JP2006308808A - Enlarging observation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire a high-quality composite image by eliminating influence caused by the change of a working distance. <P>SOLUTION: The enlarging observation device includes: an optical system of an inner focus system or a rear focus system capable of adjusting a focus by driving a focus lens along an optical axis; a focus lens driving part for moving the focus lens along the optical axis; an imaging means arranged on the optical axis of the focus lens and making the optical signal of an observation object made incident from an objective into an image so as to acquire a two-dimensional observed image; and an image compositing part for generating the composite image by compositing a plurality of two-dimensional images acquired by the imaging means. Thus, a situation that the objective projects to be brought into contact with the observation object and damages it is avoided, and a member to be driven to adjust the focus is made light in weight, so that a lens driving mechanism is made small-sized and further a movable range thereof is easily secured to be wide. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnification observation apparatus such as a microscope or a microscope that captures and displays an enlarged image.

  An optical microscope, a digital microscope, a video microscope, or the like using an optical lens is used as a magnification observation apparatus that magnifies and displays a minute object or the like. The microscope is a light receiving device such as a CCD or CMOS that electrically reads reflected light or transmitted light from an observation target fixed to an observation target fixing portion incident through an optical system for each pixel arranged two-dimensionally. The device is provided. An image electrically read using an image sensor such as a CCD is displayed on a display unit such as a display (for example, Patent Document 1).

  In a magnifying observation device, in general, when the magnifying power increases, the depth of focus becomes shallower and the in-focus area becomes narrower. Therefore, it is difficult to observe the whole if there are irregularities or height differences in the sample (workpiece) to be observed. Become. For this reason, a technique is used in which an image focused on the entire image is created by depth synthesis. In depth synthesis, the lens or sample is moved in the height direction, the relative distance in the optical axis direction is changed, multiple images are taken, and the in-focus part is extracted and synthesized, resulting in a deep focus depth. A two-dimensional image can be generated. In addition, when shooting a plurality of images, if the amount of movement of the lens or the observation target is recorded at the same time, the height information of the observation target can be obtained when creating the composite image. It is also possible to construct as three-dimensional data. By reproducing the 3D image on the display unit of the magnification observation apparatus based on the three-dimensional data, the image can be observed and evaluated in three dimensions from various viewpoints and angles, and the surface shape such as the height can be measured. .

  In order to acquire a plurality of images as a basis for combining such two-dimensional and three-dimensional images, the magnifying observation apparatus sets a lens and a camera in the head unit, and the distance between the head unit and the observation target (working distance: (WD) is changed and the image is taken in focus. For this reason, the head portion has a function of photographing while moving in the height direction in order to adjust the working distance. As a method of changing the working distance of the head part, there is a method of moving the objective lens side in the height direction, a method of moving the electric stage on which the observation target is placed in the height direction, or a drive system using a piezoelectric element. The method of moving only the objective lens of the microscope is used.

  However, in order to move the objective lens, since the objective lens uses a large number of lenses and the size itself is large and heavy, a driving mechanism for moving the objective lens requires a considerable torque. In addition, not only the objective lens is moved, but also the entire head unit such as a camera including the objective lens is often moved, and in this case, the necessary torque further increases, and the drive mechanism becomes complicated and large. There has been a problem of hindering the miniaturization and simplification of the head. Similarly, a method of moving the electric stage side on which the observation object is placed requires a corresponding torque, and it is inevitable to enlarge the head portion. Furthermore, in order to ensure the accuracy of movement, it is necessary to use a highly accurate movement mechanism, which increases the cost. In addition, the strength of the stand provided with the moving mechanism is also required.

  On the other hand, a piezoelectric element is often used to move the objective lens of a microscope, but the movable range is as short as about 100 μm, and when observing an object with a low magnification lens, a necessary measurement range should be secured. There is a problem that can not be. In addition, this system generally requires an expensive drive system, and a dedicated controller is required to realize detailed control.

Further, in the method of physically moving the working distance between the head unit and the observation target, the head unit may come into contact with the observation target and be damaged. In general, when shooting an image, first set the observation position, then change the height to shoot, so that the working distance with the observation object changes and the objective lens and the observation object do not collide It is necessary to devise a procedure. In addition, changes in working distance also change lighting conditions. In particular, when the lens is illuminated with ring illumination or the like, the angle of illumination with respect to the workpiece also changes as the distance changes, so the shaded state of the photographed image also changes due to the difference in distance. This change in the state of the shadow greatly hinders an appropriate selection when combining the images. This effect is even greater with low magnification lenses.
JP 2000-214790 A

  The present invention has been made to solve such problems. A main object of the present invention is to provide a magnifying observation apparatus capable of eliminating the adverse effects caused by changes in working distance and obtaining high-quality two-dimensional and three-dimensional images.

  In order to achieve the above object, a magnifying observation apparatus according to the first aspect of the present invention includes an objective lens for facing an observation target, a zoom lens disposed on the optical axis of the objective lens, and a zoom lens. An inner focus type or rear focus type optical system that can adjust the focus by driving the focus lens along the optical axis, and the focus lens along the optical axis. A focusing lens driving unit for moving the imaging lens, an imaging unit disposed on the optical axis of the focusing lens and imaging an optical signal to be observed incident from the objective lens, and obtaining a two-dimensional observation image; And an image composition unit for synthesizing a plurality of two-dimensional images acquired by the imaging unit to generate a composite image. This makes it possible to zoom and focus by driving the lens inside the apparatus using the inner focus method or the rear focus method while the objective lens is fixed, and it is possible to avoid the situation where the objective lens protrudes and touches or breaks the observation target. . By adopting the inner focus method, the member to be driven for focus adjustment is reduced in weight, so that the lens drive mechanism can be reduced in size and the movable range can be easily increased. In particular, the inner focus lens is light in weight because the number of lenses used is generally smaller than that of the objective lens, and requires less torque to move.

  The magnification observation apparatus according to the second aspect of the present invention further includes an illumination unit for illuminating the observation target. As a result, the working distance does not change even when the observation object is illuminated, so the illumination conditions such as the illumination angle do not change, and the image can be synthesized by the image synthesis unit under the same conditions, and a high-quality synthesized image can be obtained. Can do.

  Furthermore, the magnification observation apparatus according to the third aspect of the present invention further includes a height information acquisition unit for acquiring height information of a two-dimensional image captured by the imaging unit, and the image composition unit is an imaging unit. The plurality of captured two-dimensional images are configured so that a three-dimensional image can be constructed based on the height information acquired by the height information acquisition unit. As a result, it is possible to capture a two-dimensional image with a fixed working distance and a constant illumination condition. Therefore, when constructing a three-dimensional image, a high-quality three-dimensional image without distortion can be obtained.

  Furthermore, in the magnification observation apparatus according to the fourth aspect of the present invention, the objective lens can be replaced. Accordingly, it is possible to replace the objective lens with a different magnification according to the observation purpose, and it is possible to apply in a wide range.

  Furthermore, in the magnification observation apparatus according to the fifth aspect of the present invention, the height information acquisition unit includes an objective lens magnification acquisition unit for acquiring magnification information of the currently mounted objective lens. As a result, the magnification of the currently displayed observation image can be obtained, so that the magnification observation device automatically obtains the magnification without the user having to actually check the lens visually to calculate and input the magnification. In addition, the display magnification and scale can be displayed.

  Furthermore, in the magnification observation device according to the sixth aspect of the present invention, the height information acquisition unit includes a zoom lens magnification acquisition unit for acquiring magnification information adjusted by the zoom lens. As a result, height information can be obtained, so that a three-dimensional image can be constructed.

  Furthermore, in the magnifying observation device according to the seventh aspect of the present invention, the optical system is configured to be telecentric on both sides. This configuration enables high-precision observation with less distortion.

  According to the magnifying observation device of the present invention, by adopting an inner focus type or rear focus type optical system, the member to be driven for focus adjustment can be reduced in weight, and the drive mechanism is downsized and compact and inexpensive. An observation device can be obtained. In addition, since the lens does not protrude to the outside, it is possible to avoid a situation in which the objective lens or the like comes into contact with the observation object and is damaged.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a magnifying observation apparatus for embodying the technical idea of the present invention, and the present invention does not specify the magnifying observation apparatus as follows. Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

The connection between the magnification observation apparatus used in the embodiment of the present invention and the computer, printer, external storage device and other peripheral devices for operation, control, display, and other processing connected thereto is, for example, IEEE 1394, RS-232x, RS-422, serial connection such as USB, parallel connection, or communication via network such as 10BASE-T, 100BASE-TX, 1000BASE-T, etc. Do. The connection is not limited to a physical connection using a wire, but may be a wireless connection using radio waves such as IEEE802.1x, OFDM, etc., Bluetooth (registered trademark), infrared rays, optical communication, or the like. Furthermore, a memory card, a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, or the like can be used as a recording medium for exchanging data or storing settings. In this specification, the term “magnification observation apparatus” is used to include not only the magnification observation apparatus body but also an imaging system in which peripheral devices such as a computer and an external storage device are combined.
(First embodiment)

  Hereinafter, the magnification observation apparatus according to the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing the appearance of the magnification observation apparatus, and FIG. 2 is a block diagram showing the configuration of the magnification observation apparatus. As shown in FIG. 1, the magnification observation apparatus 100 includes an illumination unit 60 for illuminating a sample to be observed, an imaging unit 10 for imaging a sample illuminated by the illumination unit 60, and an enlarged image captured by the imaging unit 10. An information processing apparatus 50 having a display unit 52 for displaying an image is provided. Further, the magnification observation apparatus 100 in FIG. 2 is a reflected light from the sample fixing unit (stage 30 on which the sample S is mounted) for fixing the sample and the sample S fixed to the sample fixing unit incident via the optical system 11. Alternatively, an imaging device (CCD 12) that electrically reads transmitted light is provided. The sample fixing unit is provided with a stage moving unit 20 that moves the stage in the xy plane, or rotates, tilts, and moves up and down. On the other hand, the optical system 11 is driven by an optical system control unit 14 including a focus adjustment unit that adjusts a focal point by changing a relative distance between the sample fixing unit and the optical system 11 in the optical axis direction.

  Furthermore, as shown in FIG. 2, the information processing apparatus 50 displays the focal length information about the relative distance in the optical axis direction between the sample fixing unit and the optical system 11 when the focal point is adjusted by the focal point adjusting unit. A focal length information storage unit (memory 53) that stores together with the two-dimensional position information of the sample in a vertical plane, a display unit 52 that displays an image read by the image sensor, and a region of an image displayed by the display unit 52 Are stored in a focal length information storage unit for a part or all of the sample S corresponding to the region set by the setting unit (operating unit 55, pointing device 55A) and for specifying various settings. A calculation unit (control unit 51) that calculates an average height in the optical axis direction of the sample S corresponding to the region set by the setting unit based on the focal length information; Obtain. The magnification observation apparatus 100 uses an imaging element that electrically reads reflected light or transmitted light from a sample fixed to a sample fixing portion that is incident via an optical system, and the sample light corresponding to a specified region. The average height (depth) in the axial direction can be calculated.

  As shown in FIG. 2, the imaging unit 10 is optically applied to a stage 30 that is one form of a sample fixing unit on which the sample S is placed, a stage moving unit 20 that moves the stage 30, and a sample fixed to the stage 30. A CCD 12 as one form of an imaging device that electrically reads reflected light or transmitted light incident through the system for each pixel arranged two-dimensionally, and a CCD control circuit 13 that drives and controls the CCD 12 Prepare. Furthermore, the information processing apparatus 50 which is a magnification observation apparatus main body is connected to the imaging part 10. FIG. The information processing apparatus 50 displays an image based on the memory 53 as one form of an image data storage unit that stores image data electrically read by the image sensor and image data electrically read by the image sensor. A display unit 52 such as a display and a monitor, an operation unit 55 that performs input and other operations based on a screen displayed on the display unit 52, and image processing and various other processes based on information input by the operation unit 55 The control part 51 which performs is provided. The display constituting the display unit 52 is a monitor capable of high-resolution display, and a CRT, a liquid crystal panel, or the like is used.

  The operation unit 55 is connected to the computer by wire or wirelessly, or is fixed to the computer. Examples of the general operation unit 55 include various pointing devices such as a mouse, keyboard, slide pad, track point, tablet, joystick, console, jog dial, digitizer, light pen, numeric keypad, touch pad, and accu point. Further, these operation units 55 can be used for operations of the magnification observation apparatus itself and its peripheral devices in addition to the operations of the magnification observation operation program. Furthermore, using a touch screen or touch panel on the display itself that displays the interface screen, the user can directly input and operate the screen by hand, or use voice input or other existing input means, Or these can also be used together. In the example of FIG. 1, the operation unit 55 includes a pointing device 55A such as a mouse 55a. The operation unit 55 functions as a changing unit for changing an observation viewpoint and an enlargement / reduction rate, which will be described later.

  FIG. 1 shows an external view of a magnification observation apparatus according to an embodiment of the present invention. A camera 10 a having an optical system and an image sensor is attached to a camera attachment portion 43 fixed to a support column 42 extending in the vertical direction from the stand base 41. On the stand base 41, a stage moving unit 20 on which a stage 30 on which the sample S is placed is attached is arranged. The camera 10a and the stage moving unit 20 are connected to and controlled by the information processing apparatus 50. The information processing apparatus 50 includes a display unit 52 and an operation unit 55 such as a mouse 55a. An observation image is displayed on the display unit 52.

  Further, a computer 70 can be connected to the magnification observation apparatus which is the information processing apparatus 50, and a magnification observation operation program can be separately installed in the computer 70 so that the magnification observation apparatus can be operated from the computer 70 side. The magnifying observation apparatus has a built-in operation function or operation program for operating the magnifying observation apparatus in advance. This operation program can be installed or updated in the magnifying observation apparatus in the form of rewritable software, firmware, or the like.

  FIG. 2 is a block diagram of the magnification observation apparatus according to the embodiment of the present invention. The information processing apparatus 50 includes a display unit 52, a memory 53 that stores control programs, focal length information, received light data, two-dimensional information, and the like, and the information processing apparatus 50 communicates data with the camera 10a and the stage moving unit 20. Interface 54 and an operation unit 55 for an operator to perform operations related to the magnification observation apparatus. The stage moving unit 20 includes, for example, a stepping motor and a motor control unit that controls the elevation of the stepping motor. The imaging unit 10 includes, for example, a light receiving element such as a CCD 12 or a CMOS as an imaging element, a CCD control circuit 13 that drives and controls the CCD 12, and light irradiated to the sample S placed on the stage 30 from the illumination unit 60. And an optical system 11 that forms an image of the transmitted light and reflected light on the CCD 12. Furthermore, the optical system 11 is connected to an optical system control unit 14 for driving a lens and the like constituting the optical system.

  The information processing apparatus 50 moves the stage 30 as the sample fixing unit in the XY plane by inputting control data related to control of a stepping motor or the like that drives the stage moving unit 20. Specifically, the information processing apparatus 50 controls the rotation of the stepping motor by inputting control data necessary for controlling the stage moving unit 20 to the motor control circuit, and changes the X and Y positions of the stage 30. The stepping motor generates a rotation signal corresponding to the rotation. The information processing apparatus 50 stores the X and Y positions of the stage 30 as information regarding the relative distance between the sample fixing unit and the optical system 11 in the optical axis direction based on the rotation signal input via the motor control circuit.

  The CCD 12 can electrically read the amount of received light for each pixel arranged two-dimensionally in the x and y directions. The image of the sample S formed on the CCD 12 is converted into an electric signal according to the amount of received light at each pixel of the CCD 12 and further converted into digital data in the CCD control circuit 13. The information processing apparatus 50 uses the digital data converted by the CCD control circuit 13 as received light data D in a plane (x and y directions in FIG. 2) substantially perpendicular to the optical axis direction (z direction in FIG. 2). The information is stored in the memory 53 together with pixel arrangement information (x, y) as two-dimensional position information of the sample. Here, the in-plane substantially perpendicular to the optical axis direction does not need to be a plane that is exactly 90 ° with respect to the optical axis, and is such that the shape of the sample can be recognized in the resolution of the optical system and the image sensor. Any observation surface may be used as long as it is within the tilt range.

  In the above description, an example in which the sample is placed on the stage is shown as an example of the sample fixing unit. However, for example, an arm may be attached instead of the stage and the sample may be fixed to the tip. Further, the camera 10a can be mounted on the camera mounting portion 43 or the like and used at a desired position and angle by a method such as hand-holding so as to be detachable.

The illumination unit 60 shown in FIG. 1 includes an epi-illumination 60A for irradiating the sample with epi-illumination light and a transmission illumination 60B for irradiating the sample with transmitted light. These lights are connected to the information processing apparatus 50 via the optical fiber 61. The information processing apparatus 50 includes a connector 62 for connecting the optical fiber 61 and a light source (not shown) for sending light to the optical fiber 61 through the connector 62. A halogen lamp or the like is used as the light source. The optical fiber 61 may be configured integrally with a cable that connects the imaging unit 10 and the information processing apparatus 50. The light source may be provided on the imaging unit 10 side in addition to the configuration provided on the information processing apparatus 50 side. For example, a configuration in which light emitting elements such as LEDs and LDs are arranged in a ring shape on the epi-illumination 60A may be adopted. In this case, a member that transmits light from the light source such as an optical fiber to the imaging unit 10 can be omitted, and the imaging unit 10 and the information processing apparatus 50 can be connected with a cable only of an electric signal. In particular, by not using an optical fiber, it is possible to provide a cable that is excellent in flexibility as a cable only for electric signals and that can be easily routed with a large bend. Moreover, there is no transmission loss, and high-efficiency lighting with low power consumption can be realized.
(Control unit 51)

  The control unit 51, which is a control unit, controls the captured observation image to be converted into a resolution that can be displayed on the display unit 52 and displayed. In the magnification observation apparatus of FIG. 1, the imaging unit 10 displays an observation image obtained by imaging the sample S with the CCD 12 on the display unit 52. In general, the performance of an image sensor such as a CCD often exceeds the display capability of the display unit. Therefore, in order to display the captured observation image on one screen, the resolution can be displayed on one screen by thinning the image. Reduced to size and reduced. If the reading resolution when reading by the imaging unit 10 is the first resolution, the display unit 52 displays a second resolution lower than the first resolution.

  Furthermore, the control unit functions as an image composition unit for compositing a plurality of two-dimensional images acquired at different heights of the observation object based on a predetermined algorithm to compose a new two-dimensional image or three-dimensional image. Is provided.

In the above embodiments, the example in which the reflected light from the sample fixed to the sample fixing portion is electrically read has been shown. However, the transmitted light is electrically read by irradiating light from the back surface of the sample. You may comprise as follows. In the above description, an example in which the sample is placed on the stage is shown as an example of the sample fixing unit. However, for example, an arm may be attached instead of the stage and the sample may be fixed to the tip.
(3D image)

In addition, the magnification observation apparatus can display not only a two-dimensional image but also a three-dimensional image. By reproducing the 3D image on the display unit 52 of the magnification observation apparatus based on the three-dimensional data, the image is observed and evaluated three-dimensionally from various viewpoints and angles, and the surface shape such as the height and the profile are measured. be able to. In order to generate and display a three-dimensional image, for example, the relative distance in the optical axis direction, that is, the distance between the sample to be observed and the lens is changed, and a plurality of images are captured, and the movement amount at the time of image capture is recorded simultaneously. Keep it. As a result, the height information of the observation target can also be obtained when creating a composite image, so that the acquired image can be constructed as three-dimensional data.
(Inner focus method or rear focus method)

Next, FIG. 3 shows a block diagram of the imaging unit 10. An imaging unit 10 shown in this figure has a CCD 12 as an imaging unit and an optical system 11 composed of various lenses built in a head unit 10A, and each member is electrically connected to an optical system control unit 14. The optical system 11 includes an objective lens O, a zoom lens (magnification lens) Z, and a focus lens F. In addition, although each lens has shown only one lens for simplification, it cannot be overemphasized that the combination lens which combined several lens groups can be utilized. These lenses are arranged so that their optical axes coincide with each other, and are arranged so as to form an image on the image sensor. The optical system 11 employs an inner focus method or a rear focus method, and holds the objective lens O so that the zoom lens Z and the focus lens F can be moved along the optical axis. Focus adjustment is performed with the lens F. Needless to say, the optical path can be appropriately bent using a mirror or the like.
(Lens drive)

  The zoom lens Z and the focus lens F are slidable along the optical axis direction, that is, along the lens barrel in the head unit 10A. These lenses are independently driven by a lens driving unit such as a motor or an electronic cam. The focus lens F shown in FIG. 3 includes a motor 81 and a motor drive unit 82 as the focus lens drive unit 80. In the rear focus method, the position of the focus lens F is adjusted according to the subject distance and the focal length. Therefore, the optical system control unit 14 controls the motor driving unit 82 to adjust the driving amount of the motor 81, that is, the moving amount of the focus lens F. At the time of autofocus, the optical system control unit 14 drives the motor drive unit 82 so that the focus lens F traces on the focus trajectory.

The zoom lens Z is driven by the zoom lens driving unit 83 and sends the position information of the driven lens to the optical system control unit 14. The position of the lens can be detected in the optical axis direction using position detection means such as a linear potentiometer or an encoder. If a stepping motor with high position controllability is used for the lens driving unit, accurate driving amount control is possible, and the stepping motor can also be used as a position detecting means. By acquiring the position information of the zoom lens Z from the position detection means by the optical system control unit 14, the set magnification of the zoom lens Z can be detected by the optical system control unit 14.
(Objective lens O)

  On the other hand, the objective lens O is not moved and is fixed in the lens barrel. In the inner focus method or the rear focus method, as shown in FIG. 3, the zoom adjustment is performed by the zoom lens Z disposed on the front end side of the lens barrel, and the force adjustment is performed by the focus lens F disposed on the rear side. . In this method, since the focus lens F is arranged on the rear end side of the lens barrel, the focus adjustment is performed by the focus lens F having a small diameter and a light weight, so that the driving mechanism is simplified and miniaturized. It can be driven with low power consumption. Note that the cost can be reduced by using a common drive mechanism for the zoom lens and the focus lens, and the configuration can be further simplified by sharing the drive mechanism itself. The front objective lens is fixed, and the zoom lens and focus lens are arranged inside the lens barrel so that the total length of the lens does not change even when focusing. The distance between and does not change. Therefore, the user does not need to pay attention to the contact between the lens and the observation target. In addition, since the illumination state does not change, there is no unnecessary change in shadow due to the focus adjustment of the lens. This means that two-dimensional images with different focal points can be taken under the same illumination conditions, and a high-quality composite image free from distortion and noise can be obtained when combining two-dimensional and three-dimensional images later. Also contribute.

  The objective lens O can be exchanged with lenses having different magnifications. The mounting mechanism for mounting the objective lens O on the head unit 10A is a screw or engagement, and by preparing a plurality of objective lenses with different magnifications that share the mounting mechanism, the objective lens is replaced and the magnification of the magnification observation apparatus is increased. Can be changed and can be used in a wider range.

  Furthermore, the head unit 10A can detect the magnification of the objective lens O that is currently set on the magnification observation apparatus side by providing the objective lens magnification detection means 84 that reads the magnification of the objective lens O. In the example of FIG. 3, the objective lens magnification detection means 84 is disposed between the objective lens O and the optical system control unit 14, and different signals can be detected by the optical system control unit 14 depending on the type of the set objective lens O. And For example, a table in which the magnification of the objective lens is associated with a predetermined resistance value in advance is prepared, and the optical system control unit 14 detects a terminal having a different resistance value for each objective lens, thereby referring to the table. Thus, the magnification can be detected. Alternatively, a method of physically distinguishing shapes of objective lens mounts, connectors, and the like can be used. Needless to say, in addition to the configuration in which the magnification is automatically read by the magnification observation apparatus, a method in which the user manually inputs and sets the magnification can be employed.

  Thus, the optical system control unit 14 can acquire the current display magnification by acquiring the magnification of the objective lens O and the position of the zoom lens Z from the objective lens magnification detection means 84 and the position detection means, respectively. As a result, the magnification information can be displayed on the display unit or used for calculation. For example, it is possible to perform calibration for calculating an actual dimension per pixel on the screen, add a dimension or scale display on the screen, and perform calculation of a specified distance or area. In order to measure the length and area in actual size, it is necessary to calculate in advance the actual size corresponding to the pixel unit constituting the display screen. The actual size per pixel can be calculated from the magnification of the optical system (and the magnification of the screen display), and this calculation or processing is called calibration. Conventionally, when performing calibration, it has been necessary to manually input the magnification of a lens that has been set, but in this embodiment, the magnification observation apparatus automatically performs magnification from the objective lens magnification detection means and the position detection means. Can be obtained and calculated, improving usability. In addition, the fact that measurement at the actual size is possible can be used for higher-accuracy measurement by using a double-sided telecentric lens described later.

Further, in addition to being able to detect the current observation magnification by the magnifying observation apparatus, the movement amount when obtaining images having different heights is associated with the magnification, thereby facilitating automatic acquisition of a three-dimensional image. For example, an appropriate amount of movement of the focus lens can be recorded in advance in a table or the like so that the amount of movement is small when the magnification is high and the amount of movement is large when the magnification is low. . As a result, when capturing a plurality of two-dimensional images for constructing a three-dimensional image, the magnification observation device automatically detects the magnification selected by the user, and an appropriate amount of movement based on this magnification is stored in a table. A plurality of pieces of image data having different heights can be obtained based on the selected moving amount. As a result, it is possible to obtain a three-dimensional image with a simple operation, without the need for the user to specify troublesome movement amount settings one by one.
(Optical system controller 14)

The optical system control unit 14 that controls the optical system 11 includes a gate array and a CPU. As described above, the optical system control unit 14 can have data relating to the moving distance and working distance of the focus lens F that varies depending on the magnification of the lens. These data are held in the control data memory 15. The optical system control unit 14 controls the motor driving unit 82 to appropriately drive the focus lens F, so that a plurality of images having different heights are captured by the image sensor. Then, an image that is in focus within the desired imaging range is synthesized as one two-dimensional image. It is also possible to construct three-dimensional image data from image height information obtained at the time of shooting.
(Both sides telecentric)

  Furthermore, in order to perform image synthesis with high quality and high accuracy, it is desirable that the lenses constituting the optical system 11 be bilateral telecentric. A telecentric lens can image an observation object with the same size. The double-sided telecentric lens is a lens system designed such that the angle of view is close to 0 ° and the principal ray is substantially parallel to the optical axis on the object plane and the image plane. Therefore, there is an advantage that a change in magnification due to a change in the position of the subject is small. For this reason, it can be used when accurately measuring the shape and dimensions of the observation object. By adopting such a telecentric lens on both sides, it is possible to eliminate distortion when constructing a composite image. This state will be described with reference to FIGS. FIG. 4 shows an image forming state (a) and an image example (b) in a normal lens, and FIG. 5 shows an image forming state (a) and an image example (b) in a telecentric lens.

  In the construction of a three-dimensional image, it is desirable that the sizes of observation objects captured as two-dimensional images are equal. However, in a normal lens, as shown in FIG. 4A, the size changes in accordance with the distance from the lens. As a result, distortion occurs in the captured two-dimensional image as shown in FIG. This distortion changes according to the distance between the lens and the observation target. Therefore, in a two-dimensional image captured by changing the distance between the lens and the observation target, distortion differs for each image, which causes errors and noise when constructing a three-dimensional image by combining them. . In order to solve this problem, when synthesizing a three-dimensional image, some have a contour shift correction function that corrects magnification by image processing for contour shift due to focus movement, but this method requires an image processing step. As a result, the amount of processing increases and processing becomes slow, and the correction amount is limited.

In order to solve such a problem, a double telecentric lens as shown in FIG. 5 is used in this embodiment. As shown in FIG. 5, the lens does not cause distance-dependent distortion, and images are captured with the same size regardless of the distance from the lens. By using this lens, even when a plurality of two-dimensional images with different heights are taken, an image that is invariable or has little change in distance, in other words, an image with little distortion can be obtained. Therefore, when these images are combined, a beautiful three-dimensional image without distortion can be obtained as a result of a small difference between the images. Similarly, a high-quality two-dimensional image focused in a wide range can be obtained.
(Automatic 3D image construction method)

  Next, an example of a procedure for actually synthesizing a three-dimensional image to be observed using the magnification observation apparatus will be described with reference to FIG. First, the imaging unit 10, the stage moving unit 20, the information processing apparatus 50, and the like are initialized, and then the imaging range is set in step S1. Specifically, the observation target is set on the stage, and the magnification and camera angle of the image to be photographed are adjusted. Further, manually focus on a part of the observation target. At this time, a range for adjusting the focus is set in advance. For example, the range can be set automatically according to the magnification, the user can manually specify the maximum and minimum working distances, and the range of a predetermined width can be automatically set around the manually focused position. It can also be set automatically. Furthermore, the focus adjustment, that is, the movement width of the focus lens, can be arbitrarily specified by the user, in addition to being automatically set by the magnification observation apparatus according to the magnification. The case where the user arbitrarily sets the moving amount and moving range of the lens will be described in detail. The moving range of the lens is the range of the lens height. For example, the user designates a rough height as the moving start position. The amount of movement of the lens is the distance of movement of the lens per one time. The finer the setting, the more detailed images can be taken, but the longer it takes to generate, so the value is set to an appropriate value according to the purpose of observation. As the designation method, the user designates the fineness of the image, and the magnification distance is automatically set by the magnification observation device, or the user designates the movement distance directly by a numerical value, or the default default value. There is a method of using. After setting, set the lens at the specified movement start position.

  Next, the process proceeds to step S2 to instruct execution of 3D image acquisition. For example, press the start button for automatic processing. When the command is executed, the process proceeds to step S3, where the optical system control unit 14 reads the magnification of the objective lens O and the magnification of the zoom lens Z. As a result, the magnification observation apparatus can detect the currently set observation magnification.

  In step S4, the focus lens F is moved at an interval set in the height direction within a preset focus adjustment range, and a two-dimensional image is sequentially captured for each height. The captured image data is held in each memory. After imaging, the focus lens F is moved by a set amount of movement. The focal position is moved in the height direction by controlling the motor drive unit 82 with the optical system control unit 14 and driving the motor 81 to move the focus lens F. The adjustment of the movement amount of the focus position is performed by using data that has been previously obtained according to the magnification, or by performing calculation and performing lens position control. In step S5, it is determined whether or not the movement range has reached the end position. If the end position has not been reached, the process returns to step S4 to repeat the movement and imaging, and when the imaging of all the two-dimensional images is completed, the process proceeds to the image composition step of step S6.

  In the image synthesizing step, a focused part is extracted and synthesized with respect to a plurality of photographed two-dimensional images. As a result, a two-dimensional image focused in a wide range can be synthesized. Furthermore, a three-dimensional image is also obtained using the height information of the image at the time of shooting. For the construction of 3D data, a profile that changes in the height direction can be calculated from the position of the lens and the image captured at that time, so multiple 2D image data captured at different heights can be combined. By doing so, a three-dimensional shape can be constructed. For example, a continuous profile is synthesized by complementing a discrete profile obtained from a captured two-dimensional image. This process can be performed at high speed in hardware.

  The three-dimensional image constructed as described above can be freely displayed by changing the viewpoint, rotating the image, inverting, deforming, enlarging / reducing, or the like. The changing operation is performed by a pointing device 55A such as a mouse 55a which is a form of the changing unit. The image is rotated in the dragged direction by operating the mouse 55a, selecting the image, and moving the mouse pointer while dragging. For enlargement / reduction, it is possible to assign a screen enlargement / reduction function to the scroll button 55d of the wheel mouse. Not limited to these methods, operation buttons and operation tool groups are arranged on the software screen as the change unit, and operation functions are assigned to specific keys on the keyboard, or dedicated hardware for operation is used as the change unit. You can also

  As such a three-dimensional image acquisition method and a method for changing the display of the acquired three-dimensional data, a known method or a method developed in the future can be used as appropriate. For example, an API such as Open GL (Open Graphics Library) can be used.

  If necessary, the generated image is displayed on a display unit or the like or output in a predetermined format. In this way, it is possible to synthesize a two-dimensional image or a three-dimensional image that is automatically focused according to the specified condition. In particular, by adopting the inner focus method or the rear focus method for the lens, the illumination conditions are the same even when a plurality of images with different heights are shot by driving the focus lens, and an image suitable for composition can be obtained. . In addition, by adopting a telecentric lens on both sides, distortion due to differences in height can be reduced to a minimum, so images that are more suitable for composition can be acquired and combined to greatly reduce noise and distortion in the composite image. A few 3D images and 2D images can be constructed.

  By making such a double-sided telecentric lens an inner focus or a rear focus type, these are much lighter than the objective lens, so that it is smaller than the conventional objective lens moving system as described above. It can be controlled by a driving device. Therefore, the drive device can be incorporated in the lens, and the system can be made small and inexpensive. Moreover, it is easy to take a wide movable range compared to a piezoelectric element or the like. Furthermore, by using a telecentric lens on both sides, distortion of each image is reduced, and an extremely high quality image can be synthesized. Further, the range of magnification can be expanded by combining the objective lens and the zoom lens and adopting the zoom lens as an inner focus system. Furthermore, the observation lens can be changed by adopting an interchangeable structure for the objective lens, and can be used in a wider range.

  The magnification observation apparatus of the present invention can be used for a microscope, a digital microscope, and a digital camera to generate and view a two-dimensional image including three-dimensional image data.

1 is an external view of a magnification observation apparatus according to an embodiment of the present invention. It is a block diagram of the magnification observation device concerning a 1st embodiment of the present invention. The block diagram which comprises an imaging part is shown. It is explanatory drawing which shows the state of (a) image formation in a normal lens, and the example of (b) image. It is explanatory drawing which shows the state of (a) image formation in a telecentric lens, and the example of (b) image. It is a flowchart which shows an example of the procedure which synthesize | combines a three-dimensional image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Magnification observation apparatus 10 ... Imaging part; 10A ... Head part; 10a ... Camera 11 ... Optical system 12 ... CCD; 13 ... CCD control circuit 14 ... Optical system control part 15 ... Memory for control data 20 ... Stage moving part 30 ... Stage 41 ... Stand base; 42 ... Post; 43 ... Camera mounting unit 50 ... Information processing device; 51 ... Control unit; 52 ... Display unit 53 ... Memory; 54 ... Interface 55 ... Operation unit; 55A ... Pointing device; 55a ... Mouse DESCRIPTION OF SYMBOLS 60 ... Illumination part; 60A ... Epi-illumination illumination; 60B ... Transmission illumination 61 ... Optical fiber; 62 ... Connector; 70 ... Computer 80 ... Focus lens drive part 81 ... Motor 82 ... Motor drive part 83 ... Zoom lens drive part 84 ... Objective lens Magnification detection means O ... Objective lens Z ... Zoom lens F ... Focus lens S ... Sample

Claims (7)

An objective lens for facing the observation object;
A zoom lens disposed on the optical axis of the objective lens;
A focus lens disposed on the optical axis of the zoom lens;
An inner focus type or rear focus type optical system capable of adjusting the focus by driving the focus lens along the optical axis, and
A focus lens driving unit for moving the focus lens along the optical axis;
An imaging means disposed on the optical axis of the focus lens and forming an optical signal of an observation target incident from the objective lens, to obtain a two-dimensional observation image;
An image synthesis unit for synthesizing a plurality of two-dimensional images acquired by the imaging unit to generate a synthesized image;
A magnifying observation apparatus comprising: The magnification observation apparatus according to claim 1, further comprising:
A magnification observation apparatus comprising an illumination unit for illuminating an observation target. The magnification observation apparatus according to claim 2, further comprising:
A height information acquisition unit for acquiring height information of a two-dimensional image captured by the imaging unit;
The image composition unit is configured to be able to construct a plurality of two-dimensional images captured by the imaging unit based on height information acquired by the height information acquisition unit. Magnifying observation device. A magnification observation apparatus according to any one of claims 1 to 3,
A magnification observation apparatus characterized in that the objective lens can be exchanged. A magnification observation apparatus according to any one of claims 1 to 4,
The magnification observation apparatus, wherein the height information acquisition unit includes an objective lens magnification acquisition unit for acquiring magnification information of a currently mounted objective lens. A magnification observation apparatus according to any one of claims 2 to 5,
The magnification observation apparatus, wherein the height information acquisition unit includes a zoom lens magnification acquisition unit for acquiring magnification information adjusted by the zoom lens.   The magnification observation apparatus according to claim 1, wherein the optical system is configured to be telecentric on both sides.

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