Display with aligned optical shutter and backlight cells applicable for use with a touchscreen

• US 6,842,170 B1
• Filed: 03/17/1999
• Issued: 01/11/2005
• Est. Priority Date: 03/17/1999
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Ventouris, George M., Paitl, Ken, Charlier, Michael L., Akins, Robert B.
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): Alphonse, Fritz
• Application Number:
  US09/271,634
• Time in Patent Office: 2,127 Days
• Field of Search: 345/173, 345/104, 345/36, 178/18.01, 178/18.1, 349/86
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: H04M 1/22 Illumination; Arrangements for improving the visibility of characters on dials

Abstract

A display (200) with aligned optical shutter and backlight cells (239, 289) uses a patterned polymer-dispersed liquid crystal (PDLC) optical shutter material (230) and an electroluminescent (EL) backlight material (280) to provide a low-cost, low-current-drain display having good contrast in both bright-light and low-light conditions. The aligned, patterned optical shutter and backlight layers form pixel “windows” through which images printed on a background can be hidden or revealed. Specifically, a mask layer (250) bears the images and is inserted between the optical shutter and the backlight layers to show information images, cover inactive areas of the display, and cover electrode traces connecting active segments of the display. The display (200) is thin and flexible enough to be integrated with a touchscreen (290).

Claims

1. An electronic device comprising:

a housing carrying a keyless input device having;

an optical shutter pixel;

a backlight pixel aligned underneath the optical shutter pixel; and

a touchscreen disposed beneath the backlight pixel.

2. An electronic device according to claim 1 wherein the keyless input device further comprises a mask layer located above the backlight pixel.

3. A radiotelephone comprising:

an antenna;

a housing coupled to the antenna;

a keyless input device carried in the housing, having

a top layer with an ultraviolet filter and a matte surface;

an optical shutter cell, located underneath the top layer, having an optical shutter pixel;

a mask layer, located underneath the optical shutter cell;

a color layer, located underneath the mask layer;

a backlight cell, located underneath the optical shutter cell, having a backlight pixel aligned with the optical shutter pixel; and

a touchscreen, located underneath the top layer.

4. A display comprising:

a polymer-dispersed liquid crystal optical shutter cell having a plurality of optical shutter pixels;

an electroluminescent backlight cell with a plurality of backlight pixels, aligned underneath the plurality of optical shutter pixels;

at least one driver for controlling a transition of the plurality of optical shutter pixels between first and second states and a transition of the plurality of backlight pixels between first and second states; and

a touchscreen layer.

5. A display according to claim 4, the at least one driver is a matrix drive driver for matrix controlling transition of the plurality of optical shutter pixels and transition of the plurality of backlight pixels.

6. A display according to claim 4, a mask layer located below the polymer-dispersed liquid crystal optical shutter cell.

7. A display according to claim 4, a color layer located above the backlight cell.

8. A display according to claim 7, wherein the color layer comprises a transflector.

9. A display according to claim 7, wherein the color layer comprises a filter.

10. A display according to claim 9 wherein the top layer has a matte upper surface.

11. A display according to claim 4, a top layer, located above at least a portion of the optical shutter cell, having an ultraviolet barrier.

12. A display according to claim 4, the at least one driver is a single driver for simultaneously controlling transition of the plurality of optical shutter pixels and transition of the plurality of backlight pixels.

13. A display according to claim 4, the touchscreen layer is located underneath the backlight cell.

14. A display according to claim 4, the polymer-dispersed liquid crystal material located between corresponding first and second electrodes, one of which has a pixel pattern, the electroluminescent material located between corresponding first and second electrodes, one of which has the same pixel pattern as the patterned electrode of the polymer-dispersed liquid crystal material.

15. A display comprising:

an optical shutter layer having a cell disposed between optical shutter electrodes, one of the optical shutter electrodes having an optical shutter cell pattern defining optical shutter pixels;

a backlight layer having a cell disposed between backlight electrodes, one of the backlight electrodes having substantially the same pattern as the shutter electrode,

the backlight cell disposed underneath the optical shutter cell, the patterned optical shutter electrode aligned with the patterned backlight electrode;

a driver coupled to optical shutter layer and the backlight layer.

16. A display according to claim 15, the optical shutter cell comprises a polymer-dispersed liquid crystal material.

17. A display according to claim 16, the backlight cell comprises an electroluminescent material.

18. A display according to claim 15, a touchscreen layer disposed below the backlight layer.

19. A display according to claim 15, an information image mask layer located below the optical shutter cell.

20. A display according to claim 15, the driver is a single driver for simultaneously controlling the transition of the optical shutter pixels and the backlight pixels.

21. The display of claim 15, a transflector layer disposed between the optical shutter layer and the backlight layer, the transflector layer transmitting light from the backlight layer side thereof to the optical shutter layer and reflecting light from the optical shutter side thereof.

22. An electronic device comprising:

an optical shutter layer having a plurality of display pixels;

a backlight layer having a plurality of backlight pixels;

each of the plurality of display pixels aligned with not more than a single one of the plurality of backlight pixels.

23. The device of claim 22,

each of the plurality of display pixels having first and second states;

each of the plurality of backlight pixels having first and second states;

a driver coupled to the plurality of backlight pixels and to the plurality of display pixels for simultaneously driving corresponding aligned display and backlight pixels between first and second states.

24. The device of claim 23,

at least some of the display pixels having different shapes, each backlight pixel having the same shape as the corresponding display pixel with which the backlight pixel is aligned,

the first state of the optical shutter layer is a light transmitting state and the second state of the optical shutter layer is a non-transmitting state, the first state of the backlight layer is an illuminated state and the second state of the backlight layer is a non-illuminated state.

25. The device of claim 22, a reflective and transmissive layer disposed between the optical shutter layer and the backlight layer.

26. The device of claim 22, an image-bearing mask disposed between the backlight layer and the optical shutter layer.

27. The device of claim 22, the display layer is a polymer-dispersed liquid crystal material, the backlight layer is an electroluminescent material.

28. The device of claim a 22, a touchpad disposed underneath the backlight layer, the backlight layer disposed between the optical shutter layer and the touchpad.

29. An electronic device comprising:

an optical shutter layer having a plurality of shutter pixels;

a backlight layer having a plurality of backlight pixels disposed beneath and aligned with shutter pixels of the optical shutter layer,

a transflector layer disposed between the backlight layer and the optical shutter layer,

the transflector layer reflecting light from an optical shutter layer side thereof and transmitting light from a backlight layer side thereof

an image-bearing mask disposed between the backlight layer and the optical shutter layer.

30. The device of claim 29, the backlight layer having a plurality of backlight pixels, each of the plurality of backlight pixels aligned with a corresponding one of the plurality of shutter pixels.

31. The device of claim 29, the optical shutter layer includes a polymer-dispersed liquid crystal material, the backlight layer includes an electroluminescent material.

32. The device of claim 29, an image of the imaging-bearing mask aligned with corresponding optical shutter pixels.

33. The device of claim 32, the backlight layer having a plurality of backlight pixels, each of the plurality of backlight pixels aligned with a corresponding one of the plurality of shutter pixels.

34. The device of claim 33,

at least some of the shutter pixels having different shapes, each backlight pixel having the same shape as the corresponding shutter pixel with which the backlight pixel is aligned,

a driver coupled to the backlight pixels and to the shutter pixels for simultaneously driving corresponding aligned shutter pixels and backlight pixels between first and second states.

35. The device of claim 34, a touchpad disposed underneath the backlight layer, the backlight layer between the touchpad and the optical shutter layer, the backlight layer disposed between the touchpad and the optical shutter layer.

36. The device of claim 29, a touchpad disposed underneath the backlight layer, the backlight layer between the touchpad and the optical shutter layer, the backlight layer disposed between the touchpad and the optical shutter layer.

37. An electronic device comprising:

a display layer having a plurality of display pixels;

a backlight layer disposed beneath the display layer,

the backlight layer having a plurality of backlight pixels, each of the plurality of backlight pixels aligned with a corresponding one of the plurality of display pixels;

an image-bearing mask disposed between the backlight layer and the display layer.

38. The device of claim 37, an image of the image-bearing mask aligned with corresponding display pixels.

39. The device of claim 37, the display layer is an optical shutter layer, the display pixels are shutter pixels.

40. The device of claim 39, a driver coupled to the backlight pixels and to the shutter pixels for simultaneously driving corresponding aligned shutter and backlight pixels between first and second states.

41. The device of claim 39, a transflector layer disposed between the backlight layer and the optical shutter layer.

42. The device of claim 39, the display layer includes a polymer-dispersed liquid crystal material, the display pixels having a light transmitting state and another state.

43. The device of claim 42, a transflector layer disposed between the display layer and the backlight layer, the transflector layer transmitting light from the backlight layer side thereof to the display layer where the display pixels are in a light transmitting state.

44. The device of claim 37, a touchpad disposed underneath the backlight layer, the backlight layer disposed between the touchpad and the display layer.

45. An electronic device comprising:

an optical shutter layer having a plurality of shutter pixels, at least some of the shutter pixels having different shapes;

a backlight layer having a plurality of backlight pixels,

each of the shutter pixels aligned with at least one corresponding backlight pixel,

the at least one backlight pixel having the same shape as the corresponding shutter pixel with which the at least one backlight pixel is aligned.

46. The device of claim 45, not more than one backlight pixel aligned with a corresponding one of the shutter pixels, each backlight pixel and corresponding shutter pixel aligned therewith having substantially the same shape.

47. The device of claim 45, a driver coupled to the plurality of backlight pixels and to the plurality of shutter pixels, the driver simultaneously controlling corresponding aligned shutter pixels and backlight pixels.

48. The device of claim 45, a touchscreen disposed below the backlight layer.

49. The device of claim 45, a reflective and transmissive layer disposed between the optical shutter layer and the backlight layer.

50. The device of claim 45, an image-bearing mask disposed between the backlight layer and the optical shutter layer.