Optical axis adjustment system, optical axis adjustment method, and program

Abstract

The optical axis adjustment system (1) adjusts the imaging target surface of the imaging device (300) and the optical axis of the imaging device (300). A mirror (11) is disposed on the imaging target surface, and a jig is disposed on the mirror surface of the mirror (11). The jig includes a guide that can be imaged by the imaging device (300) and a support section that supports the guide at a position a predetermined distance away from the mirror surface. The system includes an imaging target surface drive section that moves or tilts the imaging target surface, an imaging device drive section that moves or tilts the imaging device (300), and a control means that controls the imaging target surface drive section or the imaging device drive section so that a real image and a mirror image of the guide overlap on the captured image.

Description

[Technical field]

[0001] The present disclosure relates to an optical axis adjustment system, an optical axis adjustment method, allusion to law and programs. [Background technology]

[0002] There are known techniques for adjusting the optical axis of an imaging device. For example, Patent Document 1 discloses a method of photographing an adjustment jig, which is made up of two plates with holes fixed apart, with a camera and adjusting the angle of the camera so that the holes in the front plate and the back plate overlap in the center when photographing. Patent Document 2 discloses a method of arranging a mirror on an adjustment jig for product assembly and adjusting the inclination of a microscope so that the real image and the mirror image reflected in the mirror of the adjustment jig match. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-049590 A [Patent Document 2] JP 2008-070218 A Summary of the Invention [Problem to be solved by the invention]

[0004] When adjusting the optical axis using an adjustment jig, a high-precision adjustment jig is often required. However, manufacturing the adjustment jig is time-consuming and has a large impact on work efficiency. For example, in the technology of Patent Document 1, the manufacturing accuracy of the adjustment jig is directly linked to the accuracy of the optical axis adjustment, so the adjustment jig needs to be manufactured, calibrated, and held with high precision, resulting in low work efficiency. In addition, in the technology of Patent Document 2, a mounting part for a mirror dedicated to optical axis adjustment is formed on an adjustment jig manufactured with high precision for product assembly, and during optical axis adjustment, the mirror needs to be mounted on the mounting part while taking into consideration parallelism, and after optical axis adjustment is completed, the mirror needs to be removed. Manufacturing and holding an adjustment jig manufactured with high precision for product assembly becomes more difficult, resulting in low work efficiency. Furthermore, since the accuracy of the optical axis of the mirror mounted on the adjustment jig is directly linked to the accuracy of optical axis adjustment, it is practically necessary to optically adjust the mirror before optical adjustment.

[0005] For this reason, it is necessary to easily adjust the optical axis using a simple jig.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and provides an optical axis adjustment system and an optical axis adjustment method that easily adjust an optical axis using a simple jig. allusion to law The purpose of this website is to provide educational and program information. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the optical axis adjustment system according to the present disclosure is an optical axis adjustment system that adjusts an image target surface of an imaging device and an optical axis of the imaging device, wherein a mirror is arranged on the image target surface, and a jig used for adjustment is arranged on the mirror surface of the mirror, and the jig includes a guide that can be imaged by the imaging device and a support part that supports the guide at a position a predetermined distance from the mirror surface, and is equipped with an image target surface drive part that moves the image target surface on which the mirror is placed, an imaging device drive part that moves the imaging device, a control means that controls the image target surface drive part or the imaging device drive part so that the positions of specific feature points derived from the real image and mirror image of the guide, respectively, match each other on the image captured by the imaging device, and a memory means that stores the amount of movement or adjustment amount of the tilt angle of the image target surface drive part or the imaging device drive part. The control means moves one of the image capture target surface and the image capture device in the horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, or adjusts the inclination angle of the other of the image capture target surface and the image capture device so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and then further the control means: Move one of the real image and the mirror image of the guide to the center of the captured image. moving one of the image pickup surface and the image pickup device in a horizontal direction at least once, and storing the amount of movement in a storage means; and The other of the real image and the mirror image of the guide is moved to the center of the captured image. The tilt angle of the other of the imaging target surface and the imaging device is adjusted at least once, and the adjustment amount of the tilt angle is stored in the storage means. Thereafter, the control means A position of one of the real image and the mirror image is obtained, and an adjustment ratio is obtained that represents a ratio of adjustment of a movement amount required to move the position of one of the real image and the mirror image to the center of the captured image based on the obtained position of the one and a position of the one obtained a predetermined period before the obtained time point, and the obtained adjustment ratio and a value stored in the storage means are compared. Amount of movement or adjustment and Based on the feature point location Move to the center of the captured image The imaging object surface driving section or the imaging device driving section is controlled so as to Effect of the Invention

[0008] According to the present disclosure, the optical axis can be adjusted by placing a mirror and a jig on the imaging target surface and imaging the target surface. This makes it easy to adjust the optical axis. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the overall configuration of an optical axis adjustment system according to a first embodiment. [Diagram 2]FIG. 1 is a diagram for explaining an example of alignment performed after optical axis adjustment by the optical axis adjustment system according to the first embodiment; [Diagram 3] 1A and 1B are diagrams for explaining an imaging device, a mirror, and a jig according to a first embodiment. [Figure 4] FIG. 1 is a diagram for explaining optical axis adjustment according to the first embodiment; [Diagram 5] FIG. 1 is a diagram for explaining optical axis adjustment according to the first embodiment; [Figure 6] FIG. 1 is a plan view illustrating horizontal movement of a mounting table in the first embodiment. [Figure 7] FIG. 1 is a side view illustrating an angle adjustment of the imaging device according to the first embodiment. [Figure 8] FIG. 1 is a block diagram showing a configuration example of an operation control unit according to a first embodiment. [Figure 9] FIG. 1 is a block diagram showing an example of the arrangement of an image processing unit according to a first embodiment. [Figure 10] 1 is a flowchart showing an optical axis adjustment control process according to the first embodiment. [Figure 11] FIG. 13 is a diagram showing an example of a translation guide according to a modification of the first embodiment; [Figure 12] FIG. 13 is a diagram showing an example of guidance for angle adjustment according to a modified example of the first embodiment. [Figure 13] 11 is a flowchart showing an optical axis adjustment control process according to the second embodiment. [Figure 14] FIG. 11 is a diagram for explaining optical axis adjustment according to the second embodiment. [Figure 15] FIG. 13 is a diagram for explaining optical axis adjustment according to a modification of the second embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Embodiment 1) The optical axis adjustment system and the optical axis adjustment method according to this embodiment will be described below. allusion to law The program and the program will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0011] The optical axis adjustment system of this embodiment is equipped with a mounting table on which a workpiece is placed and an imaging device that images the workpiece, and is applicable to various systems that require optical axis adjustment to adjust the mounting surface of the mounting table and the optical axis of the imaging device at a right angle.

[0012] As an example of an application, a substrate bonding apparatus that bonds two plate-like workpieces such as semiconductor substrates with high accuracy in a semiconductor manufacturing process will be described with reference to FIG.

[0013] A positioning marker Mk is formed on each of the two workpieces 1001 and 1002 to be bonded together. The substrate bonding apparatus positions the two workpieces 1001 and 1002 so that their markers Mk overlap, and bonds them together.

[0014] The workpiece 1002 to be assembled is placed on a flat mounting surface 102 of a mounting table 101 of an alignment mechanism 100 capable of translation and rotation. The workpiece 1001 to be assembled is moved while being held by a hand (not shown). The distance the workpiece 1001 moves from the supply position to the attachment position is long compared to the accuracy required for the final lamination, so it is not good at fine position adjustment and moves the same way every time. On the other hand, the alignment mechanism 100 has a short maximum adjustment distance but can move with high accuracy, so it performs position correction based on the relative distance between the two markers Mk obtained from the image captured by the imaging device 300. This realizes high-precision lamination of the two workpieces 1001 and 1002 at the position where the markers Mk overlap.

[0015] If the imaging device 300 used for positioning is tilted with respect to the surface to be imaged, i.e., the surface of the workpieces 1001 and 1002, a bias in the distance per pixel occurs in the entire imaging area of ​​the image element, resulting in a deterioration in the accuracy of image recognition. Image correction may be considered as a solution, but since image correction involves processing such as stretching, the bias in the image can be corrected, but the bias in the amount of information per pixel will remain in principle. For this reason, the accuracy of image recognition will be deteriorated compared to when it is facing directly.

[0016] Furthermore, as explained in the section on the prior art, it is costly to manufacture and calibrate a highly accurate jig for use and to maintain that high level of accuracy.

[0017] Therefore, in this embodiment, an optical axis adjustment function that does not require high machining precision of the jig is provided by performing the relative translation between the imaging device and the subject and adjusting the optical axis of the imaging device. Furthermore, by providing a function to assist the adjustment work, an inexpensive and highly convenient optical axis adjustment device is provided.

[0018] Next, the overall configuration of the optical axis adjustment system 1 according to the first embodiment will be described with reference to Fig. 1. The following configuration corresponds to a configuration obtained by extracting a part used for optical axis adjustment from the configuration of an apparatus that requires optical axis adjustment, for example, the above-mentioned substrate bonding apparatus.

[0019] As shown in FIG. 1, the optical axis adjustment system 1 includes an alignment mechanism 100, an imaging device 300, an operation control unit 200 that controls the alignment mechanism 100 and the imaging device 300, an image processing unit 400 that processes an image captured by the imaging device 300, and a setting terminal 500 that performs various settings used for processing in the image processing unit 400.

[0020] The alignment mechanism 100 includes a mounting table 101, and an X-axis drive unit 111, a Y-axis drive unit 112, and a θ drive unit 113 that move the mounting table 101 in the horizontal direction. The X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113 each include an actuator, and together they form an XY-θ stage. As shown in FIG. 6, this XY-θ stage moves the mounting table 101 in the horizontal X-axis direction, the Y-axis direction perpendicular to the X-axis, and around the θ-axis in the vertical direction. In addition, the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113 each include a position sensor such as an encoder, which detects the position and outputs a position signal.

[0021] 6 moves as the XY-θ stage moves the mounting table 101 horizontally. The amount of horizontal movement of the mounting table 101, i.e., the distance on the mounting table 101 and the corresponding number of pixels in the captured image are previously determined in association with each other and stored in the motion control unit 200. For this reason, the amount of movement of the image can be specified in pixel units from the amount of movement of the mounting table 101, and the amount of movement of the mounting table 101 can also be determined from the number of pixels on the image.

[0022] As shown in Fig. 1, drive control devices 121, 122, and 123 are connected to the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113, respectively. The drive control devices 121, 122, and 123 control the positions of the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113, respectively, based on a control signal from the motion control unit 200 and position signals from the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113. The drive control devices 121, 122, and 123 are each composed of, for example, a servo amplifier. The X-axis drive unit 111, the Y-axis drive unit 112, the θ drive unit 113, and the drive control devices 121 to 123 as a whole are an example of an imaging target surface drive unit that drives an imaging target surface.

[0023] The imaging device 300 is an imaging device that images the mounting table 101 from above the alignment mechanism 100, and is a camera having a resolution sufficient to realize the precision of the optical axis adjustment of the optical axis adjustment system 1. Imaging can be performed under various conditions. For example, imaging can be performed according to an imaging command sent to the imaging device 300 from another device, or imaging can be performed continuously at regular intervals during adjustment work when the captured images are continuously visually confirmed. The imaging device 300 is installed above approximately the center of the mounting table 101 of the alignment mechanism 100. The target of imaging by the imaging device 300 is the mounting surface 102 of the mounting table 101, and the optical axis is adjusted to be perpendicular to the mounting surface 102, that is, the target surface.

[0024] 3A, the imaging device 300 includes an image element 302 and a lens 304. The image element 302 includes a semiconductor image element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image element. The lens 304 forms an image of a subject on the imaging surface of the image element 302.

[0025] The imaging device 300 is provided with a gimbal mechanism 301 that adjusts the tilt angle of the imaging device 300. As shown in FIG. 1, a gimbal driver 311 is connected to the gimbal mechanism 301. The gimbal driver 311 includes an actuator and drives the gimbal mechanism 301 to individually adjust the tilt angle φx around the X-axis and the tilt angle φy around the Y-axis of the imaging device 300, as shown in FIG. 7. The gimbal driver 311 also includes an angle sensor such as a rotary encoder, detects the tilt angles φx and φy, and outputs a tilt angle signal. In FIG. 7, the tilt angle φy is indicated by the angle difference with respect to the vertical direction Ag.

[0026] The imaging position of the imaging device 300 changes due to changes in the tilt angles φx and φy of the imaging device 300. For example, as shown in Fig. 7, the imaging range Ar moves in the X-axis direction due to a change in the tilt angle φy around the y-axis. The change in the tilt angles φx and φy and the number of pixels on the captured image corresponding to the change in the tilt angles φx and φy are previously found in correspondence with each other and stored in the motion control unit 200.

[0027] 1, the gimbal driver 311 is connected to a drive control device 321. The drive control device 321 controls the gimbal driver 311 based on a control signal from the motion control unit 200 and a tilt angle signal from the gimbal driver 311, and adjusts the tilt angles φx and φy. The drive control device 321 is, for example, a servo amplifier. The gimbal driver 311 and the drive control device 321 as a whole are an example of an imaging device driver that tilts or moves the imaging device 300.

[0028] The motion control unit 200 is a motion controller that issues commands to the drive control devices 121, 122, 123, and 321 related to the operations of the X-axis drive unit 111, the Y-axis drive unit 112, the θ drive unit 113, and the gimbal drive unit 311, and includes, for example, a PLC (Programmable Logic Controller). The motion control unit 200 generates control signals based on information acquired from the drive control devices 121, 122, 123, and 321 and the image processing unit 400, and outputs the control signals to the drive control devices 121, 122, 123, and 321.

[0029] 8, the operation control unit 200 includes a processor 210, a volatile memory 220, a non-volatile memory 230, a clock 240, and a communication interface 250. The processor 210, the volatile memory 220, the non-volatile memory 230, the clock 240, and the communication interface 250 are communicatively connected to one another via a bus B1.

[0030] The processor 210 includes, for example, a CPU (Central Processing Unit), and functions as a movement amount calculation unit 212 and a command unit 213 by reading and executing a control program stored in a control program storage unit 231 of the non-volatile memory 230.

[0031] The movement amount calculation section 212 of the processor 210 calculates the movement amount of the mounting table 101 in the X direction, Y direction, and θ direction when the image processing unit 400 processes the captured image. The movement amount calculation section 212 also calculates the adjustment amount of the tilt angle of the imaging device 300 when the image processing unit 400 processes the captured image. The command section 213 outputs a control signal based on the movement amount calculated by the movement amount calculation section 212 to the drive control devices 121, 122, and 123. The command section 213 also outputs a control signal based on the adjustment amount calculated by the movement amount calculation section 212 to the drive control device 321. Details of the process performed by the movement amount calculation section 212 will be described later.

[0032] The volatile memory 220 is a work memory capable of reading and writing data at high speed during arithmetic processing executed by the processor 210, and includes, for example, a RAM (Random Access Memory). The nonvolatile memory 230 includes a control program storage unit 231 that stores a control program for implementing various functions of the motion control unit 200, and a control data storage unit 232 that stores control data including parameters used when executing the control program, past detection data, and command data. The nonvolatile memory 230 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a nonvolatile semiconductor memory such as a flash memory, a magnetic disk, or an optical disk.

[0033] The clock 240 includes a real-time clock (RTC) and synchronizes the operation of the drive controllers 121, 122, 123, and 321.

[0034] The communication interface 250 is an interface for the motion control unit 200 to communicate with the drive control devices 121, 122, 123, 321, the imaging device 300, and the image processing unit 400, and includes an interface that complies with communication standards such as CC-Link IE / field and CC-Link IE / TSN.

[0035] 1 processes the captured image acquired from the imaging device 300, and obtains adjustment information representing information related to adjustment of the position of the alignment mechanism 100 and the tilt angle of the imaging device 300. Details of the processing executed by the image processing unit 400 will be described later.

[0036] 9, the image processing unit 400 includes a processor 410, a volatile memory 420, a non-volatile memory 430, and a communication interface 440. The processor 410, the volatile memory 420, the non-volatile memory 430, and the communication interface 440 are communicatively connected to one another via a bus B2.

[0037] The processor 410 includes, for example, a CPU, and functions as an image acquisition unit 411 and an adjustment information calculation unit 414 by reading and executing a control program stored in a control program storage unit 431 of the non-volatile memory 430 .

[0038] The image acquisition unit 411 of the processor 410 acquires an image captured by the imaging device 300. The adjustment information calculation unit 414 processes the captured image to obtain adjustment information. Details of the processing will be described later.

[0039] The volatile memory 420 is a work memory capable of reading and writing data at high speed during arithmetic processing executed by the processor 410, and includes, for example, a RAM. The nonvolatile memory 430 includes a control program storage unit 431 that stores control programs for implementing various functions of the image processing unit 400, and a control data storage unit 432 that stores control data including parameters used when executing the control programs and past detection data. The nonvolatile memory 430 includes, for example, a nonvolatile semiconductor memory such as an EEPROM or a flash memory, a magnetic disk, or an optical disk.

[0040] The communication interface 440 is an interface for the image processing unit 400 to communicate with the drive control devices 121, 122, 123, 321, the motion control unit 200, and the imaging device 300, and includes an interface compliant with communication standards such as CC-Link IE / field and CC-Link IE / TSN.

[0041] 1 is a terminal in which an application program capable of managing the image processing unit 400 is installed, and includes, for example, a personal computer. The setting terminal 500 has a function of managing the image processing unit 400, including inputting or changing parameters stored in the non-volatile memory 430 of the image processing unit 400. The setting terminal 500 also displays information including calculated values ​​output by the image processing unit 400 or the operation control unit 200. The communication interface for the setting terminal 500 to communicate with the image processing unit 400 is any interface corresponding to the interface of the image processing unit 400, and includes, for example, a USB interface or an RS232C interface. The motion control unit 200 and the image processing unit 400 are an example of a control means.

[0042] In the optical axis adjustment according to this embodiment, a mirror 11 and a jig 12 are used, as shown in FIGS.

[0043] During optical axis adjustment, mirror 11 is placed approximately in the center of mounting surface 102 of mounting table 101. As shown in FIG. 3B, mirror 11 has a flat plate shape and includes back surface 11b placed on mounting table 101 and mirror surface 11a parallel to back surface 11b. Because back surface 11b and mirror surface 11a are parallel, when mirror 11 is placed on mounting table 101, mirror surface 11a becomes parallel to mounting surface 102 of mounting table 101. Therefore, by controlling the optical axis of imaging device 300 to be perpendicular to mirror surface 11a, it is possible to adjust the optical axis of imaging device 300 to be perpendicular to mounting surface 102.

[0044] 3(A), during optical axis adjustment, jig 12 is placed on mirror surface 11a of mirror 11 arranged on mounting surface 102 of mounting table 101. Jig 12 has guide 12a, support 12b that supports guide 12a, leg 12c that contacts mirror surface 11a, and column 12d that vertically connects leg 12c and support 12b.

[0045] The guide 12a is formed in a perfect circular ring shape and is supported approximately parallel to the mirror surface 11a. The position of the center point Hp of the guide 12a can be obtained by image processing of the real image of the guide 12a and image processing of the mirror image.

[0046] The support portion 12b extends in the horizontal direction to support the guide 12a. The tip of the support portion 12b extends to the center point Hp of the perfect circle of the guide 12a. The center point Hp of the guide 12a and the tip Hp of the support portion 12b are positions where the center point Hp of the real image and the center point Hp of the mirror image overlap when the jig 12 is viewed from a direction perpendicular to the mirror surface 11a, and are an example of a characteristic point. In this disclosure, the overlap of the real image and the mirror image means that "the image of the guide 12a and the image of the mirror image of the guide 12a reflected on the mirror surface 11a overlap on the captured image." In addition, the mirror image means the image of the mirror image on the captured image. Here, the image of the mirror image is abbreviated to "mirror image."

[0047] The leg portion 12c has a ring shape having a substantially circular shape larger than the circular shape of the guide 12a. The pillar portion 12d has a rod shape extending vertically upward from the leg portion 12c. The support portion 12b has a rod shape extending horizontally from the tip of the pillar portion 12d in the vertical upward direction.

[0048] Due to this structure, the imaging device 300 can capture the real image of the guide 12a and the mirror image reflected on the mirror surface 11a. The size of the mirror surface 11a is the size at which the mirror image is reflected when the imaging device 300 captures the image of the guide 12a. The distance at which the guide 12a is separated from the mirror surface 11a, which is the installation surface, is a height at which the real image and mirror image of the guide 12a are easily recognized based on the depth of field of the imaging device 300, and it is desirable for the distance to be long. The guide 12a is also disposed symmetrically with respect to a plane parallel to the mirror surface 11a.

[0049] Next, from the viewpoint of optical axis adjustment, we will explain how light rays pass through guide 12a and are formed as a real image and a mirror image on image element 302 when mirror 11 and jig 12 are placed on mounting table 101 as shown in Figure 4.

[0050] FIG. 4 shows the mirror surface 11a and the image element 302 viewed from the side, and shows the positions of the real image and mirror image of the guide 12a formed on the imaging surface of the image element 302. The light ray Ax1 shown by the solid line is reflected by the mirror surface 11a, passes through the guide 12a and the center LC of the lens 304, and is formed as a real image on the image element 302. The light ray Ax2 shown by the dashed line passes through the guide 12a, is reflected by the mirror surface 11a, passes through the center LC of the lens, and is formed as a mirror image on the image element 302. The dashed line shows the perpendicular line VL of the mirror surface 11a. In this example, the image element 302 and the mirror surface 11a are not directly opposite each other. The real image and the mirror image are formed at separate positions on the imaging surface of the image element 302. Here, if the center LC of the lens 304 and the guide 12a are adjusted so that they are positioned on the same perpendicular line VL of the mirror surface 11a, the light rays Ax1 and Ax2 will overlap, and the real image and mirror image of the guide 12a will be formed overlapping on the imaging surface of the image element 302.

[0051] In FIG. 5, similarly to FIG. 4, the imaging element 302 and the mirror surface 11a do not face each other. However, in FIG. 5, the guide 12a is located on the perpendicular line VL of the mirror surface 11a that passes through the center LC of the lens 304. As a result, the real image and the mirror image overlap. However, the imaging positions of the real image and the mirror image are away from the center of the imaging element 302. In this way, when the optical system is adjusted so that the center LC of the lens 304 is located in the perpendicular direction from the center of the imaging element 302, the imaging element 302 and the mirror surface 11a face each other when the real image and the mirror image coincide at the center of the imaging element 302.

[0052] Therefore, if the optical system is adjusted so that the center LC of the lens 304 is located in the direction perpendicular to the center of the image element 302, the optical axis of the image element 300 can be adjusted perpendicular to the mounting table 101 by adjusting the alignment mechanism 100 and the image element 300 so that the real image and mirror image of the guide 12a photographed by the image element 300 overlap at the center of the image element 302. In order to determine whether the real image and mirror image overlap accurately, for example, it is necessary to determine whether the center point Hp of the guide 12a overlaps with the real image and mirror image. From the viewpoint of the influence of aberration of the lens 304 of the imaging device 300 and securing a margin of the movement range during optical axis adjustment, it is desirable that the real image and the mirror image of the guide 12a are located near the center of the imaging surface of the image element 302. For this reason, in this embodiment, the imaging positions of the real image and the mirror image are also adjusted to the center of the image element 302.

[0053] A specific optical axis adjustment process performed by the optical axis adjustment system 1 having the above-described configuration will be described. The optical axis adjustment process is appropriately performed, for example, at the start of the substrate bonding operation described with reference to FIG. 2, or when a preset number of lots have been processed. The worker first returns the alignment mechanism 100 to the reference position, and returns the gimbal mechanism 301 to the reference tilt angle. Next, the worker places the mirror 11 with the mirror surface 11a facing up at approximately the center of the mounting table 101. Next, the worker places the jig 12 at approximately the center of the mirror 11. In this example, the jig 12 is placed on the mirror 11 with the support portion 12b oriented to extend in the X-axis direction. As a result, the mirror 11 and the jig 12 are placed within the shooting range Ar of the imaging device 300.

[0054] Next, the operator transmits a command to start the optical axis adjustment control process from the setting terminal 500 to the image processing unit 400. In response to the command, the image processing unit 400 transmits a command to the imaging device 300 to instruct the imaging device 300 to start imaging. In response to the command, the imaging device 300 starts imaging, and as shown in Fig. 10, the image acquisition unit 411 acquires the captured image from the imaging device 300 (step S101). The imaging device 300 captures images at a predetermined time interval. The imaging device 300 captures images at intervals of, for example, 10 ms (milliseconds).

[0055] The adjustment information calculation unit 414 uses image processing technology to obtain the coordinates of the center point Hp of the real image of the guide 12a in the captured image. The adjustment information calculation unit 414 outputs the obtained coordinates of the center point Hp of the real image of the guide 12a to the operation control unit 200.

[0056] The movement amount calculation unit 212 in the motion control unit 200 calculates the amount by which the mirror 11 should be moved in order to move the center point Hp of the real image to the center of the captured image. The amount by which the mirror 11 should be moved is calculated by the difference between the coordinates (Xr, Yr) of the center point Hp of the real image on the image and the coordinates (0, 0) of the center point of the captured image. The command unit 213 in the motion control unit 200 issues a command to move the center point Hp of the real image to the center of the captured image (step S102). Specifically, the motion control unit 200 outputs control signals to the drive control devices 121, 122, and 123 to realize movements in each direction. Then, the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113 move the mounting table 101 on which the mirror 11 is mounted, under the control of the drive control devices 121, 122, and 123 based on the control signals.

[0057] After moving the mounting table 101, the image acquisition unit 411 acquires a captured image from the imaging device 300 (step S103). The adjustment information calculation unit 414 uses an image processing technique to determine the coordinates of the center point Hp of the real image of the guide 12a in the captured image and the coordinates of the center point Hp of the mirror image of the guide 12a. Note that the center point Hp of the real image of the guide 12a has moved to the center (0,0) of the captured image by the process of step S102.

[0058] The adjustment information calculation unit 414 calculates the distance L between the coordinates (Xr, Yr) on the image of the center point Hp of the real image of the guide 12a and the coordinates (Xi, Yi) on the image of the center point Hp of the mirror image of the guide 12a, as follows: L=√{(Xr-Xi) 2 +(Yr-Yi) 2 It is determined whether or not {Lr} is equal to or less than a predetermined reference distance Lr (step S104).

[0059] If it is determined that the distance L>Lr (step S104: No), the command section 213 in the motion control unit 200 sends a command to the drive control device 321 to move the coordinates (Xi, Yi) of the center point Hp of the mirror image to the center coordinates (0, 0) of the captured image (step S105).

[0060] Drive control device 321 drives gimbal drive unit 311 in accordance with the command to control gimbal mechanism 301 and adjust tilt angles φx, φy of image capture device 300. For example, in the case of right-handed coordinate system, to adjust the tilt of image capture device 300 and move it to the origin, if the X coordinate is positive, it is an instruction to rotate in the positive direction around the Y axis. Also, if the Y coordinate is positive, it is an instruction to rotate in the negative direction around the X axis.

[0061] When the tilt angle of the imaging device 300 is adjusted by the process of step S105, the center point of the real image of the guide 12a moves from the image center. Therefore, the process returns to step S101, the process of acquiring the captured image (step S101) is performed, and a command process of moving the center point of the real image to the image center is performed again (step S102). Then, after the process of step S103, the processes of steps S101 to S105 are repeated until it is determined in step S104 that the distance between the center of the real image and the center of the mirror image is within a predetermined distance range (step S104: Yes).

[0062] On the other hand, if it is determined that the distance L≦Lr (step S104: Yes), it can be said that the real image and the mirror image of the guide 12b are substantially overlapping and formed, although there is a difference in the distance between the real image center and the mirror image center. As described with reference to FIG. 4, in this state, the optical axis of the imaging device 300 passes through the center point Hp of the guide 12a, and the optical axis and the mirror surface 11a of the mirror 11 are perpendicular. In addition, since the mirror surface 11a and the mounting surface 102 are parallel, the optical axis of the imaging device 300 and the mounting surface 102 are perpendicular. Therefore, the optical axis adjustment control process ends.

[0063] The image processing unit 400 notifies the operator via the setting terminal 500 that the optical axis adjustment has been completed. In response to the notification, the worker removes the mirror 11 and the jig 12 from the mounting table 101, and the operation proceeds to the normal substrate bonding process.

[0064] As described above, in the optical axis adjustment system 1 according to this embodiment, the mirror 11 and the jig 12 are placed on the mounting table 101, the guide 12a of the jig 12 is photographed by the imaging device 300, and the alignment mechanism 100 and the imaging device 300 are adjusted so that the center point of the real image of the guide 12a and the center point of the mirror image coincide with each other at the center of the image, thereby performing optical axis adjustment of the imaging device 300. Therefore, optical axis adjustment can be easily performed so that the optical axis of the imaging device 300 and the mounting surface 102 of the mounting table 101 are perpendicular to each other.

[0065] (Modification of the first embodiment) In the first embodiment, the guide 12a is circular, but is not limited to a circular shape. It may be any other shape that can identify a feature point, such as a center point or a center of gravity point, such as a square or a triangle. Also, for example, the guide 12a may not be disposed, and the tip of the support part 12b may be used as the feature point. In addition, any point can be used as the feature point as long as the position on the real image and the position on the mirror image coincide and overlap when the optical axis of the imaging device 300 is perpendicular to the placement surface 102. Also, the shape, structure, number, etc. of the support part 12b, the leg part 12c, and the column part 12d are arbitrary within a range in which the guide 12a is separated by a certain distance from the mirror surface 11a and the imaging device 300 can observe the real image and the mirror image of the guide 12a. In addition, in the first embodiment, the positions of the real image and mirror image of the guide 12a are adjusted to be the center of the image element 302. Here, the "center" does not mean the strict center or center, but means a central portion that includes the center and its preset peripheral portion to an extent that adverse effects on the optical axis adjustment are sufficiently small.

[0066] In the first embodiment, whether or not the real image and the mirror image of the guide 12a overlap is determined based on whether or not the distance L between the center points Hp of the real image and the mirror image of the guide 12a is equal to or less than the reference value Lr. This disclosure is not limited to this. For example, the guide 12a may be shaped so that the real image and the mirror image match, and whether or not the real image and the mirror image overlap may be determined based on whether or not the imaging pattern of the real image and the imaging pattern of the mirror image match. In addition, it may be determined by any method that the real image and the mirror image of the guide 12a overlap and the optical axis of the imaging device 300 is perpendicular to the imaging target surface, the mirror surface 11a, and the placement surface 102.

[0067] In the first embodiment, the adjustment amount of the angle of the imaging device 300 is the amount by which the center point of the mirror image of the guide 12a moves to the image center, but the present disclosure is not limited to this. For example, the initial angle adjustment amount of the imaging device 300 may be a value larger than the amount by which the center point of the mirror image of the guide 12a moves to the image center, for example, 2 times, 1.5 times, etc. By setting such a movement amount, the mirror 11 is translated and the angle adjustment of the imaging device 300 is repeated to asymptotically approach the image center, so that the initial large swing width reduces the number of trials.

[0068] In addition, in the process of adjusting the angle of the imaging device 300, the imaging magnification of the imaging device 300 may be lowered to a magnification lower than that during normal processing so as to enable more precise adjustment. For example, the position of the mirror image center is initially (X, Y) = (30, 20), and the angle is adjusted to the position of the image center (X, Y) = (0, 0) at a high magnification of about (a, b) = (-20 x 5, 30 x 5). When the position of the mirror image center approaches (X, Y) = (6, 4), the magnification may be lowered and adjusted to (a, b) = (-4 x 2, 6 x 2) so as not to overshoot. The calculation of (a, b) may use a unit vector that expresses only a direction without distance information, instead of (conversion value of the position of the mirror image center x magnification), and in that case, the angle may be adjusted by multiplying it by a magnification proportional to the distance to the center of the mirror image (unit vector x magnification).

[0069] Furthermore, instead of directly supplying information regarding the parallel movement of mirror 11 or the angle adjustment of imaging device 300 to drive control devices 121-123 and 321, the information may be displayed on the screen of setting terminal 500 and communicated to the adjustment operator, who may then instruct the amount of movement, etc., from setting terminal 500.

[0070] For example, as illustrated in Fig. 11, the direction in which the center point of the guide 12a moves when the X-axis drive unit 111 and the Y-axis drive unit 112 are operated may be displayed on the edge of the screen or the like. Also, the amount of movement to the center point of the image, which is the intersection of the X-axis and the Y-axis, may be displayed near the real image of the guide 12a or the like. In the example shown in Fig. 11, it is displayed that the X-axis drive unit 111 should be moved 26 in the plus direction and the Y-axis drive unit 112 should be moved 29 in the minus direction. Also, dotted line guidelines are displayed to make it easy to understand the center of the image and the movement directions of the X-axis drive unit 111 and the Y-axis drive unit 112.

[0071] Also, as shown in Fig. 12, for example, the direction and amount of movement of the real image and mirror image of the guide 12a by operating the gimbal driving unit 311 may be displayed on the edge of the screen. In the example of Fig. 12, the instruction is to adjust the angle of the imaging device 300 to the right and toward the front. When an operation based on this instruction is performed, the position of the mirror image of the guide 12a moves to the center of the image. The numerical value is the adjustment amount calculated from the number of pixels from the center of the image to the center point of the mirror image of the guide 12a, and if the calibration of the angle and number of pixels of the imaging device 300 has been completed, the numerical value will be in accordance with the calibration.

[0072] 11 and 12, the adjustment operator can instruct the translation of mirror 11 and the angle adjustment of imaging device 300 from setting terminal 500. In this case, image processing unit 400 transmits control signals according to the instructions to drive control devices 121-123 and 321 via motion control unit 200.

[0073] In addition, the angle adjustment of the imaging device 300 is performed manually by an operator, and the parallel movement to move the center point of the real image of the guide 12a to the center of the image may be achieved by a movement command issued from the command unit 213 to the drive control devices 121-123, and the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113.

[0074] The moving stage for the parallel movement of mirror 11 in optical axis adjustment system 1, in other words the XY-θ stage, may be realized in any manner as long as it has the function of moving the center point of guide 12a to the center of the image. For example, the movement command for the parallel movement of mirror 11 may be a command value for the composite movement of each drive unit, rather than the movement amount of each drive unit in the X-axis direction, Y-axis direction, or around the θ-axis.

[0075] In the optical axis adjustment system 1 according to the first embodiment, the optical axis adjustment is performed based on the real image of the guide 12a, but the optical axis adjustment may be performed based on the mirror image of the guide 12a. The real image and the mirror image are interchangeable in the optical axis adjustment of the present disclosure, and either one may be used as a reference for the optical axis adjustment.

[0076] Furthermore, any configuration may be used as long as it is possible to control the relative position between imaging device 300 and mirror surface 11a of mirror 11, in other words, to adjust the relative movement and tilt. For example, a configuration opposite to that of embodiment 1 may be used. Specifically, a translation drive unit may be provided on the imaging device 300 side, and a goniostage capable of adjusting the tilt may be disposed on the mirror 11 side.

[0077] Furthermore, the installation direction of the imaging device 300 may be changed from that of the first embodiment by using a mirror, a prism, a lens, or the like for the optical system of the imaging device 300. Furthermore, multiple image elements may be used, and optical axis adjustment may be performed between the imaging device 300, which is an integrated unit of multiple image elements, and the imaging surface. When different image elements are used, for example, light is split by a beam splitter and an image is formed on two image elements. In this case, the optical system is common, and there is one angle adjustment. Calibration of the multiple image elements in the device is performed separately.

[0078] In the optical axis adjustment control process according to the first embodiment, the optical axis adjustment control process is terminated when the coordinate distance on the image between the real image center Hp and the mirror image center Hp is within a predetermined distance range. The present disclosure is not limited to this. For example, the process may be terminated when the movement process in steps S102 and S105 is executed a predetermined number of times. The process may also be terminated when the movement amount per time falls within a reference range.

[0079] In the optical axis adjustment control process according to the first embodiment, in step S104, it is determined whether or not the end condition is satisfied, and when it is determined that the end condition is satisfied, the optical axis adjustment control process is automatically terminated. The present disclosure is not limited to this. The adjustment operator may determine whether or not to terminate the optical axis adjustment control process. For example, in step S104 of the optical axis adjustment control process in FIG. 10, as illustrated in FIG. 11 and FIG. 12, the coordinate position of the real image center Hp and the coordinate position of the mirror image center Hp are displayed on the setting terminal 500, and when the adjustment operator determines that the distance between them is within a predetermined range, the optical axis adjustment control process may be terminated by instructing the setting terminal 500 to terminate the process.

[0080] When the optical axis adjustment control process is completed, the movement amount calculation unit 212 may record or display the magnitude of the error contained in the adjusted optical axis. Here, unless estimation is done through image processing such as averaging, quantization errors remain, which means that image recognition cannot recognize changes smaller than one pixel. Although the minimum recognition accuracy differs depending on the image recognition algorithm, the amount of change per pixel can serve as a guide. 10, the optical axis adjustment control process is terminated when the distance L between the real image center Hp and the mirror image center Hp is within a predetermined range. Therefore, if the maximum number of pixels in the predetermined range, i.e., the reference value, is Tn, the distance L includes an error of up to Tn pixels. Therefore, for example, the movement amount calculation unit 212 may obtain Tn×(movement distance of the mounting table 101 per pixel) as the maximum error ΔL in the optical axis adjustment process, and record the obtained maximum error ΔL in the control data storage unit 432 of the image processing unit 400, or record or display it in the setting terminal 500.

[0081] Similarly, the movement amount calculation unit 212 may calculate the change Δφ in the angle φ of the imaging device 300 per pixel, and record or display the product of the calculated change Δφ and a predetermined reference value Tn as the maximum value of the remaining possible tilt of the optical axis. For example, regarding the tilt angle φ of the imaging device 300, the amount of angle change per pixel can be calculated based on the amount of angle adjustment and the amount of movement of the center point of the mirror image of the guide 12a in the image. This is an example that focuses only on the angle adjustment of the imaging device 300, separate from the translation of the mirror 11. For example, if the center point of the mirror image moves by 5 pixels in the Y-axis direction due to an angle adjustment of 0.01 degrees around the X-axis, the amount of angle change per pixel is calculated as 0.01 / 5. For example, the maximum value of the error contained in the optical axis thus obtained may be associated with the product lot of the processing performed using that optical axis, and the associated value may be recorded in the control data storage section 432 of the image processing unit 400, or may be displayed on the setting terminal 500, and used for subsequent defect analysis, etc., to enable the relationship between defects and the accuracy of the optical axis to be analyzed.

[0082] (Embodiment 2) A second embodiment for carrying out the present disclosure will be described below with reference to the drawings, in which the same or corresponding parts are denoted by the same reference numerals.

[0083] The overall configuration and the hardware configuration of each part of the optical axis adjustment system 1 according to the second embodiment are similar to those of the first embodiment. The optical axis adjustment system 1 according to the second embodiment is different from the first embodiment in that the optical axis adjustment control process shown in Fig. 13 is performed instead of the optical axis adjustment control process shown in Fig. 10. The second embodiment will be described below, focusing on the differences from the first embodiment.

[0084] The optical axis adjustment control process according to the second embodiment will be described below with reference to FIGS.

[0085] 13 are the same as those in embodiment 1. After the process of step S102, movement amount calculation unit 212 stores the translation amount of mirror 11 in step S102 in control data storage unit 232 (step S211). The translation amount of mirror 11 is periodically stored in control data storage unit 232.

[0086] After step S211, through step S103 similar to that of the first embodiment, the adjustment information calculation unit 414 stores the position of the center point Hp of the mirror image of the guide 12a, for example, point a1 shown in FIG. 14, in the control data storage unit 432 (step S212). Note that the position of the center point Hp of the mirror image is accumulated rather than updated even if the process of step S212 is repeated thereafter. The position of the center point Hp of the mirror image is periodically stored in the control data storage unit 432.

[0087] After step S212, the process of step S104 is performed similarly to that of embodiment 1. In step S104, if it is determined that the distance L between the position of the center point Hp of the real image and the position of the center point Hp of the mirror image is equal to or less than the reference value Lr (step S104: Yes), the optical axis adjustment control process ends similarly to embodiment 1.

[0088] If it is determined in step S104 that the distance L between the position of the center point Hp of the real image and the position of the center point Hp of the mirror image is greater than the reference value Lr (step S104: No), the adjustment information calculation unit 414 determines whether the number of center points of the mirror image stored in step S212 is two or more (step S213). At this point, the center point of the stored mirror image is one, point a1 shown in FIG. 14. Therefore, it is determined that the number of center points of the stored mirror image is not two or more (step S213: No), and the process proceeds to step S105. The process in step S105 is the same as in the first embodiment.

[0089] After the process of step S105, the movement amount calculation unit 212 stores the angle adjustment amount of the imaging device 300 in step S105 in the control data storage unit 232 (step S215). Note that the angle adjustment amount of the imaging device 300 is periodically stored in the control data storage unit 232. After step S215, the process returns to step S101, and the processes of steps S101, S102, S211, and S103 are performed.

[0090] After step S103, in step S212, the adjustment information calculation unit 414 stores the position of the center point of the mirror image, for example, point a2 shown in Fig. 14, in the control data storage unit 432 (step S212). After step S212, if it is determined in step S104 that the distance L between the position of the center point Hp of the real image and the position of the center point Hp of the mirror image is greater than the reference value Lr (step S104: No), the process proceeds to step S213.

[0091] Here, since the center points Hp of the mirror image guide 12a are the two points a1 and a2 shown in FIG. 14, it is determined that the number of stored center points Hp of the mirror image guide 12a is two or more (step S213: Yes).

[0092] The adjustment information calculation unit 414 obtains the adjustment rate α (step S214). Here, the adjustment rate α means a ratio for adjusting the amount of parallel movement of the mirror 11 and the amount of angle adjustment of the imaging device 300. Specifically, the adjustment rate α is obtained by a formula that determines how many times the distance from the center point Hp position of the current mirror image to the image center position is the difference between the position of the center point Hp of the current mirror image and the position of the center point Hp of the previous mirror image. For example, in the case of FIG. 14, if the distances from the image center to points a1 and a2 are distances d1 and d2, respectively, the adjustment rate α is obtained by α=d2 / (d1-d2). The adjustment rate α is output to the motion control unit 200.

[0093] After step S214, the process proceeds to step S105. When the process of step S105 is performed after step S214, the movement amount calculation unit 212 obtains a new angle adjustment amount by multiplying the angle adjustment amount stored in the control data storage unit 232 by the adjustment rate α calculated in step S214. Based on the new angle adjustment amount, the command unit 213 sends a command to the drive control device 321 to move the mirror image (step S105). The drive control device 321 controls the gimbal drive unit 311 based on the control signal from the command unit 213.

[0094] The movement amount calculation unit 212 stores the angle adjustment amount of the imaging device 300 in step S105 in the control data storage unit 232 (step S215). After step S215, the process returns to step S101, and the process of step S101 is performed.

[0095] After step S101, the movement amount calculation unit 212 obtains a new translation amount by multiplying the translation amount stored in the control data storage unit 232 by the adjustment rate α calculated in step S214. Based on the new translation amount, the command unit 213 sends a command to move the real image to the drive control devices 121, 122, and 123 (step S102). The drive control devices 121, 122, and 123 control the X-axis drive unit 111, the Y-axis drive unit 112, and the θ drive unit 113 based on the control signal from the command unit 213.

[0096] Movement amount calculation section 212 stores the translation amount of mirror 11 obtained in step S102 in control data storage section 232 (step S211). After step S211, the process proceeds to step S212 via step S103.

[0097] In step S212, the adjustment information calculation unit 414 stores the position of the center point Hp of the mirror image, for example, point a3 shown in FIG. 14, in the control data storage unit 432 (step S212). If it is determined that the distance L between the position of the center point Hp of the real image and the position of the center point Hp of the mirror image is equal to or less than the reference value Lr (step S104: Yes), the optical axis adjustment control process ends. If it is determined that the distance L is greater than the reference value Lr (step S104: No), the processes of steps S213 to S214, S105, S215, S101, S102, S211, S103, S212, and S104 are repeated.

[0098] As described above, in the optical axis adjustment control process of the second embodiment, the adjustment information calculation unit 414 calculates the adjustment rate α based on the position of the center point Hp of the mirror image of the guide 12a when the center point Hp of the real image of the guide 12a is moved to the image center. The movement amount calculation unit 212 multiplies the previous translation amount of the mirror 11 by the adjustment rate α to calculate a new translation amount. In addition, the movement amount calculation unit 212 multiplies the previous angle adjustment amount of the imaging device 300 by the adjustment rate α to calculate a new angle adjustment amount. The translation of the mirror 11 based on the new translation amount and the angle adjustment of the imaging device 300 based on the new angle adjustment amount can reduce the number of trials of the optical axis adjustment.

[0099] (Modification of the second embodiment) The optical axis adjustment control process may be performed from both positive and negative directions, and the midpoint between the positions where the adjustment is completed may be set as the final adjustment position. Specifically, for example, as shown in FIG. 15, when the angle adjustment is performed around the X-axis and Y-axis of the image, the first optical axis adjustment control moves to points a1, . . . , a4, and both X and Y on the image element approach the image center from the positive direction. In the second optical axis adjustment control, the point moves to points b1, . . . , b4, and both approach the image center from the negative direction. The midpoint between point a4, which is the final position of the first optical axis adjustment control, and point b4, which is the final position of the second optical axis adjustment control, may be set as the final position. For example, due to quantization error of the image element 302, an error may remain when the adjustment work is performed only from one direction. By performing the adjustment control from both the positive and negative directions and setting the midpoint therebetween as the final adjustment position, the accuracy of the optical axis adjustment work is improved.

[0100] Various embodiments and modifications are possible without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are for explaining the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and the scope of the disclosure equivalent thereto are considered to be within the scope of the present disclosure. [Explanation of symbols]

[0101] 1 Optical axis adjustment system, 11 Mirror, 11a Mirror surface, 11b Back surface, 12 Jig, 12a Guide, 12b Support portion, 12c Leg portion, 12d Pillar portion, 100 Alignment mechanism, 101 Placement table, 102 Placement surface, 111 X-axis drive portion, 112 Y-axis drive portion, 113 θ drive portion, 121, 122, 123, 321 Drive control device, 200 Motion control unit, 210 Processor, 212 Movement amount calculation portion, 213 Command portion, 220 Volatile memory, 230 Non-volatile memory, 231 Control program storage portion, 232 Control data storage portion, 240 Clock, 250 Communication interface, 300 Imaging device, 301 Gimbal mechanism, 302 Image element, 304 Lens, 311 Gimbal drive portion, 400 Image processing unit, 410 processor, 411 image acquisition unit, 414 adjustment information calculation unit, 420 volatile memory, 430 non-volatile memory, 431 control program storage unit, 432 control data storage unit, 440 communication interface, 500 setting terminal, 1001, 1002 work, a1, a2, a3, a4, b1, b2, b3, b4 points, LC center, VL perpendicular line, Ax1, Ax2 light ray, Ag vertical direction, Ar shooting range, B1, B2 bus, d1, d2 distance, HP center point, tip, φx, φy tilt angle, Mk marker.

Claims

1. An optical axis adjustment system for adjusting an imaging target surface of an imaging device and an optical axis of the imaging device, a mirror is disposed on the imaging target surface, and a jig used for adjustment is disposed on a mirror surface of the mirror, the jig including a guide that can be imaged by the imaging device, and a support portion that supports the guide at a position a predetermined distance away from the mirror surface; an imaging target surface drive unit that moves an imaging target surface on which the mirror is placed; an imaging device driving unit that moves the imaging device; a control means for controlling the imaging target surface driving unit or the imaging device driving unit so that positions of specific feature points derived from a real image and a mirror image of the guide coincide with each other on an image captured by the imaging device; a storage means for storing an adjustment amount of the movement amount or the tilt angle of the imaging object surface driving unit or the imaging device driving unit; Equipped with the control means moves one of the image capture target surface and the imaging device in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, or adjusts an inclination angle of the other of the image capture target surface and the imaging device so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and then further the control means moves one of the image capture target surface and the image capture device at least once in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, and stores the amount of movement in the storage means; and adjusts the tilt angle of the other of the image capture target surface and the image capture device at least once so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and stores the adjustment amount of the tilt angle in the storage means; and then further the control means determines a position of one of the real image and the mirror image, determines an adjustment rate representing a ratio of adjusting the amount of movement required to move the position of one of the real image and the mirror image to the center of the captured image based on the determined position of the one and a position of the one determined a predetermined period before the determination time, and controls the imaging target surface driving unit or the imaging device driving unit to move the position of the feature point to the center of the captured image based on the determined adjustment rate and the amount of movement or adjustment stored in the storage means. Optical axis adjustment system.

2. An optical axis adjustment system for adjusting an imaging target surface of an imaging device and an optical axis of the imaging device, a mirror is disposed on the imaging target surface, and a jig used for adjustment is disposed on a mirror surface of the mirror, the jig including a guide that can be imaged by the imaging device, and a support portion that supports the guide at a position a predetermined distance away from the mirror surface; an imaging target surface drive unit that moves an imaging target surface on which the mirror is placed; an imaging device driving unit that moves the imaging device; A control means for controlling the imaging target surface driving unit or the imaging device driving unit so that a real image of the guide and a mirror image of the guide reflected on the mirror surface of the guide overlap on an image captured by the imaging device; Equipped with The control means moves one of the imaging target surface drive unit and the imaging device drive unit in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, and then When it is determined that the real image of the guide and the mirror image of the guide do not overlap, the control means adjusts the tilt angle of the other of the imaging target surface drive unit and the imaging device drive unit so as to move the other of the real image and the mirror image to the center of the captured image, the control means determines a position of one of the real image and the mirror image, and determines an adjustment rate representing a rate at which to adjust a movement amount required to move the position of one of the real image and the mirror image to the center of the captured image, based on the determined position of the one and a position of the one determined a predetermined period before the determination time; the control means moves one of the imaging subject surface drive unit and the imaging device drive unit in a horizontal direction so as to move the position of one of the real image and the mirror image to the center of the captured image based on the adjustment ratio and a distance between the position of one of the real image and the mirror image and the center of the captured image; the control means adjusts the tilt angle of the other of the imaging subject surface drive unit and the imaging device drive unit so as to move the position of the other of the real image and the mirror image to the center of the captured image based on the adjustment rate and a distance between the position of the other of the real image and the mirror image and the center of the captured image. Optical axis adjustment system.

3. The control means A distance between the real image of the guide and the mirror image of the guide is obtained, and when the distance is equal to or smaller than a reference value, the process of adjusting the optical axis is terminated. the product of the reference value and a moving distance or a tilt angle of the imaging target surface per pixel of the captured image; The product of the reference value and the moving distance or tilt angle of the imaging device per pixel of the captured image is recorded as a maximum error. The optical axis adjustment system according to claim 2 .

4. A mirror is disposed above a surface to be imaged, and a guide is disposed above the mirror and spaced apart from the mirror; determining a position of a real image and a position of a mirror image of the guide on an image captured by an imaging device; controlling a relative position between the image pickup target surface and the image pickup device so that positions of specific feature points derived from the real image and the mirror image on the captured image coincide with each other; One of the image pickup target surface and the imaging device is moved in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, or the tilt angle of the other of the image pickup target surface and the imaging device is adjusted so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and then one of the image pickup surface and the imaging device is moved in a horizontal direction at least once so as to move one of the real image and the mirror image of the guide to the center of the captured image, and the amount of movement is stored; and the other of the image pickup surface and the imaging device is adjusted in tilt angle at least once so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and the amount of adjustment of the tilt angle is stored; and a position of one of the real image and the mirror image is obtained, an adjustment ratio is obtained that represents a ratio of adjusting the amount of movement required to move the position of one of the real image and the mirror image to the center of the captured image based on the obtained position of the one and a position of the one obtained a predetermined period before the time of the determination, and a relative position between the image capture target surface and the imaging device is controlled so as to move the position of the feature point to the center of the captured image based on the obtained adjustment ratio and the stored amount of movement or adjustment amount. Optical axis adjustment method.

5. On the computer, determining a position of a real image and a position of a mirror image of the guide on an image of an imaging target surface on which the mirror and the guide are arranged, the image being captured by an imaging device; controlling a relative position between the image pickup target surface and the image pickup device so that positions of specific feature points derived from the real image and the mirror image on the captured image coincide with each other; One of the image pickup target surface and the imaging device is moved in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, or the tilt angle of the other of the image pickup target surface and the imaging device is adjusted so as to move the other of the real image and the mirror image of the guide to the center of the captured image, and then the control means moves one of the image capture target surface and the image capture device at least once in a horizontal direction so as to move one of the real image and the mirror image of the guide to the center of the captured image, stores the amount of movement, and adjusts the tilt angle of the other of the image capture target surface and the image capture device at least once so as to move the other of the real image and the mirror image of the guide to the center of the captured image, stores the adjustment amount of the tilt angle, and then a position of one of the real image and the mirror image is obtained, an adjustment ratio is obtained that represents a ratio of adjusting the amount of movement required to move the position of one of the real image and the mirror image to the center of the captured image based on the obtained position of the one and a position of the one obtained a predetermined period before the time of the determination, and a relative position between the image capture target surface and the imaging device is controlled so as to move the position of the feature point to the center of the captured image based on the obtained adjustment ratio and the stored amount of movement or adjustment amount. A program that executes a process.

Images