Cutting device

Abstract

To provide a cutting device which can efficiently clean a light emitting part and a light receiving part while inhibiting adhesion of sawdust to the light emitting part and the light receiving part.SOLUTION: A cutting device includes a cutting blade detection unit 40 having a light emitting part 42 and a light receiving part 43 which face each other across a space into which a blade edge of a cutting blade cutting a workpiece enters. The cutting blade detection unit 40 includes: a light receiving amount measurement part 45 which measures a light receiving amount of the light receiving part 43; nozzles (a first nozzle 62 and a second nozzle 63) which supply a fluid to end surfaces 42-1, 43-1 of the light emitting part 42 and the light receiving part 43; a cleaning water supply passage 47 connected to the nozzles through a first valve 47-2; an air supply passage 48 connected to the nozzles through a second valve 48-2; and a control unit 49 which controls opening / closing of the first valve 47-2 and the second valve 48-2 to cause the nozzles to selectively jet water, air, or two fluids.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cutting device. [Background technology]

[0002] Cutting devices are known that use a cutting blade to cut various plate-shaped substrates, such as semiconductor wafers, resin package substrates, ceramic substrates, and glass substrates, along the streets. Cutting blades wear with use, making it necessary to adjust the cutting depth. Therefore, a non-contact detection unit has been developed that uses an optical sensor to detect the position (origin) of the blade's cutting edge (see, for example, Patent Document 1). The cutting blade is lowered and inserted into the space between the light-emitting unit and the light-receiving unit until the amount of received light decreases to a predetermined level, and the position at which the amount of received light reaches the predetermined level is detected as the origin position of the cutting edge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4590058 Summary of the Invention [Problem to be solved by the invention]

[0004] The light-emitting unit and light-receiving unit are placed in the machining chamber where cutting work is performed, so there is a risk that they may be exposed to an atmosphere or spray containing cutting debris. If cutting debris adheres to the light-emitting unit or light-receiving unit, the amount of light received will change, causing the detected origin position to fluctuate. Therefore, a mechanism was devised to continuously spray water on the light-emitting unit and light-receiving unit to prevent the adhesion of cutting debris. However, constantly spraying water consumes a large amount of water, and while intermittent supply can reduce water consumption, there is still the problem of the risk of cutting debris adhering.

[0005] The present invention was made in consideration of such problems, and its purpose is to provide a cutting device that can efficiently clean the light-emitting unit and the light-receiving unit while suppressing the adhesion of cutting debris to the light-emitting unit and the light-receiving unit. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the cutting device of the present invention is a cutting device comprising: a chuck table for holding a workpiece; a cutting unit having a spindle on which a cutting blade for cutting the workpiece held on the chuck table is attached; a moving unit for raising and lowering the cutting unit; and a cutting blade detection unit having a light emitting section and a light receiving section that face each other across a space into which the cutting edge of the cutting blade enters, wherein the cutting blade detection unit comprises a light receiving amount measuring section that measures the amount of light received by the light receiving section; a nozzle that supplies fluid to end faces of the light emitting section and the light receiving section; a cleaning water supply path that connects to the nozzle via a first valve; an air supply path that connects to the nozzle via a second valve; and a cutting device that controls opening and closing of the first valve and the second valve to supply water, air, or two fluids from the nozzle. Spray a control unit for outputting the a blade detection unit inspection section; Equipped with The blade detection unit inspection section includes an appropriate range recording section that records an appropriate range of the amount of light received by the light receiving section corresponding to the type of fluid ejected from the nozzle, a determination section that determines whether the amount of light received is within the appropriate range recorded by the appropriate range recording section for the type of fluid selected by controlling the first valve and the second valve, and a notification section that notifies the determination result of the determination section when the amount of light received is outside the appropriate range. do.

[0007] The control unit may control the first valve and the second valve to spray the two fluids from the nozzle periodically or before detecting the cutting blade to clean the light-emitting unit and the light-receiving unit.

[0008] The control unit may control the first valve and the second valve to spray the two fluids from the nozzle to clean the light-emitting unit and the light-receiving unit, and then spray the air from the nozzle to remove mist that has adhered to the light-emitting unit and the light-receiving unit due to the spraying of the two fluids.The control unit may control the first valve and the second valve to spray the water from the nozzle when cutting the workpiece with the cutting blade, to prevent chips generated by cutting the workpiece from adhering to the light-emitting unit and the light-receiving unit. [Effects of the Invention]

[0009] The present invention can efficiently clean the light-emitting section and the light-receiving section while suppressing adhesion of cutting debris to the light-emitting section and the light-receiving section. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a cutting device according to the first embodiment. [Figure 2] FIG. 2 is a perspective view showing a main part of the cutting device of FIG. [Figure 3] FIG. 3 is a schematic diagram illustrating a main part of the cutting device of FIG. [Figure 4] FIG. 4 is a table showing the relationship between the opening and closing of the valves and the type of fluid ejected from the nozzles in the cutting device of FIG. [Figure 5] FIG. 5 is a graph showing a first example of the measurement results of the amount of received light obtained by the cutting device of FIG. [Figure 6] FIG. 6 is a graph showing a second example of the measurement results of the amount of received light obtained by the cutting device of FIG. [Figure 7] FIG. 7 is a graph showing a third example of the measurement results of the amount of received light obtained by the cutting device of FIG. [Figure 8] FIG. 8 is a graph showing a fourth example of the measurement results of the amount of received light obtained by the cutting device of FIG. [Figure 9] FIG. 9 is a table showing data on the appropriate range of the amount of light received by the light receiving unit corresponding to the type of fluid ejected from the nozzle in the cutting device of FIG. [Figure 10] FIG. 10 is a perspective view showing a main part of a cutting device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Modes (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0012] [Embodiment 1] A cutting device 1 according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of the configuration of the cutting device 1 according to the first embodiment. FIG. 2 is a perspective view showing a cutting blade 21 and a part of the cutting blade detection unit 40, which are main parts of the cutting device 1 of FIG. 1. FIG. 3 is a schematic diagram explaining the main parts of the cutting device 1 of FIG. 1. FIG. 3 is a top view of a part of the cutting blade detection unit 40 seen from above, and the remaining part is schematically shown in a block diagram or the like. As shown in FIG. 1, the cutting device 1 includes a chuck table 10, a cutting unit 20, a moving unit 30, a cutting blade detection unit 40, and a control unit 80.

[0013] In the first embodiment, the workpiece 100 to be cut by the cutting device 1 is, for example, a disk-shaped semiconductor device wafer or optical device wafer made of a base material such as silicon, sapphire, silicon carbide (SiC), or gallium arsenide. As shown in FIG. 1 , the workpiece 100 has a flat surface 101 on which devices 103 are formed in areas defined by a plurality of planned division lines 102 formed in a grid pattern. In the first embodiment, the workpiece 100 has an adhesive tape 105 attached to a back surface 104 behind the front surface 101, and an annular frame 106 attached to the outer edge of the adhesive tape 105. However, the present invention is not limited to this. Furthermore, in the present invention, the workpiece 100 may be a rectangular package substrate, a ceramic plate, a glass plate, or the like, having a plurality of devices sealed with resin.

[0014] The chuck table 10 has a disk-shaped frame body with a recess formed therein and a disk-shaped suction portion fitted into the recess. The suction portion of the chuck table 10 is formed from a porous material such as porous ceramic and is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown). The upper surface of the suction portion of the chuck table 10 is a holding surface 11 on which a workpiece 100 is placed and which suction-holds the placed workpiece 100. In the first embodiment, the workpiece 100 is placed with its front surface 101 facing upward, and the holding surface 11 suction-holds the placed workpiece 100 from its back surface 104 side via adhesive tape 105. The holding surface 11 and the upper surface of the frame body of the chuck table 10 are arranged on the same plane and are formed parallel to the horizontal XY plane. The chuck table 10 is movable in the X-axis direction, which is one horizontal direction, by the X-axis moving unit 31 of the moving unit 30, and is rotatable around an axis parallel to the Z-axis direction, which is vertical and perpendicular to the holding surface 11, by a rotary drive source not shown.

[0015] 1, the cutting unit 20 includes a spindle 22 having a cutting blade 21 attached to its tip. When the spindle 22 rotates, the cutting blade 21 attached to the tip of the spindle 22 rotates about an axis parallel to a Y-axis direction that is another horizontal direction and perpendicular to the X-axis direction, thereby cutting the workpiece 100 held on the chuck table 10. The cutting unit 20 is provided so as to be movable in the Y-axis direction by a Y-axis moving unit 32 of the moving unit 30 relative to the workpiece 100 held on the chuck table 10, and is also provided so as to be movable in the Z-axis direction (up and down direction) by a Z-axis moving unit 33 of the moving unit 30.

[0016] The cutting blade 21 has an annular cutting edge formed to a predetermined thickness and made of abrasive grains such as diamond or CBN (Cubic Boron Nitride) and a bonding material such as metal or resin. The cutting blade 21 sharpens itself as the cutting edge wears down during cutting, and always maintains a certain level of sharpness.

[0017] The moving unit 30 includes an X-axis moving unit 31, a Y-axis moving unit 32, and a Z-axis moving unit 33. The X-axis moving unit 31 moves the chuck table 10 along the X-axis direction relative to the cutting unit 20. The Y-axis moving unit 32 and the Z-axis moving unit 33 move the cutting unit 20 along the Y-axis direction and the Z-axis direction, respectively, relative to the chuck table 10.

[0018] The X-axis moving unit 31, the Y-axis moving unit 32, and the Z-axis moving unit 33 are respectively provided with an X-axis position detection unit (not shown) that detects the position of the chuck table 10 in the X-axis direction, a Y-axis position detection unit (not shown) that detects the position of the cutting unit 20 in the Y-axis direction, and a Z-axis position detection unit that detects the position of the cutting unit 20 in the Z-axis direction. The X-axis position detection unit, the Y-axis position detection unit, and the Z-axis position detection unit each output the detected positions to the control unit 80. In addition, the Z-axis position detection unit outputs the detected position to a tip position detection unit 54 of the cutting blade detection unit 40, which will be described later.

[0019] The X-axis position detection unit, Y-axis position detection unit, and Z-axis position detection unit can each be configured with a linear scale parallel to the X-axis, Y-axis, or Z-axis direction, and a read head that reads the graduations of the linear scale and is provided so as to be movable in the X-axis, Y-axis, and Z-axis directions by X-axis moving unit 31, Y-axis moving unit 32, and Z-axis moving unit 33, respectively. Note that in the present invention, the X-axis position detection unit, Y-axis position detection unit, and Z-axis position detection unit are not limited to configurations having linear scales and read heads, and may each be an encoder installed on the motor of the X-axis position detection unit, Y-axis position detection unit, and Z-axis position detection unit.

[0020] The cutting device 1 uses the X-axis moving unit 31, the Y-axis moving unit 32, and the Z-axis moving unit 33 to set the cutting blade 21 at a predetermined position relative to the workpiece 100 held on the chuck table 10, and by rotating the cutting blade 21 and moving it relatively along the planned dividing line 102, the cutting blade 21 cuts the workpiece 100 and forms a cutting groove along the planned dividing line 102.

[0021] As shown in Figures 2 and 3, the cutting blade detection unit 40 includes a groove member 41, a light-emitting unit 42, a light-receiving unit 43, a light source 44, a light-receiving amount measuring unit 45, a nozzle unit 46, a cleaning water supply path 47, an air supply path 48, and a control unit 49.

[0022] 2, the groove member 41 has a base 41-1 standing upward from the cutting blade detection unit main body 40-1, and a pair of side wall portions 41-2 standing upward from the base 41-1. The pair of side wall portions 41-2 are spaced apart in the Y-axis direction, which is the direction of the rotation axis of the cutting blade 21, and the distance between them is wider than the thickness of the cutting edge of the cutting blade 21. The pair of side wall portions 41-2 form a groove 41-3, which is a space into which the cutting edge 25, which is the lower tip of the cutting edge of the rotating cutting blade 21, can enter from above.

[0023] The light-emitting unit 42 is installed on one side wall portion 41-2 as shown in Fig. 2. The light-receiving unit 43 is installed on the other side wall portion 41-2 at a position facing the light-emitting unit 42 in the Y-axis direction as shown in Fig. 2. In this way, the light-emitting unit 42 and the light-receiving unit 43 face each other across a space into which the cutting edge 25 of the cutting blade 21 enters.

[0024] The light emitting unit 42 is optically connected to a light source 44 by an optical fiber or the like, and emits light from the light source 44 toward the light receiving unit 43. The light receiving unit 43 is optically connected to a light receiving element by an optical fiber or the like, and the light receiving element receives and detects the light emitted from the light emitting unit 42 and reaching the light receiving unit 43. The light receiving unit 43 is optically connected to a photoelectric conversion unit 51 of the received light amount measurement unit 45 by an optical fiber or the like, and sends the light received from the light emitting unit 42 to the photoelectric conversion unit 51.

[0025] 3, the received light amount measuring unit 45 includes a photoelectric conversion unit 51, a reference voltage setting unit 52, a voltage comparison unit 53, and a tip position detection unit 54. The photoelectric conversion unit 51 outputs a voltage corresponding to the amount of light transmitted from the light receiving unit 43 to the voltage comparison unit 53. As the cutting edge 25 of the cutting blade 21 penetrates into the groove 41-3, the amount of light intercepted by the cutting edge of the cutting blade 21 between the light emitting unit 42 and the light receiving unit 43 increases, and the output voltage from the photoelectric conversion unit 51 gradually decreases. In the first embodiment, the photoelectric conversion unit 51 outputs a voltage of 5 V (maximum voltage) when the light receiving rate, which is the ratio of the amount of light received by the light receiving unit 43 to the amount of light emitted by the light emitting unit 42, is 100%, and a voltage of 0 V (minimum voltage) when the light receiving rate is 0%. The photoelectric conversion unit 51 is set so that the output voltage becomes a predetermined reference voltage (3 V in the first embodiment) when the amount of light received by the light receiving unit 43 reaches a predetermined amount, that is, when the cutting edge 25 of the cutting blade 21 reaches a predetermined position between the light emitting unit 42 and the light receiving unit 43. In this way, the photoelectric conversion unit 51 of the received light amount measuring unit 45 measures the amount of light received by the light receiving unit 43 by converting the light received by the light receiving unit 43 into a voltage based on the amount of light received by the light receiving unit 43.

[0026] The reference voltage setting unit 52 outputs the set predetermined reference voltage to the voltage comparison unit 53. In the first embodiment, the predetermined reference voltage is 3 V, as described above. The voltage comparison unit 53 compares the output voltage from the photoelectric conversion unit 51 with the reference voltage set by the reference voltage setting unit 52. When the output voltage from the photoelectric conversion unit 51 reaches the reference voltage, the voltage comparison unit 53 outputs a signal indicating this to the tip position detection unit 54. When the signal is output from the voltage comparison unit 53, the tip position detection unit 54 acquires the Z-axis position of the cutting unit 20 from the Z-axis position detection unit of the Z-axis movement unit 33. The tip position detection unit 54 detects the acquired Z-axis position of the cutting unit 20 as the position (tip position) of the cutting edge 25 of the cutting blade 21 and outputs the detected tip position of the cutting blade 21 to the control unit 80. In this way, the cutting blade detection unit 40 can detect the cutting edge 25 of the cutting blade 21, its position, and a rough value of the diameter of the cutting blade 21. The cutting edge 25 of the cutting blade 21, its position, and the diameter of the cutting edge of the cutting blade 21 all change as the cutting blade 21 wears and sharpens itself during cutting processing or the like.

[0027] Furthermore, the amount of light received by the light receiving part 43 measured by the light receiving amount measuring part 45 decreases when the outer edge of the cutting edge of the cutting blade 21 protrudes in the radial direction of the cutting blade 21, and increases when it is recessed in the radial direction. Therefore, the cutting blade detection unit 40 can detect the planar shape of the outer edge of the cutting edge of the cutting blade 21 (such as a slit formed in the radial direction or a chip at the tip of the cutting edge) while it is attached to the spindle 22, based on the amount of light received by the light receiving part 43 measured by the light receiving amount measuring part 45. Note that the planar shape of the outer edge of the cutting edge of the cutting blade 21 changes as the cutting blade 21 wears down and self-sharpens during cutting processing, etc.

[0028] In the first embodiment, the received light amount measurement unit 45 includes a computer system. The computer system included in the received light amount measurement unit 45 includes an arithmetic processing unit having a microprocessor such as a CPU (Central Processing Unit), a storage device having memory such as a ROM (Read Only Memory) or RAM (Random Access Memory), and an input / output interface device. The functions of the photoelectric conversion unit 51, the reference voltage setting unit 52, the voltage comparison unit 53, and the tip position detection unit 54 are realized by the arithmetic processing unit of the computer system included in the received light amount measurement unit 45 executing a computer program stored in the storage device of the computer system included in the received light amount measurement unit 45.

[0029] As shown in FIGS. 2 and 3 , the nozzle unit 46 includes a grooved member 61, a first nozzle 62, a second nozzle 63, and a fluid supply unit 64. As shown in FIG. 2 , the grooved member 61 is provided on the cutting blade detection unit main body 40-1 adjacent to the grooved member 41 in the X-axis direction. Like the grooved member 41, the grooved member 61 includes a base 61-1 erected upward from the cutting blade detection unit main body 40-1 and a pair of side wall portions 61-2 erected upward from the base 61-1, as shown in FIG. 2 . The pair of side wall portions 61-2 are spaced apart in the Y-axis direction, which is the direction of the rotation axis of the cutting blade 21, and the distance between them is wider than the thickness of the cutting edge of the cutting blade 21 and narrower than the distance between the pair of side wall portions 41-2. The pair of sidewall portions 61-2 form a groove 61-3 between them, which is a space through which the airflow around the cutting blade 21, generated as the cutting blade 21 rotates, can pass from above. That is, the groove 61-3 is narrower than the groove 41-3. By allowing the airflow around the cutting blade 21 to pass through in this manner, the groove 61-3 reduces the risk of the airflow being turbulent, thereby reducing the risk that moisture that is carried around on the cutting blade 21 due to turbulence of the airflow or that adheres to parts other than the light-emitting portion 42 and the light-receiving portion 43 will affect the measurement of the amount of light received by the cutting blade detection unit 40. Both the first nozzle 62 and the second nozzle 63 are examples of nozzles according to the present invention.

[0030] As shown in FIG. 3, the first nozzle 62 has a tip side mounted on one side wall portion 61-2 and a base side connected to the fluid supply portion 64 through the inside of the groove member 61. As shown in FIGS. 2 and 3, the tip side of the first nozzle 62 is directed toward the end face 42-1 of the light-emitting portion 42 mounted on one side wall portion 41-2 of the groove member 41 on the same side as the one side wall portion 61-2. The first nozzle 62 sprays and supplies the fluid supplied to the fluid supply portion 64 toward the end face 42-1 of the light-emitting portion 42 without crossing the path of the cutting edge 25 of the cutting blade 21 entering the groove 41-3. Here, "the same side" refers to the same side based on the cutting edge 25 of the cutting blade 21 entering the groove 41-3. The end surface 42-1 of the light-emitting part 42 refers to the surface of the light-emitting part 42 facing the inside of the groove 41-3, that is, the surface facing the cutting edge 25 of the cutting blade 21 that enters the groove 41-3.

[0031] As shown in FIG. 3, the second nozzle 63 has a distal end attached to the other side wall 61-2 and a proximal end connected to the fluid supply unit 64 through the inside of the groove member 61. As shown in FIGS. 2 and 3, the distal end of the second nozzle 63 faces the end face 43-1 of the light receiving unit 43, which is attached to the other side wall 41-2 of the groove member 41 on the same side as the other side wall 61-2. The second nozzle 63 sprays and supplies the fluid supplied to the fluid supply unit 64 toward the end face 43-1 of the light receiving unit 43 without crossing the path of the cutting edge 25 of the cutting blade 21 entering the groove 41-3. Here, the end face 43-1 of the light receiving unit 43 refers to the surface of the light receiving unit 43 facing the inside of the groove 41-3, i.e., the surface facing the cutting edge 25 of the cutting blade 21 entering the groove 41-3.

[0032] The fluid supply unit 64 has two connection parts on each of one side and the other side. The two connection parts on one side of the fluid supply unit 64 are connected to the base end side of the first nozzle 62 and the base end side of the second nozzle 63, respectively. The two connection parts on the other side of the fluid supply unit 64 are connected to the cleaning water supply channel 47 and the air supply channel 48 via the first valve 47-2 and the second valve 48-2, respectively.

[0033] The cleaning water supply path 47 has one end connected to a cleaning water supply source 47-1 and the other end connected to a fluid supply unit 64 via a first valve 47-2. That is, the cleaning water supply path 47 is connected to the first nozzle 62 and the second nozzle 63 via the first valve 47-2 and the fluid supply unit 64. When the first valve 47-2 is open, the cleaning water supply path 47 supplies cleaning water supplied from the cleaning water supply source 47-1 to the fluid supply unit 64 via the first valve 47-2. The cleaning water supplied to the fluid supply unit 64 is supplied to the first nozzle 62 and the second nozzle 63. When the first valve 47-2 is closed, the cleaning water supply path 47 stops supplying cleaning water from the cleaning water supply source 47-1 to the fluid supply unit 64. In the first embodiment, the cleaning water supplied from the cleaning water supply source 47-1 is, for example, water (pure water).

[0034] One end of the air supply path 48 is connected to an air supply source 48-1, and the other end is connected to a fluid supply unit 64 via a second valve 48-2. That is, the air supply path 48 is connected to the first nozzle 62 and the second nozzle 63 via the second valve 48-2 and the fluid supply unit 64. When the second valve 48-2 is open, the air supply path 48 supplies air supplied from the air supply source 48-1 to the fluid supply unit 64 via the second valve 48-2. The air supplied to the fluid supply unit 64 is supplied to the first nozzle 62 and the second nozzle 63. When the second valve 48-2 is closed, the air supply path 48 stops supplying air from the air supply source 48-1 to the fluid supply unit 64. In the first embodiment, the air supplied from the air supply source 48-1 is, for example, compressed air or compressed inert gas.

[0035] 4 is a table showing the relationship between the opening and closing of the first valve 47-2 and the second valve 48-2 and the types of fluids ejected from the first nozzle 62 and the second nozzle 63 in the cutting device 1 of FIG. 1. The control unit 49 controls the opening and closing of the first valve 47-2 and the second valve 48-2. When the control unit 49 controls the first valve 47-2 and the second valve 48-2 to be both closed, neither cleaning water is supplied from the cleaning water supply path 47 nor air is supplied from the air supply path 48 to the fluid supply unit 64, and therefore, as shown in FIG. 4, neither cleaning water nor air is ejected from the first nozzle 62 nor the second nozzle 63. When the control unit 49 controls the first valve 47-2 to be opened and the second valve 48-2 to be closed, cleaning water is supplied to the fluid supply section 64 from the cleaning water supply path 47, but air is not supplied from the air supply path 48, so that only cleaning water is sprayed from the first nozzle 62 and the second nozzle 63, as shown in Figure 4.

[0036] When the control unit 49 controls the first valve 47-2 to be closed and the second valve 48-2 to be opened, cleaning water is not supplied to the fluid supply unit 64 from the cleaning water supply channel 47, but air is supplied from the air supply channel 48, so that only air is sprayed from the first nozzle 62 and the second nozzle 63, as shown in Fig. 4. When the control unit 49 controls the first valve 47-2 and the second valve 48-2 to be opened, cleaning water is also supplied to the fluid supply unit 64 from the cleaning water supply channel 47, and air is also supplied from the air supply channel 48, so that the cleaning water and air supplied by the fluid supply unit 64 join and mix to form a mixed two-fluid (two-fluids in the present invention), and the mixed two-fluid is sprayed from the first nozzle 62 and the second nozzle 63, as shown in Fig. 4. In this way, the control unit 49 can selectively spray cleaning water, air, or a mixture of the two fluids from the first nozzle 62 and the second nozzle 63 by controlling the opening and closing of the first valve 47-2 and the second valve 48-2, respectively.

[0037] In the first embodiment, the control unit 49 includes a computer system having an arithmetic processing device with a microprocessor such as a CPU, a storage device with memory such as a ROM or RAM, and an input / output interface device, similar to the received light amount measurement unit 45. In the first embodiment, the functions of the control unit 49 are realized by the arithmetic processing device of the computer system included in the control unit 49 executing a computer program stored in the storage device of the computer system included in the control unit 49.

[0038] In the first embodiment, the cutting blade detection unit 40 further includes a blade detection unit inspection unit 70, as shown in Fig. 3. As shown in Fig. 3, the blade detection unit inspection unit 70 includes an appropriate range recording unit 71, a determination unit 72, and a notification unit 73. The blade detection unit inspection unit 70 is connected to the received light amount measurement unit 45 and the control unit 49 so as to be able to communicate information with them.

[0039] 5, 6, 7, and 8 are graphs showing first, second, third, and fourth examples of measurement results of the amount of light received by the light receiving unit 43 acquired by the light receiving unit 45 of the cutting blade detection unit 40 of the cutting device 1 of FIG. 1. The first, second, third, and fourth examples of measurement results of the amount of light received by the light receiving unit 43 shown in FIGS. 5, 6, 7, and 8 are graphs of the time change in output voltage acquired by the light receiving unit 45 when light is emitted from the light emitting unit 42, when all components of the cutting blade detection unit 40 are functioning normally and are not damaged or defective, and when the cutting blade 21 is not inserted into the groove 41-3. The first example shown in FIG. 5 was acquired by the light receiving unit 45 when nothing was being ejected from the first nozzle 62 and the second nozzle 63. A second example shown in Fig. 6 is obtained by the received light amount measuring unit 45 in a state where only cleaning water is being ejected from the first nozzle 62 and the second nozzle 63. A third example shown in Fig. 7 is obtained by the received light amount measuring unit 45 in a state where only air is being ejected from the first nozzle 62 and the second nozzle 63. A fourth example shown in Fig. 8 is obtained by the received light amount measuring unit 45 in a state where a two-fluid mixture is being ejected from the first nozzle 62 and the second nozzle 63.

[0040] When nothing is being ejected from the first nozzle 62 and the second nozzle 63, the output voltage acquired by the received light amount measuring unit 45 hardly changes over time and remains constant at voltage 81 (5 V, the same as the maximum voltage described above, in the first embodiment), as shown in Fig. 5. When only cleaning water is being ejected from the first nozzle 62 and the second nozzle 63, the output voltage acquired by the received light amount measuring unit 45 changes dramatically over time as shown in Fig. 6 due to the light from the light emitting unit 42 directed toward the light receiving unit 43 being scattered by the mist of cleaning water, and changes with a voltage swing range 91 representing the voltage swing from voltage 82 to voltage 83 and voltage 84, with voltage 82 smaller than voltage 81 as the median, voltage 83 larger than voltage 81 as the maximum, and voltage 84 larger than 0 V as the minimum.

[0041] When only air is being ejected from the first nozzle 62 and the second nozzle 63, the output voltage acquired by the received light amount measuring unit 45 remains constant at voltage 81, as shown in Fig. 7, and remains almost constant over time, similar to when nothing is being ejected from the first nozzle 62 and the second nozzle 63. When the two mixed fluids are being ejected from the first nozzle 62 and the second nozzle 63, the output voltage acquired by the received light amount measuring unit 45 remains constant at voltage 81, as shown in Fig. 8. When the two mixed fluids are being ejected from the first nozzle 62 and the second nozzle 63, the output voltage changes dramatically over time, as shown in Fig. 8, and varies with voltage 85, which is smaller than voltage 82, as the median, voltage 86, which is smaller than voltage 81 and voltage 83, as the maximum, and voltage 87, which is equal to voltage 84, as the minimum. In this way, the amount of light received by the light receiving unit 43 (output voltage) measured by the received light amount measuring unit 45 changes depending on the type of fluid supplied from the first nozzle 62 and the second nozzle 63.

[0042] 9 is a table showing data (appropriate range data) on the appropriate range of the amount of light received by the light receiving unit 43 corresponding to the type of fluid ejected from the first nozzle 62 and the second nozzle 63 in the cutting device 1 of FIG. 1. The appropriate range recording unit 71 records the appropriate range of the amount of light received by the light receiving unit 43 corresponding to the type of fluid ejected from the first nozzle 62 and the second nozzle 63. Specifically, the appropriate range recording unit 71 stores appropriate range data that correlates the types of fluid ejected from the first nozzle 62 and the second nozzle 63 with the appropriate range of the amount of light received by the light receiving unit 43 corresponding to each type of fluid, as shown in FIG. 9, based on the actual measurement results of the amount of light received by the light receiving unit 43 when the cutting blade detection unit 40 shown in the first, second, third, and fourth examples above is functioning normally. 9, the appropriate range recording unit 71 takes into consideration a value Δ corresponding to a certain error or variation, and records, for each type of fluid, values ​​for four items, namely, the range of the median value of the output voltage acquired by the received light amount measuring unit 45, the upper limit of the maximum value, the lower limit of the minimum value, and the range of the voltage fluctuation, as the appropriate range of the amount of light received by the light receiving unit 43, in accordance with the measurement results of the amount of light received by the light receiving unit 43 under normal conditions shown in Examples 1, 2, 3, and 4. The appropriate range data recorded by the appropriate range recording unit 71 is recorded in advance by being input by the operator of the cutting device 1 via an input unit (not shown), for example.

[0043] In addition to the appropriate range data recorded by the appropriate range recording unit 71, the blade detection unit inspection unit 70 also records data (valve fluid type comparison data) showing the relationship between information on the opening and closing of each of the first valve 47-2 and the second valve 48-2 and the types of fluids ejected from the first nozzle 62 and the second nozzle 63, as shown in Fig. 4. The valve fluid type comparison data recorded by the blade detection unit inspection unit 70 is recorded in advance by being input by the operator of the cutting device 1 via an input unit (not shown), for example.

[0044] The determination unit 72 determines whether the amount of light received by the light receiving unit 43 is within the appropriate range recorded by the appropriate range recording unit 71 for the type of fluid selected by the control unit 49 to be ejected from the first nozzle 62 and the second nozzle 63 by controlling the opening and closing of the first valve 47-2 and the second valve 48-2. The determination unit 72 first obtains information on the opening and closing states of the first valve 47-2 and the second valve 48-2 from the control unit 49, and then, by referring to the valve-fluid type comparison data shown in FIG. 4 that is previously stored in the blade detection unit inspection unit 70, obtains information on the type of fluid to be ejected from the first nozzle 62 and the second nozzle 63 that is correlated with the obtained opening and closing information in the valve-fluid type comparison data. The determination unit 72 then obtains, from the received light amount measurement unit 45, an output voltage that is a measurement result of the amount of light received by the light receiving unit 43. 9 , which is previously recorded by the appropriate range recording unit 71, and acquires information on the appropriate range of the amount of light received by the light receiving unit 43, which is correlated with the previously acquired information on the type of fluid. The determination unit 72 determines whether the output voltage acquired from the received light amount measuring unit 45 satisfies the conditions of the acquired appropriate range of the amount of light received by the light receiving unit 43.

[0045] When the determination unit 72 determines that the output voltage acquired from the received light amount measurement unit 45 does not satisfy the conditions of the appropriate range, that is, is outside the appropriate range, it outputs a determination result that it is outside the appropriate range to the notification unit 73. The notification unit 73 notifies the determination result received from the determination unit 72. When the determination unit 72 determines that the output voltage acquired from the received light amount measurement unit 45 satisfies the conditions of the appropriate range, that is, is within the appropriate range, it may output a determination result that it is within the appropriate range to the notification unit 73, and cause the notification unit 73 to notify the determination result.

[0046] The determination section 72 may also output a command signal to the control unit 49 regarding the control of opening and closing of the first valve 47-2 and the second valve 48-2 to sequentially set the type of fluid to be sprayed from the first nozzle 62 and the second nozzle 63 to none, cleaning water, air, and two mixed fluids, and sequentially determine for each of these settings whether the output voltage acquired from the received light amount measurement section 45 satisfies the condition of the appropriate range of the amount of light received by the light receiving section 43. The determination section 72 may determine which of the cleaning water supply path 47 and the air supply path 48 is more likely to be damaged or malfunctioning, based on which type of fluid was set for which a determination result outside the appropriate range was obtained, and output the determination result to the notification section 73, causing the notification section 73 to issue a notification.

[0047] In this way, the blade detection unit inspection section 70 inspects whether the function of spraying fluid from the first nozzle 62 and the second nozzle 63 toward the end face 42-1 of the light-emitting section 42 and the end face 43-1 of the light-receiving section 43 in the cutting blade detection unit 40 is operating normally, i.e., whether the fluid can be sprayed normally from the first nozzle 62 and the second nozzle 63 in accordance with the opening and closing of the first valve 47-2 and the second valve 48-2 controlled by the control unit 49.

[0048] In the first embodiment, the notification unit 73 is a display unit with its display surface facing outward, a lighting unit, a voice transmission unit, an information communication unit, or the like. The display unit, which is an example of the notification unit 73, is, for example, a liquid crystal display device, and, based on receiving a determination result from the determination unit 72 that the value is outside the appropriate range, displays a screen related to the determination result to visually notify the operator of the determination result. The lighting unit, which is an example of the notification unit 73, is, for example, a light-emitting diode, and, based on receiving a determination result from the determination unit 72 that the value is outside the appropriate range, notifies the operator of the determination result in a recognizable manner by lighting, blinking, changing the color of the light, or the like. The voice transmission unit, which is an example of the notification unit 73, is, for example, a speaker, and, based on receiving a determination result from the determination unit 72 that the value is outside the appropriate range, notifies the operator of the determination result in a recognizable manner by voice. The information communication unit, which is an example of the notification unit 73, is connected to information devices such as smartphones, tablets, wearable devices, and computers so that it can communicate information with them. Based on receiving a judgment result from the judgment unit 72 that the value is outside the appropriate range, the information communication unit transmits the judgment result to these information devices and notifies the operator of the judgment result in a manner that the operator can recognize it using the display unit, lighting unit, and audio transmission unit of these information devices.

[0049] In the first embodiment, the blade detection unit inspection section 70 includes a computer system having an arithmetic processing unit with a microprocessor such as a CPU, a storage device with memory such as ROM or RAM, and an input / output interface device, similar to the received light amount measurement section 45 and the control unit 49. In the first embodiment, the function of the appropriate range recording section 71 is realized by the storage device of the computer system included in the blade detection unit inspection section 70. In the first embodiment, the function of the determination section 72 is realized by the arithmetic processing unit of the computer system included in the blade detection unit inspection section 70 executing a computer program stored in the storage device of the computer system included in the blade detection unit inspection section 70. The notification section 73 is connected to the computer system included in the blade detection unit inspection section 70 so as to be able to communicate information with it via the input / output interface device.

[0050] The control unit 80 controls each component of the cutting device 1 to cause the cutting device 1 to perform various operations, such as the cutting process of the workpiece 100 by the cutting unit 20, the detection process of the cutting edge 25 of the cutting blade 21 and its position, the rough diameter of the cutting edge of the cutting blade 21, and the planar shape of the outer edge of the cutting edge of the cutting blade 21 by the cutting blade detection unit 40, and the inspection process of the cutting blade detection unit 40 by the blade detection unit inspection unit 70. In the first embodiment, the control unit 80 includes a computer system having an arithmetic processing unit with a microprocessor such as a CPU, a storage device with memory such as ROM or RAM, and an input / output interface device, similar to the light reception measurement unit 45, the control unit 49, and the blade detection unit inspection unit 70. In the first embodiment, the functions of the control unit 80 are realized by the arithmetic processing unit of the computer system included in the control unit 80 executing a computer program stored in the storage device of the computer system included in the control unit 80.

[0051] Next, this specification describes an example of the operation process of the cutting device 1 according to embodiment 1. When the main power supply is switched from OFF to ON and the cutting device 1 is started up, when the chuck table 10 or the cutting blade 21 is replaced, or when a predetermined operation command is received from an operator of the cutting device 1, before starting the cutting process of the workpiece 100, the cutting edge 25 of the cutting blade 21 is inserted into the groove 41-3 of the cutting blade detection unit 40 by the X-axis movement unit 31, the Y-axis movement unit 32, and the Z-axis movement unit 33 to check whether the shape of the cutting edge of the cutting blade 21 is normal or to adjust the tip position of the cutting blade 21. The cutting blade detection unit 40 then performs detection process for the cutting edge 25 of the cutting blade 21 and its position, the approximate diameter of the cutting edge of the cutting blade 21, the planar shape of the outer edge of the cutting edge of the cutting blade 21, etc.

[0052] In the first embodiment, the control unit 49 of the cutting blade detection unit 40 of the cutting device 1 periodically or before the tip position detection unit 54 of the cutting blade detection unit 40 performs the detection process of the cutting blade 21, performs a cleaning process to clean the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43. Specifically, the control unit 49 of the cutting device 1 first controls the first valve 47-2 and the second valve 48-2 to be both opened while the Z-axis movement unit 33 retracts the cutting blade 21 upward relative to the groove 41-3, and then sprays the two mixed fluids from the first nozzle 62 and the second nozzle 63 onto the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43, respectively, to clean the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43. The control unit 49 of the cutting device 1 then switches the first valve 47-2 from open to closed, and sprays air from the first nozzle 62 and the second nozzle 63 onto the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43, respectively, to remove the mist of the two-fluid mixture, i.e., the water droplets of cleaning water, that have adhered to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43 due to the spraying of the two-fluid mixture. In this way, the cutting blade detection unit 40 of the cutting device 1 can clean the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43 by spraying the two-fluid mixture and removing the cleaning water droplets by spraying air, thereby ensuring that both cutting chips and water droplets of cleaning water that could adversely affect the detection process of the cutting blade 21 are properly removed from the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43.

[0053] The control unit 49 of the cutting device 1 also constantly or intermittently performs a cutting debris adhesion suppression process to suppress adhesion of cutting debris to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43, for example, when performing a cutting process on the workpiece 100 using the cutting unit 20. Specifically, the control unit 49 of the cutting device 1 controls the first valve 47-2 to open and the second valve 48-2 to close, thereby spraying cleaning water from the first nozzle 62 and the second nozzle 63 onto the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43, respectively, thereby suppressing adhesion of cutting debris generated during the cutting process to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43. Note that when only cleaning water is sprayed from the first nozzle 62 and the second nozzle 63, the amount of mist generated is significantly smaller than when the two-fluid mixture is sprayed. Therefore, the control unit 49 of the cutting device 1 can reduce the chance of spraying the two mixed fluids, which generates a large amount of mist, by performing this cutting debris adhesion suppression process of spraying only cleaning water from the first nozzle 62 and the second nozzle 63. This reduces the risk that the large amount of mist generated by the spraying of the two mixed fluids will cross the partitions of the processing chamber and enter various places inside the cutting device 1, causing the large amount of mist to cool the framework of the cutting device 1 and affect the accuracy of the cutting process, and the risk that water droplets caused by the large amount of mist will adhere to control boards that execute control processes inside the cutting device 1 (for example, the control boards of the light reception amount measurement unit 45, control unit 49, blade detection unit inspection unit 70, and control unit 80) and the like, causing adverse effects.

[0054] In embodiment 1, the judgment unit 72 of the blade detection unit inspection unit 70 of the cutting device 1 inspects whether the function of spraying fluid from the first nozzle 62 and the second nozzle 63 toward the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43 is operating normally, either periodically or before performing cleaning processing or cutting debris adhesion prevention processing using the cutting blade detection unit 40.

[0055] The cutting device 1 according to the first embodiment having the above configuration includes a first nozzle 62 and a second nozzle 63 that selectively supply cleaning water, air, or a mixture of these two fluids to the end surface 42-1 of the light-emitting unit 42 and the end surface 43-1 of the light-receiving unit 43 of the cutting blade detection unit 40 by controlling the opening and closing of the first valve 47-2 and the second valve 48-2 by the control unit 49. As a result, the cutting device 1 according to the first embodiment selects the fluids to be supplied from the first nozzle 62 and the second nozzle 63 according to the purpose, thereby supplying cleaning water to prevent cutting debris from adhering to the light-emitting unit 42 and the light-receiving unit 43, supplying the mixture of the two fluids to powerfully clean the light-emitting unit 42 and the light-receiving unit 43 and remove cutting debris adhering to the light-emitting unit 42 and the light-receiving unit 43, and supplying air to remove the mist of the mixture of the two fluids, i.e., water droplets of cleaning water, that has adhered to the light-emitting unit 42 and the light-receiving unit 43. In this way, the cutting device 1 according to the first embodiment has the advantageous effect of being able to efficiently clean the light-emitting unit 42 and the light-receiving unit 43 while suppressing adhesion of cutting debris to the light-emitting unit 42 and the light-receiving unit 43.

[0056] Furthermore, the cutting device 1 according to the first embodiment performs a cleaning process to clean the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43 periodically or before the tip position detection unit 54 of the cutting blade detection unit 40 performs the detection process for the cutting blade 21. Therefore, the cutting device 1 according to the first embodiment can reduce the number of cleaning opportunities performed by the operator and can maintain high accuracy when the cutting blade detection unit 40 performs the detection process for the cutting blade 21.

[0057] In addition, in the cutting device 1 of embodiment 1, the blade detection unit inspection section 70 utilizes the fact that the amount of light received (output voltage) of the light receiving section 43 measured by the light receiving amount measuring section 45 changes depending on the type of fluid supplied from the first nozzle 62 and the second nozzle 63, to inspect whether the function of spraying fluid from the first nozzle 62 and the second nozzle 63 toward the end face 42-1 of the light emitting section 42 and the end face 43-1 of the light receiving section 43 is operating normally, and can detect the possibility of damage or malfunction in the cleaning water supply path 47 or the air supply path 48.

[0058] [Embodiment 2] A cutting device 1 according to a second embodiment of the present invention will be described with reference to the drawings. Fig. 10 is a perspective view showing the main parts of the cutting device 1 according to the second embodiment. In Fig. 10, the same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

[0059] The cutting device 1 according to the second embodiment is similar to that according to the first embodiment, except that it further includes a protective cover unit 95 that selectively covers the cutting blade detection unit 40 from above. As shown in FIG. 10 , the protective cover unit 95 includes a protective cover main body 96 and a drive unit 97. A rotating shaft 98 is attached to one end of the protective cover main body 96, and the rotating shaft 98 is rotatably supported on both ends of the cutting blade detection unit main body 40-1. The drive unit 97 is controlled by the control unit 49. The drive shaft is connected to the rotating shaft 98, and the drive unit 97 drives the rotating shaft 98 to move the protective cover main body 96 between an exposed position where the grooved member 41 and the grooved member 61 of the cutting blade detection unit 40 are exposed so that the cutting edge 25 of the cutting blade 21 can enter the groove 41-3, and a protected position where the grooved member 41 and the grooved member 61 of the cutting blade detection unit 40 are covered and protected from the outside.

[0060] Next, this specification will describe an example of the operation process of the cutting device 1 according to embodiment 2. The operation process of the cutting device 1 according to embodiment 2 is the same as that of embodiment 1 except that the cutting debris adhesion suppression process is changed. In the cutting chip adhesion prevention process of the cutting device 1 of embodiment 2, for example, when performing cutting processing of the workpiece 100 by the cutting unit 20, the control unit 49 of the cutting device 1 moves the protective cover main body 96 to a protective position using the drive unit 97, and the protective cover main body 96 prevents cutting chips from adhering to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43 using the protective cover main body 96.Furthermore, the control unit 49 periodically controls the first valve 47-2 to be opened and the second valve 48-2 to be closed, and sprays cleaning water from the first nozzle 62 and the second nozzle 63 onto the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43, respectively, thereby further preventing cutting chips generated by the cutting processing from adhering to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43.

[0061] The cutting device 1 according to the second embodiment having the above-described configuration is the same as that of the first embodiment except that it further includes a protective cover unit 95 that selectively covers the cutting blade detection unit 40 from above, and the other configurations are the same as those of the first embodiment, so that it achieves the same effects as those of the first embodiment. Furthermore, the cutting device 1 according to the second embodiment achieves the effect that the protective cover unit 95 can further prevent cutting chips from adhering to the end face 42-1 of the light-emitting unit 42 and the end face 43-1 of the light-receiving unit 43.

[0062] The present invention is not limited to the above-described embodiments. In other words, various modifications can be made without departing from the gist of the present invention. In the above-described first and second embodiments, the first and second valves 47-2 and 48-2 are provided with the first nozzle 62 and the second nozzle 63, which can selectively spray cleaning water, air, and the two mixed fluids. However, a draining nozzle that can spray only air toward the end surface 42-1 of the light-emitting unit 42 and the end surface 43-1 of the light-receiving unit 43 may be separately provided, and the first and second valves 47-2 and 48-2 and the draining nozzle may be selectively used. [Explanation of symbols]

[0063] 1 Cutting equipment 10 Chuck table 20 Cutting unit 21 Cutting blade 22 Spindle 25 cutting edge 30 Mobile Units 40 Cutting blade detection unit 42 Light-emitting part 42-1,43-1 End face 43 Light receiving part 45 Received light amount measuring section 47 Cleaning water supply channel 47-2 First valve 48 Air supply line 48-2 Second Valve 49 Control Unit 62 First nozzle (an example of a nozzle in the present invention) 63 Second nozzle (an example of a nozzle in the present invention) 70 Blade detection unit inspection section 71 Appropriate range recording section 72 Judgment section 73 Information Department 100 Workpiece

Claims

1. A cutting device comprising: a chuck table for holding a workpiece; a cutting unit having a spindle on which a cutting blade for cutting the workpiece held on the chuck table is attached; a moving unit for raising and lowering the cutting unit; and a cutting blade detection unit having a light emitting section and a light receiving section that face each other across a space into which the cutting edge of the cutting blade enters, The cutting blade detection unit includes: a light receiving amount measuring unit for measuring the amount of light received by the light receiving unit; a nozzle for supplying a fluid to end faces of the light-emitting portion and the light-receiving portion; a cleaning water supply line connected to the nozzle via a first valve; an air supply passage connected to the nozzle via a second valve; a control unit that controls the opening and closing of the first valve and the second valve and jets water, air, or two fluids from the nozzle; a blade detection unit inspection unit; The blade detection unit inspection section an appropriate range recording unit that records an appropriate range of the amount of light received by the light receiving unit corresponding to the type of fluid ejected from the nozzle; a determination unit that determines whether the amount of received light is within the appropriate range recorded by the appropriate range recording unit for the type of fluid selected by controlling the first valve and the second valve; and a notification unit that notifies the determination result of the determination unit when the amount of received light is outside the appropriate range.

2. The cutting device according to claim 1, wherein the control unit controls the first valve and the second valve to spray the two fluids from the nozzle periodically or before detecting the cutting blade, thereby cleaning the light-emitting unit and the light-receiving unit.

3. A cutting device as described in claim 2, wherein the control unit controls the first valve and the second valve to spray the two fluids from the nozzle to clean the light-emitting part and the light-receiving part, and then sprays the air from the nozzle to remove mist that has adhered to the light-emitting part and the light-receiving part due to the spraying of the two fluids.

4. A cutting device as described in claim 1, 2 or 3, wherein the control unit controls the first valve and the second valve to spray water from the nozzle when cutting the workpiece with the cutting blade, thereby preventing cutting chips generated by cutting the workpiece from adhering to the light-emitting element and the light-receiving element.

Images