Electronic timepiece with battery life display

Patent 4074515 Issued on February 21, 1978. Estimated Expiration Date:

February 21, 1995. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3691755

3802182

3898790

Cell replacement indication device
Patent #: 3962859
Issued on: 06/15/1976
Inventor: Ito

Digital watch with liquid crystal and light emitting diode displays
Patent #: 3984973
Issued on: 10/12/1976
Inventor: Ho

Low voltage battery indicator for a solid state watch Patent #: 3991553
Issued on: 11/16/1976
Inventor: Bergey , et al.

Inventor

Asano, Kazuhiro

Assignee

Kabushiki Kaisha Daini Seikosha (JP)

Application

No. 05/705445 filed on 07/15/1976

US Classes:

368/66, With power monitor340/636.1, Battery340/636.15, By voltage340/660, Voltage340/663, Undervoltage368/83, Solid body light emitter (e.g., LED)368/85, With pulse transforming means968/505, With means for indicating the condition of the power supply (in general G01R 31/00B) [G04C 10/04]968/958By controlling light sources, e.g., electroluminescent diodes, etc. (subclass 935 takes precedence) [G04G 9/10]

Examiners

Primary: Witkowski, Stanley J.

Attorney, Agent or Firm

Foreign Application Priority Data

1975-07-15 JA

Abstract

In a digital electronic timepiece, at least one of the digital displays changes color to indicate that the battery is nearing exhaustion. The display is made up of two sets of display elements, for example LEDs, disposed closely adjacent alongside one another. The two sets are of different display color, eg. red and green. Circuitry responsive to battery voltage causes display elements of one set to be illuminated when the battery voltage is normal and causes display elements of the other set to be illuminated when the battery voltage drops below a predetermined value. The resulting change in color of the display indicates that the battery is approaching the end of its life.