JPS63106901A - Rotating head type magnetic recording/reproducing device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a so-called insert function that inserts and records a new video signal of desired content into a part of the area on a magnetic tape where a video signal has already been recorded. The present invention relates to a rotary head type magnetic recording/reproducing device.

[Conventional technology]

Conventional rotary head type magnetic recording and reproducing devices with insert function are known, for example, from Corona Publishing Co., Ltd., October 15, 1981, co-authored by Katsuya Yokoyama and two others [Home VTR Introduction JP,
194, when insert recording is performed, the video signal (hereinafter referred to as old video signal) recorded on a desired area track (hereinafter referred to as old track) of the recorded video tracks on the magnetic tape is used. ) with a rotating erase head and record a new video signal (hereinafter referred to as new video signal) in the erased portion as a new track (hereinafter referred to as new track), or
Most of the old video signal recorded in the desired area on the magnetic tape where you want to record the new video signal is erased using a fixed full-width erase head, and the new video signal is recorded on this erased area and a few less erased areas before and after it. (At the last erased portion, a new video signal is recorded as a new track that overlaps the old track).

In such a conventional rotary head type magnetic recording/reproducing device,
If scene B is inserted in the middle of scene A, the second
As shown in the figure, a part of the old track in which the scene person is recorded disappears, and a new track in which the trap scene B is recorded is formed in its place.

FIG. 5 is a block diagram showing an example of a conventional rotary head type magnetic recording/reproducing device having such an insert function, in which 1 is a magnetic tape, 2.5 is a video head, 4 is a cylinder, 5 is a cylinder motor, 6.7 is a magnet, 8 is a video head position detector, 9 is a cylinder control circuit, 10
11 is a drive circuit, 11 is a control signal detector, 12 is a capstan, 15 is a capstan motor, 14 is an engineering drive circuit, 15 is a capstan control circuit, 16 is an input terminal for a new video signal, 17 is a synchronous separation circuit, 18 is a frequency dividing circuit.

In the figure, it is assumed that a video signal (old video signal) has already been recorded on a magnetic tape 1 by video heads 2 and 3. If you are currently in playback mode,
The drive circuit 14 drives the capstan motor 15, which rotates the capstan 12 to drive the magnetic tape 1, and the drive circuit 10 drives the cylinder motor 5, which causes the magnetic tape to be mounted on the rotating cylinder 4. The video heads 2 and 5 alternately reproduce and scan the magnetic tape 1. At this time, in the capstan control circuit 15, a control signal detected by the control signal detector 11 from the magnetic tape 1 and a reference signal from a reference oscillator (not shown) are phase-compared to form a control signal. By being supplied to the drive circuit 14, the rotational phase of the capstan motor 15 is controlled so that the control signal and the reference signal have a predetermined phase relationship.

On the other hand, in the cylinder control circuit 9, the reference signal from the reference oscillator supplied to the control circuit 9 and the pulse signal Pu output from the video head position detector 8 (rotated integrally with the cylinder motor 5) are used in the cylinder control circuit 9. The signal is output at the point when the magnet 6,7 crosses the detector 8, indicating the point at which the video heads 2, 5 start scanning the magnetic tape 1.) is compared in phase to form a control signal. By being supplied to the circuit 10, the rotational phase of the cylinder motor 5 is controlled so that the pulse signal PM and the reference signal have a predetermined phase relationship.

Through the above operations, the video heads 2, 5tX,) are sequentially reproduced and scanned alternately over the recording video tracks on the magnetic tape 1 under racking control (K).

When an insert recording operation is performed at a desired time in such a playback state, a new video signal is input from the input terminal 16, the vertical synchronization signal is separated by the synchronization separation circuit 17, and the phase is added to the new video signal from the frequency division circuit 18. Synchronized 50H2
A reference signal Pb is obtained. This reference signal Phts is supplied to the capstan control circuit 15, and its phase is compared with the control signal from the control signal detector 11 to form a phase control signal, thereby controlling the rotational phase of the capstan motor 15. Ru. The reference signal Pb is also supplied to the cylinder control circuit 9 and compared in phase with the pulse signal PH from the video head position detector 8 to form a phase control signal K, which controls the rotational phase of the cylinder motor 5. be done.

As a result, the video heads 2 and 5 alternately operate the magnetic tape 1 during each field period of a new video signal from the input terminal 16.
is rotated and scanned, and the scanning locus of the video head 2.5 coincides with the old track K on the magnetic tape 1. After stabilizing in this state, the video heads 2 and 5 have the following:
A new video signal is supplied from a recording circuit (not shown), and recording thereof is started. .

In this case, it goes without saying that the above-described rotating erase head or fixed full-width erase head starts the erase operation at a predetermined timing.

In this way, insert recording of a new video signal is performed in the manner shown in FIG.

Note that in order to finish recording the new video signal, a stop operation, a playback operation, or the like may be performed.

Further, in FIG. 6, speed control of the cylinder motor 5 and capstan motor 15 is omitted.

[Problem that the invention seeks to solve]

By the way, there are some TV programs recorded on magnetic tape or desired scenes captured by a video camera that the user would like to save. It is desirable to record at the same time - 1゜Titles, etc. may be recorded in advance before recording the TV program or scene with a video camera, but there are also cases where the title, etc. is recorded after this is recorded. , In such a case, it is necessary to record an insert such as this title.

In this case, the video signal of the TV program or the scene captured by the video camera is the old video signal, and the video signal of the title etc. is the new video signal, but in the conventional insert recording method described above, it is not possible to insert the title etc. As a result, some tracks on which old video signals were recorded will be erased. Usually, the title etc. is inserted at the beginning of the recorded scene, but
There are cases where the recorded content of that part is very important, and in such cases there is a problem in inserting a title or the like.

An object of the present invention is to solve such problems and to record a new video signal by inserting it into a desired part of the recording area of the old video signal on a magnetic tape, leaving the old video signal and recording it in combination with the new video signal. An object of the present invention is to provide a rotary head type magnetic recording/reproducing device that can perform the following operations.

[Means for solving problems]

In order to achieve the above object, the present invention provides a first . In addition to the second video head, a fifth video head is arranged to rotationally scan the video track that the first video head rotationally scans with a predetermined time delay behind the first video head; A fourth video head is provided so as to rotate and scan the video track that the first video head rotationally scans, with a delay of the predetermined time from the second video head. A delay means for delaying the video signal (old video signal) sequentially reproduced from the second video head by the predetermined time, and the output video signal from the delay means and the newly recorded video signal (new video signal) are synthesized. Combining means is provided, and the output video signals from the combining means are sequentially superimposed.3. It is configured such that it can be supplied to the fourth video head for recording.

[For production]

In the present invention, each video track on a magnetic tape has a first
．． The second video head sequentially rotates and scans the image, and after a predetermined time delay, the third and fourth video heads sequentially and overlappingly scan the image.

Therefore, when performing insert recording, the old video signal recorded on the video track in the insert area is first recorded in the first. The second video head rotates and scans for reproduction, and after delaying this reproduction video signal by the predetermined time, it is combined with a new video signal and then supplied to the third and fourth video heads. By doing this, the old video signal can be combined with the new video signal and re-recorded on the original video track, so the old video signal will not be lost during insert recording.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of a rotary head type magnetic recording and reproducing apparatus according to the present invention, in which:
20 is a combiner, 21 is a signal processing circuit, 22 is a delay means,
24 is a modulation circuit, 25 and 26 are video heads, and other configurations are the same as the conventional example shown in FIG. 3, so corresponding components to those in FIG. Explanation will be omitted.

Now, in the embodiment shown in FIG. 1, as in the conventional example shown in FIG. Based on the 5oH1 reference signal Pb, which is separated by the frequency dividing circuit 18 and divided by the frequency dividing circuit 18, the rotational phase of the cylinder motor 5 is controlled by the cylinder control circuit 9, and the rotational phase of the capstan/motor 150 is controlled by the capstan control circuit 15. controlled. With such rotational phase control, video heads 2, 5, 25, 26
However, as was the case with the dislocation earlier, when it is synchronized with the new video signal from the input terminal 16 and rotates while tracing the video track (old track) already recorded on the magnetic tape 1. , video heads 2, 5 (first .
2nd video head) is in playback mode, video head 25
．． 26 (fifth and fourth video heads) are in recording mode. In this state, the video head 2.3 reproduces the old video signal recorded on the old track on the magnetic tape 1, and this reproduced old video signal is input to the signal processing circuit 21 and demodulated. After being subjected to predetermined signal processing, the signal is supplied to delay means 22 and delayed for a predetermined time. The delayed and played back old video signal is then processed in the synthesizer 20.
After being combined with the new video signal from the input terminal 16 and FM modulated by the modulation circuit 24, the video head 25.2
6K supplied.

Here, the video heads 25 and 26 respectively follow the video heads 2.5 and are placed on the cylinder 4 so as to trace the same old track traced by these heads 2.5 with a predetermined delay. It is located in (The details will be described later.) Therefore, for example, regarding the video head 25, the composite video signal supplied to the video head 25 is recorded over the old track traced by the video head 2. Fourth
The figure shows this situation. The video heads 2 and 25 advance in the direction of the arrow, trace the same old track at a time Δt behind the video head 25 (-video head 2, and
As shown by the line, a new track is formed by overwriting the composite video signal on the old track. video head 5 and 2
6 forms a new track in the same manner. In this case, the old video signal recorded on the old track is almost erased when the new track is superimposed, so there is no need to throw an erasing head, but in some cases, the video head 2 and 2 A suitable erasing head may be provided between the video heads 5 and 26 and between the video heads 5 and 26. Here, the composite video signal recorded on the new track is adjusted so that its time axis matches the trace timing of the video heads 25 and 26. That is, the cylinder motor 5 by the cylinder control circuit 9 explained in FIG.
The rotational phase control is to synchronize the rotational phase of the video head 25, 26 with the new video signal input from the terminal 16. As a result, the time axis of the new video signal included in the composite video signal is , the trace timings of the video heads 25 and 26 match.At this time, the old video signal played back by the video heads 2 and 5 is delayed by the time difference At shown in FIG. The axis is advanced relative to the time axis of the new video signal, but this difference in time axis is caused by the delay means 22 in FIG.
This problem can be solved by setting the delay amount of the reproduced old video signal equal to the above-mentioned time difference Δt. Then, the reproduced old video signal and the new video signal whose time axes coincide with each other are sent to a synthesizer 20.
The signals are combined into a composite video signal, which is recorded on a new track by the video head 25, 2611C. As a result, the recording phase of the composite video signal on the new track is no different from the recording phase of the old video signal on the old track. Therefore, no phase discontinuity occurs in the recorded video signal at the scanning boundary between the old track and the new track, and no screen disturbance occurs at the scanning boundary during reproduction.

The above-described recording operation of the composite video signal continues for the desired insert mode setting period, and as a result, the old track (shown without diagonal lines) and the new track ( ) is formed, and when this new track portion is played back, the scene with the new video signal will be displayed overlapping with the scene with the old video signal, and as with conventional insert recording, the old video signal The scene never disappears. In addition, in order to be able to selectively display such an overlap between a scene based on the old video signal and a scene based on the new video signal, and display only the scene based on the new video signal, the synthesizer shown in FIG. It goes without saying that the old video signal added to 20 may be cut off as necessary.

Next, video heads 2 and 25. The arrangement of the video heads 5 and 26 on the cylinder 4 will be explained with reference to FIG.

FIG. 6 α) is a view of the arrangement of the video heads viewed from directly above the cylinder 4, and FIG. 4) is a view from the side of the cylinder 4. As is clear from Fig. 6 α), K.

The video heads 2 and 5 are arranged at an angular interval of 180 degrees on the cylinder 4, and the video heads 25 and 26 are at an angle θrat from the video heads 2 and 3, respectively, when viewed in the rotational direction indicated by the arrow of the cylinder 4. It is placed in a position that follows behind. Further, as shown in FIG. 6 (4), the video heads 2 and 25 are arranged with a step of cLmm in the axial direction of the cylinder 4. As described above, this step is necessary to enable the video heads 2 and 25 to trace the same track. In the diagram,
Although video heads 5 and 26 are not shown, their arrangement is the same as that of video heads 2 and 25 (
Since they are similar, the necessary conditions for the step d will be explained below using the video heads 2 and 25 as an example.

Now, the rotational angular velocity of cylinder 4 in the arrow direction ωraφ
-C, video heads 2 and 25 are also the same (ωraφ
- They will rotate with a rotational angular velocity of C, but these are
Since there is a rotational phase difference of θracL due to the above-mentioned arrangement position relationship, if the delay time of rotational scanning of the video head 25 with respect to the video head 2 is tθ, then 10=θ/ω(#=c).

Further, if the running speed of the magnetic tape 1 in the arrow direction shown in FIG. 6 α) is 1〆iac, then the video head 25
The distance X that the magnetic tape 1 travels during the delay time tθ of the 0-rotation scan is as follows: x=v, tθ=V-(deception). Here, the axial direction of the cylinder 4 is inclined at a predetermined angle with respect to the running direction of the magnetic tape 10, as is well known. Therefore, let this inclination angle be φ.When the magnetic tape 1 travels by the above-mentioned distance 5, the video head 25
The conditions for the step d necessary for tracing on the same track as the video head 2 are: d: Jc, φ=Vθ. , 4φ/−(−).

Next, a specific example of the synthesizer 20 in the embodiment of FIG. 1 will be described.

FIG. 7 is a circuit diagram showing a first specific example of the synthesizer 20, in which 51 and 52 are resistors, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In this example, the new video signal from the input terminal 16 and the old video signal from the delay means 22 are summed by resistors 51 and 52 to be combined.

FIG. 8 is a block diagram showing a second specific example of the synthesizer 20, in which 55 is a comparator, 54 is a switch, 55.
56 is a power supply, and parts corresponding to those in FIG. 1 are given the same reference numerals.

In FIG. 8, the new video signal from input terminal 16 is applied to comparator 15 and compared with a reference voltage from voltage source 55. In FIG. Now, assuming that the new video signal is a character signal representing a title, etc., this signal is a pulse signal having a 1H" level and @l, s levels corresponding to the character pattern, and the level of the reference voltage is as follows. The level is set at an appropriate level between the @H" level and @L" level of the extremely slow signal. Therefore, the comparator 55 outputs "H" at the "H" portion of the new video signal. A signal that becomes °L° is output at the part ". The switch 54c is controlled by the output signal of the comparator 35 so that it is switched to the contact bi111 when the output signal of the comparator 55 is @H1l, and to the contact α side when the output signal of the comparator 55 is °L''. be done.

On the other hand, the old video signal is supplied from the delay means 22 to the contact a side of the switch 54, and a constant voltage signal is supplied from the voltage source 36 to the contact side of the switch 34.

Therefore, the output signal of the synthesizer 2o output from the switch 54 is the old video signal from the delay means 22 when the output signal of the comparator 55 is "L", and the output signal of the synthesizer 2o output from the switch 54 is the old video signal from the delay means 22 when the output signal of the comparator 55 is "1H". are constant voltage signals from the voltage source 56, and these output signals are sequentially supplied to the modulation circuit 24 in FIG.

In this manner, the old video signal from the delay means 22 is replaced with a constant voltage signal from the voltage source 56 during a period when the level of the new video signal from the input terminal 16 becomes H# in response to a character pattern, etc. Ru. Therefore, such a synthesizer 20
When using kl, a desired pattern such as a title is inserted into the scene of the old video signal and displayed on the playback screen.

In this specific example, a voltage source 56 that outputs a constant voltage is connected to the contact side of the switch 54, but instead of this, a character generator or the like that generates a signal that selectively represents an arbitrary color may be connected. By doing this, it is also possible to display the inserted title etc. in any color.

The embodiments of the present invention have been described above, and the delay means 22 in the embodiments may be a delay element such as a CCD or a glass delay line, or a semiconductor capable of inputting and outputting simultaneously, such as a dealbort memory. A memory or the like can be used as appropriate.

Furthermore, in the above embodiments, the new video signal to be inserted recorded is mainly described as a character signal representing a title, etc. However, it goes without saying that the new video signal is not limited to this and any video signal can be used as the new video signal. Nor.

〔Effect of the invention〕

According to the present invention, in a rotary head type magnetic recording and reproducing device, when insert recording a new video signal on a recorded magnetic tape, the old video signal recorded in the insert area is once reproduced and combined with the new video signal. Since the old video signal can be re-recorded later, the old video signal will not be lost even if insert recording is performed, and during playback, the scene with the new video signal can be displayed overlapping the scene with the old video signal. can.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a track pattern by conventional insert recording, FIG. 5 is a block diagram showing a conventional example for performing insert recording, and FIG. 1 is a diagram for explaining the trace timing of the video head in the embodiment of FIG. 1, FIG. 5 is a diagram showing a track pattern when insert recording is performed according to the embodiment of FIG. 1, and FIG. 7 and 8 are diagrams showing examples of the arrangement of video heads in the embodiment shown in the figure.
Each figure shows a specific example of the synthesizer in the embodiment of FIG. 1. DESCRIPTION OF SYMBOLS 1... Magnetic tape, 2, 5, 25. 26... Video head, 20... Synthesizer, 22... Delay means. No. 11 4-・Sirin 2 t, 7-・Mac “net 12°°” 22nd story 30th 4th mouth 52nd 60 2-etsu’711! 1st story 80

Claims (1)

[Claims] 1. In a rotary head type magnetic recording and reproducing device in which a pair of first and second video heads alternately rotate and scan a magnetic tape to record and reproduce video signals, the first video head rotates and scans the video signal. a third video head arranged to rotationally scan the track with a predetermined time delay behind the first video head; a fourth video head arranged to rotate and scan with a delay of the predetermined time; a delay means for delaying the video signals sequentially reproduced from the first and second video heads by the predetermined time; composition means for combining the output video signal of the video signal with the video signal to be newly recorded, and the output video signal from the composition means can be sequentially supplied to the third and fourth video heads for recording. A rotary head type magnetic recording/reproducing device characterized by the following configuration.