KR940008340Y1 - Changing circuit of vtr/tv for vtr - Google Patents

Abstract

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Description

VTI's VTI / TI switch control circuit

The accompanying drawings are embodiments of the present invention.

* Explanation of symbols for main parts of the drawings

1: Switching signal control unit 2: Switching drive unit

3: switch part 4: microcomputer

5: RF converter

The present invention relates to a VTIAL / TIVE switching control circuit of VRT, and more particularly, when VTIAL / TIVE operates a switching switch, VTAL's playback mode is converted into a still mode, which is a still picture. At the same time, the TV mode is switched, and when the switching switch is operated again, the VT / TI is switched to the VT mode and the steel mode is released to perform the regeneration mode.

Conventionally, if you want to watch TV during the playback mode, stop the video tape that was playing by operating the stop switch, and then turn the VTI / TIV switch to the TV mode to watch TV, and then watch the video tape again. If you want to watch the VTI / TIVE switch to the V-Tal mode by operating the switch, the playback switch was operated to watch the playback screen.

However, such a switching method has a problem of complicated operation and inconvenience to the user.

The present invention is to solve this problem, and when VTI / TIV switch is pressed once in the playback mode, the TV mode is switched to TV mode and the play mode is converted to the still mode, and VT / TIV is pressed once again When the still mode is switched to the mode and the steel mode is released, the purpose of the VT / TI of VTI where the regeneration mode is performed is to provide a switching control circuit.

In order to achieve the above object, the present invention uses a VT / TV switching signal (V / T) output from the microcomputer 4 as a VT mode signal or a second control signal to the RF converter 5 ( A switching signal controller 1 for outputting CS2) and a first control signal CS1 or a second output from the switching signal controller 1 in accordance with a delayed playback signal DPB output from the microcomputer 4; It is characterized in that it consists of a switching drive part 2 which switches the control signal CS2 into a steel signal or a steel release signal, and applies it from the switch part 3. As shown in FIG.

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

The VT / TV switching signal V / T output from the microcomputer 4 drives the switching transistor Q1 to invert the input signal, and the inverting signal output from the transistor Q1 is the condenser C1 and It is applied to the differential circuit of the resistor R3 and is output as the first control signal and simultaneously drives the switching transistor Q2, and the output signal of the transistor Q2 drives the RF converter 5 to switch the output signal. At the same time, the switching signal control unit 1 is configured to be output as the second control signal CS2 through the differential circuit of the capacitor C2 and the resistor R4, and the delayed regeneration signal DPB output from the microcomputer 4 is output. Drives the switching transistor Q3 to invert the input signal, and the inverted output signal of the transistor Q3 drives the field effect transistors Q4 and Q5 to be input from the switching signal controller 1. (CS1) and second control signal (CS2) is a diode (D _l) (D ₂₎ The switching driver 2 is applied as a control signal of the field effect transistor Q6 and the output signal of the field effect transistor Q6 driven by the control signal is applied to the switch unit 3 as a steel key signal. do.

Next will be described the operation and effect of the present invention made of the configuration as described above.

When the play key PL in the switch section 3 is pressed, the play key signal K3 is applied to the microcomputer 4 so that the VT switch V / T becomes a "high" level in the microcomputer 4 so as to switch the signal. Since the transistors Q1 and Q2 in the switching signal controller 1 are turned on, the " high " level signal is applied to the mode switching terminal MD of the RF converter 5. Switched to Thial Mode.

Further, the "high" level output signal of the transistor Q2 is applied to the derivative circuit consisting of the capacitor C2 and the resistor R4 and differentiated, and the differentiated pulse signal is applied to the field effect transistor Q5 in the switching driver 2. The delayed regeneration signal DPB output from the microcomputer 4 is converted to the "high" level only after a predetermined time has elapsed since the regeneration mode has been performed, so that the transistor Q3 in the switching driver 2 Is turned off, and thus, the gate " high " level signal of the field effect transistors Q4 and Q5 is applied so that all of the field effect transistors Q4 and Q5 are " off " Off ".

When the VTI / Tive switching switch CN is pressed in the play mode, the microcomputer 4 outputs the V / T switching signal V / T of "low" level, and accordingly, in the switching signal control unit 1. Since transistor Q1 is "off" and the output of this transistor Q1 outputs a "high" level signal, which is B ⁺ voltage, transistor Q2 is also "off" so that the mode switching terminal MD of the RF converter 5 is turned off. As the "low" level signal is applied to the RF converter 5, the RF converter 5 is applied to the differential circuit composed of the capacitor C1 and the resistor R3 and differentiated, and the differentiated pulse signal is applied to the field effect transistor (2) in the switching driver 2. Q4) is applied to the source.

On the other hand, since the delay regeneration signal DPB of the microcomputer 4 maintains the "high" level, the transistor Q3 in the switching drive unit 2 is turned on so that the "low" level signal, which is the output of the transistor Q3, is transmitted. The first control signal CS1, which is a positive pulse signal applied to the gate of the effect transistors Q4 and Q5 and is thus applied to the source, is applied to the field effect transistor Q4 and Q5. Since it is applied to the gate of the field effect transistor Q6 through Q4 and the diode D1, this field effect transistor Q6 is also conducted during the positive pulse period of the first control signal CS1, so that the B in the switch 3 is turned on. ^{A positive} voltage is applied to the microcomputer 4 via the field effect transistor Q6 as a still key signal K4.

Therefore, the microcomputer 4 converts the playback mode into a still mode and performs a TV mode to output a TV broadcast signal.

In this TV mode, when VT / TV presses the changeover switch CN once again, the VT / TV switching signal V / T of the microcomputer 4 is converted into a “high” level signal again, and accordingly, it is switched. Since the transistor Q1 in the signal control unit 1 is turned on so that the transistor Q2 having the output of the transistor Q1 connected to the base is turned on, the collector output of the transistor Q2 is converted to the "high" level. This converted " high " level signal is applied to the RF converter 5 and switched back to VT mode.

On the other hand, when the converter " high " fp level signal output from the transistor Q2 is applied to the differential circuit composed of the capacitor C2 and the resistor R4 and differentiated, it becomes a positive polarity pulse signal. Since the signal CS2 is applied to the gate of the field effect transistor Q6 through the field effect transistor Q5 and the diode D2 in the switching driver 2 in the same circuit operation as described above, the field effect transistor Q6 is applied. During the pulse period, the conductive key signal K4 is applied to the microcomputer 4 again. Therefore, the microcomputer 4 releases the still mode and returns to the play mode to play the video tape.

On the other hand, when VT is not the play mode of the field effect (Q ₄ , Q ₅ ) is turned off, the original VT / Ti will perform only the switching function.

As such, the present invention operates VT / TIV only in the playback mode to switch from VRT mode to TV mode, and converts the playback mode to STILL mode at isochronous time, and also switches from TV mode to VT mode. At the same time, when the user wants to watch the TV screen while viewing the playback screen or when the TV screen is viewed again, the operation of the mode switching is a useful design having a simple and convenient effect.

Claims (3)

The VT / TV output signal from the microcomputer 4 is supplied with the V / T switching signal (V / T), and the VT / TV signal is supplied to the RF converter 5, and the VT / TV signal is the positive pulse signal. A switching signal controller 1 for outputting a first control signal CS1 or a second control signal CS2, and the switching signal controller 1 according to a delayed regeneration signal DPB output from the microcomputer 4; VTial of VTIAL, characterized in that the switching control unit (2) is applied to the switch unit (3) by switching the first control signal (CS1) or the second control signal outputted from the still signal or the steel release signal Positive switching control circuit. 2. The switching signal control unit 1 according to claim 1, wherein the switching signal controller 1 differentiates the output signal of the transistor Q ₁ and the output signal of the transistor Q ₁ from the V / T inverting the switching signal V / T. transistor (Q for outputting a switching signal (V / T) to the RF converter 5 as the output signal of the differentiating circuit (C _l, R ₃₎ and the transistor (Q ₁₎ for outputting a control signal (CS1) is ) and the transistor (Q ₂₎ by differentiating the output signal the second differential output to the control signal (CS2) circuit (C _2, C ₄₎ V tial / TV switching of V tial, characterized in that consists of the control circuit of the . According to claim 1, wherein the switching driving unit (2) is the first control signal as the output signal of the transistor (Q ₃₎ and a transistor (Q ₃₎ which outputs by inverting the delayed reproduction signal (DPB) is ( Field effect transistor Q ₄ (Q ₅ ) for outputting CS1) and second control signal CS2, respectively, and first control signal CS1 output from this field effect transistor Q ₄ (Q ₅ ), or a second control signal (CS2) to the input of the switch unit (3) for outputting a field effect transistor (Q _6), characterized in that the V consisting of V tial tial / TV switching control circuit.