Electronic timepiece

• US 6,201,770 B1
• Filed: 07/08/1998
• Issued: 03/13/2001
• Est. Priority Date: 07/09/1997
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Arikawa, Yasuo, Miyazawa, Eiichi
• Primary Examiner(s): MISKA, VIT W
• Application Number:
  US09/111,740
• Time in Patent Office: 979 Days
• Field of Search: 368/82-84, 368/239-242, 349/61, 349/64, 349/68, 349/69, 349/80, 349/96, 349/97, 349/106-108
• US Class Current: 368/84
• CPC Class Codes: G02F 1/133533 Colour selective polarisers G02F1/1347 takes precedence
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters

Abstract

An electronic timepiece provides a bright and easy-to-read display, and a greater variety of display forms of numerical information, or the like, and a greater variety of background colors. The electronic timepiece may include a polarizer, a liquid crystal element, and a polarization separating film. The polarization separating film transmits linearly polarized light polarized in a certain direction and reflects all other linearly polarized light. The internal structure of the polarization separating film may be divided, in a plane, into polarization separating portions which reflect light of different wavelengths. The polarization separating film reflects different colors in correspondence to the polarization separating portions. Using a reflecting-type polarization separating film allows a bright display to be realized, and providing a plurality of polarization separating portions allows a greater variety of display forms to be realized.

Claims

1. A display device in an electronic timepiece comprising:

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

a polarization changing element disposed at a position to receive the linearly polarized light from said first polarization separator, that selects between a state in which a polarization direction of light transmitted therethrough is changed and a state in which the polarization direction is not changed; and

a second polarization separator that transmits linearly polarized light polarized in a second direction and reflects linearly polarized light polarized in a direction perpendicular to said second direction, said second polarization separator disposed opposite said first polarization separator with said polarization changing element interposed therebetween, said second polarization separator including, within a plane, a plurality of polarization separating portions reflecting light of different wavelengths.

2. The display device in the electronic timepiece according to claim 1, further comprising a light scattering layer disposed opposite said first polarization separator with said polarization changing element interposed therebetween.

3. The display device in the electronic timepiece according to claim 1, further comprising a light emitting element that emits light to said polarization changing element through said second polarization separator.

4. The display device in the electronic timepiece according to claim 3, further comprising a translucent layer disposed between said second polarization separator and said light emitting element.

5. The display device in the electronic timepiece according to claim 3, wherein said light emitting element emits at least one of orange light, red light, and yellowish green light.

6. The display device in the electronic timepiece according to claim 4, wherein said light emitting element emits at least one of orange light, red light, and yellowish green light.

7. The display device in the electronic timepiece according to claim 3, wherein said light emitting element emits a plurality of colors from within a plane.

8. The display device in the electronic timepiece according to claim 4, wherein said light emitting element emits a plurality of colors from within a plane.

9. The display device in the electronic timepiece according to claim 3, wherein said light emitting element includes a color filter.

10. The display device in the electronic timepiece according to claim 4, wherein said light emitting element includes a color filter.

11. The display device in the electronic timepiece according to claim 1, each of said polarization separating portions of said second polarization separator having a multi-layered structure formed by alternately laminating two types of layers, with any two adjacent layers of the plurality of layers in a lamination direction having a same refractive index in a certain direction, but having a different refractive index in a direction perpendicular to the certain direction, each of said plurality of layers forming each of said polarization separating portions having different thicknesses, and said multi-layered structures of said polarization separating portions having different thickness combinations so that each of said polarization separating portions has different wavelength characteristics.

12. A display device in an electronic timepiece, comprising:

a polarizer;

a twisted nematic (TN) liquid crystal layer interposed between two substrates; and

a polarization separating film, said polarizer, said twisted nematic liquid crystal layer, and said polarized light separating film being laminated in that order to form said electronic timepiece;

wherein said polarization separating film transmits polarized light polarized in a first direction and reflects polarized light polarized in a direction perpendicular to the first direction, said polarization separating film including at least a first area and a second area,

said liquid crystal layer including at an upper portion thereof a first display area in correspondence with the first area and a second display area in correspondence with the second area.

13. The display device in the electronic timepiece according to claim 12, further comprising a light scattering layer disposed opposite said polarizer with said liquid crystal layer interposed therebetween.

14. The display device in the electronic timepiece according to claim 12, further comprising a light emitting element that emits light to said polarization changing element through said polarization separating film.

15. The display device in the electronic timepiece according to claim 14, further comprising a translucent layer disposed between said polarization separating film and said light emitting element.

16. The display device in the electronic timepiece according to claim 14, wherein said light emitting element emits at least one of orange light, red light, and yellowish green light.

17. The display device in the electronic timepiece according to claim 14, wherein said light emitting element emits a plurality of colors from within a plane.

18. The display device in the electronic timepiece according to claim 14, wherein said light emitting element includes a color filter.