JPS5812489A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a fade-in and a fade-out by providing auxiliary heads at positions several field to behind of main rotary heads, and performing recording through the main heads after mixing the reproduced signals of the auxiliary heads with a prescribed video signal. CONSTITUTION:Auxiliary heads A' and B' are positioned on recording tracks 2n fields to behind of main rotary heads A and B. While an overlap switch is closed, upon turning off the trigger switch of a camera or turning on the pause switch of a VTR, stops a run of and recording to a tape. After screen inversion is held in readiness, upon triggering the camera, switches the heads A and B to the recording sides and the heads A' and B' to the reproduction states. The reproduced signals of the heads A' and B' are mixed by a mixer with a recording signal passed through an input signal and a switch, and the resulting signals are recorded by the heads A and B. A fade-out effect is obtained by a black level video signal and a fade-in effect is obtained by a white level video signal; and the heads A' and B' are usable for monitoring.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating head type magnetic recording and reproducing apparatus (hereinafter referred to as a VTR) that provides special reproduction effects. In recent years, the use of home VTRs has become extremely widespread.■ Small VTRs and small color cameras are increasingly being used to create home movies, etc., and not just to record broadcasts.

We would also like to have a VTR that allows for effective scene changes in a simple manner by overlapping the previous and subsequent scenes at the scene change, giving the previous scene a 7-aid out, and the subsequent scene a fade in. Strong voice. Nevertheless, in order to perform this type of technique conventionally, two ICs as shown in Figure 1 + 7) VTR (VTRI, V
TR2) or one camera and one VTR (V
By mixing the reproduced video signals from the VTR (TRI) in the mixer 100 and changing the mixing ratio, an overlap part is created when changing the scene, and
) was used. In this case, not only do you need a VTR or camera that can be externally synchronized to synchronize and drive two VTRs or a camera and a VTR, but it is also necessary for general users to use the above method to synchronize and drive two VTRs or a camera and a VTR. 1m is required, and the device has the drawback of causing large flames and being expensive. It was impossible to achieve such special effects.

The present application has been made in view of this background, and its purpose is to provide a magnetic recording and reproducing device that can easily obtain the above-mentioned special effects with a single VTR with an extremely simple configuration. This is what I did.

In order to achieve such an object, the present invention provides an auxiliary head at a position several fields apart from the rotating main head, and combines the signal reproduced by the nuclear auxiliary head with a predetermined video signal. After mixing, I-recording is performed on the recording medium via the rotating main head.

This makes it easy to gradually darken or brighten the screen, or gradually switch to another screen.゛Hereinafter, the present invention will be explained based on examples.

Figures 2, 3, and 4 show the positional relationship between the rotating main head and the auxiliary head of the present invention in a two-head helical scan type VT.
The case of R is shown below.

In the conventional two-head helical scan type VTR,
As shown in FIG. 3, a magnetic tape T is wound diagonally at an angle of just over 180 degrees around a cylindrical tape guide drum (hereinafter referred to as a drum) 1, and the magnetic tape is run on the opposite side 18 inside the drum.
Rotary magnetic heads A and H provided on the magnetic tape 00 sequentially form odd fields and even fields as one track diagonally on the magnetic tape.

The situation is shown in Figure 2. In FIG. 2, odd field tracks recorded by the human head are indicated by OT, and even field tracks recorded by the B head are indicated by ET.

In the second illustrated embodiment, a pair of heads A and B provided on opposite sides of the drum in a conventional two-head helical scan type VTR are used as rotating main heads, and two heads, B' However, the present invention is not limited to a helical scan type, and may be one that scans in the width direction of the tape. Also, the number of heads is not limited to two.

In the second illustrated embodiment, the auxiliary heads, B', are located on tracks exactly 2n fields (n being an integer) behind the main heads, A and B, respectively. Figure 2 shows the case where n=1, and the main heads A and B are now located at the end and start of writing of tracks OT1 and ETI, respectively, and the auxiliary heads A' and B' are respectively located at the main head. A, H
, the position delayed by two fields, that is, the main head A
, B are arranged so that they come to the end and start positions of the tracks OTO and ETO that have already been recorded.

Therefore, if main head A;-(B) is in the m-th horizontal scanning period of a certain field, then auxiliary head A'
(B') is located in the m-th horizontal scanning period 2n fields before.

The present invention reproduces a signal already recorded on a magnetic tape (hereinafter referred to as a pre-recorded signal) using the auxiliary head, and combines the reproduced signal by the auxiliary head with a signal to be newly recorded (hereinafter referred to as a post-recorded signal). By sequentially recording the mixed signals with the main head, the ratio between the pre-recorded signal and the post-recorded signal is gradually changed, causing the pre-recorded signal to fade out and the post-recorded signal to fade in. .

Similarly, in the second illustrated embodiment, the auxiliary head is placed at a position delayed by 2n fields from the main head, but by doing so, it is possible to mix signals without using a special delay circuit. It is something.

In other words, it is sufficient that the auxiliary head is configured to have several hooks with respect to the main head and trace the track.
In that case, the auxiliary head output and the post-recording signal may be mixed after passing through a suitable delay means.

FIG. 5 is a main block diagram showing an embodiment of a control circuit for a VTR according to the present invention. 2 is a video signal input terminal, 3 is a synchronization separation circuit, blocks 4 to 9 are drum servo systems, 13 to 17
Fi Kyagustan servo system, 18-20 is recording system, 36
A, 36B, 37-39 are main head regeneration systems, 29A
, 29, 30-32 are auxiliary head reproduction systems, 21-28t
j Overlap control system, SWI to SW4. SW7. S
W8 is a switch linked to switching between recording and reproducing modes, and each P contact indicates the reproducing mode, and the R41 point indicates the recording mode.

SW5, 5W-6, SW9, and 5WIO are switches that are linked to switching between the special mode and the normal mode according to the present invention. These switches SW5. Contact a of SW9 is for normal mode, and contact s is for special mode.

Next, the fifth. The operation will be explained based on FIG.

When the recorded video signal is applied to the input terminal 2, it is synchronously separated by the synchronous separator 3, the signal is detected at K1/2, and is sent to the flip-flop circuit 7 via the block 6 composed of two monomultis. is triggered to generate a 30 Hz rectangular wave synchronized with the rotational phase of the rotary head 9. The rectangular wave is shaped into a trapezoidal wave by the travelzoid 8, and the trapezoidal wave and the Eirin signal are synchronously separated and frequency-divided into 172. A phase comparator 4 compares the phase with the detected signal to obtain an error voltage corresponding to the phase error. By applying this voltage to the drum motor drive amplifier 9, the rotational phase of the rotary head is synchronized with the vertical synchronization signal of the recording signal.

Also, at the time of this recording, it is synchronized and separated from the Eirin signal.
1 frame IEKCTL using a signal frequency divided by /2
(Control > No. 8 is sweet.

The data is recorded on one end of the tape by the CTL head CTLH via the R terminal of the chip swi.

On the other hand, in the Nakayapstan control system, during recording, a signal ($0 Hz) synchronously separated from the Eirin signal is applied to the phase comparator 13 via the switch SW4. Also, capsuta 7
The frequency detected by the head 15 which detects the frequency according to the rotational speed of 140 Hz is divided into 30 Hz by the divider 16, and is input to the phase comparator 13 via the switch 5W21. Furthermore, the phase is compared with a 30 Hz signal obtained by synchronously separating the Eirin signal, and the error voltage is applied to the capstan motor drive amplifier 17 to drive the capstan motor CM to run the magnetic tape Tt at a constant speed. .

On the other hand, the video signal input from the input terminal 2 is in the normal recording mode via the expansion switch SW5, gain-controlled to a constant level by the miniature circuit 18, and then input to the FM modulator 19.
The signal is FM modulated by the recording amplifier 20, and amplified by the recording amplifier 20.
It is applied to the 9 main heads A and B through the switch 8W7.8 and recorded on the tape.

Next, following the above-mentioned nine sickle motions, the structure and operation for performing a scene change using special modes such as overlap according to the present invention will be explained.

Overlap switch, swi, that is closed when
When shooting with a camera, turn on the trigger switch.
In the case of a VTR, this is a switch that is closed when a pause switch or the like is released. 21° and 22 are switches 5W respectively.
11 is an AND gate, 25 is a first one-shot circuit, and 26 is a high-level signal outputted from the one-shot circuit 25. Capstan motor reverse drive control circuit 27 for running the tape in reverse only while
28 is a second one-shot circuit, and 28 is a third one-shot circuit.

Since it is configured like this, the overlap switch 5
When the trigger switch is turned off (or the pause switch is turned on) with the WIO closed in advance, the switch 5W11 is turned off, thereby causing the pulse generator 21 to output a high level signal.

Therefore, the output of the AND gate 23 is also at a high level 9, so that the first one-shot circuit 25 outputs a high level signal for a predetermined period of time. During this predetermined period of time, the tape is rewound by the motor reverse rotation drive control circuit. Also, while the output of the one-shot circuit 25 is at H level, the switches SW1 to S
W4゜SW7. SW8 and the like are configured to switch from recording mode (R) to playback mode (P).

Alternatively, the configuration is such that the power to the heads A and B is cut off. This prevents the previously recorded signal from being erased while the tape is running in reverse.

Further, in conjunction with the fall of the output of the one-shot circuit 25, a pinch roller (not shown) is released, and the VTR is placed in a temporary stop mode.

In addition, the output time of the H level signal of the one-shot circuit 25 is determined by the resistor 126 so that in addition to the rise time of the reproducing servo system when the tape runs in reverse as described later, the position at which the previously recorded signal is reproduced by several fields is advanced. The settings are automatically or manually set in advance.

Oka, in the special mode according to the present invention, as in this embodiment -
There is no need to rewind the H tape.

That is, since the auxiliary head is tracing several tracks in front of the main head, it is difficult to trigger off the camera or VT.
Screen switching in the present invention is possible by simply stopping tape running and recording by turning on the R button.

Now, with the screen change preparation completed in this way, if you apply the post-recording signal that should follow the above-mentioned pre-recording signal to input terminal 2 and trigger the camera (or turn off the pause switch of the VTR), The switch 5W11 is turned on, and the pulse generator 22 outputs a high level signal.

Therefore, a high level signal is output from the AND gate 24, and the second one-shot circuit 27Fi outputs a high level signal for a predetermined period of time.

While this one-shot circuit 27 is outputting a high level signal, the switch SW3. The other control systems except SW4 are configured to be in regeneration mode. Therefore, the rotary head rotates in phase synchronization with the signal synchronously separated from the post-recorded signal, and the capstan servo system is synchronously separated from the post-recorded signal &30Hz and the reproduced CTL signal reproduced by the CTL head are output to the phase comparator 13. The output error voltage is used to drive the capstan motor via the capstan drive amplifier 17. Further, after the high level signal from the one-shot circuit 27 is output, the pinch roller pinches and presses the tape against the capstan.

In this way, the time constant of the one-shot circuit 27 is set so that the capstan and drum servo threads rise within the output period of the one-shot circuit 27, and the main heads A and B trace the previous recording signal track again. shall be.

Further, when the one-shot circuit 27 falls, an output is generated at the output end of the third one-shot circuit 28 for a certain period of time. Depending on the rise of this output, the remaining switches SWI, S
W2. SW7. SW8! At the same time as switching to the N recording mode, the switch SW5 is switched to the b side only during the output period of the third one-shot circuit 28, and the switch 5W6 is switched to the b side.
Fi is closed.

Therefore, at this time, the main heads A and B are switched to the recording side, while the auxiliary heads A' and B' are switched to the recording side, respectively.
The signal 2n fields before is reproduced for B. The reproduction signals from the auxiliary heads A' and B' are sent to the preamplifier 29.
A' and B' are alternately switched and reproduced by the output signal of the lip-flop 7. Further, after passing through a switching circuit 30 and making odd and even fields into a continuous signal, the signal is demodulated by a demodulator 31 and input to a mixer 33 via a switch SWG. The mixer 33 feeds the pre-recorded signal reproduced by B' and the post-recorded signal input via the input terminal switch SWs to the auxiliary head mentioned above, and outputs the mixed signal onto the tape by the main head B. Record.

Now, if Hml is assumed and the mixing ratio t-1 of the mixing 1i33 is 1, then at the time of output of the timing switch circuit 28, the output of the output amplifier 32 and the post-recording signal are mixed at a ratio of 1:1. Magnetic chi 45 is recorded on B. Furthermore, when recording the next frame by the main heads A and H, the ratio of the pre-recording signal and the post-recording signal distributed from the main heads A and BK to the auxiliary head before the output File frame by B' is 1:1: 1, the proportion of the previous signal in the output signal of the mixer 33 is low.In this way, after m frames, the above ratio becomes the same and the previous signal gradually attenuates.

Further, if the mixing ratio of the mixer 33 is set to p:1 between the front signal and the rear signal, the ratio of the key recording sickle signal in the recorded signal after m frames will be -''-1.

2'' (P+1) Therefore, it is possible to control the 7 aid-in and 7 aid-out times in the overlap section simply by adjusting the mixing ratio of the mixer.

That is, the larger the value of P mentioned above, the more gradual the fade-in and fade-out will be, and the longer the overlap period will be. Further, the value of p is adjusted by the volume 34. Further, due to the fall of the output of the timing switch circuit 28, SW6 is opened and SW 5 Fi
a Set to @.

The falling point of the timing switch circuit 28 is preferably immediately after the prerecorded signal has attenuated to some extent, and is configured to be linked to the volume 34 so that an optimum time constant can be set according to the auto-lap period.

In FIG. 5, 36A and B are preamplifiers for the main heads A and B, 37 is a reproduction switching circuit, 38 is a demodulator, and 3
Reference numeral 9 indicates an output amplifier, and 40 indicates an output terminal during normal reproduction.

Also, as is clear from the explanation so far, during normal recording the SW
It is also possible to monitor the signal actually recorded on the tape by outputting the a terminal of 9.

In the embodiment described above, there was one reproduction circuit for the main head and one for the auxiliary head, but these can be used for both the preamplifiers 36A and 36B.

Regeneration switching circuit 37. Demodulator 38. Output amplifier 3
Each pull of 9 is 29A and 29B respectively.

(To) 30.31.32 can be substituted.

In that case, the inputs to the 29A and 29B may be switched from the auxiliary head B+ to the main heads A and B during reproduction.

Further, in the above embodiment, it is assumed that a normal video signal is used as the post-recording signal, but if the image quality is a constant brightness, such as a black level video signal, a fade-out effect can be effectively produced. Furthermore, if both sides are used, such as a white level video signal, a fade-in effect can be easily obtained. In these cases, the above effects can be achieved with just one VTR or camera by providing a signal generator that generates such a reference signal.
You can get it with Alternatively, it is also possible to cut or amplify only the luminance component of the video signal input from the video signal input terminal before inputting it to the mixer, or by closing or fully opening the aperture on the camera side. A similar effect can be obtained. Further, at this time, if the aperture control and the operation of the one-shot circuits 27, 28, etc. are linked, the operation will be simplified.

As described above, according to the present invention, overlap recording is easily possible with one ball, and the overlap period can be adjusted with a simple configuration, and its operation is also extremely easy. This has the advantage that, in addition, during normal recording, it is also possible to monitor the first recorded signal using the auxiliary head.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the prior art, FIG. 2 is a diagram showing an embodiment of the head tracing relationship in the magnetic recording/reproducing apparatus of the present invention, and FIGS. 3 and 4 are diagrams showing the main head and the auxiliary head. Figure 3 is a view from above, Figure 4 is a view from an oblique direction, Figure @5 is a diagram showing an example of the control circuit, and Figures 6 and 6 are timing relationships. FIG. A, B... Rotating main head, A', B'... Auxiliary head, 4, 5.6.7.8.9... Drum servo system, 1
λ14, 1 to 1 to 17, ... capstan servo system,
33...Hexar, 18. IQ, 2O-8e record system, 36A, 36B, 37.3a39. -4 Head playback system, 29A, 29B, 30.31.32...Auxiliary head playback system, 5W10...Special effect switch, 5
w1l...Switch linked to trigger or pause switch. Patent applicant: Canon Co., Ltd. KAI SEFF agent: Gi Marushima-1. , -addition,, -= m- of the chisel 81 翫EEIC-5ab:11-

Claims (1)

[Scope of Claims] (1) @Reproduction output from an auxiliary head provided at a position several fields apart from the reincarnation head and a predetermined optical signal are mixed and recorded via the rotating main head. A magnetic recording/reproducing device characterized in that it is configured to be capable of recording on a medium. (ri) The magnetic recording/reproducing device according to claim (1), characterized in that the video signal # is of constant brightness. (S) The # video signal is a white level video signal. A magnetic recording and reproducing device according to claim (2), characterized in that: -) a magnetic recording and reproducing device according to claim (2), characterized in that the video signal is a black level video signal; Device. (5) The magnetic recording and reproducing apparatus according to claim (1), characterized in that the recording signal is an external input signal. (6) The magnetic recording and reproducing apparatus according to claim (1), which has a mode in which the auxiliary head is used for monitoring.