Timepiece including multiple liquid crystal displays

• US 6,643,224 B1
• Filed: 11/02/2000
• Issued: 11/04/2003
• Est. Priority Date: 11/02/2000
• 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: Akiba, Yuichi, Akiyama, Takashi, Ide, Masafumi, Nakagawa, Koji, Kikuchi, Masami, Sekiguchi, Kanetaka
• Primary Examiner(s): Gibson, Randy
• Assistant Examiner(s): Lindinger, Michael L.
• Application Number:
  US09/704,045
• Time in Patent Office: 1,097 Days
• Field of Search: 368/82-84, 368/223, 368/239, 368/242
• US Class Current: 368/242
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/13471 in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells G02F1/13475 takes precedence
• CPC Class Codes: G04G 9/0035 constructional
• CPC Class Codes: G04G 9/0064 in which functions not related to time can be displayed digital output to display devices of digital computers G06F3/14

Abstract

A timepiece, in which a first liquid crystal display panel and a second liquid crystal display panel, each of which is constituted by sealing a liquid crystal layer in a gap between a pair of substrates formed with electrodes on opposed inner faces thereof respectively, are arranged in a case body having a cover glass with at least portions thereof overlapping, a first polarizing film is provided on an upper substrate of the first liquid crystal display panel on the cover glass side, a second polarizing film is provided between the first liquid crystal display panel and the second liquid crystal display panel, and a third polarizing film is provided on the lower side of a lower substrate of the second liquid crystal display panel respectively, the second polarizing film being a reflection type polarizing film, the first polarizing film, the first liquid crystal display panel, and the second polarizing film constitutes an upper display portion, and the second polarizing film, the second liquid crystal display panel, and the third polarizing film constitutes a lower display portion, so that at least the lower display portion performs display on the time.

Claims

1. A timepiece, comprising:

a first liquid crystal display panel constituted by sealing a first liquid crystal layer in a gap between first and second substrates formed with electrodes on opposed inner faces thereof respectively;

a second liquid crystal display panel constituted by sealing a second liquid crystal layer in a gap between third and fourth substrates formed with electrodes on opposed inner faces thereof respectively,

said second substrate and said third substrate being overlaid one upon another adjacent to each other, and arranged in a case body having a cover glass with said first substrate facing said cover glass side; and

a first polarizing film disposed on said cover glass side of said first substrate, a second polarizing film located between said second substrate and said third substrate, and a third polarizing film located on an opposite side to said second liquid crystal layer of said fourth substrate;

said second polarizing film being a reflection type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and reflects the other,

further comprising;

a circuit board having a circuit for driving said first liquid crystal display panel and said second liquid crystal display panel in said case body;

a first elastic body having electrical conductivity which performs electrical connection between said first liquid crystal display panel and said circuit board, and

a second elastic body having electrical conductivity which performs electrical connection between said second liquid crystal display panel and said circuit board,

wherein said first elastic body connecting the first substrate of said first liquid crystal display panel and said circuit board,

said second elastic body connecting the third substrate of said second liquid crystal display panel and said circuit board,

said second polarizing film being bonded on said second substrate with an adhesive to substantially eliminating any gap in-between, and a space being provided by a space between said second polarizing film and said third substrate.

2. The timepiece according to claim 1,

wherein said third polarizing film is also a reflection type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and reflects the other.

3. The timepiece according to claim 1,

wherein said first polarizing film is an absorption type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and absorbs the other.

4. The timepiece according to claim 1,

wherein said first polarizing film, said first liquid crystal display panel, and said second polarizing film constitutes an upper display portion, said second polarizing film, said second liquid crystal display panel, and said third polarizing film constitute a lower display portion, and at least the lower display portion performs display on the time.

5. The timepiece according to claim 1,

wherein said first polarizing film is a polarizing film in which an absorption type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and absorbs the other and a reflection type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and reflects the other, are laminated from said cover glass side.

6. The timepiece according to claim 1,

wherein said space is formed by a printing layer provided between said second polarizing film and said third substrate, and the printing layer serves as a panel cover for a time display screen of said lower display portion.

7. The timepiece according to claim 1, further comprising:

a light source provided on an opposite side to said fourth substrate with respect to said third polarizing film for emitting light by application of voltage.

8. The timepiece according to claim 7, further comprising:

a fluorescent ink layer on said light source for absorbing light from said light source and for emitting light with a wavelength different from that of the absorbed light.

9. The timepiece according to claim 1,

wherein said upper display portion exhibits a mirror state of reflecting light made incident through said cover glass in a state where no voltage or a voltage at a predetermined value or less is applied to said first liquid crystal layer in said first liquid crystal display panel, and exhibits a transmission state of transmitting said light in a state where a voltage exceeding the predetermined value is applied.

10. The timepiece according to claim 1,

wherein said transparent electrodes are formed on the opposed inner faces of said first and second substrates of said first liquid crystal display panel so that a space between said electrodes opposed with said first liquid crystal layer interposed therebetween changes seamlessly, and

wherein a ratio of a region where said mirror state is exhibited to a region where said transmission state is exhibited in said upper display portion is changed by changing the voltage applied between said opposed electrodes.

11. The timepiece according to claim 1,

wherein, while said upper display portion is exhibiting said mirror state within almost its entire face, said second liquid crystal display panel of said lower display portion does not perform said display on the time.

12. The timepiece according to claim 1,

wherein, while said upper display portion is exhibiting said mirror state within almost its entire face, said upper display portion performs part of display on the time such as a second.

13. The timepiece according to claim 1, further comprising:

a diffusing layer provided between said fourth substrate and said third polarizing film with no diffusing layer provided between said first polarizing film and said second polarizing film.

14. The timepiece according to claim 1,

wherein said first polarizing film is an absorption type polarizing film having characteristics that an absorption rate of linearly polarized light is lower on blue side than on green and red sides in the visible light.

15. The timepiece according to claim 13,

wherein said diffusing layer is a white diffusing film, and

wherein said third polarizing film is constituted by laminating, from said fourth substrate side, an absorption type polarizing film which transmits one of linearly polarized lights of which polarization directions are orthogonal to each other and absorbs the other and a mirror reflector.

16. The timepiece according to claim 15,

wherein said mirror reflector is a transflective reflector which transmits part of light and reflects almost the other light.

17. The timepiece according to claim 1, further comprising:

a light source composed of an electro-luminescent device on an opposite side to said fourth substrate with respect to said third polarizing film.

18. The timepiece according to claim 17, further comprising:

a fluorescent ink layer on said light source for absorbing light from said light source and for emitting light with a wavelength different from that of the absorbed light.

19. The timepiece according to claim 18,

wherein said fluorescent ink layer is formed of a fluorescent ink emitting light with a specific wavelength within the visible light region.

20. The timepiece according to claim 9, further comprising:

transparent electrodes for applying voltage to said first liquid crystal layer in said first liquid crystal display panel formed at least in each region of a plurality of regions made by dividing a display region of said upper display portion to apply voltage different in each region to said first liquid crystal layer,

wherein said upper display portion is configured to be capable of turning into a first state of exhibiting said mirror state within said entire display region, into a second state of exhibiting said transmission state within part of said display region and exhibiting said mirror state within the other region, and into a third state of exhibiting said transmission state within said entire display region.

21. The timepiece according to claim 9, further comprising:

transparent electrodes for applying voltage to said first liquid crystal layer in said first liquid crystal display panel formed at least in each region of a plurality of regions made by dividing a display region of said upper display portion to apply voltage different in each region to said first liquid crystal layer,

wherein said upper display portion is configured to be capable of turning into a first state of exhibiting said mirror state within said entire display region, into a second state of performing part of display on the time such as a second within part of said display region and exhibiting said mirror state within the other region, and into a third state of exhibiting said transmission state within said entire display region.

22. The timepiece according to claim 20,

wherein, while said upper display portion is in said first state, no voltage or a voltage only at a level at which display is not performed, is applied to said second liquid crystal layer in said second liquid crystal display panel of said lower display portion.

23. The timepiece according to claim 21,

wherein, while said upper display portion is in said first state or in said second state, no voltage or a voltage only at a level at which display is not performed is applied to said second liquid crystal layer in said second liquid crystal display panel of said lower display portion.

24. The timepiece according to claim 1, wherein said first elastic body for connecting said first liquid crystal display panel and said circuit board and said second elastic body for connecting said second liquid crystal display panel and said circuit board are arranged along the same edge of the circuit board, and said first elastic body is disposed at an outer periphery side of said circuit board and said second elastic body.

25. The timepiece according to claim 1, wherein said first elastic body for connecting said first liquid crystal display panel and said circuit board and said second elastic body for connecting said second liquid crystal display panel and said circuit board are arranged along one edge and the other edge on two different sides of said circuit board.

26. The timepiece according to claim 1, wherein driving signals applied to said first liquid crystal display panel and said liquid crystal display panel are signals equal in driving voltage and frequency.