JP2001285674A - Television signal receiver provided with ghost reduction function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a television signal receiver provided with a ghost reduction function that can set a wait time after the start of ghost reduction processing until display of its image to an optimum state sufficiently matched with a state of a radio wave for each channel and a generating state of ghost or the like. SOLUTION: When a GR processing is requested, a control section 18 allows a switch section 13 to switch an output television signal from a GR processing section 17 to be led to signal processing sections 14-16. Storage sections 22, 23 are provided to set a time after the request of the GR processing until switching of the switch section 13 corresponding to each channel, and when the GR processing is requested, the control section 18 reads the time corresponding to the reception channel from the storage sections 22, 23 and controls the switch section 13 to be switched in the elapsed state of the time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a television signal receiving apparatus having a ghost reduction function for reducing ghosts.

[0002]

2. Description of the Related Art As is well known, for example, a television receiver, such as a television receiver, a VTR (Video Tape Recorder) or a television tuner, for receiving a broadcast television signal and performing processing for image display. In the John signal receiving apparatus, it is a big problem to improve reception failure due to ghost, and various ghost cancellers have been developed conventionally.

In particular, EDTV (Extended Definition Te)
levision) broadcasting and IDTV (Improved Definition Tele)
vision) In broadcasting or the like, a GCR, which is a reference signal for ghost cancellation, is used during a vertical blanking period of a television signal.
A signal is inserted and transmitted, and a ghost reduction processing unit provided on the receiving side performs ghost reduction processing based on the received GCR signal.

In the ghost reduction processing section, there are two types of ghost removal algorithms: a feedback control type and a feedforward control type. Is detected, and the ghost component is removed by calculating the tap coefficient of the ghost removal filter based on the detection result.

[0005] For this reason, immediately after the ghost reduction processing is started, the number of operations in the ghost reduction processing unit is insufficient, so that it is impossible to perform a sufficient ghost reduction processing. In some cases, a false ghost which does not exist originally is generated and added to a television signal.

However, such false ghosts are reduced along with the original ghosts as the number of calculations performed by the ghost reduction processing unit is increased with the lapse of time. In some cases, every time a ghost reduction process is performed, a false ghost is often added, which causes a problem that an image becomes hard to see.

Further, the ghost reduction processing in the ghost reduction processing section is performed stepwise with the passage of time. Therefore, depending on the state of occurrence of ghost, the image may change several times during the reduction processing. For some viewers, such a change in the image may be considered unsightly.

For this reason, in recent years, in order to prevent the occurrence of false ghosts as described above and to prevent the image from being unsightly due to the gradual ghost reduction processing or the like, a certain period of time has elapsed since the start of the ghost reduction processing. It is common practice to display a normal image that has not been subjected to ghost reduction processing and not to display an image that has been subjected to ghost reduction processing.

However, if the waiting time from the start of the ghost reduction process to the display of the image subjected to the ghost reduction process is set too long,
Since it takes too long for the image after the ghost reduction to be displayed, a problem arises in that the viewer has to watch the ghosted image for an unnecessarily long time.

Recently, there has been developed a television signal receiving apparatus in which a viewer can select and set a waiting time until an image subjected to ghost reduction processing to be displayed is long or short. However, if one of the waiting times is set, the waiting time is applied to all the channels, so that it cannot be said that it is possible to sufficiently cope with the radio wave condition and the ghost occurrence condition for each channel.

Furthermore, at present, for example,
As disclosed in Japanese Patent Application Laid-Open No. 8605, on-screen display of the on / off setting state of the ghost reduction processing unit, the presence / absence of the GCR signal, the operation state of the ghost reduction processing unit, and the like at the time of channel switching or power-on. Television receivers have also been considered.

[0012] However, even in such a television receiver, the viewer can only know the operation status of the ghost reduction processing section by on-screen display. This does not improve the unsightlyness of an image due to the ghost reduction process or the like in a step-by-step manner, sufficiently responding to the radio wave condition and the ghost occurrence condition for each channel.

[0013]

As described above, in the conventional television signal receiving apparatus having the ghost reduction function, the ghost reduction processing is performed until a certain waiting time elapses after the start of the ghost reduction processing. If the image is not displayed, if the waiting time is set too long, the viewer has to watch the ghosted image for an unnecessarily long time.

In addition, there have been developed ones in which the waiting time can be selectively set to two types, long and short, and those in which the operation status of the ghost reduction processing unit is displayed on the screen. However, there is still a problem that it cannot be said that countermeasures are sufficiently taken to cope with radio wave conditions and ghost occurrence conditions for each channel.

Therefore, the present invention has been made in view of the above circumstances, and the waiting time from the start of the ghost reduction process to the display of the image is changed according to the radio wave condition and ghost occurrence condition for each channel. It is an object of the present invention to provide a television signal receiving apparatus having an extremely good ghost reduction function which can set an optimal state corresponding to a sufficient condition.

[0016]

According to the present invention, there is provided a television signal receiving apparatus having a ghost reduction function, comprising: a ghost reduction processing section for performing ghost reduction processing on a received television signal; and a ghost reduction processing section. A switch section for selectively guiding a television signal input to the section and a television signal output from the ghost reduction processing section to a signal processing section for performing signal processing for image display; When a ghost reduction process is requested in a state where the television signal input to the ghost reduction processing unit is switched to be guided to the signal processing unit, the television signal output from the ghost reduction processing unit is changed to the switch unit. And a control unit that switches the signal to the signal processing unit. The control unit includes a storage unit that can input and set the time from when the ghost reduction process is requested to when the switch unit is switched, for each channel, and when the ghost reduction process is requested. , The time corresponding to the reception channel is read from the storage unit, and the control is performed so that the switch unit is switched when the time has elapsed.

Further, the television signal receiving apparatus having the ghost reduction function according to the present invention sets the coefficient by repeating the operation from the ghost removal reference signal included in the received television signal, and sets the coefficient. Ghost reduction processing is performed on the television signal based on the coefficient, and when the coefficient is not set, the ghost reduction processing unit that outputs the television signal as it is, and the number of calculations for setting the coefficient in the ghost reduction processing unit is defined as a channel. A storage unit that can be input and set corresponding to each case, and in a state where ghost reduction processing is requested, the number of calculations corresponding to the reception channel is read from the storage unit, and a coefficient is set in the ghost reduction processing unit based on the number of calculations. Control section Those were.

According to the above arrangement, the waiting time until the image subjected to the ghost reduction processing is displayed can be set for each channel, so that the ghost reduction processing is started. , The waiting time until the image is displayed can be set to an optimum state sufficiently corresponding to the radio wave condition and the ghost occurrence condition for each channel.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, a television broadcast wave received by an antenna 11 is supplied to a tuning unit 12, and a television signal of a desired channel is tuned. The television signal tuned by the tuning unit 12 is normally supplied to a Y (luminance signal) / C (color signal) separation unit 14 via a switch unit 13 in a switching state opposite to the illustrated state.

The Y / C separation section 14 separates the input television signal into a luminance signal Y and a chrominance signal C, and outputs the separated signals to a signal processing section 15. The signal processing unit 15 converts the input luminance signal Y and color signal C into a CPT (Co
The image is converted into a form in which an image can be displayed by the (lor Picture Tube) unit 16 and output to the CPT unit 16, where the television signal is displayed as an image.

The television signal selected by the channel selection unit 12 is supplied to a ghost reduction (hereinafter, referred to as GR) processing unit 17 and subjected to GR processing. Then, the television signal on which the GR processing has been performed is supplied to the CPT unit 16 for image display via the switch unit 13, the Y / C separation unit 14, and the signal processing unit 15, which are in the illustrated switching state. It is like that.

The ON / OFF setting of the GR processing unit 17 and the switching control of the switch unit 13 are controlled by a control unit 18.
Done by The control unit 18 includes the key operation unit 1
9 or the remote controller 20
ON / OFF setting of the GR processing unit 17 and the switch unit 1 based on the operation information transmitted from the
3 is controlled.

The control unit 18 includes a mode information storage unit 2
2 and the position information storage unit 23 are connected to each other. Of these, the mode information storage unit 22 stores the mode and the switching time in advance so that the switching time is 1 second in the mode 1 and 5 seconds in the mode 2, for example. Here, the switching time corresponds to the waiting time described above.

The position information storage unit 23 stores the position, the channel information, and the information on the GR process in association with each other. The information relating to the GR processing includes “mode 1” and “mode 2” described above.
And "OFF" for setting the GR processing unit 17 to the OFF state.

The channel information for each position and G
The information regarding the R processing can be arbitrarily input and set by the viewer by operating the key operation unit 19 or the remote controller 20.

Here, upon receiving the operation information for switching the channel to "30" from the key operation unit 19 or the remote controller 20, the control unit 18 first looks at the storage contents of the position information storage unit 23, In addition to recognizing that the information regarding the GR process corresponding to “30” is “mode 2”, looking at the contents stored in the mode information storage unit 22, it recognizes that the switching time of mode 2 is 5 seconds.

Thereafter, the control unit 18 controls the switch unit 13 to a switching state opposite to that shown in the figure, so that the television signal output from the channel selection unit 12 is guided to the Y / C separation unit 14 as it is, and The processing unit 17 is set to the ON state to start the GR processing.

After 5 seconds corresponding to the mode 2 have elapsed, the control unit 18 controls the switch unit 13 to the switching state shown in the figure to convert the GR-processed television signal into a Y / C signal.
Control is performed to guide the signal to the separation unit 14, and thereafter, the television signal subjected to the GR processing is displayed.

The control unit 18 sets the channel to “2” from the key operation unit 19 or the remote controller 20.
When the operation information for switching to is received, the contents of the GR processing corresponding to channel “2” are recognized to be “off” by looking at the storage contents of the position information storage unit 23.

In this case, the control unit 18 controls the switch unit 13
Is switched to a switching state opposite to that shown in the figure, so that the television signal output from the channel selection unit 12 is directly guided to the Y / C separation unit 14, and at the same time, the GR processing unit 17 is set to the off state to perform the GR processing. Control so as not to be.

According to the first embodiment described above, GR
The time until the processed television signal is switched to be used for image display can be set by the viewer for each channel, and the waiting time until the GR processed image is displayed is set for each channel. The waiting time from the start of GR processing to the display of the image should be set to an optimal state that sufficiently responds to the radio wave condition, ghost occurrence condition, etc. for each channel. Becomes possible.

Next, FIG. 2 shows a second embodiment of the present invention. In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals. The GR processing unit 17 converts the analog television signal output from the channel selection unit 12 into a digital signal (A / D (Analog / Digital)). Converter 17a
A digital filter 17b for performing ghost reduction processing on the digital television signal output from the A / D converter 17a; and a digital filter 17b.
D / A (Digital / Analog) that converts the digital television signal output from the
log) Based on the control of the conversion unit 17c and the control unit 18,
The coefficients to be set in the digital filter unit 17b are
And a calculation unit 17d for analyzing and calculating the GCR signal superimposed on the vertical flyback period of the television signal output from the TV signal 2 from the GCR signal.

The mode information storage unit 22 stores, for example, in mode 1 that the number of initial GCR analyzes is one, and in mode 2
Is the mode and the first GCR analysis is 4 times,
From the start of the GR process to the initial setting of the coefficient in the digital filter unit 17b, the number of times the calculation unit 17d performs the analysis and calculation process is stored in association with the number of times.

In such a configuration, the control unit 18
From the key operation unit 19 or the remote controller 20,
When the operation information for switching the channel to "30" is received, first, the storage contents of the position information storage unit 23 are checked to recognize that the information regarding the GR processing corresponding to the channel "30" is "mode 2". The first G of mode 2 is checked by looking at the storage contents of the mode information storage unit 22.
It recognizes that the number of times of CR analysis is four.

For this reason, the control unit 18 sets the number of initial GCR analyzes to "4" for the arithmetic unit 17d. Then, the calculation unit 17d performs the analysis and calculation processing of the GCR signal in four.
The coefficient is set repeatedly, and the digital filter unit 17b
To supply.

In this case, the digital filter 17b
Until the coefficient set by the calculation unit 17d is supplied, the input television signal is kept in a non-display state, that is, a signal that does not perform any processing is output, but after the coefficient is supplied, A ghost-reduced signal is output.

The operation unit 17d thereafter operates to repeat the analysis and operation of the GCR signal, update the coefficients to be given to the digital filter unit 17b, and optimize the coefficients.

The control unit 18 sets the channel to “2” from the key operation unit 19 or the remote controller 20.
When the operation information for switching to is received, the contents of the GR processing corresponding to channel “2” are recognized to be “off” by looking at the storage contents of the position information storage unit 23.

In this case, the control unit 18 controls the calculation unit 17d so as not to calculate the coefficient. For this reason,
Since the coefficients are not set by the arithmetic unit 17d, the digital filter unit 17b is set to a state in which the input television signal is output as it is, that is, is set to an off state, and is controlled so that the ghost reduction processing is not performed.

According to the second embodiment described above, GR
Analysis before setting the filter coefficient of the processing unit 17 for the first time
The viewer can set the number of calculation processes for each channel, and the waiting time until the GR-processed image is displayed can be set for each channel. Similarly to the above, the waiting time from the start of the GR process to the display of the image can be set to an optimum state sufficiently corresponding to the radio wave condition, the ghost occurrence condition, and the like for each channel.

In the first and second embodiments, the GR processing is started on the television signal of the switched channel based on the operation information for switching the channel. However, the GR processing is not limited to the time of channel switching, and when the GR processing is requested even in the same channel, for example, an operator for controlling the GR processing on / off is switched from off to on. It is only necessary to start the process when the waiting time is set, as described above.

The present invention is not limited to the above-described embodiments, but can be implemented with various modifications without departing from the scope of the invention.

[0043]

As described in detail above, according to the present invention,
An extremely good ghost that makes it possible to set the waiting time from the start of the ghost reduction process to the display of the image to an optimal state sufficiently corresponding to the radio wave condition and the ghost occurrence condition of each channel. A television signal receiving device having a reduction function can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a television signal receiving apparatus having a ghost reduction function according to a first embodiment of the present invention;

FIG. 2 is a block diagram showing a television signal receiving apparatus having a ghost reduction function according to a second embodiment of the present invention;

[Explanation of symbols]

 11 antenna, 12 channel selection unit, 13 switch unit, 14 Y / C separation unit, 15 signal processing unit, 16 CPT unit, 17 GR processing unit, 18 control unit, 19 key operation unit, 20 remote controller, 21 receiving unit, 22 mode information storage unit, 23 position information storage unit.

Claims (4)

[Claims] 1. A ghost reduction processing section for performing ghost reduction processing on a received television signal, a television signal input to the ghost reduction processing section, and a television output from the ghost reduction processing section. A switch section for selectively guiding a signal to a signal processing section for performing signal processing for image display; and a switch section for guiding a television signal input to the ghost reduction processing section to the signal processing section. When the ghost reduction process is requested in the switched state, a control unit that switches the switch unit to guide a television signal output from the ghost reduction processing unit to the signal processing unit; After the ghost reduction process is requested, the switch A time until the switching unit is switched, a storage unit that can be set to be input corresponding to each channel, and the control unit, when a ghost reduction process is requested, corresponds to a reception channel from the storage unit. A television signal receiving apparatus having a ghost reduction function, wherein time is read and control is performed so as to switch the switch section after the time has elapsed. 2. The storage unit indicates that the ghost reduction process is not performed on the television signal of the channel instead of the time from when the ghost reduction process is requested to when the switch unit is switched. The television signal receiving apparatus having a ghost reduction function according to claim 1, wherein information can also be input and set. 3. A coefficient is set by repeating calculation from a ghost removal reference signal included in the received television signal, and the television signal is subjected to ghost reduction processing based on the set coefficient. A ghost reduction processing unit that outputs the television signal as it is when the coefficient is not set; a storage unit that can input and set the number of operations for setting the coefficient in the ghost reduction processing unit for each channel; A control unit that reads the number of calculations corresponding to the reception channel from the storage unit in a state where the reduction process is requested, and sets a coefficient in the ghost reduction processing unit based on the number of calculations. TV with ghost reduction function Signal receiving apparatus. 4. The storage unit can also input and set information indicating that calculation for coefficient setting is not performed, instead of the number of calculations for coefficient setting in the ghost reduction processing unit. The television signal receiving device having a ghost reduction function according to claim 3.