JP2519571Y2 - Information recording disk clamp device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an information recording disk clamp device.

[Conventional technology]

Conventionally, a turntable, a ferromagnetic housing arranged in the center of the turntable, and an annular magnet embedded in the housing and having a part of the surface exposed are attached to a holder in contact with an information recording disk. There is also known an information recording disk clamp device that clamps the information recording disk between the holder and the turntable when a ferromagnetic plate is attracted by the magnet.

Fig. 2 shows a conventional information recording disk clamp device, or CD-R.
The front view of the motor for OM drive shows the right half section. Third
The figure is a cross-sectional view of the information disk clamping device with the information recording disk mounted on the clamping device. 3 in FIG.
Is a turntable, 4 is an annular magnet arranged coaxially with the turntable 3. 5 is a magnet housing made of iron,
It constitutes a part of the magnetic circuit that passes the magnetic lines of force of the magnet 4,
The magnet 4 is exposed in the upper part of the drawing. An information recording disk 10 is placed on the turntable 3. 12
Is connected to the holder 11 by an iron plate and is attracted by the magnet 4 so that the holder 11 attaches the information recording disk 10 to the turntable 3. The information recording disk 10, the holder 11, and the iron plate 12 are contained in the same case.

[Problems to be solved by the device]

In the above-mentioned conventional information recording disk clamp device, the magnetic flux emitted from the portion 14 of the surface of the magnet 4 facing the iron plate 12 adjacent to the magnet housing 5 does not go to the iron plate 12, and the magnetic resistance is relatively large due to the distance. There is a problem that the magnet 4 enters the low housing 5, and therefore the attraction force of the magnet 4 to the iron plate 12 is weak.

An object of the present invention is to increase the attractive force of the magnet 4 and the iron plate 12 without increasing the number of magnetized magnetic poles, changing the magnet material, or increasing the magnet volume.

[Means and Actions for Solving the Problems]

In order to achieve the above object, in the information recording disk clamping device of the present invention, the annular magnet 4 of the magnet housing 5 is used.
By providing a notch in the portion in contact with the magnet 4 to increase the magnetic resistance to the magnet 4 in this portion, the magnetic flux emitted from the adjacent portion 14 of the magnet 4 is directed to the iron plate 12, thereby attracting the magnet 4 and the iron plate 12. Increasing power.

That is, a turntable, a ferromagnetic housing arranged in the center of the turntable, and an annular magnet embedded in the housing and having a part of the surface exposed are attached to a holder in contact with an information recording disk. In an information recording disk clamp device that clamps the information recording disk between the holder and the turntable when a ferromagnetic plate is attracted by the magnet, the magnetic flux generated from the first magnetic pole of the magnet. The first and second magnetic poles of the magnet on the exposed surface of the magnet such that a magnetic circuit is formed by passing through the ferromagnetic plate into the second magnetic pole of the magnet. Provided is an information recording disk clamping device, which is provided, is adjacent to the magnet, and is provided with an annular notch at an end portion of the housing on the exposed surface side of the magnet. It is.

〔Example〕

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

FIG. 1 shows a front sectional view of an information recording disk clamping device in which an information recording disk (CD-ROM) housed in a case (not shown) is placed. Since this information recording disk clamp device is a rotating body, the right cross section is omitted.

In FIG. 1, 3 is a turntable, which is an information recording disk.
Since 10 is placed and connected to a motor (not shown) about the shaft 8, it can rotate at a predetermined speed. A magnet housing 5 is attached to the shaft 8 together with the turntable 3. An annular magnet 4 is embedded in the annular magnet housing 5 on the upper side of the turntable 3 in the drawing with the upper side of the drawing exposed. Information recording disk
When 10 is placed on the turntable 3, the holder 11 housed in the same case (not shown) as the information recording disk 10
It is placed in a state of overlapping. Then, the iron plate (adsorption plate) 12 coupled to the holder 11 is arranged so as to face the magnet 4. Therefore, the magnetic flux of the magnet 4 forms a magnetic circuit through the iron plate 12 and attracts the iron plate 12. As a result, the information recording disk 10 is held by the holder 11 and the turntable 3.

The annular magnet 4 is magnetized so that the magnetic poles are formed at positions opposite to each other by 180 °. Therefore, when the iron plate 12 is attracted, the magnetic flux emitted from the upper portion of one of the first magnetic poles in the drawing enters the iron plate 12 and passes through it to the other pole (second magnetic pole) near the position opposite by 180 °. enter. As a result, a magnetic circuit is formed and the iron plate 12 is attracted. On the other hand, of the magnetic flux emitted from the first magnetic pole of the magnet 4, the magnetic flux emitted from the lower part of the drawing is the magnetic flux emitted from the surface contacting the magnet housing 5
A magnetic circuit is formed by passing through and entering the other pole (second pole).

Reference numeral 13 denotes an annular notch provided in the magnet housing, so that when there is no notch 13, the magnetic flux contained in the magnet housing 5 on the upper surface (in the drawing) of the magnet 4 enters the iron plate 12 due to the distance. become. Therefore, the iron plate of the magnet 4
The suction power for 12 increases.

[Effect of device]

As described above, the information recording disk clamp device of the present invention has the feature that it is possible to use the same magnet as the conventional one, and a magnet made of a cheap material can be used in order to efficiently extract the attractive force to the iron plate by the same magnetization method. . Further, since a magnet using a cheap material generally has a small energy product, it has a feature that it can be easily magnetized and the life of a magnetizing yoke used for magnetizing is extended.

[Brief description of drawings]

FIG. 1 is a front sectional view in which the right half of the information recording disk clamp device of one embodiment of the present invention is omitted, showing a state in which an information recording disk is placed, and FIG. 2 is a conventional information recording disk clamp. FIG. 3 is a front sectional view of the right side of the apparatus, and FIG.
It is a figure which shows the state which mounted the information recording disc. 3 ... Turntable, 4 ... Magnet, 5 ... Magnet housing, 8 ... Shaft, 10 ... Information recording disk, 11 ... Holder, 12 ... Iron plate, 13 ... Notch, 14 ... Adjacent part.

Claims (1)

(57) [Scope of utility model registration request] 1. A holder having a turntable, a ferromagnetic housing arranged in the central portion of the turntable, and an annular magnet embedded in the housing and having a part of the surface exposed, in a holder contacting an information recording disk. An information recording disk clamp device for sandwiching the information recording disk between the holder and the turntable by the attached ferromagnetic plate being attracted by the magnet, comprising: a first magnetic pole of the magnet; The first magnetic pole and the second magnetic pole of the magnet expose the magnet so that the generated magnetic flux passes through the ferromagnetic plate and enters the second magnetic pole of the magnet to form a magnetic circuit. An information recording disk clamping device, which is provided on the above-mentioned surface, is adjacent to the magnet, and is provided with an annular notch at an end portion of the housing on the exposed surface side of the magnet. .