KR20030088188A - Digital cable broadcast tuner - Google Patents

Abstract

PURPOSE: A digital cable broadcasting tuner is provided to construct a modulator function, a tuner function, and a demodulator function in one chassis, thereby reducing the chassis cost and securing a space in designing a receiver. CONSTITUTION: A high frequency modulator(211) receives audio/video signals for modulating the audio/video signals into high frequency channel signals. A loop through terminal(212) receives digital cable broadcast signals for outputting the same to the outside. A tuner IC(213) receives the digital broadcast signals for converting the same into intermediate frequency signals. A saw filter(214) band-passes the intermediate frequency signals for removing a noise. An intermediate amplifying terminal(215) amplifies the intermediate frequency signals passed through the saw filter. A demodulator IC(216) demodulates the intermediate frequency signals into digital data. A first connector(21a) receives the digital cable broadcast signals from a digital cable for transmitting the same to the high frequency modulator and the loop through terminal. A second connector(21b) outputs the frequency signals to a TV input terminal.

Description

Digital cable broadcast tuner {DIGITAL CABLE BROADCAST TUNER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cable broadcast receiver that receives a digital cable broadcast signal and converts the digital cable broadcast signal into an over-the-air broadcast signal, and more particularly, provides a high frequency modulation function and a digital cable broadcast tuner function in one case. The present invention relates to a digital cable broadcast tuner configured to facilitate space saving when cost reduction and miniaturization.

Since the first black and white TVs have been developed, color TVs have been developed and popularized, and the types of broadcasts provided through the TVs have been diversified into digital broadcasting, analog broadcasting, and cable broadcasting and satellite broadcasting according to broadcast signal types.

In order to receive these various types of broadcasts, if a receiver suitable for each broadcast method is provided, these receivers convert the received broadcast signal to be viewed on a TV receiver and provide it to the TV for generalization of the TV and user convenience. It is commercialized.

Among them, for example, as shown in FIG. 1, the digital cable broadcast receiver transmits the digital cable broadcast signal input through the cable to the QAM-NIM 12 and is output from the MPEG decoder 13. A digital channel broadcasting signal, which is converted from the reconstructed video / audio signal into an air channel (high frequency) signal and output to a TV, and a digital cable broadcasting signal extracted from the digital cable broadcasting signal applied through the high frequency modulator 11 is extracted. QAM-NIM (Network Interface Module) 21 which demodulates data and data frames outputted from the QAM-NIM 21 are received, MPEG decoded to restore original audio / video data, and encoded and output as analog signals. Is composed of an MPEG decoder 12.

The QAM-NIM 12 is a hybrid tuner product in which a tuner unit and a demodulator unit are integrated into one chassis in accordance with the trend of miniaturization and complexation of electrical / electronic products. This is called.

As described above, the conventional digital cable broadcasting receiver has a combination of a tuner and a demodulation unit as a result of the development of the QAM-NIM 12. However, as shown, a high frequency modulator 11 and a QAM-NIM 13 having a tuner and a demodulation function are shown. ) And the MPEG decoder 12 are divided into separate chassis products, and the high frequency modulator 11 is connected to a first connector 11a and a digital cable connected to an input terminal of an external TV to provide a digital cable broadcasting signal. In addition to the input second connector 11b, a third connector 11c for transmitting a digital cable broadcast signal to the QAM-NIM 12 is provided, and the QAM-NIM 12 is provided from the high frequency modulator 11. A fourth connector 13a for receiving a digital cable broadcast signal must be provided, and a connecting means (wire or line) for connecting the third connector 11c and the fourth connector 13a is required.

Therefore, there is a limit in miniaturizing the receiver due to the provision of the connector and the connecting means as described above, there is a problem that the manufacturing of the receiver is complicated.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned conventional problems, and its object is to put a high frequency modulating function, a tuner and a demodulation function in one chassis, thereby reducing the cost of connectors and wires, and consequently unifying the product. To provide a digital cable broadcast tuner that can reduce the cost and downsize the receiver.

1 is a block diagram showing a conventional digital cable receiver.

2 is a blur configuration diagram showing a receiver having a digital cable broadcast tuner according to the present invention.

* Description of the symbols for the main parts of the drawings *

21: Digital Cable Broadcast Tuner

22: MPEG decoder

211: RF modulator

212: Loop Through End

213 Tuner IC

214: SAW Filter

215: intermediate frequency amplifier

216 QAM Demodulation IC

The present invention is a structural means for achieving the above object, in the digital cable broadcasting tuner,

A high frequency modulator for receiving an audio / video signal and modulating the high frequency channel signal into a high frequency channel signal;

A loop through stage for receiving a digital cable broadcast signal and outputting the same;

A tuner IC for receiving a digital cable broadcast signal and converting the signal into an intermediate frequency signal;

A saw filter for band-passing the intermediate frequency signal output from the tuner IC to remove noise;

An intermediate amplifier stage for amplifying the intermediate frequency signal passing through the saw filter; And

A demodulation IC for demodulating and outputting the intermediate frequency signal output from the intermediate amplifier stage into digital data;

The configuration is cased into one chassis, and receives the digital cable broadcasting signal from the digital cable and outputs the high frequency signal output from the first connector and the high frequency modulator to the high frequency modulator and the loop through stage to the TV input terminal. It characterized in that it comprises a second connector for.

And, the output of the loop-through end is characterized in that it is output to the pin formed in the chassis of the digital cable broadcasting tuner.

Hereinafter, the structure and operation of the digital cable broadcast tuner according to the present invention will be described in detail with reference to embodiments of the accompanying drawings.

FIG. 2 is a block diagram showing a digital cable broadcast receiver to which a digital cable broadcast tuner is applied according to the present invention. The digital decoder is demodulated by receiving a digital cable broadcast signal through an externally connected cable and demodulating a data frame of a selected program. Digital cable tuner 21 for transmitting the audio / video signal restored by the MPEG decoder 22 to the TV by high frequency modulation to one channel band of the TV receiving channel, and from the digital cable tuner 21. MPEG decoder 22 which receives the output data frame, decodes the MPEG, restores original audio / video data, encodes the analog signal, and outputs the encoded analog signal.

In the above, the digital cable tuner 21 is encased in a chassis provided with a first connector 21a to which a digital cable is connected and a second connector 21b to be connected to a TV input terminal. Inside the high frequency modulator unit 211 and the first connector 21a for high frequency modulation of the audio / video signal output from the MPEG decoder 22 to the set high frequency channel signal and outputting the same to the second connector 21b. Converts and outputs the loop through end 212 for passing the input digital cable broadcast signal to the outside through a pin and the digital cable broadcast signal (50 to 860 MHz) input to the first connector 21a to an intermediate frequency signal. A tuner IC 213, a saw filter 214 for band-passing the intermediate frequency signal output from the tuner IC 213, and amplifying the intermediate frequency signal passed through the saw filter 214. Intermediate frequency amplifier stage 215, and the intermediate frequency And a demodulation IC 216 for digitally demodulating and demodulating the intermediate frequency signal output from the width end 215.

Looking at the signal flow in the above configuration, first, the digital cable broadcast signal input to the first connector (21a) is the tuner IC (213) → Saw filter (214) → intermediate frequency amplifier stage 215 → demodulation IC (216) The digital cable broadcast signal input to the MPEG decoder 22 and secondly, the first connector 21a is also output to a pin formed outside the chassis through the loop through end 212. At this time, the pin can be connected to another tuner stage through a pattern line. Third, the audio / video signal output from the MPEG decoder 22 is output to the second connector 21b via the high frequency modulator 211 and applied to the input terminal of the TV.

In this case, the audio / video output terminal of the MPEG decoder 22 is implemented as a pin, and the audio / video input terminal of the digital cable broadcast tuner 21 to be connected to the high frequency modulator 211 is also implemented as a pin. The audio / video signal is connected to form a pattern line on a board, and the output terminal of the loop through stage 212 is also formed of pins, and when a plurality of tuners are implemented on the board, it is transferred to another tuner. It can be used for signal transmission.

The high frequency modulator 211, the loop through stage 212, the tuner IC 213, the saw filter 214, the intermediate frequency amplifier stage 215, and the demodulation IC 216 are connected by a line formed in a pattern. In addition, the digital cable broadcast tuner 21 and the MPEG decoder 22 may also be connected by a pattern line.

Therefore, the digital cable broadcasting tuner according to the present invention has the effect of reducing the chassis cost by configuring the modulator function, the tuner function, and the demodulation function in one chassis, as compared with the conventional case where the high frequency modulator and the QAM-NIM are commercialized. In addition, there is an effect that the space is advantageous when designing the receiver.

In addition, the digital cable broadcasting receiver designed as a digital cable broadcasting tuner according to the present invention reduces the number of components compared to the conventional one, and eliminates the need for wires for connecting the existing high frequency modulator to the QAM-NIM, thereby making it easier to secure space. Miniaturization becomes possible.

Claims (2)

In the digital cable broadcast tuner, A high frequency modulator for receiving an audio / video signal and modulating the high frequency channel signal into a high frequency channel signal; A loop through stage for receiving a digital cable broadcast signal and outputting the same; A tuner IC for receiving a digital cable broadcast signal and converting the signal into an intermediate frequency signal; A saw filter for band-passing the intermediate frequency signal output from the tuner IC to remove noise; An intermediate amplifier stage for amplifying the intermediate frequency signal passing through the saw filter; And A demodulation IC for demodulating and outputting the intermediate frequency signal output from the intermediate amplifier stage into digital data; The configuration is cased into one chassis, and receives the digital cable broadcasting signal from the digital cable and outputs the high frequency signal output from the first connector and the high frequency modulator to the high frequency modulator and the loop through stage to the TV input terminal. Digital cable broadcasting tuner comprising a second connector for. The method of claim 1, And an output of the loop through end is output to a pin formed in a chassis of the digital cable broadcasting tuner.