JP2012145747A - Stereo microscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stereo microscope apparatus capable of three dimensional observation with high resolution.SOLUTION: The stereo microscope includes: a micro lens array 14 having a plurality of micro lenses ML arranged in positions respectively receiving light from a sample S condensed by an observation optical system 10; imaging elements 15 composed by having a plurality of pixels allotted for every micro lens ML; an image processing circuit 22 for generating an image for the left eye and an image for the right eye by applying a prescribed process to output of the imaging element 15; and a display apparatus for the left eye 16 L and a display apparatus for the right eye 16R for respectively displaying the image for the left eye and the image for the right eye generated in the image processing circuit 22. In this case, the image processing circuit 22 respectively extracts image data of a prescribed number of pixels which have the identical positioning to each other for every plurality of pixels allotted to the micro lens ML, generates a plurality of parallax images with different parallax from each other by synthesizing the extracted pixel data according to the positioning and acquires the image for the left eye and the image for the right eye from the plurality of parallax images.

Description

  The present invention relates to a stereomicroscope device that can observe a specimen in three dimensions.

  Conventionally, stereomicroscopes have been widely used in applications such as stereoscopic observation in the biological field and industrial field. For example, in a parallel system stereomicroscope, the light from the object to be examined (specimen) is collected with a single objective lens, and then the left and right independent optical systems (imaging optical systems combining afocal zoom lenses and imaging lenses) are used. By dividing, images with different parallax are formed. An observer can perform stereoscopic viewing by observing each image individually with the left and right eyes through an eyepiece.

  In such a parallel stereomicroscope, the light collected by the objective lens is divided into two optical paths in the left and right optical systems, so that each effective diameter (NA of the luminous flux) of the left and right optical systems is effective for the objective lens. It becomes about half of the diameter, and the resolution is reduced accordingly. Therefore, by making the effective diameter asymmetric between the left and right optical systems and making a difference in the effective diameter, the resolution is improved in one optical system with a large effective diameter, and the depth of focus is increased in the other optical system with a small effective diameter. A deep stereo microscope has been proposed (see, for example, Patent Document 1).

JP 2007-65651 A

  However, even in the conventional stereomicroscope, since the light from the objective lens is divided into two optical paths, the effective diameter of one optical system is increased when there is a difference in effective diameter between the left and right optical systems. If secured, the effective diameter of the other optical system has to be reduced, and there is a problem that the resolution further decreases accordingly.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a stereomicroscope apparatus that can perform stereoscopic observation with high resolution.

  In order to achieve such an object, the stereomicroscope device according to the present invention includes an observation optical system that collects light from a specimen, and a position that receives light from the specimen collected by the observation optical system. A lens array having a plurality of microlenses arranged, an imaging device in which a plurality of pixels are assigned to each microlens, and a left eye image and a right by performing predetermined processing on the output of the imaging device An image processing unit that generates an image for the eye, and a display unit for the left eye and a display unit for the right eye that respectively display the image for the left eye and the image for the right eye generated in the image processing unit, The image processing unit extracts pixel data of a predetermined number of pixels having the same arrangement for each of the plurality of pixels assigned to the microlens, and the extracted pixel data is arranged in the arrangement Depending generates a plurality of parallax images with different parallaxes with each other by synthesizing, to obtain the left-eye image and the right-eye image from among the plurality of parallax images.

  In the stereomicroscope device according to the present invention, in the plurality of pixels, the predetermined number extracted for generating the left-eye image and the predetermined number extracted for generating the right-eye image. You may comprise so that a number may mutually differ.

  Further, in the stereomicroscope device according to the present invention, of the predetermined number extracted for generating the left eye image and the predetermined number extracted for generating the right eye image, One of the predetermined numbers may be 1, and the other predetermined number may be plural.

In the stereomicroscope device according to the present invention, the observation optical system receives the light from the sample and emits it as a substantially parallel light beam, and receives the light beam from the objective lens to change the light beam diameter. It is preferable that the zoom lens system has a variable magnification optical system and an imaging lens that receives a light beam from the variable magnification optical system and forms a primary image plane in the vicinity of the micro lens, and satisfies the following conditional expression.
NA _L ≦ D / 2f
p / f ≤ NA _H
However,
NA _L : NA of the light beam on the primary image plane at the minimum magnification of the zoom optical system,
NA _H : NA of the light beam on the primary image plane at the maximum magnification of the zoom optical system,
f: focal length of the microlens,
D: effective diameter of the microlens,
p: Pixel pitch of the image sensor.

  Further, in the stereomicroscope device according to the present invention, a configuration may be adopted in which a field lens is detachably disposed in an optical path between the imaging lens and the lens array in accordance with a variable magnification of the variable magnification optical system. .

  According to the present invention, it is possible to provide a stereomicroscope device that can perform stereoscopic observation with high resolution.

It is a perspective view of the stereomicroscope based on this embodiment. It is a figure which shows the principal part structure of the said stereomicroscope. It is a figure for demonstrating the outline | summary of the optical system of this embodiment. It is a figure which shows an example of ML area | region in an image pick-up element surface. It is a figure for demonstrating the detection method of the pixel signal in ML area | region. It is a figure for demonstrating the detection method of the pixel signal by the pixel block of 1 pixel unit. It is a figure which shows the process which produces | generates the image for left eyes and the image for right eyes from the output of an image pick-up element in the pixel block of 1 pixel unit. It is a figure for demonstrating the detection method of the pixel signal by the pixel block of a several pixel unit. It is a figure which shows the process which produces | generates the image for left eyes and the image for right eyes from the output of an image pick-up element in the pixel block of a several pixel unit. It is a figure which shows the change of NA of the light beam in the primary image plane when zooming a zoom optical system. It is a figure which shows the modification which has arrange | positioned the field lens in the said stereomicroscope. It is a figure which shows the mode of a change of the light ray when a field lens is inserted / extracted according to the zooming of a zoom optical system. It is a figure which shows the modification of how to take a pixel block. It is a figure which shows the process which produces | generates the image for left eyes and the image for right eyes from the output of an image pick-up element in the said modification of a pixel block.

  Hereinafter, a stereomicroscope according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments are merely for facilitating understanding of the invention, and excluding additions and substitutions that can be performed by those skilled in the art without departing from the technical idea of the present invention. It is not intended.

  FIG. 1 is a perspective view of a stereomicroscope 100 according to the present embodiment. First, the overall configuration of the stereomicroscope 100 will be outlined with reference to this figure. The stereoscopic microscope 100 is a microscope apparatus having a single objective binocular configuration, and includes a base unit (illumination unit) 101 incorporating a transmission illumination device, a zoom mirror 103 having a zoom optical system therein, and an upper portion of the zoom mirror 103. And a binocular unit 105 attached to the lens barrel 104, a focusing mechanism 106 that moves the zoom lens body 103 up and down, and the like.

  On the upper surface of the base portion 101, a specimen mounting table 102 in which stage glass is embedded is provided. Further, a support column 107 is erected on the base side of the base portion 101, and a focusing mechanism 106 is provided on the support column 107.

  The zoom lens body 103 is provided on the base portion 101 via the focusing mechanism 106, and an objective lens mounting portion 108 is provided below the zoom lens body 103, and a replaceable objective lens is attached to the objective lens mounting portion 108. ing. The objective lens mounting portion 108 has a configuration in which one of a plurality of predetermined low-power objective lenses and a plurality of high-power objective lenses is selected and mounted, and a plurality of predetermined low-power objective lenses. There are cases where a plurality of objective lenses having a magnification and a plurality of objective lenses having a high magnification are selected and attached.

  A zoom optical system (afocal zoom lens) is arranged inside the zoom lens body 103, and a zoom handle 109 for moving the zoom optical system is arranged outside the zoom lens body 103. The zoom optical system includes a movable group for zooming, and zooming is zoomed by moving in the optical axis direction in accordance with a predetermined movement amount in conjunction with the rotation operation of the zoom handle. In addition, a lens barrel 104 is attached to the upper portion of the zoom lens body 103, and left and right binocular portions 105 having eyepieces are attached to the lens barrel 104.

  The focusing mechanism 106 includes a focusing handle 110 for focusing on the specimen, and a mechanism unit (not shown) that moves the zoom lens body 103 up and down along the axis in accordance with a rotation operation of the focusing handle 110. have. Therefore, the focusing mechanism 106 moves the lens barrel 104 and the binocular unit 105 together with the zoom mirror 103 relative to the sample mounting table 102 so as to focus on the sample.

  The specimen is placed on the specimen mounting table (stage glass) 102 of the base unit 101 and is arranged near the optical axis of the objective lens, and is transmitted and illuminated by a transmission illumination device arranged inside the base unit 101. The The illuminated specimen is observed through the zoom lens body 103, the lens barrel 104, the binocular unit 105, and the like. As described above, the stereomicroscope 100 capable of stereoscopically viewing the specimen in both the left and right eyes is configured.

  Next, a more detailed configuration of the stereomicroscope 100 will be described with additional reference to FIGS. Here, FIG. 2 is a diagram illustrating a main configuration of the stereomicroscope 100.

  The stereomicroscope 100 is formed by a transmission illumination device (not shown) that irradiates the specimen S with illumination light, an observation optical system 10 that includes an objective lens for observing an image of the specimen S, and the observation optical system 10. The left-eye image and the right-eye image are displayed based on the microlens array 14 disposed on the primary image plane, the image sensor 15 disposed on the focal plane of the microlens array 14, and the output from the image sensor 15. A left-eye display device 16L and a right-eye display device 16R, and a pair of left and right eyepieces 17L and 17R. These include the base portion 101, the zoom lens body 103, the lens barrel 104, and the binocular portion 105 described above. It is mounted on. The observation optical system 10 includes, in order from the sample S side, an objective lens 11 and a zoom optical system (variable magnification optical system) that changes the diameter of the substantially parallel light beam emitted from the objective lens 11 and emits it again as a substantially parallel light beam. 12, an imaging lens 13 for focusing the parallel light flux from the zoom optical system 12 to form an image of the object.

  Furthermore, the stereomicroscope 100 includes a drive circuit 21, an image processing circuit 22, a memory 23, a control circuit 24, a user interface 25, and the like as a control unit 20 that comprehensively controls the operation of the microscope. The imaging light flux that has entered the vicinity of the focal plane of the imaging lens 13 is converted into an electrical signal by the imaging device 15. The image pickup device 15 is driven by a drive circuit 21, and an output signal from the image pickup device 15 is taken into the image processing circuit 22 through the drive circuit 21. The image processing circuit 22 synthesizes sample image data based on the output signal. The synthesized image data is stored in the memory 23 and displayed on the left and right eye display devices 16L and 16R.

  The drive circuit 21, the image processing circuit 22, and the memory 23 are controlled by the control circuit 24. The control circuit 24 is configured by, for example, a microcomputer, and executes control according to an instruction input from the user via the user interface 25. This user operation is realized, for example, by an operation of an input device such as a mouse or keyboard operation based on a GUI (Graphical User Interface) display screen displayed on a predetermined display.

  FIG. 3 shows the principle of generating a parallax image with two left and right viewpoints in the stereomicroscope 100, and this will be described below with a focus on the outline of the optical system of the stereomicroscope 100. In order to simplify the description, in FIG. 3, the objective lens 11, the zoom optical system 12, and the imaging lens 13 constituting the observation optical system 10 are collectively shown as a main lens 10L.

  In this configuration, the microlens array 14 is arranged on the surface where the surface of the sample S at a predetermined position (hereinafter also referred to as the sample surface S) forms an image with the main lens 10L, and is separated by the focal length of the microlens array 14. The image sensor 15 is disposed at the position. The microlens array 15 is an optical element formed by two-dimensionally arranging a plurality of microlenses ML. At this time, the surface of the imaging element 15 is conjugate with the pupil plane of the main lens 10L (objective lens 11), and an area where an image formed by each microlens ML can be formed (hereinafter referred to as “ML area”). The image signal of each pixel obtained from the above is an image obtained by dividing the pupil. In other words, the imaged light rays are distributed into light rays at different angles as viewed from the pupil plane.

  The imaging element 15 receives light from the microlens 14 and acquires imaging data. The imaging device 15 is a solid-state imaging device such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor) sensor, and a pixel array that receives light that has passed through each microlens ML is represented by a microlens ML. It arranges with the arrangement pattern corresponding to. That is, a plurality of pixel groups are assigned as the ML region.

  FIG. 4 is a diagram illustrating an example of the ML region on the imaging surface in the imaging element 15. In FIG. 4, each of the 6 × 6 circles indicates the microlenses ML arranged in a two-dimensional manner when the microlens array 14 is viewed from the optical axis direction of the main lens 10 </ b> L, and overlaps this. Each of the 6 × 6 square areas arranged in a grid pattern indicates an ML area in the image sensor 15. When attention is paid to one ML region, the number of pixels in the vertical direction and the number of pixels in the horizontal direction of the ML region (assigned to each microlens ML) is 5 (that is, a 5 × 5 pixel array). It is. That is, each of the images formed by the 36 microlenses ML constituting the microlens array 14 forms an ML region on a 5 × 5 pixel group on the imaging surface of the imaging device 15. . In the example of FIG. 4, it is assumed that the number of pixels of the image sensor 15 is 30 × 30, and the light rays that have passed through each microlens ML are in each of 25 (5 × 5) pixels in the ML region. Light is received.

  Here, in order to make the explanation easy to understand in FIG. 3, the five pixels a and b arranged in one direction (this is assumed to be the X direction (left and right direction)) in the plane perpendicular to the optical axis in the image sensor 15. , C, d, and e (only chief rays passing through the center of the corresponding microlens ML) are shown. In FIG. 3, the light rays from the point S1 on the specimen surface S pass through the main lens 10L to form a light ray group (here, r1 to r5) and form an image formed by each microlens ML. Area, that is, an image signal of the image sensor 15 in each ML area. As shown in the figure, rays r1, r2, r3, r4, r5 from the focal position (focus plane) gather at one point on the surface of the microlens array 14, and on the surface of the image sensor 15 by the lens action of the microlens ML. Then, pixel signals of ai, bi, ci, di, and ei correspond to the respective pixels a, b, c, d, and e in each ML region. Here, the symbols ai, bi, ci, di, ei indicate the concept of pixel signals (pixel values) output individually by the five pixels a, b, c, d, e arranged in the X direction. Here, attention is focused on only the five pixels a, b, c, d, and e arranged in the X direction, but actually, from each of the 25 pixels arranged in the X and Y directions (two directions orthogonal to each other). Pixel signals are output individually.

  In the image pickup device 15, the light ray information is read out in units of pixels in accordance with the driving operation by the driving circuit 21, and image data is obtained. In the image data captured by the imaging device 15 in this way, with respect to the light beam from the specimen surface S, the position information of the light beam as well as the intensity information and the ML region assigned to each micro lens ML together with the intensity information. The traveling direction of the light beam is detected independently by the arrangement of the pixels. That is, the parallax information of the light beam can be detected.

  In the present embodiment, for example, among the light rays from the point S1 on the sample surface S, the light rays on the right side of the central light ray r3 (for example, light rays r4 and r5) have parallax information for the right eye. It can be regarded as being. On the other hand, light rays on the left side of the central light ray r3 (for example, light rays r1 and r2) can be regarded as having parallax information for the left eye.

  The image processing circuit 22 performs predetermined image processing based on the output from the image sensor 15 to generate parallax images at the two left and right viewpoints. The resolution of this parallax image is determined by the number of microlenses ML, and the number of parallaxes is determined by the number of pixels in the ML area assigned to each microlens ML. Here, the ML area allocated to each microlens ML is divided into several areas in units of one pixel or a plurality of pixels, and image data selected and processed only in each area is generated. Since the pupil plane of the main lens 10L (objective lens 11) and the imaging plane of the imaging device 15 are conjugate, an image obtained by dividing the pupil plane by the number of area divisions is obtained.

  One region (a pixel region composed of a predetermined number of pixels) obtained by dividing the ML region in units of one pixel or a plurality of pixels in this way will be hereinafter referred to as a pixel block GB. When the ML region is divided in units of one pixel (that is, when the pixel block GB is one pixel), the maximum number of parallax images (multi-viewpoint images) that can be generated is 5 × 5 = 25.

  FIG. 5 is a diagram for explaining a pixel signal detection method in the ML region, and FIG. 6 is a diagram for explaining a pixel signal detection method of the image pickup device 15 as a whole. Here, in order to simplify the description, a case where a parallax image is generated by detecting the pixel block GB as one pixel unit in five regions different in the X direction (left and right direction) in the ML region will be exemplified. Since the imaging element 15 is optically conjugate with the pupil plane of the main lens 10L (objective lens 11), the light is emitted from the lens opening corresponding to one pixel at five viewpoints (angles) in the horizontal direction. Image data is generated. The five pixels detected here may be considered as the same pixels as the pixels a, b, c, d, and e in FIG. The number of pixels of the pixel block GB assigned to each microlens ML determines the size of the light beam (light beam diameter) detected on the pupil plane having a conjugate relationship. That is, it corresponds to the F value of the lens, and when this is small, the depth of focus becomes deep, and when it is large, the depth of focus becomes shallow. Therefore, when one pixel is detected as the pixel block GB, an image (parallax image) having a deep focal depth is obtained.

  In FIG. 6, pixel signals in pixels at the same position in each ML region (here, pixels a, b, c, d, and e aligned in the X direction) are extracted, and the extracted pixel signals are combined. Thus, five parallax images having different parallax can be obtained. That is, for each ML region, an image that collects pixel signals ai, an image that collects pixel signals bi, an image that collects pixel signals ci, an image that collects pixel signals di, and an image that collects pixel signals ei, respectively. Are generated as parallax images. Note that here, only five pixels a, b, c, d, and e arranged in the X direction in the ML region are focused on, and five parallax images are generated based on these five pixels. Thus, 25 parallax images can be generated based on 25 pixels arranged in the X and Y directions (two directions).

  Of the parallax images generated in this way, the image processing circuit 22 obtains the parallax image at the left viewpoint as the left-eye image and the parallax image at the right viewpoint as the right-eye image. For example, as illustrated in FIG. 7, a left-eye viewpoint parallax image obtained based on the output of the pixel a located in the center of the leftmost column of each ML region is a left-eye image 30L, and the center of the rightmost column of each ML region A right-eye viewpoint parallax image obtained on the basis of the output of the pixel e positioned at is defined as a right-eye image 30R. At this time, the output (pixel signal) of the pixel a in each ML region corresponds to each pixel of the left eye image 30L, and the output (pixel signal) of the pixel e in each ML region corresponds to the right eye image 30R. It corresponds to each pixel. Here, when acquiring the left-eye two-viewpoint left-eye image 30L and the right-eye image 30R based only on the outputs of the pixel a and the pixel e, pixel signals other than the pixel a and the pixel e are substantially unnecessary. Therefore, it is preferable that only the necessary pixel signals of the pixel a and the pixel e are selectively extracted from the image sensor 15 by the control of the drive circuit 21.

  However, the present invention is not limited to this, and the parallax image generated from the output of the pixel b may be used as the image for the left eye, the parallax image generated from the output of the pixel d may be used as the image for the right eye, and may be generated from the output of the pixel a. The parallax image thus generated may be used as the left-eye image, and the parallax image generated from the output of the pixel c may be used as the right-eye image. These can be arbitrarily designated by the user using the user interface 25.

  On the other hand, in FIG. 8, each ML region of the image sensor 15 is a region different in the X direction in a plane perpendicular to the optical axis, and is a plurality of pixel units (for example, six strips (2 × 3) in a strip shape). The case of detecting with (pixels) is illustrated. In FIG. 8, the pixel signals in the pixel regions (here, the six-pixel block GB filled in FIG. 8) in the same position in each ML region are extracted, and the six pixels constituting the pixel block GB are extracted. The sum of the pixel signals is obtained as a pixel signal for one pixel of the parallax image, and the four parallax images having different parallax are obtained by synthesizing the pixel signals according to the arrangement.

  Of the parallax images generated in this way, the image processing circuit 22 obtains the parallax image at the left viewpoint as the left-eye image and the parallax image at the right viewpoint as the right-eye image. For example, as shown in FIG. 9, a parallax image of the left viewpoint obtained based on the output of six pixels (pixel blocks) located at the center of the left end of the ML region is set as the left-eye image 40L, and 6 located at the center of the right end. A right viewpoint parallax image obtained based on the output of one pixel (pixel block) is defined as a right eye image 40R. At this time, the outputs (pixel signals) of the six pixels located at the center of the left end of the ML region correspond to the pixels of the left eye image 40L one by one, and the outputs of the six pixels located at the center of the right end of the ML region ( Pixel signal) corresponds to each pixel of the right-eye image 40R. Here, as in the case of the pixel block GB in units of one pixel, it is preferable that only the pixel signals of the necessary pixel block GB are selectively extracted from the image sensor 15. Also, the parallax image generated from the output of the six pixels (pixel block) shown in FIG. 8B is the left-eye image, and the parallax generated from the output of the six pixels (pixel block) shown in FIG. The image may be an image for the right eye, and these can be arbitrarily designated by the user using the user interface 25.

  In the detection of 6 pixel units as the pixel block GB, the light ray passing through the pupil plane captured by the pixel block GB is 6 times wider than that in the detection of the 1 pixel unit (the F value is small). The focal depth of the obtained parallax images (the left-eye image 40L and the right-eye image 40R) becomes shallow, but the resolution is improved. Therefore, when the pixel block GB (the NA of the luminous flux) is reduced, a parallax image with a deep focal depth is obtained, and when the pixel block GB (the NA of the luminous flux) is increased, a parallax image with a high resolution is obtained. Here, the method of taking the pixel block GB is not limited to the above-described form, and can be arbitrarily set in units of one pixel or a plurality of pixels according to a desired resolution and depth of focus.

  The image processing circuit 22 stores the parallax images of the left and right viewpoints in the memory 23 as the left-eye image and the right-eye image, and outputs them to the left-eye display device 16L and the right-eye display device 16R. An image is displayed as a magnified image. When the user looks into the display devices 16L and 16R (binocular unit 105) individually with the left and right eyes, the left eye image and the right eye image with parallax can be separately captured with the left and right eyes. Visualization is realized.

  Here, the pixel block GB is arbitrarily selected and set in each ML region by the user interface 25 (user operation), and the left-eye image and the right-eye image are both parallax images having a deep focal depth from the left and right viewpoints. The left eye image and the right eye image can be displayed from the pixel blocks GB having different numbers of pixels, and can be displayed as parallaxes for the left and right viewpoints. It can also be displayed as an image. More specifically, one of the left-eye image and the right-eye image is generated by a pixel block GB in units of one pixel (for example, as shown in FIG. The left viewpoint parallax image 30L is generated), and the other image is generated by a pixel block GB in units of multiple pixels (for example, as shown in FIG. By generating a viewpoint parallax image 40R), it is possible to capture a parallax image with a deep focal depth with one eye and a parallax image with a high resolution with the other eye. Can be observed simultaneously as a binocular parallax image.

  According to the stereomicroscope according to the present embodiment described above, since it is not necessary to divide the light beam collected by the objective lens 11 into a plurality of optical paths, a large numerical aperture of the observation optical system 10 is ensured, and the sample S Can be stereoscopically observed with high resolution. Also, by adjusting the ratio of the NA of the light beams forming the left and right images (by making the pixel block GB different on the left and right), an image with high resolution is obtained on the one hand, and the depth of focus is deep on the other hand. Images can be acquired and images with high resolution and deep depth of focus can be observed simultaneously. Accordingly, it is possible to provide a stereomicroscope that can obtain a desired resolution and depth of focus.

By the way, as shown in FIG. 10, when the zoom optical system (afocal zoom lens) 12 is used in the stereomicroscope 100, it is preferable that the following conditional expressions (1) and (2) are satisfied.
_{NA L <D / 2f ... (} 1)
2p / 2f <NA _H (2)
However,
NA _L : NA of the light beam on the primary image plane at the minimum magnification of the zoom optical system 12,
NA _H : NA of the light beam on the primary image plane at the maximum magnification of the zoom optical system 12,
f: focal length of the microlens ML,
D: effective diameter of the microlens ML,
p: Pixel pitch (pixel size) of the image sensor 15.

  Conditional expressions (1) and (2) define an appropriate range of the NA of the light beam on the primary image plane. The diameter of the light beam is at least twice the pixel size p, and the microlens ML It is desirable to adjust in a range smaller than the effective diameter D. In order to obtain a right-and-left viewpoint parallax image, two or more pixels arranged in one direction (X direction) in a pixel block GB of at least one pixel unit as the ML region of the image sensor 15 assigned to each microlens ML. Because it is necessary. A zoom operation of the zoom optical system 12 within a range that satisfies the conditional expressions (1) and (2) is performed to increase the NA of the light beam, thereby obtaining a high-resolution parallax image and reducing the NA of the light beam. Thus, a parallax image with a deep focal depth can be obtained. In FIG. 10, the number of pixels assigned to the microlens ML is 3 × 3 at the minimum magnification of the zoom optical system 12 (only three in the X direction appear in FIG. 10), and 5 × 5 at the maximum magnification. However, the number of pixels allocated by the microlens ML is not limited to this, and satisfies the conditional expressions (1) and (2). In this range, it is desirable to set appropriately according to the required resolution.

  Note that the stereomicroscope 100 according to the present embodiment is not limited to the above-described embodiment, and other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

  For example, a modification of the stereomicroscope is shown in FIG. In this stereomicroscope, as shown in FIG. 11, the field lens FL can be inserted and removed by an actuator (not shown) immediately before the microlens array 14 (between the imaging lens 13 and the microlens array 14). It is preferable that In the zoom optical system 12, the position of the exit pupil moves in accordance with the change in focal length when the magnification is changed (generally, the change in the exit pupil position increases as the magnification ratio increases). When the magnification is doubled, the imaging position on the image sensor 15 may be shifted in the in-plane direction (pixel arrangement direction). Accordingly, by arranging the field lens FL in the vicinity of the primary image plane, it is possible to correct the variation in the exit pupil position due to the zooming of the zoom optical system 12. For example, in FIG. 12, when the zoom optical system 12 has a low magnification, the field lens FL is removed from the system, and when the zoom optical system 12 has a high magnification, the field lens FL is inserted immediately before the microlens array 14 to correct the deviation of the exit pupil position. The form is illustrated. On the contrary, the field lens FL may be inserted when the zoom optical system 12 is at a low magnification, and removed from the system at a high magnification.

  Further, in the above-described stereomicroscope 100, the case where the transmission illumination optical system (transmission illumination device) incorporated in the base unit 101 is used as the illumination optical system is exemplified, but an epi-illumination optical system may be adopted.

  Further, the method of obtaining the pixel block GB (the number of pixels in the pixel array and the pixel arrangement) is not limited to the above-described embodiment, and can be appropriately set according to the resolution and the depth of focus required for observation. For example, as shown in FIG. 13, nine pixels (3 × 3 pixels) may be selected as the pixel block GB to generate the left-eye image 50L and the right-eye image 50R. At this time, as shown in FIG. 13 and FIG. 14, an area (here, the central three pixels arranged in the vertical direction) overlaps with the pair of pixel blocks selected from the left and right viewpoints in the ML area. If the overlapping area is too large, the amount of shared parallax information increases, and appropriate parallax cannot be obtained on the left and right. For this reason, it is desirable to select the pixel block GB so that overlapping regions do not occur from the left and right viewpoints.

10 observation optical system 11 objective lens 12 zoom optical system (variable magnification optical system)
13 Imaging Lens 14 Micro Lens Array 15 Image Sensor 17L Left Eye Display Device 17R Right Eye Display Device 20 Control Unit 22 Image Processing Circuit 100 Stereo Microscope S Sample ML Micro Lens GB Pixel Block (predetermined number)
FL field lens

Claims (5)

An observation optical system that collects light from the specimen;
A lens array having a plurality of microlenses arranged at positions to receive light from the specimen collected by the observation optical system;
An imaging device in which a plurality of pixels are assigned to each microlens;
An image processing unit that performs predetermined processing on the output of the imaging device to generate an image for the left eye and an image for the right eye;
A left-eye display unit and a right-eye display unit that respectively display the left-eye image and the right-eye image generated in the image processing unit;
The image processing unit extracts pixel data of a predetermined number of pixels having the same arrangement for each of the plurality of pixels allocated to the microlens, and synthesizes the extracted pixel data according to the arrangement. By doing so, a plurality of parallax images having different parallax are generated, and the left-eye image and the right-eye image are acquired from the plurality of parallax images.   In the plurality of pixels, the predetermined number extracted to generate the left-eye image and the predetermined number extracted to generate the right-eye image are different from each other. The stereomicroscope apparatus according to claim 1.   One of the predetermined number extracted to generate the left-eye image and the predetermined number extracted to generate the right-eye image is 1, 3. The stereomicroscope device according to claim 2, wherein the other predetermined number is plural. The observation optical system includes an objective lens that emits light from the sample as a substantially parallel light beam, a variable power optical system that receives the light beam from the objective lens and changes the diameter of the light beam, and the variable power optical system. An imaging lens that receives a light beam from the system and forms a primary image plane at a position near the microlens;
The stereoscopic microscope apparatus according to claim 1, wherein the following conditional expression is satisfied.
NA _L ≦ D / 2f
p / f ≤ NA _H
However,
NA _L : NA of the light beam on the primary image plane at the minimum magnification of the zoom optical system,
NA _H : NA of the light beam on the primary image plane at the maximum magnification of the zoom optical system,
f: focal length of the microlens,
D: effective diameter of the microlens,
p: Pixel pitch of the image sensor.   5. The stereomicroscope device according to claim 4, wherein a field lens is detachably disposed in an optical path between the imaging lens and the lens array in accordance with a variable magnification of the variable magnification optical system. .