Citizen Holdings Company, Ltd.

Citizen Watch Company, Ltd.

Masaaki Namekawa

Takashi Ihara

Akinari Takada

Minoru Kobayashi

Masami Fukuda

Yu Takyo

Takayuki Uchida

Takayuki Hasumi

Masao Sakuyama

Isao Kitazawa

Takuji Ike

Kohichi Satoh

Teruhiko Fujii

Provided is an electronic clock which is capable of finely controlling a driving force of a normal driving pulse and suppresses variation in current consumption without an increase in circuit size. The electronic clock is configured so that while a chopped driving pulse is output and in an interval in which coil terminals have heretofore been short-circuited, a pulse is output (hereinafter referred to as adjustment pulse) for control from a terminal that is different from a terminal of a motor driver from which the normal driving pulse has been output. The output pattern of the adjustment pulse is changed with reference to a driving rank selecting circuit to increase or decrease a motor driving current and hence change the driving force.

Electronic clock

When recovering power from a motor driver, a forward voltage across a parasitic diode can reduce the recovery efficiency, and control of a power recovery operation can take an unnecessarily long time. In order to address this problem, the power recovery operation is performed as follows without being affected by a parasitic diode: near a peak position of a waveform of an induced current resulting from free oscillation of a rotor after a drive pulse is output, a recovery pulse having such a level that the rotor does not rotate is output from a terminal different from a motor driver terminal to which the drive pulse was output. Also, by adjusting the width and output timing of the recovery pulse based on a power supply voltage, the power recovery can be optimized for the power supply voltage.

Electronic watch

The invention provides a compact and highly reliable electronic apparatus that can be driven by a small-capacity battery, and that can achieve high-speed continuous driving of a load by quickly judging the recovery state of the battery after driving the load. More particularly, the invention provides an electronic apparatus includes a power supply, a load, a load driver for driving the load by the power supply, a power supply state detecter for outputting power supply recovery information by measuring physical quantity of the power supply at predetermined intervals of time after the driving of the load is stopped, and a controller for instructing the load driver to drive the load, based on the power supply recovery information supplied from the power supply state detecter.

Electronic apparatus

An analog electronic watch of the present invention includes: a display unit () for displaying time with a position of a hand; a stepper motor () for driving the hand; a motor drive unit () for controlling driving of the stepper motor at a predetermined hand drive cycle at normal time; hand position detection means () for detecting a position of the hand; a hand position detection means control unit () for intermittently controlling driving of the hand position detection means () at a first detection cycle which is longer than the hand drive cycle; and a detection cycle changing unit () for instructing the hand position detection means () to change the detection cycle. When detecting a predetermined detection cycle changing condition, the detection cycle changing unit () changes a cycle at which the hand position detection means () detects a position of the hand, from the first detection cycle to a second detection cycle, while maintaining the hand drive cycle at which the stepper motor () drives the hand.

Analog electronic watch

A radio correcting timepiece that can reduce the influence of a radio wave situation of the standard radio wave having time information according to an area, and can make a correction to the exact time in a shorter time is provided. The radio correcting timepiece comprises a signal receiving means () for receiving a standard radio wave and a timepiece means () for correcting and displaying time on the basis of the time information outputted from the signal receiving means. The signal receiving means () can receive plural standard radio waves and includes memory means (I) which is able to store signal receiving order of the plural standard radio waves. Since the plural standard radio waves can be received, the influence of a radio wave situation according to an area can be reduced and a correction to the exact time can be made in a shorter time by using the standard radio wave transmitted every minute.

Radio corrected clock

A radio-controlled timepiece includes a regional-information storage unit that stores information on a target time region, a receiving circuit that receives a standard frequency that contains UTC time information, and that outputs a received signal, a regional-time calculating unit that calculates a current time of the target time region based on the information on the target time region and the received signal, a display unit that displays the current time calculated, a display-time correcting unit that corrects the current time to be displayed in DST or in standard time in timing determined based on the current time when information on a DST switching day is included in the received signal.

Radio-controlled timepiece, electronic device, time correcting method and computer product

The invention is directed to obtaining a radio controlled timepiece that, in a case when the user who uses it moves from one country or one region to another where the time difference is different, has simplified an operation of correcting the time difference between the countries or regions and an operation of correcting the time difference due to daylight saving time's being executed. To this end, the invention provides a radio controlled timepiecethat, in addition to the radio controlled timepiecein the prior art, it further includes offset time difference information storage meansthat stores an offset time difference between a country where reference time information is formed and a country where a standard radio wave has been received and daylight saving time information storage meansthat has stored therein for future use information on whether daylight saving time is being executed in the region where the standard radio wave has been received, and local standard time information forming meansthat, with respect to the reference time information of the standard radio wave that has been received in a particular region, executes calculation processing by using at least either one of offset time difference information with respect to the reference time information corresponding to the particular region and daylight saving time information in the particular region, to thereby form local standard time information in the particular region.

Radio controlled timepiece and method of controlling the same

The receiver receives the standard frequency signal that includes a time code. A sampling unit samples one bit of the received signal at 32 positions. A smoothing unit smoothens the result of sampling by dividing the 32 positions in two to four intervals and determines a value of the received signal in each interval. A waveform determining unit determines waveform of each bit of the received signal based on the value obtained in the smoothing unit. The decoding unit extracts the time code based on the determined waveform. A time unit correct the time based on the extracted time code.

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Kiyose, Japan

Masaaki Namekawa