JP4283932B2 - Recording medium driving device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus using a disk-shaped high-capacity recording medium utilizing light and magnetism such as CD, DVD, MO, HD, and FD, and more specifically, a recording medium drive that rotates the recording medium at high speed. Relates to the device.
[0002]
[Prior art]
In recent years, various disk-shaped recording media have been announced, and accompanying this, remarkable progress has been made in recording capacity. This is largely due to the improvement in recording density accompanying improvement in the recording medium itself, for example, improvement in the recording surface material. However, the housing in the conventional recording medium driving device has a shape that does not change so much as in the past, for example, as shown in FIGS. 8 and 9, despite the remarkable increase in recording capacity in the recording medium. That is, the housing 10 of the conventional recording medium driving apparatus has a cubic shape having a substantially rectangular cross section, and an opening for allowing the disk tray 11 (see FIG. 9) to enter and exit is formed on the front surface. From here, the disk tray 11 can be moved into the housing 10. As shown in FIG. 9, the housing 10 includes a metal cover 12, preferably a metal base 13, a chassis 15 supported by vibration-proof rubber 14 fixed to the base 13, and a pickup. 16, a drive motor 17 fixed to the chassis 15, a disk 18 mounted on the disk tray 11, and a clamp 19 that holds the disk 18. The disk is usually held in a sealed state inside the housing. This disk 18 is a CD-ROM.
[0003]
Also known is a housing 20 of a recording medium driving device as shown in FIG. 10 (Japanese Patent Laid-Open No. 7-326182). In order to prevent the temperature in the housing 20 from rising due to the heat from the driving device and approaching the environmental resistance temperature of the disk or the like, the housing 20 is formed on the opposing side wall of the housing. The air circulation openings 21 and 22 are formed, and air cooling means for preventing a temperature rise of the air in the housing 20 is provided. However, even in such a known casing, in order to prevent contamination of the disk surface by circulating air, in most cases, the disk is held in a substantially sealed state inside the casing. There have been many publications in which air-cooling means having the same purpose are disposed at portions other than the opposing side walls.
[0004]
[Problems to be solved by the invention]
Therefore, the current technology is pursuing a technology for rotating the recording medium at a higher speed in order to increase a new recording capacity for the recording medium. However, such an extreme increase in rotational speed causes various problems related to rotational friction between the high-speed rotating body and air, which is completely different from the temperature rise in a simple housing as shown in FIG. Has been found to provide for recording media. This is because, when the recording medium, i.e., the disk, is rotated at high speed in the housing, a phenomenon such that the disk vibrates due to a large swell or flapping due to the influence of the air flow surrounding the disk, particularly in a CD-ROM. As a result, it was found that a large swell of about 1 to 5 mm pp was observed at about 10,000 revolutions per minute, and when the number of revolutions was further increased, the disk floated in the housing and the disk warped in the housing. Such a phenomenon occurred in the same manner even in a case in which a known air cooling means as shown in FIG. 10 is provided. Further, not only the CD-ROM but also other recording media have substantially the same configuration, and the same phenomenon occurs although the generation conditions such as the rotational speed are slightly different.
[0005]
That is, when the disk is rotated at a higher speed than before, the disk vibrates due to the influence of the air flow surrounding the disk, and the disk is vibrated when the rotation speed is increased. It was necessary to take measures against problems such as floating and the disk warping inside the enclosure. Such a problem tends to occur when a resin or soft material such as a CD-ROM has a low rigidity, or when the apparatus is thin and the distance between the recording medium and the housing is small. confirmed. Of course, such rotation hinders an increase in recording capacity.
[0006]
Therefore, as a result of earnest research on the mechanism by which these problems occur, the applicant has clarified that such a problem occurs for the following reason. That is, for example, in the known housing 10 as shown in FIG. 11, when the disk medium 18 rotates at a high speed as described above, the air around the disk rotates along the disk surface in the vicinity of the disk surface. The disk surface flows outwardly by centrifugal force (see reference numeral 23 in FIG. 11). In such a case, the housing 10 having the conventional structure as shown in FIG. 11 has a structure in which the center of rotation is sealed from the outside by the cover 12, so that the pressure is high near the cover surface as opposed to the disk surface. An air flow is generated from a certain peripheral edge of the disk toward the disk center having a low pressure. For this reason, a pressure difference occurs between the rotation center of the disk and the peripheral edge thereof, and the pressure is high in the portion closest to the casing at the periphery of the disk, and the air flow is not equal in the circumferential direction. It was clarified that the flow was turbulent and the rigidity of the disk could not withstand the fluctuation of atmospheric pressure caused by this turbulence, and the disk was deformed arbitrarily and the disk became unstable and caused disk vibration.
[0007]
Further, in the case as shown in FIGS. 9 and 10, there is a drive motor or the like at the lower part of the disk, which is an obstacle to block the air flow, and the upper and lower wall surfaces sandwiching the disk and the disk. The spacing between is different. In other words, the pressure on the clamp side is lower than that on the motor side, so the shape of the wall that sandwiches the disk is no longer symmetrical with respect to the center of rotation, the air flow velocity and wind direction fluctuate at the vertical position across the disk, and the disk has upward force. It has been elucidated that it deforms so as to rise upon receiving.
[0008]
These factors generate a pressure difference or pressure distribution difference between the upper and lower sides of the disc, and the disc rigidity cannot be tolerated, resulting in the disc vibration, levitation, deformation, etc. as described above. I got it.
[0009]
Such knowledge is completely unpredictable in a drive device that rotates at a conventional rotational speed. This is because, until now, the disk has not rotated at such a high speed that the interaction between the disk and air becomes a problem. Accordingly, the present invention has a new problem that the disk has vibrated, floated or deformed when the disk is rotated by a recording medium driving device equipped with a driving device that rotates at an extremely high speed. An object of the present invention is to provide a completely new recording medium driving apparatus for solving the problem.
[0010]
[Means for Solving the Problems]
In a recording medium driving device having a motor and a disk positioned on one side in the axial direction of the motor and driven by the motor in a space inside the housing ,
On the wall of the housing facing the surface on one side of the disk,
A plurality of one side openings are formed taking a symmetrical arrangement with respect to the rotational axis of the disk,
Air can flow between the inside and outside of the housing through the one side opening ,
A plurality of side wall side openings are formed on the side wall surface surrounding the periphery of the disk,
The side wall-side opening is formed at a position corresponding to a space on at least one side of the disk,
A recording medium driving device characterized in that air can flow between the inside and outside of the housing through the side wall surface opening.
[0011]
The opening may be anything that makes the air pressure on the rotating surface of the recording medium substantially the same as the outside of the housing. The disk-shaped recording medium is an optical or magnetic recording medium, such as a CD, FD, MO, or HD.
[0012]
If constituted in this way, even if the recording medium rotates at a high speed, the entire surface of the medium always receives almost the same pressure as the atmospheric pressure, so that fluctuations in atmospheric pressure are eliminated, and vibrations occur with a large swell or flapping. In addition, it is possible to prevent phenomena such as lifting of the medium and warping of the medium.
[0013]
The opening may be provided in a housing corresponding to the vicinity of the rotation center of the recording medium. With this configuration, the entire surface of the medium receives almost the same pressure as the atmospheric pressure while the air in the enclosure flows so that the flow rate and wind direction of the surrounding air are substantially symmetrical with respect to the rotation center of the medium in the enclosure. As a result, the recording medium rotates more stably.
[0014]
The opening may be provided in a housing corresponding to the vicinity of the outer periphery in the circumferential direction of the recording medium. Even with this configuration, the air flow in the enclosure flows so that the flow rate and wind direction of the ambient air are substantially symmetric with respect to the center of rotation of the medium in the enclosure, while the entire surface of the medium is at the same pressure as the atmospheric pressure. Since the recording medium is received, the recording medium rotates more stably. This ventilation means may be combined with one provided near the rotation center of the recording medium.
[0015]
Further, when the rotational speed of the recording medium is 10,000 rotations per minute or more, the above effect can be obtained more remarkably.
[0016]
Further, if the recording medium is a medium made of a soft material such as a resin (for example, polycarbonate), the recording medium is less rigid than a hard material such as a metal or glass, so that the recording medium is deformed by the influence of atmospheric pressure. Although the phenomenon is likely to occur, the influence of the phenomenon can be prevented by adopting the configuration of the present invention. The resin medium refers to, for example, a CD-ROM, DVD, MO, large capacity FD, and the like.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Specific examples of the present invention will be described below. FIG. 1 is a perspective view of a housing 30 relating to the present invention, and FIG. 2 is a view taken along line 2-2 in FIG. 1. FIGS. 8 and 9 show a known recording medium driving device and its housing, respectively. It corresponds. The housing 30 of the present invention has a cubic shape with a substantially rectangular cross section, and an opening 50 is formed in the front portion for allowing the disk tray 31 (see FIG. 2) to enter and exit. 31 can be inserted into and pulled out of the housing 30. The housing 30 is fixed to the metal cover 32, preferably a metal base 33, a chassis 35 supported by a vibration isolating rubber 34 fixed to the base 33, a pickup 36, and the chassis 35. A drive motor 37; a disk 38 mounted on the disk tray 31; and a clamp 39 for holding the disk 38.
[0018]
The cover 32 includes a top plate portion 40 having a substantially rectangular shape, and side wall portions 41, 42, 43, 44 that respectively hang downward from the four peripheral edges of the top plate portion 40. have. Here, the side wall portion 41 forms a front side wall portion of the housing 30, and an opening 50 for allowing the disk tray 31 (see FIG. 2) to enter and exit is formed at the center of the front side wall portion 41. Has been. The side wall portion 42 is disposed so as to face the front side wall portion 41, and forms a side wall portion behind the housing 30. The side wall portions 43 and 44 form left and right side wall portions in the housing 30.
[0019]
The top plate portion 40 has a position that is substantially intermediate between the side wall portion 43 and the side wall portion 44 and is somewhat close to the front side wall portion 41 and coaxial with the center of rotation with respect to the disk 38. Further, an upper surface ventilation means 45 formed as an opening formed by punching the top plate portion 40 is disposed. The upper surface ventilation means 45 is formed of an opening group in which a series (six in the illustrated example) fan-shaped groups having a constant radial width (w) are arranged so as to form a substantially circular shape. . Here, assuming that the inner diameter dimension of these fan-shaped groups is r and the outer dimension is R, there is a relationship (R−r = w) between R, r, and w. Further, as shown in FIG. 2, the center position of the circular upper surface ventilation means 45 substantially coincides with the center position of the clamp 39. Therefore, the center of the upper surface ventilation means 45 and the center of the clamp 39 are mutually opposite. Alignment on one axis XX. Furthermore, when the diameter of the clamp 39 is L, the relationship between R and r is preferably 2R ≧ L ≧ 2r. Further, the upper surface of the clamp 39 and the lower surface of the top plate 40 When the dimension between and is c, it is desirable that c and w have a relationship of (w ≧ c). This is because when the disk 38 rotates at a very high speed, a sufficient amount of air is sucked into the housing 30 through the upper surface ventilation means 45 and flows on the surface of the disk 38, so that the surface of the disk 38 is at atmospheric pressure. This is to eliminate the undulation of the disk 38.
[0020]
Here, the number of fan groups forming the upper surface ventilation means 45 may be six or more, or less. In addition to the series of fan-shaped groups, for example, the upper surface ventilation means 45 can be formed by arranging triangles alternately in opposite directions and arranging them in a circular shape (see FIG. 3). That is, the shape of the upper surface ventilation means 45 is not limited as long as it defines an air passage through which a sufficient amount of air that satisfies the above purpose can be sent into the housing. When the upper surface ventilation means 45 is defined, when another component or the like is mounted on the top plate portion 40, the upper surface ventilation means 45 is punched out by the component or the like so that the disk 38 or the like inside the housing is not damaged. You need to be careful.
[0021]
The upper surface ventilation means 45 is suitable for removing dust in the outside air so that the dust contained in the outside air sucked into the inside of the housing does not damage the disk by directly touching the disk surface. It is desirable to mount a filter inside the upper surface ventilation means 45.
[0022]
In the example shown in the figure, only one upper surface ventilation means 45 is arranged on the top plate portion 40. However, as long as the strength of the top plate portion is not lost, more additional upper surface ventilation means are attached to the top plate portion. It can also be provided. In this case, the associated upper surface ventilation means can be constituted by a simple circular punched body.
[0023]
A front ventilation means 47 is provided on the front rising wall 46 of the disk tray 31 inserted into the opening 50 provided in the front side wall portion 41. The front ventilation means 47 is composed of upper and lower two rows of vent groups 48 and 49. The vent groups 48 and 49 in each row are formed by five vents having a rectangular shape that is long in the horizontal direction in the illustrated example, but the shape, number, and the like are not limited thereto. . These vent groups 48 and 49 are arranged at predetermined intervals in the vertical direction. Here, the upper vent group 48 is disposed at the same level as or slightly above the upper surface of the disk 38, while the lower vent group 49 is at the same level as the lower surface of the disk 38. Or, it is arranged so as to be located at a level slightly lower than that. Thus, each of the vent groups 48 and 49 can guide the air flowing along the upper and lower surfaces of the disk 38 so as to quickly flow out of the housing. As shown in the illustrated example, the front ventilating means 47 is not necessarily composed of two upper and lower rows of vent groups 48 and 49. It is also possible to make the upper and lower vents into five vertically long rectangular vents that are continuous in the vertical direction, and to arrange them side by side in the lateral direction. In the latter case, the shape of the air port may be circular or elliptical, or other polygonal shape instead of the rectangular shape.
[0024]
Further, side ventilation means 51 are similarly provided in the rear side wall portion 42 and the side side wall portions 43 and 44. These side vents 51 are provided by vent groups 52, 53, 54 comprising a series of continuous rectangular openings formed on each side wall portion 42, 43 and 44 (see FIG. 2). Shows only the vent group 52, and FIG. 1 shows only the vent group 53). The side wall portion having the side ventilation means 51 composed of the vent groups 52, 53, and 54 is separated from the outer circumferential portion of the disk 38 rotating at high speed, along the upper and lower surfaces of the disk 38. When the flowing air flows out to the outside of the housing, the air is substantially integrated and flows outward, so that the air flows on the upper and lower surfaces of the disk 38 as provided on the front rising wall 46. There is no need to flow the air flowing along the top and bottom separately to the outside of the housing. Therefore, the vent groups 52, 53, and 54 can be formed by a series of openings arranged in a row in the lateral direction. However, it is desirable that the height dimension b of these openings is larger than the height dimension a of each opening arranged in two upper and lower rows provided on the front rising wall 46. Of course, it is also possible to form these vent groups 52, 53, and 54 in two upper and lower rows, like the vent groups 48 and 49.
[0025]
FIG. 3 shows another surface shape of each opening or vent constituting the ventilation means 45, 47, 51. As can be seen from this figure, it is shown that these vents can have a circular shape, an elliptical shape, and other polygonal shapes in addition to the rectangular shape as shown in FIG.
[0026]
FIG. 4 shows the shape of each opening, that is, the cross section of the vent holes 48, 49, 52, 53, 54 (cross section of the casing wall). As can be seen from this figure, these vents are inclined so as to form a predetermined angle (d) with respect to the wall surfaces of the housings, in addition to extending in a direction orthogonal to the wall surfaces (YY direction). It can also be arranged in a form that extends in the direction of movement. This configuration, in particular, prevents these vents from being placed at the same level as the rotational surface level of the disk 38, for example due to factors within the enclosure, for example to a position slightly above or below the rotational surface level. When it is necessary to dispose the airflow, the airflow that has moved along the rotating surface is smoothly and quickly maintained while maintaining the airflow angle without disturbing the airflow. It is particularly effective for flowing out of the housing. Furthermore, when a wind noise is generated greatly due to air flow inside and outside the apparatus, it is also effective for reducing this sound. Of course, it will be apparent to those skilled in the art that the cross-sectional shape shown in FIG. 4 can be used in combination with the surface shape shown in FIG.
[0027]
FIG. 5 shows an overall perspective view of a housing provided with ventilation means having yet another shape. In this embodiment, the upper surface ventilation means 45 provided in the top plate portion 40 is composed of a plurality of small holes 55 that are dispersed and arranged on the average over the entire top plate portion. This is advantageous because the strength can be maintained over the entire top plate portion when a display device or an external device is mounted on the top plate portion. Similarly, the side ventilation means 51 provided in the side wall portion can be constituted by a group of a plurality of small holes 56 arranged in each side surface portion.
[0028]
FIG. 6 further shows another embodiment relating to the upper surface ventilation means 45. In the embodiment of FIG. 5, the upper surface ventilation means 45 is composed of a plurality of small holes 55 that are distributed in an average manner over the entire top plate portion 40, but in the embodiment of FIG. Small holes 57 are regularly arranged around the center. Thereby, the pressure reduction in the housing accompanying the rotation of the clamp 39 is quickly compensated.
[0029]
FIG. 7 shows still another embodiment. In this embodiment, a part of the top plate part and a part of each side wall part are hollowed, and an upper surface ventilation means and a side ventilation means are respectively formed there. Although this embodiment is easy to manufacture the housing, there is a disadvantage that it is difficult to load other devices on the housing.
[0030]
The present invention is characterized in that the housing constituting the recording medium driving device is provided with an opening through which air can flow so that the air pressure in the recording medium housing space is substantially the same as the air pressure outside the housing. However, the vents are regularly arranged on the basis of the rotation center of the recording medium, for example, in the case of the upper surface of the housing, radially (see FIGS. 1, 3, 6, and 7) or arranged in a plurality of rows (see FIG. In FIG. 5) and arranged on the side of the housing, they are arranged so as to be evenly distributed in the circumferential outer periphery of the recording medium (FIGS. 1, 3, 5, and 7). Furthermore, the present invention does not generate waviness or flutter on the surface of the recording medium even when the recording medium is rotated at a high speed. In other words, the disk is rotated at 10,000 revolutions per minute or more. When rotating at a high speed, a uniform air flow is generated in the rotational peripheral direction of the disk. This can be achieved only by having the configuration described in the above-mentioned claims, not simply passing the recording medium housing space to the outside of the housing.
[0031]
This is because, even in a known housing having a known heat-dissipating opening that communicates the recording medium housing space with the outside of the housing as shown in FIG. 9 or FIG. 10, the disk is rotated at the above-described high speed. This is also evident from the occurrence of undulations and flutters on the surface. In the present invention, the opening may be formed to have a size capable of sucking a sufficiently large amount of air on at least one of the upper surface, the lower surface, or the side surface of the housing. As the air outlet, for example, it is desirable to provide the upper and lower surfaces, the upper and side surfaces, or the lower and side surfaces of the housing, respectively. Further, when the present invention is applied to a recording medium made of a resin, which is a soft material such as a CD-ROM, the effect becomes remarkable when the rotational speed is 10,000 rpm or more. The effect can be obtained even with a recording medium made of metal or glass which is a hard material such as HD, but the remarkable rotation speed is higher than that of a soft material.
[0032]
In each of the above embodiments, the upper surface ventilation means and the side surface ventilation means or the lower surface ventilation means when provided on the lower surface, that is, the base portion, prevents dust in the air from flowing into the housing, and It is desirable to equip a filter that does not hinder free inflow and outflow.
[0033]
【The invention's effect】
According to the recording medium driving device of the present invention, even when the recording medium rotates at a high speed, the entire surface of the medium is always subjected to substantially the same pressure as the atmospheric pressure so that the fluctuation in atmospheric pressure is eliminated, resulting in large swell or flapping. It is possible to prevent phenomena such as vibration, floating of the medium, and warping of the medium. Therefore, even if the rotation speed is increased as compared with the conventional one, the recording medium rotates without any trouble.
[0034]
According to the recording medium driving apparatus of the first aspect of the present invention, the entire surface of the medium is flowing while the air in the casing flows so that the flow rate and wind direction of the surrounding air are substantially symmetrical with respect to the rotation center of the medium in the casing. Is subjected to a pressure almost equal to the atmospheric pressure, so that the recording medium rotates more stably.
[0035]
According to the recording medium driving apparatus of the first aspect of the present invention, the entire surface of the medium is flowing while the air in the casing flows so that the flow rate and wind direction of the surrounding air are substantially symmetrical with respect to the rotation center of the medium in the casing. Is subjected to a pressure almost equal to the atmospheric pressure, so that the recording medium rotates more stably.
[Brief description of the drawings]
FIG. 1 is an overall perspective view showing a recording medium driving apparatus according to the present invention.
2 is a cross-sectional view taken along line 2-2 of the housing shown in FIG.
FIG. 3 is a surface view showing another embodiment of the vent group of the side vent means.
FIG. 4 is a cross-sectional view showing another embodiment of the vent group of the side vent means.
FIG. 5 is an overall perspective view showing another embodiment of the recording medium driving apparatus according to the present invention.
FIG. 6 is a diagram showing a top plate portion of still another embodiment of the recording medium driving apparatus according to the present invention.
FIG. 7 is an overall perspective view showing still another embodiment of the recording medium driving apparatus according to the present invention.
FIG. 8 is an overall perspective view showing a known recording medium driving apparatus.
9 is a cross-sectional view of the housing shown in FIG. 8 taken along line 9-9.
FIG. 10 is a side sectional view showing another known recording medium driving device.
11 is a diagram showing an air flow state in the housing shown in FIG. 9;
[Explanation of symbols]
30 Housing 31 Disc tray 32 Cover 35 Chassis 38 Disk 40 Top plate portion 41 Front side wall portion 42 Rear side wall portions 43, 44 Side wall portion 45 Upper surface ventilation means 46 Front rising wall 47 Front ventilation means 48, 49 Vent group 50 Opening 51 Side venting means 52, 53, 54 Vent groups 55, 56, 57 Small holes

Claims (1)

In a recording medium driving device having a motor and a disk positioned on one side in the axial direction of the motor and driven by the motor in a space inside the housing ,
On the wall of the housing facing the surface on one side of the disk,
A plurality of one side openings are formed taking a symmetrical arrangement with respect to the rotational axis of the disk,
Air can flow between the inside and outside of the housing through the one side opening ,
A plurality of side wall side openings are formed on the side wall surface surrounding the periphery of the disk,
The side wall-side opening is formed at a position corresponding to a space on at least one side of the disk,
A recording medium driving device characterized in that air can flow between the inside and outside of the housing through the side wall surface opening.

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