JPS63237245A - Consecutive recording system - Google Patents

Abstract

PURPOSE:To prevent error detection in which a detected recording termination point goes to a joint in a recording part which is former than an objective detection point by detecting the recording terminal point only in the vicinity at the objective detection point. CONSTITUTION:A rewound tape length is detected in tape length detecting devices 32 and 33. time setting devices 34 and 35 set time shorter than a time required for traveling the tape length which the detecting devices 32 and 33 detect by a prescribed time. Recording termination point detecting devices 39 and 43 are operated in an AND circuit 42 after a time which time setting devices 34 and 35 set from the forward direction feeding start time of the rewound tape. The consecutive recording is executed by the recording terminal points detected by the point detection devices 39 and 43 as the joints.

Description

[Detailed description of the invention] The invention will be explained in the following order.

A. Field of industrial application B. Outline of the invention C. Prior art D. Problems to be solved by the invention E. Means for solving the problems Figure) Explanation of G2 splicing operation (Figures 1 to 5) Effect of the invention A Industrial application field This invention relates to a recording device that records video signals and audio signals using a rotating head, and particularly relates to a recorded portion. It is related to the so-called splicing technique that allows recording to be continued.

B. Summary of the Invention This invention is capable of rewinding the tape after the recording operation is completed, putting it into playback mode, checking the recording state of the previously recorded portion, and then starting a new recording from the previous recording end point. In the splicing method, the recording end point to be spliced can be detected without error by performing the operation of detecting the recording end point to be spliced only in the vicinity of the splice.

C. Prior Art For example, when images taken with a video camera are recorded on a VTR, a splicing technique is generally used to make the seams between cuts less noticeable on the playback screen.

For example, Japanese Patent Laid-Open No. 57-1981 describes the technique of splicing the recorded portion of a VTR to continue recording.
It is disclosed in Japanese Patent No. 15805. In this technology, a capstan and a pinch roller press each other between recording states, tape tension is applied, and the tape is temporarily stopped in tension, thereby creating a pause state. That is, as shown in FIG. 6, when a pause operation is performed from a recording state, the tape is not paused at the operation position P1, but is paused at a position P2 where the tape is rewound a certain amount from the pause operation position. and waits for the next recording start operation (pause release operation). The amount of rewinding from the pause operation position P1 at this time is a constant value converted to the number of control pulses.

When a pause release operation is performed, a playback state is entered, and tracking servo is performed while counting playback control pulses. Furthermore, the phase relationship between the reproduced signal and the newly recorded signal at this time is controlled so that the two are synchronized. Then, when the count value of the playback control pulse reaches a value corresponding to the tape rewind amount,
The position P3 corresponds to the position P1, and the recording state is entered from this position P3.

As a result of the above, irregularities in track intervals and intervals between recording traces of control signals are eliminated at the joint between an already recorded track and a newly recorded track, and the reproduced image is not disturbed.

By the way, there is a known device equipped with a review function for checking the recording state of the green portion. By operating the review switch, the tape is rewound by a certain amount (42 frames in the above-mentioned Japanese Patent Application Laid-Open No. 57-158056), and then the tape enters the playback state, so that the recorded edge state can be checked.

D Problems to be Solved by the Invention By the way, there is a demand for accurate splicing even after going through such a review mode. Therefore, the rewound tape length is memorized as the number of control pulses.
If the camera is kept in the playback state for the number of control pulses and is run in the forward direction, that should become the previous recording end point, so it is conceivable to take continuous shots based on the count of the number of control pulses.

However, if the machine has high mechanical precision, it is possible to accurately detect the recording end point based on the number of control pulses, but if the machine has low mechanical precision, such as a porta-pull type VTR integrated camera, Not only is the accuracy unreliable, and the trunk spacing at the joint is uneven, but also the new track is not always recorded from the point after the last track of the previous recording track, and the previous recording There is a risk that the last few tracks of the tracks may be erased due to overwriting. When this happens, various problems occur, such as not being able to capture a color frame.

Therefore, there is a need to accurately detect this recording end point.

Various methods can be considered for detecting the recording end point, such as a method using a time code recorded on the tape.

By the way, when the review switch is used to rewind the tape, there are cases where the tape goes further back than the recorded part of the immediately previous cut, and even goes back to the recorded part of the cut before that. In such a case, if the detection operation by the recording end point detection means is started from the rewound tape position, for example, the seam between the recorded part two times before and the previous recorded part (the beginning position of the previously recorded part) can be detected. It is mistakenly detected as the current seam (the last position of the previously recorded portion) at which new recording should begin.

E. Means for Solving the Problems This invention makes it possible to detect the seam at which new recording starts without error even if a review mode intervenes. In a splicing method in which the tape length set by the length setting means is rewound to perform a playback operation, the recording state is monitored, and recording is performed again from the recording end point, the rewound tape length is detected. tape length detection means < 32) (33), and time setting means for setting a time shorter by a predetermined time than the time required to run the tape length detected by the tape length detection means (32) (33). (34) and (35), and after the time set by the time setting means (34) and (35) has elapsed from the start of forward feeding of the rewound tape, the recording end point detection means (39) (43)
The recording end point detecting means (39) (42) operates the recording end point detecting means (39), and the recording end point detected by the recording end point detecting means (43) is used as a seam to perform continuous shooting.

F The recording end point detecting means substantially performs the detection operation only in the vicinity of the recording end point to be detected, so the detected recording end point is the intended seam, and the seam of the previous recorded part is not detected incorrectly. There's nothing to do.

G. Embodiment G1 Description of overall block diagram of recording and reproducing apparatus FIG. 2 is an overall block diagram of an example of the VTR portion of a VTR integrated camera as an example of an apparatus to which the present invention is applicable.

In the figure, (1) is the supply side reel, (IM) is this reel (11 drive motor, (2) is the take-up side reel, (
2M) is the motor for driving this reel (2), (3) is the drum to which the rotating head is attached, (3M) is the motor for driving this drum (3), (4) is the capstan, (4)
h) is a motor for driving this capstan (4), (5) is a pinch roller, and (6) is a tension regulator.

The tape (7) let out from the supply reel (1) goes around the tension regulator (6), is wound around the drum (3) at predetermined angular intervals, and then is passed between the capstan (4) and the pinch roller (5). This forms a tape path system that reaches the take-up reel (2).

On the magnetic surface side of the tape (7) between the tension regulator (6) and the drum (3) in this tape path system, there is a full-width erasing defining head (8) for erasing the entire width of the tape (7).
) and a control signal fixed head (9) are arranged with the full-width erasing fixed head (8) leading.

In this case, the interval l between the full-width erase fixed head (8) and the control signal fixed head in the tape running direction is selected to be longer than the recording pitch of one period of the control signal C1''L on the tape (7). Also, (
10) is a fixed head for recording and reproducing time codes.

(100) is a system controller (hereinafter abbreviated as system controller) having a microcomputer, which supplies a reel drive signal to the reel drive motor (LM) and (2M), as well as the drum servo circuit (11).
A drum drive signal is supplied to the drum drive motor (3M) via the capstan servo circuit (12), and a capstan drive signal is further supplied to the capstan drive motor (4M) via the capstan servo circuit (12).

For the servo, a signal PC indicating the rotational phase of the drum (3) is supplied to this system controller (10), and during recording, a control signal of, for example, 30 Hz is sent from the system controller (10) to the control (for a%). Head (4)
During reproduction, a reproduction control signal CTL from this head (4) is supplied to the system controller (10).

(20) is a video signal processing circuit, to which a reproduced video signal is supplied during reproduction, and after being restored to the original video signal, it is output as an output video signal.

Furthermore, during recording, an input video signal to be recorded taken by a camera is supplied, signal processing for recording is performed, and this is output as a recorded video signal. The system controller (10) supplies playback and recording mode signals PB and REC to the video signal processing circuit (20), and switching between the recording system and the playback system is performed in the circuit (20).

Further, the video signal processing circuit (20) outputs a vertical synchronization signal PBV extracted from the reproduced video signal during playback, and a vertical synchronization signal V extracted from the input video signal during recording.
D is supplied to the system controller (10) and used for the servo. In addition, in the reproduction mode during continuous shooting, which will be described later, both vertical synchronizing signals PBV and VD are supplied to this system controller (10) so that they are synchronized.

Nao, (13) is the record button switch, (14) &;t
The review button switch (15) is a pause button switch, and when these are turned on, the system controller (10) detects this and puts the device into a state according to the operated button switch.

Description of G2 continuous shooting In the above configuration, continuous shooting via the review mode is performed as follows.

That is, FIG. 3 is an explanatory diagram of the movement of the tape during this continuous shooting, and FIG. 4 is a flowchart for executing continuous shooting. Hereinafter, explanations will be made according to this flowchart with reference to FIGS. 2 and 3. .

First, from the recording state, press the pause button switch (
15) is turned on, the capstan (4) and reel (11 and (2)) are reversed by the system controller (100) (step (101)), and the tape (7) is turned on as shown in FIG. When the tape is returned, the control signal is reproduced, and this reproduction control signal C'
1'L is counted (step (102)), and when the count value k reaches a predetermined value, k = 15 in this example (step (103)), the capstan (4) is stopped (step (104) , position T2 in FIG.
), and the count value k at that time is stored (step (1)
05)), the count value k is reset (step (106)) and a pause state is entered (step (10)).
7)).

In this state, it is determined whether a switch has been operated (step (108)), and it is determined whether a switch has been operated and the operated switch is the review switch (14) (step (109)). If the review switch (14) is on, the capstan (4) and reels (1) and (2) are reversed (step (110)).
), the tape (7) is further returned as shown in FIG. Even when reversing the tape, the playback control signal CTL
is counted (step (111)), and when the count value reaches a predetermined value N (step (11)
2)), it is further determined whether the review switch (14) is still on (step (113)), and if it is on, the tape (7) is further returned and the signal CTL is
Step (114)) continues until the review switch (14) is turned off. When the review switch (14) is turned off, the capstan (4) is stopped and the tape (7) is stopped (as ffTt in FIG. 3). Count value N' at this time
is accumulated in memory (step (116)'). After that, the count value is reset to = 0 (step (1)
17)), the capstan (4) is rotated in the normal direction (step (11B)"), and the normal playback state is entered (step (119)). In this normal playback state, the playback video signal is supplied to the monitor. The reproduced image is displayed and the recording status is confirmed.

Also in this reproduction state, the reproduction control signal C'rL is counted (step (120)).
, the count value k is shorter than the count value N'+15 (which is the cumulative count value of the memory) corresponding to the returned tape amount by the count value M corresponding to a sufficient time to detect the recording end point. When the value is reached (step (121,
)) When the recording end point detection operation is started (step (122)).

When the recording end point is detected (step (123)), the capstan (4) is stopped (step (124), position T4 in FIG. 3), the count value k is reset, and the memory is cleared. (step (125)), the capstan (4) is reversed (step (12)).
6)), the signal CTL at that time is counted (step (127)), and when the count value is returned to -15 (step (12B)), the capstan (4) is stopped (step (129)). )), the count value at this time is stored in the memory (step (130)), the count value is reset (step (131)), and the pause state is entered (step (132)).
), position Ts in Figure 3).

Then, when the pose is released (step (133)),
From the position T5, the capstan (4) rotates forward (step (134)), counts the playback control signal CTL (step (135)), enters the playback mode, and the next recording signal and playback signal are phase-locked. (step (136)). Then, when the tape (7) advances by the amount that the tape (7) is returned from position T4, that is, when it reaches position TG =15 (step [137]), it enters the recording mode from position T6 (step (13B) )) Reset the count value k (step (214)).

The movement of the tape and the mode of the VTR from position T4 onwards are the same as when the pause button switch (15) is turned on from the recording state at position T4 and the pause state is released from the pause state at positions 1 to 5. In this case, position 1'→ is exactly the last position of the previous record, so it is possible to continue the operation exactly from the end of the previous record.

A specific example of the recording end point detection means is shown in FIG.

Note that the example in FIG. 1 can be realized by software of a microcomputer.

In this example, the recording end point is basically detected using the time code, but if the time code is not recorded or cannot be played back (cannot be played back reliably), the playback control Detection is performed by detecting a missing portion of the signal CTL.

That is, the reproduction control signal C'1'L from the control signal fixed head (9) is supplied to the counter (32) through the amplifier (31). This counter (
The count value of 32) is supplied to the cumulative value memory (33). A reset signal and a write signal are supplied to the counter (32) and memory (33) at the timing explained in the flowchart of FIG. 4.

Therefore, at position T3 in FIG. 3, the count value rN'+15J is stored in the memory (33).

When the reproduction mode starts from position T3, the counter (32) sequentially counts the signal Ci''L from the count value rOJ.The count value is supplied to the comparison means (36).Meanwhile, the counter (32) sequentially counts the signal Ci''L from the count value rOJ. The stored count value rN' + 15J is read out and supplied to the subtraction means (34).The subtraction means (34) has a count value M corresponding to the tape traveling distance required for end point detection. It is supplied from the starting point setting means (35). Therefore, the count value rN' +15 is supplied from the subtracting means (34).
-Ml is obtained, which is fed to the comparison means (36).

The comparison means (36) is the number 7) (+1) of the counter (32).
When becomes larger than the count value rN'+15-MJ, a window pulse WP that becomes high level is output.

On the other hand, the time code TIME! from the fixed head (10) for time code. is supplied to the time code decoder (38) via the amplifier (37), and the time code TIM
E is decoded. The decoded output is the seam detection means (
39), and by detecting the portion where the time code becomes discontinuous, the seam, that is, the recording end point is detected.

This detection means (39) is supplied with the window pulse WP from the comparison means (36), and the detection means (39) performs the detection operation only during the period when this window pulse WP is at a high level. . The detection output from the detection means (39) is taken out via the switch circuit (4o),
The end point (position T4 in FIG. 3) is detected.

In this example, the output of the time code decoder (38) is supplied to the code detection possibility determining means (41), and when the time code is not recorded or cannot be reproduced reliably, the determination output becomes, for example, a high level. is obtained. When this discrimination output becomes high level, the switch circuit (40) is thereby switched from the state shown in the figure to the opposite state, and the seam detection means (3) based on the time code is switched to the opposite state.
The output of 9) is ignored.

At this time, the gate 1-(42) is opened during the pulse width period by the window pulse WP, so that the reproduction control signal CTL is transmitted to the CTL missing detection means (43) via this gate (42). supplied to This CTL missing detection means (43) detects the end of the previous recording track, that is, the joint, by detecting the period of the reproduction control signal C'['L.

That is, as shown in FIG. 5, in the control signal track at the recording end position T1 before the pause button switch (15) was turned on, there is a distance of at least 1 (full width erased) after the last recording signal of the control signal. distance between head (8) and control signal head (9))
The part (shaded area) LK is.

Erasing is performed by a full-width erasing head (8), and even if there is an old recorded signal as shown in the figure, the recorded signal is missing in this portion LK. And this position T1
Since the tape (7) is rewound more, this recording signal missing portion LK is at the rewound position with respect to the control signal head (9). Therefore, place 1JZTx
When the playback mode is started, the control signal head (
9) always scans this missing portion LK.

Here, the distance l is the period τ of the recording signal of the control signal
Since it is longer, the missing portion L K' can be detected by detecting the cycle of the reproduction control signal CTL and detecting that the detected cycle is equal to or longer than one cycle τ. The detection method is, for example, to trigger a ridrigger-type monostable multi-bi break with a time constant slightly longer than -period τ with the playback control signal CTL, and its Q output goes low when the period of signal CTL becomes longer than τ. You can take advantage of lowering your level. Also, a counter may be used instead of the monostable multipipe rake. That is, by resetting the counter with the signal CTL and detecting the count value of the clock from reset to reset, when the count value exceeds a predetermined value, it can be detected as the missing portion LK. As described above, this missing portion LK is the recording end point, and since the signal CTL is used for detection only within the window pulse width, this recording end point T4 correctly coincides with the position ]'1.

In this way, when the time code cannot be detected, this C
The detection output of the TL missing portion detection means (43) is taken out via the switch circuit (40), thereby detecting the recording end point.

In the above example, the detected recording end point ゛I'
4 to position T5 to perform the continuous shooting operation, however, the recording mode may be entered from the recording end point T4. In this case, it is sufficient to synchronize with the recording signal during the reproduction mode from T3 to 'r4.

Furthermore, in the above example, the playback mode from position T3 to 'r4 is normal playback mode, but may be double speed playback mode. Alternatively, a reproduction signal may be obtained and monitored when the tape is returned.

In FIG. 1, if the operation for determining whether or not the time code is detected is also performed within the window pulse width or in the vicinity of the window pulse, the reliability of the recording end point detection output will be higher.

Furthermore, the present invention is not limited to video signal recording and reproducing apparatuses, but is applicable to all rotary head type helical scan type recording and reproducing apparatuses.

H Effects of the Invention According to this invention, in continuous shooting with a review mode for checking the recording state after the end of recording, the recording end point is detected only in the vicinity of the target detection point. It is possible to prevent erroneous detection in which the detected recording end point is a joint between recorded parts earlier than the intended detection point, and accurate splicing operations can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an example of the main part of this invention, FIG. 2 is a diagram showing an overview of an example of a main recording/reproducing apparatus for explaining an embodiment of this invention, and FIG. 3 is a block diagram of an example of a main part of this invention. 4 is a flowchart for explaining the details of the present invention, FIG. 5 is a diagram for explaining an example of recording end point detection means, and FIG. 6 is a diagram for explaining conventional continuous shooting. FIG. 3 is a diagram for explaining an example. (9) is a fixed head for control signals, (32) is C
Counter for TL count, (33) is memory, (36
) is a comparison means, and (100) is a system controller.

Claims (1)

[Scope of Claims] After the recording operation is completed, the tape is rewound by the tape length set by the rewind amount setting means to perform the playback operation, the recording state is monitored, and the recording is performed again from the recording end point. In the shooting method, a tape length detection means detects the length of the rewound tape, and a time setting that sets a time shorter by a predetermined time than the time required to travel the tape length detected by the tape length detection means. and means for substantially operating the recording end point detecting means after the time set by the time setting means has elapsed from the start of forward feeding of the rewound tape, and the recording end point detecting means is configured to detect the recording end point. A continuous shooting method in which continuous shooting is performed using the recording end point detected by the method as a seam.