center detection device

Abstract

Provided is a center detection device in which an operator can find the cause of failure to normally detect the center of a plate-shaped workpiece in a short time. In a case where it is determined that an alignment error has occurred, an entire image of the plate-shaped workpiece is displayed in a first monitoring area (61) of a monitor (6), and a prescribed area of the image containing one side of the plate-shaped workpiece is displayed in an enlarged manner in a second monitoring area (62). Thus, the operator can easily and in a short time find the cause of the occurrence of the alignment error by observing the two monitoring areas (61, 62) in the monitor (6).

Description

Technical Field

[0001] This invention relates to a central detection device. Background Technology

[0002] A grinding apparatus exists for grinding a plate-shaped workpiece held on the holding surface of a chuck table (Patent Document 1). In this grinding apparatus, as disclosed in Patent Document 2, the plate-shaped workpiece is illuminated by a plate-shaped illumination source, and one surface of the plate-shaped workpiece is photographed using a camera. Then, based on the image obtained by the photograph, the outer periphery of the plate-shaped workpiece is detected, and the center of the plate-shaped workpiece is detected based on the detected outer periphery. Furthermore, the plate-shaped workpiece is transported to the holding surface in a manner that aligns the detected center of the plate-shaped workpiece with the center of the holding surface of the chuck table.

[0003] In such a processing apparatus, the shape of the retaining surface used to attract and hold the plate-shaped workpiece is consistent with the shape of the plate-shaped workpiece. For example, when the plate-shaped workpiece is quadrilateral, the processing apparatus has a chuck table with a quadrilateral retaining surface of the same area and shape as the plate-shaped workpiece, which is used to attract and hold the plate-shaped workpiece.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2009-123790

[0005] Patent Document 2: Japanese Patent Application Publication No. 2014-33049

[0006] When photographing a plate-shaped workpiece to detect its center, issues such as lighting source malfunction (e.g., localized dimming) or dust accumulation on the workpiece's outer perimeter can cause uneven lighting in the image, resulting in contrasting dark and bright areas. In such cases, the outer perimeter may be undetectable or incorrectly detected. Consequently, accurate center detection becomes difficult.

[0007] In cases where the outer periphery of a plate-shaped workpiece cannot be detected, the processing device may issue an alarm and notify the operator.

[0008] Furthermore, if the outer periphery of the plate-shaped workpiece is incorrectly detected, the workpiece may be conveyed to a position deviating from the holding surface. Consequently, the attractive force becomes weaker when the holding surface is used to hold the plate-shaped workpiece. The conveying device detects this positional deviation, issues an alarm, and notifies the operator.

[0009] Upon receiving such an alarm, the operator temporarily stops the processing equipment, checks the lighting source or cleans the plate-shaped workpiece, and identifies the cause of the inability to properly detect the center of the plate-shaped workpiece. Therefore, time is spent until the cause is identified and the center of the plate-shaped workpiece can be detected normally. Summary of the Invention

[0010] Therefore, the purpose of this invention is to enable the operator to find the cause of the failure to properly detect the center of a plate-shaped workpiece in a short time.

[0011] The center detection device of the present invention (this center detection device) is a center detection device for a plate-shaped workpiece. The center detection device includes: a mounting member on which the plate-shaped workpiece is mounted; a camera having a field of view for capturing the entire surface of one side of the plate-shaped workpiece mounted on the mounting member; an illumination source for illuminating the plate-shaped workpiece; a detection unit for detecting the center of the plate-shaped workpiece based on an image obtained by the camera that includes the entire surface of one side of the plate-shaped workpiece, i.e., an alignment image; a monitor for displaying the alignment image; and a control unit, wherein the monitor has: a first monitoring area for displaying the entire plate-shaped workpiece in the alignment image; and a second monitoring area disposed next to the first monitoring area for displaying a predetermined area in the alignment image that includes the outer periphery of the plate-shaped workpiece; the control unit has: a first control unit for zooming out the alignment image and displaying it in the first monitoring area in a manner that displays the entire plate-shaped workpiece in the first monitoring area; and a second control unit for magnifying the predetermined area of ​​the alignment image in the second monitoring area.

[0012] In this central inspection device, the alignment image is zoomed out in the first monitoring area of ​​the monitor to display an overall image of the plate-shaped workpiece, while a designated area of ​​the alignment image, including the outer periphery of the plate-shaped workpiece, is magnified in the second monitoring area. Therefore, for example, if an alignment error is determined to have occurred, the operator can more easily and quickly identify the cause of the alignment error by observing the two monitoring areas. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the structure of a processing apparatus according to one embodiment of the present invention.

[0014] Figure 2 It is a perspective view showing the structure with temporary components and movable components.

[0015] Figure 3 This is an explanatory diagram showing the camera's field of view.

[0016] Figure 4 This is a perspective view showing the structure of the first conveying mechanism.

[0017] Figure 5 This is a perspective view showing the structure of the second conveying component.

[0018] Figure 6 This is an explanatory diagram showing an example of an image used for alignment.

[0019] Figure 7 This is an explanatory diagram showing an example of a defined area in an image used for alignment.

[0020] Figure 8 This is an explanatory diagram showing an example of a defined area in an image used for alignment.

[0021] Figure 9 This is an explanatory diagram showing a method for determining the center of a plate-shaped workpiece.

[0022] Figure 10 This is an explanatory diagram showing a method for determining the length of one side of a plate-shaped workpiece.

[0023] Figure 11 This is an explanatory diagram showing a monitor.

[0024] Figure 12 This is an explanatory diagram showing an example of a display in the second monitoring area of ​​a monitor.

[0025] Figure 13 This is an explanatory diagram showing the temporary workbench.

[0026] Label Explanation

[0027] 1: Machining device; 2: Plate-shaped workpiece; 3: Plate-shaped workpiece; 4: First device base; 5: Second device base; 6: Monitor; 61: First monitoring area; 62: Second monitoring area; 7: Control unit; 71: First control unit; 72: Second control unit; 8: Detection unit; 11: Grinding feed component; 13: Chuck table; 12: Holding surface; 15: Grinding component; 16: Spindle; 17: Grinding wheel; 18: Grinding tool; 40: First box mounting stage; 45: Second box 41: Box; 42: Adapter plate; 55: Camera; 551: Field of view; 56: Illumination plate; 80: Temporary workbench; 81: Illumination plate; 170: Second transport space; 100: Second transport component; 101: Housing plate; 110: Moving component; 120: Y-axis moving mechanism; 130: Z-axis moving mechanism; 137: Arm; 140: Holding part; 141: Holding plate; 142: Suction pad; 156: Cleaning component; 157: Rotary workbench; 158: Nozzle; 190: Temporary placement space; 200: Temporary placement component; 210: Temporary placement platform; 211: First temporary placement surface; 212: Second temporary placement surface; 213: Suction port; 230: X-axis moving mechanism; 180: First conveying space; 250: First conveying mechanism; 251: Housing plate; 255: Temporary moving part; 259: Y-axis moving mechanism; 257: Z-axis moving mechanism; 258: Arm; 260: Temporary holding part; 261: Shaft; 263: Motor; 265: Suction port 50: Belt moving member; 400: First belt moving member; 420: Second belt moving member; 401: Circular belt; 402: Rotating mechanism; 403: Driven roller; 404: Drive roller; 405: Motor; 500: Alignment image; 501: Workpiece image; 502: Specified area; C1~C4: Intersection point; P1: Workpiece image pixel; P2: Background image pixel; P3: Outer perimeter pixel; SL, SL1~SL4: Approximate straight line; Y1: Y-axis straight line. Detailed Implementation

[0028] like Figure 1 As shown, the processing apparatus 1 of this embodiment performs grinding processing on a quadrilateral plate-shaped workpiece 2 under the control of the control unit 7.

[0029] The processing apparatus 1 has a first apparatus base 4 and a second apparatus base 5 disposed behind the first apparatus base 4 (on the +Y direction side). The first apparatus base 4 is used for loading and unloading plate-shaped workpieces 2. The second apparatus base 5 is used for processing the plate-shaped workpieces 2.

[0030] A first box-mounting platform 40 and a second box-mounting platform 45 are provided on the front side (-Y direction side) of the first device base 4. A box 41 containing the plate-shaped workpiece 2 before processing is placed on the first box-mounting platform 40 via a transition plate 42. An identical box 41 containing the plate-shaped workpiece 2 after processing is placed on the second box-mounting platform 45 via a transition plate 42.

[0031] Box 41 has shelves that hold multiple plate-shaped workpieces 2 spaced apart in the vertical direction. Each plate-shaped workpiece 2 is held one by one on each shelf.

[0032] Box 41 has an opening facing the +Y direction. A temporary storage space 190, indicated by a dashed line, is disposed on the +Y direction side of this opening. A [fabricated item] is disposed in this temporary storage space 190. Figure 2 The illustrated components are a moving member 50 for removing the plate-shaped workpiece 2 from the box 41 and a temporary placement member 200 for temporarily placing the plate-shaped workpiece 2.

[0033] In this embodiment, the movable member 50 is disposed on the +Y direction side of the first box mounting stage 40.

[0034] like Figure 2 As shown, the belt moving member 50 has a first belt moving member 400 and a second belt moving member 420, which are belt conveyors.

[0035] The first moving member 400 has an annular belt 401 and a rotating mechanism 402 for rotating the annular belt 401.

[0036] The rotating mechanism 402 includes: a driven roller 403 disposed at the end of the annular belt 401 on the -Y direction side; a drive roller 404 disposed at the end of the annular belt 401 on the +Y direction side; and a motor 405 that drives the drive roller 404.

[0037] The annular belt 401 is crosslinked with the driven roller 403 and the drive roller 404, which are arranged in contact with their inner circumferential surfaces. In addition, a plate-shaped workpiece 2 is placed on the upper surface of the annular belt 401.

[0038] The second moving member 420 is disposed on the +Y direction side of the first moving member 400. The second moving member 420, like the first moving member 400, has an annular belt 401 and a rotating mechanism 402.

[0039] In the moving member 50, the first moving member 400 is configured to pull out the plate-shaped workpiece 2 before processing from the box 41 placed on the first box placement table 40.

[0040] That is, in the first belt moving member 400, the end of the annular belt 401 on the -Y direction side is brought under the plate-shaped workpiece 2 housed in the box 41, and the lower surface of the plate-shaped workpiece 2 is supported by this end. In this state, the plate-shaped workpiece 2 housed in the box 41 is pulled out of the box 41 by rotating the annular belt 401.

[0041] The second moving member 420 receives the plate-shaped workpiece 2 pulled out of the box 41 by the first moving member 400 via a rotating annular belt 401. The second moving member 420 positions the plate-shaped workpiece 2 at a shooting position, which is the center position of the second moving member 420, via the rotating annular belt 401. That is, the second moving member 420 is an example of a mounting member for placing the plate-shaped workpiece 2.

[0042] In addition, such as Figure 2 As shown, the processing device 1 has a camera 55 above the second moving member 420. Figure 3 As shown, the camera 55 has a field of view 551 for capturing the entire surface of one face (upper surface: the face facing the +Z direction) of the plate-shaped workpiece 2 located at the shooting position, and is configured to capture the entire surface of one face of the plate-shaped workpiece 2.

[0043] Furthermore, the plate-shaped workpiece 2 has a larger dimension than the annular belt 401 of the second belt moving member 420. Therefore, as Figure 2 and Figure 3 As shown, the plate-shaped workpiece 2 located at the shooting position is configured to cover the second moving member 420 when viewed from the camera 55.

[0044] In addition, such as Figure 2 and Figure 3 As shown, a lighting plate 56 is disposed below (in the -Z direction) the second moving member 420.

[0045] The lighting panel 56 is configured to illuminate the plate-shaped workpiece 2 located at the shooting position. That is, as shown... Figure 3 As shown, the illumination plate 56 has a light-emitting surface with an area larger than that of the plate-shaped workpiece 2, as indicated by arrow 300, enabling the illumination light to be incident approximately perpendicularly onto the entire surface of the other side (back side: the surface facing the -Z direction) of the plate-shaped workpiece 2 located at the shooting position. The illumination plate 56 is, for example, an organic EL illumination supplied with electricity from the outside, and is a surface light source emitting white light.

[0046] After the plate-shaped workpiece 2 is photographed by the camera 55, the plate-shaped workpiece 2, which is positioned on the second moving member 420, is moved toward the temporary placement member 200.

[0047] The temporary placement component 200 is used to temporarily place the plate-shaped workpiece 2 after it has been photographed by the camera 55.

[0048] The temporary placement member 200 is configured to temporarily hold a number of plate-shaped workpieces 2 corresponding to the number of holding surfaces 12 of the chuck table 13. Therefore, in this embodiment, two plate-shaped workpieces 2 can be temporarily placed in the temporary placement member 200.

[0049] like Figure 2 As shown, the temporary placement component 200 has a temporary placement platform 210 for temporarily placing the plate-shaped workpiece 2 and an X-axis moving mechanism 230 for supporting the temporary placement platform 210.

[0050] The temporary placement stage 210 has a first temporary surface 211 and a second temporary surface 212, each having a plurality of suction ports 213. The first temporary surface 211 and the second temporary surface 212 respectively attract and hold a plate-shaped workpiece 2 by connecting the suction ports 213 to a suction source (not shown).

[0051] The X-axis moving mechanism 230 supports the temporary placement stage 210 so that it can move along the X-axis direction, and adjusts the position of the first temporary surface 211 and the second temporary surface 212 of the temporary placement stage 210 in the X-axis direction.

[0052] In addition, such as Figure 1 As shown, a first transport space 180, indicated by a dashed line, is arranged above the temporary storage space 190. Furthermore, a... Figure 4 The first conveying mechanism 250 is shown. This first conveying mechanism 250 is used to convey the plate-shaped workpiece 2 disposed on the second moving member 420 to the temporary holding member 200.

[0053] like Figure 4 As shown, the first conveying mechanism 250 has a temporary holding part 260 for holding the plate-shaped workpiece 2 and a temporary moving part 255 for moving the temporary holding part 260 on the surface of the housing plate 251 in the -X direction.

[0054] The temporary holding unit 255 has a Z-axis moving mechanism 257 and a Y-axis moving mechanism 259. The Z-axis moving mechanism 257 is configured to move the temporary holding unit 260 along the Z-axis direction. On the other hand, the Y-axis moving mechanism 259 is configured to move the temporary holding unit 260 and the Z-axis moving mechanism 257 along the Y-axis direction.

[0055] The temporary holding part 260 is supported by the arm 258 of the Z-axis moving mechanism 257. The temporary holding part 260 includes: a shaft 261 which is rotatably connected to the front end of the arm 258; a motor 263 which is connected to the upper end of the shaft 261 for rotating the shaft 261; and a suction pad 265 which is connected to the lower end of the shaft 261.

[0056] The attraction pad 265, connected to an attraction source (not shown), is capable of attracting and holding the plate-shaped workpiece 2. The motor 263, by rotating the shaft 261 as shown by arrow 301, can rotate the attraction pad 265 connected to the lower end of the shaft 261, that is, can change the direction of rotation of the attraction pad 265 (θ direction, i.e., orientation in the XY plane).

[0057] In the first conveying mechanism 250 with such a structure, after the plate-shaped workpiece 2 is photographed using the camera 55 (see reference...), Figure 2 The plate-shaped workpiece 2 disposed on the second moving member 420 is held by the suction pad 265 of the temporary holding part 260, and is transported toward the temporary member 200 by the temporary moving part 255 and placed on the first temporary surface 211 or the second temporary surface 212 of the temporary placement stage 210.

[0058] In addition, such as Figure 1 As shown, a chuck table 13 for holding a plate-shaped workpiece 2 is disposed on the second device base 5 on the +Y direction side of the temporary storage space 190. The chuck table 13 has two holding surfaces 12 for attracting and holding the plate-shaped workpiece 2. Each holding surface 12 is connected to an attraction source (not shown), and is capable of attracting and holding one plate-shaped workpiece 2. Therefore, in this embodiment, the chuck table 13 can simultaneously hold two plate-shaped workpieces 2 through the two holding surfaces 12.

[0059] The chuck table 13 can rotate around a central axis that passes through the center of the chuck table 13 and extends along the Z-axis while holding the plate-shaped workpiece 2 by means of the holding surface 12.

[0060] In addition, a column 14 is erected on the rear (+Y direction side) of the second device base 5. Moreover, the processing device 1 has a grinding member 15 for grinding the plate-shaped workpiece 2 and a grinding feed member 11 for grinding the grinding member 15 on the front surface of the column 14.

[0061] The grinding member 15 has a grinding wheel 17. The grinding wheel 17 is an example of a processing member that processes the plate-shaped workpiece 2 held by the holding surface 12, and has a grinding tool 18 as an example of a processing tool.

[0062] In addition, the processing apparatus 1 has a first height gauge 19 for measuring the thickness of the plate-shaped workpiece 2 held by the holding surface 12 of the chuck table 13.

[0063] In the processing apparatus 1, the grinding member 15 is fed by the grinding feed member 11, and the grinding wheel 18 is rotated by the spindle 16 of the grinding member 15. The plate-shaped workpiece 2 held by the holding surface 12 of the rotating chuck table 13 is ground by the grinding wheel 18.

[0064] In addition, Figure 1 The second conveying space 170, indicated by dashed lines, contains the second conveying component 100 (see reference). Figure 5 ).

[0065] like Figure 5 As shown, the second conveying member 100 has a holding portion 140 capable of simultaneously holding multiple plate-shaped workpieces 2 and a moving member 110 for moving the holding portion 140 on the -X direction side of the housing plate 101 extending along the Y-axis direction.

[0066] The moving member 110 has a Z-axis moving mechanism 130 and a Y-axis moving mechanism 120. The Z-axis moving mechanism 130 is configured to move the holding part 140 along the Z-axis direction. On the other hand, the Y-axis moving mechanism 120 is configured to move the holding part 140 and the Z-axis moving mechanism 130 along the Y-axis direction.

[0067] The holding part 140 is supported by a rotating mechanism 138 connected to the front end of the arm 137 of the Z-axis moving mechanism 130. The holding part 140 has a pair of holding plates 141 arranged to clamp the rotating mechanism 138, and two suction pads 142 provided on each holding plate 141. The suction pads 142, through communication with a suction source (not shown), can attract and hold the plate-shaped workpiece 2. Since the holding part 140 has two suction pads 142 on each holding plate 141, it can hold two plate-shaped workpieces 2 simultaneously. Furthermore, the rotating mechanism 138 rotates about the arm 137. Rotation of the rotating mechanism 138 allows one holding plate 141 and the other holding plate 141 to be flipped.

[0068] In the second conveying member 100, the holding portion 140 holding two plate-shaped workpieces 2 is moved from the temporary placement member 200 to the chuck table 13 by the moving member 110. That is, the second conveying member 100 uses the holding portion 140 to simultaneously hold the two plate-shaped workpieces 2 temporarily placed on the temporary placement member 200, and conveys and places them on the two holding surfaces 12 of the chuck table 13.

[0069] In addition, in order to simultaneously transport the held plate-shaped workpieces 2 to the holding surface 12, the holding part 140 can also hold the plate-shaped workpieces 2 one by one when holding the temporarily placed plate-shaped workpieces 2, so that the holding surface 12 is aligned with the center of the plate-shaped workpieces 2 and the θ direction is aligned.

[0070] In addition, when the plate-shaped workpiece 2 is being transported to the holding surface 12, in order to make the center of the holding surface 12 and the θ direction consistent, the holding part 140 may transport the plate-shaped workpiece 2 one by one to the holding surface 12.

[0071] In this way, the second conveying member 100 receives the two plate-shaped workpieces 2 temporarily placed on the temporary placement member 200 and conveys them to the holding surface 12 of the chuck table 13 by a single action of the holding part 140 based on the moving member 110.

[0072] In addition, after the plate-shaped workpiece 2 is ground, the second conveying member 100 uses the holding part 140 to simultaneously hold the two plate-shaped workpieces 2 on the two holding surfaces 12 of the chuck table 13, for example, placed on a relay table not shown.

[0073] Then, for example, a robot (not shown) transports the plate-shaped workpiece 2, which is placed on the relay worktable, to... Figure 1 The rotating worktable 157 of the cleaning component 156 shown.

[0074] Alternatively, without using a relay worktable and robot, the plate-shaped workpiece 2 can be transported to the rotary worktable 157 of the cleaning component 156 via the second conveying component 100.

[0075] The cleaning component 156 is a rotary cleaning unit for cleaning the plate-shaped workpiece 2. The cleaning component 156 includes: a rotary table 157 that holds the plate-shaped workpiece 2; and a nozzle 158 that sprays cleaning water and drying air toward the rotary table 157.

[0076] In the cleaning component 156, the rotating worktable 157 holding the plate-shaped workpiece 2 rotates and sprays cleaning water toward the plate-shaped workpiece 2 to perform rotational cleaning. Then, dry air is blown onto the plate-shaped workpiece 2 to dry it.

[0077] The plate-shaped workpiece 2, after being cleaned by the cleaning component 156, is moved by a robot (not shown) into box 41 on the second box placement platform 45, which serves as a box for storing finished workpieces.

[0078] In addition, such as Figure 1 As shown, a monitor 6 is provided on the side of the housing (not shown) in the processing apparatus 1. The monitor 6 is capable of displaying information related to the processing of the plate-shaped workpiece 2. In addition, the monitor 6 has a touch panel function and is also used to set various information such as processing conditions. Thus, the monitor 6 functions as a display component for displaying information and also as an input component for inputting information.

[0079] like Figure 1 As shown, the processing apparatus 1 includes a control unit 7 and a detection unit 8. The control unit 7 performs various processes and provides unified control over all structural elements of the processing apparatus 1. Furthermore, as... Figure 1 As shown, the control unit 7 has a first control unit 71 and a second control unit 72.

[0080] The processing operation of the processing device 1 will be described below, together with the functions of the control unit 7, the first control unit 71, the second control unit 72 and the detection unit 8.

[0081] In the processing operation of the processing apparatus 1 in this embodiment, firstly, the control unit 7... Figure 2 The first moving member 400 with the moving member 50 shown is controlled from the box 41 on the first box mounting platform 40 (refer to...) Figure 1 The plate-shaped workpiece 2 before processing is removed. Then, the control unit 7 controls the second moving member 420 with the moving member 50, and positions the plate-shaped workpiece 2 at the shooting position on the second moving member 420.

[0082] Subsequently, the control unit 7 controls the illumination plate 56 to illuminate the entire surface of the plate-shaped workpiece 2 located at the shooting position on the second moving member 420. Then, the control unit 7 controls the camera 55 to capture an image of the entire surface of one side of the plate-shaped workpiece 2 located at the shooting position. Thus, the control unit 7 obtains an image of the entire surface of one side of the plate-shaped workpiece 2 obtained by the image captured by the camera 55, i.e., an alignment image.

[0083] Correspondingly, the detection unit 8 detects the center of the plate-shaped workpiece 2 placed at the shooting position of the second moving member 420 based on the alignment image.

[0084] Next, the control unit 7 moves the plate-shaped workpiece 2 to the temporary placement platform 210 of the temporary placement component 200.

[0085] That is, control unit 7 pairs Figure 4 The first conveying mechanism 250 shown is controlled to hold the plate-shaped workpiece 2 on the second conveyor member 420 by the suction pad 265 of the temporary holding part 260, and to convey the plate-shaped workpiece 2 to the temporary holding member 200 by the temporary moving part 255.

[0086] At this time, the control unit 7 adjusts the position of the plate-shaped workpiece 2 in the Y-axis direction, which is aligned with the position of the first temporary placement surface 211 of the temporary placement stage 210, via the Y-axis movement mechanism 259 of the temporary placement moving unit 255. Furthermore, the control unit 7 controls the motor 263 of the temporary placement holding unit 260 to rotate the plate-shaped workpiece 2, thereby adjusting the θ-direction of the plate-shaped workpiece 2 to be aligned with the θ-direction of the first temporary placement surface 211 of the temporary placement stage 210.

[0087] Furthermore, the control unit 7 controls the X-axis moving mechanism 230 of the temporary placement member 200 and adjusts the position of the first temporary placement surface 211 in the X-axis direction in accordance with the position of the plate-shaped workpiece 2 being transported.

[0088] Thus, the control unit 7 places the plate-shaped workpiece 2 on the first temporary surface 211 of the temporary placement platform 210, which serves as a temporary placement member 200, with the first temporary placement surface 211 properly aligned with the position and θ direction of the plate-shaped workpiece 2.

[0089] Next, the control unit 7 similarly performs the following: transporting the other plate-shaped workpiece 2 to the imaging position of the second belt moving member 420, acquiring the alignment image, and detecting the center of the plate-shaped workpiece 2. Then, similarly to the placement of the plate-shaped workpiece 2 relative to the first temporary placement surface 211, the control unit 7, with the second temporary placement surface 212 properly aligned with the position and θ direction of the plate-shaped workpiece 2, places the plate-shaped workpiece 2 on the second temporary placement surface 212, which serves as another temporary placement surface of the temporary placement stage 210.

[0090] In this way, the center of the two plate-shaped workpieces 2 is detected, and the two plate-shaped workpieces 2 are attracted and held here by the first temporary placement surface 211 and the second temporary placement surface 212 of the temporary placement stage 210.

[0091] Alternatively, it can have two temporary placement platforms 210, with a first temporary surface 211 disposed on one temporary placement platform 210 and a second temporary surface 212 disposed on the other temporary placement platform 210, and the interval between the first temporary surface 211 and the second temporary surface 212 is adjusted in accordance with the holding surface 12.

[0092] Next, the control unit 7 pairs Figure 5 The second conveying member 100 shown is controlled to simultaneously hold the two temporarily placed plate-shaped workpieces 2 using the holding part 140, and to convey and load them onto the surface. Figure 1 The chuck table 13 shown has two holding surfaces 12. At this time, the control unit 7 transports and places the plate-shaped workpiece 2 on the holding surface 12 in a manner that aligns the center of the plate-shaped workpiece 2 detected by the detection unit 8 with the center of the holding surface 12, and aligns the θ direction of the plate-shaped workpiece 2 with the θ direction of the holding surface 12. Afterwards, the control unit 7 controls the grinding feed member 11, the chuck table 13, and the grinding member 15 to perform grinding of the plate-shaped workpiece 2.

[0093] Next, the control unit 7 transports the ground plate-shaped workpiece 2 to the cleaning unit 156 via the second conveying member 100, a relay worktable (not shown), and a robot. Then, the control unit 7 controls the cleaning unit 156 to clean the plate-shaped workpiece 2. Afterward, the control unit 7 uses the robot (not shown) to move the cleaned plate-shaped workpiece 2 into a box for storing finished workpieces.

[0094] Next, the method for detecting the center of the plate-shaped workpiece 2 based on the detection unit 8 will be described. Furthermore, in the example shown below, a square plate-shaped workpiece 2 is used.

[0095] Figure 6 An example of an alignment image obtained by photographing a plate-shaped workpiece 2 using a camera 55 is shown. In the alignment image 500 shown in this figure, the workpiece image 501, which is an image of the plate-shaped workpiece 2, is shown in its center at a slightly tilted position. Figure 3 As shown, when viewed from camera 55, the plate-shaped workpiece 2 is positioned to block the illumination light from the illumination plate 56. Therefore, as Figure 6 As shown in the example, the workpiece image 501 is represented by a darker color (e.g., gray). Conversely, the image of the illumination panel 56 surrounding the workpiece image 501 is represented by a lighter color (e.g., white).

[0096] like Figure 6 As shown, the detection unit 8 defines a defined area 502 that includes a portion of the four edges that constitute the outer periphery of the workpiece image 501.

[0097] Figure 7 Showing one of the four sides of workpiece image 501 extending along the Y-axis ( Figure 6 The relevant specified area 502 is shown to the right of the specified area 502. Figure 7 In the example shown, the specified region 502 is an image region (100 columns and 600 rows) that is 100 pixels (100P) in the X-axis direction and 600 pixels (600P) in the Y-axis direction.

[0098] Testing Department 8 Figure 7 In the defined area 502 shown, the brightness difference between adjacent pixels is calculated for each row along the X-axis. The pixels for which the brightness difference is calculated are, for example,... Figure 8 As shown, it can also be set every 60 pixels (60P) along the Y-axis. In this example, the brightness difference of pixels in one row is calculated along the X-axis every 60 rows.

[0099] like Figure 7 As shown, in each row, the detection unit 8 identifies pixels with lower brightness as pixels corresponding to the workpiece image 501 (workpiece image pixel P1), and identifies brighter pixels with higher brightness as pixels corresponding to the image of the illumination plate 56, which forms the background of the plate-shaped workpiece 2 (background image pixel P2). Then, the detection unit 8 identifies pixels with a large brightness difference, i.e., pixels that form the boundary between the workpiece image pixel P1 and the background image pixel P2, as pixels corresponding to the outer periphery of the plate-shaped workpiece 2 (outer periphery pixel P3). Figure 7 and Figure 8 In the image, the outer peripheral pixel P3 is marked with a cross (×).

[0100] Next, as Figure 7As shown, the detection unit 8 determines the straight line connecting the outer peripheral pixels P3 and sets the straight line as an approximate straight line SL corresponding to one side of the workpiece image 501.

[0101] Next, the detection unit 8 calculates the angle θ between the approximate straight line SL and the Y-axis straight line Y1, which is a straight line parallel to the Y-axis, as the tilt angle θ of the workpiece image 501 (plate-shaped workpiece 2). The Y-axis straight line Y1 is a straight line that connects the pixels in the alignment image 500 arranged along the Y-axis direction.

[0102] Thus, as Figure 9 As shown, the detection unit 8 calculates an approximate straight line SL and tilt angle θ for all four edges of the outer periphery of the workpiece image 501 in the alignment image 500.

[0103] That is, the detection unit 8 sets a predetermined area 502 for another side of the workpiece image 501 extending along the Y-axis direction, and calculates the approximate straight line SL and the tilt angle θ. Furthermore, the detection unit 8 sets a predetermined area 502 for the two sides of the workpiece image 501 extending along the X-axis direction, and calculates the approximate straight line SL and the angle θ between the approximate straight line SL and the X-axis straight line X1, which is a straight line parallel to the X-axis, as the tilt angle θ of the workpiece image 501.

[0104] Therefore, as Figure 9 As shown, the detection unit 8 obtains four approximate straight lines SL (SL1~SL4) and four tilt angles θ (θ1~θ4).

[0105] Next, the detection unit 8 calculates the coordinates (X1, Y1), (X2, Y2), (X3, Y3), and (X4, Y4) of the four intersection points C1 to C4 of the four approximate straight lines SL1 to SL4. Based on these coordinates, the detection unit 8 calculates the following (X0, Y0). This (X0, Y0) corresponds to... Figure 6 The center coordinates of the workpiece image 501 shown.

[0106] X0 = (X1 + X2 + X3 + X4) / 4

[0107] Y0 = (Y1 + Y2 + Y3 + Y4) / 4

[0108] In this way, the detection unit 8 determines the center of the workpiece image 501 in the alignment image 500, and determines the center of the plate-shaped workpiece 2 placed on the second moving member 420 based on the center of the workpiece image 501.

[0109] Here, if an approximate straight line SL or tilt angle θ cannot be obtained for any of the four sides constituting the outer periphery of the workpiece image 501 in the alignment image 500, or if any of the coordinates of the four intersection points C1 to C4 cannot be obtained, the detection unit 8 determines that an alignment error has occurred.

[0110] Furthermore, after determining the center of the workpiece image 501, the detection unit 8 calculates the length of one side of the workpiece image 501. For example, as... Figure 10 As shown, the detection unit 8 calculates the length L0 of one side of the workpiece image 501 for an approximate straight line SL2. In this case, the detection unit 8 uses, for example, the following formula.

[0111] L0 = |(X1-X2)| / cosθ2, or L0 = |(Y1-Y2)| / sinθ2

[0112] Furthermore, if the calculated length L0 differs from the actual length of one side of the plate-shaped workpiece 2 (for example, if the difference between the calculated length L0 and the actual length is greater than or equal to a specified value), the detection unit 8 determines that an alignment error has occurred.

[0113] The following describes the processing of the control unit 7 when the detection unit 8 determines that an alignment error has occurred. In this processing, the control unit 7 uses [method / process] to display the alignment image 500. Figure 1 The monitor shown is 6.

[0114] like Figure 11 As shown, the monitor 6 has a first monitoring area 61 in the center and four second monitoring areas 62 around the first monitoring area 61 (four sides).

[0115] The first monitoring area 61 is used to display the workpiece image 501, which is an image of the entire plate-shaped workpiece 2 in the alignment image 500. The second monitoring area 62 is used to display a defined area in the alignment image 500 that includes the outer periphery of the plate-shaped workpiece 2, namely the defined area 502 described above.

[0116] If the detection unit 8 determines that an alignment error has occurred, the control unit 7 stops the processing of the plate-shaped workpiece 2, that is, the transfer of the plate-shaped workpiece 2 to the chuck table 13.

[0117] Then, the first control unit 71 of the control unit 7 reduces the alignment image 500 so that the entire plate-shaped workpiece 2 (workpiece image 501) is displayed in the first monitoring area 61 of the monitor 6. Then, the first control unit 71 displays the reduced alignment image 500 in the first monitoring area 61.

[0118] The above Figure 6This is an example of a scaled-down alignment image 500 displayed in the first monitoring area 61. The scaled-down alignment image 500 shown in this figure is, for example, an image of 1944 pixels × 2592 pixels (450mm × 600mm), scaled down by a factor of 0.25. Thus, within the alignment image 500, for example, a workpiece image 501 is displayed at a size of 390mm × 390mm.

[0119] In addition, such as Figure 12 As shown, the second control unit 72 of the control unit 7 magnifies and displays a designated area 502, which is part of the alignment image 500, in the second monitoring area 62 of the monitor 6. In this embodiment, the second control unit 72 will... Figure 6 The specified areas 502 related to the four sides of the plate-shaped workpiece 2 are respectively displayed in four second monitoring areas 62.

[0120] As described above, in this embodiment, when an alignment error is determined to have occurred, the alignment image 500 is reduced in the first monitoring area 61 of the monitor 6 to display an overall image of the plate-shaped workpiece 2, and a designated area 502 containing one side of the plate-shaped workpiece 2 in the alignment image 500 is enlarged in the second monitoring area 62. Therefore, by observing the two monitoring areas 61 and 62 of the monitor 6, the operator can more easily and quickly identify the cause of the alignment error.

[0121] For example, when using camera 55 to photograph plate-shaped workpiece 2, there is also light from illumination plate 56 (see reference). Figure 3 The light is unevenly illuminating the plate-shaped workpiece 2. In this case, when viewed from the camera 55, darker and brighter areas appear on the plate-shaped workpiece 2, easily leading to alignment errors. In this situation, the operator can easily determine the existence of such uneven brightness based on the overall image of the plate-shaped workpiece 2 displayed in the first monitoring area 61. Therefore, the operator can quickly eliminate the cause of the alignment error by taking measures such as replacing the illumination panel 56.

[0122] Furthermore, if dust adheres to the outer periphery of the plate-shaped workpiece 2, alignment errors can easily occur. In this case, the operator can easily confirm the presence of dust on the outer periphery by viewing the enlarged view of the designated area 502 displayed in the second monitoring area 62. Therefore, the operator can quickly eliminate the cause of the alignment error by taking measures such as cleaning the plate-shaped workpiece 2.

[0123] In addition, Figure 6 In the alignment image 500 shown, if it is difficult to find the outer periphery of the workpiece image 501 and thus difficult to set the specified area 502, the detection unit 8 can also determine that an alignment error has occurred.

[0124] Furthermore, if the plate-shaped workpiece 2, positioned at the imaging position on the second moving member 420, is significantly offset relative to the second moving member 420, the aforementioned tilt angles θ1 to θ4 become larger, potentially making it difficult to properly position the plate-shaped workpiece 2 on the holding surface 12 of the chuck table 13. Therefore, the detection unit 8 can determine that an alignment error has occurred if any tilt angle among the tilt angles θ1 to θ4, or if the average value of the tilt angles θ1 to θ4, exceeds a predetermined value. The average value θav of the tilt angles θ1 to θ4 is calculated using the following formula.

[0125] θav=(θ1+θ2+θ3+θ4) / 4

[0126] Furthermore, when the plate-shaped workpiece 2 is misaligned, and the workpiece 2 is held by the holding surface 12 of the chuck table 13, the holding surface 12 shifts away from the workpiece 2, causing air leakage. Therefore, the detection unit 8 can determine that an alignment error has occurred if it detects a leakage amount greater than a specified value.

[0127] In addition, the detection unit 8 can also determine... Figure 7 When the outer perimeter pixel P3 and the approximate straight line SL are as shown, calculate the distance between each outer perimeter pixel P3 and the approximate straight line SL (in Figure 7 In the example, the distance is in the X-axis direction. Furthermore, the detection unit 8 can also count the number of peripheral pixels P whose distance exceeds the allowable value, and if the number exceeds a predetermined number, it is determined that an alignment error has occurred.

[0128] Furthermore, in this embodiment, in the event of an alignment error, the first control unit 71 displays the result in the first monitoring area 61. Figure 6 The image shown serves as an overall image of the plate-shaped workpiece 2. In this regard, the first control unit 71 can also display the image in the first monitoring area 61 in the event of an alignment error. Figure 9 The image shown is based on the central detection processing of the detection unit 8 as an overall image of the plate-shaped workpiece 2.

[0129] In addition, in this embodiment, if the detection unit 8 determines that an alignment error has occurred, the first control unit 71 displays a scaled-down alignment image 500 (overall image) that includes the entire plate-shaped workpiece 2 in the first monitoring area 61, and the second control unit 72 displays an image (partial image) of a specified area 502 that is enlarged as part of the alignment image 500 in the second monitoring area 62.

[0130] Relatedly, the first control unit 71 and the second control unit 72 can also be configured to display the overall image and partial image at any time, regardless of whether there is an alignment error. For example, the first control unit 71 and the second control unit 72 can also continuously or periodically display the overall image and partial image on the first monitoring area 61 and the second monitoring area 62. Alternatively, the first control unit 71 and the second control unit 72 can also display the overall image and partial image according to the operator's instructions input via the monitor 6.

[0131] Alternatively, the first control unit 71 and the second control unit 72 may generate an overall image and a partial image each time the camera 55 photographs the plate-shaped workpiece 2, and store them in a storage unit (not shown). In this case, the first control unit 71 and the second control unit 72 may also read the overall image and the partial image from the storage unit according to the operator's instructions input via the monitor 6, and display them in the first monitoring area 61 and the second monitoring area 62.

[0132] Furthermore, in this embodiment, the second belt-moving member 420 is used as the mounting member for placing the plate-shaped workpiece 3 photographed by the camera 55. Relatedly, the mounting member could also be... Figure 13 A temporary worktable (aligned worktable) 80 as shown. This temporary worktable 80 is, for example, positioned on the -Y direction side of the first moving member 400 instead of being positioned on... Figure 2 The second belt moving member 420 and the temporary placement member 200 are shown.

[0133] exist Figure 13 In the example shown, the temporary worktable 80 is circular in shape, and a circular plate-shaped workpiece 3 is placed on the temporary worktable 80. Furthermore, a circular illumination plate 81 is arranged below the temporary worktable 80 to illuminate the plate-shaped workpiece 3 from the -Z direction during photography. Additionally, the aforementioned camera 55 is arranged above the temporary worktable 80.

[0134] In this structure, the control unit 7 is connected via... Figure 2 The first moving member 400 shown, or a robot not shown, temporarily places the plate-shaped workpiece 3 at a shooting position on the temporary worktable 80. Then, the control unit 7 illuminates the plate-shaped workpiece 3 at the shooting position using a lighting panel 81, and controls the camera 55 to capture an image of the entire surface of one side of the plate-shaped workpiece 3. Thus, the control unit 7 obtains an alignment image.

[0135] In contrast, the detection unit 8 determines the outer periphery and center of the workpiece image, which is the image of the plate-shaped workpiece 3 in the alignment image, and determines the center of the plate-shaped workpiece 3 placed on the temporary worktable 80 based on the center of the workpiece image.

[0136] In this structure, as described above, the detection unit 8 may determine that an alignment error has occurred, for example, if the outer periphery of the workpiece image cannot be detected.

[0137] in addition, Figure 13 The temporary worktable 80 shown can be any size that does not protrude from the plate-shaped workpiece 3. Additionally, the shape of the temporary worktable 80 can also be quadrilateral. Furthermore, a quadrilateral plate-shaped workpiece 2 can be placed on the temporary worktable 80 (see reference). Figure 1 ).

[0138] Furthermore, in this embodiment, the first belt moving member 400 moves from... Figure 1 The plate-shaped workpiece 2, before processing, is pulled out from the box 41 placed on the first box stage 40 and handed over to the second moving member 420, which serves as the placement member. Alternatively, a robot (not shown) may remove the plate-shaped workpiece 2 from the box 41 and place it on the second moving member 420.

Claims

1. A center inspection device for plate-shaped workpieces, the center inspection device comprising: A mounting component that holds a quadrilateral plate-shaped workpiece; A camera having a field of view for photographing the entire surface of one side of a plate-shaped workpiece placed on the mounting member; A light source that illuminates a plate-shaped workpiece; The inspection unit detects the center of the plate-shaped workpiece based on an image obtained by the camera that includes the entire surface of one side of the plate-shaped workpiece, i.e., an alignment image. A monitor, used to display the alignment image; and Control Department in, The detection unit is configured to: define four predetermined regions in the alignment image, each containing an image of the four sides of the outer periphery of the plate-shaped workpiece constituting the quadrilateral; determine the approximate straight lines and inclination angles of the four sides based on the images of these four predetermined regions; and determine the center of the plate-shaped workpiece based on these approximate straight lines and inclination angles. The monitor has: The first monitoring area is used to display the entire plate-shaped workpiece in the alignment image; and Four second monitoring areas, arranged adjacent to the first monitoring area, are used to display the four designated areas in the alignment image that respectively contain the four sides of the outer periphery of the plate-shaped workpiece constituting the quadrilateral. The control unit has: The first control unit zooms out the alignment image and displays it in the first monitoring area in such a way that the entire plate-shaped workpiece is displayed in the first monitoring area; as well as The second control unit magnifies and displays the four designated areas of the alignment image in the four second monitoring areas.

Images