JP2015210396A - Aligment device, microscope system, alignment method and alignment program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alignment device and the like that can acquire a tracing of a relative movement between a loading surface of a subject and an imaging device without providing a dedicated mechanism for alignment.SOLUTION: An alignment device comprises: an imaging optical system that is provided in such a manner that an optical axis tilts at a prescribed angle relative to a normal line of a planar object plane; movement means that relatively moves the object plane and the imaging optical system in a direction where a tilt direction of the optical axis is projected to the object plane; an imaging control unit 22 that causes the imaging optical system to execute photographing at first and second locations where a relative location with the object plane is mutually different, and thereby causes the imaging optical system to acquire first and second images corresponding to the first and second locations, respectively; and a straightness detection unit 233 that compares first and second in-focus areas respectively detected from the first and second images to thereby detect a tracing of the relative movement between the object plane and the imaging optical system.

Description

  The present invention relates to an alignment apparatus that detects straightness in relative motion between a mounting surface of an object and an imaging apparatus, a microscope system to which the alignment apparatus is applied, an alignment method, and an alignment program.

  In recent years, circuit pattern detection on a wafer in LSI manufacturing, measurement by various measuring devices, observation of a wide field of view of a sample by a microscope, and the like are performed using an image obtained by copying an inspection target or a sample using an imaging device. Yes. At this time, the inspection object or specimen is placed on the electric stage, and the electric stage is moved relative to the imaging apparatus, whereby the field of view of the imaging apparatus, that is, the inspection (measurement) position on the inspection object. And change the observation position on the specimen.

  The parallelism of the movement when the electric stage is translated in each of the XYZ directions is generally expressed by straightness. Straightness refers to the magnitude of deviation (variation) from the geometric line of a moving part that should move straight. This straightness is never completely zero due to the characteristics of the moving mechanism. For example, when the electric stage is translated in the XY plane, a fluctuation (blur) of several μm level also occurs at the Z position of the electric stage. However, when such fluctuations occur, detection errors, measurement errors, observation position errors, and the like may occur, and accurate information may not be acquired. For this reason, it is necessary to grasp the movement trajectory in a direction other than the traveling direction of the electric stage, and to perform adjustment for reducing unintended fluctuations of the electric stage based on the movement trajectory.

  As a technique related to straightness, Patent Document 1 discloses that a speckle image is generated by irradiating a laser on the surface of a linear movement mechanism, and the correlation displacement of the speckle image according to the movement of the linear movement mechanism. A technique for acquiring straightness based on the above is disclosed.

JP 2009-68957 A

  In Patent Document 1, a dedicated mechanism including a dedicated light source (laser) is provided in order to detect the straightness of the electric stage. However, when such a dedicated mechanism is provided on the electric stage, the apparatus configuration becomes complicated. In particular, it is difficult to provide a dedicated light source such as a laser on an electric stage of a commonly used microscope.

  The present invention has been made in view of the above, and an alignment apparatus that can acquire a trajectory of relative movement between an object mounting surface and an imaging apparatus without providing a dedicated mechanism for alignment, and the alignment apparatus An object of the present invention is to provide a microscope system, an alignment method, and an alignment program.

  In order to solve the above-described problems and achieve the object, the alignment apparatus according to the present invention is an imaging optical device provided such that the optical axis is inclined at a predetermined angle with respect to a normal line of a planar object surface. A first moving unit that moves the object plane and the imaging optical system relative to each other in a direction in which the tilt direction of the optical axis is projected onto the object plane, and the relative positions of the object plane are different from each other. An imaging control unit that acquires the first and second images respectively corresponding to the first and second positions by causing the imaging optical system to perform imaging at the two positions; and the first and second A detection unit configured to detect a locus of relative movement between the object plane and the imaging optical system by comparing the first and second focus areas respectively detected from the images;

  The alignment apparatus further includes a stage having a placement surface on which a subject is placed, and the moving unit relatively moves the object surface and the imaging optical system in a plane parallel to the placement surface. The detecting unit detects a relative displacement between the object plane and the imaging optical system in a normal direction of the mounting surface.

  In the alignment apparatus, the optical axis of the imaging optical system forms the angle with respect to the normal of the mounting surface, and the mounting optical system is parallel to the mounting surface. Imaging is performed using the surface of a subject placed on a surface as the object surface.

  In the alignment apparatus, an optical axis of the imaging optical system is orthogonal to the placement surface, and the imaging optical system is placed on the placement surface so as to form the angle with respect to the placement surface. Imaging is performed using the surface of the subject as the object plane.

  In the alignment apparatus, the detection unit detects a change in position in the image of the first and second in-focus areas detected from the first and second images, respectively, and based on the change in the position The trajectory is detected.

  In the alignment apparatus, the detection unit detects a change in the width of the first and second focus areas detected from the first and second images, respectively, and based on the change in the width, The apparatus further includes an adjusting unit that adjusts a relative position between the object plane and the imaging optical system in the normal direction of the mounting surface.

  The alignment apparatus further includes a calibration unit that calibrates relative movement between the object plane and the imaging optical system by the moving unit based on the locus detected by the detection unit.

  The alignment apparatus further includes a display unit that displays information for calibrating a relative motion between the object plane and the imaging optical system by the moving unit based on the locus detected by the detection unit. Features.

  A microscope system according to the present invention includes the alignment apparatus.

  The alignment method according to the present invention includes an installation step of providing an imaging optical system so that an optical axis is inclined at a predetermined angle with respect to a normal line of a planar object surface, and an inclination direction of the optical axis is set to the object surface A moving step of moving the object plane and the imaging optical system relative to each other in a direction projected onto the imaging plane, and causing the imaging optical system to perform imaging at first and second positions where the relative positions of the object plane and the object plane are different from each other. Thus, the imaging control step for acquiring the first and second images corresponding to the first and second positions, respectively, and the first and second couplings detected from the first and second images, respectively. And a detection step of detecting a locus of relative movement between the object plane and the imaging optical system by comparing focal areas.

  An alignment program according to the present invention includes: a planar object surface; and an imaging optical system provided so that an optical axis is inclined at a predetermined angle with respect to a normal line of the planar object surface. A movement control step for performing a relative movement of the tilt direction of the optical axis in the direction projected onto the object plane, and imaging with the imaging optical system at first and second positions where the relative positions with respect to the object plane are different from each other. An imaging control step for acquiring first and second images corresponding to the first and second positions, respectively, and first and second detected from the first and second images, respectively. And a detection step of detecting a locus of relative movement between the object plane and the imaging optical system by comparing the in-focus areas.

  According to the present invention, since the imaging is performed at the first and second positions with the optical axis of the imaging optical system being inclined with respect to the object plane, the imaging is performed between the object plane and the first and second positions. When a change occurs in the relative distance from the optical system, the change can be detected as a change in the first and second focus areas detected from the first and second images, respectively. Therefore, it is possible to obtain a locus of relative movement between the subject placement surface and the imaging device without providing a dedicated mechanism for alignment.

FIG. 1 is a block diagram showing a configuration example of a microscope system according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram illustrating a configuration example of the microscope apparatus illustrated in FIG. 1. FIG. 3 is a schematic diagram for explaining the principle of the alignment method according to the first embodiment of the present invention. FIG. 4 is a schematic diagram for explaining the principle of the alignment method according to the first embodiment of the present invention. FIG. 5 is a schematic diagram for explaining the principle of the alignment method according to the first embodiment of the present invention. FIG. 6 is a schematic diagram for explaining the principle of the alignment method according to the first embodiment of the present invention. FIG. 7 is a schematic diagram showing an example of a subject used in the alignment method according to Embodiment 1 of the present invention. FIG. 8 is a schematic diagram illustrating an imaging method when imaging a subject in the alignment method according to the first embodiment. FIG. 9 is a schematic diagram illustrating an imaging method when an object is imaged in the alignment method according to the first embodiment. FIG. 10 is a schematic diagram illustrating an imaging method when imaging a subject in the alignment method according to the first embodiment. FIG. 11 is a schematic diagram illustrating an imaging method when imaging a subject in the alignment method according to the first embodiment. FIG. 12 is a flowchart showing the alignment method according to the first embodiment of the present invention. FIG. 13 is a schematic diagram illustrating the moving direction (X direction) of the observation visual field with respect to the subject. FIG. 14 is a schematic diagram showing the moving direction (Y direction) of the observation field with respect to the subject. FIG. 15 is a schematic diagram illustrating an observation visual field when imaging is performed in raster order. FIG. 16 is a flowchart showing a focus area detection process executed by the focus area detection unit shown in FIG. FIG. 17 is a schematic diagram showing an example in which an image showing the observation field of view is divided into 36 small regions. FIG. 18 is a schematic diagram of an edge image showing edges extracted from one small region shown in FIG. FIG. 19 is a schematic diagram for explaining a method of selecting a focus area. FIG. 20 is a schematic diagram illustrating an example in which an in-focus area is selected from the image illustrated in FIG. FIG. 21 is a schematic diagram illustrating the comparison process of the focus area executed by the focus position comparison unit illustrated in FIG. 1. FIG. 22 is a flowchart showing a straightness characteristic detection process executed by the straightness characteristic detection unit shown in FIG. FIG. 23 is a block diagram showing a configuration of a microscope system according to Modification 1-4 of Embodiment 1 of the present invention. FIG. 24 is a block diagram showing a configuration of a microscope system according to Embodiment 2 of the present invention. FIG. 25 is a flowchart showing an alignment method according to Embodiment 2 of the present invention. FIG. 26 is a schematic diagram for explaining an imaging range setting method. FIG. 27 is a schematic diagram illustrating a display example of the straightness characteristic displayed on the display device illustrated in FIG. 24. FIG. 28 is a schematic diagram showing a display example of straightness characteristics displayed on the display device shown in FIG. FIG. 29 is a schematic diagram showing a display example of the straightness characteristic in Modification 2-1 of Embodiment 2 of the present invention. FIG. 30 is a block diagram showing a configuration of a microscope system according to Embodiment 3 of the present invention. FIG. 31 is a flowchart showing an alignment method according to Embodiment 3 of the present invention. FIG. 32 is a schematic diagram for explaining the comparison processing of the focus area executed by the focus position comparison unit shown in FIG. FIG. 33 is a schematic diagram showing an image acquired by imaging the same observation visual field as that in FIG. 32B after adjusting the Z position of the stage. FIG. 34 is a flowchart showing the alignment method shown in Modification 3-2 of Embodiment 3 of the present invention. FIG. 35 is a schematic diagram showing an image showing the current observation visual field. FIG. 36 is a block diagram showing a configuration of a microscope system according to Embodiment 4 of the present invention. FIG. 37 is a schematic diagram showing an example of a subject used in the alignment method according to Embodiment 4 of the present invention. FIG. 38 is a flowchart showing an alignment method according to Embodiment 4 of the present invention. FIG. 39 is a schematic diagram for explaining the pattern comparison processing of the focus area executed by the focus area comparison unit shown in FIG.

  Hereinafter, embodiments of an alignment apparatus, a microscope system, an alignment method, and an alignment program according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments. Moreover, in description of each drawing, the same code | symbol is attached | subjected and shown to the same part.

  Further, in the following embodiment, an example in which the present invention is applied to a microscope system that captures a subject placed on a stage and acquires a microscope observation image will be described. The present invention can be applied to any apparatus or system that can acquire an image of a subject.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a microscope system according to Embodiment 1 of the present invention. As shown in FIG. 1, the microscope system 1 according to the first embodiment aligns the microscope apparatus 10 based on the microscope apparatus 10 that generates an enlarged image of the subject and the enlarged image generated by the microscope apparatus 10. And a processing device 20.

  FIG. 2 is a schematic diagram illustrating a configuration example of the microscope apparatus 10. As shown in FIG. 2, the microscope apparatus 10 includes a substantially C-shaped arm 100, a lens barrel 102 and an eyepiece unit 103 supported on the arm 100 via a trinocular tube unit 101, and the arm 100. The incident illumination unit 110 and the transmitted illumination unit 120, the electric stage unit 130 including the stage 131 on which the subject S is placed, and the stage 131 facing the stage 131 through the trinocular tube unit 101 on one end side of the lens barrel 102. And an objective lens 140 that forms an image of observation light from the subject S. The objective lens 140, the lens barrel 102 connected via the trinocular tube unit 101, and an imaging unit 211 (described later) provided on the other end side of the lens barrel 102 are an observation optical system (imaging optical system). ) 104 is configured.

  The trinocular tube unit 101 branches the observation light incident from the objective lens 140 in the direction of an eyepiece unit 103 for the user to directly observe the subject S and an imaging unit 211 described later.

  The epi-illumination unit 110 includes an epi-illumination light source 111 and an epi-illumination optical system 112, and irradiates the subject S with epi-illumination light. The epi-illumination optical system 112 condenses the illumination light emitted from the epi-illumination light source 111 and guides it in the direction of the optical axis L of the observation optical system 104 (filter unit, shutter, field stop, aperture stop). Etc.).

  The transmitted illumination unit 120 includes a transmitted illumination light source 121 and a transmitted illumination optical system 122 and irradiates the subject S with transmitted illumination light. The transmission illumination optical system 122 includes various optical members (filter unit, shutter, field stop, aperture stop, etc.) that collect the illumination light emitted from the transmission illumination light source 121 and guide it in the direction of the optical axis L.

  Either one of the epi-illumination unit 110 and the transmission illumination unit 120 is selected and used according to the spectroscopic method. The microscope apparatus 10 may be provided with only one of the epi-illumination unit 110 and the transmission illumination unit 120.

  The electric stage unit 130 includes a stage 131, a stage driving unit 132 that moves the stage 131, and a position detection unit 133. The stage driving unit 132 is configured by, for example, a motor, and is a moving unit that moves the stage 131 under the control of the imaging control unit 22 described later. In the following description, the subject placement surface 131a of the stage 131 is the XY plane, and the normal direction of the XY plane is the Z direction. In the Z direction, the downward direction (the direction away from the objective lens 140) is the positive direction.

  The observation visual field of the objective lens 140 can be changed by moving the stage 131 in the XY plane. Further, the focal plane of the objective lens 140 can be changed by moving the stage 131 in the Z direction.

  In the first embodiment, the stage 131 can be moved by electrical control. However, the stage 131 may be manually moved by the user using an adjustment knob or the like.

  In FIG. 2, the position of the observation optical system 104 including the objective lens 140, the lens barrel 102, and the imaging unit 211 is fixed and moved on the stage 131 side, but the position of the stage 131 is fixed, The observation optical system 104 side may be moved. Alternatively, both the stage 131 and the observation optical system 104 may be moved in opposite directions. That is, any configuration may be used as long as the observation optical system 104 and the subject S are relatively movable.

  The position detection unit 133 is configured by an encoder that detects the amount of rotation of the stage driving unit 132 made of, for example, a motor, and detects the position of the stage 131 and outputs a detection signal. Instead of the stage drive unit 132 and the position detection unit 133, a pulse generation unit and a stepping motor that generate pulses in accordance with the control of the imaging control unit 22 described later may be provided.

  The objective lens 140 is attached to a revolver 142 that can hold a plurality of objective lenses having different magnifications (for example, the objective lenses 140 and 141). The imaging magnification can be changed by rotating the revolver 142 and changing the objective lenses 140 and 141 facing the stage 131. FIG. 2 shows a state in which the objective lens 140 faces the stage 131. The revolver 142 is provided with an encoder, and the output value of the encoder is input from the microscope apparatus 10 to the processing apparatus 20 at the timing when the image acquisition unit 21 described later performs imaging. In the processing device 20, the numerical aperture and magnification of the objective lens 140 facing the subject S can be acquired based on this output value.

  Referring back to FIG. 1, the processing device 20 includes an image acquisition unit 21 that acquires an image by imaging the subject S, an imaging control unit 22 that controls the imaging operation of the image acquisition unit 21, and the processing device 20. The control unit 23 that controls various operations in FIG. 5 and acquires the trajectory of the relative movement of the stage 131 relative to the observation optical system 104 based on the image acquired by the image acquisition unit 21, and the image acquired by the image acquisition unit 21 A storage unit 24 for storing various types of information such as image data and a control program, and an input unit 25 for inputting instructions and information to the processing device 20.

The image acquisition unit 21 includes an imaging unit 211 and a memory 212.
The image pickup unit 211 includes an image pickup device (imager) 211a made of, for example, a CCD or a CMOS, and pixel levels (R (red), G (green), and B (blue)) in each pixel included in the image pickup device 211a ( It is configured using a camera capable of capturing a color image having a pixel value. Or you may comprise the imaging part 211 using the camera which can image the monochrome image which outputs the luminance value Y as a pixel level (pixel value) in each pixel.

  Such an imaging unit 211 is provided at one end of the lens barrel 102 so that the optical axis L passes through the center of the light receiving surface of the image sensor 211a, and enters the light receiving surface via the objective lens 140 to the lens barrel 102. Image data corresponding to the field of view of the objective lens 104 is generated by photoelectrically converting the light.

  The memory 212 includes a recording device such as a flash memory that can be updated and recorded, a semiconductor memory such as a RAM, and a ROM, and temporarily stores the image data generated by the imaging unit 211.

  The imaging control unit 22 outputs a control signal to the microscope apparatus 10 to move the stage 131, thereby changing the relative position between the subject S on the stage 131 and the observation optical system 104, and to the imaging unit 211. By executing imaging, control is performed to acquire an image of the region of the subject S that enters the observation field of view of the observation optical system 104.

  The control unit 23 is configured by hardware such as a CPU, for example, and by reading a program stored in the storage unit 24, based on various parameters stored in the storage unit 24, information input from the input unit 25, and the like, The operation of the processing apparatus 20 and the entire microscope system 1 is comprehensively controlled. In addition, the control unit 23 generates an image by performing predetermined image processing on the image data input from the image acquisition unit 21, and acquires information on the straightness of the stage 131 based on the image.

  Here, when the stage 131 is moved in the XY plane, the stage 131 is not completely moved in the XY plane due to the characteristics of the moving mechanism, but is displaced at a level of several μm in the Z direction. Therefore, even if the focusing surface of the observation optical system 104 is once adjusted to a desired plane, if the stage 131 is moved when the observation field of view is changed, the focusing surface is deviated from the previously adjusted plane. There is a risk that accurate image information cannot be acquired. Therefore, the control unit 23 detects the displacement (straightness) in the Z direction caused by the movement of the stage 131 in the XY plane as a trajectory associated with the coordinates in the X direction and the Y direction.

  More specifically, a focusing area detection unit 231 that detects a focusing area from an image captured at each position where the stage 131 is moved, and a focusing that compares the position of the focusing area in each image with a predetermined reference. A position comparison unit 232 and a straightness characteristic detection unit 233 that detects the straightness characteristic of the stage 131 based on the comparison result of the position of the focus area.

  The storage unit 24 includes a recording device such as a flash memory that can be updated and recorded, a semiconductor memory such as a RAM and a ROM, a recording medium such as a built-in or data communication terminal connected to a hard disk, MO, CD-R, and DVD-R, and the recording And a recording device including a reading device that reads information recorded on the medium. The storage unit 24 includes a parameter storage unit 241 that stores parameters used for calculation in the control unit 23 and a program storage unit 242 that stores various programs. The parameter storage unit 241 includes parameters such as numerical apertures and magnifications of the objective lenses 140 and 141 that can be exchanged in the microscope apparatus 10, image magnifications based on the magnifications, and a subject placement surface 131a of the stage 131 as described later. In contrast, information such as an inclination angle when the optical axis L of the observation optical system 104 is inclined is stored. The program storage unit 242 stores a control program for causing the processing device 20 to execute a predetermined operation, an alignment program for detecting a locus of relative movement between the observation optical system 104 and the stage 131, and the like.

  The input unit 25 includes input devices such as a keyboard, various buttons, and various switches, a pointing device such as a mouse and a touch panel, and the like, and inputs signals corresponding to operations on these devices to the control unit 23.

  Such a processing apparatus 20 can be configured by combining a general-purpose digital camera via an external interface (not shown) with a general-purpose apparatus such as a personal computer or a workstation. The alignment apparatus according to the first embodiment includes the processing apparatus 20 and an electric stage unit 130 including a stage 131 provided in the microscope apparatus 10.

Next, the principle of the alignment method according to the first embodiment of the present invention will be described. 3 to 6 are schematic diagrams for explaining the principle of the alignment method according to the first embodiment.
As shown in FIG. 3A, the optical axis L of the objective lens 140 is tilted with respect to the normal line of the planar object surface Ps, and the in-focus angle Pf and the object surface Ps of the objective lens 140 are tilted. When imaging is performed in a state of α, only the region R ₀ included in the depth of field DOF of the objective lens 140 is focused on the object plane Ps that enters the observation field of view V. Therefore, as shown in FIG. 3B, only a part of the image M0 in which the observation visual field V is copied becomes the focus area R _focus0 .

As shown in FIG. 4, it is assumed that the object plane Ps is shifted in the direction approaching the objective lens 140 (upward). In this case, of the object plane Ps that enters the observation field of view V, the region R ₀ that enters the depth of field DOF of the objective lens 140 is shifted with respect to FIG. This shift direction is determined according to the inclination direction of the focusing surface Pf, and shifts to the left in the figure in FIG. This shift amount is determined according to the shift amount (displacement amount in the Z direction) of the object plane Ps. Therefore, as shown in FIG. 4B, the focus region R _focus1 in the image M1 in which the observation field of view V is copied is also the shift direction and shift amount of the object plane Ps with _respect to the focus region R _focus0 in the image M0. Move according to.

On the other hand, as shown in FIG. 5, it is assumed that the object plane Ps is shifted in the direction away from the objective lens 140 (downward). In this case, among the object plane Ps entering the observation field of view V, the region R ₀ entering the depth of field DOF of the objective lens 140 is different from FIG. 4A depending on the shift direction and the shift amount of the object plane Ps. Shift in the opposite direction (rightward in FIG. 5A). Therefore, as shown in FIG. 5B, the focus area R _focus2 in the image M2 in which the observation field of view V is copied is also _{changed in} the object plane shift direction and shift amount with respect to the focus area R _focus0 in the image M0. Move accordingly.

  As described above, when imaging is performed in a state where the focusing plane Pf is inclined with respect to the object plane Ps, the position of the focusing area in the image changes according to the position of the object plane Ps in the Z direction. Therefore, by detecting the position of the focus area in the image, the change in the position of the object plane Ps in the Z direction can be acquired.

Specifically, as shown in FIG. 6, the region R ₀ included in the depth of field DOF has a certain width, and the centroid position of the region R ₀ matches the centroid position of the observation field of view V. The state that is present is the reference state. At this time, the width W _focus of the focusing area R _focus0 in the image M0 also becomes a predetermined width, and the center of gravity position of the image M0 matches the center of gravity position of the focusing area R _focus0 . The position of the image M0 in the reference state and the in-focus area (hereinafter referred to as the reference in-focus area) R _{focus0 in} the image M0 is stored in the parameter storage unit 241 in advance. Then, in-focus areas (in-focus areas R _focus1 and R _focus2 ) in an image (for example, images M1 and M2 shown in FIGS. 4 and 5) when the observation field of view V is moved in the XY plane. Is compared with the position of the reference focus area, and the shift direction and the shift amount of the focus area with respect to the position of the reference focus area are detected. Thereby, the displacement amount and the displacement direction from the reference state of the object plane Ps when the image is captured can be acquired. That is, the straightness (displacement in the Z direction from the reference state) of the stage 131 when the stage 131 is moved in the XY plane can be measured.

Here, the field size Fov (μm) of the observation optical system 104, the subject depth DOF (μm), the inclination angle α (rad) of the focusing surface Pf with respect to the object plane Ps, and the object plane Ps generated in the observation field Vs. Using the inclination height z (μm), the size (image size) W _image (pixel) of the image M0 corresponding to the visual field size Fov, and the width W _focus (pixel) of the focusing area R _focus0 in the image M0, the inclination angle α And the slope height z are given by the following equations (1) and (2), respectively.

Of the variables shown in Expressions (1) and (2), the field size Fov, the depth of field DOF, and the image size W _image are parameters that depend on the specifications of the microscope apparatus 10 and the imaging unit 211. In addition, the inclination angle α is setting information (imaging conditions) when performing imaging.

The width W _focus of the focus area R _focus0 is determined based on the average straightness of the stage 131 and the depth of field DOF. For example, assuming that the average value of the straightness is 1 μm, and under the observation condition of the observation magnification β = 40 × and the depth of field DOF = 0.2 μm, the width W _focus of the focus area R _{focus0 with} respect to the image size W _{image Assume that the} ratio W _focus / W _image is 1/10.

When the focusing plane Pf is tilted with respect to the object plane Ps, the ratio of the width W _focus of the focusing area to the image size W _image corresponds to the ratio of the depth of field DOF to the tilt height z in Expression (1). To do. Accordingly, as shown in FIG. 6A, assuming that a displacement of ± 1 μm occurs on the object plane Ps ₀ in the reference state (see the object planes Ps _max and Ps _min ), an area included in the depth of field DOF In order to keep R _min and R _max within the observation field of view V, in other words, as shown in FIG. 6B, the focus areas R _{focus (max)} and R _{focus (min)} are _converted into the images M _max and M _min. In order to be able to detect from the inside, the inclination height z needs a displacement width that can cover a total displacement of 2 μm. The inclination angle α is determined from the relationship with the visual field size Fov so that this displacement can be covered.

  FIG. 7 is a schematic diagram illustrating an example of a subject used in the alignment method according to the first embodiment. When performing this alignment method, it is preferable to use, as the subject S, an object in which the flatness of the object plane (the surface of the subject S) is guaranteed, such as a transmission optical evaluation chart (test chart). This is because by using the subject S with guaranteed flatness, the straightness detected based on the image of the subject S can be used as it is as the straightness of the stage 131. When the test chart described above is used as the subject S, the pattern of the test chart is not particularly limited, and a general-purpose chart can be used. In the following, it is assumed that a test chart on which a pattern illustrated in FIG.

  8 to 11 are schematic diagrams illustrating a method for imaging the subject S in the alignment method according to the first embodiment. In the alignment method according to the first embodiment, as shown in FIGS. 8 to 11, the observation optical system 104 including the objective lens 140 to the imaging unit 211 with respect to the normal of the object plane Ps that is the surface of the subject S is used. The optical axis L is relatively inclined by a known inclination angle α, and imaging is performed in a state where the focusing surface Pf makes an inclination angle α with respect to the object plane Ps. 8 and 9 show the case where the tilt direction is the X direction, and FIGS. 10 and 11 show the case where the tilt direction is the Y direction.

  In order to incline the optical axis L relative to the object plane Ps, as shown in FIGS. 8 and 10, the subject S is placed on the subject placement surface 131a of the stage 131 installed horizontally. The optical axis L makes an inclination angle α with respect to the normal line of the subject placement surface 131a (that is, the subject placement surface 131a and the optical axis L make an angle (90 ° −α)), The observation optical system 104 may be installed at an angle. In this case, an inclination adjustment driving unit 105 that changes the inclination of the observation optical system 104 by electrical control may be further provided. Alternatively, as shown in FIGS. 9 and 11, the observation optical system 104 is installed such that the optical axis L is orthogonal to the subject placement surface 131a, and a pedestal 106 having an inclination angle α is provided on the subject placement surface 131a. It may be installed and the subject S may be arranged on the pedestal 106. In addition, the mechanism for inclining the optical axis L with respect to the object surface Ps is not limited to these examples. In the following description, as shown in FIGS. 8 and 10, the observation optical system 104 is inclined with respect to the subject placement surface 131a. In this case, the object plane Ps is parallel to the subject placement surface 131a of the stage 131.

  FIG. 12 is a flowchart showing the alignment method according to the first embodiment of the present invention. First, in step S10 of FIG. 12, the control unit 23 acquires an imaging condition, and determines a moving direction and a moving amount for moving the stage 131 each time imaging is performed based on the imaging condition.

As imaging conditions, the tilt angle of the optical axis L with respect to the normal line of the object plane Ps (that is, the tilt angle of the focusing plane Pf with respect to the object plane Ps) α and the tilt direction (X direction or Y direction), the observation optical system 104 Observation magnification β and imager characteristics (the size of the light receiving surface of the image sensor 211a, hereinafter referred to as an imager size) I _{W (X)} × I _{W (Y)} (mm). These imaging conditions are stored in advance in the parameter storage unit 241, and the control unit 23 reads out these imaging conditions from the parameter storage unit 241 when the alignment operation is started.

  Further, the control unit 23 determines the moving direction and moving amount of the stage 131 relative to the observation optical system 104 based on the acquired imaging conditions. The moving direction of the stage 131 is a direction in which the optical axis extends on the object plane Ps when the optical axis L of the observation optical system 104 is projected onto the object plane Ps from the normal direction of the object plane Ps. Specifically, as shown in FIG. 8, when the optical axis L is inclined in the X direction with respect to the object plane Ps, the observation visual field V is in the X direction with respect to the subject S as shown in FIG. The stage 131 is moved in the X direction so as to move sequentially. On the other hand, when the optical axis L is inclined in the Y direction with respect to the object plane Ps as shown in FIG. 10, the observation visual field V sequentially moves in the Y direction with respect to the subject S as shown in FIG. Thus, the stage 131 is moved in the Y direction.

The amount of movement of the stage 131 in each direction of XY corresponds to the visual field size Fov (= Fov (x) × Fov (y)) of the observation visual field V imaged at one time by the observation optical system 104. The visual field size Fov is given by the following expressions (3-1) and (3-2) by the imager size I _{W (X)} × I _{W (Y)} (mm) and the observation magnification β.
Fov (x) = (I _{W (X)} / β) × 1000 (μm) (3-1)
Fov (y) = (I _{W (Y)} / β) × 1000 (μm) (3-2)

  In subsequent step S11, the microscope system 1 captures a predetermined observation field and acquires an image. For example, as shown in FIG. 15, when imaging is performed in raster order, an observation field of view V (1) including coordinates (0, 0) on the object plane Ps is set as the first observation field of view. Note that the processing device 20 adjusts the Z position of the stage 131 in advance so that the central region of the observation visual field V (1) is focused (see FIG. 3).

  In subsequent step S12, the control unit 23 causes the parameter storage unit 241 to store the barycentric coordinates of the observation visual field V imaged in step S11.

  In subsequent step S <b> 13, the microscope system 1 performs imaging by moving the observation visual field V, and acquires an image in which the observation visual field V as the movement destination is copied. Specifically, the observation field V adjacent in the movement direction set in step S10 is imaged.

  In subsequent step S <b> 14, the focus area detection unit 231 detects the focus area from the image acquired in step S <b> 13. FIG. 16 is a flowchart showing a focus area detection process executed by the focus area detection unit 231.

In step S141 shown in FIG. 16, the focus area detection unit 231 calculates a cutoff frequency Fc given by the following equation (3) based on the numerical aperture NA of the objective lens 140 and the observation magnification β.
In Expression (3), the symbol λ indicates the wavelength of light irradiated on the subject S (for example, 550 nm).

  In subsequent step S142, the focus area detecting unit 231 removes a frequency component higher than the cutoff frequency Fc calculated in step S141 from the image of the observation visual field V acquired in step S13. More specifically, the focus area detection unit 231 uses a Hamming window or the like based on the cutoff frequency calculated in step S141 and the pixel pitch of the imaging element 211a provided in the imaging unit 211. Filter design is performed by a known method. Then, a frequency space image is generated by performing Fourier transform on the image of the observation visual field V, and a high frequency component is cut by applying a designed filter to the frequency space image. Thereafter, an inverse Fourier transform is performed on the frequency space image to obtain an image from which noise is removed.

  In subsequent step S143, the focus area detection unit 231 divides the image from which the high-frequency component has been removed into a plurality of small areas. The number of divisions into small areas is arbitrary, and FIG. 17 shows an example in which the image M3 is divided into 36 small areas m1 to m36. As the number of divisions increases, the detection accuracy of the in-focus area can be improved. However, since the amount of calculation also increases, the number of divisions is appropriately determined in consideration of hardware calculation speed and required accuracy. Just decide.

  In subsequent step S144, the in-focus area detection unit 231 calculates an evaluation value for evaluating the in-focus degree of each small area divided in step S143. Hereinafter, this evaluation value is referred to as an image evaluation value.

More specifically, first, edge strength (horizontal edge strength, vertical edge strength) in each of the X direction and the Y direction is calculated by applying a Sobel filter process to each small region. Figure 18 shows, as an example, with respect to the small region m4 shown in FIG. 17, Sobel filter Sb _x applied to the resultant edge image m4 to extract horizontal edge and (x), Sobel filter for extracting vertical edges is a schematic diagram showing an edge image m4 (y) obtained by applying a sb _y.

Subsequently, the focused area detection unit 231 normalizes the horizontal edge intensity and the vertical edge intensity calculated for each small area by the maximum value of the edge intensity in the image. Pixels in the small region are represented by _pn (n = 1 to N, N is the number of pixels in the small region), edge intensities in the X direction and Y direction are represented by Ex _(Pn) , Ey _(Pn) , and X in the image. direction and Y the maximum value of the edge strength in the direction Ex _max, when the Ey _max, edge intensity of each pixel p _n of the normalized Cx _(Pn), Cy _(Pn) respectively, the following equation (4-1), (4-2).
Cx _(Pn) = Ex _(Pn) / Ex _max (4-1)
Cy _(Pn) = Ey _(Pn) / Ey _max (4-2)

The average value of these normalized edge strengths is set as the image evaluation values EX and EY in each direction. Specifically, the image evaluation values EX and EY are given by the following equations (5-1) and (5-2).

  Note that the edge extraction method is not limited to the method using the Sobel filter described above, and a known edge extraction filter such as a LOG filter may be used. Further, the calculation method of the image evaluation value is not limited to the methods shown in the equations (5-1) and (5-2).

  In subsequent step S145, the focus area detection unit 231 selects a focus area from the image based on the image evaluation values EX and EY calculated in step S144. Specifically, a small area in which the image evaluation value EX in the X direction is higher than a predetermined threshold Tx and the image evaluation value EY in the Y direction is higher than a predetermined threshold Ty is selected as the focusing area. The threshold values Tx and Ty are set based on statistical values such as an average value and standard deviation of image evaluation values in the entire area of the image.

  FIG. 19 is a schematic diagram for explaining a method of selecting a focus area. A graph shown below the image M3 shown in FIG. 19 shows the image evaluation values EX of the small regions arranged in a certain row in the image M3. Further, the graph shown on the right side of the image M3 indicates the image evaluation value EY of the small area arranged in a certain row in the image M3.

As shown in FIG. 19, the in-focus area detection unit 231 compares the image evaluation value EX of each small area with the threshold value Tx for each row where the small areas are arranged, and the image evaluation value EY of each small area. Comparison with the threshold value Ty is performed for each column in which small regions are arranged. Then, a small area where the image evaluation value EX is larger than the threshold value Tx and the image evaluation value EY is larger than the threshold value Ty is selected as the focus area. FIG. 20 is a schematic diagram illustrating an example in which a focusing area R _focus3 is selected from the image M3.
After the focus area is detected, the process returns to the main routine.

In step S15 following step S14, the in-focus position comparison unit 232 reads out the position information of the reference in-focus area stored in the parameter storage unit 241, and determines the position of the in-focus area detected from the image in step S14. Compare with the position of the reference focus area. FIG. 21 is a schematic diagram for explaining the comparison process of the focus area executed by the focus position comparison unit 232. Of these, FIG. 21 (a) shows the reference image M _base, which copy the observation field in the reference state. The in-focus position comparison unit 232 reads out the coordinates (x _BG , y _BG ) of the centroid position BG of the reference in-focus region R _base in the reference image M _base from the parameter storage unit 241 as the position information of the reference in-focus region. .

As shown in FIG. 21B, when the in-focus area R _focus3 is detected from the image M3 showing the current observation visual field, the in-focus position comparison unit 232 coordinates the centroid position OG of the in-focus area R _focus3. Calculate (x _OG , y _OG ). Then, the shift amount of the in-focus region R _focus3 from the reference state, that is, the shift amount ΔC (x _OG −x _BG or y _OG −y _BG ) (pixel) and the shift direction between the centroid positions BG and OG are obtained. And stored in the parameter storage unit 241. The shift direction of the focus area R _focus3 is represented by the sign of the shift amount ΔC. Specifically, as shown in FIG. 21B, when the focus area R _focus3 is shifted rightward, the sign of the shift amount ΔC is positive.

  In subsequent step S16, the straightness characteristic detection unit 233 detects the straightness characteristic of the stage 131 based on the shift amount ΔC and the shift direction of the in-focus area obtained in step S15. FIG. 22 is a flowchart showing a straightness characteristic detection process executed by the straightness characteristic detection unit 233.

First, in step S161, the straightness characteristic detection unit 233 calculates the displacement direction and the displacement amount δZ of the object plane Ps (that is, the stage 131) along the Z axis from the shift amount ΔC and the shift direction of the focus area. . The displacement amount δZ (μm) of the object plane Ps is given by the following equation (6) using the depth of field DOF and the width W _{focus of the} focused area in the image.
δZ = (DOF × ΔC) / W _focus (6)

Further, the displacement direction of the object plane Ps is obtained based on the shift direction of the focusing area R _focus3 from the reference state. For example, as shown in FIG. 6, when the focusing plane Pf is inclined so that the focusing plane Pf decreases (the Z coordinate increases) with respect to the object plane Ps, the focusing area R _focus3 When the sign of the shift direction is plus (moves to the right in the figure), the displacement direction of the object plane Ps is plus Z direction (down in the figure downward). The same determination is made when the object plane Ps is inclined in the Y direction.

  In subsequent step S162, the straightness characteristic detection unit 233 uses the coordinates of the center of gravity of the current observation visual field V and the displacement direction and displacement of the object plane Ps calculated in step S161 with respect to the observation visual field V as straightness characteristics. The parameter is stored in the parameter storage unit 241. Thereafter, the process returns to the main routine.

  In step S <b> 17 following step S <b> 16, the control unit 23 determines whether imaging has been completed for the entire region on the subject S (for example, the test chart shown in FIG. 7) placed on the stage 131. If an area that has not yet been imaged remains (step S17: No), the process returns to step S13. In this case, the microscope system 1 performs imaging by moving the observation visual field V to a region that has not yet been imaged.

  By executing these steps S13 to S17 for the entire region on the subject S while sequentially moving the observation visual field V, the movement of the observation visual field V in the XY plane, that is, the observation optical system 104 and the stage 131 are moved. Changes in the Z position accompanying the relative movement (ie, straightness) can be collected in association with the coordinates of the observation field of view V. When imaging has been completed for the entire area on the subject S (step S17: Yes), the process ends.

  The straightness characteristics of the stage 131 accumulated in the parameter storage unit 241 as described above can be read from the parameter storage unit 241 and used at any time when the electric stage unit 130 is calibrated.

  As described above, according to the first embodiment of the present invention, the locus of relative movement between the observation optical system 104 and the stage 131 can be detected without providing the microscope apparatus 10 with a dedicated mechanism for alignment. It becomes possible. Therefore, by calibrating the Z position of the stage 131 based on this trajectory, it is possible to acquire accurate image information when observing a specimen or the like with the microscope apparatus 10.

  Further, according to the first embodiment of the present invention, there is an effect that straightness can be detected with an accuracy of depth of field or less. Here, when imaging is performed with the object plane Ps and the focusing plane Pf being parallel, even if the Z position of the object plane Ps varies, if the variation range is within the depth of field, the object plane Ps. Is always in focus. Therefore, this change can be detected from the image only when the Z position of the object plane Ps changes with a width equal to or greater than the depth of field. On the other hand, according to the first embodiment, since imaging is performed in a state where the focal plane Pf is inclined with respect to the object plane Ps, the variation in the Z position of the object plane Ps is minute within the depth of field. Even if there is a variation, this variation can be detected in the form of movement of the in-focus area in the image. Therefore, according to the first embodiment, it is possible to detect the change in the Z position of the object plane Ps, that is, the straightness of the stage 131 with high accuracy.

(Modification 1-1)
Next, Modification 1-1 of Embodiment 1 of the present invention will be described.
In the first embodiment, the case where the straightness of the stage 131 is detected by fixing the position of the observation optical system 104 and moving the stage 131 side has been described. However, the straightness of the observation optical system 104 may be detected by providing a movement mechanism in the observation optical system 104 and moving the observation optical system 104 side while fixing the position of the stage 131. Even in this case, the straightness of the observation optical system 104 can be detected with high accuracy by the same image processing as in the first embodiment.

(Modification 1-2)
Next, a modified example 1-2 of the first embodiment of the present invention will be described.
In the first embodiment, each time the observation visual field is moved, the stage 131 is stopped and imaging is performed. However, continuous imaging (that is, moving image imaging) may be performed without stopping the stage. In this case, the visual field size Fov of the observation visual field V is determined based on the moving speed of the stage 131 and the frame rate of the imaging unit 211.

(Modification 1-3)
Next, Modification 1-3 of Embodiment 1 of the present invention will be described.
In the first embodiment, the position of the in-focus area detected in step 12 is compared with the position of the reference in-focus area stored in advance in the parameter storage unit 241 (see step S15). However, a focus area may be detected from an image in which the observation visual field is copied at the start of alignment, and the center of gravity position and width may be stored in the parameter storage unit 241 with this focus area as a reference focus area.

(Modification 1-4)
Next, Modification 1-4 of Embodiment 1 of the present invention will be described.
FIG. 23 is a block diagram illustrating a configuration of a microscope system according to Modification 1-4. As shown in FIG. 23, the microscope system 1-2 according to the modified example 1-4 includes a microscope apparatus 10 and a processing apparatus 30. Among these, the configuration and operation of the microscope apparatus 10 are the same as those in the first embodiment (see FIG. 2). The alignment apparatus according to Modification 1-4 includes the processing apparatus 30 and the electric stage unit 130 provided in the microscope apparatus 10.

  The processing device 30 further includes a calibration unit 31 with respect to the processing device 20 shown in FIG. The configuration and operation of each unit of the processing apparatus 30 other than the calibration unit 31 are the same as those in the first embodiment.

  The calibration unit 31 generates calibration information of the Z position of the stage 131 according to the barycentric coordinates of the observation visual field based on the straightness characteristic detected by the straightness characteristic detection unit 233 and stored in the parameter storage unit 241. Specifically, when the straightness in a certain observation visual field is plus 1 μm, that is, when the stage 131 is lowered by 1 μm from the reference state, the calibration unit 31 raises the stage 131 by 1 μm when imaging the observation visual field. The calibration information to be generated is generated.

  In this case, when observing a sample or the like in the microscope apparatus 10, the imaging control unit 22 moves the stage 131 in the XY plane so that the observation visual field matches the sample, and based on the calibration information generated by the calibration unit 31. Control for adjusting the Z position of the stage 131 is performed. As a result, it is possible to image the specimen in a state in which it is accurately focused.

  According to the modified example 1-4 of the first embodiment described above, the Z position of the stage 131 is automatically calibrated based on the straightness characteristic stored in the parameter storage unit 241. Therefore, accurate image information is acquired. It becomes possible to do.

  In Modification 1-4, the Z position of the stage 131 is adjusted. However, the observation optical system 104 side including the objective lens 140 is moved along the optical axis, and the relative position with respect to the stage 131 is set. Calibration may be performed by adjusting.

(Embodiment 2)
Next, a second embodiment of the present invention will be described.
FIG. 24 is a block diagram showing a configuration of a microscope system according to Embodiment 2 of the present invention. As shown in FIG. 24, the microscope system 2 according to the second embodiment includes a microscope apparatus 10 and a processing apparatus 40. Among these, the configuration and operation of the microscope apparatus 10 are the same as those in the first embodiment (see FIG. 2). The alignment apparatus according to the second embodiment includes the processing apparatus 40 and the electric stage unit 130 included in the microscope apparatus 10.

  The processing device 40 includes an imaging control unit 41 instead of the imaging control unit 22 in the processing device 20 illustrated in FIG. 1, and further includes an output unit 42. A display device 43 is connected to the processing device 40. The configuration and operation of each unit of the processing device 40 other than the imaging control unit 41 and the output unit 42 are the same as those in the first embodiment.

  The imaging control unit 41 includes an area setting unit 411 that sets a predetermined range on the subject placement surface 131a as an imaging range in accordance with an instruction signal input from the input unit 25 in response to an external operation, and a set imaging range. And a moving condition setting unit 412 for setting a moving direction and a moving amount for moving the imaging visual field based on the imaging condition.

  The output unit 42 outputs an image based on the image data acquired by the image acquisition unit 21 and information such as straightness stored in the parameter storage unit 241 to an external device such as the display device 43 and displays the information in a predetermined format. External interface

  The display device 43 is configured by, for example, an LCD, an EL display, a CRT display, and the like, and displays an image, straightness, and the like output from the output unit 42 on the screen. In the second embodiment, the display device 43 is provided outside the processing device 40, but may be provided inside the processing device 40.

Next, an alignment method according to the second embodiment will be described. FIG. 25 is a flowchart showing the alignment method according to the second embodiment.
First, in step S20, the area setting unit 411 sets an imaging range for the subject placement surface 131a. FIG. 26 is a schematic diagram for explaining an imaging range setting method.

  Here, in the general microscope apparatus 10 as shown in FIG. 2, the area on which the user actually places the specimen and uses it for observation is usually narrower than the subject placement surface 131 a of the stage 131. Since the area used for specimen observation is used more frequently than other areas, the straightness of the stage 131 has changed from the time of product shipment due to deterioration with time due to repeated movement of the stage 131 (becomes larger). There is a high possibility. On the other hand, accurate calibration is desired only in such a region used for specimen observation. Therefore, in the second embodiment, a frequently used region of the subject placement surface 131a is set as the imaging range A, and the straightness is detected only in the imaging range A.

  The imaging range A is set according to a signal input from the input unit 25 according to a user operation, for example. Specifically, when a signal representing a user-desired sample size is input from the input unit 25, the region setting unit 411 captures an area corresponding to the sample size around the center position of the subject placement surface 131a. Set as A. Alternatively, when a signal designating a specific area on the subject placement surface 131a is input from the input unit 25, the area setting unit 411 may set the specific area as the imaging range A. Furthermore, the stage movement history is accumulated in the parameter storage unit 241 every time the user uses the microscope apparatus 10, and the frequency of use is based on the stage movement history accumulated in the parameter storage unit 241 when performing alignment. A region within the subject placement surface 131a having a high height may be set as the imaging range A.

  In subsequent step S21, the user tilts the optical axis L of the observation optical system 104 (see FIG. 2) with respect to the object plane Ps. As a result, the focusing surface Pf of the observation optical system 104 is inclined with respect to the object plane Ps. The inclination angle α of the optical axis L with respect to the normal of the object plane Ps is defined by the relationship between the average straightness value and the depth of field DOF in the microscope apparatus 10.

  As a method of inclining the optical axis L with respect to the object plane Ps, as shown in FIGS. 8 and 10, a stage 131 is set so that the subject placement surface 131a is horizontal, and the subject S is placed thereon. The observation optical system 104 may be tilted so that the optical axis L forms an inclination angle α with respect to the normal of the subject placement surface 131a. Alternatively, as shown in FIGS. 9 and 11, the observation optical system 104 is installed so that the optical axis L is orthogonal to the subject placement surface 131a, and a pedestal 106 having an inclination angle α on the subject placement surface 131a. And the subject S may be placed on the pedestal 106.

  At this time, when detecting the straightness in the X direction, the user tilts the optical axis L in the X direction with respect to the object plane Ps, and when detecting the straightness in the Y direction, the user moves to the object plane Ps. In contrast, the optical axis L is inclined in the Y direction. In addition, the user uses the input unit 25 to input the inclination direction of the optical axis L with respect to the object plane Ps. In the second embodiment as well, a test chart with a guaranteed flatness as illustrated in FIG.

  In subsequent step S <b> 22, the control unit 23 acquires an imaging condition, and determines a moving direction and a moving amount for moving the stage 131 each time imaging is performed based on the imaging condition.

As imaging conditions, the tilt angle of the optical axis L with respect to the normal line of the object plane Ps (that is, the tilt angle of the focusing plane Pf with respect to the object plane Ps) α and the tilt direction (X direction or Y direction), the observation optical system 104 Examples include an observation magnification β and an imager size I _{W (X)} × I _{W (Y)} (mm). These imaging conditions are stored in advance in the parameter storage unit 241, and the control unit 23 reads out these imaging conditions from the parameter storage unit 241 when the alignment operation is started.

  Further, the control unit 23 determines the moving direction and moving amount of the stage 131 relative to the observation optical system 104 based on the acquired imaging conditions. Specifically, first, the control unit 23 acquires the tilt direction of the optical axis L with respect to the object plane Ps by a signal input from the input unit 25 according to a user operation, and the stage 131 moves based on the tilt direction. Determine the direction. Alternatively, the observation optical system 104 may be provided with detection means (for example, a gravity sensor) for detecting the inclination direction of the observation optical system 104, and the inclination direction of the optical axis L may be acquired from the detection result by the detection means. .

  The moving direction of the stage 131 is a direction in which the optical axis extends on the object plane Ps when the optical axis L of the observation optical system 104 is projected onto the object plane Ps from the normal direction of the object plane Ps. Specifically, as shown in FIG. 8, when the optical axis L is inclined in the X direction with respect to the object plane Ps, the observation visual field V is set within the imaging range A as shown in FIG. The stage 131 is moved in the X direction so as to move sequentially in the X direction. On the other hand, as shown in FIG. 10, when the optical axis L is inclined in the Y direction with respect to the object plane Ps, the observation visual field V is in the Y direction within the imaging range A as shown in FIG. The stage 131 is moved in the Y direction so as to move sequentially. The amount of movement of the stage 131 is given by equations (3-1) and (3-2) as in the first embodiment.

  In subsequent step S23, the microscope system 2 captures a predetermined observation field and acquires an image. Specifically, as shown in FIG. 26A or 26B, the observation visual field V at the upper left of the imaging range A is imaged. Note that the microscope system 2 adjusts the Z position of the stage 131 in advance so that the central region is substantially focused in the first observation visual field V (see FIG. 3).

  In subsequent step S24, the focus area detection unit 231 detects the focus area from the image acquired in step S23, and uses the coordinates of the center of gravity and the width (pixel) of the focus area as information on the reference focus area. The parameters are stored in the parameter storage unit 241 together with the barycentric coordinates of the observation visual field V. The focus area detection processing by the focus area detection unit 231 is the same as that in the first embodiment (see FIG. 16).

  The subsequent steps S13 to S17 are the same as in the first embodiment (see FIG. 12). Among these, in step S15, the position of the focus area detected from the image in which the first observation visual field V is copied is read from the parameter storage unit 241 and used as the position of the reference focus area. In step S16, the width of the in-focus area detected from the image showing the first observation field is read from the parameter storage unit 241 and used. After the process for all the areas in the imaging range A is completed (step S17: Yes), the process ends.

  The straightness characteristic of the stage 131 detected in this way and stored in the parameter storage unit 241 is used when the user observes the sample or the like so that the sample can be imaged while manually calibrating the Z position of the stage 131. Can be used. When observing a specimen or the like, the object plane is restored by returning the tilt of the observation optical system 104 (see FIGS. 8 and 10) or removing the pedestal 106 (see FIGS. 9 and 11). Ps and the focusing surface Pf are installed in parallel.

  Specifically, the output unit 42 reads the straightness characteristic from the parameter storage unit 241 in response to an instruction signal input from the input unit 25 in response to a user operation, and outputs the straightness characteristic to the display device 43 to display in a predetermined format. Let 27 and 28 are schematic diagrams illustrating display examples of straightness characteristics displayed on the display device 43. FIG.

  On the screen of the display device 43, a window 43a as shown in FIGS. 27 and 28 is displayed in addition to an image showing the current observation visual field in the microscope apparatus 10 (hereinafter referred to as an observation image). The window 43a includes a map display field d1 in which a straightness map on the subject placement surface 131a is displayed, a graph display field d2 in which a graph indicating a change in straightness in the X direction or the Y direction is displayed, and a straightness. And a message display field d3 in which a message indicating the adjustment method of the corresponding stage 131 is displayed.

  In the straightness map displayed in the map display field d1, the horizontal axis indicates the X coordinate of the observation visual field, and the vertical axis indicates the Y coordinate of the observation visual field. Further, the hue assigned to the pixel at each coordinate in the straightness map represents the degree of straightness at the corresponding coordinate on the subject placement surface 131a. In FIGS. 27 and 28, the difference in hue is represented by gray shades, and the higher the straightness, the higher the gray density. In the straightness map, a point p1 representing the coordinates of the current observation visual field in the microscope apparatus 10 is displayed.

  When the user performs an operation of moving the observation visual field in the X direction using the input unit 25, as shown in FIG. 27, a point p2 representing the coordinates of the observation visual field adjacent to the current observation visual field in the X direction is displayed. In addition to being displayed on the straightness map, a graph indicating the change in straightness in the X direction is displayed in the graph display field d2. Further, the adjustment method of the stage 131 to be performed by the user in accordance with the change in straightness between the points p1 and p2 is displayed in the message display field d3. On the other hand, when the user performs an operation of moving the observation visual field in the Y direction using the input unit 25, as shown in FIG. 28, the point representing the coordinates of the observation visual field adjacent in the Y direction with respect to the current observation visual field. p3 is displayed on the straightness map, and a graph indicating the change in straightness in the Y direction is displayed in the graph display field d2. Furthermore, the stage 131 adjustment method to be performed by the user in accordance with the change in straightness between the points p1 and p3 is displayed in the message display field d3.

  The user can adjust the Z position of the stage 131 by rotating an adjustment knob or the like provided on the stage 131 by a predetermined amount in a predetermined direction as displayed in the message display field d3. In the message display field d3, the rotation direction (clockwise, counterclockwise) and the rotation amount (○ scale, △ scale) of the adjustment knob are specifically shown. Calibration can be performed.

  As described above, according to the second embodiment of the present invention, since the straightness characteristic of the stage 131 in the region where the frequency of use by the user is high is detected, the alignment of the stage 131 is performed according to the user's own usage situation. Can be performed efficiently at any time.

  In the second embodiment, since the user manually tilts the focusing plane Pf with respect to the object plane Ps, the tilt angle formed between the object plane Ps and the focusing plane Pf is constant every time alignment is performed. It may not be. However, in the second embodiment, since the position of the in-focus area detected from the image in the observation range that is first imaged in the imaging range A when performing the alignment is used as a reference, straightness in other observation fields of view Can be accurately detected.

(Modification 2-1)
Next, Modification 2-1 of Embodiment 2 of the present invention will be described. FIG. 29 is a schematic diagram illustrating a display example of the straightness characteristic in the modification 2-1. When displaying the straightness characteristic of the stage 131 on the screen of the display device 43, a window 43b shown in FIG. 29 may be displayed instead of the window 43a shown in FIG. The window 43b includes, in place of the map display field d1 shown in FIG. 27, an image display field d4 on which an image (hereinafter referred to as a macro image) showing the entire subject S placed on the stage 131 is displayed. .

  The macro image is an image acquired by imaging the subject S using the objective lens with a relatively low magnification (for example, 1 to 4 times) in the microscope apparatus 10. The user may first take a macro image after setting the subject S on the stage 131.

  When the macro image is acquired, the control unit 23 reads the straightness characteristic from the parameter storage unit 241 and outputs the coordinates in the macro image and the straightness characteristic at each coordinate of the stage 131 in association with each other. Thereby, the window 43b shown in FIG. 29 is displayed on the screen of the display device 43. In the macro image displayed in the image display field d4 in the window 43b, a point p1 representing the coordinates of the current observation visual field in the microscope apparatus 10 is displayed.

  When the user designates a region to be observed in detail at a higher magnification by a pointer operation (for example, a click operation) using the input unit 25 for the macro image, a point (for example, the point p2) representing the region is displayed on the macro image. At the same time, the observation field of view in the microscope apparatus 10 shifts to the region. Further, a graph showing the change in straightness in the direction from the point p1 to the point p2 (X direction in FIG. 29) is displayed in the graph display field d2, and in accordance with the change in straightness between the points p1 and p2. The adjustment method of the stage 131 to be performed by the user is displayed in the message display field d3.

  By referring to the macro image displayed in the image display field d4, the user can easily select an area of the subject S that he / she wants to observe in detail at a higher magnification, and a graph corresponding to the selected area. The Z position of the stage 131 can be adjusted easily and accurately by referring to the graphs and messages displayed in the display column d2 and the message display column d3, respectively.

(Modification 2-2)
Also in the second embodiment, a calibration unit may be provided in the same manner as in Modification 1-4, and the Z position of the stage 131 may be automatically calibrated according to the straightness characteristic stored in the parameter storage unit 241.

(Embodiment 3)
Next, a third embodiment of the present invention will be described.
FIG. 30 is a block diagram showing a configuration of a microscope system according to Embodiment 3 of the present invention. As shown in FIG. 30, the microscope system 3 according to the third embodiment includes a microscope apparatus 10 and a processing apparatus 50. Among these, the configuration and operation of the microscope apparatus 10 are the same as those in the first embodiment (see FIG. 2). The alignment apparatus according to the third embodiment includes the processing apparatus 50 and the electric stage unit 130 included in the microscope apparatus 10.

  The processing device 50 includes a control unit 51 instead of the control unit 23 in the processing device 20 illustrated in FIG. 1, and further includes a Z position adjustment unit 52. The configuration and operation of each part of the processing apparatus 50 other than the control unit 51 and the Z position adjustment unit 52 are the same as those in the first embodiment.

  The control unit 51 includes a focusing area detection unit 231, a focusing area comparison unit 511, and a straightness characteristic detection unit 233. Among these, the operations of the focus area detection unit 231 and the straightness characteristic detection unit 233 are the same as those in the first embodiment.

The focus area comparison unit 511 compares the position and width of the focus area detected by the focus area detection unit 231 with the position and width of the reference focus area stored in the parameter storage unit 241.
The Z position adjustment unit 52 adjusts the Z position of the stage 131 based on the comparison result of the position and width of the in-focus area with the in-focus area comparison unit 511.

Here, when the straightness of the stage 131 is large, the region R ₀ (see FIG. 3) in the object plane Ps focused on the observation optical system 104 protrudes from the observation visual field V, and an image in which the observation visual field V is copied. In some cases, the entire focusing area may not fit. In this case, it becomes impossible to accurately acquire the shift amount of the focus area from the reference focus area. Therefore, in the third embodiment, the Z position adjustment unit 52 adjusts the Z position of the stage 131 based on the comparison result by the focus region comparison unit 511, thereby accurately acquiring the shift amount of the focus region. It can be so.

  Next, an alignment method according to Embodiment 3 will be described. FIG. 31 is a flowchart showing the alignment method according to the third embodiment. Note that steps S10 to S14 shown in FIG. 31 are the same as those in the first embodiment (see FIG. 12). Also in the third embodiment, as illustrated in FIGS. 8 to 11, alignment is performed in a state where the focusing surface Pf is inclined with respect to the object surface Ps.

In step S31 following step S14, the in-focus area comparison unit 511 reads out the position information of the reference in-focus area stored in the parameter storage unit 241, and the position of the in-focus area detected from the image in step S14 and The width is compared with the position and width of the reference focusing area, respectively. FIG. 32 is a schematic diagram for explaining the focus area comparison processing executed by the focus area comparison unit 511. Among these, FIG. 32A is a schematic diagram showing the reference image M _base captured in the reference state. Focused region comparison unit 511, the coordinates (x _BG, y _BG) of the center-of-gravity position BG of the reference focus area R _base in the reference image M _base a and a width BW, previously read from the parameter storage unit 241.

As shown in FIG. 32 (b), when the focus area R _focus4 is detected from the image M4 in which a certain observation field of view is detected in step S14, the focus area comparison unit 511 _displays the barycentric position of the focus area R _focus4 . OG coordinates (x _OG , y _OG ) and width OW (pixel) are calculated. Then, the shift amount of the in-focus region R _focus3 from the reference state, that is, the shift amount ΔC (x _OG −x _BG or y _OG −y _BG ) (pixel) and the shift direction between the centroid positions BG and OG are obtained. And stored in the parameter storage unit 241. The shift direction of the focus area R _focus4 is represented by the sign of the shift amount ΔC. Specifically, as shown in FIG. 32B, when the focus area R _focus4 is shifted in the right direction, the sign of the shift amount ΔC is positive.

Further, the focus area comparison unit 511 calculates a change amount ΔW = BW−OW (pixel) of the width of the focus area R _focus4 from the reference state.

In subsequent step S32, the in-focus area comparing unit 511 determines whether or not the Z position of the stage 131 needs to be adjusted in the observation visual field to be processed. Here, as shown in FIG. 6, when the object plane is far away from the object plane Ps _{0 in the} reference state (for example, the object plane is further lowered from the object plane Ps _max ), the object plane is focused. Area does not fit in the image. In such a case, as shown in FIG. 32, the shift amount of the focus area R _{focus4 with} respect to the reference focus area R _base becomes large, and the width OW of the focus area R _focus4 detected from the image M4 is equal to the reference focus area R _base4. It becomes smaller than the width BW of the focal region _Rbase . Therefore, the amount of change ΔW of the focus area width calculated in step S32 is greater than zero. In this case, the focus area comparison unit 511 determines that adjustment of the Z position of the stage 131 is necessary (step S32: No), and the process proceeds to step S33.

In step S33, the in-focus area comparison unit 511 calculates an adjustment amount and adjustment direction for adjusting the Z position of the stage 131 based on the in-focus area shift amount ΔC calculated in step S31. In response to this, the Z position adjustment unit 52 performs control to adjust the Z position of the stage 131 based on the calculated adjustment amount and adjustment direction. The adjustment amount δA _Z for the Z position of the stage 131 is given by the following equation (7) based on the depth of field DOF, the width W _focus of the reference focus area, and the change amount ΔW of the width of the focus area.
δA _Z = (DOF × ΔW) / W _focus (7)

  Further, the adjustment direction of the Z position of the stage 131 is determined based on the sign of the shift amount ΔC of the in-focus area. As shown in FIG. 6, when the focal plane Pf is inclined so that the focal plane Pf decreases (the Z coordinate increases) as the X coordinate increases with respect to the object plane Ps, the shift amount of the focal area When the sign of ΔC is positive, the stage 131 is moved in the direction in which the object plane Ps approaches the observation optical system 104. On the other hand, when the focal plane Pf is similarly inclined and the sign of the shift amount ΔC of the focal area is negative, the stage 131 is moved in a direction in which the object plane Ps moves away from the observation optical system 104. As a result, the in-focus area is within the observation field of view. The same applies to the Y direction.

In subsequent step S <b> 34, the processing device 20 acquires an image by imaging the same observation visual field. Thereafter, the process proceeds to step S14. FIG. 33 is a schematic diagram showing an image acquired by imaging the same observation visual field as that in FIG. As shown in FIG. 32, after the Z position of the stage 131 is adjusted, an in-focus area R _focus4 ′ having the same width OW as the reference in-focus area R _base (see FIG. 32A) is obtained from the image M4 ′. Will be detected.

  On the other hand, when the shift amount ΔC of the focus area calculated in step S31 is not so large and the entire focus area is within the image, the change amount ΔW of the focus area width is zero. In this case, the focus area comparison unit 511 determines that adjustment of the Z position of the stage 131 is unnecessary (step S32: Yes), and the process proceeds to step S16.

The subsequent processing in step S16 is generally the same as that in the first embodiment (see FIG. 22), but in step S161, the straightness ΔZ given by the equation (6) as the final straightness ΔZ ′, The sum of the adjustment amount δA _Z calculated in step S33 is calculated (ΔZ ′ = ΔZ + δA _Z ).
The subsequent processing in step S17 is the same as in the first embodiment.

  As described above, according to the third embodiment of the present invention, straightness characteristics can be obtained by adjusting the Z position of the stage 131 even if the stage 131 has a large variation in the Z direction. Is possible.

  Further, according to the third embodiment of the present invention, when the variation in the Z direction (straightness) of the stage 131 is large, the Z position of the stage 131 is adjusted. The possibility that the in-focus area fits in the adjacent observation visual field increases. Therefore, it is possible to improve the detection accuracy of the focus area for the image in which each observation area is copied.

In the third embodiment, since the straightness characteristic can be calculated by using the adjustment amount δA _Z calculated in step S33, the _Z of the stage 131 is not necessarily based on the adjustment amount δA Z. There is no need to adjust the position. However, in this case, it is necessary to consideration to include calculation errors in the adjustment amount .delta.A _Z. Therefore, preferably, after adjusting the Z position of the stage 131, it is confirmed that the entire focusing area is included in an image that is captured in the same observation visual field, and the straightness ΔZ ′ is based on the position of the focusing area. = may calculate the ΔZ + δA _Z.

(Modification 3-1)
Also in the third embodiment, the straightness characteristic may be acquired by limiting the area where the frequency of use is high by the user by setting the imaging range as in the second embodiment.

(Modification 3-2)
Next, Modification 3-2 of Embodiment 3 of the present invention will be described. Note that the configuration of the processing apparatus and the overall configuration of the microscope system including the same in the modified example 3-2 are the same as those in the third embodiment.

  FIG. 34 is a flowchart showing the alignment method according to the modification 3-2. Note that steps S10 to S13 shown in FIG. 34 are the same as those in the third embodiment.

  In step S14 following step S13, the in-focus area detection unit 231 detects the in-focus area from the image acquired in step S13. The focus area detection process is generally the same as in the first embodiment (see FIG. 16), but in step S145, the image evaluation value EX in the X direction is higher than a predetermined threshold Tx and in the Y direction. A small area whose image evaluation value EY is higher than a predetermined threshold value Ty is selected as a focus area, and the number of small areas selected as the focus area is counted.

  In subsequent step S41, the in-focus area comparison unit 511 determines whether or not an in-focus area has been detected in step S14. Specifically, when the number of small areas selected as the focus area is 1 or more, the focus area comparison unit 511 determines that the focus area has been detected (step S41: Yes). In this case, the process proceeds to step S31. The subsequent steps S31 to S33, S16 and S17 are the same as those in the third embodiment.

On the other hand, when the number of small areas selected as the focus area is zero, the focus area comparison unit 511 determines that no focus area has been detected (step S41: No). In this case, in step S42, the Z position adjustment unit 52 is based on the adjustment direction and the adjustment amount δA _Z of the Z position of the stage 131, which is executed in the process for the observation field captured before the current observation field. Thus, control for adjusting the Z position of the stage 131 is performed.

  FIG. 35 is a schematic diagram showing an image showing the current observation visual field. As shown in FIG. 35, when the in-focus area is not detected from the image M5 showing the current observation field, the in-focus area comparison unit 511 is executed in the process for the previous observation field (one field before). The adjustment amount and adjustment direction of the Z position of the stage 131 thus read out are read from the parameter storage unit 241.

For example, when the previous observation visual field is first imaged, as shown in FIG. 32 (b), an image M4 that cannot capture the entire focus area R _focus4 is acquired, so the Z position of the stage 131 is adjusted. (See step S33 in FIG. 31) As a result, as shown in FIG. 33, it is _assumed that an image M4 ′ including the entire focusing area R _focus4 ′ has been acquired. In this case, the adjustment amount δA _Z given by equation (7) and the adjustment direction of the Z position of the stage 131 determined based on the shift amount ΔC of the in-focus area from the reference state are read from the parameter storage unit 241. It is.

Focused region comparison unit 511 outputs the adjustment amount .delta.A _Z and adjustment direction Z position adjusting section 52. In response to this, Z position adjusting unit 52, based on the adjustment amount .delta.A _Z and the adjustment direction, performs control to change the Z position of the stage 131 relative to the microscope apparatus 10. Thereby, the in-focus area can be brought close to the current observation visual field. Thereafter, the process proceeds to step S34.

  After the adjustment of the Z position of the stage 131, when the in-focus area is detected again from the image (see step S34) that shows the observation field of view (step S14, step S41: Yes), the process proceeds to step S31. On the other hand, when the in-focus area is not detected from the image showing the observation field of view (step S41: No), the process proceeds to step S42 again. In this case, the in-focus area comparison unit 511 sequentially goes back the observation field in the order of 2 fields before → 3 fields before ... with respect to the observation field, and the adjustment amount of the Z position calculated in the process for each observation field and Based on the adjustment direction, the adjustment of the Z position of the stage 131 is repeated until a focused region appears in the image.

  As described above, according to the modified example 3-2 of the third embodiment of the present invention, the variation in the Z direction of the stage 131 is large, and the in-focus area cannot be detected from the image showing the current observation visual field. Even in such a case, by adjusting the Z position of the stage 131 based on the straightness characteristic in the nearby observation visual field, the focused region appears in the image, so that the straightness characteristic is also reliably acquired for the observation visual field. It becomes possible.

(Modification 3-3)
Next, a modification 3-3 of the third embodiment of the present invention will be described.
In the modified example 3-3, when an in-focus area is not detected from an image showing the current observation visual field, the adjustment amount δA _Z and the adjustment direction of the Z position of the stage 131 are sequentially traced back to the observation visual field. I got it. However, the Z position of the stage 131 in the current observation visual field may be adjusted using the adjustment amount δA _Z of the Z position in the observation visual field around the current observation visual field (near 4 or 8) and the adjustment direction. This is because the Z position variation of the stage 131 is considered to be small between the current observation visual field and the surrounding observation visual fields.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described.
FIG. 36 is a block diagram showing a configuration of a microscope system according to Embodiment 4 of the present invention. As shown in FIG. 36, the microscope system 4 according to the fourth embodiment includes a microscope apparatus 10 and a processing apparatus 60. Among these, the configuration and operation of the microscope apparatus 10 are the same as those in the first embodiment (see FIG. 2). The alignment apparatus according to the fourth embodiment includes the processing apparatus 60 and the electric stage unit 130 included in the microscope apparatus 10.

  The processing device 60 includes a control unit 61 instead of the control unit 23 illustrated in FIG. 1, and further includes an XY position adjustment unit 62. The configuration and operation of each unit of the processing device 60 other than the control unit 61 and the XY position adjustment unit 62 are the same as those in the first embodiment.

  The control unit 61 includes a focusing area detection unit 231, a focusing area comparison unit 611, and a straightness characteristic detection unit 612. Among these, the operation of the focus area detection unit 231 is the same as that of the first embodiment.

  The focus area comparison unit 611 compares the position of the focus area (center of gravity coordinates) detected by the focus area detection unit 231 with the position (center of gravity coordinates) of the reference focus area stored in the parameter storage unit 241. At the same time, the pattern in the focus area is compared with the pattern in the reference focus area.

  The straightness characteristic detection unit 612 detects the straightness characteristic of the stage 131 in the Z direction based on the comparison result of the position of the in-focus area by the in-focus area comparison unit 611, and uses the comparison result of the pattern of the in-focus area. Based on this, straightness characteristics of the stage 131 in the X direction and the Y direction are detected.

  The XY position adjustment unit 62 adjusts the position of the stage 131 in the X direction and the Y direction based on the straightness characteristics in the X direction and the Y direction detected by the straightness characteristic detection unit 612.

Next, an alignment method according to Embodiment 4 of the present invention will be described.
FIG. 37 is a schematic diagram illustrating an example of a subject used in the alignment method according to the fourth embodiment. In the fourth embodiment, the subject S is such that the flatness is guaranteed and the same pattern appears in all the small areas when the image showing the observation field of view is divided into a plurality of small areas. Is used. As a specific example, a test chart on which a pattern as shown in FIG. 37 is formed is used.

  Also in the alignment method according to the fourth embodiment, as illustrated in FIGS. 8 to 11, the optical axis L of the observation optical system 104 is inclined with respect to the object plane Ps that is the surface of the subject S. Alignment is performed.

FIG. 38 is a flowchart showing the alignment method according to the fourth embodiment. Note that steps S10 to S14 shown in FIG. 38 are the same as those in the first embodiment.
In step S51 following step S14, the in-focus area comparison unit 611 compares the in-focus area pattern detected in step S14 with the reference in-focus area pattern stored in the parameter storage unit 241.

FIG. 39 is a schematic diagram for explaining the pattern comparison process of the focus area executed by the focus area comparison unit 611. Among these, FIG. 39A shows an image in the reference state, and FIG. 39B shows an image showing the current observation visual field. As shown in FIG. 39, when the in-focus area R _focus6 in the image M6 of the current observation visual field is compared with the reference in-focus area R _base in the image M _base , a pattern shift occurs in the y direction.

Thus, when there is a change in the position of the pattern between the in-focus area and the reference in-focus area in the image showing the current observation field of view (step S52: Yes), the straightness characteristic detection unit 612 A change amount and a change direction of the pattern position are detected (step S53). For example, in the case of FIG. 39, the position of the pattern in the in-focus area R _focus6 changes by δy in the minus y direction with respect to the position of the pattern in the reference in-focus area R _base . The straightness characteristic detection unit 612 outputs information about the detected change amount (for example, δy) and the change direction (for example, the minus y direction) to the XY position adjustment unit 62.

  In subsequent step S54, the XY position adjustment unit 62 determines the X position and Y position of the stage 131 with respect to the microscope apparatus 10 based on the change amount and change direction of the pattern position output from the straightness characteristic detection unit 612. Control to adjust.

  Here, when the straightness in the X direction and the Y direction of the stage 131 is zero, that is, when the stage 131 is moving as controlled by the imaging control unit 22 in the XY plane, an image showing each observation field of view. The pattern in should exactly match the pattern in the reference state image. In other words, if there is a shift in the position of the pattern in the image showing the observation field with respect to the pattern in the reference state image, it can be said that there is a variation in the linear motion of the stage 131 in the X direction or the Y direction. .

Therefore, the XY position adjustment unit 62 adjusts the pattern in the plus y direction so that the position of the pattern in the image showing the observation field completely coincides with the position of the pattern in the image in the reference state (in the case of FIG. 39B). Control is performed to adjust the X position or the Y position of the stage 131 so as to increase by δy.
The same applies when the position of the pattern in the image showing the observation field is shifted in the x direction. Thereafter, the process proceeds to step S15.

  On the other hand, when there is no change in the position of the pattern in step S51 (step S52: No), the process proceeds to step S15. Subsequent steps S15 to S17 are the same as those in the first embodiment.

  As described above, according to the fourth embodiment of the present invention, the straightness in the X direction and the Y direction can be detected in addition to the straightness in the Z direction of the stage 131. In the fourth embodiment, the straightness in the X direction and the Y direction is detected, and the X position and the Y position of the stage 131 are adjusted at the timing, so that the accuracy of detecting the straightness in the Z direction is improved. Can do.

  The first to fourth embodiments and the modifications described above are not limited as they are, and various inventions are formed by appropriately combining a plurality of components disclosed in the embodiments and the modifications. be able to. For example, some components may be excluded from all the components shown in the embodiment. Or you may form combining the component shown in different embodiment suitably.

DESCRIPTION OF SYMBOLS 1, 1-2, 2, 3, 4 Microscope system 10 Microscope apparatus 100 Arm 101 Trinocular tube unit 102 Lens tube 103 Eyepiece unit 104 Observation optical system 105 Inclination adjustment drive part 106 Base 110 Epi-illumination unit 111 Epi-illumination light source 112 Epi-illumination optical system 120 Transmitted illumination unit 121 Transmitted illumination light source 122 Transmitted illumination optical system 130 Electric stage unit 131 Stage 132 Stage drive unit 133 Position detection unit 140, 141 Objective lens 142 Revolver 20, 30, 40, 50, 60 Processing Device 211 Imaging unit 21 Image acquisition unit 212 Memory 22, 41 Imaging control unit 23, 51, 61 Control unit 231 Focus area detection unit 232 Focus position comparison unit 233, 612 Straightness characteristic detection unit 24 Storage unit 241 Parameter storage unit 242 Program storage unit 2 Input unit 42 Output unit 31 calibration unit 43 display 43a screen 411 area setting unit 412 moves condition setting unit 52 Z position adjusting section 511, 611 Go focal region comparison unit 62 XY position adjusting unit

Claims (11)

An imaging optical system provided such that the optical axis is inclined at a predetermined angle with respect to the normal of the planar object surface;
Moving means for relatively moving the object plane and the imaging optical system in a direction in which the tilt direction of the optical axis is projected onto the object plane;
By causing the imaging optical system to perform imaging at first and second positions whose relative positions with respect to the object plane are different from each other, first and second images corresponding to the first and second positions, respectively, are obtained. An imaging control unit to be acquired;
A detector that detects a locus of relative movement between the object plane and the imaging optical system by comparing the first and second focus areas detected from the first and second images, respectively;
An alignment apparatus comprising: A stage having a placement surface on which a subject is placed;
The moving means relatively moves the object surface and the imaging optical system in a plane parallel to the placement surface,
The detection unit detects a relative displacement between the object plane and the imaging optical system in a normal direction of the mounting surface;
The alignment apparatus according to claim 1. The optical axis of the imaging optical system forms the angle with respect to the normal of the mounting surface described above,
The imaging optical system performs imaging using the surface of a subject placed on the placement surface so as to be parallel to the placement surface, as the object plane.
The alignment apparatus according to claim 2. The optical axis of the imaging optical system is orthogonal to the mounting surface,
The imaging optical system performs imaging using the surface of a subject placed on the placement surface as the object plane so as to form the angle with respect to the placement surface;
The alignment apparatus according to claim 2.   The detection unit detects a change in position in the image of the first and second in-focus areas detected from the first and second images, respectively, and detects the locus based on the change in the position. The alignment apparatus according to any one of claims 2 to 4, wherein The detection unit detects a change in width of the first and second focus areas detected from the first and second images, respectively;
5. The apparatus according to claim 2, further comprising an adjusting unit that adjusts a relative position between the object surface and the imaging optical system in a normal direction of the mounting surface based on the change in the width. The alignment apparatus according to item 1.   The calibration unit according to any one of claims 1 to 6, further comprising a calibration unit that calibrates relative movement between the object plane and the imaging optical system by the moving unit based on the locus detected by the detection unit. The alignment apparatus according to item 1.   The apparatus further comprises a display unit that displays information for calibrating a relative motion between the object plane and the imaging optical system by the moving unit based on the trajectory detected by the detection unit. The alignment apparatus of any one of 1-6.   A microscope system comprising the alignment apparatus according to claim 1. An installation step of providing an imaging optical system so that an optical axis is inclined at a predetermined angle with respect to a normal line of a planar object surface;
A moving step of relatively moving the object plane and the imaging optical system in a direction in which the tilt direction of the optical axis is projected onto the object plane;
By causing the imaging optical system to perform imaging at first and second positions whose relative positions with respect to the object plane are different from each other, first and second images corresponding to the first and second positions, respectively, are obtained. An imaging control step to be acquired;
A detection step of detecting a locus of relative movement between the object plane and the imaging optical system by comparing the first and second focus areas detected from the first and second images, respectively;
An alignment method comprising: A planar object surface, and an imaging optical system provided such that an optical axis is inclined at a predetermined angle with respect to a normal line of the planar object surface, the inclination direction of the optical axis being the object A movement control step for performing control of relative movement in the direction projected on the surface;
By causing the imaging optical system to perform imaging at first and second positions whose relative positions with respect to the object plane are different from each other, first and second images corresponding to the first and second positions, respectively, are obtained. An imaging control step to be acquired;
A detection step of detecting a locus of relative movement between the object plane and the imaging optical system by comparing the first and second focus areas detected from the first and second images, respectively;
An alignment program for causing a computer to execute.