Microscope Unit

Abstract

To provide a microscope unit that can reduce the size of a whole illuminance lens barrel and thus can reduce the size of a microscope unit.SOLUTION: The microscope unit includes: a main lens tube of an image forming optical system, to which an imaging element and an objective lens can be attached; and an illuminance lens tube of an illuminance optical system connected to the main lens tube, a light source being freely attached to the illuminance lens tube. The illuminance optical system includes: a collector lens for collecting light emitted from the light source; a fly-eye lens for transmitting light from the collector lens; a first relay lens having a plurality of lenses for relaying light from the fly-eye lens; a field diaphragm for narrowing the range of light from the first relay lens; a second relay lens for relaying light from the first relay lens to a beam splitter; and a beam splitter provided in the optical axis of the main lens tube, the beam splitter guiding at least a part of incident light to an objective lens and transmitting at least a part of the light from the objective lens to the imaging element side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a microscope unit that can be attached to a target device. [Background technology]

[0002] Conventionally, there has been known a microscope unit that includes a main lens barrel of an imaging optical system configured to be able to mount an image sensor and an objective lens, and an illumination lens barrel of an illumination optical system that is connected to the main lens barrel and is configured to be able to mount a light source. Such a microscope unit is configured, for example, to collect a light beam (a diverging beam of light) emitted from the light source using a collector lens, and then reflect it on a mirror through a relay lens system and a field stop, and then illuminate an observation surface through the relay lens system, aperture stop, and condenser lens.

[0003] Such microscope units may be able to accommodate various light sources. However, depending on the type of light source attached to the microscope unit, the illuminance on the observation surface may become uneven. Therefore, for example, in the microscope illumination device described in Patent Document 1 below, a fly's eye lens is placed in the illumination optical system to achieve uniform illuminance on the observation surface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-6225 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above microscope illumination device, a fly-eye lens must be provided in the illumination optical system. Furthermore, a relay lens must be provided between the fly-eye lens and the field stop to relay light from the fly-eye lens. In such a configuration, a certain length must be ensured as the focal length from the relay lens to the field stop. This increases the optical path length of the illumination tube, which in turn may result in an increase in the size of the illumination tube, and ultimately in an increase in the size of the microscope unit.

[0006] The present invention has been made in view of such problems, and has an object to provide a microscope unit that can reduce the size of the entire illumination lens barrel, and ultimately the microscope unit itself. [Means for solving the problem]

[0007] A microscope unit according to one embodiment of the present invention includes a main barrel of an imaging optical system configured to accommodate an image sensor and an objective lens, and an illumination barrel of an illumination optical system connected to the main barrel and configured to accommodate a light source, wherein the illumination optical system includes a collector lens that collects light emitted from the light source, a fly's-eye lens that transmits light from the collector lens, a first relay lens that relays light from the fly's-eye lens, a field diaphragm that narrows the range of light from the first relay lens, a second relay lens that relays light from the first relay lens to a beam splitter, and a beam splitter that is disposed on the optical axis of the main barrel and guides at least a portion of incident light to the objective lens and transmits at least a portion of light incident from the objective lens to the image sensor. The first relay lens includes multiple lenses that are not cemented together.

[0008] In such a microscope unit, the first relay lens of the illumination optical system is composed of multiple lenses that are not cemented together. Therefore, it is possible to shorten the focal length from the first relay lens to the field stop compared to when the first relay lens is composed of, for example, a single lens or a cemented lens that is considered to be a single lens. This reduces the optical path length of the illumination barrel, shortening its overall length, and enabling the overall size of the illumination barrel and, ultimately, the microscope unit to be made smaller.

[0009] The distance in the optical path from the first relay lens to the second relay lens may be five times or less the outer diameter of the second relay lens.

[0010] The first relay lens may have a first lens and a second lens each made of a plano-convex lens, and the first lens and the second lens may be arranged so that the convex surfaces thereof face each other.

[0011] The microscope unit may have a reflecting mirror disposed between the field stop and the second relay lens to reflect light from the first relay lens toward the main lens barrel. In this case, the second relay lens may be configured to relay light reflected by the reflecting mirror to the beam splitter.

[0012] The illumination barrel may have a first barrel configured to allow attachment of a light source, and an intermediate barrel connecting the main barrel and the first barrel. In this case, the first barrel may house a collector lens, a fly's eye lens, and a first relay lens, the intermediate barrel may house a field stop, a second relay lens, and a reflecting mirror, and the main barrel may house a beam splitter.

[0013] The reflecting mirror may be accommodated in the intermediate barrel while being held by a mirror frame member.

[0014] The field stop may be located inside the outer peripheral surface of the mirror frame member, or may be part of the first lens barrel. [Effects of the Invention]

[0015] With this configuration, it is possible to provide a microscope unit that can reduce the size of the entire illumination lens barrel, and thus the microscope unit itself. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic explanatory diagram showing the overall configuration of a microscope unit according to a first embodiment. [Figure 2] FIG. 2 is a schematic explanatory diagram showing the overall configuration of a microscope unit. [Figure 3] FIG. 2 is a schematic side view showing the configuration of a mirror frame member of the microscope unit. [Figure 4] FIG. 2 is a schematic perspective view showing the configuration of a mirror frame member of the microscope unit. [Figure 5] 10A and 10B are diagrams for explaining the relationship between the orientation of the illumination lens barrel relative to the main lens barrel of the microscope unit and the illumination range. [Figure 6] 10A and 10B are diagrams for explaining the illumination range when the mounting position has been adjusted and when it has not been adjusted. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, with reference to the accompanying drawings, a microscope unit according to several embodiments of the present invention will be described in detail. However, the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. In the following embodiments, the scale and dimensions of each component may be exaggerated, and some components may be omitted.

[0018] In the following explanation, the "X-axis direction" refers to the left-right direction when facing the plane (front) of the microscope unit shown in Figure 1, the "Y-axis direction" refers to the depth direction in this case, and the "Z-axis direction" refers to the up-down direction in this case, i.e., the optical axis direction of the main lens barrel. Note that the basic structure of the microscope unit is known, so only an outline of the overall configuration will be explained here unless necessary.

[0019] [First embodiment] [composition] 1 and 2 are schematic explanatory diagrams showing the overall configuration of a microscope unit 100 according to a first embodiment. In FIGS. 1 and 2, the illumination optical system of the microscope unit 100 is depicted with solid lines, with part of it shown as a cross-sectional view and part of it shown as a see-through view. FIG. 2 shows a state in which the attitude of the illumination lens barrel 20 relative to the main lens barrel 10 is 180° different from that shown in FIG. 1. The state shown in FIG. 1 will be described below as the basic attitude of the microscope unit 100.

[0020] As shown in FIGS. 1 and 2, the microscope unit 100 constitutes part of a microscope (not shown), and includes a main lens barrel 10 and an illumination lens barrel 20 connected to the main lens barrel 10.

[0021] The main lens barrel 10 constitutes the so-called imaging optical system of the microscope, and is configured so that, for example, a camera 31 incorporating an image sensor 30 can be attached to the end on the upper side (hereinafter simply referred to as the "upper side") in the Z axis direction illustrated in Fig. 1, and an objective lens 32 can be attached to the end on the lower side (hereinafter simply referred to as the "lower side") in the Z axis direction illustrated in Fig. 1. The image sensor 30 includes various image sensors (CMOS, CCD), etc.

[0022] The main lens barrel 10 has a cylindrical first sleeve portion 11 arranged on the upper side (camera 31 side) and a cylindrical second sleeve portion 12 arranged below the first sleeve portion 11. The first sleeve portion 11 is formed so that its minimum outer diameter is slightly smaller than the minimum outer diameter of the second sleeve portion 12.

[0023] The main barrel 10 also has a housing main body 13 that is rectangular in appearance and is located below the second sleeve portion 12, and a cylindrical third sleeve portion 14 that is located below the housing main body 13 and to which the objective lens 32 is connected. The housing main body 13 is made up of a first housing 15 and a second housing 16 that is located below the first housing 15.

[0024] An imaging lens (tube lens) 17 is housed inside second sleeve portion 12 of main barrel 10 and first housing 15 of housing body 13. A beam splitter (hereinafter referred to as "B / S") 18, which will be described later, is housed inside second housing 16 of housing body 13 so as to be inclined at a predetermined angle with respect to the optical axis ML of main barrel 10. First sleeve portion 11, second sleeve portion 12, housing body 13, and third sleeve portion 14, which make up main barrel 10, are arranged coaxially and linearly in the Z-axis direction along the optical axis ML of main barrel 10.

[0025] Illumination barrel 20 constitutes the so-called illumination optical system of the microscope, and has a first barrel 21 to which various light sources LS can be detachably attached at the upper end in the Z-axis direction when in the basic position, and an intermediate barrel 22 that connects first barrel 21 to main barrel 10. First barrel 21 forms an optical axis L1 in the Z-axis direction, and intermediate barrel 22 forms an optical axis L2 in the X-axis direction.

[0026] The first lens barrel 21 has a cylindrical fourth sleeve portion 23 that is arranged on the upper side in the basic position, and a cylindrical fifth sleeve portion 24 that is arranged below the fourth sleeve portion 23. The fourth sleeve portion 23 is formed so that its minimum outer diameter is smaller than the minimum outer diameter of the fifth sleeve portion 24.

[0027] The first lens barrel 21 also has a connecting housing portion 26 that has an externally stepped annular shape and is disposed below the fifth sleeve portion 24, and a sixth sleeve portion 27 that has an externally stepped cylindrical shape and is disposed below the connecting housing portion 26. The connecting housing portion 26 connects the fifth sleeve portion 24 and the sixth sleeve portion 27. A portion of the sixth sleeve portion 27 (the portion disposed within the intermediate lens barrel 22) is a truncated cone portion 27a that is formed in a truncated cone shape that tapers downward. In the illustrated example, the fifth sleeve portion 24 and the sixth sleeve portion 27 have approximately the same outer diameter, and the minimum outer diameter of the connecting housing portion 26 is larger than these outer diameters; however, the fifth sleeve portion 24, the connecting housing portion 26, and the sixth sleeve portion 27 may be configured to have approximately the same outer diameter.

[0028] The emission end LE of the attached light source LS is housed inside the fourth sleeve portion 23 of the first lens barrel 21. Also, the fifth sleeve portion 24 of the first lens barrel 21 houses a collector lens (light-collecting lens) 33 inside its upper side. Furthermore, a fly's eye lens 34 is housed inside the connection portion between the fifth sleeve portion 24 and the connecting housing portion 26.

[0029] The sixth sleeve portion 27 of the first barrel 21 houses a first relay lens group 35 serving as a first relay lens within its upper portion. The first relay lens group 35 includes multiple lenses that are not cemented together. For example, in the illustrated example, the first relay lens group 35 includes a first lens 35a, which is a plano-convex lens with a convex surface facing downward in the Z-axis direction, and a second lens 35b, which is a plano-convex lens with a convex surface facing upward in the Z-axis direction. The first lens 35a and the second lens 35b are arranged so that their convex surfaces face each other. The first lens 35a and the second lens 35b may be spaced apart from each other, or their convex surfaces may be partially in contact. This configuration reduces the amount of spherical aberration and shortens the focal length to the field stop 36 (described later) compared to, for example, using a biconvex lens such as a single lens or a cemented lens as the first relay lens. This is because the refractive power of the lens system can be shared between the first lens 35a and the second lens 35b. Furthermore, plano-convex lenses can be manufactured more cheaply than aspherical lenses, which require additional initial mold costs, and therefore it is possible to reduce the manufacturing costs of the illumination optical system.

[0030] An inner peripheral surface 27b of the sixth sleeve portion 27 in the first barrel 21 below the location where the first relay lens group 35 is accommodated is formed in a tapered shape that gradually reduces in diameter toward the bottom. Also, an annular flange portion 27c that protrudes in the outer circumferential direction is formed on part of the outer periphery of the sixth sleeve portion 27.

[0031] Below the lower end surface 27d of the flange portion 27c of the sixth sleeve portion 27 in the first lens barrel 21, there is arranged an outer peripheral portion 27e having a diameter smaller than the minimum outer diameter of the sixth sleeve portion 27, and then a step portion formed further downward, and there is arranged an outer peripheral portion 27f of the truncated cone portion 27a which is formed in a tapered shape and whose diameter gradually decreases downward.

[0032] The fourth sleeve portion 23, the fifth sleeve portion 24, the connecting housing portion 26, and the sixth sleeve portion 27 that constitute the first lens barrel 21 are arranged coaxially and linearly along the optical axis L1 of the first lens barrel 21. The lower end of the truncated cone portion 27a of the sixth sleeve portion 27 constitutes the field stop 36. That is, the field stop 36 in the illumination lens barrel 20 of the first embodiment is constituted by a part of the first lens barrel 21 (the lower end of the truncated cone portion 27a).

[0033] The intermediate barrel 22 connects the first barrel 21 and the main barrel 10, and has an intermediate housing section 28 with a rectangular appearance, on the end side away from the main barrel 10 in the X-axis direction in the basic position, with an inclined wall 28a that slopes diagonally downward from the upper side toward the main barrel 10.

[0034] The end of intermediate housing section 28 on the main barrel 10 side in the X-axis direction is formed as a cylindrical fitting section 28b, which fits into a hole-shaped fitting section 16a formed in second housing 16 of housing main body 13. This allows intermediate barrel 22 to be connected to main barrel 10 so as to be rotatable about optical axis L2, which is perpendicular to optical axis L1 of first barrel 21 (see FIG. 2). A second relay lens 38 is housed inside fitting section 28b.

[0035] Furthermore, in the basic position, an engagement hole 28d is formed in the upper wall portion 28c of the intermediate housing portion 28, into which the sixth sleeve portion 27 of the first lens barrel 21 is fitted. That is, the sixth sleeve portion 27 is fitted into the intermediate housing portion 28 in a state in which the lower end surface 27d of the flange portion 27c abuts against the outer wall surface of the upper wall portion 28c, and the outer peripheral portion 27e is fitted into the inner peripheral surface on the opening end side of the engagement hole 28d.

[0036] The sixth sleeve portion 27 is fixed to the intermediate housing portion 28 by attaching the flange portion 27c to the upper wall portion 28c with the mounting bolts 19. As a result, the first lens barrel 21 is positioned and fixed relative to the intermediate lens barrel 22. According to this configuration, since the first lens barrel 21 is fixed to the intermediate lens barrel 22 in this manner, the field stop 36 of the first lens barrel 21 described above is positioned inside the outer peripheral surface of the intermediate lens barrel 22 (the outer wall surface of the upper wall portion 28c of the intermediate housing portion 28).

[0037] The intermediate barrel 22 also houses a reflecting mirror 37 and a mirror frame member 40 that holds the reflecting mirror 37. The intermediate barrel 22 is also provided with a position adjustment mechanism (not shown) that adjusts the mounting position of the mirror frame member 40 relative to the intermediate barrel 22 (mounting position relative to the intermediate housing portion 28).

[0038] Fig. 3 is a schematic side view showing the configuration of the mirror frame member 40 of the microscope unit 100. Fig. 4 is a schematic perspective view showing the configuration of the mirror frame member 40 of the microscope unit 100.

[0039] 3 and 4, the mirror frame member 40 is formed of a cylindrical frame body 49 with one end cut at an angle so that it can be housed inside the intermediate housing portion 28. The frame body 49 of the mirror frame member 40 holds the reflecting mirror 37. This reflecting mirror 37 is formed in an outer shape, for example, an ellipse or a polygon (such as an octagon), so that the reflecting portion has an elliptical shape that matches the shape of the elliptical opening 41 of the frame body 49. Furthermore, the portion of this reflecting mirror 37 excluding the reflecting portion is adhered to the frame body 49 of the mirror frame member 40, for example, with an adhesive or the like (not shown).

[0040] Furthermore, the frame body 49 of the mirror frame member 40 has a main barrel side opening 42 formed at the end opposite the elliptical opening 41 in the X-axis direction, and a first barrel side opening 43 formed at a position spaced apart in the Z-axis direction from the elliptical opening 41. The first barrel side opening 43 has an opening diameter that is larger than the outer diameter of the field stop 36 of the truncated cone portion 27a in the sixth sleeve portion 27 of the first barrel 21, and larger than the outer diameter of the outer circumferential portion 27f in a predetermined range above the field stop 36 in the Z-axis direction. This allows the field stop 36 to be positioned as close as possible to the reflecting mirror 37, without the frame body 49 of the mirror frame member 40 interfering with the truncated cone portion 27a of the sixth sleeve portion 27.

[0041] After the mirror frame member 40 configured in this manner is housed inside the intermediate housing portion 28, its mounting position relative to the intermediate housing portion 28 is adjusted by a position adjustment mechanism (not shown). Although not shown, the position adjustment mechanism is composed of, for example, a plurality of adjustment screws that are threaded into a pair of countersunk holes drilled in the Y-axis direction in the intermediate housing portion 28. After adjusting the mounting position, the mirror frame member 40 is fixed to the intermediate housing portion 28, for example, with screws.

[0042] Furthermore, the intermediate lens barrel 22 thus formed and the separately assembled first lens barrel 21 can be integrated with a simple structure in which the truncated cone portion 27a is inserted into the mating hole 28d and the flange portion 27c is screwed to the intermediate housing portion 28 with the mounting bolt 19, so the illumination lens barrel 20 can be easily manufactured.

[0043] [Optical system] The imaging optical system of the microscope unit 100 according to this embodiment includes an objective lens 32 and an imaging lens (tube lens) 17. The illumination optical system of the microscope unit 100 according to this embodiment includes a collector lens (condensing lens) 33, a fly's eye lens 34, a first relay lens group 35, a field stop 36, a reflecting mirror 37, a B / S 18, and a second relay lens 38.

[0044] The exit end LE of the light source LS, the position of the objective lens 32 (the pupil of the objective lens 32), and the exit end surface of the fly-eye lens 34 are in a conjugate relationship. Moreover, these positions are not in a conjugate relationship with the B / S 18 and the reflecting mirror 37. Moreover, the field stop 36, the focal position of the objective lens 32, and the focal position of the imaging lens 17 are in a conjugate relationship.

[0045] A light beam (diverging light beam) from the exit end LE of the light source LS is converted into a collected light beam (converging light beam) via a collector lens 33, and is then split through a fly-eye lens 34 by the number of lenses constituting the fly-eye lens 34. As a result, light source images (secondary light sources) are formed on the exit end surface of the fly-eye lens 34 by the number of lenses constituting the fly-eye lens 34, and the light beams (diverging light beams) emitted from each of the lenses constituting the fly-eye lens 34 are collected via a first relay lens group 35 and relayed so as to overlap on a field stop 36 separated by a designed focal length. Therefore, even when various light sources LS with different light distribution characteristics are used, a pseudo-surface light source (secondary light source) with nearly uniform light distribution characteristics and little unevenness in light distribution is formed on the exit end surface of the fly-eye lens 34.

[0046] The light beam (divergent light beam) that passes through the field stop 36 along the optical axis L1 and has a narrowed light range is reflected by a reflecting mirror 37 in the intermediate barrel 22 to become a light beam (divergent light beam) that travels along the optical axis L2, and is then condensed through a second relay lens 38 and relayed to be irradiated onto the B / S 18. The B / S 18 reflects and guides at least a portion of the light beam (condensed light beam) that has entered through the second relay lens 38 toward the aperture stop and objective lens 32 (not shown), and also transmits at least a portion of the light beam from the imaging surface IS that has entered through the objective lens 32, etc., toward the imaging lens 17.

[0047] [Rotation of the illumination barrel 20 and positioning of the reflecting mirror 37] As described above, in the microscope unit 100 according to this embodiment, the illumination tube 20 is configured to be rotatable relative to the main tube 10. Here, if the position of the reflecting mirror 37 relative to the B / S 18 is not suitably adjusted, there is a risk that the center position of the field stop 36 will be displaced from the optical axis of the illumination optical system when the illumination tube 20 is rotated relative to the main tube 10. Therefore, the microscope unit 100 according to this embodiment is configured so that the position of the reflecting mirror 37 relative to the B / S 18 is adjustable. This point will be explained below.

[0048] Fig. 5 is a diagram for explaining the relationship between the attitude of the illumination tube 20 relative to the main tube 10 of the microscope unit 100 and the illumination range. Fig. 6 is a diagram for explaining the illumination range when the mounting position has been adjusted and when it has not been adjusted. Note that the appearance of the microscope unit 100 in Figs. 5 and 6 is different from that shown in Figs. 1 and 2. Also, the following description will be given assuming that the mounting position and mounting angle of the B / S 18 of the main tube 10 have already been adjusted.

[0049] As shown in Figure 5(a), in the microscope unit 100 in the basic position in which the optical axis ML of the main tube 10 and the optical axis L1 of the first tube 21 of the illumination tube 20 are in the Z-axis direction, as shown in Figure 5(b), the center of the imaging range 51 on the imaging plane IS and the center of the illumination range 52 of the light from the light source LS that has passed through the illumination tube 20 are determined to be normal positions centered on the optical axis ML of the main tube 10, i.e., positions where the center of the imaging range 51 and the center of the illumination range 52 coincide with the optical axis ML.

[0050] In the microscope unit 100 according to this embodiment, from this basic posture, for example, the illumination barrel 20 can be rotated 90° around the optical axis L2 relative to the main barrel 10, as shown in Fig. 6(a). As a result, the illumination range 52 rotates 90° while the image in the imaging range 51 remains the same.

[0051] Here, for example, if the mounting position of the mirror frame member 40 is adjusted by the position adjustment mechanism described above, as shown in Figure 6(b), it is possible to maintain the center of the imaging range 51 and the center of the illumination range 52 aligned with the optical axis ML, even if there is a change in posture indicated by the arrow in the figure.

[0052] On the other hand, if the mounting position of the mirror frame member 40 is not adjusted, the center of the illumination range 52 will be significantly shifted from the center of the imaging range 51, as shown in Figure 6(c), and the illumination distribution by the light source LS within the field of view will become uneven.

[0053] To avoid such a situation, in the microscope unit 100 according to this embodiment, the mounting position of the mirror frame member 40 relative to the intermediate barrel 22 is adjusted via a position adjustment mechanism. The mounting position of the mirror frame member 40 is adjusted, for example, after assembling the illumination barrel 20, by operating these adjustment screws to adjust the position of the mirror frame member 40 relative to the intermediate housing unit 28 in the X-axis direction and in the rotational direction about the X-axis direction.

[0054] During adjustment, adjustment is made so that the amount of eccentricity of optical axis L2 that accompanies a change in the attitude of first barrel 21 falls within a predetermined range when optical axis L1 of light from light source LS is converted into light of optical axis L2 by reflecting mirror 37. This makes it possible to freely change the attitude of illumination barrel 20 relative to main barrel 10 without shifting illumination range 52 of the illumination optical system.

[0055] [Miniaturization of microscope unit] Conventionally, there has been known a microscope unit that includes a main lens barrel of an imaging optical system configured to be able to mount an image sensor and an objective lens, and an illumination lens barrel of an illumination optical system that is connected to the main lens barrel and is configured to be able to mount a light source. Such a microscope unit is configured, for example, to collect a light beam (a diverging beam of light) emitted from the light source using a collector lens, and then reflect it on a mirror through a relay lens system and a field stop, and then illuminate an observation surface through the relay lens system, aperture stop, and condenser lens.

[0056] Such microscope units may be able to be fitted with various light sources. However, depending on the type of light source fitted to the microscope unit, the illuminance on the observation surface may become uneven. Therefore, in the microscope unit 100 according to this embodiment, a fly-eye lens 34 is provided in the illumination optical system, thereby achieving uniform illuminance on the observation surface.

[0057] However, when such a configuration is adopted, the number of optical components that make up the illumination optical system increases, which increases the overall length and may make it difficult to achieve miniaturization. Therefore, in the illumination lens barrel 20 of the microscope unit 100 according to the first embodiment, the following method is used to achieve miniaturization of the microscope unit.

[0058] [Addition of first relay lens group 35] As described above, the first relay lens group 35 according to the first embodiment includes a first lens 35a and a second lens 35b that are not cemented together. With this configuration, as described above, compared to using a biconvex lens such as a single lens or a cemented lens as the first relay lens, it is possible to reduce the focal length to the field stop 36 (described later) while suppressing spherical aberration. Therefore, even though the first relay lens group 35 is housed in the first barrel 21 in addition to the fly-eye lens 34, the focal length from the first relay lens group 35 to the field stop 36 can be designed to be short, thereby shortening the overall length of the first barrel 21. This shortens the overall length of the illumination barrel, thereby achieving overall miniaturization, and ultimately achieving miniaturization of the microscope unit. From the perspective of miniaturizing the entire illumination barrel, it is preferable to set the distance in the optical path from the first relay lens group 35 to the second relay lens 38 to, for example, five times the outer diameter of the second relay lens 38 or less. This allows the overall length of the illumination barrel to be designed to be short.

[0059] [Adjusting the position of field stop 36] In the microscope unit 100 according to the first embodiment, the field stop 36 is disposed inside the outer peripheral surface of the intermediate barrel 22. Therefore, compared to a case where the field stop 36 is disposed outside the outer peripheral surface of the intermediate barrel 22 (for example, above the lower end surface 27d of the flange portion 27c of the sixth sleeve portion 27 in FIG. 1), it is possible to effectively utilize the space inside the first barrel 21. This makes it possible to shorten the overall length of the illumination barrel, thereby reducing the size of the entire illumination barrel and, ultimately, the size of the microscope unit.

[0060] When miniaturizing the microscope unit 100 using this configuration, it is desirable to position the field diaphragm 36 as close as possible to the reflecting mirror 37. For example, as shown in FIG. 1, it is desirable to position the field diaphragm 36 inside the inner circumferential surface 28e of the intermediate barrel 22. However, if the field diaphragm 36 interferes with the light beam from the reflecting mirror 37, the illumination performance (brightness and uniformity of illuminance) of the illumination optical system will deteriorate. Therefore, as shown in FIG. 1, for example, it is desirable to position the field diaphragm 36 far enough from the reflecting mirror 37 so as not to interfere with the light beam from the reflecting mirror 37. Furthermore, as described above, the field diaphragm 36 and the focal position of the objective lens 32 are configured to have a conjugate relationship. Here, if the reflecting mirror 37 is not positioned outside the range of the depth of focus of the field diaphragm 36, dirt or scratches on the surface of the reflecting mirror 37 may be reflected on the imaging plane IS. Therefore, it is desirable to position the reflecting mirror 37 outside the range of the depth of focus of the field diaphragm 36.

[0061] 1, the sixth sleeve portion 27 of the illumination barrel 20 according to this embodiment has a truncated cone portion 27a formed at its lower end, and the lower end of this truncated cone portion 27a forms the field stop 36. This field stop 36 can be produced using a single chuck, for example, on a lathe or the like, when molding the sixth sleeve portion 27, and can therefore be produced with high precision while minimizing the number of manufacturing steps. Furthermore, it can be realized without using any additional parts for the stop.

[0062] Furthermore, as described above, in the microscope unit 100 according to this embodiment, the illumination tube 20 can be rotated relative to the main tube 10. Here, depending on the configuration of the field diaphragm, when the illumination tube 20 is rotated relative to the main tube 10, there is a risk that the center position of the field diaphragm will be displaced from the optical axis of the illumination optical system. Here, the field diaphragm 36 according to this embodiment is made up of part of the sixth sleeve portion 27 that houses the first relay lens group 35. Therefore, even when the illumination tube 20 is rotated relative to the main tube 10, it is possible to preferably maintain the positional relationship between the center position of the field diaphragm and the optical axis of the illumination optical system.

[0063] [Other embodiments] The outer shape, dimensions, and the like of each part of the microscope unit 100 of the above-described embodiment can be changed as appropriate. For example, the housing main body 13 of the main tube 10 can be formed cylindrical, and the entire first sleeve section 11 to the third sleeve section 14 can be formed cylindrical. Alternatively, the first sleeve section 11, the second sleeve section 12, and the third sleeve section 14 can be formed rectangular, and the entire first sleeve section 11 to the third sleeve section 14 can be formed rectangular (square tube). Furthermore, the outer diameters of the first sleeve section to the third sleeve section 14 can be different from those described above. These can also be applied to the illumination tube 20. Furthermore, what is exemplified as a configuration consisting of multiple members may be formed from a single member, and what is exemplified as a configuration consisting of a single member may be formed from multiple members.

[0064] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0065] 10 Main barrel 11 First sleeve part 12 Second sleeve part 13. Housing body 14 Third sleeve section 18 Beam splitter (B / S) 20. Illumination tube 21 First telescope 22 Intermediate tube 23 4th sleeve section 24 5th sleeve section 26 Connecting housing part 27 6th sleeve section 28 Intermediate housing section 30 Image sensor 32 Objective Lens 33 Collector lens 34 Fly-eye lens 35 First relay lens group 35a 1st lens 35b Second lens 36,36A Field stop 37 Reflective mirror 38 Second relay lens 40,40A Mirror frame material 100 Microscope Unit

Claims

1. A main lens barrel of an imaging optical system extending along a first optical axis and configured to be able to mount an imaging element and an objective lens; an intermediate barrel extending along a second optical axis perpendicular to the first optical axis and having one end along the second optical axis connected to an outer circumferential surface of the main barrel; a first lens barrel extending along a third optical axis perpendicular to the second optical axis, one end of which along the third optical axis is connected to an outer peripheral surface of the intermediate lens barrel, and which is configured to be able to mount a light source; Equipped with The first lens barrel is a collector lens that collects light emitted from the light source; a fly-eye lens that transmits light from the collector lens; a first relay lens that relays light from the fly-eye lens; Accommodates The intermediate lens barrel is a field diaphragm for narrowing the range of light from the first relay lens; a reflecting mirror that reflects the light from the first relay lens, the range of which has been narrowed by the field diaphragm, toward the main lens barrel; a second relay lens that relays the light from the reflecting mirror to a beam splitter; Accommodates the main barrel is provided on the first optical axis, and houses the beam splitter which guides at least a portion of incident light to the objective lens and transmits at least a portion of light incident from the objective lens to the image sensor side; the one end of the first lens barrel along the third optical axis includes a truncated cone portion tapered toward the reflecting mirror, the truncated cone portion is inserted into the intermediate barrel and constitutes the field stop; The first relay lens has a plurality of lenses that are not cemented together. Microscope unit.

2. The intermediate lens barrel and the first lens barrel are configured to be rotatable relative to the main lens barrel with the second optical axis as a rotation axis. The microscope unit according to claim 1.

3. The distance in the optical path from the first relay lens to the second relay lens is five times or less the outer diameter of the second relay lens.

3. The microscope unit according to claim 1 or 2.

4. the first relay lens has a first lens and a second lens each consisting of a plano-convex lens, The first lens and the second lens are arranged so that their convex surfaces face each other. The microscope unit according to any one of claims 1 to 3.

5. The reflecting mirror is accommodated in the intermediate barrel while being held by a mirror frame member. The microscope unit according to any one of claims 1 to 4.

6. The truncated cone portion is disposed inside the outer peripheral surface of the mirror frame member. The microscope unit according to claim 5.

Images