JPH0454286B2 - - 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 magnetism from 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 turns on and off by moving the degaussing head. Proposed.

It is true that this demagnetizer can easily degauss the degaussing head of a cassette tape recorder, but
For example, degaussing is not performed on anything other than the degaussing head such as a capstan, and furthermore, 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 tape recorder, as shown in Figure 1, the degaussing head section 3 is pulled out from the case 1, carried to the part to be demagnetized, and brought into contact with it to demagnetize it. It's summery.

By the way, this demagnetizer is not without its drawbacks. That is, when demagnetizing anything other than the magnetic head of a cassette tape recorder, the degaussing head section 3 is pulled out from the case 1, the degaussing head section 3, which has a relatively small external shape, is held between fingers and held, for example, to the position of the capstan inside the tape recorder. 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 and a power supply unit that supplies power to the degaussing signal generating circuit 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 a long and thin arm, and the arm is slidably attached to the case. When the arm is in the case storage position, the degaussing head is arranged at the magnetic head insertion position of the case, and when the arm is in the sliding position, the degaussing head protrudes away from the case via the arm. It is characterized by being configured as follows.

[Embodiments of the invention]

Next, embodiments of the present invention will be described with reference to the drawings.
Inside the case 11, which has the same specifications as the Phillips-type compact cassette, there is a degaussing signal generating circuit 12 that generates an attenuated alternating voltage, and a button-shaped silver battery that supplies power to the degaussing signal generating circuit 12, as shown in FIG. A battery 13 such as the like is arranged. The case 11 is constructed by overlapping an upper case 11a and a lower case 11b molded from synthetic resin, and has a drive shaft insertion hole 14 penetrating at a predetermined position.
There are one.

FIG. 6 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 16V), and the voltage V ₃ is applied to the large-capacity 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
Open and connect DC-DC converter 15 and capacitor 1
7 is completely separated, and the output voltage V ₂ of the DC-DC converter 15 is lowered to a voltage low enough 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 from switching circuit 16 to capacitor 17
At the same time as V ₃ is applied, the oscillation circuit 20 starts self-excited oscillation, but at this moment the replenishment of power to the capacitor 17 is cut off, so the capacitor 17 continues to discharge and the voltage between the terminals drops, and the oscillation circuit 20 starts to oscillate. circuit 20
, a damped alternating voltage V _{4 whose} peak value drops with a certain time constant is obtained. This alternating voltage V ₄ is
It is applied to a demagnetizing head section 21, which will be described later, and is converted into an attenuated alternating magnetic field.

As shown in FIG. 3, the demagnetizing 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 bobbin 23 made of synthetic resin.
A coil 24 is wound around it a predetermined number of turns, and a protective piece 25 made of soft synthetic resin is placed on the front side.
, head case 27 , and limit switch 32
It is composed of. The core 22 and the bobbin 2
4 and the protection piece 25 are arranged so as to be able to slide slightly in the front and rear directions with respect to the head case 27, and the actuator 32 of the limit switch 32 is in elastic contact with the rear end of the core 22. Note that the limit switch 32 is connected to the head case 27.
Fixed.

This degaussing head section 21 is rotatably attached to the tip of an elongated arm 26. The arm 26 is made by overlapping an upper arm 26a and a lower arm 26b, which have the same shape, and is made of transparent synthetic resin. The presence or absence of this can be visually checked.

As shown in FIGS. 2 and 4, an arm accommodating recess 28 is formed in the center of the case 11 from the rear toward the front, and the arm 26 is accommodated here. An elongated slide groove 29 corresponding to the sliding length of the arm 26 (demagnetizing head section 21) is bored at the bottom of the housing recess 28, while the upper arm 26a and the lower arm 26b have grooves 29 as shown in FIG. A retaining portion 30 that engages with this slide groove 29 is provided. A finger hook 31 for sliding is formed on the surface of the arm 26.

FIG. 2 shows a state in which the arm 26 is accommodated in the accommodation recess 28 of the case 11. As shown in FIG. In this state, the demagnetizing head section 21 is located 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 portion 21, and the core 22, bobbin 23, coil 24, and protective piece 25 are moved back to close the limit switch 32.

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

FIGS. 3 to 5 are diagrams for explaining other ways of using this demagnetizer. In this case, as shown in FIG. 3, when the arm 26 is pinched with the fingers 34 and pushed forward, the demagnetizing head 21 also moves together, and then the demagnetizing head 21 is moved onto the arm 26 as shown in FIG. Rotate 90 degrees and stand up. Then, by holding the case 11 and pressing the degaussing head 21 against the peripheral surface of the capstan 35 to be demagnetized, the core 22 and other integral parts are retracted, the limit switch 32 is closed, and demagnetization is performed in the same manner as described above. .

Although not shown, the case 11 and the arm 26 are used to maintain the position when the arm 26 is in the storage position, when it has been slid forward by a predetermined distance from that position, and when the degaussing head 21 is rotated. between the arm 26 and the degaussing head 2
A moderation imparting means is provided between 1 and 1.

In the above embodiment, the arm 26 and the degaussing head section 21
The degaussing head section 21 is separated from the arm 26.
Although we have explained the case where the core 22, the bobbin 23,
It is also possible to house the degaussing head, which is an integral part of the coil 24 and the protective piece 25, together with the limit switch 32.

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 with terminals may be used. In addition, in the example, a limit switch was placed inside the arm, but
These may be provided inside the case, and the limit switch may be manually operated.

〔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 slid to project the degaussing head from the case, and the case can be held to demagnetize it.
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.

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 the drawing]

Figure 1 is a perspective view of a previously proposed demagnetizer;
The figure is a plan view of a demagnetizer according to an embodiment of the present invention.
Figures 4 and 5 are sectional views, perspective views, and 6
The figure is a block diagram of a degaussing signal generating circuit used in a degaussing device. 11... Case, 12... Degaussing signal generation circuit,
13...Battery, 21...Degaussing head section, 26...
Arm, 34...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 having a tip at the tip is slidably attached to the case, and when the arm is in the case storage position, the degaussing head section is placed in the magnetic head insertion position of the case, and the arm is in the slidable position. A degaussing device characterized in that the degaussing head is configured to project away from the case via the arm when the degaussing head is in position.