Large-panel table-top rear projection television

• US 20050270431A1
• Filed: 06/02/2004
• Published: 12/08/2005
• Est. Priority Date: 06/02/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Conner, Arlie R., Cannon, Bruce L., Kingsley, Gary B.
• Granted Patent: US 7,259,801 B2
• Time in Patent Office: Days
• US Class Current: 348/744
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: H04N 7/0122 the input and the output signals having different aspect ratios
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3141 Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14

Abstract

A table-top rear projection television employs a single large-panel (e.g., 7 inch-15 inch, 17.5 cm-38 cm, diagonal), multi-color transmissive imaging device (e.g., an amorphous silicon liquid crystal display). The rear projection television has a cabinet with a pedestal having a height and a depth that are each less than or equal to about 0.65 the height of the display screen. The display screen may have any aspect ratio of a wide format (e.g., 16:9, 15:9, 16:10) or a conventional format (i.e. 4:3).

Claims

1. A table-top rear projection television, comprising:

a cabinet having a pedestal positioned below and supporting a display screen having a display screen height H, the pedestal having a height and a depth that each are less than or equal to 0.65H;

an illumination system positioned in the pedestal and directing light along an optical path;

a large-panel pixelated, transmissive multicolor display panel receiving the light from the illumination system and imparting video images on the light;

a first fold mirror and a short vertex-to-vertex projection lens that receive the light with the imparted video images; and

a long conjugate fold mirror that folds the optical path from the projection lens and directs the light through the display screen.

2. The television of claim 1 in which the first fold mirror is a short conjugate fold mirror.

3. The television of claim 1 in which the large-panel pixelated, transmissive multicolor display includes a liquid crystal display.

4. The television of claim 3 in which the liquid crystal display has a diagonal dimension of at least 17.5 cm.

5. The television of claim 1 in which the large-panel pixelated, transmissive multicolor display has a diagonal dimension of at least 17 cm.

6. The television of claim 1 in which the projection lens has an output half-angle of 44°

-46°

to diagonal corners.

7. The television of claim 1 in which the long conjugate fold mirror folds the optical path by a half-angle of 33°

-35°

.

8. The television of claim 1 in which the projection lens has a vertex-to-vertex dimension of 70 mm-150 mm.

9. The television of claim 1 in which the projection lens has a retrofocus characteristic.

10. The television of claim 1 in which the projection lens has a vertex-to-vertex dimension and the large-panel pixelated, transmissive multicolor display has a diagonal dimension, and in which a ratio between the vertex-to-vertex dimension and the diagonal dimension is less than or equal to 0.4.

11. The television of claim 1 in which the projection lens has plural lens elements each with a diameter less than a maximum lens diameter and the large-panel pixelated, transmissive multicolor display has a diagonal dimension, and in which a ratio between the maximum lens diameter and the diagonal dimension is less than or equal to 0.3.

12. A table-top rear projection television optical system, comprising:

an illumination system positioned in the pedestal and directing light along an optical path;

only one large-panel pixelated, transmissive multicolor display panel receiving the light from the illumination system and imparting video images on the light;

a first fold mirror and a short vertex-to-vertex projection lens that receive the light with the imparted video images; and

a long conjugate fold mirror that folds the optical path from the projection lens and directs the light through the display screen,

whereby the illumination system, the large multicolor display panel, the short conjugate fold mirror, and the short vertex-to-vertex projection lens are positioned and sized to fit within a pedestal positioned below and supporting a display screen having a display screen height H, the pedestal having a height and a depth that each are less than or equal to 0.65H.

13. The television of claim 12 in which the first fold mirror is a short conjugate fold mirror.

14. The system of claim 12 in which the large-panel pixelated, transmissive multicolor display includes a liquid crystal display.

15. The system of claim 14 in which the liquid crystal display has a diagonal dimension of at least 17 cm.

16. The system of claim 12 in which the large-panel pixelated, transmissive multicolor display has a diagonal dimension of at least 17 cm.

17. The system of claim 12 in which the projection lens has an output half-angle of 44°

-46°

to diagonal corners.

18. The system of claim 12 in which the long conjugate fold mirror folds the optical path by a half-angle of 33°

-35°

.

19. The system of claim 12 in which the projection lens has a vertex-to-vertex dimension of 70 mm-150 mm.

20. The system of claim 12 in which the projection lens has a retrofocus characteristic.

21. The system of claim 12 in which the projection lens has a vertex-to-vertex dimension and the large-panel pixelated, transmissive multicolor display has a diagonal dimension, and in which a ratio between the vertex-to-vertex dimension and the diagonal dimension is less than or equal to 0.4.

22. The system of claim 12 in which the projection lens has plural lens elements each with a diameter less than a maximum lens diameter and the large-panel pixelated, transmissive multicolor display has a diagonal dimension, and in which a ratio between the maximum lens diameter and the diagonal dimension is less than or equal to 0.3.

23. A table-top rear projection television, comprising:

a cabinet having a pedestal positioned below and supporting a display screen having a display screen height H, the pedestal having a height that each is less than or equal to 0.55H;

an illumination system positioned in the pedestal and directing light along an optical path;

a large-panel pixelated, transmissive multicolor display panel receiving the light from the illumination system and imparting video images on the light;

a first fold mirror and a short vertex-to-vertex projection lens that receive the light with the imparted video images; and

a long conjugate fold mirror that folds the optical path from the projection lens and directs the light through the display screen.

24. The television of claim 23 in which the first fold mirror is a short conjugate fold mirror.

25. The television of claim 23 in which the large-panel pixelated, transmissive multicolor display includes a liquid crystal display.

26. The television of claim 25 in which the liquid crystal display has a diagonal dimension of at least 17 cm.

27. The television of claim 23 in which the large-panel pixelated, transmissive multicolor display has a diagonal dimension of at least 17 cm.

28. The television of claim 23 in which the projection lens has an output half-angle of 44°

-46°

to diagonal corners.

29. The television of claim 23 in which the long conjugate fold mirror folds the optical path by a half-angle of 33°

-35°

.

30. The television of claim 23 in which the projection lens has a vertex-to-vertex dimension of 70 mm-150 mm.

31. The television of claim 23 in which the projection lens has a retrofocus characteristic.