KR960002167B1 - Tv/vcr mode auto switching circuit & the method thereof - Google Patents

Abstract

The eject and inserting of a tape to a VCR is detected and the TV or VCR mode of a television is changed according to the detected the motion of a VCR. The circuit includes a video signal level comparator(11) for comparing the levels of a video signal transmitted through a VCR input terminal and a video signal transmitted through a intermediate frequency processing pack(2), a controller(5') for generating output control signals of video signal output line and audio signal output line according to setting status of mode selection switches(SW1,SW2) and an output signal of the comparator(11), and an output line switching unit(4') for sending a VCR signal or a TV signal to a video signal output unit(6) and an audio signal output unit(7) according to the control signal generated by the controller(5').

Description

TV / BC mode automatic switching circuit and method of TV receiver

1 is a conventional mode switching circuit block diagram.

2 is a flowchart of mode switching operation of FIG.

3 is a mode switching circuit block diagram according to the present invention.

4 is a flowchart of mode switching operation of FIG.

* Explanation of symbols for main parts of the drawings

1: Tuner 2: Medium Frequency (IF) Pack

3: VR input part 4 ': output line switching part

5 ': controller 6: video output

7: audio output unit 11: image level comparison unit

AL: Voice output line SW1: TV / VSAL mode selection switch

SW2: Auto / Manual Mode Selection Switch VL: Video Output Line

The present invention relates to a TV / V-Cal automatic switching circuit and method of the TV receiver, and in particular, to switch from the TV mode to the V-Cal mode by only inserting / ejecting the V-Cal tape when the TV / V-Cal mode selection is automatically switched. Or, it automatically converts the transition from voice mode to TV mode.

Conventional TV / TV mode switching device is a tuner (1) for selecting one of the frequencies of the various channels input to the antenna as shown in Figure 1, and the intermediate frequency (Intermediate Frequency: less than IF selected from this tuner) IF pack 2 for dividing the signal of the video signal and the audio signal to the video output line and the audio output line, and the V-Cal input unit 3 for inputting the video signal and audio signal of Video synchronization detection unit 10 for detecting the synchronization signal coming through V-Cal input unit 3, TV / VCR mode selection switch (SWI) and automatic / manual (QUTO / MANU) mode selection A controller 5 which checks the output of the switch SW2 and the video simultaneous detection unit 10 and floats the output control signal OC of the video signal output line VL and the audio signal output line AL; Switched to the output of V / Consists of a television signal to the video output section 6 and the audio output unit (7) selectively to an output line switching unit (4) Export to the television receiver.

The TV receiver as described above outputs an IF signal by selecting one broadcast frequency to be viewed from the tuner 1 among the frequencies of several channels inputted through an antenna, and then separates the video signal and the audio signal from the IF signal and outputs the video output unit ( 6) and on the audio output unit 7.

At this time, the video signal and the audio signal of the TV and the video signal and the audio signal input to the VR input unit 3 is selected by switching the switching switch in the case of MANU as shown in the operation flowchart of FIG. In the case of (AUTO), the video sync detection unit 10 determines whether or not the synchronization signal of V-Cal is present and controls the output line switching 4 through the controller 5 to automatically switch the TV / VCR mode. It is supposed to be.

In addition, in many other technologies, the controller 5 of the TV receiver determines whether the TV or V-CAL key is pressed to display an output control signal on the output line switching unit 4.

However, in the above conventional technology, it is determined whether or not the synchronization signal of the TV / V-Cal is changed to the TV / V-CAL mode. When switching to the V-Cal mode (automatic mode) is unclear, and the tape of the unrecorded part is played back, the same method as described above causes an ambiguous situation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in particular, the controller determines the output signal change of the video level comparator that compares the video signal level of the TV with the video signal level of the TV. It is to provide a TV / V-Cal mode automatic switching circuit and method of the TV receiver to automatically select the following, the configuration of the present invention will be described in detail by the accompanying drawings.

FIG. 3 is a block diagram of a TV / BC mode automatic switching circuit according to the present invention. As shown in the drawing, a tuner 1 for selecting one broadcasting frequency among frequencies of various channels input to an antenna, and the tuner An IF pack (2) for separating the IF signal selected in (1) into a video signal and an audio signal and outputting the video output line (VL) and the audio output line (AL); The V-Cal input unit 3 and the video signal level of the TV through the IF pack 2 and the V-Cal video signal level through the V-Cal input unit 3 are input to change the output signal according to the input state. The video signal output line VL and the audio are checked by checking the output change of the video level comparator 11, the TV / BT mode selection switch SW1, the automatic / manual mode selection switch SW2, and the video level comparator. Output control signal of signal output line AL OC) controller 5 and an output line switching unit 4 for selectively outputting the TV / V-Cal signal to the video output unit 6 and the audio output unit 7 of the TV receiver according to the output of the controller. Construct ').

4 is an operation flowchart showing the TV / VCal mode automatic switching method in the controller according to the present invention. As shown in the figure, the switching state of the manual / automatic mode selection switch SW2 is checked (step S11). If the manual mode is selected, the output control signal OC is displayed by controlling the output line switching unit 4 'according to the setting state of the TV / BT mode selection switch SW1 (step S12). If the automatic mode is selected (steps S14 and S15), the video signal level of the TV input through the tuner 1 and the IF pack 2 and the video signal level of the VRC input through the VRC input unit 3 In response to the S / N (signal-to-noise) output change check state of the image level comparison unit 11 according to the comparison result (step S13), an output control signal OC is displayed to control the output line switching unit 4 '. Mode and VR mode The operation flow is made to set (steps S14, S15).

The operation and effects of the present invention configured as described above are as follows.

In FIG. 3, a high frequency signal outputs a video output (VL) and an audio output (AL) through an IF pack (2) via a tuner (1), while watching a broadcasting channel through a TV receiver. When the VRC is turned on when the tape is inserted, the TV broadcast signal and the VRC signal are added together, resulting in a blurry screen with no noise unless manually switched.

In this case, the video level comparison unit 11 compares the video levels of the TV broadcast signal and the VAL signal, and outputs the signal level of the existing broadcast channel and the signal level of the VAL signal, which is displayed on the controller 5 '. As shown in FIG. 4, the controller 5 'first checks the switching state of the manual / automatic mode selection switch SW2 (step S11), and if the manual mode MANU is selected, the TV / BT mode selection switch SW1 is selected. According to the switching state of (step S12), the output line switching unit 4 'is controlled to be set to TV mode or BC mode, and if the automatic mode (AUTO) is selected, the output change of the image level comparison unit 11 is changed. Check (Step S13) to display the output control signal (OC) according to the change state to control the output line switching unit 4 'to set to TV mode or V-Cal mode (Steps S14 and S15). Sleep Mode It is switched to.

Therefore, the present invention is useful to be able to switch from the TV mode to the V-Cal mode immediately by inserting only the V-Cal tape, not the manual mode, when the automatic mode is selected.

Claims (2)

A video level comparator 11 for comparing the video signal level of the V-Cal inputted through the V-Cal input unit 3 and the broadcast video signal level of the broadcasted V-CV received through the intermediate frequency pack 2 as an input; Output of the image output line VL and the audio output line AL by checking the setting state of the switch SW1 (SW2) for mode selection and automatic / manual mode selection and the output change of the image level comparison unit 11. The controller 5 'which raises the control signal OC, and selectively outputs the TV signal or V-Cal signal to the image output unit 6 and the audio output unit 7 according to the output of the controller 5'. TV / VCAL automatic switching circuit of the TV receiver, characterized in that it comprises an output line switching unit (4 '). If the manual mode is selected by checking the switch setting for manual / auto mode selection, set the TV mode and V-CAL mode according to the switch setting state for the TV / V-Cal mode selection, and if the automatic mode is selected, TV / V of the TV receiver characterized by automatically setting the TV mode and V-CAL mode by checking the S / N (signal-to-noise) output change according to the comparison result of the video signal level of Automatical mode switching method.