Eyeglass tubes

Abstract

To provide an eyepiece barrel which offers an AR display function while maintaining the eye point of a microscope at an appropriate hight.SOLUTION: An eyepiece barrel 200 provided herein is a microscope eyepiece barrel for attaching an eyepiece lens 103. The eyepiece barrel 200 has a projector 210 for superimposing an auxiliary image on an image plane where an optical image is formed with light from a microscope.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The disclosure of this specification relates to an eyepiece barrel.

Background Art

[0002] Even today when the automation of work by robots and the like is progressing, there are still many products that require manual assembly. For example, medical devices are one such example. Since the assembly of precision devices such as medical devices involves many detailed operations, it is often performed under a microscope, and a stereomicroscope that allows the object to be viewed stereoscopically with both eyes is often used.

[0003] However, in order to check the procedure manual while performing the assembly work while observing the object, the user has to temporarily move the eyes away from the eyepiece and shift the line of sight to a display or the like on which the procedure manual is displayed. And after confirmation, since the user has to look into the eyepiece again to continue the assembly work, it is difficult to improve the work efficiency.

[0004] A technique related to such a problem is described in, for example, Patent Document ɪ. In the microscope system described in Patent Document ɪ, by projecting an image (hereinafter, this image is referred to as an AR image) at the intermediate image position of the microscope, necessary information can be obtained while looking into the eyepiece lens.

Prior Art Documents

Patent Documents

[0005]

Patent Document ɪ

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, the microscope system described in Patent Document 1 employs a configuration in which an intermediate tube containing a projector is attached between the eyepiece tube and the main body of the microscope to project an AR image. However, when an intermediate tube is added to a microscope, the eye point, which is designed to be at a good height beforehand, becomes higher by the height of the intermediate tube. A change in the height of the eye point may degrade the ergonomics of the system and negatively affect the user's posture during observation.

[0007] Based on the circumstances described above, one aspect of the present invention is to provide an AR display function while maintaining the eye point of the microscope at an appropriate height. [Means for solving the problem]

[0008] An eyepiece tube according to one aspect of the present invention is an eyepiece tube for a microscope into which an eyepiece lens is attached, This is a three-eyepiece tube for mounting a digital camera, with separate optical paths for the right and left eyes, and is attached to a stereomicroscope. A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope. The optical system comprises: a first optical element that merges the light from the superimposing device into the optical path of the light from the microscope; a folding optical system that folds back the propagation directions of both the light from the superimposing device and the light from the microscope; an imaging lens disposed between the first optical element and the folding optical system; a second optical element that splits the light from the microscope into light directed toward the eyepiece and light directed toward the digital camera, the second optical element disposed in one of the optical paths for the right eye and the optical path for the left eye; and an optical element that suppresses the amount of light disposed in the other of the optical paths for the right eye and the optical path for the left eye. The superposition device is provided at a position offset from the center line between the two eyepieces attached to the eyepiece barrel. Furthermore, a projector that projects the aforementioned auxiliary image onto the image plane. ru. Another aspect of the present invention relates to an eyepiece tube, An eyepiece tube for a microscope, into which an eyepiece lens is attached, comprising: a superposition device that superimposes an auxiliary image onto the image plane where an optical image is formed by light from the microscope; a first optical element that merges the light from the superposition device into the optical path of the light from the microscope; a folding optical system that folds back the propagation directions of both the light from the superposition device and the light from the microscope; and an imaging lens disposed between the first optical element and the folding optical system, wherein the superposition device is a projector that projects the auxiliary image onto the image plane, provided at a position offset from the center line between two eyepiece lenses attached to the eyepiece tube, and the first optical element is a beam splitter that forms more transmitted light than reflected light with respect to incident light. An eyepiece tube according to yet another aspect of the present invention is: An eyepiece tube for a microscope, which is fitted with an eyepiece, wherein the eyepiece tube is a three-eyepiece tube for fitting a digital camera, and comprises: a superposition device that superimposes an auxiliary image onto the image plane where an optical image is formed by light from the microscope; a first optical element that merges the light from the superposition device into the optical path of the light from the microscope; a folding optical system that folds back the propagation directions of both the light from the superposition device and the light from the microscope; an imaging lens disposed between the first optical element and the folding optical system; and a second optical element that splits the light from the microscope into light toward the eyepiece and light toward the digital camera, wherein the superposition device is a projector that projects the auxiliary image onto the image plane, and is provided at a position offset from the center line between the two eyepieces attached to the eyepiece tube, and the second optical element is a beam splitter that forms more transmitted light than reflected light with respect to incident light. An eyepiece tube according to yet another aspect of the present invention is an eyepiece tube for a microscope, which is fitted with an eyepiece lens, and the eyepiece tube is attached to a stereomicroscope having an optical path for the right eye and an optical path for the left eye, and includes: a superposition device that superimposes an auxiliary image onto an image plane on which an optical image is formed by light from the microscope; a first optical element that merges the light from the superposition device into the optical path of the microscope, the first optical element including: a first right-eye optical element positioned in the optical path for the right eye and merging the light from the superposition device into the optical path for the right eye; a first left-eye optical element positioned in the optical path for the left eye and merging the light from the superposition device into the optical path for the left eye; a folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope; an imaging lens positioned between the first optical element and the folding optical system; and the light from the superposition device The superimposing device comprises a third optical element that splits light toward a first right-eye optical element and light toward a first left-eye optical element, a first adjustment unit that adjusts the position of the auxiliary image for the right eye formed in the optical path for the right eye, and a second adjustment unit that adjusts the position of the auxiliary image for the left eye formed in the optical path for the left eye, wherein the superimposing device is a projector that projects the auxiliary image onto the image plane, provided at a position offset from the center line between two eyepieces attached to the eyepiece barrel, and one of the first and second adjustment units includes a first reflective member whose orientation can be adjusted, disposed on the optical path between the superimposing device and the third optical element, and the other of the first and second adjustment units includes a second reflective member whose orientation can be adjusted, disposed on the optical path between the third optical element and the first right-eye optical element or the first left-eye optical element. . An eyepiece tube according to yet another aspect of the present invention is an eyepiece tube for a microscope, which is fitted with an eyepiece lens, the eyepiece tube comprising: a superposition device that superimposes an auxiliary image onto an image plane where an optical image is formed by light from a microscope; a first optical element that merges the light from the superposition device into the optical path of the light from the microscope; a folding optical system that folds back the propagation directions of both the light from the superposition device and the light from the microscope; an imaging lens disposed between the first optical element and the folding optical system; and a height adjustment unit provided on the eyepiece lens side of the folding optical system for adjusting the height of the eye point, wherein the superposition device is a projector that projects the auxiliary image onto the image plane, provided at a position offset from the center line between two eyepiece lenses attached to the eyepiece tube, and the height adjustment unit includes a rotating part on which the eyepiece lens is fitted and which rotates in a tilting direction around a horizontal axis, and a reflective member attached to the axis of the rotating part that rotates around the axis by half the amount of rotation of the rotating part. An eyepiece tube according to yet another aspect of the present invention is: An eyepiece tube for a microscope, into which an eyepiece lens is attached, comprising a superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from the microscope, and an operating section on the front of the eyepiece tube into which the eyepiece lens is attached for inputting instructions to the superposition device. The operating section is positioned on one side of the center line between the two eyepiece lenses attached to the eyepiece barrel. . [Effects of the Invention]

[0009] According to the above embodiment, it is possible to provide an AR display function while maintaining the eye point of the microscope at an appropriate height. [Brief explanation of the drawing]

[0010] [Figure 1] The configuration of a microscope system according to an embodiment of the present invention is shown. [Figure 2] It is a diagram showing the configuration of a microscope according to an embodiment of the present invention. [Figure 3] It is a diagram for explaining the configuration of an image formed on the image plane. [Figure 4] It is a perspective view of a microscope according to an embodiment of the present invention as viewed from obliquely forward. [Figure 5] It is a perspective view of a microscope according to an embodiment of the present invention as viewed from obliquely backward. [Figure 6] It is a perspective view of an eyepiece tube according to an embodiment of the present invention. [Figure 7] It is a front view of an eyepiece tube according to an embodiment of the present invention. [Figure 8] It is a top view of an eyepiece tube according to an embodiment of the present invention. [Figure 9] It is a diagram showing the configuration of an eyepiece tube according to an embodiment of the present invention. [Figure 10] It is a diagram showing the optical path inside an eyepiece tube according to an embodiment of the present invention as viewed from obliquely forward. [Figure 11] It is a diagram showing the optical system inside an eyepiece tube according to an embodiment of the present invention as viewed from obliquely forward. [Figure 12] It is a diagram showing the optical path inside an eyepiece tube according to an embodiment of the present invention as viewed from obliquely backward. [Figure 13] It is a diagram showing the optical system inside an eyepiece tube according to an embodiment of the present invention as viewed from obliquely backward. [Figure 14] It is a diagram showing a configuration for guiding light branched from the observation optical path of a stereomicroscope to an imaging device. [Figure 15] It is a diagram showing a configuration for guiding light emitted from a projector 210 as viewed from obliquely above to the observation optical path of a stereomicroscope. [Figure 16] It is a diagram showing a configuration for guiding light emitted from a projector 210 as viewed from above to the observation optical path of a stereomicroscope.

Mode for Carrying Out the Invention

[0011] FIG. 1 shows the configuration of a microscope system according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of a microscope according to an embodiment of the present invention. FIG. 3 is a diagram for explaining the configuration of an image formed on an image plane. The microscope system 1 shown in FIG. 1 provides necessary information to a user during work under a microscope while the user is looking through an eyepiece 103. The configuration of the microscope system 1 will be described while referring to FIGS. 1 to 3.

[0012] As shown in FIG. 1, the microscope system 1 includes a microscope 100, a plurality of input devices 400, a monitor 500, a Web camera 600, and a control device 700.

[0013] The microscope 100 is a stereomicroscope capable of both visual observation using an eyepiece 103 and digital photography using an imaging device 300. As shown in FIG. 2, the microscope 100 has independent optical paths for the right eye and the left eye for visual observation, and the optical images of a sample formed in each of the optical paths for the right eye and the left eye are observed with each eye via the eyepiece 103 (eyepiece 103a, eyepiece 103b), so that the sample can be observed stereoscopically. Therefore, the microscope 100 is suitable for applications such as the assembly work of precision instruments.

[0014] The microscope 100 includes a focusing handle 110. By operating the focusing handle 110, the distance between the sample and the objective lens 101 can be changed to focus on the sample.

[0015] The microscope 100 includes a zoom lens 102 (zoom lens 102a, zoom lens 102b) that can be operated by a zoom handle 120. By operating the zoom handle 120, the observation magnification can be changed while continuing to observe the sample while looking through the eyepiece 103.

[0016] The microscope 100 is equipped with a detachable eyepiece tube 200. The eyepiece tube 200 is an eyepiece tube for a microscope that is attached to a stereomicroscope, and has the aforementioned optical paths for the right eye and left eye inside. The eyepiece tube 200 is a tripod that mounts the eyepiece 103 (eyepiece 103a, eyepiece 103b) and the imaging device 300.

[0017] The eyepiece tube 200 has a dovetail joint 201 for attachment and detachment to the microscope 100. The dovetail joint 201 is a fastening part that securely fastens the eyepiece tube 200 to the microscope 100. The dovetail joint 201 has an inlet formed into which light from the microscope 100 enters.

[0018] The eyepiece tube 200 has a dovetail joint 202 for attachment and detachment to the imaging device 300. The dovetail joint 202 is a fastening part that securely fastens the eyepiece tube 200 to the imaging device 300. The dovetail joint 202 has an outlet formed therein through which light from the eyepiece tube 200 is emitted to the imaging device 300.

[0019] The eyepiece tube 200 is equipped with a projector 210. The projector 210 projects information required by the user as an auxiliary image onto the image plane where the optical image of the sample is formed by light from the microscope 100 when the eyepiece tube 200 is attached to the microscope 100. The projector 210 may be composed of, for example, a liquid crystal device, a DMD (registered trademark) device, or an organic EL device, and may be a single-chip or three-chip type.

[0020] The projector 210 is a superposition device that projects an auxiliary image onto the image plane and superimposes it onto the optical image. More specifically, the projector 210 projects an auxiliary image specified by a command from the control device 700 onto the image plane. As a result, by looking through the eyepiece 103, the user can observe a superimposed image, for example, as shown in Figure 3, in which the auxiliary image B1 formed on the image plane is superimposed onto the optical image A1.

[0021] By operating the control unit 230, the user can switch the projection function of the projector 210 ON / OFF and instruct the start or stop of superimposing an auxiliary image onto the image surface.

[0022] The auxiliary image is equivalent to augmented reality, displayed overlaid on the optical image of a real sample. For this reason, the auxiliary image will also be referred to as an AR image, and the act of projecting the auxiliary image onto the image plane, that is, making the auxiliary image visually recognizable to the user, will also be referred to as AR display.

[0023] Light from the projector 210 is guided to optical paths for the right eye and left eye via the projection lens 211, beam splitter 213, and adjustment mechanisms (adjustment mechanisms 212 and 214). Adjustment mechanisms 212 and 214 are mechanisms that adjust the position of the auxiliary image on the image plane.

[0024] Hereafter, the optical paths for the right eye and the left eye will be collectively referred to as the observation optical path. The optical path from the projector 210 to the point where it merges with the observation optical path will be called the AR optical path. Furthermore, as will be described later, the optical path that branches off from the observation optical path to the imaging device 300 will be called the imaging optical path.

[0025] The optical paths for the right and left eyes provided in the eyepiece barrel 200 have basically the same configuration. Specifically, the eyepiece barrel 200 is equipped with a beam splitter 224 (beam splitter 224a, beam splitter 224b), an imaging lens 225 (imaging lens 225a, imaging lens 225b), and a folded optical system 226 (folded optical system 226a, folded optical system 226b) for each of the optical paths for the right and left eyes. The beam splitter 224 is an example of the first optical element. The light that has passed through these optical systems is then guided to the eyepiece lens 103 via the eye point height adjustment mechanism 227 and the interpupillary distance adjustment mechanism 228.

[0026] However, the optical paths for the right eye and the left eye differ in that only one of them is equipped with a beam splitter 221 to guide light to the imaging optical path. The beam splitter 221 is an example of a second optical element. In addition, the optical path for the right eye and the optical path for the left eye that is not equipped with a beam splitter 221 is equipped with an ND prism 222 instead of a beam splitter 221.

[0027] In the optical path for the right and left eyes, where the beam splitter 221 is installed, a portion of the light incident on the beam splitter 221 is directed to the imaging optical path. As a result, the amount of light reaching the eyepiece 103 is reduced accordingly. The ND prism 222 reduces the incident light by the same amount as the amount of light directed to the imaging optical path by the beam splitter 221, thereby minimizing the difference in the amount of light reaching the eyepiece 103 from the optical paths for the right and left eyes.

[0028] The microscope 100 is equipped with an imaging device 300 that images a sample and acquires a digital image of the sample. The imaging device 300 is attached to the eyepiece tube 200 by a round dovetail joint 202. An imaging lens 223, separate from the imaging lens 225 on the observation light path, is provided in the imaging optical path within the eyepiece tube 200. The imaging lens 223 is an example of a second imaging lens and focuses the light guided from the observation optical path to the imaging optical path by the beam splitter 221 onto the imaging surface of the imaging device 300.

[0029] The imaging device 300 is a digital camera having a two-dimensional image sensor. The image sensor is not particularly limited, but examples include a CCD image sensor and a CMOS image sensor. The digital image acquired by the imaging device 300 is output to the control device 700. Alternatively, the digital image may be output directly to the monitor 500.

[0030] The input device 400 and the monitor 500 are connected to the control device 700. The input device 400 is not particularly limited, but may include, for example, a mouse 401, a keyboard 402, a foot switch 403, a barcode reader 404, etc., as shown in Figure 1. The monitor 500 is, for example, a liquid crystal display, an organic EL display, etc. The webcam 600 transmits the captured images to the control device 700 via a network such as the internet. The webcam 600 captures, for example, a user using the microscope system 1.

[0031] With the microscope system 1 configured as described above, the projector 210 projects an auxiliary image onto the image plane, allowing the user to obtain the necessary information without taking their eyes off the eyepiece 103. In other words, the user can obtain the necessary information by utilizing the AR display function.

[0032] Furthermore, the microscope system 1 achieves the aforementioned AR display function, which is an extension of existing microscopes, by housing a complete set of components for projecting an auxiliary image onto the image plane within the eyepiece tube 200, instead of using an intermediate microscope tube for function extension. This avoids significantly changing the eye point height of the microscope 100 from that of existing microscopes. In other words, the eyepiece tube 200 and the microscope system 1 make it possible to provide the AR display function while maintaining the microscope's eye point at an appropriate height.

[0033] The eyepiece tube 200, which provides the AR display function, will be described in more detail below. Figure 4 is a perspective view of a microscope according to one embodiment of the present invention, viewed from the front at an oblique angle. Figure 5 is a perspective view of a microscope according to one embodiment of the present invention, viewed from the rear at an oblique angle. Figure 6 is a perspective view of the eyepiece tube according to one embodiment of the present invention. Figure 7 is a front view of the eyepiece tube according to one embodiment of the present invention. Figure 8 is a top view of the eyepiece tube according to one embodiment of the present invention. First, the eyepiece tube 200 will be described, focusing on its external shape with reference to Figures 4 to 8.

[0034] As shown in Figures 4 and 6 to 8, the eyepiece tube 200 has an operating section 230 for inputting instructions to the projector 210 on the front where the eyepiece lens 103 is mounted. Furthermore, as shown in Figures 4 to 8, the eyepiece tube 200 has a main power switch 240 for the eyepiece tube 200 with an AR display function on its side.

[0035] As shown in Figure 7, the control unit 230 is equipped with a switch 231 for switching the AR display function ON / OFF, and switches 232 and 233 for adjusting the brightness of the AR display. Switch 232 is for increasing the brightness of the AR display. When switch 232 is pressed, the amount of light emitted from the projector 210 increases. On the other hand, switch 233 is for decreasing the brightness of the AR display. When switch 232 is pressed, the amount of light emitted from the projector 210 decreases.

[0036] As shown in Figures 7 and 8, both the control unit 230 and the switch 240 are positioned to the left of the user looking through the eyepiece 103. By positioning the control unit 230 and the switch 240 together in the same direction relative to the user, the user can perform various switch operations with one hand.

[0037] As shown in Figure 7, when the eyepiece tube 200 is viewed from the front, the dovetail joint 201, which is the fastening part to the microscope 100, and the dovetail joint 202, which is the fastening part to the imaging device 300, are located on a plane P that passes through the middle of the binocular eyepiece lenses 103. In other words, the central axes of the dovetail joint 201 and the dovetail joint 202 both coincide approximately with the plane P.

[0038] The midline of the user looking through the eyepiece 103 is approximately located on the plane P. Therefore, by positioning the round dovetail joint 201, which has an entrance for light rays from the objective lens 101, on the plane P, the sample to be observed is positioned directly in front of the user looking through the eyepiece 103. This configuration is important for facilitating various tasks performed on the sample by the user while looking through the eyepiece 103, and contributes to ensuring high workability for the microscope 100 equipped with the eyepiece tube 200.

[0039] The eyepiece barrel 200 houses the AR display configuration, which is an extended function, on one side of the plane P, more specifically, on the left side when viewed from the front. That is, the projector 210 is positioned offset from the center line between the two eyepieces (eyepiece 103a and eyepiece 103b) to which the eyepiece 103 is attached. For this reason, the eyepiece barrel 200 is not symmetrical with respect to the plane P, but has a shape that protrudes to the left, as shown in Figures 4 to 8. More specifically, as shown in Figures 4 to 6 and 8, the portion that protrudes to the left extends further to the rear.

[0040] This shape allows for securing space within the eyepiece tube 200 to accommodate the AR display function while avoiding excessive protrusion on one side (left side). Furthermore, it allows for securing a large rear space behind the detachable structure (fastening part), which can be used as space for positioning the support columns of the stand, as shown in Figures 4 and 5. As a result, the eyepiece tube 200 can provide an AR display function while maintaining high compatibility with other microscope products.

[0041] On the back of the eyepiece tube 200, more specifically on the back of the portion that protrudes to the left and extends to the rear, a connector 250 is provided, as shown in Figure 5, through which a cable for exchanging signals with the projector 210 is inserted and removed. The projector 210 is housed facing forward at the innermost part of the portion that protrudes to the left and extends to the rear, that is, near the connector 250.

[0042] Specifically, power cables, control cables, and video input cables are plugged into and unplugged from connector 250, and these cables supply power and signals to the projector 210. Of the three cables, the control cable and the other end of the video input cable are connected to the control device 700.

[0043] Figure 9 shows the configuration of the eyepiece tube according to one embodiment of the present invention. Figure 10 shows the optical path inside the eyepiece tube according to one embodiment of the present invention as viewed from the front at an oblique angle. Figure 11 shows the optical system inside the eyepiece tube according to one embodiment of the present invention as viewed from the front at an oblique angle. Figure 12 shows the optical path inside the eyepiece tube according to one embodiment of the present invention as viewed from the rear at an oblique angle. Figure 13 shows the optical system inside the eyepiece tube according to one embodiment of the present invention as viewed from the rear at an oblique angle. Figure 14 shows a configuration that guides light branched from the observation optical path of the stereomicroscope to the imaging device. Figure 15 shows a configuration that guides light emitted from the projector 210 to the observation optical path of the stereomicroscope as viewed from above at an oblique angle. Figure 16 shows a configuration that guides light emitted from the projector 210 to the observation optical path of the stereomicroscope as viewed from above. Hereinafter, the eyepiece tube 200 will be described with reference to Figures 9 to 16, focusing on the internal configuration of the eyepiece tube 200.

[0044] As shown in Figure 9, the light passing through the objective lens 101 and the zoom lens 102 enters the eyepiece barrel 200 as a parallel beam from the entrance opening 201a formed in the round dovetail joint 201.

[0045] Of the light incident from the microscope 100 into the eyepiece tube 200, the light traveling along one of the optical paths (the optical path for the left eye in this example) is first incident on the beam splitter 221, as shown in Figures 9 to 11, for example. The beam splitter 221 splits the light from the microscope 100 into light heading towards the eyepiece lens 103 (i.e., light traveling along the observation optical path) and light heading towards the imaging device 300 (i.e., light traveling along the imaging optical path), as shown in Figure 9.

[0046] In this configuration, where the beam splitter 221, which branches the observation light path into an imaging light path, is positioned on the incident side of the beam splitter 224, which merges the AR light path into the observation light path, it is possible to prevent light from the projector 210 from entering the imaging device 300. As a result, only light from the sample can be guided to the imaging device 300, and the imaging device 300 can acquire a digital image of the sample that does not contain AR images. Since the digital image does not include AR images, for example, in the analysis of the digital image using artificial intelligence, the state of the sample can be correctly determined without the AR images interfering with the image analysis.

[0047] Even in a configuration where the beam splitter 224 is positioned closer to the incident beam than the beam splitter 221, the imaging device 300 can acquire a digital image of the sample in which the AR image is not captured by controlling the exposure timing and projection timing so that they do not overlap. However, in this case, especially if the projector 210 employs a plane-sequential method, it becomes difficult to individually adjust the brightness of the optical image and the auxiliary image. Therefore, it is desirable to position the beam splitter 221 closer to the incident beam than the beam splitter 224. The synthesis of the digital image and the AR image can be performed arbitrarily on the control device 700.

[0048] The beam splitter 221 is a beam splitter that generates more transmitted light than reflected light with respect to incident light, and is configured to direct more light to the observation light path (transmitted light path) than to the imaging light path (reflected light path). Specifically, the beam splitter 221, although not particularly limited, has optical characteristics that favor transmission, for example, transmitting 80% and reflecting 20%. This makes it possible to observe the sample brightly while acquiring a digital image with the imaging device 300.

[0049] On the other hand, of the light incident from the microscope 100 into the eyepiece tube 200, the light traveling along the other of the optical paths for the right eye and the left eye (in this example, the optical path for the right eye) first enters the ND prism 222, as shown in Figures 14 and 15.

[0050] The ND prism 222 is an optical element that suppresses the amount of light. Since the ND prism 222 is provided to suppress the difference in light intensity between the left and right optical paths, it should transmit incident light in proportion to the amount of light transmitted through the beam splitter 221. If the beam splitter 221 has optical characteristics that transmit 80%, it is desirable that the ND prism 222 also has a light-reducing performance of 20%.

[0051] The ND prism 222 is also used to suppress the difference in optical path length between the left and right optical paths. By matching the length of the beam splitter 221 with the prism length, the optical path lengths for the right and left eyes can also be matched, thereby suppressing differences in optical performance such as peripheral light intensity.

[0052] The light reflected by the beam splitter 221 and guided into the imaging optical path is incident on the imaging lens 223, as shown in Figures 9 and 14. The imaging lens 223 is positioned between the beam splitter 221 and the imaging device 300.

[0053] The imaging lens, which is placed inside the eyepiece barrel, is often positioned near the entrance. In contrast, in the eyepiece barrel 200, the beam splitter 221 is positioned between the imaging lens 223 and the round dovetail joint 201. As a result, the imaging lens 223 is positioned inside the housing of the eyepiece barrel 200 so that it is not exposed to the outside of the housing, thus reducing the likelihood of the imaging lens 223 becoming dirty and minimizing degradation of its optical performance.

[0054] Light incident on the imaging lens 223 is converted into a converged beam and reflected vertically upward by the reflecting member 229, as shown in Figures 9, 12, and 14. Subsequently, it is focused onto the imaging surface of the imaging device 300 via the exit port formed in the round dovetail joint 202.

[0055] Furthermore, the beam splitter 221 that guides light to the imaging light path is positioned to reflect the incident light toward the back of the eyepiece tube 200. That is, the imaging light path extends from the observation light path toward the back of the eyepiece tube 200, and then changes direction below the dovetail joint 202, extending vertically upward toward the imaging device 300 mounted on the top of the eyepiece tube 200. In this way, both the dovetail joint 201 and the dovetail joint 202 are positioned on a plane P passing through the center of the eyepiece lens 103, as shown in Figure 8, while minimizing the number of times the light ray folds before reaching the imaging device 300.

[0056] The configuration in which the dovetail joints 201 and 202 are placed on a plane P is desirable in order to minimize adverse effects caused by the uneven distribution of the center of gravity of the eyepiece tube 200 to which the imaging device 300 is mounted. For example, since the plane P shared by the dovetail joints 201 and 202 is parallel to the vertical direction, it is possible to reduce the influence of the imaging device 300, which is a relatively heavy structure fixed to the upper surface of the eyepiece tube 200, and as a result, it is possible to avoid applying excessive bending stress to the dovetail joint 201, for example.

[0057] The light from the left and right optical paths, after passing through beam splitter 221 and ND prism 222 respectively, then enters beam splitter 224a and beam splitter 224b, as shown in Figures 9 to 13 and 15. Meanwhile, the light from the AR optical path also enters beam splitter 224a and beam splitter 224b, as shown in Figures 9 to 13, 15 and 16.

[0058] More specifically, the light from the projector 210 is first converted into a parallel beam by the projection lens 211. The projection lens 211 is set to a magnification that maximizes the number of projection elements of the projector 210 (e.g., mirrors in a digital mirror device) included in the field of view, i.e., the number of pixels, and that the image of the projector 210 fills the field of view of the eyepiece lens 103, meaning the image of the projector 210 is projected to be larger than the number of fields of view. In addition, the projection lens 211 has a numerical aperture (NA) that provides a resolution finer than the pixel size, thereby enabling the projection of a high-definition auxiliary image across the entire field of view.

[0059] The light converted into a parallel beam by the projection lens 211 is then reflected by the adjustment mechanism 212 before being incident on the beam splitter 213. The beam splitter 213 splits the incident light into light directed towards beam splitter 224a, located in the optical path for the left eye, and light directed towards beam splitter 224b, located in the optical path for the right eye. Specifically, the beam splitter 213 is an example of a third optical element and has optical properties that transmit 50% and reflect 50% of the light. This allows light to be directed equally to the optical paths for the right eye and the left eye.

[0060] Of the light split by the beam splitter 213, the light directed toward the beam splitter 224a is incident directly on the beam splitter 224a. On the other hand, the light directed toward the beam splitter 224b is reflected by the adjustment mechanism 214 before being incident on the beam splitter 224b.

[0061] Each of the two adjustment mechanisms includes a reflective member and a mechanism that allows adjustment of the direction of the normal to the reflective surface of the reflective member in two axes relative to the reflective surface of the reflective member. The reflective member included in adjustment mechanism 212 is positioned in the optical path between the projector 210 and the beam splitter 213. By changing the orientation of the reflective member, the direction of propagation of the light reflected by adjustment mechanism 212 can be changed, thereby adjusting the positions of the auxiliary image for the left eye and the auxiliary image for the right eye on the image plane. Adjustment mechanism 212 is mainly used to adjust the position of the auxiliary image for the left eye formed in the optical path for the left eye. In other words, adjustment mechanism 212 is an adjustment unit that adjusts the position of the auxiliary image for the left eye formed in the optical path for the left eye.

[0062] On the other hand, the reflective member included in the adjustment mechanism 214 is positioned in the optical path between the beam splitter 213 and the beam splitter 224b. By changing the orientation of the reflective member, the direction of propagation of the light reflected by the adjustment mechanism 214 can be changed, thereby adjusting the position of the auxiliary image for the right eye on the image plane. The adjustment mechanism 214 is used to adjust the position of the auxiliary image for the right eye that is formed in the optical path for the right eye. In other words, the adjustment mechanism 214 is an adjustment unit that adjusts the position of the auxiliary image for the right eye that is formed in the optical path for the right eye.

[0063] In the eyepiece tube 200, the positions of the left and right auxiliary images relative to the left and right optical images can be independently adjusted by adjusting the position of the auxiliary images on the image plane using the adjustment mechanism 212 and the adjustment mechanism 214, respectively. This allows for individual adjustment of the relative positional relationship between the optical image and the auxiliary images, thereby improving the simultaneous fusion of the optical image and the auxiliary images.

[0064] Light from the microscope 100 and light from the projector 210 are incident on the beam splitter 224. As shown in Figure 9, the beam splitter 224 merges the light from the projector 210 into the optical path of the light from the microscope 100. More specifically, as shown in Figures 15 and 16, the beam splitter 224 includes a beam splitter 224a, which is a first left-eye optical element positioned in the optical path for the left eye and merges the light from the projector 210 into the left-eye optical path, and a beam splitter 224b, which is a first right-eye optical element positioned in the optical path for the right eye and merges the light from the projector 210 into the right-eye optical path.

[0065] The beam splitter 224 (beam splitter 224a, beam splitter 224b) is a beam splitter that generates more transmitted light than reflected light with respect to incident light, and is configured to combine the light from the microscope 100 with the light from the projector 210 while minimizing light loss from the microscope 100. Specifically, the beam splitter 224 is not particularly limited, but for example, it has optical properties that are predominantly transmission-oriented, transmitting 80% and reflecting 20%. This allows the light from the microscope 100 to be combined with the light from the projector 210 without significant dimming.

[0066] The light combined by the beam splitter 224 then enters the imaging lens 225. Both beams of light combined by the beam splitter 224 are parallel beams. Therefore, both beams of light (light from the microscope 100 and light from the projector 210) are converted into converged beams by the imaging lens 225, forming an image on the same plane. This forms an auxiliary image on the image plane where the optical image is formed. More specifically, as shown in Figure 11, the light traveling through the optical path for the left eye is converted into a converged beam by the imaging lens 225a, and the light traveling through the optical path for the right eye is converted into a converged beam by the imaging lens 225b.

[0067] The light, converted into a converged beam by the imaging lens 225, then enters the folding optical system 226, as shown in Figure 9. The folding optical system 226 is an optical system that folds the direction of propagation of the incident light, and here, it folds the direction of propagation of both the light from the projector 210, which is traveling vertically upward, and the light from the microscope 100, so that they are traveling downward.

[0068] The folded optical system 226 includes a folded optical system 226a arranged in the optical path for the left eye and a folded optical system 226b arranged in the optical path for the right eye, as shown in Figures 2 and 10 to 13. For example, a Porro prism can be used for the folded optical system 226 (folded optical system 226a and folded optical system 226b). By directing the direction of light propagation downward in the folded optical system 226, it is possible to prevent the eye point height from becoming too high and to keep the eye point height down.

[0069] In the eyepiece tube 200, the imaging lens 225 is positioned between the beam splitter 224 and the folded optical system 226. As a result, the imaging lens 225 is located inside the housing of the eyepiece tube 200 and is not exposed to the outside of the housing, making it less susceptible to dirt and thus reducing the likelihood of deterioration in optical performance.

[0070] Furthermore, compared to the configuration often used in eyepiece barrels, where the imaging lens is placed near the entrance, in the eyepiece barrel 200, the imaging lens 225 is positioned at a higher location within the eyepiece barrel 200. By positioning the imaging lens 225 at a higher location, that is, near the folded optical system 226, a longer optical path can be secured downwards from the folded optical system 226 than in conventional designs. This makes it possible to design the eye point height to be lower.

[0071] Light emitted downwards from the folded optical system 226 then passes through the eye point height adjustment mechanism 227 and the interpupillary distance adjustment mechanism 228 before entering the eyepiece lens 103, as shown in Figure 9.

[0072] The eye point height adjustment mechanism 227 is a height adjustment unit that adjusts the height of the eye point, and is located on the eyepiece lens 103 side of the folded optical system 226. As shown in Figure 9, the eye point height adjustment mechanism 227 includes a rotating part 227a that rotates in the tilt direction together with the eyepiece lens 103 around a horizontal axis, and a reflective member 227b attached to the axis of the rotating part 227a that rotates around the axis by half the amount of rotation of the rotating part 227a.

[0073] As the reflective member 227b rotates by half the amount of rotation of the rotating part 227a, the angle of incidence of light incident on the reflective member 227b from the folded optical system 226 and the angle of emission of light reflected by the reflective member 227b each increase (or decrease) by half the amount of rotation. In other words, the light incident on the reflective member 227b from the folded optical system 226 is deflected by the reflective member 227b by an angle equal to the amount of rotation.

[0074] Therefore, regardless of the orientation of the rotating part 227a, the angle of incidence of light to the eyepiece 103 is always maintained at a constant angle, and the image formation position relative to the eyepiece 103 is also maintained. As a result, the eye point height can be freely adjusted using the eye point height adjustment mechanism 227 according to the user's height, without causing any deterioration in observation performance.

[0075] The interpupillary distance adjustment mechanism 228 may employ, for example, a G-tentop type. However, other types of structures may also be used. By using the interpupillary distance adjustment mechanism 228, the distance between the eyepieces 103 can be adjusted to match the user's interpupillary distance.

[0076] By providing an eye point height adjustment mechanism 227 and an interpupillary distance adjustment mechanism 228, the height of the eye point and the distance between the left and right eye points can be adjusted to suit the user's physical characteristics (e.g., height, sitting height, interpupillary distance). This achieves high ergonomics and contributes to reducing the workload of the user of the microscope system 1.

[0077] Furthermore, because the eye point height adjustment mechanism 227 and the interpupillary distance adjustment mechanism 228 are located downstream of the point where the AR optical path and the observation optical path merge, the slight image shift caused by the mechanical movement of these adjustment mechanisms occurs in the same amount for both the optical image and the auxiliary image. Therefore, various adjustments can be made while maintaining the simultaneous fusion of the optical image and the auxiliary image.

[0078] Light that has passed through the eye point height adjustment mechanism 227 and the interpupillary distance adjustment mechanism 228 enters the eyepiece lens 103. The eyepiece lens 103 may be, for example, a concave lens, and the microscope 100 may be a Galilean stereomicroscope. By using a concave lens for the eyepiece lens 103, the eyepiece tube 200 can be made compact. The user can look through the eyepiece lens 103 to see an image in which an auxiliary image is superimposed on the optical image.

[0079] In the eyepiece tube 200 configured as described above, the eye point height can be kept low by positioning the imaging lens 225 closer to the folded optical system 226, as mentioned above. Therefore, by housing the components necessary for AR display in the eyepiece tube 200, the increase in eye point height compared to when an intermediate tube is used is suppressed, and the eye point height can be kept even lower with the eyepiece tube 200 alone. Thus, the increase in eye point height caused by functional expansion can be suppressed for the entire microscope system 1.

[0080] Furthermore, the eyepiece tube 200 is equipped with separate imaging lenses: an observation lens 225 and an imaging lens 223. This allows for different focal lengths between the two imaging lenses. Specifically, the imaging lens 225 has a shorter focal length than the imaging lens 223. By shortening the focal length of both the imaging lens 225 and the imaging lens 223, the imaging device 300 can obtain an image of a wider area than the sample observed by the user looking through the eyepiece 103. In addition, the short focal length of the imaging lens 225 allows the eyepiece tube 200 to be designed to be thinner in the height direction than conventional designs, resulting in a more compact eyepiece tube 200. Furthermore, the installation height of the imaging device 300 is also lowered, which lowers the center of gravity of the eyepiece tube 200 with the imaging device 300 attached.

[0081] Furthermore, the eyepiece tube 200 with AR display functionality has an observation light path, an AR light path, and an imaging light path within a single housing, and their relative positions are always constant within the housing. Therefore, compared to extending the AR display function with an intermediate tube, the adjustment work that the user must perform when observing using the AR display function can be significantly reduced.

[0082] The embodiments described above are specific examples provided to facilitate understanding of the invention, and the present invention is not limited to the embodiments described above. Modified forms of the embodiments described above and alternative forms that replace the embodiments described above may be included. In other words, the components of the embodiments can be modified without departing from the spirit and scope thereof. Furthermore, new embodiments can be implemented by appropriately combining multiple components disclosed in one or more embodiments. In addition, some components may be deleted from the components shown in each embodiment, or some components may be added to the components shown in the embodiments. Furthermore, the processing steps shown in each embodiment may be performed in a different order, as long as they do not contradict each other. That is, the eyepiece barrel of the present invention can be modified in various ways without departing from the scope of the claims. [Explanation of Symbols]

[0083] 1. Microscope System 100 Microscopes 101 Objective lens 102, 102a, 102b zoom lenses 103, 103a, 103b eyepieces 130 Post 200 Eyepiece tube 201, 202 Round dovetail joint 210 Projector 211 Projection lens 212, 214 Adjustment mechanism 213, 221, 224, 224a, 224b Beam Splitter 222 ND prism 223, 225, 225a, 225b imaging lenses 226, 226a, 226b folded optical system 227 Eye Point Height Adjustment Mechanism 227a Rotating part 227b, 229 Reflective material 228 Eye width adjustment mechanism 230 Operation section 250 connectors 300 Imaging devices

Claims

1. An eyepiece tube for a microscope, into which an eyepiece lens is attached, The aforementioned eyepiece tube is It is a three-barreled optical sight for mounting a digital camera. This is an eyepiece tube that can be attached to a stereomicroscope, having separate optical paths for the right and left eyes. A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, An imaging lens disposed between the first optical element and the folded optical system, A second optical element that splits the light from the microscope into light directed toward the eyepiece and light directed toward the digital camera, the second optical element being positioned in one of the optical paths for the right eye and the optical path for the left eye, The optical element for suppressing light intensity is located on the other side of the optical path for the right eye and the optical path for the left eye, The superimposing device is a projector that projects the auxiliary image onto the image plane, and is positioned at an offset location from the center line between the two eyepiece lenses attached to the eyepiece tube. An eyepiece tube characterized by the following features.

2. An eyepiece tube for a microscope, into which an eyepiece lens is attached, The aforementioned eyepiece tube is A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, The system comprises an imaging lens disposed between the first optical element and the folded optical system, The superposition device is a projector that projects the auxiliary image onto the image plane, and is positioned at an offset location from the center line between the two eyepiece lenses attached to the eyepiece tube. The first optical element is a beam splitter that generates more transmitted light than reflected light with respect to incident light. An eyepiece tube characterized by the following features.

3. An eyepiece tube for a microscope, into which an eyepiece lens is attached, The aforementioned eyepiece tube is It is a three-barreled optical sight for mounting a digital camera. A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, An imaging lens disposed between the first optical element and the folded optical system, The microscope comprises a second optical element that splits the light from the microscope into light directed toward the eyepiece and light directed toward the digital camera. The superposition device is a projector that projects the auxiliary image onto the image plane, and is positioned at an offset location from the center line between the two eyepiece lenses attached to the eyepiece tube. The second optical element is a beam splitter that generates more transmitted light than reflected light with respect to incident light. An eyepiece tube characterized by the following features.

4. An eyepiece tube for a microscope, into which an eyepiece lens is attached, The aforementioned eyepiece tube is This is an eyepiece tube that can be attached to a stereomicroscope, having separate optical paths for the right and left eyes. A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A first right-eye optical element is positioned in the optical path for the right eye and merges the light from the superimposing device into the optical path for the right eye, A first optical element, including a first left-eye optical element positioned in the left-eye optical path and merging light from the superimposing device into the left-eye optical path, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, An imaging lens disposed between the first optical element and the folded optical system, A third optical element that splits the light from the superimposing device into light directed toward the first optical element for the right eye and light directed toward the first optical element for the left eye, A first adjustment unit for adjusting the position of the auxiliary image for the right eye formed in the optical path for the right eye, It includes a second adjustment unit for adjusting the position of the auxiliary image for the left eye formed in the optical path for the left eye, The superposition device is a projector that projects the auxiliary image onto the image plane, and is positioned at an offset location from the center line between the two eyepiece lenses attached to the eyepiece tube. One of the first and second adjustment units includes a first reflective member whose orientation can be adjusted, which is positioned on the optical path between the superposition device and the third optical element. The other of the first and second adjustment units includes a second reflective member whose orientation can be adjusted, which is positioned in the optical path between the third optical element and the first right-eye optical element or the first left-eye optical element. An eyepiece tube characterized by the following features.

5. An eyepiece tube for a microscope, into which an eyepiece lens is attached, The aforementioned eyepiece tube is A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, An imaging lens disposed between the first optical element and the folded optical system, It includes a height adjustment unit for adjusting the height of the eye point, which is provided on the eyepiece side of the aforementioned folded optical system, The superposition device is a projector that projects the auxiliary image onto the image plane, and is positioned at an offset location from the center line between the two eyepiece lenses attached to the eyepiece tube. The height adjustment unit is The aforementioned eyepiece is attached to a rotating part that rotates in the tilt direction around a horizontal axis, Includes a reflective member attached to the shaft of the rotating part, which rotates around the shaft by half the amount of rotation of the rotating part. An eyepiece tube characterized by the following features.

6. An eyepiece tube for a microscope, into which an eyepiece lens is attached, A superposition device that overlays an auxiliary image onto the image plane where an optical image is formed by light from a microscope, The front surface of the eyepiece barrel, into which the eyepiece lens is mounted, is provided with an operating section for inputting instructions to the superposition device. The operating section is positioned on one side of the center line between the two eyepieces attached to the eyepiece barrel. An eyepiece tube characterized by the following features.

7. In the eyepiece barrel according to claim 6, The superposition device is a projector that projects the auxiliary image onto the image plane. The eyepiece tube further, A first optical element that merges the light from the superposition device into the optical path of the light from the microscope, A folding optical system that folds back the direction of propagation of both the light from the superposition device and the light from the microscope, The system comprises an imaging lens disposed between the first optical element and the folded optical system. An eyepiece tube characterized by the following features.

8. In the eyepiece barrel according to claim 2, claim 4, claim 5, claim 6, or claim 7, The aforementioned eyepiece tube is a three-eyepiece tube for mounting a digital camera, and further, The device includes a second optical element that splits the light from the microscope into light directed towards the eyepiece and light directed towards the digital camera. An eyepiece tube characterized by the following features.

9. In the eyepiece barrel according to claim 1, claim 3, or claim 8, further, A fastening portion for fastening the eyepiece tube to the microscope, which has an entrance for light from the microscope formed therein, The digital camera and the second optical element are positioned between them, and the second imaging lens is provided. The second optical element is positioned between the imaging lens and the fastening portion. An eyepiece tube characterized by the following features.

10. In the eyepiece tube according to claim 9, The imaging lens has a focal length different from that of the second imaging lens. An eyepiece tube characterized by the following features.

11. In the eyepiece tube according to claim 9, The second imaging lens has a focal length shorter than the focal length of the first imaging lens. An eyepiece tube characterized by the following features.

12. In the eyepiece barrel according to any one of claims 9 to 11, The second imaging lens is provided inside the housing so as not to be exposed to the outside of the housing of the eyepiece barrel. An eyepiece tube characterized by the following features.

13. In the eyepiece barrel according to claim 3 or claim 8, The aforementioned eyepiece tube is This is an eyepiece tube that can be attached to a stereomicroscope, having separate optical paths for the right and left eyes. The optical element for suppressing light intensity is further provided, located on the other side of the optical path for the right eye and the optical path for the left eye. The second optical element is positioned in either the optical path for the right eye or the optical path for the left eye. An eyepiece tube characterized by the following features.

14. In the eyepiece barrel according to claim 1 or claim 8, The second optical element is a beam splitter that generates more transmitted light than reflected light with respect to incident light. An eyepiece tube characterized by the following features.

15. In the eyepiece barrel according to claim 1, claim 2, claim 3, claim 5, or claim 7, The aforementioned eyepiece tube is an eyepiece tube that is attached to a stereomicroscope and has an optical path for the right eye and an optical path for the left eye. The first optical element is, A first right-eye optical element is positioned in the optical path for the right eye and merges the light from the superimposing device into the optical path for the right eye, Includes a first left-eye optical element positioned in the left-eye optical path and merging light from the superimposing device into the left-eye optical path. An eyepiece tube characterized by the following features.

16. In the eyepiece barrel according to claim 15, further, A third optical element that splits the light from the superimposing device into light directed toward the first optical element for the right eye and light directed toward the first optical element for the left eye, A first adjustment unit for adjusting the position of the auxiliary image for the right eye formed in the optical path for the right eye, It includes a second adjustment unit for adjusting the position of the auxiliary image for the left eye formed in the optical path for the left eye, One of the first and second adjustment units includes a first reflective member whose orientation can be adjusted, which is positioned on the optical path between the superposition device and the third optical element. The other of the first and second adjustment units includes a second reflective member whose orientation can be adjusted, which is positioned in the optical path between the third optical element and the first right-eye optical element or the first left-eye optical element. An eyepiece tube characterized by the following features.

17. In the eyepiece barrel according to any one of claims 1 to 4 or claim 7, further, It includes a height adjustment section provided on the eyepiece side of the aforementioned folded optical system for adjusting the height of the eye point. An eyepiece tube characterized by the following features.

18. In the eyepiece barrel according to claim 17, The height adjustment unit is The aforementioned eyepiece is attached to a rotating part that rotates in the tilt direction around a horizontal axis, Includes a reflective member attached to the shaft of the rotating part, which rotates around the shaft by half the amount of rotation of the rotating part. An eyepiece tube characterized by the following features.

19. In the eyepiece barrel according to claim 1, claim 3, claim 4, claim 5, or claim 7, The first optical element is a beam splitter that generates more transmitted light than reflected light with respect to incident light. An eyepiece tube characterized by the following features.

20. In the eyepiece barrel according to any one of claims 1 to 5, claim 7, or any one of claims 15 to 19, The imaging lens is provided inside the housing so as not to be exposed to the outside of the housing of the eyepiece barrel. An eyepiece tube characterized by the following features.

21. In the eyepiece barrel according to any one of claims 1 to 20, further, The eyepiece is provided as described above, The eyepiece is a concave lens. An eyepiece tube characterized by the following features.

22. In the eyepiece barrel according to any one of claims 1 to 21, The eyepiece tube consists of a single housing. An eyepiece tube characterized by the following features.

23. The eyepiece barrel according to any one of claims 1 to 22, further, The back of the eyepiece tube is provided with a connector through which a cable for exchanging signals with the superimposing device is inserted and removed. An eyepiece tube characterized by the following features.

24. The eyepiece barrel according to any one of claims 1 to 5, further, The front surface of the eyepiece barrel, into which the eyepiece lens is mounted, is provided with an operating section for inputting instructions to the superposition device. The operating section is positioned on one side of the center line between the two eyepieces attached to the eyepiece barrel. An eyepiece tube characterized by the following features.

Images