KR910003394Y1 - Safety compensating circuit of cassette tape - Google Patents

Abstract

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Description

Compensation circuit for safety piece of cassette tape for video recorder (VTR)

1 is a perspective view of a cassette tape for a VTR.

State diagram of the cassette tape safety tab of FIG.

3 is a circuit diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

SW1: first switch SW2: second switch

AN: AND gate Dl-Dn: diode

60: system control

The present invention relates to a recording tab for protecting a tape already recorded in a cassette tape for a video recorder (VTR). In particular, a recording locking switch is selected externally no matter what state the recording safety piece is in. The present invention relates to a safety piece compensating circuit of a cassette tape for an image recording / reproducing player capable of recording / playback.

In general, a set of video recorders (hereinafter referred to as VTRs) is a recording protection device that protects tapes already recorded (so that no other content can be recorded). It was made as part A in the perspective view.

For example, in the case of 8 mm VTRs, the use of a record locking device on the cassette tape to switch the safety piece attached to the cassette could determine whether the record function was possible, In this case, you can protect the recorded contents by removing the recording safety piece, but if you want to record other contents again, you need to block the recording safety part before you can use it. (B) is a state in which the recorded contents can be protected when the safety piece is out of the state.

As described above, it was inconvenient to operate the recording safety piece of the cassette tape one by one, or to use a complicated blocking of the fallen part.

Accordingly, an object of the present invention is to provide a circuit that enables recording / playback by an external key operation even when the recording safety piece of a cassette tape is in a state.

Another object of the present invention is to provide a high-performance system while eliminating the inconvenience of blocking the conventional safety piece.

Therefore, in order to carry out the purpose of the present invention, a recording key for selecting a recording, a system control microcomputer that outputs a control signal by receiving an input signal of the recording key, and a control signal sensing stage capable of knowing a control signal according to each signal. In the recording safety piece compensating circuit of a cassette tape for a video recording / reproducing player, the control signal according to the recording key operation is received from the system control micom, and even if there is no selection signal of the first switch and the recording safety piece to determine the presence or absence of the recording safety piece. A first means comprising an end gate driven by an output signal of a second switch to enable recording according to a selection, and a sensing end driven in accordance with the output of the first means in parallel with the control signal sensing end A second number for inputting a signal generated here to the system control microcomputer to output a recording function signal to a line; Characterized in that consisting of stages.

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

3 is a circuit diagram according to the present invention, the first switch (SW1) that is turned on or off in accordance with the presence or absence of the recording safety piece of the cassette tape to the power supply end 50, and the recording safety piece is dropped to record a tape that cannot be recorded. The second switch SW2 is connected in parallel. The first and second switches SW1 and SW2 may be switched by a dip switch and a sensor.

The first and second switches SW1 and SW2 are connected to the first input terminal 101 of the AND gate AN, and the control line 80 is generated from the system control micom 60 at the second input terminal 102. To the output terminal of the AND gate (AN) is connected to the diode (D1) for detecting the presence or absence of the recording according to the state of the safety, and to sense the sensing signal of the sensor (not shown) in accordance with the operation of other functions It is connected in parallel to the diode (D2-Dn), and the output signal of the diode (D1-Dn) is connected to the system control microcomputer 60 to be input as a signal for recording mode control, lines 10, 20 In order to generate a signal generated by the operation to the recording key 70 of the keyboard is connected to the system control microcom 60.

Therefore, according to the above-described configuration, one embodiment of the present invention will be described in detail. For example, when the recording key 70 of the keyboard is pressed in, the system control micom 60 senses the key to make the line 80 “high”. "I do it. When the recording safety piece is removed from the existing 1/2 "VHS cassette tape, the first switch SW1 for determining whether the recording safety piece is present is turned off, and the line 80 of the system control micom 60 is inserted. "High" state is inputted to the AND gate (AN), when the record-locked second switch (SW2) is off, since the first and second switches (SW1, SW2) are all off, line 80 is " There is no output of the AND gate AN even in the high " state.

Therefore, the system control microcomputer 60 does not output the recording control signal for performing the recording function to the line 30 because there is no signal through the diode D1.

However, when the second switch SW2 for locking the record is in the on state, even if the first switch SW1 is turned off (even if the recording safety piece is in the second FIG. 101 becomes "high". When the recording key 70 is press-fitted, the system control micom 60 outputs "high" to the line 80 so that the second input terminal 102 of the AND gate AN is "high" and thus the AND gate AN. The output of "high" outputs a "high", so the output of the diode (D1) detecting the presence or absence of the recording according to the state of the safety "high" is prevented the reverse voltage by the diodes (D2-Dn) to accurately cross the line (40) It is input to the system control microcomputer 60 to output the recording signal from the system control microcomputer 60 to the line 30 so as to enable recording on the cassette tape.

That is, the diode (D1) is separated from the signal generated during the pressing of the recorder 70 according to the kiken of the system control micom 60 and the first switch (SW1) or the recording safety piece of the recording safety piece is turned on or off. It is to detect the presence or absence of recording by outputting a signal input by the switch of the switch SW2 for recording a tape which cannot be performed through the AND gate AN.

The diodes D2-Dn detect a signal sensed by a sensor by an operation in another part for recording, while preventing a voltage from being introduced into another place when there is an output from the diode D1. The output of the diode D1 is correctly recognized by the microcomputer 60.

Therefore, since the diodes D2-Dn have a wired-or configuration, there is a detection signal of any diode in the “high” state and is applied to the system control micom 60 through the line 40 to the system control micom 60. ) To accurately recognize the recording control signal.

Therefore, the diode D1 detects the presence or absence of recording according to the state of the safety pin of the tape of the video cassette, and the diode D2-Dn detects the presence or absence of the recording according to the detection of the line according to other functions and operations. The reverse voltage is prevented with respect to the output so that it is correctly input to the line 40.

Since the first input terminal 101 of the AND gate AN is “high” even when the second switch SW2 is in the off state and the first switch SW1 is in the on state, the recording function is generated depending on whether or not the recording safety piece is present. The control is the same as above.

As described above, even when the existing cassette tape is used as it is, the recording safety piece is dropped, that is, the inconvenience of having to close the hole where the green ring safety piece is dropped even in a non-recording state is eliminated, and there is an advantage that the system can be highly functionalized.

Claims (1)

In the recording safety piece compensating circuit of a cassette tape for a video recording / reproducing player, the first switch (SW1) which is turned on or off in accordance with the presence or absence of the recording safety piece of the cassette tape in the power supply stage 50 cannot be recorded. A second switch SW2 for recording a tape is connected in parallel, and the first and second switches SW1 and SW2 are connected to the first input terminal 101 of the AND gate AN. A diode which connects the control line 80 generated from the system control microcomputer 60 to the second input terminal 102 of the gate AN, and detects the presence or absence of recording according to the state of the safety piece at the output terminal of the AND gate AN. (D1), connected in parallel to the diode (D2-Dn) for sensing the sensing signal of the sensor in accordance with the operation of other functions, and the diode (D1-Dn) output signal to the system control microcomputer 60 Connect to input as signal for recording mode control, and 10) and (20), a safety piece compensation circuit of a video recording, reproducing and recording cassette tape, characterized in that the signal generated by the operation of the recording key (70) of the keyboard is input to the system control microcomputer (60).