JPH08147765A - Disk rotating device and disk testing device - Google Patents

Abstract

PURPOSE: To provide a disk rotating device capable of surely rotating a disk to be tested without the runout while securing spaces on both sides of the disk to be tested. CONSTITUTION: This disk rotating device has a central opening part with a prescribed inner diameter. This device is provided with a rotating head 14 having a diameter smaller than the inner diameter above, capable of rotating around an oblique rotary shaft inclined from the vertical direction by a prescribed angle and being in frictional contact with the inner wall of the central opening part of the disk, a rotary driving mechanism 10 rotary driving the relevant rotating head and non-contact supporting means 18 supporting the disk during rotation on a plane perpendicular to the rotary shaft. Consequently, since the constitution is simple, the cost is sharply reduced, the exchange of the disk is easy and the disk is exactly rotated without the runout of rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc testing device and a disc rotating device suitable for the disc testing device.

[0002]

2. Description of the Related Art The surface of a disk under test such as a magnetic disk or an optical disk is irradiated with light from a light source, and the light reflected from the surface is observed by an image pickup device such as a camera to be tested. Disc testers are known for testing the surface of a disc. In the conventional apparatus, a disc is placed on a rotary table and only one side of the disc is tested. However, for efficient testing, it is desirable to test both sides of the disk simultaneously.
In this case, it suffices to provide the surface test devices on both sides of the disk, but it is necessary to stably rotate the disk under test while ensuring a space for installing these surface test devices.

In order to rotate the disc under test while ensuring a space on both sides of the disc under test, a plurality of rotating rollers are provided at the outer peripheral end of the disc under test and the discs under test are rotated by rotating these rollers. It is conceivable to rotate while holding. However, this method is not suitable for a surface testing apparatus that requires a clean environment because dust is generated due to friction between the disk under test and the rotating roller.

As another method, a method may be considered in which a rotating shaft is passed through the center opening of the disk so that the outer diameter of the rotating shaft can be increased and the disk under test is held at the center. However, the thickness of the disk under test is only 0.8 mm, so when the rotating shaft at the center is enlarged and held, the disk under test is held completely perpendicular to the rotation axis of the rotating shaft. It is not easy to do so, and there is a problem that the rotational shake of the disk under test becomes large due to a slight deviation. With this method, it is difficult to suppress rotational shake within 10 μm, and a highly accurate surface test cannot be performed.

It is an object of the present invention to provide a disk rotating device capable of reliably rotating the disk under test without any rotational shake while securing spaces on both sides of the disk under test.

Another object of the present invention is to provide a disc testing apparatus capable of simultaneously testing both surfaces of a disc under test.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a disk rotating device having a central opening portion with a predetermined inner diameter, the inclination having a diameter smaller than the predetermined inner diameter and inclined by a predetermined angle from the vertical direction. It is rotatably provided around the axis of rotation,
A rotary head that makes frictional contact with the inner wall of the central opening of the disk; and a rotary drive mechanism that rotationally drives the rotary head,
And a non-contact supporting means which is provided in the vicinity of the rotary head and which supports the rotating disk in a non-contact manner on a plane perpendicular to the rotation axis.

Further, the present invention is a disk testing apparatus including the disk rotating apparatus described above, and further comprising surface testing means for testing both major surfaces of the disk at substantially the same time.

[0009]

1 is a perspective view schematically showing the structure of a disk rotating device according to the present invention. This disk rotating device includes a rotation driving motor 10, a shaft 12 for transmitting the rotation driving force, and a rotary head 14 fixed to the tip of the shaft 12. As shown in FIG. 1, the direction of the rotation axis that is the central axis of the shaft 12 (see arrow 15)
Is inclined by a predetermined angle θ from the vertical direction indicated by the arrow 16. The adoption of such an inclined rotary shaft is the most characteristic point of the disk rotating device of the present invention. Above and below the rotary head 14, non-contact supporting devices 18 for supporting the disk in a non-contact manner are provided substantially symmetrically. The non-contact support device 18 is composed of two divided parts, each of which is provided with an air injection port 20. Further, the tip end portion of the rotary head 14 is configured to protrude from the non-contact supporting device 18, and the center opening portion of the disk 22 is placed on the tip end portion of the rotary head 14. Since the diameter of the rotary head 14 is smaller than the inner diameter of the central opening of the disk 22, the disk 22 only makes frictional contact with the upper end of the tip portion of the rotary head 14.

FIG. 2 is a sectional view showing a state in which the disc 22 is placed on the disc rotating device shown in FIG. As described above, since the inner diameter of the central opening of the disk 22 is larger than the diameter of the rotary head 14, the rotary head 14 and the inner diameter of the disk 22 make a point contact. Further, FIG. 3 is a view seen from the direction of arrow 24 in FIG. As shown in FIG.
Since the disk 22 is supported by the air from the air ejection port 20 in a non-contact manner, the rotation resistance is substantially zero, and the disk 22 can be satisfactorily rotated along with the rotation of the rotary head 14 even though it is almost point contact. it can. The rotation speed in this example was as low as 10 rotations per minute (1 rotation in 6 seconds), and it was proved from the experimental results that an extremely good rotation state can be maintained. In addition, the disc 2 is balanced by the force of the air jetted from the air jet port 20 toward the disc 22 and the gravity component of the disc 22.
Since 2 is supported in a non-contact manner, it is possible to easily hold the disk 22 in a fixed position by controlling the air injection speed from the air injection port 20 to be constant. Such air injection control can be easily realized by so-called servo control, and is a technique well known to those skilled in the art, and thus detailed description thereof will be omitted. According to the experiment, the rotational shake of the disk 22 could easily satisfy the allowable range of ± 10 μm or less. As shown in FIG. 3, since the diameter of the rotary head 14 is smaller than the inner diameter of the central opening of the disk 22, the disk 2 is rotated as the rotary head 14 rotates.
Even if 2 rotates without slipping, it is inevitable that a slight deviation will occur in the rotation angle between the two. However, it is easy to correct this deviation of the rotation angle by the control of the motor 10, and there is no problem in reality.

FIG. 4 is a side view of an essential part of a disk testing device using the disk rotating device shown in FIGS. Figure 1
The parts corresponding to those in the embodiment of FIG. 3 are designated by the same reference numerals. In this disc testing apparatus, in order to test both sides of the disc 22 at the same time, surface test means for testing both sides of the disc 22 at substantially the same time is provided. This surface testing means is composed of first and second light projectors 26 that irradiate both surfaces of the disk 22 and first and second light receivers 28 that receive the reflected light from both surfaces of the disk 22, respectively. The projector 26 shapes the light from the halogen lamp through the slit and irradiates the information recording area between the central opening and the outer periphery of the disc 22 with the light. The light receiver 28 is a CC
An imaging device such as a D camera is suitable, and the imaged information is converted from analog to digital, and the obtained digital image data is analyzed by a computer. Since such data analysis processing is well known to those skilled in the art, further description will be omitted.

The preferred embodiment of the present invention has been described above.
It will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the gist of the present invention.

[0013]

According to the present invention, since the disk is mounted on a rotary head with an inclined arrangement and is supported in a non-contact manner by air jet or the like, the cost can be greatly reduced and the disk can be replaced. It is easy and the disk can be rotated accurately without causing rotational shake. Further, by using this disc rotating device, the testing means can be easily arranged on both sides of the disc, so that a disc testing device capable of simultaneously testing both sides of the disc can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of a disk rotation device of the present invention.

2 is a cross-sectional view of the device of FIG.

3 is a diagram of the disk and the rotary head as seen from the direction of arrow 24 in FIG.

FIG. 4 is a side view of an embodiment of a disc testing apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Motor (rotary drive mechanism) 12 Shaft 14 Rotary head 18 Non-contact support device 20 Air injection port 22 Disk 26 1st and 2nd light projector 28 1st and 2nd light receiver

Claims (4)

[Claims] 1. A rotating device for a disk having a central opening with a predetermined inner diameter, the device having a diameter smaller than the predetermined inner diameter and being rotatable about an inclined rotation axis inclined by a predetermined angle from the vertical direction. A rotary head that is provided to make frictional contact with the inner wall of the central opening of the disk, a rotary drive mechanism that rotationally drives the rotary head, and a disk that is provided near the rotary head and that is rotating and that has the rotating shaft A non-contact supporting means for supporting in a non-contact manner on a vertical plane, the disk rotating device. 2. The disk rotating device according to claim 1, wherein the non-contact support means is an air injection means for injecting air toward the disk. 3. A disk testing apparatus comprising the disk rotating apparatus according to claim 1 or 2, further comprising surface testing means for testing both major surfaces of the disk substantially at the same time. 4. The surface testing apparatus comprises: a first light projector for irradiating a first main surface of the disk with light; a first light receiver for receiving reflected light from the first main surface; and a second surface of the disk. 4. The disk test apparatus according to claim 3, further comprising a second light projector that irradiates the main surface with light, and a second light receiver that receives the reflected light from the second main surface.