further comprising means for adjusting the angles of said facets.

4. A transparent display device comprising:

a transparent display cell having a back side and a planar front side and

a multifaceted back reflector disposed adjacent the back side of said cell, said back reflector comprising a repeated array of four reflecting facets oriented at respective angles with respect to said front side, of 104°

±

5°

, 10°

±

5°

, 157°

±

5° and

45°

±

5°

.

5. A transparent display device comprising:

a transparent display cell having a back side and a planar front side, and

a multifaceted back reflector disposed adjacent the back side of said cell, said back reflector comprising a repeated array of four reflecting facets oriented at respective angles with respect to said front side of 200°

±

5°

, 0°

±

5°

, 225°

±

5° and

140°

±

5°

.