JPH06133334A - Recording and reproducing device for edtv television signal - Google Patents

Abstract

PURPOSE:To record a video signal with high picture quality and high definition for the letter box system EDTV and the NTSC system by implementing demodulation processing to a vertical and a horizontal reinforcement signal in the letter box system EDTV system and implementing the masking processing in the NTSC system. CONSTITUTION:The demodulation processing using a vertical reinforcement signal and a horizontal reinforcement signal is applied to a television signal of the letter box EDTV system to convert the signal into a picture signal series and the converted picture signal series is recorded. Furthermore, the two kinds of the video recording modes as the standard mode and the wide mode corresponding to two kinds of patterns whose aspect ratio is 4:3 and 16:9 are provided and the masking processing suitable for each mode in the television signal of the NTSC and the letter box system EDTV is applied to the television signal, it is converted into the picture signal series and recorded. That is, the input television signal of the letter box system EDTV is a standard form signal without jitter and the superimposed vertical and horizontal reinforcement signals are correctly demodulated to the original high frequency component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal recording / reproducing device, and more particularly to an analog recording system recording / reproducing device for recording both television signals of the current NTSC system and letterbox system EDTV.

[0002]

2. Description of the Related Art Development of an EDTV, which has compatibility with the current NTSC system, aims for a wider screen, higher definition, and higher image quality, and provides higher quality realistic TV images Has been.

Of these, the letterbox EDTV
Is for transmitting and receiving a horizontally long image having a horizontally long aspect ratio different from 4: 3 by providing non-image areas at the top and bottom of the screen, and is being studied as the next-generation television system in Japan. .

In this letterbox EDTV, vertical reinforcement signals for improving the vertical resolution are provided in the upper and lower non-image areas of the screen, and horizontal resolution is provided for the horizontally long image area. A television signal is formed by superimposing horizontal reinforcement signals and the like. Then, on the image receiving side, a high-definition television image is reproduced by using these vertical reinforcement signal and horizontal reinforcement signal.

The letterbox EDTV television signal is compatible with the current NTSC television signal in terms of transmission line and receiver. Therefore, it can be received by the current receiver, and the current home V
It is also possible to record on a CR or the like. That is,
If the deterioration of image quality is allowed to some extent, a television signal of a letterbox EDTV can be recorded even by a conventional recording / reproducing apparatus of an analog recording system such as a home VCR.

[0006]

The television signal reproduced by the above-mentioned recording / reproducing apparatus of the prior art contains jitter and is a non-standard signal in which the phase relationship of color subcarriers is different from the normal standard. . On the other hand, letterbox ED
In the TV, it is necessary to perform signal processing such as time-series conversion, time axis expansion, inter-field calculation, etc. for demodulation of the vertical reinforcement signal and the horizontal reinforcement signal on the image receiving side. However, in the recording / reproducing apparatus of the prior art, it is almost impossible to perform the above-mentioned signal processing because the reproduced signal contains jitter and the like, and it becomes difficult to correctly demodulate the vertical reinforcing signal and the horizontal reinforcing signal. . Therefore, in the recording according to the conventional technique, the image reproduction is performed without using these reinforcement signals, which causes a problem that the image quality is deteriorated such as the reduction of the resolution.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a recording / reproducing apparatus of an analog recording system capable of reproducing a television signal of a letter box system EDTV with a high resolution image quality and recording an NTSC system television signal.

[0008]

In order to achieve the above object, in the present invention, an image signal sequence is obtained by demodulating a television signal of a letterbox EDTV using a vertical reinforcement signal and a horizontal reinforcement signal. A means for converting and recording the converted image signal series is adopted. Also,
In the present invention, two kinds of recording modes, that is, a standard mode and a wide mode corresponding to a screen having an aspect ratio of 4: 3, 16: 9 are provided, and NTSC and letterbox type EDT are provided.
A means for converting and recording an image signal sequence in which a V television signal is subjected to masking processing suitable for each mode is adopted.

[0009]

Since the input television signal of the letter box EDTV is a standard signal without jitter, the superimposed vertical reinforcement signal and horizontal reinforcement signal are correctly demodulated to the original vertical high frequency component and horizontal high frequency component. be able to. Then, recording / reproduction is performed on a high-definition image signal sequence obtained by adding these high-frequency components to the signal of the horizontally long image portion.
Therefore, unlike the prior art, the present invention does not require demodulation processing of the vertical reinforcement signal and the horizontal reinforcement signal with respect to the reproduction signal, and can reproduce a high-definition image signal sequence including jitter.

Further, in the present invention, either the standard mode or the wide mode is selected and recorded in accordance with the aspect ratio of the image receiver owned, so that the aspect ratio is either 4: 3 or 16: 9. NTS in the most suitable form for the machine
C, It can receive recorded images of letterbox EDTV.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the overall block diagram shown in FIG.

The input television signal VS (NTSC or letterbox EDTV signal) is sent to the A / D converter 1
Then, for example, sampling is performed at a frequency that is four times as high as the color subcarrier fsc of the NTSC system and converted into a digital signal VSD.

The auxiliary signal demodulation unit 2 performs signal processing for separating and demodulating the vertical reinforcement signal superimposed on the upper and lower non-image areas of the screen of the letterbox EDTV, and demodulates the vertical high frequency component VH of the luminance. .

The image signal demodulation unit 3 separates the luminance / color signal,
The color demodulation and the signal processing for separating and demodulating the horizontal reinforcement signal superimposed on the horizontally long image portion of the letterbox EDTV are performed to generate a luminance signal Y, a color difference signal IQ, and a color signal C.

The 3-4 conversion unit 4 displays the horizontally long image portion of the television EDTV on the entire screen having an aspect ratio of 16: 9. Therefore, the vertical high frequency component VH is used for the luminance signal to determine the number of scanning lines. Signal processing of 3-4 conversion is performed. And N
Same scanning mode as TSC system (525 scanning lines, 30 scanning lines)
A luminance signal YWE having 480 effective pixel scanning lines in a frame, 2: 1 interlaced scanning) is generated. Also, 3-4
The conversion unit 7 has three to four scanning lines for the color difference signals I and Q.
The conversion and color modulation signal processing is performed to generate a color signal CWE having the same scanning form as the NTSC system and having 480 effective pixel scanning lines.

In the time axis compression unit 5, NTSC is provided with masking areas on both sides of the screen having an aspect ratio of 16: 9.
In order to display an image with an aspect ratio of 4 to 3, the number of pixels in the horizontal direction is converted to 4 to 3, and the time axis compression (3 /
4), signal processing such as time series conversion and masking processing is performed, and luminance signal YWN and color signal C compatible with the NTSC system
Generate WN.

On the other hand, the masking section 6 displays a horizontally long image of a letterbox type EDTV in which the upper and lower non-image areas of the screen having an aspect ratio of 4: 3 are masked, so that the upper and lower screens of the luminance signal are not displayed. By performing masking processing on the image area, a luminance signal YSE having the same scanning mode as the NTSC system and having 360 effective pixel scanning lines is generated.

In the selection circuit 8, if the input television signal is a letterbox type EDTV, the signals YWE, C are used.
Signals YWN, Y, CWN in case of WE, NTSC system
Are selected and output as signals YW, YS, and CW, respectively. The selection control is performed by the control signal VSMD generated by detecting the presence or absence of the identification signal of the input television signal in the identification unit 9 (letter box EDTV).
The television signal has an identification signal added so that it can be discriminated from the NTSC system. ).

On the other hand, in the selection circuit 10, the aspect ratio 16 is selected according to the recording mode signal RMD of the standard mode or the wide mode which is selected according to the form of the receiver owned by the user.
In the wide mode corresponding to the pair 9 receiver, signals YW and C
In the standard mode corresponding to a receiver having W and an aspect ratio of 4: 3, the signals YS and C are selected and output.

These signals are converted into analog signals RY and RC by the D / A converter 11 and input to the recording modulator 12. If the input television signal is an S-mode signal (composed of two types of signals, a luminance signal and a color signal), this signal is input to the recording modulator 12.

The recording modulator 12 performs predetermined signal processing necessary for performing analog recording, such as color under recording, similar to the conventional technique. Then, the signal is recorded on the recording medium 14 through the recording amplifier 13.

Above, the description of the recording section shown in FIG. 9A is completed, and then the reproducing section in FIG. Recording medium 1
The signal reproduced from No. 4 is amplified by the preamplifier 15 and input to the reproduction demodulation unit 16.

The reproducing / demodulating section 16 performs a predetermined signal process opposite to that of the recording section to demodulate the luminance signal Y and the color signal C.
Then, the adder circuit 17 adds the luminance signal and the chrominance signal and converts them into a composite type signal.

The process units 18 and 19 add predetermined synchronizing signals, burst signals, etc. to produce output television signals VSO and S mode signals in composite form.

FIG. 2 is a form diagram of a recorded image obtained in the present invention. In recording in a standard mode corresponding to a receiver with an aspect ratio of 4: 3, an NTSC television signal has an image with 480 effective pixel scanning lines, and a letterbox EDTV television signal has a specific upper and lower screen. An image having 360 effective pixel scanning lines masked with a signal is reproduced.

On the other hand, in recording in a wide mode corresponding to a receiver having an aspect ratio of 16: 9, an NTSC television signal has 480 effective pixel scanning lines in which both sides of the screen are masked with specific signals. The image and the television signal of the letterbox EDTV are reproduced with an image having 480 effective pixel scanning lines.

In any mode, the scanning form is NT.
The same number of scanning lines as the SC system, 525 lines, 30 frames,
It is a 2: 1 interlaced scan.

Each block section in this embodiment will be described below.

First, the 3-4 converter will be described with reference to FIGS. FIG. 3 shows an outline of signal processing of 3-4 conversion of the number of scanning lines. As shown in FIG. 3A, the number of effective pixel scanning lines is 480 based on the signals of three scanning lines x, y, z having 360 effective pixel scanning lines (hereinafter abbreviated as 360I system). The signals of four scanning lines a, b, c, d of the present (hereinafter abbreviated as 480I system) are generated. An example of a conversion matrix used for 3-4 conversion of this scanning line is shown in FIG. Regarding the low-frequency component of the luminance signal, the matrix calculation of the inverse matrix of the conversion matrix used in the 4 to 3 conversion on the image transmission side of the letterbox EDTV and the signals of the scanning lines x, y, z and the vertical high-frequency component VH. By scan line a,
b, c, d signal components are generated. On the other hand, with respect to the high frequency component (1 MHz or more) of the luminance signal and the color difference signal, the signal components of the scanning lines a, b, c, d are generated by, for example, the calculation by the conversion matrix of the characteristic of linear interpolation.

FIG. 4 shows a 3-4 conversion unit 4 for the luminance signal.
FIG. 7A is a configuration diagram and FIG. 8B is an operation explanatory diagram of signal processing.

The signals of the scanning lines x, y, z of the signal Y (360I system) are written in the RAM 20 by the WT operation. On the other hand, this reading is performed by the RD operation of reading the signals of the scanning lines x, y, z in a cycle of four scanning lines, and the signal YR
Generate D. Then, the conversion matrix calculation units 21 and 2
In 2, the calculation is performed by the conversion matrix shown in (2) and (1) of FIG. And HPF
In the circuit 23, the high frequency component (1 MHz or more), the LPF circuit 2
In 4, the low frequency component (1 MHz or less) is extracted, and the addition circuit 2
Both are added at 5. Then, the luminance signal YWE converted into the 480I system by the 3-4 conversion of the scanning line is generated.

FIG. 5 shows a 3-4 conversion unit 7 for color difference signals.
FIG. The color difference signals I and Q (360I system) signals are subjected to the same signal processing operation as that shown in FIG. 4 by the RAM 20 and the conversion matrix calculation unit 21 to generate the 480I system color difference signals IW and QW. Then, the color modulation unit 26 performs quadrature amplitude modulation using the color subcarrier fsc, and
An 80I system color signal CWE is generated.

Next, the time axis compression section will be described with reference to FIGS.
Described in. First, the outline of the signal processing will be described with reference to FIG. As shown in FIG. 6A, signal processing of 4 to 3 conversion of sampling points is performed to compress the time axis by 3/4. That is, three sample points X, Y, Z from the four sample points A, B, C, D pixels.
Generate a signal sequence of pixels. Then, the time axis of this signal sequence is compressed by 3/4 to realize the signal processing of time axis compression. FIG. 11B is a conversion matrix when the 4 to 3 conversion of the sample points is realized by the characteristic of linear interpolation.

FIG. 7 shows an embodiment of the time axis compression unit 5 for the luminance signal. The conversion matrix calculation unit 27 uses the conversion matrix shown in FIG.
3 conversion processing is performed, and the effective pixel number of one scanning line is 76
From the eight signals Y, the number of effective pixels is 576 (768 × 3 /
4) The signals of the pixels X, Y, and Z which have been converted into 4 to 3 are generated. Then, by the WT operation shown in FIG.
The signals of the pixels X, Y, and Z that have been converted from 4 to 3 are written in. On the other hand, the signal YTC is continuously read out from the RAM 28 by the RD operation and the time axis is compressed by 3/4 to generate a signal YTC having 576 effective pixels. In the selection circuit 29, the signal YTC
In the period of the shaded area where there is no shadow masking signal YMSK having a specific value (for example, black or gray) is selected and output, both sides of the screen are masked, and the time axis is set to 3
A luminance signal YWN that is / 4 times compressed is generated.

FIG. 8 shows an embodiment of the time axis compression unit 5 for color difference signals. With respect to the color difference signals I and Q, the conversion matrix calculation unit 27, the RAM 28, and the selection circuit 29 perform the same signal processing as in the embodiment of FIG. ) Masking processing is performed, and a signal whose time axis is compressed by 3/4 is generated. Then, the color modulator 26 performs quadrature amplitude modulation by the color subcarrier fsc to generate a color signal CWN.

Next, one embodiment of the image signal demodulation section 3 is shown in FIG.
Shown in. In the YC separation unit 30, for example, the luminance signal and the color signal are separated in a horizontal / vertical two-dimensional frequency domain, and the luminance component SY and the color component SC are extracted. Color demodulator 3
In 1, synchronous detection is performed by the color subcarrier fsc to generate color difference signals I and Q. Further, the delay circuit 32 adjusts the time delay due to the signal processing of color demodulation to generate the luminance signal Y and the color signal C.

FIG. 10 shows another embodiment of the picture signal demodulation unit 3, which is suitable for a television signal in which a horizontal reinforcement signal is superimposed on a horizontally long image portion of a letterbox EDTV.

In the YC separation unit 30, for example, horizontal / vertical /
The luminance signal and the color signal are separated in the three-dimensional frequency domain of time, and the luminance component SY and the color component SC are separated. The color component SC is subjected to synchronous detection by the color subcarrier fsc in the color demodulation unit 31 to generate color difference signals I and Q. The horizontal reinforcement signal separating unit 33 extracts the horizontal reinforcement signal HH superimposed on the horizontally long image portion in the three-dimensional frequency domain of horizontal, vertical and time. Note that the horizontal reinforcement signal HH does not exist in the NTSC system television signal. Therefore, the control signal VSM
In the case of an NTSC system television signal, a zero component signal is output as HH. The demodulation unit 34 performs synchronous detection using the subcarrier μ ₀ to obtain a horizontal high frequency component Y of luminance.
H (4.2 MHz or higher) is generated. Then, this signal is added to the horizontal low-frequency component YL (4.2 MHz or less) of the luminance by the addition circuit 35 to generate the luminance signal Y.

Next, one embodiment of the masking section 6 is shown in FIG.
Shown in 1. In the selection circuit 36, a letterbox type ED
The signal Y (360I system) is displayed during the period of the main part area corresponding to the horizontally long image part of the TV, and the masking signal YMSK is selected and output in the non-image part areas above and below the screen shown in the perspective view of FIG. To generate a luminance signal YSE.

Next, an embodiment of the recording modulator 12 is shown in FIG.
2 will be described. This is suitable for recording by the color under system and can be realized with the same configuration as the conventional technique.

In the selection circuit 37, the input signal is NTSC,
In the case of a letter box type EDTV television signal, the luminance signal RY, the color signal RC, and the S mode signal are selected and output. The main emphasis unit 38 performs predetermined high-frequency emphasis signal processing on the luminance signal. In the clip part 39,
The level is limited so that the signal level falls within a predetermined level range. The FM modulator 40 performs predetermined low carrier FM modulation processing, and the HPF 41 extracts high frequency components. Then, the recording signal of the luminance signal component is generated. On the other hand, the color signal is frequency-shifted to a low frequency band signal by an AM modulation operation in the frequency conversion unit 42, and a predetermined low frequency component is extracted by the LPF 43 to generate a recording signal of the color signal component. Then, the addition section 44 adds the two signals to generate a recording signal of a predetermined form. This recording signal is recorded on a recording medium through a recording amplifier and a rotary transformer.

Next, an embodiment of the reproduction / demodulation unit 16 will be described with reference to FIG.

The signal read out from the recording medium via the rotary transformer and amplified by the preamplifier is input to the reproduction / demodulation section. The HPF 41 and the LPF 43 respectively extract predetermined high-frequency components and low-frequency components, and reproduce the FM-modulated luminance signal component and the frequency-shifted chrominance signal component, respectively. The equalizer section 45 performs signal processing for waveform equalization that compensates for waveform distortion that occurs during recording and reproduction, and the limiter section 46 performs limiter processing that limits the signal level within a specific range. The FM demodulation unit 47 performs predetermined FM demodulation signal processing, the LPF 48 extracts the low-frequency component, and demodulates the luminance signal. Then, the de-emphasis section 49 performs de-emphasis processing with characteristics opposite to those on the recording side to reproduce the original luminance signal Y.

On the other hand, the amplitude control of the color signal component is performed by the ACC section 50 so that the level of the burst signal becomes a specific constant value. Then, the frequency conversion unit 51 performs demodulation by detection processing, the BPF 52 extracts a predetermined band component, and reproduces the original color signal C.

As described above, according to this embodiment, the NTSC system,
It is possible to realize a recording / reproducing apparatus for an analog recording type television signal which records any letterbox type television signal with high image quality and high definition with little deterioration in image quality.

In the case of the television signal of the letterbox EDTV, when the S / N ratio of the input signal is poor, the noise added to the vertical reinforcement signal is converted into a visually noticeable noise component by the demodulation process and reproduced. In the image, the image quality deteriorates. Therefore, in the 3 to 4 converter 4 of the present embodiment, the vertical high frequency component VH of the luminance obtained by demodulating the vertical reinforcement signal is not used in the case of a signal having a poor S / N ratio, and FIG.
It is possible to avoid the image quality deterioration due to the deterioration of the S / N ratio by adopting the configuration of performing the 3-4 conversion processing of the scanning line by using the signal shown by the dotted line.

[0047]

According to the present invention, the letterbox system E
An analog recording type television signal recording / reproducing apparatus capable of recording a DTV television signal with high image quality and high definition and also recording an NTSC type television signal with high image quality can be realized.

[Brief description of drawings]

FIG. 1 is an overall block configuration diagram of an embodiment of the present invention.

FIG. 2 is a form diagram of a recorded image according to the present invention.

FIG. 3 is a schematic diagram of signal processing in a 3-4 conversion unit.

FIG. 4 is a diagram showing an example of a 3-4 conversion unit for a luminance signal.

FIG. 5 is a diagram showing an embodiment of a 3-4 conversion unit for color signals.

FIG. 6 is a schematic diagram of signal processing in a time axis compression unit.

FIG. 7 is a diagram showing an embodiment of a time axis compression unit for a luminance signal.

FIG. 8 is a diagram showing an embodiment of a time axis compression unit for color signals.

FIG. 9 is a diagram showing an embodiment of an image signal demodulation unit.

FIG. 10 is a diagram showing an embodiment in which a horizontal reinforcement signal is used in an image signal demodulation section.

FIG. 11 is a diagram illustrating an example of a masking unit.

FIG. 12 is a diagram showing an embodiment of a recording modulator.

FIG. 13 is a diagram showing an embodiment of a reproduction / demodulation unit.

[Explanation of symbols]

1 ... A / D converter, 2 ... Auxiliary signal demodulator, 3 ... Image signal demodulator, 4, 7 ... 3-4 converter, 5 ... Time axis compressor, 6 ...
Masking unit, 8, 10 ... Selection circuit, 9 ... Identification unit, 11
... D / A conversion section, 12 ... Recording modulation section, 13 ... Recording amplifier, 14 ... Recording medium, 15 ... Preamplifier, 16 ... Reproduction / demodulation section, 17 ... Addition section, 18, 19 ... Process section, 20 ...
RAM, 21, 22 ... Transformation matrix operation unit, 23 ... H
PF circuit, 24 ... LPF circuit, 25 ... Adder circuit, 26 ...
Color modulation unit, 27 ... Conversion matrix calculation unit, 28 ... RA
M, 29 ... Selection circuit, 30 ... YC separation section, 31 ... Color demodulation section, 32 ... Delay circuit, 33 ... Horizontal reinforcement signal separation section, 34
... Demodulator, 35 ... Adder circuit, 36, 37 ... Selection circuit, 3
8 ... Main emphasis part, 39 ... Clip part, 40 ...
FM modulator, 41 ... HPF, 42 ... Frequency converter, 43
... LPF, 44 ... Adder, 46 ... Equalizer, 46 ...
Limiter section, 47 ... FM demodulation section, 48 ... LPF, 49 ...
De-emphasis section, 50 ... ACC section, 51 ... Frequency conversion section, 52 ... BPF.

Claims (3)

[Claims] 1. A television signal recording / reproducing apparatus for analog recording of an NTSC television signal and a letterbox EDTV television signal, wherein two types of recording modes, a standard mode and a wide mode, are provided, and recording in the standard mode is performed. Has an aspect ratio of 4 to 3
The image displayed on the screen is full screen for NTSC television signals, and for letterbox EDTV television signals, it has a horizontally long aspect ratio with masked non-image areas at the top and bottom of the screen. In the recording by the image signal in the form of being displayed as an image and the recording in the wide mode, the display image on the screen having the aspect ratio of 16: 9 is a non-image part in which the NTSC television signal is masked on both sides of the screen. An EDTV television signal recording / reproducing apparatus characterized in that an image having an aspect ratio of 4: 3 and a letterbox EDTV television signal having a region are recorded by an image signal in a form of being displayed on a full screen. 2. The EDTV according to claim 1, wherein the video signal recording system is a color under recording system.
Recording and reproducing device for television signals. 3. The EDTV television signal recording / reproducing apparatus according to claim 1, wherein a user selects a recording mode in the standard mode or a recording mode in the wide mode.