JPH076572A - Tape recording and reproducing method - Google Patents

Abstract

PURPOSE:To provide a tape recording and reproducing method capable of judging the continuity of a time code or a track number with a simple method, preventing the possibility of malfunction of a system and warning. CONSTITUTION:In a tape recording and reproducing method recording and reproducing positional information increasing monotonically or decreasing monotonically from a tape start end along with the data on a tape, a flag of (1)/the flag of (0) is recorded together with the positional information when the recording is performed from the tape start end/when the recording where the positional information becomes discontinuous on the way of the tape is performed. Further, the flag of (1)/the flag of (0) is recorded together with the positional information when the recording is performed on a track in a period of time when the flag is (1) continuously/when the recording is performed on the track in the period of time when the flag is (0) continuously.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape recording / reproducing method for recording an absolute time code or continuous track number on a tape-shaped medium.

[0002]

2. Description of the Related Art An example of a conventional tape recording / reproducing method will be described below.

First, a helical scan type magnetic recording / reproducing method usually used in recording / reproducing of a VTR will be described. FIG. 7 shows an example of a tape pattern recorded by this method. A helical track 2 recorded by a rotary head (not shown) and a linear track 3 recorded by a fixed head (not shown) are recorded on the tape 1. In addition to the information to be originally recorded such as a video signal, incidental information such as time code and character information is recorded on the helical track by utilizing the blanking period of the video signal. In addition, the linear track 3 generally has a relative positional deviation between the rotary head and the helical track during reproduction,
That is, in order to control the tracking deviation, a control signal synchronized with the rotary head at the time of recording, a search,
The time code etc. used for editing are recorded,
Tracking control is performed during reproduction based on these signals.

FIG. 8 shows an example of a tape pattern that does not have the above-mentioned linear track. Tracking control in this case is performed by an 8 mm type VTR and DAT (Digital Audio Taper).
The ATF method that has been put to practical use in ecorder) is used. In this ATF system, a signal called a pilot signal for tracking is multiplexed and recorded on an information signal, and at the time of reproduction, the traveling of the magnetic tape is controlled by using the reproduced pilot signal, so that the relative position between the head and the track. It is a method to keep the relationship normal. This ATF method is described in, for example, Japanese Patent Laid-Open No. 52-88314.

As shown in FIG. 8, one track is divided into four areas. These are insert tracking areas 2 for obtaining a tracking control signal without rewriting at the time of insert editing (when rewriting a part of a recorded video signal or audio signal).
a, an audio area 2b for mainly recording an audio signal, a video area 2c for mainly recording a video signal, a subcode area 2d for recording information necessary for retrieval and editing and information incidental to the recorded information
Is. Here, the above-mentioned time code is recorded in a subcode area in which the track is divided, a video accompanying information recording area provided in the video signal area, or an audio accompanying information recording area provided in the audio signal area.

A method of changing the value of the time code recorded by such a magnetic recording / reproducing method will be described with reference to FIG. In the figure, during the period indicated by the solid line A, the value is recorded from the beginning of the tape, and as the time code, a value that monotonically increases according to the position on the tape is recorded. In the period of the solid line B, the entire area of the track is suddenly rewritten after the recording of A, and the time code is recorded with a value discontinuous with the value of the previous track. Further, the period indicated by the solid line C is the case where the recording is performed after the track is fed from the recording section of A to the area where no track is recorded by fast-forwarding, and in this case as well, a value discontinuous with the previous time code is recorded. .

Such discontinuity is not limited to the time code,
For example, even when recording track number information for managing the number of recording tracks from the start end of the tape, similar discontinuity may occur. This kind of discontinuity can be avoided by always performing the run-back reproduction of the previous track at the time of recording to perform tracking, reading the time code previously written, and then performing a joint recording operation to start recording. However, if the recording operation is performed in the area where no track is recorded as in the case of period C, it is necessary to rewind the tape to the recorded area first, and recording should be started immediately. There is a drawback that you cannot do. Therefore, such discontinuity of time code and track number information cannot be systematically completely avoided on the tape.

[0008]

Therefore, in the method as described above, the user records in the middle of the tape without connecting to the previous track,
In some cases, there were areas where the continuity could not be maintained, such as time code and track number. With such time code and track number information alone, it is not possible to confirm whether or not the read time code and track number accurately represent the elapsed time from the tape start end or the position on the tape. Therefore, if the time code or track number is subsequently used in a search or the like, a malfunction occurs such that the time code is stopped at a different place or the original position cannot be found.

In view of the above problems, the present invention can notify the existence of the discontinuity of the time code and track number in advance by a simple method.
It is an object of the present invention to provide a tape recording / reproducing method capable of determining whether a track number is a reliable value.

[0010]

In order to solve the above problems, a tape recording / reproducing method of the present invention is a tape recording / reproducing for recording / reproducing position information which monotonously increases or monotonically decreases from a tape start end together with data on a tape medium. In the method, a flag of "1" is recorded together with the position information when recording from the beginning of the tape, and a flag of "0" is recorded together with the position information when recording the position information is discontinuous in the middle of the tape. A flag of "1" is recorded on the track of the period of "1" at the time of continuous recording, and a flag of "0" is recorded together with the position information at the time of continuous recording on the track of the period of flag "0". It was done like this.

[0011]

According to the present invention, by the method described above, it is possible to easily determine whether or not the continuity of the time code and the track number is maintained by reading the flag, and prevent the system from malfunctioning. It is possible to provide a tape recording / reproducing method capable of warning this.

[0012]

EXAMPLE An example of a tape recording / reproducing method of the present invention will be described below by taking a helical scan type magnetic recording / reproducing method as an example.
A description will be given with reference to the drawings.

FIG. 3 shows an example of a tape pattern diagram in one embodiment of the present invention. The tape 1 is obliquely wound around a cylinder (not shown) equipped with a plurality of rotary heads, and the rotary head records and reproduces tracks 2. This embodiment is an example without a linear track, and tracking control at the time of reproduction is performed by using a pilot signal (for example, a signal having two different frequencies f1 and f2) superimposed on recording information (video signal, audio signal, etc.). Alternately recorded every other track). As described in the conventional example, one track has four areas, that is, an insert tracking area 2a for obtaining a tracking control signal without rewriting at the time of insert editing, an audio area 2b for mainly recording an audio signal, and an image. Video area 2 where signals are mainly recorded
c, a sub-code area 2d for recording information necessary for retrieval and editing and information incidental to the recorded information. Here, the sub-code area 2d is further composed of several sync blocks starting from a sync signal.

FIG. 4 is an explanatory diagram showing a method of recording a signal in the synchronization block which constitutes the sub-code area 2d.
It is composed of a sync signal section, a sync block attribute, an ID section including a sync block number indicating which sync block in the track, a data section for recording original subcode data, and the like. A time code and a flag described later are recorded as sub code data in some of the data parts of the sub code area 2d in the order of header, hour, minute, second, frame and flag as shown in FIG.

Next, a method of recording the time code and the flag will be described. When recording from the beginning of the tape, a monotonically increasing time code indicating the elapsed time from the beginning of the tape and a flag with a value of "1" are recorded. However, when recording from the middle of the tape and suddenly rewriting the entire area without connecting to the previously recorded track, or when fast-forwarding to start recording from the non-recorded area, it is possible I cannot know the correct position and elapsed time. Therefore, for example, a new value starting from 0 and a rough time code estimated from the speed of the reel motor at that time are recorded, and discontinuity occurs with the previously recorded time code. When such an operation is performed in the middle of the tape, "0" is also recorded in the flag at the same time.

FIG. 1 is an explanatory diagram showing changes in time code and flag values according to the recording / reproducing method of this embodiment. The period of the solid line A is recorded from the beginning of the tape, and the time code is recorded as a value that monotonically increases according to the position on the tape, and the flag at this time is "1". The period of B is
When the entire area of the track is suddenly rewritten after the recording of A, the time code of this period is recorded as a value discontinuous with the value of the lower track and "0" is recorded as the flag. . Further, the period C is a case where the recording is performed after the track is fed from the recording section of A to the area where the track is not recorded fast, and in this case also, a value discontinuous with the previous time code is recorded, and the flag is " 0 ”is recorded. By doing this, by reading the flag during reproduction, it is possible to know whether or not a discontinuity has occurred in the time code.

FIG. 2 shows a case where the tape position is estimated from the rotation speed of the reel motor and the corresponding time code is recorded in the case shown in FIG. However, in this case, an error occurs in the estimated value due to the winding irregularity of the reel, so that discontinuity in the time code cannot be avoided.

Next, a case where a joint recording operation is performed will be described. FIG. 5 is an explanatory diagram of a tape pattern when performing joint recording, and signals are already recorded on tracks 2d-1 to 2d-5. At the time of splicing recording, a capstan motor (not shown) rewinds the tape from the position of the splicing track 2d-6 to the front, and then the run-back reproduction is performed to reproduce the previously recorded track. Tracking is performed by using the track 2d-6 connected to the recording mode. Since the time code and flag recorded in the sub code area can be read during the run-up playback period,
From the connection, it is possible to record a time code that is continuous with the previous time code. In this case, the flag records the same value as the flag read during the running reproduction period.

Next, a case where the insert recording operation is performed will be described. FIG. 6 is an explanatory diagram of a tape pattern when insert recording is performed, and signals are already recorded on the tracks 2d-1 to 2d-5. Even when performing insert recording, the tape is first rewound before the position of the insert start track 2d-6, and then run-back reproduction is performed to track the previous track and start track 2d-6.
Rewrite the insert part from. In this case, the tracking control can be continued by the pilot signal recorded in the insert tracking area 2a even during the insert recording. Similar to the time of splicing, the time code and flag recorded in the subcode area can be read during the run-back playback period, so the time code that is continuous with the previous time code is recorded from the insert start track. be able to. In this case, the flag records the same value as the flag read during the running reproduction period. As described above, according to the present invention, by recording the flag with the same value as that of the previous track, the time code can be reliably recorded as continuous data from the beginning of the tape in both the continuous recording and the insert recording. Whether or not can be immediately determined by the flag.

In this embodiment, the time code and the flag are recorded in the subcode area. However, it goes without saying that the recording location of the time code and the flag is not limited to this. For example, it may be recorded in a part of the video or audio area, or a linear track may be formed and recorded there. Further, for example, in the case of segment recording in which the video signal of one frame is recorded over several tracks, it is not necessary to record the time code and the flag on each track. Further, it is obvious that the present invention can be applied not only to the time code but also to recording track number information for managing the number of recording tracks from the start end of the tape.

Further, in the present embodiment, a flag of "1" is set when recording is performed from the beginning of the tape, and "0" is set when recording is performed where the position information becomes discontinuous in the middle of the tape.
The above flags "1" are "1" and "0" are "0" in the positive logic, and the above "1" are "0" and "0" in the negative logic. Needless to say, “” becomes “1”, and the present invention includes both of them.

[0022]

As described above, according to the tape recording / reproducing method of the present invention, in the tape recording / reproducing method of recording / reproducing the position information which monotonously increases or decreases from the tape start end together with the data on the tape medium, the recording is performed from the tape start end. When performing the recording, a flag of "1" is recorded, and when recording is performed in which the position information is discontinuous in the middle of the tape, a flag of "0" is recorded together with the position information. When recording continuously, the flag of "1" is recorded on the track in the period when the flag is "0", and when recording continuously, the flag of "0" is recorded together with the position information. It is possible to determine whether or not the time code and the track number are continuous from the beginning of the tape by reading the flag recorded as. Therefore, it is possible to immediately judge the reliability of the time code or the track number, and to prevent the system from malfunctioning when searching using the time code or calculating the remaining time using the track number. It can be prevented and warned, which can significantly improve the reliability of the system.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing changes in time code and flag values in a tape recording / reproducing method of the present invention.

FIG. 2 is an explanatory diagram showing changes in time code and flag values in the tape recording / reproducing method of the present invention.

FIG. 3 is a tape pattern diagram according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a method of recording a signal of a synchronization block according to an embodiment of the present invention.

FIG. 5 is a tape pattern diagram when joint recording is performed in an embodiment of the present invention.

FIG. 6 is a tape pattern diagram when insert recording is performed in an embodiment of the present invention.

FIG. 7 is a tape pattern diagram in the case where a linear track recorded by a conventional magnetic recording / reproducing method exists.

FIG. 8 is a tape pattern diagram when there is no linear track recorded by the conventional magnetic recording / reproducing method.

FIG. 9 is an explanatory diagram illustrating a change in the value of a time code recorded by a conventional magnetic recording / reproducing method.

[Explanation of symbols]

 1 Tape 2 Track 2a Insert Tracking Area 2b Audio Area 2c Video Area 2d Subcode Area

Claims (2)

[Claims] 1. A tape recording / reproducing method for recording / reproducing position information which monotonously increases or decreases monotonically from a tape start end together with data on a tape-shaped medium, and when recording from the tape start end, a flag of "1" is set in the middle of the tape. A tape recording / reproducing method characterized by recording a flag of "0" together with the position information when the position information is recorded discontinuously. 2. A track of which the flag is "1", a flag of "1" is continuously recorded, a flag of "0" is continuously recorded, and a flag of "0" is continuously recorded. The information is recorded together with the information.
The tape recording and reproducing method described.