JP3128484B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus such as a video tape recorder (hereinafter referred to as "VTR"), and more particularly to a splicing method for audio and video signals.

[0002]

2. Description of the Related Art In a conventional VTR, splicing in which a new signal is recorded in succession to audio and video signals recorded on a magnetic tape is performed by the method shown in FIG. 1 as follows.

When recording a recorded signal from a reproduction state to a next new signal, the magnetic head is brought into a reproduction state, and a phase reference signal (hereinafter referred to as CTL) in a magnetic tape running direction recorded on a control track of the magnetic tape. Pulse) is reproduced by the control head, and the CTL pulse is counted to rewind the magnetic tape by a predetermined amount, and the magnetic tape is further reproduced by a predetermined amount smaller than the count number rewinded by a predetermined amount from that position.

At the same time, the phase of the signal to be newly recorded is adjusted to record a new signal.

At the end of recording, when the tape is rewound by a predetermined amount of CTL pulses and the next signal is recorded,
Further reproduction is performed by a predetermined amount smaller than the count number rewinded from the position, and at the same time, the phase is adjusted with a signal to be newly recorded to shift to a recording state.

In this case, if the CTL pulse can always be accurately reproduced, it is possible to make the rewind amount and the reproduction amount of the phase adjustment almost the same amount. As a result, the CTL pulse may not be accurately reproduced.

[0007] Therefore, the reproduction amount of the phase matching is made smaller than the rewind amount as described above.

[0008] However, in this method, it is necessary to provide a large margin in order to ensure safety, and the amount of superposition increases.

Furthermore, since the reproduced CTL pulse itself varies, and the amount of superposition also varies, there is a problem in that it is not possible to perform an accurate continuous photographing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when connecting a new signal to a signal recorded on a magnetic tape and taking a new signal, the amount of superposition can be reduced to reduce the amount of overlap. It is a technical task to perform splicing.

[0011]

According to the present invention, there is provided a magnetic recording / reproducing apparatus for recording / reproducing a video and an audio on / from a magnetic tape. A STREC button for setting a recording state; and a control signal recording means for selectively recording control signals of first and second duty ratios on a control track on the tape.
When the REC button is pressed in a still image output state by pressing the button, the magnetic tape is caused to run in the reverse direction, and a control signal of a second duty ratio is transmitted to the control track by the control signal recording means. Is written in a predetermined number, and then the tape is run in the forward direction.
After a predetermined number of duty ratio control signals are counted, recording is started.

Also, in a magnetic recording and reproducing apparatus for recording and reproducing video and audio on a magnetic tape, a PAUSE button for temporarily stopping the tape feed during recording, a REC button for recording, and a control track on the tape. Control signal recording means for selectively recording control signals of the first and second duty ratios. In a pause state by pressing the PAUSE button, when the REC button is pressed, The magnetic tape is caused to travel in the reverse direction, and a control signal having a second duty ratio is written in the control track by the control signal recording means in a predetermined number. Recording is started after the detection signal of the tea ratio is detected.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic recording / reproducing apparatus according to the present invention will be described below with reference to FIGS.

FIG. 2 is a block diagram of the magnetic recording / reproducing apparatus of the present invention.

In the figure, (1) is a magnetic tape, which is a video track which is helically scanned by a rotating magnetic head,
It has a control track (3) in which CTL pulses are recorded / reproduced by a fixed control head (2).

(4) is a recording CTL signal generation circuit,
The CPU (5) generates a CTL signal in accordance with an instruction from the duty switching circuit (6).

The duty switching circuit (6) includes a first
The duty ratio is switched by a control signal between 60% and 25% as the second duty ratio.

(7) is a reproduced CTL signal amplifying circuit,
The CTL signal reproduced and traced by the control head (2) is amplified.

Recording CTL signal generation circuit (4) and reproduction CT
The L signal amplifier circuit (7) is connected to the control head (2) via the switch circuit (8),
Switching is performed according to the instruction of (5) or the timing generation circuit (9).

A duty detecting circuit (10) determines the duty ratio of the output of the reproduced CTL signal amplifying circuit (7) and outputs it to the CPU (5).

(11) is a capstan motor;
The running of the magnetic tape (1) is controlled by the motor control circuit (12) according to the instruction of the PU (5).

(13) is a STILL key,
The CPU (5) is instructed to shift to the still image reproduction mode.

Also, (14) is a PAUSE key,
The CPU (5) is instructed to shift to the temporary stop mode.

(15) is a REC key, which is a CPU (5)
To the recording mode.

When the transition from the reproduction state to the continuous shooting is performed, the following operation is performed.

In the reproducing state, the STILL key (1
When 3) is pressed, a key input interrupt occurs in the CPU (5), and processing is performed in accordance with the still image reproduction routine shown in FIG.

That is, when this mode is entered, a mode value corresponding to the still image mode is stored in the memory in step 1.

Thereafter, in step 2, the motor control circuit (1
A stop command for the capstan motor (11) is sent to 2).

When the capstan motor is stopped, in step 3, the same video track on the magnetic tape (1) is repeatedly traced by the rotating magnetic head to read a video signal.

By outputting this signal, a still image is output.

In this state, if the REC key (15) is further pressed, a key input interrupt occurs,
The CPU (5) performs the splicing shooting process according to the REC routine of FIG.

In this routine, first, the mode value of the previous state stored in the memory in step 1 is read, and
In step 2, the previous state mode is determined.

If it is determined that the previous state mode is the still image mode or the pause mode, step 3
Issues a rotation command to the motor control circuit (12) in the reverse direction,
The capstan motor is rotated in the reverse direction to move the magnetic tape (1) in the reverse direction.

Further, in steps 4 and 5, the duty switching circuit (6) is instructed to switch to the second duty ratio, and the duty track is supplied to the control track (3) of the magnetic tape (1). 25% CTL
Write a predetermined number of signals.

That is, the number of times of writing the CTL pulse is counted, and when the number reaches the predetermined number N1, the control is shifted to step 6.

Here, N1 is set to 10.

In step 6, the reproduction CTL is supplied to the switch circuit.
An instruction to select a signal amplifying circuit is issued, and tape running is performed in steps 7 and 8 while tracing the CTL track in the reverse direction.
Count the pulses.

Here, when the count value reaches 40 (N2), the tape running is stopped in step 9 and the control is transferred to step 10.

In step 10, the capstan motor (11) is rotated in the forward direction to reproduce the magnetic tape (1) in the normal direction, and the switch circuit (8) is switched to the reproducing CTL amplifier by the instruction of the CPU (5). Let me choose, step 1
At step 1, a reproduction control signal is read.

In step 12, the phase of the read CTL signal and the phase of the recorded CTL signal are adjusted.

In step 13, the duty ratio of the read CTL signal is determined. If it is determined that the second duty ratio is 25%, the control is transferred to step 14, and the CTL signal is recorded. Switch to the side.

Thus, the CTL of the second duty ratio
Steps 10 to 12 are repeatedly executed until is read.

In this step 14, the switch circuit (8) is switched to the recording CTL while the phase of the CTL pulse and the recording CTL pulse is kept constant by the timing generation circuit (9).
Switch to the generator circuit side.

In steps 15 and 16, a CTL pulse having a duty ratio of 60% is written N1 times (10 times).

Thereafter, in step 17, switching to the recording mode for the video head and the audio head is performed to start recording.

Under the above control, the operation shown in FIG. 5 is performed.

That is, when the STILL key is pressed in the reproducing state, a mark signal is recorded on the control track while rewinding, and after rewinding, the mark signal is searched for while performing phase adjustment in the normal direction, and recording is started. I do.

The transition shooting from the recording state to the recording state again can be performed by writing a mark signal at the start of rewinding after the recording is completed in the same manner as described above.

Also, the count number in step 16 is set to N
By setting the value smaller than 1, the amount of the overlapping portion can be adjusted.

[0050]

As described above, the magnetic recording / reproducing apparatus according to the present invention is capable of recording still or still images from a reproduction or recording state to a still (still image reproduction) or pause (pause) state. Immediately after the start of rewinding from the pause position, a control signal for positioning is written to the control track, and a new signal is recorded based on the control signal, thereby reducing the amount of superimposition at the time of joint shooting, Accurate transition shooting is possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a splicing operation of a conventional magnetic recording / reproducing apparatus.

FIG. 2 is a block diagram of a magnetic recording and reproducing apparatus according to the present invention.

FIG. 3 is a control flowchart of a still image mode of the magnetic recording / reproducing apparatus of the present invention.

FIG. 4 is a control flowchart of a recording mode of the magnetic recording / reproducing apparatus of the present invention.

FIG. 5 is an explanatory diagram of a splicing operation of the magnetic recording and reproducing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic tape 2 Control head 3 Control track 4 Recording CTL signal generation circuit 5 CPU 6 Duty switching circuit 7 Reproduction CTL signal amplification circuit 8 Switching circuit 9 Timing generation circuit 10 Duty detection circuit 11 Capstan motor 12 Motor control circuit 13 STILL key 14 PAUSE key 15 REC key

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 15/467

Claims (4)

(57) [Claims] 1. A magnetic recording / reproducing apparatus for recording and reproducing video and audio on a magnetic tape, comprising: a STILL button for stopping the tape feed and outputting a still image during reproduction; a REC button for entering a recording state; And control signal recording means for selectively recording control signals of the first and second duty ratios on the control track. In a still image output state by pressing the STILL button, the REC button is pressed. Then, the magnetic tape is caused to run in the reverse direction, and the control signal recording means is used to move the magnetic tape to the second control track.
A predetermined number of duty ratio control signals are written, and then the tape is run in the forward direction.
A magnetic recording / reproducing apparatus, wherein recording is started after the predetermined number of control signals for the tea ratio have been counted. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the control signal having the first duty ratio is written after the control signal having the second duty ratio is detected. Playback device. 3. A magnetic recording / reproducing apparatus for recording and reproducing video and audio on a magnetic tape, wherein said tape feed is temporarily stopped during recording.
An E button, a REC button for setting a recording state, and control signal recording means for selectively recording control signals of the first and second duty ratios on a control track on the tape, wherein the PAUSE In the pause state by pressing the button,
When the REC button is pressed, the magnetic tape is caused to run in the reverse direction, and the control signal recording means is used to move the magnetic tape to the control track.
A predetermined number of duty ratio control signals are written, and then the tape is run in the forward direction.
A magnetic recording / reproducing apparatus, which starts recording after detecting a control signal of a tee ratio. 4. A magnetic recording / reproducing apparatus according to claim 3, wherein said control signal of said first duty ratio is written after detecting the control signal of said second duty ratio. Playback device.