KR19980047358A - Input Signal Selection Method of TV with Input Signal Selection Function at Power-On - Google Patents

Abstract

The present invention relates to a TV, and more particularly, to provide a method for selecting an external signal of a TV having an external signal selection function by which a user does not need to check it by connecting an external signal according to a priority of power-on of the TV. To this end, detecting whether a power switch of a television is input, turning on the power when the power switch is input, selecting an external terminal having the highest priority while the power is turned on, and selecting the terminal. Detecting whether a signal input from the terminal exists, and switching to a terminal of a next order if a signal input from the selected terminal does not exist.

Description

Input Signal Selection Method of TV with Input Signal Selection Function at Power-On

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to TVs, and more particularly, to an input signal selection method of a television having an input signal selection function suitable for selecting an external device connected thereto according to priority.

A typical television receiver receives and demodulates a broadcast signal transmitted from a broadcasting station and outputs it as a video signal and an audio signal through a CRT and a speaker. At this time, the OSD (ON SCREEN DISPLAY) function is used as a display function of a character or a picture. 1 is a block diagram illustrating a schematic configuration and function of a television receiver having a general OSD function.

In FIG. 1, reference numeral 101 denotes an antenna, 102 denotes an RF amplifying unit for amplifying a radio frequency signal (RF) received through the antenna 101, and 103 denotes an RF amplification unit. A first frequency outputting an intermediate frequency signal (hereinafter referred to as IF) by receiving and mixing the radio frequency signals output from the unit 102 and the oscillation frequency signals output from the local oscillation circuit 117 which will be described later. Indicates a mixer. Also, reference numeral 104 denotes an IF amplification unit for amplifying the intermediate frequency signal output from the first mixer 103, and 105 denotes an image intermediate frequency signal (PIF) in the intermediate frequency signal output from the IF amplifier 104. And a P / S separation unit such as a surface acoustic wave filter for separating the voice intermediate frequency signal SIF, and 106 denotes a voice signal from the voice intermediate frequency signal SIF output from the P / S separation unit 105. 107 denotes an audio detector for detecting an image signal from an image intermediate frequency signal PIF output from the P / S separation unit 105. In addition, reference numeral 108 denotes a remote control device which allows the viewer to select a desired channel or to select each mode of the television, for example, a TV / AV mode, and 109 denotes an electrical signal of the infrared signal from the remote control device 108. A receiver converts a code signal, 110 denotes a channel memory in which predetermined channel data is stored, and 111 denotes a microprocessor that controls the entire system according to an input signal from the remote controller 108. In addition, reference numeral 112 denotes a screen display for overlapping and outputting a character or a picture, etc., on a screen on which a broadcast signal is output separately from the broadcast signal according to the control signal of the microprocessor 111 (hereinafter referred to as OSD). ) Denotes a PWM generator for generating a predetermined pulse width modulation (PWM) signal according to a control signal from the microprocessor 111, and 114 denotes the PWM generator ( An integrated circuit for integrating the PWM signal output from 113) and generating a predetermined level signal is shown.

At this time, if the viewer selects a predetermined channel using the remote control device 108, the microprocessor 111 reads out the channel data corresponding to the channel selected by the viewer from the channel memory 110, and then based on the selected channel. By controlling the PWM generator 113 to generate a predetermined PWM signal, the PWM signal is output as a voltage control signal corresponding to the channel selected by the viewer through the integration circuit 114 at this time.

In addition, reference numeral 115 is provided for a precise tuning operation, and denotes an Auto Fine Tunning circuit (hereinafter referred to as AFT) circuit 115, and 116 is a voltage signal applied from the integrating circuit 114. An adder for adding a voltage signal applied from the AFT circuit 115 is shown, and 117 shows a local oscillating circuit for outputting a predetermined oscillation frequency. At this time, the local oscillator circuit 117 generates a predetermined frequency signal according to the level of the voltage signal applied through the adder 116 and outputs it to the mixer 103 to execute broadcast tuning. In addition, the local oscillation circuit 117 is a local oscillation frequency that is output in accordance with the change in the ambient temperature or time elapses. However, if the local oscillation frequency is changed as described above, the intermediate frequency output from the mixer 103 is changed, thereby making it impossible to reproduce stable images. The AFT circuit 115 is provided to solve the above problem, which outputs the voltage signal (± ΔV) for the variation range Δf of the intermediate frequency to the adder 116 to the local oscillation circuit. This is to stabilize the local oscillation frequency output from 117. In addition, in the TV, the magnitude of the input signal received through the antenna 101 changes due to the strength or fluctuation of the received signal.

In addition, reference numeral 118 denotes the image detector 134 by controlling the amplification degree of the above-described RF amplifier 102 and the IF amplifier 104 based on the level of the image signal detected by the image detector 107. Auto Gain Control (hereinafter referred to as AGC) circuit which controls the video signal output level from 107 constantly. In addition, reference numeral 119 denotes an external AV device such as a VCR or a laser disc player, and 120 denotes the voice detector 106 and the image detector 107 according to the switching signal from the microprocessor 111. And a switching unit for selectively outputting audio and video signals from the external AV device 119. Although reference numeral 121 is not shown for the audio signal output from the switching unit 120, the base, treble, and volume according to the control signal from the microprocessor 111. An audio processing unit that executes audio processing such as the above is shown, and 122 represents an audio amplifying unit which amplifies the audio signal processed by the audio processing unit 121 and outputs it to the speaker. Further, reference numeral 123 is not shown for the image signal output from the switching unit 120, but according to the control signal from the microprocessor 111 Color, tint, Brightness ), And outputs R (Red), G (Green), and B (Blue) signals corresponding to the video signal. The RGB signal output from the image processor 123 is mixed with the RGB and OSD blanking signal Y ′, which are the output signals of the OSD generator 112 described above, in a second mixer indicated by reference numeral 124, and is output. 125 denotes a CRT driver for driving the CRT based on the RGB signal output from the mixer 124. That is, in the above-described TV, when the viewer selects the TV / AV mode using the remote control device 108, the microprocessor 111 controls the switching unit 120 to control the voice detector 106 and By selectively outputting the video and audio signals from the video detector 107 and the video and audio signals from the external AV device 119 to the video processor 123 and the audio processor 121, the viewer Video and audio played back by the external AV device 119 can be heard and viewed through the CRT and the speaker of the TV. Therefore, the television receiver as described above has a function of simply outputting a broadcast signal and its use range is limited.

For example, when the user turns on the TV, the user cannot know whether it is a program provided by a broadcasting station or a signal input from external devices, and because the user cannot know the type of external device that provides the input signal. There was a problem that you should check with

An object of the present invention is to select the input signal at the time of power-on that the user can select the external device that provides the current input signal according to the priority and inform the user when the user turns on the power of the TV in the TV connected to various external devices It is to provide a method for selecting an input signal of a television having a function.

The present invention for achieving the above object is a step of detecting whether the power switch of the television input is turned on if the power switch is turned on, and the external terminal having the highest priority at the same time the power is turned on And selecting a signal, detecting whether a signal input from the selected terminal exists, and switching to a terminal of a next order if the signal input from the selected terminal does not exist.

1 is a block diagram for explaining the configuration and function of a general television receiver having an OSD function.

Fig. 2 is a block diagram illustrating main parts for explaining the configuration of a TV having an input signal selection function of the present invention.

3 is a flowchart illustrating a method of selecting an input signal at power on according to the present invention.

Explanation of symbols on the main parts of the drawings

201: tuner portion 202: switching portion

203: Video and audio IC 204: R, G, B driver section

205: amplifier 206: micom

Referring to FIG. 2, a television having an input signal selection function at power-on of the present invention includes a tuner unit for selectively amplifying a radio wave of a channel to be received in a television radio wave received from an antenna and converting the signal into an intermediate frequency signal of video and audio. 201 and the switching unit 202 and the switching unit 202 for switching the input terminals of the external device connected to the tuner unit 201 and the television to the input terminals of the following video and audio ICs in order of priority. R, G, and B images output through the video and audio IC 203 and the video and audio IC 203 for separating the original color difference signal and the audio signal from the broadcast signal or the input signal of an external device applied according to the result. R, G, B driver unit 204 for converting the signal into an appropriate signal for display on the CRT, and amplified audio signal detected by the video and audio IC 203 to a predetermined width And an amplification unit 205 and a microcomputer 206 for controlling the entire system.

When the user turns on the television, the switching unit 202 switches the input terminal of the external device according to the priority according to the control signal of the microcomputer 206 and connects it to the video and audio IC 203. In this case, the priority is determined by the airwaves transmitted from the satellite signal terminal, the external device terminal, and the broadcasting station. The input terminal of the external device includes the satellite signal terminal. When the satellite signal terminal is selected according to the priority, if a signal input from the satellite signal terminal exists, it is output through the CRT and the speaker through a normal signal processing process through the video and audio IC 203. If there is no signal input from the satellite signal terminal, the switch is switched to the external device terminal of the next rank. Such switching switching is performed by the control signal of the microcomputer 206 as described above. Even though the switch is switched to the external device terminal, if there is no signal input from the external device terminal, the switch is switched to the TV terminal for inputting the airwaves transmitted from the broadcasting station of the next rank. Through this process, the user does not have to check the input state of various external devices connected to the television system. 3 is a flowchart illustrating a method of selecting an input signal of a television according to the present invention.

As shown in FIG. 3, first, it is determined whether a power key of a television for selecting an external device is input (S101). If a power-on key is input, the power of the television is turned on (S102). Subsequently, the satellite signal terminals are switched to the video and audio IC input terminals according to the priorities (S103), and it is determined whether there is a signal input from the satellite signal terminals (S104). Subsequently, if there is no input signal, the external device terminal having the next priority is switched to the video and audio IC (S105). Then, it is detected whether there is a signal input from the external device terminal (S106), and if there is no input signal, the switching is finally switched to the TV terminal (S107).

As described above, the external signal selection method of the TV having the input signal selection function at power-on of the present invention turns on the power of the TV and at the same time makes a test connection to the priority to determine what signal the user is currently displaying. This eliminates the hassle of having to check on purpose, which has the effect of improving convenience.

Claims (2)

Detecting whether a power switch of the television is input and turning on the power if the power switch is input; Selecting an external terminal having the highest priority while the power is turned on; Detecting whether there is a signal input from the selected terminal; And switching to a next priority terminal when a signal input from the selected terminal does not exist. The input signal selection method of a TV having an input signal selection function at power ON. The input signal selection method of a TV having an input signal selection function at power-on, according to claim 1, wherein the priority is satellite television terminal external device terminal television aerial order.