AUTO-TRACKING DEVICE

Japanese Patent JP3416293

B2

PURPOSE: To correct the amplitude difference between FM signals at different carrier frequencies and to suppress the fluctuation in amplitude of reproduced FM signals by using a gain-frequency characteristic correction circuit of a simple circuitry.
CONSTITUTION: The FM signals reproduced from a magnetic tape 1 on which a first kind of FM signals of carrier frequency f1 are recorded and a magnetic tape 1 on which a second kind of FM signals of carrier frequency f2(>f1) are corrected in amplitude by a gain-frequency characteristic correction circuit 5 to be detected by the use of a detection circuit 7 and to obtain amplitude information for tracking phase control. From the high-frequency loss between the magnetic tape 1 and the rotary magnetic head 2 and the difference of track pitches on the magnetic tape 1 between the first and second FM signals, the amplitude of the second FM signals reproduced is smaller than that of the first FM signals and both the FM signals have amplitude fluctuation. However, the circuit 5 has such a characteristic that the gain increases as the frequency increases in the bands of the first and second FM signals. Therefore, the amplitudes of the first and second FM signals are equalized and the amplitude fluctuation is suppressed.

Hiroyuki Hori
Eiji Moro
Kenichiro Uemura

JP24290894A

June 16, 2003

October 06, 1994

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株式会社日立製作所
株式会社日立アドバンストデジタル

G11B5/588; G11B15/467; G11B20/06; (IPC1-7): G11B15/467; G11B5/588; G11B20/06

JP5120765A
JP63168882A
JP328539U
JP60127650U

Kiyoshi Maruyama (5 others)

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