Image acquisition device, substrate inspection device, and image acquisition method

Abstract

This image acquisition device acquires images of a plurality of objects disposed on a plane when inspecting the plurality of objects, and is provided with: a camera unit that has a camera capable of capturing an image of the plurality of objects from above, and that is capable of changing the focus height at which the camera focuses; and a control unit that determines the focus height at each time of imaging by determining the width in the height direction that can be covered by one time of imaging by the camera on the basis of the height difference between the highest object and the lowest object among the plurality of objects that can be simultaneously imaged by the camera and the depth of field of the camera. And controlling the camera unit to focus at each determined focus height and then to capture an image.

Description

Technical Field

[0001] This specification discloses an image acquisition device, a substrate inspection device, and an image acquisition method. Background Art

[0002] Conventionally, an image inspection device is known which uses an image to inspect an object to be inspected and inspects the position and orientation of the object to be inspected based on images obtained by simultaneously photographing a plurality of objects to be inspected. For example, Patent Document 1 discloses simultaneously photographing one of a plurality of objects to be inspected (hereinafter referred to as a reference object) and an object to be inspected whose distance from the surface of the reference object is less than the depth of field of a camera. Prior Art Documents Patent Documents

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015 - 145797. Summary of the Invention Technical Problem to be Solved by the Invention

[0004] However, in the above-described image inspection device, even when the distances between a plurality of objects to be inspected other than the reference object are less than the depth of field of the camera, an object to be inspected whose distance from the reference object is greater than the depth of field of the camera is separately photographed from the reference object. Therefore, the number of times the camera takes images increases, and the time required to take images may become longer.

[0005] The main object of the present disclosure is to shorten the time required to take images.

[0006] To achieve the above main object, the present disclosure takes the following means. Means for Solving the Technical Problem

[0007] The image acquisition device of the present disclosure acquires images of a plurality of objects arranged on a plane, and is characterized in that it includes: a camera unit having a camera capable of photographing the plurality of objects from above and capable of changing the focus height of the camera; and a control unit that calculates the width in the height direction that can be covered by one photograph by the camera based on the height difference between the highest object and the lowest object among the plurality of objects that can be simultaneously photographed by the camera and the depth of field of the camera, thereby determining the focus height at each time of photographing, and controls the camera unit to focus at each of the determined focus heights and then photograph images separately.

[0008] In this image acquisition device, based on the height difference and the depth of field of the camera, the width in the height direction that can be covered by one-time shooting of the camera is obtained, thereby determining the focus height at each shooting, and controlling the camera unit to focus at each determined focus height and then shoot images respectively. Thus, the maximum number of shootings of the camera can be set to the number corresponding to the ratio of the height difference to the width in the height direction. Therefore, the time required for shooting images can be shortened.

[0009] The substrate inspection device of the present disclosure inspects the mounting states of a plurality of components mounted on a substrate. The gist lies in that it includes: a camera unit having a camera capable of shooting the plurality of components from above and capable of changing the focus height of the camera; a control unit that, based on the height difference between the highest object and the lowest object among the plurality of objects that the camera can shoot simultaneously and the depth of field of the camera, obtains the width in the height direction that can be covered by one-time shooting of the camera, thereby determining the focus height at each shooting, and controls the camera unit to focus at each determined focus height and then shoot images respectively; and an inspection unit that inspects the mounting states of the plurality of components with respect to the substrate based on the images.

[0010] This substrate inspection device has the same effect as the image acquisition device of the present disclosure.

[0011] The image acquisition method of the present disclosure is an image acquisition method when using a camera unit to acquire images of a plurality of objects arranged on a plane. The camera unit has a camera capable of shooting the plurality of objects from above and capable of changing the focus height of the camera. The gist of the image acquisition method lies in that, based on the height difference between the highest object and the lowest object among the plurality of objects that the camera can shoot simultaneously and the depth of field of the camera, the height range that can be covered by one-time shooting of the camera is obtained, thereby determining the focus height at each shooting; and controlling the camera unit to focus at each determined focus height and then shoot images respectively.

[0012] This image acquisition method has the same effect as the image acquisition device and the substrate inspection device of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic structural diagram of the component mounting system 1. Figure 2 It is a schematic structural diagram of the head lifting device 50. Figure 3 It is a block diagram showing the electrical connection relationship of the component mounting system 1. Figure 4 It is a flowchart showing an example of a focus height determination processing routine. Figure 5 It is a flowchart showing an example of a shooting height range setting processing subroutine. Figure 6A It is an explanatory diagram showing a method of calculating the height difference ΔH. Figure 6B It is an explanatory diagram showing a method of calculating the width h in the height direction. Figure 6C It is an explanatory diagram showing a method of setting the shooting height range R. Figure 6D It is an explanatory diagram showing a method of determining the presence or absence of shooting and the focus height in each shooting height range R. Figure 7 It is an explanatory diagram showing an example of the focus data 63a. Figure 8 It is a flowchart showing an example of a post-installation component inspection processing routine. Detailed implementation manners

[0014] Next, a manner for implementing the invention of the present disclosure will be described with reference to the accompanying drawings. Figure 1 It is a schematic structural diagram of the component mounting system 1. Figure 2 It is a schematic structural diagram of the head lifting device 50. Figure 3 It is a block diagram showing the electrical connection relationship of the component mounting system 1. In addition, in Figure 1 , Figure 2 , the left-right direction is set as the X-axis direction ( Figure 2 is the direction perpendicular to the paper surface in

[0015] ), the front-back direction is set as the Y-axis direction, and the up-down direction is set as the Z-axis direction.

[0015] The component mounting system 1 includes a component mounter 10 and a management device 70 (refer to Figure 3 ). As Figure 1 shows, the component mounter 10 picks up the component C supplied from the component supply device 21 and mounts it on the substrate S. As Figure 1 shows, the component mounter 10 includes a component supply device 21, a substrate transfer device 22, a head 40, a head moving device 30, a head lifting device 50 (refer to Figure 2 ), a parts camera 24, a mark camera 25, and a control device 60 (refer to Figure 3 ).

[0016] The component supply device 21 includes, for example, a tray supply device 21a that supplies a tray having a plurality of storage bags for storing the components C, a tape feeder 21b that conveys a tape having a plurality of chambers for storing the components C, and the like.

[0017] The substrate transfer device 22 transfers the substrate S from left to right by driving a pair of conveyor belts. For example, the substrate transfer device 22 has a pair of conveyor belts that are arranged at a predetermined interval in the front-rear (Y-axis direction) and spanned in the left-right (X-axis direction).

[0018] The head 40 holds the nozzle 41 of the pick-up (adsorption) element C. Although not shown, the nozzle 41 is connected to a negative pressure source via a solenoid valve (on-off valve), and the nozzle 41 adsorbs the element C by receiving negative pressure supply from the negative pressure source. The head 40 includes a Z-axis actuator 42 (see Figure 3 ), and a Z-axis position sensor 43 (see Figure 3 ). The Z-axis actuator 42 (see Figure 3 ) drives to move the nozzle 41 in the up-down direction (Z-axis direction). The Z-axis position sensor 43 detects the position of the nozzle 41 in the Z-axis direction and outputs it to the control device 60 (see Figure 3 ).

[0019] The head moving device 30 moves the head 40 in the front-rear, left-right (XY-axis directions). As Figure 1 shown, the head moving device 30 includes an X-axis slider 32 and a Y-axis slider 34. The X-axis slider 32 is supported on a pair of upper and lower X-axis guide rails 33 provided on the front surface of the Y-axis slider 34 so as to extend in the left-right direction (X-axis direction). The X-axis slider 32 moves in the X-axis direction along the X-axis guide rails 33 by the drive of an X-axis actuator 36 (see Figure 3 ). The Y-axis slider 34 is supported on a pair of left and right Y-axis guide rails 35 provided on the upper part of the housing 12 so as to extend in the front-rear direction (Y-axis direction). The Y-axis slider 34 moves in the Y-axis direction along the Y-axis guide rails 35 by the drive of a Y-axis actuator 38 (see Figure 3 ). In addition, the X-axis slider 32 has its position in the X-axis direction detected by an X-axis position sensor 37 (see Figure 3 ). Moreover, the Y-axis slider 34 has its position in the Y-axis direction detected by a Y-axis position sensor 39 (see Figure 3 ). The head 40 is mounted on the X-axis slider 32. Therefore, by driving and controlling the head moving device 30 (X-axis actuator 36 and Y-axis actuator 38), the head 40 moves along the XY plane (horizontal plane).

[0020] The head lifting device 50 raises and lowers the head 40. As Figure 2 shown, the head lifting device 50 is provided on the X-axis slider 32. The head lifting device 50 includes a Zs-axis actuator 51, a ball screw 52, a movable body 53, and a Zs-axis position sensor 54 (see Figure 3). The ball screw 52 is provided so as to extend in the vertical direction (Z-axis direction) and is screwed with a ball nut (not shown) fixed to the movable body 53. Therefore, the movable body 53 rotationally drives the ball screw 52 by the Zs-axis actuator 51 and moves up and down in the vertical direction. And the movable body 53 holds the head 40. Therefore, the head lifting device 50 moves the movable body 53 up and down by the drive of the Zs-axis actuator 51, thereby moving the head 40 up and down. The Zs-axis position sensor 54 detects the position of the head 40 in the Z-axis direction and outputs it to the control device 60 (see Figure 3 ).

[0021] When the component camera 24 picks up the component C supplied by the component supply device 21 and mounts it on the substrate S conveyed by the substrate transfer device 22, when the component C passes above the component camera 24, the component C is photographed from below. As Figure 1 shown, the component camera 24 is provided between the component supply device 21 and the substrate transfer device 22. The component camera 24 outputs the photographed image to the control device 60 (see Figure 3 ).

[0022] The mark camera 25 photographs the substrate S carried into by the substrate transfer device 22, the component C supplied by the component supply device 21, the component C mounted on the substrate S, etc. from above. As Figure 1 shown, the mark camera 25 is mounted on the head 40 and moves in the XY-axis direction together with the head 40 by the head moving device 30. In addition, the mark camera 25 moves in the Z-axis direction together with the head 40 by the head lifting device 50. The mark camera 25 outputs the photographed image to the control device 60 (see Figure 3 ).

[0023] As Figure 3 shown, the control device 60 is configured as a microprocessor centered on the CPU 61. In addition to the CPU 61, it also includes a ROM 62, a memory (such as an HDD or SSD) 63, and a RAM 64. The control device 60 is input with position signals from the X-axis position sensor 37, the Y-axis position sensor 39, the Z-axis position sensor 43, and the Zs-axis position sensor 54. In addition, the control device 60 is also input with image signals from the component camera 24 and the mark camera 25. And the control device 60 calculates the adsorption deviation amount of the component C adsorbed to the nozzle 41 using the image input from the component camera 24, and checks the mounting state of the component C with respect to the substrate S using the image input from the mark camera 25. On the other hand, drive signals are output from the control device 60 to the component supply device 21, the substrate transfer device 22, the X-axis actuator 36, the Y-axis actuator 38, the Z-axis actuator 42, and the Zs-axis actuator 51. In addition, control signals are also output from the control device 60 to the component camera 24 and the mark camera 25. The memory 63 stores data for inspecting the substrate S.

[0024] As shown Figure 3 The management device 70 is configured as a microprocessor centered around the CPU 71. In addition to the CPU 71, it also includes a ROM 72, a memory 73, and a RAM 74. The management device 70 is communicably connected to the control device 60. The memory 73 stores shape data of each component C to be mounted on the substrate S, a production plan, target mounting position data, etc. The shape data is data that records the outer shape of the component C including the height, the type of the component C mounted on the substrate S, etc. The production plan records which component C is to be mounted in what order in the component mounter 10, and how many substrates S (products) are to be produced after such mounting. The target mounting position data records at which position on the substrate S each component C is to be mounted. The target mounting position data includes, for example, the value of the X-axis coordinate of each component C when a specified point on the substrate S is taken as the origin, the value of the Y-axis coordinate, the angle formed by the long side of the component C and a straight line parallel to the Y-axis, etc.

[0025] Next, the operation of the component mounting system 1 configured as described above will be described. First, the component mounting process executed by the CPU 61 of the component mounter 10 will be described. When the CPU 61 inputs a production start instruction from the management device 70 and inputs the shape data, the production plan, and the target mounting position data and stores them in the memory 63, this process is started.

[0026] At the start of this process, the CPU 61 causes the nozzle 41 to adsorb the component C supplied from the component supply device 21. Specifically, the CPU 61 controls the head moving device 30 (the X-axis actuator 36 and the Y-axis actuator 38) to move the nozzle 41 above the supply position of the component C supplied by the component supply device 21, and then controls the Z-axis actuator 42 to lower the nozzle 41, and controls the solenoid valve to supply negative pressure to the nozzle 41. Next, the CPU 61 mounts the component C on the substrate S. Specifically, the CPU 61 controls the head moving device 30 to move the component C adsorbed on the nozzle 41 above the mounting position on the substrate S, and controls the Z-axis actuator 42 to press the component C against the substrate S, and controls the solenoid valve to release the adsorption of the component C. The CPU 61 repeats these processes until all the components C to be mounted by this machine are mounted.

[0027] Next, the post-component installation inspection process executed by the CPU 61 of the control device 60 after the component installation process is described. When the post-component installation inspection process starts, the CPU 61 controls the head moving device 30 (the X-axis actuator 36 and the Y-axis actuator 38) to move the marking camera 25 above the substrate S. Next, the CPU 61 controls the marking camera 25 to capture an image of the substrate S including the component C. Then, the CPU 61 designates one of the installed components C as the inspection target component. And, the CPU 61 performs image processing on the captured image to identify the actual installation position (the value of the X-axis coordinate, the value of the Y-axis coordinate, and the angle) of the inspection target component with respect to the substrate S. Next, the CPU 61 calculates the position deviation amount based on the difference between the actual installation position and the target installation position. If at least one of the value of the X-axis coordinate, the value of the Y-axis coordinate, and the angle exceeds the allowable range, the CPU 61 determines that the installation state of the inspection target component is abnormal. On the other hand, if all of the value of the X-axis coordinate, the value of the Y-axis coordinate, and the angle are within the allowable range, the CPU 61 determines that the installation state of the inspection target component is normal. And, the CPU 61 stores the determination result in the memory 63. The CPU 61 executes these processes for all components to be inspected.

[0028] However, various types of components C with different heights are installed on the substrate S. Therefore, if the substrate S is only captured once with the focus of the marking camera 25 fixed at a specified position, there may be a component C that is captured in a state not included in the depth of field D of the marking camera 25. For a component C that is captured in a state not included in the depth of field D of the marking camera 25, its installation state may not be correctly determined. Thus, in the present embodiment, the shooting height range R that can be covered by one shooting (included in the depth of field D of the marking camera 25) is determined, and the focus height P at which the marking camera 25 focuses within the shooting height range R is determined. The marking camera 25 is focused at each focus height P to capture the substrate S multiple times, and the installation state of the component C with respect to the substrate S is inspected based on multiple images. Here, first, use Figures 4 to 7 to describe the focus height determination process routine for determining the focus height P. Figure 4 is a flowchart showing an example of the focus height determination process routine. This process is executed by the CPU 61 of the control device 60 before the above-described component installation process and post-component installation inspection process. The CPU 61 executes this routine after inputting the start instruction from the management device 70 and inputting and storing the shape data, production plan, and target installation position data from the management device 70 in the memory 63. In addition, when the substrate S is larger than the shooting range (horizontal direction) of the marking camera 25, shooting and inspection are performed by dividing it multiple times in the horizontal direction.

[0029] At the start of this routine, the CPU 61 obtains the height H of each component C with reference to the shape data, and identifies the target mounting position of each component C with reference to the target mounting position data (S100). Next, as Figure 6A shown, the CPU 61 obtains, with reference to the shape data, the component C with the highest height among the components C mounted on the substrate S by this machine ( Figure 6A component C4 in the example shown) as height H1 (S105). Then, as Figure 6A shown, the CPU 61 obtains, with reference to the shape data, the component C with the lowest height among the components C included in the horizontal shooting range of the marking camera 25 and being the inspection target ( Figure 6A component C3 in the example shown) as height H2 (S110). And, as Figure 6A shown, the CPU 61 subtracts height H2 from height H1 to calculate the height difference ΔH (= H1 - H2) between the two components C (S115).

[0030] Next, the CPU 61 obtains the depth of field D of the marking camera 25 (S120). The depth of field D of the marking camera 25 is pre-stored in the memory 63. Then, the CPU 61 calculates the ratio of the height difference ΔH to the depth of field D (= ΔH / D), rounds up the decimal part of the calculated ratio, and calculates the integer value N and stores it in the memory 63 (S125). And, as Figure 6B shown, the CPU 61 divides the height difference ΔH by the integer value N to calculate the height direction width h of the shooting height range R (= ΔH / N) (S130).

[0031] Next, the CPU 61 executes the shooting height range setting processing sub-routine as Figure 5 shown (S135). The shooting height range setting processing sub-routine is a process for setting the shooting height range R.

[0032] At the start of the shooting height range setting processing sub-routine, the CPU 61 first sets the value 1 for the variable k (S300). Next, as Figure 6C shown, the CPU 61 adds the product of the height direction width h and (k - 1) to the height H2 to calculate the height TBk at the lower end of the k-th shooting height range R (= H2 + h×(k - 1)) (S305). Then, as Figure 6C shown, the CPU 61 adds the product of the height direction width h and k to the height H2 to calculate the height TUk at the upper end of the k-th shooting height range R (= H2 + h×k) (S310). And, as Figure 6C shown, the CPU 61 sets the range from the lower end height TBk to the upper end height TUk as the k-th shooting height range R (S315). Additionally, Figure 6CIn the figure, the numbers within the circles indicated by the dashed lines represent which shooting height range R the shooting height range R is. By repeatedly executing these processes, the CPU 61 sets N shooting height ranges R (with equal widths h) in the area from the surface of the component C with the lowest height to the surface of the component C with the highest height when the component C is mounted on the substrate S ( Figure 6C in the example shown, there are 3).

[0033] Next, the CPU 61 increments the value of the variable k by 1 (S320). And the CPU 61 determines whether the value of the variable k is greater than the integer value N (S325). If the value of the variable k is greater than the integer value N, the CPU 61 makes a negative determination judging that N shooting height ranges R have not been set yet. On the other hand, if the value of the variable k is greater than the integer value N, the CPU 61 makes an affirmative determination judging that N shooting height ranges R have been set. If a negative determination is made in S325, the CPU 61 returns to S305 again. On the other hand, if an affirmative determination is made in S325, the CPU 61 ends the shooting height range setting processing subroutine and enters Figure 4 S140 of the focus height determination processing routine shown.

[0034] Then, the CPU 61 sets the value of the variable i to 1 (S140). And the CPU 61 compares the height H of each component C obtained in S100 with the lower end height TB i and the upper end height TB i of the i-th shooting height range R set by the shooting height range setting processing subroutine, and determines whether there is a component C with a height (upper surface) H within the i-th shooting height range R when the component C is mounted on the substrate S (S145). In addition, the CPU 61 determines that the component C with the lowest height H among the multiple components C is the component with a height H within the 1st shooting height range R; and determines that the component C with the highest height H is the component with a height H within the N-th shooting height range R. In addition, if the height H of the component C is a height H that coincides with the boundary between adjacent shooting height ranges R, the CPU 61 determines that either one of the two adjacent shooting height ranges R contains the component C with a height (upper surface) H.

[0035] If there is no component C with height H within the i-th shooting height range R, the CPU 61 makes a negative determination. On the other hand, if there is a component C with height H within the i-th shooting height range R, the CPU 61 makes an affirmative determination. If a negative determination is made in S145, the CPU 61 determines to skip the shooting of the i-th shooting height range R in the post-installation component inspection processing routine described later, and sets the information related to the presence or absence of shooting in the i-th shooting height range R to "none" (S150). Next, the CPU 61 determines not to set the image processing object in the post-installation component inspection processing routine described later (S155). Then, the CPU 61 determines not to determine the focus height P (S160).

[0036] On the other hand, if an affirmative determination is made in S145, the CPU 61 determines to perform the shooting of the i-th shooting height range R in the post-installation component inspection processing routine described later, and sets the information related to the presence or absence of shooting in the i-th shooting height range R to "yes" (S165). Then, the CPU 61 sets the component C with height H within the i-th shooting height range R as the image processing object (S170). And, the CPU 61 determines whether there are two or more components C with height (upper surface) H within the i-th shooting height range R (S175). If it is determined that there are two or more components C with height H within the i-th shooting height range R, the CPU 61 makes an affirmative determination. On the other hand, if it is determined that there is one component C with height H within the i-th shooting height range R, the CPU 61 makes a negative determination. If an affirmative determination is made in S175, the CPU 61 determines the focus height P in the i-th shooting height range R as the average height of the two or more components C (S180). On the other hand, if a negative determination is made in S175, the CPU 61 determines the focus height P in the i-th shooting height range R as the height H of the component C (S185).

[0037] Here, use Figure 6D to illustrate an example of the processing from S145 to S185. Additionally, Figure 6DAmong them, the number within the circle indicated by the dashed line represents which shooting height range R it is. Since components C1, C2, and C3 exist as components C with height (upper surface) H within the first shooting height range R, the CPU 61 sets the information related to whether shooting is required within the first shooting height range R to "Yes" (S165). Next, the CPU 61 sets components C1, C2, and C3 as the image processing objects of the image captured within the first shooting height range R (S170). And the CPU 61 determines the focus height P within the first shooting height range R as their average height (focus height P1) (S180). Additionally, since there is no component C with height H within the second shooting height range R, the CPU 61 sets the information related to whether shooting is required within the second shooting height range R to "No" (S150). Next, the CPU 61 determines not to set an image processing object (S155). And the CPU 61 determines not to determine the focus height P within the second shooting height range R (S160). Furthermore, since only component C4 exists as a component C with height H within the third shooting height range R, the CPU 61 sets the information related to whether shooting is required within the third shooting height range R to "Yes" (S165). Next, the CPU 61 sets component C4 as the image processing object of the image captured within the third shooting height range R (S170). And the CPU 61 determines the focus height P within the third shooting height range R as the height of component C4 (focus height P3) (S185).

[0038] Next, as Figure 7 shown, the CPU 61 stores in the memory 63 in correspondence the information related to the shooting height range R (the i-th), the information related to whether shooting is required, the focus height P, and the image processing object within the i-th shooting height range R (S190). Next, the CPU 61 increments the value of the variable i by 1 (S195). And the CPU 61 determines whether the value of the variable i is greater than the integer value N (S195). If the value of the variable i is less than or equal to the integer value N, the CPU 61 determines that there is still a shooting height range R for which the information related to whether shooting is required and the focus height P must be set, and makes a negative determination. On the other hand, if the value of the variable i is greater than the integer value N, the CPU 61 determines that the information related to whether shooting is required and the focus height P have been set for all shooting height ranges R, and makes an affirmative determination. If a negative determination is made in S190, the CPU 61 returns to S145 again. On the other hand, if an affirmative determination is made in S190, the CPU 61 ends this routine. Additionally, the data obtained by repeatedly executing the processes from S145 to S175 is referred to as focus data 63a in this embodiment.

[0039] Next, the post-mount component inspection process executed by the CPU 61 of the control device 60 after the component mounter 10 mounts the component C on the substrate S in the above-described component mounting process will be described. Figure 8 It is a flowchart showing an example of a post-mount component inspection process routine.

[0040] When this routine starts, the CPU 61 sets the value of the variable i to 1 (S400). Next, the CPU 61 controls the head moving device 30 to move the marking camera 25 above the substrate S (S405). Then, the CPU 61 refers to Figure 7 the focus data 63a shown, and acquires information related to the presence or absence of shooting in the i-th shooting height range R (S410). And the CPU 61 determines whether the information related to the presence or absence of shooting acquired in S410 is "yes" (S415). If the information related to the presence or absence of shooting acquired in S410 is "no", the CPU 61 determines that shooting is skipped in the i-th shooting height range R, and makes a negative determination. On the other hand, if the information related to the presence or absence of shooting acquired in S410 is "yes", the CPU 61 determines that shooting is executed in the i-th shooting height range R, and makes a positive determination. If a negative determination is made in S415, the CPU 61 proceeds to S465. On the other hand, if a positive determination is made in S415, the CPU 61 refers to Figure 7 the focus data 63a shown, and acquires the focus height P in the i-th shooting height range R (S420). And the CPU 61 sets the target height of the head 40 such that the focus height of the marking camera 25 coincides with the focus height P acquired in S420, and controls the head lifting device 50 (Zs-axis actuator 51) to move the head 40 to this target height (S425).

[0041] Next, the CPU 61 controls the marking camera 25 to capture an image of the substrate S (S430). Then, the CPU 61 refers to Figure 7 the focus data 63a shown, and identifies the component C that is the image processing object of the image captured in the i-th shooting height range R (S435). And the CPU 61 processes the image captured in S430 and calculates the position deviation amount of the component C (S440).

[0042] Next, the CPU 61 determines whether the position deviation amount of the component C obtained in S440 is within the allowable range (S445). If an affirmative determination is made in S445, it is determined that the mounting state is normal (S450). On the other hand, if a negative determination is made in S445, it is determined that the mounting state is abnormal (S455). In addition, in the present embodiment, the processes from S435 to S455 are referred to as inspection processes, and the specific content of the inspection processes is as described above. After S450 or after S455, the CPU 61 stores the determination result in the memory 63 (S460).

[0043] Next, the CPU 61 increments the value of the variable i by 1 (S465). And the CPU 61 determines whether the value of the variable i is greater than the integer value N (S470). The integer value N is the value stored in the memory 63 in S125 of the focus height determination processing routine. If the value of the variable i is less than or equal to the integer value N, the CPU 61 makes a negative determination, judging that there is still a shooting height range R for which information regarding the presence or absence of shooting has not been obtained and there is a component C that has not been the object of the inspection process. On the other hand, if the value of the variable i is greater than the integer value N, the CPU 61 makes an affirmative determination, judging that information regarding the presence or absence of shooting has been obtained for all shooting height ranges R and the inspection process has been executed for all components C. If a negative determination is made in S470, the CPU 61 returns to S410 again. On the other hand, if an affirmative determination is made in S470, the CPU 61 ends this routine.

[0044] In the component mounter 10, for the height range from the lowest component C to the highest component C, shooting is performed separately while adjusting the focus height for each shooting height range R divided according to the depth of field D of the marker camera 25. In addition, in S145 of the focus height determination processing routine, if it is determined that there is no component C having the height H within the shooting height range R, the CPU 61 sets the presence or absence of shooting in that shooting height range R to "none". And in the post-mounting component inspection processing routine, when the information regarding the presence or absence of shooting is "none", the CPU 61 skips the processes from S420 to S460 (shooting of the substrate S). Therefore, the number of shootings of the marker camera 25 can be reduced, and the time required for shooting images can be shortened.

[0045] Here, the correspondence between the constituent elements of this embodiment and those of the present disclosure is clarified. That is, the component mounter 10 of this embodiment corresponds to the image acquisition device of the present disclosure, the marking camera 25 and the head lifting device 50 correspond to the camera unit of the image acquisition device, and the CPU 61 that executes the processes of S105 to S180 of the focus height determination processing routine corresponds to the control unit of the image acquisition device. In addition, the component mounter 10 corresponds to the substrate inspection device of the present disclosure, the marking camera 25 and the head lifting device 50 correspond to the camera unit of the substrate inspection device, the CPU 61 that executes the processes of S105 to S165 of the focus height determination processing routine corresponds to the control unit of the substrate inspection device, and the CPU 61 that executes the post-installation component inspection processing routine corresponds to the inspection unit.

[0046] In the component mounter 10 described in detail above, the width in the height direction that can be covered by one shot of the camera is obtained, so as to determine the focus height at each shot, and the camera unit is controlled to focus at each of the determined focus heights and then take images respectively. Based on the height difference ΔH and the depth of field D of the marking camera 25, the width h in the height direction that can be covered by one shot of the marking camera 25 is obtained, so as to determine the focus height at each shot, and the marking camera 25 and the head lifting device 50 are controlled to focus at each of the determined focus heights and then take images respectively. Thus, the maximum number of shots of the marking camera 25 can be set to the number corresponding to the ratio of the height difference ΔH to the width h in the height direction. Therefore, the number of shots of the marking camera 25 can be reduced, and the shooting time of the marking camera 25 can be shortened.

[0047] In addition, in the component mounter 10, the integer value N of the ratio of the height difference ΔH to the depth of field D of the marking camera 25 is calculated, and the height difference ΔH is equally divided by the integer value N, so as to obtain the width h in the height direction. Thus, the width h in the height direction can be set to an appropriate length.

[0048] Moreover, in the component mounter 10, based on the width h in the height direction, each shooting height range R covered by each shot is set between the highest component C and the lowest component C, and each focus height P is determined within each shooting height range R. Thus, based on the width h in the height direction, the number of shots for shooting all components C can be set to an appropriate number.

[0049] In addition, in the component mounter 10, when a certain shooting height range R in each shooting height range R does not contain any component C, the shooting of the image within the corresponding shooting height range R is skipped. Thus, the number of shots of the marking camera 25 can be further reduced.

[0050] In addition, in the component mounting machine 10, when a plurality of components C are included in a certain shooting height range R among the respective shooting height ranges R, the focal height within the corresponding shooting height range R is determined as the average height of the plurality of components C included within the corresponding shooting height range R. Thereby, it becomes possible to shoot a plurality of components C at a position closer to the focal position of the lens of the marking camera 25.

[0051] Furthermore, it goes without saying that the present disclosure is not limited at all to the above-described embodiments, and can be implemented in various ways as long as it belongs to the technical scope of the present disclosure.

[0052] In the above-described embodiment, it is assumed that the focal height determination processing routine is executed by the CPU 61 of the control device 60. However, it may also be assumed that the focal height determination processing routine is executed by the CPU 71 of the management device 70.

[0053] In the above-described embodiment, the focal height P in the shooting height range R is determined based on the number of components C included within the shooting height range R. However, the focal height P in the shooting height range R may also be set as a fixed position determined for each shooting height range R regardless of the number of components C having the height (upper surface) H within the shooting height range R. In this case, the focal height P may be set as the center height in the height direction in each shooting height range R.

[0054] In the above-described embodiment, the height TBk of the lower end of the k-th shooting height range R is calculated by adding the product of the height direction width h and (k - 1) to the height H2; the height TUk of the upper end of the k-th shooting height range R is calculated by adding the product of the height direction width h and k to the height H2. However, the height TBk of the lower end of the k-th shooting height range R may also be calculated by subtracting the product of the height direction width h and k from the height H1; the height TUk of the upper end of the k-th shooting height range R may be calculated by subtracting the product of the height direction width h and (k - 1) from the height H1.

[0055] In the above-described embodiment, the post-mounting component inspection process is executed by the component mounting machine 10. However, the post-mounting component inspection process may also be executed using a dedicated inspection device (for example, an appearance inspection device).

[0056] In the above-described embodiment, the components C mounted by this machine can be used as the object for post-mounting component inspection. Alternatively, in a component mounting line having a plurality of component mounting machines 10, the components C mounted by the component mounting machine 10 arranged on the upstream side of this machine can also be used as the object for post-mounting component inspection. In this case, the post-mounting component inspection can be performed by the component mounting machine 10 arranged at the most downstream in the component mounting line.

[0057] In the above-described embodiment, the present disclosure has been described as the component mounter 10, but it may also be an image acquisition method.

[0058] In addition, in the present specification, the technical idea of changing "the image acquisition device according to claim 3" to "the image acquisition device according to claim 3 or 4" in the original claim 5 is also disclosed. Further, in the present specification, the technical idea of changing "the image acquisition device according to claim 1 or 2" to "the image acquisition device according to any one of claims 1 to 5" in the original claim 6 is also disclosed. Industrial Applicability

[0059] The present disclosure can be applied to the manufacturing industries such as component mounters and component mounting systems. Explanation of Reference Numerals

[0060] 1: Component mounting system, 10: Component mounter, 12: Housing, 21: Component supply device, 21a: Tray supply device, 21b: Tape feeder, 22: Substrate transfer device, 24: Component camera, 25: Marking camera, 30: Head movement device, 32: X-axis slider, 33: X-axis guide rail, 34: Y-axis slider, 35: Y-axis guide rail, 36: X-axis actuator, 37: X-axis position sensor, 38: Y-axis actuator, 39: Y-axis position sensor, 40: Head, 41: Nozzle, 42: Z-axis actuator, 43: Z-axis position sensor, 50: Head lifting device, 51: Zs-axis actuator, 52: Ball screw, 53: Movable body, 54: Zs-axis position sensor, 60: Control device, 61: CPU, 62: ROM, 63: Memory, 63a: Focus data, 64: RAM, 70: Management device, 71: CPU, 72: ROM, 73: Memory, 74: RAM, C, C1 to C4: Components, D: Depth of field, H1: Height, H2: Height, N: Integer value, P, P1, P3: Focus height, R: Shooting height range, S: Substrate, ΔH: Level difference.

Claims

1. An image acquisition device that acquires images of a plurality of objects arranged on a plane when inspecting the plurality of objects. The image acquisition device includes: A camera unit having a camera capable of photographing the plurality of objects from above and capable of changing the focus height of the camera; and A control unit that calculates the width in the height direction that can be covered by one shot of the camera based on the height difference between the highest object and the lowest object among the plurality of objects that the camera can simultaneously photograph and the depth of field of the camera, thereby determining the focus height for each shot, and controls the camera unit to focus at each determined focus height and then photograph images respectively.

2. The image acquisition device according to claim 1, wherein the control unit calculates an integer value of the ratio of the height difference to the depth of field, and equally divides the height difference by the integer value to obtain the width in the height direction.

3. The image acquisition device according to claim 1 or 2, wherein the control unit sets each shooting height range covered by each shot between the highest object and the lowest object based on the width in the height direction, and determines each focus height within each shooting height range.

4. The image acquisition device according to claim 3, wherein when a certain shooting height range among the respective shooting height ranges does not include any of the objects, the control unit skips photographing of images within the corresponding shooting height range.

5. The image acquisition device according to claim 3, wherein when a certain shooting height range among the respective shooting height ranges includes a plurality of the objects, the control unit determines the focus height within the corresponding shooting height range as the average height of the plurality of objects included within the corresponding shooting height range.

6. The image acquisition device according to claim 1 or 2, wherein the camera unit has a lifting unit capable of lifting and lowering the camera to change the focus height, and the control unit controls the lifting unit to move the camera to the lifting position corresponding to the determined focus height.

7. A substrate inspection device that inspects the mounting states of a plurality of components mounted on a substrate, The substrate inspection device includes: A camera unit having a camera capable of photographing the plurality of components from above and capable of changing the focus height of the camera; A control unit that calculates the width in the height direction that can be covered by one shot of the camera based on the height difference between the highest object and the lowest object among the plurality of objects that the camera can simultaneously photograph and the depth of field of the camera, thereby determining the focus height for each shot, and controls the camera unit to focus at each determined focus height and then photograph images respectively; and An inspection unit that inspects the mounting states of the plurality of components with respect to the substrate based on the images.

8. An image acquisition method is an image acquisition method for acquiring images of a plurality of objects arranged on a plane by using a camera unit. The camera unit has a camera capable of photographing the plurality of objects from above and capable of changing the focal height of the camera focus. In the image acquisition method, Based on the height difference between the highest object and the lowest object among the plurality of objects that can be simultaneously photographed by the camera and the depth of field of the camera, the height range that can be covered by one shot of the camera is obtained, and thus the focal height at each shot is determined; The camera unit is controlled to photograph images respectively after focusing at each of the determined focal heights.

Images