Microscope unit

Abstract

A microscope unit includes: a main lens barrel of an imaging optical system; and an illumination lens barrel of an illumination optical system connected to the main lens barrel, the illumination optical system having: a condenser lens that collects light that has been irradiated from a light source; an eye lens that allows the light from the condenser lens to transmit therethrough; a first relay lens that has a lens that relays the light from the eye lens; a field stop that narrows down a range of the light from the first relay lens; a second relay lens that relays the light from the first relay lens to a beam splitter; and the beam splitter that guides at least a part of the light incident thereon to an objective lens, and allows at least a part of the light incident thereon from the objective lens to transmit therethrough to one side of an imaging sensor.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims the benefit of Japanese Patent Application No. 2021-088020, filed on May 25, 2021, the entire contents of which are incorporated herein by reference. Background Technology Technical Field

[0003] This invention relates to a microscope unit that can be assembled into a target device.

[0004] Description of the prior art

[0005] To date, a microscope unit is known, comprising: a main tube for an imaging optics system configured to house an imaging sensor and an objective lens; and an illumination tube for an illumination optics system connected to the main tube and configured to house a light source. Such a microscope unit is configured such that, for example, luminous flux (the flux of diverging rays) emitted from the light source is collected by a condenser lens, reflected by a mirror through a relay lens system and a field stop, and illuminated on the observation surface through the relay lens system, the aperture stop, and the condenser lens.

[0006] Such microscope units can sometimes be equipped with multiple light sources. However, sometimes the illumination at the observation surface can become uneven, depending on the type of light source assembled into the microscope unit. Therefore, for example, in the microscope illumination device described in Japanese Patent Application Publication No. 2002-6225, a compound eye lens is provided in the illumination optics system, thereby achieving uniform illumination at the observation surface. Attached Figure Description

[0007] Figure 1 This is an illustrative schematic diagram showing the overall configuration of the microscope unit according to the first embodiment.

[0008] Figure 2 This is an illustrative schematic diagram showing the overall configuration of the microscope unit.

[0009] Figure 3 This is a schematic side view showing the configuration of the mirror frame components of the microscope unit.

[0010] Figure 4 This is a schematic perspective view showing the configuration of the reflector frame components of the microscope unit.

[0011] Figure 5a and 5b This diagram illustrates the relationship between the orientation of the illumination tube relative to the main tube of the microscope unit and the illumination range.

[0012] Figure 6a, 6b Figures 6 and 6c are used to illustrate the lighting range with and without the assembly position adjustment already performed. Detailed Implementation

[0013] In the aforementioned microscope illumination setup, a compound eye lens needs to be integrated into the illumination optics system. Furthermore, a relay lens needs to be positioned between the compound eye lens and the field stop to relay light from the compound eye lens. In this configuration, a fixed length is required as the focal length from the relay lens to the field stop. The risk is that this will ultimately lead to an increase in the size of the illumination tube along with the increase in the optical path length of the illumination tube, and thus ultimately an increase in the size of the microscope unit.

[0014] The present invention was made in view of the following problems, and its object is to provide a microscope unit that can reduce the size of the entire illumination tube and thus the size of the microscope unit.

[0015] A microscope unit according to an embodiment of the present invention includes: a main tube of an imaging optics system configured to mount an imaging sensor and an objective lens; and an illumination tube of an illumination optics system connected to the main tube and configured to mount a light source, the illumination optics system comprising: a condenser lens for collecting light irradiated from the light source; a compound eye lens for allowing light from the condenser lens to pass through it; a first relay lens for relaying light from the compound eye lens; a field stop 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 disposed on the optical axis of the main tube, the beam splitter guiding at least a portion of the light incident thereon to the objective lens and allowing at least a portion of the light incident thereon from the objective lens to pass through it and be transmitted to one side of the imaging sensor. Furthermore, the first relay lens has a plurality of non-interlocking lenses.

[0016] In this microscope unit, the first relay lens of the illumination optics system is configured from multiple lenses that do not interlock. Therefore, compared to when the first relay lens is configured, for example, from a single lens or from a cemented lens considered as a single lens, the focal length from the first relay lens to the field stop can be shortened. This reduces the optical path length of the illumination tube, thus shortening the overall length of the illumination tube and consequently reducing the size of the microscope unit.

[0017] The optical path distance from the first relay lens to the second relay lens can be no greater than five times the outer diameter of the second relay lens.

[0018] The aforementioned first relay lens may have a first lens and a second lens, each composed of a plano-convex lens. Furthermore, the first lens and the second lens may be configured such that their similar convex surfaces face each other.

[0019] The microscope unit described above may have a reflecting mirror positioned between the field stop and the second relay lens, reflecting light from the first relay lens toward the main microscope tube. In this case, the second relay lens may be configured to relay the light reflected by the reflecting mirror to the beam splitter.

[0020] The aforementioned illumination tube may include: a first tube configured to house a light source; and an intermediate tube connecting the main tube and the first tube. In this case, the configuration can be adjusted such that the first tube houses a light-collecting lens, a compound eye lens, and a first relay lens; the intermediate tube houses a field stop, a second relay lens, and a reflector; and the main tube houses a beam splitter.

[0021] The aforementioned reflector can be housed in the intermediate mirror tube while remaining within the reflector frame component.

[0022] Furthermore, the field stop can be positioned further inward than the outer peripheral surface of the mirror frame member, and can be part of the first mirror tube.

[0023] This configuration allows for the provision of a microscope unit that enables a reduction in the overall size of the illumination tube, and thus a reduction in the size of the microscope unit itself.

[0024] The microscope unit according to several embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments do not limit the invention according to each of the claims, and the combinations of features described in the embodiments are not all necessary for the means of solving the problems of the present invention. Note that in the following embodiments, the scale, size, etc. of each configuration element are sometimes shown in magnification, and some configuration elements are sometimes omitted.

[0025] Furthermore, in the following description, "X-axis direction" refers to the direction directly opposite to the x-axis. Figure 1 The microscope unit shown is positioned horizontally (with the paper side facing out) in the left-right direction. The "Y-axis" refers to the depth direction under the same conditions, and the "Z-axis" refers to the vertical direction, i.e., the optical axis of the main tube under the same conditions. Note that the basic structure of the microscope unit is known; therefore, only a general description of the overall configuration is given here, unless necessary.

[0026] [First Embodiment]

[0027] [Configuration]

[0028] Figure 1 and Figure 2This is an illustrative schematic diagram showing the overall configuration of the microscope unit 100 according to the first embodiment. Figure 1 and Figure 2 In the image, the microscope unit 100 has an illumination optical system indicated by solid lines, and is further shown in part in a cross-sectional view and part in a perspective view. Figure 2 It shows the relationship with Figure 1 Compared to the case where the orientation of the illumination tube 20 relative to the main tube 10 differs by 180°, the following will assume... Figure 1 The state shown is a description of the basic posture of the microscope unit 100.

[0029] like Figure 1 and Figure 2 As shown, a microscope unit 100 configured as a part of a microscope (not shown) includes: a main microscope tube 10; and an illumination tube 20 connected to the main microscope tube 10.

[0030] The main tube 10 of the so-called imaging optics system of the microscope is configured, for example, such that it is in Figure 1 The upper end (hereinafter referred to as "upper side") in the Z-axis direction, as illustrated, can be fitted with a camera 31 incorporating an imaging sensor 30, and it is in Figure 1 The lower end (hereinafter referred to as the "lower side") in the Z-axis direction illustrated in the diagram can be fitted with an objective lens 32. Note that the imaging sensor 30 includes various image sensors (CMOS, CCD, etc.).

[0031] The main lens barrel 10 has: a cylindrical first sleeve portion 11 disposed on the upper side (camera 31 side); and a cylindrical second sleeve portion 12 disposed on the lower side of the first sleeve portion 11. The first sleeve portion 11 is formed such that its minimum outer diameter is slightly smaller than the minimum outer diameter of the second sleeve portion 12.

[0032] Furthermore, the main tube 10 has: a rectangular-shaped outer shell of a main body portion 13 disposed below the second sleeve portion 12; and a cylindrical third sleeve portion 14 disposed below the outer shell of the main body portion 13 and connected to the objective lens 32. Note that the outer shell of the main body portion 13 is configured as follows: a first outer shell 15; and a second outer shell 16 disposed below the first outer shell 15.

[0033] An imaging lens (tube lens) 17 is housed inside the second sleeve portion 12 and the first housing 15 of the main body portion 13 in the main lens barrel 10. Furthermore, a beam splitter (hereinafter referred to as "B / S") 18, which will be described later, is housed inside the second housing 16 of the main body portion 13 in the main lens barrel 10 so as to be tilted at an angle to the optical axis ML of the main lens barrel 10. These first sleeve portions 11, second sleeve portions 12, the housing of the main body portion 13, and the third sleeve portion 14 of the main lens barrel 10 are arranged linearly and coaxially along the optical axis ML of the main lens barrel 10 in the Z-axis direction.

[0034] The illumination tube 20, which is configured with the illumination optics system of a microscope, includes: a first tube 21 capable of having various light sources LS freely attachable / detachable at its end in the upper part of the Z-axis direction in a basic orientation; and an intermediate tube 22 connecting the first tube 21 to the main tube 10. Note that the first tube 21 has an optical axis L1 formed in the Z-axis direction, and the intermediate tube 22 has an optical axis L2 formed in the X-axis direction.

[0035] The first lens barrel 21 has: a cylindrical fourth sleeve portion 23 disposed on the upper side in a basic orientation; and a cylindrical fifth sleeve portion 24 disposed on the lower side of the fourth sleeve portion 23. Note that the fourth sleeve portion 23 is formed such that its minimum outer diameter is smaller than the minimum outer diameter of the fifth sleeve portion 24.

[0036] Furthermore, the first lens barrel 21 has: a connector housing of a portion 26 with a stepped annular appearance disposed below the fifth sleeve portion 24; and a sixth sleeve portion 27 with a stepped cylindrical appearance disposed below the connector housing of portion 26. The connector housing of portion 26 connects the fifth sleeve portion 24 and the sixth sleeve portion 27. Note that a portion of the sixth sleeve portion 27 (the portion disposed within the intermediate lens barrel 22) is configured as a frustoconical portion 27a that tapers downwards. Although in the illustrated example, the outer diameters of the fifth sleeve portion 24 and the sixth sleeve portion 27 are shown to be substantially the same, and the minimum outer diameter of the connector housing of portion 26 is shown to be larger than these outer diameters, the outer diameters of the fifth sleeve portion 24, the connector housing of portion 26, and the sixth sleeve portion 27 can be configured to be substantially the same.

[0037] Inside the fourth sleeve portion 23 of the first lens barrel 21, the light-emitting end LE of the assembled light source LS is housed. Furthermore, the fifth sleeve portion 24 of the first lens barrel 21 houses a light-collecting lens 33 on its upper inner side. Additionally, a compound eye lens 34 is housed inside the connection point between the fifth sleeve portion 24 and the connector housing of portion 26.

[0038] The sixth sleeve portion 27 in the first lens barrel 21 houses a first relay lens group 35, which serves as a first relay lens, on its inner upper side. The first relay lens group 35 has multiple lenses that are not joined together. For example, in the illustrated example, the first relay lens group 35 includes: a first lens 35a, which is a plano-convex lens having a convex surface pointing downwards in the Z-axis direction; and a second lens 35b, which is a plano-convex lens having a convex surface pointing upwards in the Z-axis direction. These first lenses 35a and second lenses 35b are arranged such that their similar convex surfaces face each other. The first lenses 35a and second lenses 35b can be separated from each other, or their convex surfaces can be partially in contact. Compared to using a biconvex lens or a single lens, such as a cemented lens, as the first relay lens, this configuration results in a smaller focal length to the field stop 36 (described later) while suppressing more spherical aberration. This is because the magnitude of the refractive power of the lens system can be shared by each lens (i.e., the first lens 35a and the second lens 35b). Furthermore, plano-convex lenses can be manufactured at a lower cost compared to aspherical lenses, which require initial molding fees, thus reducing the manufacturing cost of illumination optical systems.

[0039] Note that the inner peripheral surface 27b, which is located lower than the receiving position of the first relay lens group 35 in the sixth sleeve portion 27 of the first lens barrel 21, is formed into a tapered shape with a diameter that gradually decreases in the downward direction. In addition, a portion of the outer peripheral portion of the sixth sleeve portion 27 has an annular flange portion 27c that protrudes in the outer peripheral direction.

[0040] Compared to the lower end surface 27d of the flange portion 27c of the sixth sleeve portion 27 in the first lens barrel 21, the outer peripheral portion 27e, whose diameter is smaller than the minimum outer diameter of the sixth sleeve portion 27, passes through the stepped portion formed further below, where the outer peripheral portion 27f of the truncated cone portion 27a is provided. The truncated cone portion 27a is formed into a cone shape whose diameter gradually decreases in the downward direction.

[0041] Note that the connector housings of the fourth sleeve portion 23, the fifth sleeve portion 24, and the portion 26 of the first lens barrel 21, and the sixth sleeve portion 27 are arranged coaxially along the optical axis L1 of the first lens barrel 21. Furthermore, a field stop 36 is disposed at the lower end of the truncated cone portion 27a of the sixth sleeve portion 27. That is, the field stop 36 in the illumination lens barrel 20 of the first embodiment is formed by a portion of the first lens barrel 21 (the lower end portion of the truncated cone portion 27a).

[0042] The intermediate lens barrel 22 connects the first lens barrel 21 and the main lens barrel 10, and has a rectangular portion 28 of the intermediate housing, wherein in the basic orientation, a sloping wall 28a is formed on the side of its end that is separated from the main lens barrel 10 along the X-axis direction, which slopes downward from the top towards the main lens barrel 10.

[0043] Note that the intermediate housing of portion 28 has a cylindrical mating cylindrical portion 28b formed at one end of the main lens barrel 10 in the X-axis direction, and it mates with a perforated mating portion 16a formed in the second housing 16 of the main body portion 13. Therefore, the intermediate lens barrel 22 is connected to the main lens barrel 10 so that it can rotate relative to the main lens barrel 10 about an optical axis L2 orthogonal to the optical axis L1 of the first lens barrel 21 (see [link]). Figure 2 Note that a second relay lens 38 is accommodated inside the mating cylindrical portion 28b.

[0044] Furthermore, in the basic orientation, a mating hole 28d is formed in the upper wall portion 28c of the intermediate outer shell of portion 28, which mates with the sixth sleeve portion 27 of the first lens barrel 21. That is, the mating of the sixth sleeve portion 27 with the intermediate outer shell of portion 28 causes the lower end surface 27d of the flange portion 27c to abut against the outer wall surface of the upper wall portion 28c, and the outer peripheral portion 27e engages with the inner peripheral surface of the opening end side of the mating hole 28d.

[0045] Note that the sixth sleeve portion 27 is secured to the intermediate housing of portion 28 by mounting the flange portion 27c to the upper wall portion 28c with mounting bolts 19. Therefore, the first lens barrel 21 is secured after being positioned relative to the intermediate lens barrel 22. This configuration results in the first lens barrel 21 being secured to the intermediate lens barrel 22 in such a way that the aforementioned field stop 36 of the first lens barrel 21 is set further inward than the outer peripheral surface of the intermediate lens barrel 22 (the outer wall surface of the upper wall portion 28c of the intermediate housing of portion 28).

[0046] Furthermore, the intermediate mirror tube 22 already houses: a reflector 37; and a reflector frame member 40 that holds the reflector 37. In addition, the intermediate mirror tube 22 is equipped with a position adjustment mechanism (not shown) for adjusting the position of the reflector frame member 40 assembled into the intermediate mirror tube 22 (the position of the assembly into the intermediate housing of part 28).

[0047] Figure 3 This is a schematic side view showing the configuration of the mirror frame member 40 of the microscope unit 100. Furthermore, Figure 4 This is a schematic perspective view showing the configuration of the mirror frame member 40 of the microscope unit 100.

[0048] like Figure 3 and Figure 4As shown, the mirror frame member 40 is formed of a frame 49, which has a cylindrical shape with one end side obliquely cut to allow the mirror frame member 40 to be housed within the intermediate housing of portion 28. The frame 49 of the mirror frame member 40 holds the mirror 37. The mirror 37 is formed, for example, in an elliptical or polygonal (octagonal, etc.) shape, such that its reflective portion has an elliptical shape that matches the shape of the elliptical opening 41 of the frame 49. Furthermore, the portion of the mirror 37 other than the reflective portion is bonded to the frame 49 of the mirror frame member 40, for example, via an adhesive (not shown).

[0049] Furthermore, the frame 49 of the mirror frame member 40 has: a main mirror barrel side opening 42, formed at the end of the frame 49 on the X-axis direction opposite to the elliptical opening 41; and a first mirror barrel side opening 43, formed at a position separated from the elliptical opening 41 in the Z-axis direction when viewed from the elliptical opening 41. The opening diameter of the first mirror barrel side opening 43 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 mirror barrel 21 and larger than the outer diameter of the outer peripheral portion 27f located within a certain range above the field stop 36 in the Z-axis direction. Therefore, the field stop 36 can be positioned as close as possible to the mirror 37, and the frame 49 of the mirror frame member 40 will not interfere with the truncated cone portion 27a of the sixth sleeve portion 27.

[0050] Note that after the mirror frame member 40, configured in this way, has been housed within the intermediate housing of section 28, its assembly position is adjusted relative to the intermediate housing of section 28 by a position adjustment mechanism (not shown). Although the position adjustment mechanism is not illustrated, it is configured, for example, by a plurality of adjusting screws that have been screwed into a pair of countersunk mounting holes drilled in the Y-axis direction of the intermediate housing of section 28. After the assembly position is adjusted, the mirror frame member 40 is secured to the intermediate housing of section 28, for example, by threaded fastening.

[0051] Note that because the intermediate lens barrel 22 formed in this way and the separately assembled first lens barrel 21 can be integrated by a simple structure consisting only of a flange portion 27c, which is fixed to the intermediate housing of portion 28 by the threaded fastening of the mounting bolt 19 by the truncated cone portion 27a already inserted into the mating hole 28d, the illumination lens barrel 20 can be easily manufactured.

[0052] [Optical System]

[0053] 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. Furthermore, the illumination optical system of the microscope unit 100 according to this embodiment includes a light-collecting lens 33, a compound 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.

[0054] The emitting end LE of the light source LS, the mounting position of the objective lens 32 (the pupil of the objective lens 32), and the exit surface of the compound eye lens 34 are conjugates. However, these positions are not conjugates with B / S 18 and the reflecting mirror 37. Furthermore, the field stop 36, the focal position of the objective lens 32, and the focal position of the imaging lens 17 are conjugates.

[0055] The luminous flux (diverging ray flux) from the emitting end LE of the light source LS is converted into collected luminous flux (focused ray flux) via the light-collecting lens 33, and is divided into the same number of lenses as the plurality of lenses configured with the compound eye lens 34. Therefore, the same number of light source images (secondary light sources) as the plurality of lenses configured with the compound eye lens 34 are formed on the emitting end surface of the compound eye lens 34, and the luminous flux (diverging ray flux) emitted by each of the plurality of lenses configured with the compound eye lens 34 is collected overlapping each other at field stops 36 separated by designed focal lengths via the first relay lens group 35. Therefore, a pseudo-surface light source (secondary light source) is formed on the emitting end surface of the compound eye lens 34, and even when multiple light sources LS with different light distribution characteristics are used, this pseudo-surface light source has substantially uniform light distribution characteristics and minimal light distribution variation.

[0056] The luminous flux (the flux of diverging rays) that has passed through the field stop 36 along the optical axis L1 and whose light range has been reduced is reflected so that it forms a luminous flux (the flux of diverging rays) along the optical axis L2 through the mirror 37 in the intermediate lens barrel 22, and the luminous flux that has been collected by the second relay lens 38 is relayed to irradiate onto the B / S 18. Note that the B / S 18 guides at least a portion of the luminous flux (the flux of focused rays) that has passed through the second relay lens 38 to be incident on the B / S 18 to reflect it to one side of the aperture stop (not shown) and objective lens 32, and allows at least a portion of the luminous flux from the imaging surface IS that has passed through the objective lens 32 and the like to be incident on the B / S 18 to be transmitted through the B / S 18 to one side of the imaging lens 17.

[0057] [Rotation of the illumination tube 20 and positioning of the reflecting mirror 37]

[0058] 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. Now, without proper adjustment of the position of the reflecting mirror 37 relative to the B / S 18, there is a risk that the center position of the field aperture 36 will eventually deviate 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 to allow adjustment of the position of the reflecting mirror 37 relative to the B / S 18. This will be described below.

[0059] Figure 5a and 5b This is a diagram used to illustrate the relationship between the orientation of the illumination tube 20 relative to the main tube 10 of the microscope unit 100 and the illumination range. Figure 6a , 6b Figures 6 and 6c are used to illustrate the lighting range with and without assembly position adjustment completed. Note that in... Figure 5a , 5b In 6a, 6b, and 6c, the appearance of microscope unit 100 is similar to... Figure 1 and Figure 2 The differences are shown. Furthermore, this description assumes that the assembly position and angle of the B / S 18 of the main lens barrel 10 have been adjusted.

[0060] In the basic orientation, the optical axis ML of the primary lens tube 10 and the optical axis L1 of the first lens tube 21 of the illumination lens tube 20 are as follows: Figure 5a In the microscope unit 100 shown in the Z-axis direction, the center of the imaging range 51 on the imaging surface IS and the center of the illumination range 52, which has passed through the illumination tube 20 from the light source LS, are fixed at a regular position centered on the optical axis ML of the main tube 10. That is, at the position where the center of the imaging range 51 and the center of the illumination range 52 coincide with the optical axis ML, such as... Figure 5b As shown.

[0061] In the microscope unit 100 according to this embodiment, the illumination tube 20 can (e.g., from this basic orientation) rotate 90° relative to the main tube 10 about the optical axis L2, such as... Figure 6a As shown. Therefore, the illumination range 52 is rotated by 90°, while the image of the imaging range 51 remains unchanged.

[0062] Now, for example, if the assembly position of the reflector frame component 40 has been adjusted by the aforementioned position adjustment mechanism, then as follows: Figure 6b As shown, the state in which the center of the imaging range 51 and the center of the illumination range 52 coincide with the optical axis ML can be maintained, regardless of whether the orientation indicated by the arrow in the figure changes.

[0063] On the other hand, if the assembly position of the reflector frame component 40 is not adjusted, the center of the illumination range 52 will eventually be in a state that is significantly deviated from the center of the imaging range 51, such as... Figure 6c As shown, the illumination distribution caused by the light source LS in the field of view will eventually become uneven.

[0064] To avoid this situation, in the microscope unit 100 according to this embodiment, the position of the reflecting mirror frame member 40 assembled to the intermediate microscope tube 22 is adjusted via a position adjustment mechanism. The adjustment of the assembly position of the reflecting mirror frame member 40 is performed such that, for example, after the illumination microscope tube 20 has been assembled, the aforementioned adjusting screw is operated, thereby adjusting the position of the reflecting mirror frame member 40 in the X-axis direction relative to the intermediate housing of portion 28 and its position in the rotational direction centered on the X-axis direction relative to the intermediate housing of portion 28.

[0065] The adjustment is performed such that whenever the optical axis L1 of the light from the light source LS is converted to the optical axis L2 by the reflector 37, the eccentricity of the optical axis L2, along with the change in the attitude of the first lens barrel 21, will fall within a certain range. This allows the attitude of the illumination lens barrel 20 relative to the main lens barrel 10 to be freely changed without causing the illumination range 52 to deviate due to the illumination optics system.

[0066] [Small reduction in microscope unit size]

[0067] To date, a microscope unit is known comprising: a main tube for an imaging optics system configured to house an imaging sensor and an objective lens; and an illumination tube for an illumination optics system connected to the main tube and configured to house a light source. Such a microscope unit is configured such that, for example, luminous flux (the flux of diverging rays) emitted from the light source is collected by a condenser lens, reflected by a mirror through a relay lens system and a field stop, and illuminated on the observation surface through the relay lens system, the aperture stop, and the condenser lens.

[0068] Such microscope units can sometimes be equipped with multiple light sources. However, sometimes the illumination at the observation surface can become uneven, depending on the type of light source assembled into the microscope unit. Therefore, in the microscope unit 100 according to this embodiment, the illumination optics system has a compound eye lens 34 disposed therein, thereby achieving uniform illumination at the observation surface.

[0069] However, with such a configuration, the number of optical components in the illumination optical system increases, which sometimes leads to an increase in the overall length and ultimately makes it difficult to reduce the size. Therefore, in the illumination tube 20 of the microscope unit 100 according to the first embodiment, the size reduction of the microscope unit is achieved by a method of the following type.

[0070] [Addition of the first relay lens group 35]

[0071] 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 joined together. As described above, compared to using a biconvex lens or a single lens, such as a cemented lens, as the first relay lens, this configuration results in a shorter focal length to the field stop 36 (described later), while simultaneously suppressing more spherical aberration. Therefore, even though the first relay lens group 35, excluding the compound eye lens 34, is housed within the first microscope tube 21, the focal length from the first relay lens group 35 to the field stop 36 can be designed to be short, thus allowing the overall length of the first microscope tube 21 to be configured to be short. Therefore, the overall length of the illumination tube can be shortened, thereby achieving a reduction in the overall size of the illumination tube, and consequently, a reduction in the size of the microscope unit. Note that from the viewpoint of reducing the overall size of the illumination tube, for example, the distance of the optical path from the first relay lens group 35 to the second relay lens 38 is appropriately set to be no more than five times the outer diameter of the second relay lens 38. This allows for a shorter overall length of the illumination tube.

[0072] [Adjustment of the position of field stop 36]

[0073] In the microscope unit 100 according to the first embodiment, the field stop 36 is disposed further inward than the outer peripheral surface of the intermediate microscope tube 22. Therefore, the field stop 36 is disposed further outward than, for example, when it is disposed further outward than the outer peripheral surface of the intermediate microscope tube 22 (e.g., with). Figure 1 Compared to the case where the lower end surface 27d of the flange portion 27c of the sixth sleeve portion 27 is closer to the upper side, the space inside the first tube 21 can be utilized more efficiently. This allows for a shorter overall length of the illumination tube, thereby reducing the overall size of the illumination tube and thus reducing the size of the microscope unit.

[0074] In achieving a reduction in the size of the microscope unit 100 through this configuration, the field stop 36 is ideally positioned as close as possible to the reflecting mirror 37. For example, as Figure 1 As shown, it is desirable that the field stop 36 is positioned further inward than the inner circumferential surface 28e of the intermediate mirror tube 22. However, if the field stop 36 ultimately interferes with the light flux of the reflector 37, then the illumination performance of the illumination optics system will eventually deteriorate (brightness or illumination uniformity will deteriorate). Therefore, as Figure 1As shown, for example, the field stop 36 is ideally sufficiently separated from the mirror 37 to prevent it from interfering with the light throughput of the mirror 37. Furthermore, as described above, the focal positions of the field stop 36 and the objective lens 32 are configured in a conjugate relationship. Now, if the mirror 37 is not positioned outside the depth of focus of the field stop 36, there is a risk that dirt or scratches on the surface of the mirror 37 will eventually be projected onto the imaging surface IS. Therefore, the mirror 37 is ideally positioned outside the depth of focus of the field stop 36.

[0075] Note that, according to this embodiment, the sixth sleeve portion 27 of the illumination lens barrel 20 has a formed in Figure 1 The lower end portion of the sleeve 27a is a truncated cone portion, and a field stop 36 is disposed at the lower end of the truncated cone portion 27a. Such a field stop 36 can be manufactured by a single chuck using a lathe or the like when forming the sixth sleeve portion 27, thus enabling manufacturing with high accuracy while suppressing manufacturing time. Furthermore, it can be achieved without using components for separating the field stop, etc.

[0076] Furthermore, as described above, in the microscope unit 100 according to this embodiment, the illumination tube 20 is rotatable relative to the main tube 10. Now, depending on the configuration of the field stop, when the illumination tube 20 rotates relative to the main tube 10, there is a risk that the center position of the field stop 36 will eventually deviate from the optical axis of the illumination optical system. Now, according to this embodiment, the field stop 36 is configured by a portion of the sixth sleeve portion 27 that houses the first relay lens group 35. Therefore, even when the illumination tube 20 rotates relative to the main tube 10, the positional relationship between the center position of the field stop and the optical axis of the illumination optical system can be appropriately maintained.

[0077] [Other Embodiments]

[0078] The external shape, size, etc., of each part of the microscope unit 100 in the above embodiment can be appropriately modified. For example, the outer shell of the main body part 13 of the main tube 10 can also be formed into a cylindrical shape, and the entire first sleeve part 11 to the third sleeve part 14 can also be formed into a cylindrical shape. In addition, the first sleeve part 11, the second sleeve part 12, and the third sleeve part 14 can also be formed into a rectangular shape, and the entire first sleeve part 11 to the third sleeve part 14 can also be formed into a rectangular (rectangular tubular) shape. Furthermore, the outer diameter of the first to third sleeve parts 11, 12, and 14 can also be different from those described above. The above modifications can also be applied to the illumination tube 20. Furthermore, the part of the microscope unit 100 that is illustrated as being composed of multiple components can be configured as a single component, or the part of the microscope unit 100 that is illustrated as being composed of a single component can be configured as multiple components.

[0079] Although certain embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. In fact, the novel methods and systems described herein can be implemented in many other forms; furthermore, various omissions, substitutions, and changes can be made to the form of the methods and systems described herein without departing from the spirit of the invention. The appended claims and their equivalents are intended to cover these forms or modifications that fall within the scope and spirit of the invention.

Claims

1. A microscope unit, comprising: The main lens barrel of the imaging optical system extends along a first optical axis and is configured to be equipped with an imaging sensor and an objective lens; An intermediate lens barrel extends along a second optical axis orthogonal to the first optical axis and includes an end connected to the outer peripheral surface of the main lens barrel in the direction of the extension of the second optical axis; as well as A first lens barrel extends along a third optical axis orthogonal to the second optical axis, includes an end connected to the outer peripheral surface of the intermediate lens barrel in the direction of the extension of the third optical axis, and is configured to be fitted with a light source. The first lens tube accommodates: A light-collecting lens that collects light that has been irradiated from the light source; A compound eye lens that allows light from the light-collecting lens to pass through its transmission; as well as A first relay lens relays light from the compound eye lens. The intermediate mirror tube accommodates: The field stop reduces the range of light from the first relay lens; A reflector that reflects light from the first relay lens, whose range is reduced by the field stop, toward the main mirror tube; as well as The second relay lens relays the light from the reflector to the beam splitter; The main lens barrel houses a beam splitter positioned on the first optical axis. The beam splitter guides at least a portion of the light incident upon it to the objective lens and allows at least a portion of the light incident upon it from the objective lens to pass through and be transmitted to one side of the imaging sensor. The first lens barrel includes a frustoconical portion at its end in the direction extending along the third optical axis, the frustoconical portion being formed to taper towards the mirror. The truncated conical portion is inserted into the intermediate lens tube and forms the field stop. The first relay lens has multiple lenses that do not interlock.

2. The microscope unit according to claim 1, wherein, The distance of the optical path from the first relay lens to the second relay lens is no greater than five times the outer diameter of the second relay lens.

3. The microscope unit according to claim 1, wherein, The first relay lens has a first lens and a second lens, each composed of a plano-convex lens, and The first lens and the second lens are configured such that their similar convex surfaces face each other.

4. The microscope unit according to claim 2, wherein, The first relay lens has a first lens and a second lens, each composed of a plano-convex lens, and The first lens and the second lens are configured such that their similar convex surfaces face each other.

5. The microscope unit according to claim 1, wherein, The reflector is housed in the intermediate mirror tube in a state where it is held within the reflector frame member.

6. The microscope unit according to claim 5, wherein, The truncated cone-shaped portion is set further inward than the outer peripheral surface of the reflector frame component.

7. The microscope unit according to claim 1, wherein, The intermediate lens barrel and the first lens barrel are configured to rotate about the second optical axis relative to the main lens barrel.

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