KR20000012522U - TV tuners for satellite broadcasting - Google Patents

Abstract

The present invention relates to a television tuner for receiving a television broadcast signal via satellite broadcasting. In the prior art, the intermediate frequency of the satellite broadcasting supplied from the low noise block down converter to the satellite broadcasting receiver is affected by the multiplication frequency on the television broadcasting signal provided by the satellite broadcasting receiver to the television tuner by the electromagnetic interference (EMI) phenomenon. Crazy Therefore, there is a disadvantage that the image quality of the television is lowered. Therefore, in the present invention, the satellite tuner 16 is provided with a band cancellation filter 26 for removing the satellite broadcast intermediate frequency, thereby removing the satellite broadcast intermediate frequency so that the satellite broadcast intermediate frequency does not affect the television broadcast signal. Do not Therefore, there is an effect that the image quality of the television is improved. In addition, since the satellite broadcast intermediate frequency is eliminated inherently, the quality of the intermediate frequency is further improved since it does not affect the local frequencies of the first and second intermediate frequency generators 34 and 44.

Description

TV tuners for satellite broadcasting

The present invention relates to a television tuner for satellite broadcast reception, and more particularly, to a television tuner for receiving a television broadcast signal through satellite broadcast.

Conventional television tuners eliminate CB band traps that eliminate CB (Citizen Band) bands 25-30 MHz, television intermediate frequency traps that eliminate television intermediate frequency 45.75 MHz, and frequency modulation (FM) bands 88-108 MHz. It is configured to include an FM band trap.

The television tuner having the above-described configuration uses a CB band trap, a TV intermediate frequency trap, and an FM band trap to remove all CB bands, TV intermediate frequencies, and FM bands from the selected television broadcast signal, thereby creating a television intermediate frequency. Serve

On the other hand, in order to receive satellite broadcasts, a low noise block down converter (LBN) and a satellite broadcast receiver are used in addition to the above-described television tuner.

The low noise block down converter is mounted on a satellite antenna to provide a satellite broadcast intermediate frequency of 1035-1335 MHz to the satellite broadcast receiver via a coaxial cable.

The satellite broadcast receiver receives the satellite broadcast intermediate frequency from the low noise block down converter and generates 50-806 MHz of the television broadcast signal based on the television channel selection to provide the television tuner.

Therefore, the satellite broadcasting intermediate frequency supplied from the low noise block down converter to the satellite broadcasting receiver affects the television broadcasting signal provided by the satellite broadcasting receiver to the television tuner as the multiplication frequency due to the phenomenon of electromagnetic interference (EMI). Therefore, there is a disadvantage that the image quality of the television is lowered.

The present invention has been made to solve the above drawbacks of the prior art, and the satellite TV intermediate tuner is provided with a band cancellation filter that removes the satellite broadcast intermediate frequency, thereby eliminating the satellite broadcast intermediate frequency. It is an object of the present invention to provide a television tuner for receiving a satellite broadcast so as not to affect the broadcast signal.

In order to achieve the above object, the present invention provides a satellite broadcast receiving television having a television tuner for receiving a television broadcast signal for satellite broadcasting, wherein the television tuner is provided with a satellite broadcasting television broadcast signal to remove a CB band. One band cancellation filter; A second band cancellation filter for removing television intermediate frequencies from the output provided from the first band cancellation filter; A third band cancellation filter for removing the satellite broadcasting intermediate frequency from the output provided from the second band cancellation filter; A UHF filter passing only an Ultra High Frequency (UHF) signal among the outputs provided from the third band cancellation filter; A first intermediate frequency generator for receiving an output provided from the UHF filter to generate a television intermediate frequency; A fourth band cancellation filter for removing the FM band from the output provided from the third band cancellation filter; A VHF filter for passing only a Very High Frequency (VHF) signal among the outputs provided from the fourth band cancellation filter; And a second intermediate frequency generator which receives the output provided from the VHF filter and generates a television intermediate frequency.

1 is a block diagram showing an embodiment of a satellite broadcast receiving system according to the present invention;

2 is a block diagram illustrating one embodiment of the television tuner shown in FIG. 1;

Explanation of symbols for main parts of the drawings

12: low noise block down converter 14: satellite broadcasting receiver

16: TV tuner

22, 24, 26, 36: first to fourth band cancellation filters

28, 32, 38, and 42: first to fourth band pass filter

30: UHF amplifier 40: VHF amplifier

34, 44: 1st, 2nd intermediate frequency generator

46: intermediate frequency amplifier

Hereinafter, an embodiment of the present invention for achieving the above object will be described in detail.

1 is a block diagram showing an embodiment of a satellite broadcast receiving system according to the present invention, which is composed of a low noise block down converter 12, a satellite broadcast receiving unit 14, and a television tuner 16.

In the figure, the low noise block down converter 12 is mounted on a satellite antenna to provide a satellite broadcast intermediate frequency to the satellite broadcast receiver 14.

The satellite broadcast receiver 14 receives the satellite broadcast intermediate frequency from the low noise block down converter 12 to generate a television broadcast signal based on the television channel selection, and provides the television broadcast signal to the television tuner 16.

The television tuner 16 uses the CB band trap, the TV intermediate frequency trap, the satellite broadcast intermediate frequency trap, and the FM band trap to select all of the CB band, TV intermediate frequency, satellite broadcast intermediate frequency, and FM band from the selected television broadcast signal. Removes it and produces a television intermediate frequency from it.

FIG. 2 is a block diagram showing an embodiment of the television tuner 16 shown in FIG. 1, wherein the first to fourth band cancellation filters 22, 24, 26, and 36 and the first to fourth band pass filters 28 are shown. 32, 38, 42, UHF amplifier 30, VHF amplifier 40, the first and second intermediate frequency generator 34, 44, and the intermediate frequency amplifier 46.

In the figure, the first band cancellation filter 14 in the television tuner 16 receives the satellite broadcasting television broadcast signal from the satellite broadcasting receiver 14 and removes the CB band to provide it to the second band cancellation filter 24. do.

The second band cancellation filter 24 removes the television intermediate frequency from the output provided from the first band cancellation filter 22 and provides it to the third band cancellation filter 26.

The third band cancellation filter 26 removes the satellite broadcasting intermediate frequency from the output provided from the second band cancellation filter 24 and provides it to the first band pass filter 28 and the fourth band cancellation filter 36, respectively. .

The first band pass filter 28 passes only the UHF signal 367 to 806 MHz out of the output provided from the third band cancellation filter 26 to provide it to the UHF amplifier 30.

The UHF amplifier 30 amplifies the output provided from the first band pass filter 28 and provides it to the second band pass filter 32.

The second band pass filter 32 passes only the UHF signal from the output provided from the UHF amplifier 30 and provides it to the first intermediate frequency generator 34.

The first intermediate frequency generator 34 is composed of a mixer and a local frequency generator, and receives the output provided from the second band pass filter 32 to generate a television intermediate frequency to provide to the intermediate frequency amplifier 46.

The fourth band cancellation filter 36 removes the FM band from the output provided from the third band cancellation filter 26 and provides it to the third band pass filter 38.

The third band pass filter 38 passes only 50 to 360 MHz of the VHF signal from the output provided from the fourth band cancellation filter 36 to provide it to the VHF amplifier 40.

The VHF amplifier 40 amplifies the output provided from the third band pass filter 38 and provides it to the fourth band pass filter 42.

The fourth band pass filter 42 passes only the VHF signal among the outputs provided from the VHF amplifier 40 and provides it to the second intermediate frequency generator 44.

The second intermediate frequency generator 44 is composed of a mixer and a local frequency generator, and receives the output provided from the fourth band pass filter 42 to generate a television intermediate frequency to provide to the intermediate frequency amplifier 46.

The intermediate frequency amplifier 46 amplifies each television intermediate frequency provided from the first and second intermediate frequency generators 34 and 44.

As described above, the present invention provides a satellite TV reception tuner 16 with a band cancellation filter 26 for removing the satellite broadcast intermediate frequency, thereby removing the satellite broadcast intermediate frequency so that the satellite broadcast intermediate frequency is applied to the television broadcast signal. Do not affect. Therefore, there is an effect that the image quality of the television is improved. In addition, since the satellite broadcast intermediate frequency is eliminated inherently, the quality of the intermediate frequency is further improved since it does not affect the local frequencies of the first and second intermediate frequency generators 34 and 44.

Claims (1)

A satellite broadcast receiving television having a television tuner for receiving a television broadcast signal for satellite broadcasting, comprising: The television tuner includes: a first band cancellation filter receiving the satellite television signal and removing a CB band; A second band cancellation filter for removing television intermediate frequencies from the output provided from the first band cancellation filter; A third band cancellation filter for removing the satellite broadcasting intermediate frequency from the output provided from the second band cancellation filter; A UHF filter passing only a UHF signal among the outputs provided from the third band cancellation filter; A first intermediate frequency generator for receiving an output provided from the UHF filter to generate a television intermediate frequency; A fourth band cancellation filter for removing the FM band from the output provided from the third band cancellation filter; A VHF filter passing only a VHF signal among the outputs provided from the fourth band cancellation filter; And a second intermediate frequency generator for receiving an output provided from the VHF filter to generate a television intermediate frequency.