Display device and electronic watch

• US 6,147,934 A
• Filed: 06/08/1998
• Issued: 11/14/2000
• Est. Priority Date: 06/09/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Hirakawa, Tomoaki, Arikawa, Yasuo, Miyazawa, Eiichi
• Primary Examiner(s): MISKA, VIT W
• Application Number:
  US09/092,865
• Time in Patent Office: 890 Days
• Field of Search: 368/82, 368/84, 368/239, 368/242, 349/62, 349/96, 359/485-500
• US Class Current: 368/84
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605

Abstract

In a display device used in an electronic watch or the like, information such as numeric characters or the like and a background are bright and easily displayed. In addition, various information is provided to a viewer, and attracting the viewer'"'"'s interest is facilitated. The display device includes components of a polarizer, a liquid crystal panel and a polarization separation film. The polarization separation film has a function of transmitting linearly polarized light in one direction and of reflecting other linearly polarized light. A pattern such as a logo, a mark, a character or the like is formed by printing on a light-reflecting layer provided at the back of the polarization separation film. Information such as numeric characters or the like is not displayed as a background of a single color with no pattern, but after rendering a pattern such as a character or the like a background, both information such as numeric characters or the like and the background can be displayed simultaneously.

Claims

1. A display device, comprising:

a first polarization separator that transmits linearly polarized light polarized in a first direction and that does not transmit linearly polarized light polarized in a direction perpendicular to the first direction;

a polarization changing element disposed at a position to receive the linearly polarized light transmitted from the first polarization separator, the polarization changing element selecting between one of a changing state and a non-changing state of a polarization of the transmitted linearly polarized light;

a second polarization separator placed opposite to said first polarization separator with the polarization changing element interposed therebetween, the second polarization separator transmits linearly polarized light polarized in a second direction and reflects linearly polarized light polarized in a direction perpendicular to the second direction; and

a light-reflecting layer that reflects light, placed opposite to said polarization changing element with the second polarization separator interposed therebetween;

the light-reflecting layer including a pattern on a light-reflecting surface.

2. An electronic timepiece comprising:

a first polarization separator that transmits linearly polarized light polarized in a first direction and that does not transmit linearly polarized light polarized in a direction perpendicular to the first direction;

a polarization changing element disposed at a position to receive the linearly polarized light transmitted from the first polarization separator, the polarization changing element selecting between one of a changing state and a non-changing state of a polarization of the transmitted polarized light;

a second polarization separator placed opposite to said first polarization separator with the polarization changing element interposed therebetween, the second polarization separator transmitting linearly polarized light polarized in a second direction and reflecting linearly polarized light polarized in a direction perpendicular to the second direction; and

a light-reflecting layer that reflects light, placed opposite to said polarization changing element with the second polarization separator interposed therebetween;

the light-reflecting layer including a pattern on a light-reflecting surface.

3. The electronic timepiece according to claim 2, wherein said pattern is formed on the light-reflecting layer by printing.

4. The electronic timepiece according to claim 2, wherein said pattern is a logo, a mark or a character.

5. The electronic timepiece according to claim 2, the light-reflecting layer including a fluorescent material.

6. The electronic timepiece according to claim 2, wherein the first polarization separator is rotatable in relation to the polarization changing element.

7. The electronic timepiece according to claim 6, further comprising:

a casing for surrounding the first polarization separator, the polarization changing element, the second polarization separator and the light-reflecting layer; and

a rotary ring rotatably mounted to the casing, said first polarization separator being integrally rotated with said rotary ring.

8. The electronic timepiece according to claim 2, wherein the light-reflecting layer is movable in relation to the second polarization separator.

9. The electronic timepiece according to claim 2, said second polarization separator having a multilayered structure in which two types of layers are alternately laminated;

two adjacent ones of the layers having a same refractive index in one direction and having a different refractive index in a direction perpendicular to said one direction; and

said plurality of layers having varying thicknesses from layer to layer.

10. A display device, comprising:

a first polarization separator that transmits linearly polarized light polarized in a first direction and that does not transmit linearly polarized light polarized in a direction perpendicular to the first direction;

a polarization changing element disposed at position to receive the linearly polarized light transmitted from the first polarization separator, the polarization changing element selects one of a changing state and a non-changing state of a polarization of the transmitted linearly polarized light;

a second polarization separator, placed opposite to said first polarization separator with the polarization changing element interposed therebetween, the second polarization separator transmits linearly polarized light polarized in a second direction and reflects linearly polarized light polarized in a direction perpendicular to the second direction; and

a light-reflecting layer that reflects light, placed opposite to said polarization changing element with the second polarization separator interposed therebetween;

the light-reflecting layer having characteristics such that a visually recognized state is changed in response to a viewing angle.

11. An electronic timepiece comprising:

a first polarization separator that transmits linearly polarized light polarized on a first direction and that does not transmit linearly polarized light polarized in a direction perpendicular to the first direction;

a polarization changing element disposed at a position to receive the linearly polarized light transmitted from the first polarization separator, the polarization changing element selecting between one of a changing state and a non-changing state of a polarization of the transmitted linearly polarized light;

a second polarization separator, placed opposite to said first polarization separator with the polarization changing element interposed therebetween, the second polarization separator transmitting linearly polarized light polarized in a second direction and reflecting linearly polarized light polarized in a direction perpendicular to the second direction; and

a light-reflecting layer that reflects light, placed opposite to said polarization changing element with the second polarization separator interposed therebetween;

the light-reflecting layer having characteristics such that a visually recognized state is changed in response to a viewing angle.

12. The electronic timepiece according to claim 11, the light-reflecting layer including a Fresnel lens.

13. The electronic timepiece according to claim 11, the light-reflecting layer including a rugged geometrical pattern.

14. The electronic timepiece according to claim 11, the light-reflecting layer including a hologram sheet.

15. The electronic timepiece according to claim 11, the light-reflecting layer including a hologram sheet having a mosaic pattern, and hologram characteristics of respective pattern portions of the mosaic pattern having variations.

16. The electronic timepiece according to claim 11, said second polarization separator having a multilayered structure in which two types of layers are alternately laminated;

two adjacent ones of the layers having a same refractive index in one direction and having a different refractive index in a direction perpendicular to said one direction; and

said plurality of layers having varying thicknesses from layer to layer.

17. The electronic timepiece, comprising:

a first polarization separator that transmits linearly polarized light polarized in a first direction and that does not transmit linearly polarized light polarized in a direction perpendicular to the first direction;

a polarization changing element disposed at a position to receive the linearly polarized light transmitted from the first polarization separator, the polarization changing element selecting between one of a changing state and a non-changing state of a polarization of the transmitted linearly polarized light;

a second polarization separator placed opposite to said first polarization separator with the polarization changing element interposed therebetween, the second polarization separator transmitting linearly polarized light polarized in a second direction and reflecting linearly polarized light polarized in a direction perpendicular to the second direction; and

a light-reflecting layer that reflects light, placed opposite to said polarization changing element with the second polarization separator interposed therebetween;

the light-reflecting layer including a light-accumulative luminescent layer accumulating light as energy when an outside is bright, and emitting the accumulated energy as light when an outside is dark.

18. The electronic timepiece according to claim 17, said first polarization separator transmitting linearly polarized light polarized in a third direction and absorbing linearly polarized light polarized in a direction perpendicular to said third direction;

and

said second polarization separator transmitting linearly polarized light polarized in a fourth direction and reflecting linearly polarized light in a direction perpendicular to said fourth direction.

19. The electronic timepiece according to claim 17, said light-accumulative luminescent layer holding electrons excited by absorbed light in its excited state, and including a substance which causes light emission by recombination of the held electrons and positive holes.

20. The electronic timepiece, comprising:

a polarization changing element that changes a polarization direction;

a first polarization separator having first and second sides and a second polarization separator having third and fourth sides, the first and second polarization separators placed on opposite sides of the polarization changing element; and

a third polarization separator having fifth and sixth sides, the third polarization separator placed opposite to said polarization changing element with respect to the second polarization separator;

said first polarization separator emitting, in a first direction, linearly polarized light incident on the first side to the second side and emitting, in the first direction, linearly polarized light incident on the second side to said first side;

said second polarization separator transmitting, linearly polarized light incident on said third side, as linearly polarized light in a second direction, reflecting to said third side linearly polarized light in a first wavelength region of the light incident on said third side, in a third direction perpendicular to said second direction, as linearly polarized light in said third direction, and emitting to said fourth side, a linearly polarized light in a second wavelength region of the light incident on said third side, as linearly polarized light in a third direction; and

said third polarization separator transmitting to the sixth side, linearly polarized light incident on said fifth side, as linearly polarized light in a fourth direction, reflecting to said fifth side linearly polarized light in a third wavelength region of the light incident on said fifth side, as linearly polarized light in a fifth direction, perpendicular to said fourth direction, and emitting to the sixth side, linearly polarized light in a fourth wavelength region of the light incident on said fifth side in said fifth direction.

21. The electronic timepiece according to claim 20, said polarization changing element including a liquid crystal display device.

22. The electronic timepiece according to claim 21, wherein said liquid crystal display device is a TN liquid crystal device, an STN liquid crystal device, or an ECB liquid crystal device.

23. The electronic timepiece according to claim 20, said first polarization separator including a polarizer.

24. The electronic timpiece according to claim 20, wherein an angle formed by said second direction and said fourth direction is 45°

to 90°

.

25. The electronic timepiece according to claim 20, wherein an angle formed by said second direction and said fourth direction is 60°

to 90°

.

26. The electronic timepiece according to claim 20, wherein an angle formed by said second direction and said fourth direction is 75°

to 90°

.

27. The electronic timepiece according to claim 20, further comprising a light-diffusing element.

28. The electronic timepiece according to claim 20, further comprising a light-absorber.

29. The electronic timepiece according to claim 20, further comprising a light source.

30. The electronic timepiece according to claim 20, said second polarization separator being a laminated product in which a plurality of layers are laminated by being adhered to each other;

and

a refractive index of said plurality of layers being equal in a sixth direction between adjacent layers, and being different in a seventh direction perpendicular to the sixth direction.

31. The electronic timepiece according to claim 20, said third polarization separator being a laminated product in which a plurality of layers are laminated by being adhered to each other;

and

a refractive index of said plurality of layers being equal in an eighth direction between adjacent layers, and being in a ninth direction perpendicular to the eighth direction.