JPH0537960A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Structure] The magnetic recording / reproducing apparatus has a field memory 5 and a control signal memory 6. Upon receiving the still reproduction command, the control circuit 10 writes the reproduction control signal in the control signal memory 6.
Then, the control circuit 10 prohibits writing to the control signal memory 6. After this, the control circuit 10
Thus, the reproduced video signal is written in the field memory 5 in the normal reproduction state. After this, the field memory 5
Still reproduction is performed on the basis of the reproduction video signal read from the memory and the reproduction control signal read from the control signal memory 6. [Effect] Since the reproduced video signal written in the field memory 5 in the normal reproduction state corresponds to the reproduction control signal, a good still reproduced image can be obtained.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a MUSE (Multiple Sub) recorded by band-compressing a so-called high-definition signal.
-Nyquist Sampling Encoding) The present invention relates to a magnetic recording / reproducing apparatus for still reproducing a signal.

[0002]

2. Description of the Related Art The MUSE system is a band compression system developed by NHK (Japan Broadcasting Corporation) for transmitting high-definition signals by broadcasting satellites, and its contents are, for example, NHK Technical Research, Showa 62, Vol. No. 2, PP. 18-53.

According to the method disclosed herein, the baseband high-definition signal is band-compressed to 8.1 MHz by performing offset sub-sampling. In the broadcasting satellite, the data is transmitted with the configuration shown in FIG. In other words, one line is sampled at 480 points, and HD
11 points for (horizontal synchronization signal) and 94 points for color difference signal (C signal)
374 points are assigned to the points and the luminance signal (Y signal), and the color difference signal and the luminance signal are line-sequentially time-division multiplexed and transmitted.

Further, as shown in FIG. 8, the sampling phase of each field of the MUSE signal is formed into a sampling pattern, and this sampling phase is cyclic in 4 fields.

Here, referring to FIG. 9, M for restoring the MUSE signal to a high-definition baseband signal.
A basic configuration example of the USE decoder will be described below.

In the MUSE decoder having the configuration shown in FIG. 9, when the MUSE signal is input to the input terminal 21, the MUSE signal input by the A / D (analog / digital) conversion circuit 22 is converted into a digital signal. ,
De-emphasis circuit 24 and control signal separation
It is sent to the detection circuit 23. In the de-emphasis circuit 24, a process reverse to the emphasis process performed for transmission is performed and then sent to the moving image processing circuit 27, the still image processing circuit 26, and the motion detection circuit 25, respectively.

The moving image processing circuit 27 performs only the interpolation processing within the field to generate a moving image signal, and this moving image signal is sent to the mixing circuit 28. On the other hand, in the still image processing circuit 26, inter-frame interpolation processing is performed after performing inter-frame interpolation processing using signals of 4 fields. That is, a still image signal is generated using all of the four types of sample points shown in FIG.
Sent to.

The still image processing circuit 26 performs still image processing as follows to generate a still image signal. That is, as described above, the still image signal is generated by performing the interpolation process using all the sampling points of 4 fields. Therefore, in order to perform such an interpolation process, it is necessary to accurately grasp the sampling phase of the sample point.

Data indicating the sampling phase is written in the control signal shown in Table 1. This data is separated and detected by the control signal separation / detection circuit 23, and the phase with respect to the previous frame and the previous field is judged based on this to obtain a good image.

In the motion detection circuit 25, the input MUS
E signal 1st. Between (first) frames and 2n
d. By taking the difference between (second) frames,
A motion signal is generated by detecting a moving area of the image, and this motion signal is sent to the mixing circuit 28.

The control signal separation / detection circuit 2
In 3, the control signal in the input MUSE signal is separated and detected as shown in Table 1. Based on the control signal thus separated and detected, the data processing method in the still image processing circuit 26 and the motion signal which is the output signal of the motion detection circuit 25 are controlled.

[0012]

[Table 1]

In the mixing circuit 28, the moving image signal and the still image signal are mixed for each pixel based on the above motion signal,
Alternatively, after switching, TCI (Time Compressed In
integration) is sent to the decoding circuit 29. In the TCI decoding circuit 29, the line-sequential / time-division multiplexed luminance signal and chrominance signal, which are the output signals of the mixing circuit 28, are transmitted to the TCI decoding circuit 29.
Is decoded. The TCI-decoded luminance signal and chrominance signal are D / A (digital / analog) conversion circuit 30.
After being input to and converted to an analog signal, output terminal 3
It is designed to be output from 1.

As a means for performing noiseless still reproduction, NTSC such as VHS system (Video Home System) is used.
(National Television System Committee) In a device for recording and reproducing a signal, the television technique Vol.
9, No. 26 (November 1985), a method using a field memory is disclosed. This method will be described below with reference to FIG.

For example, a pair of a magnetic head having a positive azimuth angle (hereinafter referred to as + azimuth head) A and a magnetic head having a negative azimuth angle (hereinafter referred to as −azimuth head) B (none shown). ) Is a magnetic head arrangement provided on the periphery of a rotating drum (not shown) at a head mounting angle of 180 °, and a magnetic recording / reproducing apparatus in which a winding angle of a magnetic tape (not shown) is set to 180 ° is used. A signal recorded in one track and one field is reproduced.

According to the above construction, as shown in FIG. 10A, when a video signal is recorded in one track and one field, the + azimuth head A and the −azimuth head B alternately reproduce RF (Radio). Frequency) signal is picked up (see FIG. 10 (b)), and reproduction RF at that time
The signal envelope changes as shown in FIG. The numbers in FIG. 10A correspond to the corresponding fields.

At this time, when a still reproduction command signal (see FIG. 10 (d)) is input from the system controller of the magnetic recording / reproducing apparatus, a write control signal (FIG. 10 (e)).
Based on the above), the video signal data for one field is written in the field memory (not shown) in the normal reproduction state (see FIG. 10 (f)).

After that, the above data is read from the field memory and reproduced. That is, since the video signal of the field memory is a video in a normal reproduction state, a noise-free (noiseless) still reproduction video can be obtained.

[0019]

However, in the above-mentioned conventional MUSE signal, the still image processing is performed by using the data of 4 fields.
Providing a field memory for fields is not preferable from the viewpoint of the scale of the circuit configuration or the manufacturing cost.

Therefore, as described above, it is conceivable to perform still reproduction in the field memory for one field instead of providing the field memory for four fields in the magnetic recording / reproducing apparatus.

However, since the control signal reproduced at the same time as the video signal data corresponds to the next field of the normal reproduction, when the control signal and the video signal of the same field are written in the field memory, the read control signal is the video. It no longer corresponds to the signal data. As a result, erroneous interpolation processing is performed in the decoder, resulting in a problem that image quality is significantly deteriorated.

In view of the above point, in the present invention, when the still command signal is received, the reproduction control signal is made to correspond to the video signal data, and the interpolation process in the MUSE decoder is performed at the correct phase to realize a good still reproduction. It is a thing.

[0023]

In order to solve the above-mentioned problems, the magnetic recording / reproducing apparatus according to the invention of claim 1 samples the screen information in the case of a still image in order to compress the band, and the adjacent information is displayed. When the sampling phases of the fields are sequentially shifted, and N is an integer of 2 or more, one field of information is formed by making one cycle in N fields, and in the case of a moving image, information of one screen is sampled and one field is sampled. A magnetic recording / reproducing apparatus for magnetically recording / reproducing a video signal, which is formed by sequentially shifting the sampling phases of adjacent fields and superimposing a control signal indicating the state of a still image or a moving image, by taking the following means. There is.

That is, a field memory for storing a video signal, a first control means for controlling writing in the field memory, a means for recording and reproducing a control signal included in the video signal, and a reproduced control signal A control signal memory to be stored and second control means for controlling writing to the control signal memory are provided, and during still reproduction, the control signal writing is stopped first, and the video signal writing is stopped in the next field. By doing so, the control signal is made to correspond to still reproduced video data.

In order to solve the above problems, the magnetic recording / reproducing apparatus according to the second aspect of the present invention adopts the following means in the configuration of the first aspect of the invention.

That is, a means for changing the motion information in the control signal into a signal indicating the motion state is provided,
The interpolation process in the decoder is a complete field interpolation process.

[0027]

When the still reproduction command is received, the second control means controls the control signal memory to the write state. When the control signal included in the video signal is written in the control signal memory, the second control means prohibits writing in the control signal memory.

After the above operation is completed, the first control means controls the field memory to the write state. Then, when the writing of the video signal to the field memory is completed in the normal reproduction state, the writing to the field memory is prohibited by the first control means.

After that, still reproduction is performed based on the video signal read from the field memory and the control signal read from the control signal memory.

As described above, the control signal corresponding to the video signal written in the field memory in the normal reproduction state can be surely obtained.

According to the second aspect of the invention, since the signal indicating the motion state of the motion information included in the control signal is changed, it is possible to avoid the deterioration of the image quality due to the fact that the phase information in the control signal does not circulate. With M
Since the processing in the USE decoder can be field interpolation processing, a good still reproduced image can be surely obtained.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

The main part of the configuration example of the magnetic recording / reproducing apparatus according to this embodiment will be described below with reference to FIG.

For example, as shown in FIG. 5, a magnetic head having a positive azimuth angle (hereinafter referred to as + azimuth head) 11 and a magnetic head having a negative azimuth angle (hereinafter referred to as −azimuth head) 12 are provided. When a magnetic recording / reproducing apparatus in which the winding angle of the magnetic tape 13 is set to 180 ° in a magnetic head arrangement provided on the periphery of the rotary drum 14 at a head mounting angle of 180 °,
A signal recorded in one track and one field is reproduced.

The reproduced video signal 1 reproduced from the magnetic tape 13 via the + azimuth head 11 and the −azimuth head 12 is input to the field memory 5 (field memory) as shown in FIG. A video signal memory write control signal 3 output from the control circuit 10 (first and second control means) based on a still reproduction command is input to the field memory 5. The output of the field memory 5 is sent to the CTL (control) signal adding circuit 7.

The reproduced CTL (control) signal is separated and detected from the reproduced video signal 1 by the control signal separation / detection circuit (not shown) as described above, and the CTL (control) signal memory 6 (control signal) is detected. Memory). To the CTL signal memory 6, the CTL signal memory write control signal 4 output from the control circuit 10 based on a still reproduction command is input.

The output of the CTL signal memory 6 is the above-mentioned CTL.
It is sent to the signal adding circuit 7, and the output of the CTL signal adding circuit 7 is sent to the subsequent TCI decoder (not shown) via the output terminal 8.

According to the above configuration, as shown in FIG. 2A, when the video signal is recorded in one track and one field, the + azimuth head 11 and the −azimuth head 12 are used.
The reproduced RF signal is picked up alternately by and (Fig. 2
(See (b)), and the envelope of the reproduction RF signal at that time changes as shown in FIG. 2 (c). Note that FIG.
The numbers in (a) correspond to the corresponding fields.

For example, when the control circuit 10 receives a low level still reproduction command signal (see FIG. 2D) from a system controller (not shown) of the magnetic recording / reproducing apparatus for a predetermined period, the control circuit 10 causes the CTL signal memory. The write control signal 4 (see FIG. 2E) is sent to the CTL signal memory 6. The CTL signal memory 6 stores the input reproduced CTL signal 2 based on the CTL signal memory write control signal 4 (see FIG. 2 (h)).

Both the still reproduction command signal and the memory write control signal 4 for the CTL signal are kept at a low level for a predetermined period, and then return to a high level after a lapse of the predetermined period.
Further, after the still reproduction command signal returns from the low level to the high level, the memory write control signal 4 for the CTL signal becomes active (maintains the low level for about one field period).

After the CTL signal memory write control signal 4 returns from the low level to the high level (non-active state), the control circuit 10 controls the video signal memory write control as shown in FIG. 2 (f). The signal 3 is maintained at the low level for a predetermined period (approximately one field period) (at this time, the field is shifted to the next field). Based on the video signal memory write control signal 3, the reproduced video signal 1 is written in the field memory 5.

After the above operation, the reproduced video signal 1 is read from the field memory 5 (see FIG. 2 (g)), and the CTL
It is sent to the signal adding circuit 7. Also, the CTL signal adding circuit 7
Is the reproduction CT read from the CTL signal memory 6.
The L signal 2 (see FIG. 2 (h)) is input. And C
The TL signal adding circuit 7 adds the reproduced CTL signal 2 to the reproduced video signal 1 to re-form the MUSE signal in the transmission form.

As a result, the reproduced video signal 1 and the reproduced CTL signal 2 corresponding to the reproduced video signal 1 follow the MUS.
Since it is sent to the E decoder (not shown), the interpolation processing is performed at the correct phase, and as a result, a good still reproduced image is obtained (see FIGS. 2 (g) (h)).

By the way, in the still reproduction image obtained as described above, the still image in the original MUSE signal is 4
While it is composed of data for one field, it is composed of data for one field, so the reproduced CTL signal 2
The motion information contained inside is normal

In the case of [0] or complete still image [1], the MUSE decoder performs still image processing. As a result, the phase information in the reproduced CTL signal 2 does not circulate, and the obtained image quality may deteriorate.

As shown in Table 1, there are eight types of motion information, and [3] represents a scene change.
[4] to [7] represent the degree of movement.

Therefore, in order to solve the above problems, the following measures are taken in this embodiment. That is, as shown in FIG. 3, a CTL (control) signal changing circuit 9 (means for changing the motion information in the control signal to a signal indicating a motion state) is added to the configuration of FIG. It is provided between the CTL signal adding circuit 7.

According to the above configuration, after the reproduction CTL signal 2 is written in the CTL signal memory 6 at the timing as described above, the reproduction CTL signal 2 is read out and the CTL is read.
It is sent to the signal changing circuit 9.

Then, the reproduction CT is performed by the CTL signal changing circuit 9.
The motion information contained in L signal 2 is normal

[0], or M after the complete still image [1] is changed to the degree [7]
The interpolating process in the USE decoder can be an in-field process. As a result, the still reproduction image is not affected by the fact that the phase does not circulate due to being composed of data for one field. Therefore, a good still reproduced image can be obtained.

In the above embodiment, the CTL signal changing circuit 9 is provided between the CTL signal memory 6 and the CTL signal adding circuit 7, but the present invention is not limited to this. However, the same result as described above can be obtained even if the configuration is provided in the subsequent stage of the CTL signal adding circuit 7, for example.

In the above embodiment, the reproduced CTL signal 2 in the reproduced video signal 1 obtained by reproducing the video signal in which one field is recorded in one track is used for the CTL signal provided separately from the field memory 5. Although the case of writing in the memory 6 has been described, the present invention is not limited to this, and can be applied to reproduction of a signal recorded by various recording methods.

For example, in an analog VCR (Video Cassette Recorder) which records the input MUSE signal in order, the reproduced video signal 1 and the reproduced CTL signal 2 are written in the same memory, and at this time, they are written independently. If controlled, the same result as in the above embodiment can be obtained.

Further, in the above-described embodiment, the structure for reproducing the video signal in which one field is recorded in one track has been described, but the present invention is not limited to this, and as shown in FIG. 6, for example. A pair of + azimuth heads 41 and 43 and −azimuth heads 42 and 44 is arranged at a magnetic head provided at the periphery of the rotary drum 46 at a head mounting angle of 180 °, and the winding angle of the magnetic tape 45 is 180 °.
It is also possible to use a magnetic recording / reproducing apparatus set to No. 1 to reproduce the video signal. The rest of the configuration of the magnetic recording / reproducing apparatus is the same as that of FIG. 1 or FIG.

According to the above configuration, as shown in FIG. 4A, when the video signal is recorded by dividing into two channels, + azimuth heads 41 and 43 (see FIG. 4B).
Or-Azimuth heads 42 and 44 (see FIG. 4 (d))
Thus, the reproduction RF signal is picked up alternately, and the envelope of the reproduction RF signal at that time changes as shown in FIGS. 4C and 4E, respectively.

In FIG. 4A, for example, 1-
Reference numeral 1 denotes a signal divided and recorded in the first channel of the first field, and 3-2 represents a signal divided and recorded in the second channel of the third field.

As described above, for example, when the control circuit 10 receives a still reproduction command signal (see FIG. 4F) from the system controller (not shown) of the magnetic recording / reproducing apparatus, the control circuit 10 causes the CTL signal memory. The write control signal 4 (see FIG. 4 (g)) is sent to the CTL signal memory 6 and the reproduced CTL signal 2 input based on the control signal 4 is stored (see FIG. 4 (j)).

After the CTL signal memory write control signal 4 is returned from the low level to the high level, the control circuit 10 outputs the video signal memory write control signal 3 for a predetermined period as shown in FIG. 4 (h). It is maintained at a low level (approximately one field period) (at this time, the field is transferred to the next field). Based on the video signal memory write control signal 3, the reproduced video signal 1 is written in the field memory 5.

After the above operation, the reproduced video signal 1 (see FIG. 4 (i)) is read from the field memory 5 and sent to the CTL signal adding circuit 7. Further, the CTL signal adding circuit 7 includes a reproduction CTL read from the CTL signal memory 6.
The signal 2 (see FIG. 4 (j)) is input. And CT
Playback video signal 1 to playback CTL signal 2 by L signal addition circuit 7
Is added to re-form the MUSE signal in the transmission form.

As a result, along with the reproduced video signal 1, the reproduced CTL signal 2 corresponding to the reproduced video signal 1 follows the MUS.
Since it is sent to the E decoder (not shown), the interpolation processing is performed with the correct phase, and as a result, a good still reproduced image is obtained (see FIGS. 4 (i) (j)).

[0059]

According to the magnetic recording / reproducing apparatus of the present invention,
As described above, the field memory that stores the video signal and the first memory that controls writing to the field memory
Control means, means for recording and reproducing the control signal included in the video signal, a control signal memory for storing the reproduced control signal, and second control means for controlling writing to the control signal memory During still reproduction, writing of the control signal is stopped first, and writing of the video signal is stopped in the next field, so that the control signal corresponds to the still-reproduced video data.

Therefore, since the control signal corresponding to the video signal stored in the field memory in the normal reproduction state can be surely obtained, the interpolation process is performed in the correct phase in the subsequent decoder, and a good still image is obtained. A reproduced image can be reliably obtained.

Further, a control signal decoding circuit and a coding circuit are not required, and the circuit structure can be made compact. Therefore, there is an effect that it can be sufficiently applied to a home magnetic recording / reproducing apparatus that requires a circuit miniaturization.

Further, in the magnetic recording / reproducing apparatus of the invention of claim 2, as described above, in addition to the configuration of the invention of claim 1, means for changing the motion information included in the control signal into a signal indicating a motion state. Is provided.

Therefore, in addition to the effect of the first aspect of the invention, by changing the motion information in the control signal to a signal indicating the motion state, the deterioration of the image quality due to the fact that the phase information in the control signal does not circulate. This can be avoided, and since the processing in the subsequent decoder can be the field interpolation processing, there is an effect that a good still reproduced image can be surely obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main configuration of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is an explanatory diagram illustrating a case where a signal recorded in one track and one field is subjected to a still reproducing operation in the magnetic recording / reproducing apparatus according to the present invention.

FIG. 3 is a block diagram showing a main configuration of a magnetic recording / reproducing apparatus to which a control signal changing circuit is added in FIG.

FIG. 4 is an explanatory diagram for explaining a case where a signal reproduced by two-channel division recording is subjected to a still reproduction operation in the magnetic recording / reproducing apparatus according to the present invention.

FIG. 5 is an explanatory diagram showing an arrangement of magnetic heads for reproducing signals recorded in one track and one field according to the present invention.

FIG. 6 is an explanatory diagram showing an arrangement of magnetic heads for reproducing signals recorded on two channels separately according to the present invention.

FIG. 7 is an explanatory diagram showing a configuration of a conventional MUSE signal.

8 is an explanatory diagram showing a sampling pattern showing a sampling phase of a video portion of the MUSE signal of FIG. 7. FIG.

FIG. 9 is a block diagram showing a main configuration of a conventional MUSE decoder.

FIG. 10 is an explanatory diagram explaining a case where a still reproduction operation is performed by a field memory in the conventional VHS system.

[Explanation of symbols]

5 field memory (field memory means) 6 control signal memory (control signal memory means) 7 control signal addition circuit 10 control circuit (control means)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michiyuki Sugino             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Within Yap Co., Ltd.

Claims (2)

[Claims] 1. For band compression, in the case of a still image, screen information is sampled, sampling phases of adjacent fields are sequentially shifted, and N is an integer of 2 or more,
The information of one screen is formed by N fields by making one round in N fields, and in the case of a moving image, the information of one screen is sampled and formed by one field, and the sampling phase of adjacent fields is sequentially shifted to obtain a still image or a moving image, respectively. A magnetic recording / reproducing apparatus for magnetically recording / reproducing a video signal, in which a control signal indicating the above state is superimposed, comprising: a field memory for storing the video signal; and a first control means for controlling writing to the field memory, Second means for recording / reproducing a control signal included in the video signal, a control signal memory for storing the reproduced control signal, and a control for writing to the control signal memory
It is characterized by including a control means, and at the time of still reproduction, the writing of the control signal is stopped first, and the writing of the video signal is stopped in the next field, so that the control signal corresponds to the still reproduced video data. Magnetic recording / reproducing device. 2. A means for changing motion information in a control signal into a signal indicating a motion state, wherein the interpolation processing in the MUSE decoder is a complete field interpolation processing. The magnetic recording / reproducing apparatus described.