Inspection apparatus and inspection method for annular substrates

Abstract

To provide an inspection device and an inspection method for an annular substrate, which can continuously perform inspection without providing a preparation process in advance or stopping conveyance means during the inspection, and accurately detect a defect of the annular substrate punched from a rolled metal plate without requiring a plurality of light sources or correction processing.SOLUTION: An inspection device for an annular substrate comprises: an adjustment portion that detects rolling marks or grinding marks of the annular substrate to be conveyed and adjusts the rolling marks or the grinding marks of the annular substrate so as to align the detected rolling marks or grinding marks in a fixed direction; and a first defect inspection portion that has an inspection conveyor for conveying the annular substrate in which the rolling marks or the grinding marks are aligned in the fixed direction, a first illumination device for irradiating the annular substrate with light from above, and a first line camera for capturing a light irradiation surface of the annular substrate, and detects a defect on a surface of the annular substrate using the image of the light irradiation surface captured by the first line camera.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an inspection apparatus and an inspection method for an annular substrate that inspects defects such as flaws present on the surface of an annular substrate punched out from a rolled metal plate.

Background Art

[0002] Disk substrates used in information storage devices such as hard disk drives are generally made of aluminum. In the manufacture of disk substrates, an aluminum alloy is rolled, the rolled aluminum plate is punched into an annular shape to form a disk blank, the disk blank is subjected to pressure annealing for planarization, and mirror finishing by grinding is performed to form a ground substrate (hereinafter also referred to as an aluminum substrate). Thereafter, nickel-phosphorus plating is applied to the surface of this substrate, mirror finishing by polishing is performed, and then a magnetic film is formed thereon by sputtering.

[0003] At that time, if there are defects such as flaws and rust on the surface of the aluminum substrate, they may not be removed even by the subsequent polishing operation and may become defective products. Currently, from the perspective of resource depletion, recycling of various things is progressing, and recycling of metals that are consumed in large quantities has also been carried out for a long time. Therefore, in order to achieve efficient reuse from aluminum substrate to aluminum substrate, it is important to surely select and eliminate defective aluminum substrates before shipment. Therefore, before annealing the aluminum substrate for correction, the presence or absence of defects consisting of flaws and foreign substances on the surface of the aluminum substrate may be inspected.

[0004] In general, an optical inspection apparatus is used for the inspection of the surface of this aluminum substrate. The surface of the disk substrate conveyed to the inspection apparatus is illuminated by an illumination device, an image of the surface of the aluminum substrate is captured by an imaging device, and the presence or absence of defects is determined.

[0005] However, the surface of the aluminum substrates transported to the inspection device has minute, streaky irregularities that run in one direction, known as "rolling marks" from the rolling of the aluminum alloy or "grinding marks" from the mirror-finishing process by grinding. These irregularities affect the reflection of the illumination light. Since these rolling marks are not always aligned in a consistent direction when the substrates are transported to the inspection device, the illumination light is scattered and reflected depending on the direction of the rolling marks, resulting in insufficient contrast and making it difficult to accurately identify defects on the surface of the aluminum substrates.

[0006] To address these problems, for example, Patent Document 1 proposes a method for correcting laminated blanks, characterized by rotating the blank mounting table to align the rolling marks on the surface of each blank material in a consistent direction before performing corrective annealing on the blank blank material for magnetic disks, which is obtained by punching out metal strip material after rolling, and then stacking them one by one in a state where the rolling marks are aligned.

[0007] Furthermore, Patent Document 2 proposes a method for inspecting the position of a compound coating on a can lid, which involves changing the illumination direction that lights up the shoulder-side boundary of the compound applied to the curled portion of the can lid in accordance with the change in the rolling direction of the can lid due to the rotation of the turntable, thereby equalizing the brightness of the portion being measured and taking an image. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2001-148119 [Patent Document 2] Japanese Patent Publication No. 151803 / 1983 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] However, while Patent Document 1 describes a process for laminating blanks with aligned rolling marks beforehand, which allows for the straightening and annealing of aluminum substrates with aligned rolling marks, it does not describe or suggest that inspection problems can be resolved by aligning the rolling marks immediately before inspecting the aluminum substrates.

[0010] Furthermore, Patent Document 2 states that in order to perform inspections with high precision, it is necessary to move the lighting device or increase the number of lighting devices in order to appropriately change the direction of illumination by the lighting device, which makes it difficult to perform high-precision inspections.

[0011] The present invention has been made in view of the above circumstances, and aims to provide an inspection apparatus and inspection method for annular substrates that can perform inspections continuously without providing a prior preparation process or stopping the transport means during inspection, and can efficiently and accurately detect defects in annular substrates punched out from rolled metal sheets without providing multiple light sources irradiating from different angles or performing correction processing. [Means for solving the problem]

[0012] The above object of the present invention is achieved by the configuration of the inspection apparatus for annular substrates [1]. [1] An inspection apparatus for annular substrates that inspects defects present on the surface of annular substrates punched out from rolled metal sheets, An adjustment unit that detects the rolling marks or grinding marks on the transported annular substrate and adjusts the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction, The system comprises an inspection conveyor for transporting the annular substrate in which the rolled or ground marks are aligned in a certain direction; a first illumination device for irradiating the annular substrate with light from above; and a first line camera for photographing the light-irradiated surface of the annular substrate; and a first defect inspection unit for inspecting defects on the surface of the annular substrate using the image of the light-irradiated surface captured by the first line camera. An inspection device for annular substrates.

[0013] The above objective of the present invention is achieved by the configuration described in [2] below, relating to a method for inspecting an annular substrate. [2] A method for inspecting defects present on the surface of an annular substrate punched out from a rolled metal sheet, An adjustment step involves detecting the rolling marks or grinding marks on the annular substrate being transported, and adjusting the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction. The invention comprises a first defect inspection step in which, for an annular substrate that is transported with its rolled or ground marks aligned in a certain direction, light is irradiated onto the annular substrate from above using a first illumination device, and defects on the surface of the annular substrate are inspected using an image of the light-irradiated surface of the annular substrate captured by a first line camera. A method for inspecting annular substrates. [Effects of the Invention]

[0014] According to the inspection method for annular substrates of the present invention, even annular substrates with uneven rolling or grinding marks can be continuously inspected without stopping the transport means, and defects in annular substrates punched from rolled metal sheets can be efficiently and accurately detected without the need to provide multiple light sources irradiating from different angles or to perform correction processing. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the configuration of the inspection apparatus for an annular substrate according to the present invention. [Figure 2] This is a plan view showing the peeling device. [Figure 3] (A) to (C) are model diagrams illustrating the function of the detached nail portion. [Figure 4] (A) is a schematic diagram showing the operation of the peeling and conveying device, and (B) is a bottom view showing the suction conveyor. [Figure 5] This is a schematic diagram showing a phase adjustment device, a surface inspection device, and a back surface inspection device. [Figure 6](a) is a schematic diagram showing the light emitted from the surface of the metal substrate, and (b) is a schematic diagram showing the angle α formed by the conveyance direction of the metal substrate and the light. [Figure 7] It is a top view showing the phase matching part. [Figure 8] It is a side view showing the phase matching part. [Figure 9] It is a plan view showing the unloading device.

Embodiments for Carrying out the Invention

[0016] Hereinafter, an inspection apparatus for an annular substrate and an inspection method for an annular substrate according to an embodiment of the present invention will be described with reference to the drawings. Further, this embodiment shows an example of the present invention, and the present invention is not limited to this embodiment. Also, various changes or improvements can be made to this embodiment, and forms with such changes or improvements can also be included in the present invention.

[0017] As shown in FIG. 1, the inspection apparatus for an annular substrate of the present embodiment includes, in order from the upstream side in the conveyance direction, a loading device 10, a peeling device 20, a phase adjustment device 40, a surface inspection device 60, a back surface inspection device 70, and an unloading device 80. Hereinafter, each device will be described in detail. In the inspection apparatus of the present invention, an annular rolled substrate punched from a rolled aluminum plate in the manufacturing process of a disk substrate for HDD, or a ground substrate (annular aluminum substrate) obtained by subjecting this to pressure annealing and grinding is the object of inspection. Therefore, in this embodiment, this aluminum substrate is shown as a metal substrate W, and a stack obtained by laminating the metal substrates W is shown as a laminate 2. Further, this laminate 2 is obtained by laminating about 20 to 40 metal substrates W between two flat annular spacers inserted through shaft support portions (not shown) in the vertical direction and performing correction annealing. The laminate 2 has a columnar shape with a vertically penetrating through-hole formed at the center by pressing the flat surfaces of the metal substrates W stacked in the vertical direction against each other. Furthermore, the loading device 10, peeling device 20, phase adjustment device 40, surface inspection device 60, back surface inspection device 70, and unloading device 80 are connected to the processing unit 100 by wire or wireless connection, and control is performed for each device. Note that each of the devices 10, 20, 40, 60, 70, and 80 may be provided with a separate control unit (not shown).

[0018] (Loading device 10) The loading device 10 transports the laminated body 2, which has been loaded to a predetermined loading position by a transport conveyor (not shown), to the vicinity of the peeling device 20, and then transports the laminated body 2 to the laminated body support section 21 of the peeling device 20, which will be described later, by a transfer section.

[0019] (Peeling device 20) As shown in Figure 2, the peeling device 20 includes a laminate support section 21, a pressing section 22, a peeling claw section 23, an air blow device 24, a height detection device 25, a suction conveyor 30, a first transport conveyor 26, a thickness detection sensor 27, and an overlapping substrate discharge section 28. The peeling device 20 performs a peeling step in which one metal substrate W is peeled from the upper surface of the laminate 2 supported by the laminate support section 21 in the loading step and transported to the phase adjustment device 40 side, and an overlapping substrate discharge step in which, if an overlapping state is detected in which two or more metal substrates W peeled from the laminate 2 in the peeling step are stacked on top of each other, the metal substrates W are discharged from the transport path.

[0020] The peeling process begins by adjusting the support height of the laminate 2 so that the upper surface of the laminate 2, which was brought into the laminate support section 21 by the loading process, is at a predetermined working height. Next, the outer surface of the laminate 2 is pressed down by the pressing section 22. Then, the first metal substrate W from the top of the laminate 2 is peeled off by the peeling claws 23A. At this time, the air blow device 24 supplies air towards the laminate 2 to assist in the peeling of the metal substrate W from the laminate 2. Next, the upper surface of the metal substrate W peeled off from the laminate 2 is picked up by the suction conveyor 30 and transported towards the first transport conveyor 26.

[0021] At this point, the height of the laminate 2 decreases due to the removal of the metal substrate W from the top surface of the laminate 2. Therefore, the support position of the laminate 2 is adjusted using the laminate support section 21 and the height detection device 25 to bring the top surface of the laminate 2 to a predetermined working height. The above process is then repeated until all of the metal substrate W has been removed from the laminate 2.

[0022] The overlapping substrate discharge process first detects whether two or more metal substrates W are overlapping by detecting the thickness of the metal substrates W being transported by the first conveyor belt 26 using a thickness detection sensor 27. Next, if an overlapping state of metal substrates W is detected, the overlapping substrate discharge unit 28 discharges the overlapping metal substrates W from the transport path of the first conveyor belt 26.

[0023] The laminate support section 21 includes a support shaft (not shown) inserted through the center of the laminate 2, and a support base that can adjust the support position of the placed laminate 2 in the vertical direction. As shown in Figure 2, the laminate support sections 21 are arranged in pairs so as to sandwich the transport start end side of the suction conveyor 30 in a plan view.

[0024] The pressing portions 22 are arranged in pairs so as to sandwich the laminate 2 in a plan view. Each pressing portion 22 has a pressing piece 22A that extends in the vertical direction and presses the outer surface of the laminate 2, excluding the first annular substrate from the top, and a pressing piece support portion 22B that supports the pressing piece 22A so that it can move back and forth in an advance direction toward the outer surface of the laminate 2 and in a retraction direction away from the outer surface of the laminate 2.

[0025] The pressing piece 22A has a pressing surface formed in an arc shape in plan view along the outer circumferential surface of the laminate 2, and is molded from a high-friction rubber or polymer material. The pressing piece support 22B can switch between a pressing position in which a pair of pressing pieces 22A are simultaneously in contact with the outer circumferential surface of the laminate 2, and a non-pressing position in which the pair of pressing pieces 22A are separated from the laminate 2.

[0026] Furthermore, the pressing portion 22 only needs to be configured to allow the peeling operation to be performed by the peeling claw portion 23 to peel off the first metal substrate W from the top of the laminate 2 by pressing on the outer surface of the laminate 2. In other words, the pressing piece 22A is not limited to a configuration that presses on the outer surfaces of all metal substrates W except for the first one from the top of the laminate 2. For example, it may be configured to press only on the outer surface of the second annular substrate from the top of the laminate 2.

[0027] The peeling claw portions 23 are arranged at three equal intervals on the outer circumference of the laminate 2 in a plan view. Each peeling claw portion 23 has a peeling claw 23A that contacts the outer surface side of the first metal substrate W from the top of the laminate 2, and a claw support portion 23B that supports the peeling claw 23A so that it can move back and forth in an advance direction toward the outer surface of the laminate 2 and in a separation direction away from the outer surface of the laminate 2.

[0028] The peeling claw 23A extends horizontally toward the outer circumferential surface of the laminate 2, and its base end is supported by the claw support portion 23B via a horizontal pivot axis 29 that allows only upward oscillation. As a result, as shown in Figures 3(A) to (C), when the peeling claw 23A contacts the outer circumferential surface of the first metal substrate W from the top of the laminate 2, it oscillates upward due to the reaction force received from the laminate 2 side. In other words, the peeling claw portion 23 can lift the metal substrate W, so that the first metal substrate W from the top of the laminate 2 can be peeled off efficiently and reliably.

[0029] Furthermore, the peeling claws 23A are not limited to the above configuration, as long as they can act simultaneously from three locations on the outer circumferential surface of the laminate 2 to peel off the first metal substrate W from the top of the laminate 2. For example, the peeling claws 23A may be configured to have an insertion part (not shown) that enters between the first metal substrate W from the top and the second metal substrate from the top of the laminate to peel off the first metal substrate W from the top of the laminate 2.

[0030] Multiple air blow devices 24 are arranged around the laminate 2 in a plan view; in the illustrated example, there are two. Each air blow device 24 supplies air from different angles toward the upper outer surface of the laminate 2 in a plan view. In other words, the air blow devices 24 promote the peeling of the metal substrate W from the top surface of the laminate 2, and the peeling claws 23 lift the metal substrate W that has been peeled from the laminate 2, allowing it to be smoothly and reliably picked up by the suction conveyor 30.

[0031] The height detection device 25 includes a height detection sensor 25A, which consists of a laser sensor or optical sensor, etc., that is irradiated toward the outer surface of the laminate; a sensor support part 25B that supports the height detection sensor 25A in a height-adjustable manner; and a receiving plate 25B that is installed in the direction of irradiation of the height detection sensor 25A and on the opposite side of the laminate 2 in a plan view. The height detection device 25 can detect when the laminate 2, supported by the laminate support part 21, is supported at a working height at which the peeling device 20 can perform the peeling operation of the first metal substrate W from the top.

[0032] Specifically, when the first metal substrate W from the top of the laminate 2 is removed by the peeling device 20, the height of the laminate 2 decreases by the height of one metal substrate W. As a result, the laser or light from the height detection sensor passes above the top surface of the laminate 2 and shines onto the receiving plate 25C. Therefore, it is possible to detect that the top surface of the laminate 2 is lower than the height position at which the peeling operation is performed. When this condition is detected, the support position of the laminate 2 by the laminate support part 21 is raised until the laser or light from the height detection sensor 25A is blocked by the outer surface of the laminate 2, thereby adjusting the laminate 2 to a predetermined working height.

[0033] The thickness detection sensor 27 is positioned above the transport path of the first transport conveyor 26, which receives the metal substrate W peeled off from the suction conveyor 30. By detecting the height distance from above the first transport conveyor 26 to the metal substrate W, the thickness detection sensor 27 can determine whether the metal substrate W peeled off from the laminate by the peeling device 20 is a single peeled sheet or a stack of two or more sheets.

[0034] The overlapping substrate discharge unit 28 includes a discharge chute 28A located on one side of the first conveyor belt 26 and an extrusion device 28B located on the other side of the first conveyor belt 26 that moves back and forth toward the discharge chute 28A. When the thickness detection sensor 27 detects that the metal substrates W on the first conveyor belt 26 are overlapping, the overlapping metal substrates W on the first conveyor belt 26 are pushed toward the discharge chute 28A by the extrusion device 28B.

[0035] Here, the suction conveyor 30 will be described in detail based on Figure 4. Figure 4(A) is a model diagram showing the operation of the suction conveyor, and Figure 4(B) is a bottom view of the main part of the suction conveyor.

[0036] The suction conveyor 30 comprises a rectangular parallelepiped housing 31 with an open bottom, a pair of left and right suction conveying belts 32A and 32B extending along the longitudinal direction on the lower surface of the housing 31, a suction device 33 positioned on the upstream side of the conveying on the upper part of the housing 31, and a vertical pivot support 34 provided on the downstream side of the conveying on the upper part of the housing 31.

[0037] As shown in Figure 4(A), the suction conveying belts 32A and 32B are routed by a plurality of driven pulleys 35 arranged in a row along the longitudinal direction of the housing 31 and a drive pulley 36 driven by a motor (not shown). The suction conveying belts 32 are arranged in pairs on both sides in the width direction of the conveying path on the lower surface of the housing 31, thereby supporting both outer edges of the upper surface of the metal substrate W. As a result, an opening is formed between the pair of suction conveying belts 32, on the longitudinal center side of the lower surface of the housing 31.

[0038] As shown in Figure 4(B), the suction conveying belts 32A and 32B are formed with a circular cross-section to reduce the contact area with the metal substrate W, while the use of two conveying belts 32A and 32B distributes the load on the metal substrate W. As a result, even if the conveying belts 32A and 32B come into sliding contact with the metal substrate W when the metal substrate W is peeled off from the laminate 2, the metal substrate W can be conveyed at high speed without damage.

[0039] The suction device 33 is positioned between a pair of left and right suction conveying belts. The suction device 33 is located upstream of the suction conveyor 30 and is positioned so as to overlap with the laminated body 2 of the laminated body support section 21 in a plan view.

[0040] According to the suction conveyor 30 configured above, first, the metal substrate W detached from the laminate 2 is sucked up by a suction device 33 positioned directly above the laminate 2, and both ends of the upper surface of the metal substrate W are supported by suction conveying belts 32A and 32B. Next, the metal substrate W supported by the suction conveying belts 32A and 32B by the suction device 33 is conveyed by the suction conveying belts 32A and 32B to the first conveying conveyor 26 downstream. Then, the metal substrate W that has been conveyed to the starting end of the first conveying conveyor 26 by the suction conveying belts 32A and 32B falls freely onto the first conveying conveyor 26 by its own weight because the suction force received from the suction device 33 weakens as the distance to the suction device 33 increases.

[0041] Furthermore, the suction conveyor 30 is supported so as to be able to swing from side to side on a pivot shaft inserted through the shaft support 34. As a result, when the suction conveyor 30 swings to one side, the suction device 33 is positioned directly above one of the laminate support sections 21 in a plan view, and when it swings to the other side, the suction device 33 is positioned directly above the other laminate support section 21 in a plan view.

[0042] As a result, when the suction conveyor 30 swings to one side on the pivot axis 34, the peeling device 20 peels the metal substrate W from the laminate 2 supported by the laminate support section 21 on the swinging side. At this time, the loading device 10 loads the laminate 2 into the laminate support section 21 on the other side. Next, when the peeling of all the metal substrates W from the laminate 2 located on one side is completed, the suction conveyor 30 automatically swings from one side to the other, and the peeling device 20 peels the metal substrate W from the laminate 2 supported by the laminate support section 21 on the other side. At this time, the loading device 10 loads the laminate 2 into the laminate support section 21 on one side.

[0043] With the above-described loading device 10 and peeling device 20, the loading of the laminate 2 by the loading device 10 and the peeling of the metal substrate W from the laminate 2 by the peeling device 20 can be performed continuously without interruption, thus increasing work efficiency.

[0044] (Phase adjustment device 40) The phase adjustment device 40 includes a phase detection unit 41 and a phase alignment unit (phase adjustment conveyor) 42. In the phase adjustment device 40, as the next step after the peeling process of the metal substrate by the peeling device 20, the phase detection unit 41 detects the phase of the conveyed metal substrate W, which consists of the rolling marks Wa or grinding marks, and the phase alignment unit 42 performs a phase adjustment process (adjustment process) to align the phase of the metal substrate W in a certain direction.

[0045] The phase detection unit 41 first receives the metal substrate W, which is transported from the peeling device 20 by the first transport conveyor 26, on the second transport conveyor 46, and irradiates light from a ring illumination device 47, which is a phase detection illumination device positioned above the metal substrate W. The surface of the metal substrate W has minute streaks of irregularities, i.e., rolling marks (or grinding marks due to mirror finishing by grinding), Wa formed on it due to rolling. When light is irradiated onto the surface of the metal substrate W, as shown in Figure 6(a), light rays 15 appear perpendicular to the rolling marks Wa, and these light rays 15 are photographed by a CCD camera 48, which is an area camera used as an imaging device for phase detection.

[0046] Then, as shown in Figure 6(b), the processing unit 100 determines the angle α between the axis C1 of the light ray 15 and the axis C2 of the transport direction of the metal substrate W.

[0047] The phase alignment section 42 is located downstream of the second conveyor belt 46 and includes a first angle-swinging conveyor section 51 and a second angle-swinging conveyor section 52, which are provided on both sides in the width direction of the conveying path and are driven independently of each other to convey at different speeds. Figure 7 is a top view of the phase alignment section 42, and Figure 8 is a side view thereof.

[0048] The first angle-swinging conveyor section 51 and the second angle-swinging conveyor section 52 each include servo motors (drive motors) 51a and 52a mounted on the housing 50, a power transmission section 58 such as a belt pulley arranged inside the housing 50 to transmit power from the servo motors 51a and 52a to the drive pulley 53a, and a plurality of conveyor belts 54 and 55 with a circular cross-section (two in this embodiment) wrapped around the drive pulley 53a and a plurality of driven pulleys 53b.

[0049] Furthermore, the first angle-swinging conveyor section 51 and the second angle-swinging conveyor section 52 are provided with resin guide members 56 having guide surfaces that extend along the conveying direction, on the portion of the housing 50 facing the outer surface of the metal substrate W being conveyed, so as to guide the outer surface of the metal substrate W.

[0050] As a result, the transport speed of the first angle-swinging conveyor section 51 is adjusted by the rotation speed of the servo motor 51a, and the transport speed of the second angle-swinging conveyor section 52 is adjusted by the rotation speed of the servo motor 52a. Furthermore, by making the transport speeds of the first angle-swinging conveyor section 51 and the second angle-swinging conveyor section 52 different, the metal substrate W rotates horizontally while being transported at high speed through the phase alignment section 42 in approximately 0.5 seconds, guided by the guide surface of the guide member 56.

[0051] In other words, if the transport speed of the first angle-swinging conveyor section 51 is set faster than the transport speed of the second angle-swinging conveyor section 52, the metal substrate W will rotate clockwise in Figure 7. Conversely, if the transport speed of the second angle-swinging conveyor section 52 is set faster than the transport speed of the first angle-swinging conveyor section 51, the metal substrate W will rotate counterclockwise in Figure 7. Therefore, by adjusting the difference in transport speed between the first angle-swinging conveyor section 51 and the second angle-swinging conveyor section 52 according to the angle α formed by the axis C1 of the light ray 15 detected by the phase detection section 41 and the axis C2 of the transport direction of the metal substrate W, the angle α of the metal substrate W can be kept within a predetermined range.

[0052] Furthermore, the first angle-swinging conveyor section 51 and the second angle-swinging conveyor section 52 reduce the contact area with the metal substrate W by using conveyor belts 54 and 55 with a circular cross-section, while the load on the metal substrate W can be distributed by using two conveyor belts 54 and 55. As a result, even if the conveyor belts 54 and 55 come into sliding contact with the metal substrate W during phase adjustment, the metal substrate W can be transported at high speed without being damaged.

[0053] The rolled edges Wa of the metal substrates W transported from the peeling device 20 are oriented in various directions for each substrate W, and the angle α also has various values. However, the phase alignment unit 42 ensures that the rolled edges Wa of all metal substrates W are substantially aligned in the transport direction. In this embodiment, the resolution of the angle α by the phase alignment unit 42 is ±2°, and the correction accuracy is within ±5°.

[0054] Furthermore, the phase alignment unit 42 is equipped with an upstream transmission sensor 57A and a downstream transmission sensor 57B on the upstream and downstream sides of the first angle swing conveyor unit 51 and the second angle swing conveyor unit 52, respectively. Furthermore, if the upstream transmission sensor 57A detects the input of a metal substrate W before the downstream transmission sensor 57B detects the discharge of the metal substrate W, the surface inspection device 60 will either not perform the inspection on the metal substrate W detected by the upstream transmission sensor 57A, or will not treat the inspection result as a correct inspection, and will send it to the next process.

[0055] In this embodiment, the phase detection unit 41 detects the angle α when the metal substrate W is on the second conveyor belt 46, but it may also be performed when the metal substrate W is on the first angle swing conveyor belt 51 and the second angle swing conveyor belt 52 of the phase alignment unit 42. In this case, the phase detection unit 41 detects the angle α upstream of the first angle swing conveyor belt 51 and the second angle swing conveyor belt 52, and then the adjustment of the conveying speed of the first angle swing conveyor belt 51 and the second angle swing conveyor belt 52 is started.

[0056] (Surface inspection device 60) The surface inspection device 60 performs a first defect inspection process in the next step after the phase alignment unit 42, which involves inspecting defects on the surface of the metal substrate W. As shown in Figure 5, the inspection method involves irradiating the surface of the metal substrate W, which is being transported by the inspection conveyor 63, with light from a first illumination device 64 positioned above the inspection conveyor 63, and then using a CCD line camera, which is a first imaging device 65 positioned above the first illumination device 64, to photograph the surface of the metal substrate W and perform image analysis to check for defects.

[0057] The first illumination device 64 uses line-type illumination so that the entire width of the metal substrate W to be photographed by the first imaging device 65 is illuminated. Since the first imaging device 65 uses a CCD line camera, observation is possible if there is a gap the size of one line of the CCD array, and stable inspection is possible by scanning and combining the imaging results.

[0058] Furthermore, because the direction of the rolling marks Wa of the metal substrate W is aligned by the phase alignment unit 42, the metal substrate W imaged by the first imaging device 65 is eliminated from the camera image for all metal substrates W, preventing diffuse reflection and dark-field conditions, thus enabling high-precision line inspection.

[0059] (Back surface inspection device 70) The back surface inspection device 70 performs a second defect inspection process in the next step after the first defect inspection process, in which defects on the back surface of the metal substrate W are inspected. As shown in Figure 5, the inspection method involves lifting the top surface of the metal substrate W with a suction conveyor 71, irradiating the back surface of the metal substrate W with light using a second illumination device 72 positioned below the suction conveyor 71, and taking a picture of the back surface of the metal substrate W using a CCD line camera, which is a second imaging device 73, and then analyzing the image to check for defects.

[0060] The second illumination device 72 uses line-type illumination so that the entire width of the metal substrate W, which is photographed by the second imaging device 73, can be illuminated. Since the second imaging device 73 uses a CCD line camera, observation is possible if there is a gap the size of one line of the CCD array, and stable inspection is possible by scanning and combining the imaging results.

[0061] The suction conveyor 71 comprises a rectangular parallelepiped housing 74 with an open bottom, a pair of left and right suction conveying belts 75, 75 extending along the longitudinal direction on the lower surface of the housing 74, and a suction device 76 positioned on the upper upstream side of the housing 74.

[0062] The suction conveyor 71, like the suction conveyor 30 shown in Figure 4(A), can transport a metal substrate W that has been adsorbed onto the suction conveying belt 75 by the suction device 76. At this time, the metal substrate W is supported on its upper side by the suction conveying belt 75 and its lower side is open. Therefore, as shown in Figure 5, the lower side of the metal substrate W can be photographed by the second imaging device 73 located below the suction device 76.

[0063] Furthermore, the rolling marks Wa formed on the front and back surfaces of the metal substrate W are formed in substantially the same direction on both sides of the metal substrate W. Therefore, the metal substrate W received by the suction conveyor 71 of the back surface inspection device 70 from the inspection conveyor 63 of the surface inspection device 60 is maintained in a state of aligned phase by the phase alignment unit 42. In other words, the suction conveyor 71 can transport metal substrate W with aligned rolling marks Wa on the back surface.

[0064] The metal substrates W imaged by the first imaging device 65 and the second imaging device 73 are aligned in the direction of the rolling grain Wa of the metal substrates W by the phase alignment unit 42. As a result, diffuse reflection and dark field conditions do not occur in the camera image for all metal substrates W, enabling high-precision line inspection.

[0065] As described above, the defect inspection of the front and back surfaces of the metal substrate W is completed. Note that the front surface inspection device 60 and the back surface inspection device 70 may be arranged in reverse order, provided that the metal substrate W to be inspected has undergone the phase adjustment process by the phase adjustment device 40.

[0066] (Unloading device 80) As shown in Figures 5 and 9, the discharge device 80 includes a third transport conveyor 81 that receives the metal substrates W that have been transported by suction at the transport end of the suction conveyor 71, a sorting conveyor 82 that sorts the metal substrates W received from the third transport conveyor 81 to three locations according to the inspection results, and three discharge conveyors 83, 84, and 85 that discharge the metal substrates W that have been inspected from the sorting conveyor 82.

[0067] The distribution conveyor 82 is positioned downstream of the third transport conveyor 81 and is pivotally supported so as to be able to swing from side to side around its transport base end.

[0068] Downstream of the sorting conveyor 82, the following conveyors are arranged radially in a plan view as destinations for the inspection-completed metal substrates W: a first discharge conveyor 83 for discharging metal substrates W1 in which no defects were found, a second discharge conveyor 84 for discharging metal substrates W2 in which defects were found, and a third discharge conveyor 85 for discharging metal substrates W3 in which there were problems in the inspection process.

[0069] As described above, the surface inspection device 60 and the back surface inspection device 70 determine whether the product is a good product W1 without defects, a defective product W2, or a product W3 that has not been properly inspected or requires re-inspection. For this reason, the sorting conveyor 82 sorts the metal substrates W1, W2, and W3 to their respective destinations by oscillating from side to side according to the inspection results of the good product W1, the defective product W2, and the product W3 that requires re-inspection.

[0070] At the transport end of the first discharge conveyor 83, a good product recovery device 86 is provided for recovering metal substrates W1 in which no defects were found. The good product recovery device 86 includes a disc-shaped turntable with vertically oriented support shafts arranged at predetermined angles through which the central holes of the metal substrates W1 are inserted, a motor (not shown) that rotates the turntable around the central shaft, and a sensor (not shown) that detects the height of the metal substrates W stacked on the support shafts. In the illustrated example, the support shafts on the turntable are arranged at 90° intervals around a central rotation axis and rotated at 90° intervals by the motor.

[0071] A defective product recovery device 87 for recovering metal substrates W2 in which defects have been found is provided at the transport end of the second discharge conveyor 84, and a re-inspection product recovery device 88 for recovering metal substrates W3 that require re-inspection is provided at the transport end of the third discharge conveyor 85. The defective product recovery device 87 and the re-inspection product recovery device 88 each consist of a turntable made of a longitudinal plate-shaped member with vertical support shafts arranged at both ends through which the central holes of the metal substrates W2 and W3 are inserted, a motor (not shown) that rotates the turntable around the central shaft, and a sensor (not shown) that detects the height of the metal substrates W stacked on the support shaft. In the illustrated example, the turntable rotates every 180° by the motor.

[0072] As described above, each recovery device 86, 87, and 88 positions a support shaft on the transport end side of each discharge conveyor 83, 84, and 85, and stacks the metal substrates W with their centers inserted through the support shafts. When it is detected that the stacked metal substrates W on the turntable have reached a predetermined height, the turntable is rotated so that the adjacent support shafts are positioned on the transport end side of each discharge conveyor. In other words, the worker can efficiently discharge the metal substrates W1, W2, and W3 being discharged from each discharge conveyor 83, 84, and 85 after stacking a predetermined number of them using each recovery device 86, 87, and 88.

[0073] According to the inspection apparatus of this embodiment, it is possible to inspect with high precision for defects in a ground substrate board, which is obtained by grinding a blank punched out from a metal plate with a PVA grinding wheel. The disk substrates that pass both the surface inspection apparatus 60 and the back surface inspection apparatus 70 are subjected to zincate treatment, electroless nickel-phosphorus plating, polishing, and then a magnetic film is deposited thereon by sputtering, according to conventional methods.

[0074] It should be noted that the present invention is not limited to the embodiments described above, and can be modified or improved as appropriate. For example, the phase adjustment conveyor of this embodiment is not limited to surface inspection systems, but can be applied to any system that requires a mechanism to rotate a ring-shaped metal substrate while transporting it.

[0075] As described above, the following matters are disclosed in this specification: (1) An inspection device for annular substrates that inspects defects present on the surface of annular substrates punched out from rolled metal sheets, An adjustment unit that detects the rolling marks or grinding marks on the transported annular substrate and adjusts the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction, The system comprises an inspection conveyor for transporting the annular substrate in which the rolled or ground marks are aligned in a certain direction; a first illumination device for irradiating the annular substrate with light from above; and a first line camera for photographing the light-irradiated surface of the annular substrate; and a first defect inspection unit for inspecting defects on the surface of the annular substrate using the image of the light-irradiated surface captured by the first line camera. An inspection device for annular substrates. With this configuration, even annular substrates with uneven rolling or grinding marks can be inspected continuously without stopping the transport mechanism, and defects in each annular substrate punched from a rolled metal sheet can be accurately detected without requiring multiple light sources or correction processing.

[0076] (2) A second defect inspection unit comprising: a substrate holding device that suctions and transports the upper surface of the annular substrate having rolled or ground marks aligned in a certain direction; a second illumination device that irradiates light from below onto the annular substrate whose upper surface is held by the substrate holding device; and a second line camera that photographs the light-irradiated surface of the annular substrate, and further comprising a second defect inspection unit that inspects defects on the back surface of the annular substrate using the image of the light-irradiated surface captured by the second line camera, (1) An inspection apparatus for the annular substrate described above. This configuration allows for consistent defect inspection of both the front and back surfaces of a ring-shaped substrate, and also enables inspection of the back surface of the ring-shaped substrate without having to flip it over, thus improving work efficiency.

[0077] (3) The substrate holding device comprises a suction device positioned in a location that overlaps with the second line camera in a plan view and which sucks the central side of the upper surface of the annular substrate, and a pair of left and right suction conveying belts that extend along the conveying direction and are arranged to support both ends of the outer circumference of the upper surface of the annular substrate, (2) An inspection apparatus for the annular substrate described above. With this configuration, the back surface of the annular substrate can be photographed while the substrate holding device is holding and transporting the annular substrate. Furthermore, since the substrate holding device and the second line camera are arranged to overlap in a plan view, and the configuration for flipping the annular substrate can be omitted, the second defect inspection unit can be simplified.

[0078] (4) The adjustment unit is The system includes an illumination device for detecting rolling marks or grinding marks on the annular substrate, an area camera for photographing the light-illuminated surface of the annular substrate, and a first angle-swinging conveyor section and a second angle-swinging conveyor section arranged side by side along the transport direction and driven independently of each other to transport at different transport speeds. The area camera captures the light rays appearing in a direction perpendicular to the rolling or grinding marks of the annular substrate, and detects the angle that the axis of the light rays makes with respect to the transport direction. Based on this angle, the transport speeds of the first angle-swinging conveyor section and the second angle-swinging conveyor section are adjusted to rotate the annular substrate horizontally while transporting it, thereby aligning the angle within a predetermined range with respect to the transport direction of the annular substrate. An inspection apparatus for annular substrates as described in any one of (1) to (3). With this configuration, annular substrates with aligned rolling or grinding marks can be sent to the first defect inspection unit, thereby enabling accurate defect inspection of the annular substrates.

[0079] (5) A loading mechanism provided upstream of the adjustment section for loading a cylindrical laminate formed by stacking multiple annular substrates, The system includes a peeling mechanism for peeling off the first annular substrate from the top of the laminate that has been brought in by the aforementioned loading mechanism. An inspection apparatus for annular substrates as described in any one of (1) to (4). With this configuration, the process of loading the laminate into the inspection device and the process of peeling the annular substrate from the laminate can be automated as an integrated unit, thus enabling efficient inspection of annular substrates.

[0080] (6) The peeling mechanism comprises a pressing portion that presses the outer surface of the laminate excluding the first annular substrate from the top, a peeling claw that peels the first annular substrate from the top of the laminate, and a peeling and transporting device that transports the annular substrate peeled off by the peeling claw. (5) An inspection apparatus for the annular substrate described above. With this configuration, the annular substrates can be peeled off one by one from the top of the laminate, and the peeled annular substrates can be efficiently transported to the adjustment section.

[0081] (7) The peeling and conveying device comprises a suction device positioned in a location that overlaps with the laminate in a plan view and sucks the central side of the upper surface of the annular substrate, and a pair of suction conveying belts arranged on the left and right so as to extend along the conveying direction and support both ends of the outer circumference of the upper surface of the annular substrate, (6) An inspection apparatus for the annular substrate described above. With this configuration, by positioning the suction device between a pair of left and right suction conveying belts, the suction force from the suction device can be efficiently applied to the upper surface of the annular substrate. As a result, the peeling and conveying device can smoothly and reliably suction, hold, and convey the annular substrate peeled from the upper surface of the laminate.

[0082] (8) The peeling mechanism further includes a thickness detection sensor that detects that two or more annular substrates peeled from the laminate are stacked on top of each other, and an overlapping substrate discharge unit that discharges the overlapping annular substrates from the transport path. An inspection apparatus for annular substrates as described in any one of (5) to (7). With this configuration, if the annular substrates that have been peeled from the laminate by the peeling mechanism become overlapped, the overlapping annular substrates can be discharged from the transport path before being transported to the adjustment unit. This prevents inspection defects from occurring due to inspecting the overlapping annular substrates as they are, and also prevents malfunctions from occurring when the overlapping annular substrates are transported to the adjustment unit or the first defect inspection unit.

[0083] (9) The device is equipped with an unloading mechanism for unloading the annular substrate after inspection has been completed, The discharge mechanism distributes the annular substrates that have been inspected to a first discharge section for discharging those annular substrates in which no defects were found, a second discharge section for discharging those annular substrates in which defects were found, and a third discharge section for discharging those annular substrates that had problems during inspection by the first defect inspection section. An inspection apparatus for annular substrates as described in any one of (1) to (8). With this configuration, the discharge mechanism automatically sorts the annular substrates into those that did not show any defects, those that did show defects, and those that had problems in the inspection process, according to the inspection results. This allows for the efficient extraction of annular substrates with good inspection results. Furthermore, by re-inspecting the annular substrates that had problems in the inspection process, it is possible to efficiently prevent the discarding of annular substrates that do not have defects.

[0084] (10) A method for inspecting defects present on the surface of an annular substrate punched out from a rolled metal sheet, An adjustment step involves detecting the rolling marks or grinding marks on the annular substrate being transported, and adjusting the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction. The invention comprises a first defect inspection step in which, for an annular substrate that is transported with its rolled or ground marks aligned in a certain direction, light is irradiated onto the annular substrate from above using a first illumination device, and defects on the surface of the annular substrate are inspected using an image of the light-irradiated surface of the annular substrate captured by a first line camera. A method for inspecting annular substrates. With this configuration, the first defect inspection process can be performed on an annular substrate with aligned rolling or grinding marks, thus enabling efficient and accurate defect inspection of the annular substrate.

[0085] (11) A substrate holding device for adsorbing and transporting the upper surface of the annular substrate having rolled or ground marks aligned in a certain direction; a second illumination device for irradiating light from below onto the annular substrate whose upper surface is held by the substrate holding device; and a second line camera for photographing the light-irradiated surface of the annular substrate, further comprising a second defect inspection step for inspecting defects on the back surface of the annular substrate using the image of the light-irradiated surface captured by the second line camera. (10) The method for inspecting the annular substrate described above. This configuration allows for consistent defect inspection of both the front and back surfaces of a ring-shaped substrate, and also enables inspection of the back surface of the ring-shaped substrate without having to flip it over, thus improving work efficiency.

[0086] (12) The second defect inspection step involves using a suction device positioned to overlap with the second line camera in a plan view to suck the central side of the upper surface of the annular substrate, and using a pair of left and right suction conveying belts extending along the conveying direction to support both ends of the outer circumference of the upper surface of the annular substrate, thereby holding and conveying the upper surface of the annular substrate in which the rolled or ground marks are aligned in a certain direction. (11) The method for inspecting the annular substrate described. With this configuration, the substrate holding device can photograph the back surface of the annular substrate while it is being transported, allowing for efficient inspection without having to flip the annular substrate over.

[0087] (13) The adjustment step involves irradiating the annular substrate with light using an illumination device for detecting rolling marks or grinding marks, detecting the angle that the axis of the light rays appearing perpendicular to the rolling marks or grinding marks of the annular substrate makes with respect to the transport direction using an image of the light-irradiated surface of the annular substrate captured by an area camera, and adjusting the transport speeds of the first angle-swinging conveyor section and the second angle-swinging conveyor section, which are arranged side by side along the transport direction and driven independently of each other to transport at different transport speeds, based on the angle, and rotating the annular substrate horizontally while transporting it, thereby aligning the angle within a predetermined range with respect to the transport direction of the annular substrate. A method for inspecting an annular substrate as described in any one of (10) to (12). This configuration allows for the inspection of annular substrates with aligned rolling or grinding marks, thus enabling accurate defect inspection of annular substrates.

[0088] (14) The adjustment step further comprises a loading step of loading a cylindrical laminate formed by stacking a plurality of the annular substrates, and a peeling step of peeling off the first annular substrate from the top of the laminate loaded in the loading step. A method for inspecting an annular substrate as described in any one of (10) to (13). With this configuration, the process of loading the laminate into the inspection device and the process of peeling the annular substrate from the laminate can be automated as an integrated unit, allowing for more efficient inspection of the annular substrate.

[0089] (15) The peeling step involves pressing the outer surface of the laminate, excluding the first annular substrate from the top, with a pressing part, peeling the first annular substrate from the top of the laminate with a peeling claw, and transporting the annular substrate peeled from the laminate with a peeling transport device. (14) The method for inspecting the annular substrate described. With this configuration, the annular substrates can be peeled off one by one from the top of the laminate, and the peeled annular substrates can be efficiently transported to the adjustment section.

[0090] (16) The peeling step involves using a suction device positioned to overlap with the laminate in a plan view to suck the central side of the upper surface of the annular substrate, and using a pair of left and right suction conveying belts extending along the conveying direction to support both ends of the outer circumference of the upper surface of the annular substrate, thereby holding and conveying the upper surface of the annular substrate that has been peeled from the laminate. (15) The method for inspecting the annular substrate described. With this configuration, the suction force from the suction device can be efficiently applied to the upper surface of the annular substrate, allowing the annular substrate, which has been peeled off from the upper surface of the laminate, to be smoothly and reliably adsorbed, held, and transported.

[0091] (17) A thickness detection sensor is provided to detect that two or more annular substrates peeled from the laminate are stacked on top of each other, and a double substrate discharge step is provided for discharging the stacked annular substrates from the transport path, further comprising: A method for inspecting an annular substrate as described in any one of (14) to (16). This configuration prevents overlapping annular substrates from undergoing adjustment operations for rolled or ground marks during the adjustment process, and also prevents them from being inspected as they are during the first defect inspection process.

[0092] (18) The process further comprises an unloading step for unloading the annular substrate after the inspection has been completed, The aforementioned unloading process sorts the annular substrates that have been inspected into a first unloading section for unloading those in which no defects were found, a second unloading section for unloading those in which defects were found, and a third unloading section for unloading those in which there were problems in the inspection process. A method for inspecting an annular substrate as described in any one of (10) to (17). With this configuration, the discharge mechanism automatically sorts the annular substrates into those that did not show any defects, those that did show defects, and those that had problems in the inspection process, according to the inspection results. This allows for the efficient extraction of annular substrates with good inspection results. Furthermore, by re-inspecting the annular substrates that had problems in the inspection process, it is possible to efficiently prevent the discarding of annular substrates that do not have defects. [Explanation of Symbols]

[0093] 2 Laminate 10 Loading device (loading mechanism) 15 Ray of Light 20. Peeling device (peeling mechanism) 22 Pressing part 23A Peeling nail 27 Thickness detection sensor 28 Overlapping substrate ejection section 30. Suction conveyor (peeling and conveying device) 32 Suction conveyor belt 33 Suction device 40 Phase adjustment device (adjustment unit) 47. Ring illumination (illumination device for detecting rolling marks or grinding marks) 48 CCD cameras (area cameras) 51 First angle-swinging conveyor section 52 Second angle-swinging conveyor section 60 Surface inspection device (first defect inspection unit) 63 Inspection conveyor 64. First lighting device 65 First imaging device (first line camera) 71. Suction conveyor (substrate holding device) 72 Second lighting device 73. Second imaging device (second line camera) 75 Suction conveyor belt 76 Suction device 80 Unloading device (unloading mechanism) 83. First discharge conveyor (first discharge section) 84. Second discharge conveyor (second discharge section) 85. Third discharge conveyor (third discharge section) W Metal substrate (annular substrate) Wa Rolling

Claims

1. An inspection apparatus for an annular substrate for inspecting defects present on the surface of an annular substrate after straightening annealing, An adjustment unit that detects the rolling marks or grinding marks on the transported annular substrate and adjusts the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction, The system comprises an inspection conveyor for transporting the annular substrate having rolled or ground marks aligned in a certain direction, a first illumination device for irradiating the annular substrate with light from above, and a first line camera for photographing the light-irradiated surface of the annular substrate, and a first defect inspection unit for inspecting defects on the surface of the annular substrate using the image of the light-irradiated surface captured by the first line camera, The device comprises a substrate holding device that suctions and transports the upper surface of the annular substrate, which has rolling marks or grinding marks aligned in a certain direction; a second illumination device that irradiates light from below onto the annular substrate, whose upper surface is held by the substrate holding device; and a second line camera that photographs the light-irradiated surface of the annular substrate, and further comprises a second defect inspection unit that inspects defects on the back surface of the annular substrate using the image of the light-irradiated surface captured by the second line camera. The substrate holding device includes a suction device positioned in a location overlapping with the second line camera in a plan view and which sucks the central side of the upper surface of the annular substrate, and a pair of left and right suction conveying belts that extend along the conveying direction and are arranged to support both ends of the outer circumference of the upper surface of the annular substrate. A loading mechanism is provided upstream of the adjustment section for loading a cylindrical laminate formed by stacking multiple annular substrates, The system includes a peeling mechanism for peeling off the first annular substrate from the top of the laminate that has been brought in by the aforementioned loading mechanism, An inspection device for annular substrates.

2. An inspection apparatus for an annular substrate for inspecting defects present on the surface of an annular substrate after straightening annealing, An adjustment unit that detects the rolling marks or grinding marks on the transported annular substrate and adjusts the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction, The system comprises an inspection conveyor for transporting the annular substrate having rolled or ground marks aligned in a certain direction, a first illumination device for irradiating the annular substrate with light from above, and a first line camera for photographing the light-irradiated surface of the annular substrate, and a first defect inspection unit for inspecting defects on the surface of the annular substrate using the image of the light-irradiated surface captured by the first line camera, The adjustment unit is, The system includes an illumination device for detecting rolling marks or grinding marks on the annular substrate, an area camera for photographing the light-illuminated surface of the annular substrate, and a first angle-swinging conveyor section and a second angle-swinging conveyor section arranged side by side along the transport direction and driven independently of each other to transport at different transport speeds. The area camera captures the light rays appearing in a direction perpendicular to the rolling or grinding marks of the annular substrate, and detects the angle that the axis of the light rays makes with respect to the transport direction. Based on this angle, the transport speeds of the first angle-swinging conveyor section and the second angle-swinging conveyor section are adjusted to rotate the annular substrate horizontally while transporting it, thereby aligning the angle within a predetermined range with respect to the transport direction of the annular substrate. A loading mechanism is provided upstream of the adjustment section for loading a cylindrical laminate formed by stacking multiple annular substrates, The system includes a peeling mechanism for peeling off the first annular substrate from the top of the laminate that has been brought in by the aforementioned loading mechanism, An inspection device for annular substrates.

3. The peeling mechanism comprises a pressing portion that holds down the outer surface of the laminate excluding the first annular substrate from the top, a peeling claw that peels the first annular substrate from the top of the laminate, and a peeling and conveying device that conveys the annular substrate peeled off by the peeling claw. An inspection apparatus for an annular substrate according to claim 1 or 2.

4. The peeling and conveying device comprises a suction device positioned to overlap with the laminate in a plan view and to suck the central side of the upper surface of the annular substrate, and a pair of suction conveying belts arranged on the left and right so as to extend along the conveying direction and support both ends of the outer circumference of the upper surface of the annular substrate. An inspection apparatus for an annular substrate according to claim 3.

5. The peeling mechanism further includes a thickness detection sensor that detects that two or more of the annular substrates peeled from the laminate are stacked on top of each other, and an overlapping substrate discharge unit that discharges the overlapping annular substrates from the transport path. An inspection apparatus for an annular substrate according to claim 1 or 2.

6. The system includes an unloading mechanism for unloading the annular substrate after inspection has been completed. The discharge mechanism distributes the annular substrates that have been inspected to a first discharge section for discharging those annular substrates in which no defects were found, a second discharge section for discharging those annular substrates in which defects were found, and a third discharge section for discharging those annular substrates that had problems during inspection by the first defect inspection section. An inspection apparatus for an annular substrate according to claim 1 or 2.

7. A method for inspecting defects present on the surface of an annular substrate after straightening annealing, An adjustment step involves detecting the rolling marks or grinding marks on the annular substrate being transported, and adjusting the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction. The invention comprises a first defect inspection step in which, for an annular substrate that is transported with its rolled or ground marks aligned in a certain direction, light is irradiated onto the annular substrate from above using a first illumination device, and an image of the light-irradiated surface of the annular substrate captured by a first line camera is used to inspect defects on the surface of the annular substrate, The invention further comprises a substrate holding device that suctions and transports the upper surface of the annular substrate, which has rolling marks or grinding marks aligned in a certain direction; a second illumination device that irradiates light from below onto the annular substrate, whose upper surface is held by the substrate holding device; and a second line camera that photographs the light-irradiated surface of the annular substrate, and a second defect inspection step that inspects defects on the back surface of the annular substrate using the image of the light-irradiated surface captured by the second line camera, The second defect inspection step involves using a suction device positioned to overlap with the second line camera in a plan view to suck the central side of the upper surface of the annular substrate, and supporting both ends of the outer circumference of the upper surface of the annular substrate with a pair of left and right suction conveying belts extending along the conveying direction, thereby holding and conveying the upper surface of the annular substrate in which the rolled or ground marks are aligned in a certain direction. Prior to the adjustment step, the method further comprises a loading step of loading a cylindrical laminate formed by stacking multiple annular substrates, and a peeling step of peeling off the first annular substrate from the top of the laminate loaded in the loading step. A method for inspecting annular substrates.

8. A method for inspecting defects present on the surface of an annular substrate after straightening annealing, An adjustment step involves detecting the rolling marks or grinding marks on the annular substrate being transported, and adjusting the rolling marks or grinding marks on the annular substrate so that the detected rolling marks or grinding marks are aligned in a certain direction. The invention comprises a first defect inspection step in which, for an annular substrate that is transported with its rolled or ground marks aligned in a certain direction, light is irradiated onto the annular substrate from above using a first illumination device, and an image of the light-irradiated surface of the annular substrate captured by a first line camera is used to inspect defects on the surface of the annular substrate, The adjustment step involves irradiating the annular substrate with light using an illumination device for detecting rolling marks or grinding marks, detecting the angle that the axis of the light rays appearing perpendicular to the rolling marks or grinding marks of the annular substrate makes with respect to the transport direction using an image of the light-irradiated surface of the annular substrate captured by an area camera, and adjusting the transport speeds of the first angle-swinging conveyor section and the second angle-swinging conveyor section, which are arranged side by side along the transport direction and driven independently to transport at different transport speeds, based on the angle, and rotating the annular substrate horizontally while transporting it, thereby aligning the angle within a predetermined range with respect to the transport direction of the annular substrate. Prior to the adjustment step, the method further comprises a loading step of loading a cylindrical laminate formed by stacking multiple annular substrates, and a peeling step of peeling off the first annular substrate from the top of the laminate loaded in the loading step. A method for inspecting annular substrates.

9. The peeling step involves pressing down on the outer surface of the laminate, excluding the first annular substrate from the top, using a pressing part, peeling off the first annular substrate from the top of the laminate using a peeling claw, and transporting the annular substrate peeled off from the laminate by a peeling transport device. A method for inspecting an annular substrate according to claim 7 or 8.

10. The peeling process involves using a suction device positioned to overlap with the laminate in a plan view to suck the central side of the upper surface of the annular substrate, and supporting both ends of the outer circumference of the upper surface of the annular substrate with a pair of left and right suction conveying belts extending along the conveying direction, thereby holding and conveying the upper surface of the annular substrate that has been peeled from the laminate. The method for inspecting an annular substrate according to claim 9.

11. The system further includes a thickness detection sensor that detects whether two or more annular substrates peeled from the laminate are stacked on top of each other, and a double substrate discharge step that discharges the stacked annular substrates from the transport path. A method for inspecting an annular substrate according to claim 7 or 8.

12. The system further includes a discharge process for discharge of the annular substrate after inspection has been completed, The aforementioned unloading process sorts the annular substrates that have been inspected into a first unloading section for unloading those in which no defects were found, a second unloading section for unloading those in which defects were found, and a third unloading section for unloading those in which there were problems in the inspection process. A method for inspecting an annular substrate according to claim 7 or 8.

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