JPH0175336U - - Google Patents

Description

[Brief explanation of the drawing]

1 and 2 are block configuration diagrams of the first and second embodiments of the magnetic recording/reproducing apparatus according to the present invention, and FIGS. 3A to 3J show timing signals for each part of the block configuration shown in FIG. 2. 4 is a diagram for explaining a recording track pattern recorded on a magnetic tape, FIG. 5 is a block diagram of a conventional magnetic recording/reproducing device, and FIGS. 4 is a diagram showing timing signals of each part of the block configuration shown in FIG. 4. FIG. 1a, 1b...rotating head, 2...capstan,
8...Low pass filter (first extraction circuit), 9,
10...Band pass filter (second and third extraction circuit), 11...Envelope detection circuit, 12, 14
...First and second sample and hold circuits, 13...Differential amplifier, 15...Switching circuit, 16...Comparator, 17, 18...First and second sampling signal generation circuits, 32, 35...Variable gain amplifier, SP1 ，
SP2...first and second sampling signals, T...magnetic tape (magnetic recording medium), _f1 ...pilot signal, _f2 , _f3 ...first and second timing signals.

Claims (1)

[Claims for Utility Model Registration] A PCM signal obtained by pulse code modulating an information signal to be recorded, a pilot signal positioned before and after the PCM signal at a predetermined time interval, and adjacent tracks having different frequencies and recording lengths. different first and second
a recording signal having a timing signal of A magnetic recording/reproducing device for controlling a magnetic recording device, which includes a first extraction circuit for extracting the pilot signal from a reproduction signal reproduced by the rotary head during reproduction; and a first extraction circuit for extracting the pilot signal from the reproduction signal reproduced by the rotary head; a detection circuit that performs envelope detection on the output signal of this variable gain amplifier; a first sample and hold circuit that samples and holds the detected signal from this detection circuit with a first sampling signal; a differential amplifier to which the output signal from the first sample-and-hold circuit and the detection signal are supplied; a second sample-and-hold circuit that samples and holds the differential output of this differential amplifier with a second sampling signal; second and third extraction circuits that extract the first and second timing signals from the reproduced signal; and selectively output signals of the second and third extraction circuits in response to switching of the rotary head. a comparator that compares a selection signal level from the switching circuit with a predetermined voltage level; and a first output signal that outputs the first and second sampling signals based on the comparison output from the comparator. and a second sampling signal generation circuit, and a control circuit that outputs the control signal that varies the gain of the output signal of the variable gain amplifier based on the comparison output, and a main track that the rotating head is scanning. the second sampling signal based on the signal obtained by sampling the pilot signal reproduced from the adjacent track adjacent to the first sampling signal and the second sampling signal.
The tracking detection signal output from the sample and hold circuit is used to control the rotational phase of the capstan for running the magnetic recording medium, and the control signal having a timing that does not overlap with the first and second sampling signals is used to 1. A magnetic recording and reproducing apparatus characterized in that the gain of a variable gain amplifier is varied so that the level of the pilot signal supplied to the detection circuit is constant.