JPH0564205A - Television receiver - Google Patents

Abstract

PURPOSE:To reproduce a picture having small degradation of picture quality even when the reception signal of an EDTV is a nonstandard form which does not conform to an identification broadcasting specification by reproducing the picture for a signal in a non-standard state without using an auxiliary signal. CONSTITUTION:In a discrimination circuit 1, a decision whether a reception signal is a standard form or a non-standard form is performed by the phase relation of color sub-carrier wave fsc every line cycle and every frame cycle and the result is supplied as a MOD signal to a decoder circuit 2. In the decoder circuit 2, a normal prescribed decode processing by a main signal and an auxiliary signal is performed for the signal in the standard state in accordance with the MOD signal and signal groups VD of the three original colors R, G, B of a scanning system are successively reproduced. In the case of the signal in a non-standard state, signal columns VD of the scanning system are successively reproduced by the decode processing by only the main signal. These signal groups VD are successively supplied to a scanning display part 4 and picture displays are successively performed in the scanning forms.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver, and more particularly to a television receiver suitable for reproducing an image of a non-standard type EDTV television signal.

[0002]

2. Description of the Related Art Development of an EDTV system, which has compatibility with the current television system and realizes high image quality and wide screen, is under way. In this EDTV system, various types of television signal configurations have been proposed. However, in any format, by transmitting an auxiliary signal in addition to the main signal, higher image quality and wider screen are realized. is doing. Then, this auxiliary signal is transmitted by being superimposed on a vacant frequency band which is not used by the main signal, or a horizontal or vertical blanking period, an overscan area, an upper and lower bar area, or the like.

On the receiver side, the auxiliary signal is separated and extracted from the received EDTV signal and demodulated, and the reproduced auxiliary signal is added to the main signal to reproduce an image having a high resolution characteristic.

In the EDTV system, this auxiliary signal is superimposed by frequency division multiplexing, time division multiplexing, etc., but its frequency band must be within the range of the current system in order to maintain compatibility with the current television system. There is. For this reason, the auxiliary signal often has a form in which the frequency conversion processing is performed by an operation such as frequency shift by amplitude modulation or time base compression.

Therefore, it is necessary for the receiver side to reproduce the original auxiliary signal by performing frequency inverse conversion processing.

[0006]

In the received signal of the EDTV, when the phase of the color subcarrier f _SC is a signal of a standard form in which the polarity is inverted every line period and every frame period, the standard form of the signal is received at the receiver side. The auxiliary signal can be reproduced correctly. However, in the reproduction signal from a home VTR or the like, the phase relationship of the color subcarrier f _SC does not satisfy the broadcasting standard due to jitter or the like, and is a so-called non-standard form signal. For such a nonstandard signal, a malfunction occurs in operations such as separation / extraction and demodulation of the auxiliary signal, and the auxiliary signal is reproduced by mistake. Therefore, when an image is reproduced using this auxiliary signal, there is a problem in that the image quality is deteriorated due to this.

An object of the present invention is to provide a television receiver capable of reproducing an image with little deterioration in image quality even when the received signal of the EDTV has a non-standard form that does not conform to the broadcasting standard.

[0008]

In order to achieve the above object, the present invention is provided with means for discriminating whether a received signal is in a standard form or a non-standard form. Image reproduction is performed using both signals. On the other hand, for a non-standard format signal, the auxiliary signal is not used and only the main signal is used to reproduce the image, thereby reproducing the image with little deterioration in image quality.

[0009]

In the present invention, whether the received signal is in the standard or non-standard form is discriminated by the phase relationship for each line period and each frame period of the color subcarrier f _SC . The standard signal and the non-standard signal can be accurately discriminated by determining that the signals have a standard form when these phase relationships match the broadcast standard and a non-standard form when they do not match.

Further, in the present invention, for the non-standard signal, the image is reproduced by using only the main signal. That is,
Since the auxiliary signal that is erroneously reproduced is not used for image reproduction, deterioration of image quality due to this can be eliminated. Therefore, it is possible to reproduce an image with little deterioration in image quality even for a non-standard signal.

On the other hand, for the standard signal, since the image is reproduced by using both the main signal and the auxiliary signal, it is possible to reproduce the image with high quality.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the basic block configuration of the present invention is shown in FIG.
Shown in. The received television signal (assuming a signal in the baseband region) is input to the discrimination circuit 1, the decoder circuit 2, and the control signal generation circuit 3.

The discriminating circuit 1 discriminates whether the received signal is in the standard form or the non-standard form based on the phase relationship of the color subcarrier f _SC for each line period and frame period, and the result is used as a MOD signal for the decoder circuit. Supply to 2.

In the decoder circuit 2, a standard predetermined signal is decoded by a main signal and an auxiliary signal in response to the MOD signal in accordance with the MOD signal, and the three primary colors R, G, B of the progressive scanning system are processed. The signal sequence V _D is reproduced. on the other hand,
In the case of a non-standard form signal, the sequential scanning system signal series V _D is reproduced by decoding processing using only the main signal.
This signal series V _D is supplied to the progressive scan display unit 4 to display an image in the form of progressive scan.

The control signal generation circuit 3 generates various control signals necessary for the operation of each block.

Next, FIG. 2 shows an embodiment of the discrimination circuit 1 in this embodiment. The color subcarrier extraction circuit 5 extracts the color subcarrier f _SC synchronized with the burst signal. Also,
In the sync separation circuit 6, the horizontal sync signal HD,
The vertical sync signal VD is extracted.

The phase comparison circuit 7 uses the color subcarrier f _SC and the horizontal synchronizing signal HD to determine the phase relationship of f _SC for each line period.
The phase relationship of f _SC for each frame period is compared with the color subcarrier f _SC and the vertical synchronizing signal VD. Then, if the phase of f _SC is inverted every line period and every frame period, the received signal is determined to be a standard form signal. On the other hand, if this phase inversion relationship is not satisfied for each line period and frame period, the received signal is determined to be a non-standard form signal.

Next, the decoder circuit 2 in this embodiment
An example of this is shown in FIG. It should be noted that this corresponds to the case of the television signal of the EDTV of the letterbox technique shown in FIG. In this television signal, an image having a wide aspect ratio (16: 9) is formed by the main signal (the number of scanning lines is 360) of the main portion area, and the vacant upper bar area and the lower bar area (each having 60 scanning lines). The vertical high frequency component VH of the luminance signal is time-division-multiplexed and transmitted as an auxiliary signal. The main signal of this television signal is frequency-multiplexed with color signal components in the same form as the current television system (NTSC).

The television signal is input to the YC separation circuit 8, the motion detection circuit 9, and the auxiliary signal reproduction circuit 11.

The YC separation circuit 8 separates and extracts the luminance signal component Y and the color signal component C from the main signal of the television signal. As will be described later, in the case of a standard form signal, a separation operation is performed by motion-adaptive three-dimensional signal processing according to the motion information of the image obtained from the motion detection circuit 9. On the other hand, in the case of a non-standard form signal, for example, the parameter fixed 1
Separation operation is performed by dimensional signal processing.

In the motion detection circuit 9, motion information necessary for YC separation and progressive scan conversion of motion adaptation processing for a standard form signal is calculated by calculating the difference between two frames of a television signal, 1
It is extracted from the low-frequency component of the difference between frames.

The auxiliary signal reproducing circuit 11 separates the auxiliary signal components superimposed on the upper and lower bar regions and reproduces the vertical high frequency component VH of the original luminance signal by the time axis rearrangement processing and the time axis expansion processing. .. In the case of a nonstandard signal, the output of the auxiliary signal reproducing circuit is set to zero.

In the color demodulation circuit 10, similar to the current television system, the synchronous detection is performed by the color subcarrier f _SC , the low frequency component thereof is extracted and the color difference signals I and Q are demodulated.

The progressive scan conversion circuit 12 performs a process between scan line assists on the main signal in the main region to generate a progressive scan signal series V _P having 360 scan lines. In addition,
As will be described later, in the standard form, the signal VH is used to generate the signal of the auxiliary scanning line, but in the non-standard form, it is generated only by the main signal.

In the scanning line number conversion circuit 13, a sequential scanning signal series V _P having 360 scanning lines is sequentially scanned so that an image can be fully reproduced on a display system having a wide aspect ratio. The number of scanning lines is converted into the series V _P ′.

The RGB conversion circuit 14 converts the signal series of the luminance signal and the color difference signals I and Q into a signal series V _D of the three primary colors R, G and B by a predetermined matrix calculation operation.

Next, an embodiment of each block of the decoder circuit 2 will be described.

FIG. 5 shows an embodiment of the YC separation circuit 8. The television signal is transmitted through the three-dimensional C separation circuit 15, the two-dimensional C separation circuit 16, and the one-dimensional C separation circuit 17 to a frame comb type, a line comb type, and a horizontal BPF (Band Pass Filter), respectively.
er), the color signal components C _3D , C _2D and C _1D are extracted.
These components are processed by the coefficient weighting circuit 18 into coefficient values k ₁ , k ₂ , k
₃ is weighted, and the addition circuit 19 adds them to extract the color signal component C.

The subtraction circuit 21 subtracts the color signal component C from the television signal delayed by the delay circuit 20 to separate and extract the luminance signal component Y.

Numerical values are set for the coefficient values k ₁ , k ₂ , k ₃ by the output signal CT of the motion detection circuit 9, and one characteristic diagram thereof is shown in FIG. For a standard form signal, as shown in (a) of the figure, a signal C _3D mainly extracted by a frame comb type in a region from static to small motion and a signal C _3D extracted by a line comb type in a large motion region. _The coefficient values k ₁ and k ₂ are changed so that _2D is dominant.

On the other hand, for non-standard form signals, k ₃ =
By using the signal C _1D by the horizontal BPF of 1, the malfunction of the separation operation due to the non-standard form is reduced.

Next, an embodiment of the auxiliary signal reproducing circuit 11 is shown in FIG. The time axis rearrangement circuit 22 is composed of a memory circuit, and controls a write operation (hereinafter abbreviated as WT operation) and a read operation (hereinafter abbreviated as RD operation) to and from the memory circuit to control the upper and lower mask portions of a television signal. The processing of rearranging the auxiliary signals on the time axis is performed. That is, the component of the auxiliary signal superimposed in the time division multiplex form is subjected to the WT operation during the period of the upper and lower mask portions and written in the memory circuit. The reading operation from the memory circuit is performed in the period of the area of the main portion, the component of the auxiliary signal for the scanning line corresponding to the main signal is read, and the auxiliary signal series subjected to the time axis rearrangement processing is generated.
The time-axis expansion interpolation filter 23 performs time-axis expansion processing by the interpolation filter on this auxiliary signal sequence,
The vertical high frequency component VH of the luminance signal is reproduced.

Next, an embodiment of the progressive scan conversion circuit 12 is shown in FIG. This is a conversion circuit suitable for the luminance signal Y.

The luminance signal Y of the main signal in the main area and the 1-line delay circuit 24 are used for the interlace scanning system 1
The signal delayed by the scanning line period is weighted with the coefficient value 1/2 in the coefficient weighting circuit 18, and both are added in the adding circuit 25 to generate a signal corresponding to the interpolation scanning line. Then, in the non-standard form signal, this signal component is selected as it is by the switch circuit 28 (indicated by B in the drawing), and the signal YIP corresponding to the interpolation scanning line of the luminance signal is generated.

On the other hand, in the case of the standard form signal, the vertical high frequency component VH is added to the luminance signal Y, the low frequency component is extracted by the LPF circuit 26, and the high frequency component extracted by the HPF circuit 27 is added. The generated signal indicated by B in the figure is selected by the switch circuit 28 and becomes the signal YIP corresponding to the interpolation scanning line of the luminance signal. Therefore, in the signal of the standard form, it is possible to generate the signal of the interpolation scanning line having a high vertical resolution by the vertical high frequency component superimposed as the auxiliary signal.

For the signal YM corresponding to the main scanning line, the luminance signal Y of the main signal is used in either standard or non-standard form.

On the other hand, since the color difference signals I and Q have deteriorated visual characteristics as compared with the luminance signal, they can be realized by the progressive scan conversion circuit having the configuration shown in FIG. That is, the signal I of the interpolation scanning line
IP (QIP) is generated by the average value of the upper and lower scanning lines.

The progressive scan conversion circuit described above generates a progressive scan signal series V _P having 360 scanning lines corresponding to the area of the main portion.

In order to fully display the image of this signal series on the display portion having a wide aspect ratio, the scanning line number conversion circuit 13
Then, the signal series of 360 scanning lines is converted into 480 signal series V _P ′ by the operation of scanning line number conversion. An example of this conversion operation is shown in FIG. In this example, the coefficient values k _a and k are set for the scanning lines a, b, and c of 360 line sequential scanning.
_{The weights} of _b are added to generate progressive scanning lines a ', b', c ', d'of 480 lines. FIG. 11 shows an embodiment for realizing this operation.

The main scanning line signal YM (IM, QM) and the interpolating scanning line signal YIP (IIP, QIP) are stored in the memory circuit 29 by the WT operation with one scanning line period of the interlaced scanning system as a cycle. Written. On the other hand, from the memory circuit 29, the signal series YM and YIP are sequentially read by the RD operation (the operation speed is twice as fast as the WT operation) in which one scanning line period of the progressive scanning system is a cycle, and the signal series YPP is generated. .. The memory control circuit 30 generates various signals necessary for WT and RD operations. With respect to this signal and the signal delayed by the 1-line delay circuit 31 for the 1-line period of the sequential scanning system, the coefficient weighting circuit 18 calculates the coefficients k _a and k _b.
Respectively, and the addition circuit 25 adds the two together to produce a progressive scanning signal sequence YP '(IP', Q) with a scanning line number of 480.
P ') is generated. Note that the coefficient values of the coefficients k _a and k _b change with four lines as a cycle, as shown in FIG.

This is the end of the description of the embodiment in each block of the decoder circuit 2. The RGB conversion circuit 1
Since 4 can be realized by weighting and adding a predetermined coefficient value to the luminance and color difference signals, the embodiment will be omitted.

[0042]

According to the present invention, the decoding process using both the main signal and the auxiliary signal for the standard form signal,
Since the image is reproduced by the decoding process using the main signal for the non-standard form signal, it is possible to display a high-quality image without deterioration of the image quality in any of the standard and non-standard form signals.

Although the EDTV of the letterbox technique has been described as an example in the present embodiment, the present invention is not limited to this, and the present invention is also applied to an EDTV for widening the screen by a side panel technique, an intermediate mode technique, or the like. It is possible to apply.

In this embodiment, the time division multiplexing has been described as an example of the superimposing mode of the auxiliary signal, but this superimposing mode can be applied to the frequency division multiplexing, the frequency interleave multiplexing, or a combination thereof. It is obvious that the present invention can be applied.

Further, although the vertical high frequency component of the luminance signal is described as an example of the auxiliary signal component in the present embodiment, the present invention is not limited to this, and the auxiliary signal component may be the luminance signal or the color difference. Horizontal high-definition component of signal, time
The present invention can be applied to auxiliary signals of various components such as high frequency components in the vertical frequency domain.

[Brief description of drawings]

FIG. 1 is a basic block configuration diagram of the present invention.

FIG. 2 is a diagram showing an embodiment of a discrimination circuit.

FIG. 3 is a diagram showing an embodiment of a decoder circuit.

FIG. 4 is a diagram showing a form of a television signal on which an auxiliary signal is superimposed.

FIG. 5 is a diagram showing an embodiment of a YC separation circuit in a decoder circuit.

FIG. 6 is a characteristic diagram of a coefficient load of the YC separation circuit.

FIG. 7 is a diagram showing an embodiment of an auxiliary signal reproducing circuit of a decoder circuit.

FIG. 8 is a diagram illustrating an example of a progressive scan conversion circuit of a decoder circuit.

FIG. 9 is a diagram illustrating an example of a progressive scan conversion circuit of a decoder circuit.

FIG. 10 is an operation explanatory diagram of the scanning line number conversion circuit of the decoder circuit.

FIG. 11 is a diagram showing an embodiment of a scanning line number conversion circuit of a decoder circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Discrimination circuit, 2 ... Decoder circuit, 3 ... Control signal generation circuit, 4 ... Sequential scanning line display part, 5 ... Color subcarrier extraction circuit,
6 ... Synchronous separation circuit, 7 ... Phase comparison circuit, 8 ... YC separation circuit, 9 ... Motion detection circuit, 10 ... Color demodulation circuit, 11 ... Auxiliary signal reproduction circuit, 12 ... Sequential scanning conversion circuit, 13 ... Scanning line number conversion Circuits, 14 ... RGB conversion circuit, 15 ... Three-dimensional C separation circuit, 16 ... Two-dimensional C separation circuit, 17 ... One-dimensional C separation circuit, 18 ... Coefficient weighting circuit, 19 ... Addition circuit, 20 ... Delay circuit, 21 ... Subtraction circuit, 22 ... Time axis rearrangement circuit,
23 ... Time axis expansion interpolation filter, 24 ... 1 line delay circuit, 25 ... Adder circuit, 26 ... LPF circuit, 27 ... HPF
Circuit, 28 ... Switch circuit, 29 ... Memory circuit, 30 ...
Memory control circuit, 31 ... 1 line delay circuit.

Claims (4)

[Claims] 1. A means for discriminating between a standard form and a non-standard form based on the regularity of a color subcarrier of a television signal, wherein at least a non-standard form signal is included in a television signal on which an auxiliary signal is superimposed. A television receiver characterized by reproducing an image without using an auxiliary signal. 2. The television receiver according to claim 1, wherein the television signal on which the auxiliary signal is superimposed is a television signal compatible with the existing television system. 3. The television receiver according to claim 1, wherein an image is displayed in a scanning mode of progressive scanning. 4. The television receiver according to claim 1, 2, or 3, wherein the image display portion has a laterally long aspect ratio as compared with a current television system.