Abstract: An electronic watch in which the display on a liquid crystal display 236 is prohibited in the case where the output voltage of a secondary battery 220 drops and reaches a first voltage based on the result of detecting the voltage of the secondary battery 220, the initialization processing is performed in the case where the voltage of the secondary battery 220 drops and reaches a second voltage lower than the first voltage, and the display on the liquid crystal display unit 236 is restarted in the case where the voltage of the secondary battery 220 reaches a third voltage not lower than the first voltage after reaching the second voltage.

Abstract: A voltage and internal resistance of a battery are measured in advance as its capacity decreases. In a flash memory of a device powered by the battery, voltages necessary to drive a motor, an EL display, and a bezel input unit are stored. By comparing the voltage of the battery with a resistor connected as a dummy load and the voltage read from the flash memory, it can be determined whether it is possible to drive the motor, the EL display, or the bezel input unit.

Abstract: By using a CR oscillating circuit and a PLL oscillating circuit selectively, these two oscillating circuits are used as a high frequency, low power consumption, short waiting time for stable oscillation, and low operating voltage oscillating circuit.

Abstract: In an electronic device in which a charge path to a secondary battery and a signal path to a reception device are partially shared and a receiving-time current due to the reception is made to be a charging current for the secondary battery, even in a case in which the voltage across the secondary battery is close to a maximum voltage, by bypassing the charging current due to the signal reception, the voltage across the secondary battery is controlled so as not to exceed the maximum voltage.

Abstract: A first circuit having a first coil electrically charges a second circuit having a second coil through electromagnetic coupling of the two coils. When data signals are to be transferred between the first and second circuits, signal transfer is started only after the second circuit has been charged for a predetermined period of time. The position relationship between the coils is also detected, and a charging/transfer selector changes a duty ratio between charge transfer and data transfer in accordance with the detected result. The charge is transferred in an intermittent manner, and the charging rate is adjusted according to the difference between the voltage of a secondary battery observed during a charging phase and the voltage of the secondary battery observed a certain time after interruption of the charging phase, or vice versa.

Abstract: An electronic unit for charging a unit to be charged having an accumulator section which can be repeatedly charged has a charging section for charging the accumulator section according to a charging control signal and a charging control section. The charging control section monitors a battery voltage (or a charging current), and maintains an effective charging period per unit time for a long term when the battery voltage (or the charging current) of an accumulator battery is lower than a limit voltage (or the charging current corresponding to the limit voltage) selected in advance. After the battery voltage (or the charging current) reaches the limit voltage (or the charging current corresponding to the limit voltage), however, the charging control section reduces the effective charging period per unit time.

Abstract: When emitted light from LED 31 is incident on photodiodes 32 and 33 with luminance Pa and Pb, currents ia and ib are generated according to luminance Pa and Pb. When outside light is incident through the finger tissues on photodiodes 32 and 33 with luminance Pc, current ic is produced. The current i1 (=ia+ic) generated by photodiode 32, and the current i2 (=−ib−ic) generated by photodiode 33, are added at node X, and the current ic corresponding to outside light is thus cancelled. In addition, photodiodes 32 and 33 are disposed at different distances from LED 31. As a result, the current flowing to opamp 34 is current ia corresponding to luminance Pa because luminance Pb is extremely low. The opamp 34 then applies a current voltage conversion to generate pulse wave signal Vm.

Abstract: The present invention relates to a pulse wave detecting device for detecting pulse waves, and to a pulse measurer employing this pulse wave detecting device. The present invention addresses the problem of obtaining a pulse wave signal in which the noise components have been suitably removed from a pulse waveform, and of determining the pulse rate with high accuracy based on this pulse wave signal.The method for deriving the pulse wave signal and pulse rate is as follows.The pulse wave signal from pulse wave detecting sensor unit (30) is temporarily stored in buffer (503). When impulse noise is detected in the pulse wave signal in buffer (503) by impulse noise detecting means (505), the band pass for first digital filter (506) becomes a hill-shaped curve centered on the frequency corresponding to the preceding pulse rate, and impulse noise in the pulse wave signal output from buffer (503) is decreased.

Abstract: A pulse counter is provided in which the value displayed for the detected value is highly reliable. An SN condition detecting means detects the SN condition of a pulse wave signal (step S201). The SN condition detecting means then determines whether or not the detected SN condition is good based on a specific threshold value (step S202). When a determination is made that the SN condition is good, a display control signal to display the pulse rate on a display means is output to a display method switching means (step S203). Conversely, when a determination is made in step S202 that the SN condition is not good, the pulse rate is not displayed on the display means, but rather a display control signal indicating that no information at all be displayed is output to the display method switching means (step S204).

Abstract: A pulsimeter analyzes a pulse wave signal output by a pulse wave sensor worn on a part of the body while exercising, enables extraction of only the pulse wave component without being affected by movement of the body, and evaluates a detection state indicative of whether the pulse wave sensor is detecting the pulse. A pulse wave component extractor extracts a pulse wave component from the result of a time-frequency analysis of a pulse wave signal. A pulse rate calculator calculates the pulse rate per minute based on the pulse wave component extracted by the pulse wave component extractor. The pulse rate is then displayed. A detection state of the pulse wave sensor is also displayed by providing a detection state evaluator for determining the presence of a pulse wave component based on the result output by the pulse wave component extractor.

Abstract: A variable accuracy biosignal detector includes a biosignal detector for detecting a biosignal such as a pulse wave from a living body and supplies the detected signal to a biosignal analog-to-digital converter. The analog-to-digital converter converts the biosignal to digital biosignal data values and stores the data in a memory. An input switch generates a start signal. In response to the start signal, a timing signal generating circuit generates a timing signal used as a sampling signal for driving the analog-to-digital converter and changes the sampling frequency of the analog-to-digital converter progressively on a time series basis. A biosignal calculating circuit performs frequency domain analysis when the number of stored digital biosignal data values reaches a predetermined value. By progressively reducing the sampling frequency of the analog-to-digital converter, measured results can be quickly displayed, while the accuracy of the displayed results is progressively increased.

Abstract: To provide FFT computing units, FFT computation devices, and pulse counters that can achieve computational precision using the smallest possible circuit size. FFT computing unit 602 comprises a data shift circuit for standardizing FFT computation target data to a specified bit width, adders/subtracters, multipliers, and data converters for standardizing the bit width to a certain bit width by truncating part of the output data of each computing unit, etc.

Abstract: A period and frequency measurement device is provided having a sensor for measuring pulse waves and body movements. A window determination circuit sets a reference value in accordance with previously measured pulse waves and body movements and determines whether currently measured pulse waves and body movements is within a window defined by upper and lower margins relative to the reference value. A window correction circuit corrects the window to be used for a next pulse waves and body movement measurement by applying a specified correction to the current pulse waves and body movements measurement if a determination result of the window determination circuit indicates that the current pulse waves and body movements measurement is outside a current window.