JPH0156467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video signal recording device, and is particularly suitable for use in a device for duplicating video tapes.

To make large copies of identical videotapes,
A master tape is repeatedly played back on one or two master video tape recorders (VTRs), and the playback signals are recorded on a plurality of (for example, 100) VTRs. In order to automatically operate such a duplication device, the positions of the start and end of the recorded portion of the master tape are stored in a control device, and this control device also controls playback and rewinding of the master VTR. The positions of the start and end of the recorded portion are also represented by the count value of the control signal, but since there is a count error, it is not possible to accurately detect the editing point of the tape.

In view of the above-mentioned problems, the present invention is capable of accurately detecting the start and end points of a program recorded on a magnetic tape and controlling the tape position, and which can be realized with an extremely simple configuration. The purpose is to

The present invention provides a cue track that corresponds to each inclined video track on a magnetic tape and is provided so as to extend in the longitudinal direction of the magnetic tape, and a time code recording circuit that records a standardized time code on the cue track. and a time code reproducing circuit for reproducing the standardized time code from the cue track. The time code may be, for example, an SMPTE time code as shown in FIG.
It is shown as. Time codes are generally used for program editing, but in the present invention they can be used for automatic operation during playback.

A memory circuit is provided for temporarily storing time codes at the start and end points of the program recorded on the tape among the time codes reproduced by the code signal reproduction circuit. This memory circuit is shown as RAM 18 in the microcomputer 4 in FIG.
When a key is operated at the start and end points of a program, the playback time code at that point is transferred from the time code reader to the microcomputer and stored in the RAM 18.

The time codes of the start and end points of the program stored in the memory circuit are recorded at the beginning of the magnetic tape by the time code recording circuit, with identification bits substituted with specific value time codes added. A recording control circuit (microcomputer 4) is provided to perform various controls.

By adding a simple circuit to the standardized time code recording and reproducing circuit in this way, it is possible to record and play back the time codes of the program start and end points at the beginning of the tape, and to automatically play programs using time codes. Allows program search.

The identification bit consists of a time code, which may be data of a specific value, such as a frame of 0:00:00:00, and acts as a data sink for the time code recorded at the beginning of the tape, and is used for high-speed recording. The search mode allows you to quickly read code data indicating the program start and end points. Furthermore, since the time code reader functions as a matching circuit for the identification bit pattern, the configuration is simple.

Embodiments of the present invention will be described below with reference to the drawings.

In a helical scan VTR, a method is known in which the address code or time code of the video track is recorded at frame intervals on the cue track along the length of the tape. Figure 1 shows an example of such an address or time code, SMPTE.
Shows time code. As shown in Figure 1, one frame consists of 80 bits (1 bit = 1/(80×
30)sec), of which 64 bits are used as time code and user bits, and the remaining 16 bits are a synchronization word. In the time code portion, each data of hour (x10 and x1), minute (x10 and x1), second (x10 and x1), and frame (x10 and x1) is written. The space between these data is used as user bits. The 16-bit synchronization word consists of a 12-bit (all "1") synchronization signal and 2-bit direction determination signals "00" and "01" added before and after the synchronization signal.
The direction discrimination signal is provided so that the time code reader can operate correctly regardless of whether the tape is running in the forward direction F or the reverse direction R.

FIG. 2 is a block diagram of a videotape duplicating apparatus showing one embodiment of the present invention. This duplication device (printer) consists of two master VTRs 1A and 1B and multiple (for example, 100) copy VTRs 2a and 2b.
It is equipped with 2c... Master VTR1A,1
A master tape or original tape is wound on B, and these VTRs are operated alternately.
The reproduced outputs are recorded in parallel on the copy VTRs 1a, 1b, . . . For each VTR1a, 1b...
A raw roll tape for 24 hours is wound, and the same content source is recorded multiple times on each roll tape by alternate operation of two master VTRs 1A and 1B. After recording is completed, the roll tape is cut into pieces and wound into cassettes.

One of master VTRs 1A and 1B (for example, A)
Immediately before the end of playback of A, the other side (B) starts playing, and A
It is switched to B when the playback ends. Master A, which has finished playing, is rewound and waits until the next playback. The playback output of the master VTRs 1A and 1B can also be switched using switcher 3, and the copy VTR
It is sent to 1a, 1b... The switcher 3 is controlled by a microcomputer 4, and an operation command signal is given to the microcomputer 4 from a console 5.

A time code writing/reading circuit 6 is connected to the master VTRs 1A and 1B, and lines 7a and 7
The time code of the editing point is recorded at the beginning of the tape via line 8a and 8b during playback. The write data is sent from the microcomputer 4 to the time code write/read circuit 6 via the data bus 9, and the read data and the time code during playback are sent from the write/read circuit 6 to the microcomputer via lines 10 and 11. It is sent to the computer 4.

The editing point data and playback time code are processed by the microcomputer 4, and in the mode set by the console 5, control signals are sent to the master VTRs 1A and 1B via line 12, and to the switcher 3 via line 13. A switching control signal is sent. The microcomputer 4 and the write/read circuit 6 are also coupled by a control line 14. The microcomputer 4 includes a central processing unit 16, a ROM 17, and a RAM 18.

FIG. 3 is a circuit diagram of the time code write/read circuit 6 of FIG. This circuit 6 includes a SMPTE time code generator 19, which is well known in the art. The time code is generated by a counter 2 that counts the output of a clock circuit 20 in the generator 19.
Formed by 1. The time code formed for each frame is transmitted through the OR circuit 22 and the line 7a.
7b to the master VTRs 1A and 1B. Further, time code data indicating the editing point is sent from the microcomputer 4 to the data recording circuit 23 via the data bus 9, and further to the OR circuit 23.
2. Master VTR1 through lines 7a and 7b
A, 1B is supplied. The data recording circuit 23 is also operated by a control signal sent from the microcomputer 4 through the control line 14, whereby edit point data is written on the cue track at the beginning of the tape.

The time code outputs of the master VTRs 1A and 1B are supplied from lines 8a and 8b via the generator 19 to an identification circuit 24, where the time code during playback and the editing point data at the beginning of the tape are identified. The time code is sent from line 11 through microcomputer 4 to console 5 and displayed. Edit point data is also sent to the microcomputer 4 through line 10, where processing such as storage and comparison with playback time code is performed.
Based on this processing, control signals for the system are formed.

FIG. 4 is a front view of the operation console 5 of FIG. 2. FIG. 5 is a time chart showing the edit point data recording mode and a diagram showing the contents of the edit point data.

Knob 27 in Figure 4 is the master VTR 1A, 1
This knob 27 is the knob for changing the playback speed of B.
When set to zero, the VTRs 1A and 1B perform still playback, and by rotating the knob 27 in the F direction and R direction, playback can be performed at any speed (from slow to fast) in the forward and reverse directions. . FIG. 5A shows the recorded contents of the master tape, in which a color bar 50 is recorded on the video track _T2 for about 120 seconds from the beginning of the tape, and a 1KHz reference signal 50 is recorded on the audio track _T1 .
1 is recorded. A further 30 seconds after these color bars and reference signals, video software 52 (master software or original software) to be copied is recorded together with the audio signal. Furthermore, an SMPTE time code 53 is recorded on the queue track _T3 corresponding to each frame of the video track _T2 . Note that the SMPTE time code may indicate an absolute address with zero at the beginning of the tape.
Alternatively, it may indicate real time when the software 52 is recorded.

By operating the manual key 28 shown in FIG.
1A or 1B can be placed in playback mode. In this state, operate the speed variable knob 27 and watch the video software 52 of FIG. 5A while looking at the monitor screen.
The soft top t of is detected. At this time, when the memory in key 35 (KEY IN) shown in FIG. 4 is operated, the system shown in FIG. 2 goes into memory mode. When the soft top key 36 is further operated, the time code at the soft top t changes to the writing/writing shown in FIG.
The data is written to the RAM 18 in the microcomputer 4 through the read circuit 6. Note that the time code of the soft top is displayed on the display section 37 of the console 4. After that, perform the same operation and press the soft end key 38 to open the video software 5.
The time code at the end (soft end) of 2 is
Written to RAM18. Also video software 5
If there is an edit instruction point at the intermediate point of 2, the time code of this edit point is written into the RAM 18 by operating the soft edit key 39. In Fig. 4, among the operation mode keys 30 to 34, the standby key 30 is the master VTR 1A.
Or the operation key to rewind 1B and make it playable, and the shuttle key 34 is the master key.
This is an operation key for operating the VTRs 1A and 1B alternately.

When the memory input is completed, the check key 40 is operated, thereby confirming the timing of sending out the software during duplication. When the code recording key 42 is operated after the check is completed, the system enters the code recording mode. In the code recording mode, first convert the standard speed from the soft top t in Figure 5A.
The master tape is fast-forwarded backwards to a position 120 seconds earlier, and from this position the recording mode is switched to standard speed. Code recording is performed in a 30 second period, during which a zero reset pulse b shown in FIG. 5B is sent from the microcomputer 4 through the control line 14 as shown in FIG. supplied to the input. As a result, the time code output of the counter 21 becomes zero, and the data of frame 0:00:00:00 is recorded on cue track _T3 of the tape.

On the other hand, when the code recording mode is entered, a data transfer pulse c shown in FIG.
Edit point data such as soft top and soft end stored in the RAM 18 is transferred to the data recording circuit 23 shown in FIG. 3 through the data bus 9. The data recording circuit 23 converts the input data into SMPTE time code and outputs the OR circuit 22 and lines 7a and 7.
The data is sent to the master VTRs 1A and 1B through b.
This code is sent by the microcomputer 4.
The recording start pulse d of approximately 6 msec width shown in FIG. 5D is generated at This start pulse d is approximately 15 seconds from the code recording mode start point.
is generated at the position of control line 1 as shown in Figure 3.
4 to the data recording circuit 23. As a result, as shown in Figure 5E, the queue track
0 data D ₀ is recorded at T ₃ for a period of 15 seconds, then edit point code data D _c is recorded, and further thereafter, 0 data is recorded for a period of about 13 seconds. Note that the 0 data _D0 is the code output (0:00:00:00 frame) when the counter 21 is reset as described above, but this may also be a code of all "1"s.

FIG. 5F is an enlarged view of the code recording portion shown in E. As shown in FIG. 5F, soft top data and soft end data are recorded in the code recording portion _Dc . Each data area is divided into five blocks _B1 to _B5 , and the same data is written in each block. When these code data are read and written into the memory RAM 18 of the microcomputer 4 during tape duplication, only when it is confirmed that, for example, three data matches among the five reproduction signals of the same data, the code data is written into the memory as official data. That's what I do. This increases the reliability of data reading.

FIG. 5G is an enlarged view of one block in FIG.
The soft top or soft end time code corresponding to the fourth frame of minutes and 16 seconds is written in the code format shown in FIG. Note that the video software may have a maximum of 1.5 digits in the (×10) time (4 bits) digit _H10 of the time code shown by the hatching in Figure 5G.
Since it is about the time, without entering the time code,
Contains an identification signal for video software. If multiple video sources are recorded on one master tape, the code data D _c shown in Figure 5F
A plurality of video sources are recorded, and in this case, a signal (code) for identifying each video source is written in the most significant digit _H10 . Note that instead of this identification signal, data indicating the editing time width may be written. It is also possible to put such an identification code in the user bit described above, but in this case, the user code cannot be read unless an option for reading the user code is provided.

Next, the operation of tape duplication will be explained. Fourth
When the auto mode key 43 of the operation console 5 shown in the figure is operated, the system enters an autorotating state, and the video software 52 of the master tape is repeated based on the soft end data and soft top data stored in the RAM 18 of the microcomputer 4. and the playback signal is sent to the copy VTR 2a, 2b.
It will be sent to... The master VTRs 1A and 1B are alternately in playback mode, and while one is playing, the other is in standby. The recording section of the video software 52 is detected by comparing the soft top and soft end data with the reproduced SMPTE code, and when a match is detected, the microcomputer 4 starts the master VTR 1A, 1B. Various control signals such as rewind are sent. Soft duplication is a copy
This process continues for about 24 hours until the raw roll tape of VTR2a, 2b... is used up.

When a master tape on which a code has already been recorded at the beginning of the tape is wound onto the master VTR 1A, 1B, the beginning is first moved to the vicinity of the soft top using manual operation, and then the search key 44 on the operation console 5 is operated. be done. When the search key 44 is operated, the tape is once reversed to the code recording portion, and then the playback mode is entered and the edit point data of the code recording portion is read out. The read data is registered in the memory of the microcomputer 4, and thereafter the above-mentioned automatic tape duplication operation is performed. When detecting a code recording portion in the search mode, the 0 data D ₀ written before and after the code data D _c described above acts as a data sink. Since the 0 data D ₀ is inserted before and after the code data D _c , the recording position of the code data D _c can be detected whether the tape is fed backwards or forwards. Furthermore, if the time code writing/reading circuit 6 is controlled by the data sink (0 data), malfunctions such as reading time codes other than the code data recording area can be prevented. The code data D _c (edit point data) and the time code corresponding to each recording field are identified by the identification circuit 24 shown in FIG.

In addition, when the auto mode key 43 is operated and the print start key 47 is operated on the operation console 5 of FIG. 4, the edit point data (soft top, soft end) and the master VTR 1A,
The operating mode of 1B, etc. are printed by a printer (not shown). In this case, the duplication operation continues until the prescribed number of recordings specified by the daisy switch 48 is completed. Mode clear key 4 on console 5
When operating 6, the specified mode (auto, manual, memory in, search, etc.)
is cleared. Further, when the emergency stop key 45 is operated, the entire system is suddenly stopped.

In the above example, the time code is
Although SMPTE timecode was used, other timecodes such as EBU timecode (European type) could also be used.

According to the present invention, since a standardized time code is used as data indicating the tape playback position (program start point and end point), by decoding this, the playback point can be accurately specified without error. . In addition, a cue track in the longitudinal direction of the tape is used to record incrementally increasing time codes, and since the playback position instruction data is recorded with time codes at the beginning of the tape, a standardized time code writer/reader ( decoder) and simple additional circuits (time code memory indicating program start and end points, etc.)
By simply providing , you can specify the playback position and automatically play the program.

Additionally, identification bits are added to the time codes at the start and end points of the program using a time code with a specific value, such as 0:00:00:00 frame, and are recorded at the beginning of the tape. The instruction data of the program position can be read accurately without error by distinguishing it from the time code that increases in steps, and the instruction data of the program position can be read quickly in a high-speed search mode.

Therefore, by making a simple modification to a tape recorder/player equipped with a standardized time code writer/reader using cue tracks in the longitudinal direction of the tape, it is possible to add an automatic playback function for specific programs. Automation and labor saving of the program transmission system are possible with a simple configuration.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the contents of the SMPTE time code, Fig. 2 is a block diagram of a videotape duplicating device showing an embodiment of the present invention, and Fig. 3 is a block diagram of the time code writing/reading circuit shown in Fig. 2. Figure, 4th
The figure is a front view of the operation console shown in FIG. 2, and FIG. 5 is a time chart showing the recording contents of edit point data and the recording process. In addition, in the symbols used in the drawings, 1
A, 1B...Master VTR, 2a~...For copying
VTR, 4... microcomputer, 6... time code writing/reading circuit, 19... SMPTE time code generator.

Claims (1)

[Scope of Claims] 1. A cue track provided to correspond to each inclined video track on a magnetic tape and extending in the longitudinal direction of the magnetic tape, and a time for recording a standardized time code on the cue track. From the code recording circuit and the above Kew Track,
In a video signal recording and reproducing device having a time code reproducing circuit for reproducing the standardized time code, a program recorded on the magnetic tape among the time codes reproduced by the time code reproducing circuit; a memory circuit that temporarily stores time codes of the start point and end point of the program, and a time code of a specific value that stores the time codes of the start point and end point of the program stored in the memory circuit at the starting end of the magnetic tape. A video signal recording and reproducing apparatus is provided with a recording control circuit for controlling the time code recording circuit to add an identification bit substituted by the above-mentioned time code recording circuit.