Birch, Stewart, Kolasch & Birch, LLP
Recording and reproducing apparatus and recording medium
The present invention provides a recording and reproducing apparatus that can perform high-precision tracking servo control by removing noise from detected servo signals. The recording and reproducing apparatus performs tracking servo control while reading servo signals 10 that are formed on a surface 9 of a recording medium 2 so as to produce optical contrast, the apparatus including a modulated irradiator 20 for irradiating the servo signals 10 with a light beam, the intensity of the light beam being modulated by a modulating wave that is frequency-modulated; a photoelectric converter 30 for converting reflected light from the servo signals 10 into electric signals; and a synchronous demodulator 15 for subjecting the electrical signal to synchronous demodulation using the modulating wave as a reference wave.
Hitachi Maxell, Ltd.
G G
G11B G11B
additional inventional
Kenji Sadamu Masao Shinji
Tanaka Kuse Fujita Kawakami