JPH04139603A - Recording/reproducing method for data recorder - Google Patents

Abstract

PURPOSE:To surely read re-recorded data by forming the track of plural frames as an ATF margin following a recording failure part in the case that the judgement of the recording failure part is executed, and in addition, a level is judged to be low by a read-after-write circuit. CONSTITUTION:When an error is detected by the read-after-write circuit 13, after the data is sent again from a buffer memory 14 to a digital signal processing circuit 12 by a buffer control circuit 15, re-recording is performed. At that time, the monitoring of the level by a level detection circuit 17 is performed, and in the case that the drop of the level is detected in addition to it in the recording failure part whose error was detected by the circuit 13, the data of a plural frames poriton is recorded as the AFT margin for tracking before the re-recording of the data is started. Thus, since the tracking is stabilized by the AFT margin even if the tracking of the recording failure part becomes unstable at the time the re-recording, the re-recorded data can be read.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a recording/reproducing method for a computer external storage device (data recorder) using a rotary head type magnetic recording/reproducing device such as an R-DAT.

(B) Conventional technology Traditionally, R-DAT uses a rotating head to form tracks on a tape, and divides main information such as music, ATF information for tracking, and subcode information used for searches into areas. and recorded. The main information is recorded in units of frames consisting of two adjacent tracks with different azimuth angles, and a product code called the C]-C2 code is used, which has a high speed that can correct burst errors of 792 symbols. Has the ability to make corrections.

When such an R-DAT is used as a data recorder in the field of information equipment, it is necessary to further increase the reliability of the information being recorded and reproduced.To this end, a monitor head is provided to store data in a buffer memory and monitor the recording state. How to re-record bad frames and C1 that completes within a track
・Third error 9 not only for C2 code but also for multiple tracks
There is a method using a triple error correction detection code using a correction detection code.

Furthermore, a data recorder using R-DAT that re-records frames in poor recording condition is disclosed in Japanese Patent Application Laid-Open No. 1-849.
This is proposed in Publication No. 91 (G11B29/12).

(C) Problems to be Solved by the Invention However, when a tape recorded using a method of installing a monitor head, storing data in a buffer memory, and re-recording frames with poor recording conditions is played back, the signal is not recorded normally. Tracking may become unstable in areas where signals have not been recorded properly, and even if the head reaches an area where signals have not been properly recorded again, it may take time for tracking to stabilize, resulting in playback failure. Ta.

This will be specifically explained below with reference to FIG. In this figure, the B head becomes unrecordable from frame number 3, and after re-recording is performed until normal recording is possible, the B head is unable to record normally. ...record in order. When that tape is played back, there is a risk that the tracking will shift in the recording defective area (19) where the signal is not recorded normally due to the re-recording, making it impossible to play back the frame (F) after the recording defective area (19). Ta.

(d) Means for Solving the Problems The present invention is intended to solve the above problems, and provides a read-after-write circuit for checking whether or not the signal has been recorded normally from the signal reproduced from the monitor head during the recording operation. and,
Buffer memory for temporarily storing data to be recorded,
and a level detection circuit that detects a decrease in the level of the reproduced signal from the monitor head, and the level detection circuit determines that data is not normally recorded in the read-after-write circuit, and the level detection circuit detects a decrease in the level. This paper proposes a recording/reproducing method for a data recorder, which is characterized by forming an ATF margin for tracking when re-recording is performed after it is determined that the data has been recorded.

(E) Effect With the above configuration, when recording is performed after a frame in a poor recording state, sufficient frames can be inserted to stabilize tracking.

(F) Embodiment Next, the recording/reproducing method of the data recorder of the present invention will be explained.

In Fig. 1, (1) is a rotary head cylinder around which a magnetic tape (2) is wound approximately 90 degrees, and (3) and (4) are recording/reproducing heads mounted 180 degrees opposite the cylinder (1). heads, (5) and (6) are recording/playback heads (3
) The monitor head is installed 90 degrees behind (4), (7) is the recording amplifier, (8) is the playback amplifier, (
9) is an ATF circuit, (10) is a servo circuit that performs tracking based on the tracking error signal of the ATF circuit (9), (11) is an EQ-PLL circuit for waveform shaping, and (12) is a digital signal processing (13) is a read-after-write circuit that uses error correction codes such as parity check to determine whether data is being recorded normally; (14) is a buffer memory that stores data during recording; (15) is the system control microcomputer (1
6) and the buffer memory (1
4), a level detection circuit (17) for detecting the reproduced signal level, and (18) an interface circuit for transmitting and receiving data from a host computer (not shown).

An embodiment of the recording/reproducing method of the data recorder having the above configuration will be described below.

First, when recording data from a host computer (not shown), the data is stored in the buffer memory (14) through the interface circuit (18). The data in the buffer memory (14) is sequentially sent to the digital signal processing circuit (12) by the buffer management circuit (15) and subjected to predetermined processing, then amplified by the recording amplifier (7), and then recorded. Recording is performed on the magnetic tape (2) by the reproducing head (3) (4"). At the same time, the monitor head (5) (6")
), the digital signal processing circuit (12) detects and demodulates the synchronization signal via the reproduction amplifier (8), the EQ-PLL circuit (11), and the read-after-write circuit (
Error detection is performed in step 13). If an error is detected in this read-after-write circuit (13), the buffer management circuit (13)
After the data is sent again from the buffer memory (14) to the digital signal processing circuit (12) in step 5), re-recording is performed, but the level is constantly monitored by the level detection circuit (17), and the read Afterlight circuit (13
) If there is a further drop in the level in the recording defect area (19) where an error was detected, for example, 6 frames worth of data as shown in Figure 2 should be recorded before starting to re-record the data. Data is recorded as an ATF margin (20) for tracking.

In addition, if the level does not decrease in the recording defect area (19) where an error was detected in the read-after-write circuit (13), the ATF margin (20) is not recorded and data re-recording is started. .

To explain Fig. 2 specifically, frame number 1
．． 2 data is recorded normally, frame number 3.4.5 is determined to be a recording failure by the read-after-write circuit (13) and level detection circuit (17), and re-recording is performed, but the B head does not record. After re-recording started, normal recording was possible at the 9th frame, and then data with frame numbers 3.4.5 was recorded twice, with a total of 6 frames of ATF margin (20 )
After recording the frame number 3.4.5.6.7.
...and sequentially record the data.

Even if the tracking becomes unstable due to the recording defect (19) during reproduction, the ATF margin (20) stabilizes the tracking so that the re-recorded data can be read.

(G) Effects of the Invention According to the present invention, the read-after-write circuit monitors the recording state during recording, and the level detection circuit detects the level. If the level is determined to be low, a track of multiple frames is formed as an ATF margin following the recording failure area before re-recording the data, so tracking may be lost due to the recording failure area during playback. Even if it becomes stable, the re-recorded data can be reliably read, so it is extremely useful for use in the recording/reproducing method of a data recorder using R-DAT.

[Brief explanation of the drawing]

Fig. 1 is a schematic block diagram for explaining the present invention, Fig. 2 is a schematic block diagram for explaining the present invention;
The figure shows the state of tracks recorded on a magnetic tape for explaining the present invention in detail, and FIG. 3 shows the state of tracks recorded on a magnetic tape when re-recording is performed in the conventional art. It is a diagram. (13)...Read-after-write circuit, (14)...
Buffer memory, (15)...buffer management circuit, (
17)... Level detection circuit, (19)... Recording defect area, (20)... ATF margin.

Claims (1)

[Claims] (1) A read-after-write circuit that checks the signal reproduced from the monitor head during recording to see if it has been recorded correctly, a buffer memory that temporarily stores the data to be recorded, and the level of the reproduced signal from the monitor head. and a level detection circuit for detecting a decrease in the level of data, and when the read-after-write circuit determines that the data is not recorded normally and the level detection circuit determines that the level has decreased and re-recording is performed. A data recorder recording/reproducing method characterized by forming an ATF margin for tracking.