Cutting device

Abstract

This invention provides a cutting apparatus that accurately detects the condition of the side surface of the cutting edge, and provides excellent prediction of the timing of tool replacement and the condition of grooves formed on the workpiece. The cutting apparatus includes a monitoring unit for monitoring the cutting edge of the cutting tool. The monitoring unit includes: an imaging unit that captures images of the cutting edge of the cutting tool; a pulse light source that emits pulsed light to illuminate the imaging area of ​​the imaging unit; and a camera that captures the images emitted by the imaging unit. The imaging unit includes: a first imaging unit that captures images of one side surface of the cutting edge of the cutting tool; a second imaging unit that captures images of another side surface of the cutting edge of the cutting tool; and a third imaging unit that captures images of the outer peripheral end of the cutting edge.

Description

Technical Field

[0001] The present invention relates to a cutting apparatus having a monitoring unit that monitors the cutting edge that cuts a workpiece held by a chuck table. Background Technology

[0002] A wafer with multiple ICs, LSIs, and other devices formed on its front side is divided into individual device chips by a cutting device equipped with cutting tools, which is divided by multiple intersecting predetermined dividing lines. The resulting device chips are used in electronic devices such as mobile phones and personal computers.

[0003] In addition, the applicant has proposed a cutting device having a tool detection unit (see Patent Document 1) that monitors the state of the cutting edge formed in a ring around the outer periphery of the cutting tool. The tool detection unit can be used to detect the state of the cutting edge of the cutting tool, thereby determining the replacement period of the cutting tool.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2007-042855

[0005] However, in the technology disclosed in Patent Document 1, since the structure of using a light-emitting element and a camera arranged across the cutting edge and using light irradiated from the light-emitting element to monitor the contour of the cutting edge is not possible, it is impossible to detect detailed conditions such as whether cutting chips are attached to the side of the cutting edge or whether abrasive grains are detached from the side of the cutting edge. Therefore, it cannot be said that the accuracy of predicting the timing of cutting tool replacement, the state of the groove formed on the workpiece, and the state of chipping (edge ​​notch) is high, and further improvement is required. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a cutting device that can accurately detect the state of the side of the cutting edge, the timing of cutting tool replacement, the state of the groove formed on the workpiece, etc. with excellent predictive accuracy.

[0007] According to the present invention, a cutting apparatus is provided, comprising: a chuck table for holding a workpiece; a cutting unit including a cutting tool having a cutting edge arranged in a ring for cutting the workpiece held by the chuck table; a monitoring unit for monitoring the cutting edge of the cutting tool; and a monitor comprising: an imaging unit for capturing images of the cutting edge of the cutting tool; a pulse light source for emitting pulse light to illuminate the imaging area of ​​the imaging unit; and a camera for capturing images emitted by the imaging unit, the imaging unit comprising: a first imaging unit for capturing images of one side of the cutting edge of the cutting tool; and a second imaging unit for capturing images of the other side of the cutting edge of the cutting tool. The second imaging unit includes: a first prism having an end face facing one side of the cutting edge; a first imaging lens disposed on the other end face of the first prism; and a first optical fiber for transmitting a first image, one end face of the first optical fiber being connected to the first imaging lens. The second imaging unit includes: a second prism having an end face facing the other side of the cutting edge; a second imaging lens disposed on the other end face of the second prism; and a second optical fiber for transmitting a second image, one end face of the second optical fiber being connected to the second imaging lens. The first image emitted from the other end face of the first optical fiber and the second image emitted from the other end face of the second optical fiber are transmitted to the camera and displayed on the monitor.

[0008] Preferably, the imaging unit further includes a third imaging unit, which includes: a third imaging lens facing the outer peripheral end of the cutting edge; and a third optical fiber for transmitting a third image, one end face of the third optical fiber being connected to the third imaging lens, and the third image emitted from the other end face of the third optical fiber being transmitted to the camera along with the first image and the second image and displayed on the monitor.

[0009] Preferably, the monitoring unit further includes a beam splitter disposed between the imaging unit and the camera. The pulsed light emitted by the pulsed light source is guided through the beam splitter from the other end face of each optical fiber disposed in the imaging unit and directed to an end face facing the imaging area of ​​the cutting edge of the cutting tool, illuminating the imaging area. Preferably, the monitoring unit also includes an illumination optical fiber for transmitting pulsed light, one end of which is optically coupled to the pulsed light source, illuminating the imaging area through the illumination optical fiber.

[0010] Preferably, when the number of times the monitoring unit captures images of the cutting edge during one revolution of the cutting edge of the cutting tool is set to X, and the rotational speed of the spindle that rotates the cutting tool in one second is set to Y,

[0011] The repetition frequency of the pulsed light source = X × Y [Hz].

[0012] Preferably, the monitoring unit further includes: a light-emitting element and a light-receiving element, which are arranged such that they are separated from the cutting edge of the cutting tool; and a rotary encoder, which is arranged on the spindle that rotates the cutting tool. When the amount of light received by the light-receiving element changes, the control unit controls the emission of pulse light from the pulse light source at a time corresponding to the value detected by the rotary encoder, and illuminates and captures the area where the amount of light received by the light-receiving element changes as the shooting area to be captured by the imaging unit.

[0013] According to the present invention, it is possible to detect whether cutting chips adhere to the side of the cutting edge, whether abrasive grains fall off the side of the cutting edge, etc., thereby improving the accuracy of predicting the timing of cutting tool replacement and the state of the grooving. In addition, by providing a third imaging unit facing the outer peripheral end of the cutting edge, it is also possible to monitor the condition of the outer peripheral end of the cutting edge, further improving the accuracy of predicting the timing of cutting tool replacement, the state of the grooving, and the state of edge chipping. Attached Figure Description

[0014] Figure 1 This is an overall perspective view of the cutting device according to an embodiment of the present invention.

[0015] Figure 2 (a) is a perspective view showing a portion of the cutting unit magnified. Figure 2 (b) shows that Figure 2 (a) is a perspective view of the cutting unit with the movable part of the tool cover raised.

[0016] Figure 3 It shows from Figure 2 (b) is a perspective view showing the state of the camera holding block removed from the tool housing.

[0017] Figure 4 It shows the configuration in Figure 1 A conceptual diagram of the structure of the monitoring unit 30 of the cutting device.

[0018] Figure 5 It is shown Figure 1 The diagram shows a conceptual representation of the structure of the first, second, and third imaging units of the monitoring unit.

[0019] Figure 6 It is used for Figure 4 A conceptual diagram illustrating the functions of the light-emitting element and the light-receiving element.

[0020] Label Explanation

[0021] 1: Cutting device; 1A: Housing; 3: Transfer mechanism; 4: Box placement area; 4A: Box; 5: Temporary workbench; 6: Transfer mechanism; 10: Holding unit; 10a: Chuck workbench; 11: Imaging unit; 13: Transfer mechanism; 14: Operation panel; 20: Cutting unit; 21: Housing; 22: Cutting tool; 22a: Cutting edge; 22b: Retaining ring; 24: Tool cover; 241: Main part; 242: Movable part; 25: Imaging part holding block; 251: Lifting knob; 252: Lifting component; 252a: Detection space; 26: Cutting water supply unit; 30: Monitoring unit; 35: Monitor; 40: Imaging part; 42: First imaging part; 421: First prism; 421a: One end face; 421b: Another End face; 422: First imaging lens; 423: First optical fiber; 423a: One end face; 423b: Another end face; 44: Second imaging unit; 441: Second prism; 441a: One end face; 441b: Another end face; 442: Second imaging lens; 443: Second optical fiber; 443a: One end face; 443b: Another end face; 46: Third imaging unit; 462: Third imaging lens; 463: Third optical fiber; 463a: One end face; 463b: Another end face; 47: Collimating lens; 48: Imaging lens; 49: Condenser lens; 50: Pulse light source; 60: Camera; 70: Beam splitter; 72: Reflecting surface; 100: Control unit; 110: Storage unit; W: Wafer; T: Grating strip; F: Frame. Detailed Implementation

[0022] Hereinafter, the cutting apparatus according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0023] As shown in the figure, by Figure 1 The workpiece processed by the cutting device 1 shown is, for example, a semiconductor wafer W held by a ring-shaped frame F using a dicing belt T. The cutting device 1 includes: a generally rectangular parallelepiped housing 1A; a cassette 4A, which is placed in the cassette holding area 4 of the housing 1A; a transfer mechanism 3, which transfers the wafer W, as the workpiece, from the cassette 4A to a temporary worktable 5; a holding unit 10, which holds the wafer W; a conveying mechanism 6, which has a rotary arm that conveys the wafer W transferred to the temporary worktable 5 and places it on the chuck worktable 10a of the holding unit 10; an imaging unit 11, which takes pictures of the wafer W placed and held on the chuck worktable 10a; a cutting unit 20, which performs cutting processing on the wafer W; a conveying mechanism 13, which moves the cut wafer W from the chuck worktable 10a to a cleaning position; a monitor 35, which displays various information; and an operation panel 14, which allows the operator to set processing conditions, etc.

[0024] Furthermore, inside the housing 1A of the cutting device 1, there is a moving mechanism that moves the holding unit 10 in the direction indicated by arrow X in the figure, a moving mechanism that moves the cutting unit 20 in the directions indicated by arrow Y and arrow Z (both omitted from the figure), and a control unit 100 (indicated by dashed lines). The control unit 100 controls the loading and unloading mechanism 3, the conveying mechanism 6, the holding unit 10, the cutting unit 20, and the moving mechanism that moves them.

[0025] In addition to the aforementioned known structure, the cutting device 1 also includes a monitoring unit 30 for monitoring the cutting edge of the cutting tool. A portion of the monitoring unit 30 in this embodiment is integrally disposed within the cutting unit 20. Figure 2 A portion of the cutting unit 20 is shown in enlarged view. (See image below.) Figure 2 As shown in (a), the cutting unit 20 includes: a housing 21 that supports a spindle 23, on which a cutting tool 22 with a cutting edge 22a is fixed at its front end, for rotational freedom; a tool cover 24 that covers the cutting tool 22 at the front end of the housing 21; and a cutting water supply valve 26 that supplies cutting water to the machining area cut by the cutting tool 22. A camera holding block 25 is mounted on the tool cover 24, which holds a portion of the camera 40 constituting the monitoring unit 30 described later. The spindle 23 is rotated by a motor (not shown). The tool cover 24 consists of a main part 241 and a movable part 242, the main part 241 being fixed to the front end of the housing 21, and the movable part 242 being supported for swinging freely relative to the main part 241. When changing the cutting tool 22, the fixing screw 242a that secures the movable part 242 is loosened, as shown in the diagram. Figure 2 As shown in (b), the movable part 242 is lifted in the direction indicated by arrow R1 to expose the cutting tool 22, and the retaining ring 22b that fixes the cutting tool 22 at the front end of the spindle 23 is removed to replace the cutting tool 22.

[0026] return Figure 1 Continuing the explanation, the wafer W, removed from the cassette 4A by the infeed / outfeed mechanism 3, is conveyed by the transport mechanism 6 and placed on the chuck stage 10a of the holding unit 10, where it is attracted and held. The wafer W held on the chuck stage 10a is photographed by the imaging unit 11 to detect the processing position (predetermined dividing line), and is positioned below the cutting unit 20. Cutting is performed based on the position information of the predetermined dividing line detected by the imaging unit 11. The wafer W, after cutting, is transported by the transport mechanism 13 to the cleaning position for cleaning and drying, and then returned to the designated position in the cassette 4A via the transport mechanism 6 and the infeed / outfeed mechanism 3.

[0027] Figure 3The image shows the state where the imaging holding block 25 has been removed from the tool cover 24 of the cutting unit 20. As shown, the imaging holding block 25 has an upper part 25a and a lower part 25b that hold the lifting member 252 from the vertical direction. By rotating the lifting knob 251 in the direction indicated by arrow R3, the lifting member 252, which is screwed to the rotation shaft 251a, can be raised and lowered in the direction indicated by arrow R4. A detection space 252a is formed at the front end of the lifting member 252 to position the cutting edge 22a when it is being imaged. This detection space 252a is approximately inverted U-shaped.

[0028] In addition, refer to Figure 4 and Figure 5 The monitoring unit 30 of this embodiment will be described. For example... Figure 4 As shown, the monitoring unit 30 includes: a camera 40 that captures images of the cutting edge 22a of the cutting tool 22 of the cutting unit 20 (the tool cover 24 is omitted for ease of explanation); a pulse light source 50 that emits pulse light L to illuminate the area captured by the camera 40; and a camera 60 that captures images emitted by the camera 40.

[0029] The camera unit 40 includes a first camera unit 42, a second camera unit 44, and a third camera unit 46 housed in the front end of the lifting component 252. Figure 5 More specifically, the first imaging unit 42, the second imaging unit 44, and the third imaging unit 46 are shown. The first imaging unit 42 includes: a first prism 421 having an end face 421a facing one side of the cutting edge 22a when the cutting edge 22a is positioned in the detection space 252a of the lifting member 252; a first imaging lens 422 disposed on the other end face 421b of the first prism 421; and a first optical fiber 423 having one end face 423a connected to the first imaging lens 422 to transmit an image of one side of the cutting edge 22a.

[0030] The second imaging unit 44 includes: a second prism 441 having an end face 441a facing the other side of the cutting edge 22a when the cutting edge 22a is positioned in the detection space 252a of the lifting member 252; a second imaging lens 442 disposed on the other end face 441b of the second prism 441; and a second optical fiber 443 having one end face 443a connected to the second imaging lens 442 to transmit an image of the other side of the cutting edge 22a. That is, one end face 421a of the first prism 421 and one end face 441a of the second prism 441 are disposed at opposite positions across the detection space 252a.

[0031] The third imaging unit 46 includes: a third imaging lens 462, which faces the outer peripheral end of the cutting edge 22a when the cutting edge 22a is positioned in the detection space 252a of the lifting member 252; and a third optical fiber 463, one end face 463a of which is connected to the third imaging lens 462 to transmit an image of the outer peripheral end of the third cutting edge 22a. In this embodiment, the cutting device 1 is provided with a first imaging unit 42, a second imaging unit 44, and a third imaging unit 46. However, the present invention is not limited to this, and a structure may be adopted in which only the first imaging unit 42 and the second imaging unit 44 are provided without the third imaging unit 46.

[0032] return Figure 4 Continuing the explanation, the other end face 423b of the first optical fiber 423, the other end face 443b of the second optical fiber 443, and the other end face 463b of the third optical fiber 463 converge at one point and are positioned facing the collimating lens 47. Furthermore, the images emitted from the other end face of each optical fiber are paralleled by the collimating lens 47 and captured by a camera 60 positioned between the beam splitter 70 and the imaging lens 48. The images captured by the camera 60 are stored in the storage unit 110 provided in the control unit 100 and displayed on the monitor 35. Additionally, as described above, the other end face 423b of the first optical fiber 423, the other end face 443b of the second optical fiber 443, and the other end face 463b of the third optical fiber 463 converge at one point, and the images (42A, 44A, 46A) emitted from each end are simultaneously captured by the camera 60, therefore... Figure 4 The image shown is captured into a single image.

[0033] In this embodiment, a pulsed light source 50 is provided, which illuminates pulsed light L onto the reflecting surface 72 of the beam splitter 70 via a condenser lens 49. The pulsed light source 50 can be, for example, a white light source or a laser diode (LD) light source with speckle processing. The pulsed light L illuminated by the pulsed light source 50 is reflected by the reflecting surface 72 of the beam splitter 70 and guided from the other end face 423b of the first optical fiber 423, the other end face 443b of the second optical fiber 443, and the other end face 463b of the third optical fiber 463 of the imaging unit 40. It is then illuminated from one end face 423a of the first optical fiber 423, one end face 443a of the second optical fiber 443, and one end face 463a of the third optical fiber 463, thereby illuminating the imaging area of ​​the cutting edge 22a positioned in the detection space 252a. The pulsed light source 50 is connected to the control unit 100, and the timing and repetition frequency of the pulsed light L are controlled by the control unit 100.

[0034] Furthermore, in the above embodiment, the pulsed light L emitted by the pulsed light source 50 is guided to the imaging area of ​​the cutting edge 22a of the cutting tool 22 via the beam splitter 70 disposed between the imaging unit 40 and the camera 60, and via the first optical fiber 423, the second optical fiber 443, and the third optical fiber 463 constituting the imaging unit 40. However, the present invention is not limited to this, and for example, it may be as follows: Figure 4 As shown by the dashed line, the pulsed light L emitted from the pulsed light source 50' is guided into the detection space 252a via illumination fibers 423', 443', and 463', which are separately arranged from the fibers of the imaging unit 40, to illuminate the imaging area of ​​the cutting edge 22a of the cutting tool 22. In this case, a beam splitter 70 is not required.

[0035] like Figure 4 As shown, a rotary encoder 29 is provided at the rear end of the cutting unit 20. The rotary encoder 29 outputs a value (electrical signal) indicating the rotational position of the spindle 23. The value output by the rotary encoder 29 is transmitted to the control unit 100 to calculate the position and rotational speed of the spindle 23.

[0036] Furthermore, in this embodiment, such as Figure 6 As shown, in the rotation direction of the cutting tool 22 (indicated by arrow R5), a light-emitting element 82 and a light-receiving element 84 are provided on the upstream side of the lifting member 252, arranged such that they are separated from the outer peripheral end of the cutting edge 22a of the cutting tool 22 (also referred to). Figure 4 In region P1 detected by the light-emitting element 82 and the light-receiving element 84, the cutting edge 22a blocks approximately two-thirds of the light emitted from the light-emitting element 82, and the remaining approximately one-third of the light is received by the light-receiving element 84. An electrical signal indicating the amount of light received is then transmitted to the control unit 100. Figure 6 As shown, the angle between the positions of the light-emitting element 82 and the light-receiving element 84 and the positions of the first imaging part 42, the second imaging part 44 and the third imaging part 46 in the rotation direction is α°.

[0037] The cutting device 1 of this embodiment generally has the structure described above. Hereinafter, the steps and functions of using the cutting device 1 to monitor the state of the cutting edge 22a of the cutting tool 22 will be explained.

[0038] In order to monitor the state of the cutting edge 22a of the cutting tool 22 by means of the imaging unit 40 constituting the monitoring unit 30, the lifting knob 251 of the imaging unit holding block 25 is rotated to lower the lifting component 252, such as... Figure 4 and Figure 5As shown, the cutting edge 22a of the cutting tool 22 is positioned in the detection space 252a of the lifting member 252. At this time, while referring to the monitor 35, the pulse light source 50 is activated to adjust the position of the lifting member 252, thereby positioning the outer peripheral end of the cutting edge 22a at a predetermined position in the imaging area captured by the imaging unit 40.

[0039] Next, the cutting unit 20 is activated to rotate the cutting tool 22. The rotational speed of the spindle 23 of the cutting tool 22 is, for example, 18,000 rpm. Here, when observing the outer periphery of the cutting edge 22a of the cutting tool 22 along the rotation direction of the cutting tool 22 and taking pictures at 1-degree intervals, the number of times (X) pictures are taken during one rotation of the cutting tool 22 is 360. Moreover, since the rotational speed (Y) per second is Y = 18,000 [rpm] / 60 [seconds], the repetition frequency when the pulse light source 50 emits light is as described below. In addition, the pulse width of the pulse light L at this time is set to a pulse width that is shorter than the time taken for the spindle 23 to rotate 1 degree, for example, 1 / 1,000,000 [seconds] = 1 μs.

[0040] The repetition frequency of the pulsed light source = 360 times × 18,000 rpm / 60 seconds

[0041] =108,000 [Hz]

[0042] The pulsed light source emits light like a flash at the aforementioned repetition frequency, and images are captured by the imaging unit 40 and stored in the control unit 100. Then, by referring to the 360 ​​images stored during the period when the cutting tool 22 rotates one revolution, the state of one side (first image 42A), the other side (second image 44A), and the outer peripheral end (third image 46A) of the cutting edge 22a of the cutting tool 22, as recorded in each image, is confirmed. Furthermore, by taking the range where the width of the first image 42A and the second image 44A is wider than the width moved when the cutting edge 22a rotates 1 degree as the object, the entire circumference of the cutting edge 22a can be confirmed through the aforementioned 360 images.

[0043] The monitoring unit 30 according to this embodiment does not simply observe the outline of the outer peripheral end using a light-emitting element and a camera. Instead, it can irradiate pulsed light across the entire circumference of the cutting edge 22a and capture and confirm images of one side, the other side, and the outer peripheral end using the camera 60. Therefore, it can not only confirm the outline of the outer periphery of the cutting edge 22a, but also the condition of one side and the other side of the cutting edge 22a of the cutting tool 22 (e.g., whether the cutting chips are adhered to a level requiring maintenance, whether the abrasive grains have fallen off from the side to a level requiring replacement, etc.). In addition, by having a third imaging unit 46, it can also confirm the wear condition in the thickness direction of the outer peripheral end of the cutting edge 22a. That is, it further improves the accuracy of predicting when to replace the cutting tool 22, the condition of the groove, the condition of the chipped edge, etc.

[0044] In this embodiment, in addition to the imaging unit 40, there is also a light-emitting element 82 and a light-receiving element 84. The pulse light source 50 can also be operated at a repetition frequency different from the above-mentioned repetition frequency (108,000Hz) to monitor the state of the cutting edge 22a of the cutting tool 22.

[0045] As described above, the angle between the positions of the light-emitting element 82 and the light-receiving element 84 and the positions of the first imaging part 42, the second imaging part 44, and the third imaging part 46 is α° (refer to...). Figure 6 Here, while the spindle 23 of the cutting tool 22 rotates at a speed of 18,000 rpm, and light irradiated from the light-emitting element 82 is received by the light-receiving element 84, the amount of light received by the light-receiving element 84 is almost imperceptible when there is no notch on the outer periphery of the cutting edge 22a. In contrast, as Figure 6 As shown, in region P1 where the amount of light received is confirmed by the light-emitting element 82 and the light-receiving element 84, the amount of light received changes instantaneously (increases) when the cutting edge 22a has a notch C. When the control unit 100 detects this change in the amount of light received based on the change in the signal of the light-receiving element 84, the rotational position of the spindle 23 of the cutting unit 20 at the detection moment is detected by the rotary encoder 29. Moreover, according to the timing corresponding to the value (electrical signal) detected by the rotary encoder 29, that is, when region P1 where the amount of light received changes drastically detected by the light-receiving element 84 is positioned in the shooting region P2 captured by the shooting unit 40, the pulse light source 50 is activated to irradiate the shooting region with pulse light L to capture the cutting edge 22a. Then, the first image 42A, the second image 44A, and the third image 46A obtained by the shooting unit 40 are transmitted to the control unit 100 and stored in the storage unit 110 of the control unit 100, and displayed on the display unit 16.

[0046] As described above, the region P1 where the amount of light received by the light-receiving element 84 changes drastically is a region where the cutting edge 22a of the cutting tool 22 is more likely to be damaged. When determining whether the cutting tool 22 needs to be replaced, the region where the damage is more likely can be identified efficiently. In addition, the repetition frequency of the pulse light L at this time is 18,000 [rpm] / 60 [seconds] = 300 [Hz].

Claims

1. A cutting device, wherein, The cutting device has the following features: A chuck table holds the workpiece in place; A cutting unit includes a cutting tool having a cutting edge arranged in a ring for cutting the workpiece held by the chuck table; A monitoring unit that monitors the cutting edge of the cutting tool; and Monitor, The monitoring unit has: The photography unit takes pictures of the cutting edge of the cutting tool. A pulsed light source that emits pulsed light to illuminate the imaging area of ​​the camera unit; and A camera that captures images emitted by the imaging unit. The filming department includes: The first imaging unit captures an image of one side of the cutting edge of the cutting tool; and The second imaging unit captures an image of the other side of the cutting edge of the cutting tool. The first camera unit includes: The first prism has an end face that faces one side of the cutting edge; A first imaging lens is disposed on the other end face of the first prism; and A first optical fiber, which transmits a first image, has one end face connected to the first imaging lens. The second camera unit includes: The second prism has an end face that faces the other side of the cutting edge; A second imaging lens is disposed on the other end face of the second prism; and A second optical fiber, which transmits a second image, has one end face connected to the second imaging lens. The first image emitted from the other end of the first optical fiber and the second image emitted from the other end of the second optical fiber are transmitted to the camera and displayed on the monitor. The cutting device also has a control unit, which has a storage unit for storing images of the cutting edge of the cutting tool captured by the monitoring unit. The monitoring unit also features: The light-emitting element and the light-receiving element are arranged such that they are separated from the cutting edge of the cutting tool; and A rotary encoder is mounted on the spindle that rotates the cutting tool. When the amount of light received by the light-receiving element changes, the control unit controls the emission of pulse light from the pulse light source at the timing corresponding to the value detected by the rotary encoder, and illuminates and captures the area where the amount of light received by the light-receiving element changes as the shooting area to be captured by the imaging unit.

2. The cutting device according to claim 1, wherein, The filming department also includes a third filming department. The third shooting unit includes: A third imaging lens faces the outer peripheral end of the cutting edge; and A third optical fiber, which transmits a third image, has one end face connected to the third imaging lens. The third image, emitted from the other end of the third optical fiber, is transmitted to the camera along with the first and second images and displayed on the monitor.

3. The cutting device according to claim 1 or 2, wherein, The monitoring unit also has a beam splitter disposed between the imaging unit and the camera. The pulsed light emitted by the pulsed light source is introduced from the other end face of each optical fiber disposed in the imaging unit through the beam splitter and is guided to an end face facing the imaging area of ​​the cutting edge of the cutting tool to illuminate the imaging area.

4. The cutting device according to claim 1 or 2, wherein, The monitoring unit also has an illumination fiber that is optically coupled to the pulse light source at one end, and the area being filmed is illuminated by the illumination fiber.

5. The cutting device according to claim 1 or 2, wherein, When the number of times the monitoring unit captures images of the cutting edge during one revolution of the cutting tool is set to X, and the rotational speed of the spindle that rotates the cutting tool in one second is set to Y, The repetition frequency of the pulsed light source = X × Y [Hz].

Images