Other

Victor Company of Japan, Limited

Jvc Kenwood Corporation

Toru Fujimoto

Yasuhiro Ueki

Kenji Koishi

Makoto Usui

Yutaka Osada

Yoshiyuki Miyabata

Tomonori Ueno

Kohjyu Konno

Koji Hirose

A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.

Receiver, reception method for receiving FSK signals

Playback signal amplitude drops and continuity of the signal track amplitude is lost at the beginning the data recording area when data is incrementally written to optical discs such as DVD-R or DVD-RW media. Feed-forward control quickly settles semiconductor laser recording power to the target power level immediately after an incremental recording starts. While recording continues, feedback control maintains laser power at a desired recording power level even when the required current supply varies due to the temperature characteristics of the semiconductor laser when recording lasts for an extended period of time. A semiconductor laser control method and semiconductor laser control device thereby maintain laser power at a stable target recording power level quickly and for as long as recording continues.

Semiconductor laser control method and semiconductor laser control device

A position and speed detecting device is provided. This device includes a detection-signal generator comprising a rotor magnet assembly having a plurality of magnetic poles and a coil pattern for signal detection which moves relatively facing magnetized bodies of the rotor magnet assembly, a speed-signal detector for taking out a signal for frequency detection from said coil pattern for frequency-signal detection to produce a signal for speed detection; and a position-signal detector for producing a signal for position detection from said coil pattern for position-signal detection. An interface of at least one pair of S and N magnetic poles slanted at an angle different from that of interfaces of other magnetic poles and a part of coil pattern in the coil pattern for signal detection is slanted at an angle substantially the same as that of the magnetic poles for position-signal detection and other part of coil pattern is formed at an angle substantially the same as that of the magnetic poles for frequency-signal detection to make it a coil pattern for frequency-signal detection.

Position and speed detecting device

Growing community of inventors

Yokohama, Japan

Toru Fujimoto