KR920005105Y1 - Reel stoping control circuit of vtr - Google Patents

Abstract

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Description

Reel stop control circuit for high speed driving of recording and playback device

1 is a conventional circuit diagram.

2 is an operating waveform diagram of each part of the circuit shown in FIG.

3 is a circuit diagram of an embodiment according to the present invention.

* Explanation of symbols for main parts of the drawings

10: micom 11, 12: 1st, 2nd reel

13: solenoid 14, 15: 1st, 2nd motor

16: reel high speed adjustment circuit 17, 18: first and second non-recording section detection sensor

30: transmission limit means 31: second solenoid control means

SW1, SW2: First and second analog switches D1-D3: Diode

The present invention relates to a circuit for controlling a reel in a recording and reproducing apparatus, and more particularly to a circuit for suddenly stopping a reel in high speed rotation.

In general, a recording and reproducing apparatus refers to a device for recording audio or video information on a recording medium or reproducing audio or video information recorded on a recording medium, and a reel is a motor for driving a tape-type recording medium. The rotating body which rotates by the rotational force of).

The conventional reel high speed control circuit for driving the tape at high speed or stopping the tape in motion is constructed as shown in FIG. 1, and FIG. 2 is shown in FIG. Output waveform diagram for each part of the circuit.

The operation of the circuit shown in FIG. 1 will be described with reference to the waveform diagram shown in FIG. 2, and for convenience, explanation will be given by dividing the reel into a case of rotating the reel at high speed and the case of stopping the reel being rotated at high speed.

First, a case in which the reel is rotated at a high speed will be described. The microcomputer 10 (hereinafter referred to as a microcomputer) 10 commands a command to rotate the reel at a high speed from the command generator (ie, fast forward key data (Fast forward key data). Reel operation control of low logic to rotate the reel and the direction control signal in the form of a logic signal for the running direction of the tape when the rewind key data or the retrieval key data or the search key data is introduced. The signal is supplied to the reel high speed adjustment circuit 16.

The reel high speed adjustment circuit 16 is connected to the first output terminal side in accordance with the logic state of the direction control signal supplied from the microcomputer 10 while the reel operation control signal of the low logic state is applied from the microcomputer 10. The speed control voltage to the first motor 14 or the second motor 15 connected to the second output terminal side, and at this time, the speed control supplied to the first motor 14 or the second motor 15. The voltage has a slightly different voltage depending on the amount of tape wound on the reel on the side rotated by the motor.

The first motor 14 connected to the first output terminal of the reel high speed regulating circuit 16 or the second motor 15 connected to the second output terminal of the reel high speed regulating circuit 16 has its own speed control. It operates while voltage is applied to rotate the first reel 11 or the second reel 12 in contact with the central axis.

The first reel 11, which is in contact with the central axis of the first motor 14, rotates while the first motor 14 is in operation to drive the tape in high speed in the forward direction. The second reel 12 in contact with the center side rotates while the second motor 15 is operated to rewind the tape in the reverse direction. Accordingly, the first reel 11 and the first motor 14 are called supply reel and supply reel motor, respectively, and the second reel 12 and the second motor 15 are Each is called a take-up reel and a take-up reel motor.

Second, a description will be given of a case where a reel in high speed rotation is stopped.

In this case, the microcomputer 10 receives the second non-recording section detection signal of the high logic state as shown in FIG. 20 from the first and second non-recording section detection sensors 17 and 18. The low logic state of the reel operation control signal applied to the reel high speed adjustment circuit 16 is changed to the high logic state, and the reel stop control signal of the high logic state as shown in FIG. Generate and apply to the solenoid (Solenoid) (13). The non-recording section detecting signal of the high logic state is generated by the first non-recording section detecting sensor 17 or the second non-recording section detecting sensor 18. The non-recording section detecting sensor 17 will be described. Is installed on the side of the second reel 12 and the end of the tape (for example, the transparent portion to which the magnetic powder is not applied) is driven by the first reel 11 so as to drive the second reel (20). A non-recording section detection signal of a high logic state, such as), and a second non-recording section detection sensor 18 is installed on the first reel 11 shaft and is driven in the reverse direction by the second reel 12. When the first part of (ie, the transparent part without magnetic powder applied) is driven, a non-recording section detection signal in high logic state is generated.)

The reel high speed adjustment circuit 16 is connected to the first output terminal as shown in FIG. 2 when the logic state of the reel operation control signal applied from the microcomputer 10 is changed from the low logic state to the high logic state. The speed control voltage being supplied to the second motor 15 connected to the first motor 14 or the second output terminal side is interrupted to stop the first motor 14 or the second motor 15 in operation.

Meanwhile, when the high logic reel stop control signal is applied from the microcomputer 10, the solenoid 13 generates magnetic force by the reel stop control signal of the high logic state to rotate the first and second reels. Force (11, 12) to stop.

However, when stopping the reel in the high-speed rotation as described above, the microcomputer 10 is the first or second non-recording period detection signal having a high logic state at the actual time point t ₁ as shown in the waveform diagram shown in FIG. Even when applied from the section detection sensors 17 and 18, at a time point t ₁ due to the chattering time, which is unstable in the logic state due to the transient phenomenon, and the delay time due to the cycle of reading its input port. a period of time (T ₁₎ the processing period in with the time (t ₂₎ from at the time point (t ₂₎ to recognize its own (T ₂₎ the elapsed time (t ₃₎ the logic state of the reel operation control signal is high not until Transitioning from the logic state to the low logic state and changing the logic state of the reel stop control signal from the low logic state to the high logic state.

In addition, even if the reel speed adjustment circuit 16 changes the logic state of the reel operation control signal applied from the microcomputer 10 at the time point t ₃ from the high logic state to the low logic state, the processing period (T ₃ ) in the reel speed adjusting circuit 16 is changed. At a time elapsed by t ₄ ), the speed control voltage applied to the first motor 11 or the second motor 12 is cut off, and the solenoid 13 also changes the electrical energy into mechanical energy. It takes some time to generate magnetic force with (Coil).

In this way, the delay time in the microcomputer 10, reel speed adjusting circuit 16, solenoid 13, and the like amounts to several msce.

As a result, the length of the first and the end of the tape is about 60mm at maximum, so the speed of winding by the reel during high speed driving (that is, about 200 times normal speed driving)

Extremely short time is required. (Where 8.15mm / sec is the length of tape wound per msec in normal driving)

Therefore, the reel should be stopped within 36.8 msec from the point where the end or the beginning of the tape is detected. However, the reel is not stopped by the delay time of the processing time of the microcomputer 10 and the reel high speed adjustment circuit 20. In this case, due to the centrifugal force of the reel is applied to the tape, there is a problem that the tape is severely cut.

Accordingly, an object of the present invention is to provide a reel stop control circuit for high-speed driving, which can stop the tape in a fast time when the reel in high-speed driving stops.

In order to achieve the above object, the present invention provides a microcomputer for controlling the system, a first reel for driving the tape forward, a second reel for driving the tape backward, and rotating the first and second reels, respectively. First and second motors, a solenoid for stopping the first and second reels under the control of the micom, and a first motor and a second output terminal connected to the first output terminal under the control of the micom. A reel high speed control circuit for supplying a driving voltage to two motors, first and second non-recording section detection sensors for sensing and applying the non-recording section located at the first and end portions of the tape to the microcomputer, respectively, and the first Transmission limiting means for limiting transmission of the driving voltage output from the reel high speed adjusting circuit 16 to the first and second motors by the output of the second non-recording period detection sensor; and the first and second non-recording. Section detection sensor output It characterized in that it comprises a second solenoid control means for driving the solenoid by the force.

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

3 is a circuit diagram of an embodiment according to the present invention, the configuration is as follows.

First, second reel (11, 12), solenoid (13), first, second motor (14, 15), reel high speed control circuit (16), first, second non-recording The section detection sensors 17 and 18 have the same reference numerals and the same functions as the blocks shown in FIG.

The transmission limiting means 30 includes first and second selection contacts SP11 and SP12 connected to the first output terminal and the ground potential GND of the reel high speed regulating circuit 16, and the first motor 11, respectively. ) And a first analog switch SW1 comprising a reference contact SP10 and a control terminal CP1 connected to the first non-recording period detection sensor 17, respectively, and a second output of the reel high speed adjustment circuit 16. First and second select contacts SP21 and SP22 connected to the terminal and the ground potential GND, respectively, and a reference contact SP20 connected to the second motor 12 and the second non-recording interval sensor 18, respectively. And a second analog switch SW2 composed of a control terminal CP2.

The second solenoid control means 31 connects the cathode to the input terminal of the solenoid 13 in common, and connects the anode to the output terminals of the first and second non-recording interval detection sensors 17 and 18 and the micom, respectively. It consists of three diodes D1-D3 connected to the reel stop control signal output terminal (10).

Next, the operation of the circuit shown in FIG. 3 will be described in detail.

Among the blocks of the circuit shown in FIG. 3, the first and second reels 11 and 12, the solenoid 13, the first and second motors 14 and 15, and the reel high speed adjustment circuit 16, as well as the microcomputer 10 are illustrated. , The first and second non-recording interval detection sensors 17 and 18 are disclosed in the operation description of FIG. 1, and thus, detailed descriptions of the transmission limiting means 30 and the second solenoid control means 31 are omitted. Explain.

First, the operation of the transmission limiting means 30 is as follows.

The first analog switch SW1 is a reference when the recording section of the tape to which the non-recording section detection signal in a low logic state is applied from the first non-recording section detection sensor 17 to the control terminal CP1 is running in the forward high speed direction. The contact SP10 is brought into contact with the first selective contact SP11 to transfer the speed control voltage on the first output terminal of the reel high speed regulating circuit 16 to the first motor 14, whereas the first non-recording is performed. When the non-recording section detection signal of the high logic state from the section detecting sensor 17 is introduced into the control terminal CP1 (that is, when the end of the transparent tape not coated with magnetic powder is driven), the reference contact point ( SP10 is brought into contact with the second selective contact SP12 to supply the electropotential GND to the first motor 14. Then, the first motor 14 is stopped by the ground potential GND supplied through the first analog switch SW1. In addition, while the second analog switch SW2 receives the non-recording section detection signal in the low logic state from the second non-recording section detecting sensor 18 to the control terminal CP2 (that is, the recording section of the tape is in reverse high-speed driving). In this case, the reference contact SP20 is brought into contact with the first selection contact SP21 so that the speed control voltage on the second output terminal of the reel high speed adjustment circuit 16 is transmitted to the second motor 12. When the non-recording section detection signal in a high logic state from the second non-recording section detecting sensor 18 is applied to the control terminal CP2 (that is, when the first part of the transparent tape is driven because no magnetic powder is applied), The reference contact SP20 is brought into contact with the second selection contact SP22 to transfer the ground potential GND to the second motor 15 instead of the speed control voltage. At this time, the second motor 15 is stopped by the ground potential GND supplied instead of the speed control voltage.

Secondly, the operation of the second solenoid control means 31 will be described in detail. The diode D1 is turned on when a high logic reel stop control signal is inputted from the reel stop control signal output terminal of the microcomputer 10 to the anode so as to output the high logic reel stop control signal to the solenoid 13. Pass to the input terminal of. The diode D2 receives a high logic non-recording section detection signal from the first non-recording section detecting sensor 17 to the anode (i.e., when the non-recording section located at the end of the tape is forward-fast running). Only the turn-on (D) (Turn-On) is transmitted to the input terminal of the solenoid 13 of the non-recording section detection signal of the high logic state that is introduced into the anode.

The diode D3 also operates only when the non-recording section detection signal in the high logic state from the second non-recording section detecting sensor 18 is introduced into the anode (that is, when the non-recording section located at the beginning of the tape is driven backward). A non-recording section detection signal in a high logic state, which is turned on and drawn on the anode, is transmitted to the input terminal of the solenoid 13. The solenoid 13 generates a magnetic force when a reel stop control signal or a non-recording section detection signal in a high logic state is introduced from either of the cathode terminals of the three diodes D1-D3. Even after the motors 14 and 15 stop operating, the centrifugal force prevents the rotation of the first and second reels 11 and 12 which are still rotating.

In addition, the analog switches SW1 and SW2 used in the transmission limiting means 30 can be used in place of other control switch elements, and the diodes used in the second solenoid control means 31 and ( D1-D3 can also be used in combination with a buffer element having a unidirectional pass characteristic, and the three diodes (D1-D3) also function as a logic sum element with respect to the logic of the hard tuning (+).

As described above, the present invention directly stops the operation of the first and second motors 14 and 15 by the output signals of the first and second non-recording period detection sensors 17 and 18, and drives the solenoid to drive the microcomputer 10. And by stopping the reel rotation as soon as the delay time delayed by the reel high speed adjustment circuit 16, there is an advantage to reduce the force applied to the tape and to prevent the tape is cut.

Claims (4)

A recording and reproducing apparatus using a tape having a non-recording section at both ends as a recording medium, comprising: a microcomputer 10 for controlling a system and first and second reels 11 for driving the tape in different directions, respectively; 12) and the solenoid 13 for stopping the reels (11, 12) under the control of the microcomputer 10, and the first, for rotating the first, second reels (11, 12) in the direction, respectively; The driving voltage is supplied to the two motors 14 and 15 and the first motor 11 connected to the first output terminal side or the second motor 12 connected to the second output terminal side under the control of the microcomputer 10. A reel high speed regulating circuit 16 to supply, first and second non-recording interval detection sensors 17 and 18 for sensing and respectively transmitting both ends of the tape to the microcomputer 10, and the first and second. The driving voltage, which is the output of the reel high speed regulating circuit 16, is transmitted to the first and second motors 11 and 12 by the output of the non-recording period sensing sensors 17 and 18. A transmission limiting means 30 for limiting and a second solenoid control means 31 for driving the solenoid 13 by the output of the first and second non-recording interval sensing sensors 17, 18. Reel stop control circuit for high-speed driving, characterized in that. The solenoid 13 according to claim 1, wherein the second solenoid control means 31 is output by the micom 10 when there is no output of the first and second non-recording period detection sensors 17 and 18. Reel stop control circuit for high-speed driving, characterized in that it comprises a passage in the form of a logical operation so that is driven. 3. The unidirectional current according to claim 2, wherein said logically-operated path is a unidirectional current from the output terminals of said microcomputer 10 and the first and second non-recording period sensors 17 and 18 toward the input terminal of said solenoid 13. A reel stop control circuit for high-speed driving, characterized by comprising unidirectional current passing elements (D1-D3) each providing a passage. 2. The transmission limiting means (30) according to claim 1, wherein the transmission limiting means (30) connects switching contacts to the first output terminal of the reel high speed adjustment circuit (16) and the first motor (14) and the control terminal detects the first recording section. The first control switch element SW1 connected to the sensor 17, the second output terminal of the reel high speed adjustment circuit 16, and the switching contacts are connected to the second motor 15, and the second non-recording section. And a second control switch element (SW2) having a control terminal connected to the detection sensor (18).