Seiko Epson Corporation

Shinji Nakamiya

Yoshiki Makiuchi

Tadao Kadowaki

Hiroshi Yabe

Yoshitaka Iijima

Kenji Iida

Teruhiko Fujisawa

Takashi Kawaguchi

Hidenori Nakamura

Fumiaki Miyahara

Kunio Koike

Hidehiro Akahane

Sho Matsuzaki

Tsuneaki Furukawa

Katsuyoshi Takahashi

An electronic device that has a secondary battery and a controller which receives power supply from the secondary battery so as to perform a drive control on one or other multiple circuits driven by receiving the power supply from the secondary battery includes an initializing unit that starts processing for outputting an initializing signal to instruct the controller to perform initializing at predetermined timing, in response to a starting point in which a voltage of the secondary battery becomes equal to or lower than a first threshold voltage which is set to be higher than an operation-guaranteed voltage of the controller and a lower state thereof continues for a predetermined period of time.

Electronic device and method of initializing controller of electronic device

A motor drive control circuit that operates using a primary power supply and controls driving a motor has a drive circuit that drives the motor, a power supply circuit that is disposed between the primary power supply and the drive circuit, and uses electrical energy supplied from the primary power supply to supply a drive voltage to the drive circuit, and a power supply control circuit that controls operation of the power supply circuit. The power supply control circuit monitors the drive voltage, stops the power supply circuit and stops supplying the drive voltage when the drive voltage is greater than or equal to a prescribed constant voltage, and activates the power supply circuit and supplies the drive voltage when the drive voltage is less than the prescribed constant voltage.

Motor drive control circuit, semiconductor device, electronic timepiece, and electronic timepiece with a power generating device

An electronic apparatus wherein an abnormal control routine of the control unit can be prevented, or an abnormal control routine that has been started by the control unit can be rapidly halted is provided. An electronic apparatus having a control unit, peripheral circuits whose operations are controlled by the control unit, and a rechargeable battery for feeding operation power to the control unit and the peripheral circuits, wherein an initialization signal RTis continuously output to the control unit during a period of time (during time tto t) that the voltage fed to the control unit is equal to or less than the voltage Vfor assured operation of the control unit, and is equal to or greater than the start voltage VX for starting the operation of the control unit.

Electronic apparatus and control method thereof

A power supply apparatusand a storage devicethat stores power supplied by the power supply apparatusinterpose a power supply control circuit. The circuit has a charging current detectorto detect charging current IC flowing from the power supply apparatusto the storage device; a blocking unitto interrupt the backflow current IR that flows from the storage device to the power supply apparatus on the basis of an inputted blocking control signal SH; and a backflow monitoring unitto monitor by sampling for the presence of the charging current IC until the charging current IC is detected, constantly to monitor for the presence of the charging current IC after the charging current IC has been detected, and to output a blocking control signal SH for cutting off the backflow current IR when the charging current IC is not flowing.

Power supply control circuit, electronic apparatus, semiconductor device, control method for power supply control circuit, and control method for electronic apparatus

This invention relates to a crystal oscillation circuit that oscillates stably with a low power consumption. This crystal oscillation circuit comprises an inverting amplifier, a crystal oscillator, and a feedback circuit that inverts the phase of an output from this inverting amplifier and feeds it back as an input. The sum of the absolute value of the threshold voltage of a first semiconductor switching element and the absolute value of the threshold voltage of a second semiconductor switching element is set to be greater than or equal to the absolute value of the potential difference between first and second potentials, when said inverting amplifier includes the first and second semiconductor switching elements.

Oscillation circuit, electronic circuit using the same, and semiconductor device, electronic equipment, and timepiece using the same

This oscillation circuit includes a crystal oscillator and a main circuit portion connected by a signal path to the crystal oscillator and driven by the crystal oscillator. The main circuit portion is provided with a DC-cutting capacitor that galvanically separates the signal path between the input side of an inverter that is connected by the signal path to the crystal oscillator and an input terminal Xin of the signal path. A potential stabilization circuit is also provided, connecting the input terminal Xin of the signal path to the output side of the inverter through a resistance element.

Oscillation circuit, electronic apparatus, and timepiece using a potential stabilization circuit with resistive terminations

An electrical timepiece comprises external input units for receiving an external input signal, a motor unit for driving an analog hand unit for displaying time, a battery unit capable of charging, a voltage detect circuit for measuring the voltage of the stored electricity in the battery and comparing the voltage with a reference voltage, and a stored electricity unit discharge control circuit for starting discharge from the battery when an external input signal is received by one of the external input unit, and for stopping discharge from the battery when the comparison result by the voltage detect circuit satisfies a prescribed condition.

Electronic timepiece with checking function and its checking method

A constant-voltage generation circuit creates a constant voltage. This constant-voltage generation circuit comprises a first voltage creation circuit for creating a reference voltage and a second voltage creation circuit for creating the constant voltage which has a predetermined relationship with the reference voltage. The first voltage creation circuit comprises a first constant-current source - for supplying a constant current and a first voltage-control transistor through which this constant current flows, for outputting the reference voltage on the basis of a predetermined potential. The constant current is set to a value within the saturated operating region of the first voltage control transistor

Electronic circuit, semiconductor device, electronic equipment, and timepiece

A power-generation detection circuit for detecting a power-generation state by an AC voltage supplied from a power-generation device including a capacitor, and switching element, a resistor, and an inverter circuit which controls the charging of the capacitor by a power-generation device. The switching element is switched by the AC voltage from the power-generation device. The voltage of the capacitor is detected by the inverter circuit thereby performing power-generation detection.

Power-generation detection circuit for use in an electronic device and power-generation detection method and power consumption control method for use in connection therewith

An oscillation circuit including a first electrostatic protection circuit connected between a signal path of the oscillation circuit and a constant-voltage side, and bypassing an electrostatic voltage of a first polarity that intrudes into the signal path to a side of a constant bypass voltage through a first semiconductor rectifier element. A second electrostatic protection circuit is connected between the signal path and a reference potential side, and bypassing an electrostatic voltage of a second polarity that intrudes into the signal path to the reference potential side through a second semiconductor rectifier element. The constant bypass voltage is set to a value such that the first and second semiconductor rectifier elements are not turned on by voltage change in the signal path caused by a leakage current, even when a leakage current is generated between the signal path and a power-supply voltage line.

Oscillation circuit and electronic circuit, and semiconductor device, timepiece and electronic equipment provided with the same

A voltage detection and a remaining battery voltage display for a secondary power source so as to notify the user of the remaining battery voltage of the secondary power source at the optimal timing and in an accurate manner. A voltage correlated to the power source capacity of the secondary power source is detected as a detection voltage. The detection voltage is directly output if a rapid charging is not being detected. If the rapid charging is being detected, the detection voltage is output after being corrected for an amount of the apparent voltage boost which occurs in the secondary power source due to the rapid charging. The detection voltage thus obtained is compared with a predetermined reference voltage so as to discriminate the remaining capacity of the secondary power source.

Voltage detecting device, battery remaining voltage detecting device, voltage detecting method, battery remaining voltage detecting method, electronic timepiece and electronic device

An electronic timepiece charging device for charging an electronic timepiece comprising: a generator for converting external energy into electric energy; a secondary power source for storing the electric energy generated by the generator; a timepiece driving circuit for performing a time-keeping operation; and a time display circuit for displaying time information from the timepiece driving circuit, wherein, the timepiece driving circuit is connected in parallel to the secondary power source; and the secondary power source comprises an equivalent capacitive component for storing an electric charge and a resistive component formed by a part of the equivalent capacitive component. The resistance value of the resistive component is set to a value such that a voltage drop is caused, whereby when the generator generates a current equal to or greater than a predetermined value, a voltage to be applied to the timepiece driving circuit by the generator is equal to or greater than the lowest operation starting voltage.

Charging device for electronic timepiece, electronic timepiece, and method for controlling charging device

In an electronic apparatus including a generator device for generating power, a storage device for storing the generated electric energy, and a motor driven by the electric energy stored in the storage device, it is detected whether a magnetic field is generated by power generation. If it is detected that a magnetic field is generated by power generation, a correcting driving-pulse signal having an effective power larger than a normal driving-pulse signal, which is output for controlling the driving of the motor, is output to the motor. In performing this operation, a determination is made by assuming that a magnetic field is generated while the storage device is in the charging state.

Electronic apparatus and control method for electronic apparatus

A pulse motor driving device having a rotation detecting unit adapted to detect whether or not a pulse motor rotates. In this device, a control unit performs an operation of increasing the effective value of the driving power of the pulse motor and periodically performs an operation of lowering the effective value of the driving power thereof when it is detected by the rotation detecting unit that the pulse motor does not rotate. Further, the control unit interrupts the operation of lowering the effective value of the driving power of the pulse motor when a magnetic field is detected by a magnetic detecting unit.

Pulse motor driving device, pulse motor driving method, timepiece device, and timepiece device control method

An electronic timepiece comprises a battery, capable of charging, a charging section for charging the battery, a timepiece control circuit performing time keeping operation by using a stored electric power in the battery, a display for displaying time kept by the timepiece control circuit, a voltage detecting circuit for detecting a voltage of the stored voltage of the battery, and a charging detecting section for detecting a state of charging to the battery, and this timepiece, when the voltage of the stored voltage declines below a first prescribed voltage which is higher than an operation stop voltage of the timepiece control circuit, and non-charging state is detected for a prescribed time period, executes a forcible stop upon the time keeping operation by lowering or shutting off a current for the timepiece control circuit, and lifts the forcible stop when a prescribed operation return condition is satisfied.

Growing community of inventors

Matsumoto, Japan

Shinji Nakamiya