JPH04314280A - MUSE signal magnetic recording and reproducing device - Google Patents

Abstract

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

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a MUSE signal (Multiple S
ub-Nyquist Sampling Encodi
The present invention relates to a magnetic recording and reproducing device for recording and reproducing .ng signals).

0002

[Prior Art] The MUSE method is a band compression method developed by NHK (Japan Broadcasting Corporation) to transmit high-definition signals by satellite broadcasting.
Showa 62, Volume 39, No. 2, pp. It has been introduced as 18th to 53rd mag. This method performs offset subsampling to compress the baseband high-definition signal to 8.1 MHz, and is transmitted by a broadcasting satellite in the configuration shown in FIG. FIG. 8 is a sampling pattern showing the sampling phase of each field of the MUSE signal. As is clear from the figure, the sampling phase cycles in four fields.

FIG. 9 shows an example of the basic configuration of a MUSE decoder for restoring a MUSE signal to a high-definition baseband signal. The MUSE signal is input from an input terminal 1, converted into a digital signal by an A/D (analog/digital) conversion circuit 2, and sent to a control signal separation/detection circuit 3 and a de-emphasis circuit 4. In the control signal separation/detection circuit 3, Table 1 below
Various control signals (b1 to b32) in the MUSE signal as shown in Table 2 are detected, and the data processing method in the still image processing circuit 6 and the content of the output signal of the motion detection circuit 5 are controlled depending on the contents. It has become so. Furthermore, in the de-emphasis circuit 4, M
The USE signal is subjected to processing opposite to the emphasis processing performed during transmission, and is sent to the motion detection circuit 5, the still image processing circuit 6, and the moving image processing circuit 7.

In the motion detection circuit 5, the input MUSE
1st signal. (first) between frames and 2nd
．． By taking the difference between the (second) frames, a moving area of the image is detected and a motion signal is generated and sent to the mixing circuit 8. Furthermore, the still image processing circuit 6 uses four fields of signals, performs interframe interpolation, then performs interfield interpolation, and sends the still image signal to the mixing circuit 8. That is, the still image processing circuit 6 uses all four types of sample points shown in FIG. 4 to generate a still image signal. Further, the moving image processing circuit 7 performs only intra-field interpolation to generate a moving image signal, and sends it to the mixing circuit 8.

[0005] In the mixing circuit 8, the moving signal and still image signal are mixed or switched for each pixel according to the above-mentioned motion signal, and TCI (Time Compress) is generated.
ed Integration) is output to the decoder 9. In the TCI decoder 9, the line-sequential/time-division multiplexed luminance signal and color difference signal are TCI-decoded, and then converted into an analog signal in a D/A (digital/analog) conversion circuit 10, which is output from an output terminal 11. It is now possible to do so.

In the still image processing circuit 6, as mentioned above,
Since interpolation output is performed using all the sample points of the four fields and a still image signal is created, it is necessary to know the sampling phase of the sample points for interpolation processing. The data indicating this sampling phase is written in bits b9, b10, etc. shown in Table 1, so the contents are detected by the control signal separation/detection circuit 3, and the phase with respect to the previous frame and field is judged to be good. Now you can get a clear image.

[0007] Therefore, even when performing so-called variable-speed playback such as high-speed search, in which tracks on a medium are played back in a different order than when they were recorded, interpolation processing in the MUSE decoder is essential in order to obtain a good image. , it is necessary to read out a control signal corresponding to the video data.

However, regarding video data to be reproduced during variable speed reproduction, for example, the magnetic head arrangement shown in FIG. Considering the case where a video signal is divided into four channels and recorded and reproduced on the magnetic tape 17, the head trajectory and the envelope of the reproduced RF signal at double speed are as shown in FIG. In the figure, the +azimuth head 12 is set to No. 1
, - The azimuth head 13 is set to No. 2. Set the +azimuth head 14 to No. 3. - Set the azimuth head 15 to No. It is shown as 4. In addition, in the same figure, for example, 1-1 is the first channel of the first field, 3-2 is the second channel of the third field, and so on, and one field during double-speed playback is a sequence of two fields. It can be seen that it is composed of data. That is, during variable speed reproduction, one field of video itself is composed of data of a plurality of fields having different subsampling phases. Therefore, it is not possible to make the phase information of the control signal correspond to all video data, and as a result, M
The USE decoder performs incorrect interpolation processing, resulting in a significant deterioration of image quality.

In order to solve this problem, as disclosed in Japanese Patent Laid-Open No. 2-47981, the value of the control signal is changed to the value of the complete still image mode, the value of the complete still image mode, or Alternatively, a device that sets the value to a video mode has been previously proposed. That is, this device controls the motion information of the control signal according to the speed of variable speed playback, and in the case of relatively slow playback such as 2x speed or 4x speed, the complete still image mode is selected, For high-speed playback, the video mode is selected.

0010

[Problems to be Solved by the Invention] However, the conventional configuration described above does not solve the problem of incorrect interpolation processing being performed during variable speed playback, and also does not solve the problem of incorrect interpolation processing being performed during variable speed playback. The envelope of the RF signal that is generated is as shown in FIG. 11, and since there are many parts that cannot be demodulated, it contains a large amount of interpolated data. Therefore, there is a problem in that high quality images cannot be obtained during variable speed reproduction.

[0011]

[Means for solving the problem] MUS of the invention of claim 1
In order to solve the above-mentioned problem, the E signal magnetic recording and reproducing device is equipped with a movable head that can move in the width direction of a scanning track on a magnetic recording medium, and magnetically records and reproduces a MUSE signal that is a band-compressed high-definition signal. The following measures are taken in the magnetic recording/reproducing device.

That is, during variable speed playback, the movable head controls the position of the movable head in the track width direction in accordance with the variable speed playback speed so that one field during variable speed playback is composed of data of a single field. Position control means and MUS reproduced from a magnetic recording medium during variable speed reproduction
MUS the phase information of the control signal included in the E signal.
and control signal changing means for changing the phase information to correspond to the video data of the E signal.

In order to solve the above-mentioned problem, the magnetic recording and reproducing device for MUSE signals according to the invention of claim 2 is provided with a movable head movable in the width direction of a track to be scanned on a magnetic recording medium. Compressed MUS
In a magnetic recording and reproducing device that magnetically records and reproduces an E signal,
The following measures have been taken:

That is, during variable speed playback, the movable head controls the position of the movable head in the track width direction in accordance with the variable speed playback speed so that one field during variable speed playback is composed of data of a single field. Position control means and MUS reproduced from a magnetic recording medium during variable speed reproduction
MUS the phase information of the control signal included in the E signal.
The control signal changing means changes the phase information to correspond to the video data of the E signal, and sets the control signal to information such that the interpolation processing performed by the MUSE decoder is only intra-field interpolation.

In order to solve the above problem, the magnetic recording and reproducing device for MUSE signals according to the invention of claim 3 is provided with a movable head that is movable in the width direction of a track to be scanned on a magnetic recording medium, and is capable of transmitting high-definition signals in a band. Compressed MUS
In a magnetic recording and reproducing device that magnetically records and reproduces an E signal,
The following measures have been taken:

That is, during variable speed playback, the movable head controls the position of the movable head in the track width direction in accordance with the variable speed playback speed so that one field during variable speed playback is composed of data of a single field. a position control means, a storage means for storing a plurality of control signals each having phase information set therein and information such that the interpolation processing performed by the MUSE decoder is only intra-field interpolation, and variable speed reproduction. At times, control signal reading means is provided for reading out a control signal corresponding to the phase of the video data of the reproduced MUSE signal from the storage means based on the variable speed reproduction speed, and during variable speed reproduction, the control signal is read out from the magnetic recording medium. and control signal changing means for changing the control signal included in the MUSE signal into the control signal read out from the storage means by the control signal reading means.

[0017]

[Operation] According to the structure of claim 1, during variable speed regeneration,
The movable head is controlled by the movable head position control means to change the speed so that one field during variable speed reproduction is composed of data of a single field, that is, so that data of different subsampling phases are not mixed in the data of one field. The position in the track width direction is controlled according to the playback speed. Further, the control signal changing means changes the phase information of the control signal included in the MUSE signal reproduced from the magnetic recording medium to the phase information corresponding to the video data of the MUSE signal.

With such an operation, the MUSE decoder performs interpolation processing without causing a phase shift, and a high-quality reproduced image can be obtained during variable speed reproduction.

According to the structure of claim 2, in addition to the effect of the structure of claim 1, the control signal changing means further controls the interpolation process performed by the MUSE decoder to be only intra-field interpolation during variable speed reproduction. Set the information to the control signal. Specifically, for example, the motion information of the control signal is changed to the degree of motion 7. Therefore, M.U.
The interpolation process performed by the SE decoder is only intra-field interpolation. This prevents deterioration of the image quality of the reproduced image due to the phase rotation error.

According to the structure of claim 3, the phase information is set individually, and information is set so that the interpolation process performed by the MUSE decoder is only intra-field interpolation, for example, when the degree of motion is 7. and a storage means for storing a plurality of control signals set to
A control signal corresponding to the phase of the video data of the E signal is read out, and the control signal included in the MUSE signal reproduced from the magnetic recording medium is changed to the control signal read out from the storage means by the control signal reading means. Therefore, the circuit configuration can be simplified.

[0021]

[Embodiment] An embodiment of the present invention is shown in FIGS. 1 to 5, FIG.
This will be explained below based on FIGS. 9 and 10.

As shown in FIG. 2, the MUSE signal magnetic recording/reproducing apparatus (hereinafter referred to as VTR) 31 of this embodiment includes a control signal changing circuit 32 as a control signal changing means shown in FIG. The magnetic head device 33 shown in FIG. MUSE
The signal is subjected to predetermined processing and then supplied to the MUSE decoder 36 shown in FIG.

The control signal changing circuit 32 described above is
It has a control signal addition circuit 21, a control signal switching circuit 22, a control signal detection circuit 23, a control signal decoding circuit 24, a control signal rewriting circuit 25, and a control signal encoding circuit 26.

The control signal detection circuit 23 described above is as follows:
+Azimuth head 1 as a movable head shown in FIG.
A control signal is detected from the MUSE signal taken out from the magnetic tape 17 by the azimuth heads 13 and 15, and is supplied to a control signal switching circuit 22 and a control signal decoding circuit 24.

The control signal decoding circuit 24 decodes the control signal transmitted after being subjected to extended Hamming encoding, and outputs it to the control signal rewriting circuit 25.

The control signal rewriting circuit 25 rewrites the phase information of the control signal to phase information corresponding to the video data of the reproduced MUSE signal, and rewrites the motion information of the control signal to the degree of motion 7, thereby encoding the control signal. The signal is output to the circuit 26.

The control signal encoding circuit 26 performs expanded Hamming encoding on the control signal and outputs it to the control signal switching circuit 22 for variable speed reproduction.

The control signal switching circuit 22
Information indicating whether the reproduction of R is normal reproduction or variable speed reproduction is input from the system controller 35 as a normal reproduction/variable speed reproduction switching signal 27, and in the case of normal reproduction, it is input directly from the control signal detection circuit 23. On the other hand, in the case of variable speed playback, control signals input from the control signal encoding circuit 26 are selected and outputted to the control signal adding circuit 21, respectively.

The control signal addition circuit 21 inserts the control signal input from the control signal switching circuit 22 into a predetermined position of the MUSE signal shown in FIG.
It is designed to reshape the MUSE signal in transmission form.

The magnetic head device 33 shown in FIG. 10 is capable of dynamic tracking. That is, each of the heads 12 to 15 is provided on the rotating drum 16 via, for example, a piezoelectric element, and each head 12 to 1 is connected to the rotating drum 16 in response to a control signal supplied from the head position control device 34 to the piezoelectric element.
5 is displaced in the track width direction of the magnetic tape 17 to change the track to be scanned.

The head position control device 34 sends a control signal to the magnetic head device 33 for setting a track to be scanned by each of the heads 12 to 15, based on a signal indicating the playback speed supplied from the system controller. supply.

In the above configuration, first, the present VTR 31
Dynamic tracking during variable speed playback will be explained. When dynamic tracking is performed at double speed with the arrangement of the heads 12 to 15 shown in FIG. 10, the head trajectory and the envelope of the reproduced RF signal are as shown in FIG. In this case, sufficient RF signals for demodulation can be secured, and one field of double-speed reproduction is composed of a single field.

Next, in consideration of the problem of recording density, when dynamic tracking is performed in so-called segment recording, in which the rotary drum 16 of the magnetic head device 33 is rotated at 3600 rpm and one field is recorded and reproduced on four tracks. The result will be as shown in Figure 4. in this case,
By controlling the positions of the heads 12 to 15 as shown in the figure, a sufficient RF signal can be secured. However, in this case, data of a plurality of fields will be mixed in one field of double speed reproduction. Therefore, as shown in FIG. 5, by controlling the positions of the heads 12 to 15, the field to be reproduced can be composed of data of a single field, that is, data of the same subsampling phase.

Next, the operation of the control signal changing circuit 32, which generates a control signal corresponding to the subsampling phase of the video data reproduced without the coexistence of a plurality of fields as described above, will be explained.

In FIG. 1, the control signal detected by the control signal detection circuit 23 is output to the control signal switching circuit 22 for normal reproduction, and is also output to the control signal decoding circuit 24. The control signal decoding circuit 24 decodes the control signal transmitted after being expanded Hamming encoded, and outputs it to the control signal rewriting circuit 25.

The control signal rewriting circuit 25 rewrites the phase information of the decoded control signal to phase information corresponding to the reproduced video data, and also rewrites the motion information of the control signal to the degree of motion 7 and encodes the control signal. Output to circuit 26. The above rewriting of the phase information is performed by predicting the next field during variable speed playback, since the phase information of the demodulated control signal corresponds to the next field during normal playback. The control signal encoding circuit 26 performs expanded Hamming encoding on the control signal to make it into a form for transmission, and outputs it to the control signal switching circuit 22 for variable speed reproduction.

The control signal switching circuit 22 selects the control signal directly input from the control signal detection circuit 23 in the case of normal reproduction based on the normal reproduction/variable speed reproduction switching signal 27 input from the system controller 35; In the case of variable speed playback, control signals input from the control signal encoding circuit 26 are selected and outputted to the control signal adding circuit 21, respectively.

The control signal adding circuit 21 inserts the control signal input from the control signal switching circuit 22 into a predetermined position of the MUSE signal shown in FIG.
Reshaping the MUSE signal for transmission.

In the control signal changing circuit 32 described above, the phase information of the control signal is made to correspond to the sampling phase of the video signal reproduced using dynamic tracking, so that the interpolation process in the MUSE decoder 36 is performed without a phase shift. It is possible to obtain high-quality reproduced images during variable speed reproduction. In addition, by rewriting the motion information of the control signal to the degree of motion 7, the interpolation process in the MUSE decoder 36 becomes only intra-field interpolation, thereby preventing phase cycling errors from affecting the reproduced image. There is. In other words, when scanning an area that is originally a still image and the motion information of the control signal is 1, that is, a completely still image, interpolation processing using 4 fields is performed, so phase cycling is normally reproduced. However, when still image processing is performed, the image quality may actually deteriorate. Therefore, this problem is solved by setting the movement information of the control signal as described above.

Another embodiment of the present invention will be described below with reference to FIG. For convenience of explanation, means having the same functions as the means shown in the drawings of the above-mentioned embodiment are denoted by the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the control signal changing circuit 37 as control signal changing means includes a control signal adding circuit 21, a control signal switching circuit 22, a control signal detecting circuit 23, a control signal decoding circuit 24, and a memory. control signal generation ROM (
Read Only Memory) 28. That is, the control signal rewriting circuit 2 shown in FIG.
5 and the control signal encoding circuit 26, a control signal generation ROM 28 is provided.

The control signal generation ROM 28 has eight types of phase information that can be considered as phase information, that is, eight types of phase information that are set by combinations of sub-sample phases of bits b1, b9, and b10 shown in Table 1. In each case, the motion information has a motion degree of 7, and each control signal that has been subjected to extended Hamming encoding for transmission is stored.

In the above configuration, the operation is similar to that of the control signal changing circuit 32 shown in FIG. 1, except for the operation of generating a control signal during variable speed reproduction. In addition, in the operation of generating a control signal during variable speed playback, a signal indicating the speed of variable speed playback obtained from the system controller 35 and phase information obtained from the control signal decoding circuit 24 are sent to an upper address of the control signal generation ROM 28. A control signal corresponding to the phase information of the video data is selected and read out, and outputted as a control signal during variable speed playback.

In the configuration of this embodiment, as described above, the control signal generation ROM 28 replaces the control signal rewriting circuit 25 and the control signal encoding circuit 26.
Since the control signal for variable speed playback is obtained by the above, the circuit configuration is simplified.

[0045]

Effects of the Invention As described above, the MUSE signal magnetic recording/reproducing device of the invention as claimed in claim 1 is capable of movable during variable speed reproduction so that one field during variable speed reproduction is composed of data of a single field. a movable head position control means for controlling the position of the head in the track width direction according to the variable speed reproduction speed;
The phase information of the control signal included in the USE signal is
The configuration includes a control signal changing means for changing the phase information to correspond to the video data of the USE signal.

[0046] As a result, during variable speed playback, the MUS
The E-decoder can perform interpolation processing without causing a phase shift, and has the advantage of being able to obtain high-quality reproduced images.

As described above, the MUSE signal magnetic recording/reproducing device according to the second aspect of the present invention is configured such that during variable speed reproduction, one field during variable speed reproduction is composed of data of a single field. A movable head position control means for controlling the position in the track width direction according to a variable speed reproduction speed, and an MU reproduced from a magnetic recording medium during variable speed reproduction.
The phase information of the control signal included in the SE signal is
The control signal changing means changes the phase information to correspond to the video data of the SE signal, and sets the control signal to information such that the interpolation processing performed by the MUSE decoder is only intra-field interpolation. .

Accordingly, in addition to the effect of the invention of claim 1, it is possible to prevent deterioration of the image quality of the reproduced image due to an error in phase circulation during variable speed reproduction.

As described above, the MUSE signal magnetic recording/reproducing device according to the third aspect of the present invention is configured such that during variable speed reproduction, one field during variable speed reproduction is composed of data of a single field. MUSE
A storage means for storing a plurality of control signals in which information is set such that the interpolation processing performed by the decoder is only intra-field interpolation; control signal reading means for reading out a control signal corresponding to the phase of the video data of the MUSE signal read out, and controlling the control signal included in the MUSE signal reproduced from the magnetic recording medium from the storage means during variable speed reproduction. The control signal changing means changes the control signal to the control signal read by the signal reading means.

[0050] This has the effect that the circuit configuration can be simplified.

[0051]

[Table 1]

[0052]

[Table 2]

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a control signal changing circuit according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a VTR equipped with the control signal changing circuit shown in FIG. 1;

3 is a diagram showing a head trajectory and an envelope of a reproduced RF signal when dynamic tracking is performed at double speed by the magnetic head device shown in FIG. 10; FIG.

4 is a diagram showing a head trajectory and an envelope of a reproduced RF signal when dynamic tracking is performed at double speed for segment recording using the magnetic head device shown in FIG. 10; FIG.

5 shows a head trajectory and an envelope of a reproduced RF signal when the head position is controlled so that the reproduced field is composed of data of a single field in the dynamic tracking shown in FIG. 4; FIG. It is a diagram.

FIG. 6 is a block diagram showing a control signal changing circuit according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a MUSE signal.

FIG. 8 is an explanatory diagram showing a sampling pattern of a MUSE signal.

FIG. 9 is a block diagram showing an example of a MUSE decoder.

FIG. 10 is an explanatory diagram showing an example of a head arrangement of a VTR that records and reproduces a MUSE signal.

FIG. 11 is an explanatory diagram showing a reproduction RF signal during reproduction at double speed in a conventional VTR.

[Explanation of symbols]

12 + Azimuth head (movable head) 13
- Azimuth head (movable head) 14 + Azimuth head (movable head) 15 - Azimuth head (movable head) 21 Control signal addition circuit 22 Control signal switching circuit 23
Control signal detection circuit 24 Control signal decoding circuit 25 Control signal rewriting circuit 26 Control signal encoding circuit 28
Control signal generation ROM (storage means, control signal reading means) 32 Control signal changing circuit (control signal changing means) 33 Magnetic head device 34 Head position control device 35 System controller 37 Control signal changing circuit (control signal changing means)

Claims (3)

[Claims] 1. A magnetic recording and reproducing apparatus comprising a movable head movable in the width direction of a scanning track on a magnetic recording medium and magnetically recording and reproducing a MUSE signal obtained by band-compressing a high-definition signal. 1
a movable head position control means for controlling the position of the movable head in the track width direction according to a variable speed reproduction speed so that the field is composed of data of a single field; M that was done
The phase information of the control signal included in the USE signal is
1. A magnetic recording and reproducing device for a MUSE signal, comprising control signal changing means for changing phase information to correspond to video data of the USE signal. 2. A magnetic recording and reproducing device comprising a movable head movable in the width direction of a scanning track on a magnetic recording medium and magnetically recording and reproducing a MUSE signal obtained by band-compressing a high-definition signal. 1
a movable head position control means for controlling the position of the movable head in the track width direction according to a variable speed reproduction speed so that the field is composed of data of a single field; M that was done
The phase information of the control signal included in the USE signal is
The control signal changing means changes the phase information of the USE signal to correspond to the video data, and sets the control signal to information such that the interpolation processing performed by the MUSE decoder is only intra-field interpolation. A magnetic recording and reproducing device for MUSE signals. 3. A magnetic recording and reproducing apparatus that includes a movable head movable in the width direction of a scanning track on a magnetic recording medium and magnetically records and reproduces a MUSE signal obtained by band-compressing a high-definition signal, during variable speed reproduction. No. 1
A movable head position control means for controlling the position of the movable head in the track width direction according to a variable playback speed, and phase information set individually so that the field is composed of data of a single field. ,MUS
A storage means for storing a plurality of control signals in which information is set such that the interpolation processing performed by the E decoder is only intra-field interpolation, and at the time of variable speed playback, from the storage means, based on the variable playback speed, Regenerated MUSE
The control signal reading means has a control signal reading means for reading a control signal corresponding to the phase of the video data of the signal, and during variable speed reproduction, the control signal reading means reads out the control signal included in the MUSE signal reproduced from the magnetic recording medium from the storage means. 1. A magnetic recording and reproducing device for a MUSE signal, comprising: control signal changing means for changing the control signal to the control signal read by the MUSE signal.