JP2004054996A - Magnetic recording device and magnetic recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording device having a unsealing detection function which surely detects unsealing of an enclosure and making a person trying to open the enclosure cannot easily prevent the detection of unsealing of the enclosure. <P>SOLUTION: The magnetic recording device 1 has a magnetic disk 10 which has a magnetic layer 12 on a substrate 11 and a magnetic head 4 which performs recording and reproducing of various kinds of information to the magnetic layer 12 of the magnetic disk 10; an enclosure 2 housing the magnetic head 4 and the magnetic disk 10; and an unsealing detection sensor 9 disposed in the enclosure 2. In the enclosure 2, a prescribed gas G which is not contained or contained a little in the air is enclosed and the unsealing detection sensor 9 can detect a variation of the concentration of the prescribed gas G in the enclosure 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic recording device provided with a magnetic recording medium having a magnetic layer.
[0002]
[Prior art]
At present, various contents are installed in advance in terminal devices such as commercially available personal computers. Also, with the spread of telecommunication lines such as the Internet, users can obtain (download) desired contents via the telecommunication lines and easily use the obtained contents. On the other hand, as various contents are more easily and widely distributed, it is necessary to prevent illegal use of the contents and to strengthen copyright protection.
[0003]
Conventionally, in order to prevent unauthorized use of content, it has been practiced to limit the unauthorized use of content by setting an ID number, a password, and the like. However, if the legitimate contractor leaks the ID number or password to a third party, the third party can easily use the content illegally. For this reason, as a new measure for preventing unauthorized use of content, an ID number or the like is embedded in the recording medium itself for recording content, and a release key ( There has been proposed a system that permits use of content by acquiring or creating a content key).
[0004]
[Problems to be solved by the invention]
However, it is not very difficult for a person having specialized knowledge or technology to disassemble the hard disk device or the like, read the recorded content of the recording medium with a magnetic head, perform signal processing, and steal the ID. In light of this, in order to protect the rights of the content provider and to promote the distribution of content via the Internet, etc., it is necessary to use any means to open the content from the magnetic recording medium when the housing is opened. It is considered effective to disable reading of ID and ID. For this purpose, it is extremely important to reliably detect that the housing of the hard disk device or the like has been opened.
[0005]
Here, some magnetic recording devices such as hard disk devices are provided with a limit switch which is turned on when the housing is opened. In such a magnetic recording device, it is possible to disable reading of contents, IDs, and the like from the magnetic recording medium by some means when the housing is opened and the limit switch is turned on. However, once the location of the limit switch is known, it is possible to open the housing so that the limit switch is not turned on. In order to prevent the use more reliably, there is a problem in terms of effectiveness. Further, in the case of a mass-produced magnetic recording apparatus, it is not practical to change the position of the limit switch for each individual device in terms of manufacturing cost and manufacturing efficiency.
[0006]
Therefore, the present invention provides a magnetic recording apparatus having an opening detection function capable of reliably detecting the opening of a housing, and in which a person trying to open the housing cannot easily prevent the detection of opening of the housing. The purpose is to provide.
[0007]
[Means for Solving the Problems]
A magnetic recording device according to the present invention is a magnetic recording device comprising: a magnetic recording medium having a magnetic layer on a substrate; and a magnetic head for recording and reproducing various information on and from the magnetic layer of the magnetic recording medium. And a sensor disposed in the housing, the housing has a small content in the air, or a predetermined gas not contained in the air is sealed, The sensor is capable of detecting a change in concentration of a predetermined gas inside the housing.
[0008]
In this magnetic recording apparatus, a predetermined gas that is low in the air content or not contained in the air is sealed in a housing that houses the magnetic recording medium. Therefore, when a person or the like having specialized knowledge or technology tries to illegally read the recorded content of the magnetic recording medium and opens the housing, ambient air immediately flows into the housing. Thereby, the concentration of the predetermined gas inside the housing changes, and the opening of the housing is reliably detected by the sensor that detects the change in the concentration. Also, in this magnetic recording device, no matter where the housing is opened, once the housing is opened, air always flows into the housing and the concentration of the predetermined gas inside the housing changes. Therefore, it is extremely difficult for a person who attempts to open the housing to prevent the sensor from detecting the opening of the housing.
[0009]
As a result, according to this magnetic recording apparatus, when the opening of the housing is detected by the sensor, the reading of the content, the ID, and the like from the magnetic recording medium is disabled by any means, thereby preventing the illegal use of the content and the like. It can be prevented very reliably.
[0010]
Further, it is preferable that the airtight chamber is provided inside the housing and further contains a magnetic recording medium and a magnetic head, and air is sealed in the airtight chamber.
[0011]
In general, a magnetic recording apparatus is designed such that a gap (flying height of a magnetic head) between a magnetic head and a magnetic layer is about several nm in air when recording / reproducing is performed. It is extremely important to keep the gap between the magnetic head and the magnetic layer substantially constant in order to stabilize the recording / reproducing performance. On the other hand, when the gas existing around the magnetic head and the recording medium is other than air, the gap between the magnetic head and the magnetic layer changes from the gap in air, and the desired recording / reproducing performance is improved. In order to achieve this, it is necessary to review the design related to the magnetic head and the magnetic recording medium.
[0012]
In view of this point, in this magnetic recording apparatus, an airtight chamber for housing the magnetic recording medium and the magnetic head is provided inside the housing, and air is sealed inside the airtight chamber. This makes it possible to make the conditions inside the airtight chamber the same as those inside the housing of a general magnetic recording device, and the magnetic head and the magnetic head designed to operate in air. The recording medium can be used as it is.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a magnetic recording apparatus according to the present invention will be described in detail with reference to the drawings.
[0014]
FIG. 1 is a schematic configuration diagram showing a magnetic recording device according to the present invention. The magnetic recording device 1 shown in FIG. 1 is applicable to various uses including an external storage device for a computer (hard disk device). As shown in FIG. 1, the magnetic recording device 1 has a housing 2, and a magnetic disk (magnetic recording medium) 10 is housed inside the housing 2.
[0015]
The magnetic disk 10 includes a disk-shaped substrate 11 made of resin such as aluminum, glass, or plastic. On substantially the entire surface (the upper surface in FIG. 2) of the substrate 11, a magnetic layer 12 capable of recording various information such as various contents and IDs necessary for using the contents is formed in an annular shape. On the magnetic layer 12, a lubricating layer 14 is formed by a spin coater. Such a magnetic disk 10 is mounted on a rotating shaft 3a of a spindle motor 3, and is driven to rotate at a desired speed by the spindle motor 3.
[0016]
A magnetic head (slider) 4 for reading / writing information from / on a magnetic disk 10 and a head arm (suspension) 5 for supporting the magnetic head 4 are provided at the tip of the housing 2. I have. The head arm 5 is turned by a voice coil motor (actuator) 6, whereby the magnetic head 4 is positioned on a desired track of the magnetic disk 10. Further, a circuit board 7 on which a control circuit for controlling reading / writing by the magnetic head 4, operation of the spindle motor 3, operation of the voice coil motor 6, and the like is mounted inside the housing 2. ing. A lamp (not shown) for evacuating the magnetic head 4 when the rotation of the disk is stopped is disposed on the side of the magnetic disk 10 in the housing 2.
[0017]
FIG. 2 is a cross-sectional view for explaining the structure of the housing 2 included in the magnetic recording device 1 described above. As shown in FIG. 2, the housing 2 includes an upper half portion 2a and a lower half portion 2b formed of a material that melts when heat is applied. One of the upper half portion 2a and the lower half portion 2b (the upper half portion 2a in the present embodiment) has no opening or the like except for an open portion (the lower open portion in FIG. 2). Absent. On the other hand, the other of the upper half 2a and the lower half 2b (the lower half 2b in the present embodiment) is formed with a protruding portion 2c that defines a communication port with the outside. I have. The upper half part 2a and the lower half part 2b accommodate components such as the magnetic head 4 and the magnetic disk 10 inside the two parts, and the ends of both parts are attached to each other. It is arranged between V and the base body B and is strongly and densely ultrasonically welded.
[0018]
The upper half portion 2a and the lower half portion 2b which are tightly and tightly joined in a state in which the components such as the magnetic head 4 and the magnetic disk 10 are housed, that is, the inside of the housing 2 contains, for example, Ar in the air. A small amount of the predetermined gas G or a predetermined gas G not contained in the air, such as He, is sealed.
[0019]
When the gas G is sealed in the housing 2, first, the inside of the housing 2 is depressurized using the opening of the protrusion 2 c, and then the gas G is discharged from the protrusion 2 c into the housing 2. Introduce inside. Then, as shown in FIG. 3A, a plate 2h made of a material that generates heat when supplied with power such as tungsten, nickel, or chromium is arranged on the protrusion 2c, and a current is applied to the plate 2h. As a result, the protrusion 2c is melted by the heat of the plate 2h, and the protrusion 2c and the plate 2h are welded as shown in FIG. 3B. As a result, the housing 2 is completely sealed, and the gas G is sealed inside the housing 2.
[0020]
Further, an unsealing detection sensor 9 (see FIG. 1) capable of detecting a change in the concentration of the gas G inside the housing 2 is disposed inside the housing 2. The opening detection sensor 9 is connected to the circuit board 7 and, when detecting that the concentration of the gas G inside the housing 2 has changed by a predetermined amount from the concentration when the housing 2 is not opened, generates an opening detection signal. It is given to a predetermined switching circuit incorporated in the circuit board 7. When the switching circuit of the circuit board 7 receives the unsealing detection signal from the unsealing detection sensor 9, the switching circuit is disposed inside the housing 2, and activates the means for making the contents of the magnetic disk 10 unreadable. As means for making such content unreadable, a means for heating and demagnetizing the magnetic disk 10 to erase the content or a means for making the magnetic disk 10 shock or heat to make the content unreadable is employed. can do.
[0021]
Note that the opening detection sensor 9 may have any configuration and operation as long as it can detect a change in the concentration of the gas G inside the housing 2. That is, the opening detection sensor 9 may be a sensor that monitors the concentration of the gas G with sensitivity to the gas G sealed in the housing 2, and may detect a gas (for example, nitrogen) that is largely contained in the air. , Oxygen, etc.) to monitor the concentration of a gas such as nitrogen.
[0022]
Now, in the magnetic recording device 1 according to the present invention, as described above, the predetermined gas having a small content in the air or a predetermined gas not contained in the air is provided inside the housing 2 accommodating the magnetic disk 10. G is enclosed. Therefore, when a person or the like having specialized knowledge or technology attempts to illegally read the recorded contents of the magnetic disk 10 and opens the housing 2, the surrounding air immediately flows into the housing 2. As a result, the concentration of the gas G inside the housing 2 changes, and the opening of the housing 2 is reliably detected by the unsealing detection sensor 9 that detects the change in the concentration. In addition, in the magnetic recording device 1, no matter where the casing 2 is opened, once the casing 2 is opened, air always flows into the casing 2 and the gas G inside the casing 2 is removed. Since the concentration changes, it is extremely difficult for a person who intends to open the housing 2 to prevent the opening detection sensor 9 from detecting the opening of the housing 2.
[0023]
In the magnetic recording device 1, when the opening detection sensor 9 detects that the housing 2 has been opened, the means for disabling the reading of the content is activated. Becomes possible.
[0024]
In addition, since heat is generated during the recording / reproducing operation inside the magnetic recording device 1, at least one of the upper half portion 2a and the lower half portion 2b constituting the housing 2 is shown in FIG. It is preferable that the metal heat radiating member 20 be firmly and densely fixed. In the magnetic recording device 1A shown in FIG. 4, the lower half 2b is made of a metal plate and a heat-fusible material.
[0025]
FIG. 5 is a schematic configuration diagram showing still another embodiment of the magnetic recording apparatus according to the present invention. The same elements as those described in the above embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0026]
In the magnetic recording device 1 </ b> B shown in FIG. 5, a partition 30 is disposed inside the housing 2. The partition wall 30 accommodates, along with the bottom surface of the lower half 2b, components related to recording and reproduction of information such as the spindle motor 3, the magnetic head 4, the head arm 5, the voice coil motor 6, and the magnetic disk 10. A closed room 31 is defined. In the magnetic recording device 1B, the space defined between the housing 2 and the partition wall 30 is filled with a predetermined gas G having a small content in air or not contained in air. On the other hand, air is sealed in the airtight chamber 31 defined by the partition 30.
[0027]
The reason why such a configuration is preferable is as follows. That is, in general, a magnetic recording apparatus is designed such that a gap between a magnetic head and a magnetic layer is about several nm in air when recording / reproducing is performed. It is extremely important to keep the gap between the magnetic head and the magnetic layer substantially constant in order to stabilize the recording / reproducing performance. On the other hand, when the gas existing around the magnetic head and the recording medium is other than air, the gap between the magnetic head and the magnetic layer changes from the gap in air, and the desired recording / reproducing performance is improved. In order to achieve this, it is necessary to review the design related to the magnetic head and the magnetic recording medium.
[0028]
On the other hand, in the magnetic recording device 1B of FIG. 5, the inside of the airtight chamber 31 in which components related to recording and reproduction of information, such as the spindle motor 3, the magnetic head 4, the voice coil motor 6, and the magnetic disk 10, are accommodated. Is filled with air similarly to the inside of the housing of a general magnetic recording device. Therefore, various conditions inside the airtight chamber 31 can be made similar to those inside the housing of a general magnetic recording apparatus. As a result, in the magnetic recording apparatus 1B, the magnetic head 4 and the magnetic disk 10 designed on the assumption that they operate in the air can be used as they are.
[0029]
Of course, also in the magnetic recording device 1B, the space defined between the housing 2 and the partition 30 has a small content in air or a predetermined gas not contained in air. Since G is enclosed, if a person having specialized knowledge or technology opens the casing 2 to illegally read the recorded content of the magnetic disk, the surrounding air immediately flows into the casing 2. . As a result, the concentration of the gas G inside the housing 2 changes, and the opening of the housing 2 is reliably detected by the unsealing detection sensor 9 that detects the change in the concentration. Also in the magnetic recording device 1B, no matter where the casing 2 is opened, once the casing 2 is opened, air always flows into the casing 2 and the gas G inside the casing 2 is removed. Since the concentration changes, it is extremely difficult for a person who intends to open the housing 2 to prevent the opening detection sensor 9 from detecting the opening of the housing 2.
[0030]
【The invention's effect】
As described above, according to the present invention, an opening detection function capable of reliably detecting opening of a housing is provided, and a person who intends to open the housing can easily detect opening of the housing. It is possible to realize a magnetic recording device that cannot be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a magnetic recording device according to the present invention.
FIG. 2 is a cross-sectional view for explaining a structure of a housing included in the magnetic recording device of FIG.
FIGS. 3A and 3B are schematic views illustrating a structure for sealing a predetermined gas in a housing.
FIG. 4 is a schematic configuration diagram showing another embodiment of the magnetic recording device according to the present invention.
FIG. 5 is a schematic configuration diagram showing still another embodiment of the magnetic recording device according to the present invention.
[Explanation of symbols]
1, 1A, 1B Magnetic recording device 2 Case 2a Upper half 2b Lower half 2c Projection 2h Plate 3 Spindle motor 4 Magnetic head 5 Head arm 6 Voice coil motor 7 Circuit board 9 Opening detection sensor 10 Magnetic disk 11 Substrate 12 Magnetic layer 14 Lubricating layer 20 Heat radiating member 30 Partition wall 31 Airtight chamber G Gas

Claims (2)

In a magnetic recording device having a magnetic recording medium having a magnetic layer on a substrate, and a magnetic head for executing recording / reproducing of various information with respect to the magnetic layer of the magnetic recording medium,
A housing for housing the magnetic recording medium;
A sensor disposed in the housing,
The casing has a small content in the air or a predetermined gas not contained in the air is sealed, and the sensor detects a change in concentration of the predetermined gas inside the casing. A magnetic recording device characterized by being detectable. The airtight room which is provided in the inside of the above-mentioned case, and is provided with the above-mentioned magnetic recording medium and the above-mentioned magnetic head, and is enclosed, and the inside of the above-mentioned airtight room is enclosed, Air is enclosed, The above-mentioned. 2. The magnetic recording device according to 1.

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