JPH0575971A - Video signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the degradation of the picture quality at the time of system conversion between the NTSC system and the high vision system. CONSTITUTION:An up converter 103 and a down converter 104 are incorporated in a video tape recorder where the video signal of the high vision system is recorded. The video signal of the NTSC system is converted into video data of the high vision system by a digital signal processing circuit 145 and is recorded on a magnetic tape 123. Video data of the high vision system reproduced from the magnetic tape 123 is converted into the video signal of the NTSC system by a digital signal processing circuit 151.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal recording / reproducing apparatus suitable for use in a video tape recorder capable of recording or reproducing a high definition television type video signal represented by, for example, a high-definition television.

[0002]

2. Description of the Related Art Recently, in place of the NTSC television system, a high-definition system has been proposed in which higher quality images can be obtained. Since the formats of these two systems are basically different, it is not possible to record or reproduce a high-definition video signal as it is with a conventional NTSC video tape recorder. Therefore, an up-converter that converts a conventional NTSC video signal into a high-definition video signal and a down converter that converts a high-vision video signal into an NTSC video signal are considered.

FIG. 3 shows an example in which the HDTV video tape recorder 1, the up converter 2 and the down converter 3 are connected. As shown in the figure, a high-definition type video tape recorder 1
Has low-pass filters 11 to 13 for removing unnecessary high-frequency components from the input luminance signal Y and color difference signals P _B and P _R , respectively. The outputs of the low-pass filters 11 to 13 are A / D converted by the A / D converters 14 to 17 and then supplied to the digital signal processing circuit 17. The signal processed by the digital signal processing circuit 17 is supplied to the analog signal processing circuit 18 and further recorded on the magnetic tape 20 via the magnetic head 19.

A magnetic head 21 is used instead of the magnetic tape 20.
The signal reproduced by is supplied to the analog signal processing circuit 22, is subjected to predetermined processing, and is then supplied to the digital signal processing circuit 23. The digital signal processing circuit 23 performs various digital processes and then separates and outputs the luminance signal Y and the color difference signals P _B and P _R. These signals are D / A converted by the D / A converters 24 to 26, respectively, and are output after the unnecessary high frequency components are removed by the low pass filters 27 to 29.

That is, the low-pass filters 11 to 13
The luminance signal Y and the color difference signals P _B and P _R input from the magnetic tape 20 are recorded on the magnetic tape 20 through a predetermined process, and the signals reproduced from the magnetic tape 20 are low-pass filters 27 to 2.
9 will be output.

For the video tape recorder 1 which records and reproduces such a high definition video signal, the NTS
The up-converter 2 is connected to record the video signal of the C system. The up converter 2 has a luminance signal Y
After removing unnecessary high frequency components of the color signal C and the color signal C by the low-pass filters 41 and 42, respectively, the A / D converters 43 and 4
4, A / D conversion is performed and it is supplied to the digital signal processing circuit 45. Digital signal processing circuit 45
Is connected to a field memory 46, and the A / D converted data is once stored in the field memory 46. The digital signal processing circuit 45 converts the data stored in the field memory 46 into high definition video data. Then, the luminance data and the color difference data converted into the high definition image data are respectively D /
D / A conversion is performed by the A converters 47 to 49, unnecessary high frequency components are removed by the low pass filters 50 to 52, and the luminance signals Y and the color difference signals P _B and P _R are output.

The luminance signal Y and the color difference signals P _B and P _R are supplied to the low pass filters 11 to 13 of the video tape recorder 1. Therefore, the up-converter 2 can convert an NTSC video signal into a high-definition video signal and record it on the magnetic tape 20.

On the other hand, the high-definition type video signal thus recorded on the magnetic tape 20 is reproduced by the magnetic head 21 and output from the low-pass filters 27 to 29 so that it can be viewed on the high-definition type monitor. Also,
By connecting the down converter 3, it is possible to convert into an NTSC video signal and monitor it.

That is, in this case, the luminance signal Y and the color difference signals P _B and P _R output from the low-pass filters 27 to 29 of the video tape recorder 1 are input to the low-pass filters 61 to 63 of the down converter 3, and unnecessary high frequencies are input. The component is removed. The A / D converters 64 to 66 are respectively provided.
A / D converted by, and supplied to and stored in the field memory 68 via the digital signal processing circuit 67. The digital signal processing circuit 67 processes the data stored in the field memory 68 and converts the high-definition video signal into an NTSC video signal. Brightness data is D
A / A converter 69 performs D / A conversion, a low-pass filter 71 removes unnecessary high-frequency components, and a luminance signal Y
Is output as. Further, the color data is D / A converter 70.
After being D / A converted by, the unnecessary high frequency components are removed by the low pass filter 72 and output as the color signal C.

[0010]

As described above, the conventional apparatus is provided with the converter 2 and the down converter 3 separately from the video tape recorder 1, and connects them to the video tape recorder 1 as required. Therefore, the signal is often A / D-converted or D / A-converted, which causes a problem that the image quality is deteriorated. Further, a large number of A / D converters and D / A converters are required, and there is a problem that the cost as a whole becomes high.

The present invention has been made in view of such a situation, and it is possible to prevent deterioration of image quality and reduce cost.

[0012]

A video signal recording / reproducing apparatus of the present invention converts a high-definition television system video signal represented by a high-definition system into a standard television system video signal represented by an NTSC system. It is characterized by including a down converter 104 as a first converting means for converting the signal and an up converter 103 as a second converting means for converting a video signal of the NTSC system into a video of the high definition system.

[0013]

In the video signal recording / reproducing apparatus having the above structure,
An NTSC video signal input from the outside is converted into a high-definition video signal by the built-in up converter 103 and recorded on a recording medium. Further, the HDTV video signal reproduced from the recording medium is converted into an NTSC video signal by the built-in down converter 104 and output.

Therefore, the video signal is A / D converted, and D
The number of times A / A conversion is performed is smaller than in the conventional case, and deterioration of image quality can be prevented. Also, that much A
The number of D / D converters and D / A converters is small, and the cost can be reduced.

[0015]

1 is a block diagram showing the construction of an embodiment of a video tape recorder to which the video signal recording / reproducing apparatus of the present invention is applied. This video tape recorder is a recording / reproducing section 10 for recording or reproducing a high definition video signal.
1 and a conversion unit 102 that converts the video signal system. The conversion unit 102 includes an up converter 103 that converts an NTSC video signal into a high definition video signal, and a down converter 104 that converts an NTSC video signal into a high definition video signal.

A high-definition luminance signal Y and color difference signals P _B and P _R are input to the recording / reproducing unit 101. These signals are supplied to the A / D converters 114 to 116 after unnecessary high frequency components are removed by the low pass filters 111 to 113, respectively. The outputs of the A / D converters 114 to 116 are transmitted via the switches 117 to 119 to the recording / reproducing block 1.
It is designed to be supplied to 24.

The recording / reproducing block 124 has a recording system including a digital signal processing circuit 120, an analog signal processing circuit 121 and a magnetic head 122, a magnetic head 131, an analog signal processing circuit 132 and a digital signal processing circuit 1.
33 and a reproducing system. A signal recorded on the magnetic tape 123 by the magnetic head 122 is reproduced by the magnetic head 131, but one magnetic head 122 and 131 can be shared. Luminance data Y and color difference data P _B , P _{R of} the high-definition system output from the recording / reproducing block 124.
Are D / A converters 134 to 136, respectively.
After the A conversion, unnecessary high frequency components are removed by the low pass filters 137 to 139 and output.

On the other hand, the up converter 103 is an NTSC.
It has a low-pass filter 141 to which a luminance signal Y and a color signal C of the system are input, and a band-pass filter 142. Low-pass filter 141 and band-pass filter 14
The output of 2 is A / D converted by A / D converters 143 and 144 and input to the digital signal processing circuit 145. Digital signal processing circuit 14
The luminance signal Y and the color-difference signals P _B and P _R , which are processed by H. 5 and converted into a high-definition video signal, are respectively passed through the switches 117 to 119 to the digital signal processing circuit 12
It is designed to be supplied to 0. The switch 146 turns on and off the power supplied to the digital signal processing circuit 145.

Further, the down converter 104 converts the luminance data Y and the color difference data P _B and P _R supplied from the digital signal processing circuit 133 into NTSC video data, and a digital signal processing circuit 151. D / A converters 153 and 154 for respectively D / A converting the luminance data Y and the color data C output from
Luminance signal Y output from the D / A converters 153 and 154
The low-pass filter 155 and the band-pass filter 15 which remove the unnecessary components and output the color signal C and the color signal C, respectively.
6 and a switch 152 that controls the supply of power to the digital signal processing circuit 151.

The field memory 147 has a switch 14
9 is provided, and the digital signal processing circuit 14 is provided if necessary.
5 or the digital signal processing circuit 151. That is, the field memory 147 is shared by the up converter 103 and the down converter 104. The switch 148 is switched by the output of the OR gate 150 and controls the power supply of the field memory 147.

The operation will be described below. The high-definition luminance signal Y and the color difference signals P _B and P _R are supplied to the A / D converters 114 to 116 via the low-pass filters 111 to 113 and are A / D converted. Then, it is further supplied to the digital signal processing circuit 120 via the switches 117 to 119. The digital signal processing circuit 120 shuffles the input data, adds a code for error detection and correction, and supplies the code to the analog signal processing circuit 121. The analog signal processing circuit 121 analog-processes the input data and records it on the magnetic tape 123 via the magnetic head 122.

On the other hand, in the case of recording an NTSC system video signal, the luminance signal Y and the color signal C are input to the A / D converters 143 and 144 via the low pass filter 141 and the band pass filter 142, respectively. / D converted. The digital signal processing circuit 145 is the A / D converter 1
The brightness data and the color data input from 43 and 144 are supplied to the field memory 147 via the switch 149 and stored therein. The digital signal processing circuit 145 converts the data stored in the field memory 147 from the NTSC system data to the high definition system data.
Then, the luminance data Y and the color difference data P _B and P _R converted into the high-definition system in this way are switched by the switch 11 respectively.
7 to 119, the analog signal processing circuit 121, the magnetic head 12 are supplied to the digital signal processing circuit 120.
2 is recorded on the magnetic tape 123.

Next, the signal recorded on the magnetic tape 123 is reproduced by the magnetic head 131 and supplied to the analog signal processing circuit 132. Analog signal processing circuit 132
Performs analog processing on the signal input from the magnetic head 131 and supplies the analog signal to the digital signal processing circuit 133. The digital signal processing circuit 133 subjects the input digital data to deinterleaving, error correction, etc.
It is supplied to the A converters 134 to 136 to be D / A converted.
The luminance signal Y and the color difference signals P _B and P _R , which have been D / A converted by the D / A converters 134 to 136, have unnecessary high-frequency components removed by the low-pass filters 137 to 139, respectively. Output to the monitor for
Will be displayed.

When a high-definition video signal recorded on the magnetic tape 123 is viewed on an NTSC monitor, the down converter 104 is operated. That is, at this time, the digital signal processing circuit 151 is
33. Luminance data Y and color difference data P _B , P _R
Is supplied to and stored in the field memory 147 via the switch 149, and converted into NTSC luminance data Y and color data C. The luminance data Y and the color data C are D
After being D / A converted by the A / A converters 153 and 154, respectively, only the necessary frequency band is extracted by the low pass filter 155 and the band pass filter 156 and output to an NTSC monitor (not shown) for display. It

As described above, since the field memory 147 is shared by the up converter 103 and the down converter 104, the number of memories can be reduced and the cost can be reduced.

Further, when the up-converter 103 is not operated, the switch 146 is turned off and the power supply to the digital signal processing circuit 145 is stopped. When the down converter 104 is not operated, the switch 152 is turned off and the digital signal / signal processing circuit 15 is turned on.
The power supply to 1 is stopped. Further, when both the up converter 103 and the down converter 104 are not used, the switch 148 is turned off via the OR gate 150, and the power supply to the field memory 147 is stopped. In this way, by stopping the supply of power to the circuits that are not used, useless power consumption is suppressed.

FIG. 2 is a block diagram showing the configuration of the second embodiment of the video tape recorder of the present invention. The parts corresponding to those in FIG. 1 are designated by the same reference numerals. In this embodiment, the recording / playback unit 101 and the conversion unit 102.
The A / D converter and the D / A converter in 1 are shared. That is, the A / D converters 143 and 144 of the up converter 103 in FIG. 1 are omitted,
The outputs of the low-pass filter 141 and the band-pass filter 142 are A / A via switches 161 and 162, respectively.
It is adapted to be supplied to the D converters 115 and 116. The outputs of the A / D converters 115 and 116 are supplied to the digital signal processing circuit 145.

Similarly, the down converter 10 in FIG.
The four D / A converters 153 and 154 are omitted, and the output of the digital signal processing circuit 151 is supplied to the D / A converters 135 and 136 via the switches 171 and 172, respectively. Then, the D / A converter 135
And 136 outputs are supplied to low pass filters 138 and 139 or low pass filter 155 and band pass filter 156, respectively, via switches 174 and 175, respectively. The output of the D / A converter 134 is also supplied to the low-pass filter 137 via the switch 173 for matching. Other configurations are similar to those in FIG.

That is, in the embodiment of FIG. 2, A /
Since the number of D converters and D / A converters is reduced, the cost can be further reduced as compared with the case of the embodiment of FIG. The operation is similar to that in FIG.

[0030]

As described above, according to the video signal recording / reproducing apparatus of the present invention, the means for mutually converting the video signals of the high-definition television system and the standard devision system is incorporated, so that the image quality is deteriorated. It is possible to prevent this and reduce the cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a video tape recorder to which a video signal recording / reproducing apparatus of the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a second embodiment of a video tape recorder to which the video signal recording / reproducing device of the present invention is applied.

FIG. 3 is a diagram illustrating a relationship between a conventional video tape recorder and an up converter and a down converter.

[Explanation of symbols]

 1 Video Tape Recorder 2 Up Converter 3 Down Converter 101 Recording / Reproducing Unit 102 Converting Unit 103 Up Converter 104 Down Converter 123 Magnetic Tape 124 Recording / Reproducing Unit 147 Field Memory

Claims (3)

[Claims] 1. A video signal recording / reproducing apparatus for recording / reproducing a high-definition television system video signal on a recording medium, wherein the first high-definition television system video signal is converted into a standard television system video signal. And a second converting means for converting the standard television system video signal into the high-definition television system video signal. 2. The video signal recording / reproducing apparatus according to claim 1, further comprising a power supply stopping means for stopping the supply of power when the first or second converting means is not used. . 3. The video signal recording / reproducing apparatus according to claim 1, wherein the first and second conversion means further include a common storage means for storing data during format conversion.