JPH08329568A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To minimize a time before a consecutive recording becomes possible by making it clear with a reproducing track number which part of a frame a reproduction of track is executed to. CONSTITUTION: At least one or more frame information is recorded on at least three or more tracks of a tape 1 obliquely recorded on with a rotary magnetic head. Also, this device is provided with the tape 1 on which information of a track number D capable of discriminating its track position in the same frame is recorded in each track, a tape driving means running the tape 1 in its longitudinal direction, a cylinder 3 outputting a regenerative signal by executing rotation-scanning with the rotary magnetic head to the tape 1, a control means controlling a tape driving means and the cylinder 3, and a reference signal generation means 11 generating a rotation reference signal as a rotation reference for the cylinder 3 and a reference frame signal. Further, synchronism lead-in is possible by a reproducing track number detection means 10 detecting a track number from the output of the regenerative signal outputted from the cylinder 3 and by varying a timing of the reference frame signal depending on a track number.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a frame synchronization pull-in during reproduction.

[0002]

2. Description of the Related Art Recently, a video tape recorder (hereinafter referred to as V
In a magnetic recording / reproducing apparatus such as TR (abbreviated as TR), the importance of frame synchronization pull-in at the time of reproducing has been recognized together with the amount of recorded information.

First, conventional frame synchronous reproduction will be described. As is well known, in a magnetic recording / reproducing apparatus for reproducing an information signal recorded as an oblique track on a tape, a helical scan is usually performed by a rotary magnetic head. On the other hand, the signal recorded on the tape is divided into tracks for the convenience of this reproducing system. At this time, there may be a reference signal with which the reproduction signal should be synchronized, as in the case of a run-up section for joint recording. In such a case, synchronization can be achieved by directly or indirectly comparing the phases of the reference signal and the signal reproduced from the tape and reflecting the result in the tracking control.

In the case of a consumer VTR (VHS (registered trademark) type VTR or the like), one field is recorded as one track, that is, one frame is recorded as two tracks. When reproducing this, a control signal (usually one pulse per frame) is recorded on a linear track provided separately from the diagonal track, and tracking control is performed so as to synchronize this with the reference signal. At this point, frame synchronization is complete.

Further, in a camera-integrated VTR, a cylinder for rotating a rotary magnetic head is often stopped during recording standby for the purpose of power saving. In this case, the cylinder is started after the recording start key is pressed, and the rotation reference signal and the head switching signal (hereinafter referred to as H
The phase of the SW signal is abbreviated). At this time, in order to accelerate the phase pull-in, a method has been devised in which the rotation reference signal is reset at the timing of the HSW signal to match the phases of the HSW signal and the rotation reference signal (for example, Japanese Patent Publication No. 3-7187). ).

[0006]

In the example described in the above-mentioned prior art, the rotation reference signal and the HSW signal can be phase-aligned, but this is one field per track,
A signal recorded with one frame as two tracks is reproduced, and a control signal (usually one pulse per frame) is provided on a linear track provided separately from the diagonal track.
Is recorded and the simultaneous frame synchronization is completed only in the magnetic recording / reproducing apparatus in which the tracking control is performed so as to synchronize this with the reference signal.

However, the amount of recorded information becomes large, and FIG.
When the frame synchronization of the tape on which the information signal in which one or a plurality of frames of information signals are recorded is recorded on three or more tracks as shown in, the frequency of the rotation reference signal and the frequency of the reference frame signal match. However, there is a problem that the frame synchronization is not always completed even if the rotation reference signal is reset at the timing of the HSW signal.

[0008]

In order to solve the above problems, the magnetic recording / reproducing apparatus of the present invention has at least one or more frames recorded on at least three tracks diagonally recorded on a tape by a rotary magnetic head. A tape on which information is recorded and information of a track number capable of identifying the track position in the same frame is recorded on each track,
Tape drive means for running the tape in its longitudinal direction,
A cylinder that rotationally scans a rotary magnetic head with respect to the tape to output a reproduction signal, a control means that controls the tape driving means and the cylinder, and a reference signal generation that generates a rotation reference signal and a reference frame signal that are rotation references of the cylinder. And a reproduction track number detecting means for detecting a track number from the output of the reproduction signal output from the cylinder, and a timing control means for changing the timing of the reference frame signal according to the track number.

[0009]

According to the present invention, the above-described structure enables high-speed frame synchronization pull-in by detecting the track position in the frame on the tape when the tape is running and changing the timing of the reference frame signal accordingly.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention. In the figure, 1 is a tape, 2 is a capstan for running the tape 1, and 3 is a cylinder on which a rotary magnetic head (not shown) is mounted, and a precision is obtained by a motor and a motor drive circuit (both not shown). It rotates well. Reference numeral 12 denotes an HSW generating means, which inputs a rotation signal from the cylinder and outputs an HSW signal. 6 is a servo circuit, which has an HSW signal, a cylinder 3,
Each rotation signal head is input from the capstan 2, the cylinder 3 and the capstan 2 are controlled, and tracking control for scanning a track on the tape is performed. Numeral 10 is a reproducing track number detecting means for detecting the reproducing track number which is being reproduced from the head output outputted from the cylinder 3.
Reference numeral 9 is a timing control means microcomputer, which inputs the reproduction track number of the reproduction track number detecting means 10 and outputs a reset pulse. Reference numeral 11 is a reference signal generating means which outputs a rotation reference signal and also outputs a reference frame signal from the reset pulse E from the input microcomputer 9.

The operation of the magnetic recording / reproducing apparatus having the above structure will be described with reference to FIGS. FIG. 2 is a time chart of the signals A to E in FIG. The servo circuit 6 has a reference signal generating means 11
The cylinder 3 is rotated by synchronizing the rotation reference signal B generated in 1) with the head switching signal (HSW signal) A generated by the HSW creating circuit 12. A head mounted on the cylinder 3 reads data from the tape 1 wound around the cylinder 3 and outputs a reproduction signal F.

The reproduction track number detecting means 10 extracts the track number from the reproduction signal F output from the cylinder 3, outputs the reproduction track number E and inputs it to the microcomputer 9.

When the capstan 2 is activated and the tracking control is completed, a frame synchronization operation start permission command is input to the microcomputer 9 from the terminal 4. Upon receiving this command, the microcomputer 9 generates a reset pulse E for resetting the circuit for generating the reference frame signal of the reference generating means 11 according to the information of the reproduction track number D. The frame synchronization can be completed by initializing the reference frame signal C at the next edge of the HSW signal A to which the reset pulse E is output.

Next, the operation of the reproduction track number detecting means 10 will be briefly described. This is a part for detecting the reproduction track number, but since this concrete configuration method depends on the method of recording the track number on the track, its details are not mentioned here. In general, the configuration is such that the track number information embedded in a specific portion of the data is extracted from the reproduction signal through clock extraction, data reproduction (binarization), sync detection, and the like.

Next, the software processing of the microcomputer 9 will be described with reference to FIGS. FIG.
Is a flow chart of the main processing of the software of the microcomputer 9, and FIG. 4 is a flow chart of the microcomputer 9 when an external interrupt occurs.

First, after the power is turned on, the main processing shown in FIG. 3 is performed. In FIG. 3, a process 301 is a process for initializing, and is a process for clearing the RAM flg0 and the port pt1 (abbreviated as clr in the figure). Next process 30
Reference numeral 2 is a determination process, and when a frame synchronization operation start permission command is input from the input terminal 4, the process proceeds to process 303. Otherwise, the process 302 is repeated. A process 303 is a determination process, which is a process of determining whether or not the reproduction track number is 5, and when it is 5, the process proceeds to a process 304, and otherwise, a process 305.
Proceed to. The process 304 is a process of storing 1 in the RAM flg0, and the process 305 is a process of storing 0 in the RAM flg0. When the process 304 ends, the process returns to the process 302, and when the process 305 ends, the process returns to the process 303. When the process 304 ends, the process 302 is performed until the next frame synchronization operation start permission command is input.

Next, FIG. 4 will be described. FIG. 4 is a process performed when an external interrupt of the microcomputer 9 is input, and specifically, a process performed when both edges of the rotation reference signal A are input. In FIG. 4, process 401 is a determination process, and if RAM flg0 is 1, the process proceeds to process 402. Otherwise, the external interrupt processing ends. Process 4
Reference numeral 02 is a process for outputting “H” from the port 1 of the microcomputer 9. Generally, "H" is the power supply voltage and "L"
Indicates 0V. Process 403 is a process of outputting “L” from port 1. The process 404 is a process of storing 0 in the RAM flg0. The output from the port 1 becomes the reset pulse E in FIG.

The reset pulse E makes it possible to match the phases of the subsequent reproduction track number D and the reference frame signal C as shown in FIG.

In the embodiment shown in FIG. 2, the track numbers are 6 tracks of 0 to 5, but it is obvious that the number of tracks may be any value of 3 or more.

The track number is generally address information for identifying a data block unit obtained by subdividing a frame, and includes a frame number, a block number, etc. in addition to the in-frame track number shown in the embodiment. There are many. The reproduction track number detecting means may use such information as needed.

Further, there is no particular limitation on the concrete transmission mode of the output of the reproduction track number detecting means, and it goes without saying that it may be a serial transmission signal, a parallel transmission signal or a multilevel signal.

Although the timing control means for realizing the high-speed frame synchronization is a software method, the timing control means may be realized by an equivalent logic circuit.

[0023]

As described above, according to the present invention, in a magnetic recording / reproducing apparatus for recording and reproducing one or a plurality of frames of information signals on three or more tracks, which part of the frame is being reproduced. Since it is known by the reproduction track number, even if the frame synchronization is lost when the tape is running, pulling in of the frame synchronization can be completed in the shortest time, and an excellent magnetic recording / reproducing apparatus that minimizes the time until continuous shooting is possible Can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a time chart showing signals of each part.

FIG. 3 is a flowchart of a main processing program of the same microcomputer.

FIG. 4 is a flowchart of an external interrupt processing program of the same microcomputer.

FIG. 5 is a phase relationship diagram of an example of 1-frame information and track numbers.

[Explanation of symbols]

 1 Tape 2 Capstan 3 Cylinder 4 Command Input Terminal 6 Servo Circuit 9 Microcomputer 10 Playback Track Number Detection Means 11 Reference Input Generation Means 12 HSW Creation Circuit

Claims (1)

[Claims] 1. A track number in which information of at least one frame is recorded on at least three tracks obliquely recorded on a tape by a rotary magnetic head and each track can identify a track position within the same frame. Information recorded on the tape, tape driving means for running the tape in the longitudinal direction thereof, a cylinder for rotationally scanning the rotary magnetic head with respect to the tape to output a reproduction signal, the tape driving means, and the tape driving means. Control means for controlling the cylinder, reference signal generating means for generating a rotation reference signal and a reference frame signal which are rotation references for the cylinder, and a reproduction track number for detecting the track number from the output of the reproduction signal output by the cylinder. Timing means for changing the timing of the reference frame signal by the detecting means and the track number A magnetic recording / reproducing apparatus including a control unit.