Liquid crystal display and timepiece

• US 6,504,590 B1
• Filed: 06/07/2000
• Issued: 01/07/2003
• Est. Priority Date: 10/07/1998
• Status: Expired due to Fees

• Current Assignee: Citizen Holdings Co., Ltd. (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Murakami, Tomomi, Kikuchi, Masami, Toida, Takashi
• Primary Examiner(s): Sikes; William L.
• Assistant Examiner(s): AKKAPEDDI, PRASAD R
• Application Number:
  US09/555,969
• Time in Patent Office: 944 Days
• Field of Search: 349/113,142 368/84,240 396/300 395/479 364/246
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605

Abstract

A liquid crystal display device (1) comprises a liquid crystal display panel (3) and a reflector (5) disposed on the side of the liquid crystal display panel, opposite from the visible side thereof. The liquid crystal display panel (3) comprises liquid crystal (3f) sandwiched between two transparent substrates (3a, 3b), and display electrodes (3c, 3d) made up of a transparent and electrically conductive film provided on the inner faces of the respective substrates (3a 3b). The reflector (5) is provided with protrusions (5a) formed at positions corresponding to the display electrodes (3c, 3d) on a face thereof opposite to the liquid crystal display panel (3). Accordingly, light transmitted through the liquid crystal display panel (3) falls on the protrusions (5a) of the reflector (5), and respective components of light reflected from the surface of the respective protrusion (5a) will reach the eyes of a viewer with differences in arrival time due to the surface condition of the respective protrusions (5a), so that information displayed by characters and so forth is three-dimensionally perceived by the viewer.

Claims

1. A liquid crystal display device comprising:

a liquid crystal display panel comprising liquid crystal sandwiched between two transparent substrates, and display electrodes made up of a transparent and electrically conductive film formed on the inner face of the respective substrates; and

a reflector disposed on a side of the liquid crystal display panel opposite from a visible side thereof and provided with protrusions formed in respective areas corresponding to location of the display electrodes on a face thereof opposite to the liquid crystal display panel, no protrusions being provided in other areas not corresponding to the locations of the electrodes, so that a portion of incident light is reflected on a surface of the reflector and a portion of incident light is reflected on a surface of the protrusions.

2. A liquid crystal display device according to claim 1, wherein the liquid crystal is scattering type liquid crystal that undergoes switching back and forth between a light scattering state and a transparent state by voltage applied from the display electrodes.

3. A liquid crystal display device according to claim 2, wherein the scattering type liquid crystal is any one selected from the group consisting of polymer network liquid crystal, polymer dispersion liquid crystal, and dynamic scattering liquid crystal.

4. A liquid crystal display device according to claim 1, wherein the liquid crystal is guest-host liquid crystal provided with a dichroic dye.

7. A liquid crystal display device according to claim 1, wherein the protrusions of the reflector are formed in a shape having a curved convex surface without ridgelines.

8. A liquid crystal display device according to claim 1, wherein the protrusions of the reflector are mushroom-shaped in section, with the uppermost face thereof having a curved convex surface, and extending sideways from the base of the respective protrusions.

9. A liquid crystal display device according to claim 1, wherein the reflector including the protrusions is made of aluminum.

10. A liquid crystal display device according to claim 1, wherein the reflector is made up of an aluminum sheet, and the protrusions are made of a material having a surface reflectance higher than that of aluminum, such as gold, silver, nickel, and so forth.

11. A liquid crystal display device according to claim 1, wherein the reflector is made up of an aluminum sheet, and the protrusions are formed of copper, a thin gold film is formed on the surfaces thereof.

12. A liquid crystal display device according to claim 1, wherein the reflector is formed of a non-metallic material while a thin film made of material having a high surface reflectance is formed on a reflection face of the reflector, including the surfaces of the protrusions.

15. A liquid crystal display device according to claim 1, wherein:

the respective substrates of the liquid crystal display panel are provided with a plurality of display electrodes for displaying different pieces of information;

the reflector is provided with a plurality of protrusions at positions corresponding to the plurality of the display electrodes, respectively, formed on the face thereof opposite to the liquid crystal display panel and;

at least respective reflection faces of the plurality of the protrusions of the reflector are formed of materials in reflection colors differing from each other, depending on spots of formation thereof.

16. A liquid crystal display device according to claim 15, wherein the materials in reflection colors differing from each other are two or more metals among gold, silver or nickel, and copper.

17. A liquid crystal display device according to claim 16, wherein a protective film of clear paint is formed on respective reflection faces of the plurality of the protrusions of the reflector.

18. A liquid crystal display device according to claim 15, wherein the plurality of the protrusions are formed of a coating of paints in different colors depending on spots of formation thereof on a reflection face of the reflector.

37. A liquid crystal display device according to claim 12, wherein the non-metallic material is a resin.

38. A liquid crystal display device according to claim 12, wherein the material having a high surface reflectance is aluminum, gold, silver or nickel.

5. A liquid crystal display device comprising:

a liquid crystal display panel comprising liquid crystal sandwiched between two transparent substrates, and display electrodes made up of a transparent and electrically conductive film formed on the inner face of the respective substrates; and

a reflector disposed on a side of the liquid crystal display panel opposite from a visible side thereof and provided with protrusions formed in respective areas corresponding to locations of the display electrodes on a face thereof opposite to the liquid crystal display panel,

wherein a plane pattern of the protrusions formed on the reflector is substantially in the form of a figure similar to a figure of a plane pattern of the display electrodes of the liquid crystal display panel.

6. A liquid crystal display device according to claim 5, wherein the protrusions formed on the reflector has a pattern width narrower than that of the display electrodes of the liquid crystal display panel.

13. A liquid crystal display device comprising:

a liquid crystal display panel comprising liquid crystal sandwiched between two transparent substrates, and display electrodes made up of a transparent and electrically conductive film formed on the inner face of the respective substrates; and

a reflector disposed on a side of the liquid crystal display panel opposite from a visible side thereof and provided with protrusions formed in respective areas corresponding to locations of the display electrodes on a face thereof opposite to the liquid crystal display panel,

wherein a surface reflectance of an uppermost face of the respective protrusions of the reflector is differentiated from a surface reflectance of side faces thereof.

14. A liquid crystal display device according to claim 13, wherein the uppermost face of the respective protrusions of the reflector is a mirror-finished surface while the side faces of the respective protrusions are light scattering surfaces.

19. An electronic timepiece provided with a liquid crystal display device comprising a liquid crystal display panel for displaying at least either of time information and calendar information, and a reflector disposed on the side of the liquid crystal display panel, opposite from the visible side thereof, wherein:

the liquid crystal display panel of the liquid crystal display device comprises liquid crystal sandwiched between two transparent substrates, and display electrodes for displaying at least either of the time information and calendar information made up of a transparent and electrically conductive film formed on the inner face of the respective substrates; and

the reflector is provided with protrusions formed in respective areas corresponding to locations of the display electrodes on a face thereof opposite to the liquid crystal display panel, no protrusions being provided in other areas not corresponding to the locations of the electrodes, so that a portion of incident light is reflected on a surface of the reflector and a portion of incident light is reflected on a surface of the protrusions.

20. An electronic timepiece according to claim 19, wherein:

the liquid crystal is scattering type liquid crystal that undergoes switching back and forth between a light scattering state and a transparent state by voltage applied from the display electrodes.

21. An electronic timepiece according to claim 20, wherein:

the scattering type liquid crystal is any one selected from the group consisting of polymer network liquid crystal, polymer dispersion liquid crystal and dynamic scattering liquid crystal.

22. An electronic timepiece according to claim 19, wherein:

the liquid crystal is guest host liquid crystal provided with a dichroic dye.

25. An electronic timepiece according to claim 19, wherein:

the protrusions of the reflector are formed in a shape having a curved convex surface without ridgelines.

26. An electronic timepiece according to claim 19, wherein:

the protrusions of the reflector are mushroom-liked shape in section, with the uppermost face thereof having a curved convex surface and extending sideways from the base of the respective protrusions.

27. An electronic timepiece according to claim 19, wherein:

the reflector including the protrusions is made of aluminum.

28. An electronic timepiece according to claim 19, wherein:

the reflector is made up of an aluminum sheet, and the protrusions are made of material having a surface reflectance higher than that of aluminum, such as gold, silver, nickel, and so forth.

29. An electronic timepiece according to claim 19, wherein:

the reflector is made up of an aluminum sheet, the protrusions are formed of copper, and a thin gold film is formed on the surfaces thereof.

30. An electronic timepiece according to claim 19, wherein:

the reflector is formed of a non-metallic material while a thin film made of material having a high surface reflectance is formed on a reflection face of the reflector, including the surfaces of the protrusions.

33. An electronic timepiece according to claim 19, wherein:

the respective substrates of the liquid crystal display panel are provided with a plurality of display electrodes for displaying different pieces of information;

the reflector is provided with a plurality of protrusions at positions corresponding to the plurality of the display electrodes, respectively, formed on the face thereof opposite to the liquid crystal display panel;

and at least respective reflection faces of the plurality of the protrusions of the reflector are formed of materials in reflection colors differing from each other, depending on spots of formation thereof.

34. An electronic timepiece according to claim 33, wherein:

the materials in different reflection colors are two or more metals among gold, silver or nickel, and copper.

35. An electronic timepiece according to claim 34, wherein:

a protective film of clear paint is formed on respective reflection faces of the plurality of the protrusions of the reflector.

36. An electronic timepiece according to claim 33, wherein:

the plurality of the protrusions are formed of a coating of paints in different colors depending on spots of formation thereof on a reflection face of the reflector.

39. An electronic timepiece according to claim 30, wherein the non-metallic material is a resin.

40. An electronic timepiece according to claim 30, wherein the material having a high surface reflectance is aluminum, gold, silver or nickel.

23. An electronic timepiece provided with a liquid crystal display device comprising a liquid crystal display panel for displaying at least either of time information and calendar information, and a reflector disposed on the side of the liquid crystal display panel, opposite from the visible side thereof, wherein:

the liquid crystal display panel of the liquid crystal display device comprises liquid crystal sandwiched between two transparent substrates, and display electrodes for displaying at least either of the time information and calendar information made up of a transparent and electrically conductive film formed on the inner face of the respective substrates;

the reflector is provided with protrusions formed in respective areas corresponding to locations of the display electrodes on a face thereof opposite to the liquid crystal display panel, and

a plane pattern of the protrusions formed on the reflector is substantially in the form of a figure similar to a figure of a plane pattern of the display electrodes of the liquid crystal display panel.

24. An electronic timepiece according to claim 23, wherein:

the protrusions formed on the reflector has a pattern width narrower than that of the display electrodes of the liquid crystal display panel.

31. An electronic timepiece provided with a liquid crystal display device comprising a liquid crystal display panel for displaying at least either of time information and calendar information, and a reflector disposed on the side of the liquid crystal display panel, opposite from the visible side thereof, wherein:

the liquid crystal display panel of the liquid crystal display device comprises liquid crystal sandwiched between two transparent substrates, and display electrodes for displaying at least either of the time information and calendar information made up of a transparent and electrically conductive film formed on the inner face of the respective substrates;

the reflector is provided with protrusions formed in respective areas corresponding to locations of the display electrodes on a face thereof opposite to the liquid crystal display panel; and

a surface reflectance of an uppermost face of the respective protrusions of the reflector is differentiated from a surface reflectance of side faces thereof.

32. An electronic timepiece according to claim 31, wherein:

the uppermost face of the respective protrusions of the reflector is a mirror-finished surface while the side faces of the respective protrusions are light scattering surfaces.