JPH0462411B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in a demagnetizer for erasing the magnetism attached to each member in a tape recorder.

[Background of the invention]

Normally, when a tape recorder is used for a long period of time, each component such as the magnetic head and capstan becomes magnetized due to the magnetic field generated internally, which has a negative effect on the recording and playback characteristics. There is a need to.

Conventionally, in order to facilitate degaussing of the magnetic head in a cassette-type tape recorder, a case of the same standard as a Phillips-type compact cassette was used.
A compact cassette-type demagnetizer is provided that includes a degaussing signal generation circuit, a degaussing head slidably supported in correspondence with a magnetic head insertion slot, and a switch means that is turned on and off by movement of the degaussing head. Proposed.

It is true that this demagnetizer can easily demagnetize the magnetic head of a cassette tape recorder, but
For example, it does not demagnetize anything other than magnetic heads such as capstans, and it cannot be applied to different types of tape recorders such as open reel type and endless type, or to different sizes of the same cassette type tape recorder. Missing.

In order to eliminate this drawback, the applicant first
We proposed a demagnetizer with the configuration shown in the figure. That is, a degaussing signal generating circuit for generating an attenuated alternating voltage, a power supply section (none of which are shown) for supplying power to the circuit, etc. are arranged in a case 1 of the same standard as a Philips type compact cassette.
The central part of the front of this case 1 is cut out to form a recess 2.
is formed, and the degaussing head section 3 is removably attached thereto. The degaussing head section 3 and the degaussing signal generating circuit are connected to each other by a sufficiently long flexible lead wire 4.
connected with.

When demagnetizing the magnetic head of a cassette-type tape recorder, insert the degaussing head section 3 into the recess 2 and attach this degausser to the tape recorder, so that the magnetized magnetic head will meet the front surface of the degaussing head section 3. Demagnetization occurs upon contact. In the case of demagnetizing a capstan or other type of recorder, as shown in Figure 1, the demagnetizing head section 3 is pulled out from the case 1, waits for the member to be demagnetized, and then comes into contact with it to demagnetize it. ing.

By the way, this demagnetizer is not without its drawbacks. That is, when degaussing anything other than the magnetic head of a cassette tape recorder, the degaussing head section 3 is pulled out from the case 1, the relatively small external shape of the degaussing head section 3 is held between fingers, and the degaussing head section 3 is held until it reaches the position of the capstan in the tape recorder, for example. I will go and demagnetize it. Especially in the case of a cassette tape recorder, the space near the capstan is narrow, so
The degaussing head 3 is not easy to use, and the degaussing head 3 may not be in close contact with a magnetized member such as a capstan, resulting in incomplete demagnetization.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a demagnetizer that eliminates the above-mentioned drawbacks of the prior art, is easy to use, and can perform complete demagnetization.

[Summary of the invention]

In order to achieve this object, the present invention provides a degaussing signal generating circuit that generates an alternating voltage, a power supply unit that supplies power to the degaussing signal generating circuit, and a degaussing signal generating circuit that is provided in a case of the same standard as, for example, a Philips type compact cassette. A demagnetizing head section consisting of at least a pair of cores and an excitation coil that converts an alternating voltage generated from the demagnetizing signal generating circuit into an alternating magnetic field is provided at the tip of an elongated arm, and the arm is rotated near the corner of the case. When the arm is in the case storage position, the degaussing head is placed in the magnetic head insertion position of the case, and when the arm is in the rotated position, the degaussing head is separated from the case via the arm. It is characterized by being configured to protrude.

[Embodiments of the invention]

Next, a first embodiment of the present invention will be described with reference to the drawings. Inside the case 11, which is of the same standard as the Philips type compact cassette, there is a degaussing signal generating circuit 12 that generates an attenuated alternating voltage, as shown in FIG.
A battery 13 such as a button-type silver battery that supplies power to the degaussing signal generation circuit 12 is arranged. Case 11 is upper case 1 molded from synthetic resin.
It is constructed by overlapping a lower case 1a and a lower case 11b, and is provided with two penetrating drive shaft insertion holes 14 at predetermined positions.

FIG. 4 is a block diagram of the degaussing signal generating circuit 12. The output voltage V ₁ of the battery 13 is DC-DC
After boosting in converter 15, this output voltage V ₂
is applied to the switching circuit 16. The switching circuit 16 is configured such that the input voltage V ₂ is set to a set voltage V ₃ (e.g.
The transistor switch is preset to turn on when the voltage reaches about 16 V), and the voltage V is applied to the large capacitor 17 by turning on the transistor switch. At the same time, by sending a signal from the input side of the switching circuit 16 to the control circuit 18 through the light emitting diode 19, the switching circuit 16 is opened and the DC-DC converter 15 and capacitor 17 are connected.
is completely separated, and the output voltage V ₂ of the DC-DC converter 15 is lowered to a voltage sufficiently low to cause the light emitting diode 19 to emit light to indicate that the battery 13 is normal. Connected to both ends of the capacitor 17 is a self-excited oscillation circuit 20 that generates an alternating voltage having a peak value approximately proportional to the input voltage value, like an astable multivibrator. Voltage V ₃ from switching circuit 16 to capacitor 17
At the same time as the application of , a damped alternating voltage V _{4 whose} peak value drops with a certain time constant is obtained. This alternating voltage _V4 is applied to a degaussing head section 21, which will be described later, and is converted into an attenuated alternating magnetic field.

As shown in FIG. 3, the degaussing head section 21 includes a core 22 made of sintered ferrite or a laminate of silicon steel plates, a bobbin 23 made of synthetic resin, and a coil 24 wound around the core a predetermined number of turns. A protective piece 25 made of soft synthetic resin is placed on the front surface.

The degaussing head section 21 is provided at the tip of an elongated arm 26, and the protective piece 25 protrudes from the front surface of the arm 26. Arm 26
As shown in FIG. 2, it is constructed by overlapping an upper arm 26a and a lower arm 26b, which have almost the same shape, and the base end thereof is located at the left corner of the front surface of the case 11. It is supported rotatably in the horizontal direction by being sandwiched between the two.

Note that the degaussing head 21 is located at the tip of the arm 26.
As shown in FIG. 3, a limit switch 32 is arranged behind the motor. The degaussing head 21 can be moved slightly back and forth within the arm 26, and is moved by the actuator 33 of the millimeter switch 32.
is in elastic contact with the rear of the degaussing head section 21.

As shown in the second figure, an arm storage recess 27 is formed in the left half of the front surface of the case 11, and the arm 26 is stored in the arm storage recess 27. Third
The arm 26 shown by a solid line in the figure is in the storage position, and the arm 26 is held in that position by the tip of the locking piece 29 protruding from the leaf spring 28 engaging the side surface of the arm 26. Then, the demagnetizing head section 21 is placed at the magnetic head insertion position of the case 11.

When the demagnetizer in this state is attached to a cassette tape recorder and the play button is pressed, the magnetic head moves to the magnetic head insertion position in the case 11.
With this movement, the head surface of the magnetic head comes into contact with the front surface of the magnetic head section 21, and the demagnetizing head section 2
1 moves back and closes the limit switch 32.

Based on this operation, the demagnetizing signal generating circuit 12 generates an attenuated alternating voltage, which is applied to the demagnetizing head section 21 and converted into an attenuating alternating magnetic field, thereby demagnetizing the magnetic head.

The base end of the leaf spring 28 is fixed to the case 11, and the free end slightly protrudes from the front surface of the case 11 to such an extent that a finger can be placed on it. Therefore, this leaf spring 2
By moving the free end of the arm 26 against its elasticity, the aforementioned engagement between the locking piece 29 and the arm 26 is released. As shown in FIG. 3, an arm push-out spring 30 is provided behind the storage position of the arm 26, and when the arm 26 is stored in the storage recess 27, the arm push-out spring 30 is compressed. Therefore, when the engagement between the lock piece 29 and the arm 26 is released as described above, the arm 26 rotates slightly due to the repulsive force of the arm push-out spring 30, and a portion of the arm 26 protrudes from the front surface of the case 11. By pinching this protruding portion and horizontally rotating the arm 26 to a predetermined position, the degaussing head 21 protrudes away from the case 11 via the arm 26, as shown in FIG. Then, the user holds the case 11 and presses the demagnetizing head 21 against the peripheral surface of, for example, the capstan 31 to be demagnetized. Due to this pressure contact, the demagnetizing head 21 is retracted, the limit switch 32 is closed, and demagnetizing is performed in the same manner as described above.

Although not shown, moderation means is provided between the case 11 and the arm 26 to maintain the position of the arm 26 when it is rotated by a predetermined angle from the storage position.

5 and 6 are diagrams showing a second embodiment of the present invention. In this embodiment, the arm 26 includes a first upper arm 26a-1 and a first lower arm 26b.
-1, cylindrical arm 26c, and second upper arm 26
a-2 and a second lower arm 26b-2. and second upper arm 2
A degaussing head section 21 and a limit switch 32 are housed between the second lower arm 6a-2 and the second lower arm 26b-2. This second upper arm 26a-2 and the second
Assembly of lower arm 26b-2 (demagnetizing head section 2
1) can be rotated in the direction shown by the arrow in FIG. 5 via the cylindrical arm 26c, and is convenient for demagnetizing magnetic heads, capstans, etc. located in narrow spaces.

FIG. 7 is a diagram showing a third embodiment of the present invention. In this embodiment, the base end of the arm 26 is supported near the corner of the case 11, and the arm 26 is rotatable in the vertical direction, unlike the previous embodiment.

Although a battery was used as the power source in the above embodiment, the power source is not limited to this, and for example, a large-capacity capacitor equipped with a terminal portion that can be charged and supplied from the outside may be used. Further, in the embodiment, the limit switch is disposed within the arm, but it may also be disposed within the case and operated manually.

〔Effect of the invention〕

The present invention is constructed as described above, and when demagnetizing a capstan or other type of tape recorder, the arm is rotated to project the degaussing head from the case, and the case can be held and demagnetized.
Therefore, it is easy to use, and the demagnetizing head portion can be reliably brought into close contact with the member to be demagnetized, resulting in complete demagnetization.

In particular, since the arm is supported near the corner of the case, the degaussing head can be moved far away from the case when the arm is rotated. Therefore, the degaussing head can be inserted even into a narrow space without the case getting in the way.

Since the demagnetizer of the present invention has the above-described structure, it can be used to degauss not only tape recorders for Phillips type compact cassettes but also other types of tape recorders such as open reel type, endless type, and microcassette type. can.

[Brief explanation of drawings]

Figure 1 is a perspective view of a previously proposed demagnetizer;
The figure is a perspective view of a demagnetizer according to a first embodiment of the present invention,
Fig. 3 is a plan view of the demagnetizer with the upper case removed, Fig. 4 is a block diagram of a degaussing signal generation circuit used in the demagnetizer, and Fig. 5 is a diagram showing a second embodiment of the present invention. FIG. 6 is an exploded perspective view of an arm used in the demagnetizer, and FIG. 7 is a perspective view of a demagnetizer according to a third embodiment of the present invention. 11... Case, 12... Degaussing signal generation circuit,
13...Battery, 21...Degaussing head section, 26...
Arm, 27...Arm accommodation recess.

Claims (1)

[Claims] 1. A degaussing head unit that includes a demagnetizing signal generating circuit that generates an alternating voltage and a power supply unit that supplies power to the demagnetizing signal generating circuit in a case, and converting the alternating voltage generated from the demagnetizing signal generating circuit into an alternating magnetic field. An arm provided at the tip thereof is rotatably attached near a corner of the case, and when the arm is in the case storage position, the degaussing head portion is placed in the magnetic head insertion position of the case, and the arm is rotated. 1. A degaussing device characterized in that the degaussing head is configured to project away from the case via the arm when in the degaussing position.