Timepiece

• US 6,169,708 B1
• Filed: 02/09/2000
• Issued: 01/02/2001
• Est. Priority Date: 03/03/1998
• Status: Expired due to Fees

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Kaneko, Yasushi, Akiyama, Takashi, Ide, Masafumi
• Primary Examiner(s): MISKA, VIT W
• Application Number:
  US09/485,392
• Time in Patent Office: 328 Days
• Field of Search: 368/82-84, 368/239-242, 349/86, 349/96-98, 349/104, 349/106, 349/112-115
• 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 1/133543 Cholesteric polarisers
• 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 2201/08 light absorbing layer
• CPC Class Codes: G02F 2203/03 scattering
• CPC Class Codes: G04G 9/0035 constructional

Abstract

A timepiece with a liquid crystal display panel 40 having at least either of a time display section 40a and a calendar display section 40b, and comprising a TN liquid crystal cell with about 90° twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes, a first polarizing film disposed on the visible side of the TN liquid crystal cell, a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof. With such a constitution, time display and calendar display are rendered visible even at night by lighting up the backlight, and colored display in a metallic tone can be indicated.

Claims

1. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

a TN liquid crystal cell with about 90°

twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes;

a first polarizing film disposed on the visible side of the TN liquid crystal cell; and

a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof.

2. A timepiece according to claim 1, wherein a luminescence center wavelength of the backlight of said liquid crystal display panel is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

3. A timepiece according to claim 1, wherein the backlight of said liquid crystal display panel has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

4. A timepiece according to claim 1, wherein the second polarizing film of said liquid crystal display panel is a reflection-type polarizing film.

5. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

an STN liquid crystal cell with 180°

to 270°

twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes;

a retardation film disposed on the visible side of the STN liquid crystal cell;

a first polarizing film disposed on the outer side of the retardation film; and

a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a translucent light absorbing member and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof.

6. The timepiece according to claim 5, wherein the retardation film of said liquid crystal display panel is a twisted retardation film.

7. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

a TN liquid crystal cell with about 90°

twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes;

a first polarizing film disposed on the visible side of the TN liquid crystal cell; and

a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof,

wherein a face of said backlight, opposite to said cholestric liquid crystal polymer sheet, has a function of scattering polarized light.

8. A timepiece according to claim 7, wherein a luminescence center wavelength of the backlight of said liquid crystal display panel is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

9. A timepiece according to claim 7, wherein the backlight of said liquid crystal display panel has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

10. A timepiece according to claim 7, wherein the second polarizing film of said liquid crystal display panel is a reflection-type polarizing film.

11. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

an STN liquid crystal cell with 180°

to 270°

twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes;

a retardation film disposed on the visible side of the STN liquid crystal cell;

a first polarizing film disposed on the outer side of the retardation film; and

a second polarizing film, a retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof,

wherein a face of said backlight, opposite to said cholestric liquid crystal polymer sheet, has a function of scattering polarized light.

12. A timepiece according to claim 11, wherein the retardation film of said liquid crystal display panel is a twisted retardation film.

13. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

a TN liquid crystal cell with about 90°

twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes;

a first polarizing film disposed on the visible side of the TN liquid crystal cell; and

a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film, a translucent light absorbing member and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof.

14. A timepiece according to claim 13, wherein a luminescence center wavelength of the backlight of said liquid crystal display panel is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

15. A timepiece according to claim 13, wherein the backlight of said liquid crystal display panel has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

16. A timepiece according to claim 13, wherein the second polarizing film of said liquid crystal display panel is a reflection-type polarizing film.

17. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

an STN liquid crystal cell with 180°

to 270°

twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes;

a retardation film disposed on the visible side of the STN liquid crystal cell;

a first polarizing film disposed on the outer side of the retardation film; and

a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film, a translucent light absorbing member and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof.

18. A timepiece according to claim 17, wherein the retardation film of said liquid crystal display panel is a twisted retardation film.

19. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

a TN liquid crystal cell with about 90°

twisted nematic liquid crystals sealed in-between a pair of transparent substrates having respective transparent electrodes;

a first polarizing film disposed on the visible side of the TN liquid crystal cell; and

a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film and a backlight disposed successively on a side of the TN liquid crystal cell, opposite from the visible side thereof,

wherein a face of said backlight, opposite to said second polarizing film, has a function of scattering polarized light.

20. A timepiece according to claim 19, wherein a luminescence center wavelength of the backlight of said liquid crystal display panel is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

21. A timepiece according to claim 19, wherein the second polarizing film of said liquid crystal display panel is a reflection-type polarizing film.

22. A timepiece according to claim 19, wherein the backlight of said liquid crystal display panel has not less than two luminescence center wavelengths, and at least one of the luminescence center wavelengths is deviated by not less than 50 nm from a selected scattering center wavelength of the cholestric liquid crystal polymer sheet.

23. A timepiece comprising a liquid crystal display panel capable of displaying at least either of time information and calendar information, said liquid crystal display panel comprising:

an STN liquid crystal cell with 180°

to 270°

twisted nematic liquid crystals sandwiched between a pair of transparent substrates having respective transparent electrodes;

a retardation film disposed on the visible side of the STN liquid crystal cell;

a first polarizing film disposed on the outer side of the retardation film; and

a first retardation film for circularly polarized light, a cholestric liquid crystal polymer sheet, a second retardation film for circularly polarized light, a second polarizing film and a backlight disposed successively on a side of the STN liquid crystal cell, opposite from the visible side thereof,

wherein a face of said backlight, opposite to said second polarizing film, has a function of scattering polarized light.

24. A timepiece according to claim 23, wherein the retardation film of said liquid crystal display panel is a twisted retardation film.