JPH053647B2 - - 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 degausser can easily degauss the magnetic head of a cassette tape recorder, but it cannot degauss anything other than the magnetic head, such as a capstan, and it can also be used with different types of tape recorders such as open reel type or endless type, or with the same cassette. Even standard tape recorders lack versatility, as they cannot be applied to devices of different sizes.

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 forms a degaussing head section that converts an alternating voltage into an alternating magnetic field as a separate member from the case, and allows the degaussing head section to be freely attached to and removed from a plurality of positions including the magnetic head insertion position of the case. The present invention is characterized in that the degaussing head is electrically connected to the degaussing signal generating circuit provided in the case when the degaussing head is installed in such a removable position.

[Embodiments of the invention]

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

Fig. 2 is a perspective view of a demagnetizer according to an embodiment of the present invention, Fig. 3 is a plan view of the demagnetizer with the upper case removed, and Fig. 4 is a degaussing signal generation used in the demagnetizer. FIG. 5 is an exploded perspective view of the demagnetizing head portion of the demagnetizer, and FIG. 6 is a side view showing an example of how the demagnetizer shown in FIG. 2 is used.

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 an upper case 11a molded from synthetic resin.
The drive shaft insertion hole 14 is formed by overlapping the lower case 11b and the lower case 11b.
There are one.

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 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 an automatic 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 FIGS. 3 and 5, the degaussing head section 21 includes a core 22 made of sintered ferrite, a laminate of silicon steel plates, etc., a bobbin 23 made of synthetic resin, and a bobbin 23 wound around it by a predetermined number of turns. It consists of a coil 24 and a protective piece 25 made of soft synthetic resin placed on the front side.

The degaussing head section 21 is slidably provided at the tip of a head case 26 whose front surface is open, and the protective piece 25 is in a state of protruding from the front surface of the head case 26. The head case 26 is the fifth
The upper case 26 has almost the same shape as shown in the figure.
A and a lower case 26b are stacked on top of each other, and a plurality of partition walls 27 are provided protruding from the rear end inside the head case 26. A board 28 is positioned within these partition walls 27, and a limit switch 29 is mounted on the board 28, the actuator 30 of which is in contact with the rear end surface of the core 22. Further, a plurality of plugs 31 for connecting terminals to be connected to the demagnetizing head section 21 and the limit switch 29 are attached to the back surface of the board 28, and these demagnetizing head section 21, the board 28, the limit switch 29, and the plugs 31 are connected to the upper case 26a. and the lower case 26b so as not to shake.

On the other hand, at the magnetic head insertion position of the case 11 and at the rear center of the upper case 11a, there is a head insertion chamber 3 into which a head case 26 is fitted, as shown in FIG.
2 and 33 are formed respectively, and a plurality of jacks 34 and 35 for connecting terminals to be connected to the output side terminal of the degaussing signal generating circuit 12 are respectively faced to both the head insertion chambers 32 and 33. The head case 26 can be freely inserted into and removed from both head insertion chambers 32 and 33.
When the plug 31 on the head case 26 side is inserted into the head insertion chambers 32 and 33 to the rearmost end, the plug 31 on the head case 26 side is inserted into the case 1.
The degaussing head section 21 is connected to the jack 33 or 34 on the 1 side, thereby causing the degaussing head section 21 to be connected to the degaussing signal generating circuit 12.
connected to. A colored transparent plate 36 is fixed to the center of the upper case 11a, and the light from the light emitting diode 19 is emitted to the outside of the case 11 through the transparent plate 36.

Next, a method of using the thus configured demagnetizer will be described.

First, when demagnetizing the magnetic head, the third
As shown in the figure, the head case 26 is inserted into the head insertion chamber 32 on the front side of the case 11, and in this state, the demagnetizer is attached to the cassette type tape recorder and the play button is pressed. Then, the magnetic head moves to the magnetic head insertion position of the case 11, and as a result, the head surface of the magnetic head presses the protective piece 25 of the degaussing head section 21 inward to the head case 26, and the actuator 30 moves to the core as described above. Limit switch 29 driven by 22
contacts are closed. Based on this operation, an attenuated alternating voltage is generated from the demagnetizing signal generating circuit 12, and this voltage is applied to the demagnetizing head section 21 and converted into an attenuating alternating magnetic field, thereby demagnetizing the magnetic head.

When demagnetizing parts other than the magnetic head of a cassette tape recorder, such as the capstan, insert the head case 26 into the head insertion chamber 33 at the rear of the upper surface of the case 11 as shown in FIG. The protective piece 25 of the degaussing head section 21 is pressed against the circumferential surface of the capstan 37. This operation causes the protective piece 25 of the degaussing head section 21 to
is moved inside the head case 26, and the demagnetizing head section 21 applies an attenuating alternating magnetic field necessary for demagnetization to the capstan 37 in the same manner as described above, and demagnetization is completed.

In addition, in the above embodiment, the head insertion chambers 32 and 33
The magnetic head insertion position of case 11 and upper case 1
Although the head insertion chamber 33 provided at the rear center position of the upper case 11a has been described, the location of the head insertion chamber 33 provided at the rear center position of the upper case 11a is not limited to the above embodiment. It may be provided at either the left or right end, or may be provided at a plurality of positions depending on the case.

Further, the means for connecting the degaussing signal generating circuit 12 on the case 11 side and the degaussing head section 21 on the head case 26 side is not limited to the plug 31 and jacks 34, 35 as in the above embodiment, but is simply connected to the case 26. The electrical connection may be established by contacting the connection terminal on the head case 26 side with the connection terminal on the head case 26 side.

In addition, in order to easily and reliably attach and detach the head case 26 to and from the case 11, appropriate guide means are provided at the contact portion between the two, for example, a guide groove is provided on the case 11 side, and a guide that can fit into the guide groove is provided on the head case 26 side. A protrusion may be provided.

Further, the light emitting diode 19 may be attached to the head case 26 side instead of the case 11 side.

Further, the power supply unit that supplies power to the degaussing signal generation circuit 12 is not limited to the battery 13 as in the above embodiment, but may instead be a large-capacity capacitor equipped with a terminal unit that is charged and supplied from the outside. But it's okay.

Furthermore, although the above embodiments have been described as being applied to a Philips type compact cassette, the present invention can also be applied to other endless type cassettes, micro cassettes, and other cassettes of different sizes.

〔Effect of the invention〕

As described above, the present invention includes a case provided with a degaussing signal generating circuit that generates an alternating voltage inside, a power supply unit that supplies power to the degaussing signal generating circuit, and a connecting terminal that converts the alternating voltage into an alternating magnetic field. In the demagnetizer consisting of a degaussing head section, connecting terminals are formed at multiple positions of the case, including the magnetic head insertion position, to be electrically and detachably connected to the connecting terminals of the degaussing head section. When degaussing a type of tape recorder, the degaussing head section is attached to the case at a location other than the magnetic head insertion position, and the case can be degaussed by holding 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;
FIG. 3 is a perspective view of a demagnetizer according to an embodiment of the present invention, FIG. 3 is a plan view of the demagnetizer with the upper case removed, and FIG. 4 is a degaussing signal generation used in the demagnetizer of the present invention. Block diagram showing an example of the circuit, No. 5
This figure is an exploded perspective view of the degaussing head portion of the demagnetizer shown in FIG. 2, and FIG. 6 is a side view showing an example of the mode of use of the demagnetizer shown in FIG. 2. 11... Case, 12... Degaussing signal generation circuit,
13...Battery, 21...Degaussing head section, 26...
Head case, 31...Plug, 32, 33...
Head insertion room, 34, 35...jack.

Claims (1)

[Claims] 1 Consists of a case equipped with a degaussing signal generation circuit that generates an alternating voltage inside, a power supply section that supplies power to the degaussing signal generation circuit, and a degaussing head section that has a connection terminal and converts the alternating voltage into an alternating magnetic field. A degaussing device characterized in that connection terminals electrically and detachably connected to connection terminals of the degaussing head portion are formed at a plurality of positions of the case including a magnetic head insertion position.