JPH0614286A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To remarkably prolong the recording time by performing recording and reproduction while keeping the clear picture. CONSTITUTION:A video selection circuit 6 selects an n-field of video signal for each m-field of video signal from an input video signal. The recording with the conventional track width can be performed by reducing the information amount and concurrently recording two magnetic heads 11a and 11b with dissimilar azimuths at the speed of n/m of the normal speed. At the time of reproduction, the recorded n-field video signal is reproduced several times by a video storage circuit 7. The consecutive video signals are taken out and the recording time can be remarkably prolonged while keeping the clear picture without deteriorating the reproduction output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has the same recording track width as the conventional one by intermittently selecting an input video signal in field units, reducing the amount of information, and recording / reproducing at a speed slower than a normal speed. The present invention relates to a magnetic recording / reproducing device for performing recording / reproducing for a long time.

[0002]

2. Description of the Related Art In recent years, not only terrestrial television broadcasting but also satellite broadcasting using broadcasting satellites and communication satellites has increased,
Information sources for consumer video tape recorders are ever increasing. Increasing the number of information sources accelerates the recording time, and it is strongly desired to record for a long time with one magnetic tape.

A conventional magnetic recording / reproducing apparatus will be described below. FIG. 3 is a block diagram of a conventional magnetic recording / reproducing apparatus. In FIG. 3, 1 is a capstan motor for running the magnetic tape 10, 2 is a rotary drum in which two magnetic heads 11a and 11b having different azimuth angles are fixed at 180 degree intervals, and 3 is a capstan motor 1 and a rotary drum. Reference numeral 4 is a control circuit for controlling rotation, 4 is a signal processing circuit for converting an externally input video signal, and 5 is a controller for controlling the control circuit 3 and the signal processing circuit 4.

The operation of the magnetic recording / reproducing apparatus configured as described above will be described below. The rotating drum 2 is fixed to the magnetic tape 10 with a predetermined inclination, and the magnetic tape 10 is wound about 180 degrees.
The controller 5 sends a signal instructing each mode such as recording and reproduction to the control circuit 3 and the signal processing circuit 4. Based on this command signal, the control circuit 3 controls the capstan motor 1 so that the magnetic tape 10 runs at a constant speed, and controls the rotating drum 2 to rotate at a constant speed. By the rotation of the rotary drum 2 and the running of the magnetic tape 10, recording tracks having a predetermined inclination with respect to the magnetic tape 10 are alternately formed at different azimuth angles. On the other hand, as the video signal to be recorded, standards such as the NTSC system and the PAL system have been determined, and one picture is divided into two pictures by an interlace method in which every other scanning line is skipped. It Each picture after being divided into two corresponds to one field,
One picture before being divided corresponds to one frame. For example, in the NTSC system, a video signal of 60 fields is sent per second, and in the VHS standard, this one field corresponds to one track on the magnetic tape.

In order to lengthen the recording time of the above magnetic recording / reproducing apparatus, the recording track width is set to standard recording (track width 58
The magnetic tape speed is 11.3 which is 1/3 of standard recording (33.35 mm / s).
By setting it to 2 mm / s, it has been possible to achieve a time length that is three times that of standard recording.

[0006]

However, in order to further increase the recording time by using such a conventional magnetic recording / reproducing apparatus, the recording track width is set to be three times as large as the recording track width (track width 19 μm). , Must be narrower. However, if the track width is made narrower than this, the reproduction output is lowered and a clear image cannot be obtained, and it is difficult to increase the recording time more than 3 times recording while maintaining the clear image. .

The present invention has been made in view of the above problems of the conventional magnetic recording / reproducing apparatus. In order to lengthen the recording time, the magnetic tape is run at a speed slower than the normal speed and the input video signal is inputted. Is selected intermittently in units of fields to reduce the amount of information and record with the same track width as before,
By playing the recorded video signal multiple times during playback and outputting continuous video signals, clear video can be obtained without lowering the playback output, and the recording time is further extended than before. It is an object of the present invention to provide a magnetic recording / reproducing device capable of achieving the above.

[0008]

In order to solve the above-mentioned problems, n video image signals of m fields are input from the input video signal.
Video selection means for extracting the video signal of the field, storage means for storing the video signal selected by the video selection means, and normal speed m for recording all input video signals.
A traveling means for traveling the magnetic tape at a speed of n minutes and 2
Recorded n-field video signals were reproduced a plurality of times from two magnetic heads having different azimuth angles which simultaneously scan over a recording track and a magnetic tape running at a speed of n / m. It has a configuration including a reproducing means for outputting a video signal.

[0009]

According to the present invention, with the above-described structure, at the time of recording, the video selecting means intermittently selects the video signal of the n fields to be recorded among the input video signals of the m fields, and records the number of fields to be recorded per unit time, that is, the recording. Number of tracks is m
Reduce to n minutes. At this time, when the magnetic tape is run at a speed of n / m of the normal speed by the running means, the number of tracks recorded on a fixed length of the magnetic tape is the same as when all input video signals were recorded at the normal speed. And the width of the recording track is the same as during normal recording. Further, since the recording tracks having different azimuth angles are simultaneously formed by the image storage means and the two magnetic heads having different azimuth angles, it becomes possible to perform azimuth recording in which different azimuths are alternately formed as in the conventional case. Next, when reproducing at a speed n / m of the normal speed, the reproducing means reproduces the recorded n-field video signal as it is, and the video selecting means discards the video signal (mn). By reproducing the recorded video signal of n fields a plurality of times during the field period, the video signal can be continuously output. Since the recording track width at this time is the same as the conventional one, a clear image can be obtained without lowering the reproduction output, and the recording time can be lengthened.

[0010]

(Embodiment 1) A magnetic recording / reproducing apparatus according to a first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention. In the present embodiment, the same parts as those in the above-mentioned conventional example are designated by the same reference numerals, and detailed description thereof will be omitted. In the figure, 6 is a video selection circuit for extracting a video signal of one field for every video signal of two fields from the input video signal. The magnetic head 11a is a magnetic head having a track width of 19 μm and an R azimuth angle, and the magnetic head 11b is a magnetic head having a track width of 19 μm and an L azimuth angle. Further, the heights of the magnetic heads 11a and 11d are adjusted so that two adjacent recording tracks having a track width of 19 μm are simultaneously scanned. Reference numeral 7 stores the video signal output from the video selection circuit 6 at the time of recording, and at the time of reproduction, the magnetic head 1
A video storage circuit 5 for storing the video signals reproduced by 1a and 11b is a controller for controlling the control circuit 3, the signal processing circuit 4, the video selection circuit 6, and the video storage circuit 7.

The operation of the magnetic recording / reproducing apparatus having the above-described structure at the time of 6 times recording, which is twice the conventional 3 times recording, will be described. The controller 5 sends a signal instructing the 6 × recording mode to the control circuit 3, the signal processing circuit 4, the image selection means 6, and the image storage circuit 7. Based on this command signal, the video signal input from the outside is extracted by the video selection circuit 6 from the video signal of one field for every video signal of two fields, and the first video signal is first stored in the video storage circuit 7.
Sent to and stored in. Next, the video selection means 6 discards the video signal of one field and then the second video of one field.
To the video storage circuit 7. The video storage circuit 7 does not store the video signal, but sends the second video signal as it is to the signal processing circuit 4 and simultaneously sends the stored first video signal to the signal processing circuit 4. The signal processing circuit 4 converts the first video signal and the second video signal into a form that is actually recorded on the magnetic tape 10, and the first video signal is transferred to the magnetic head 11a and the second video signal is transferred to the magnetic tape 11a.
Is sent to the magnetic head 11b. At this time, the magnetic tape 10 is half the speed of the conventional triple recording (11.12 mm / s) by the capstan motor 1.
It is traveling at 56 mm / s. Magnetic heads 11a and 11b
Have their head heights adjusted so that two adjacent recording tracks are simultaneously scanned, and the first video signal is recorded on a recording track having R azimuth with a track width of 19 μm on the magnetic tape 10. , L azimuth, the second video signal is recorded on the recording track.

By repeating the above operation, two recording tracks having different azimuth angles are simultaneously formed in four fields, that is, in 4/60 seconds. On the other hand, the magnetic tape 10 is running at half the speed of the conventional triple recording, and the moving amount of the magnetic tape 10 during this time is 0.37 mm.
Therefore, the moving amount of the magnetic tape 10 when recording two tracks in the conventional triple recording becomes equal to that of the conventional triple recording, and the recording tracks having the azimuth angles different from each other by R and L are alternately arranged. It is formed.

Next, the operation during reproduction will be described. According to the above-described recording operation, recording tracks having R and L azimuth angles are alternately formed on the magnetic tape 10. The speed of the magnetic tape 10 is controlled by the capstan motor 1 so that it runs at 5.56 mm / s, which is the same as when recording.
Magnetic head 1 every 4 fields or 4/60 seconds
The phase control of the capstan motor 1 and the rotary drum 2 is performed so that 1a traces a recording track of R azimuth angle. The head heights of the magnetic heads 11a and 11b are adjusted so that two adjacent recording tracks are simultaneously scanned, and at the same time as the magnetic head 11a, the magnetic head 11b traces a recording track having an L azimuth angle. It will be. The first video signal reproduced by the magnetic head 11a and the second video signal reproduced by the magnetic head 11b.
The video signal is sent to the signal processing circuit 4, converted, and then sent to the video storage circuit 7. The video storage circuit 7 is the first
The video signal and the second video signal are stored, the first video signal is output twice, and then the second video signal is output twice. Four
While outputting the field video signal, that is, 4/60
The magnetic tape 10 moves 0.37 mm per second, which is equal to the moving amount of two tracks at the time of conventional triple recording, and the next two recording tracks can be reproduced in the same manner.

By repeating the above operation, the video signal of one recording track can be continuously output twice, and the video signal can be continuously output and reproduced with the same recording track width as the conventional one. A clear image can be obtained without lowering the reproduction output, and the recording time can be increased to 6 times that of the conventional recording (2 times that of 3 times recording).
In addition, since 30 pictures are reproduced per second in the recording and reproduction, a smooth moving image can be reproduced without jerking.

In the above embodiment, the video signal of one field is selected for every two fields, but one video signal is selected for every two frames.
The same effect can be obtained by selecting the video signal of the frame, and the recording time can be further lengthened by increasing m in the selected m field.

(Embodiment 2) A magnetic recording / reproducing apparatus according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of a magnetic recording / reproducing apparatus according to a second embodiment of the present invention. In the present embodiment, the same parts as those in the above-mentioned conventional example are designated by the same reference numerals, and detailed description thereof will be omitted. In the figure, 6 is a video selection circuit for extracting a 1-field video signal for every 2-field video signal from the input video signal signal, and 12a and 12b are movable heads having different azimuth angles fixed to the tips of the bimorph elements, and recording tracks. It is a movable head that can move in a direction orthogonal to. The track widths of the movable heads 12a and 12b are 19 μm for conventional triple recording, the movable head 12a has a R azimuth angle, and the movable head 12b has L.
It is a movable head with an azimuth angle. Reference numeral 7 is a video storage circuit for storing the video signal output from the video selection circuit 6 during recording, and for storing the video signal reproduced by the magnetic heads 12a and 12b during reproduction, and 5 is a control circuit 3 and a signal processing circuit. 4 is a controller for controlling the image selection circuit 6 and the image storage circuit 7.

The operation of the magnetic recording / reproducing apparatus having the above-described structure at the time of 6 times recording, which is twice the conventional 3 times recording, will be described. The controller 5 sends a signal instructing the 6 × recording mode to the control circuit 3, the signal processing circuit 4, the image selection means 6, and the image storage circuit 7. Based on this command signal, the video signal input from the outside is extracted by the video selection circuit 6 from the video signal of one field for every video signal of two fields, and the first video signal of the first field selected first.
Is sent to the video storage circuit 7 and stored therein. The stored first video signal is delayed by a time corresponding to one field, then sent to the signal processing circuit 4, converted into a form actually recorded on the magnetic tape 10, sent to the movable head 12a, The first video signal is recorded on the tape 10 as a recording track of R azimuth. Next, the video selection circuit 6 selects the second video signal of one field and sends it to the video storage circuit 7. The video storage circuit 7 does not store the video signal and sends the second video signal to the signal processing circuit 4 as it is. The signal processing circuit 4 converts the second video signal into a form actually recorded on the magnetic tape 10 and sends it to the movable head 12b. At this time, the magnetic tape 10 is moved by the capstan motor 1 to
Since it is running at 5.56 mm / s, which is half the speed of double recording (11.12 mm / s), the amount of movement of the magnetic tape 10 in one field, that is, 1/60 seconds, is 0.093.
mm, which is half that of conventional 3x recording. When the movable head 12a and the movable head 12b have the same height, the recording track formed by the movable head 12a and the recording track formed by the movable head 12b overlap each other by about 9.5 μm. The position is corrected in advance by about 9.5 μm so that the recording track formed by the movable head 12a and the recording track formed by the movable head 12b do not overlap each other.
Image signal is recorded as a recording track of L azimuth. After that, the video selection means 6 discards the video signal of one field.

By repeating the above operation, two recording tracks having azimuth angles different in R and L with the same track width as in the conventional triple recording are formed in four fields, that is, in 4/60 seconds. .

Next, the operation during reproduction will be described. According to the above-described recording operation, recording tracks having R and L azimuth angles are alternately formed on the magnetic tape 10. The speed of the magnetic tape 10 is controlled by the capstan motor 1 so that it runs at the same speed of 3.71 mm / s as when recording, and when the movable heads 12a and 12b are in the initial position, the magnetic tape 10 is moved every four fields. The phase is controlled by the capstan motor 1 and the rotating drum 2 so that the head 12a traces a recording track of R azimuth angle and the movable head 12b traces a recording track of L azimuth angle. At the time of recording, only one field is recorded for every two fields, so that if the same recording track is continuously reproduced twice for each field, the video signal is continuously output. . First, the movable head 12a
Is in the initial position and traces and reproduces a recording track having R azimuth. The first video signal reproduced by the movable head 12a is sent to the signal processing circuit 4, converted, and then sent to the video storage circuit 7. The video storage circuit 7 stores the first video signal and outputs the first video signal twice. On the other hand, after the movable head 12a traces and reproduces a recording track having R azimuth, the movable head 12b moves to L
Although the recording track having azimuth is traced, when the movable head 12b is in the initial position, the trace is shifted by about 9.5 μm from the center of the recording track having L azimuth. Correct only 9.5 μm so that the recording track having L azimuth is completely traced. The second video signal reproduced by the movable head 12b is sent to the signal processing circuit 4, converted, and then sent to the video storage circuit 7. The video storage circuit 7 stores the second video signal, and after outputting the first video signal twice, outputs the second video signal twice.

By repeating the above operation, the video signal of one recording track can be continuously output twice, and the video signal can be continuously output and reproduced with the same recording track width as the conventional one. A clear image can be obtained without lowering the reproduction output, and the recording time can be increased to 6 times that of the conventional recording (2 times that of 3 times recording).
In addition, since 30 pictures are reproduced per second in the recording and reproduction, a smooth moving image can be reproduced without jerking.

In the above embodiment, the video signal of one field is selected for every two fields, but one video signal is selected for every two frames.
The same effect can be obtained by selecting the video signal of the frame, and the recording time can be further lengthened by increasing m in the selected m field. Further, although the bimorph element is used as the moving means of the movable head, the same effect can be obtained by correcting the off-track of the movable head with respect to the magnetic tape by using a moving means such as a moving magnet type actuator or a moving coil type actuator. be able to.

[0024]

As described above, according to the present invention, during recording,
The video selecting means intermittently selects the video signals of the n fields to be recorded among the input video signals of the m fields, and reduces the number of fields to be recorded per unit time, that is, the number of tracks to be recorded, to n for m, and the traveling means. Thus, when the magnetic tape is run at a speed of n / m of the normal speed, the number of tracks recorded on a fixed length of the magnetic tape becomes the same as when all input video signals were recorded at the normal speed. The width of the recording track can be made the same as that during normal recording. Further, since the recording tracks having different azimuth angles are simultaneously formed by the image storage means and the two magnetic heads having different azimuth angles, it becomes possible to perform azimuth recording in which different azimuths are alternately formed as in the conventional case. Next, when reproducing at a speed n / m of the normal speed, the reproducing means reproduces the recorded n-field video signal as it is, and the video selecting means discards the video signal (mn).
By reproducing the recorded video signal of n fields a plurality of times during the field period, the video signal can be continuously output. Since the recording track width at this time is the same as the conventional one, a clear image can be obtained without lowering the reproduction output, and the recording time can be lengthened. In addition, when recording and reproducing 6 times,
Since 30 pictures are reproduced per second, it can be reproduced as a smooth moving image without jerking.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 1 Capstan Motor 2 Rotating Drum 3 Control Circuit 4 Signal Processing Circuit 5 Controller 6 Video Selection Circuit 7 Video Storage Circuit 10 Magnetic Tape 11a, 11b, 12a, 12b Magnetic Head

Claims (2)

[Claims] 1. An image selection unit for extracting an n-field image signal for each m-field image signal from an input image signal, a storage unit for storing the image signal selected by the image selection unit, and all input image signals. A traveling means for traveling the magnetic tape at a speed of n / m of a normal speed for recording the data, two magnetic heads having different azimuth angles for simultaneously scanning two recording tracks, and the speed of the n / m. A magnetic recording / reproducing apparatus comprising: a reproducing unit that reproduces a recorded n-field video signal a plurality of times from a magnetic tape running on the tape and outputs a continuous video signal. 2. An image selection unit for extracting an n-field image signal for each m-field image signal from an input image signal, a storage unit for storing the image signal selected by the image selection unit, and all input image signals. A traveling means for traveling the magnetic tape at a speed of n / m of a normal speed for recording, a movable head movable in a direction orthogonal to the recording track, and a magnetic tape traveling at a speed of the n / m, A magnetic recording / reproducing apparatus comprising: a reproducing unit that reproduces a recorded n-field video signal a plurality of times and outputs a continuous video signal.