Seiko Epson Corporation

Casio Computer Co., Ltd.

Cosmo System Corporation

Makoto Okeya

Hiroshi Yabe

Hiroyuki Kojima

Joji Kitahara

Noriaki Shimura

Takashi Kawaguchi

Teruhiko Fujisawa

Yutaka Yamazaki

Akihiro Sawada

Norio Ito

Yasunori Ueki

Tatsuya Shimoda

Jun Matsuzaki

Toshiyuki Ishibashi

Katsuaki Karasawa

Hideyuki Arai

Sumitaka Wako

Mitsuho Matsuzawa

Across the entire operating temperature range, and without requiring a new transistor element, the constant voltage output by a constant voltage circuit can be controlled to a voltage greater than or equal to the stop-oscillating voltage and as low as possible. A resistancethat negatively feeds back a reference current Iref is connected between the gate and source of a depletion mode n-channel transistorconfigured to produce the reference current Iref on which the constant voltage VREG is based. The resistance of resistancehas a gradient to temperature change of the same sign as the gradient of the difference between the constant voltage and the stop-oscillating voltage to temperature change when the gradient of the resistance value of the resistance to temperature change is 0.

Oscillator

An analog electronic timepiece is an analog electronic watch capable of displaying a plurality of types of calendar information, and includes a first index adapted to indicate the type of the calendar information, and a second index adapted to indicate a value of the calendar information of the type indicated by the first index.

Timepiece

An analog electronic timepiece including: a second hand; a driver configured to drive the second hand; a current time display processor configured to control the driver to move the second hand at a first time interval such that the second hand indicates a second of a current time; and a measured time display processor configured to control the driver to move the second hand at a second time interval different from the first time interval such that the second hand indicates a second of a measured time.

Analog electronic timepiece

An electronic device comprising a power source, a piezoelectric actuator A, and a drive control apparatusfor controlling the driving of the piezoelectric actuator, wherein the drive control apparatusis provided with a drive circuitfor supplying a drive signal SDR to the piezoelectric element of the vibrating body, a phase difference detection meansfor detecting the phase difference indicating the vibration state of the vibrating body, a comparison voltage setting circuitfor correcting the target phase difference to be the target for the vibration state, and a drive frequency setting meansfor comparing the phase difference with the target phase difference; and the piezoelectric actuator A can be driven with high efficiency independent of the drive voltage by modifying the drive frequency of the drive signal SDR so that the phase difference approaches the target phase difference based on the results of the above comparison.

Drive apparatus of piezoelectric actuator, electronic apparatus, drive method of electronic apparatus, drive control program of electronic apparatus, and medium

In an electronic devicecomprising a batteryand a piezoelectric actuator A, a power source voltage before drive control is started is maintained by a sample holding circuita reference voltage is set by a reference voltage generating circuiton the basis of the power source voltage, and a control circuitstops driving when the power source voltage falls below a drive stop voltage as compared by a second comparison circuitand begins driving the piezoelectric actuator A again when the power source voltage exceeds the reference voltage as compared by a first comparison circuitTherefore, the device can be more easily reduced in size by using a small power source, and the driving time can be markedly reduced using an intermittent driving procedure that corresponds to the conditions of the battery voltage.

Drive control apparatus, electronic apparatus, method of controlling drive of electronic apparatus, drive control program, and recording medium

A drive apparatus for a piezoelectric actuator prevents locking drive frequency in a state of resonance due to harmonics. There is no need to provide external components to filter, and circuitry can easily be reduced in size. The drive apparatus has a phase difference-DC conversion circuit to detect vibrating state of the vibrating body, a comparison circuit, a harmonics detection circuit to detect that the vibrating body is resonating due to harmonics and outputting a harmonics detection signal, an integration circuit to control the frequency of the drive signal supplied to the piezoelectric element of the vibrating body, a variable frequency oscillation circuit, and a drive circuit. The integration circuit, the variable frequency oscillation circuit, and the drive circuit control the frequency of the drive signal on the basis of the output of the comparison circuit when a harmonics detection signal is not outputted and continue to vary the frequency of the drive signal without controlling the frequency of the drive signal on the basis of the output of the comparison circuit when a harmonics detection signal is being outputted.

Drive apparatus for piezoelectric actuator, drive method for piezoelectric actuator, electronic device, control program for drive apparatus for piezoelectric actuator, and recording medium

A drive device for a piezoelectric actuator, wherein the time needed to achieve highly efficient drive conditions is shortened to reduce power consumption, and stabilized control can be performed. The device has a phase difference detection device (phase difference/voltage conversion circuit ()) for detecting detection signals of longitudinal oscillation and bending oscillation from an oscillator () and detecting the phase difference between these two signals, frequency control devices (to) for comparing the phase difference detected by the phase difference detection device with a standard phase difference value and controlling the frequency of a drive signal sent to a piezoelectric element () on the basis of the results of this comparison, and an amplitude detection device (amplitude detection circuit ()) for detecting the amplitude of the detection signal of the piezoelectric element (). The frequency control device compares the amplitude with a standard amplitude value and controls the frequency of the drive signal on the basis of the results of this comparison.

Driving method of piezoelectric actuator, driving apparatus of piezoelectric actuator, electronic watch, electronics, control program of piezoelectric actuator, and storage medium

A time measurement device includes a power generator, secondary power source, current time countersand, receiver circuitfor receiving a time standard radio wave, time display meansfor displaying the current time, power detectorfor outputting a power detection signal when the power generatoris in a power generating state or when a voltage stored in the secondary power sourceis at a predetermined voltage value, operation mode switcherswitching, in response to the power detection signal, between a power saving mode in which time display is suspended and a standard mode in which time display is not suspended. The operation mode switchercauses the time display meansto display the current time based on the time information counted by the time countersandand the time information received by the receiver circuit in response to the device being switched from the power saving mode to the standard mode.

Time measurement device and method of controlling the time measurement device

When an electronic timepiece is in a power-saving mode in which the current time display is suspended, it is determined whether or not the charge voltage supplied from a high-capacity capacitor is higher than a predetermined reference voltage, and if higher, enough electrical energy is stored in the high-capacity capacitor to return from the power-saving mode to the display mode, so that a current time restoration process is performed upon detecting power generation. On the other hand, if the charge voltage is less than or equal to the predetermined reference voltage, the supply of the power supply voltage to the control circuits is stopped to prevent the electrical energy stored in the high-capacity capacitor from being consumed needlessly. As a result, the electronic timepiece can be reactivated quickly when the power generating device begins to generate power.

Electronic device and control method for electronic device

If a supply voltage reaches a voltage level that may lead to detection errors of a supply voltage detecting circuit, then a voltage detecting operation is prohibited if generation of power that can be charged into a high-capacity secondary power source is not detected, while the voltage detecting operation is continued if the generation of power that can be charged into the high-capacity secondary power source is detected.

Electronic equipment and method of controlling electronic equipment

An oscillation circuit produces an oscillation signal in accordance with the oscillation frequency of a quartz oscillator 81, and a frequency dividing circuit divides the frequency of the oscillation signal to produce a sampling clock CKs having a duty ratio of 1/8. A constant-voltage circuit is operated during the period in which the sampling clock CKs takes an &ldquo;H&rdquo; level, and is stopped during the period in which the sampling clock CKs takes an &ldquo;L&rdquo; level. During the period in which the constant-voltage circuit stops the operation, a voltage Vreg affected by fluctuations in a second lower potential side voltage Vss is generated. However, since the cycle of the sampling clock CKs is short, a fluctuation width of the voltage Vreg is suppressed. Power consumption of the constant-voltage circuit is reduced.

Power supply device, control method for the power supply device, portable electronic device, timepiece, and control method for the timepiece

To provide a portable electronic device which is easily shifted into a power save mode at the discretion of an operator, such as a user, and optimally reduces power consumption in accordance with the current use of the device. An operator can force an electronic device into a power save mode at the operator's discretion by manipulating a control. Electrical energy stored is thus reliably saved in accordance with the usage by the operator, and unnecessary power consumption is efficiently reduced, even more than in a method in which a device automatically stops the time display and is shifted into a power save mode in accordance with the presence or absence of power generation. Setting a time limit within which the operational state of the control needs to be complete, the operator is prevented from erroneously shifting into the power save mode, and the ease of use of the time measurement device is still assured.

Portable electronic device and control method for controlling the portable electronic device

In the transition from a state in which charge is being transferred from a large-capacitance secondary power supply to an auxiliary capacitor through a step-up/down circuit by a step-up/down multiplying factor M&prime; (M&prime; is a positive real number excluding one) to a state in which the large-capacitance secondary power supply and the auxiliary capacitor are electrically directly coupled, the electrical energy is transferred from the large-capacitance secondary power supply to the auxiliary capacitor through the step-up/down circuit by a step-up/down multiplying factor M&equals;1 in a non-stepping-up/down state. A potential difference between the large-capacitance secondary power supply and the auxiliary capacitor is less than a predetermined potential difference. Since a sudden variation in a power supply voltage due to changing the step-up/down multiplying factor is prevented, malfunctioning in an electronic apparatus resulting from the sudden variation in the power supply voltage is prevented.

Electronic apparatus and control method for electronic apparatus

To reduce electric power consumed during the operation of adjusting the indication of time and reduce the time required for the time adjusting operation. Using a second hand driving motor and a hour/minute hand driving motor both capable of rotating in both clockwise and counterclockwise directions, the indication of time is adjusted by driving the second hand driving motor and the hour/minute hand driving motor at times different from each other. The hand driving method (hand driving direction) is determined on the basis of the time elapsed during the power saving mode measured by a time information adjusting part such that the hands are driven in a direction which results in a reduction in the power consumption or the adjusting time.

Time-measurement device and method of controlling the same

A reliable power supply control function in a portable electronic device which includes a limiter circuit, or includes the limiter circuit and a voltage step-up circuit, to reduce power consumption. It is detected whether or not a voltage generated by a power generator or a voltage accumulated in a power supply device exceeds a preset limiter-ON voltage. When the voltage generated by the power generator or the voltage accumulated in the power supply device has become not lower than the preset limiter-ON voltage, a voltage of electrical energy supplied to the power supply device is limited to a predetermined reference voltage set in advance. When it is determined based on a detection result of a status-of-power-generation detecting section that power is not generated by the power generator , detecting operation of a limiter-ON-voltage detecting circuit A is prohibited. Power consumption required for operating the limiter-ON-voltage detecting circuit can be thus reduced.

Growing community of inventors

Shiojiri, Japan

Makoto Okeya