JPH06217257A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide the magnetic recording and reproducing device which can accurately record and reproduce a video auxiliary signal even if the video auxiliary signal is present at a rotary head switching point. CONSTITUTION:A video signal is inputted to a synchronizing signal separating means 2 and a head switching position detecting means 3 detects the rotary head switching position from the output of the means 2. With the output of the detecting means 3, a video signal which becomes absent owing to head switching is stored in a storage means 4. With the output of the synchronizing signal separating means 2, an auxiliary signal recording position detecting means 5 detects a position where the video auxiliary signal which is stored in the storage means 4 and becomes absent should be recorded and a signal to be recorded is switched by a switch 6 between a signal inputted from an input terminal 1 and the signal stored in the storage means 4 and recorded on a magnetic tape 9. This recorded signal is reproduced through a magnetic head 8, an auxiliary signal recording position detecting means 12 detects the position where the video auxiliary signal is recorded, and a switch 14 switches the output of a reproducing process means 10 and the output of a signal delay means 13 and outputs the signal from an output terminal 15.

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 (hereinafter referred to as VTR) for recording / reproducing a video signal having a higher definition than that of a current television system.

[0002]

2. Description of the Related Art In recent years, compared with current television systems,
A broadcasting system has been proposed that realizes a high-definition and wide screen by transmitting horizontal and vertical high-frequency components (for example, EDII broadcasting system video signal).

FIG. 4A shows an example of a transmission method of a video signal of a broadcasting system which realizes a high definition and wide screen.
This shows the transmission method of the video auxiliary signal when transmitted by the letterbox method. A high frequency component for increasing the vertical resolution is transmitted to a portion corresponding to 60 lines above and below the horizontal line, and a high frequency component for increasing the horizontal resolution is multiplexed at the center portion of 360 lines where the video signal is transmitted. Transmitted. In the upper and lower 60 video auxiliary signals, signals for making the 360 video signals high definition are compressed and recorded in 1/3. Therefore, one video auxiliary signal can convert three video signals into a high-definition video. When this signal is received by the current type receiver (referred to as receiver 1), the upper and lower 6
The 0 part has no image, and the image appears only in the center 360 parts. When received by a receiver dedicated to this broadcasting system (referred to as receiver 2), as shown in FIG. 4B, the aspect ratio is 16: 9 and the width is wide. You can see the optimized video.

In a VTR which records and reproduces a video signal of such a high definition broadcasting system, it is necessary to accurately record and reproduce the video auxiliary signal. For example, if a high-definition video signal is transmitted in NTSC mode, one field has 262.5H (horizontal line).
(A) 30 video auxiliary signals, 180 video signals, 30 video auxiliary signals, and 21 vertical sync signals and 21 signals inserted in the vertical blanking period, for a total of 261. Therefore, the number of horizontal lines that must be recorded in one field is 261 from the beginning of the field, the first 21H (where H is the horizontal scanning period) is a signal related to vertical synchronization, and the next 30H is a video auxiliary signal. Next 18
0H is a video signal, and the next 30H is a video auxiliary signal.

FIG. 5 shows the relationship between the head switching signal and the horizontal line of the video signal when the video signal is recorded on the VTR. As shown in the figure, assuming that the rotary head switching position is 7H before the vertical synchronizing signal as in VHS-VTR, the rising edge of the head switching signal is the end of 258H of the previous field.

[0006]

However, 258
Since the video auxiliary signal is to be recorded at H, if the rotary head is switched, it becomes impossible to accurately record and reproduce, and there is a problem that it is not possible to achieve high definition using the video auxiliary signal. It was

In view of the above problems, it is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of accurately recording / reproducing an image auxiliary signal even if the image auxiliary signal exists at the rotary head switching point.

[0008]

In order to solve the above-mentioned problems, the magnetic recording / reproducing apparatus of the present invention is a vertical recording method in which a video auxiliary signal of a high-definition video present at a rotary head switching point is not transmitted by the video signal. It is characterized in that the video auxiliary signal recorded during the line period and returned during reproduction is returned to the original position and output as a normal high-definition video signal.

[0009]

According to the present invention, since the video auxiliary signal of the high definition video signal can be recorded / reproduced without being lost by the above-mentioned structure, a high definition video can be obtained by using the video auxiliary signal. it can.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

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

In FIG. 1, reference numeral 1 is a video signal input terminal, and the video signal input from the video signal input terminal 1 is the first
Is input to the synchronizing signal separating means 2 and the head switching position detecting means 3 detects the rotary head switching position by the output of the first synchronizing signal separating means 2. By the output of the head switching position detecting means 3, the video signal which is missing due to the head switching is stored in the storage means 4. Further, the output of the first synchronizing signal separating means 2 causes the first auxiliary signal recording position detecting means 5 to detect the position where the missing video auxiliary signal stored in the storing means 4 should be recorded, and the first switch. By means of the means 6, the signal to be recorded is switched between the signal inputted from the video signal input terminal 1 and the signal stored in the storage means 4 and inputted to the recording processing means 7, and the magnetic tape 9 is passed through the magnetic head 8. To record.

The signal recorded on the magnetic tape 9 is reproduced via the magnetic head 8 and input to the reproduction processing means 10 to be output as a video signal. The reproduced video signal is input to the second sync signal separation means 11 and the signal delay means 13. The second auxiliary signal recording position detecting means 12 detects the position where the video auxiliary signal is recorded by the output of the second synchronizing signal separating means 11, and the second switching means 14 outputs the reproduction processing means 10. And the output of the signal delay means 13 is switched to output as a reproduced video signal from the video signal output terminal 15.

FIG. 2 is a diagram for explaining a recording operation of a video auxiliary signal which is lost due to head switching. a is an input video signal, and b is a head switching signal. Reference numeral c is a video auxiliary signal output from the storage means 4, and each number represents the number of horizontal lines to be transmitted. The head switching signal is 7H before the 4Hth which is the vertical synchronizing pulse of the video signal a, and is 2 in the previous field.
It is around 58H and 259H. Therefore, the video auxiliary signals of 258H and 259H are lost due to the head switching.

Of the vertical blanking intervals 1H to 21H, the 9th H is used as an equivalent pulse and a vertical synchronizing pulse, and 14H to 21H is used for character multiplexing and cannot be used. Therefore, 10H
Since up to 13H is a section which is not used for a video signal, it is possible to transfer the video auxiliary signal which is lost due to head switching to this section and record it.

The operation of the magnetic recording / reproducing apparatus configured as described above will be described below with reference to FIGS. 1 and 2.

First, in FIG. 1, the vertical synchronizing signal and the horizontal synchronizing signal are separated from the video signal input from the video signal input terminal 1 by the first synchronizing signal separating means 2. In addition,
The first synchronizing signal separating means 2 may be a well-known one used in a receiver or the like.

Based on the vertical synchronizing signal and the horizontal synchronizing signal separated by the first synchronizing signal separating means 2, the head switching position detecting means 3 detects the position where the rotary head switches. For example, by detecting the vertical synchronizing signal and then counting the number of horizontal synchronizing signals, it is possible to detect that the head switches 7H before the vertical synchronizing signal. Due to the output of the head switching position detection means 3, the missing video signal is stored in the storage means 4. Here, 2
The 58H and 259H video auxiliary signals are stored in the storage means 4.

Next, the first auxiliary signal recording position detecting means 5
By the same operation as the head switching position detecting means 3,
The position where the video auxiliary signal stored in the storage means 4 should be recorded is detected. For example, as shown in FIG.
The video auxiliary signal of 9H is applied to the next field of 10H and 11H.
When moving to and recording, the first auxiliary signal recording position detecting means 5 counts the number of horizontal synchronizing signals after detecting the vertical synchronizing signal, so that the 10th and 11th horizontal lines to be recorded are recorded. Can be detected.

The first switch means 6 is normally connected to the video signal input terminal 1 side, and is connected to the storage means 4 side by the output of the first auxiliary signal recording position detecting means 5.
The time connected to the storage means 4 is the time during which the video auxiliary signal is stored in the storage means 4, and is 2H in this embodiment. The signal from the first switch means 6 is recorded on the magnetic tape 9 by the magnetic head 8 after being subjected to processing such as modulation by the recording processing means 7. That is, 258H, 2
The video auxiliary signal of 59H is delayed by 14H and recorded in the next field of 10H and 11H.

As described above, at the time of recording, the portion where the video auxiliary signal is lost due to the head switching is moved to the vertical blanking section and is recorded, so that the recording can be performed without the loss.

Next, the operation during reproduction will be described. FIG. 3 is a diagram for explaining a reproducing operation from a magnetic tape recorded by moving a video auxiliary signal that is missing due to head switching to a vertical blanking interval, and a is a time point when the recorded signal is reproduced. , B is a head switching signal, c is a signal output from the signal delay means 13,
Each number represents the number of horizontal lines transmitted.

The video auxiliary signal at the head switching point is shown in FIG.
Thus, since the video signal is recorded with a delay of 14H, the video auxiliary signal delayed during recording can be returned to its original position by delaying the video signal by 14H during reproduction.

The operation will be described below with reference to FIGS. 1 and 3. First, in FIG. 1, the video signal recorded on the magnetic tape 9 is reproduced by the magnetic head 8, and the reproduction processing means 10 is used.
A video signal is obtained by performing a reproduction process with.
The second auxiliary signal recording position detecting means 12 records the video auxiliary signal by using the signal obtained by separating the obtained video signal into the vertical synchronizing signal and the horizontal synchronizing signal by the second synchronizing signal separating means 11. Detect the position. The position of the video auxiliary signal can be detected by counting the horizontal synchronizing signal from the vertical synchronizing signal.

Since the signal delay means 13 constantly delays the reproduced video signal by 14H, when the second auxiliary signal recording position detecting means 12 detects the position of the video auxiliary signal, the second switch means 14 causes the video signal output terminal. The connection to 15 is switched from the signal delay means 13 to the output of the reproduction processing means 10. Therefore, since the reproduced video auxiliary signal can be brought to the position 14H before, the video auxiliary signal can be returned to the original position.

In FIG. 3A, the positions of the video auxiliary signals recorded at the 10th and 11th positions are the positions of 258H and 259H of the reproduced signal delayed by 14H in FIG. By switching the output by the second switch means 14, the video auxiliary signal recorded with a delay of 14H can be set to the position of the normal video auxiliary signal.

The second switch means 14 is connected to the normal signal delay means 13 side, and is connected to the reproduction processing means 10 side by the output of the second auxiliary signal recording position detecting means 12. The connection time is the time stored in the storage means 4 at the time of recording, and is 2H in this embodiment.

As described above, during recording, the portion where the video auxiliary signal is lost due to head switching is moved to the vertical retrace line section, and the recorded video auxiliary signal is returned to the normal position for output and output. It is possible to record and reproduce a high-definition video signal in which the auxiliary signal is not lost.

In this embodiment, since the first synchronizing signal separating means 2 and the second synchronizing signal separating means 11 have the same function, one can be used for time division if they are not used at the same time. . First auxiliary signal recording position detecting means 5,
The same applies to the second auxiliary signal recording position detecting means 12. The storage unit 4 may have a function of delaying the video signal input from the video signal input terminal 1 for a predetermined time, like the signal delay unit 13.

[0030]

As described above, according to the present invention, the video auxiliary signal missing due to head switching is stored in the storage means during recording, moved to the vertical blanking interval and recorded, and reproduced during reproduction. Since the video auxiliary signal can be returned to the normal position by delaying the recorded video signal by the time moved during recording, it is possible to record and reproduce without missing the video auxiliary signal by switching the head, and it is possible to achieve high definition. Recording and playback of video signals is possible.

[Brief description of drawings]

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

FIG. 2 is a diagram for explaining a recording operation of the magnetic recording / reproducing apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining a reproducing operation of the magnetic recording / reproducing apparatus in the embodiment of the present invention.

FIG. 4 is a diagram for explaining a transmission method of a high definition video signal.

FIG. 5 is a diagram for explaining the operation of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 video signal input terminal 2 first synchronizing signal separating means 3 head switching position detecting means 4 storage means 5 first auxiliary signal recording position detecting means 6 first switch means 7 recording processing means 8 magnetic head 9 magnetic tape 10 reproduction Processing means 11 Second synchronization signal separation means 12 Second auxiliary signal recording position detection means 13 Signal delay means 14 Second switch means 15 Video signal output terminal

Claims (1)

[Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing a high-definition video signal transmitted in a letterbox format on a magnetic tape by a rotary head system, wherein a video auxiliary of the high-definition video signal at a head switching position. A signal is recorded in a section where the high definition video signal is not transmitted, and at the time of reproduction, the video auxiliary signal recorded in the section where the high definition video signal is not transmitted is returned to its original position to obtain a normal high definition. A magnetic recording / reproducing device characterized by outputting as a video signal.