JPH04305875A - Magnetic reproducing device - Google Patents

Abstract

PURPOSE:To prevent the omission of a time code by interpolatively processing based on a switching pulse signal. CONSTITUTION:A reproducing signal outputted from a magnetic head 6 is demodulated at a signal processing circuit 4 by a video tape recorder 2 and a video signal OS gained is outputted to a display device 12. A signal from the circuit 4 is demodulated, reproduced and outputted to a system control circuit 8 by a marker processing circuit 10. When time code data DA, etc., are outputted, the data DA is interpolatively processed and the omission is prevented by the circuit 8 based on a switching pulse signal SWP synchronized with the rotary cycle of a rotary drum. That is, at a marker signal ma identification data is allocated to the head block of five blocks and data to be recorded is detected based on the identification data.

Description

[Detailed description of the invention]

0001

[Table of Contents] The present invention will be explained in the following order. Industrial field of application Conventional technology (Figs. 7 and 8) Problems to be solved by the invention (Figs. 7 to 9) Means for solving the problems (Figs. 1, 4, and 5) Effects (Fig. 1 , Figures 4 and 5) Example (Figures 1 to 6) (1) Overall configuration (Figure 1) (2) Interpolation of time code data (Figures 1 to 4) (3)
Interpolation of code data (FIGS. 1, 5, and 6) (4) Operation of the embodiment (5) Effects of the embodiment (6) Effects of the invention of other embodiments

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic reproducing apparatus, and is particularly suitable for application to a video tape recorder which reproduces video signals from recording tracks sequentially formed diagonally on a magnetic tape.

0003

2. Description of the Related Art Conventionally, in this type of video tape recorder, a recording track is divided to record digital audio signals and video signals, and a time code or the like can be recorded between the recording areas of the digital audio signals and video signals. Something like this has been proposed.

Specifically, as shown in FIG. 7, in a video tape recorder, an audio signal recording area PCM and a video signal recording area VD are formed in the longitudinal direction of a recording track 1 (FIG. 7(A)), and the audio signal recording area VD is formed in the longitudinal direction of a recording track 1 (FIG. 7(A)). Area P
Recording of the digital audio signal is completed 3 [H] minutes before the boundary of the CM and video signal recording area VD (represented by the symbol pcm).

Furthermore, in the video tape recorder, recording of the video signal is started after 3.8 [H] have elapsed from the boundary between the audio signal recording area PCM and the video signal recording area VD (represented by the symbol vd), and the audio signal is recorded. A predetermined area is secured between the recording area PCM and the video signal recording area VD.

Furthermore, in the video tape recorder, recording of the digital audio signal is completed and the recording time is 2.6.
After 5 [H] has elapsed, a marker signal ma (FIG. 7(B)) is recorded for a period of 1.5 [H], thereby recording a time code and the like on the magnetic tape 1. That is, in a video tape recorder, during playback, a window signal ea (FIG. 7(C)) that rises before and after the marker signal ma is formed, and the playback signal is taken in based on the window signal ea, so that the playback signal is Extract marker signal ma.

Here, the marker signal ma (FIG. 7(D)) is
A period of 1.26 [H] from the beginning is allocated to the header portion, and a search signal for cueing etc. is recorded as necessary.

On the other hand, the following 0.2 of the marker signal ma
The period 4 [H] is allocated for recording data such as time code (represented by the symbol dm), and 5 blocks of 8-bit data with a code start marker sm and a code end marker em placed before and after each are allocated. (Fig. 7(E)).

Here, the 5 blocks are as shown in FIG.
For even-numbered frames with even-numbered seconds and odd-numbered frames with odd-numbered seconds, time code data is assigned, and along with identification data indicating that it is a time code, hours, minutes, seconds,
Frame data is recorded.

On the other hand, in odd frames of even seconds and even frames of odd seconds, recording date and time information (hereinafter referred to as date data), index data for program index, etc. are recorded together with identification data. It is done like this. This makes it possible to reproduce time codes, date data, index data, etc. without omission even when variable speed reproduction is performed, for example.

[0011]

[Problem to be Solved by the Invention] By the way, when time codes, date data, index data, etc. are allocated and recorded in frame units, as shown by hatching in FIG. There is a problem in that the data cannot be played back, making it inconvenient for editing work, for example.

On the other hand, if a mark signal for indexing is inserted into the header part after recording, it is inevitable that the time code data, date data, index data, etc. will be destroyed, which will also cause inconvenience during editing work. There is a problem.

[0013] Furthermore, when such data is lost due to drop-out or the like, it also poses a problem in editing work.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a magnetic reproducing device that can effectively avoid omissions of time code data, date data, index data, etc. .

[0015]

[Means for Solving the Problem] In order to solve the problem, in the first invention, a video signal SV is recorded on recording tracks formed obliquely in the longitudinal direction, and the video signal SV is recorded on even-numbered and odd-numbered recording tracks. A magnetic reproducing device 2 that reproduces a magnetic tape 1 recording first and second data DS includes a video signal processing circuit 4 that reproduces and outputs a video signal S0, and a video signal processing circuit 4 that reproduces the first and second data DS. data reproducing circuits 4 and 10 that generate first and second reproduced data DS; The interpolation circuit 8 interpolates and outputs the reproduced data DS.

Furthermore, in the second invention, the video signal SV is recorded on the recording tracks formed obliquely in the longitudinal direction, and the first and second data DS are recorded on the even-numbered and odd-numbered recording tracks, respectively. In a magnetic reproducing device 2 that reproduces a magnetic tape 1 that has been recorded, a video signal processing circuit 4 that reproduces and outputs a video signal S0, and a first and a second
by reproducing the data DS of the first and second reproduced data DS.
data reproducing circuits 4 and 10 that generate data, and data reproducing circuits 4 and 10 that generate data based on the first or second reproduced data DS so that the first or second reproduced data DS sequentially and continuously change in even-numbered or odd-numbered recording tracks. and an interpolation circuit 8 that interpolates and outputs the missing first or second reproduced data DS.

Furthermore, in the third invention, the video signal SV is recorded on the recording tracks formed obliquely in the longitudinal direction, and the first and second data DS are recorded on the even-numbered and odd-numbered recording tracks, respectively. In a magnetic reproducing device 2 that reproduces a magnetic tape 1 that has been recorded, a video signal processing circuit 4 that reproduces and outputs a video signal S0, and a first and a second
by reproducing the data DS of the first and second reproduced data DS.
When the first or second reproduction data DS is missing in an even-numbered or odd-numbered recording track, the data reproduction circuits 4 and 10 generate the immediately preceding first or second reproduction data DS.
and a reproduced data processing circuit that holds and outputs the data.

[0018]

[Operation] If the second and first reproduction data DS are interpolated and output for even and odd recording tracks based on the first and second reproduction data DS, the first and second reproduction data DS can be alternately output. Even if two pieces of data are recorded, continuous first and second data can be obtained on the recording track.

Furthermore, at this time, if the reproduced data DS is interpolated and outputted so that the first or second reproduced data DS changes sequentially and continuously in even-numbered or odd-numbered recording tracks, for example, time code data, etc. Even if the data is recorded, the loss of the data can be effectively avoided.

Furthermore, when the first or second reproduction data DS is missing in an even or odd numbered recording track, if the immediately preceding first or second reproduction data DS is held,
Even if data is lost due to mark signal recording, dropout, etc., the data loss can be effectively avoided.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Overall configuration In FIG. 1, 2 indicates a video tape recorder as a whole, in which a signal processing circuit 4 converts a video signal SV into a recording signal, and then records it on a magnetic tape 1 via a magnetic head 6. .

At this time, the entire operation of the video tape recorder 2 is controlled based on the reference signal output from the system control circuit 8, thereby sequentially forming recording tracks in synchronization with the video signal SV.

Further, in the video tape recorder 2, date data can be set in advance in the system control circuit 8, and the date data is outputted to the marker processing circuit 10 together with time code data and the like. As a result, the video tape recorder 2 sequentially outputs marker signals ma to the magnetic head 6 at predetermined timings via the marker processing circuit 10, thereby sequentially recording time code data, etc. in the recording format described above with reference to FIG. is being done.

On the other hand, during playback, in the video tape recorder 2, the playback signal output from the magnetic head 6 is demodulated by the signal processing circuit 4, and the resulting video signal SO is output to the display device 12. This allows the video tape recorder 2 to monitor the reproduced signal via the display device 12.

Further, the signal processing circuit 4 captures the reproduced signal at a predetermined timing and then outputs the captured reproduced signal to the marker processing circuit 10. The marker processing circuit 10 is
The reproduced signal is demodulated, thereby reproducing time code data, etc., and sequentially outputting the reproduced data to the system control circuit 8.

The system control circuit 8 selectively outputs the time code data DA etc. to the display device 12 in response to the user's operation, and thereby outputs the time code data etc. as necessary via the display device 12. This is done so that it can be visually confirmed.

(2) Time code data interpolation system control circuit 8, when outputting time code data DA etc., interpolates the time code data based on the switching pulse signal SWP synchronized with the rotation period of the rotating drum. This process effectively avoids the loss of time code data.

That is, as shown in FIG. 2, the marker signal m
In a, identification data is assigned to the first block of five blocks, and the data to be recorded can be detected based on the identification data.

Incidentally, in the case of mode 1, the data of the five blocks are such that the data of hours, minutes, seconds, and frames of the time code are allocated to the following four blocks.

Here, the system control circuit 8 uses the identification data as a reference to determine the output data D of the marker processing circuit 10.
It is determined whether or not S is time code data, and as shown in FIG.
Time code data is interpolated based on FIG. 3(A)).

In other words, in this type of recording format, since time code data cannot be obtained on the recording track indicated by the broken line, the switching pulse signal SWP rises in the recording track that receives the time code data input immediately before. After up-counting at the timing, the time code data (FIG. 3(B)) is held.

As a result, as shown in FIG. 4, interpolated time code data DH is output on recording tracks where time code data cannot be obtained.

[0034] In this way, even when time code data is recorded every other frame, continuous time code data can be output, thereby effectively avoiding the loss of time code data and improving the efficiency of editing work, etc. can. Furthermore, if the presence or absence of time code is detected and interpolated in this way, even if it is difficult to reproduce the time code data due to a dropout, the missing time code data can be compensated for and the missing time code data can be effectively compensated for. can be avoided.

Furthermore, the system control circuit 8 uses a counter circuit to count the time during which the time code data is missing, and stops outputting the time code data when the missing time exceeds 30 consecutive seconds. That is, some video tape recorders cannot record time code data.

Therefore, when recording is performed by replacing the video tape recorder midway through, the time code may be recorded on the magnetic tape 1 only halfway. In this case, in this embodiment, the missing time is 30 consecutive times.
When more than one second has elapsed, the output of the time code data is stopped, thereby stopping the time code interpolation processing and output processing for the portion where no time code is recorded.

In practice, when inputting mark signals for indexing, etc., it usually takes 10 seconds (2 seconds in long-time recording mode).
0 [seconds]), and in this embodiment, if the missing time code is within 30 seconds, mark signals etc. are inserted by interpolating and outputting the missing time code. Even in such cases, time code loss can be effectively avoided.

(3) Interpolation of code data On the other hand, the system control circuit 8 interpolates date data, index data, etc. (hereinafter, data other than time code data will be referred to as data code) in units of recording tracks. The processing procedure shown in FIG. 5 is executed, and data is interpolated as necessary.

That is, the system control circuit 8 moves from step SP1 to step SP2, and after taking in the reproduced data DS from the marker processing circuit 10, the system control circuit 8 moves to step SP2.
Move on to P3. Here, the system control circuit 8 detects the mode of the captured playback data DS based on the identification data, and thereby detects the type of the playback data. Here, the system control circuit 8 detects the presence or absence of a data code in the reproduced data, and if a data code is detected here, the system control circuit 8 moves to step SP4 and sets a built-in correction timer to 3.
Set to 0 seconds.

Next, the system control circuit 8 performs step S.
The process moves to P5 and data codes are accumulated. Here, the system control circuit 8 is configured to be able to store data codes in a predetermined memory circuit for each mode, and to update the previously stored playback data for each mode of playback data DS that is sequentially input. is being done.

Furthermore, the system control circuit 8 outputs the playback data stored in the memory circuit to the display device 12,
It is superimposed on the display screen of the display device 12. This allows the video tape recorder 2 to display the data code as needed, thereby improving the efficiency of, for example, editing work. After outputting the data code, the system control circuit 8 moves to step SP6 and ends the processing procedure.

On the other hand, for example, when time code data is played back, playback data DS
If the system itself is missing, in the system control circuit 8,
If a negative result is obtained in step SP3, the process moves to step SP7. Here, the system control circuit 8 determines whether or not the correction timer has elapsed for 30 seconds. If a negative result is obtained here, the system control circuit 8 moves to step SP8 and directly transfers the data code stored in the memory circuit to the display device 12.
After outputting the data, the process moves to step SP6 and ends the processing procedure.

Thus, when time code data is reproduced, the system control circuit 8 interpolates the code data of the recording track using the immediately preceding code data, and outputs the interpolation result. Similarly, even when the reproduced data DS itself is missing due to dropout, the system control circuit 8 interpolates the code data of the recording track using the immediately preceding code data, and outputs the interpolation result.

On the other hand, when reproducing the magnetic tape 1 recorded with a model that cannot record code data, the system control circuit 8 skips steps SP1-SP2- because code data cannot be obtained continuously. SP3-S
Processing steps P7-SP8-SP6 are repeated for each recording track, and when 30 seconds have elapsed, step SP7 is executed.
By obtaining a positive result in step SP
Move on to 9.

[0045] Here, the system control circuit 8 clears the code data stored in the memory circuit and stops outputting the code data, and then proceeds to step SP6 to end the processing procedure, thereby completing the process as necessary. The code data is interpolated and output only.

As a result, as shown in FIG. 6, the code data D0, D1, D2, D3, D
4, ... is recorded on the magnetic tape 1 (FIG. 6(A)), even if the mark signal is recorded during the period TM and the code data D2, D3 (FIG. 6(B)) is missing, the missing The generated code data D2 and D3 can be interpolated and output (FIG. 6(C)), and the efficiency of editing work etc. can be improved. Furthermore, even for frames for which only time code data can be obtained, it is possible to interpolate with the immediately preceding code data and output it.

In practice, if interpolation processing is performed using the immediately preceding code data in this way, missing code data can be effectively eliminated by simply recording the same type of code data repeatedly at a cycle shorter than the 30-second count cycle of the correction counter. can be avoided. Therefore, the usability of the video tape recorder 2 can be improved by sequentially and cyclically recording more types of code data.

(4) Operation of the embodiment Among the reproduced signals obtained by reproducing the magnetic tape 1, the video signal S0 is outputted to the display device 12 via the signal processing circuit 4, thereby monitoring the reproduced signal. can do.

On the other hand, in the reproduced data DS,
After being demodulated by the marker processing circuit 10, it is output to the system control circuit 8 in units of recording tracks. Here, in the reproduced data DS, the type of data is determined based on the identification data.

[0050] Of these, in the time code data,
If the time code data is not obtained, time code data updated based on the switching pulse signal SWP is output, and if the time code data is not obtained for a predetermined period, the time code data is updated and output. is controlled to stop.

[0051] This makes it possible to effectively avoid missing time codes, and to stop outputting time codes on the magnetic tape 1 on which no time codes are recorded.

On the other hand, in the case of code data, if the code data cannot be obtained, it is interpolated with the previous code data of the same type, and the interpolated code data is output.

Therefore, the loss of code data can be effectively avoided, and if the code data is not obtained for a predetermined period, the code data stored in the memory circuit is cleared, and the magnetic field where the code data is not recorded can be cleared. For tapes, output of code data can be stopped.

(5) Effects of the Embodiment According to the above configuration, for time code data,
By performing interpolation processing based on the switching pulse signal, it is possible to effectively avoid missing time codes.However, regarding code data, by retaining the immediately preceding code data, missing time codes can be avoided. can be effectively avoided.

(6) Other Embodiments Although the above-mentioned embodiments have described the case where time code data and code data are recorded alternately in even and odd fields, the present invention is not limited to this. Accordingly, it can be widely applied when recording time information other than time code data and code data, user information, etc.

Further, in the above-described embodiments, the case where the present invention is applied to a video tape recorder has been described, but the present invention is not limited to this, but can be widely applied to playback-only video tape recorders and the like.

[0057]

As described above, according to the present invention, different types of data are alternately recorded in units of recording tracks by interpolating the reproduced data so that they are consecutive or by retaining the immediately preceding reproduced data. Even in such a case, it is possible to obtain a magnetic reproducing device that can effectively avoid the loss of reproduced data and reproduce continuous data on a recording track.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a video tape recorder according to an embodiment of the present invention.

FIG. 2 is a chart showing modes of the data.

FIG. 3 is a signal waveform diagram for explaining time code correction.

FIG. 4 is a schematic diagram showing the correction results.

FIG. 5 is a flowchart showing the processing procedure of the code data.

FIG. 6 is a signal waveform diagram for explaining interpolation of code data.

FIG. 7 is a signal waveform diagram for explaining a marker signal.

FIG. 8 is a chart showing the types of data.

FIG. 9 is a schematic diagram showing the recording state of time codes.

[Explanation of symbols]

1...Magnetic tape, 2...Video tape recorder, 4...
... signal processing circuit, 8 ... system control circuit, 10 ... marker processing circuit.

Claims (3)

[Claims] 1. A magnetic tape for recording a video signal on recording tracks formed diagonally in the longitudinal direction, and for reproducing a magnetic tape in which first and second data are recorded on the even-numbered and odd-numbered recording tracks, respectively. In the playback device,
a video signal processing circuit that reproduces and outputs the video signal;
a data reproducing circuit that reproduces the first and second data to generate first and second reproduced data; and a data reproducing circuit that reproduces the even-numbered and odd-numbered recording tracks based on the first and second reproduced data. A magnetic reproducing apparatus comprising: an interpolation circuit that interpolates and outputs the second and first reproduced data. 2. A magnetic tape for recording video signals on recording tracks sequentially formed diagonally in the longitudinal direction, and for reproducing a magnetic tape in which first and second data are recorded on even-numbered and odd-numbered recording tracks, respectively. In the playback device,
a video signal processing circuit that reproduces and outputs the video signal;
a data reproducing circuit that reproduces the first and second data to generate first and second reproduced data; and a data reproducing circuit that reproduces the first and second data to generate first and second reproduced data, and the first or second reproduced data are sequentially consecutive on the even or odd numbered recording tracks. The above first or second
and an interpolation circuit that interpolates and outputs the missing first or second reproduced data based on the reproduced data. 3. A magnetic tape for recording video signals on recording tracks sequentially formed diagonally in the longitudinal direction, and for reproducing a magnetic tape in which first and second data are recorded on even-numbered and odd-numbered recording tracks, respectively. In the playback device,
a video signal processing circuit that reproduces and outputs the video signal;
a data reproducing circuit that reproduces the first and second data to generate first and second reproduced data; and a data reproducing circuit that reproduces the first and second data and the first or second reproduced data is missing in the even-numbered or odd-numbered recording track. When the above 1st or 2nd immediately preceding
1. A magnetic reproducing device comprising: a reproduced data processing circuit that holds and outputs reproduced data.