Seiko Epson Corporation

Yugen Kaisha K. R & D

Yugen Kaisha Dijianet

Makoto Murakami

Fumito Komatsu

Akira Tooyama

Hideaki Osada

A control method of a piezoelectric driving device which includes a vibrator including a piezoelectric element and vibrating by application of a drive signal to the piezoelectric element, a driven unit moving by the vibration of the vibrator, a drive signal generation unit generating the drive signal based on a pulse signal, the control method including: stopping the application of the drive signal to the piezoelectric element at the time when a driving speed of the driven unit is a reference speed, in a case of stopping driving of the driven unit.

Control method of piezoelectric driving device and piezoelectric driving device

A control unit of a piezoelectric drive device calculates a maximum deceleration &#x3b1; applied to a driven part by the piezoelectric drive device using a friction force Fmax between the piezoelectric drive device and the driven part and a mass m of the driven part, calculates a distance Ln to a target position from a present position of the driven part detected by a position sensor, calculates a reference velocity vth of the driven part using the maximum deceleration &#x3b1; and the distance Ln from the present position of the driven part to the target position, calculates a velocity vn of the driven part from a temporal change of the present position of the driven part detected by the position sensor, and performs control to apply a drive force from the piezoelectric drive device to the driven part when the present velocity vn of the driven part is lower than the reference velocity vth, and apply a brake force from the piezoelectric drive device to the driven part when the present velocity vn is equal to or higher than the reference velocity vth.

Piezoelectric drive device and control method therefor

A positioning signal reception device receives a positioning signal transmitted from a position information satellite, and includes: a signal reception portion that obtains a reception signal by receiving the positioning signal; an A/D conversion portion that generates a digital signal by converting the reception signal into a digital form; a filter portion that subjects the digital signal to frequency separation, a characteristic of the filter portion being changeable; a filter characteristic change portion that changes the characteristic of the filter portion according to an operating state of the positioning signal reception device and an external environmental condition of the positioning signal reception device; and a code synchronization establishment portion that establishes synchronization of spreading codes contained in the reception signal.

Positioning signal reception device and control method of positioning signal reception device

A multiplication section multiplies a signal output from a GPS antenna by a local oscillation signal generated by a local oscillation signal generation section to down-convert the signal output from the GPS antenna into an intermediate-frequency signal. A sampling circuit section samples a generated signal generated by a portable electronic circuit using a sampling clock signal having a frequency lower than a frequency of the generated signal. An attenuation section generates a cancellation signal by attenuating the sampled signal, and an addition section adds the cancellation signal to the signal output from the multiplication section to cancel in-band noise superimposed on the received signal.

Method of canceling noise contained in received signal

In a portable phone, a signal received by a GPS antenna passes through a SAW filter and is amplified by an LNA. An addition section adds a cancellation signal generated by a cancellation signal generation section to the amplified signal to cancel noise superimposed on the received signal.

Receiver circuit, electronic instrument, and signal processing method

A multipath signal determination method includes carrying out correlation operation between a received signal of a positioning signal spread-modulated with a spread code and a replica signal of the spread code with respect to each of IQ components at a predetermined sampling phase interval, and determining whether the received signal is a multipath signal or not, in accordance with a plot position in the case where each correlation value in each of the sampling phases is sequentially plotted on an IQ coordinate.

Multipath signal determination method, signal suitability determination method, positioning operation method, program, and multipath signal determination circuit

An inexpensive, productivity-enhanced single-phase AC synchronous motor in which stabilized synchronous pull-in can be carried out by suppressing generation of counter torque during a starting operation. Starting operation is performed while the energizing range of motor current is suppressed such that the energizing direction of motor current waveform lagging in a phase behind the output waveform from a detection sensor () is switched at at least the zero cross point of the output waveform from the sensor when the number of revolutions of a permanent magnet rotor () reaches a predetermined number of revolutions in the vicinity of the synchronous number of revolutions.

Single phase AC synchronous motor

Integrated correlation values (I and Q integrated correlation values) between each of I and Q signals obtained from a received signal and a code replica are calculated by a coherent integration process performed by a correlation process circuit section. A coherent integration enhancement circuit section converts a phase angle &#x3b8; of each of the I and Q integrated correlation values (IQ coordinate values) into a double angle, and further integrates the converted I and Q integrated correlation values (IQ coordinate values) to calculate I and Q enhanced integrated correlation values. An incoherent integration circuit section performs an incoherent integration process on the I and Q enhanced integrated correlation values. A coherent integration time Tof the correlation circuit section is set to be 20 ms or less, and an integration time Tof the coherent integration enhancement circuit section is set to be longer than 20 ms.

Coherent integration enhancement method, positioning method, storage medium, coherent integration enhancement circuit, positioning circuit, and electronic instrument

A positioning apparatus that measures a current position by using measurement basis codes carried on satellite waves from a plurality of positioning satellites includes: a first phase error information generating unit that generates first phase error information indicating an error of a first phase on the basis of a frequency difference between a first frequency which is an estimated value of a receiving frequency of the satellite wave and a second frequency which is a frequency corresponding to a maximum value of a correlation value under a condition of the estimated phase; a second phase information generating unit that generates second phase information indicating a second phase by correcting a first phase information on the basis of the first phase error information; and a positioning unit that measures the current position on the basis of the second phase information on at least three of the positioning satellites.

Positioning apparatus, control method of positioning apparatus, control program for positioning apparatus, and computer-readable recording medium having control program for positioning apparatus recorded therein

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Nagano, Japan

Makoto Murakami