KR920006749Y1 - Recording mode switching over circuit - Google Patents

Abstract

No content.

Description

Recording mode transition circuit

1 is a conventional circuit diagram for shifting a recording mode by detecting the presence or absence of a recording prevention piece (TAB).

2 is a recording mode transition circuit diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

10: system controller 20: mode selector

30: first latch portion 40: second latch portion

50: Logic combination part SW1: Video detection switch

SW2: Recording mode transition control switch

The present invention relates to a circuit for transitioning to a recording mode irrespective of a tape-taking prevention piece (TAB) in a system for recording and reproducing arbitrary data on a tape.

In a device for recording and reproducing predetermined data using a tape such as a VTR or the like, a recording prevention (or erasing device) piece is used at the bottom of the tape as a means for preventing accidental recording. That is, when the tape with the recording prevention piece is seated on the deck part, the switch SW1 is turned "on" in the circuit shown in FIG. 1 so that the "low" signal is supplied to the input port P1 of the system controller 1. Therefore, the system controller 1 determines that there is a recording prevention piece on the currently seated tape and controls the system to perform the recording mode when controlling the recording mode. On the other hand, when a tape without a recording prevention piece is seated on the deck, the switch SW1 is " off " so that the opposite logic signal as described above is supplied to the input port P1 of the system controller 1, so that the system controller 1 ) Determines that there is no recording prevention piece on the currently seated tape and the recording mode is controlled so that the system does not perform the recording mode.

In order to record arbitrary data on the tape from which the cost of recording is eliminated using the circuit operated in this way, the user must artificially "on" the switch SW1 in order to bring it to the same state as the case where the recording prevention piece is present. There was a problem.

Accordingly, the present invention has been made in order to solve the above-mentioned drawbacks, and its object is to provide a recording mode transition circuit capable of recording data desired by a user on a tape regardless of whether there is a convenience for preventing recording.

In order to achieve the above object, the present invention provides a recording mode transition circuit of a recording / playback apparatus including a tape as a recording medium and having a system controller for controlling all functions of the system; A mode selection unit for selecting a playback or recording mode according to a user's control command or information; A switch (SW1) for detecting a unit for preventing the recording of the tape; A switch (SW2) for controlling the transition to the recording mode when the recording prevention piece of the tape does not exist as a result of the detection of the switch (SW1); And a logic combination unit for outputting a recording mode transition control signal to the system controller by a logical combination of an output signal of the mode selection unit and a predetermined signal generated according to the operation of the switches SW1 and SW2.

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

As shown in FIG. 2, the recording mode transition circuit according to the present invention is connected to the system controller 10 and the system controller 10 for controlling all functions of the system, and the user's control command or The mode selector 20 and the first latch unit 30 for selecting a playback or recording mode based on the information, and the first latch unit 30 are " high " generated when the recording mode (or recording mode) is selected in the mode selector 20. It consists of a flip-flop FF1 which latches an input signal using a signal as a clock signal. In this case, the mode selector 20 may generally be substituted as a key input means for controlling other functions. The second latch unit 40 includes a flip-flop FF2 for latching an input signal using a signal supplied according to the operation of the recording mode transition control switch SW2 as a clock signal. The logic combination unit 50 is an AND gate A1 for logically multiplying the signal supplied according to the operation of the switch SW1 for detecting the presence or absence of a recording prevention bias and the signal output from the first latch unit 30, and the first gate. The AND gate A2, which logically multiplies the signals output from the second latch units 30 and 40, and the output signals of the AND gates A1 and A2 are processed in a negative logic to shift the recording mode to the system controller 10. It is composed of a NOR (NOR) for outputting and controlling the control signal.

Referring to the operation of the recording mode transition circuit having the configuration described above as follows.

First, look at the operation relationship when the tape on which the anti-tagging piece has not been removed is seated on the deck. When the tape with the anti-taking piece is seated in the tech section, the anti-taking detecting switch SW1 shown in FIG. Therefore, the "low" potential GND is applied to the inverter NOT through the diode D2 so that the inverter NOT outputs a "high" logic.

Since the output signal of the inverter NOT is applied to one input terminal of the AND gate A1 of the logic combination unit 50, the one input signal of the AND gate A1 is in a "high" state. In this state, when the user sets the recording mode through the mode selector 20 to record arbitrary data, the clock terminal of the flip-flop FF1 in the first latch unit 30 through the diode D1 ( Since the clock signal is supplied to CK, the output terminal Q of the flip-flop FF1 becomes " high " and is supplied to the other input terminal of the AND gate A1. Therefore, the output signal of the AND gate A1 becomes a "high" state and is applied to one input terminal of the NOA gate NOR, so that the NOA gate NOR outputs a "LOW" signal regardless of the signal applied to the other input terminal. . Therefore, since the signal supplied to the input port P1 of the system controller 10 is in the "low" state, the system controller 10 controls the peripheral system to record arbitrary data on the tape.

The following describes the procedure for transitioning to the recording mode when the tape on which the anti-tagging piece is removed is seated on the deck.

When the tape on which the anti-recording strip is removed is seated on the deck and the user sets the recording mode through the mode selector 20, the output of the first latch unit 30 is in a "high" state as described above. However, since the anti-recording piece detecting switch SW1 is "off", the signal output through the diode D2 and the inverter NOT goes into a "low" state, so that the end gate of the AND gate A1 in the logic combination section 50 is reduced. Since the one side input signal is in the "low" state, the AND gate A1 outputs the signal in the "low" state. Therefore, the input signal of one side of the NOR gate NOR becomes "low" and the logic of the output signal is determined according to the signal applied to the other input terminal.

At this time, when the user “on” the recording mode understanding control switch SW2 protruding outside the set SET, the clock terminal CK of the flip-flop FF2 of the second latch unit 40 is connected to the second latch unit 40 via the diode D3. Since the clock signal is supplied and the output of the second latch unit 40 is in the "high" state, the output of the AND gate A2 combining the levels of the output signals of the first and second latch units 30 and 40 is It is in a "high" state.

Therefore, the output of the NOR gate NOR, which combines the levels of the output signals of the AND gates A1 and A2, becomes a "low" state so that a "low" signal is supplied to the input port P1 of the system controller 10. Enters the recording mode.

However, the flip-flop FF2 of the second latch unit 40 outputs a "low" state through the output terminal Q when the initial state or the recording mode transition control switch SW2 is not "on". The input signal of one side of A2) becomes the "low" state and outputs the "low" state to the noar gate NOR. As a result, the NOA gate NOR is applied to the P1 terminal of the system controller 10 so that the system controller 10 recognizes it as an anti-tape tape and does not perform a recording mode.

The present invention adopts a recording mode shifting circuit that operates as described above in a general recording and reproducing apparatus such as a VTR or a cassette, so that arbitrary data can be recorded on a tape from which an anti-recording strip is removed.

Claims (3)

A recording mode shifting circuit of a recording / playback apparatus having a system controller (10) for controlling all functions of a system and using a tape as a recording medium; A mode selection unit 20 for selecting a playback or recording mode according to a user's control command or information; A first switch (SW1) for detecting the presence or absence of the recording prevention bias of the tape; A second switch (SW2) for controlling the transition to the recording mode when there is no recording prevention piece of the tape; A logic combination unit 50 for outputting a recording mode transition control signal to the system controller by a logical combination of an output signal of the mode selection unit 20 and a predetermined signal generated according to operations of the switches SW1 and SW2 Recording mode transition circuit comprising a. 2. The logic combination unit of claim 1, wherein the logic combination unit 50 includes an AND gate A1 that logically multiplies the signal supplied by the operation of the first switch SW1 and the signal output from the mode selector 20; The system controller combines the AND gate A2 for logically multiplying the signal output from the mode selector 20 and the second switch SW2 and the output signals of the AND gates A1 and A2. A recording mode shifting circuit, characterized in that it comprises a noar gate (NOR) for controlling (10). The recording mode shifting circuit of claim 1, further comprising: a first latch unit configured to generate the predetermined signal by latching an input signal according to a signal generated because the recording mode is selected through the mode selection unit 20; And a second latch unit (40) for latching an input signal according to the operation of the second switch (SW2) to generate the predetermined signal.