JPS6232533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When a magnetic tape is wound up to the end of the tape on a take-up reel, the amount of mechanical displacement based on the detection of an auto-stop sensor that mechanically detects this is detected by an electrical signal. The present invention relates to an auto-stop circuit for a tape recorder, etc., in which the converted electrical signal is used to drive a mechanism related to a stop mode of the tape recorder, etc.

Conventional auto-stop circuits for tape recorders and the like have a take-up reel fitted with a ring magnet having a plurality of N-S magnetic poles surrounding it, and the magnetic field from the ring magnet as the take-up reel rotates. In order to detect changes, a Hall element is placed close to the ring magnet, and there is a device that detects the change in the output of the Hall element when the take-up reel stops rotating at the end of the tape, but the circuit configuration is It was extremely complicated. On the other hand, when the magnetic tape is wound up to the end of the tape, the tape tension generated between the take-up reel and the supply reel is used to move a lever, and the amount of mechanical displacement of this lever is used to drive a tape recorder, etc. There are devices that perform an auto-stop operation, but because they utilize changes in tape tension, even slight changes in tape tension caused by vibrations may result in an auto-stop operation, resulting in operational instability.

Therefore, the applicant provided an "auto-stop device for tape recorders, etc." according to Japanese Patent Application No. 150089/1989.

That is, this "auto-stop device for a tape recorder, etc." is capable of interlocking with the take-up reel stand at a certain angle, and performs an auto-stop operation by utilizing the release of the interlock when the take-up reel stand stops at the end of tape winding. In an auto-stop device such as a tape recorder having an auto-stop sensor, the auto-stop sensor is arranged so as to be at a different angle from the direction of the auto-stop operation when the auto-stop sensor is operating. A drum pin is provided on the periphery of the drum which is constantly rotating, and an auto-stop sensor that can be interlocked with the take-up reel stand is connected to the drum pin in the auto-stop operation direction while the take-up reel stand is rotating. The drum pin is arranged so as not to press against it, and is also arranged so as to slide against the engaging body and bias it in a direction to release the rotation of the rotating auto-stop sensor, which utilizes changes in tape tension. The auto-stop operation is extremely stable.

However, although this auto-stop device has an auto-stop sensor, a complicated auto-stop circuit is required to convert the mechanical displacement of the auto-stop sensor into an electrical signal to drive a mechanism related to the stop mode of a tape recorder, etc. In need of. The mechanical displacement of the auto stop sensor is
In order to directly drive the stop mode mechanism of a tape recorder, etc., an extremely large load force is required on the auto-stop sensor, so an auto-stop circuit is usually not used, even if it is complex and expensive. I don't get it.

The present invention has been made to solve the above-mentioned problems by providing an element that is linked to the auto-stop operation of the auto-stop sensor described in the specification of Japanese Patent Application No. 52-150089. The object of the present invention is to provide an auto-stop circuit with an extremely simple circuit configuration.

The auto-stop circuit according to the present invention has an element that is linked to the auto-stop operation of the auto-stop sensor. An electric signal receiving terminal of a drive circuit that electrically drives a mechanism related to the stop mode, an electric signal storage terminal of an electric signal storage circuit, and a supply terminal of an electric signal supply circuit are arranged in parallel, and the element is In the case of a device that slides, the element is configured to be in constant contact with the storage terminal, and in the case of a device that rotates, the rotating base end of the device is configured to be in constant contact with the storage terminal. A first electrical short circuit mode between the storage terminal and the supply terminal made through the element is configured such that the element is pivotally connected, and the element is slid or rotated in conjunction with the auto-stop operation. In particular, the present invention is configured to shift to a second electrical short-circuit mode between the storage terminal and the receiving terminal via the element.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Fig. 1 shows a conventional auto-stop circuit. To explain this figure, numeral 1 is an element that is linked to the auto-stop operation of an auto-stop sensor (described later), and the base end of the element 1 is electrically connected. It is pivotally connected to the storage terminal 3 of the signal storage circuit 2,
Along the rotation range of the other end of the rotation of the element 1, a supply terminal 5 of the electric signal supply circuit 4 and a drive circuit 6 for electrically driving a mechanism (not shown) related to a stop mode of a tape recorder or the like are connected. Receiving terminals 7 are arranged in parallel. The storage circuit 2 has a capacitor C ₁ inside, and the electric signal supply circuit 4 has a resistor R ₁ connected to a DC power supply +B. Drive circuit 6
The transistors Q ₁ and Q ₂ are connected in Darlington, and a resistor R ₂ is inserted between the base of the transistor Q ₁ and the receiving terminal 7, and a resistor R ₃ is inserted between this base and ground. ing. Collector of transistor _Q1 and DC power supply +B
A resistor _R4 is inserted between the transistors
The emitter of _Q2 is grounded, and a backflow prevention diode _D1 and plunger solenoid _L1 are interposed between its collector and the DC power supply +B.

The auto-stop sensor in this conventional circuit has a forward operation in which the other end of the rotation of the element 1 shifts from a mode in which it is in contact with the receiving terminal 7 side to a mode in which it is in contact with the supply terminal 5 side by one auto-stop operation. (in the direction of arrow A) and a return operation (opposite to the direction of arrow A) of shifting from the mode in which it abuts on the supply terminal 5 side to the mode in which it abuts on the receiving terminal 7 side. has conductivity, so when the forward operation is completed, that is, in the mode in which the storage terminal 3 is electrically short-circuited to the supply terminal 5 via this element 1, the voltage of the power supply +B is applied to the resistor. Via R ₁ , the capacitor C ₁ of the storage circuit is charged. This capacitor C ₁
charges the amount of electricity to a predetermined level before element 1 starts the backward operation, and when element 1 completes the backward operation, the receiving terminal 7 and storage terminal 3 receive electricity via this element. When short-circuited, the electrical signal stored in the accumulator _C1 is transferred to the transistor of the drive circuit.
It will be applied to the base of Q ₁ through resistor R ₂ , transistor Q ₁ will be conductive, the next stage transistor Q ₂ will also be conductive, and plunger solenoid L ₁ will be applied to the base of Q 1.
is energized.

Since the plunger solenoid _L1 drives a mechanism related to a stop mode of a tape recorder or the like, the tape recorder or the like automatically stops.

The conventional autostop circuit shown in FIG. 1 has an extremely simple configuration as described above. However, if the operator puts the tape recorder into stop mode during the forward motion of element 1, the element rotates without the other end of the rotation being in contact with either the receiving terminal 7 or the supply terminal 5. be stopped.

This is because the tape recorder has already finished playing the song at the end of the tape, so the user operates the stop button even though the auto-stop operation is activated. This is the place to do it. When this element is stopped in the middle of the forward motion, the auto-stop sensor is activated to complete the auto-stop operation in the playback mode, fast-forward mode, or rewind mode. After coming into contact with the supply terminal 5, it is reversed and rotated so as to come into contact with the receiving terminal 7, and as a result, an auto-stop operation is performed. At this time, the operator had replaced the cassette tape when the element stopped during the forward movement process, and even though it was a new cassette tape that was not at the end of the tape, the auto-stop function was activated as soon as the device was set to playback mode, as described above. The action is very inconvenient.

An improved version of this is the auto-stop circuit of the present invention shown in FIG.
1 is constructed to be interlocked with the above-mentioned auto-stop sensor. Reference numeral 22 denotes a storage circuit, which includes a series circuit of a capacitor _C1 and a resistor _R6 . 23 is a storage terminal of the storage circuit, and the slide element 21 is always in contact with this storage terminal 23 at any sliding position. 24 is a power supply circuit.

To explain this power supply circuit 24, a series connection circuit of a resistor R _{1 and a capacitor C 2 is} inserted between the DC power supply +B ₁ and the ground, a resistor R ₅ is connected between this connection and the ground, and a regeneration button is connected. Switch SW ₁ , which is linked to the operation of the fast forward/rewind button, and switch SW ₂ , which is linked to the operation of the fast forward _/ rewind button, are inserted in this order. Switch SW ₃ is inserted. Switch SW ₁
is also connected to a motor M for fast forwarding and rewinding.
The slide elements of switches SW ₂ and SW ₃ slide in the directions of arrows A ₁ and A ₂ by fast forwarding and rewinding operations, and switch SW ₁ slides in the arrow B direction by reproducing operations. The sliding element slides in the direction.

25 is a supply terminal for supplying power supply voltage. 2
6 is a drive circuit that drives a mechanism related to the stop mode of the tape recorder, and this drive circuit 26 is composed of transistors Q ₂₁ , Q ₂₂ , resistors R ₂ to _{R 4} , a backflow prevention diode D ₂₁ , and a plunger solenoid L ₂₁ .

When the power switch of the tape recorder is turned off, the element 21 is normally set to be in a position that electrically shorts the receiving terminal 27 and the storage terminal 23, and at this time, electricity is supplied to the storage device _C1 . Since no signal is stored, the base potential of transistor Q ₂₁ is low, and therefore transistors Q ₂₁ , Q ₂₂
are both in a non-conducting state and the plunger solenoid
L ₂₁ is not energized.

Next, when the power switch of the tape recorder is turned on, a resistor is connected to the capacitor _C2 of the power supply circuit 24.
The electrical signal passing through R ₁ has a charging time constant T ₁ (R ₁ , R ₅ ,
By _C2 . ) is accumulated by This capacitor C ₂
The amount of electricity stored in resistor _R5 is the switch _SW1
Among the fixed contacts C ₁ to _{C 5} , the sliding element is in contact with C ₁ and C ₃ , and the fixed contact of switch SW ₂
Among _C6 to _C8 , the sliding elements are in contact with _C6 and _C7 and are grounded, so the divided voltage of resistors _R1 and _R5 becomes _V1 . This divided voltage V ₁ is the transistor
The base voltage V _B required for conduction of Q ₂₁ is below.

Next, when the playback button is operated to put the tape recorder into playback mode, the slide element of switch SW ₁ slides on the fixed contact in the direction of arrow B, and
Touches C ₃ and C ₅ . At this time, the fixed contact C ₁ of the resistor R ₅ is separated from the grounding portion, so that it is no longer grounded, and the amount of electricity stored in the capacitor C increases to the power supply voltage +B ₁ according to the time constant T ₂ =C ₂ R ₁ . At this time, an amount of electricity larger than the base voltage V _B required for conduction of the transistor Q ₁ , that is, a voltage V ₂ is applied to the capacitor C ₂
is accumulated in Then, when the end of the tape is reached,
The auto-stop sensor starts operating, and in conjunction with this, the element 21 also closes the terminals 27, 23, 23 in the direction of arrow C.
25.

That is, in one auto-stop operation, the element 21 changes from a first mode in which the receiving terminal 27 and the storage terminal 23 are electrically short-circuited to a second mode in which the supply terminal 25 and the storage terminal 23 are electrically short-circuited. A forward movement toward the second mode and a backward movement from the second mode to the first mode are performed.

In the second mode, capacitor C ₁ is replaced by capacitor C ₂
In the first mode, the amount of electricity is applied to the base of the transistor Q ₂₁ to conduct the transistors Q ₂₁ and Q ₂₂ and energize the plunger solenoid L ₂₁ .

Now, at the end of the tape, the auto-stop operation has started, and if you put the tape recorder in stop mode while the element 21 is moving forward, the element 21 will stop in the middle of the forward movement, as in the case of Fig. 1. do. At this time, since the tape recorder is in the stop mode, the electricity in the accumulator C ₂ is changed to the switch SW ₁ ,
SW ₂ and SW ₃ slide their sliding elements in the opposite direction to the arrows B, A ₁ and A ₂ respectively, and the contacts C ₁ and C ₃ of switch SW ₁ and the contacts C ₆ and C of switch SW _{2 7} , the contacts _C9 and _C10 of the switch _SW3 are electrically short-circuited, resulting in the above-mentioned voltage _V1 .

The discharge time constant T ₃ is determined by the resistor R ₅ and the capacitor C ₂ , so it is a short time, and the time it takes for the operator to change the cassette and press the play button again is extremely long, so the auto-stop operation is disabled. Even if it continues to operate, the amount of electricity, that is, the voltage, in the capacitor C ₂ is V _1. Therefore, when the element 21 completes its forward operation, the amount of electricity stored in the capacitor C ₁ is V ₁ . Therefore, upon completion of the reverse operation, transistor Q ₂₁
The amount of electricity V ₁ will be applied to the base of Q 21 , and this transistor Q ₂₁ will not conduct. Then, when the cassette is replaced and the playback button is operated for a short period of time, the capacitor C ₂ returns to voltage V ₂ .
Electricity is stored up to. As described above, the autostop circuit shown in FIG. 2 does not suffer from the problem of malfunctioning of the autostop after the autostop operation is interrupted midway.

As described above, according to the present invention, the configuration of the autostop circuit is extremely simple.

[Brief explanation of the drawing]

1 and 2 show embodiments of an autostop circuit according to the present invention. In the figure, 1, 21; element; 2, 22; storage circuit;
3, 23; storage terminal; 4, 24; power supply circuit;
5, 25; Supply terminal, 6, 26; Drive circuit, 7,
27; Receiving terminal.

Claims (1)

[Scope of Claims] 1. An auto-stop circuit for a tape recorder, etc., which performs an auto-stop operation to automatically put the tape recorder, etc. in a stop mode based on the operation of an auto-stop sensor when the magnetic tape of the tape recorder, etc. reaches the end. , a plunger drive circuit for putting the tape recorder etc. in a stop mode, a first time constant circuit, a second time constant circuit connected to a power supply, and a first time constant circuit connected to the plunger drive circuit. a terminal, a second terminal connected to the first time constant circuit, a third terminal connected to the second time constant circuit, and between the second terminal and the first or third terminal. a switch means comprising a movable contact piece that selectively closes; and a switch means connected to the second time constant circuit, which is connected to the second time constant circuit when a magnetic tape of the tape recorder or the like is running. to a first voltage level that is higher than the operating level of the plunger drive circuit and, in a stop mode, charges the second time constant circuit to a second voltage level that is lower than the operating level of the plunger drive circuit. and a control circuit, from a forward movement in which the movable contact piece closes between the second and third terminals based on the operation of the auto-stop sensor when the magnetic tape reaches the end, to the first and second terminals. supplying the voltage at the first voltage level charged in the second time constant circuit to the drive circuit via the first time constant circuit so as to perform a double operation of closing the second terminal; to perform the auto-stop operation, and during the forward movement of the movable contact piece to close the second and third terminals, the tape recorder, etc. is put into a single-stop mode by an external operation, and the above-mentioned movable contact is brought to a stop mode. When the magnetic tape starts running again after the contact piece stops its operation and the movable contact piece performs the forward and backward movements, the voltage at the second voltage level is changed to the first time constant. An auto-stop circuit for a tape recorder, etc., characterized in that the power is supplied to the plunger drive circuit through a circuit.