JPH06164991A - Edtv television receiver - Google Patents

Abstract

PURPOSE:To provide high quality pictures at low cost by detecting interfering components such as ghosts and noise, etc., with the ghost cancel reference signals of a letter box system EDTV and selecting a picture demodulation means corresponding to the presence and absence of the interfering components. CONSTITUTION:The TV signals VS of the letter box system EDTV are converted to digital signals by an A/D conversion part 1 and picture signals VM, horizontal strengthening signals HP, vertical strengthening signals VP and the ghost cancel reference signals GCR are separated by a separation part 2. A vertical strengthening signal decoder part 4 inputs the signals VP and demodulates the vertical high frequency components LD ad VH of luminance. An interference detection part 10 detects the presence and absence of noise components and ghost components in the specified period of the signals GCR and successively supplies control signals CT for which an N mode without using the components LD or VH and an F mode for using them are set to a scanning conversion part 5 and a scanning line 3-4 conversion part 6. The conversion parts 5 and 6 generate luminance signals corresponding to the signals CT and successively display the pictures without picture quality interference on a display part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to signal processing of a television receiver, and more particularly to a television of a letterbox type EDTV for transmitting and receiving a horizontally long image having a horizontally long aspect ratio by providing non-image areas at the top and bottom of the screen. The present invention relates to a television receiver suitable for receiving a television signal.

[0002]

2. Description of the Related Art Research and development of an EDTV aiming at high image quality, high definition of television image and widening of screen while maintaining compatibility with the current television system have been advanced.

There are various implementation forms of EDTV, and the letterbox EDTV is one of them. According to this method, a horizontally long image having a horizontally long aspect ratio different from 4: 3 is transmitted and received by providing a non-image area on the upper and lower sides of the screen to realize widening of the screen. In addition, the vertical high-frequency component of the luminance,
The horizontal high-frequency component is superimposed and transmitted as a vertical reinforcement signal and a horizontal reinforcement signal, and these reinforcement signals are demodulated on the image receiving side to realize high definition and high image quality.

This letterbox EDTV television signal has an advantage that it can receive a horizontally long image having a horizontally long aspect ratio even when it is received by a current television receiver, which is one of the next-generation television systems in Japan. The study work is proceeding as one. Further, research and development on a television receiver compatible with the letterbox EDTV have also been started.

[0005]

[Problems to be Solved by the Invention] Letterbox method E
In the DTV, the vertical reinforcement signal is superimposed in a form in which signals obtained by time-axis compression and time-sequential rearrangement processing of vertical high frequency components are time-division multiplexed. Then, on the image receiving side, time series rearrangement,
Time axis expansion processing is performed to demodulate the vertical high frequency components. Therefore, the ghost component, noise component, etc. added to the vertical reinforcement signal in the transmission line become a visually disturbing component due to time-axis expansion processing on the image receiving side, which causes annoying image quality disturbance. is there.

Among these, it is possible to improve the ghost by providing a ghost removing function on the image receiving side, but there is a problem that the cost of the image receiving device becomes high. In addition, there is a problem in that the improvement effect is hardly obtained with respect to the image quality disturbance due to the noise.

The object of the present invention is to solve the above mentioned problems,
An object of the present invention is to provide a television receiver of a letterbox EDTV capable of receiving a high-quality image from which annoying image quality disturbance caused by a ghost and a noise component is removed and realizing a low cost receiver.

[0008]

In order to achieve the above object, the present invention is provided with an interference detecting means for detecting components such as ghost and noise in a ghost cancel reference signal of a letterbox EDTV. Further, in the demodulation of a television signal, a first image demodulation unit that restores an image signal without using a vertical reinforcement signal and a second image demodulation unit that restores an image signal using a vertical reinforcement signal are provided. Provided. Then, depending on the presence or absence of the interference component detected by the interference detecting means, either one of the corresponding first and second image demodulating means is selected to reproduce the image.

Further, in the present invention, there is provided means for selecting the first and second image demodulating means in response to the viewer's instruction.

[0010]

In the present invention, when there is no ghost component or noise component, the image is reproduced by the image signal by the second image demodulating means. Then, a high-definition image can be reproduced by the vertical reinforcement signal. On the other hand, if there are ghost components, noise components, etc., the image is reproduced by the image signal from the first image demodulating means. That is, since the demodulated image signal is used for reproduction without using the vertical reinforcement signal, it is possible to reproduce a high-quality image without annoying image quality disturbance such as ghost and noise generated by demodulation of the vertical reinforcement signal.

Further, according to the present invention, since the ghost component and the noise component are detected by the ghost cancellation reference signal whose signal form is regulated, the detection accuracy is high and the occurrence of malfunction is extremely small.

Further, according to the present invention, since the viewer can select the first and second image demodulating means to reproduce the image, it is possible to receive the image with the image quality according to the taste of the viewer. is there.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A letter-box type EDT in which a vertical reinforcement signal VP in the form of time axis compression and time division multiplexing is superimposed on the upper and lower non-image areas of a screen, and a horizontal reinforcement signal HP is superimposed on the image portion of a landscape image.
An embodiment of the present invention will be described by taking a V television signal as an example.

FIG. 1 is an overall block diagram of the first embodiment of the present invention. This is suitable for the progressive scanning mode in which the image display section has a horizontally long aspect ratio (for example, 16: 9).

The television signal VS (signal in the baseband region) of the letterbox EDTV is sampled by the A / D converter 1 at, for example, four times the frequency of the color subcarrier fsc and converted into a digital signal. To do. In the separation unit 2, the image signal VM of the image portion of the horizontally long image and the horizontal reinforcement signal HP, the vertical reinforcement signals VP of the upper and lower non-image areas of the screen,
And a ghost cancellation reference signal GCR.

The image signal decoder unit 3 performs signal processing such as predetermined luminance / color signal separation, horizontal reinforcement signal separation, color demodulation, and horizontal reinforcement signal demodulation, and the number of effective pixel scanning lines is 360: 2.
The luminance signal Y1, the color difference signals I1 and Q1 of one interlaced scanning signal series (hereinafter abbreviated as 360I system) are demodulated.

The vertical reinforcement signal decoder unit 4 performs signal processing such as predetermined time series rearrangement and time axis extension to demodulate the vertical high frequency components LD and VH of luminance.

The progressive scan conversion unit 5 performs signal processing from interlace to progressive scan conversion, and the effective pixel scan line 360.
A luminance signal Y2, color difference signals I2, Q2 of a 1: 1 progressive scanning signal sequence (hereinafter abbreviated as 360P system) are generated.
When the output control signal CT of the interference detection unit 10 is in the N mode, signal processing that does not use the vertical high frequency component LD, F
In the case of the mode, signal processing using the vertical high frequency component LD is performed to generate the luminance signal Y2.

In the scanning line 3-4 conversion section 6, the scanning lines 3-4 are converted.
4 conversion signal processing is performed, 480 effective pixel scanning lines,
1: 1 progressive scan signal sequence (hereinafter abbreviated as 480P system)
Luminance signals Y3, color difference signals I3, Q3 are generated. The luminance signal Y3 is the output control signal C of the interference detection unit 10.
When T is in the N mode, signal processing is performed without using the vertical high-frequency component VH, and in the case of F mode, signal processing is performed using the vertical high-frequency component VH.

The RGB conversion unit 7 converts the system of luminance and color differences I and Q into a system of three primary colors R, G and B by signal processing of a predetermined matrix operation, and performs three primary color signals RP and GP of 480P system. , BP are generated.

The D / A converter 8 converts to an analog signal to create a 480P analog three primary color signal series VDP. Then, in the sequential display unit 9, for example, the aspect ratio is 16: 9, the number of scanning lines is 525, 60 frames, and 1: 1.
The analog three primary color signal series VDP is displayed in the form of the sequential scanning of.

The interference detecting section 10 detects the presence or absence of a ghost component and a noise component in the ghost case reference signal GCR in a specific period, and sets an N mode in which the vertical high frequency component is not used and an F mode in which it is used. Control signal CT
To make. In addition, a control signal CT whose mode is set according to the MOD signal selected by the viewer is also included.

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 an interlaced scanning mode in which the image display section has a horizontally long aspect ratio (for example, 16: 9).

The television signal VS (signal in the baseband region) of the letterbox EDTV is sampled by the A / D converter 1 at a frequency four times as high as the color subcarrier fsc and converted into a digital signal. To do. In the separation unit 2, the image signal VM of the image portion of the horizontally long image and the horizontal reinforcement signal HP, the vertical reinforcement signals VP of the upper and lower non-image areas of the screen,
And a ghost cancellation reference signal GCR.

The image signal decoder unit 3 performs predetermined signal processing of luminance / color signal separation, horizontal reinforcement signal separation, color demodulation, and horizontal reinforcement signal demodulation, and demodulates 360I luminance signal Y1, color difference signals I1, Q1. To do.

The vertical reinforcement signal decoder unit 4 performs signal processing such as predetermined time series rearrangement and time axis extension to demodulate the vertical high frequency component VH of luminance.

The interlaced scanning line 3 to 4 conversion section 11 performs signal processing for 3 to 4 conversion of scanning lines, and 480 effective pixel scanning lines, 2: 1 interlaced scanning signal series (hereinafter referred to as 480I system). Abbreviation) luminance signal Y4, color difference signal I
4 and Q4 are generated. The luminance signal Y4 is processed by using the vertical high frequency component VH when the output control signal CT of the interference detection unit 10 is in the N mode, and is processed by using the vertical high frequency component VH in the F mode. Is generated by.

In the RGB conversion section 7, the three primary colors R, R and
Converted to G, B system, and 480I system three primary color signals R
I, GI, BI are generated.

The D / A converter 12 performs conversion into an analog signal, and a 480I system analog three primary color signal series VDI.
To make. Then, on the interlaced display unit 13, for example, a signal sequence VDI in the form of an interlaced scan with an aspect ratio of 16: 9, 525 scanning lines, 30 frames, and 2: 1.
Is displayed.

The interference detection unit 10 detects the presence or absence of a ghost component and a noise component in a specific period of the ghost cancellation reference signal GCR, and sets the mode to the N mode in which the vertical high frequency component is not used and the F mode to be used. Control signal CT
To make. In addition, a control signal CT whose mode is set according to the MOD signal selected by the viewer is also included.

Each block section in these embodiments will be described below.

FIG. 3 is a diagram showing an embodiment of the image signal decoder section 3. FIG. 3A shows the configuration and FIG. 3B shows the signal spectrum of each section. This is suitable for a signal in which the horizontal reinforcement signal HP is superimposed on the Fukinuki Hole region that is conjugate with the color signal in the time / vertical frequency region.

The horizontal reinforcement signal separation unit 14 uses the horizontal, vertical, and time three-dimensional filters to provide the first, third, and f-ν frequency regions of the time frequency f and the vertical frequency ν shown in FIG.
The components of the horizontal reinforcement signal HP in the area of the Fukinuki Hole in the quadrant are extracted. Then, the horizontal reinforcement signal demodulation unit 15 performs signal processing of synchronous detection by the subcarrier μ ₀ (μ ₀ = 16 fsc / 7), and the horizontal high frequency component YH (4.2 to 6 MHz) of the luminance.
Demodulate.

In the YC separation section 16, three-dimensional motion adaptation,
Alternatively, signal processing for separating luminance and color components according to horizontal and vertical two-dimensional characteristics is performed, and the luminance component YL and color component C are separated and extracted. Then, the luminance component YL is compensated by the delay unit 17 for the time delay caused by the signal processing,
In step 8, the horizontal high frequency component YH is added to demodulate the 360I system luminance signal Y1. On the other hand, the color demodulation unit 19 performs signal processing for synchronously detecting the color component C with the color subcarrier fsc to demodulate it into color difference I and Q signals, and demodulates the color difference signals I1 and Q1 of the 360I system.

Next, the vertical reinforcement signal decoder unit 4 is shown in FIG.
An example will be shown. The vertical reinforcement signals VP in the non-picture area above and below the screen are interlaced in the demultiplexer 20.
Signal component S1 used for sequential scan conversion, scan line 3 to
The signal component S2 used in the four conversion is separated. Then, these signals are written in the memory circuit 21 by the WT operation shown in FIG. On the other hand, from the memory circuit 21, R shown in FIG.
By the D operation, the signals SR1 and SR2 read out during the period of the region of the horizontally long image of 360I system or the period of 480P system (the period of 480I system in the second embodiment) are generated. The sample point interpolation circuit 22 performs signal processing of conversion into a signal sequence of the original sampling structure, that is, extension processing of the time axis and processing of inserting a zero value at a sample point having no sample value. Then, the interpolation filter 23 extracts a predetermined band component, and demodulates the vertical high-frequency components LD and VH of the luminance.

Next, an embodiment of the progressive scan conversion unit 5 will be described with reference to FIG. The figure (a) is an outline of this signal processing,
(b) shows a structure, respectively.

Conversion from a 360I system signal of interlaced scanning to a 360P system signal of progressive scanning is realized by calculation by two kinds of conversion matrices 1 and 2 shown in FIG. In the F mode, the luminance low-frequency component is subjected to arithmetic processing by the conversion matrix 1 on the signals of the scanning line X of the 360I system and the vertical high-frequency component LD to generate the signals of the scanning lines A and B of the 360P system. Further, the luminance high frequency component and the color difference signal component are 360I.
The scanning lines X1 and X2 of the system are subjected to arithmetic processing by the conversion matrix 2 to generate signals of the scanning lines A and B of the 360P system. On the other hand, in the N mode, both the luminance and color difference signal components are processed by the conversion matrix 2 to generate the signals of the scanning lines A and B of the 360P system.

An embodiment for realizing this signal processing is shown in FIG.
It shows in (b). The arithmetic circuit 24 performs arithmetic processing by the conversion matrix 2 to generate signals IA, QA, YA and IB, QB, YB corresponding to the scanning lines A, B of the 360P system. Then, these signals are written in the memory circuit 29 by a WT operation in which one scanning line period of interlaced scanning is a cycle. On the other hand, from the memory circuit 29, signals IA, QA,
YA and the signals IB, QB, YB are alternately read to generate the color difference signals I2, Q2 of the 360P system and the luminance signal SY1 in the N mode.

The luminance high frequency signal (for example, a component of 1 MHz or more) extracted by the HPF circuit 26 is arithmetically processed by the conversion matrix 2 in the arithmetic circuit 24 to generate luminance high frequency components YAH and YBH in the F mode. To do. On the other hand, LPF circuit 2
The luminance low-frequency signal (for example, a component of 1 MHz or less) extracted in 7 is subjected to arithmetic processing by the conversion circuit 1 using the vertical high-frequency component LD in the arithmetic circuit 25 to obtain luminance low-frequency components YAL and YBL in the F mode. To generate. The adder circuit 28 adds both signals to generate luminance signals YAF and YBF corresponding to the scanning lines A and B of the 360P system. Then, these signals are written into the memory circuit 29 by a WT operation in which one scanning line period of interlaced scanning is a cycle. On the other hand, the signals YAF and YBF are alternately read from the memory circuit 29 by an RD operation in which one scanning line period of sequential scanning is a cycle, and F
A 360P system luminance signal SY2 in the mode is generated. Then, the selection circuit 30 selects and outputs the signal SY1 in the N mode and the signal SY2 in the F mode by the control signal CT to output the 360P luminance signal Y2.

Next, the scanning line 3-4 conversion section 6 will be described with reference to an embodiment shown in FIG.

FIG. 4A shows an outline of signal processing for 3-4 conversion of scanning lines. In F mode, the brightness low-frequency component is 360P
The scanning lines X, Y, Z of the system and the scanning lines A of the 480P system by the operation of the conversion matrix 3 for the signals of the vertical high frequency component VH.
B, C, and D signals are generated to realize 3-4 conversion of scanning lines. On the other hand, in N mode, the conversion matrix 4 gives 360
The signals of the scanning lines A, B, C, D of the 480P system are generated from the signals of the scanning lines X, Y, Z of the P system to realize the 3-4 conversion of the scanning lines.

FIG. 6B shows an example of the configuration for realizing this signal processing. The luminance signal Y2, the color difference signal I2, of the 360P system
Q2 writes the signals of the scanning lines X, Y, Z, ... Into the memory circuit 31 by the WT operation in the period of the horizontally long image area in a cycle of one frame period of sequential scanning. On the other hand, from the memory circuit 31, the scanning lines X, Y, Z, X,
The X, Y, Z, ... Signals are read.

The arithmetic circuit 32 performs an arithmetic operation by the conversion matrix 4 to generate color difference signals I3 and Q3 of 480P system and a luminance signal SY3 in the N mode. Further, the HPF circuit 34 extracts the high frequency component SYH and generates a high frequency component in the F mode. On the other hand, in the arithmetic circuit 33, the calculation by the conversion matrix 3 using the vertical high frequency component VH is performed, and the low frequency component is extracted by the LPF circuit 35 to generate the low frequency component SYL in the F mode. Then, the adder circuit 28 adds the both signals to generate a 480P system luminance signal SY4 in the F mode. In the selection circuit 30, the control signal CT causes N
In the mode, the signal SY3 and in the F mode, the signal SY4 is selected and output to generate a 480P system luminance signal Y3.

Next, an embodiment of the interlaced scanning line 3-4 conversion section 11 will be described with reference to FIG.

FIG. 7A shows an outline of this signal processing. Three
60I scanning lines X, Y, Z and vertical high-frequency component VH
The signals of the scanning lines A, B, C, and D of the 480I system are generated by the arithmetic processing by the conversion matrix of the signal of 4 to realize the 3-4 conversion of the scanning lines. An example of the conversion matrix in N mode is shown in the same figure.
Note that the 480I system signal generated by the 3-4 conversion is 2: 1.
In order to satisfy the relationship of the interlaced scanning of, the conversion matrix is generated in the first field period of the interlaced scanning, the conversion matrix 5 is generated in the second field period, and the conversion matrix having different coefficient values is generated. In addition, the conversion matrix in F mode is the first
In the field period, the conversion matrix 3 of FIG. 6 (a) is used,
In the period of the second field, those having different coefficient values are similarly used.

FIG. 6B shows an example of the configuration for realizing this signal processing. In the memory circuit 36, the interlace scanning 1
With the field period as a cycle, the 360I-system luminance signal Y1, color difference signals I1, and Q1 signals are written by the WT operation in the period of the horizontally long image region. On the other hand, from the memory circuit 36, the scanning line X, Y, Z, X, X,
The signals are read in the order of Y, Z, ....

The arithmetic circuit 37 performs the arithmetic operation by the conversion matrix 4 and the conversion matrix 5 shown in FIG. 9A for each field period to generate the 480I color difference signals I4, Q4 and the luminance signal SY5 in the N mode. To do. In addition, the HPF circuit 26
Thus, the high-luminance signal in the F mode is extracted.

On the other hand, in the arithmetic circuit 38, the vertical high frequency component V
The conversion matrix is calculated using H, and the LPF circuit 27 extracts the low-frequency signal. Then, the both signals are added by the addition circuit 28 to obtain the luminance signal S in the F mode of the 480I system.
Y6 is generated. In the selection circuit 30, the signal SY5 in the N mode and the signal SY in the F mode are generated according to the control signal CT.
6 is selected and output, and a 480I system luminance signal Y4 is generated.

Next, the interference detection section 10 will be described with reference to FIGS.

FIG. 8 is an explanatory diagram of this signal processing. The ghost cancellation reference signal (GCR signal) necessary for ghost removal on the image receiving side is inserted in the form shown in FIG. That is, the rising edge of the signal is SIN during the period of one scanning line 63.56 μs (color subcarrier 227.5 cycle).
It is made up of a signal in which X / X and the falling edge are formed by the 2T characteristic. The waveform of (2) in the figure is a 1-clock differential signal of the GCR signal obtained in an ideal system in which there is no ghost or noise on the transmission path. In this case, no signal component is generated in the area excluding the rising and falling periods of the signal. On the other hand, (3) in the figure is a 1-clock differential signal when the received signal has a ghost. In this case, a ghost component is generated in a region other than the predetermined rising and falling periods. Further, FIG. 4 (4) is a 1-clock differential signal when the received signal has noise, and in this case as well, a noise component is generated in a region other than the predetermined rising and falling periods.

FIG. 5 (5) shows a gate signal GT indicating a region for detecting a ghost component and a noise component in the present invention. The number of ghost components and noise components generated in the period of this region is measured, and the presence or absence of ghost and noise is detected according to the measurement value obtained by latching with the measurement value latch signal CCK shown in FIG.

FIG. 9 shows an embodiment for realizing this signal processing. FIG. 9A shows the configuration, and FIG. 8B shows an example of characteristics of each part.

The GCR signal and the signal delayed by one clock in the one-clock delay circuit 39 are input to the difference circuit 40 and the one-clock difference signal SD is extracted. In the quantizing circuits 41 and 42, the difference signal SD is quantized with the quantization characteristics of the dotted line of the threshold value Δ1 and the solid line of Δ2 as shown in FIG. Then, the quantizing circuit 42 mainly detects a ghost component, and the quantizing circuit 41 mainly detects a noise component.
In the measuring circuit 43, 1 generated during the period of the gate signal GT
The number of is measured. Then, the latch circuit 44 latches with the latch signal CCK and outputs the measured values NN and NG. The determination circuit 45 makes a determination according to the numerical values of the measured values NN and NG, for example, with the characteristic shown in FIG.
Control signal C indicating either the F mode or the F mode
Generate T. For example, when the signal NG is 0 and the signal NN is less than or equal to the threshold value NTH, it is determined that there is no ghost or noise component, and the F mode is set to perform demodulation processing using the vertical reinforcement signal. On the other hand, the signal NG is 0 and the signal NN is the threshold value NTH.
If it exceeds, it is determined that there is a lot of noise and the N mode is set without using the vertical reinforcement signal. If the signal NG is other than 0, it is determined that there is a ghost, and the N mode is set.

The mode may be set, for example, for each frame period, but it is preferable to set it for each material with a certain time constant.

FIG. 10 shows another embodiment, which is also suitable for a viewer to select a mode.

The GCR signal and the signal delayed by 1 clock in the 1-clock delay circuit 39 are input to the difference circuit 40 and the 1-clock difference signal SD is extracted. In the quantizing circuits 41 and 42, the difference signal SD is quantized with the quantization characteristics of the dotted line with a threshold of Δ1 and the solid line of Δ2 as shown in FIG. Then, the measurement circuit 43 measures the number of 1s generated during the period of the gate signal GT. Then, in the latch circuit 44, the measured value NN is latched by the latch signal CCK,
And NG are output. In the judgment circuit 46, the measured value N
N, NG, and mode signal MOD selected by the viewer
Accordingly, the determination is performed based on the characteristic shown in FIG. 7B, and the control signal CT is generated. The MOD signal selected by the viewer is N
In the case of the mode, the control signal CT is set to the N mode. On the other hand, when the MOD signal is in F mode, the measured value N
The F mode is set only when G is 0 and NN is less than or equal to the threshold value NTH. Then, if NG> 0 or NN exceeds the threshold value NTH, it is determined that there are ghost components and noise components, and the N mode is set. In addition, this mode setting is
Although it can be performed for each frame period, it is preferable to set a certain time constant, for example, for each material.

This is the end of the description of each main block part. It should be noted that the other block portions can be easily configured by the conventional technique, and thus the description thereof will be omitted.

As described above, according to the first and second embodiments, the receiver for receiving the television signal of the letterbox type EDTV is low in the influence of ghost and noise and the stable image quality. Can be realized at cost.

In this embodiment, the television signal in the form in which the vertical reinforcement signal VP and the horizontal reinforcement signal HP are superposed has been described as an example, but it can be applied to various superimposition television signals other than this. The present invention can be applied.

[0060]

According to the present invention, a letter-box type ED which can receive a high-quality image without annoying image quality disturbance caused by ghosts and noises and is economical and economical
A television receiver of TV can be realized.

[Brief description of drawings]

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

FIG. 2 is an overall block configuration diagram of a second embodiment of the present invention.

FIG. 3 is a diagram showing an embodiment of a picture signal decoder section.

FIG. 4 is a diagram illustrating an embodiment of a vertical reinforcement signal decoder unit.

FIG. 5 is a diagram illustrating an example of a progressive scan conversion unit.

FIG. 6 is a diagram showing an example of a scanning line 3-4 conversion unit.

FIG. 7 is a diagram showing an embodiment of an interlaced scanning line 3-4 conversion unit.

FIG. 8 is an explanatory diagram of signal processing in an interference detection unit.

FIG. 9 is a diagram illustrating an embodiment of an interference detection unit.

FIG. 10 is a diagram showing another embodiment of the interference detection unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... A / D conversion part, 2 ... Separation part, 3 ... Image signal decoder part, 4 ... Vertical reinforcement signal decoder part, 5 ... Sequential scanning conversion part, 6 ... Scanning line 3-4 conversion part, 7 ... RGB conversion part , 8 ...
D / A conversion unit, 9 ... Sequential display unit, 10 ... Interference detection unit, 1
DESCRIPTION OF SYMBOLS 1 ... Interlaced scanning line 3-4 conversion part, 12 ... D / A conversion part, 13 ... Interlaced display part, 14 ... Horizontal reinforcement signal separation part, 15 ... Horizontal reinforcement signal demodulation part, 16 ... YC separation part, 17 ... delay section, 18 ... addition circuit, 19 ... color demodulation section,
20 ... Demultiplexing section, 21 ... Memory circuit, 22 ...
Sample point interpolation circuit, 23 ... Interpolation filter, 24, 25 ... Arithmetic circuit, 26 ... HPF circuit, 27 ... LPF circuit, 28 ...
Adder circuit, 29 ... Memory circuit, 30 ... Selection circuit, 31 ...
Memory circuit, 32, 33 ... Operation circuit, 34 ... HPF circuit, 35 ... LPF circuit, 36 ... Memory circuit, 37, 38
... arithmetic circuit, 39 ... 1-clock delay circuit, 40 ... difference circuit, 41, 42 ... quantization circuit, 43 ... measurement circuit, 44 ...
Latch circuit, 45, 46 ... Judgment circuit.

Claims (4)

[Claims] 1. A television signal of a letterbox type EDTV for transmitting and receiving a horizontally long image having a horizontally long aspect ratio different from 4: 3 by providing a non-image area at the top and bottom of the screen. In a television receiver for receiving an image on the image display unit, the letter box system E
Interference detection means for detecting ghost and noise by a ghost cancellation reference signal of a DTV television signal, and an upper and lower part of the screen for demodulating a television signal in the area of the horizontally long image into an image signal to be displayed on the image display unit. First demodulation without using the vertical reinforcement signal in the non-image area
Image demodulating means and second image demodulating means for demodulating using the vertical reinforcement signal, and when the interference detecting means detects ghost and noise, the first image demodulating means, An EDTV television receiver characterized in that, when the ghost and noise are not detected, an image signal obtained by selecting the second image demodulating means is displayed on an image display section. 2. The first image demodulating means according to claim 1,
An EDTV television receiver characterized in that a viewer can select an image signal of the second image demodulating means. 3. The image display unit according to claim 1, wherein the aspect ratio is 16: 9, the scanning mode is 525 scanning lines, 60 frames, and 1: 1 sequential scanning. EDTV television receiver. 4. The image display unit according to claim 1, wherein the aspect ratio is 16: 9, the scanning mode is 525 scanning lines, 30 frames, and 2: 1 interlaced scanning.
An EDTV television receiver according to the item.