JPH0654301A - Simple edtv decoder - Google Patents

Abstract

PURPOSE:To obtain a letter box system EDTV decoder where a picture is reproduced with a well-balanced resolution characteristic from a still part to an animation part, a signal is easily processed and profitability is superior with the small quantity of required memory capacitance. CONSTITUTION:A luminance component Y and a chrominance component C are separated to a letter box system EDTV signal V1 by a horizontal/vertical two-dimensional YC separation processing. Then, scanning line 3-4 conversion is processed by an interlace scanning system so that the picture with 480 valid pixel scanning lines are reproduced in the display part where an aspect ratio is 16:9 with the 525 scanning lines, 30 frames and 2:1 interlace scanning. In order to prevent the degradation of picture quality caused by superposed reinforcing signals, the picture is reproduced without using these reinforcing signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal receiver, and more particularly, to a horizontal image having an aspect ratio of 16: 9, which is compatible with the current television system, and has a non-image area at the top and bottom of the screen. The present invention relates to a simplified EDTV decoder device suitable for receiving a letter box type EDTV television signal for transmitting and transmitting an image.

[0002]

2. Description of the Related Art EDT that provides higher image quality, higher definition of television images, and wider screens and provides a more realistic image service while maintaining compatibility with current television systems.
V research and development is underway.

There are various types of EDTV implementations. Among them, the letterbox EDTV is excellent in compatibility with the current television system, and is therefore considered to be the most likely system to be adopted in Japan. . This has an aspect ratio of 1
This is a method of transmitting a 6: 9 landscape image by providing non-picture areas on the top and bottom of the screen, and superimposing a reinforcement signal on the top and bottom non-picture areas and landscape image areas to improve horizontal and vertical resolution. And configure the television signal.

On the image receiving side, in order to reproduce a high-quality and high-definition image by displaying a horizontally long image in a full screen on a display unit with a wide aspect ratio of 16: 9, motion adaptive three-dimensional YC separation and vertical reinforcement are performed. It is expected to perform demodulation processing by advanced signal processing technology such as vertical resolution improvement by scanning conversion from interlaced scanning using signals to progressive scanning and conversion of the number of scanning lines, and widening of luminance signals using horizontal reinforcement signals. ing. Further, a study on a signal processing method for faithfully realizing these demodulation processes is also underway. It should be noted that Japanese Patent Application Laid-Open No. Hei 1
Examples thereof include those described in JP-A-258581, JP-A-2-113688, JP-A-3-179986, and JP-A-3-206788.

[0005]

In the above prior art,
On the image receiving side, in order to demodulate the reinforcement signal superimposed on the non-image area and the horizontally long image area at the top and bottom of the screen into the original vertical high-frequency component and horizontal high-frequency component, separation by motion adaptive three-dimensional signal processing or time It is necessary to perform complex signal processing such as sequence conversion, rearrangement, and time axis expansion. Moreover, in order to realize these signal processing, the memory capacity is 10 to 20 Mb.
It needs about it. Further, the display is performed in the form of progressive scanning. Therefore, there is a problem that the cost of the image receiving device becomes extremely high.

Further, the vertical reinforcement signal is easily affected by noise, and in an image receiving situation where the S / N is poor, these noise components are converted into low frequency components to cause annoying image quality disturbance, resulting in a significant deterioration in image quality. There's a problem.

Furthermore, the resolution of the moving image part is lowered due to the motion adaptive three-dimensional processing, and the imbalance of the resolution occurs between the still part and the moving image part, and the reproduced image is unnatural even in the image receiving condition with a good S / N. There is a problem of feeling.

The object of the present invention is to solve the above problems,
A simple ED that can reproduce images with a sense of naturalness and stability with well-balanced resolution characteristics from the static part to the moving image part, and also can realize the cost of the image receiving device at a low price and is excellent in economic efficiency.
It is to provide a TV decoder device.

[0009]

According to the present invention, in order to achieve the above object, in the demodulation of a composite format signal in a horizontally long image area, a luminance signal component and a chrominance signal component are separated horizontally and vertically in two dimensions. It is performed by signal processing of YC separation. Also,
Conversion of the number of scanning lines necessary for displaying the horizontally long image part on the display unit having an aspect ratio of 16: 9 in a full screen (for example, a signal of 360 effective pixel scanning lines is converted into a signal of 480).
Performs signal processing in a 2: 1 interlaced scanning system.
Then, in the display unit with the aspect ratio of 16: 9, the current N
An image is displayed by the same scanning mode as that of the TSC system television signal, that is, the number of scanning lines is 525, 30 frames / sec, and 2: 1 interlace scanning.

In the present invention, the letterbox system E is used.
A vertical reinforcement signal, a horizontal reinforcement signal, etc. superimposed on a DTV television signal are not reproduced and are not used in image reproduction.

[0011]

In the present invention, the letterbox type EDT is used.
Demodulation processing such as YC separation and scanning line number conversion is performed on the horizontally long image area of the V television signal, and no demodulation processing is performed on auxiliary signals. Therefore, it can be realized by simple signal processing, and the memory capacity required for this can be significantly reduced. In addition, the display is also the current NT
Since the 2: 1 interlaced scanning has the same form as the SC system television signal, it can be realized at an extremely low cost as compared with the progressive scanning system. Therefore, according to the present invention, it is possible to provide an image receiving device which is extremely low in cost and excellent in economic efficiency.

In the present invention, all signal processing is horizontal.
It is realized by vertical two-dimensional in-field calculation, and calculation in the time direction is not performed. Also, the parameters are fixed, and motion adaptive processing is not performed. Therefore, it is possible to achieve a well-balanced resolution characteristic from the still portion to the moving image portion, and it is possible to reproduce an image with a natural feeling and a stable feeling.

Further, according to the present invention, since the auxiliary signals are not reproduced, the deterioration of the image quality due to the auxiliary signals can be avoided even in the image receiving condition where the S / N is bad, and a high quality reproduced image can be received. can do.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the overall block diagram shown in FIG. This is suitable for receiving a baseband television signal of a letterbox EDTV.

A letter-box EDTV baseband television signal VI (the horizontal image portion of the main portion area is composed of, for example, 360 effective pixel scanning lines) is A /
The D conversion unit 1 performs sampling with a frequency that is, for example, four times as high as the color subcarrier fsc, and converts it into a digital signal VID.

In the YC separation unit 2, horizontal and vertical two-dimensional Y
The luminance component and the color component are separated by the characteristic of C separation, and the luminance signal Y and the color signal C of the main area are separated and extracted.

The color demodulation section 3 generates a signal IQT in which the color difference I and Q signals reproduced by the synchronous detection by the color subcarrier fsc are multiplexed in a time division manner.

The scanning line 3-4 conversion unit 4 performs scanning line number conversion by 3-4 conversion processing, and the effective pixel scanning line number is 3
A signal series Yw and IQTW having 480 effective pixel scanning lines is generated from 60 signal series.

The color-difference signal reproducing section 5 separates the color-difference I and Q components, which are time-division multiplexed by the signal IQTW, and produces color-difference signals IW and QW by interpolation processing.

The RGB conversion section 6 converts the YIQ sequence into the three primary color RGB sequences, and thus performs a predetermined matrix operation to generate the three primary color signals RD, GD and BD.

The D / A converter 7 performs conversion into analog signals to generate analog three primary color signals R, G, B. In the wide aspect ratio display unit 8, the aspect ratio is 16: 9, the scanning mode is the same as the current NTSC television signal, the number of scanning lines is 525, and 30 frames /
An image having 480 effective pixel scanning lines is displayed by second 2: 1 interlaced scanning.

The control signal generator 9 generates signals necessary for the above signal processing.

Next, each block portion in this embodiment will be described.

FIG. 2 shows an example of the YC separation unit 2.
(A) shows a structure, (b) shows a separation characteristic in a horizontal / vertical two-dimensional frequency domain. The LPF circuit 10 extracts a horizontal 2 MHz or less component as a signal YL as shown in (b). On the other hand, the subtraction circuit 11 subtracts the signal YL from the signal VID to extract a horizontal component of 2 MHz or more as the signal VIH. Since luminance and color signal components are mixed in this signal, a line comb filter is configured by combining the 1H delay circuit 12, the coefficient weighting circuit 13, and the adding circuit 14, and the color component is extracted.

In other words, the coefficient delayed by the 1H delay circuit 12 for one scanning line period is multiplied by the coefficient weighting circuit 13 to obtain the coefficient value −
1/4, 1/2, and -1/4 are weighted, respectively, and these are added by the adder circuit 14 to separate and extract the component of the dot area of (b) as the color signal C. Then, the subtraction circuit 11 subtracts the signal C from the signal VIHD, and the shaded area in (b) is extracted as the luminance mid-range component YM. And adder circuit 1
In step 4, the signal YL is added to the signal whose time delay is adjusted by the 1H delay circuit 12 to separate and extract the luminance signal Y.

Another embodiment of the YC separation unit 2 is shown in FIG. In the figure, (a) is a structure of the YC separation unit, (b) is horizontal
The separation characteristic in a vertical two-dimensional frequency domain is shown. The 1H delay circuit 12, the coefficient weighting circuit 13, and the adding circuit 14 are combined to form a line comb filter, and the BPF circuit 15 extracts a component of horizontal 2 MHz or more of this output, and the area of the dot portion in (b) is extracted. The component is separated and extracted as the color signal C. Then, the subtraction circuit 11 outputs the signal VID to the 1H delay circuit 12
The signal C is subtracted from the signal VIDD whose time delay has been adjusted in step 1 to separate and extract the luminance signal Y.

Next, FIG. 4 shows an embodiment of the color demodulation unit 3. The figure (a) is a structure and the figure (b) is a signal in each part.
Since the A / D conversion unit 1 described above performs sampling with the phase of the color difference I and Q signals, the color signal C is represented by (b) and (1) in FIG.
As shown in, the sample value at every T = 1/4 fsc is a signal sequence of I, Q, −I, and −Q at every 4 sample point periods. Therefore, with respect to this color signal C, cos2πfst and sin2πfsct (where t =
nT, T = 1/4 fsc)
Color difference signals IO and QO shown in (2) and (3) of (b) are obtained. Then, the selection circuit 17 alternately selects and outputs the signals IO and QO for each sampling point to form a signal IQT in which the color difference I and Q signals are time-division multiplexed for each sampling point.

Next, regarding the scanning line 3-4 conversion section 4,
This will be described with reference to FIGS. 5 and 6. First, the operation principle is shown in FIG.
Shown in. As shown in (a) of the figure, letterbox method E
The number of effective pixel scanning lines forming the main part of the DTV is 360
The signal of the horizontally long image portion of the book is displayed as a signal of which the number of effective pixel scanning lines of the full screen is 480 on the display portion having an aspect ratio of 16: 9. Therefore, it is necessary to perform a scanning line number conversion process for converting the number of scanning lines from 360 to 480. An example of a characteristic of 3-4 conversion of scanning lines that realizes the scanning line number conversion processing in a 2: 1 interlaced scanning system is shown in FIG. In the period of the first field of the interlaced scanning, the coefficient values ai, b are added to the signals of the scanning lines L ₁₁ , L ₁₂ , L ₁₃ , ...
i are weighted and added, and 480 scanning lines LW ₁₁ and LW
₁₂ , LW ₁₃ , ... Signals are generated. In the period of the second field, the scanning lines L ₂₁ , L ₂₂ , L _23, ...
Are added and weighted with the coefficient values ai and bi to generate scanning lines LW ₂₁ , LW ₂₂ , LW ₂₃ , ... Of 480 lines. Even in the 480 line system in which the number of scanning lines is converted, the value is 2:
Coefficient value a so that the relationship of 1 interlaced scanning is satisfied
i and bi are different from each other in the period of the first field and the period of the second field.

FIG. 6 shows an embodiment of the scanning line 3-4 conversion section 4 for performing the 3-4 conversion. In the memory circuit 18, the scanning lines (first and second field periods 18 in the first and second field periods, respectively) in the horizontally long image portion area of the main portion are operated by the WT operation shown in FIG.
A total of 360 signals are stored with 0 signal. On the other hand, from the memory circuit 18, by the RD operation of FIG. 6B, the operation of reading out the signals of the same scanning line for every 3 scanning lines is repeated in each field in 240 scanning line periods. The signal RDS of the form shown in 4) is read out. Then, this signal and the signal delayed by one scanning line period by the 1H delay circuit 12 are weighted by the coefficients weighting circuit 19 with the coefficients ai and bi, and the addition circuit 14 adds both of them to perform scanning line number conversion 480. A 2: 1 interlaced scanning signal sequence of this system is obtained. The control circuit 20 performs RD of the memory circuit 18, generation of control signals necessary for WT operation, and setting of coefficient values ai and bi. The coefficient weighting circuit 19 can be realized by a table lookup using a ROM.

Next, an embodiment of the color difference signal reproducing section 5 is shown in FIG. The dividing circuit 21 divides the signal IQTW of the form shown in (b) and (1) of the figure into components of color difference I and Q signals, respectively, and inserts a value of 0 at the missing sampling point (b ) Signals IWO and QW in the form shown in (2) and (3)
Make O. Then, the LPF circuits 22 and 23 extract the low frequency components to reproduce the color difference signals IW and QW.

Next, FIG. 8 shows an embodiment of the RGB converter 6. In the matrix coefficient weighting circuit 24, the color difference signal I
A predetermined matrix coefficient is weighted on W and QW, and the addition circuit 1
In step 4, these signals and the luminance signal YW are added, and the three primary colors R
The signals RS, GS, and BS converted into the GB system are generated. In the selection circuit 25, the signals RS, GS, B are supplied during the period of the image area.
S, the signal BLKS (reference signal corresponding to the black level) is selected and output in the period of the blanking area, and the three primary color signals R
Obtain D, GD, BD.

The A / D converter 1, the D / A converter 7,
Control signal generator 9 and wide aspect ratio display 8
Since the above can be easily realized by the conventional technique, description thereof will be omitted.

As described above, according to this embodiment, an ED which receives a letterbox type EDTV television signal with a well-balanced resolution characteristic, is low in cost, and is excellent in economical efficiency.
A TV decoder device can be realized.

Next, a second embodiment of the present invention will be described with reference to the overall block diagram shown in FIG. This is suitable for receiving a letterbox EDTV and a current NTSC baseband television signal.

A baseband television signal VI (a horizontally long image portion of a letterbox type EDTV, assuming that the number of effective pixel scanning lines in the NTSC system is 360 and 480, respectively) is supplied to the A / D converter 1. Sampling is performed at sampling points of a phase synchronized with the color difference I and Q components at a frequency that is, for example, four times the frequency of the color subcarrier fsc, and converted into a digital signal VID.

In the YC separation unit 2, horizontal and vertical two-dimensional Y
The luminance component and the color component are separated by the characteristic of C separation, and the separated and extracted luminance signal Y and color signal C are output.

The color difference signal demodulation section 26 synchronously detects the color signal C with the color subcarrier fsc, extracts the low frequency component thereof, and demodulates the color difference signals I and Q.

In the scanning line 3-4 conversion section 4, the number of scanning lines is 3
The number of scanning lines is converted by the .about.4 conversion processing, and a signal of 480 effective pixel scanning lines and 2: 1 interlaced scanning is generated from a signal of 360 effective pixel scanning lines and 2: 1 interlaced scanning.

In the pixel 4 to 3 conversion section 27, the number of effective pixels included in each scanning line is exchanged by the pixel 4 to 3 conversion processing, and a signal in which the effective pixel area is compressed to 3/4 is generated. .

In the selection circuit 28, the letter box method E is used.
When receiving a DTV television signal, the signals YW, IW, QW of the scanning lines 3 to 4 converter 4 and the signal Y of the pixel 4 to 3 converter 27 when receiving an NTSC type television signal are received.
Selects and outputs HC, IHC, and QHC. The image receiving signal is determined by detecting the presence or absence of an identification code signal (a signal added to the letterbox EDTV) in the control signal generating section 9.

The RGB conversion section 6 performs a predetermined matrix operation for converting the YIQ sequence into the three primary color RGB sequences to generate the three primary color signals RD, GD, BD.

The D / A converter 7 performs conversion into analog signals and creates analog three primary color signals R, G and B.

The wide aspect ratio display section 8 has an aspect ratio of 16: 9, and the scanning mode is the same as the current NTSC television signal, the number of scanning lines is 525, and 30 frames / frame.
Second, image is displayed by 2: 1 interlaced scanning. In the letterbox system EDTV, a full screen with 480 effective pixel scanning lines is displayed, and in the NTSC system, an image with an aspect ratio of 4: 3 in which non-image areas are provided at the left and right edges of the screen is displayed.

Further, the control signal generation unit 9 identifies the above-mentioned image receiving television signal and also generates signals necessary for signal processing of each unit.

FIG. 10 shows an embodiment of the color difference signal demodulation unit 26 in this embodiment. In the multiplication circuit 16, the color signal C is changed to c
os2πfsct, sin2πfsct (t = nT, T
= 1/4 fsc) for synchronous detection and LPF
The low frequency components are extracted by the circuits 22 and 23, and the color difference signals I and Q are demodulated.

Next, referring to FIGS. 11 and 12, pixels 4 to 3 are
The operation of the converter 27 and its embodiment will be described. First,
This principle and one characteristic example thereof are shown in FIG. Pixels 4 to 3
In the conversion, the coefficients ai and bi are weighted on the pixels a, b, c and d, and these are added to generate signals corresponding to the pixels a ′, b ′ and c ′, and conversion from 4 pixels to 3 pixels is performed. To realize.
Then, the time axis compression of the generated pixels a'b'c '... Is performed. As a result, an image with an aspect ratio of 4: 3 can be displayed on the display unit with an aspect ratio of 16: 9.

FIG. 12 shows this embodiment. input signal,
The coefficient values ai and bi are weighted by the coefficient weighting circuit 19 to the signal delayed by one pixel in the 1-pixel delay circuit 29, and added by the adding circuit 14 to obtain the pixel a ′ shown in FIG.
Generate the signal WTD of b ', c'. This signal WTD is stored in the memory circuit 30 by the WT operation shown in FIG.
Then, information of the effective pixel number of each scanning line is stored, for example, from 768 pixels to 576 pixels generated by 4 to 3 conversion,
On the other hand, from the memory circuit 30, the information of 576 pixels is continuously read out by the RD operation in the period corresponding to the image region of aspect ratio 4: 3 displayed on the screen of aspect ratio 16: 9, and the signal RDD is obtained. In the selection circuit 32, the signal RDD is used in the image area period, and the signal MS is used in other areas.
K (for example, a specific value corresponding to a black level for a luminance signal and a zero value for a color difference signal) is selected and output. The memory control circuit 31 generates control signals necessary for controlling the coefficient values ai and bi, the operation of the memory circuit 30, the control of the selection circuit 32, and the like.

Further, the pixel 4 to 3 conversion section 27 has a function of merely delaying for one scanning line period (for example, coefficients ai = 1, b).
If the input image signal is 480 effective pixel scanning lines and the aspect ratio is 16: 9, this By operating the pixels 4 to 3 conversion unit 27 as a delay circuit for one scanning line, the aspect ratio of 16:
This input image signal can be displayed in full screen on the display section 9.

The other block parts can be realized in the same manner as in the first embodiment, and the description thereof will be omitted.

As described above, according to the present embodiment, it is possible to receive the television signals of the letterbox EDTV and the current NTSC system with a well-balanced resolution characteristic, and to realize at a low cost with excellent cost efficiency. An EDTV decoder device is possible.

Next, a third embodiment of the present invention will be described with reference to the overall block diagram shown in FIG. This is suitable for receiving a baseband television signal of a letterbox EDTV and an S mode signal (a signal separated into a luminance signal and a color signal).

The baseband television signal VI of the letterbox EDTV (the horizontal image portion of the main portion is composed of, for example, 360 effective pixel scanning lines) is subjected to horizontal and vertical two-dimensional YC separation by the YC separation portion 33. The luminance and color components are separated according to the characteristic (1) to separate the luminance signal SY and the color signal SC. In the A / D converter 1, sampling is performed at a frequency, for example, four times that of the color subcarrier fsc, the phase of which is synchronized with the color difference I and Q components, and the luminance signal Y converted into a digital signal is obtained.
Create a color signal C. In the A / D converter 1 and the control signal generator 9, the input signal is a letterbox type ED.
The operation is performed by selecting a solid line in the case of a TV and a signal indicated by a dotted line in the case of an S mode signal (the number of effective pixel scanning lines is 360).

The color demodulation section 3 time-divisionally multiplexes the color difference I and Q signals reproduced by the synchronous detection by the color subcarrier fsc to form a signal IQT.

In the scanning line 3 to 4 conversion section 4, the scanning line number conversion processing is performed by the 3 to 4 conversion, and the effective pixel scanning line number 360 is obtained.
This signal series is converted into a signal series YW and IQTW having 480 effective pixel scanning lines.

The color-difference signal reproducing section 5 separates the color-difference I and Q components multiplexed in a time-division manner and produces color-difference signals IW and QW by interpolation processing.

The RGB conversion unit 6 performs a predetermined matrix operation to convert the YIQ series into the three primary color RGB series, and generates the three primary color signals RD, GD and BD. Then, the D / A conversion unit 7 converts the analog signal into three primary color signals R, G, and B. Then, the wide aspect ratio display unit 8 displays the aspect ratio of 16: 9 and the scanning mode is the current N.
The same number of scanning lines as the TSC television signal 525
Book, 30 frames / second, 2: 1 interlace scanning, to display a horizontally long image portion on a full screen.

On the other hand, in the color modulator 34, the signal IQTW is amplitude-modulated by the color subcarrier fsc to generate the color signal CS. Then, one of these is added to the signal YW by the adder circuit 14 to form a composite formation signal. The D / A conversion unit 7 performs conversion into an analog signal and has an aspect ratio of 16: 9 and an effective pixel scanning line number of 480.
Composed of books. The composite format image signal VS and the S mode signal (luminance signal YOU, color signal COW) are output.

FIG. 14 shows the color modulation section 3 in this embodiment.
4 is an example diagram of FIG. The input signal IQTW has a color difference I,
It is a signal in which the Q component is time-division multiplexed for each pixel (signals of I, Q, I, Q, ... In time series). Polarity inversion circuit 35
Then, create a signal with its polarity reversed. Then, the selection circuit 36 selects the signal IQTW during the 1/2 clock period of the color subcarrier fsc, and the signal in which the polarity of the polarity inversion circuit 35 is inverted during the remaining 1/2 clock period. Inverted signal (ie I, Q, -I,-
Q, I, Q, -I, -Q, ...) are generated. Then, the burst adding circuit 37 adds a burst signal to a predetermined position to generate a color signal CS of an S mode signal.

The other block parts are the same as those in the first block.
Since it can be realized by a configuration similar to that of the above embodiment, the description thereof will be omitted.

As described above, according to the present embodiment, it is possible to realize the EDTV decoder device which receives both the letterbox type EDTV and the S mode signal with a well-balanced resolution characteristic, and is low in cost and excellent in economical efficiency.

Next, a fourth embodiment of the present invention will be described with reference to an overall block diagram shown in FIG. This is a letterbox EDTV (effective pixel scanning line number 360
Book), current NTSC system (480 effective pixel scanning lines)
Line) and S-mode signal (the number of effective pixel scanning lines is 360
(Or 480) television signals.

Input image signal VI (letterbox type E
DTV or NTSC system television signal) is Y
The C separation unit 33 separates the luminance signal and the color component by the characteristic of horizontal / vertical two-dimensional YC separation, and separates the luminance signal SY and the color signal SC. In the A / D converter 1, the color subcarrier fs
For example, sampling is performed at a frequency four times as high as that of c in synchronism with the color difference I and Q components, and a luminance signal Y and a color signal C are converted into digital signals. When the image receiving signal is the input image signal VI, the signals shown by the solid line in the figure and the dotted line in the figure when the signal is the external input S mode signal are selected by the A / D converter 1 and the control signal generator 9, respectively. To operate.

The chrominance signal demodulator 26 synchronously detects the chrominance signal C with the chrominance subcarrier fsc, extracts the low frequency component thereof, and demodulates the chrominance signals I and Q.

In the scanning line 3-4 conversion section 4, the number of scanning lines is 3
The number of scanning lines is converted by 4 to 4 conversion, and the signal series of 360 effective pixel scanning lines is converted into 480 effective pixel scanning lines.
Convert to the book signal series YW, IW, QW.

In the pixels 4 to 3 conversion section 27, pixels 4 to 3
The number of effective pixels is converted by conversion, and the effective pixel area is, for example, a signal sequence of 768 pixels and the effective pixel number is 576.
Convert to a signal sequence compressed to / 4. Incidentally, in some cases, it also operates as a delay circuit for one scanning line period.

In the selection circuit 28, in the system in which the number of effective pixel scanning lines of the image receiving signal is 360, the signal series of the scanning line 3 to 4 conversion section 4 is set, and in the system in which the number of effective pixel scanning lines is 480, the pixel 4 to 3 conversion section is set. 27 signal sequences (however, for those with an aspect ratio of 16: 9, signal sequences obtained by the operation as a delay circuit) are selected and output as signals YS, IS, and QS. The control signal generator 9 determines the signal necessary for this selection by determining the identification code signal added to the image receiving signal.

The RGB conversion section 6 performs a matrix operation for converting the YIQ series into the RGB series of the three primary colors to generate the three primary color signals RD, GD and BD. Then, the D / A conversion unit 7 converts the analog signal to an analog three primary color signal R,
G and B are generated.

In the wide aspect ratio display section 8, the aspect ratio is 16: 9, the scanning mode is the same as the current NTSC television signal, the number of scanning lines is 525, and 30 frames /
Second, image is displayed by 2: 1 interlaced scanning.

On the other hand, the color difference signal modulator 38 performs quadrature amplitude modulation with the color subcarrier fsc to generate the color signal CS. Then, one of these signals is added to the signal YS by the adding circuit 14.
And add to create a composite format signal. These signals are converted into analog signals by the D / A converter 7, and the image signal VS in the composite format and the S mode signal (luminance signal YOUW), which has an aspect ratio of 16: 9 and 480 effective pixel scanning lines. , Color signal COW) is output.

FIG. 16 is a diagram showing one embodiment of the color difference signal modulating section 38 in this embodiment. The color difference signals IS and QS are supplied to the multiplication circuit 16 for cos2πfsct and sin2π, respectively.
Amplitude modulation is performed by multiplying by fsct (t = nT, T = 1/4 fsc). Then, both signals are added by the adder circuit 14. Further, the burst adding circuit 37 adds a burst signal to a predetermined position to generate a color signal CS of an S mode signal.

Since the other block portions can be realized by the same construction as the second embodiment, the description thereof will be omitted.

As described above, according to the present embodiment, television signals in any form of letterbox EDTV, current NTSC, and S-mode signals can be received with well-balanced resolution characteristics and at a low price. It is possible to realize an EDTV decoder device excellent in economic efficiency.

[0073]

According to the present invention, image reproduction is performed with a well-balanced resolution characteristic from a static portion to a moving image portion, and
It is possible to realize an EDTV decoder device which is low in cost and excellent in economy.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an embodiment of a YC separation unit used in the present invention.

FIG. 3 is a diagram showing another embodiment of the YC separation unit used in the present invention.

FIG. 4 is a diagram showing an embodiment of a color demodulation unit used in the first embodiment.

FIG. 5 is an explanatory view of the principle of scanning line 3-4 conversion in the present invention.

FIG. 6 is a diagram showing an embodiment of the scanning line 3-4 conversion unit used in the present invention.

FIG. 7 is a diagram showing an embodiment of a color difference signal reproducing section used in the first embodiment.

FIG. 8 is a diagram showing an embodiment of an RGB conversion unit used in the present invention.

FIG. 9 is an overall block configuration diagram of a second embodiment of the present invention.

FIG. 10 is a diagram showing an embodiment of a color difference signal demodulation unit used in the second embodiment.

FIG. 11 is an explanatory view of the principle of pixel 4 to 3 conversion in the second embodiment.

FIG. 12 is a diagram showing an embodiment of the pixels 4 to 3 conversion unit used in the second embodiment.

FIG. 13 is an overall block configuration diagram of a third embodiment of the present invention.

FIG. 14 is a diagram illustrating an example of a color modulator used in the third embodiment.

FIG. 15 is an overall block configuration diagram of a fourth embodiment of the present invention.

FIG. 16 is a diagram showing an embodiment of a color difference signal modulator used in the fourth embodiment.

[Explanation of symbols]

1 ... A / D conversion unit, 2 ... YC separation unit, 3 ... Color demodulation unit, 4
... Scanning line 3 to 4 converter, 5 ... Color difference signal reproducing unit, 6 ... RG
B conversion section, 7 ... D / A conversion section, 8 ... Wide aspect ratio display section, 9 ... Control signal generation section, 10 ... LPF circuit, 11
... Subtraction circuit, 12 ... 1H delay circuit, 13 ... Coefficient weighting circuit, 14 ... Addition circuit, 15 ... BPF circuit, 16 ... Multiplication circuit, 17 ... Selection circuit, 18 ... Memory circuit, 19 ... Coefficient weighting circuit, 20 ... Control Circuit, 21 ... Dividing circuit, 22, 23
... LPF circuit, 24 ... Matrix coefficient weighting circuit, 25 ...
Selection circuit, 26 ... Color difference signal demodulation unit, 27 ... Pixels 4 to 3 conversion unit, 28 ... Selection circuit, 29 ... 1 pixel delay circuit, 30 ...
Memory circuit, 31 ... Memory control circuit, 32 ... Selection circuit,
33 ... YC separation part, 34 ... Color modulation part, 35 ... Polarity inversion circuit, 36 ... Selection circuit, 37 ... Burst addition circuit, 38 ...
Color difference signal modulator.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 11/20 7337-5C

Claims (4)

[Claims] 1. A luminance signal component and a chrominance signal component in an EDTV decoder device for receiving a letterbox type EDTV television signal for transmitting a horizontally long image having an aspect ratio of 16: 9 by providing non-image areas at the top and bottom of the screen. For horizontal and vertical two-dimensional YC separation signal processing, and the number of effective pixel scanning lines is 3 to 4 conversion signal processing of the number of effective pixel scanning lines of 2: 1 interlaced scanning. 4N / 3
A means for converting the number of scanning lines for converting into a 2: 1 interlaced scanning signal series is provided, and the image signal series of 4N / 3 effective pixel scanning lines demodulated by the means is the same as the NTSC television signal. A simple EDTV decoder device characterized by displaying on a wide aspect ratio display unit having an aspect ratio of 16: 9 in a 2: 1 interlaced scanning mode with 525 scanning lines and reproducing an image. 2. The simplified EDTV decoder device according to claim 1, wherein the vertical reinforcement signal and the horizontal reinforcement signal superimposed on the letterbox EDTV television signal are not used for image reproduction. 3. A means for discriminating between a letterbox type EDTV television signal and an NTSC type television signal, and in receiving an NTSC type television signal, an image having an aspect ratio of 4: 3 is displayed on the left and right edges of the screen without a picture. 3. The simplified EDTV decoder device according to claim 1, wherein the image reproduction is carried out by providing a. 4. A composite color television of an image signal series having the same number of scanning lines as 525 NTSC system television signals, 4N / 3 effective pixel scanning lines in a 2: 1 interlaced scanning mode, and an aspect ratio of 16: 9. John signal VS or S
2. The apparatus according to claim 1, further comprising means for outputting a luminance signal YO and a color signal CO corresponding to the modes as output signals.
The simplified EDTV decoder device according to items 2 and 3.