Electronic timepiece

• US 4,280,208 A
• Filed: 07/24/1978
• Issued: 07/21/1981
• Est. Priority Date: 07/29/1977
• 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: Nomura, Yasushi
• Primary Examiner(s): Weldon, Ulysses
• Application Number:
  US05/927,445
• Time in Patent Office: 1,093 Days
• Field of Search: 368/66, 368/73, 368/203, 368/204
• 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

Abstract

An electronic timepiece having a battery lifetime detection mechanism is provided with a control circuit and external operation member the suitable manipulation of which permits a battery lifetime warning indication, produced in response to a signal from the detection mechanism, to be temporarily displayed in the normal time display mode, transferred to an permanently displayed in another display mode, or converted to an audible warning tone if suitable acoustic means are provided.

Claims

1. An electronic timepiece powered by a battery, comprising:

means for generating a relatively high frequency signal;

means for providing a time unit signal in response to the relatively high frequency signal;

a driver circuit responsive to the time unit signal to produce first driving pulses;

a stepping motor operative in response to the first driving pulses;

time indicating hand means driven in a normal mode by the stepping motor to provide a display of time data;

external operation means adapted to provide a switching signal when actuated;

battery lifetime detection means adapted to provide a detection signal when a battery voltage drops below a predetermined value;

gate means responsive to the switching signal and the detection signal to provide an output signal; and

means responsive to the output signal for causing the driver circuit to produce second driving pulses to actuate the stepping motor such that the time indicating hand means is driven in a mode different from the normal mode to provide a display of a battery lifetime warning only when the external operation means is actuated in the presence of the detection signal.

2. In an electronic timepiece powered by a battery and having a standard signal generator, a frequency divider providing a time unit signal and a clock signal higher in frequency than the time unit signal in response to a relatively low frequency signal from the standard signal generator, a driver circuit responsive to the time unit signal to provide first driving pulses, a reversible stepping motor responsive to the first driving pulses to rotate in a normal direction, a wheel train and time indicating hands driven by the stepping motor through the stepping motor to rotate in the normal direction to provide a display of time data, the improvement comprising:

changeover means normally passing the time unit signal to the driver circuit;

external operation means adapted to produce a switching signal when actuated;

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value; and

gate means responsive to the switching signal and the detection signal to provide an output signal;

a control circuit responsive to the output signal from the gate means to generate the first control signal and a second control signal;

said changeover means including means responsive to the first control signal to pass the clock signal to the driver circuit; and

clockwise/counter-clockwise switching means being responsive to the second control signal from the control circuit and cooperating with the driver circuit;

whereby the driver circuit generates second driving pulses in response to the clock signal so that the stepping motor rotates in an opposite direction so that the time indicating hands are rotated in a reverse direction at a higher than normal speed to provide a display of a battery lifetime warning.

3. In an electronic timepiece powered by a battery and having a display device to display time data comprising:

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value;

means for providing a battery lifetime warning indication in response to said detection signal;

external operation means adapted to provide a switching signal when actuated; and

control circuit means responsive to said switching signal for thereby disenabling said battery lifetime warning indication providing means.

4. The improvement according to claim 3, in which said timepiece includes means for generating a relatively high frequency signal, and a frequency divider for producing a time unit signal in response to said relatively high frequency signal, said control circuit means being controlled by said time unit signal so as to release the disenabling function of said control circuit means.

5. The improvement according to claim 4, in which said control circuit means includes a timer responsive to said time unit signal to automatically enable said battery lifetime warning indication providing means at a predetermined time instant after it has been disenabled by said control circuit means.

6. In an electronic timepiece powered by a battery, the improvement comprising:

external operation means comprising at least two switching members adapted to produce a switching signal when said at least two switching members are simultaneously actuated;

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value;

means for providing a battery lifetime warning indication; and

means for rendering said battery lifetime warning indication providing means operative only when said switching signal is produced in the presence of said detection signal.

7. The improvement according to claim 6, in which said electronic timepiece has time indicating hands to provide a display of time data in a normal mode, and in which said battery lifetime warning indication providing means comprises said time indicating hands, with the hands being adapted to be driven in a mode different from said normal mode by said rendering means to provide said battery lifetime warning indication.

8. The improvement according to claim 7, in which said time indicating hands are rotated clockwise and counter-clockwise at a higher than normal speed by said rendering means, with a combination of clockwise and counter-clockwise rotation of said time indicating hands providing said battery lifetime warning indication.

9. The improvement according to claim 8, in which said rendering means includes means for causing said time indicating hands to provide said battery lifetime warning indication for a predetermined time interval and automatically returning said time indicating hands to its normal mode after said predetermined time interval has elapsed.

10. In an electronic timepiece powered by a battery, the improvement comprising:

external operation means including a switch member and counter means adapted to produce a switching signal when said switch member is actuated a predetermined number of times;

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value;

means for providing a battery lifetime warning indication; and

means for rendering said battery lifetime warning indication providing means operative only when said switching signal is produced in the presence of said detection signal.

11. The improvement according to claim 10, in which said electronic timepiece has time indicating hands to provide a display of time data in a normal mode, and in which said battery lifetime warning indication providing means comprises said time indicating hands, with the hands being adapted to be driven in a mode different from said normal mode by said rendering means to provide said battery lifetime warning indication.

12. The improvement according to claim 11, in which said time indicating hands are rotated clockwise and counter-clockwise at a higher than normal speed by said rendering means, with a combination of clockwise and counter-clockwise rotation of said time indicating hands providing said battery lifetime warning indication.

13. The improvement according to claim 12, in which said rendering means includes means for causing said time indicating hands to provide said battery lifetime warning indication for a predetermined time interval and automatically returning said time indicating hands to its normal mode after said predetermined time interval has elapsed.

14. In an electronic timepiece powered by a battery and having time indicating hands to provide a display of time data in a normal mode, the improvement comprising:

external operation means adapted to produce a switching signal when actuated;

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value;

means for providing a battery lifetime warning indication; and

means for rendering said battery lifetime warning indication providing means operative only when said switching signal is produced in the presence of said detection signal;

said battery lifetime warning indication providing means comprising said time indicating hands, with the hands being adapted to be driven in a mode different from said normal mode by said rendering means to provide said battery lifetime warning indication.

15. The improvement according to claim 14, in which said time indicating hands are rotated clockwise and counter-clockwise at a higher than normal speed by said rendering means, with a combination of clockwise and counter clockwise rotation of said time indicating hands providing said battery lifetime warning indication.

16. The improvement according to claim 15, in which said rendering means includes means for causing said time indicating hands to provide said battery lifetime warning indication for a predetermined time interval and automatically returning said time indicating hands to its normal mode after said predetermined time interval has elapsed.

17. In an electronic timepiece powered by a battery and having means for providing a relatively high frequency signal, a frequency divider for providing a time unit signal in response to the relatively high frequency signal, a timekeeping circuit responsive to the time unit signal to provide time information signals, and a display device to provide a display of time information in response to the time information signal, the improvement comprising:

battery lifetime detection means adapted to produce a detection signal when a battery voltage drops below a predetermined value;

switching means coupled to receive said time information signals and said detection signal and having first and second output terminals, said switching means providing said time information signals at one of said first and second terminals which is selected by means of said detection signal;

signal generation circuit means including a first signal generator responsive to said time information signal from the first output terminal of said switching means for generating a battery lifetime warning signal, and a second signal generator responsive to said time information signal from the second output terminal of said switching means for generating a time tone signal indicative of said time information; and

audible warning tone generation means responsive to said warning signal for generating an audible warning tone indicative of said battery dropping below said predetermined value, said audible warning tone generation means being responsive in said time tone signal to provide an audible time tone at a predetermined time instant determined by said time information signals.

18. The improvement according to claim 17, further comprising external operation means to provide a switching signal when actuated, and means for disenable said switching means to provide said time information signals at the first output terminal in response to said switching signal.