Electronic device for monitoring power consumption of an electro-optical display

• US 4,001,808 A
• Filed: 06/25/1975
• Issued: 01/04/1977
• Est. Priority Date: 07/17/1974
• Status: Expired due to Term

• Current Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Original Assignee: Citizen Watch Co Limited (Citizen Electronics Company Limited)
• Inventors: Ebihara, Heihachiro, Sekiya, Fukuo
• Primary Examiner(s): Curtis, Marshall M.
• Application Number:
  US05/590,197
• Time in Patent Office: 559 Days
• Field of Search: 340/248 B, 340/249, 340/336, 340/324 R, 58/50 R, 58/152 R, 58/23 BA
• US Class Current: 340/653
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G04C 10/04 with means for indicating the condition of the power supply in general G01R31/36
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G09G 3/04 for presentation of a single character by selection from a plurality of characters, or by composing the character by combination of individual elements, e.g. segments using a combination of such display devices for composing words, rows or the like, in a frame with fixed character positions

Abstract

An electronic device for use with a battery driven electro-optical display, wherein the device includes circuitry for detecting an increase in the rate of electric power consumption of the display, and generates a signal upon detecting the increase. The device includes an alarm which operates, when the signal is received and includes circuitry, which stops power supply to the display when the signal is received. Surplus power consumption of the electric cell is thereby eliminated.

Claims

1. An electronic device for use with electronic appliances, wherein said appliances include a battery cell for supplying electric power, a reference signal generator for generating a reference signal, logic circuitry responsive to said reference signal for supplying an operating signal for driving said display device, wherein said device comprises:

a detection circuit disposed between said battery cell and said driving circuit;

means within said detection circuit for monitoring power consumption of said driving circuit and thereby measuring the power consumption of said display device;

means within said detection circuit for generating a detection signal, when the power consumption exceeds a predetermined level.

2. An electronic device, as defined in claim 1, which further includes means for generating an alarm by altering the indication of said display.

3. An electronic device as defined in claim 1 which further comprises means for interrupting the electric power supplied to at least a part of said display.

4. An electronic device, as defined in claim 1, wherein said detecting circuit includes a resistor disposed between said battery and said energizing circuit for causing a voltage corresponding to the power consumption in said display.

5. An electronic device, as defined in claim 4 further including a Metal-Oxide-Semiconductor transistor connected to said detection circuit for connecting both ends of said resistor, when turned on by the detection signal from said detecting circuit.

6. An electronic device, as defined in claim 5, wherein said detecting circuit includes means for intermittently monitoring the power consumption in said display, a memory for storing the result of monitoring by said detecting means, and means for intermittently clearing said memory.

7. An electronic device as defined in claim 1 wherein said electro-optical display comprises a liquid crystal display element.

8. An electronic device, as defined in claim 7, wherein said means for interrupting electric power includes means for supplying signals to all of the electrodes of said display, which are equal in voltage, phase and frequency.

9. An electronic device, as defined in claim 7, wherein said means for interrupting electric power includes means for supplying signals to the selected electrodes of said display, which are equal in voltage, phase and frequency.

10. The electronic device of claim 1 further comprising:

means for generating an alarm signal, in response to generation of said detection signal.

11. An electronic device as defined in claim 10 wherein said alarm generating means includes means for generating a signal for indicating a specified pattern on said display.

12. The electronic device of claim 10, wherein the display includes means for indicating generation of the alarm signal.

13. The electronic device of claim 3, wherein said means for interrupting the power consumption continues to function, as long as the detection signal is generated.

14. The electronic device of claim 1, wherein the appliance is a timepiece.

15. The electronic device of claim 1, wherein the appliance is an electronic calculator.

16. The electronic device of claim 13, wherein the appliance is a timepiece.

17. The electronic device of claim 13, wherein the appliance is a calculator.