Phase contrast microscope

Abstract

To provide a phase contrast microscope capable of reducing the size.SOLUTION: The phase contrast microscope includes: a light source unit; a light guide that has multiple optical fibers for transmitting light emitted by the light source unit via the multiple optical fibers and outputs the same; and an objective lens that has a lens and an annular phase film placed at the side from which the light of the lens is emitted and enlarges an image of a sample illuminated by the light from the light guide. The light exit surface of the multiple optical fibers is arranged to form a circular ring, and the light guide is arranged so that the positions of the multiple exit surfaces forming the circular ring is conjugate with the position of the phase film.SELECTED DRAWING: Figure 2B

Description

[Technical field]

[0001] The present disclosure relates to phase contrast microscopes. [Background technology]

[0002] As a phase-contrast microscope, for example, the configuration described in Patent Document 1 is known. In the phase-contrast microscope described in Patent Document 1, the ring slit is arranged at a position conjugate with the position of the phase film arranged on the phase plate in the objective lens. Light emitted from the light source of the phase-contrast microscope is emitted as annular light from the opening of the ring slit, passes through a condenser lens, and is irradiated onto a sample. The image of the sample irradiated with light is enlarged by the objective lens. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-122027 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the phase-contrast microscope described in Patent Document 1, in order to emit annular light to the condenser lens, it is necessary to place an optical system such as a ring slit and a lens between the light source and the condenser lens, so the phase-contrast microscope cannot be made compact.

[0005] An object of the present disclosure is to provide a phase-contrast microscope that can be made compact. [Means for solving the problem]

[0006] The phase contrast microscope of the present disclosure comprises a light source unit, a light guide having a plurality of optical fibers and transmitting and emitting light emitted by the light source unit through the plurality of optical fibers, an objective lens having a lens and a ring-shaped phase film arranged on the side of the lens from which the light is emitted and enlarging an image of a sample irradiated with light from the light guide, and a configuration for changing the magnification of the objective lens, wherein the light emission surfaces of the plurality of optical fibers are arranged to form a plurality of concentric rings, and the light guide is arranged such that the position of the plurality of emission surfaces forming each ring of the plurality of rings is conjugate with the position of the phase film of the objective lens of each magnification, The light source unit emits light, From the emission surface forming one selected ring among the plurality of rings The conjugate relationship between the size of the circular ring Emits light mosquito , By selectively causing the light source unit to emit light and switching between emitting annular light having a size that is not in the conjugate relationship from the emission surface that forms one selected from the plurality of rings, the capturing of a phase contrast image and the capturing of a bright field image are switched. . Effect of the Invention

[0007] According to the present disclosure, it is possible to reduce the size of a phase-contrast microscope. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a phase-contrast microscope according to a first embodiment; [Figure 2A] FIG. 1 is a schematic diagram showing an end face of a light guide according to a first embodiment on the side where light is incident; [Figure 2B] FIG. 1 is a schematic diagram showing an end face of a light guide according to a first embodiment from which light is emitted; [Diagram 3] FIG. 1 is a schematic diagram showing a configuration of a main part of a phase-contrast microscope according to a first embodiment; [Figure 4A] FIG. 1 is a schematic diagram showing a state in which the intensity distribution of light emitted from an optical fiber according to a first embodiment is uniform with respect to the emission angle; [Figure 4B] FIG. 1 is a schematic diagram showing a state in which the intensity distribution of light emitted from an optical fiber according to a first embodiment is non-uniform with respect to the emission angle; [Diagram 5] FIG. 13 is a schematic diagram showing the configuration of a phase-contrast microscope according to a second embodiment. [Figure 6]FIG. 11 is a schematic diagram showing an arrangement state of first to fourth exit surfaces of first to fourth optical fibers according to a second embodiment; [Figure 7] FIG. 13 is a schematic diagram showing an example of light irradiation control according to the second embodiment; [Figure 8] FIG. 13 is a schematic diagram showing the configuration of the main parts of a phase-contrast microscope according to a third embodiment; [Figure 9] FIG. 13 is a schematic diagram showing an arrangement state of the first to third exit surfaces of the first to third optical fibers according to the third embodiment; [Figure 10] FIG. 13 is a schematic diagram showing the configuration of a phase-contrast microscope according to a fourth embodiment. [Figure 11] FIG. 2 is a schematic diagram showing the arrangement of the first to third exit surfaces of the first to third optical fibers; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] The first embodiment of the present disclosure will be described below.

[0010] <Configuration of a phase contrast microscope> First, the configuration of a phase-contrast microscope will be described. Fig. 1 is a schematic diagram showing the configuration of a phase-contrast microscope according to a first embodiment.

[0011] The phase-contrast microscope 1 shown in FIG. 1 includes a light source unit 11, a light guide 12, a condenser lens 13, a sample mounting stage 14, an objective lens 15, an imaging lens 16, and a two-dimensional image sensor 17.

[0012] The light source unit 11 includes one light source 111. The light source 111 is configured, for example, by an LED (Light Emitting Diode). The light source 111 may also be configured by a halogen lamp, a semiconductor laser, or the like.

[0013] The light guide 12 has a structure in which a plurality of optical fibers 121 that transmit light emitted by the light source 111 are bundled together. The end of the light guide 12 on the side where light enters is connected to the light source 111. The end of the light guide 12 on the side where light exits is disposed so as to face the condenser lens 13. A detailed description of the light guide 12 will be given later.

[0014] The condenser lens 13 irradiates the light L emitted from the light guide 12 onto the sample S placed on the sample placement stage 14 .

[0015] The objective lens 15 is an objective lens for phase contrast observation, and enlarges and projects the sample S irradiated with the light L. The objective lens 15 has a lens 151 and a ring-shaped phase film 152. The lens 151 is disposed closer to the sample S than the phase film 152, that is, on the side where the light from the light source unit 11 is incident. The phase film 152 is disposed such that the center of the ring shape overlaps with the optical axis 151A of the lens 151 at a position on the light exit surface side of the lens 151. The phase film 152 has a function of shifting the phase of the incident light by ¼ wavelength.

[0016] The imaging lens 16 , in combination with the objective lens 15 , enlarges the image of the sample S and forms an image on the detection surface of the two-dimensional image sensor 17 .

[0017] The two-dimensional image sensor 17 converts the image of the focused sample S into a digital signal. In general, a complementary metal oxide semiconductor (CMOS) sensor or a charge coupled device (CCD) sensor is used as the two-dimensional image sensor 17.

[0018] <Explanation of the main parts of a phase contrast microscope> Next, the main parts of the phase-contrast microscope 1 will be described. Fig. 2A is a schematic diagram showing an end face of the light guide on the side where the light enters. Fig. 2B is a schematic diagram showing an end face of the light guide on the side where the light exits. Fig. 3 is a schematic diagram showing the configuration of the main parts of the phase-contrast microscope. Fig. 4A is a schematic diagram showing a state in which the intensity distribution of the light emitted from the optical fiber is uniform with respect to the emission angle. Fig. 4B is a schematic diagram showing a state in which the intensity distribution of the light emitted from the optical fiber is non-uniform with respect to the emission angle.

[0019] 2A, light incident surfaces 122 of the multiple optical fibers 121 are arranged to form a circle on the side of the light guide 12 where the light enters, i.e., end face 12A on the side facing the light source 111. On the other hand, as shown in Fig. 2B, light exit surfaces 123 of the multiple optical fibers 121 are arranged to form a ring on the side of the light guide 12 where the light exits, i.e., end face 12B facing the incident surface of the condenser lens 13. The position of the exit surface 123 of the optical fiber 121 that forms the ring is the pupil position of the illumination optical system that irradiates the sample S with light.

[0020] The light guide 12 shown in FIG. 3 is arranged so that the distance from the exit surface 123 of the optical fiber 121 to the condenser lens 13 is approximately equal to the focal length of the condenser lens 13. The light guide 12 is arranged so that the exit surfaces 123 of the optical fibers 121 form a ring centered on the optical axis 13A of the condenser lens 13. The light guide 12 is arranged so that the position of the exit surface 123 of the optical fiber 121 forming the ring, that is, the pupil position of the illumination optical system, is optically conjugate with the position of the phase film 152. Here, the conjugate position means a position where the same image with different magnifications can be obtained. It is preferable that the light guide 12 is arranged so that the traveling direction of the light L emitted from the multiple optical fibers 121 is parallel to the optical axis 13A of the condenser lens 13, that is, the exit surface 123 of the multiple optical fibers 121 is approximately perpendicular to the optical axis 13A of the condenser lens 13.

[0021] When the diameter of the core of the optical fiber 121 is D1, the width of the phase film 152 is D2, and the imaging magnification of the lens 151 is β, it is preferable that the optical fiber 121 and the phase film 152 are configured to satisfy the following formula (1). D1 <D2 / β ··· (1)

[0022] In this way, if the optical fiber 121 and the phase film 152 are configured so that the core diameter D1 is equal to or less than the value obtained by dividing the width D2 of the phase film 152 by the imaging magnification, all of the light emitted from the optical fiber 121 and traveling straight through the sample S without being diffracted can be made to enter the phase film 152.

[0023] 4A and 4B, the light L emitted from the emission surface 123 of the optical fiber 121 spreads radially. The intensity distribution A of the light L with respect to the emission angle is preferably uniform as shown in Fig. 4A, but may be non-uniform as shown in Fig. 4B. In order to make the intensity distribution A uniform, the optical fiber 121 is preferably composed of a multimode fiber.

[0024] <Operation of phase contrast microscope> Next, the operation of the phase-contrast microscope 1 will be described. As shown in FIG. 1, the light emitted by the light source 111 enters the light guide 12. The light that enters the light guide 12 exits from the end face 12B on the light exit side. At this time, the exit face 123 of the optical fiber 121 is arranged to form a ring on the end face 12B, so that the light guide 12 emits annular light L. In this way, the phase-contrast microscope 1 can emit annular light L without arranging an optical system such as a ring slit and a lens between the light source 111 and the condenser lens 13, so that the phase-contrast microscope 1 can be made compact. In addition, the phase-contrast microscope 1 can be easily incorporated into an apparatus that does not have enough space, such as an automatic cell culture apparatus.

[0025] The circular ring-shaped light L emitted from the light guide 12 passes through the condenser lens 13 and is irradiated onto, for example, a colorless and transparent sample S. The light L transmitted through the sample S passes through the objective lens 15 and the imaging lens 16 and is imaged on the detection surface of the two-dimensional image sensor 17. The position of the exit surface 123 of the optical fiber 121 forming the circular ring is set to a position optically conjugate with the position of the phase film 152, so that a phase contrast image can be captured.

[0026] [Second embodiment] Next, a phase-contrast microscope according to a second embodiment of the present disclosure will be described. The same components as those in the phase-contrast microscope 1 of the first embodiment will be given the same names and symbols, and descriptions thereof will be simplified or omitted. Fig. 5 is a schematic diagram showing the configuration of a phase-contrast microscope according to the second embodiment. Fig. 6 is a schematic diagram showing the arrangement of the first to fourth emission surfaces of the first to fourth optical fibers. Fig. 7 is a schematic diagram showing an example of light irradiation control.

[0027] The phase-contrast microscope 2 according to the second embodiment shown in FIG. 5 has a plurality of arc-shaped light beams constituting an annular light beam. For example, the phase-contrast microscope 2 irradiates the sample S with an arc-shaped light selected based on the installation position of the sample S in the container 9. The phase-contrast microscope 2 differs from the phase-contrast microscope 1 of the first embodiment in that it includes a control unit 28 and in the configurations of the light source unit 21 and the light guide 22.

[0028] The light source unit 21 includes a first light source 21A, a second light source 21B, a third light source 21C, and a fourth light source 21D. In the second embodiment, the light source unit 21 includes four light sources, but may include two, three, five or more light sources.

[0029] An end of the light guide 22 on the side connected to the light source of the light source section 21 is branched into the same number of parts as the light sources. In the second embodiment, the end of the light guide 22 is branched into four parts. Hereinafter, the four branched parts of the light guide 22 may be referred to as a first branch section 220A, a second branch section 220B, a third branch section 220C, and a fourth branch section 220D, respectively.

[0030] A plurality of optical fibers 221 are arranged in each of the first branching portion 220A, the second branching portion 220B, the third branching portion 220C, and the fourth branching portion 220D. Hereinafter, the optical fibers 221 arranged in the first branching portion 220A, the second branching portion 220B, the third branching portion 220C, and the fourth branching portion 220D may be referred to as the first optical fiber 221A, the second optical fiber 221B, the third optical fiber 221C, and the fourth optical fiber 221D (see FIG. 6). The numbers of the first to fourth optical fibers 221A to 221D may be the same or different.

[0031] As shown in FIG. 6, the light emission surfaces 223 of the optical fibers 221 are arranged to form a ring at the end surface 22B of the light guide 22 from which the light is emitted. The respective emission surfaces 223 of the first optical fiber 221A, the second optical fiber 221B, the third optical fiber 221C, and the fourth optical fiber 221D are arranged to form different arc-shaped regions of the ring. Hereinafter, the respective light emission surfaces 223 of the first optical fiber 221A, the second optical fiber 221B, the third optical fiber 221C, and the fourth optical fiber 221D may be referred to as the first emission surface 223A, the second emission surface 223B, the third emission surface 223C, and the fourth emission surface 223D, respectively. The light guide 22 is arranged so that the position of the emission surface 223 forming the ring is optically conjugate with the position of the phase film 152.

[0032] 5, the first branching portion 220A, the second branching portion 220B, the third branching portion 220C, and the fourth branching portion 220D are connected to the first light source 21A, the second light source 21B, the third light source 21C, and the fourth light source 21D, respectively. With this configuration, the light emitted from the first to fourth light sources 21A to 21D is emitted from the emission surface 223 that forms different arc-shaped regions among the emission surface 223 that forms a ring. In other words, the light emitted from the first to fourth light sources 21A to 21D is emitted as arc-shaped light from the first to fourth emission surfaces 223A to 223D, respectively.

[0033] The control unit 28 causes a light source selected from the first to fourth light sources 21A to 21D to emit light, thereby causing light to be emitted from the emission surface 223 forming at least one of the multiple arc-shaped regions constituting the ring. For example, as shown in FIG. 7, when the sample S is placed at a position close to the wall surface 91 of a container 9 having a high aspect ratio such as a well plate, the control unit 28 causes the first light source 21A to emit the arc-shaped light L2 shown by the solid line that does not interfere with the wall surface 91, without causing the fourth light source 21D to emit the arc-shaped light L1 shown by the two-dot chain line that interferes with the wall surface 91 to emit light. By performing such irradiation control by the control unit 28, a good phase contrast image can be obtained regardless of the shape or material of the container 9 in which the sample S is placed, or the installation position of the sample S in the container 9. The selection of the light source to be emitted by the control unit 28 may be performed based on the detection result of a sensor (not shown) that detects the positional relationship between the wall surface 91 and the sample S, or may be performed based on the operation of an operation unit (not shown) by a user.

[0034] The control unit 28 may cause two or three of the first to fourth light sources 21A to 21D to emit light simultaneously, and irradiate the sample S with arc-shaped light having a larger central angle than when one light source emits light. Furthermore, when the light from all the light sources constituting the light source unit 21 does not interfere with the wall surface 91, the control unit 28 may cause all the light sources to emit light simultaneously, and irradiate the sample S with annular light.

[0035] [Third embodiment] Next, a phase-contrast microscope according to a third embodiment of the present disclosure will be described. The same components as those in the phase-contrast microscope 1 of the first embodiment will be given the same names and symbols, and descriptions thereof will be simplified or omitted. Fig. 8 is a schematic diagram showing the configuration of the main parts of the phase-contrast microscope according to the third embodiment. Fig. 9 is a schematic diagram showing the arrangement of the first to third emission surfaces of the first to third optical fibers.

[0036] 8 has a function of independently emitting a plurality of concentric circular lights, and irradiates a sample S with one circular light selected based on the magnification of the objective lens 15. The phase-contrast microscope 3 differs from the phase-contrast microscope 1 of the first embodiment in that it includes a control unit 38, in that the configurations of the light source unit 31 and the light guide 32, and in that the magnification of the objective lens 15 can be changed.

[0037] The light source unit 31 includes a first light source 31A, a second light source 31B, and a third light source 31C. In the third embodiment, the light source unit 31 includes three light sources, but may include two or four or more light sources.

[0038] An end of the light guide 32 on the side connected to the light source of the light source section 31 is branched into the same number of parts as the light sources. In the third embodiment, the end of the light guide 32 is branched into three parts. Hereinafter, the three branched parts of the light guide 32 may be referred to as a first branch section 320A, a second branch section 320B, and a third branch section 320C, respectively.

[0039] A plurality of optical fibers 321 are arranged in each of the first branching portion 320A, the second branching portion 320B, and the third branching portion 320C. Hereinafter, the optical fibers 321 arranged in the first branching portion 320A, the second branching portion 320B, and the third branching portion 320C, respectively, may be referred to as the first optical fiber 321A, the second optical fiber 321B, and the third optical fiber 321C (see FIG. 9). The numbers of the first to third optical fibers 321A to 321C may be the same or different.

[0040] As shown in FIG. 9, the emission surfaces 323 of the first optical fiber 321A, the second optical fiber 321B, and the third optical fiber 321C are arranged to form three concentric rings at the end surface 32B of the light guide 32 from which light is emitted. Hereinafter, the emission surface 323 of the first optical fiber 321A that forms the largest ring of the three rings may be referred to as the first emission surface 323A. The emission surface 323 of the second optical fiber 321B that forms the second largest ring of the three rings may be referred to as the second emission surface 323B. The emission surface 323 of the third optical fiber 321C that forms the smallest ring of the three rings may be referred to as the third emission surface 323C. The light guide 32 is arranged so that the positions of the emission surfaces 323 that form the rings are optically conjugate with the position of the phase film 152.

[0041] 8, the first branching portion 320A, the second branching portion 320B, and the third branching portion 320C are connected to the first light source 31A, the second light source 31B, and the third light source 31C, respectively. With this configuration, the light emitted from the first to third light sources 31A to 31C is emitted from the emission surface 323 forming annular shapes of different sizes. In other words, the light emitted from the first to third light sources 31A to 31C is emitted as annular lights of different sizes from the first to third emission surfaces 323A to 323C, respectively.

[0042] As described above, the phase-contrast microscope 3 of the third embodiment is configured to be able to change the magnification of the objective lens 15. When changing the magnification of the objective lens 15, at least one of the size of the phase film 152 and the distance from the phase film 152 to the lens 151 is also changed. Therefore, in order to capture a good phase-contrast image while maintaining the conjugate relationship between the position of the phase film 152 and the pupil position (position of the exit surface 323) of the illumination optical system, it is necessary to change the size of the annular light emitted from the light guide 32. In the microscope described in the above Patent Document 1, a plurality of ring slits for emitting different annular lights are held by a slider, and the lens slit for emitting the light is switched by moving the slider based on the magnification of the objective lens.

[0043] The control unit 38 causes the light source selected from the first to third light sources 31A to 31C to emit light based on the magnification of the objective lens 15, thereby causing light to be emitted from the emission surface 323 that forms a ring of a size that can maintain the conjugate relationship between the position of the phase film 152 and the pupil position of the illumination optical system among a plurality of concentric rings. By such control, the sample S can be irradiated with annular light of a size that can maintain the conjugate relationship between the position of the phase film 152 and the pupil position of the illumination optical system regardless of the magnification of the objective lens 15, and a good phase contrast image can be taken. In addition, by controlling the emission of the three light sources constituting the light source unit 31, the size of the light emitted from the light guide 32 is changed, so that the phase contrast microscope 3 can be made compact and the size of the light can be switched quickly according to the magnification of the objective lens 15. The selection of the light source to be emitted in the control unit 38 may be performed based on the detection result of a sensor (not shown) that detects the magnification of the objective lens 15, or may be performed based on the operation of an operation unit (not shown) by the user.

[0044] Furthermore, when capturing a bright field image, the control unit 38 can selectively cause one of the first to third light sources 31A to 31C to emit light, and emit annular light of a size such that the position of the phase film 152 and the pupil position of the illumination optical system are not in a conjugate relationship from the light guide 32. By such control, it is possible to quickly switch between capturing a phase contrast image and capturing a bright field image.

[0045] [Fourth embodiment] Next, a phase-contrast microscope according to a fourth embodiment of the present disclosure will be described. The same components as those in the phase-contrast microscope 1 of the first embodiment will be given the same names and symbols, and descriptions thereof will be simplified or omitted. Fig. 10 is a schematic diagram showing the configuration of a phase-contrast microscope according to the fourth embodiment. Fig. 11 is a schematic diagram showing the arrangement of the first to third exit surfaces of the first to third optical fibers.

[0046] 10 has a function of irradiating a sample S with a plurality of lights having different peak wavelengths, and irradiates the sample S with any one of the plurality of lights having different peak wavelengths. The phase-contrast microscope 4 differs from the phase-contrast microscope 1 of the first embodiment in that it includes a control unit 48 and in the configurations of a light source unit 41 and a light guide 42.

[0047] The light source unit 41 has a first light source 41A, a second light source 41B, and a third light source 41C. In the fourth embodiment, the light source unit 41 has three light sources, but may have two or four or more light sources. The first light source 41A, the second light source 41B, and the third light source 41C emit light having different peak wavelengths.

[0048] The end of the light guide 42 on the side connected to the light source of the light source section 41 is branched into the same number of parts as the light sources. In the fourth embodiment, the end of the light guide 42 is branched into three parts. Hereinafter, the three branched parts of the light guide 42 may be referred to as a first branch section 420A, a second branch section 420B, and a third branch section 420C, respectively.

[0049] A plurality of optical fibers 421 are arranged in each of the first branching portion 420A, the second branching portion 420B, and the third branching portion 420C. Hereinafter, the optical fibers 421 arranged in the first branching portion 420A, the second branching portion 420B, and the third branching portion 420C, respectively, may be referred to as the first optical fiber 421, the second optical fiber 421, and the third optical fiber 421. The numbers of the first to third optical fibers 421 may be the same or different.

[0050] As shown in FIG. 11, the emission surfaces 423 of the first optical fiber 421, the second optical fiber 421, and the third optical fiber 421 are arranged to form a ring at the end surface 42B of the light guide 42 from which light is emitted. Hereinafter, the emission surfaces 423 of the first optical fiber 421, the second optical fiber 421, and the third optical fiber 421 may be referred to as the first emission surface 423A, the second emission surface 423B, and the third emission surface 423C, respectively. The first emission surface 423A, the second emission surface 423B, and the third emission surface 423C are arranged periodically in the circumferential direction of the ring. In other words, the first emission surface 423A, the second emission surface 423B, and the third emission surface 423C are arranged to form rings of the same size.

[0051] The first branching portion 420A, the second branching portion 420B, and the third branching portion 420C are connected to the first light source 41A, the second light source 41B, and the third light source 41C, respectively. With this configuration, the first to third emission surfaces 423A to 423C, which emit light beams having different peak wavelengths from each other, are arranged so as to be repeatedly lined up in a certain order in the circumferential direction of the ring. The light beams having different peak wavelengths emitted from the first to third light sources 41A to 41C, respectively, are emitted as ring-shaped light beams of the same size from the first to third emission surfaces 423A to 423C, respectively.

[0052] The control unit 48 emits light from any one of the first light source 41A, the second light source 41B, and the third light source 41C selected based on the color of the dye of the transparent sample S, for example, to emit light that spreads radially from the emission surface 323 that emits light of a predetermined peak wavelength among a plurality of lights having different peak wavelengths. By such control, the sample S can be irradiated with annular light having a wavelength suitable for capturing a phase contrast image of the sample S and emitted from the emission surface 323 arranged at a position conjugate with the position of the phase film 152, and a good phase contrast image can be captured. The control unit 48 may simultaneously emit light from any two of the first light source 41A, the second light source 41B, and the third light source 41C, or may simultaneously emit light from all of the first light source 41A, the second light source 41B, and the third light source 41C. The selection of the light source to be emitted in the control unit 48 may be performed based on, for example, the detection result of a sensor (not shown) that detects the color of the sample S, or may be performed based on the user's operation of an operation unit (not shown).

[0053] [Variations] It goes without saying that the present disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present disclosure.

[0054] The optical fiber 121, 221, 321, 421 is composed of a core and a clad covering the core. Usually, light passes through the core, but coupling between the optical fiber 121, 221, 321, 421 and the light source constituting the light source unit 11, 21, 31, 41, or light leaking from the core may propagate through the clad. In this case, if the light that has passed through the clad passes outside the phase film 152, the contrast of the image decreases, so it is necessary to remove the clad mode light that passes through the clad. Therefore, a clad mode light removing unit that removes such clad mode light may be provided in the phase contrast microscope 1, 2, 3, 4 or the light guide 12, 22, 32, 42. An example of the clad mode light removing unit provided in the phase contrast microscope 1, 2, 3, 4 is a mandrel that bends the optical fiber 121, 221, 321, 421 at a radius that can remove the clad mode light. A material having a refractive index matching with the cladding can be exemplified as the cladding mode light removal portion provided in the light guides 12, 22, 32, and 42. By attaching a material having a refractive index matching with the cladding to the cladding, it is possible to remove the cladding mode light.

[0055] In the second embodiment, a configuration was exemplified in which arc-shaped light was irradiated onto the sample S by individual light emission control of the first to fourth light sources 21A to 21D. However, it is also possible to provide only one light source and, for example, place a mask having an arc-shaped slit on the end surface 22B of the light guide 22 and rotate the mask by the control unit 28 to irradiate arc-shaped light that does not interfere with the wall surface 91.

[0056] In the fourth embodiment, the first to third light sources 41A to 41C have different peak wavelengths. Although the configuration used has been exemplified above, it is also possible to provide only one light source that emits a specified light, and to place one of a plurality of filters that transmit only light of different peak wavelengths in front of end face 42B of light guide 42 under the control of control unit 48.

[0057] The configuration of the second embodiment may be applied to the third embodiment, and arc-shaped light constituting one of three concentric rings may be irradiated onto the sample S. Also, the configuration of the fourth embodiment may be applied to the third embodiment, and in each of the three rings, emission surfaces that emit light having different peak wavelengths may be periodically arranged in the circumferential direction. [Industrial Applicability]

[0058] The phase-contrast microscope of the present disclosure has the effect of miniaturizing a phase-contrast microscope that visualizes a transparent sample, and can also be used for inspection and other purposes in the industrial field. [Explanation of symbols]

[0059] 1,2,3,4 Phase contrast microscope 9 containers 11,21,31,41 Light source section 12,22,32,42 Light Guide 12A,12B,22B,32B,42B End face 13 Condenser Lens 13A optical axis 14 Sample placement table 15 Objective Lens 16 Imaging Lens 17 2D Image Sensor 21A,31A,41A 1st light source 21B,31B,41B 2nd light source 21C,31C,41C 3rd light source 21D 4th light source 28,38,48 Control section 91 Wall 111 Light source 121,221,321,421 Optical fiber 122 Incidence plane 123,223,323,423 Exit surface 151 Lens 151A optical axis 152 Phase film 220A, 320A, 420A First branch 220B, 320B, 420B Second branch 220C, 320C, 420C 3rd branch 220D 4th branch 221A, 321A, 421 First optical fiber 221B, 321B, 421 Second optical fiber 221C, 321C, 421 3rd optical fiber 221D 4th optical fiber 223A,323A,423A 1st exit surface 223B, 323B, 423B 2nd exit surface 223C,323C,423C 3rd exit surface 223D 4th exit surface A intensity distribution L,L1,L2 light S Sample

Claims

1. A light source unit; a light guide having a plurality of optical fibers and transmitting the light emitted by the light source unit through the plurality of optical fibers and emitting the light; an objective lens having a lens and a ring-shaped phase film arranged on the light exit side of the lens, the objective lens enlarging an image of a sample irradiated with light from the light guide; A configuration for changing the magnification of the objective lens, the light emission surfaces of the optical fibers are arranged to form a plurality of concentric rings; the light guide is arranged such that the positions of the plurality of exit surfaces forming each of the plurality of rings are conjugate with the positions of the phase films of the objective lenses of each magnification; switching between capturing a phase contrast image and capturing a bright field image by switching between emitting light from the light source unit to emit an annular light having a size that is in the conjugate relationship from the emission surface that forms one of the multiple annular rings selected from the multiple annular rings, and selectively emitting light from the light source unit to emit an annular light having a size that is not in the conjugate relationship from the emission surface that forms one of the multiple annular rings selected from the multiple annular rings; Phase contrast microscope.

2. light is emitted from the emission surface forming one of the plurality of annuli selected in accordance with the changed magnification of the objective lens; 2. A phase-contrast microscope according to claim 1.

3. the light source unit includes a plurality of light sources that emit light to different optical fibers; A control unit is further provided that causes only a light source that emits light that does not interfere with a wall surface of a container in which the sample is placed to emit light from among the plurality of light sources, and causes the light to be emitted only from the emission surface of a part of the optical fiber that transmits the light from the emitted light source, among the plurality of emission surfaces.

3. A phase-contrast microscope according to claim 1 or 2.

4. The control unit emits light from the emission surface that forms a selected arc-shaped region among a plurality of arc-shaped regions that form the annulus.

4. A phase-contrast microscope according to claim 3.

5. the emission surfaces emitting light beams having different peak wavelengths are arranged in a repeated manner in a fixed order in the circumferential direction of the ring, The control unit emits light from the emission surface that emits light having a selected peak wavelength from the light having different peak wavelengths.

5. A phase-contrast microscope according to claim 3 or 4.

6. The optical fiber is a multimode fiber. A phase-contrast microscope according to any one of claims 1 to 5.

Images