Electronic device

• US 6,593,901 B1
• Filed: 10/03/2000
• Issued: 07/15/2003
• Est. Priority Date: 12/15/1998
• 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: Fujioka, Hiroshi, Osa, Takashi, Kitazawa, Isao, Sase, Masahiro, Okigami, Tomio
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Jorgensen, Leland R.
• Application Number:
  US09/622,449
• Time in Patent Office: 1,015 Days
• Field of Search: 345/4, 345/33, 345/40, 345/903, 368/84
• US Class Current: 345/4
• CPC Class Codes: G04G 9/0023 by light valves in general G04G9/06, G04G9/12 takes precedence; electro-, magneto- or acousto-optic devices in general G02F1/00
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/00 Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
• CPC Class Codes: G09G 3/18 using liquid crystals
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

An electronic device provided with a multilayer display panel (60), in which during information display by any display panel layer (1 or 2) of the multilayer display panel (60), display driving means (40) maintains all the display segments of the other display panel layer (1 or 2) to be off, allowing simple display control.

Claims

1. An electronic device comprising information generating means for generating information, a display apparatus, display driving means for outputting driving signals for display to said display apparatus on the basis of information from said information generating means, wherein said display apparatus comprises a multi-layer display panel, and when information display is performed on one arbitrary display panel layer among said multi-layer display panel, said display driving means clears all segments of other display panel layers, and wherein a state transition controlling means is provided for controlling said multi-layer display panel to indicate a content of a next display state at a time of display transitions of said display apparatus.

2. An electronic device according to claim 1 wherein said information generating mean comprises reference signal generating means, and means for generating information on the basis of reference signal from said reference signal generating means, said display apparatus comprises a multi-layer display panel, and all or part of at least one layer of said multi-layer display panel has a dot-matrix format, said display driving means having a dot-matrix controller for controlling the display of a dot-matix display panel.

3. An electronic device according to claim 2 wherein said multi-layer display panel has a quadrilateral display screen, of which only the central area is a dot-matrix display.

4. An electronic device according to claim 1 or 2 wherein said display apparatus is constructed by multi-layer liquid crystal cells.

5. An electronic device according to claim 4 wherein a reflecting-type polarizing plate is used for at least one liquid crystal cell of said display apparatus.

6. An electronic device according to claim 5 wherein said display apparatus is a multi-layer liquid crystal display panel comprising a plurality of overlapping liquid crystal cells, the lowest layer liquid crystal display cell having a reflecting-type polarizing plate opposing a backface member.

7. An electronic device according to claim 6 wherein said display apparatus has disposed a plurality of overlapping liquid crystal cells, and a light diffusion layer between said backface member disposed on the lowest layer side of said multi-layer liquid crystal display panel and said lowest layer liquid crystal display cell.

8. An electronic device according to claim 6 wherein a surface of said backface member is colored.

9. An electronic device according to claim 6 wherein said backface member is either a reflecting plate or an EL plate.

10. An electronic device according to claim 6 wherein, except for a reflecting-type polarizing plate of said lowest layer liquid crystal cell, at least one of the other polarizing plates is a reflecting-type polarizing plate.

11. An electronic device according to claim 10 wherein, said multi-layer liquid crystal display panel comprises two layers of liquid crystal cells, and three polarizing plates, with the uppermost polarizing plate an absorption-type polarizing plate and the middle layer polarizing plate a reflecting-type polarizing plate.

12. An electronic device according to claim 11 wherein said middle layer reflecting-type polarizing plate is affixed to an upper layer liquid crystal cell and separated from a lower layer liquid crystal cell.

13. An electronic device according to claim 11 wherein a display on said liquid crystal panel is in a reflecting state when no voltage is applied to said uppermost layer liquid crystal cell.

14. An electronic device according to claim 11 wherein a display on said liquid crystal panel is in a reflecting state when a voltage is applied to said uppermost layer liquid crystal cell.