JP2001093254A - Recording medium housing member, recording disk and recording medium rotary-driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording medium housing member having an improved shape to enhance the rotational performance of a recording medium during the rotary-driving of the recording medium, a recording disk, and a recording medium rotary-driving device. SOLUTION: A projecting part 4a is provided in an inner surface of an upper cartridge case 4 opposite the recording medium 2. A plurality of such projecting parts 4a are provided radially so as to obliquely intersect a rotational circumferential direction (arrow direction A in Fig. 1) of the recording medium 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium storage member, a recording disk, and a recording medium rotation drive device.
More specifically, the present invention relates to a recording medium accommodating member, a recording disk, and a recording medium rotation driving device for improving the rotational performance of the recording medium when the recording medium is rotationally driven.

[0002]

2. Description of the Related Art CDs, FDs, MDs and the like are known as media used for recording or reproducing various information. The recording medium itself is used for the CD, and the recording medium for the FD and MD is housed inside the recording medium housing member. Hereinafter, in this specification, a recording medium accommodated in a recording medium accommodation member is referred to as a recording disk.

[0003] These CDs and recording disks read recorded information and write information under high-speed rotation conditions by a recording medium rotation drive device. Further, in order to cope with the recent increase in the density of information, further higher-speed rotation of the recording medium is desired.

With reference to FIG. 4, a general structure of a conventional recording disk will be described. The recording disk 20 has a disk-shaped recording medium 2, and the recording medium 2 is housed by an upper case 4 and a lower case 6 so as to be sandwiched from above and below.

When writing information on the recording medium 2 or
At the time of reading information from the recording medium 2, a recording medium rotation driving device (not shown) on which the recording disk 20 is set.
The purpose is realized by rotating the recording medium 2 at a high speed by the rotating shaft 100 provided in the recording medium 2.

[0006]

As described above, when writing information to the recording medium 2 or reading information from the recording medium 2, the recording medium 2 is rotated at a high speed.
At this time, an air flow is generated based on the rotation of the recording medium 2.

Here, ideally, as shown in FIG. 5A, the distance (H0) from the front side of the recording medium 2 to the upper case 4 and the distance (H0) from the rear side of the recording medium 2 to the lower case 6 Are equal to each other (here, the shape of the space formed by the front side of the recording medium 2 and the upper case 4, and the space formed by the back side of the recording medium 2 and the lower case 6). Is equal to the shape of the space)
A flow velocity diagram U at a point P1 on the surface side of the recording medium 2;
The flow velocity diagram L at a point P2 on the back surface side of the recording medium 2 has a symmetric shape with the recording medium 2 interposed therebetween. This can be said to be the same at any point of the recording medium 2.

Therefore, the pressure on the surface of the recording medium 2 obtained based on the flow velocity diagram decreases as shown in FIG. 5B from the end of the recording medium 2 toward the center of rotation. Pressure S1 on the front side and pressure S2 on the back side
Means that the locus of the same pressure line is drawn. as a result,
Since the pressures generated on the front side and the back side of the recording medium 2 are balanced at any point, the high-speed rotation of the recording medium 2 can be stabilized.

However, in reality, as shown in FIG. 6A, the distance (H0-dh) from the front side of the recording medium 2 to the upper case 4 and the distance from the back side of the recording medium 2 to the lower case 4 6 (H0 + dh) in most cases (here, the surface side of the recording medium 2 and the upper case 4).
And the shape of the space formed by the back side of the recording medium 2 and the lower case 6 is different).

Therefore, the flow velocity diagram U at the point P1 on the front surface side of the recording medium 2 and the flow velocity diagram L at the point P2 on the rear surface side of the recording medium 2 have different shapes with the recording medium 2 interposed therebetween. . As a result, the pressure S2 on the back surface of the recording medium 2 is larger than the pressure S1 on the front surface of the recording medium 2 as shown in FIG. As a result, the flow of air based on the rotation of the recording medium 2 amplifies the instability of vibration generated when the recording medium 2 rotates at high speed. Thus, it can be confirmed that the occurrence of the unstable vibration of the recording medium 2 depends on the internal shape of the case accommodating the recording medium 2.

[0011] In addition, in the recent demand for higher speed rotation of the recording medium 2, as shown in FIG. 7, as the number of rotations of the recording medium 2 increases, the front side and the back side of the recording medium 2 change. The pressure difference between the two increases significantly, and it is important to solve this problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above-mentioned problems, and it is possible to prevent amplification of unstable vibration of a recording medium when the recording medium is rotationally driven, thereby improving the rotational performance of the recording medium. An object of the present invention is to provide a recording medium housing member, a recording disk, and a recording medium rotation drive device in which the shape of the recording medium housing member that can be improved is improved.

[0013]

A recording medium accommodating member according to the present invention is a recording medium accommodating member for accommodating a disk-shaped recording medium in a rotatable manner. In the area facing the medium,
A protrusion is provided on at least one of the front side and the back side of the recording medium on the inner surface of the recording medium housing member.

Preferably, the projections are provided radially so as to cross obliquely with respect to the circumferential direction of rotation of the recording medium.

By providing the convex portion on the inner surface of the recording medium accommodating member as described above, the air flow between the recording medium accommodating portion and the recording medium is adjusted, and the air flow on the front surface side of the recording medium and the back surface side are adjusted. And the difference between the pressure on the front side and the pressure on the back side of the recording medium is reduced. As a result, it is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated when the recording medium rotates at high speed.

A recording disk according to the present invention is a recording disk having a disk-shaped recording medium,
The recording medium accommodation member is used to accommodate the recording medium.

In a recording medium rotation driving device according to the present invention, a recording medium rotation driving device for rotationally driving a disk-shaped recording medium, wherein the recording medium accommodating member is provided as a rotation driving portion of the recording medium. Have.

Thus, the flow of air between the recording medium accommodating portion and the recording medium is adjusted, so that the air flow on the front side of the recording medium is equal to the air flow on the back side of the recording medium. And the pressure on the back side are reduced. Therefore, it is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated at the time of high-speed rotation of the recording medium. As a result, it is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated when the recording medium rotates at high speed.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a recording medium accommodating member, a recording disk, and a recording medium rotating drive device according to an embodiment of the present invention. In the following description, the recording medium housing member is
This is provided to protect the recording medium, and in this embodiment, is referred to as a cartridge case for convenience.
The recording disk has a structure in which a recording medium is housed in a cartridge case, and generally includes an FD,
It has a structure like MD.

<Structure of Recording Disk 10> Next, the structure of the recording disk 10 according to the present embodiment will be described with reference to FIGS. FIG. 1 is an inner view of the upper cartridge case 4 of the recording disk 10.
FIG. 2 is a cross-sectional view taken along the line XX ′ in FIG. The recording disk 10 according to the present embodiment has a disk-shaped recording medium 2 as in the related art, and the recording medium 2 is accommodated by the upper cartridge case 4 and the lower cartridge case 6 so as to be sandwiched from above and below. ing.

At the time of writing a record to the recording medium 2 or reading information from the recording medium 2, as in the conventional case,
The object is realized by rotating the recording medium 2 at a high speed by a rotating shaft 100 provided in a recording medium rotation driving device (not shown) on which the recording disk 10A is set.

Here, as shown in FIG. 1, a projection 4a is provided on the inner surface of the upper cartridge case 4 facing the recording medium 2 in the present embodiment. A plurality of specific shapes of the projections 4a are provided radially so as to cross obliquely with respect to the rotational circumferential direction of the recording medium 2 (the direction of arrow A in FIG. 1). Generally, since the upper cartridge case 4 is provided with a window 4b,
The projection 4a is not provided in this portion.

<Simulation Result> FIG. 3 shows a simulation result of the air flow on the back side and the front side of the recording medium 2. The simulation results shown in FIG. 3 indicate that the height (h) of the convex portion 4a is 0.4 mm and the width (W1)
1.5 mm, arc radius (R) 30 mm, recording medium 2
Of the upper cartridge case 4 is 56.5 mm, the size (L2) is 59.5 mm, and the window 4c is The opening width (W) is 18.7 mm, the diameter of the recording medium 2 is 2 inches, the distance from the back side of the recording medium 2 to the lower cartridge case 6 is 0.95 mm, and the upper side cartridge from the front side of the recording medium 2 is 0.95 mm. The distance to Case 4 is 0.85 mm, and the rotation speed of the recording medium 2 is 7000 rpm.
1 shows the flow of air under the condition of (1).

<Operation / Effect> In consideration of this simulation result, the recording medium between the upper cartridge case 4 and the recording medium 2 can be provided by providing the convex portion 4a having the above-mentioned shape with the high-speed rotation of the recording medium 2. 2, the flow direction of the air flowing along the high-speed rotation direction is returned to the inside by the convex portion 4a, so that the air flow on the front surface side of the recording medium 2 and the air flow on the rear surface side become equal. As a result, the recording medium 2
The difference between the pressure on the front side and the pressure on the back side is reduced.

As described above, in the present embodiment, by providing the convex portion 4a on the inner surface of the upper cartridge case 4, the flow of air on the front surface side of the recording medium 2 and the flow of air on the rear surface side become equal. Thus, the difference between the pressure on the front side of the recording medium 2 and the pressure on the back side decreases. As a result, the recording medium 2
It is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated at the high-speed rotation of the recording medium.

In the above embodiment, the convex portion 4a
Is provided in the upper cartridge case 4 of the recording disk 10, but may be provided in the lower cartridge case 6 or in the upper and lower cartridge cases as necessary. In addition, a necessary arrangement is appropriately selected for the arrangement of the protrusions 4a.

The groove 4b as a pressure difference reducing means is provided not only in the recording medium storage member and the recording disk having the recording medium storage member but also in the rotation drive unit of the recording medium rotation driving device for storing the recording medium. It does not matter.

Although the above embodiment has been described by taking air as an example, similar effects can be obtained even when a fluid having similar properties is used.

As described above, each of the embodiments disclosed above is an example in all respects, and is not a basis for restrictive interpretation. Therefore, the technical scope of the present invention is not interpreted only by each of the above embodiments,
It is defined based on the description in the claims. In addition, all changes within the meaning and scope equivalent to the claims are included.

[0030]

According to the recording medium accommodating member according to the present invention, the air flow between the recording medium accommodating portion and the recording medium is adjusted, and the air flow on the front surface side of the recording medium and the air flow on the rear surface side are adjusted. And the difference between the pressure on the front side and the pressure on the back side of the recording medium decreases. Therefore, it is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated at the time of high-speed rotation of the recording medium. As a result, it is possible to stabilize the high-speed rotation of the recording medium by suppressing the amplification of the unstable vibration of the recording medium due to the flow of air generated when the recording medium rotates at high speed.

[Brief description of the drawings]

FIG. 1 is a plan view showing a structure of a recording disk according to an embodiment.

FIG. 2 is a cross-sectional view showing a structure of a recording disk according to the embodiment.

FIG. 3 is a diagram showing a simulation result of the air flow on the back surface side and the front surface side of the recording medium 2 when the pressure difference reducing unit according to the embodiment is employed.

FIG. 4 is a cross-sectional view showing a structure of a recording disk according to a conventional technique.

FIG. 5A is a schematic diagram showing an ideal state of a flow velocity diagram generated on the back side and the front side of the recording medium 2;
FIG. 3B is a diagram illustrating a change in pressure received from the fluid on the back side and the front side of the recording medium 2 in that case.

FIG. 6A is a schematic view showing a state of a flow velocity diagram generated on the back side and the front side of the recording medium 2 in the related art, and FIG. 6B is a diagram showing the back side and the front side of the recording medium 2 in that case. It is a figure which shows the change of the pressure which arises on the side.

FIG. 7 is a diagram showing a relationship between a pressure difference generated on the front side and the back side of the recording medium 2 and the number of rotations of the recording medium 2;

[Explanation of symbols]

2 recording medium, 4 upper cartridge case, 4a projection, 4b window, 6 lower cartridge case, 10 recording disk, 100 rotation axis.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Masaya Matsuoka 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. (reference) 5D109 AA01

Claims (4)

[Claims] 1. A recording medium accommodating member for rotatably accommodating a disk-shaped recording medium, wherein a front surface side and a rear surface side of the recording medium in a region of the recording medium accommodation member facing the recording medium. The recording medium housing member, wherein a projection is provided on the inner surface of at least one of the recording medium housing members. 2. The method according to claim 1, wherein the convex portion is provided radially so as to obliquely intersect with a rotation circumferential direction of the recording medium.
The recording medium housing member according to claim 2. 3. A recording disk having a disk-shaped recording medium, wherein the recording medium accommodating member according to claim 1 is used for accommodating the recording medium. 4. A recording medium rotation driving device for rotating a disk-shaped recording medium, the recording medium rotation driving device having the recording medium housing member according to claim 1 in a rotation driving section of the recording medium. apparatus.