JPH0124742Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cassette-type cleaning and demagnetizing device for cleaning and demagnetizing magnetic heads of tape recorders, etc., in which a fitting opening for an accidental erasure prevention claw on the deck side is formed on one side of the rear surface of the cassette. In addition, a detector for the above-mentioned erroneous erasure prevention claw is provided in the insertion opening, and the excitation of the degaussing head is controlled to open and close by turning on and off the detector.

Magnetic heads for recording and playback in tape recorders, etc.
During long-term use, recording and playback characteristics deteriorate due to magnetization and dust adhesion, and therefore it is necessary to periodically demagnetize and clean the magnetic head. For this reason, a degaussing device is built into a cassette of the same size and shape as various cassettes such as the well-known Phillips compact cassette and 8-track cassette, and when the cassette is set on the deck and the play button is pressed, the magnetic head on the deck side A cassette type demagnetizer, a dry type demagnetizer, a wet type demagnetizer, a dry type demagnetizer, a dry type demagnetizer, a wet type demagnetizer, etc., which enter the cassette and hit the degaussing head constituting the demagnetizer, and in that state, generate an alternating gradually decreasing magnetic field in the demagnetizer head to erase the magnetization of the magnetic head. When the cleaning tape is loaded into the cassette, the cassette is set on the deck, and the play button is pressed, the magnetic head enters the cassette and comes into contact with the tape, and in this state the tape feeding device is driven. A cassette-type cleaning device has already been put into practice that cleans and removes dust adhering to a magnetic head by sliding the tape along the front surface of the magnetic head.

By the way, it is conceivable to incorporate the degaussing device and the cleaning device in the same cassette so that the magnetic head can be degaussed and cleaned at the same time, but in this case, both the degaussing device and the cleaning device can be operated by pressing the play button. Since the magnetic head automatically starts driving when it enters the cassette, cleaning and demagnetization of the magnetic head are always performed simultaneously. However, since cleaning and demagnetizing the magnetic head have very different work purposes, they should not necessarily be performed at the same time. Instead, the degaussing device is stopped and only the cleaning device is driven, and only the cleaning work is performed. There are times when you want to. In particular, this type of degaussing device generally uses a primary battery as its power source, so if the device is driven unnecessarily, the primary battery will be wasted and its discharge will be completed prematurely.
From this point of view as well, it is desirable to be able to stop the drive of the degaussing device at will.

Therefore, the present invention was developed taking the above points into consideration and noting that this type of deck is generally equipped with a claw to prevent accidental erasure of the magnetic tape. In the cassette type cleaning and degaussing device, a fitting opening for the accidental erasure prevention claw on the deck side is formed on one side of the rear surface of the cassette, and a detector for the accidental erasure prevention claw is installed in the insertion opening, and the detection The detector is connected to the excitation circuit of the degaussing head, and the excitation circuit is opened and closed by turning on and off the detector.In this way, the cassette can be set on the deck with one main surface facing upward. When cleaning and demagnetizing the magnetic head, when the cassette is set on the deck with the other main surface facing up, the driving of the excitation circuit is stopped and the cleaning tape is used to demagnetize the magnetic head. It is designed to perform only cleaning.

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

In Fig. 1, reference numeral 1 denotes a cassette of the same size and shape as a Phillips-type compact cassette, and inside it there are a feed reel 2 and a take-up reel 3.
are rotatably arranged, and a dry cleaning tape 4 is wound around both reels 2 and 3. 5,
Reference numerals 6 and 6 denote a magnetic head insertion port and a pinch roller insertion port provided on the front side of the cassette 1, and the tape 4 is inserted along guide rollers 7, 7 rotatably mounted on both sides of the front side of the cassette 1. The magnetic head 8 is fed along the respective insertion ports 5, 6, and 6, and at that time, the magnetic head 8 slides into contact with the front surface of the magnetic head 8 inserted from the magnetic head insertion port 5, and dust adheres to the magnetic head 8. Clean and remove. 9 is a pinch roller.

Reference numeral 10 denotes a demagnetizing head, which is provided adjacent to the magnetic head insertion slot 5, and whose back surface is supported by wires or plate springs 11 fixed to the cassette 1 at both ends so as to be able to move forward and backward. 12 is a micro switch which connects the magnetic head 8 to the insertion slot 5.
When inserted from the top, the degaussing head 10
The lever 12a of the micro switch 12 is pressed through the wire spring 11 to operate the micro switch 12, and the excitation wired on the excitation circuit board 13 at the rear is activated. The circuit is activated to generate an alternating gradually decreasing magnetic field in the degaussing head 10, thereby demagnetizing the magnetic head 8.
Reference numeral 14 designates a power source battery for the excitation circuit, and reference numeral 15 designates capstan insertion ports formed on both upper and lower surfaces of the cassette 1 corresponding to the pinch roller insertion port 6.

Reference numeral 16 denotes a fitting opening for an accidental erasure prevention claw 23 of a tape recorder formed on one side of the rear surface of the cassette 1;
A light emitting diode 17a and a phototransistor 17 constitute a detector 17 that detects the accidental erasure prevention claw 23 on the tape recorder side that is inserted into the cassette 1.
b is provided in the fitting opening 16 at a small interval for the tip of the preventing claw 23 to enter (the second
(see also the figure), the excitation circuit of the degaussing head 10 is opened and closed by turning on and off the detector 17.

Reference numeral 20 denotes a tape recorder into which the main cassette 1 is set, and a cassette mounting opening 22 is provided on the top surface of the main body 21.
is recessed, and an erroneous erasure prevention claw 23 is protruded from one side of the rear surface. 24, 24 is a rotating shaft installed on the bottom surface of the mounting port 22, and 25 is a rotating shaft provided on the bottom surface of the mounting port 22.
2 is a leaf spring for positioning the cassette 1 which is erected at the center of the rear surface; 26 is a rotatable cover plate for opening and closing the mounting opening 22; and 27a to 27e are play buttons. The rightmost play button 27a is a recording button, and this button 27a is connected to the accidental erasure prevention claw 23.
When the claw 23 is inserted into the fitting opening 16, the button 27a is locked and cannot be pressed.

FIG. 3 shows the excitation circuit wired on the excitation circuit board 13, in which 14 is the power battery, 12 is the micro switch, and the detector 17 is configured in parallel with the power battery 14. A light emitting diode 17a and a phototransistor 17b are connected. 18 and 19 are light emitting diodes 17a
and a resistor connected to the phototransistor 17b. 30 is a DC booster circuit for boosting the terminal voltage of the power supply battery 14, and is composed of resistors 31, 32, transistors 33, 34, capacitors 35, 36, diodes 37, 38, 39, coils 40, 41, etc. The emitter pole of the phototransistor 17b is connected to the base pole of a transistor 34 via a resistor 32 and a diode 38.

45 is a display circuit, which is composed of a light emitting element 46, a switching transistor 47, a resistor 48, etc., and 50 is a switching circuit, which is composed of switching transistors 51, 52 and resistors 53, 54, 55. , each of the above circuits 4
5 and 50 are connected to the output stage of the DC booster circuit 30. Reference numeral 56 denotes a constant voltage circuit connected to the switching circuit 50, which includes a constant voltage element 57 such as a Zener diode and a resistor 58 for detecting the constant voltage level. It is configured. The resistor 60 on the low potential side also serves as a current limiting resistor of the booster circuit 30, and is connected to the base pole of the transistor 34 via the diode 39.

61 is a large capacity capacitor connected in parallel to both ends of the constant voltage circuit 56; 62 is an oscillation circuit driven by the accumulated charge of this capacitor 61;
5, 66, output transistors 67, 68, etc., and is connected to the degaussing head 10, which consists of an excitation coil 69, a capacitor 70, etc.

The collector pole of the switching transistor 52 is directly connected to each emitter pole of the output transistors 67 and 68 in the oscillation circuit 62,
Thereby, the switching transistor 52 is configured as a switching transistor for forming a closed loop between the capacitor 61 and the oscillation circuit 62.

This device has the above-mentioned configuration, and its handling operation will be explained next.

When cleaning and demagnetizing the magnetic head (not shown) built into the tape recorder 20, place the insertion opening 16 formed on one side of the rear surface of the cassette 1 on the side of the accidental erasure prevention claw 23 of the tape recorder 20. The cassette 1 is set in the mounting port 22, and the tip of the preventing claw 23 is inserted through the mounting port 16 between the light emitting diode 17a and the phototransistor 17b inside the cassette 1. Next, close the lid plate 26 and press the play button 27.
When b is pressed, the magnetic head on the tape recorder 20 side enters the cassette 1 through the magnetic head insertion slot 5 on the front of the cassette 1, and its front surface contacts the cleaning tape 4, and the motor built in the deck starts. The feed reel 2 and take-up reel 3 start rotating, the cleaning tape 4 starts to be fed, and the front surface of the magnetic head 8 is cleaned. When the magnetic head 8 enters the cassette 1 through the magnetic head insertion slot 5, the degaussing head 10, which is supported by the wire spring 11, is pushed back by the magnetic head 8, and the lever 12a of the micro switch 12 is pushed back by the wire spring 11. The microswitch 12 is activated, the excitation circuit is closed, and the light emitting diode 17a emits light. However, the light emitted from the light emitting diode 17a is blocked by the tip of the prevention claw 23 fitted from the fitting opening 16, and therefore does not enter the phototransistor 17b.
maintains the cutoff state. Therefore, the base current from the power supply battery 14 flows through the transistor 33 of the booster circuit 30 through the resistor 31, the booster circuit 30 is driven, and the terminal voltage of the power supply battery 14 is boosted by the booster circuit 30. When the output voltage of the booster circuit 30 is applied to the switching circuit 45, the switching transistor 51 becomes conductive and charging of the capacitor 61 is started.

When the capacitor 61 is charged to a predetermined voltage, a reverse current rapidly flows through the constant voltage element 57, the terminal voltage of the level detection resistor 58 rises, the switching transistors 47 and 52 become conductive, and the light emitting element becomes conductive. 46 emits light to indicate that it is being demagnetized, and the switching transistor 51 is cut off to remove the voltage from the booster circuit 30 to the capacitor 6.
1 is stopped. Further, the voltage of the voltage dividing resistor 60 of the level detection resistor 58 is applied to the base pole of the transistor 34 of the booster circuit 30 to limit the current of the booster circuit 30, and the light emitting element 46 is driven at a relatively constant voltage. Emits light.

On the other hand, when the switching transistor 52 becomes conductive, a closed loop is formed between the capacitor 61 and the oscillation circuit 62, and the charge accumulated in the capacitor 61 flows to the oscillation circuit 62, so that the oscillation circuit 62 is driven. Therefore, an alternating magnetic field is generated in the degaussing head 10, which gradually decreases over time as the capacitor 61 discharges, and the magnetization of the magnetic head 8 is eliminated. When the cassette 1 is set with the insertion opening 16 formed on one side of the rear surface of the cassette 1 facing the accidental erasure prevention claw 23 of the tape recorder 20 as described above, the detector 17 detects the prevention claw 23. The excitation circuit is driven to clean and demagnetize the magnetic head.

If it is desired to stop the drive of the excitation circuit and only clean the magnetic head, the cassette 1 is set in the tape recorder 20 so that the insertion opening 16 is located on the opposite side of the prevention claw 23. In this case, the prevention claw 23 does not fit into the cassette 1 through the insertion opening 16. Next, when the cover plate 26 is closed and the play button 27a is pressed, the magnetic head enters the cassette 1 from the magnetic head insertion slot 5 in the same manner as above, the tape 4 is fed, and the magnetic head is cleaned. The light emitted from the generation diode 17a enters the phototransistor 17b, and the phototransistor 17b becomes conductive. Therefore, the current from the power supply battery 14 flows from the phototransistor 17b to the negative line, the excitation circuit is not driven, and no alternating demagnetizing field is generated in the degaussing head 10. When the cassette 1 is thus set in the tape recorder 20 facing the opposite side from the above case, the magnetic head is not demagnetized but only cleaned.

FIG. 4 shows another embodiment of the present invention, in which a detector 17 comprising the light emitting element 17a and the phototransistor 17b is mounted on the excitation circuit board 13 disposed in the cassette 1. Instead, a detector 71 consisting of a micro switch is provided. Therefore, the accidental erasure prevention claw 23 fits into the cassette 1 through the insertion opening 16, and the detector 71
When the lever 71a is turned on and the detector 71 is activated, the excitation circuit remains stopped and no alternating gradually decreasing magnetic field is generated in the degaussing head 10, and only the cleaning tape 4 cleans the magnetic head.

Furthermore, when the cassette 1 is set in the tape recorder 20 with the direction opposite to that described above, the prevention claw 23 does not enter into the cassette 1 through the insertion opening 16, and the lever 71a of the detector 71 remains open. Detector 71 is not activated. The excitation circuit is therefore actuated to create an alternating gradually decreasing magnetic field in the demagnetizing head 10, both cleaning and demagnetizing the magnetic head.

Note that in the above embodiment, the dry cleaning tape 4
has been described as an example, but a wet cleaning tape may be used instead of the dry cleaning tape 4, and the same structure can be used for micro cassettes and other devices having accidental erasure prevention claws. It can also be applied to cassettes.

As explained above, the cassette type cleaning and degaussing device according to the present invention includes a cleaning tape 4 placed in the cassette 1, a degaussing head 10, and an excitation circuit for the degaussing head 10. A fitting opening 16 for the accidental erasure prevention claw 23 on the side of the deck 20 is formed on one side of the rear surface, and a detector 17 of the accidental erasure prevention claw 23 is formed in the insertion opening 16.
The detector 17 is connected to the excitation circuit, and the excitation of the degaussing head 10 is opened and closed by turning on and off the detector 17. Therefore, the magnetic head can be cleaned and demagnetized at the same time. In addition, it is possible to perform only cleaning of the magnetic head, which has the effect of preventing wasteful consumption of the power supply battery 14.

[Brief explanation of the drawing]

The figure shows an embodiment of the present invention.
2 is a perspective view of a cassette-type cleaning and degaussing device and a tape recorder, FIG. 2 is a plan view of a main part, FIG. 3 is an excitation circuit diagram, and FIG. 4 is a side view of a main part of another embodiment of the present invention. 1...Cassette, 4...Cleaning tape,
10... Degaussing head, 16... Insertion port, 17,7
1...detector, 20...deck, 23...accidental erasure prevention claw.

Claims (1)

[Scope of utility model registration request] A cleaning tape 4 is placed in the cassette 1, and a demagnetizing head 10 and an excitation circuit for the demagnetizing head 10 are arranged.
An insertion opening 16 for the accidental erasure prevention claw 23 on the side of the deck 20 is formed on one side of the rear surface, and a detector 17 of the accidental erasure prevention claw 23 is provided in the insertion opening 16, and the detector 17 is connected to the excitation circuit. Connect the detector 1 to
A cassette type cleaning and demagnetizing device in which the excitation of the demagnetizing head 10 is opened and closed by turning on and off the degaussing head 10.