JPS60258750A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain accurate consecutive recording without using an erasure signal generator by overwriting a cue track at DC saturated recording at tape reverse transfer of the consecutive recording. CONSTITUTION:When a temporary stop signal 9 is inputted to a control circuit 11 during video recording, a gate of a gate circuit 3 is opened while transferring reversely a magnetic tape 8 and a signal from a reference signal generator 2 is subjected to saturating recording for prescribed number of pulses on a cue track 20 by a cue head 7 through the 1st amplifier 4. When the recording of the prescribed pulse is finished, the gate of the gate circuit 3 is closed while the changeover switch 5 is set to the recording side and the signal recorded already on the said cue track 20 is reversely transferred continuously while being erased by applying overwrite to the DC saturated recording. Thus, an unnecessary signal on the cue track is erased without requiring any erasure signal generator.

Description

[Detailed description of the invention] [Technical portion of the invention! ] This breakthrough applies to magnetic recording and reproducing devices (hereinafter abbreviated as VTR), in particular, to ensure that the seams of recording on the magnetic tape will not be disturbed when the recording is paused and the next recording is resumed. In other words, it relates to a VTR with improved continuous shooting.

[Prior art] Figure 1 is a block diagram of a conventional pilot signal method using a cue trunk, and in the figure,
Reference numeral 7 denotes a cue head for both recording and playback, and during recording, the reference frequency from the reference signal generator 2 or the erasure signal (after the erasure signal from the signal generator 1 is amplified by the first amplifier 4, the signal is Saturation recording is performed on the cutlass 20 (see FIG. 2) on the magnetic tape 8 via the switch 5 and the capacitor 6.

3B data 1-circuit limits the time for recording the number of pulses from the reference signal generator 2 and the erasing signal from the erasing signal generator 1 on the cue track 20. During reproduction, the pulse signal reproduced from the cue track 20 on the magnetic tape 8 is amplified by the second amplifier 13 via the recording/reproduction switch 5, and the waveform is shaped by the waveform shaping circuit 12 and sent to the control circuit. 11.

Reference numeral 14 denotes a servo circuit, which controls tape running using a biloft signal system using a capstan motor 15 in response to commands from the control circuit 11.

FIG. 3 (al is a diagram showing the vicinity of the cue head 7; the signal from the changeover switch 5 is input to the cue head 7 via the capacitor 6.

Next, the operation will be explained. Assuming that recording is currently in progress, after the magnetic tape 8 is erased by a full erase head (not shown), a diagonal video track is formed as shown by fal in FIG. The pilot signals F1 to F4 are then recorded in a circular manner.

When the pause J-signal 9 is input to the control circuit 11 in this state, the control circuit 11 stops recording after the recording of the video track currently being recorded, and issues a reverse rotation (h command) to the servo circuit 14. , the capstan motor 15 is rotated in the reverse direction to transport the magnetic tape 8 in the reverse direction.

At the same time, the gate circuit 3 first uses the reference signal generator 2.
gate the signal from the first amplifier 4. Changeover switch5. A predetermined number of pulses of the reference frequency are recorded in the cue trunk 20F by the cue head 7 through the capacitor 6. The recording current amplitude value at this time is assumed to be Vl (see Fig. 3 (bl)). When the recording of this predetermined pulse is completed, the gate circuit 3 erases the cue track 20 and moves it backward by a certain amount. The erase current amplitude value at this time is set to ■2.
(see Figure 3 [bl)]. At this time, as shown in FIG.
The other terminal of is connected to ground. Therefore, the waveform at point A of cue line 7 is as shown in FIG. 3(b). The state of the magnetic tape at this time is shown in FIG. 2(b). In addition, in the figure, 21 indicates a pulse recorded on the cue trunk 20.

Next, when the pause is released, the servo circuit 14 rotates the capstan motor 15 in the forward direction, transports the magnetic tape 8 in the forward direction, and switches each circuit to the playback state, so that the Tape running is controlled by the capstan motor 15 so that the recorded pilot frequencies match the order of newly recorded pilot frequencies. At this time, the changeover switch 5 is connected to the outgoing side, and the cue head 7 is connected to the cue track 20.
Play the pulse recorded above. This regenerated pulse is passed to the second amplifier 13. The pulses are input to the control circuit 11 via the waveform shaping circuit 12, and the number of pulses is counted.

This state is shown in FIG. 2 (cl).

When the number of pulses reproduced in this way becomes the same as the number of pulses recorded during reverse transport, the head switch pulse 1
Recording of the video signal is restarted in synchronization with 0. The state on the magnetic tape 8 at this time is shown in FIG. 2 (dl). In the same figure, 22 indicates the state of the newly recorded video track.

Since the continuous shooting using the cue trunk of the conventional viroft signal system is configured as described above, an erasure signal generator l is required. Further, in the case of a high 11C tape with high recording retention power such as a metal tape, it is necessary to increase the erasing current amplitude value V2 with respect to the required signal recording current amplitude value 1.

[Summary of the Invention] This invention has been made to eliminate the above-mentioned drawbacks of the conventional ones, and it uses a cue head to record a predetermined number of pulses on the cue track when the tape is transferred backwards during a continuous shooting operation. After that, by overriding the cue trunk with DC saturation recording, unnecessary pulses on the cue trunk can be erased without using an erasure signal generator like in conventional devices, and the erasure can be ensured, making it more accurate. The object of the present invention is to provide a magnetic recording/reproducing device that can perform various link operations.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Fourth
The figure is a block diagram of a VTR according to an embodiment of the present invention.
The difference from the conventional device shown in FIG. 1 is that the erase signal generator 1
and capacitor 6 are not provided, and a predetermined bias voltage Vref is applied to the cue head.

FIG. 5(a) shows the vicinity of the queue head 7 according to an embodiment of the present invention. The signal from the changeover switch 5 is directly input to one terminal of the cue head 7, and the bias voltage V ref, which is half the signal amplitude, is applied to the other terminal, indicating a state in which DC saturation recording is performed. .

Figure 5 tc+, (dl) respectively show how the changeover switch 5 and gate circuit 3 change in the reverse transfer section. Figure 5(e) shows the current flowing through the cue head 7.Here, the selector switch 5 is on the recording side and the gate circuit 3 is closed. Time is cue head 7
Since a DC saturation recording current of -IP flows through the signal, the cue trunk 20 is overridden by this, and the signal already recorded in the cue trunk 20 is erased.

Next, the operation will be explained.

When the pause signal 9 is input to the control circuit 11 during recording, the control circuit 11 stops the recording operation after finishing recording the video track currently being recorded, issues a reverse rotation command to the servo circuit 14, and starts the capstan motor. 15 is reversely rotated to reversely transport the magnetic tape 8, and the selector switch 5 is set to the recording side.

At the same time, while the magnetic tape 8 is being transported backwards, the gate of the gate circuit 3 is opened, and the signal from the reference signal generator 2 is transmitted through the first amplifier 4 to the cue head 7 onto the cue track 20. Record the pulse number saturation. When the recording of this predetermined pulse is completed, the gate of the gate circuit 3 is closed while the changeover switch 5 is set to the recording side, and the signal already recorded on the ±neat rank 20 is overridden by DC saturation recording. Continue back transport while erasing. This situation is shown in FIG. 5) to (fl).

Next, when the magnetic tape 8 has been reversely transported by a certain amount, the reverse transport is stopped, the tape is temporarily stopped, and the recording standby state is entered. Then, the changeover switch 5 is connected to the playback side, and the following operation is the same as the conventional continuous shooting operation.

In this embodiment, the capacitor of the cue head is removed, a predetermined bias is applied to the cue head, and the signal already recorded in the cue trunk is erased by overriding it with DC saturation recording. , unnecessary signals on the queue trunk can be canceled without the need for a conventional cancellation signal generator. In addition, for magnetic tapes with high Hc such as metal tapes, it is necessary to increase the erasing current in AC erasing, but with DC erasing, erasing is ensured even when erasing at the same level as the recorded signal amplitude, making it possible to perform continuous shooting with high precision. can be done.

Note that in the above embodiment, the bias applied to the cue head was set to a voltage half the amplitude of the signal, but if the first and second amplifiers operate on positive and negative power supplies, the bias may be at ground potential. .

〔Effect of the invention〕

As described above, according to the present invention, during tape reverse transport in a splicing operation, after a predetermined number of pulses are recorded on the cue track by the cue head, the cue track is overridden with direct current saturation recording. Since unnecessary signals on the rank are erased, there is no need for an erase signal generator that was required in the conventional device, and there is an effect that highly accurate linking operations can be performed.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing splicing using a cue trunk of the conventional pilot signal system, Fig. 2 is a diagram showing a recording pattern on a conventional magnetic tape, and Fig. 3 (al is the cue head of the conventional device). FIG. 3 (bl is a diagram for explaining its operation, FIG. 4 is a block diagram showing an example of continuous shooting of a VTR according to an embodiment of the present invention, and FIG. 5 fal is a queue diagram of the device. Diagrams showing the head section, FIG.
- Cue head, 8... Magnetic tape, 11... Control circuit, 14... Servo circuit, 15... Capstan motor, 20... Cue track, 21... (Cue) pulse. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 2 Figure 3 (b) Figure 5 Procedural amendment (voluntary) 2. Name of the invention Magnetic recording and reproducing device 3. Relationship to the case of the person making the amendment Patent applicant address Chiyoda-ku, Tokyo Marunouchi 2-chome 2-3 Name
(601) Mitsubishi Electric Co., Ltd. Representative Jinhachi Katayama 4, Attorney 5, Although there is "although it is necessary," on page 9, line 17 of the detailed description of the invention subject to amendment. As a result of conducting an experiment based on the example shown in Fig. 4,
Correct. (2) On page 9, line 20, "I can do it." is corrected to "I was able to do it."that's all

Claims (1)

[Claims] (1) A plurality of pilot signals with different frequencies are superimposed on a video signal and recorded on a video track on a magnetic tape.
When a pause signal is input during the recording mode, the recording is stopped and the magnetic tape is moved in the opposite direction! While transporting the magnetic tape, at least one or more pulses are recorded in saturation on a cue track provided separately from the video track by the cue head, and then the cue track is energized by direct current while the magnetic tape is transported in the opposite direction for a predetermined period of time. Overwrite due to saturated recording of
Afterwards, the tape is stopped by reverse transport, pulse recording, erasing,
a stopping means, which transports the magnetic tape in the forward direction when the temporary stop is released, and transfers the pilot signal 'a frequency recorded on the magnetic tape and the frequency of the pilot signal to be newly recorded;
The tape is controlled to run so that the number order matches, and the pulses recorded on the cue track are reproduced, and when the number of bidirectional pulses matches the number of pulses recorded during the reverse transfer, the recording operation is started. What is claimed is: 1. A magnetic recording and reproducing device comprising: recording start means.