JPH04315037A - Apparatus for inspecting appearance of end surface of work - Google Patents

Abstract

PURPOSE:To efficiently inspect the appearance of the end surface of a work. CONSTITUTION:A turntable 1 having work holding parts 2 holding a plurality of works within a plane in a freely detachable manner around the rotary shaft thereof is arranged so as to be freely rotated and stopped. At least a work receiving stage I and a work taking-out stage V1 are set around the rotary shaft of the turntable 1. The work fed from the process of the previous stage to be held to each of the work holding parts 2 at the work receiving stage I is sent to the work taking-out stage VI through respective stages by the intermittent rotation of the turntable 1 and further sent to the process of the next stage. During this process, the appearance of the end surface of the work is inspected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for inspecting the appearance of a workpiece end surface for inspecting the presence or absence of surface defects on the outer peripheral end surface and/or inner peripheral end surface of a workpiece such as an aluminum (including its alloy) magnetic disk substrate. .

0002

[Prior Art] Works such as aluminum magnetic disk substrates are required to have a high level of surface precision, such as a mirror surface or a near-mirror surface, and must be free from localized surface defects such as scratches, pinholes, and bulges. required. At the same time, such aluminum magnetic disk substrates and the like are also required to have surface smoothness on the outer peripheral end face and/or the inner peripheral end face. The reason why the surface smoothness of the outer peripheral end face is required is that the formation of a magnetic film on the substrate surface by sputtering method is generally performed by chucking the outer peripheral end face, so if there are surface defects on the outer peripheral end face, the magnetic disk substrate This is because there is a possibility that it may have a subtle effect on the horizontality and may even cause non-uniformity in the thickness of the magnetic film. In addition, the reason why the surface smoothness of the inner peripheral end face is required is that when an aluminum magnetic disk substrate is actually used in computers, etc., the inner peripheral end face is chucked and rotated, so the inner peripheral end face has a smooth surface. This is because if a defect exists, the substrate is chucked in an inclined state, and there is a possibility that the distance between the magnetic head and the substrate cannot be maintained constant. For this reason, in the manufacturing process of aluminum magnetic disk substrates, which are generally manufactured through various processes such as precision cutting, polishing, washing and drying, the outer peripheral end face and/or the inner peripheral end face are Appearance inspections are conducted to check for the presence or absence of surface defects.

[0003] Conventionally, the appearance inspection of the end face of a workpiece has been carried out according to the following procedure. In other words, after chucking the workpiece sent in a case from the previous process into the holding part of the visual inspection machine, the workpiece is rotated and the visual inspection of the end face is performed. When the inspection is completed, the workpiece is removed and the next process is carried out. The workpiece is inspected by mounting it on the holder, and thereafter this operation is repeated one by one.

0004

[Problem to be solved by the invention] However, in the above method, it takes time to attach and detach the workpiece, and
Since the end face inspection of the next workpiece cannot be performed until the inspection process of one workpiece is completed, there is a drawback that the number of workpieces inspected per unit time is small and the inspection efficiency is poor.

It is an object of the present invention to eliminate such drawbacks and to improve the efficiency of visual inspection of the end face of a workpiece.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a work holding part (2 ) around the rotating shaft.
1) is arranged so as to be able to rotate and stop freely, and at least a receiving stage (I) and a take-out stage (VI) for the workpieces are set around the rotation of the turntable (1), and the workpieces have been transported from the previous process. After the workpiece (A) is held in the workpiece holding part (2) at the workpiece receiving stage (I), it is moved around each stage by intermittent rotational feeding of the turntable (1) and transferred to the workpiece takeout stage (VI
) The present invention provides an apparatus for inspecting the appearance of the end face of a workpiece, characterized in that the appearance of the end face of the workpiece is inspected during the process of transporting the workpiece to the next process.

[0007]

[Operation] In FIG. 2, the workpiece (A) transported from the previous process to the workpiece receiving stage (I) by the transporting device (3) is transferred to the holding section (2) on the turntable (1) and chucked. (2a). The mounted workpiece (A) goes around each stage by repeating intermittent rotational feeding in the counterclockwise direction of the turntable (1), and then is transferred to the outer peripheral end face inspection stage (V), where the outer peripheral end face is inspected. undergo a visual inspection. At the receiving stage (I), the next workpiece is transported from the previous process by the transporting device (3), and is sequentially mounted on the next stage holding section (2) waiting on the receiving stage (I). After the inspection of the outer peripheral end surface is completed, the turntable (1) further rotates intermittently to move on to the next workpiece (A).
is transferred to the outer peripheral end face inspection stage (V), and the workpiece on the outer peripheral end face inspection stage (V) is sent to the takeout stage (VI). The workpiece sent to the take-out stage is taken out from the holding part (2a) by the transport device (8),
The inner circumferential end surface is visually inspected by the inner circumferential end surface inspection device (9). In this way, by intermittent rotational feeding of the turntable (1), the workpieces are successively transferred to the outer peripheral end face inspection stage (V
) and the take-out stage (VI), where the peripheral end surface is visually inspected. The workpiece (A) that has been inspected for its inner circumferential end face is sent to the next process by the transport device (8).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment in which the present invention is applied to an apparatus for inspecting the end surface appearance of a doughnut-shaped aluminum magnetic disk substrate (A) as a workpiece as shown in FIG.

In the appearance inspection apparatus shown in FIG. 1, (1)
is a disc-shaped vertical turntable with its rotation axis oriented in the front-back horizontal direction. On the front surface of this turntable (1), there are six workpiece holders (2
) is provided. Each workpiece holding part (2) has a forwardly protruding chuck part (2a) that can freely expand and contract in diameter, and when the chuck part (2a) is passed through the shaft hole of the substrate (A), the diameter is expanded. By doing so, while the substrate (A) is chucked from the inner periphery, the chuck of the substrate (A) can be released by reducing the diameter of the chuck portion. And each chuck part (2a)
is capable of rotating around its own axis, and the chucked substrate (A) is rotated as required by this rotational drive.

At six equal positions around the rotation of the turntable (1), in order from the upper left in a counterclockwise direction, there are a work receiving stage (I) and a first disk surface inspection stage (II).
, an inversion stage (III), a second disk surface inspection stage (IV), an outer peripheral end surface inspection stage (V), and a workpiece take-out stage (VI). The turntable (1) can be freely controlled to stop rotating in a vertical plane by a drive device (not shown), and repeats rotational feeding and stopping every 1/6 rotation in a counterclockwise direction. (2) The substrate (A) mounted on the stage is transferred around each stage.

Each of the above stages will be explained as follows. That is, the work receiving stage (I)
This is a stage for mounting the magnetic disk substrate (A), which has been transported from the previous process by the transport device (3), onto the holder (2). Note that mounting of the disk substrate (A) from the transport device (3) to the holding portion (2) is performed via a chucker of an outer circumferential chuck type provided in the transport device.

[0012] The first disk surface inspection stage (II)
is for inspecting one side of the magnetic disk substrate (A) for the presence or absence of surface defects such as surface scratches and pinholes, and a disk surface inspection device (4) for this purpose is installed. Although the configuration of the disk surface inspection device (4) is not particularly limited, in this embodiment, as shown in FIG. , an imaging device such as a CCD camera that receives reflected light from the magnetic disk substrate in synchronization with the irradiation light (
42), and a defect detection device (42) that electrically detects the presence or absence of surface defects from the shading of the image taken by the imaging device.
3) are used. Then, by rotating the magnetic disk substrate by rotationally driving the chuck part (2a) and, if necessary, moving the light source and the imaging device in the radial direction, the appearance of the entire surface of one side of the magnetic disk substrate (A) is inspected. ing.

The reversing stage (III) is for reversing the magnetic disk substrate (A) from front to back and remounting it on the workpiece holder (2), and is provided with a reversing device (5) for this purpose. This reversing device (5) has an arm portion that chucks the outer periphery of the substrate (A), and this arm portion chucks the outer periphery of the substrate (A) that has been transferred to the reversing stage (III) and moves it sideways. By moving the substrate (A)
Once removed from the chuck part (2a), the arm part is rotated 180 degrees to turn over the substrate (A) and attach it to the chuck part (2a) of the work holding part (2) again. .

[0014] The second disk surface inspection stage (IV)
is a disk surface inspection device (6) that performs an appearance inspection on the other side of the magnetic disk substrate (A) that has been inverted on the inversion stage (III), and has the same configuration as the first appearance inspection stage (II). is installed.

The outer peripheral end surface inspection stage (V) is for performing an external appearance inspection of the outer peripheral end surface (A1) of the magnetic disk substrate (A) for the presence or absence of surface defects, and includes an outer peripheral end surface inspection device (7) for this purpose. is installed. Although the configuration of the inspection device (7) is not particularly limited, in this embodiment, the above-mentioned disk surface appearance inspection device (4) (6) is used.
) adopts a similar configuration. That is, the inspection device (7)
As shown in FIG.
1); a light source (71) that intermittently irradiates light toward the substrate; an imaging device (72) that receives reflected light from the end face of the substrate in synchronization with the irradiation light; A device equipped with a defect detection device (73) that electrically detects the presence or absence of a surface defect from light and shade is used. The magnetic disk substrate (
The external appearance of the outer peripheral end face (A1) of the magnetic disk substrate (A) is inspected over the entire circumference while rotating the magnetic disk substrate (A).

The workpiece retrieval stage (VI) takes out the magnetic disk substrate (A), which has been transferred to the stage after the inspection of the outer peripheral end face, from the workpiece holder (2) by means of the conveyance device (8), and also This is to transport the magnetic disk substrate to the next process. The removal of the magnetic disk substrate (A) is also performed via an outer circumferential chuck type chucker (not shown) provided on the transport device (8).

By the way, in this embodiment, the inner peripheral end surface (A2) of the magnetic disk substrate (A) is mounted on the take-out stage (VI).
An inner peripheral end face inspection device (9) is installed for performing an external appearance inspection. In this inner peripheral end surface inspection device (9), a magnetic disk substrate (A) is chucked at its outer peripheral end surface by a transport device (8) on a workpiece take-out stage (VI), and the holding portion (
2a), the magnetic disk substrate (A)
This is to inspect the presence or absence of surface defects on the inner circumferential end surface of. For this purpose, the inner peripheral end surface inspection device (9) includes a light source (91), an imaging device (92), a defect detection device (
93), and while rotating the magnetic disk substrate (A) by rotationally driving the chuck part of the transport device (8), the light source (91) rotates the inner peripheral end surface (A) of the magnetic disk substrate (A).
2), the reflected light is received by the imaging device (92), and the signal is transmitted to the defect detection device (93).
) to inspect the presence or absence of surface defects. The basic configuration of the inner peripheral end surface inspection device (9) is the same as the aforementioned outer peripheral end surface inspection device (7), but
In this embodiment, an ultra-small CCD is used as the imaging device (92).
A camera (for example, a gastrocamera) is used. The reason for this is as follows. That is, the inner peripheral end surface of the magnetic disk substrate (A) has a larger curvature and a smaller inner diameter, especially as the size of the magnetic disk substrate becomes smaller, such as a 3.5-inch type.
PMT (Photomultiplier Tube)
Or a normal CCD camera is too large to ensure a sufficient posture for receiving reflected light with respect to the inner circumferential end surface of the magnetic disk substrate (A), and as a result, highly accurate appearance inspection cannot be performed. Another problem is that it is inconvenient to handle. Therefore, the purpose is to use an ultra-small CCD camera and arrange it comfortably near the inner circumferential end face (A2) to perform a highly accurate external inspection. Furthermore, it is preferable to use a fisheye lens as the lens of the CCD camera. By using a fisheye lens, the reflected light from the inner peripheral end face can be received over a wide range, and the detection range at one time can be expanded.
As a result, the inspection time can be shortened. Note that (A3) shown in FIG. 5 is a chamfer portion formed in an inclined shape on both edges in the thickness direction of the inner peripheral end surface. Although the surface smoothness of the chamfer part (A3) is not really required, if necessary, the appearance of the chamfer part (A3) may be inspected in addition to the inner peripheral end face (A2).

Next, the operation of the visual inspection apparatus shown in FIG. 1 will be explained with reference to FIG. 2, together with its control system.

[0019] In the previous process, for example, from the washing and drying process to the conveying device (
The magnetic disk substrate (A) transferred to the work receiving stage (I) by 3) is passed from the chucker of the transport device (3) to the work holding part (2) of the turntable (1), and is transferred to the work holding part (2) of the turntable (1). ).

Next, the transport device (3) moves to the front process side to transport the next magnetic disk substrate, while the turntable (1) rotates 1/6 counterclockwise and stops. Due to this rotational feeding of the turntable (1), each workpiece holder (2) located on the previous stage moves to the next stage. That is, the holder (2) on which the magnetic disk substrate (A) is mounted on the receiving stage (I) moves to the first disk surface inspection stage (II), and then moves to the ejecting stage (
The holding part (2) which was located at the receiving stage (I
) and stop there.

[0021] At the first disk surface inspection stage (II), the surface of one side of the transferred magnetic disk substrate (A) is inspected to determine the presence and number of surface defects such as scratches and pinholes. . During this time, on the receiving stage (I), the next magnetic disk substrate is transported from the previous process by the transporting device (3), and is mounted on the next stage holding section (2) waiting on the receiving stage (I).

After the above-mentioned appearance inspection is completed, the turntable (1) is further rotated by 1/6. As a result, the magnetic disk substrate (A) of the first disk surface inspection stage (II) is transferred to the reversing stage (III), and the magnetic disk substrate (A) of the receiving stage (I) is transferred to the first disk surface inspection stage (I).
The work holding part (2), which was transferred to the receiving stage (I) and located at the take-out stage (VI), moves to the receiving stage (I). The magnetic disk substrate transferred to the reversing stage (III) is once removed from the chuck part (2a) by the reversing device (5) and turned over, and then transferred to the work holding part (2).
be reattached to. During this time, the appearance of one side of the second magnetic disk substrate is inspected on the first disk surface inspection stage (II), and the third magnetic disk substrate is mounted on the receiving stage (I).

After the reversing process on the reversing stage (III) is completed, the turntable (1) further rotates 1/6, and each magnetic disk substrate (A) is transferred to the next stage, and the take-out stage ( The work holding section (2) located at the stage VI) moves to the receiving stage (I). Magnetic disk substrate (A) transferred from the reversal stage (III) to the second disk surface inspection stage (IV)
Next, the appearance inspection device (4) performs an appearance inspection of the other side of the disk surface to determine the presence or absence of surface defects and the number thereof. During this time, the reversing stage (III), the first disk surface inspection stage (II), and the receiving stage (I) perform a reversing operation, a one-sided visual inspection, and a receiving operation of the magnetic disk substrate, respectively.

After the appearance inspection at the second disk surface inspection stage (IV), the turntable (1) is further inspected by 1/6
Rotating, each magnetic disk substrate is transferred to the next stage, and the magnetic disk (A) on the second disk surface inspection stage (IV) is then transferred to the outer peripheral end surface inspection stage (V). Then, on the stage, the appearance inspection device (7) performs an appearance inspection of the outer peripheral end surface of the magnetic disk substrate (A). At the same time, each stage performs its intended operation.

After the visual inspection of the outer peripheral end surface is completed, the turntable (1) rotates another 1/6 rotation, and each magnetic disk substrate is transferred to the next stage. Outer edge inspection stage (
The magnetic disk substrate (A) transferred from V) to the take-out stage (VI) is taken out from the work holding part (2) by the chucker of the transport device (8). During this time, the outer edge surface inspection stage (V), the second disk surface inspection stage (IV), the reversing stage (III), the first disk surface inspection stage (II), and the receiving stage (I) each inspect the next magnetic disk substrate. The outer peripheral end face inspection, other side visual inspection, reversal operation, one side visual inspection, and receiving operation are performed.

After the removal stage (VI) finishes taking out the magnetic disk substrates (A), the turntable (1) rotates another 1/6, and each magnetic disk substrate is transferred to the next stage. The empty work holding section (2) of the take-out stage (VI) is moved to the receiving stage (I).
Then, the same operation is repeated. Meanwhile, during this time, the magnetic disk substrate (A
) undergoes an external appearance inspection of the inner circumferential end surface by an inner circumferential end surface inspection device (9).

[0027] In this way, 1/1 of the turntable (1)
Since the magnetic disk substrates are transferred while sequentially moving around each stage by feeding and stopping in six rotations, a large number of magnetic disk substrates can be continuously and automatically subjected to visual inspection one after another. The magnetic disk substrate (A) whose inner circumferential end surface has been inspected is sent to, for example, a pass/fail screening process by the transport device (8), and is transferred to the first and second disk surface inspection stages (II) (IV) and the outer circumference. Based on the appearance inspection result at the end face inspection stage (V) and the inspection result of the inner peripheral end face, the products are sorted into non-defective products, defective products, and reworked products.

Note that in the end surface visual inspection apparatus according to the illustrated embodiment, the outer peripheral end surface inspection stage is provided, and the visual inspection of the inner peripheral end surface is performed on the workpiece take-out stage, but the inner peripheral end surface inspection stage is provided as a separate stage. You can set it, or you can inspect the outer edge surface on the extraction stage.
Alternatively, only one of them may be inspected for appearance. In short, any configuration is sufficient as long as the end face can be visually inspected at any time after the workpiece is transported from the previous process to the receiving stage, until it is taken out at the takeout stage and sent to the next process.

[0029]

Effects of the Invention In accordance with the above, the present invention includes a turntable having a workpiece holder around a rotating shaft which holds a plurality of workpieces detachably within a plane, and which is arranged so as to be rotatable and stopable. At least a workpiece receiving stage and a workpiece take-out stage are set around the rotation of the turntable, and after the workpiece conveyed from the previous process is held in the workpiece holding section at the workpiece receiving stage, the turntable is rotated intermittently. This is characterized in that the appearance of the end face of the workpiece is inspected during the process of rotating through each stage and transferring it to the workpiece take-out stage until it is further sent to the next step. Therefore, without having to wait for the end of the inspection process of one workpiece to finish, it is possible to perform visual inspections of a large number of workpieces one after the other. Compared to the case where end face inspection is performed, the number of workpieces that can be inspected per unit time can be increased to a large extent, and the efficiency of visual inspection of end faces can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a front view of a visual inspection device according to an embodiment of the present invention.

FIG. 2 is a front view of a state in which a visual inspection of the end face of a workpiece is actually performed.

FIG. 3 is a schematic configuration diagram of a disk surface inspection device.

FIG. 4 is a schematic configuration diagram of an outer peripheral end surface inspection device.

FIG. 5 is a schematic configuration diagram of an inner peripheral end surface inspection device.

FIG. 6 is a perspective view showing an aluminum magnetic disk substrate as a workpiece used in an example.

[Explanation of symbols]

A... Aluminum magnetic disk substrate (work) A1... Outer circumferential end surface A2... Inner circumferential end surface 1... Turntable, 2... Work holding part I... Work receiving stage V... Outer circumferential end surface inspection stage VI... Work taking out stage

Claims (2)

[Claims] Claim 1: A turntable (1) having a work holding part (2) for holding a plurality of workpieces (A) in a plane in a detachable manner around a rotating shaft is arranged so as to be rotatable and stopable, and At least a workpiece receiving stage (I) and a take-out stage (VI) are set around the rotation of the turntable (1), and the workpiece (A) conveyed from the previous step is transferred to the workpiece receiving stage (I). After being held in the workpiece holding section (2), the workpiece is transferred to the workpiece take-out stage (VI) through each stage by intermittent rotational feeding of the turntable (1), and is further sent to the next step. 1. An apparatus for inspecting the appearance of an end face of a workpiece, characterized in that the appearance inspection of the end face of the workpiece is performed. [Claim 2] An end face inspection stage (V) is set between the receiving stage (I) and the taking-out stage (VI) of the workpiece, and the workpiece (A) is transferred from the receiving stage (I) to the taking-out stage (VI). 2. The apparatus for visually inspecting the end face of a workpiece according to claim 1, wherein the end face of the workpiece is visually inspected on the peripheral end face inspection stage (V) during the process of being fed.