JP2011013484A - Microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficient dark-field illumination state.SOLUTION: A control unit 40 controls individually each of a plurality of micro mirrors that are two-dimensionally arranged on the surface of a light deflecting element 36, and switches between bright-field illumination and dark-field illumination, by turning on micro mirrors in a bright-field illumination region Awhen performing bright-field illumination and by turning on micro mirrors in a dark-field illumination region Awhen performing dark-field illumination. Thereby, since a region other than a dark-field illumination optical path can be prevented from being irradiated with illumination light when switching from bright-field illumination to dark-field illumination, a sufficient dark-field illumination state can be obtained. Therefore, for example, the application to a microscope performing illumination for both bright-field illumination and dark-field illumination can be performed.

Description

  The present invention relates to a microscope.

  As an observation method using a microscope, in addition to observation using bright field illumination in which a sample is directly illuminated by a light beam emitted from a light source, a light beam near the optical axis is shielded from the light beam emitted from the light source, Observation by dark field illumination in which a sample is illuminated only by a light beam is known.

  Some microscopes can perform both bright-field observation and dark-field observation by enabling switching between bright-field illumination and dark-field illumination.

  Patent Document 1 discloses bright field illumination by controlling the transmission characteristics of a spatial light modulator in a microscope that uses a spatial light modulator such as a digital mirror device (DMD) in the illumination optical system. And achieving switching of dark field illumination is disclosed.

Special table 2001-521205 gazette

  However, the conventional technology including the above-mentioned Patent Document 1 only discloses that pixels other than the vicinity of the optical axis are brought into an illumination state when switching from bright field illumination to dark field illumination. The dark field illumination state was not obtained. For this reason, since the contrast does not increase between the position where the diffused light of the test object is generated and the other position, it is difficult to find a minute scattering object.

  The present invention has been made in view of such a situation, and makes it possible to obtain a sufficient dark field illumination state when switching from bright field illumination to dark field illumination.

  The microscope of the present invention has different optical paths for bright-field illumination and dark-field illumination, and an illumination optical system that illuminates the sample with light from each position of a light source for illuminating the sample as parallel light fluxes, It consists of a plurality of micromirrors that can selectively control deflection, and is arranged in the optical path of the illumination optical system in which light from each position of the light source becomes a parallel light beam, and a part of the parallel light beam is directed in a predetermined direction A light deflection element for deflecting, and a control means for performing deflection control of the plurality of micromirrors to switch between bright-field illumination and dark-field illumination by light that has become a parallel light beam, and the control means comprises bright-field illumination When switching from dark field illumination to dark field illumination, a part of the parallel light flux is deflected to the dark field illumination optical path, and the plurality of micromirrors are controlled to be deflected so that other parallel light fluxes do not enter the bright field illumination optical path.

  According to the present invention, a sufficient dark field illumination state can be obtained.

It is a figure which shows the structure of one Embodiment of the epi-illumination type microscope to which this invention is applied. It is a figure which shows the structure of one Embodiment of the epi-illumination type microscope to which this invention is applied. It is a figure explaining operation | movement of the micromirror which an optical deflection element has. It is a schematic diagram which shows the example of the shape of an objective lens. Is a diagram showing details of the bright field illumination area A _b and dark field illumination area A _d. It is a figure which shows the structure of one Embodiment of the transmission illumination type microscope to which this invention is applied. It is a figure which shows the structure of one Embodiment of the transmission illumination type microscope to which this invention is applied. It is a figure which shows the example of control of the micromirror which an optical deflection element has. It is a figure which shows the other structure of one Embodiment of the transmission illumination type microscope to which this invention is applied. It is a figure which shows the other structure of one Embodiment of the transmission illumination type microscope to which this invention is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show the configuration of an embodiment of an epi-illumination microscope to which the present invention is applied.

  FIG. 1 is an external view of the epi-illumination microscope 1 during bright-field observation as viewed from the side, and FIG. 2 is an external view of the epi-illumination microscope 1 during dark-field observation as viewed from the side. In FIGS. 1 and 2, a part is shown in cross section so that the configuration of the optical system arranged in the microscope 1 can be seen, and the members shown by the cross section are hatched.

  As shown in FIG. 1, in the microscope 1, a stage 12 on which a sample S is placed is attached to the main body 11, and the stage 12 is movable in the X direction and the Y direction.

  A revolver 13 is rotatably disposed above the stage 12. Several objective lenses 14 are detachably attached to the revolver 13, and the spectroscope can rotate the revolver 13 as necessary to selectively place a desired objective lens 14 on the optical axis. . Further, a driving device (not shown) is connected to the stage 12, and the stage 12 and the objective lens 14 are relatively moved in the Z direction.

  An eyepiece tube 15 is disposed on the upper surface of the main body 11. An eyepiece lens 16 is attached to the eyepiece tube 15. Thereby, the spectrographer can observe the image of the sample S through the eyepiece lens 16. In addition, a lamp house 17 for epi-illumination is disposed on the back surface of the main body 11, that is, on the opposite side of the eyepiece tube 15. In addition, a control unit 40 and an instruction unit 41 are provided in the main body unit 11. The control unit 40 is connected to a later-described light deflection element 36 and an instruction unit 41, and controls the light deflection element 36 according to the illumination state input to the instruction unit 41.

  Next, an optical system arranged in the microscope 1 will be described.

  As shown in FIG. 1, a light source 31 and a collimator lens 32 are accommodated in the lamp house 17. The illumination light beam emitted from each position of the light source 31 such as a halogen lamp includes a collimator lens 32, a relay lens 33, a field stop 34, a field lens 35, a light deflection element 36, a half mirror 37, and an objective lens 14. The light enters the illumination optical system. The illumination light beam is converted into parallel light by the collimator lens 32 and then guided into the main body 11. In the main body 11, the illumination light beam is partially blocked by the relay lens 33 and the field stop 34. Then, the light beam from the image of the light source that has passed through the field stop 34 reaches the field lens 35, becomes a parallel light beam, and reaches the light deflection element 36. The light beam deflected to the half mirror 37 by the light deflection element 36 is condensed by the objective lens 14 and illuminates the sample S.

  The light deflection element 36 is disposed in a region opposite to the light source 31 with respect to the optical axis of the objective lens 14. Since the region in the main body 11 is generally a region where no optical element is disposed (dead space), by disposing the light deflection element 36, a region that is not used is effectively used.

  The light deflection element 36 has a plurality of minute light deflection mirrors (hereinafter referred to as minute mirrors) that can be selectively deflected in accordance with control from the control unit 40, and independently control these minute mirrors. Accordingly, light incident from one direction can be deflected in various directions independently for each region. As this light deflection element 36, for example, a DMD (Digital Micromirror Device) which is a unit having a pixel structure in which minute micromirrors are two-dimensionally arranged is used.

In the optical deflection element 36 such as DMD, as shown in FIG. 3, the orientation of each of the micromirrors 51 arranged in two dimensions is controlled by on / off control of the voltage applied to the holding unit that holds each micromirror. The angle can be controlled in two directions. Specifically, among the plurality of micromirrors 51 _{i, j} arranged in two dimensions of i × j (i, j: natural number), micromirrors 51 _{m, n} (1 ≦ m ≦ i, 1 ≦ n) ≦ j) and the minute mirror 51 _{p, q} (1 ≦ p ≦ i, 1 ≦ q ≦ j), the light from the right direction in the figure guided by the field lens 35 is the minute mirror 51. It enters each of _{m, n} and micromirrors 51 _{p, q} . At this time, since the micromirrors 51 _{p, q} are in the on state, the incident light is deflected toward the half mirror 37 in the upper right direction in the figure. On the other hand, since the micromirrors 51 _{m, n} are in the off state, the incident light is deflected toward the light attenuating member 38 in the upward direction in the figure. That is, micromirrors 51 _i, by performing on / off control of _j, the micromirrors 51 _i, by each of _j, the light incident from one direction, and the upper right direction of the half mirror 37 in the figure, in the figure It is possible to guide in two directions with the light dimming member 38 in the upward direction.

  By the way, when performing bright-field illumination or dark-field illumination, a region where the illumination is performed corresponds to the shape of the objective lens 14. Therefore, the shape of the objective lens 14 will be described with reference to FIG. In FIG. 4, the upper drawing shows a top view of the objective lens 14, and its AA sectional view is shown as the lower drawing.

As shown in FIG. 4, the objective lens 14 is in its lens barrel 14A, the tube 14B to be secured is provided by the fixing member 14C ₁ to 14C _3. In the hollow portion of the inner cylinder 14B, lenses 14a to 14d are held along the optical axis, whereby a plurality of lenses for obtaining a predetermined magnification are arranged in the lens barrel 14A. When performing bright field illumination, it is necessary to illuminate the sample S with an incident angle near the optical axis of the objective lens 14 with a luminous flux near the center of the luminous flux emitted from the light source 31, and thus the objective lens in 14, the light beam of the illumination light is guided to the bright field illumination light path OP _b in the hollow portion of the inner tube 14B.

That is, when performing bright field observation, when a bright field observation instruction is input to the instruction unit 41, the control unit 40 gives the light deflection element 36 the following control. In the bright field observation, it is necessary to incident illumination light to bright field illumination optical path OP _b, in the light deflector 36 is emitted from the light source 31 is incident on the illumination optical system and reaches the light deflection element 36 Of the light, the control unit 40 turns on all the micromirrors 51 for each location so that light in the vicinity of the optical axis of the objective lens 14, that is, light in a portion contributing to bright field illumination is deflected to the half mirror 37 side. Control the off state.

Specifically, FIG. 5a, are arranged in a two-dimensional in the optical deflection element 36 the micromirrors 51 _i, and _j, which illustrates the relationship between the illumination optical path of the objective lens 14, the micro mirror 51 _i, a _j Illumination light emitted from the light source 31 is guided to the illumination optical path of the objective lens 14 corresponding to the area that is turned on. That is, in the case of bright field illumination, the illumination light passing through the bright field illumination light path OP _b in FIG. 4, since to illuminate the sample S at an incident angle of the optical axis near the objective lens 14, the optical deflection element 36, two-dimensional Among the micromirrors 51 _{i, j} arranged in the center of the objective lens 14, that is, as shown in FIG. 5 _b , a region corresponding to the bright field illumination optical path OP _b of the objective lens 14 (hereinafter, bright field). Control is performed to turn on the micromirrors 51 _{i, j} in the illumination area _Ab ) and turn off the micromirrors 51 _{i, j} arranged in the other areas.

Returning to Figure 1, micro-mirror 51 i of bright field illumination area A _b, a _j by the ON state in the optical deflection element 36, the light reflected by the half mirror 37, a bright field illumination optical path of the objective lens 14 Illuminate sample S through OP _b . On the other hand, in the present embodiment, the objective lens 14, the imaging lens 39, and the eyepiece lens 16 form an imaging optical system. The reflected light from the illuminated sample S passes through the objective lens 14 and the half mirror 37, forms an image in the eyepiece tube 15 by the imaging lens 39, and is guided to the eyepiece 16. Thereby, the spectroscope can observe the image of the sample S in bright field.

At this time, the light deflected toward the light attenuating member 38 by the micro mirrors 51 _{i, j} in the off state becomes unnecessary light that does not contribute to the image, and is thus attenuated by the light attenuating member 38. As the light attenuating member 38, for example, a member that absorbs light such as a neutral density (ND) filter or flocking paper is used. By disposing such a light attenuating member 38, unnecessary light is prevented from becoming stray light and affecting observation. The same effect can be obtained by painting the region in black instead of arranging the light dimming member 38, but an image with better contrast can be obtained by arranging the light dimming member 38. Further, regarding stray light, it is preferable that the same treatment is applied to the light passing through the half mirror 37 among the illumination light directed from the light deflection element 36 to the half mirror 37.

Thus, at the time of bright field observation, the micromirrors 51 i arranged in a two-dimensional optical deflector element _36, among the _j, be micromirrors 51 i of bright field illumination area A _{b, j} to the on state Thus, the light reflected by the micromirrors 51 _{i, j} turned on is deflected to the half mirror 37 side, and the deflected light is guided to the bright field illumination optical path OP _b at the center of the objective lens 14. As a result, the sample S is illuminated.

Next, the microscope 1 during dark field observation will be described with reference to FIG. In the microscope 1 in FIG. 2, the same parts as those in the microscope 1 at the time of bright field observation in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. That is, the microscope 1 that performs observation with dark field illumination in FIG. 2 has the same configuration as the microscope 1 in FIG. 1, but the illumination light that irradiates the sample S is changed from bright field illumination to dark field illumination. Since they are switched _, the on / off states of the micromirrors 51 _{i, j} arranged in two dimensions of the light deflection element 36 are different.

As shown in FIG. 2, when performing dark field illumination, it is necessary to block the light beam near the central portion of the light beam of the illumination light emitted from the light source 31 and illuminate the sample S only with the light beam in the peripheral portion. since, in the objective lens 14, as shown in FIG. 4, the luminous flux of the illumination light is guided to the darkfield illumination optical path OP _d is a space between the barrel 14A and the inner tube 14B.

That is, when performing dark field observation, when an instruction for dark field observation is input to the instruction unit 41, the control unit 40 gives the light deflection element 36 the following control. The dark field observation, it is necessary to incident illumination light to the darkfield illumination optical path OP _d, in the light deflector 36 is emitted from the light source 31 is incident on the illumination optical system and reaches the light deflection element 36 Of the light, the control unit 40 turns on / off all the micromirrors 51 for each location so that the light around the objective lens 14, that is, the light that contributes to dark field illumination is deflected toward the half mirror 37. Control off state.

Specifically, in the case of dark field illumination, so to illuminate the sample S by the illumination light passing through the dark field illumination optical path OP _d in FIG. 4, the light deflector 36, the minute and two-dimensionally arrayed mirror 51 _{i, j} of the outer objective lens 14, that is, as shown in FIG. 5c, the region corresponding to the dark field illumination optical path OP _d of the objective lens 14 (hereinafter, dark field illumination of the area a _d) micromirrors 51 i _in, a _j in the on state, and the other region arranged micromirrors 51 _{i, j} control that turns off the is performed.

Returning to Figure 2, the micro mirrors 51 i darkfield illumination area A _d, illumination light which is formed in a substantially donut shape by the on-state _j is deflected by the half mirror 37, darkfield objective lens 14 It is led to the illumination optical path OP _d, to illuminate the sample S. The light scattered by the sample S is imaged in the eyepiece tube 15 by the objective lens 14, the half mirror 37, and the imaging lens 39 and guided to the eyepiece lens 16. Thereby, the spectrographer can observe the image of the sample S in the dark field.

On the other hand, the light becomes unnecessary to dark field illumination, i.e., light that does not reach the darkfield illumination optical path OP _d light and the objective lens 14 to reach the center of the lens of the objective lens 14, off the micromirrors 51 of the light deflector 36 By setting it in the state, it is guided to the light attenuating member 38 in the upward direction in the figure as in FIG.

As shown in FIG. 4, in the objective lens 14, the inner cylinder 14 </ b> B for holding the lenses 14 a to 14 d is fixed at three positions by the fixing members 14 </ b> C ₁ to 14 </ b> C ₃ . In addition, originally, it is desirable to turn off the micromirrors 51 _{i, j} in the regions corresponding to the three fixing members, but when the control is difficult, the micromirrors 51 _{i, j} correspond to the three fixing members. micromirrors 51 i of the _region, the state of _j is in the oN state, a dark-field illumination area a _d may be a complete donut. That is, since the holding member consisting of an inner cylinder 14B and the fixing member 14C ₁ to 14C ₃ results in devoted illumination light causes stray light, in the dark field illumination area A _{d (FIG.} 5c), corresponding to the holding member by micromirrors 51 i of the _region, the _j off, but to prevent stray light from occurring, as the illumination light from entering the bright field illumination light path OP _b, further, with respect to the inner cylinder 14B Therefore, stray light can be suppressed simply by avoiding illumination light.

Thus, at the time of dark field observation, the micromirrors 51 i arranged in a two-dimensional optical deflector element _36, among the _j, be micromirrors 51 i darkfield illumination area A _{d, j} to the on state Thus, the light reflected by the micromirrors 51 _{i, j} turned on is deflected toward the half mirror 37, and the deflected light formed in a substantially donut shape is the dark field illumination optical path of the objective lens 14. It is guided to OP _d and the sample S is illuminated. At this time, not only to make the illumination light from entering the bright field illumination light path OP _b, avoid exposure illumination light with respect to the inner cylinder 14B and the fixed member 14C ₁ to the holding member such as 14C _3, fine Since the mirror 51 is controlled, a sufficient dark field illumination state can be obtained. Thereby, for example, the contrast between the position where the diffused light of the test object is generated and the position other than that becomes large, and it becomes possible to easily find a minute scattered object.

  In the above-described example, the case where epi-illumination is adopted as an illumination method has been described as an example. However, the present invention can also be applied to transmitted illumination in which illumination light is irradiated from behind the sample S. Next, a transmission illumination type microscope to which the present invention is applied will be described with reference to FIGS. As for this microscope, FIG. 6 shows a configuration during bright field observation, and FIG. 7 shows a configuration during dark field observation.

  The microscope 101 in FIG. 6 differs from the microscope 1 in FIG. 1 in the illumination method between the epi-illumination type and the transmission illumination type. The configuration corresponds to the main body 11 or the lamp house 17 in FIG. In addition, regarding the illumination optical system arranged in the main body 111, whether the arrangement position is in the case above the stage on which the sample S is placed as compared with the illumination optical system in the main body 11 of FIG. The optical members are basically the same, but the light source 131 to the light deflection element 136 in FIG. 6 is replaced with the light source 31 to the light deflection element 36 in FIG. It corresponds. Further, as shown in the lower side of FIG. 6, the light deflection element 136 has two-dimensionally arranged micro mirrors 151, as in the case of the light deflection element 36 of FIG. By performing control according to the illumination state input to the unit 141, the direction of each micromirror 151 is controlled in two directions.

That is, in the case of performing bright field illumination, the light deflection element 136 emits from the light source 131 and enters the illumination optical system as shown in FIG. The portion of light that contributes to the light is deflected toward the condenser lens 137 by the on-state micromirror 151. For example, in the case of bright field illumination, the light deflection element 136 needs to illuminate the sample S with a light beam near the center of the parallel light beams that have reached the light deflection element 136. of the mirrors 151, like the bright field illumination area a _b of Figure 5b as described above, the illumination circular area centered on the optical axis of the optical system (hereinafter, bright field illumination area a _{b 'hereinafter)} micromirrors 151 in Is turned on, and the micromirrors 151 arranged in other regions are turned off.

  The illumination light deflected by the light deflection element 136 passes through the condenser lens 137 to illuminate the sample S, passes through the objective lens 114, and then is an imaging lens (not shown) disposed in the eyepiece tube 115. ) And is guided to the eyepiece lens 116. On the other hand, the light deflected to the light attenuating member 138 side by the micro mirror 151 in the off state becomes unnecessary light that does not contribute to the image, and therefore has the same properties as the light attenuating member 38 in FIG. Dimmed by member 138.

Further, as shown in FIG. 7, when performing dark field illumination, illumination light needs to be incident only from the periphery of the condenser lens 137, and light directly incident on the objective lens 114 must be blocked. The light deflection element 136 causes the condenser lens 137 to emit light from the peripheral part of the condenser lens 137, that is, the part that contributes to dark field illumination, of the parallel light flux that has reached the light deflection element 136, by the on-state micromirror 151. Deflect to the side. For example, in the light deflection element 136, a substantially donut-shaped region (hereinafter referred to as a dark region) formed concentrically around the bright field illumination region A _b ′ of the transmitted illumination in FIG. The micromirrors 151 in the field illumination area A _d ′) are turned on, and the micromirrors 151 arranged in other areas are turned off.

The bright-field illumination area A _b ′ of the transmitted illumination in FIG. 6 is a circular area formed around the optical axis of the illumination optical system, and the dark-field illumination area A _d ′ of the transmitted illumination in FIG. These are substantially donut-shaped regions formed concentrically around the circular region, and the boundary between these regions is arbitrary. Further, the dark field illumination area A _d ′ is different from the dark field illumination area Ad in FIG. 5 c, although areas corresponding to holding members such as the inner cylinder 14 </ _b > B and the fixing members 14 </ _b > C ₁ to 14 </ _b > C ₃ are not excluded. in the microscopic 101 of transmissive illumination type, provided holding member for holding the optical member, when the illumination light hits on its holding member, as with dark field illumination area a _d of FIG. 5c, the holding member The micro mirror 151 in the region corresponding to the above may be turned off.

  The illumination light formed in a substantially donut shape is deflected to the condenser lens 137 and illuminates the sample S from the periphery of the condenser lens 137. Although the illumination at this time is light with an angle smaller than the NA of the objective lens 114, the illumination light is directly incident on the objective lens 114 when such illumination is performed. Instead, only the light scattered by the sample S is incident. On the other hand, the light deflected to the light attenuating member 138 side by the off-state micromirror 151 is attenuated by the light attenuating member 138.

  6 and 7, the illumination light is deflected toward the condenser lens 137 when the micromirror 151 is turned on. However, as shown in FIG. The illumination light may be deflected toward the condenser lens 137 when the micromirror 151 is turned off. 8a shows the configuration of the bright field illumination, and FIG. 8b shows the configuration of the dark field illumination, which are the same as those of the microscope 101 in FIGS. 6 and 7 except that the deflection direction of the light not incident on the condenser lens 137 side is different. An optical dimming member 138 (not shown) similar to that shown in FIGS. 6 and 7 is arranged at the tip of the light deflected by the micro mirror 151 in the ON state. By adopting such a configuration, the size of the field lens 135 and the optical deflection element 136 can be reduced.

Further, as shown in FIGS. 9 and 10, a total reflection mirror 139 for guiding the illumination light to the condenser lens 137 is further arranged in the illumination optical system, and the total reflection mirror 139 is separated from the field lens 135. The arrangement of the light deflection element 136 may be changed so that the parallel light flux can be guided. That is, when performing bright field illumination, the parallel light flux from the field lens 135 is within the bright field illumination region A _b ′ of the micromirrors 151 arranged two-dimensionally in the light deflection element 136 as shown in FIG. In the case of performing the dark field illumination by being deflected toward the total reflection mirror 139 by the on-state micro mirror 151, as shown in FIG. 10, the on-state micro mirror 151 in the dark field illumination area A _d ′ It is deflected to the 139 side. The illumination light deflected to the condenser lens 137 by the total reflection mirror 139 passes through the condenser lens 137 and illuminates the sample S. 9 and 10, an optical dimming member 138 is disposed at the tip of the light deflected in a direction different from the total reflection mirror 139 by the micro mirror 151 in the off state. The light is attenuated by the light attenuating member 138.

  In this way, by adopting the configuration of FIGS. 9 and 10, the light is not deflected directly to the condenser lens 137 by the light deflecting element 136 but is once deflected to the total reflection mirror 139 and then to the condenser lens 137. Thus, the deflection angle becomes smaller, and consequently the size of the optical deflection element 136, the field lens 135, and other optical members can be reduced. In addition, since the light deflection element 136 and the light dimming member 138 can be disposed in the dead space in the microscope 101, the apparatus itself can be configured in a compact manner.

  As described above, according to the present invention, when switching from the bright field illumination to the dark field illumination, the deflection control of the micromirrors 51 and 151 arranged in two dimensions of the light deflection elements 36 and 136 is used to control other than the dark field illumination optical path. Since it is possible to prevent the region from being irradiated with illumination light, a sufficient dark field illumination state can be obtained. Further, according to the present invention, the bright field illumination and the dark field illumination can be switched by the deflection control of the micro mirrors 51 and 151 arranged two-dimensionally by the light deflection elements 36 and 136. The observation method can be switched.

  In addition, according to the present invention, compared to the conventional switching mechanism between bright field illumination and dark field illumination, driving parts such as a required diaphragm and guide are not necessary, and the number of parts can be reduced. As durability increases, manufacturing costs can be kept low.

  Furthermore, in the present invention, since only the light deflection elements 36 and 136 such as DMD perform drive control, the switching speed between bright field illumination and dark field illumination can be increased, and dust generation is reduced. Can be suppressed. This leads to prevention of contamination due to dust generation, which is a great advantage particularly for a microscope for semiconductor inspection.

  The operating range of individual micromirrors of DMD, which is an example of the light deflection elements 36, 136, is a narrow range of about 10 degrees to 20 degrees. In order to arrange this DMD in the illumination optical system, it is necessary to provide one or more reflecting surfaces in the illumination optical system including the reflection on the DMD to deflect the illumination optical axis. However, since the operating range of the micromirror is narrow as described above, the deflection angle of the illumination optical axis cannot be configured with an efficient angle, for example, 90 degrees. In the case of substantially V-shape and twice reflection, the illumination optical axis is substantially Z-shape, and a large space is required in the microscope. However, according to the present invention, the DMD can be arranged closer to the spectrographer side than the imaging optical axis, which is a dead space in the microscope, and the optical system can be arranged in a very small space. Can be made compact.

  In the present embodiment, the illumination optical system in which the light sources 31 and 131 and the sample S are in a conjugate relationship is illustrated. However, the illumination optical system is not limited to such an illumination optical system. For example, it may be used for an illumination optical system in which S is not in a conjugate relationship, for example, Koehler illumination. In that case, the illumination direction to the sample S can be switched by providing the light deflection elements 36 and 136 at positions where the images of the light sources 31 and 131 in the illumination optical system are formed.

  Furthermore, in this embodiment, instead of the light deflection elements 36 and 136 that totally reflect light, for example, a two-dimensional light such as a liquid crystal element that reflects light in a certain state and transmits light in a certain state. It is also possible to use an element that can change the distribution of reflecting the light in a desired direction. However, since the type that totally reflects light can reduce the attenuation of light, it is preferable to use a total reflection type such as the light deflection elements 36 and 136 of the present embodiment.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

1,101 microscope, 11, 111 main body, 12, 112 stage, 13, 113 revolver, 14, 114 objective lens, 14A lens barrel, 14B inner tube, 14C ₁ to 14C ₃ fixing member, 15, 115 eyepiece tube, 16, 116 eyepiece, 17, 117 lamp house, 31, 131 light source, 32, 132 collimator lens, 33, 133 relay lens, 34, 134 field stop, 35, 135 field lens, 36, 136 light deflection element, 37 half Miller, 38, 138 light dimming member, 39 an imaging lens, 40, 140 controller, 41, 141 instructing unit, 51, 151 micromirrors 137 a condenser lens, 139 a total reflection mirror, _{A b} brightfield illumination area, A _d dark field illumination area, OP _b bright field illumination optical path, OP _d dark field illumination Optical path, S sample

Claims (5)

An illumination optical system that illuminates the sample with different light paths for bright-field illumination and dark-field illumination, with light from each position of a light source for illuminating the sample as parallel light fluxes, and
It consists of a plurality of micromirrors that can selectively control deflection, and is arranged in the optical path of the illumination optical system in which light from each position of the light source becomes a parallel light beam, and a part of the parallel light beam is directed in a predetermined direction An optical deflection element for deflecting;
Control means for performing deflection control of the plurality of micromirrors and switching between bright-field illumination and dark-field illumination by light that has become a parallel light beam,
When the control means switches from bright field illumination to dark field illumination, the control means deflects part of the parallel light flux to the dark field illumination optical path, and prevents the other parallel light flux from entering the bright field illumination optical path. A microscope characterized by controlling deflection of a micromirror. A condensing optical element for condensing the parallel light beam deflected in the predetermined direction by the light deflection element on the sample when held by a holding member provided in the lens barrel and performing bright field illumination. In addition,
When the control means switches from bright field illumination to dark field illumination, the control means deflects a part of the parallel luminous flux in the dark field illumination optical path between the lens barrel and the holding member, and other parallel luminous fluxes The microscope according to claim 1, wherein deflection control of the plurality of micromirrors is performed so as not to hit the holding member. The microscope according to claim 2, wherein the light deflection element is disposed in a region opposite to the light source with respect to an optical axis of the condensing optical element. The microscope according to any one of claims 1 to 3, further comprising a light dimming member for dimming light unnecessary for illumination deflected by the plurality of micromirrors. 5. The condensing optical element also serves as an objective lens constituting an imaging optical system provided in a microscope, and introduces light from the light source to illuminate the sample incidentally. The microscope according to any one of the above.

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