JPH04281284A - Magnetic recording/reproducing method - Google Patents

Abstract

PURPOSE:To offer a method for magnetic recording/reproducing capable of improving remarkably the precision of editing at the time of editing even in a tracking system using a pilot signal. CONSTITUTION:Based on a positioning signal 23 recorded in a first area 21 formed on the top of a recording track, a timing signal indicating the recording position of a second area 22 recording an information signal is generated and the information signal is recorded in the above-mentioned second area 22 by this timing signal. Since the timing of starting to record in a track at the time of editing is decided based on its own signal, a positional relation with the track recorded previously is held accurately on the tape. Further, at the time of editing to insert, as well, since tracking information is obtained from the first area, the positional relation with the previous track is matched even at the time of the completion of editing and the precision of the editing is remarkably improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording and reproducing method for recording and reproducing images, audio, data, etc. on a tape.

0002

2. Description of the Related Art Magnetic recording and reproducing devices using magnetic tape as a medium, such as video tape recorders (hereinafter abbreviated as VTR), have been put into practical use and are now in widespread use. In addition, various companies are making efforts to miniaturize and digitalize devices by achieving higher density recording. In order to increase recording density and ensure compatibility, it is important to accurately track the head and track. A pilot signal is multiplexed with the information signal during recording, and this pilot signal is used during playback. VTRs have been put into practical use that employ a tracking control method called the ATF method, in which tracking is performed by using the ATF method. An example of the conventional magnetic recording and reproducing method described above will be described below with reference to the drawings.

FIG. 4 shows the principle of tracking control in the conventional magnetic recording and reproducing method. In FIG. 4, 1 is a head attached to a rotating cylinder (not shown), and 2a, 2b, and 2c are tracks formed on the tape 8, respectively. 3a and 3b are band pass filters,
4a and 4b are AM detection circuits, 5 is a differential circuit, and 6 is a capstan control circuit, which controls the capstan motor 7. 9 is a reel for winding up the tape 8.

First, during recording, diagonal recording tracks are sequentially formed on the tape 8 by the head 1 attached to a rotating cylinder. At this time, in addition to the information signal to be recorded, a pilot signal for tracking is frequency-multiplexed on the head 1. In this case, different frequencies f1,
An example is shown in which two types of pilot signals P1 and P2 recorded at f2 are alternately recorded on every other track. Generally, one to four low frequencies that do not interfere with the information signal are selected as the pilot signal, and are sequentially switched and recorded.

[0005] How to track the tracks thus formed during reproduction will be described below. Now, when the head 1 passes over the track 2a to be reproduced, in addition to the information signal, the head 1 also receives the information signal from the adjacent track 2b.
, 2c are induced, and by comparing their amounts, it is possible to know the relative positional relationship between the head and the desired track. That is, f detected by the bandpass filters 3a and 3b
The AM detection circuits 4a and 4b convert the 1 and f2 components into DC components according to their levels, respectively, and the difference circuit 5 compares the DC components. The output of the differential circuit 5 is the relative position error between the head 1 and the track 2a to be reproduced;
In other words, this is a tracking error. This tracking error is applied to the capstan control circuit 6, which moves the capstan motor 7 to control tape feeding so that the head 1 is in the center of the track 2a. Reference numeral 9 denotes a reel for winding the tape 8 with an appropriate tension force (for example, Japanese Patent Laid-Open No. 2-59538).

[0006] Regarding the operation of rewriting an information signal on a recorded tape to another information signal (hereinafter referred to as insert editing), at the time of rewriting, the mode is switched from playback to recording and overwriting is performed. At the same time as erasing the information signal, a new information signal is recorded. At this time, data is sequentially written onto the tape one track at a time while timing is determined by the output of a rotational position detection sensor attached to the rotating cylinder.

[0007]

[Problems to be Solved by the Invention] However, in the above method, the recording start point of a track is determined only by the output of the rotational position sensor of the rotating cylinder during insert editing, so there is a possibility that the recording start point of the track may be incorrect due to mechanical variations, adjustment errors, etc. Tracks recorded on the system could not be completely erased, and the unerased tracks could cause system malfunctions. Furthermore, when rewriting a part of a track, there is a risk of erasing parts that should not be erased. This tendency is especially noticeable when editing is done using different decks, and it seriously impairs the stability of the system. In addition, in the system described above that tracks by multiplexing the pilot signal with the information signal, there is no way to obtain tracking information during insert editing, so when editing is completed, the time alignment with the previously written track is This has caused problems such as not being able to obtain the same tracking information, disrupting the sequence of tracking information that is multiplexed together, and leaving tracks with incomplete widths.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a magnetic recording and reproducing method with excellent editing accuracy.

[0009]

[Means for Solving the Problems] In order to solve the above problems, the magnetic recording and reproducing method of the present invention provides an information signal based on a positioning signal recorded in a first area formed at the beginning of a recording track. The present invention is characterized in that a timing signal indicating the recording position of the second area where the information is recorded is generated, and the information signal is recorded in the second area using this timing signal. Furthermore, after multiplexing a tracking pilot signal in the first area, reproducing the tracking pilot signal recorded in the first area, and performing tracking control based on this pilot signal,
It is characterized in that an information signal is recorded in the second area.

0010

According to the present invention, since the recording start timing of a track during editing is determined based on its own signal, the positional relationship with the previously recorded track on the tape can be maintained accurately. Also, when editing inserts, the first
Since tracking information can be obtained from the area of
Even at the end of editing, the position can be matched with the previous track, and editing accuracy can be significantly improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording and reproducing method according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the operating principle during insert editing of the magnetic recording and reproducing method according to the embodiment of the present invention. In FIG. 1, 11 is a detection means, 12 is a timing generation circuit, 13 is a changeover switch, 20a is a track to be edited, and 20b and 20c are tracks adjacent to track 20a. Here, the same parts as in the conventional example are denoted by the same reference numerals, and detailed explanation will be omitted.

(FIG. 2) is a diagram showing the configuration of each track shown in (FIG. 1), in which a first area 21 is formed at the beginning of an area usually called a preamble from the beginning of the track, and a part or A positioning signal 23 is recorded in all of them. Further, in this region 21, pilot signals for tracking are sequentially frequency-multiplexed, and in this embodiment, as in the conventional example described above, these pilot signals are
Two different frequencies f1 and f2 are alternately recorded on every other track. In addition, a second area following the first area 21
An information signal is recorded in the area 22 .

(FIG. 3) shows a recorded spectrum at a portion of the first area 21 where the positioning signal 23 is recorded. As shown in Figure 3, the frequencies f1 and f2 of the two different types of pilot signals are relatively low, which is less affected by head azimuth loss, and positioning signals are relatively high, which is less affected by adjacent tracks. A frequency is selected. During insert editing in which information signals are re-recorded from above on tracks formed in this way, in the first area 21 at the beginning of the track 20a (see FIG. 1), the switch 13 is first connected to the terminal 13b, and the head 1 It is put into a playback state where it receives a signal from. At this time, since the output from the head 1 includes leakage components of different pilot signal components f1 and f2 recorded on the tracks 20b and 20c next to the track 20a, tracking The control means 10 can control the tracking between the head 1 and the track 20a to be reproduced.

Further, the signal from the head 1 is further input to the detection means 11, and the positioning signal 23 recorded in the first area 21 is detected. This detected positioning signal is input to the timing generation circuit 12, and the timing generation circuit 12 generates a timing signal indicating the position of the second area 22. The start and end positions of the second region 22 can be timed using a monostable multivibrator triggered by the detected positioning signal. The switch 13 is switched from the terminal 13b to the terminal 13a by the timing signal generated in this way, a new information signal is applied to the head 1, and the information signal recorded in the second area 22 is changed to a new information signal. It is rewritten into an information signal. Even if only the first area 21 has been previously recorded and the second area 22 is newly recorded, the operation is the same. While the second area 22 is being recorded, tracking information cannot be obtained as in the conventional case, but the tracking information in the first area 21 can be sampled and controlled.

As described above, according to this embodiment, a positioning signal is recorded in the first area to determine the recording timing when rewriting or newly recording the second area, and furthermore, the positioning signal is recorded in the first area. By multiplexing a tracking pilot signal into the area, the recording start timing of the track during editing can be determined based on the own signal.
The positional relationship with previously recorded tracks on the tape can be maintained accurately. Furthermore, since tracking information can be obtained from the first area, even at the end of editing, the position can be matched with the previous track, and editing accuracy can be significantly improved.

[0017] In this embodiment, two types of tracking pilot signals are shown, but pilot signals of four types of frequencies such as those used in 8mm video may also be used, and further, digital audio It is also possible to use a method such as a tape recorder (DAT) in which one type of pilot signal is recorded by changing the recording location of the pilot signal, and the method of inputting the pilot signal is not limited. Further, the method of inputting the positioning signal is not limited to this embodiment, and it is also possible to detect coincidence of digital patterns.

[0018]

As described above, the present invention can instruct the recording position of the second area where the information signal is recorded based on the positioning signal recorded in the first area formed at the beginning of the recording track. A timing signal is generated to record an information signal in the second area using this timing signal, and a tracking pilot signal is multiplexed in the first area, and a tracking pilot signal recorded in the first area is recorded. Since the information signal is recorded in the second area after reproducing the pilot signal and performing tracking control based on this pilot signal, the recording start timing of the track during editing is determined by the own signal. The positional relationship with previously recorded tracks on the tape can be maintained accurately. Also, since tracking information can be obtained from the first area even during insert editing, the position can be matched with the previous track even when editing is finished, greatly improving editing accuracy. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the operating principle during insert editing of a magnetic recording and reproducing method according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a recording track in an embodiment of the present invention.

FIG. 3 is a recording spectrum of a pilot signal and a positioning signal recorded on a recording track in an embodiment of the present invention.

FIG. 4 is a diagram showing the principle of tracking control in a conventional magnetic recording and reproducing method.

[Explanation of symbols]

1 Head 20a, 20b, 20c track 10 Tracking means 11 Detection means 12 Timing generation circuit 21 First area 22 Second area 23 Positioning signal

Claims (3)

[Claims] Claim 1: A first recording track formed at the beginning of a recording track.
Based on the positioning signal recorded in the area, a timing signal indicating a recording position of a second area where the information signal is recorded is generated, and the information signal is recorded in the second area using this timing signal. A magnetic recording and reproducing method characterized by: 2. The magnetic recording and reproducing method according to claim 1, wherein a tracking pilot signal is multiplexed in the first area. 3. A tracking pilot signal recorded in a first area is reproduced, tracking control is performed based on the pilot signal, and then an information signal is recorded in a second area. The magnetic recording and reproducing method according to claim 2.