JPH09116787A - Ghost removing device for television reception - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable viewing a screen without a ghost by re-converting a video signal where a ghost component is removed and an audio signal into the radio wave of a channel which is different from the one received by means of a tuner and where a broadcasting is not executed. SOLUTION: The tuner 3 operates a controller 6, receives the TV radio wave of a first channel, for example, by the signal from CPU 7 and outputs the video signal and the audio signal. A signal processing circuit 4 removes the ghost component in the video signal which is outputted from the tuner 3 and outputs the video signal where the ghost component is removed. A modulating circuit 5 converts the audio signal outputted from the tuner 3 and the video signal outputted from the signal processing circuit 4 into the radio wave of the channel which is different from the TV channel which is received by the tuner 3 and where the broadcasting is not executed (called as a vacant channel) so as to output it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television reception ghost eliminating device which is inserted and connected in the middle of a transmission line for transmitting television waves received by an antenna to a television receiver.

[0002]

2. Description of the Related Art Television waves are reflected by buildings, mountains, etc., and overlapping or distorted screens are likely to appear on a receiver, and even in the UHF band, this ghost phenomenon is particularly remarkable in the VHF band. is there. In order to reduce or eliminate the ghost phenomenon, various attempts have been made such as changing the position and height of the antenna and processing the image signal, but there is no guarantee that the ghost will disappear even if the antenna is made extremely high. , There are restrictions even if the standing position is changed. Therefore, the video signal is electrically processed, but the conventional ghost removing device outputs the video signal from which the ghost is removed by the radio wave of the same television channel as the broadcast channel received by the tuner. It was

[0003]

As shown in FIG. 6, a conventional ghost removing device includes a ghost in a branch cable 22a branched from a cable 22 for sending a reception radio wave from an antenna to each television receiver in a home. A ghost elimination device 24 that is set to match the TV channel that is connected to the TV channel, while connecting the cable 22 to a trap or band as a filter for radio wave removal for the same TV channel as the TV channel that contains the ghost. Since the erasing filter (BEF) 25 has to be connected and the outputs thereof must be mixed and sent out through the mixer 26, the work is troublesome. Also, if the ghost wave is only a single channel, there are few problems, but if the ghost wave spreads over many channels, the number of filters increases, in which case the interaction of the filters adversely affects the signal,
It cannot be compared with the state before removing the ghost, for example, when the ghost occurs again on the TV channel for which the ghost removing process has been completed. As another method, there is also a synchronization format in which the video carrier frequency matches the video carrier frequency of the reception channel or the latent co-channel TV broadcast wave, but the circuit configuration is complicated and the cost is increased.
There is a problem that the front ghost phenomenon is likely to occur because the radio waves directly enter the cable and the television receiver.

[0004]

The present invention is easy to install, and even when the ghost wave spreads over many channels,
The present invention provides a ghost elimination device for television reception that does not affect the image of each television channel, and the configuration thereof is a tuner that receives a VHF band or UHF band television channel signal containing a ghost component, and a tuner for receiving the signal. A signal processing circuit for removing a ghost component of the output video signal, for example, a GCR signal sent from a broadcasting station,
A circuit that extracts the distorted GCR signal on the receiving side, compares it with the GCR signal that the signal processing circuit has, detects a ghost (reflection) component, and performs processing to cancel it, and remove the ghost component. The processed video signal and the audio signal output from the tuner (for example, separated from the middle of the video intermediate frequency amplification circuit and enter the audio detection circuit,
A 4.5 MHz FM-modulated signal) into a radio wave of a VHF band or UHF band channel which is different from the television channel received by the tuner and is not broadcast, and an input terminal. It has a bypass circuit for passing the received radio wave from the side toward the output terminal side. The television reception ghost elimination device is provided with a reception radio wave passage circuit or a current passage circuit for the BS band or the CS band in parallel with the bypass circuit, or the tuner, the signal processing circuit, the modulation circuit, and the bypass circuit,
Can be combined in one case.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A television receiving ghost removing device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a single-channel specification ghost elimination device for television reception, in which 1 is an input terminal, 2 is an output terminal, and a tuner 3, a signal processing circuit 4, The modulation circuit 5 is connected in series, and the tuner 3 operates the controller 6 to receive, for example, a television radio wave of the first channel by a signal from the CPU 7 and output the video signal and the audio signal. Has become
The signal processing circuit 4 removes a ghost component included in the video signal output from the tuner 3 and outputs a video signal from which the ghost component is removed (a signal from DC to 4.2 MHz). The modulation circuit 5 is a channel which is different from the television channel received by the tuner 3 and which does not broadcast the audio signal output from the tuner 3 and the video signal output from the signal processing circuit 4 (also called an empty channel). , For example, it is converted into a radio wave of channel 28 and output.

Capacitors 8 and 9 for blocking the passage of current are interposed between the input terminal 1 and the tuner 3 and between the modulation circuit 5 and the output terminal 2, respectively. 3, or between the modulator circuit 5 and the branch circuit (distributor) 10a, 10b having a wide band electric characteristic.
b, the demultiplexer 11a and the mixer 11b are arranged, and the bypass circuit 1 is provided between the branch terminals of the branchers 10a and 10b.
0 is connected without passing through the tuner 3, the signal processing circuit 4, the modulation circuit 5 and the like, and the branching terminal of the branching filter 11a and the mixing terminal of the mixing block 11b are for the BS band or the CS band, or both. Is connected by the receiving radio wave passing circuit 11 of
An amplifier 12 is attached in the middle of the bypass circuit 10. The branching devices 10a and 10b bypass the radio waves in the VHF band and the UHF band.
Only one of HF and UHF may be used. The amplifier 12 amplifies radio waves in the VHF band and the UHF band, and includes the branching devices 10a and 10b and the demultiplexer 11
a, used to compensate the loss of the mixer 11b.
The amplifier 12 has a wide band (90 MHz to 2 G) capable of passing broadcast waves in each band of VHF, UHF, BS, and CS.
In the case of the (Hz) type, the reception radio wave passage circuit 11 can be omitted. Further, the demultiplexer 11a and the mixer 1
1b also plays a role of a filter that eliminates interference due to the distortion when the distortion occurs in the amplifier 12. Further, between the input / output terminals 1 and 2, coils 13a and 1 for blocking the passage of a high frequency signal and passing the electric power (DC or AC) for operating the reception converter or the amplifier in the preceding stage.
They are connected by a current passing circuit 13 with 3a interposed.

Further, on the input side, the demultiplexer 11a and the branch 1
An input level adjusting circuit 14 is provided between the output level adjusting circuit 15 and the output 0, and an output level adjusting circuit 15 is provided between the modulating circuit 5 and the branching device 10b on the other output side. The input level adjusting circuit 14 is for adjusting the broadcast wave to an appropriate level when the ghost component is removed by the signal processing circuit 4 of the embodiment having an appropriate input level of 70 to 90 dBμ, and is shown in FIG. So that the through circuit 14a, the attenuation circuit 14b,
It is composed of an amplifier circuit 14c and a switch element 14d,
If the broadcast wave is in the range of 70 to 90 dBμ, the through circuit 14a is used. If it is over, the attenuation circuit 14b is used.
On the contrary, if the level is too small, the amplifier circuit 14c is switched to three stages by selecting the switch element 14d. It should be noted that CH shown in FIG. 4 is a choke coil, D is a pin diode that functions as a switch, and C is a capacitor, which contains a ghost component received by a tuner by operating the CPU 7 with the controller 6. The ghost component removal processing is executed together with the change of the television channel or the television channel converted by the modulator. The television receiving ghost removing device includes a tuner 3, a signal processing circuit 4, a modulating circuit 5,
All circuits such as the bypass circuit 10 and the received radio wave passing circuit 11 are incorporated in one case 16.

In the television receiving ghost removing device thus constructed, as shown in FIG. 3, the VHF band receiving antenna 17, the UHF band receiving antenna 18 and the BS band receiving antenna 19 respectively receive. The mixed television waves are mixed by the mixer 20, and each of the television receivers 21, 21 ...
・ By inserting and connecting the case 16 in which the ghost elimination device for television reception is integrally assembled to the main line of the cable (coaxial) 22 sent to the, the television wave including all channels in the VHF band and the UHF band is bypassed by the bypass circuit 10. Are transmitted to each of the television receivers 21, 21, ... through the TV channel containing the ghost component, for example, the radio wave of the first channel in the VHF band is transmitted to the signal processing unit 4.
The ghost component is removed by the modulation circuit 5, and the ghost component is converted into a radio wave of a non-broadcast channel, for example, the 28th channel of the UHF band, unlike the first channel which is the television channel containing the ghost component. It is sent to each of the television receivers 21, 21 ... Since this television reception ghost elimination device is provided with the reception radio wave passage circuit 10 and the current passage circuit 12 for the BS band or the CS band, the television wave in the BS band is transmitted from the branching filters 11a to B.
After passing through the reception radio wave passing circuit 10 for the S band or the CS band, or for both the BS band and the CS band, the mixer 10b passes the VHF band and the UH band.
Re-mixed with F-band TV waves and each TV receiver 2
1, 21 ... Also, BS band receiving antenna 1
The current supplied to the converter of No. 9 is the current passing circuit 13
Sent through.

Therefore, it can be installed by a simple operation of inserting and connecting it in the middle of the cable. On the receiver side, when the first channel of the VHF band is selected, an image containing a ghost component sent from the antenna side is displayed. However, if the 28th channel of the UHF band is selected, an image containing no ghost component can be seen, and the effect can be confirmed in comparison with the screen before the ghost removal processing.

The TV channel containing the ghost component received by the tuner is not limited to the first channel, and can be changed to a TV channel for which the ghost is desired to be eliminated by the controller, and the TV channel to be converted is also an empty channel. If properly selected, there will be no interference from the current broadcast radio waves.

Although the above-mentioned embodiment has a single channel specification,
If a tuner, a signal processing circuit, a modulation circuit, etc. are integrated into a plug-in type unit, as shown in FIG. 4, it is possible to add a unit 23 to provide multi-channel specifications. It is possible to easily change the number of channels for removing ghost components by attaching and detaching 23, 23 ..., and install it not only in private homes but also in collective housing such as condominiums and apartments and large-scale shared reception facilities. it can. Further, it is also possible to form a unit in which the TV channel containing the ghost component and the TV channel for converting are fixed, and by combining these units, the product can be made into a region-specific type. Furthermore, the occurrence of ghosts may differ even within the same area, or due to new building construction,
Until then, ghosts may start appearing on TV channels that do not have a ghost phenomenon.
In that case, since the television reception ghost elimination device of the present invention has a bypass circuit, as shown in FIG.
The TV radio waves received by the VHF band receiving antenna 17, the UHF band receiving antenna 18, and the BS band receiving antenna 19 are mixed by the mixer 20 and sent to the TV receivers 21, 21 ... In the condominium. .. in which the television reception ghost elimination devices are integrally assembled are connected in series to the trunk line of the cable 22, and the television reception ghost elimination device in the case 16a removes, for example, ghosts. The converted radio wave of the first channel is converted to the eighth channel, and the case 16
For example, the fourth channel in which the ghost-removing device for television reception in b converts the radio wave of the third channel into the eighth channel, and the ghost-removing device for television reception in case 16c removes the ghost, for example. It is also possible to connect a plurality of television reception ghost elimination devices in series depending on the installation conditions, regardless of whether it is a plug-in type or a region-specific type, such as converting the radio wave of No. 12 to the 12th channel.

In the embodiment, the CS band receiving antenna is not connected to the cable, but the CS band or both the BS band and the CS band receiving radio wave passing circuit and current passing circuit are provided, so that It is also possible to add additional band reception antennas. On the contrary, the reception radio wave passing circuit and the current passing circuit for the BS band or the CS band are omitted and the VHF
It is also possible to use a model exclusively for the obi and UHF bands.

[0013]

According to the present invention, the electric wave of the television channel containing the ghost component removed from the ghost component is converted into the electric wave of the television channel different from the television channel containing the ghost component and then sent out. ,
By selecting the converted TV channel on the receiver side, a ghost-free screen can be viewed.
Further, by providing a reception wave passage circuit or a current passage circuit for the BS band or the CS band, it is possible to cope with the reception of the BS band or the CS charging wave. Further, if all the circuits including the tuner, the signal processing circuit, the modulation circuit, and the bypass circuit are housed in one case, it can be easily installed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a television reception ghost elimination device according to the present invention.

FIG. 2 is an explanatory diagram of an input level adjusting circuit.

FIG. 3 is an explanatory diagram illustrating an installation example of a television reception ghost removal device.

FIG. 4 is an explanatory diagram of a modified embodiment.

FIG. 5 is an explanatory diagram of a modified installation example.

FIG. 6 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1 ... Input terminal, 2 ... Output terminal, 3 ... Tuner, 4
..Signal processing circuits, 5 ... Modulation circuits, 6 ... Controllers, 7 ... CPUs, 8,9 ... Capacitors, 10..Bypass circuits, 10a, 10b..Branching devices, 11 ... Reception radio wave passing circuits , 11a..Demultiplexer, 11b..Mixer,
12 ... Amp, 13 ... Current passing circuit, 13a ... Coil, 14 ... Input level adjusting circuit, 14a ... Through circuit, 14b ... Attenuating circuit, 14c ... Amplifying circuit, 14
d ... Switch element, 15 ... Output level adjustment circuit, 1
6, 16a, 16b, 16c ··· Case, 17 · · VH
F band receiving antenna, 18 ... UHF band receiving antenna, 19 ... BS band receiving antenna, 20 ... Mixer,
21..TV receiver, 22..cable, 22a ..
Branch cable, 23..Unit, 24..Ghost removing device, 25..TV channel filter, 26 ..
・ TV channel filters, 26 ・ ・ Mixers, CH
..Choke coil, D..pin diode, C..capacitor

Claims (3)

[Claims] 1. A ghost elimination device for television reception, which is inserted and connected in the middle of a transmission line for sending television radio waves received by an antenna to a television receiver, and receives radio waves of a television channel containing a ghost component. A tuner, a signal processing circuit for removing a ghost component of a video signal output from the tuner, a video signal from which the ghost component is removed and an audio signal output from the tuner, and a channel received by the tuner. A ghost elimination device for television reception, comprising a modulation circuit for re-converting television radio waves of different non-broadcast channels and a bypass circuit for passing the received radio waves from the input terminal side toward the output terminal side. 2. The ghost elimination device for television reception according to claim 1, further comprising a reception radio wave passing circuit and a current passing circuit for the BS band or the CS band, or for both the BS band and the CS band, which are provided in parallel with the bypass circuit. apparatus. 3. The tuner, the signal processing circuit, the modulation circuit,
The television reception ghost elimination device according to claim 1, wherein the bypass circuit and the bypass circuit are incorporated in one case.