JPH05128822A - Magnetic recording/reproducing method - Google Patents

Abstract

PURPOSE:To edit auxiliary information constituted of plural items of an information signal for each item and further to improve the probability of a detection depending on the item of its auxiliary information at the time of searching at a high speed. CONSTITUTION:The information signal and the auxiliary information of the information signal constituted of at least one synchronized unit are seperately recorded on the areas 3 and 4 of a track 2 formed in an oblique direction on a tape 1. Further, plural information items are included in the synchronized unit and the recording is operated by changing tracks in accordance with the plural information items included in the synchronized unit. Thus, the probability of detecting the auxiliary information at the time of high speed searching is improved and the magnetic recording/reproducing method provided with high- level editing function is realized.

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 method for recording / reproducing images, sounds, data, etc. on a tape.

[0002]

2. Description of the Related Art A magnetic recording / reproducing apparatus using a magnetic tape as a medium, such as a video tape recorder (hereinafter abbreviated as VTR), has been put into practical use and has become popular. In addition, downsizing of devices by further high density recording and development of digitization are being carried out by each company. When recording an information signal, include a cue signal indicating the data recording start position, an absolute time code indicating the absolute address on the tape, a user time code determined by the user, and additional information such as a title indicating the content of the information. The additional information is recorded in a specific area of each track.

FIG. 5 shows the track pattern.
In FIG. 5, 51 is a magnetic tape, 52a to 52j.
Is a track, area 53 is an information signal area, and areas 54a-5
4j is an incidental information area. Here, the additional information area 54
a to 54j have different items for each of a plurality of continuous tracks, for example, a reference signal is given to 54a to 54c, and 54d to 54d.
If 54f is an absolute time code and 54g to 54j are user areas to be used for each user, it is possible to edit each item, Japanese Patent Application No. 3-178.
No. 004.

A high-speed search is one of the essential functions for future high-performance VTRs. In particular, the cueing of the information signal requires a high-speed search, and the cueing function must be highly reliable.

[0005]

However, when the supplementary information is recorded in different tracks for each item as described above, the ability to detect each supplementary information is not sufficient when trying to search at high speed.

The present invention provides a magnetic recording / reproducing method capable of editing incidental information consisting of a plurality of items of an information signal for each item, and further improving the incidental information detecting capability during high speed search. With the goal.

[0007]

In order to solve the above-mentioned problems, the magnetic recording / reproducing method of the present invention is such that the additional information of the information signal and the information signal consisting of at least one synchronization unit is provided for each diagonal same track on the tape. Each area is divided, and the synchronization unit includes a plurality of information items, and different tracks are recorded in accordance with the plurality of information items included in the synchronization unit.

[0008]

According to the present invention, the number of tracks to be recorded can be increased for the information items requiring high-speed search, and the tracks are recorded differently according to the combination of a plurality of information items. Can be edited, and the detection capability during high-speed search can be improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing method of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a track configuration on a tape in a magnetic recording / reproducing method according to an embodiment of the present invention. Here, 10 tracks are 1 frame,
The case where recording and reproduction are performed in frame units is shown. (Fig. 1)
In FIG. 1, 1 is a magnetic tape, 2 is a track, area 3 is an information signal area, and area 4 is an accompanying information signal area.
Further, the area 5 is an area usually called a preamble, and the positioning signal 6 is recorded in a part or all of the preamble of one track. Preamble 5
A pilot signal for tracking is sequentially frequency-multiplexed on. Further, the supplementary information area 4 has a synchronization unit Aij.
(I = 1, 2, 3, 4, j = 1, 2, 3, 4), Bkl
(K = 1, 2, 3, l = 1, 2, 3, 4), Cmn (m
= 1, 2, 3, n = 1, 2, 3, 4).

FIG. 2 is a diagram showing the structure of one synchronization unit that constitutes the incidental information area. Reference numeral 21 is an area generally called a sync, in which a signal indicating the recording start position of the synchronization unit is recorded. Reference numerals 22 and 23 are areas for recording information items. Items of information items and their data are recorded. Reference numeral 24 is an area called parity, in which a signal for detecting (and further correcting) a signal reading error is recorded.

Here, the synchronization unit Aij in (FIG. 1)
(I = 1 to 4, j = 1 to 4) all include two information items of the same combination, and the synchronization unit Bkl (k = 1
~ 3, l = 1 to 4) all include two information items of the same combination, and further, the synchronization unit Cmn (m = 1 to 1)
3, n = 1 to 4) similarly include two information items of the same combination.

When only the supplementary information is rewritten on the recorded tape, the tracking can be performed at the time of editing by the signal of the preamble 5 even if the conventional ATF method is used. Further, the positioning signal 6 makes it possible to obtain accurate timing for starting and ending recording in the auxiliary information signal area 4. Although details are omitted here, it is possible to rewrite only a partial area of one track by using a conventional method.

As shown in this embodiment, the synchronization unit includes a plurality of information items, the combinations of information items included in the synchronization unit within one track are all the same, and the combinations of information items included in the synchronization unit are the same. If different tracks are used for recording, editing can be performed for each combination of the information items, and the editing function of the VTR can be enhanced. For information items that need to be read during high-speed search, the read probability can be improved by increasing the number of tracks to be inserted.

Here, in the case where at least one of the plurality of information items is a cue signal indicating the recording start position of the continuously recorded information signal and included in all synchronization units and recorded in all tracks. Think It is very effective when searching for the recording start position of the information signal if the cue signal is recorded in the incidental information area of the recording start frame of the information signal to be distinguished from the others (or the frame of a certain section before and after it). is there. Further, the cue signal is required to have the highest detection probability during high-speed search. Therefore, it is very advantageous from the viewpoint of the high-speed search function to insert the cue signal into the synchronization unit of the incidental information areas of all the tracks and increase the detection probability by increasing the amount of information. Moreover, since the cue signal is usually recorded only in a very short period, if the cue signal is not recorded even in one track, at the time of search,
In some cases, the head may not be detected at the speed at which the head passes each time only on that track, resulting in a significant decrease in the reliability of the detection. Further, in order to expand the application of the cue function, it is preferable that the cue signal can be attached to any recording position of the recorded tape and can be deleted. , Only the cue signal should be rewritable. This method will be described later.

Furthermore, if at least one of the plurality of information items is an absolute time code indicating an absolute address on the tape, it is very advantageous when performing a search operation with continuous information signals. That is, when the correspondence between the absolute time code and the content of the information signal is known, it is possible to quickly access the location where the information signal to be searched is recorded. Since the absolute time code is a numerical value that increases or decreases at a constant rate for each frame, it is easy to correct the absolute time code before and after that location even if a reading error occurs, so the tape runs at high speed. Even when it is set, it is relatively easy to read the absolute time code compared to the cue signal. That is, the function can be realized even with a small amount of information as compared with the cue signal. Also, in order to realize this function, in order to ensure the continuity of the time code over the entire tape,
Of the plurality of information items of the supplementary information, it is preferable that only the time code can be rewritten. This method will be described later.

Next, consider a case where at least one of the plurality of information items is a user time code capable of time-controlling the information signal for each user. By using the user time code, not only the position on the tape but also the information signal can be managed in the format of year, month, day, hour, minute and second at the time of recording, which is easier for the user to use.
Moreover, the search using the user time code is very easy to use because it is managed by the user. Therefore, the merit of using at least one of the plurality of information items as the user time code is very large. In addition, it is preferable that only the user time code can be rewritten independently in order to provide flexibility with this function. This method will be described later.

Further, if the synchronization unit consisting of the same combination of information items is to be continuously recorded on a plurality of tracks, it will be overwritten when rewriting with a magnetic head wider than the track width. It is possible to significantly reduce the degree to which the adjacent track becomes thin due to the light. FIG. 3 shows how only one track is rewritten among the continuous tracks. In (Fig. 3),
31 is a magnetic tape, 32a to 32c are tracks, and 32d.
Is a track after rewriting, and 37 is a magnetic head. It can be seen that rewriting only a certain track with the wide head, both adjacent tracks become significantly thin. Here, the combination of the information items of the synchronization unit is recorded differently for each track, and when the additional information (synchronization unit) recorded on both adjacent tracks of a certain track is rewritten, it is sandwiched. The track is overwritten on both sides, and it loses weight significantly. However, if a sync unit consisting of the same combination of information items is recorded on a plurality of consecutive tracks, both sides of the track on which a sync unit is recorded are not overwritten during editing, that is, Only one side is overwritten, and the degree to which the adjacent track becomes thin due to rewriting of the synchronization unit is significantly reduced.

Next, consider a case where the number of information units included in a certain information item is larger than the number of information units included in another information item. In this case, there is a method in which the information unit is divided into two (or more) synchronization units and included in the information item. This case will be described with reference to FIG. In FIG. 4, 40a is a first synchronization unit, 40b is a second synchronization unit, 41a and 41b are syncs, 42a and 42b are first information items, and 42-1a and 4-1.
2-1b is a first information unit, 42-2a is a second information unit, 42-3b is a third information unit, 43a and 43b are second information items, and 44a and 44b are parities. First
The information units included in the information items are
Since they are the same in each synchronization unit, they are not shown in this figure. That is, the case is shown in which the synchronization unit recorded on a certain track consists of two information items, and one of the information items further includes three information units. The second and third information units are included in different synchronization units.
Considering the case of performing a high speed search for the contents of the first information item in the case of such a configuration, the following can be said.

First, the detection probability of the contents of the first information unit is the same as the probability of detecting the second information item (or the information unit contained therein). And
For the contents of the second information unit, its detection probability is reduced (in this case by half). However, there is an advantage that the number of information units can be increased when the amount of data recorded in the area of one information item is regulated. Moreover, the information unit for which the detection probability is desired to be increased during the high speed search may be recorded in the first information unit area without causing any inconvenience. As an example corresponding to such a case, consider the case of recording a user time code that is effective when it is one of the information items. As the contents corresponding to the information unit in the user time code, the year,
There are months, days, days of the week, hours, minutes, seconds, etc. A plurality of sync units of a track for recording user time codes are divided into, for example, two groups, and the sync units of the first group include year, month, and
The date, day of the week, and hour are recorded, and the synchronization unit of the second group is the year, month, day, as the information unit of the user time code.
Record minutes and seconds. If you do this
Regarding the year, month, and day, the detection probability does not change even during high-speed search, and the number of information units can be increased. Of course, in this case, the information unit whose detection probability is desired to be increased may be included in many synchronization units. In addition, here, the case where the synchronization unit is divided into two groups and the synchronization unit further includes two information items, and one information item includes three information units has been described.
It goes without saying that the number is not limited.

When the number of information units included in an information item is small, or when the amount of data is small, the synchronization units recorded in one track are all equal even in the information unit at the time of high speed search. This is preferable when the detection probability is taken into consideration.

Next, an editing method for rewriting only a specific information item among a plurality of information items will be described. As described above, there is no problem in rewriting all the plurality of information items included in a certain synchronization unit at the same time.

In the most general case, the synchronization unit contains two information items as shown in FIG. 2, one of which is a cue signal, and the cue signal is recorded on all tracks. However, the other one will be described with an example of a time code such as an absolute time code, a user time code, or a free area. (1) At the time of writing the cue signal The absolute time code is written by incrementing the time code immediately before the previous frame to write the time code correctly. In order to leave the contents of the free area correctly, it is possible to leave the contents of the free area correctly by pre-reading and securing them in the memory. (2) At the time of rewriting the time code The cue signal in the free area is detected, and the cue signal is also added to the synchronization unit including the time code to rewrite. (3) When rewriting the free area The head code search signal of the time code is detected and rewritten by adding the head search signal to the synchronization unit including the free area.

From the above consideration, it can be seen that there is no problem in rewriting each information item in this embodiment as well.

Needless to say, the present invention is not limited to the tracking method as in the above embodiments.
The ATF method using the pilot signal may be used as described in this embodiment, or the control signal recorded in a dedicated area such as a VTR of the VHS standard may be used. Further, the method of inserting the positioning signal is not limited to that of this embodiment, and the coincidence of the digital patterns may be detected. Further, in the present embodiment, the case where the recording / reproducing is performed by the magnetic head having only one channel has been described, but the same effect can be obtained even if the recording / reproducing is performed at almost the same time for two channels.

[0025]

According to the magnetic recording / reproducing method of the present invention, the information items of the incidental information of the information signal can be edited individually for each item, and the amount of information is set for the items for which high speed search is highly necessary. By increasing the number, the detection probability can be improved. If the magnetic recording / reproducing method of the present invention is used, a magnetic recording / reproducing method such as a VTR having an extremely advanced editing function and high-speed search function can be used. Can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a truck according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a synchronization unit of an incidental information area according to an embodiment of the present invention.

FIG. 3 is a diagram showing how adjacent tracks become thin due to overwriting when rewriting a certain track.

FIG. 4 is a configuration diagram of a synchronization unit of an incidental information area according to an embodiment of the present invention.

FIG. 5 is a configuration diagram of a track in a conventional example.

[Explanation of symbols]

1 magnetic tape 2 tracks 3 information signal area 4 additional information area 5 preamble 6 positioning signal Aij (i = 1 to 4, j = 1 to 4), Bkl (k = 1 to 3, l = 1 to 4), Cmn ( m = 1 to 3, n
= 1 to 4) Sync unit

Claims (7)

[Claims] 1. An information signal and ancillary information of the information signal consisting of at least one synchronization unit are divided into respective areas on the same oblique track on the tape, and the synchronization unit includes a plurality of information items. A magnetic recording / reproducing method characterized in that recording is performed by changing tracks according to a plurality of information items included in a synchronization unit. 2. At least one of the plurality of information items is a cue signal indicating a recording start position of a continuously recorded information signal, and the cue signal is included in all synchronization units and all tracks. The data is recorded in
The magnetic recording and reproducing method described. 3. The magnetic recording / reproducing method according to claim 1, wherein at least one of the plurality of information items is an absolute time code indicating an absolute address on the tape. 4. At least one of the plurality of information items is a user time code capable of time-controlling an information signal for each user.
The magnetic recording and reproducing method described. 5. The magnetic recording / reproducing method according to claim 1, wherein the synchronization unit including the information items of the same combination is continuously recorded on a plurality of tracks. 6. The magnetic recording / reproducing method according to claim 1, wherein the synchronization units recorded in one track are all the same in one track. 7. The information item comprises a plurality of information units,
2. The magnetic recording / reproducing method according to claim 1, further comprising an information unit common to different information units for each synchronization unit in one track.