KR20010107263A - Receiver capable of receiving multi-media and the control method thereof - Google Patents

Abstract

The present invention relates to a receiver capable of multimedia reception and a control method thereof. In an integrated receiver of a multimedia type that receives an RF signal corresponding to a TV signal and an RF signal corresponding to a TV signal, the input RF signal is divided into a predetermined area. A first filtering means for filtering and amplifying and outputting an amplified output of an IF signal, a first filtering means for filtering only a frequency of a desired region of the IF signal supplied from the tuner, and a video signal and an audio signal among signals output from the first filtering means A second filtering means, a demodulator for detecting a video signal and an audio signal output from the second filtering means according to respective local oscillation signals, and a local oscillation signal corresponding to the video signal and the audio signal. A local oscillation unit serving as a demodulation unit The.

Therefore, according to the present invention, the first IF signal is constantly output irrespective of the RF signal input through the antenna, and the structure and the detection process of the circuit are simplified by detecting and outputting a required signal from each demodulation circuit. The volume can be reduced when designing the circuit.

Description

Receiver capable of multimedia reception and control method thereof {RECEIVER CAPABLE OF RECEIVING MULTI-MEDIA AND THE CONTROL METHOD THEREOF}

The present invention relates to a receiver, and more particularly, to a multimedia receiver, in which a tuner outputs an intermediate frequency of a predetermined band irrespective of the frequency of a TV signal and an FM signal, and a demodulator demodulates a video signal and an audio signal at an intermediate frequency. This relates to a possible receiver and a control method thereof.

In general, a multimedia receiver capable of receiving a TV signal and an FM signal is divided into two types according to the tuner configuration.

As shown in FIG. 1, the first tuner includes a plurality of antennas (Ant.A, Ant.B) for receiving a TV signal and an FM signal, and each of the antennas (Ant.A, Ant.B). Input switching unit 1 for switching only a specific signal of the TV signal or FM signal of the RF signal flowing through the), and the first band pass filter unit for filtering a specific RF signal input through the input switching unit (1) (2), an RF amplifying section 3 for amplifying the RF signal passed through the first band pass filter section 2, and a specific RF signal amplified and output from the RF amplifying section 3 to an internal switching circuit ( A second band pass filter 4 for filtering to a desired frequency band according to switching of S / W), and a specific RF signal output from the second band pass filter 4 is mixed with an input local oscillating signal. The mixer unit 6 for outputting the primary IF signal, and the internal switching circuit (S / W) according to the input RF signal It consists of a local oscillator 5 which is switched to output different local oscillation signals.

The receiver shown in FIG. 2 shows an example in which the above-described tuner is applied. The configuration of the receiver includes a tuner 20 and a demodulation circuit 30.

Of the plurality of antennas (Ant.A, Ant.B) for receiving the TV signal and the FM signal, respectively, and only a specific signal of the TV signal or the FM signal among the RF signals flowing through the antennas (Ant.A, Ant.B) Through the input switching unit 21 for switching to be selected, the first band pass filter 22 for filtering a specific RF signal input through the input switching unit 21, and the first band pass filter 22 An RF amplifier 23 for amplifying the passed RF signal and a specific RF signal amplified by the RF amplifier 23 to filter to a desired frequency band according to switching of an internal switching circuit S / W, respectively. A mixer section 26 for mixing a two-pass filter section 24, a specific RF signal output from the second band pass filter section 24, and a local oscillating signal inputted to output a first order IF signal; The internal switching circuit (S / W) switches according to the RF signal to output different local oscillation signals. Is composed of a local oscillator 25 and a primary IF amplifier 27 that amplifies and outputs a primary IF signal output from the mixer 26.

The demodulation circuit 30 also includes a first order IF band pass filter 31, a TV demodulation unit 32, and an FM demodulation unit 38.

The primary IF band pass filter 31 selectively outputs only the IF signal of a desired band among the primary IF signals supplied from the primary IF amplifier 27.

The TV demodulator 32 includes a TV band filter 33 for filtering a TV band signal among the primary IF signals output from the primary IF band pass filter 31, and a TV IF among the signals filtered by the TV band filter 33. SAW filter 34 passing only a signal (e.g., NTSC 45.75MHz), a TV demodulator 35 for detecting an IF signal supplied from the SAW filter 34 as an input local oscillation signal, and a TV demodulator 35. A TV local oscillation circuit 36 for supplying a local oscillation signal and a band pass / band rejection filter 37 for removing unnecessary audio signals from the video signals output from the TV demodulator 35 and passing only a predetermined band.

The FM demodulator 38 inputs a ceramic filter 39 for passing only an IF signal corresponding to an audio signal among the signals output through the first IF band pass filter 31, and an IF signal supplied from the ceramic filter 39. The FM demodulator 40 detects the local oscillation signal, the FM local oscillator circuit 41 for supplying the local oscillation signal to the FM demodulator 40, and passes only a predetermined band of audio signals output from the FM demodulator 40. It consists of a band pass filter 42.

As shown in FIG. 2, the second tuner includes a TV antenna (Ant.A) for receiving a TV signal and a TV RF amplifier for amplifying an RF signal input through the TV antenna (Ant.A). (11) and a TV band pass filter (12) for filtering to a desired frequency band among RF signals amplified and output through the TV RF amplifier (11), and the RF signal output from the TV band pass filter (12). TV demodulator comprising a TV mixer 14 for mixing with an inputted local oscillation signal and outputting a primary IF signal, and a TV local oscillating circuit 13 for outputting a local oscillation signal according to the input RF signal. 10, an FM antenna (Ant.B) for receiving FM signals, an FM RF amplifier 16 for amplifying an RF signal input through the FM antenna (Ant.B), and an FM RF amplifier FM band pass filter 17 for filtering each desired frequency band among RF signals amplified and output through 16 and FM band FM mixer 19 for mixing the RF signal output from the pass-pass filter 17 with the local oscillation signal input and outputting the first IF signal, and the FM local for outputting the local oscillation signal according to the input RF signal. It consists of the FM demodulation part 15 containing the oscillation circuit 18. As shown in FIG.

However, the tuner of such a conventional receiver uses a different band pass filter and a local oscillation circuit according to each RF signal, or a band pass filter and a local oscillation circuit having a switching circuit therein and integrated two circuits. Since the IF signal output from the local oscillator circuit of the tuner is detected as the original signal by using each demodulation circuit, the detection process is very complicated, and the number of circuit elements used is very large, which limits the size of the circuit design. There is a problem.

In addition, since the tuner of the conventional receiver uses each local oscillation circuit, there is another problem that affects performance by generating mutual interference or noise between the local oscillation circuits.

In addition, the antenna of the conventional receiver is divided into a TV and FM for use, and the TV signal can only be used as an antenna for the FM FM signal can be used only for the FM antenna, there is another problem that the signal is not received if the antenna is incorrectly connected.

In order to solve the above problems of the present invention, irrespective of the RF signal input through the antenna to output a single-band primary IF signal, and to detect and output the required received signal in the demodulation circuit circuit By simplifying the structure and detection process of the circuit, it is possible to reduce the volume in the circuit design.

Another object of the present invention is to prevent the occurrence of mutual interference or noise by outputting the primary IF signal using one local oscillation circuit, instead of outputting the primary IF signal using each local oscillator circuit in the tuner. It is.

In addition, another object of the present invention is to use a plurality of antennas, regardless of the TV signal and FM signal using the signal input through the antenna with a better reception rate is separated into a video signal and an audio signal, so no antenna without distinguishing the antenna It is to be able to receive both TV signal and FM signal even if is connected.

1 is a block diagram showing a general multimedia tuner

2 is a block diagram illustrating a multimedia receiver to which the tuner of FIG. 1 is applied.

3 is a block diagram illustrating a general multimedia tuner.

4 is a block diagram showing a receiver capable of multimedia reception according to the present invention.

5 is a waveform diagram illustrating a frequency band output from an IF band pass filter of a receiver capable of receiving multimedia according to the present invention.

6 is a waveform diagram showing a frequency band output from a SAW filter of a receiver capable of receiving multimedia according to the present invention;

7 is a block diagram showing a receiver having a 3-band tuner to which the present invention is applied.

<Explanation of symbols for main parts of the drawings>

110: tuner 111: input switching unit

112: first band pass filter 113: RF amplifier

114: second band pass filter 115: local oscillator

116 mixer section 117 IF amplifier

120: IF band pass filter 130: SAW filter

140: demodulation unit 150: local oscillation circuit for video signals

160: local oscillation circuit for audio signals

Features of the present invention for achieving the above objects,

In the integrated receiver of the multimedia type for receiving an RF signal corresponding to the TV signal and an RF signal corresponding to the FM signal,

A tuner which converts an input RF signal into an IF signal of a predetermined range and amplifies and outputs it;

First filtering means for filtering only frequencies of a desired region of the IF signals supplied from the tuner;

Second filtering means for dividing a video signal and an audio signal among signals output from the first filtering means, respectively;

A demodulator for detecting a video signal and an audio signal output from the second filtering means according to each local oscillation signal input;

And a local oscillator for providing each local oscillation signal corresponding to a video signal and an audio signal to the demodulator.

Here, the demodulation unit,

A band pass / band rejection filter for passing only a signal of a desired region of a video signal and an audio signal, and removing an audio signal included in the video signal;

Switching means for passing the video signal supplied from said second filtering means to ground upon selection of the FM signal.

Here also the tuner,

At least one antenna for receiving an RF signal,

An input switching unit which switches according to a selection signal of a TV or FM and selectively transmits an RF signal supplied from the antenna;

An RF amplifying unit for amplifying an RF signal input through the input switching unit;

A band pass filter for filtering the RF signal amplified and output from the RF amplifier into a desired frequency band, respectively;

A mixer unit for mixing an RF signal output from the band pass filter unit with an input local oscillation signal and outputting an IF signal;

A local oscillator for supplying the local oscillation signal to the mixer;

And an IF amplifier for amplifying and outputting an IF signal output from the local oscillator.

Here, the local oscillation unit,

A first local oscillation circuit for providing a local oscillation signal corresponding to a video signal to the demodulator;

And a second local oscillation circuit for providing a local oscillation signal corresponding to an audio signal to the demodulator.

Another feature of the invention,

An IF signal output step of amplifying and filtering an RF signal input through one of a plurality of antennas selected from a plurality of antennas, converting the RF signal into a predetermined area, and then amplifying and outputting the IF signal;

A filtering step of filtering only IF signals of a predetermined region among the IF signals output in the step;

A separation step of separating and passing the IF signal filtered in the step into a video signal and an audio signal,

And detecting the local oscillation signal by applying the respective local oscillation signals to the separated video and audio signals.

In the detecting step, when the system selects the FM signal, the system passes the video signal to the ground to block the output of the video signal.

Hereinafter, the configuration and operation of a receiver capable of receiving multimedia according to the present invention and a control method thereof will be described in detail with reference to FIGS. 4 to 7.

4 is a block diagram illustrating a receiver capable of multimedia reception according to the present invention, FIG. 5 is a waveform diagram illustrating a frequency band output from an IF band pass filter of a receiver capable of receiving multimedia according to the present invention, and FIG. A waveform diagram showing a frequency band output from a SAW filter of a receiver capable of receiving multimedia according to the present invention.

Referring to FIG. 4, a receiver 100 capable of receiving multimedia according to the present invention includes a tuner 110, an IF band pass filter 120, a SAW filter 130, a demodulator 140, and a video signal. A local oscillation circuit 150 and a local oscillation circuit 160 for an audio signal.

The tuner 110 is a plurality of antennas (101, 102) for receiving both a TV signal and an FM signal, and the RF signal is switched in accordance with an external control signal supplied from any one of the plurality of antennas (101, 102) Through the input switching unit 111 for selectively transmitting the first, the first band pass filter 112 for filtering the RF signal input through the input switching unit 111, and through the first band pass filter 112 An RF amplifier 113 for amplifying the output RF signal, a second band pass filter 114 for filtering the RF signal amplified by the RF amplifier 113 to a desired frequency band, and a second band pass A mixer unit 116 for mixing an RF signal output from the filter unit 114 with an input local oscillation signal and outputting an IF signal, a local oscillator 115 for supplying a local oscillation signal to the mixer unit 116, IF amplification to amplify and output the IF signal output from the mixer section 116 It consists of 117. Here, the tuner 110, unlike the conventional tuner, amplifies and passes only a signal of a predetermined band irrespective of the signals input through the respective antennas 101 and 102, and detects it through a single local oscillation signal to detect a single IF signal. Output only.

The IF band pass filter 120 filters only frequencies of a desired region of the IF signals output from the tuner 110. Here, the IF band pass filter 120 passes an IF signal having an area as shown in FIG. 5.

The SAW filter 130 divides the video signal and the audio signal from among the IF signals output from the IF band pass filter 120, respectively. Here, the reason why the SAW filter 130 can pass the video signal and the audio signal separately is that the IF signal band passed by the IF band pass filter 120 is different from the video signals of the different bands as shown in FIG. 6. Because it contains all of the audio signals, this signal is clearly distinguished into the video band (45.75MHz) and the audio band (41.25MHz).

The demodulator 140 includes an IC chip demodulator 141. The demodulator 141 outputs a video signal output from the SAW filter 130 to a local oscillation signal for a video signal supplied from a local oscillator circuit 150 for a video signal. The audio signal is detected by the local oscillation signal for audio signal supplied from the local oscillation circuit 160 for audio signal. Here, the demodulator 140 passes only signals of a desired region of the video signal and the audio signals, and has a band pass / band provided with a plurality of trap circuits (not shown) to remove the audio signal included in the video signal. A cancellation filter 142 and switching means 143 for passing the video signal supplied from the SAW filter 130 to ground when the FM signal is selected. Here, as the switching means 143, a transistor which is switched under the control of the demodulator 141 is preferably used.

The local oscillation circuit 150 for video signals generates a local oscillation signal for video signals that can detect video signals, and the local oscillation circuit 160 for audio signals generates a local oscillation signal for audio signals that can detect audio signals.

Hereinafter, an operation of a receiver capable of receiving multimedia according to the present invention will be described in detail with reference to FIG. 4.

First, the TV signal and the FM signal are selected according to the user's selection or the system's selection. When the TV signal is selected, the input switching circuit 111 is switched according to the control signal to select the switching among the plurality of antennas 101 and 102. Accordingly, the first band pass filter 112 is electrically connected to the connected antenna. The RF signal received through any antenna is filtered by the first band pass filter 112 and then amplified by the RF amplifying unit 113 and supplied to the second band pass filter 114, and passed through the second band pass. The filter unit 114 passes the input RF signal only a frequency of a desired band. The mixer unit 116 receiving this signal mixes with the local oscillation signal supplied from the local oscillator 115 to output an IF signal, and the IF amplifier 117 amplifies the IF signal supplied from the mixer unit 116 Will print.

If the IF band pass filter 120 passes only the IF signal of the desired band among the IF signals supplied from the IF amplifier 117 of the tuner 100, the SAW filter 130 receiving the signal receives the video signal and the audio signal from the IF signal. Pass the signal apart. When the video signal and the audio signal are supplied to the demodulator 140 from the SAW filter 130, the demodulator 140 detects the video signal as a local oscillation signal for the video signal supplied from the local oscillation circuit 150 for the video signal, and audio The signal is detected as a local oscillation signal for the audio signal supplied from the local oscillation circuit 160 for audio signal, and then filtered using the band pass / band rejection filter 142 and finally outputs both a video signal and an audio signal.

On the contrary, when the FM signal is selected, the input switching circuit 111 electrically connects the first band pass filter 112 to the connected antenna according to the switching selection of the plurality of antennas 101 and 102. The RF signal received through any antenna is filtered by the first band pass filter 112 and then amplified by the RF amplifying unit 113 and supplied to the second band pass filter 114, and passed through the second band pass. The filter unit 114 passes the input RF signal only a frequency of a desired band. The mixer unit 116 receiving this signal mixes with the local oscillation signal supplied from the local oscillator 115 to output an IF signal, and the IF amplifier 117 amplifies the IF signal supplied from the mixer unit 116 Will print.

If the IF band pass filter 120 passes only the IF signal of the desired band among the IF signals supplied from the IF amplifier 117, the SAW filter 130 receiving the signal receives an audio signal and a video signal (unnecessary noise component) of the IF signal. Pass). The SAW filter 130 receives the signal and passes the video signal and the audio signal separately from the IF signal. When the video signal and the audio signal are supplied to the demodulator 140 from the SAW filter 130, the demodulator 140 detects the video signal as a local oscillation signal for the video signal supplied from the local oscillation circuit 150 for the video signal, and audio The signal is detected as a local oscillation signal for an audio signal supplied from the local oscillation circuit 160 for an audio signal, and then filtered using the band pass / band rejection filter 142 and finally outputs a video signal and an audio signal. At this time, the demodulator 140 switches the switching means 143 to pass unnecessary video signals to the ground to prevent the video signals from being output and to output only desired audio signals.

7 is a block diagram illustrating a receiver having a three-band tuner to which the present invention is applied. In the tuner 210, an RF signal received through an antenna 201 is supplied to a high band tuner 220, and an input switching means 250 is provided. And RF signals received through the antenna 202 are selectively supplied to the middle band tuner 230 or the low band tuner 240.

In the high band tuner 220, the middle band tuner 230 or the low band tuner 240, the input RF signals are converted into IF signals in a predetermined range and output through the IF amplifier 226.

Then, as described above, by performing the same process, the IF signal is separated into a video signal and an audio signal through the SAW filter 270 and applied to the demodulator 280, and the demodulator 281 of the demodulator 280 is a TV. Outputs both the video signal and the audio signal upon selection of, and switches the input switching means 283 when selecting the FM to pass the video signal to ground, and outputs only the audio signal.

Therefore, the tuner outputs only a single band IF signal regardless of TV or FM selection, detects and outputs video and audio signals when TV is selected on the demodulator side, and detects and outputs only audio signals when FM is selected. In this way, the circuit configuration can be simplified while simplifying the detection method.

As described above, according to the receiver capable of receiving multimedia according to the present invention and a control method thereof, the primary IF signal is constantly output irrespective of the RF signal input through the antenna, and the demodulator detects the required received signal. By simplifying the structure and detection process of the circuit, the volume can be reduced when designing the circuit.

In addition, according to the present invention, it is possible to prevent mutual interference or noise from occurring by outputting the primary IF signal by using one local oscillator circuit without outputting the primary IF signal by using each local oscillator circuit to the tuner. have.

In addition, according to the present invention, since a plurality of antennas are used, regardless of the TV signal and the FM signal, the signals input through the antenna having a better reception rate are separated into the video signal and the audio signal, so that any antenna is connected without distinguishing the antenna. Even if it can receive both TV signal and FM signal.

Claims (6)

In the integrated receiver of the multimedia type for receiving an RF signal corresponding to the TV signal and an RF signal corresponding to the FM signal, A tuner which converts an input RF signal into an IF signal of a predetermined range and amplifies and outputs it; First filtering means for filtering only frequencies of a desired region of the IF signals supplied from the tuner; Second filtering means for dividing a video signal and an audio signal among signals output from the first filtering means, respectively; A demodulator for detecting a video signal and an audio signal output from the second filtering means according to each local oscillation signal input; And a local oscillator for providing each local oscillation signal corresponding to a video signal and an audio signal to the demodulator. The method of claim 1, The demodulation unit, A band pass / band rejection filter for passing only a signal of a desired region of a video signal and an audio signal, and removing an audio signal included in the video signal; And switching means for passing the video signal supplied from the second filtering means to ground when the FM signal is selected. The method of claim 1, The tuner is, At least one antenna for receiving an RF signal, An input switching unit which switches according to a selection signal of a TV or FM and selectively transmits an RF signal supplied from the antenna; An RF amplifying unit for amplifying an RF signal input through the input switching unit; A band pass filter for filtering the RF signal amplified and output from the RF amplifier into a desired frequency band, respectively; A mixer unit for mixing an RF signal output from the band pass filter unit with an input local oscillation signal and outputting an IF signal; A local oscillator for supplying the local oscillation signal to the mixer; And an IF amplifier for amplifying and outputting an IF signal output from the local oscillator. The method of claim 1, The local oscillation unit, A first local oscillation circuit for providing a local oscillation signal corresponding to a video signal to the demodulator; And a second local oscillation circuit for providing a local oscillation signal corresponding to an audio signal to the demodulator. An IF signal output step of amplifying and filtering an RF signal input through one of a plurality of antennas selected from a plurality of antennas, converting the RF signal into a predetermined area, and then amplifying and outputting the IF signal; A filtering step of filtering only IF signals of a predetermined region among the IF signals output in the step; A separation step of separating and passing the IF signal filtered in the step into a video signal and an audio signal, And a detection step of detecting and applying respective local oscillation signals to the video signal and the audio signal separated in the step. The method of claim 5, And in the detecting step, the system passes the video signal to ground when the FM signal is selected to block the output of the video signal.