JPH08237646A - Tuner - Google Patents

Abstract

PURPOSE: To make the tuner small and to reduce the cost by using a digital demodulator demodulating a voice signal in common between a satellite broadcast tuner and a UHF/VHF tuner. CONSTITUTION: The tuner is provided with a 1st intermediate frequency signal amplifier 2 for satellite broadcast, a UHF/VHF signal high frequency amplifier 8, a 1st mixer circuit 3 converting a frequency of a satellite broadcast signal into an intermediate frequency, a 2nd mixer circuit 9 converting a frequency of the UHF/VHF signal into an intermediate frequency, a 1st SAW filter 4 for satellite broadcast, a 2nd SAW filter 10 for UHF/VHF, a demodulator 5 FM demodulating the satellite broadcast signal, a demodulator 6 demodulating the video signal of the satellite broadcast subject to FM demodulating, a demodulator 11 for the UHF/VHF video signal, a digital demodulator 12 demodulating the satellite broadcast and the UHF/VHF audio signal, and a microcomputer 13 selecting the audio signal and conducting channel selection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuner device for satellite broadcasting.

[0002]

2. Description of the Related Art In recent years, satellite tuners, TVs and VTs
Many R are on sale. A satellite broadcasting tuner and a UHF / VHF tuner are now mounted on the same TV set or the like. For example, as proposed in Japanese Patent Laid-Open No. 4-248777, a satellite broadcasting tuner and a UHF / VHF tuner are installed.
Parts can now be shared with VHF tuners.

FIG. 2 shows a block diagram of a conventional tuner device. In FIG. 2, reference numeral 14 is a first intermediate frequency signal input terminal for satellite broadcasting. Reference numeral 15 is a first intermediate frequency signal high frequency amplifier for satellite broadcasting. Reference numeral 16 is a first mixer circuit for frequency-converting the first intermediate frequency signal of satellite broadcasting into the second intermediate frequency band. Reference numeral 17 is a first SAW filter that selects a desired signal from the satellite broadcast signals. 18 is a signal of the second intermediate frequency of satellite broadcasting F
This is a device for M demodulation. Reference numeral 19 is a device for demodulating a video signal and an audio signal of satellite broadcasting. 20 is UHF / VH
It is an F signal input terminal. 21 is a UHF / VHF signal high frequency amplifier. Reference numeral 22 is a second mixer circuit that frequency-converts the UHF / VHF signal into an intermediate frequency band.
A second SAW filter 23 selects a desired signal from the UHF / VHF signals. 24 is UHF / V
It is a device for demodulating a video signal and an audio signal of an HF signal.
Reference numeral 25 is a PLL circuit unit for both satellite broadcasting and UHF / VHF. Reference numeral 26 is a microcomputer for channel selection.

The operation principle of the conventional tuner device having the above structure will be described below with reference to the drawings. The signal obtained by converting the signal transmitted from the satellite by the antenna into the first intermediate frequency signal is input to the first intermediate frequency signal input terminal 14 of the satellite broadcast, and is amplified by the satellite broadcast high frequency amplifying unit 15 to obtain the satellite broadcast first signal. The one intermediate frequency signal is a signal oscillated by the PLL circuit unit 25 commonly used for satellite broadcasting and UHF / VHF, and is frequency-converted into a second intermediate frequency band by the first mixer circuit 16, and is channeled by the SAW filter 17 for satellite broadcasting. The channel is selected, and FM demodulated by the FM demodulator 18. The FM-demodulated satellite broadcast video and audio signals are demodulated by the video and audio signal demodulation device 19. Further, the signal received by the antenna is input to the UHF / VHF signal input terminal 20, and the UHF / VHF signal high frequency amplifier 21.
The UHF / VHF signal amplified by is a signal oscillated by the PLL circuit unit 25 for both satellite broadcasting and UHF / VHF, and is frequency-converted into an intermediate frequency band by the second mixer circuit 22 to be a SAW filter for UHF / VHF. Two
The channel is selected by 3, and the video and audio signals are demodulated by the video and audio signal demodulation device 24.

As described above, the audio signal demodulating device is constructed separately for the satellite broadcasting and the UHF / VHF.

[0006]

However, in the above-mentioned conventional tuner device, the UHF / V and UHF / V for satellite broadcasting are used.
Two demodulators are needed, one for HF audio.

In view of the above problems, it is an object of the present invention to reduce the size and cost of a device by sharing a voice demodulation device between a satellite broadcast tuner and a UHF / VHF tuner.

[0008]

A satellite broadcast high frequency amplifying section for amplifying a satellite broadcast signal, a UHF / VHF high frequency amplifying section for amplifying a UHF / VHF signal, and a frequency of the satellite broadcast signal F in an intermediate frequency band. Mixer part to convert and U
A mixer unit for frequency-converting HF / VHF signals to an intermediate frequency band, a satellite broadcast SAW filter for channel selection of a desired signal from satellite broadcast signals, and UHF / V
Channel selection of desired signal from HF signal U
HF / VHF SAW filter and satellite broadcast signal FM
An FM demodulation device for demodulating, a video signal demodulating device for demodulating a video signal of the FM-demodulated satellite broadcast signal, and UH
A video signal demodulation device for demodulating a video signal of an F / VHF signal, a digital audio demodulation device for demodulating an audio signal of a satellite broadcast signal and an audio signal of a UHF / VHF signal, channel selection and audio signal selection It is configured with a microcomputer.

[0009]

According to the present invention, the first intermediate frequency signal of the satellite broadcasting amplified by the satellite broadcasting high frequency amplifying section is frequency-converted into the second intermediate frequency band by the first mixer circuit by the above-mentioned constitution, The channel is selected by the SAW filter, and F is selected by the FM demodulator.
M demodulated. The image signal of the satellite broadcast demodulated by FM is
It is demodulated by the video signal demodulation device. Also UHF / V
UHF / VH amplified by HF signal high frequency amplifier
The F signal is frequency-converted into an intermediate frequency band by the second mixer circuit, the channel is selected by the UHF / VHF SAW filter, and the video signal is demodulated by the video signal demodulating device. The satellite broadcast audio signal and the UHF / VHF audio signal are selected by the microcomputer and demodulated by the digital audio signal demodulating device.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A tuner device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a tuner device of the present invention. In FIG. 1, reference numeral 1 is a first intermediate frequency signal input terminal for satellite broadcasting. Reference numeral 2 is a first intermediate frequency signal high frequency amplifier for satellite broadcasting. Reference numeral 3 is a first mixer circuit for frequency-converting the first intermediate frequency signal of satellite broadcasting into the second intermediate frequency band. A first SAW filter 4 selects a desired signal from the satellite broadcast signals. Reference numeral 5 is an apparatus for FM demodulating a signal of the second intermediate frequency of satellite broadcasting. A device 6 demodulates a satellite broadcast video signal. 7 is UHF /
It is a VHF signal input terminal. Reference numeral 8 denotes a UHF / VHF signal high frequency amplifier. Reference numeral 9 is a second mixer circuit that frequency-converts the UHF / VHF signal into an intermediate frequency band. Reference numeral 10 is a second SAW filter that selects a desired signal from the UHF / VHF signals. 11 is UHF
A device for demodulating a video signal of a / VHF signal. 12
Is a digital demodulator for demodulating satellite broadcast and UHF / VHF audio signals. Reference numeral 13 is a microcomputer for selecting a channel and selecting an audio signal.

With the above-mentioned structure, the operation principle of the tuner device of one embodiment of the present invention will be described below with reference to the drawings. The signal obtained by converting the signal transmitted from the satellite by the antenna into the first intermediate frequency signal is input to the first intermediate frequency signal input terminal 1 of the satellite broadcast and is amplified by the satellite broadcast high frequency amplifying unit 2 to obtain the satellite broadcast first signal. The one intermediate frequency signal is frequency-converted into the second intermediate frequency band by the first mixer circuit 3, channel-selected by the SAW filter 4 for satellite broadcasting, and FM demodulated by the FM demodulator 5. The FM-demodulated satellite broadcast video signal is demodulated by the video signal demodulation device 6.
The signal received by the antenna is UHF / VH.
The UHF / VHF signal input to the F signal input terminal 7 and amplified by the UHF / VHF signal high frequency amplifier 8 is
The second mixer circuit 9 frequency-converts the signal into an intermediate frequency band, the UHF / VHF SAW filter 10 tunes the channel, and the video signal is demodulated by the video signal demodulation device 11.

Audio signal frequency band of domestic satellite broadcasting is
It is 5.7272 MHz. Also domestic UHF / VHF
The voice signal frequency band of is 4.5 MHz. The voice signal frequency band of NICAM in the UK is 6.5.
MHz, which is the same modulation method as QPSK, which is different from the audio signal frequency band of domestic satellite broadcasting. Therefore, a digital audio signal demodulator used in a TV set in Europe, etc., which can digitally control a desired audio signal frequency band filter and a desired modulation method in a place where different audio signal frequency bands and different modulation methods coexist. 12 can be used to select and demodulate various audio signals with a microcomputer, so it is not necessary to provide an audio demodulator for satellite broadcasting, UHF / VHF, and downsizing of the device and cost reduction are possible. Can be achieved.

[0013]

As described above, according to the present invention, the voice demodulating device is shared between the satellite broadcasting tuner and the UHF / VHF tuner, so that the device can be downsized and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a tuner device according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of a conventional tuner device.

[Explanation of symbols]

 1 Satellite Broadcasting First Intermediate Frequency Signal Input Terminal 2 Satellite Broadcasting First Intermediate Frequency Signal High Frequency Amplifier 3 First Mixer Circuit 4 First SAW Filter 5 FM Demodulating Device 6 Video Signal Demodulating Device 7 UHF / VHF Signal input terminal 8 UHF / VHF signal high frequency amplifier 9 Second mixer circuit 10 Second SAW filter 11 Device for demodulating video signal 12 Digital demodulator 13 Microcomputer

Claims (1)

[Claims] 1. A satellite broadcast high frequency amplifier for amplifying a satellite broadcast signal, and a UHF / V for amplifying a UHF / VHF signal.
HF high-frequency amplifier section, mixer section for frequency-converting satellite broadcast signal F signal to intermediate frequency band, mixer section for frequency-converting UHF / VHF signal to intermediate frequency band, desired signal from satellite broadcast signal SAW filter for satellite channel selection, UHF / VHF SAW filter for channel selection of desired signal from UHF / VHF signals, FM demodulator for FM demodulating satellite broadcast signal, and FM demodulation Video signal demodulation device for demodulating a video signal of a satellite broadcast signal, a video signal demodulation device for demodulating a video signal of a UHF / VHF signal, audio signal of a satellite broadcast signal and audio of a UHF / VHF signal A tuner device comprising a digital audio demodulation device for demodulating a signal and a microcomputer for channel selection and audio signal selection.