KR0171817B1 - Circuit and method for maintaining first channel - Google Patents

Abstract

The present invention relates to an RF reception system, and more particularly, to a circuit and a method for maintaining an existing selection channel while scanning a channel during channel selection.

A circuit for maintaining an existing selection channel is connected to the antenna 12, and the tuner 14 extracts and outputs only a desired RF signal from the RF signals received from the antenna 12 by input tuning data; It is connected to the antenna 12, and has the channel scanning part 24 which detects the RF signal of the poor channel among the RF signals input by the input tuning data, and detects and outputs a valid signal from the detected RF signal.

Maintaining the existing selection channel outputs the existing selection channel selection data from the tuner 14 upon inputting the channel up / down signal, and outputs the valid signal from the channel scanning unit 24 until the valid signal is output. The selected channel of the channel scanning section 24 is tuned and maintained by the control of the microprocessor 18 that provides channel tuner data of the channel scanning section 24 to the tuner section 14 when a valid signal is input.

As such, when the channel is newly selected, the existing channel is maintained until the tuning is completed, thereby controlling the noise appearing at every channel change.

Description

First channel retention circuit and method

1 is a circuit diagram according to the present invention.

2 is an operation control flow chart according to the present invention.

3 is an operational waveform diagram of FIG.

TECHNICAL FIELD The present invention relates to an RF receiving system, and more particularly, to a circuit and a method for maintaining an existing selection channel while scanning a channel during channel selection.

Looking at the electronic tuning circuit of a conventional RF system, a separate memory has to be set up for channel setting on a microprocessor in order to perform channel scanning.

RF reception system without channel memory For example, in TV, TCR, etc., channels are upset and down when EE noise is not displayed on the screen. Has been.

Accordingly, an object of the present invention is to select and display an existing selected preset broadcast as an EE (Eletric to Electtic) signal until the next broadcast is received, while the channel is tuned up / down, so that a channel without a broadcast signal source is displayed. It is to provide a circuit and a control method for suppressing the noise of the.

Another object of the present invention is to provide a circuit for detecting RF of a corresponding channel when selecting a channel up / down.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram according to the present invention, wherein an antenna 12 for receiving an RF signal and a RF signal received from the antenna 12 by input channel data are connected to the antenna 12. A tuner 14 which extracts and outputs only an RF signal, and connected to the antenna 12, detects an RF signal of an RF signal-decreasing channel input by input channel data and is effective in the detected RF signal. A channel scanning unit 24 which detects and outputs a signal, and outputs existing channel selection data from the tuner 14 when a channel CU (DOWN) signal is input, and is effective from the channel scanning unit 24. The microprocessor 18 tunes a selected channel of the channel scanning unit 24 until a signal is output, and provides channel tuning data of the channel scanning unit 24 to the tuner unit 14 when a valid signal is input. It consists of.

In this case, the microprocessor 18 is a tuner control microprocessor (TCMP).

The channel scanning unit 24 of FIG. 1 includes an RF detector 20 that tunes and outputs a received RF signal by input of channel scan data, and an image or an image on a signal output from the RF detector 20. And a signal detector 22 for detecting whether there is an audio signal and, as a result, outputting the signal as a logic state signal.

The OMP (Operating Micro Processor) shown in FIG. 1 is configured to output keycan pulses, scan keys to read key data, analyze input key data, and output channel data to the TCMP 18. FIG. .

This description number 30 is the key matrix.

In the configuration of FIG. 1, the tuner 14 and the RF detector 20 are electronic tuning circuits for tuning signals by PLL data.

FIG. 2 is a control flow chart of a TCMP according to the present invention. The first process of outputting channel selection data to the channel scanning unit at the same time as the channel selection unit outputs the previously selected channel data when the channel scan results in channel up / down. A second step of searching whether a signal discrimination signal is output from the channel scan unit after performing step 1; and if it is determined that there is no search result signal discrimination result signal in the second step, the first step is repeated. And a third process of providing channel scan data to the tuner.

3 is an operational waveform diagram of FIG.

(A) is the channel up / down pulse,

(B) is tuning data output from the TCM P 18 to the RF detector 20,

(C) is the output of the signal detector 22,

(D) shows channel selection data output from the TCMP 18 to the tuner unit.

Hereinafter, an operation example according to the present invention will be described in detail with reference to the accompanying drawings.

When the user presses a channel up or down key on the key matrix 30 while watching a channel broadcast, the OMP 16 recognizes it. The OMP 16 searches in step 34 whether the key is an up or down key.

The TCMP 18, which inputs the channel search data from the OMP 16, determines that the search data of the channel up / down data is input in step 34, and selects the previous channel to the tuner 14 through the line 28 in step 36. The data PLL is held and output in the section T2 of FIG. 3 (d). At this time, the tuner 14 tunes the channel signal by the previous channel tuning data (PLL Data) output from the TCMP 18 and maintains it as an EE signal.

The TCMP 18 performing the process of FIG. 36 performs the selected channel (channel up / down) data (PLL data) through the line 26 until fine tuning is completed in FIG. 38. During the T1 section of FIG. 3 (b), the input signal is input to the RF detector 20 to perform a channel scan corresponding to the channel up or down, and the output of the signal detector 22 is searched in step 40.

The R detector 20 which inputs channel channel data (PLL Data) output from the TCMP 18 outputs an RF signal tuned by the channel channel data (PLL Data) to the signal detector 22.

The signal detector 22 determines whether a video signal or an audio signal is present in the signal output from the RF detector 20 and provides a high or low signal to the TCMP 18 according to the result.

For example, if there is a video signal or an audio signal, the high logic signal is inputted to the TCMP 18 when the RF signal is input, and a low signal is output.

In this case, the TCMP 18 inputting the output of the signal detector 22 determines whether there is a signal in step 40 described above, and repeats steps 36 and 38 when there is no signal.

That is, when the output of the signal detector 22 is low (when it is determined that there is no signal), the TCMP 18 maintains and outputs previous channel tuning data so that the previous channel of the tuner 14 is held and received as an EE signal. The channel tuner 14 is controlled by controlling the tuner unit 14 and controlling channel channel data (PLL Data) of the RF detector 20 until the signal output from the signal detector 22 becomes high, as shown in FIG. Continue.

If the output of the signal detector 22 is high (if it is determined that there is a signal), the TCMP 18 displays the channel channel data (PLL Data) output to the RF detector 20 in step 42 (D). As shown by T3, the tuner unit 14 selects the changed channel broadcast. In operation 44, the operation of the RF detector 20 is stopped. That is, when the output of the signal detector 22 is high as shown in FIG. 3C, the TCMP 18, the RF detector 18, and the channel tuner data PLL data set by the RF detector 20 are tuner units. And the newly selected channel broadcast is received.

Therefore, even if the channel is changed while the existing broadcast is being listened to, the reception blank can be eliminated when the channel is changed by receiving the existing broadcast until the selected channel is fine tuned.

As described above, the present invention can eliminate the discomfort generated during viewing by eliminating the noise generated when the channel is changed by continuously receiving the existing received broadcast signal source until the channel tuning is completed when the channel is up / down.

Claims (4)

A first channel holding circuit having an antenna (12) for receiving an RF signal, wherein only a desired RF signal is received from among the RF signals received from the antenna (12) connected to the antenna (12) and inputted by preset channel data. It is connected to the tuner 14 which extracts and outputs, and the antenna 12, and detects the RF signal of a poor channel among the RF signals input by input channel data, and detects a valid signal from the detected RF signal. When the channel scanning unit 24 outputs the channel selection data of the channel selected from the tuner 14 when the channel up channel (CH UP / DOWN) signal is input, and the valid signal is output from the channel scanning unit 24. It is composed of a microprocessor 18 that tunes the selected channel of the channel scanning unit 24 and provides channel tuning data of the channel scanning unit 24 to the tuner unit 14 when a valid signal is input. First channel maintenance circuit characterized by. 2. The RF detector 20 according to claim 1, wherein the channel scanning unit 24 tunes and outputs a received RF signal by the input of the channel scan data, and an image or audio signal to the signal output from the RF detection unit 20. And a signal detector (22) for detecting whether there is a signal and outputting the signal as a logic state signal. 3. The apparatus according to claim 1 or 2, further comprising an operating microprocessor (16) for scanning a state of a channel up / down key and providing corresponding channel scanning data to the microprocessor (128). The first channel holding circuit, wherein when the channel is selected by pressing the / down key, the selected channel is received until the broadcasting of the selected channel is completed. A tuner unit 14 for receiving and outputting a desired channel broadcast among RF signals by channel tuning data input, and a channel for tuning an RF signal by channel scan and data input, and determining whether or not a valid signal is output from the tuning signal. 1. A first channel holding method comprising a scanning unit 24, a channel up / down signal input unit upper tuner unit 14, and a microprocessor 18 for controlling the channel scanning unit 24. A first process of outputting channel scan data to the channel scanning unit at the same time as outputting the previously selected channel data to the tuner unit at the time of down, and searching whether the signal discrimination signal is output from the channel scan unit after performing the first process. In the second process and the second process, if the search result signal determination result is determined that there is no signal, the first process is repeatedly performed. Maintaining first channel method which comprises a can yirueojim data in a third step of providing to the tuner section.