Teaching unit

Abstract

This teaching unit measures the position of a positioning pin of a mounting table. The teaching unit comprises: an imaging device that images the positioning pin from above; a unit body on which the imaging device is mounted; and a light shielding cover that is attached to the unit body and extends downward from the unit body so as to surround the imaging range of the imaging device.

Description

Teaching Unit

[0001] The present disclosure relates to teaching units.

[0002] Known technology relating to a teaching unit that measures the position of a measurement target is, for example, the teaching unit described in Patent Document 1. The teaching unit described in Patent Document 1 has a main body and a touch panel provided on the underside of the main body, and detects the position of a positioning pin on a target plate installed on a load port by contacting the touch panel with the positioning pin.

[0003] JP 2019-139474 A

[0004] In some teaching units, the position of the measurement object is measured using an imaging device such as a camera. In this case, the position of the measurement object can be measured without contact, thereby reducing measurement errors associated with contact with the measurement object. However, in an environment where ambient light is present around the teaching unit, the teaching unit may be adversely affected by this ambient light, making it difficult to accurately measure the measurement object.

[0005] Therefore, an object of the present disclosure is to provide a teaching unit that enables accurate measurement even in an environment where ambient light is present.

[0006] (1) The teaching unit according to the present disclosure is a teaching unit that measures the position of a measurement object, and includes an imaging device that captures an image of the measurement object from above, a unit body on which the imaging device is mounted, and a light-shielding cover that is attached to the unit body and extends downward from the unit body so as to surround the imaging range of the imaging device.

[0007] This teaching unit has a light-shielding cover that extends downward from the unit body to surround the imaging range of the imaging device, which can suppress ambient light from entering the imaging range of the imaging device, thereby enabling accurate measurements even in environments where ambient light is present.

[0008] (2) In the teaching unit described in (1) above, the light-shielding cover may be provided so as to be movable up and down relative to the unit body. In this case, the lowering movement of the unit body can be prevented from being restricted by the light-shielding cover.

[0009] (3) In the teaching unit described in (1) or (2) above, the light-shielding cover may be supported by the unit body, and the light-shielding cover may be supported by a structure other than the unit body, thereby releasing the support of the light-shielding cover by the unit body and separating the light-shielding cover from the unit body. In this case, the position of the unit body is no longer restricted by the light-shielding cover being supported by a structure other than the unit body, allowing for more accurate measurements.

[0010] (4) In the teaching unit described in (3) above, the unit body may have a base and a flange extending horizontally outward from the base, the light-shielding cover may have an upper wall having an opening through which the base passes and a side wall extending downward from the upper wall, and the flange may abut against the upper wall from below to support the light-shielding cover. With this configuration, when the light-shielding cover is supported from below by a structure other than the unit body, the light-shielding cover can be easily separated from the unit body.

[0011] (5) In the teaching unit described in (4) above, the flange may have a convex portion protruding from the upper surface of the flange, the outer side surface of the convex portion being inclined inward from the vertical plane as it extends upward, and the light-shielding cover may abut against the outer side surface of the convex portion at the inner side surface of the upper wall portion. With this configuration, after the light-shielding cover separates from the unit body, the inner side surface of the upper wall portion of the light-shielding cover abuts against the outer side surface of the convex portion of the unit body as the unit body rises, and the light-shielding cover is again supported by the unit body. At this time, even if the light-shielding cover is misaligned horizontally relative to the unit body, the inclination of the outer side surface of the convex portion can be used to correct the misalignment.

[0012] (6) In the teaching unit according to any one of (1) to (5) above, the imaging device may capture an image of the measurement object from above while the unit body is allowed to move horizontally relative to the measurement object. In this case, the horizontal shaking of the unit body is not impeded when the imaging device captures an image, enabling more accurate measurement by taking the shaking into account.

[0013] (7) In the teaching unit according to any one of (1) to (6), at least a part of the inner surface of the light-shielding cover may be black. In this case, for example, even if ambient light enters the cover, the influence of the ambient light can be suppressed.

[0014] (8) In the teaching unit according to any one of (1) to (7), the vertical length of the light-shielding cover may be equal to or greater than the vertical length from the bottom surface of the unit body to the focal position of the imaging device. In this case, ambient light incident on the focal position of the imaging device can be more effectively suppressed.

[0015] (9) In the teaching unit according to any one of (1) to (8), a sensor is mounted on the unit body and emits light downward, and the light-shielding cover may extend downward from the unit body so as to further surround the optical path of the sensor. In this case, the light-shielding cover can also suppress ambient light that attempts to enter the optical path of the sensor, thereby improving the detection accuracy of the sensor.

[0016] According to the present disclosure, accurate measurements can be made even in an environment where ambient light is present.

[0017] Fig. 1 is a side view of a ceiling transport vehicle holding a teaching unit according to an embodiment. Fig. 2 is a cross-sectional view of the teaching unit of Fig. 1 in a state where a light-shielding cover is supported by a unit body. Fig. 3 is a cross-sectional view of the teaching unit of Fig. 1 in a state where the light-shielding cover and the unit body are separated from each other.

[0018] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant description will be omitted.

[0019] 1 , a teaching unit 1 according to one embodiment is used to teach an overhead transport vehicle 10 the position of a load port 3 in an overhead transport vehicle system 100. First, the overhead transport vehicle system 100 will be described. The overhead transport vehicle system 100 includes a traveling rail 2, an overhead transport vehicle 10, and a load port 3.

[0020] The traveling rail 2 is installed, for example, near the ceiling of a clean room where semiconductor devices are manufactured. The load port 3 is installed, for example, in a processing device that performs various processes on semiconductor wafers. Hereinafter, the direction parallel to the traveling direction of the overhead transport vehicle 10 is defined as the X direction, the direction parallel to the horizontal plane and perpendicular to the traveling direction of the overhead transport vehicle 10 is defined as the Y direction, and the direction parallel to the vertical direction is defined as the Z direction.

[0021] The ceiling transport vehicle 10 travels along the traveling rails 2, transports a transported object, for example, a cassette (a so-called FOUP (Front Opening Unified Pod)) containing a plurality of semiconductor wafers, and transfers the transported object at the load port 3. The ceiling transport vehicle 10 includes a traveling unit 11, a lateral feed unit 12, a rotating unit 13, a lifting / lowering unit 14, a holding unit 15, and a controller 16. The traveling unit 11 travels along the traveling rails 2 by receiving a contactless supply of power from a high-frequency current line laid along the traveling rails 2. The lateral feed unit 12 moves the rotating unit 13, the lifting / lowering unit 14, and the holding unit 15 in the Y direction. The rotating unit 13 rotates the lifting / lowering unit 14 and the holding unit 15 in both directions within a horizontal plane. The lifting unit 14 raises and lowers the holding units 15 relative to the load port 3 by reeling out or reeling in a plurality of belts 14a, each having a holding unit 15 attached to its lower end. The holding units 15 have a pair of claw members 15a. The holding units 15 hold the transported object by opening and closing the pair of claw members 15a.

[0022] The controller 16 controls the operation of each part of the overhead transport vehicle 10. The controller 16 controls the operation of the overhead transport vehicle 10 based on the set teaching data, and transfers the transported object to the load port 3. The teaching data are control parameters (or transfer conditions) for transferring the transported object to the load port 3. The controller 16 also controls the teaching operation when the teaching unit 1 is attached to the overhead transport vehicle 10.

[0023] The teaching data may include translation (X, Y) which is the position of the holder 15 in the X and Y directions, a position in the Z direction (height Z), and a rotation angle (rotation θ) of the holder 15 in the horizontal plane when the transported object is transferred to the load port 3. Furthermore, for example, the teaching data may include translation (X, Y) which is the X direction position of the travel unit 11 (or the drive amount of the travel unit 11) and the Y direction positions of the rotator 13, the lifting unit 14, and the holder 15 (or the drive amount of the lateral feed unit 12), rotation θ which is the rotation angle of the lifting unit 14 and the holder 15 (or the drive amount of the rotator 13), height Z which is the Z direction position of the holder 15 (or the drive amount of the lifting unit 14), and tilt (αx, αy) which is the tilt from the horizontal in the X and Y directions. The teaching data (translation (X, Y), height Z, rotation θ, tilt (αx, αy)) is stored in the storage unit of the controller 16.

[0024] In such an overhead transport vehicle system 100, teaching is performed using the teaching unit 1 when constructing the overhead transport vehicle system 100 or periodically as part of maintenance, to use the overhead transport vehicle 10 to transfer an object to the load port 3. Teaching involves determining how much the position of the holding unit 15 deviates from the target position when the traveling unit 11 stops at a predetermined position on the traveling rail 2 and the holding unit 15 is lowered a predetermined distance so that the overhead transport vehicle 10 can transfer an object to the load port 3, and calculating or storing teaching data, which is the operation to be performed by the overhead transport vehicle 10, so that there is no deviation from the target position when the overhead transport vehicle system 100 is in operation.

[0025] The teaching unit 1 is gripped by a pair of claw members 15a of the holding part 15 when teaching is performed. The teaching unit 1 measures the position of a positioning pin 62 (described below) on a mounting table 60 installed on the upper surface 3a of the load port 3. The mounting table 60 has three positioning pins 62 (measurement objects). The three positioning pins 62 are positioning members formed at predetermined positions on the upper surface 60a of the mounting table 60. The three positioning pins 62 are composed of positioning pins 62a, 62b, and 62c (see FIGS. 2 and 3).

[0026] Next, a detailed description will be given of the teaching unit 1. As shown in Figures 2 and 3, the teaching unit 1 includes a unit main body 20, two image capturing devices 30, three sensors 40, and a light-shielding cover 50.

[0027] The unit main body 20 includes a base 21, an upper flange 22, and a lower flange 23 (flange portion). The base 21 has, for example, a rectangular prism-like appearance extending vertically. The upper flange 22 extends horizontally outward from the upper end of the base 21. The upper flange 22 is formed to surround the base 21 when viewed from above. The upper flange 22 has, for example, a rectangular outer shape when viewed from above. The upper flange 22 is held (suspended) from above by a pair of claw members 15a of the holding portion 15.

[0028] The lower flange portion 23 extends horizontally outward from the lower end of the base portion 21. The lower flange portion 23 is formed so as to surround the base portion 21 when viewed from above. The lower flange portion 23 has, for example, a rectangular outer shape when viewed from above. The upper surface 23a of the lower flange portion 23 is, for example, flat. A convex portion 24 that protrudes upward is formed on the upper surface 23a of the lower flange portion 23.

[0029] The protrusion length of the convex portion 24 (the length in the vertical direction from the upper surface 23a) corresponds to the thickness of the upper wall portion 51 of the light-shielding cover 50, which will be described later. When viewed from above, the convex portion 24 is formed to surround the base portion 21. Specifically, the convex portion 24 is formed around the base portion 21 in an area other than the outer edge portion 23c of the upper surface 23a. The outer side surface 24b of the convex portion 24 is inclined so that it slopes inward from the vertical plane as it extends upward. The inclination angle of the side surface 24b from the vertical plane is preferably, for example, about 45 degrees. This unit main body 20 can support the light-shielding cover 50 by the lower flange portion 23 (details will be described later).

[0030] The two imaging devices 30 are mounted on the unit main body 20. The two imaging devices 30 are attached to the underside 20a of the unit main body 20. Each imaging device 30 captures an image of the positioning pin 62 of the mounting base 60 from above. In this example, the two imaging devices 30 are composed of imaging devices 30a and 30b. The imaging device 30a captures an image of an area including the positioning pin 62a from above. The imaging device 30b captures an image of an area including the positioning pin 62b from above. The imaging devices 30a and 30b are preferably positioned directly above the positioning pins 62a and 62b, respectively, during measurement. Note that the imaging devices 30a and 30b each have a built-in lighting device to clearly capture the positioning pins 62a and 62b. This lighting device may be separately provided in the space inside the light-shielding cover 50.

[0031] The imaging device 30 captures an image of an imaging range A. For example, the imaging range A corresponds to the range that appears in an image captured by the imaging device 30. For example, the imaging range A is an area that includes a range that corresponds to the angle of view between the imaging surface of the imaging device 30a and the focal position. Based on the positions of the positioning pins 62a and 62b captured by the two imaging devices 30, the controller 16 measures the relative position in the X direction, the relative position in the Y direction, and the relative rotation angle in the Z direction of the unit body 20 with respect to the positioning pin 62.

[0032] The three sensors 40 are mounted on the unit body 20. The sensors 40 are attached to the underside 20a of the unit body 20. The sensors 40 emit light downward. Each of the three sensors 40 measures the vertical distance from the underside 20a of the unit body 20 to the mounting table 60. The sensors 40 are, for example, distance measuring devices that use laser light. The controller 16 calculates the inclination of the unit body 20 with respect to the horizontal direction based on the distances measured by each sensor 40.

[0033] The light-shielding cover 50 is attached to the unit body 20. The light-shielding cover 50 extends downward from the unit body 20 so as to surround the imaging range A of the imaging device 30. The light-shielding cover 50 includes an upper wall portion 51 and a side wall portion 52. The upper wall portion 51 is formed, for example, in the shape of a rectangular plate with its thickness direction in the Z direction. The upper wall portion 51 is formed, for example, from aluminum. An opening 51a is formed in the center of the upper wall portion 51, through which the base portion 21 of the unit body 20 passes.

[0034] The opening 51a is formed in a shape and size corresponding to the protrusion 24. When viewed from above, the opening 51a is formed larger than the outer edges of the base 21 and the upper flange 22. When viewed from above, the opening 51a is also formed in a size that allows the claw members 15a of the holding portion 15 to pass through. When the light-shielding cover 50 is supported by the unit main body 20, the opening 51a abuts against the outer side surface 24b of the protrusion 24. In other words, when the light-shielding cover 50 is supported by the unit main body 20, the protrusion 24 is fitted into the opening 51a.

[0035] The upper wall portion 51 includes an inner side surface 51b that forms the inner surface of the opening 51a. The side surface 51b is inclined inward from the vertical plane as it goes upward. The side surface 51b is inclined in accordance with the outer side surface 24b of the convex portion 24. When the light-shielding cover 50 is supported by the unit body 20, the side surface 51b abuts against the side surface 24b of the convex portion 24. In other words, the light-shielding cover 50 abuts against the outer side surface 24b of the convex portion 24 at the inner side surface 51b of the upper wall portion 51. The inclination angle of the side surface 51b from the vertical plane is preferably, for example, about 45 degrees.

[0036] The upper wall portion 51 is supported by contacting the lower flange portion 23 of the unit body 20 from below. In other words, the lower flange portion 23 contacts the upper wall portion 51 from below to support the light-shielding cover 50. Specifically, the lower surface 51c of the upper wall portion 51 and the outer edge portion 23c of the lower flange portion 23 contact each other.

[0037] The side wall portion 52 includes a side wall main body 53 and a contact member 54. The side wall main body 53 extends downward from the upper wall portion 51. The side wall main body 53 is formed in a rectangular tube shape extending in the up-down direction. A lower end 53a of the side wall main body 53 opens downward. The side wall main body 53 is formed of, for example, aluminum. An inner surface 53b of the side wall main body 53 is, for example, black. When viewed from above, the side wall main body 53 surrounds the imaging range A of the imaging device 30. Furthermore, when viewed from above, the side wall main body 53 further surrounds the optical path of the sensor 40.

[0038] The contact member 54 is attached to the lower end surface 53c of the side wall main body 53. The contact member 54 extends around the entire periphery of the end surface 53c. The rigidity of the contact member 54 is lower than the rigidity of the side wall main body 53. In other words, the contact member 54 is softer than the side wall main body 53. The contact member 54 is made of, for example, rubber.

[0039] The light-shielding cover 50 is made of a material having light-shielding properties. The light-shielding cover 50 blocks, for example, visible light. As long as the positioning pins 62a and 62b can be clearly imaged, the light-shielding cover 50 does not need to block all light, and may transmit or allow some light to pass through. Furthermore, the light-shielding cover 50 may have a plurality of through-holes formed therein that allow external light to pass through to the interior of the light-shielding cover 50.

[0040] In this embodiment, the light-shielding cover 50 is provided so as to be movable up and down relative to the unit main body 20. Specifically, for example, when not performing measurement, the light-shielding cover 50 is supported by abutting against the lower flange portion 23 from below. Furthermore, for example, when performing measurement, the light-shielding cover 50 is supported from below by a structure other than the unit main body 20 (for example, the mounting base 60), thereby releasing the support of the light-shielding cover 50 by the unit main body 20 and separating the light-shielding cover 50 from the unit main body 20. This allows the light-shielding cover 50 to be movable up and down relative to the unit main body 20.

[0041] More specifically, when the unit body 20 and the light-shielding cover 50 are lowered toward the mounting base 60, the light-shielding cover 50 comes into contact with the mounting base 60. When the unit body 20 is then further lowered, the support of the light-shielding cover 50 by the unit body 20 is released, and the light-shielding cover 50 and the unit body 20 are separated from each other. At this time, the light-shielding cover 50 is raised relative to the unit body.

[0042] The length D1 of the light-shielding cover 50 in the vertical direction is equal to or greater than the length D2 from the lower surface 20a of the unit body 20 to the focal position of the imaging device 30. Here, the length D1 of the light-shielding cover 50 is the length in the vertical direction from the lower surface 20a of the unit body 20 to the lower end 52a of the side wall portion 52 (the lower end of the contact member 54). Therefore, when the unit body 20 is lowered and separated from the light-shielding cover 50, the length D1 of the light-shielding cover 50 is shorter than when the light-shielding cover 50 is supported by the unit body 20 (see FIG. 3 ).

[0043] Next, an example of teaching using the teaching unit 1 in the ceiling transport vehicle system 100 will be described. As shown in Fig. 1, first, the holding unit 15 of the ceiling transport vehicle 10 holds the upper flange portion 22 of the teaching unit 1, and the teaching unit 1 is mounted on the ceiling transport vehicle 10. As shown in Fig. 2, based on the set transfer conditions, the traveling unit 11 stops at a predetermined position on the traveling rail 2, and the lifting unit 14 lowers the holding unit 15 a predetermined distance. This brings the teaching unit 1 close to the positioning pin 62 of the mounting table 60 on the load port 3.

[0044] Next, the lifting unit 14 lowers the holding unit 15 to a position where the lower end 52a of the light-shielding cover 50 contacts the mounting base 60. As shown in FIG. 3 , the lifting unit 14 lowers the holding unit 15 to a position where the focal point of the imaging device 30 is aligned with the positioning pin 62. As a result, the light-shielding cover 50 is supported from below by the mounting base 60, the support of the light-shielding cover 50 by the unit body 20 is released, and the light-shielding cover 50 and the unit body 20 are separated from each other. Specifically, the protrusion 24 that was fitted in the opening 51a moves downward out of the opening 51a. As a result, the unit body 20 is allowed to move horizontally relative to the positioning pin 62. In other words, when the focal point of the imaging device 30 is aligned with the positioning pin 62, the unit body 20 is able to swing horizontally.

[0045] In this state, the imaging device 30 captures an image of the positioning pin 62 from above, thereby making it possible to obtain a change in the relative position of the positioning pin 62 with respect to the unit body 20, which is caused by the horizontal swing of the unit body 20. Furthermore, in this state, the imaging range A including the positioning pin 62 and the optical path of the sensor 40 are enclosed by the light-shielding cover 50, so that the effects of ambient light can be suppressed, enabling accurate measurements to be performed.

[0046] In this state, the two imaging devices 30 detect the positions of the positioning pins 62. In addition, the three sensors 40 detect the degree of tilt of the unit body 20. Based on these detection results, the transfer conditions or the amount of correction for the transfer conditions are acquired as teaching data.

[0047] After the above-described position detection is completed, the lifting unit 14 raises the holding unit 15, and the unit body 20 again supports the light-shielding cover 50 from below. Specifically, the convex portion 24 of the unit body 20 is fitted into the opening 51a of the upper wall portion 51. At this time, the outer side surface 24b of the convex portion 24 abuts against the inner side surface 51b of the upper wall portion 51. Furthermore, the outer edge portion 23c of the lower flange portion 23 abuts against the upper wall portion 51. At this time, for example, even if the light-shielding cover 50 is misaligned horizontally relative to the unit body 20, the misalignment can be corrected by utilizing the slope of the outer side surface 24b of the convex portion 24. In other words, even if the light-shielding cover 50 is misaligned horizontally relative to the unit body 20, the light-shielding cover 50 can slide along the slope of the outer side surface 24b of the convex portion 24 and move relative to the unit body 20, thereby correcting the misalignment.

[0048] As described above, the teaching unit 1 of this embodiment measures the position of the positioning pin 62 of the mounting table 60. The teaching unit 1 includes the imaging device 30 that captures an image of the positioning pin 62 from above, the unit main body 20 on which the imaging device 30 is mounted, and the light-shielding cover 50 that is attached to the unit main body 20 and extends downward from the unit main body 20 so as to surround the imaging range A of the imaging device 30. This allows the light-shielding cover 50 to suppress ambient light that attempts to enter the imaging range A of the imaging device 30. Therefore, accurate measurement is possible even in an environment where ambient light is present.

[0049] In the teaching unit 1, the light-shielding cover 50 is provided so as to be movable up and down relative to the unit body 20. This prevents the light-shielding cover 50 from restricting the downward movement of the unit body 20.

[0050] In the teaching unit 1, the light-shielding cover 50 is supported by the unit body 20. The light-shielding cover 50 is supported by a mounting base 60, which is a structure other than the unit body 20. This releases the light-shielding cover 50 from the unit body 20, and the light-shielding cover 50 and the unit body 20 are separated. This eliminates the restriction on the position of the unit body due to the light-shielding cover being supported by a structure other than the unit body, enabling more accurate measurements. In other words, if the light-shielding cover 50 does not separate from the unit body 20 when supported by the mounting base 60, the light-shielding cover 50 may restrict the horizontal movement of the unit body, potentially making it difficult to accurately measure the position of the positioning pin 62. In contrast, in the teaching unit 1, the light-shielding cover 50 is separated from the unit body 20, enabling more accurate measurements.

[0051] In the teaching unit 1, the lower flange portion 23 of the unit body 20 abuts against the upper wall portion 51 of the light-shielding cover 50 from below to support the light-shielding cover 50. This allows the light-shielding cover 50 to be easily separated from the unit body 20 when the light-shielding cover 50 is supported from below by a mounting base 60, which is a structure other than the unit body 20.

[0052] In the teaching unit 1, the outer side surface 24b of the convex portion 24 of the lower flange portion 23 is inclined so as to tilt inward from a vertical plane as it goes upward, and the light-shielding cover 50 abuts against the outer side surface 24b of the convex portion 24 at the inner side surface 51b of the upper wall portion 51. According to this configuration, after the light-shielding cover 50 is separated from the unit body 20, when the light-shielding cover 50 is again supported by the unit body 20 as the unit body 20 rises, the inner side surface 51b of the upper wall portion 51 of the light-shielding cover 50 abuts against the outer side surface 24b of the convex portion 24 of the unit body 20, and the light-shielding cover 50 is again supported by the unit body 20. At this time, for example, even if the light-shielding cover 50 is misaligned horizontally with respect to the unit body 20, the inclination of the outer side surface 24b of the convex portion 24 can be used to correct the misalignment.

[0053] In the teaching unit 1, the imaging device 30 captures an image of the positioning pin 62 from above while horizontal movement of the unit body 20 relative to the positioning pin 62 is permitted. This allows the horizontal shaking of the unit body 20 to be unimpeded when the imaging device 30 captures an image, enabling more accurate measurements that take the shaking into account.

[0054] In the teaching unit 1, the inner surface 53b of the side wall main body 53 of the light-shielding cover 50 is black. This makes it possible to suppress the influence of ambient light, for example, even if the ambient light enters the inside of the light-shielding cover 50.

[0055] In the teaching unit 1, the vertical length D1 of the light-shielding cover 50 is equal to or greater than the vertical length D2 from the undersurface 20a of the unit body 20 to the focal position of the imaging device 30. This makes it possible to more effectively suppress external light incident on the focal position of the imaging device 30.

[0056] In the teaching unit 1, the side wall body 53 of the light-shielding cover 50 extends downward from the unit body 20 so as to further surround the optical path of the sensor 40. This allows the light-shielding cover 50 to suppress ambient light that attempts to enter the optical path of the sensor 40, thereby improving the detection accuracy of the sensor.

[0057] Although the embodiments have been described above, one aspect of the present disclosure is not limited to the above-described embodiments.

[0058] In the above embodiment, the light-shielding cover 50 is provided so as to be able to rise and fall relative to the unit body 20, but the light-shielding cover 50 may be fixed rather than rise and fall relative to the unit body 20. Even in this case, it is possible to suppress external light that attempts to enter the imaging range A of the imaging device 30.

[0059] In the above embodiment, the light-shielding cover 50 may be raised and lowered without being separated from the unit body 20 while attached to the unit body 20. For example, the light-shielding cover 50 may be attached to the unit body 20 via a lifting mechanism for raising and lowering the light-shielding cover 50 relative to the unit body 20. Even in this case, the light-shielding cover 50 can be raised and lowered relative to the unit body 20.

[0060] In the above embodiment, the light-shielding cover 50 is supported by the mounting base 60, which is a structure other than the unit body 20, and thereby the light-shielding cover 50 is separated from the unit body 20. The structure other than the unit body 20 is not limited to the mounting base 60, and may be various other structures. The mounting base 60 may be, for example, a target plate.

[0061] In the above embodiment, during measurement, the light-shielding cover 50 may be supported by the unit body 20 rather than by the mounting base 60. Even in this case, the light-shielding cover 50 can suppress ambient light that attempts to enter the imaging range A of the imaging device 30. In this case, it is preferable to perform measurement with the light-shielding cover 50 slightly elevated relative to the mounting base 60, for example.

[0062] In the above embodiment, the lower flange portion 23 does not have to have the convex portion 24 protruding upward from the upper surface 23a. The outer side surface 24b of the convex portion 24 does not have to be inclined so as to be tilted from the vertical plane, but may be aligned in the vertical direction. The inner side surface of the upper wall portion 51 does not have to be inclined in accordance with the outer side surface 24b of the convex portion 24, but may be aligned in the vertical direction. The inner side surface 51b of the upper wall portion 51 does not have to abut against the outer side surface 24b of the convex portion 24.

[0063] In the above embodiment, the light-shielding cover 50 may be in contact with both the unit body 20 and the mounting base 60 during measurement. In the above embodiment, the color of the inner surface of the light-shielding cover 50 does not have to include black and may be a color other than black. In the above embodiment, the vertical length D1 of the light-shielding cover 50 may be less than the vertical length D2 from the lower surface 20a of the unit body 20 to the focal position of the imaging device 30. Even in this case, for example, external light from above the light-shielding cover 50 can be suppressed by the light-shielding cover 50.

[0064] In the above embodiment, the upper wall portion 51 and the side wall main body 53 may be made of a material other than aluminum, for example, they may be made of resin. In the above embodiment, taking into consideration the swinging of the unit main body 20, the positioning pin 62 may be measured multiple times by the imaging device 30.

[0065] The above-described embodiments and configurations are not limited to the above-described shapes, and various shapes can be applied. Some of the configurations in the above-described embodiments can be omitted as appropriate without departing from the spirit of one aspect of the present invention.

[0066] 1...teaching unit, 20...unit main body, 20a...lower surface, 21...base, 23...lower flange portion (flange portion), 23a...upper surface, 24...convex portion, 24b...side surface, 30, 30a, 30b...imaging device, 40...sensor, 50...light-shielding cover, 51...upper wall portion, 51a...opening, 51b...side surface, 52...side wall portion, 53b...inner surface, 62...positioning pin (object to be measured), A...imaging range.

Claims

1. A teaching unit for measuring the position of a measurement object, comprising: an imaging device for imaging the measurement object from above; a unit body on which the imaging device is mounted; and a light-shielding cover attached to the unit body and extending downward from the unit body so as to surround the imaging range of the imaging device.

2. The teaching unit according to claim 1, wherein the light-shielding cover is provided so as to be movable up and down relative to the unit body.

3. A teaching unit as described in claim 1 or 2, wherein the light-shielding cover is supported by the unit body, and when the light-shielding cover is supported by a structure other than the unit body, the support of the light-shielding cover by the unit body is released, and the light-shielding cover and the unit body are separated.

4. A teaching unit as described in claim 3, wherein the unit body has a base and a flange portion extending horizontally outward from the base, the light-shielding cover has an upper wall portion having an opening through which the base passes and a side wall portion extending downward from the upper wall portion, and the flange portion abuts against the upper wall portion from below to support the light-shielding cover.

5. A teaching unit as described in claim 4, wherein the flange portion is formed with a convex portion protruding from the upper surface of the flange portion, the outer side surface of the convex portion is inclined so as to slope inward from a vertical plane as it goes upward, and the light-shielding cover abuts against the outer side surface of the convex portion on the inner side surface of the upper wall portion.

6. A teaching unit according to claim 1 or 2, wherein the imaging device captures an image of the object to be measured from above while horizontal movement of the unit body relative to the object to be measured is permitted.

7. The teaching unit according to claim 1 or 2, wherein at least a part of the inner surface of the light-shielding cover is black.

8. A teaching unit as described in claim 1 or 2, wherein the vertical length of the light-shielding cover is equal to or greater than the vertical length from the bottom surface of the unit body to the focal position of the imaging device.

9. A teaching unit as described in claim 1 or 2, further comprising a sensor mounted on the unit body and emitting light downward, and the light-shielding cover extending downward from the unit body so as to further surround the optical path of the sensor.