Electric timepiece for displaying the operating condition thereof

• US 3,998,043 A
• Filed: 11/25/1974
• Issued: 12/21/1976
• Est. Priority Date: 12/26/1973
• 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: Watanabe, Minoru, Sato, Hideo, Morokawa, Shigeru, Kume, Kazunari, Tamaru, Munetaka, Oono, Hideshi
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US05/526,980
• Time in Patent Office: 757 Days
• Field of Search: 58/85.5, 58/50 R, 58/28 R, 58/23 A, 58/23 R, 58/23 BA
• US Class Current: 368/66
• CPC Class Codes: G04C 10/04 with means for indicating the condition of the power supply in general G01R31/36
• CPC Class Codes: G04G 21/02 Detectors of external physical values, e.g. temperature
• CPC Class Codes: G04G 9/00 Visual time or date indication means

Abstract

In a battery operated electric timepiece operated by a battery of the type including a time display, such as a second hand, when the voltage of the battery decreases below a predetermined value, the movement of the second hand is modified to give an alarm that the life of the battery has terminated.

Claims

1. In an electronic timepiece, wnich includes a battery means for producing a voltage of a predetermined level to drive a customary time display and associated circuitry for transmitting power at a predetermined frequency from the battery means to the customary display, wherein the associated circuitry includes:

a reference signal source for producing a divisible signal to drive the customary time display;

a counter for dividing the signal produced by the reference signal source, and for producing the signal of a predetermined frequency to drive said customary time display;

an auxiliary signal generator driven by the counter and having an output signal of a first frequency, different from the predetermined frequency;

a modulator including a frequency divider and a logic circuit, wherein said modulator has first and second inputs from the counter and an input from the auxiliary generator, wherein the first input from the counter is applied through the frequency divider, then to the logic circuit;

wherein the second input from the counter is applied to the logic circuit; and

wherein the input from the auxiliary signal generator is applied to the logic circuit;

wherein the logic circuit generates a signal of a second frequency different from said first frequency;

detecting means for detecting, when the battery means produces a low voltage below said predetermined level, and for producing an alarm signal upon detecting said low voltage; and

signal transfer means activated in response to said alarm signal for selecting whether the signal having the predetermined frequency, or the signal having the second frequency will be applied to the display.

2. The electric timepiece of claim 1, wherein the signal transfer means includes an AND gate circuit, and wherein the alarm signal from the detecting means is a switching signal, which causes said transfer means to switch from said signal of the predetermined frequency to said signal of the second frequency.

3. The electronic timepiece of claim 1, wherein the modulator generates repeating signals having a cycle, in which n pulses are produced within a time period having a duration of n seconds, wherein the n pulses occur during a first portion of each time period

4. The electronic timepiece of claim 2, wherein the modulator generates repeating signals having a cycle, in which n pulses are produced within a time period having a duration of n seconds, wherein the n pulses occur during a first portion of each time period.

5. The electronic timepiece of claim 1, wherein the associate circuitry further includes an auxiliary counter, which receives signals from said counter and said detecting means, said auxiliary counter generating a third signal of a third frequency different from that of said modulator, and supplying the third signal to said signal transfer means to provide the signal transfer means with a third frequency for application to the signal transfer means.

6. The electronic timepiece of claim 1, wherein the logic circuit includes first and second AND gates, wherein the first and gate has an input from the frequency divider, an input having the predetermined frequency from the counter and an output, which is the product of the inputs;

and wherein the second AND gate has an input, which is the output of the first AND gate and an input, which is the output of said auxiliary signal generator, wherein the output of the second AND gate is the signal of the second frequency.