JP2000134509A - Television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the side effect of pseudo ghost addition or the like in the convergence process of a filter coefficient by varying the coring level of a differential signal by means of the input processing part of a ghost reducing means in accordance with the noise state of an input/video signal. SOLUTION: A video signal is inputted to a ghost reducing system(GRS) 6 from an RF tuner 1 by way of a video detection circuit 2. The video signal inputted to GRS: 6 is differentiated by a video differentiation circuit 3, coring is executed in a coring part 4, the cored output signal is inputted to a ghost reducing filter (GR filter part) and a coefficient operation is executed for reducing a ghost. Then detection is executed by the voltage detecting circuit 8 of RF.AGC which is connected from the video detection circuit 2 to the RF tuner 1, the coring level (threshold) of the coring part 4 is controlled in a coring level control circuit 7 in the case of exchanging the RF channel and the addition of a ringing component such as the pseudo ghost suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television receiver provided with ghost removing means.

[0002]

2. Description of the Related Art Conventionally, fixed circuits and coefficients have always been used for an input video signal processing section in a ghost reduction means of a television receiver, regardless of the state of an input video signal.

[0003]

In the ghost reduction, the mainstream means is to feed back and accumulate filter coefficients so as to reproduce the frequency spectrum of the GCR signal superimposed on the video signal to the state at the time of transmission. However, in the case of a signal containing a lot of noise having a poor S / N ratio, a pseudo ghost may be added until the calculation of the filter coefficient converges, and there is a problem that the quality is poor.

[0004]

In order to solve the above-mentioned problems, according to the present invention, the coring level of the differential signal is varied in the input signal processing section of the ghost reduction means in accordance with the noise state of the input video signal. In addition, it is possible to reduce side effects such as the addition of pseudo ghosts in the process of converging the filter coefficients.

[0005]

1 is a block diagram showing a configuration of a television receiver according to a first embodiment of the present invention; FIG. 2 is a block diagram showing a configuration of a television receiver according to a first embodiment of the present invention; Means to do,
Means for detecting the level of RF / AGC at the time of image reception, and means for varying the threshold value of the coring unit of the ghost reduction function in accordance with the detected level of RF / AGC; By varying the coring level of the input section of the ghost reduction function according to the RF / AGC level, it is possible to suppress the generation of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

According to a second aspect of the present invention, in the television receiver, the ghost reducing means includes a coring means for eliminating a vicinity of a zero cross of the differentiated video signal, and a means for varying a threshold value for the coring. Means for detecting the noise level of the received video signal before the ghost reduction processing, and means for varying the threshold value of the coring unit of the ghost reduction function in accordance with the detected noise level. By varying the coring level of the input section of the ghost reduction function according to the noise level of the selected video signal, it is possible to suppress the occurrence of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

According to a third aspect of the present invention, in the ghost reducing means, the ghost reducing means includes a coring means for eliminating a vicinity of a zero cross of the differentiated video signal, and a means for varying a threshold value for the coring. Means for detecting the noise level of the received video signal after the ghost reduction processing, and means for varying the threshold value of the coring unit of the ghost reduction function according to the detected noise level, and By varying the coring level of the input section of the ghost reduction function according to the noise level of the selected video signal, it is possible to suppress the occurrence of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

According to a fourth aspect of the present invention, in the television receiver, the ghost reducing means includes a coring means for deleting a vicinity of a zero cross of the differentiated video signal, and a means for varying a threshold value for the coring. Means for detecting the level of RF / AGC at the time of image reception;
Means for varying the threshold of the coring unit of the ghost reduction function according to the level of the F / AGC, and varying the coring level of the input unit of the ghost reduction function according to the RF / AGC level of the channel being received. By doing so, it is possible to suppress the generation of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

According to a fifth aspect of the present invention, in the television receiver, the ghost reducing means includes a coring means for eliminating a vicinity of a zero crossing of the differentiated video signal, and a means for varying a threshold for coring. Means for detecting the noise level of the received video signal before the ghost reduction processing, and means for varying the threshold value of the coring unit of the ghost reduction function according to the detected noise level. By varying the coring level of the input section of the ghost reduction function according to the noise level of the signal, it is possible to suppress the occurrence of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

According to a sixth aspect of the present invention, in the ghost reduction means, the ghost reducing means includes a coring means for eliminating a vicinity of a zero cross of the differentiated video signal, and a means for varying a threshold for coring. Means for detecting the noise level of the received video signal after the ghost reduction processing, and means for varying the threshold value of the coring unit of the ghost reduction function according to the detected noise level. By varying the coring level of the input section of the ghost reduction function according to the noise level of the signal, it is possible to suppress the occurrence of unnecessary ringing components due to pseudo ghosts and the like in the ghost reduction process.

(Embodiment 1) FIG. 1 shows a first embodiment of the present invention.
FIG. 1 is a schematic configuration diagram of a television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the cored output signal is input to the ghost reduction filter 5 (hereinafter referred to as a GR filter). Then, coefficient calculation for ghost reduction processing is performed. Here, the voltage of the RFAGC connected to the RF tuner 1 from the video detection circuit 2 is detected by the detection circuit 8, and the coring level control circuit 7 controls the coring level (threshold) of the coring unit 4. By performing the switching at the time of switching the RF channel, the addition of a ringing component such as a pseudo ghost is suppressed in the ghost reduction process.

(Embodiment 2) FIG. 2 shows a second embodiment of the present invention.
2 is a schematic configuration diagram of the television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the correlated output signal is output to the GR.
It is input to the filter 5 and is subjected to coefficient calculation for ghost reduction processing. Here, the noise level of the video signal input to the GRS is detected by the noise level detection circuit 9 at the input part of the GRS 6, and the coring level (threshold) of the coring part 4 is detected by the coring level control circuit 7. By performing the control when the video input is switched, the addition of a ringing component such as a pseudo ghost is suppressed in the ghost reduction process.

(Embodiment 3) FIG. 3 shows a third embodiment of the present invention.
FIG. 3 is a schematic configuration diagram of the television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the correlated output signal is subjected to GR.
The coefficient is input to the filter 5 and subjected to coefficient calculation for ghost reduction processing. Here, the noise level of the video signal input to the GRS is detected by the noise level detection circuit 9 at the output unit of the GRS 6, and the coring level (threshold) of the coring unit 4 is detected by the coring level control circuit 7. By performing the control when the video input is switched, the addition of a ringing component such as a pseudo ghost is suppressed in the ghost reduction process.

(Embodiment 4) FIG. 4 shows a fourth embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of the television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the correlated output signal is output to the GR.
It is input to the filter 5 and is subjected to coefficient calculation for ghost reduction processing. Here, the voltage of the RFAGC connected to the RF tuner 1 from the video detection circuit 2 is detected by the detection circuit 8, and the coring level control circuit 7 controls the coring level (threshold) of the coring unit 4. By doing
In the ghost reduction process, addition of a ringing component such as a pseudo ghost is suppressed.

(Embodiment 5) FIG. 5 shows a fifth embodiment of the present invention.
FIG. 5 is a schematic configuration diagram of the television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the correlated output signal is output to the GR.
It is input to the filter 5 and is subjected to coefficient calculation for ghost reduction processing. Here, the noise level of the video signal input to the GRS is detected by the noise level detection circuit 9 at the input part of the GRS 6, and the coring level (threshold) of the coring part 4 is detected by the coring level control circuit 7. By performing the control, the addition of a ringing component such as a pseudo ghost is suppressed in the ghost reduction process.

(Embodiment 6) FIG. 6 shows a sixth embodiment of the present invention.
FIG. 6 is a schematic configuration diagram of the television receiver described in FIG.
In, the video signal is input from the RF tuner 1 via the video detection circuit 2 to the ghost reduction system 6 (hereinafter referred to as GRS). The video signal input to the GRS 6 is differentiated by the video differentiating circuit 3, subjected to a core link by the coring unit 4, and the correlated output signal is output to the GR.
It is input to the filter 5 and is subjected to coefficient calculation for ghost reduction processing. Here, the noise level of the video signal input to the GRS is detected by the noise level detection circuit 9 at the output section of the GRS 6, and the coring level (threshold) of the coring section 4 is detected by the coring level control circuit 7. By performing the control, the addition of a ringing component such as a pseudo ghost is suppressed in the ghost reduction process.

[0017]

As described above, according to the present invention, the ghost removal performance is improved by controlling the coring level of the input processing stage of the GRS according to the noise state of the input video signal without deterioration. In the ghost reduction process, temporary image quality deterioration due to the addition of a pseudo ghost or the like can be eliminated, and a clear image can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing Embodiment 1 of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing a sixth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 RF tuner 2 video detection circuit 3 video differentiation circuit 4 coring unit 5 GR filter unit 6 GRS 7 coring level control circuit 8 RF / AGC detection circuit 9 noise level detection circuit

Claims (6)

[Claims] 1. A ghost reduction function provided in an input signal processing unit with a coring unit for deleting the vicinity of zero crossing of a differentiated video signal, and a unit for varying a threshold value for the coring, and an RF / AGC for receiving an image. Level detecting means, and means for varying a threshold value of the coring unit of the ghost reduction function according to the detected level of RF / AGC.
A television receiver characterized by varying a coring level of an input section of a ghost reduction function according to an AGC level. 2. A ghost reduction function provided in an input signal processing unit with a coring means for deleting the vicinity of a zero crossing of a differentiated video signal, and a means for varying a threshold value for coring, and inserted before the ghost reduction processing. Means for detecting a noise level of the received video signal, and means for varying a threshold value of the coring unit of the ghost reduction function according to the detected noise level. A television receiver characterized in that the coring level of the input section of the ghost reduction function is varied according to the condition. 3. A ghost reduction function and a ghost reduction process in which an input signal processing unit includes a coring unit that deletes the vicinity of a zero crossing of a differentiated video signal and a unit that varies a threshold value for the coring. Means for detecting the noise level of the received video signal inserted later, and means for varying the threshold of the coring unit of the ghost reduction function according to the detected noise level, A television receiver characterized by varying a coring level of an input section of a ghost reduction function according to a noise level. 4. A ghost reduction function provided in an input signal processing unit with a coring means for deleting the vicinity of a zero crossing of a differentiated video signal, and a means for varying a threshold value for the coring, and a function of RF / AGC at the time of image reception. Level detecting means, and means for varying a threshold value of the coring unit of the ghost reduction function according to the detected level of RF / AGC. A television receiver characterized by varying the coring level of the input section of the reduction function. 5. A ghost reduction function provided in an input signal processing unit with coring means for deleting the vicinity of zero crossing of a differentiated video signal, and means for varying a threshold value for coring, and inserted before ghost reduction processing. Means for detecting the noise level of the received video signal, and means for varying the threshold of the coring unit of the ghost reduction function according to the detected noise level, and A television receiver characterized by varying the coring level of the input section of the ghost reduction function. 6. A ghost reduction function and a ghost reduction process in which an input signal processing unit includes a coring unit that deletes a vicinity of a zero crossing of a differentiated video signal and a unit that varies a threshold value for the coring. Means for detecting the noise level of the received video signal which is inserted later, and means for varying the threshold of the coring unit of the ghost reduction function according to the detected noise level, wherein the noise level of the video signal being received is A television receiver characterized in that the coring level of the input section of the ghost reduction function is varied according to the condition.