KR100360119B1 - Tuner of pip television - Google Patents

Abstract

The present invention relates to a television tuner for a P.I.P (hereinafter referred to as "PIP"), the present invention relates to a television tuner (20), comprising: a low noise amplifier (21) for amplifying an input signal with low noise; A divider (22) for distributing the signal from the low noise amplifier (21) in two stages; A main tuner 23 performing tuning on one signal distributed by the distributor 22; By having a built-in integrated into one structure (tuner chassis), it is possible to distribute the signal to the sub-tuner from one main tuner itself in one-body type without a separate distribution module, By carrying out the low noise amplification according to the signal level, the production process can be simplified, the production cost can be reduced, and the reception sensitivity can be improved.

Description

TV tuner for P.I.P {TUNER OF PIP TELEVISION}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television tuner for P.P. (hereinafter referred to as " PIP "), in particular a signal from one main-tuner itself to a sub-tuner without a separate distribution module. The present invention relates to a television tuner for a PIP that can be distributed and can perform a low noise amplification according to a signal level, thereby simplifying the production process and reducing the production cost, and improving reception sensitivity.

In general, a television tuner for a picture-in-picture (PIP) television receives a main signal and a sub-signal to receive two different broadcast screens, that is, a main screen (large screen) and a sub-screen (small screen), on one television. Should be distributed and provided.

In the conventional PIP television tuner, as shown in FIG. 1, the main tuner 12 does not distribute main signals and sub signals by itself, but uses a separate divider 11 connected to the outside.

As described above, in the conventional case of using a separate distributor, a process of connecting and assembling the main tuner 12 and the distributor 11 at the time of television production, a process of connecting and assembling a sub-tuner to the distributor 11, and the like. Since more demands, the production process is complicated, and accordingly the production cost has a problem that will automatically rise.

The present invention has been made to solve the above problems, and therefore, an object of the present invention is to distribute a signal from one main tuner itself to a sub-tuner without a separate distribution module. By providing a low noise amplification according to the signal level, it is possible to simplify the production process, reduce the production cost, and provide a PIP television tuner that can improve reception sensitivity.

1 is a block diagram of a conventional PIP television tuner.

2 is a block diagram of a PIP television tuner according to the present invention.

3 is a detailed circuit diagram of FIG. 2.

Explanation of symbols on the main parts of the drawings

20 TV Tuner 21 Low Noise Amplifier

21a filter 21b amplifier circuit

22: splitter 23: main tuner

24: switching control unit

As a technical means for achieving the above object of the present invention, the present invention provides a television tuner, comprising: a low noise amplifier for amplifying an input signal with low noise; A divider for distributing the signal from the low noise amplifier in two stages; A main tuner which performs tuning on one signal distributed in the distributor; It is provided with, characterized in that built in one structure (tuner chassis) integrally configured.

EMBODIMENT OF THE INVENTION Hereinafter, the P.E. television tuner which concerns on this invention is demonstrated in detail with reference to attached drawing. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

FIG. 2 is a block diagram of a PIP television tuner according to the present invention. Referring to FIG. 2, the PIP television tuner 20 according to the present invention includes a low noise amplifier 21 for amplifying an input signal with low noise and the low noise. Tuning is performed on the divider 22 which distributes the signal from the amplifier 21 in two stages, and one signal distributed by the divider 22, and the on / off switching signal ( A main tuner 23 for providing a SW) is provided, and the PIP television tuner 20 is integrated into one structure (tuner chassis).

In addition, the television further comprises a switching controller 24 in which the tuner switches the bias voltage of the amplifier in accordance with the on / off switching signal SW from the main tuner 23.

When the bias voltage is supplied by the filter 21a for filtering the input signal and the switching control of the switching controller 24, the low noise amplifier 21 makes the signal from the filter 21a low noise. An amplifying circuit 21b which amplifies and provides a signal of the filter 21a to the divider 22 without amplifying when a bias voltage is not supplied.

FIG. 3 is a detailed circuit diagram of FIG. 2. Referring to FIG. 3, the switching controller 24 includes a first transistor Q1 and a first transistor Q1 turned on when the switching signal SW is at a high level. The second transistor Q2 which is turned off as it is turned on to cut off the supply of the bias voltage BM of the amplifying circuit 21b, and is continuously turned on as the first transistor Q1 is turned on to be biased on the bypass path. The third and fourth transistors Q3 and Q4 for providing the voltage BM are configured, and the capacitor C24 for charging and providing a voltage is provided at the output terminal of the fourth transistor Q4.

3, the filter 21a of the low noise amplifier 21 is configured to pass a television broadcast signal band using a coil, a zener diode, and a resistor.

The amplification circuit 21 of the low noise amplifier 21 may include first and second diodes D1 and D2 of the input and output terminals turned on by a bias voltage supplied by the second transistor Q2 of the switching controller 24. ), An amplifier circuit including a transistor (Q) to amplify an input signal through the first diode (D1) and output a second diode (D2), and a second transistor (Q2) of the switching controller (24). And third and fourth diodes D3 and D4 that are turned on by the bias voltage BM supplied by the second transistor to form a bypass path to provide the input signal to the divider 22 without amplification.

Operation according to the present invention configured as described above will be described in detail below based on the accompanying drawings.

The present invention can distribute a signal to a sub-tuner in one main body itself, which is a one-body type, without a separate distribution module connected externally, and a PIP television tuner for performing low noise amplification according to signal level. As the invention, it will be described below in detail.

Referring to FIGS. 2 and 3, first, a high frequency signal received and input through an antenna (not shown) is amplified by the low noise amplifier 21 and then divided into two stages, that is, one stage in the divider 22. The main signal of the first stage is distributed to the television 30 after being tuned by the main tuner unit 23 on the rear stage, and the other sub-signal of the other stage is provided to the external sub. Provided as a tuner.

The switching control unit 24 and the low noise amplification 21 will be described in more detail with reference to FIG. 3.

First, the filter 21a of the low noise amplifier 21 band-passes only a television broadcast signal among the input signals, and blocks unnecessary signals such as noise.

On the other hand, when the operation of the switching control unit 24 is described, when the reception sensitivity is good and there is no need to amplify, that is, when the switching signal SW provided from the main tuner 23 is high level, the first transistor is used. As Q1 is turned on, the second transistor Q2 is turned off, and the third and fourth transistors Q3 and Q4 are turned on, respectively, through the third and fourth transistors Q3 and Q4. A bias voltage BM is provided on the bypass path of the amplification circuit 21b in (21).

On the other hand, when the reception sensitivity is low, that is, when the switching signal SW provided from the main tuner 23 is at the low level, the second transistor Q2 is turned on as the first transistor Q1 is turned off. The third and fourth transistors Q3 and Q4 are turned off, respectively, to provide a bias voltage BM to the transistor Q of the amplifier circuit 21b in the low noise amplifier 21 through the second transistor Q2. do.

According to the control of the switching controller 24, the operation of the low noise amplifier 21 will be described. First, when the reception sensitivity is good, that is, the third and fourth transistors Q3 and Q4 of the switching controller 24 are described. When the bias voltage BM is supplied on the bypass path through the first and second diodes D1 and D2 of the amplifier circuit 21b, the third and fourth diodes D3 and D4 are turned on. The signal from the filter 21a is provided to the distributor 22 at the rear end through the third and fourth diodes D3 and D4 without amplification.

On the other hand, when the reception sensitivity is low, that is, when the bias voltage BM is supplied to the bias voltage of the transistor Q through the second transistor Q2 of the switching control unit 24, the amplification circuit 21b may be used. The first and second diodes D1 and D2 are turned on and the third and fourth diodes D3 and D4 are turned off so that the signal from the filter 21a is input through the first diode D1 and then the transistor Q. It is amplified in the amplification circuit consisting of, and is then provided to the distributor 22 of the S stage through the second diode (D2).

The received signal as described above is provided in the splitter 22 with two stages for the PIP, one stage to the internal main tuner section and the other to the external subtuner, which is shown in FIG. As one was constructed using a trans.

Thereafter, each tuner unit provides an intermediate frequency signal by tuning an input high frequency signal, and a description thereof is omitted since it is a general technology of a tuner.

As described above, by incorporating a low noise amplifier, a distributor, and a main tuner into one tuner chassis, a separate external distribution module becomes unnecessary, thereby reducing production processes and reducing production costs.

According to the present invention as described above, it is possible to distribute the signal to the sub-tuner in one main-tuner itself that is a one-body type without a separate distribution module, by performing a low noise amplification according to the signal level, By simplifying the production process, the production cost can be reduced, and there is a special effect to improve the reception sensitivity.

The above description is only a description of one embodiment of the present invention, the present invention is capable of various changes and modifications within the scope of the configuration.

Claims (3)

In the television tuner 20, When the bias voltage is supplied by the filter 21a for filtering the input signal and input switching control, the signal from the filter 21a is amplified with low noise, and when the bias voltage is not supplied, the filter ( A low noise amplifier 21 for amplifying the input signal with low noise, including an amplifier circuit 21b for providing the signal of 21a to the divider 22 without amplification; A divider (22) for distributing the signal from the low noise amplifier (21) in two stages; A main tuner 23 performing tuning on one signal distributed by the distributor 22 and providing an on / off switching signal SW according to the reception sensitivity of the signal; And A first transistor Q1 and a first transistor turned on when the switching signal SW is at a high level to switch the bias voltage of the amplifier according to the on / off switching signal SW from the main tuner 23; The second transistor Q2 which turns off as Q1 is turned on to cut off the supply of the bias voltage BM of the amplifying circuit 21b, and is continuously turned on and bypassed as the first transistor Q1 is turned on. Consists of third and fourth transistors Q3 and Q4 that provide a bias voltage BM on a path, and a capacitor C24 that charges and provides a voltage at an output terminal of the fourth transistor Q4 to ground. With the configured switching control unit 24, A TV tuner for a P.I.P, characterized in that it is integrally built in one structure (tuner chassis). delete delete