JPH02203458A - Recording method for rotary head type magnetic recording/reproducing device - Google Patents

Abstract

PURPOSE:To attain an accurate overwriting operation by reproducing only an ATF area of a recorded track as long as the ATF area is already recorded and overwriting both a PCN area and a subcode area in a tracking control state. CONSTITUTION:A PCM area 62 is secured at the center of each track of a magnetic tape 61 to record the user data. The ATF areas 63 are secured at both sides of the area 62 to record the ATF signals so that a head traces accurately the center of a track. Furthermore the subcode areas 64 are formed outside the areas 63, i.e., at the initiation of the track to record the subcode signals related to the user data. In an overwrite state, the areas 63 of an existing track are left as they are and at the same time used for the tracking control. At the same time, only the areas 62 and 64 are overwritten. Thus an accurate over overwriting operation is carried out.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention relates to a data recorder that uses a rotating head type digital audio tape recorder (R-DAT) to record and reproduce digital data from a computer, etc. In particular, the present invention relates to a recording method of the data recorder.

(b) Conventional technology Many technologies related to data recorders using R-DAT have been proposed, and the applicant has previously proposed a device with enhanced error correction in such data recorders (
(Japanese Patent Application No. 63-275421).

The structure of such a data recorder will be explained with reference to FIGS. 2 to 4. That is, (1) in Figure 2
The mechanism (1) has the same structure as the R-DAT for audio, and the mechanism (1) is provided with a rotating cylinder, a capstan motor, a reel motor, etc. (2) is a recording/playback amplifier that sends and receives recording and playback signals to and from two recording/playback rotary heads (heads A and B) placed 180 degrees apart on a rotating cylinder; Adding primary and secondary check codes when recording in units of programs (C,,C,)
(4) is an intra-frame signal processing circuit that performs interleaving, etc., and performs error detection and error correction using the first and second codes and de-interleaving, etc. during playback; 32 frames)
This is an intra-group signal processing circuit that adds a tertiary check code during recording and performs error detection and error correction using the tertiary check code during playback.The intra-group signal processing circuit (4) is as shown in FIG. It is configured. That is, (5) is an error correction circuit that adds a tertiary check code to each group during recording, and performs error detection and error correction using the tertiary check code during playback. (7) and (8) are recording circuits. The first and second group memories temporarily store data sent from the host computer in groups during (save), and temporarily store data played back from the tape in groups during playback (load). For storage in the group memory (8), the data stored in the first group memory (7) is added with an error correction code from the error correction circuit (5) and sent to the intraframe signal processing circuit ( 3), and data storage/reading is performed alternately in both group memories (7) and (8). (10) are the first and second group memories (7), (8), and
This is a control circuit that controls the error correction circuit (5), and is read from the first and second group memories (7) and (8) during recording. Add check codes to data in groups,
During playback, the first and second group memories (
7) Control is performed so that the error correction circuit (5) performs error detection and error correction after being stored in (8). (
11) is a cylinder servo circuit that drives and controls the rotating cylinder, (12) is a reel servo circuit that drives and controls the reel motor, (13) is a capstan servo circuit that drives and controls the capstan motor, and (14) is a frame control circuit during playback. This is an ATF circuit that extracts the signal in the ATF area from the output of the recording/playback amplifier (2) via the inner signal processing circuit (3) and generates a tracking error signal.This error signal is supplied to the capstan servo circuit (13). and is used to control the rotational speed of the capstan motor. (15) is connected to the recording/reproducing amplifier (
The subcode processing circuit (16) extracts signals in the subcode area from the output of (2), and the subcode processing circuit (16) extracts the signals within the group by various manual operation keys, the output from the subcode processing circuit (15), or the output from the command circuit described later. Processing circuit (4), in-frame signal processing circuit (3), cylinder servo circuit (
11), a system control circuit that controls a reel servo circuit (12), and a capstan servo circuit (13). (17) is an input/output device that becomes an input/output terminal to the host computer, and (18) is this input/output device (1
7) which gives commands to the system control circuit (16) in response to commands from the host computer, and the command circuit (18) is configured as shown in FIG.

That is, (19) is a data buffer memory that temporarily stores data sent from the host computer when saving, and temporarily stores data played from the tape when loading, and (20) is a data buffer memory that decodes instructions from the host computer and will be described later. An instruction decoding circuit (21) is a control circuit that receives the output from the instruction decoding circuit (20) and controls the data buffer memory (19) and the system control circuit (16). 22) to control data transfer between the data buffer memory (19) and the first and second group memories (7) (8'').

Next, the operation when saving such a configuration will be explained. First, when a data save command is issued by a keyboard operation on the host computer side, the save command is sent to the control circuit (21) and the system through the input/output device (17) and the command decoding circuit (20) in the command circuit (18). It is transmitted to the control circuit (16) and the R-DAT mechanism is set to the recording state, and at the same time, the data is sent from the host computer through the input/output device (17) and partially stored in the data buffer memory (19). After the data is stored in the first group memory (7) via the control circuit (10) of the intra-group signal processing circuit (4), a check code is added and the data is sent from the control circuit (10) via the interface circuit (9). The signals are supplied to the A and B heads through the intra-frame signal processing circuit (3) and the recording/reproducing amplifier (2), and are recorded on the tape one track at a time in groups as shown in FIG.

Figure 5 shows the group layout when the tertiary check code is selected. In the figure, (51) is the tertiary check code located approximately in the center of one group (32 frames). (52) and (
53) is two data frames of approximately 128 bytes, (
54) and (55) are the leading margin frames of one group, and (56) is the trailing margin frame of one group.

(c) Problems to be Solved by the Invention However, in a tape in which digital data in units of predetermined frames (one group) are sequentially recorded from the beginning of the tape, a part (one group or multiple groups) of the recorded portion of the tape is When making changes (overwriting), the integrity of the tracks may be disrupted at the joint, or the beginning or end of the track containing the necessary data may disappear. Therefore, this has been a serious problem, especially in data recorders using R-DAT that require high reliability.
(d) Means for Solving the Problems In the present invention, when recording digital signals on a magnetic tape by forming diagonal tracks using a plurality of rotating heads without forming a guard band, the main signal is A PCM area for recording, a subcode area for recording subcode signals related to the main signal, and an ATF signal for tracking control are recorded. In a rotary head type magnetic recording/reproducing device that adopts an area-divided ATF method that divides the ATF area and performs tracking control based on tracking error information obtained from the ATF area during playback, there is a recorded portion. When re-recording (overwriting) digital signals on a tape, it is determined whether the area to be overwritten is a recorded area or an unrecorded area, and if it is a recorded area, the previously recorded track is used. ATF of
A rotary head type magnetic recording/reproducing device characterized in that it reproduces only the area, overwrites the PCM area and subcode area while controlling tracking, and newly records all unrecorded areas. How to record.

(E) Effect According to the present invention, when overwriting is performed in a recorded portion of a tape, the ATF area of the existing track (track recorded before overwriting) is used to create an area other than the ATF area. Since the configuration is configured to overwrite the track, the integrity of the track is maintained especially at the joint where the overwrite ends, and if the necessary track is overwritten, the data before and after the overwritten part will be destroyed. It will be gone.

(F) Example This example will be explained below. The configuration is different from the conventional one, so its explanation will be omitted.

In the system of the present invention, when recording digital data from an external device such as a computer onto a tape, a TOC (Table Of Contents) area is formed at the beginning of the tape, data is recorded or changed, and data is recorded and changed every time the tape is removed from the device. The TOC information recorded in the TOC area is also recorded and changed. Further, in the subcode area of the track where data from an external device is recorded, a track number that is counted up for each track is recorded. The seven-track format will be explained with reference to FIG. 6. At the center of each track on the magnetic tape (61) there is a PCM area (PCM area) where user data (main signal) is recorded.
62) is formed, and on both sides of the PCM area (62) there is an ATF for the head to accurately trace the center of the track.
ATF areas (63), (63) in which signals are recorded are formed, and subcode signals related to user data are recorded outside the ATF areas (63), (63), that is, at the beginning and end of the track. subcode area (64), (
64) is formed.

Next, the actual operation will be specifically explained with reference to the tape pattern diagram shown in FIG. , Next, when overwriting is performed from the track with track number M (M≦N), first, the tape is rewound a predetermined amount from the track where overwriting is started (track number M), and normal playback is performed to adjust the tracking accurately. Immediately after the head traces the track (track number (M-1)), only the ATF area is played back from the next track (track number M) and tracking is controlled.
It overwrites the PCM area and subcode area.

If you want to record beyond the last track with track number N (track number (L-3
), (L-2), (I, -1), L tracks) are switched to normal recording immediately after tracing the track number N.

Incidentally, when overwriting, the new track number to be recorded is the same as the existing track, so that the track numbers are continuous. Furthermore, all of the above operations are configured to be controlled by a system control circuit (16) (see FIG. 2), that is, a microcomputer.

Furthermore, by changing the TOC area at the beginning of the tape when taking out an overwritten tape from this apparatus, overwriting can be quickly and smoothly performed using the TOC information when the tape is inserted next time.

(g) Effects of the invention Based on the present invention. When overwriting, the ATF area of the existing track is left and the ATF area is used to perform tracking control, while only the PCM area and subcode area are overwritten. Track consistency is maintained even at track joints at the end point, and necessary tracks are not overwritten and unnecessary tracks are not left behind, allowing for accurate overwriting.
It is extremely useful for use in data recorders using AT.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing a tape pattern for explaining the recording method of the present invention, and FIGS. 2, 3, and 4 are R
-A diagram showing the configuration of a data recorder using the DAT, Figure 5 is a diagram schematically showing the recording state of the tape recorded using the data recorder, and Figure 6 is a diagram showing the recording state of the tape recorded using the R-DAT. FIG. 3 is a diagram schematically showing a seven-track format. (16)...System control circuit, (61)...Magnetic tape, (62)...PCM area, (63)...A
TF area, (64)...subcode area.

Claims (1)

[Claims] (1) PCM in which the main signal is recorded when digital signals are recorded on a magnetic tape by forming diagonal tracks with multiple rotating heads without forming a guard band.
area, a subcode area where subcode signals related to the main signal are recorded, and an AT for tracking control.
An area-divided ATF that divides the ATF area where the F signal is recorded and performs tracking control based on tracking error information obtained in the ATF area during playback.
When re-recording (overwriting) a digital signal on a tape on which a recorded portion exists in a rotating head type magnetic recording/reproducing device that uses this method, it is necessary to check whether the overwritten portion is a recorded portion. Determine if it is an unrecorded part, and if it is a recorded part, use the ATF of the last recorded track.
A rotary head type magnetic recording/reproducing device characterized in that it reproduces only the area, overwrites the PCM area and subcode area while controlling tracking, and newly records all unrecorded areas. How to record.