JPH0722725Y2 - Recording / playback mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a recording / reproducing mechanism such as a video tape recorder.

(Prior Art) A video tape recorder (VTR) is widely used as an apparatus for recording and reproducing image and audio information using a magnetic tape.

In a VTR, in general, a magnetic tape is wrapped around a rotating drum equipped with a rotary recording / reproducing head and a rotary erasing head (flying erase head), and the rotary recording / reproducing head performs oblique scanning (helical scan) to display information such as images. Is being recorded and played.

On this magnetic tape, not only image information but also voice information and control information are recorded.

FIG. 4 shows a track configuration diagram of the magnetic tape used in the VTR.

In the figure, the magnetic tape 1 is roughly provided with three tracks.

First, at the upper end of the magnetic tape 1, an audio track 2 on which audio information is recorded is provided along the longitudinal direction. Next, an image track 3 on which image information is mainly recorded is provided in the middle portion of the magnetic tape 1. Finally, at the lower end of the magnetic tape 1, a control track 4 on which control information is recorded is provided.

Audio information is recorded on the audio track 2 in parallel with the running direction 5 (longitudinal direction) of the magnetic tape 1 by an audio head (not shown). In image track 3,
Image information is mainly recorded in the direction of arrow 6 by a rotary head (not shown). Further, high-fidelity audio (also referred to as high-fidelity audio information) may be recorded in the deep-layer portion of the image track 3 by the deep-layer recording method. Finally, on the control track 4, control information for controlling the traveling speed of the magnetic tape 1 to be constant by a control head (not shown) is written.

In order to record / reproduce information on each of these tracks, a recording / reproducing mechanism including several magnetic heads arranged on the traveling path of the magnetic tape 1 is used.

FIG. 5 and FIG. 6 show configuration diagrams of a conventional recording / reproducing mechanism.

FIG. 5 is a block diagram of the recording / reproducing mechanism when viewed from the back surface of the magnetic tape 1, and FIG. 6 is a block diagram of the recording / reproducing mechanism showing the running of the magnetic tape 1.

In the figure, this recording / reproducing mechanism comprises a rotary head 7 arranged on a rotary drum 22, a full erase head 8 and an audio control head 9.

The rotating drum 22 shown in FIG. 6 has a flying erase head 7a and an image recording / reproducing head 7b (rotating recording / reproducing head 7b) for scanning the tracks 3a on the image track 3 shown in FIG. 5 one by one. ) And a pair are provided. Flying erase head 7a is track 3a of image track 3
It is a magnetic head that erases each one. The rotary recording / reproducing head 7b is a magnetic head for recording / reproducing the tracks 3a one by one.

The full erase head 8 includes an audio track 2, an image track 3 and a control track 4 on the magnetic tape 1.
Is a magnetic head for erasing at once.

The audio control head 9 is provided with an audio erasing head 10 for erasing the audio track 2, an audio recording / reproducing head 11 (audio head 11) for recording / reproducing, and a control head 12 for recording / reproducing the control track 4. There is.

By the recording / reproducing mechanism having the above-described configuration, reproduction (reproduction operation) and recording (recording operation) of the magnetic tape 1 are performed.

First, the case of performing the reproducing operation will be described.

When performing the reproducing operation, in FIG. 5, the magnetic tape 1 is run in the direction of arrow 13 and the rotary head 7 is rotated in the direction of arrow 14. At the same time, the rotary recording / playback head 7b, the audio head 11, and the control head 12 are played back. As a result, the rotary recording / reproducing head 7b moves in the direction
The magnetic tape 1 is scanned in the direction, that is, along the track 3a, and the image information is reproduced. The audio head 11 and the control head 12 scan the magnetic tape 1 in the direction of the arrow 13, that is, along the audio track 2 and the control track 4, respectively, and reproduce the audio information and the control information, respectively. In this way, the magnetic tape 1 can be reproduced.

Next, the case of performing the recording operation will be described.

Similar to the reproducing operation, the magnetic tape 1 is run in the direction of arrow 13 and the rotary head 7 is rotated in the direction of arrow 14. at the same time,
The full erase head 8 and the flying erase head 7a are operated. Further, the rotary recording / reproducing head 7b, the audio head 11, and the control head 12 are caused to perform a recording operation.

Regarding the recording operation of the audio track 2, first, after erasing by the full erase head 8 and the audio erasing head 10, the audio information is recorded by the audio head 11.

Regarding the recording operation of the image track 3, after erasing by the flying erase head 7a and the full erase head 8, image information is recorded by the rotary recording / reproducing head 7b.

Regarding the recording operation of the control track 4, after erasing with the full erase head 8,
Record the control information by 12.

Now, when the recording operation is performed by the conventional recording / reproducing mechanism as described above, the flying erase head 7a is operated for a predetermined time (actually, the surface of the magnetic tape 1 erased by the full erase head 8 is the flying erase head). After the track 3a is erased, the erase operation is stopped. This is because it is not necessary to re-erase the portion erased by the full erase head 8.

Therefore, after the operation of the flying erase head 7a is stopped, the image track 3 is erased by the full erase head 8 until the recording operation is completed.

(Problems to be Solved by the Invention) By the way, there is a case where so-called re-recording is performed in which new image information is recorded on the image track 3 on which image information is already recorded, by using the recording / reproducing mechanism having the above-described configuration. is there.

When this re-recording is performed, the operation is the same as the normal recording, so at the start of the recording operation, the flying erase head 7a erases it along the track 3a, and then recording by the rotary recording / reproducing head 7b is performed. . Therefore, the already recorded image information and the newly recorded image information are well connected seamlessly.

However, as explained earlier, the flying erase head
7a stops its operation after a predetermined time,
3a is erased exclusively by the full erase head 8. As a result, at the end of recording, if the running of the magnetic tape 1 in the direction of arrow 13 is stopped, a non-recorded portion 1a is mainly formed between the rotary recording / reproducing head 7b and the full erase head 8. This is because even if the data is erased by the full erase head 8, nothing is recorded until it reaches the rotary recording / reproducing head 7b. The image track 3 portion (broken line 15 in the figure) near the full erase head 8 at the end of recording is
A normal track 3a is not formed, and a track 3b in which a part of the track is missing is formed.

At the beginning of the recording operation, the flying erase head
In order to drive the 7a and the full erase head 8 at the same time, a large amount of circuit current is required and a large capacity power source must be secured.

Further, focusing on the control track 4, since the control track 4 is only erased by the full erase head 8, the full erase head 8 can be erased at the start of recording.
From the position of to the position of the control head 12, new control information is recorded while the previously recorded control information is not erased. For this reason, the previously recorded control information is not sufficiently erased, which may disturb the running control of the magnetic tape 1.

The present invention has been made in view of the above points, and an object thereof is to provide a recording / reproducing mechanism that does not cause image distortion when re-recording and does not require a full erase head. is there.

(Means for Solving the Problems) A recording / reproducing mechanism of the present invention includes an audio recording head for recording audio information, a control head for recording control information, and a recording head mounted on a rotary drum for recording image information and hi-fi audio information. In a recording / reproducing mechanism provided with, a rotation erasing head dedicated to erasing the image information and hi-fi sound information provided on the rotating drum so as to precede the recording head in the rotation direction of the rotating drum. An audio erasing head dedicated to erasing the audio information prior to recording the audio information of the audio recording head; and a control erasing head dedicated to erasing the control information prior to recording the control information of the control head. It is characterized by having.

(Operation) In the recording / reproducing mechanism of the present invention, an audio erasing head for erasing audio tracks, a flying erase head for erasing image tracks, and a control erasing head for erasing control tracks are provided exclusively for each track. Since the erasure is performed, the non-recorded portion and the disorder of the image do not occur even when the re-recording is performed.

(Embodiment) FIG. 1 is a block diagram of a recording / reproducing mechanism of the present invention.

The figure is a block diagram of the recording / reproducing mechanism when viewed from the back surface of the magnetic tape 1.

In the figure, this recording / reproducing mechanism is composed of a rotary head 7 and an audio control head 16.

The rotating drum 22 is provided with a flying erase head 7a for scanning the tracks 3a of the image track 3 one by one and an image recording / reproducing head 7b (rotating recording / reproducing head 7b). Flying Erase Head 7a, Image Track 3
This is a magnetic head that erases each of the tracks 3a. The rotary recording / reproducing head 7b is a magnetic head for recording / reproducing the tracks 3a one by one.

The magnetic head includes a video signal head for recording and reproducing image information on the track 3a of the image track 3 as described above, and a high-fidelity audio head for deeply recording and reproducing high-fidelity audio information on the deep layer of the track 3a. And shall be included.

The audio control head 16 includes an audio erasing head 17 for erasing the audio track 2 and an audio recording / reproducing head 18 (audio head 18) for recording / reproducing, and a control erasing head 19 and recording / reproducing for erasing the control track 4. A control head 20 for performing is provided.

With the recording / reproducing mechanism having the above-described configuration, reproduction (reproducing operation) and recording (recording operation) of the magnetic tape 1 can be performed.

The recording / reproducing mechanism of the present invention described with reference to FIG. 1 performs the same reproducing operation as the conventional recording / reproducing mechanism described with reference to FIG. That is, the rotary recording / reproducing head 7b, the audio head 18, and the control head 20 are reproduced.

Next, a case where the recording / reproducing mechanism of the present invention performs a recording operation will be described.

Similar to the reproducing operation, the magnetic tape 1 is run in the direction of arrow 13 and the rotary head 7 is rotated in the direction of arrow 14. at the same time,
Flying erase head 7a and audio erase head
17 and the control erasing head 19 are operated. Furthermore, a rotating recording / reproducing head 7b, an audio head 18,
The control head 20 is operated for recording.

Regarding the recording operation of the audio track 2, first, after erasing by the audio erasing head 17, the audio information is recorded by the audio head 18.

Regarding the recording operation of the image track 3, after the erasing by the flying erase head 7a, the rotating recording / reproducing head 7b
The image information is recorded by.

Regarding the recording operation of the control track 4, after erasing by the control erasing head 19, control information is recorded by the control head 20.

As a result, each track on the magnetic tape 1 can be erased and recorded.

Here, the rotary head 7 has the same configuration as the rotary head 7 described in FIGS. 5 and 6. Further, the audio control head 16 is different from the audio control head 9 described in FIG. 5 in that a control erasing head 19 is added.

A more specific configuration of the control erasing head 19 will be described here.

Generally, the structure of the erasing head includes two types, one using direct current erasing for supplying a direct current to the magnetic head and the other using alternating current erasing for supplying an alternating current to the magnetic head.

In the case of DC erasing, there are advantages that the circuit current of the erasing circuit (control erasing head 19) is small and the circuit configuration is simple.

2 and 3 show circuit diagrams of the control erasing head.

FIG. 2 is a circuit diagram when DC erasing is performed.

In the figure, one end of the control erasing head 19 is a resistor
The power supply Vcc is connected via R1. The collector of the NPN transistor Q1 is connected to the other end of the control erasing head 19. A control signal is input to the base of the NPN transistor Q1 via a resistor R2, and the emitter is grounded.

In the circuit having the above configuration, when the control signal is input to the base of the NPN transistor Q1, the NPN transistor Q1 is turned on. Therefore, the control erase head 19
Becomes an operating state by the collector current of the NPN transistor Q1. This allows control track 4 (Fig. 1)
Can be erased.

Next, FIG. 3 is a circuit diagram when AC erasing is performed.

In the figure, an oscillator 21 is connected to one end of the control erasing head 19 and the other end is grounded. The collector of the PNP transistor Q2 is connected to the oscillator 21. PNP
The power supply Vcc is connected to the emitter of the transistor Q2, and P
A control signal is connected to the base of the NP transistor Q2 via a resistor R3.

In the circuit having the above configuration, when a control signal is input to the base of the PNP transistor Q2, the PNP transistor Q2 is turned on, and the oscillator 21 is operated by the collector current of the PNP transistor Q2. Therefore, the AC output of the oscillator 21 is input to the control erasing head 19 to be in an operating state. This allows control track 4
(FIG. 1) can be erased.

The flying erase head 7a can also be configured such that one flying erase head 7a erases a plurality of tracks 3a at the same time.

Comparing the device having the above configuration with the conventional device (FIG. 5), when focusing on the image track 3, the image information already recorded is erased only by the flying erase head 7a, and then the rotary recording / reproducing head 7b. The image to be re-recorded is recorded by. Therefore, a non-recorded portion does not occur on the image track 3. Also, the track 3a will not be chipped.

When attention is paid to the control track 4, the control information already recorded is erased only by the control erasing head 19, and then the control head 20 records new control information. Therefore, there is no portion where control information is overwritten, and the running control of the magnetic tape 1 is not disturbed.

When the upper end portion of the control erasing head 19 is made to slightly protrude from the control track 4 toward the image track 3 side, when re-recording is performed on the magnetic tape 1 recorded by another recording / reproducing mechanism in which the boundary position of the track varies. However, the remaining part of the control signal could not be erased and the magnetic tape 1
Driving control is not disturbed.

(Effect of the Invention) In the recording / reproducing mechanism of the present invention having the above-described configuration, the conventional full erase head is removed, and the flying erase head, the control erasing head, and the audio erasing head are used to record on the image track. It is possible to erase the video information and hi-fi audio information, the control information recorded on the control track, and the audio information recorded on the audio track individually and independently. There is an effect that the reproduced image and the hi-fi sound are not disturbed. Further, since the full erase head is removed, the structure of the recording / reproducing mechanism can be downsized, and the circuit current can be reduced by omitting the full erase head. Just prepare the current,
Also, since the power supply shared with other circuits can be used,
There is an effect that it is possible to reduce the size and weight of a device equipped with the recording / reproducing mechanism.

[Brief description of drawings]

FIG. 1 is a block diagram of a recording / reproducing mechanism of the present invention, FIGS. 2 and 3 are circuit diagrams of a control erasing head according to the present invention,
FIG. 4 is a track configuration diagram of the surface of the magnetic tape used in the VTR, FIG. 5 is a configuration diagram of a conventional recording / reproducing mechanism, and FIG. 6 is a configuration diagram of the recording / reproducing mechanism showing the running of the magnetic tape. 1 ... Magnetic tape, 2 ... Audio track, 3 ...
Image track, 4 ... Control track, 7a ... Flying erase head, 7b ... Rotation recording / playback head,
17 …… Audio erasing head, 18 …… Audio head, 19 …… Control erasing head, 20 …… Control head, 22 …… Rotating drum.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 62-162202 (JP, A) JP 59-16106 (JP, A) Actual development JP 54-23618 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A recording / reproducing mechanism provided with an audio recording head for recording audio information, a control head for recording control information, and a recording head mounted on a rotary drum for recording image information and hi-fi audio information. A rotation erasing head dedicated to erasing the image information and high-fidelity audio information provided on the rotating drum so as to precede the recording head in the direction of rotation of the drum, and prior to audio information recording by the audio recording head. A recording / reproducing mechanism comprising: an audio erasing head dedicated to erasing the voice information, and a control erasing head dedicated to erasing the control information prior to recording control information by the control head.