Seiko Instruments Inc

Seiko Epson Corporation

Naokatsu Nosaka

Motomu Hayakawa

Kazumi Sakumoto

Hiroshi Odagiri

Keisuke Tsubata

Chiaki Nakamura

Tsukasa Kosuda

Residual battery capacity is calculated in an electronic apparatus having an ultrasonic motor driven by a battery based on the revolution speed of the ultrasonic motor. This permits residual capacity to be calculated extremely close to actual battery life with a simplified circuit structure. An electronic watch having an ultrasonic motor as a driving source of a calendar display mechanism is provided with a residual battery capacity display device having a revolution speed detector for detecting a revolution speed of the ultrasonic motor, a memory for storing comparison representing a relationship between detected revolution speed and battery life, and a CPU for determining residual battery life based on the detected revolution speed and the comparison data. An alarm is generated when the battery life is over.

Electronic apparatus with ultrasonic motor as driving source

A movement rate monitor comprises extraction circuitry for extracting a selected movement frequency component from a power spectrum output of a movement sensor, and a movement rate calculation circuit for calculating movement rate in accordance with the extracted frequency component. A display device may be included to display the calculated movement rate.

Movement rate monitor

When an analog indicator is enabled, the position of the time indicator is detected by an indicator position detection circuit. When the indicator arrives at a predetermined position, typically 24:00, a CPU advances calendar data to a correct date and stores the calculation result in a calendar counter. The CPU outputs a drive instruction signal to a date-indicating wheel drive pulse generating circuit to drive a date-indicating wheel to the correct date. The date-indicating wheel drive pulse generating circuit then drives the date-indicating wheel to a renewed position. At this time, a time counter is cleared to 0:00 and is synchronized with the position of the analog indicator. When driving of the analog indicator is disabled, such as by the pulling out of a crown switch, and the time counted by the time counter arrives at a predetermined time, typically 24:00, the CPU advances the present calendar data to the correct date and stores the calculation result in the calendar counter. The CPU outputs a drive instruction signal to the date-indicating wheel drive pulse generating circuit to drive the date-indicating wheel to indicate the correct date. The date-indicating wheel drive pulse generating circuit then drives the date-indicating wheel to the correct date. At this time, the time counter is cleared to 0:00.

Electronic watch with autocalendar

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. FFT computation device comprises FFT computing unit 602, sensor 620, amplification circuit 621, gain control circuit 623, AD converter 622, first RAM 625 for sequentially storing the A/D conversion data, second RAM 626 for storing the FFT computation target data and the data being computed, coefficient ROM 101, and level determination circuit 624; and the level determination circuit determines the size of the data being transferred when the data is being transferred from RAM 1 to RAM 2, and the result is used for the data shift adjustment and gain control during FFT computation.

Fast fourier transformation computing unit and a fast fourier

A pulse rate monitor having an enhanced accuracy, reduced power consumption and reduced calculation time comprises a pulse wave extraction circuitry for extracting pulse wave frequency components from a power spectrum output of a pulse wave sensor and a movement sensor, and a pulse rate calculation circuit for calculating a pulse rate in accordance with the extracted pulse wave frequency components. A display device may be included to display the calculated pulse rate. In order to reduce power consumption, unnecessary circuitry may be deactivated and unnecessary operations may be avoided by use of a changing circuit which changes the method of calculation when movement of the user is not detected. Accordingly, when no movement has been detected for a predetermined period of time, the pulse rate may be calculated based upon a direct output of the pulse rate sensor, while the frequency analysis circuitry and calculation circuitry may remain deactivated.

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Chiba, Japan

Naokatsu Nosaka