Parts Imaging Device

Abstract

To provide a component imaging device capable of correcting misalignment of an optical axis of a camera that images components.SOLUTION: A component imaging device (component recognition camera 20) includes: multiple cameras (first camera unit 22A-22D, second camera unit 23A-23D) in which fields of view A1-A8 are arranged in series for imaging components; and a positional deviation amount calculation unit that calculates a positional deviation amount of imaging fields of view A1-A8 of multiple cameras on the basis of marks 25 provided within the imaging fields of view A1-A8 of the multiple cameras and outside an imaging range (component imaging field of view 24a) when the multiple cameras capture an image of the component and a result of imaging the marks 25 by the multiple cameras.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an imaging device for imaging a component. [Background technology]

[0002] In a component mounting device, components supplied by a component supply unit are picked up by a nozzle of a mounting head that moves horizontally, and the components are mounted on a board held by a board transport conveyor. Some of these component mounting devices are known to be equipped with a component recognition camera (component imaging device) that captures the position of the component held by the nozzle in order to improve the accuracy of mounting the components, and a board recognition camera that moves together with the mounting head to capture the image of a mark formed on the board (for example, Patent Document 1).

[0003] In Patent Document 1, in order to ensure component mounting accuracy by correcting the positional relationship between the nozzle of a detachable mounting head and the board recognition camera, a glass plate with a reference mark formed thereon is placed on the upper surface of the component recognition camera so that the reference mark is within the field of view of the component recognition camera, and the mounting head is moved so that the nozzle is within this field of view. In this state, the positions of the nozzle and the reference mark are detected by the component recognition camera, and the positional relationship between the nozzle and the board recognition camera is calculated from the reference mark imaged by the board recognition camera and the position of the optical axis of the board recognition camera. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-179636 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the component recognition camera detects the position of the component held by the nozzle from the position of the camera's optical axis, but in the process of continuously producing mounted boards, the camera's optical axis may shift (distort) due to changes over time caused by heat generation in the imaging element of the component recognition camera, and in order to maintain the mounting accuracy of the components, it is necessary to periodically detect the shift in the optical axis of the component recognition camera and appropriately correct it. However, the conventional technologies including Patent Document 1 do not disclose a method for detecting the shift in the optical axis of the component recognition camera during the production of mounted boards, and there is room for further improvement in order to improve the mounting accuracy of the components.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a component imaging device capable of correcting deviation of the optical axis of a camera that images a component. [Means for solving the problem]

[0007] The component imaging device of the present invention comprises: a plurality of cameras each having an imaging field of view arranged in series and adapted to image a component; A transparent plate disposed between the plurality of cameras and the component; and The system includes a mark that is provided within the imaging field of view of the multiple cameras but outside the imaging range when the multiple cameras image a part, and a positional deviation calculation unit that calculates a positional deviation amount of the imaging field of view of the multiple cameras based on the imaging results of the multiple cameras each capturing an image of the mark. Effect of the Invention

[0008] According to the present invention, it is possible to correct the deviation of the optical axis of a camera that captures an image of a part. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a component mounting apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 1 is a configuration explanatory diagram of a component mounting device according to an embodiment of the present invention; [Diagram 3] FIG. 1 is a perspective view showing the inside of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 4]1A is a perspective view showing a main part of a first camera unit of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; FIG. 1B is a perspective view showing a main part of a second camera unit of the component recognition camera; [Diagram 5] FIG. 1 is a perspective view showing a main part of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 6] 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a side view showing a main part of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention. [Figure 7] FIG. 2A is an explanatory diagram of an optical system of a first camera unit of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; FIG. 2B is an explanatory diagram of an optical system of a second camera unit of the component recognition camera; [Figure 8] FIG. 13 is an explanatory diagram of another example of the optical system of the first camera unit of the component recognition camera provided in the component mounting device according to the embodiment of the present invention. [Figure 9] 1A and 1B are explanatory diagrams illustrating an imaging field of a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 10] 1A and 1B are explanatory diagrams of an imaging field of a second component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 11] FIG. 1 is a block diagram showing a configuration of a control system of a component mounting apparatus according to an embodiment of the present invention. [Figure 12] 1A and 1B are explanatory diagrams illustrating an image of a component held by a nozzle by a component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 13] 1A and 1B are explanatory diagrams illustrating an image of a component held by a nozzle by a second component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; [Figure 14] 1A and 1B are diagrams showing examples of images of marks captured by a second component recognition camera included in a component mounting apparatus according to an embodiment of the present invention; [Figure 15] FIG. 13 is a diagram showing an example of a combined image of components held by a nozzle captured by a second component recognition camera provided in the component mounting apparatus according to the embodiment of the present invention; [Figure 16]FIG. 13 is a perspective view showing a main part of a component recognition camera having another optical axis bending unit provided in the component mounting apparatus according to the embodiment of the present invention; [Figure 17] 1A is a plan view, FIG. 1B is a front view, and FIG. 1C is a side view showing a main part of a component recognition camera having another optical axis bending unit provided in a component mounting device according to an embodiment of the present invention. [Figure 18] FIG. 13 is a perspective view showing a main part of a third component recognition camera provided in the component mounting apparatus according to the embodiment of the present invention; [Figure 19] FIG. 13 is an explanatory diagram of an imaging field of a third component recognition camera provided in a component mounting apparatus according to an embodiment of the present invention; FIG. 14 is an explanatory diagram of an imaging field of a third component recognition camera provided in the component mounting apparatus according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described in detail below with reference to the drawings. The configurations, shapes, etc. described below are examples for explanation and can be appropriately changed according to the specifications of the component mounting device and the component recognition camera. In the following, the same reference numerals are used for corresponding elements in all the drawings, and duplicated explanations are omitted. In FIG. 1 and in a part described later, the X-axis (left and right direction in FIG. 1) in the board transport direction and the Y-axis (up and down direction in FIG. 1) perpendicular to the board transport direction are shown as two axes perpendicular to each other in the horizontal plane. In FIG. 2 and in a part described later, the Z-axis (up and down direction in FIG. 2) is shown as the height direction perpendicular to the horizontal plane.

[0011] First, the configuration of the component mounting apparatus 1 will be described with reference to Figs. 1 and 2. Fig. 2 shows a schematic view of a part of the component mounting apparatus 1 in Fig. 1. The component mounting apparatus 1 has a function of performing a component mounting operation in which components supplied from a component supply unit are mounted on a board. A board transport mechanism 2 is arranged along the X-axis in the center of the base 1a. The board transport mechanism 2 transports the board 3 transported from the upstream side to the mounting operation position, positions it, and holds it. In addition, the board transport mechanism 2 transports the board 3, on which the component mounting operation has been completed, to the downstream side.

[0012] Component supply units 4 are disposed on both sides (front and rear directions of the Y axis) of the board transport mechanism 2. Multiple tape feeders 5 are attached in parallel along the X axis to each component supply unit 4. The tape feeders 5 pitch-feed a component tape, on which pockets for storing components D are formed, in a direction (tape feed direction) from the outside of the component supply unit 4 toward the board transport mechanism 2, thereby supplying components D to component supply positions 5a from which the components D are picked up by a mounting head, which will be described below.

[0013] 1 and 2, a Y-axis table 6 equipped with a linear drive mechanism is arranged along the Y-axis at both ends of the X-axis on the upper surface of the base 1a. A beam 7 similarly equipped with a linear drive mechanism is coupled to the Y-axis table 6 so as to be freely movable along the Y-axis. The beam 7 is arranged along the X-axis. A mounting head 8 is attached to the beam 7 so as to be freely movable along the X-axis. The mounting head 8 is equipped with a suction unit 8a that can lift and lower while suction-holding a component D. A nozzle 8b that suction-holds the component D is attached to the lower end of each of the suction units 8a.

[0014] 1, the Y-axis table 6 and the beam 7 constitute a head moving mechanism 9 that moves the mounting head 8 along the X-axis and the Y-axis. The head moving mechanism 9 and the mounting head 8 perform a mounting turn in which the nozzle 8b picks up and removes the component D from the component supply position 5a of the tape feeder 5 arranged in the component supply unit 4, and mounts it at the mounting position of the board 3 positioned by the board transport mechanism 2. In other words, the Y-axis table 6, the beam 7 and the mounting head 8 constitute a component mounting means that holds the component D supplied to the component supply position 5a of the tape feeder 5 with the nozzle 8b and mounts it on the board 3.

[0015] 1 and 2, a component recognition camera 20 is disposed between the component supply unit 4 and the board transport mechanism 2. When the mounting head 8 which has taken out a component D from the component supply unit 4 moves above the component recognition camera 20, the component recognition camera 20 captures an image of the component D held by the mounting head 8 to recognize the holding posture of the component D. A board recognition camera 10 is attached to the plate 7a to which the mounting head 8 is attached. The board recognition camera 10 moves integrally with the mounting head 8.

[0016] As the mounting head 8 moves, the board recognition camera 10 moves above the board 3 positioned by the board transport mechanism 2, and captures an image of the board mark 3a provided on the board 3 to recognize the position of the board 3. In the component mounting operation on the board 3 by the mounting head 8, the mounting position is corrected taking into account the recognition result of the component D by the component recognition camera 20 and the recognition result of the board position by the board recognition camera 10.

[0017] 2, a carriage 11 with a number of tape feeders 5 already attached to a feeder base 11a is set in the component supply section 4. The carriage 11 holds a tape reel 13 that stores in a wound state a component tape 12 holding components D. The component tape 12 pulled out from the tape reel 13 is pitch-fed by the tape feeders 5 to the component supply position 5a.

[0018] 1, a touch panel 14 operated by an operator is provided at a position where an operator works on the front side of the component mounting device 1. The touch panel 14 displays various information on its display section, and the operator inputs data and operates the component mounting device 1 using operation buttons and the like displayed on the display section.

[0019] Next, an overview of the configuration of the component recognition camera 20 will be described with reference to Fig. 3. Fig. 3 shows a schematic view of the inside of the component recognition camera 20 seen through the housing 21 of the component recognition camera 20. The component recognition camera 20 is provided with a plurality of first camera units 22 (four in this example) arranged in a straight line along the X-axis. The plurality of first camera units 22 constitute a first camera group G1. The component recognition camera 20 is also provided with a plurality of second camera units 23 (four in this example) arranged in a straight line along the X-axis. The plurality of second camera units 23 constitute a second camera group G2.

[0020] The first camera group G1 and the second camera group G2 are disposed adjacent to each other along the Y axis. The first camera unit 22 of the first camera group G1 and the second camera unit 23 of the second camera group G2 are disposed so that their positions in the X axis direction are staggered (staggered arrangement). That is, the second camera unit 23 is disposed so that its center is located at the boundary position between two adjacent first camera units 22 in the X axis direction. Similarly, the first camera unit 22 is disposed so that its center is located at the boundary position between two adjacent second camera units 23. A transparent plate 24 on which a plurality of marks 25 are formed is disposed above a predetermined position where parts of the first camera unit 22 and the second camera unit 23 are alternately disposed.

[0021] Next, the configuration of the component recognition camera 20 will be described in detail with reference to Figures 4 to 7. For convenience, the housing 22a of the first camera unit 22 and the housing 23a of the second camera unit 23 are omitted in Figures 5 to 7 to clearly show the positional relationship of the internal components of the component recognition camera 20.

[0022] In Fig. 6(b) and Fig. 6(c), the transparent plate 24 is disposed on an opening 21b formed by cutting out the upper portion 21a of the housing 21 of the component recognition camera 20. The transparent plate 24 is formed of a plate-like glass that transmits light. In Fig. 6(a), a component imaging field of view 24a is set in the center of the transparent plate 24 in the Y-axis direction, through which the optical axes of the cameras pass when the first camera unit 22 and the second camera unit 23 image the component D held by the nozzle 8b. On the transparent plate 24, a plurality of marks 25 are arranged in series along the X-axis, and are arranged in two rows in the Y-axis direction, sandwiching the component imaging field of view 24a. That is, the plurality of marks 25 are disposed in positions that do not interfere with the imaging of the component D by the first camera unit 22 and the second camera unit 23.

[0023] Next, the optical system of the first camera unit 22 will be described with reference to Fig. 4(a) and Fig. 7(a). Fig. 4(a) is a schematic diagram showing the inside of the first camera unit 22 seen through the housing 22a of the first camera unit 22. For convenience, Fig. 7(a) shows only the configuration related to the first camera unit 22 inside the component recognition camera 20. The first camera unit 22 has a first imaging section 22b having an imaging element such as a two-dimensional CMOS sensor inside the housing 22a, and a first lens 22c located between the component D to be imaged and the first imaging section 22b.

[0024] The first camera unit 22 is installed with its optical axis 22d facing upward, and captures an image of the object to be imaged, component D, from below. A first illumination unit 26 is installed above the first lens 22c at a position that does not interfere with the imaging by the first camera unit 22. The first illumination unit 26 is configured with a plurality of LED chips, etc., and irradiates light 26a that illuminates the object to be imaged (such as component D) or the mark 25 on the transparent plate 24 from below.

[0025] Next, the optical system of the second camera unit 23 will be described with reference to Fig. 4(b) and Fig. 7(b). Fig. 4(b) is a schematic view of the inside of the second camera unit 23 seen through the housing 23a of the second camera unit 23. For convenience, Fig. 7(b) shows only the configuration related to the second camera unit 23 inside the component recognition camera 20. The second camera unit 23 has a second imaging section 23b having an imaging element such as a two-dimensional CMOS sensor inside the housing 23a, and a second lens 23c located between the component D to be imaged and the second imaging section 23b.

[0026] The second camera unit 23 is installed with its optical axis 23d facing upward. In the second camera unit 23, a first mirror 27 is disposed below the transparent plate 24. A second mirror 28 is disposed above the second lens 23c, at a position along the Y-axis from the first mirror 27. The optical axis 23d of the second camera unit 23 is refracted by the second mirror 28 toward the first mirror 27. Furthermore, the optical axis 23d is refracted upward by the first mirror 27.

[0027] In this manner, optical axis 23d is refracted by second mirror 28 and first mirror 27, so that second camera unit 23 captures an image of target component D from below. That is, first mirror 27 and second mirror 28 (mirrors) form optical axis refraction section R that guides an image of component D held in nozzle 8b to second camera unit 23 (camera of second camera group). In component recognition camera 20, first mirror 27 and second mirror 28 are disposed for each camera (second camera unit 23) of second camera group G2 (see FIGS. 5 and 6).

[0028] 7(b), a second illumination unit 29 is installed above the second lens 23c at a position that does not interfere with imaging by the second camera unit 23. The second illumination unit 29 is configured with a plurality of LED chips and the like, and emits light 29a that illuminates the imaging target (such as component D) or the mark 25 on the transparent plate 24. The light 29a emitted from the second illumination unit 29 is refracted by the second mirror 28 and the first mirror 27, thereby illuminating the imaging target (such as component D) or the mark 25 on the transparent plate 24 from below.

[0029] 7(a) and 7(b), when the component recognition camera 20 (component imaging device) images the component D held by the nozzle 8b, the nozzle 8b holding the component D is moved along the Y axis (arrow a) while light 26a, 29a is being irradiated from the first illumination unit 26 and the second illumination unit 29. The first camera unit 22 and the second camera unit 23 image (scan image) the component D from below when the component D passes above the component imaging field of view 24a of the transparent plate 24.

[0030] Here, with reference to Fig. 8, another embodiment of the optical system of the first camera unit 22 will be described. This embodiment of the optical system of the first camera unit 22 differs from the optical system of the first camera unit 22 described above in that a half mirror 30 is disposed above the first lens 22c. The optical axis 22d of the first camera unit 22 passes through the half mirror 30, and the first camera unit 22 captures an image of the target part D from below.

[0031] A third illumination unit 31 is provided at a position along the Y-axis from the half mirror 30. The third illumination unit 31 is configured with a plurality of LED chips and the like, and irradiates light 31a laterally to illuminate the imaging target (such as the component D) or the mark 25 on the transparent plate 24. The light 31a irradiated from the third illumination unit 31 is refracted upward by the half mirror 30, thereby illuminating the imaging target (such as the component D) or the mark 25 on the transparent plate 24 from below. In this way, the component recognition camera 20 includes illumination units (the first illumination unit 26, the second illumination unit 29, the third illumination unit 31) that are provided for each of the plurality of cameras (the first camera unit 22, the second camera unit 23) and that illuminate the component D held by the nozzle 8b and the mark 25 on the transparent plate 24.

[0032] Next, the imaging field of view of the component recognition camera 20 will be described with reference to Fig. 9. In Fig. 9, the four first camera units 22 of the first camera group G1 are referred to as first camera unit 22A to first camera unit 22D in order from the left in the X-axis direction. Also, the four second camera units 23 of the second camera group G2 are referred to as first camera unit 23A to first camera unit 23D in order from the left in the X-axis direction.

[0033] 9(a) and 9(b), the center in the X-axis direction of second camera unit 23A is located at the boundary position between first camera unit 22A and first camera unit 22B, which are adjacent in the X-axis direction. Also, the center in the X-axis direction of first camera unit 23B is located at the boundary position between second camera unit 23A and second camera unit 23B, which are adjacent in the X-axis direction. Similarly, first camera units 22A to 22D and second camera units 23A to 23D are installed.

[0034] As a result, on the transparent plate 24 including the component imaging field of view 24a (dotted in Figure 9(b)), the imaging fields of view A1, A3, A5, A7 of the first camera units 22A to 22D and the imaging fields of view A2, A4, A6, A8 of the second camera units 23A to 23D are alternately arranged, such as, from the left in the X-axis direction, the imaging field of view A1 of the first camera unit 22A, the imaging field of view A2 of the second camera unit 23A, the imaging field of view A3 of the first camera unit 22B, and the imaging field of view A4 of the second camera unit 23B.

[0035] In Fig. 9(b), the width LX1 in the X-axis direction and the width LY1 in the Y-axis direction of the imaging fields A1, A3, A5, and A7 of the first camera units 22A to 22D are the same as the width LX2 in the X-axis direction and the width LY2 in the Y-axis direction of the imaging fields A2, A4, A6, and A8 of the second camera units 23A to 23D. In addition, in the X-axis direction, the imaging field A2 of the second camera unit 23A is in contact with the imaging field A1 of the first camera unit 22A and the imaging field A3 of the first camera unit 22B, which are adjacent to each other on the left and right. In other words, the imaging fields A1, A3, A5, and A7 of the first camera units 22A to 22D and the imaging fields A2, A4, A6, and A8 of the second camera units 23A to 23D are arranged so as to be in contact with each other alternately in one direction (X-axis direction).

[0036] The first lens 22c and the first imaging section 22b of the first camera units 22A to 22D and the second lens 23c and the second imaging section 23b of the second camera units 23A to 23D are a telecentric optical system in which the chief ray is parallel to the optical axes 22d, 23d. That is, the multiple cameras of the first camera group G1 (first camera units 22A to 22D) and the multiple cameras of the second camera group G2 (second camera units 23A to 23D) have a telecentric optical system.

[0037] Alternatively, the multiple cameras (first camera units 22A-22D and second camera units 23A-23D) are optical systems in which the chief ray and optical axes 22d, 23d are substantially parallel and the angle of view is small (narrow). In this manner, the component recognition camera 20 realizes a component imaging field of view 24a that is long in one direction without using a lens with a large diameter by arranging the cameras (first camera units 22A-22D and second camera units 23A-23D) of an optical system with a small angle of view such that the imaging fields of view A1-A8 are alternately arranged in one direction (X-axis direction).

[0038] As described above, the component recognition camera 20 is a component imaging device including a first camera group G1 including a plurality of cameras (first camera units 22A-22D) arranged in series in one direction (X-axis direction) and imaging the component D, a second camera group G2 including a plurality of cameras (second camera units 23A-23D) arranged in series in one direction parallel to the first camera group G1 and imaging the component D, and an optical axis refraction unit R that arranges the imaging fields A1, A3, A5, and A7 of the cameras of the first camera group G1 and the imaging fields A2, A4, A6, and A8 of the cameras of the second camera group in series. In the component recognition camera 20, the cameras of the first camera group G1 and the cameras of the second camera group G2 are arranged such that the imaging fields A1-A8 are arranged alternately.

[0039] Next, the second component recognition camera 32 (hereinafter simply referred to as "component recognition camera 32") will be described with reference to Fig. 10. The component recognition camera 32 includes four first camera units 33A-33D arranged in the X-axis direction, each having a first lens 33b and a first imaging section 33a, and four second camera units 34A-34D arranged in the X-axis direction, each having a second lens 34b and a second imaging section 34a. The first camera units 33A-33D and second camera units 34A-34D of the component recognition camera 32 have a larger (wider) angle of view than in the example of Fig. 9, which is different from the component recognition camera 20. Hereinafter, the same components as those of the component recognition camera 20 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0040] 10(a) and 10(b), the width LX3 in the X-axis direction of the imaging fields B1, B3, B5, and B7 of the first camera units 33A-33D and the width LX4 in the X-axis direction of the imaging fields B2, B4, B6, and B8 of the second camera units 34A-34D are larger than the widths LX1 and LX2 in the X-axis direction of the imaging fields A1-A8 in Fig. 9(b). As a result, in the component recognition camera 32, adjacent imaging fields B1-B8 of the first camera units 33A-33D and the second camera units 34A-34D partially overlap each other in one direction (the X-axis direction).

[0041] By partially overlapping the imaging fields of view B1 to B8 of the component recognition camera 32, even if a misalignment occurs in the optical axes 33c, 34c of the first camera units 33A to 33D or the second camera units 34A to 34D due to heat generation or manufacturing of the component recognition camera 32 as described below, it is possible to prevent gaps from occurring between adjacent imaging fields of view B1 to B8 (component imaging fields of view 24a that are long in one direction).

[0042] Next, the configuration of the control system of the component mounting device 1 equipped with the component recognition camera 20 (component imaging device) will be described with reference to FIG. 11. The configuration of the control system of the component mounting device 1 equipped with the second component recognition camera 32 (component imaging device) is similar, and detailed description will be omitted. The component mounting device 1 is equipped with a control unit 40, a board conveying mechanism 2, a tape feeder 5, a mounting head 8, a head moving mechanism 9, a component recognition camera 20, a board recognition camera 10, and a touch panel 14. The control unit 40 is equipped with a mounting operation processing unit 41, a component imaging processing unit 42, an image processing unit 43, a pickup component position calculation unit 44, a mark imaging processing unit 45, a positional deviation amount calculation unit 46, and a mounting storage unit 47. The mounting storage unit 47 is a storage device, and stores mounting data 48, a component imaging result 49, a mounting correction value 50, a mark imaging result 51, an imaging field position deviation amount 52, and the like.

[0043] The mounting data 48 stores information required for component mounting work, such as the size of the board 3, the type and mounting position (XY coordinates) of the component D to be mounted, and the type of mounting head 8, for each type (board type) of board 3. The mounting operation processing unit 41 controls each unit of the component mounting device 1 based on the mounting data 48, holds the component D supplied by the tape feeder 5 with the nozzle 8b of the mounting head 8, corrects the position (X-axis direction, Y-axis direction) of the nozzle 8b based on a mounting correction value 50 described later, and controls the component mounting work of mounting the component D at the mounting position on the board 3 held at the mounting work position.

[0044] 11, the component imaging processing unit 42 controls the head moving mechanism 9 and the component recognition camera 20 during the component mounting operation to image (scan) the component D held by the nozzle 8b while moving the mounting head 8 holding the component D on the nozzle 8b above the component recognition camera 20. At that time, the component imaging processing unit 42 images the component D with the first camera unit 22 and the second camera unit 23 while illuminating the component D with the first illumination unit 26 and the second illumination unit 29. The imaging result of the component D is processed by the image processing unit 43 and then stored in the mounting storage unit 47 as the component imaging result 49. The pickup component position calculation unit 44 calculates the position of the center of the component D as viewed from the center (pickup position) of the nozzle 8b based on the stored component imaging result 49, and stores the calculated position in the mounting storage unit 47 as the mounting correction value 50.

[0045] Here, with reference to Figs. 12 and 13, the imaging of the component D by the component recognition camera 20 or the component recognition camera 32 (component imaging device) shown in Fig. 9 will be described in detail. Fig. 12 shows an example of imaging by the component recognition camera 20 having the imaging fields A1 to A8 shown in Fig. 9, and Fig. 13 shows an example of imaging by the component recognition camera 32 having the imaging fields B1 to B8 shown in Fig. 10. Fig. 12 shows an example of using a mounting head 8 having 16 nozzles 8b for holding a small component D1 (hereinafter referred to as a "16-nozzle mounting head"). The 16-nozzle mounting head has eight nozzles 8b arranged in series along the X-axis in two rows in the front-rear direction in the Y-axis direction. The pitch (spacing) of the nozzles 8b arranged along the X-axis is designed to be the same as the pitch in the X-axis direction of the centers (optical axes 22d, 23d) of the imaging fields A1 to A8 of the component recognition camera 20.

[0046] In FIG. 12(b), the component imaging processing unit 42 first moves the 16-nozzle mounting head to a position where the center of the nozzle 8b at the left end in the X-axis direction passes through the center of the imaging field of view A1. Next, the component imaging processing unit 42 scans and images the components D1 held by the eight nozzles 8b on the front side while moving the 16-nozzle mounting head along the Y-axis (arrow b). Next, the component imaging processing unit 42 scans and images the components D1 held by the eight nozzles 8b on the rear side while moving the 16-nozzle mounting head along the Y-axis (arrow b). The image processing unit 43 corrects the imaging results of the components D1 by each camera based on the imaging field of view position deviation amount 52 described later, and stores the corrected results in the mounting storage unit 47 as the component imaging results 49.

[0047] In this example, multiple cameras (first camera units 22A-22D, second camera units 23A-23D) are arranged corresponding to the position of the component D1 to be imaged, so that the components D1 held by multiple nozzles 8b can be imaged at once in the imaging fields A1-A8 of each camera. For example, the component D1 held by the nozzle 8b at the left end in the X-axis direction of the 16-nozzle mounting head is imaged by the first camera unit 22A when passing through the imaging field A1. Since the distortion of the lenses (first lens 22c, second lens 23c) is small near the center of the imaging fields A1-A8, the vicinity of the nozzle 8b of the component D1 held by the nozzle 8b can be imaged (recognized) more accurately.

[0048] 13 shows an example in which a mounting head 8 having four nozzles 8b for holding a large component D2 (hereinafter referred to as a "four-nozzle mounting head") is used. The four-nozzle mounting head has four nozzles 8b arranged in series along the X-axis. The pitch (spacing) of the nozzles 8b arranged along the X-axis is designed to be twice the pitch in the X-axis direction of the centers (optical axes 33c, 34c) of the imaging fields of view B1 to B8 of the component recognition camera 32.

[0049] 13(b), the component imaging processing unit 42 first moves the four-nozzle mounting head to a position where the center of the nozzle 8b at the left end in the X-axis direction passes through the midpoint between the center of the imaging field of view B1 and the center of the imaging field of view B2. Next, the component imaging processing unit 42 scans and images the component D2 held by each of the four nozzles 8b while moving the four-nozzle mounting head along the Y-axis (arrow c). The image processing unit 43 corrects the imaging results of the component D2 taken by each camera based on the imaging field of view position deviation amount 52, and further combines the images to store in the mounting storage unit 47 as the component imaging result 49.

[0050] In this example, the component D2 held by the nozzle 8b at the left end in the X-axis direction of the four-nozzle mounting head is imaged by the first camera unit 33A and the second camera unit 34A when passing through the imaging visual field B1 and the imaging visual field B2. That is, the component recognition camera 32 images one component D2 with the camera of the first camera group G1 (the first camera unit 33A) and the camera of the second camera group G2 (the second camera unit 34A). The imaging results by the first camera unit 33A and the second camera unit 34A are corrected by the image processing unit 43 based on the imaging visual field position deviation amount 52, and then combined into one image in which the component D2 is captured, and stored as the component imaging result 49 (see FIG. 15).

[0051] In this way, the component recognition camera 32 (component imaging device) can simultaneously image the components D2 held by the multiple nozzles 8b. When imaging a component larger than the component D2, the component is recognized based on the image of the camera in the imaging field of view through which the component passes. For example, for a component that is large enough to pass across the imaging fields of view B1 to B4, four imaging results captured by the two first camera units 33A and 33B of the first camera group G1 and the two second camera units 34A and 34B of the second camera group G2 are image-processed (corrected and combined) to create an image of one component.

[0052] 11, when correcting the imaging field of view, the mark imaging processing unit 45 causes the first camera unit 22 and the second camera unit 23 to capture (still image) the mark 25 while illuminating the mark 25 provided outside the component imaging field of view 24a of one transparent plate 24 with the first illumination unit 26 and the second illumination unit 29. The mark imaging processing unit 45 also causes the mounting storage unit 47 to store the imaging results of the mark 25 as mark imaging results 51 for each of the multiple cameras (first camera units 22A to 22D, second camera units 23A to 23D). The positional deviation amount calculation unit 46 calculates the positional deviation amount from the ideal state of the imaging fields of view of the multiple cameras based on the stored mark imaging results 51. The calculated positional deviation amount is stored in the mounting storage unit 47 as the imaging field of view positional deviation amount 52.

[0053] 14, the imaging of mark 25 by component recognition camera 32 when correcting the imaging field of view will be described. The method of correcting the imaging field of view using mark 25 by component recognition camera 20 is similar to that of component recognition camera 32, and therefore a description thereof will be omitted. In the process of repeatedly capturing images of components held by nozzle 8b during component mounting work, first camera units 33A-33D and second camera units 34A-34D of component recognition camera 32, distortion over time may occur in the housing of component recognition camera 32 and the housings of each unit due to heat generated by the imaging element and heat generated by the illumination units (first illumination unit 26, second illumination unit 29).

[0054] In order to obtain imaging field position shift amount 52 for canceling distortion of first camera units 33A-33D and second camera units 34A-34D, marks 25 are provided within imaging fields B1-B8 of the multiple cameras (first camera units 33A-33D, second camera units 34A-34D) on one transparent plate 24 and outside the imaging range (component imaging field 24a) when the multiple cameras image the component, The transparent plate 24 is disposed between the multiple cameras and the component held by nozzle 8b to be imaged.

[0055] Fig. 14(a) shows a captured image 60 obtained by the mark imaging processing unit 45 causing the first camera unit 33A to capture a still image of the mark 25 in the component recognition camera 32 having the imaging fields of view B1 to B8 shown in Fig. 9. That is, the captured image 60 is an image within the range of the imaging field of view B1 of the first camera unit 33A. Fig. 14(b) shows a captured image 61 obtained by the mark imaging processing unit 45 causing the second camera unit 34A to capture a still image of the mark 25. That is, the captured image 61 is an image within the range of the imaging field of view B2 of the second camera unit 34A.

[0056] In this example, the multiple cameras (first camera units 33A to 33D and second camera units 34A to 34D) are arranged so that within the imaging fields B1 to B8 of the multiple cameras, four marks 25 are captured by the component recognition camera 32 without distortion. That is, at least two marks 25 are provided on the transparent plate 24 in each of the imaging fields B1 to B8 of the multiple cameras. In Fig. 14(a) and Fig. 14(b), the four circles indicated by dotted lines indicate the positions of the marks 25 in an ideal state. The four circles (or parts of the circles) indicated by solid lines indicate the marks 25 captured by the first camera unit 33A and the second camera unit 34A. The optical axes 33c and 34c are misaligned due to distortion, so the positions of the captured marks 25 are deviated from the ideal state.

[0057] In Fig. 14(a), the four marks 25 captured in the imaging field of view B1 are referred to as marks 25A to 25D in order clockwise from the upper left. The center 60c of the captured image 60 is the center of the imaging field of view B1 of the first camera unit 33A. In Fig. 14(b), the four marks 25 captured in the imaging field of view B1 are referred to as marks 25E to 25H in order clockwise from the upper left. The center 61c of the captured image 61 is the center of the imaging field of view B2 of the second camera unit 34A.

[0058] 14(a), an imaging field of view positional deviation calculation process will be described in which the positional deviation calculation unit 46 calculates the amount of positional deviation of the imaging field of view B1 of the first camera unit 33A based on a captured image 60 (imaging result) of the marks 25A to 25D captured by the first camera unit 33A. In the imaging field of view positional deviation calculation process, the positional deviation calculation unit 46 first processes the captured image 60 to extract the center positions of the marks 25A to 25D. In this example, the mark 25B is partially outside the imaging field of view B1, so the center position cannot be extracted.

[0059] The positional deviation calculation unit 46 selects two marks, 25A and 25D, from the three marks 25A, 25C, and 25D whose center positions have been extracted. Next, the positional deviation calculation unit 46 calculates the center position (XA, YA) of the selected mark 25A and the center position (XD, YD) of the mark 25D, with the center 60c (center of the imaging field of view B1) of the captured image 60 as the origin.

[0060] 14(a), the positional deviation amount calculation unit 46 then calculates the positional deviation amount (ΔXK1, ΔYK1) of the position of the center K1 of the four marks 25A to 25D from the center 60c (center of the imaging visual field B1) of the captured image 60 and the deviation amount ΔθK1 in the θ direction with the Z axis as the rotation axis from the calculated center position (XA, YA) of the mark 25A, the center position (XD, YD) of the mark 25D, and the center position (XA0, YA0) of the mark 25A in the ideal state and the center position (XD0, YD0) of the mark 25D. The positional deviation amount calculation unit 46 stores the calculated positional deviation amount (ΔXK1, ΔYK1) of the center K1 and the deviation amount ΔθK1 in the θ direction as the imaging visual field positional deviation amount 52 in the mounting storage unit 47. Note that the center K1 of the four marks 25A to 25D in the ideal state coincides with the center 60c (center of the imaging visual field B1) of the captured image 60.

[0061] In FIG. 14B, in the case of the second camera unit 34A, the positional deviation amount calculation unit 46 selects two marks 25E and 25F from the four marks 25E to 25H whose center positions have been extracted, and calculates the positional deviation amount (ΔXK2, ΔYK2) of the position of the center of gravity K2 of the four marks 25E to 25H and the deviation amount ΔθK2 in the θ direction. In this way, the positional deviation amount calculation unit 46 calculates the imaging field of view positional deviation amount 52 (the positional deviation amount of the imaging field of view of one camera) from the center positions of at least two marks 25E and 25F captured in the imaging field of view B2 of the second camera unit 34A (one of the multiple cameras). By using the center positions of the two marks 25E and 25F, in addition to the positional deviation amount (ΔXK2, ΔYK2) of the center of gravity K2, the deviation amount ΔθK2 in the θ direction can also be calculated.

[0062] The still image capturing of the mark 25 by the multiple cameras (first camera units 33A-33D, second camera units 34A-34D) of the component recognition camera 32 by the mark imaging processing unit 45 and the calculation of the imaging field of view positional deviation amount 52 by the positional deviation amount calculation unit 46, that is, the correction of the imaging fields of view B1-B8, are performed during spare time in the component mounting operation. For example, these are performed during spare time when the mounting head 8 is not above the component recognition camera 32, such as while the mounting head 8 is removing the component D from the tape feeder 5 or mounting the component D on the board 3.

[0063] That is, the mark imaging processing unit 45 images the mark 25 during the spare time, and the positional deviation amount calculation unit 46 calculates the latest imaging field of view positional deviation amount 52, and the data in the mounting storage unit 47 is updated. This allows the deviation (imaging field of view positional deviation amount 52) ​​of the optical axes 33c, 34c of the cameras (the multiple cameras of the component recognition camera 32) that image the component D to be corrected without reducing the efficiency of the component mounting work, and the component D can be mounted at the mounting position with high accuracy. Note that when the component D held by the nozzle 8b is imaged, the mark 25 may also be imaged at the same time to calculate the positional deviation amount of the imaging fields of view B1 to B8.

[0064] Next, image processing of the imaging results by the image processing unit 43 will be described with reference to Fig. 15. Fig. 15 shows a combined image 62 obtained by image processing unit 43 processing the imaging results of the first camera unit 33A and the second camera unit 34A imaging the component D2 held by the nozzle 8b at the left end in the X-axis direction of the four-nozzle mounting head shown in Fig. 13. Here, the positions of the center of the nozzle 8b and the center of the component D2 are the same, that is, the positional deviation of the pickup position of the component D2 relative to the nozzle 8b is zero. Also, the optical axes 33c, 34c of the first camera unit 33A and the second camera unit 34A are shifted by the imaging field positional deviation amount 52, as shown in Figs. 14(a) and 14(b).

[0065] 15, the left side of the combined image 62 is an image obtained by correcting the imaging result obtained by scanning and imaging by the first camera unit 33A when the part D2 passes through the imaging field of view B1, based on the imaging field of view position shift amount 52 (ΔXK1, ΔYK1, ΔθK1) by the image processing unit 43. Also, the right side of the combined image 62 is an image obtained by correcting the imaging result obtained by scanning and imaging by the second camera unit 34A when the part D2 passes through the imaging field of view B2, based on the imaging field of view position shift amount 52 (ΔXK2, ΔYK2, ΔθK2) by the image processing unit 43.

[0066] A dotted line figure 63 on the left side of the combined image 62 indicates an image of the part D2 when the imaging result captured by the first camera unit 33A is not corrected by the imaging field of view position shift amount 52. A dotted line figure 64 on the right side of the combined image 62 indicates an image of the part D2 when the imaging result captured by the second camera unit 34A is not corrected by the imaging field of view position shift amount 52. By combining the images after the image processing unit 43 corrects the shift of the optical axes 33c and 34c based on the imaging field of view position shift amount 52, an image without distortion of the part D2 held by the nozzle 8b can be obtained in the combined image 62. In this example, the center 62c of the combined image 62, the center of the nozzle 8b, and the center of the part D2 are aligned.

[0067] The image processing unit 43 stores the combined image 62 as the component imaging result 49 in the mounting storage unit 47. The pickup component position calculation unit 44 calculates the position of the center of the component D2 as viewed from the center (pickup position) of the nozzle 8b based on the stored component imaging result 49 (combined image 62). In this way, in the case of the component D2 that straddles a plurality of adjacent imaging fields B1 and B2, the pickup position of the component D2 is calculated from an image of the component D2 without distortion in which the shift of the optical axes 33c and 34c is corrected based on the position shift amount (imaging field position shift amount 52) ​​of the mark 25 in the imaging fields B1 and B2. In this way, the mounting accuracy of the component D2 can be improved by correcting the shift of the optical axes 22d and 23d using the mark 25 that is precisely provided on one transparent plate 24.

[0068] As described above, the imaging fields of view B1 to B8 are arranged in series, and a plurality of cameras (first camera units 33A to 33D, second camera units 34A to 34D) that image the component D2, the component recognition camera 32 having the mark 25 that is within the imaging fields of view B1 to B8 of the multiple cameras but outside the imaging range (component imaging field of view 24a) when the multiple cameras image the component D2, and the position deviation amount calculation unit 46 that calculates the position deviation amount (imaging field of view position deviation amount 52) ​​of the imaging fields of view B1 to B8 of the multiple cameras based on the imaging results (mark imaging results 51) of the multiple cameras each capturing an image of the mark 25 constitute a component imaging device that can correct the deviation of the optical axes 33c, 34c of the cameras that image the component D2.

[0069] Next, the configuration of a component recognition camera 70 having another optical axis refraction section R1 (hereinafter simply referred to as "optical axis refraction section R1") will be described with reference to Figures 16 and 17. Hereinafter, the same components as those in the component recognition camera 20 are given the same reference numerals, and detailed description will be omitted. Inside the housing 71 of the component recognition camera 70, a first camera group G1 consisting of a plurality of first camera units 22 and a second camera group G2 consisting of a plurality of second camera units 23 are arranged.

[0070] Optical axes 23d of the multiple second camera units 23 are refracted in the direction of a first mirror 72 arranged below the transparent plate 24 by a second mirror 73 arranged above the second camera units 23. Furthermore, optical axes 23d are refracted upward by the first mirror 72. The first mirror 72 and the second mirror 73 are each a single mirror extending in the X-axis direction, and are shared by the multiple second camera units 23. Furthermore, the first mirror 72 is a half mirror through which optical axes 22d of the multiple first camera units 22 pass, and is shared by the multiple first camera units 22.

[0071] 16 and 17, the third illumination unit 31 is disposed at a position along the Y axis from the first mirror 72. The light 31a emitted from the third illumination unit 31 is refracted upward by the first mirror 72. In this manner, the first mirror 72 and the second mirror 73 (mirror) constitute an optical axis refraction unit R1 that guides an image of the component D held in the nozzle 8b to the second camera unit 23 (camera of the second camera group). In addition, the first mirror 72 and the second mirror 73 are each a single mirror that is shared by multiple cameras (second camera unit 23) of the second camera group G2.

[0072] Next, the configuration of the third component recognition camera 80 (hereinafter simply referred to as "component recognition camera 80") will be described with reference to Figures 18 and 19. The component recognition camera 80 has only a third camera group G3 consisting of a plurality of cameras (third camera units 82) that are arranged in series in one direction (X-axis direction) and capture images of components D, and differs from the component recognition camera 20 that has the first camera units 22 of the first camera group G1 and the second camera units 23 of the second camera group G2 that are arranged alternately. Hereinafter, the same components as those of the component recognition camera 20 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

[0073] 18 is a schematic diagram showing the inside of the component recognition camera 80 seen through a housing 81 of the component recognition camera 80 and a housing of the third camera unit 82. The component recognition camera 80 is provided with a plurality of (four in this example) third camera units 82 arranged in a straight line along the X-axis and constituting a third camera group G3. The third camera unit 82 has a third imaging section 82a having an imaging element such as a two-dimensional CMOS sensor inside the housing, and a third lens 82b located between the component D to be imaged and the third imaging section 82a. A transparent plate 24 having a mark 25 is provided above the third lens 82b.

[0074] 18 and 19, the third camera unit 82 is installed with its optical axis 82c facing upward, and captures an image of the target component D from below. A fourth illumination unit 83 is installed above the third lens 82b at a position that does not interfere with imaging by the third camera unit 82. The fourth illumination unit 83 is configured with a plurality of LED chips and the like, and emits light that illuminates the target object (such as component D) or the mark 25 on the transparent plate 24 from below.

[0075] In Fig. 19(a), the four third camera units 82 of the third camera group G3 are referred to as third camera units 82A to 82D in order from the left in the X-axis direction. In Fig. 19(a) and Fig. 19(b), the third imaging units 82a and the third lenses 82b of the third camera units 82A to 82D are optical systems with a large (wide) angle of view. The width in the X-axis direction of the imaging fields C1 to C4 of the third camera units 82A to 82D is approximately twice as large as the width LX1 in the X-axis direction of the imaging fields A1, A3, A5, and A7 of the first camera units 22A to 22D. In the component recognition camera 80, adjacent imaging fields C1 to C4 of the third camera units 82A to 82D partially overlap each other in one direction (X-axis direction).

[0076] FIG. 19(c) shows an example of imaging of a 16-nozzle mounting head in which small components D1 are held by 16 nozzles 8b, by the component recognition camera 80. The imaging fields C1 to C4 of the third camera units 82A to 82D are designed so that two components D1 pass through each of them. The processing by the component imaging processing unit 42, image processing unit 43, component pickup position calculation unit 44, and mark imaging processing unit 45 is similar to that of the component recognition camera 20 described above, and a description thereof will be omitted. The position deviation amount calculation unit 46 calculates the position deviation amount (imaging field position deviation amount 52) ​​of the imaging fields C1 to C4 of the multiple cameras based on the imaging results of the multiple cameras (third camera units 82A to 82D) capturing still images of the marks 25. This corrects the deviation of the optical axes 82c of the third camera units 82A to 82D.

[0077] In this way, the imaging fields of view C1 to C4 are arranged in series, and multiple cameras (third camera units 82A to 82D) that image component D, the component recognition camera 80 having a mark 25 that is located within the imaging fields of view C1 to C4 of the multiple cameras but outside the imaging range (component imaging field of view 24a) when the multiple cameras image component D1, and the positional deviation calculation unit 46 constitute a component imaging device that can correct deviation in the optical axis 82c of the camera that images component D1. [Industrial Applicability]

[0078] INDUSTRIAL APPLICABILITY The component imaging device of the present invention has the effect of being able to correct misalignment of the optical axis of a camera that images a component, and is useful in the field of mounting components on a board. [Explanation of symbols]

[0079] 20, 32, 70, 80 Part recognition camera (part imaging device) 22, 22A-22D, 33A-33D First camera unit (camera) 23, 23A-23D, 34A-34D Second camera unit (camera) 24 Transparent plate 24a Part imaging field of view (imaging range) 25, 25A~25H Mark 26 First Lighting Section (Lighting Section) 29 Second Lighting Section (Lighting Section) 31 3rd Lighting Section (Lighting Section) 82, 82A-82D 3rd camera unit (camera) 83 4th Lighting Section (Lighting Section) A1~A8, B1~B8, C1~C4 Imaging field D, D1, D2 parts

Claims

1. A plurality of cameras each having an imaging field of view arranged in series for imaging a component; a transparent plate disposed between the plurality of cameras and the component; a mark provided on the transparent plate within the imaging field of view of the plurality of cameras and outside the imaging range when the plurality of cameras images an image of a component; and a positional deviation amount calculation unit that calculates a positional deviation amount of the imaging fields of the multiple cameras based on imaging results of the multiple cameras capturing images of the marks.

2. The part imaging device according to claim 1 , further comprising an illumination unit that illuminates the mark.

3. The component imaging device according to claim 2 , wherein the illumination unit is provided for each of the plurality of cameras.

4. 4. The component imaging device according to claim 1, wherein at least two of the marks are provided on the transparent plate in each of the imaging fields of the plurality of cameras.

5. The component imaging device according to claim 4 , wherein the positional deviation amount calculation unit calculates a positional deviation amount of an imaging field of one of the plurality of cameras from positions of at least two of the marks captured in the imaging field of the one of the plurality of cameras.

Images