Timepiece

• US 6,414,910 B1
• Filed: 07/27/1999
• Issued: 07/02/2002
• Est. Priority Date: 11/28/1997
• Status: Expired due to Fees

• Current Assignee: Citizen Holdings Co., Ltd.
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Kaneko, Yasushi, Yoshikawa, Kazuhiko
• Primary Examiner(s): Roskoski, Bernard
• Application Number:
  US09/355,275
• Time in Patent Office: 1,071 Days
• Field of Search: 368/241-243, 368/203-205, 368/84
• US Class Current: 368/242
• CPC Class Codes: G04G 9/0082 by building-up characters using a combination of indicating elements and by selecting desired characters out of a number of characters or by selecting indicating elements the positions of which represents the time, i.e. combinations of G04G9/02 and G04G9/08

Abstract

To provide a colorful timepiece capable of displaying in multiple Dolors at a low power consumption and with a low development cost using a typical monochrome liquid crystal driving IC, a birefringence color liquid crystal display device (17) and a driving module (27) for driving the liquid crystal display device are installed inside a case (25) with a cover glass. A time display portion displaying normal time in a single color and a mark display portion displaying in a plurality of colors, are provided in a display portion of the liquid crystal display device (17). A liquid crystal driving circuit for driving the liquid crystal display device (17) to supply a scanning signal to scanning electrodes for the time display portion and a data signal to data electrodes for the mark display portion, is provided in the driving module (27).

Claims

1. A timepiece, comprising:

a birefringence color liquid crystal display device consisting of a liquid crystal cell in which nematic liquid crystal is sandwiched and filled in a gap between a transparent first substrate having first electrodes and a transparent second substrate having second electrodes, a pair of polarizing films respectively arranged on and under the liquid crystal cell, and a reflector arranged on a face of one of the polarizing films, the face being on the opposite side to said liquid crystal cell;

a driving module for driving said liquid crystal display device; and

a case for accommodating said liquid crystal display device and said driving module,

wherein the display portions of said liquid crystal display device consists of a time display portion displaying in a single color and a mark display portion displaying in a plurality of colors, and

wherein said driving module has a liquid crystal driving circuit for driving said liquid crystal display device to supply a scanning signal to said first electrodes for said time display portion, a data signal to said first electrode for said mark display portion, and a data signal to said second electrodes for both said time display portion and said mark display portion.

2. The timepiece according to claim 1,

wherein the reflector of said birefringence color liquid crystal display device is a transflective reflector,

further comprising a backlight unit for lighting the liquid crystal display device through said transflecive reflector, which is provided between said liquid crystal display device and said driving module in said case.

3. The timepiece according to claim 1,

wherein said liquid crystal display device has a retardation film between said liquid crystal cell and said polarizing film positioned on the visible side.

4. The timepiece according to claim 2,

wherein said liquid crystal display device has a retardation film between said liquid crystal cell and said polarizing film positioned on the visible side.

5. The timepiece according to claim 1,

wherein said liquid crystal display device has a twisted retardation film between said liquid crystal cell and said polarizing film positioned on the visible side.

6. The timepiece according to claim 2,

wherein said liquid crystal display device has a twisted retardation film between said liquid crystal cell and said polarizing film positioned on the visible side.

7. The timepiece according to claim 1,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1300 nm to 1600 nm.

8. The timepiece according to claim 2,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1300 nm to 1600 nm.

9. The timepiece according to claim 3,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1500 nm to 1800 nm, and a retardation value of said retardation film ranges from 1600 nm to 1900 nm.

10. The timepiece according to claim 4,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1500 nm to 1800 nm, and a retardation value of said retardation film ranges from 1600 nm to 1900 nm.

11. The timepiece according to claim 3,

wherein said retardation film is a retardation film forming relations of nx>

nz>

ny, where nx is the refractive index of a phase delay axis, ny is the refractive index in a direction orthogonal to the phase delay axis, and nz is the refractive index in a thickness direction.

12. The timepiece according to claim 4,

wherein said retardation film is a retardation film forming relations of nx>

nz>

ny, where nx is the refractive index of a phase delay axis, ny is the refractive index in a direction orthogonal to the phase delay axis, and nz is the refractive index in a thickness direction.

13. The timepiece according to claim 5,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1500 nm to 1800 nm, and a Δ

nd value of said twisted retardation film ranges from 1400 nm to 1800 nm.

14. The timepiece according to claim 6,

wherein said liquid crystal cell is an STN liquid crystal cell in which said nematic liquid crystal is aligned at a twist angle in the range from 180°

to 270°

, and a Δ

nd value which is the product of a value Δ

n in the birefringence of the liquid crystal and a gap d of the liquid crystal cell, ranges from 1500 nm to 1800 nm, and a Δ

nd value of said twisted retardation film ranges from 1400 nm to 1800 nm.

15. A timepiece, comprising:

a first liquid crystal display device consisting of a first liquid crystal cell in which nematic liquid crystal is sandwiched and filled in a gap between a transparent first substrate having first electrodes and a transparent second substrate having second electrodes, a pair of polarizing films respectively arranged on and under the first liquid crystal cell, and a reflector arranged on a face of one of the polarizing films, the face being on the opposite side to said liquid crystal cell;

a second liquid crystal display device consisting of a second liquid crystal cell in which nematic liquid crystal is sandwiched and filled in a gap between a transparent first substrate having a first electrode and a transparent second substrate having a second electrode, and a third polarizing film arranged on a face of the second liquid crystal cell on the visible side;

a driving module for driving said first and second liquid crystal display devices; and

a case for accommodating said first and second liquid crystal display devices and said driving module, said second liquid crystal display device being arranged on a face of said first liquid crystal display device on the visible side,

wherein said driving module has a liquid crystal driving circuit for driving said first and second liquid crystal display devices to supply a scanning signal to said first electrodes of said first liquid crystal cell, a data signal to said second electrodes of said first liquid crystal cell, and data signals to said first electrode and said second electrode of said second crystal liquid cell.

16. The timepiece according to claim 15,

wherein said second liquid crystal display device has a reflection-type polarizing film on the opposite side of said second liquid crystal cell from the visible side.