JPH0454285B2 - - 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 adversely affects the recording and playback characteristics. Therefore, each component mentioned above must be demagnetized after each use for a certain period of time. 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 includes a degaussing signal generating circuit that generates an alternating voltage, a power supply unit that supplies power to the degaussing signal generating circuit, and an alternating voltage generated from the degaussing signal generating circuit in an alternating magnetic field. a degaussing head section consisting of at least one pair of cores and an excitation coil for converting the demagnetization signal into a degaussing signal generating circuit;
A degaussing unit consisting of, for example, an elongated unit having a substantially T-shaped planar shape that accommodates a power supply part and a degaussing head part is removably attached to, for example, a case body of the same standard as a Philips type compact cassette, and the degaussing unit is attached to the case body. The device is characterized in that, when attached to the main body, the demagnetizing head section is arranged at a demagnetizing head insertion position of the case main body.

[Embodiments of the invention]

Next, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 2, a unit storage recess 22 having a substantially T-shaped planar shape is formed on the upper surface of the case body 11, which has the same specifications as a Philips type compact cassette. The case body 11 is constructed by overlapping an upper case 11a and a lower case 11b molded from synthetic resin, and is provided with two penetrating drive shaft insertion holes 14 at predetermined positions.

The spool 23 corresponds to this drive shaft insertion hole 14.
are rotatably housed in the case body 11, and the magnetic head cleaning tape 25 fed out from one spool 23 is guided by a guide member 26.
is guided to the front of the case body 11 by the spool 23, and is wound onto the other spool 23.

A degaussing unit 24 is removably mounted in the unit storage recess 22.
This degaussing unit 24 includes a unit case 27 that is constructed by overlapping an elongated upper unit case 27a and a lower unit case 27b, each having a substantially T-shaped planar shape, and a damped alternating voltage that is accommodated in this unit case 27. A printed circuit board 28 on which a degaussing signal generating circuit 12 (see reference 4), a button-type battery 13 that supplies power to the degaussing signal generating circuit 12, and a light emitting diode 19 are mounted.
, limit switch 32 , and degaussing head section 21
It is mainly composed of.

As shown in FIG. 4, the demagnetizing signal generating circuit 12 and the battery 13 are arranged side by side, and the printed circuit board 28
The limit switch 32 and the degaussing head section 21 are arranged side by side on the central projecting section with the limit switch 32 in between.

FIG. 5 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 a transistor switch that is preset to turn on when the input voltage V ₂ reaches a set voltage _{V 3} C (for example, about 16V). do.
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 1
6 to completely separate the DC-DC converter 15 and capacitor 17, and connect the output voltage _V2 of the DC-DC converter 15 to the light emitting diode 19.
The voltage is lowered to a level low enough to cause the battery 13 to emit light and 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 the demagnetizing head section 21 and converted into an attenuated alternating magnetic field.

As shown in FIG. 4, the demagnetizing head section 21 includes a core 22 made of sintered ferrite or a laminate of silicon steel plates, a bobbin 30 made of synthetic resin, and a bobbin 30 made of synthetic resin.
A coil 31 is wound around it for a predetermined number of turns, and a protective piece 34 made of soft synthetic resin is placed on the front side.
It is composed of. This degaussing head section 21 is slidably disposed at the tip of the central projecting section of the unit case 27, and an actuator 33 of a limit switch 32 is in elastic contact with the rear end.

FIG. 3 shows that the degaussing unit 24 is connected to the case body 11.
It shows the state accommodated in the accommodation recess 22 of. In this state, the demagnetizing head section 21 is located at the magnetic head insertion position of the case body 11.

When the demagnetizer in this state is attached to a cassette type tape recorder and the play button is pressed, the magnetic head moves to the magnetic head insertion position in the case body 11. With this movement, the head surface of the magnetic head comes into contact with the front surface of the magnetic head section 21 via the cleaning tape 25, and the degaussing head section 21 retreats 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.

Further, by pressing the play button, the spool 23 rotates, thereby moving the cleaning tape 25 and cleaning the magnetic head at the same time as demagnetization.

When demagnetizing components other than the magnetic head of a cassette tape recorder, the demagnetizing unit 24 is taken out from the case body 11, the unit case 27 is held, and the demagnetizing head portion 21 is brought into pressure contact with the peripheral surface of, for example, a capstan 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 a battery was used as the power source in the above embodiment, the power source is not limited to these, and for example, a large-capacity capacitor provided with a terminal portion for charging and supplying power from the outside may be used.

In the above embodiment, a degaussing unit having a T-shaped planar shape was used, but an L-shaped planar shape may also be used.

〔Effect of the invention〕

The present invention is constructed as described above, and when degaussing a capstan or other type of tape recorder, the degaussing unit is removed from the case body and the degaussing signal generating circuit, power supply unit, degaussing head unit, etc. are housed. It can be demagnetized by holding a relatively large unit case. 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;
3 and 3 are a perspective view and a plan view of a degaussing device according to an embodiment of the present invention, FIG. 4 is a plan view of a degaussing unit used in the demagnetizing device with the upper unit case removed, and FIG. FIG. 2 is a block diagram of a degaussing signal generation circuit used in a degaussing device. 11... Case, 12... Degaussing signal generation circuit,
13... Battery, 21... Demagnetizing head section, 22...
Unit housing recess, 24... degaussing unit, 27
...Unit case.

Claims (1)

[Claims] 1. A degaussing signal generation circuit that generates an alternating voltage, a power supply unit that supplies power to the demagnetization signal generation circuit,
A degaussing unit consisting of a degaussing head section that converts the alternating voltage generated from the degaussing signal generating circuit into an alternating magnetic field, and a unit case housing the degaussing signal generating circuit, the power supply section, and the demagnetizing head section is removably attached to the case body. 1. A degaussing device characterized in that when the degaussing unit is attached to a case body, the degaussing head section is arranged at a magnetic head insertion position of the degaussing case body.