KR900006359Y1 - Automatic regulating circuit of selection key for vcr - Google Patents

Abstract

No content.

Description

Function key automatic control circuit of video recorder

1 is a block diagram according to the present invention.

2 is a detailed circuit diagram of an embodiment of FIG.

* Explanation of symbols for main parts of the drawings

10: power signal generation circuit 20: operation signal generation circuit (PLAY SIGNAL)

30: eject signal generating circuit 40: function key circuit

The present invention relates to a function key automatic control circuit of a video recorder, and in particular, to automatically adjust a function key of a video recorder to automatically perform a function key operation by inserting a tape to perform a basic operation of the video recorder. It is about a circuit.

In general, a video recording player has a function key circuit for outputting a general operation behavior signal as a pressing signal of a key. The video recording player has level-sensed a selection signal of a function key circuit to perform an operation corresponding thereto. .

In addition, the video recording player has a cassette switch for indicating whether or not a tape is inserted. At this time, the cassette switch is "on" for a predetermined time when the cassette tape is inserted or ejected to notify the state of the tape insertion and ejection has been applied to almost all VTRs.

In addition, the VTR has an end sensor (normally a photo sensor) that detects a transparent portion (trailer tape) at the end of the cassette tape and outputs a signal. When the end sensor detects the trailer tape, The automatic stopper stops the drive of the tape and automatically rewinds. This same function is applied to all VTRs.

Automatic stop device when the end sensor of the tape detects the tracer part of the tape (end of tape) and the rewind is automatically performed, and the leader tape (the tip of the tape) is detected by the start sensor (normal photo sensor). The rewind operation is stopped by.

Currently, all VTR products have a built-in cassette switch for detecting the presence or absence of cassette tape, an end sensor for detecting the tracer tape which is the end of the cassette tape, and a start sensor for detecting the leader tape of the cassette tape. Further, the start sensor may stop the rewind of the tape when the start sensor detects the leader tape region at the tip of the tape, and then stop the leader tape section of the tape at a high speed to stop it.

However, the video recorder having the function described above has a problem in that power consumption is caused by the continuous supply of the supply voltage to the circuit part even when the tape is finished running by the end sensor or the start sensor. Must be operated by pressing a function signal, or the Play function key or the wide or fast forward key.

Accordingly, an object of the present invention is to provide a function key automatic control circuit of an image recording and reproducing apparatus that can automatically generate an image recording player by automatically generating a power key, a playy wind key, and an eject selection key signal after inserting a tape.

Another object of the present invention is to provide a circuit that automatically ejects the tape and automatically cuts off the power supply voltage after the tape stops being driven by the automatic stop device.

In order to achieve the above object, the present invention provides a video recording and reproducing apparatus equipped with a system control circuit which performs level sensing of an input state of a function key. A power signal generation circuit for inputting a cassette switch signal to generate and output a power control signal, a play signal generation circuit for inputting a cassette switch signal to generate a play signal after a predetermined time delay, and a tape output from the start sensor An eject signal generating circuit for inputting a start detection signal to output a tape eject signal. It has a power key, a play key, a rewind key, an eject key, and a fast forward key, and has the power signal, the play signal, and the eject signal, and functions as a system control circuit by inputting the power signal, the play signal, and the eject signal. And a function key circuit for outputting an operation signal and outputting a pushed function key signal to a system control circuit.

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

1 is a block diagram according to the present invention, and a power signal generating circuit 10 for generating a power control signal by inputting an output signal of a cassette switch input to the terminal 100, and after a predetermined time delay of the output of the cassette switch. A play signal generation circuit 20 for generating a play operation signal, an eject signal generation circuit 30 for outputting an output signal of the start sensor input to the terminal 200 as a cassette eject signal, and the power signal generation circuit 10; Input the power " on / off " signal outputted from the < RTI ID = 0.0 > and the play signal < / RTI > And a function key circuit 40 for outputting the signal of the pressed selection key to the system control circuit while outputting the system control circuit (not shown).

Terminal 100 in the above-described configuration of FIG. 1 is an output terminal of a cassette switch (not shown), which is a cassette which is operated "on" when the cassette is inserted into or ejected from a cassette tape of a VTR. The switch signal is output.

The terminal 200 is an output terminal of a start sensor (not shown), and a "high" signal is input when the start sensor detects a leader tape (transparent portion) of the cassette tape.

The terminal 300 is a key signal input terminal of a system control circuit (not shown). In this case, the system control circuit is generally composed of a one-chip microprocessor and the port of the key signal input terminal is an analog / digital conversion port so that the input level is sensed to determine whether a function key is pressed according to an internal program. .

For example, if the voltage of input function key is OV voltage, it is recognized as a key such as eject, V1 play, V2 power on / off, V3 rewind, V4 fast forward, etc., and mechanism control (usually called mechacon). ). [V1 < V2 < V3 < V4] and the function key circuit 40 in the configuration of FIG. 1 has an eject key, a power key, a play key, a rewind key, a fast forward key, and the like. When the level of the corresponding key is configured to output.

When the tape is inserted into the housing now, the cassette switch (not shown) is "on" for a certain period of time, and the voltage of the "high" state is transmitted through the power signal generating circuit 10 and the play signal generating circuit 20 through the terminal 100. )

The power signal generation circuit 10 which inputs the signal of which the cassette switch is "on" generates a power control signal and outputs it to the function key circuit 40, and the play signal generation circuit 20 is "on" of the input cassette switch. The signal is delayed for a predetermined time and output to the function key circuit 40 as a play signal.

The function key circuit 40 inputting the power control signal and the play signal output from the power signal generation circuit 10 does not show the power control signal of a predetermined level and the play signal of another predetermined level through the terminal 300. The system control circuit recognizes the power control signal and the play signal by level sensing the input signal.

The system control circuit recognizing the input key signal as described above supplies the power supply voltage to the system to the input of the power control signal, and controls the megacon to put the operation into the play mode. At this time, the power control of the system control circuit is a toggle method.

For example, if the power control signal is the first (odd) input, the power should be " on ", and if the second (even) input, the power must be " off '. Such a configuration (program) of the system control circuit to turn on / off the power according to the number of power control number inputs can be easily implemented by those skilled in the art.

Therefore, when the signal is generated from the power signal generation circuit 10 and the play signal generation circuit 20 as described above, the system control circuit performs a play operation automatically after supplying power to the system.

When the tape finishes running as described above, the end sensor detects the trailer section of the tape. At this time, the detection of the end sensor is input to the system control circuit, and the system control circuit drives the automatic stop device and automatically rewinds the tape.

After the execution of the auto rewind function, a start sensor detects a leader section that is the beginning of the tape. At this time, the leader tape detection signal of the start sensor is input to the eject signal generation circuit 30 through the terminal 200, and the eject signal generation circuit 30 inputting the detection signal of the start sensor generates a tape eject signal. Output to function key circuit 40.

The function key circuit 40 which inputs the tape eject signal outputs an eject signal of a predetermined level, such as a tape eject signal due to the pressing of a user's function key, to the system control circuit. The system control circuit then drives the mecharon to eject the tape.

Therefore, power on, auto play, auto wind and auto eject are performed with one cassette tape insertion.

FIG. 2 is a detailed circuit diagram of an embodiment of FIG. 1, wherein a plurality of resistors R9-R14 and a plurality of resistors R9-R14 connected in series to a first power supply voltage, for example, a power supply voltage VDD. A function key circuit 40 composed of eject, play, power, rewind, fast forward, and stop keys SW1-SW6 connected between each connection node and a second power supply voltage, for example, ground (GND), and a terminal ( A power signal generation circuit 10 connected between one end of the power key SW3 of the function key circuit 40 and inverting the output of a cassette switch to output a power control signal, and a resistor; (R1-R8), capacitors (C1-C3), diodes (D1-D2), zener diodes (ZD1-ZD2), transistors (Q1), and inverters (INV1) to determine the output of the terminal (100). A play signal generation circuit 20 and a terminal 200 for delaying and inverting the signal and outputting the inverted signal to one end of the play key SW2 of the function key circuit 40; The function is connected between one end of the eject key (SW1) of the key circuit 40 inverts the output of the start sensor consists of an eject signal generating circuit 30 for outputting an eject signal.

The power signal generating circuit 10 and the eject signal generating circuit 20 in the configuration of FIG. 2 are constituted by a single inverter, and the cassette switch " on " (high pulse) signal inputted to the terminals 100 and 200; Inverts with the detection signal (high pulse) of the start sensor. The reason for inverting the input signal using the power signal generating circuit 10 and the eject signal generating circuit 20 is that the output of the cassette switch and the start sensor typically outputs a “high” pulse.

When the tape is now inserted into the deck of the housing, a cassette switch (not shown) is " on " for a period of time, and a logic " high " (pulse having a predetermined duration) signal is outputted to the terminal 100 to generate a power signal generating circuit ( 10) and the capacitor C1.

The power signal generation circuit 10 inputting the logic "high" signal output from the cassette switch converts the input signal into a "low" signal, which is the second power supply voltage, to convert the third signal of the power key SW2. Output to node C.

Therefore, the third node C of the power key SW3 becomes the "0" (GND) potential instantaneously, and the voltage Vout of the input terminal 300 of the system control circuit is a voltage as shown in Equation (1) below. Is input.

However, it is assumed that all the resistances of the resistors R9-R14 in FIG. 2 are the same size "R".

When the level of the voltage as shown in Equation (1) is input to the system control circuit through the terminal 300, the system control circuit recognizes it as a power control key signal and supplies a power supply voltage to the system.

Therefore, the voltage level (power key level) generated by outputting " low " from the power signal generation circuit 10 as shown in Equation (1) is the same as the voltage level when the power key SW3 is " on ". At this time, the level of the voltage level of the output terminal 300 is sensed, the key signal is a system control circuit, the voltage of the following formula (2), the eject key, the voltage of the formula (3) if the play key, the voltage of the formula (4) It is recognized that the power key and the voltage of the formula (5) are rewind, the voltage of the formula (6) is the fast key, and the voltage of the formula (6) is the stop key signal.

However, in the above formulas (2)-(6), all the resistances are assumed to be R.

On the other hand, the "on" signal of the cassette switch in the "high" state input to the capacitor C1 is the "on" signal of the cassette switch in the "high" state input to the capacitor C1 and the capacitor (C1) and the resistance ( After differentiation by E5), the non-inverting terminal (+) of the operational amplifier OP1 is input to the non-inverting terminal (-) of the operational amplifier OP1 by the diode D2 and the resistors R3-R4. The voltage of the time constant by the resistor R1 and the capacitor C2 is input to the input. Therefore, the operational amplifier OP1 outputs a signal of "high" through the resistor R2 by a time constant set by the resistor R1 and the capacitor C2.

The voltage output from the operational amplifier OP1 is clamped to a constant voltage by the zener diodes ZD1-ZD2 to output a logic "high" pulse to the base of the transistor Q1.

Transistor Q1 that has input the logic " high " pulse is turned off so that capacitor C3 is charged with the time constant of resistor R6 and capacitor C3, and the voltage charged in capacitor C3 is resistor R7. Is input to the inverter INV1. Therefore, a signal of logic " low " which is the second power supply voltage is output to the second node B of the play key SW2. At this time, the second node B of the play key SW2 is " low ", so that a voltage as shown in Equation (2) is input to the system control circuit through the output terminal 300.

At this time, the system control circuit inputting the voltage level as shown in Equation (3) determines that the play key SW2 is pressed and operates the system in the play mode.

Therefore, when the tape is inserted into the deck of the housing, the level of the third node C of the power key SW3 becomes "low" by the power signal generation circuit 10 and then the second node B of the play key SW2. It can be seen that the level of " low " becomes, so that the play operation signal is input to the system control circuit after the control signal of the power supply voltage is supplied.

As described above, the system control circuit that inputs the power control signal and the play operation signal executes the play operation.

When the tape is reproduced to the end by the play operation as described above, and the end sensor detects the trailer section of the tape and inputs it to the system control circuit, the system control circuit automatically rewinds the tape.

On the other hand, when the auto rewind operation is completed, the leader tape section, which is the beginning of the tape, is detected by the start sensor. At this time, the start sensor transmits a "high" pulse signal to the tape eject signal generation circuit 30 through the terminal 200. Enter it.

The tape eject signal generation circuit 30 which inputs the "high" pulse signal by the start sensor inverts the input pulse to generate a logic "low" signal as the tape eject signal to generate the tape eject key SW1. Output to one node (A).

Therefore, the first node A of the tape eject key SW1, which has been kept high through the resistor R9, becomes "low" which is a state signal in which the tape eject key SW1 is pressed. The voltage level of the OV becomes OV as shown in Equation (2), and the system control circuit inputting this determines that the eject key is pressed and performs a tape eject operation.

When the tape is ejected from the housing by the tape eject operation, the cassette switch, which is switched at the moment when the tape is inserted or ejected, is "on" and outputs a signal of "high" to the power signal generation circuit 10 through the terminal 100. .

The power signal generation circuit 10 inputting the "high" pulse signal output from the cassette switch outputs a "low" power control signal to the third node C of the power key SW3 as described above. . Therefore, the potential of the third node C of the power key SW3, which has been kept "high" through the resistors R9-R11, becomes the "low" state in which the power key SW3 is pressed. As 300, a voltage similar to that of Expression (4) described above is output. At this time, the system control circuit inputting the voltage level as shown in Equation (4) determines that the power key signal is input and toggles the current power state. The current state is that power is supplied and the power is turned off.

Therefore, by one operation of inserting the tape into the housing, the operations of power-on-play-rewind-eject-eject-power-off are automatically operated in sequence.

As described above, the operation of all the function keys can be automatically adjusted by only inserting into the tapered housing of the present invention, so that the operation of the video recorder can be automated and simplified, and at the same time, the tape is automatically stopped when the driving stops after the playback ends. It has the disadvantage of reducing power consumption by ejecting and automatically cutting off the supply voltage.

Claims (1)

A system control circuit which senses the input of the function key by sensing the voltage level input to the level sensing terminal 300 and controls the operation of the video recorder, and a cassette which outputs a predetermined pulse when the cassette tape is inserted or ejected. A function key automatic adjustment circuit of a video recording / reproducing apparatus having a terminal 100 of a switch and an output terminal 200 of a start sensor for detecting a leader tape section of a cassette tape and outputting a detection signal, the first power supply voltage being 1st, 2nd. A resistor is connected in series between a third node (A) (B) and (C) so that the first node (A) is connected to the level sensing terminal (300) and the first, second, and third nodes (A) are connected in series. A function key circuit 40 for outputting a level signal of an eject, play, and power function key to the level sensing terminal 300 when a second power supply voltage is applied to each of (B) and (C); A power signal connected between the third nodes C of the function key circuit 40 to convert a pulse output from the cassette switch into a second power supply voltage to output a power on / off control signal to the third node C. It is connected between the generating circuit 10 and the second node B of the terminal 10 and the function key circuit 40, and converts the pulse output from the cassette switch into a second power supply voltage with a predetermined delay. A play signal generation circuit 20 for outputting a play control signal to the second node B, and a first north A of the terminal 20 and the function key circuit 40. And an eject signal generating circuit 30 which converts the leader tape section detection signal outputted from the start sensor and is outputted from the start sensor into a second power supply voltage and outputs an eject control signal to the first node A. Circuit.