Magnifying observation device

Abstract

To provide a highly convenient magnifying observation device.SOLUTION: A magnifying observation device 10 comprises a revolver 41. The revolver 41 is a lens switching unit that selectively arranges one of a plurality of objective lenses on an optical path of an image pick-up device 7. The objective lenses attached to the revolver 41 include at least one wide-angle objective lens 40d. An image registration unit 207 registers, as a navigation image, an observation image created by an image creation unit 301 in a state in which the wide-angle objective lens 40d is arranged on the optical path of the image pick-up device 7 by the revolver 41. The image registration unit 207 generates navigation correction information for correcting the correspondence between a position in the navigation image and a position in an observation object. A movement control unit 302 controls the movement of a placement stage 2 made by a placement stage control unit 23 on the basis of designation of a position with respect to the navigation image and the navigation correction information.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a magnification observation device. [Background technology]

[0002] A magnification observation device is sometimes used to magnify and observe an observation target. In the magnification observation device of Patent Document 1, a user can move a mounting table supporting an observation target while viewing a live image captured by an imaging unit so that the observation target is within the field of view of the imaging unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-86298 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the magnification observation device of Patent Document 1, the user cannot grasp the positional relationship between the field of view and the observation object unless he or she actually moves the mounting table, which poses a problem in terms of usability.

[0005] In view of the above problems, an object of the present invention is to provide a highly convenient magnification observation device. [Means for solving the problem]

[0006] In order to solve the above problem, a magnifying observation device as one example of an embodiment according to the present invention includes an image sensor that captures an image of an observation object, an image generation unit that controls the image sensor to generate an observation image, a plurality of objective lenses, a lens switching unit that selectively places one of the plurality of objective lenses on an optical path of the image sensor, a mounting table on which the observation object is placed, a mounting table control unit that moves the mounting table in a horizontal direction, a movement control unit that controls the movement of the mounting table by the mounting table control unit, and an image registration unit that can register a navigation image based on the observation image generated by the image generation unit, wherein the plurality of objective lenses include at least one telecentric objective lens and at least one wide-angle objective lens having a larger distortion aberration than the telecentric objective lens, and the lens switching unit The unit has a plurality of lens mounting holes formed therein, and the telecentric objective lens and the wide-angle objective lens are respectively mounted in the lens mounting holes. The image registration unit registers, as a navigation image, an observation image generated by the image generation unit as an image having a field of view size larger than the aperture of the wide-angle objective lens, with the wide-angle objective lens placed on the optical path of the image sensor by the lens switching unit, and generates navigation correction information for correcting deviations caused by distortion aberration of the wide-angle objective lens in the corresponding relationship between positions in the navigation image and positions in the observed object. The movement control unit controls the movement of the mounting table by the mounting table control unit based on the position designation for the navigation image and the navigation correction information. Effect of the Invention

[0007] According to the present invention, the user can move the mounting table based on a position specification for the navigation image, thereby improving the convenience of the magnification observation device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a perspective view of an imaging unit of the magnification observation device from above and in front. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 2 is a block diagram illustrating a schematic configuration of a magnification observation device. [Figure 6] FIG. 2 shows the underside of the revolver with the objective lens removed. [Figure 7] 1A and 1B are diagrams for explaining an image observed through a telecentric objective lens. [Figure 8] 4A and 4B are diagrams for explaining an image observed through a wide-angle objective lens. [Figure 9] 11A and 11B are diagrams for explaining the deviation between the indicated position on the navigation image and the center of the visual field. [Figure 10] FIG. 1 shows a calibration board. [Figure 11] 4A and 4B are diagrams showing vertical movement of an observation head accompanying switching of objective lenses. [Figure 12] FIG. [Figure 13] FIG. 13 is a diagram showing a state where the focus value has passed its peak. [Figure 14] FIG. 4 is a flow diagram showing a procedure for registering a navigation image. [Figure 15] FIG. 4 is a flow diagram showing a flow of objective lens switching. [Figure 16] FIG. 11 is a flow diagram showing a flow of movement control using a navigation image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a magnification observation device 10 as an example of an embodiment according to the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference symbols and will not be described repeatedly. In the following description, terms meaning positions or directions such as front, back, left, right, up, and down may be used, but these terms are used for convenience to facilitate understanding of the embodiment. Unless otherwise clearly stated, these terms are not limited to front, back, left, right, up, and down in the strict geometric sense.

[0010] Fig. 1 is a perspective view from above the front of the imaging unit 1 of a magnification observation device 10 of this embodiment. As shown in Fig. 1, the magnification observation device 10 includes the imaging unit 1, an information processing unit 71, a display unit 72, and an operation unit 73. The imaging unit 1 is connected to the information processing unit 71 by a communication cable 9. The information processing unit 71 is connected to the display unit 72 and the operation unit 73 by the communication cable 9.

[0011] Here, the communication cable 9 is a cable for transmitting and receiving signals between the components of the magnifying observation device 10, that is, between the imaging unit 1, the information processing unit 71, the display unit 72, and the operation unit 73. As the communication cable 9, for example, a cable for transmitting and receiving electric signals, such as a USB cable (USB: Universal Serial Bus), a LAN cable (LAN: Local Area Network), or an HDMI cable (HDMI: High-Definition Multimedia Interface, a registered trademark), is used. Note that cables of different standards may be used depending on the components to be connected. As long as signals can be transmitted and received between the imaging unit 1, the information processing unit 71, the display unit 72, and the operation unit 73, the communication cable 9 may be an optical cable for transmitting and receiving optical signals. Also, instead of the communication cable 9, signals may be transmitted and received between the components by wireless communication using electromagnetic waves.

[0012] The information processing unit 71 is a unit including a processor such as a CPU (Central Processing Unit) and a storage device such as a RAM (Random Access Memory), and executes various information processing in the magnification observation device 10. The information processing unit 71 also functions as an image processing device for the magnification observation device 10.

[0013] The display unit 72 is a unit including an image display device such as an LCD (Liquid Crystal Display) and displays an image to a user of the magnification observation device 10. The operation unit 73 is a unit that receives operations from a user of the magnification observation device 10. The operation unit 73 includes user interface devices such as a keyboard, a mouse, and a joystick. The operation unit 73 may also include a controller designed exclusively for the magnification observation device 10.

[0014] The magnification observation device 10 is a device for enlarging and observing an observation object OB. First, the observation object OB is imaged by the imaging element 7 of the imaging unit 1 to generate an observation image. Then, a display screen based on the observation image is generated by the information processing unit 71, and the display screen is displayed on the display unit 72. The display screen displayed on the display unit 72 includes an image in which the observation object OB is enlarged. A user of the magnification observation device 10 can enlarge and observe the observation object OB by observing the display screen of the display unit 72. In Figs. 1, 2, 3, and 4, an electronic circuit board on which a plurality of electronic components are mounted is shown as an example of the observation object OB.

[0015] The imaging unit 1 will be described with reference to Figs. 1, 2, 3, and 4. Fig. 2 is a perspective view of the imaging unit 1 from above and behind. Fig. 3 is a right side view of the imaging unit 1. Fig. 4 is a front view of the imaging unit 1. An information processing unit 71, a display unit 72, and an operation unit 73 are omitted from Figs. 2, 3, and 4. The imaging unit 1 in Figs. 1, 2, 3, and 4 includes a mounting table 2, an observation head 4, a support column 5, a Z-direction stage 6, and an imaging element 7.

[0016] 1, 2, 3, and 4, a rotating plate 100 is placed on the upper surface 20 of the mounting table 2. An observation object OB is placed on an upper surface 107 of the rotating plate 100. The upper surface 107 of the rotating plate 100 has a circular shape in a plan view, and the observation object OB is placed at the center thereof. Radial pins 109 are also radially arranged on the circumference of the rotating plate 100. A user of the magnifying observation device 10 can change the arrangement angle of the observation object OB placed at the center of the upper surface 107 by gripping the radial pins 109 and rotating the rotating plate 100.

[0017] The mounting table 2 is supported by a mounting table control unit 23. The mounting table control unit 23 moves the mounting table 2 in the X direction and the Y direction (horizontal direction). The mounting table control unit 23 in the figure includes a moving mounting unit 21 and a base unit 22. The base unit 22 is fixed, and the moving mounting unit 21 is supported on the base unit 22. The moving mounting unit 21 is movable in the X direction and the Y direction relative to the base unit 22. The moving mounting unit 21 moves in the X direction and the Y direction, thereby moving the mounting table 2 in the X direction and the Y direction. The mounting table control unit 23 moves the mounting table 2 in the X direction and the Y direction, thereby changing the range in which the observation object OB is captured by the image sensor 7.

[0018] The observation head 4 is disposed above the mounting table 2. The observation head 4 includes an imaging element 7 for imaging the observation object OB. The imaging element 7 is an element that converts reflected light or transmitted light from the observation object OB into an electrical signal, and for example, a CCD (Charge Coupled Device) or the like is used.

[0019] The observation head 4 is attached to a Z-direction stage 6. The Z-direction stage 6 moves the observation head 4 relative to the upper surface 20 of the mounting table 2 along the Z direction (vertical direction). The observation head 4 is rotatable about a first rotation axis 11 that passes through the Z-direction stage 6 and extends in the Y direction (horizontal direction).

[0020] A revolver 41 is provided at the bottom of the observation head 4. The revolver 41 is a lens switching unit that selectively places one of a plurality of objective lenses on the optical path of the image sensor 7. A plurality of objective lenses are attached to the revolver 41. The plurality of objective lenses each have a different magnification. One of the plurality of objective lenses is selected as a lens for observing the observation object OB and is placed on the optical path of the image sensor 7. Specifically, the objective lens 40 that is directed to the observation object OB (placed on the optical path of the image sensor 7) is switched by rotating the revolver 41.

[0021] The objective lenses attached to the revolver 41 (lens switching unit) include at least one telecentric objective lens and at least one wide-angle objective lens. In Figs. 1, 2, 3, and 4, the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d are attached to the revolver 41. The first objective lens 40a, the second objective lens 40b, and the third objective lens 40c are telecentric objective lenses in which the chief ray and the optical axis are parallel. On the other hand, the wide-angle objective lens 40d is a non-telecentric lens. The wide-angle objective lens 40d is a lens with a larger distortion aberration than the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c, which are telecentric objective lenses.

[0022] The Z-direction stage 6 is attached to a rotating holder 8. The rotating holder 8 is connected to a support column 5 so as to be rotatable about a first rotation axis 11. The support column 5 extends in the Z direction and supports the rotating holder 8, the Z-direction stage 6, and the observation head 4. The rotating holder 8 is provided with a rod-shaped handle 81 that protrudes outward. A user of the magnification observation device 10 can rotate the observation head 4 together with the Z-direction stage 6 and the rotating holder 8 around the first rotation axis 11 by operating the rod-shaped handle 81. By rotating the observation head 4, the user can observe the observation object OB not only from the vertical direction but also from an oblique direction.

[0023] The configuration of the magnification observation device 10 will be described with reference to Fig. 5. Fig. 5 is a block diagram that shows an example of the configuration of the magnification observation device 10. As shown in Fig. 5, the observation head 4 of the imaging unit 1 includes a revolver control unit 45, an imaging lens 240, a lens control unit 241, an illumination unit 250, and an aperture control unit 260 in addition to the imaging element 7, a revolver 41, a first objective lens 40a, a second objective lens 40b, a third objective lens 40c, and a wide-angle objective lens 40d.

[0024] The revolver control unit 45 rotates the revolver 41 to select one of the multiple objective lenses (here, the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d) as a lens for observation toward the observation object OB. The selected lens is placed on the optical path of the image sensor 7. The imaging lens 240 forms the light that has passed through the objective lens into an image to be captured by the image sensor 7.

[0025] The lens control unit 241 moves the imaging lens 240 to change the relative position with respect to the objective lens 40, thereby changing optical conditions such as magnification and focal length. Note that a plurality of lenses having different optical conditions such as magnification and focal length may be provided as the imaging lens 240, and the lens control unit 241 may perform control to selectively place one of the plurality of imaging lenses 240 on the optical path of the image sensor 7. Note that various optical elements such as additional lenses and half mirrors may be disposed on the optical path between the objective lens 40 and the imaging lens 240.

[0026] The illumination unit 250 irradiates light onto the observation object OB in order to obtain reflected light or transmitted light from the observation object OB. The illumination unit 250 includes, for example, a ring illumination and a coaxial epi-illumination. The aperture control unit 260 controls an aperture (not shown) provided in the optical path between the objective lens and the imaging lens 240 to adjust the aperture amount.

[0027] The information processing unit 71 includes a calculation unit 300 and a storage unit 311. The calculation unit 300 includes an image generation unit 301, a movement control unit 302, an analysis processing unit 303, a display control unit 304, a lighting control unit 305, an input / output control unit 306, and an image registration unit 307.

[0028] The calculation unit 300 is a unit including a processor such as a CPU. The storage unit 311 is a unit including a storage device such as a RAM. The calculation unit 300 executes a program stored in the storage unit 311, thereby realizing the functions of an image generation unit 301, a movement control unit 302, an analysis processing unit 303, a display control unit 304, an illumination control unit 305, an input / output control unit 306, and an image registration unit 307.

[0029] The image generating unit 301 controls the image sensor 7 to generate an observation image based on reflected light or transmitted light from the observation object OB. The movement control unit 302 transmits a command to the mounting table control unit 23 of the imaging unit 1 to control the movement of the mounting table 2 by the mounting table control unit 23.

[0030] The analysis processing unit 303 executes image analysis processing on the observation image generated by the image generating unit 301. The display control unit 304 generates a display screen to be displayed on the display unit 72 based on the observation image.

[0031] The illumination control unit 305 controls the illumination unit 250 to adjust the light irradiated onto the observation object OB. The input / output control unit 306 is a communication interface unit, and controls signals input to and output from the information processing unit 71 in accordance with various communication standards so that the information processing unit 71 can communicate with external devices such as the imaging unit 1, the display unit 72, and the operation unit 73.

[0032] The image registration unit 307 is capable of registering a navigation image based on the observation image generated by the image generation unit 301. The navigation image is an image used by the user to specify the observation field of view by the image sensor 7. The image registration unit 307 stores the navigation image to be registered in the storage unit 311 together with navigation correction information to be described later.

[0033] Next, the relationship between the revolver 41 and the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d will be described with reference to Fig. 6. Fig. 6 is a diagram showing the bottom of the revolver 41 with the objective lenses removed.

[0034] A plurality of lens mounting holes are formed on the underside of the revolver 41. In Fig. 6, a first lens mounting hole 44a, a second lens mounting hole 44b, a third lens mounting hole 44c, and a fourth lens mounting hole 44d are formed. An objective lens is attached to each of these lens mounting holes. In Fig. 6, a first objective lens 40a is attached to the first lens mounting hole 44a. A second objective lens 40b is attached to the second lens mounting hole 44b. A third objective lens 40c is attached to the third lens mounting hole 44c. A wide-angle objective lens 40d is attached to the fourth lens mounting hole 44d.

[0035] The revolver 41 can selectively place one of the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d on the optical path of the image sensor 7 by rotating the revolver 41 around the revolver central axis 42 located at the center of the lens mounting holes. The objective lenses of the magnification observation device 10, here the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d, have different optical characteristics such as magnification and numerical aperture. The user of the magnification observation device 10 can selectively place one of the objective lenses on the optical path of the image sensor 7 by rotating the revolver 41, and can perform observation by switching the objective lens used for observation to an objective lens suitable for the desired observation conditions (magnification, etc.).

[0036] Each of the objective lenses may be a small device in which an optical lens is assembled in a cylindrical housing so that the objective lenses can be easily attached to the lens mounting holes of the revolver 41. The objective lens device may be configured to transmit information about the objective lens (mechanical characteristics such as the length and diameter of the cylinder, optical characteristics such as the focal length and optical magnification of the assembled optical lens, management information such as the model number and date of manufacture, etc.) to the magnifying observation device 10. For example, a storage medium storing the above-mentioned information may be assembled in the cylindrical housing, and a terminal capable of receiving information from the storage medium may be provided in the lens mounting hole of the revolver 41. If information about the objective lens is transmitted to the magnifying observation device 10, appropriate control according to the characteristics of the objective lens is possible in the control of autofocus and the like described later.

[0037] With reference to Fig. 7, an observation image 48a will be described when the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c, which are telecentric objective lenses, are selectively arranged on the optical path of the image sensor 7. Fig. 7 is a diagram for explaining an observation image 48a when an observation range 48 on an observation object OB is observed by a telecentric objective lens. Note that various specific shapes can be used for the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c, so in Fig. 7, the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c are shown by virtual lines, and the specific shapes are not shown. In addition, various optical elements may be arranged in the optical path between the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the image sensor 7, but Figure 7 omits the illustration of the optical path between the first objective lens 40a, the second objective lens 40b, the third objective lens 40c, and the image sensor 7.

[0038] As shown in FIG. 7, in telecentric objective lenses (first objective lens 40a, second objective lens 40b, third objective lens 40c), light rays passing through the lens become parallel to the optical axis on one side of the lens (here, the side of the observation object OB on the left side in the figure). In general, telecentric objective lenses have small distortion aberration, and by using a telecentric objective lens, an observation image 48a with little distortion can be obtained. For example, if a square lattice pattern is written in the observation range 48 of the observation object OB, the square lattice pattern also appears in the observation image 48a without distortion.

[0039] With reference to FIG. 8, an observation image 48b in a case where a non-telecentric wide-angle objective lens 40d is selectively arranged on the optical path of the image sensor 7 will be described. FIG. 8 is a diagram for explaining an observation image 48b in a case where an observation range 48 on an observation object OB is observed by the wide-angle objective lens 40d. Note that various specific shapes of the wide-angle objective lens 40d can be used, so in FIG. 8, the wide-angle objective lens 40d is shown by a virtual line, and the specific shape is not shown. In addition, various optical elements can be arranged on the optical path between the wide-angle objective lens 40d and the image sensor 7, but in FIG. 8, the optical path between the wide-angle objective lens 40d and the image sensor 7 is omitted from illustration.

[0040] As shown in FIG. 8, in the non-telecentric wide-angle objective lens 40d, the light passing through the lens is not parallel to the optical axis on one side of the lens. In FIG. 8, the light passing through the wide-angle objective lens 40d from the image sensor 7 side on the right side of the figure spreads toward the observation object OB side on the left side of the figure. In this way, since the wide-angle objective lens 40d has the property of spreading the light, the observation image 48b obtained by the wide-angle objective lens 40d is likely to be distorted. For example, if a square lattice pattern is written in the observation range 48 of the observation object OB, the lattice pattern appears in the observation image 48b as if the peripheral part is shrunk relative to the center, resulting in a so-called barrel distortion.

[0041] 7 and 8, for the sake of explanation, the case where the same observation range 48 is observed with a telecentric objective lens and a wide-angle objective lens is described, but if a wide-angle objective lens 40d that has the property of spreading light rays is used, an observation image with a wide imaging range can be obtained. In particular, the wide-angle objective lens 40d can be used to obtain an observation image with a field of view size larger than the aperture of the lens. For example, if an electronic circuit board as shown in Figs. 1, 2, 3, and 4 is the observation object OB, if the wide-angle objective lens 40d is used, an observation image in which the entire electronic circuit board is captured can be obtained.

[0042] In the magnifying observation device 10, a navigation image may be used so that the user can easily specify the observation field of view for the observation object OB. For example, in the display unit 72, the navigation image is displayed on a screen (window) separate from the current observation field of view (live image) by the image sensor 7, and when the user clicks a desired position in the navigation image, the mounting table 2 on which the observation object OB is placed is moved so that the position on the observation object OB corresponding to that position becomes the observation field of view. Since the user can move the mounting table 2 based on the position specification for the navigation image, the convenience of the magnifying observation device 10 is improved.

[0043] Here, when an observation image in which the entire observation object OB such as an electronic circuit board is captured is used as the navigation image, the user can specify any position of the observation object OB as the observation field. By using the wide-angle objective lens 40d, the entire observation object OB can be captured within the shooting range, so that a navigation image with a wide field of view can be obtained in which the entire observation object OB is captured in a single observation image without combining multiple observation images.

[0044] However, as mentioned above, distortion occurs in the observation image obtained by the wide-angle objective lens 40d, so if the observation image obtained by the wide-angle objective lens 40d is used as the navigation image as is, the position indicated by the user may not coincide with the center of the field of view after the mounting table 2 is moved.

[0045] 9 is a diagram for explaining the deviation between the indicated position on the navigation image 500 and the visual field center 515. In FIG. 9, the display screen 400 displayed on the display unit 72 includes a live image 490 and a navigation image 500.

[0046] The live image 490 is an image showing an observation image currently being captured by the imaging element 7. The live image 490 shows an enlarged view of the observation object OB. The display of the live image 490 is updated at regular time intervals (for example, every 1 / 60 seconds). A navigation image 500 is displayed superimposed on a part of the live image 490 (lower right in FIG. 9). In FIG. 9, an observation image in which the entire observation object OB is captured is used as the navigation image 500.

[0047] The navigation image 500 includes a cursor 511. When the user specifies a desired position in the navigation image 500 using the cursor 511, the mounting table 2 is moved so that a position on the actual observation object OB corresponding to the specified position becomes the center of view 515 of the live image 490.

[0048] Here, the movement control unit 302 of the mounting table 2 calculates the amount of movement of the mounting table 2 required to move the field of view center 515 to a position corresponding to the specified position, based on the current position of the mounting table 2, the position specified by the user, and the optical magnification of the navigation image 500. If the navigation image 500 is captured by a telecentric objective lens, the mounting table 2 is moved by the calculated amount of movement, whereby the field of view center 515 is moved to a position corresponding to the specified position.

[0049] However, when the navigation image 500 is captured using a non-telecentric wide-angle objective lens 40d, the correspondence between one pixel and the actual distance differs between the central portion and the peripheral portion of the navigation image 500. Therefore, the movement control unit 302 cannot calculate the correct movement amount only based on the optical magnification of the navigation image 500.

[0050] 9, cursor 511 is aligned with electronic component 33, and the position of electronic component 33 is specified as center of field of view 515. However, since electronic component 33 is located away from the center in navigation image 500, the amount of movement is not calculated correctly, and after placement table 2 moves, center of field of view 515 is shifted from the position of electronic component 33 shown in live image 490.

[0051] Therefore, when registering the navigation image 500 by the wide-angle objective lens 40d, the image registration unit 507, which registers the navigation image 500, generates navigation correction information for correcting the correspondence between the position in the navigation image 500 and the position in the observed object OB, in particular, the deviation in the correspondence caused by the distortion aberration of the wide-angle objective lens 40d.

[0052] For example, if the optical characteristics (lens design values) of the wide-angle objective lens 40d are known, the navigation correction information can be generated based on the optical characteristics. As a method other than generating the navigation correction information using the optical characteristics of the wide-angle objective lens 40d, the image registration unit 507 can generate the navigation correction information based on an observation image actually captured using the wide-angle objective lens 40d.

[0053] As an example of generating navigation correction information based on an observation image actually captured using the wide-angle objective lens 40d, the image registration unit 507 can generate navigation correction information using a calibration board 141 having a predetermined periodic pattern 143 as shown in Figure 10.

[0054] 10 is marked with a dot pattern in which dots are arranged at a predetermined constant interval as a periodic pattern 143. When the image generating unit 301 generates an observation image using this calibration board 141 as an observation target and the wide-angle objective lens 40d is used, an observation image is obtained in which the intervals between dots appear to be different between the center and the periphery.

[0055] However, since the actual interval between dots is a predetermined constant interval, the image registration unit 507 can generate navigation correction information indicating the correct positional relationship between the position in the observation image and the position of the actual observation object by comparing an observation image in which the calibration board 141 is the observation object with the predetermined constant interval. Note that, since the process for generating the navigation correction information includes a process corresponding to image analysis, the image registration unit 507 may generate the navigation correction information by having the analysis processing unit 303 analyze an observation image obtained by capturing an image of the calibration board 141.

[0056] When generating navigation correction information using this calibration board, it is preferable to also generate information on the correspondence between one pixel of the navigation image and the actual distance (calibration value). The calibration value is generated based on the optical magnification of the navigation image, for example. At this time, the magnification of the imaging lens 240 may be changed by the lens control unit 241, and the calibration value may be calculated using an observation image captured of the calibration board 141 when the magnification of the imaging lens 240 is high. By using an observation image in a state where the magnification of the imaging lens 240 is increased, even if the calibration board 141 has a short interval between the periodic patterns 143 (mainly used for calibrating high-magnification lenses), an observation image suitable for calibrating the wide-angle objective lens 40d with a small magnification is obtained, and an accurate calibration value is generated.

[0057] Once the navigation correction information has been generated in the above manner, the image registration unit 507 stores the navigation correction information in the storage unit 311 together with the navigation image 500. When the user specifies a position for the navigation image 500, the movement control unit 302 controls the movement of the mounting table 2 by the mounting table control unit 23 based on the position specification and the navigation correction information, thereby enabling the visual field center 515 to be correctly moved to a position desired by the user.

[0058] As a result, in the magnification observation device 10 of this embodiment, the center of field of view 515 can be moved to the desired position using the navigation image 500 in which a wide range (e.g., the entire object to be observed OB) is captured, making it highly convenient.

[0059] It should be noted that the calculation related to the movement of the mounting table 2 using the navigation correction information may be performed when the user specifies a position with respect to the navigation image 500. Therefore, it is not necessary to perform the calculation using the navigation correction information every time the live image 490 is updated, and the calculation load on the information processing unit 71 can be kept low.

[0060] Note that a navigation corrected image in which the navigation image 500 itself is corrected may be generated as the navigation correction information. For example, the image registration unit 507 can calculate the degree of distortion occurring in the navigation image based on the optical characteristics of the wide-angle objective lens 40d, etc., and generate a navigation corrected image in which the distortion has been corrected. Then, the navigation corrected image in which the distortion has been corrected may be registered in the storage unit 311. When a navigation corrected image is registered, the navigation corrected image is used as the navigation image 500, so that the position specified by the user with respect to the navigation image 500 and the center of the field of view 515 after the movement of the mounting table 2 correctly coincide with each other.

[0061] When a navigation correction image is registered, the registered navigation correction image may be displayed superimposed on the live image 490. When the live image 490 is updated, the navigation correction image may remain the same as when it was registered, so that there is no need to perform calculations using the navigation correction information every time the live image 490 is updated, and the calculation load on the information processing unit 71 can be kept low.

[0062] In the magnification observation device 10 of this embodiment, both telecentric objective lenses (first objective lens 40a, second objective lens 40b, third objective lens 40c) and a non-telecentric wide-angle objective lens 40d are attached to the revolver 41, so that when the objective lenses are switched, the observation head 4 may move significantly in the vertical direction (Z direction) together with the objective lenses.

[0063] Fig. 11 shows the vertical movement of the observation head 4 accompanying the switching of the objective lens. Since the wide-angle objective lens 40d has a long working distance (the distance from the lens to the observation object OB when in focus), when the wide-angle objective lens 40d is directed toward the observation object OB (placed on the optical path of the image sensor 7), the Z-direction stage 6 (vertical movement unit) raises the wide-angle objective lens 40d to a position far away in the Z direction from the observation object OB in order to adjust the focus of the wide-angle objective lens 40d to the observation object OB, as shown by the solid line in Fig. 11.

[0064] In this state, when the objective lens (placed on the optical path of the image sensor 7) directed to the observation object OB is switched to one of the telecentric objective lenses, for example, the first objective lens 40a, the Z-direction stage 6 lowers the observation head 4 together with the first objective lens 40a in order to adjust the focus of the first objective lens 40a to the observation object OB. That is, when the objective lens is switched, the Z-direction stage 6 moves the objective lens in the vertical direction (Z direction) according to the difference in the parfocal distance (the distance from the mounting surface of the objective lens in the revolver 41 to the observation object OB when in focus) between the objective lens before the switching and the objective lens after the switching. In particular, when the objective lens is switched between any of the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c, which are telecentric lenses, and the wide-angle objective lens 40d, which is a non-telecentric lens, the Z-direction stage 6 moves the objective lens vertically by a vertical movement amount (e.g., 30 mm) that is determined in advance according to the difference in parfocal distance between the telecentric lens and the non-telecentric lens. Note that telecentric lenses may be designed to have the same parfocal distance, and if the parfocal distance between the objective lens before and after switching is the same, the Z-direction stage 6 does not move the objective lens vertically.

[0065] Here, for example, when the observation object OB is an electronic circuit board, an electronic component 33 with a large height (Z-direction dimension) and an electronic component 34 with a small height may be mounted closely on the electronic circuit board. When the Z-direction stage 6 lowers the first objective lens 40a to focus the first objective lens 40a on the top surface of the electronic component 34 with a small height, if the working distance of the first objective lens 40a is short, the other objective lenses (the second objective lens 40b, the third objective lens 40c, and the wide-angle objective lens 40d) also approach close to the observation object OB, and there is a risk that the other objective lenses (for example, the second objective lens 40b) may come into contact with the electronic component 33 with a large height, as shown by the virtual line in FIG.

[0066] Therefore, when switching from the wide-angle objective lens 40d to the telecentric objective lenses (the first objective lens 40a, the second objective lens 40b, and the third objective lens 40c), it is preferable to predict the working distance of the objective lens after switching. The working distance can be calculated according to the optical characteristics (focal length, etc.) of the objective lens after switching and the viewing angle of the observed image, etc.

[0067] It is preferable that a warning is issued according to the working distance of the objective lens after switching. For example, when the objective lens used is switched from the wide-angle objective lens 40d to one of the telecentric lenses and the objective lens is lowered with a vertical movement amount of 30 mm, if the working distance of the objective lens after switching is expected to be 10 mm, a collision between the objective lens and the observation object OB may occur. Therefore, it is preferable that a warning such as "The Z-direction stage will be lowered by 30 mm. Please make sure that it will not collide with the sample before clicking the OK button" is displayed on the display unit 72 together with an "OK" button and a "Cancel" button.

[0068] If the user presses the "OK" button in response to this warning, the objective lens will be switched and the observation head 4 will be lowered. On the other hand, if the user presses the "Cancel" button, the objective lens will not be switched and the observation head 4 will not be lowered. This prevents the objective lens from coming into contact with part of the observation object OB (such as a tall electronic component 33).

[0069] In addition to displaying a warning to the user, collision of the objective lens can also be prevented by actually lowering the objective lens while monitoring the focus value of the objective lens.

[0070] 12 shows a focus value graph 520 of the objective lens. This focus value graph 520 may be displayed on the display unit 72 when the objective lens is moved in the Z direction. The focus value graph 520 includes a calculation result display unit 521, a calculation value graph 522, a current value bar 525, a maximum value marker 528, and a lens position marker 530.

[0071] While the objective lens is moved in the Z direction, the analysis processing unit 303 calculates a focus value based on an observation image generated by capturing an image of the observation object OB by the imaging element 7. The calculated focus value is stored in the storage unit 311 together with the Z direction position (height) of the objective lens at that time.

[0072] The focus value graph 520 is plotted by the display control unit 304 based on the focus value calculated by the analysis processing unit 303 and the Z direction position of the objective lens, and is displayed on the display unit 72. Note that the focus value graph 520 is preferably displayed on a screen (window) separate from the observation image.

[0073] The correspondence relationship between the Z direction of the objective lens and the focus value is displayed in calculation result display section 521 of focus value graph 520. Specifically, calculation result display section 521 displays calculation value graph 522 with the Z direction position on the vertical axis and the focus value on the horizontal axis.

[0074] Lens position marker 530 displays the current position of the objective lens in the Z direction in correspondence with the vertical axis of calculation result display section 521. While the objective lens continues to descend, lens position marker 530 is displayed along the lower end of the vertical axis of calculation result display section 521. When the objective lens rises, lens position marker 530 moves upward away from the lower end of the vertical axis of calculation result display section 521.

[0075] Current value bar 525 indicates the ratio between the maximum focus value calculated while the objective lens is moving in the Z direction and the current focus value. Maximum value marker 528 is disposed along the right end of the horizontal axis of calculation result display section 521. While the focus value continues to increase, bar tip 526 of current value bar 525 coincides with maximum value marker 528.

[0076] The display contents of calculation result display section 521 are updated each time the objective lens descends, but the size of the display frame of calculation result display section 521 is constant. Therefore, the scale of calculation value graph 522 is changed (the scale becomes smaller) as the objective lens descends so that the entire calculation value graph 522 fits within the display frame of calculation result display section 521. By reducing the scale, a wider range in the Z direction comes to fit within the display frame of calculation result display section 521, so the display range in the Z direction expands as the objective lens descends.

[0077] 13 is a diagram showing a state in which the focus value has passed its peak in focus value graph 520. As shown in FIG 13, when the focus value passes its peak, bar tip 526 moves away from maximum value marker 528.

[0078] If the objective lens continues to move down after the focus value has passed its peak, there is a risk that the objective lens will collide with the object of observation OB. Therefore, when the focus value passes its peak, the descent of the objective lens is stopped. For example, it is preferable that the descent of the objective lens is stopped when the bar tip 526 of the current value bar 525 is separated from the maximum value marker 528 by a certain distance or more.

[0079] When the descent of the objective lens is stopped because the focus value has passed its peak, a confirmation message may be displayed to the user. For example, a message such as "Stage movement has been stopped because there is a possibility of contact with the sample" may be displayed on the display unit 72. When the focus value has passed its peak, after the descent of the objective lens is stopped, the Z-direction stage 6 may be controlled so that the objective lens rises (focuses) to the position in the Z direction where the focus value reaches its peak.

[0080] According to the magnification observation device 10 of this embodiment, telecentric lenses (first objective lens 40a, second objective lens 40b, third objective lens 40c) and wide-angle objective lens 40d (non-telecentric lens) are both attached to the revolver 41 (lens switching unit) as objective lenses, so that it is possible to obtain a navigation image with a wide observation field of view using the wide-angle objective lens 40d while observing the observation object OB at high magnification using the telecentric lens, which is highly convenient.

[0081] Furthermore, since the navigation correction information is registered in association with the navigation image using the wide-angle objective lens 40d, the user can move the mounting table 2 as intended using the navigation image.

[0082] When the objective lens is switched between the telecentric lens and the wide-angle objective lens 40d, the Z-direction stage 6 moves according to the difference in their parfocal distances, so that the user can confirm an observation image that is in focus on the observation object OB even when the objective lens is switched. In addition, when the Z-direction stage 6 moves in response to objective lens switching, a warning or the like is issued according to the predicted working distance of the objective lens after switching, thereby preventing the objective lens and the like from coming into contact with the observation object OB.

[0083] Next, the flow of registering the navigation image will be described with reference to Fig. 14. For the sake of explanation, it is assumed that the first objective lens 40a, which is a telecentric objective lens, is placed on the optical path of the image sensor 7 when the magnification observation device 10 is started up.

[0084] When the magnification observation device 10 is started (START), first in step S11, the observation object OB is observed by the first objective lens 40a (telecentric objective lens) directed toward the observation object OB.

[0085] In step S12, it is confirmed whether or not there is a request from the user to generate a navigation image. If there is no request to generate a navigation image (NO in step S12), the process returns to step S11 and observation of the observation object OB by the first objective lens 40a continues.

[0086] When a request for generating a navigation image is made (YES in step S12), in step S13, the Z-direction stage 6 retracts the observation head 4 in the Z direction. For example, the observation head 4 may be raised by an amount corresponding to the difference in the parfocal length between the first objective lens 40a and the wide-angle objective lens 40d.

[0087] When the observation head 4 is retracted in the Z direction, in step S14, the revolver 41 switches the objective lens arranged on the optical path of the image sensor 7 to the wide-angle objective lens 40d. Then, in step S15, autofocusing of the wide-angle objective lens 40d is performed. Note that in autofocusing, the lens control unit 241 controls the imaging lens 240 and the aperture control unit 260 adjusts the aperture, so that the autofocusing may be performed at a magnification with a narrower depth of field.

[0088] In the autofocus of the wide-angle objective lens 40d, the Z-direction stage 6 moves the wide-angle objective lens 40d little by little in the Z direction while searching for a position where the focus of the wide-angle objective lens 40d is aligned with the observation object OB. For example, every time the wide-angle objective lens 40d moves a little in the Z direction, the image sensor 7 captures an image of the observation object OB, and the analysis processing unit 303 calculates a focus value of the image capture result.

[0089] When the focus value meets a predetermined criterion, it is determined that the focus of the wide-angle objective lens 40d is matched with the observation object OB, and autofocusing is completed. For example, if the focus value decreases whether the wide-angle objective lens 40d is raised or lowered from the current position (or whether the focal length of the imaging lens 240 is extended or shortened), the focus value at the current position is determined to be maximum, and autofocusing is completed. Alternatively, if the focus value exceeds a predetermined reference value, it is determined that the focus of the wide-angle objective lens 40d is sufficiently matched with the observation object OB, and autofocusing is completed.

[0090] After autofocusing is completed, that is, after the focus of the wide-angle objective lens 40d is adjusted to the observation object OB, the navigation image registration process proceeds to step S16, and an observation image is generated using the wide-angle objective lens 40d.

[0091] During autofocusing, calculations related to the focus value may be performed with the magnification of the imaging lens 240 increased, and after autofocusing is completed, the magnification of the imaging lens 240 may be restored to capture an observation image. By performing autofocusing with the magnification of the imaging lens 240 increased, appropriate focus adjustment is performed. Then, when capturing an observation image, the magnification of the imaging lens 240 is restored to its original state, so that an observation image of the imaging range (for example, the entire observation object OB) as intended by the user can be obtained.

[0092] Next, in step S17, the distortion of the observation image by the wide-angle objective lens 40d is corrected (distortion correction). For example, if the optical characteristics (lens design values) of the wide-angle objective lens 40d are known, navigation correction information for correcting the deviation caused by the distortion aberration of the wide-angle objective lens 40d in the correspondence relationship between the position in the navigation image (observation image by the wide-angle objective lens 40d) and the position in the observation object OB is generated based on the optical characteristics.

[0093] When the optical characteristics of the wide-angle objective lens 40d are unknown, the navigation correction information may be generated using a calibration board 141 as shown in Fig. 10. When a wide-angle objective lens 40d with unknown optical characteristics is used, it is preferable to generate an observation image of the calibration board 141 captured through the wide-angle objective lens 40d before observation of the observation object OB is started (before step S11). If an observation image of the calibration board 141 is generated in advance, it becomes possible to generate the navigation correction information in step S17 while the observation object OB is placed on the mounting table 2 (without replacing the observation object OB with the calibration board 141).

[0094] After the navigation correction information is generated, calibration is then performed in step S18. In the calibration, a correspondence (calibration value) between one pixel of the navigation image and the actual distance is generated. The calibration value is generated, for example, based on the optical magnification of the navigation image. The optical magnification of the navigation image is calculated (generated) based on the magnifications of the wide-angle objective lens 40d and the imaging lens 240. Note that, when an observation image of the calibration board 141 is generated, the calibration value can also be calculated from the periodic pattern 143 of the calibration board 141 shown in the observation image. At this time, the magnification of the imaging lens 240 is changed by the lens control unit 241, and the calibration value may be calculated using an observation image of the calibration board 141 captured when the magnification of the imaging lens 240 is large.

[0095] Once the navigation correction information and calibration values ​​have been generated, in step S19, the image registration unit 507 stores the navigation image captured by the wide-angle objective lens 40d together with the navigation correction information and the calibration values ​​in the memory unit 311, thereby completing the registration of the navigation image (END).

[0096] Next, the flow of objective lens switching will be described with reference to Fig. 15. For the sake of explanation, it is assumed that the process starts from a state in which the wide-angle objective lens 40d is disposed on the optical path of the image sensor 7 (START).

[0097] First, in step S21, the observation object OB is observed by the wide-angle objective lens 40d. Then, in step S22, it is confirmed whether or not the user has instructed to switch from the wide-angle objective lens 40d to a telecentric objective lens (for example, the first objective lens 40a).

[0098] If switching to the telecentric objective lens has not been instructed (NO in step S22), the process returns to step S21, and observation of the observation object OB through the wide-angle objective lens 40d continues.

[0099] When switching to a telecentric objective lens is instructed (YES in step S22), the process proceeds to step S23, where it is confirmed whether the expected working distance is short or not. Specifically, the expected working distance is calculated based on optical characteristics such as the focal length of the telecentric objective lens after switching. Then, it is confirmed whether the expected working distance is short enough that there is a possibility of collision between the objective lens and the observation object OB. In determining whether the expected working distance is short or not, for example, the expected working distance may be compared with a predetermined reference value (e.g., 10 mm). Also, it may be determined whether the expected working distance is short or not (e.g., 80% or less of the downward amount) by comparing with the downward amount of the objective lens accompanying the switching of the objective lens (e.g., 30 mm).

[0100] If the expected working distance is not short, i.e., if the calculated expected working distance does not satisfy a predetermined standard (e.g., 10 mm or less) (NO in step S23), the process proceeds to step S26, and switching to a telecentric objective lens is performed by the revolver 41 (e.g., the first objective lens 40a is placed on the optical path of the image sensor 7).

[0101] On the other hand, if the calculated expected working distance meets the predetermined criteria (YES in step S23), the process proceeds to step S24, where a warning message for the user is displayed on the display unit 72 (a warning is issued). For example, an "OK" button and a "Cancel" button are displayed on the display unit 72 together with a warning message saying "The Z-direction stage will be lowered by 30 mm. Please make sure that it will not collide with the sample before clicking the OK button."

[0102] After the warning message is displayed, in step S25, it is confirmed whether the switching has been cancelled, i.e., whether the "Cancel" button has been pressed. If the "Cancel" button has been pressed (YES in step S25), the switching of the objective lens is cancelled and the process returns to step S21, and observation of the observation object OB through the wide-angle objective lens 40d continues.

[0103] If the switching is not canceled, that is, if the user presses the "OK" button (NO in step S25), the process proceeds to step S26, and switching to a telecentric objective lens is performed by the revolver 41 (for example, the first objective lens 40a is placed on the optical path of the image sensor 7).

[0104] When the switching to the telecentric objective lens is completed, the process proceeds to step S27, where the objective lens is lowered by the Z direction stage 6. While the objective lens is being lowered, the analysis processing unit 303 measures the focus value.

[0105] Then, in step S28, it is confirmed whether the focus value has passed the peak. If it is not confirmed that the focus value has passed the peak (NO in step S28), the objective lens is lowered until it reaches a predetermined lowering amount (a lowering amount determined according to the difference in parfocal length between the telecentric objective lens and the wide-angle objective lens 40d, for example, 30 mm), and the switching of the objective lens is completed (END).

[0106] On the other hand, if it is confirmed that the focus value has passed the peak (YES in step S28), the process proceeds to step S29, the descent of the objective lens is stopped, and the switching of the objective lens is completed (END). At this point, a message may be displayed on the display unit 72 to inform the user that the descent was stopped midway before reaching the target descent amount. For example, a message such as "Stage movement has been stopped due to the possibility of contact with the sample" may be displayed.

[0107] It should be noted that when the descent of the predetermined descent amount is completed, the focus of the switched objective lens may not be aligned with the observation object OB. Therefore, when the Z-direction stage 6 (vertical movement unit) moves the objective lens in the vertical direction, the focus of the objective lens may be further adjusted thereafter. For example, the vertical position of the objective lens may be adjusted by the Z-direction stage 6 so that the focus of the objective lens is aligned with the observation object OB. For the focus adjustment, the lens control unit 241 may control the imaging lens 240, and the aperture control unit 260 may adjust the aperture.

[0108] Furthermore, the height of the objective lens may be measured when the Z-direction stage 6 moves the objective lens in the vertical direction. The height of the objective lens is calculated, for example, based on the amount of movement of the Z-direction stage 6 and the dimensions of the objective lens.

[0109] Next, the flow of movement control using the navigation image will be described with reference to Fig. 16. For the sake of explanation, it is assumed that the process starts (START) from a state in which the objective lens is switched after the navigation image generated using the wide-angle objective lens 40d is registered and the telecentric objective lens (e.g., the first objective lens 40a) is placed on the optical path of the image sensor 7.

[0110] First, in step S31, observation is performed using a telecentric objective lens, and then in step S32, it is confirmed whether or not a moving target has been accepted, that is, whether or not a position on the navigation image has been specified by the user.

[0111] If the moving target has not been accepted (NO in step S32), the process returns to step S31 and observation with the telecentric objective lens is continued. On the other hand, if the moving target has been accepted (YES in step S32), the process proceeds to step S33 and the amount of movement is calculated.

[0112] In calculating the amount of movement, the navigation correction information and the calibration value stored in the storage unit 311 together with the navigation image when the navigation image was registered are read out. The movement control unit 302 calculates the amount of movement based on the position (position on the navigation image) specified by the user with respect to the navigation image, the navigation correction information, and the calibration value. In other words, it is calculated how far the mounting table 2 needs to be moved so that the center of the field of view of the image sensor 7 coincides with the position on the observed object OB that corresponds to the position on the navigation image specified by the user.

[0113] After the calculation of the movement amount is completed, in step S34, the movement control unit 302 controls the movement of the mounting table 2 by the mounting table control unit 23 to move the mounting table 2 by the calculated movement amount.

[0114] When the movement of the mounting table 2 is completed, autofocusing is performed at the position after the movement in step S35. That is, the Z-direction stage 6, the lens control unit 241, the aperture control unit 260, etc. are controlled to adjust the focus so that the objective lens is focused on the observation object OB at the position after the movement. When the autofocusing is completed, the movement control is completed (END), and the observation of the observation object OB is continued at the position of the movement destination. Note that autofocusing does not necessarily have to be performed. For example, if the objective lens is focused on the observation object OB (in focus) at the time when the movement of the mounting table 2 is completed, autofocusing is not necessary. On the other hand, when the observation object OB is an object with many irregularities on the surface, or when a high-magnification lens with a shallow depth of field is used as the objective lens, it is expected that the focus will not be achieved at the time when the movement of the mounting table 2 is completed, it is desirable to perform autofocusing.

[0115] According to the above embodiment, the user can move the mounting table 2 based on the position specification for the navigation image in which a wide range is captured using the wide-angle objective lens 40d. In addition, the movement is performed using navigation correction information that takes into account the distortion occurring in the image captured by the wide-angle objective lens 40d, so that the center of the field of view moves to the position intended by the user, and the convenience of the magnifying observation device 10 is improved.

[0116] The image registration section 507 may be capable of generating a concatenated image by concatenating a plurality of observation images in which different parts of the observation object OB are captured, and registering the concatenated image as a navigation image.

[0117] For example, when the observation object OB is large, two observation images each capturing half of the observation object OB may be joined to form one navigation image. Before joining the multiple observation images, navigation correction information may be generated for each observation image, and when generating the joined image, navigation correction information for the joined image may be generated based on the navigation correction information for each observation image.

[0118] The above embodiments are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. Among the configurations described in the above embodiments, those other than those described as one aspect of the present invention in the "Means for solving the problem" are optional configurations and can be deleted or modified as appropriate. [Industrial Applicability]

[0119] INDUSTRIAL APPLICABILITY The present invention provides a magnification observation device and has industrial applicability. [Explanation of symbols]

[0120] 1. Imaging unit 2. Placement table 4 Observation head 6 Z-direction stage 7. Image sensor 10. Magnifying observation device 40a First objective lens 40b Second objective lens 40c 3rd objective lens 40d wide-angle objective lens 41 Nosepiece 71 Information Processing Section 72 Display section 73 Operation section 141 Calibration Board 143 Periodic Patterns 300 Arithmetic section 301 Image Generation Unit 302 Movement control section 303 Analysis Processing Section 304 Display control section 305 Lighting control unit 306 Input / Output Control Unit 307 Image Registration Department 311 Storage section 400 display screen 500 Navigation Images 511 Cursor 515 Center of visual field 520 Focus Value Graph

Claims

1. an imaging element for imaging an object to be observed; A plurality of objective lenses; a lens switching unit that selectively places one of the plurality of objective lenses on an optical path of the image sensor; an image generating unit that controls the image sensor to generate an observation image; a mounting table on which the observation object is placed; A mounting table control unit that moves the mounting table in a horizontal direction; a movement control unit that controls movement of the mounting table by the mounting table control unit; an image registration unit capable of registering a navigation image based on the observation image generated by the image generation unit, The plurality of objective lenses include at least one telecentric objective lens and at least one wide-angle objective lens having a larger distortion aberration than the telecentric objective lens, a plurality of lens mounting holes are formed in the lens switching portion, and the telecentric objective lens and the wide-angle objective lens are mounted in the lens mounting holes, respectively; the image registration unit, in a state in which the wide-angle objective lens is disposed on the optical path of the image sensor by the lens switching unit, registers the observation image generated by the image generation unit as an image having a field of view size larger than the aperture of the wide-angle objective lens as a navigation image, and generates navigation correction information for correcting a deviation caused by distortion aberration of the wide-angle objective lens in a correspondence relationship between a position in the navigation image and a position in the observed object; The movement control unit controls movement of the placement table by the placement table control unit based on a position designation for the navigation image and the navigation correction information.

2. 2. The magnification observation device according to claim 1, wherein the image registration section generates the observation image after focusing the wide-angle objective lens on the observation object, and registers the generated observation image as the navigation image.

3. The image registration unit includes, as the navigation correction information, 2. The magnification observation device according to claim 1, further comprising: a navigation corrected image that is generated by correcting the navigation image in accordance with a correspondence relationship between a position in the navigation image and a position in the observed object.

4. 2. The magnification observation device according to claim 1, wherein the image registration section generates the navigation correction information based on the observation image generated using a calibration board on which a predetermined periodic pattern is marked as the observation object.

5. A vertical movement unit that moves the objective lens in a vertical direction is further provided. The magnification observation device described in claim 1, wherein when the lens switching unit switches the objective lens arranged on the optical path of the imaging element, the vertical movement unit moves the objective lens vertically in accordance with the difference in parfocal length between the objective lens before switching and the objective lens after switching.

6. When the lens switching unit switches the objective lens disposed on the optical path of the image sensor from the wide-angle objective lens to the telecentric objective lens, 6. A magnification observation device according to claim 5, wherein a working distance of the objective lens after switching is predicted, and a warning is given in response to the predicted working distance.

7. 6. The magnification observation device according to claim 5, wherein when said vertical movement section moves said objective lens in the vertical direction, a height of said objective lens is measured and a focus of said objective lens is adjusted.

8. The magnification observation device according to claim 1 , wherein the image registration unit is capable of generating a concatenated image by concatenating a plurality of the observation images in which different portions of the observation object are captured, and registering the concatenated image as the navigation image.

Images