JP2010175623A - Variable filter device and confocal microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable filter device for efficiently shielding a specified wavelength of light. <P>SOLUTION: Divergent light passing through an incident pinhole plate 2 is converted into collimated light flux by a collimating lens 3, and made incident on an acousto-optical variable filter 4. The acousto-optical variable filter 4 is applied with a prescribed frequency of voltage to serve as a diffraction grating, diffraction light is emitted diagonally to an optical axis as shown by a dotted line, and only zeroth-order light travels straight. The light flux emitted from the acousto-optical variable filter 4 is condensed by a condensing lens 5, in this case, the straight zeroth-order light passes through a pinhole of an emission pinhole plate 6, and is emitted toward the outside of the variable filter device 1. The diffraction light collides with a plate part of the emission pinhole plate 6 to be shielded, and is not emitted toward the outside of the variable filter device 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a variable filter device and a confocal microscope.

  In recent years, fluorescence observation of living organisms using a microscope requires illumination at various wavelengths, and it is common to use a microscope using light of a plurality of wavelengths as a light source. In particular, in a fluorescence confocal microscope, a sample is irradiated using a plurality of lasers having different wavelengths as an excitation light source, and a fluorescence signal generated therefrom is received.

Actually, not only fluorescence but also reflected light of excitation light returns from the specimen. In order to receive fluorescence that is weaker than the excitation light, the excitation light must be removed. As an example of the method, Japanese Patent Laid-Open No. 2006-153763 (Patent Document 1) discloses that light having passed through a pinhole of a fluorescent confocal microscope in a light receiving unit is dispersed by a spectroscope and light having a wavelength of excitation light passes. There has been considered a method of shielding excitation light by placing a mechanical shielding plate in a region to be excited. This method, unlike the method of shielding excitation light with an interference filter or the like, has no loss of light amount in the transmitted wavelength range. Furthermore, the wavelength range for receiving light and the wavelength range for shielding light can be made variable by rotating the diffraction grating.
JP 2006-153763 A

  However, in such a method, the excitation light leaks into the light receiving area that is not shielded by the shielding plate due to the scattering of the optical members around the light receiving element such as the diffraction grating, and enters the light receiving area where the excitation light should not enter. , It may be detected as a flare and the signal quality may deteriorate.

  The present invention has been made in view of such circumstances, and is suitable for use in a confocal microscope capable of efficiently shielding excitation light and receiving only fluorescence, and efficiently using light of a specific wavelength. It is an object of the present invention to provide a variable filter device that can shield light well.

  The first means for solving the above problems includes an incident pinhole provided on the incident surface of the light beam, a collimating lens that makes the light that has passed through the incident pinhole parallel light, and receives and emits the parallel light. An acousto-optic variable filter, a light-shielding / heat-dissipating member composed of an oriented graphite sheet that shields diffracted light deflected by the acousto-optic variable filter, and a heat bonded to the light-shielding / heat dissipating member and a heat conductive resin A pipe, a heat dissipating fin joined to the heat pipe by a heat conductive resin, a cover member having an opening exposing the heat dissipating fin, a condensing lens for condensing light emitted from the acousto-optic variable filter, A variable filter device having an output pinhole provided at a condensing point of the condensing lens.

  The second means for solving the problem is the first means, wherein the diameter of the incident pinhole is D1, the diameter of the output pinhole is D2, and the diffracted light from the acousto-optic variable filter When the wavelength of the zero-order light is λ1, λ0, the separation angle is θ, the focal length of the collimating lens is f1, the focal length of the condenser lens is f2, and the diameter of the parallel light is D3,

It is characterized by being.

  A third means for solving the above problem is a variable filter device in which the variable filter devices which are the first means or the second means are connected in series.

  A fourth means for solving the above-mentioned problems is a light-shielding / light-shielding structure constituted by an acousto-optic variable filter that receives and emits parallel light and an oriented graphite sheet that shields diffracted light deflected by the acousto-optic variable filter. A heat radiation member, a heat pipe joined to the light shielding / heat radiation member with a heat conductive resin, a heat radiation fin joined to the heat pipe with a heat conductive resin, and a cover member having an opening for exposing the heat radiation fin; A variable filter device comprising: a condensing lens for condensing light emitted from the acousto-optic variable filter; and an output pinhole provided at a condensing point of the condensing lens.

  The fifth means for solving the above-mentioned problem is that the light from the light source is converted into scanning light through the scanner, the sample placed at a position conjugate with the light source is scanned, and the reflected light generated from the sample And a confocal microscope which converts the fluorescence into non-scanning light by passing through the scanner in the reverse direction and receives light by a light receiving device through a pinhole placed at a position conjugate to the sample, from the first means. 3. A confocal microscope comprising the variable filter device according to any one of the means 3, wherein the pinhole is an incident pinhole of the variable filter device, and the reflected light is shielded by the variable filter device. It is.

  The sixth means for solving the above-mentioned problem is that reflected light generated from the sample is obtained by converting light from the light source into scanning light through a scanner, scanning a sample placed at a position conjugate with the light source, and And a confocal microscope which converts the fluorescence into non-scanning light by passing through the scanner in the reverse direction and receives light by a light receiving device through a pinhole placed at a position conjugate to the sample, from the first means. 3. The variable filter device according to any one of 3), wherein the pinhole and the incident pinhole of the variable filter device are coupled by an optical fiber, and the reflected light is shielded by the variable filter device. It is a confocal microscope characterized by this.

  A seventh means for solving the above-mentioned problem is the sixth means, characterized in that the pinhole is substituted by an end face of the optical fiber.

  The eighth means for solving the above-mentioned problem is that the light from the light source is converted into scanning light through the scanner, the sample placed at a position conjugate with the light source is scanned, and the reflected light generated from the sample And the fluorescence is converted into non-scanning light of a parallel light flux by passing through the scanner in the reverse direction, is incident on the variable filter device of the fourth means, the reflected light is shielded by the variable filter device, and the fluorescence is In this confocal microscope, light is received by a light receiving device through an output pinhole of the variable filter device placed at a position conjugate with the sample.

  A ninth means for solving the above problem is any one of the fifth to eighth means, wherein the light receiving device is a spectral detector.

  According to the present invention, a confocal microscope that can efficiently block excitation light and receive only fluorescence, and a variable filter device that is suitable for use in the microscope and can efficiently block light of a specific wavelength. Can be provided.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same components as those shown in the previous drawings may be denoted by the same reference numerals and description thereof may be omitted.

  FIG. 1 is a diagram showing an outline of an optical system of a variable filter device according to a first embodiment of the present invention. The variable filter device 1 includes an incident pinhole plate 2, a collimating lens 3, an acoustooptic variable filter 4 (AOTF), a condenser lens 5, and an output pinhole plate 6.

  The acousto-optic variable filter 4 is a well-known filter that has an action equivalent to that of a diffraction grating due to the generation of an acoustic wave by an electroacoustic effect when an AC voltage is applied. By changing the frequency of the applied AC voltage, the same effect as changing the grating pitch of the diffraction grating is obtained. Further, by applying alternating voltages of different frequencies at the same time, an operation equivalent to that of a diffraction grating having a plurality of grating pitches can be achieved.

  The divergent light that has passed through the incident pinhole plate 2 is converted into a parallel light beam by the collimating lens 3 and is incident on the acousto-optic variable filter 4. A voltage of a predetermined frequency is applied to the acousto-optic variable filter 4 to act as a diffraction grating so that the diffracted light is emitted obliquely with respect to the optical axis as indicated by a broken line, and only the 0th-order light travels straight. Like that. The light beam emitted from the acousto-optic variable filter 4 is collected by the condenser lens 5. At this time, the 0th-order light that travels straight passes through the pinhole of the emission pinhole plate 6 and is external to the variable filter device 1. To be released. The diffracted light is shielded by the plate portion of the output pinhole plate 6 and hardly emitted to the outside of the variable filter device 1.

  In the cover member (housing member) of the variable filter device 1, an output pinhole plate 6 made of an oriented graphite sheet that shields and absorbs the excitation light is provided in a region where the excitation light strikes.

  The cover member has an opening that exposes the output pinhole plate 6.

  The heat generated in the output pinhole plate 6 due to the shielding and heat absorption of the excitation light is released to the outside from the portion exposed from the opening of the cover member.

  The oriented graphite sheet has a thermal conductivity of 400 to 1700 W / (m · K), and can utilize characteristics exceeding the thermal conductivity (390 W / (m · K)) of copper having excellent thermal conductivity.

  In addition, the oriented graphite sheet has a low reflectance and can utilize light absorption.

  Furthermore, the specific gravity of the oriented graphite sheet is 1/9 that of copper, and weight reduction can be realized.

  Since the wavelength of the diffracted light can be changed by changing the frequency of the voltage applied to the acousto-optic variable filter 4, the voltage applied so that the light of that wavelength is diffracted when it is desired to cut light of the predetermined wavelength. Select the frequency. At this time, by applying voltages having a plurality of frequencies to the acousto-optic variable filter 4, it is possible to block light having a plurality of wavelengths as diffracted light.

  The incident pinhole plate 2 can be changed to an end face of an optical fiber that propagates incident light, and the output pinhole plate 6 can be changed to an end face of an optical fiber that propagates outgoing light. The terms “incident pinhole” and “exit pinhole” in the claims are not limited to a pinhole plate, but also include such an optical fiber end face.

  Here, the size of the opening of the incident pinhole plate 2 is the diameter D1, the size of the opening of the output pinhole plate 6 is the diameter D2, and the wavelengths of the diffracted light and the 0th-order light at the acoustooptic variable filter 4 are λ1, respectively. λ0, the separation angle θ, the focal length of the collimating lens 3 is f1, the focal length of the condenser lens 5 is f2, and the diameter of the parallel light incident on the acoustooptic variable filter 4 is D3. Considering the magnification from the incident pinhole plate 2 to the outgoing pinhole plate 6 and the Airy disk size at the outgoing pinhole plate 6, the spot diameters of the diffracted light and the 0th-order light are respectively

The image height of the diffracted light with respect to the 0th order light is
f2 × tanθ
It is. Therefore, in order for zero-order light to pass through the output pinhole,

In addition, in order for the output pinhole plate 6 to shield the diffracted light without passing through the output pinhole,

Need to be. From these,

If so, the diffracted light of the wavelength to be removed and the other zero-order light can be well separated, and the zero-order light can be passed efficiently.

  If only one variable filter device 1 is used and the separation of diffracted light and zero-order light is not complete due to internal stray light or the like, a plurality of variable filter devices 1 are connected in series to obtain diffracted light And 0th-order light can be separated. FIG. 2 is a diagram illustrating an example in which variable filters are connected in series. In FIG. 2A, the output pinhole plate 6 of the front stage variable filter device 1 and the incident pinhole plate 2 of the rear stage variable filter device 1 are shared, and the variable filter device 1 is connected in series. In FIG. 2B, the light emitted from the opening of the output pinhole plate 6 of the front stage variable filter device 1 is received by the optical fiber 7, and the light emitted from the optical fiber 7 is incident on the rear stage variable filter device 1. The light is incident on the pinhole plate 2. In this case, by using the optical fiber 7 itself as an opening, at least one of the output pinhole plate 6 of the upstream variable filter device 1 and the incident pinhole plate 2 of the downstream variable filter device 1 may be eliminated. Since the optical fiber 7 only has a role of transmitting light, a multimode optical fiber can be used, and the light does not need to be coherent light.

  In FIG. 2, two variable filter devices 1 are connected in series, but three or more variable filter devices 1 can be connected in series in the same manner. In that case, one part may be connected as shown in FIG. 2 (a) and the other part may be connected as shown in FIG. 2 (b).

  FIG. 3 is a diagram showing an outline of the optical system of the variable filter according to the second embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 1 only in that the incident pinhole plate 2 and the collimating lens 3 are not provided. In this embodiment, a parallel light beam parallel to the optical axis needs to be incident on the acousto-optic variable filter 4 as incident light. Since the function of other components is the same as that of the embodiment shown in FIG. 1, the description thereof is omitted.

  FIG. 4 is a diagram showing an outline of the configuration of a confocal microscope according to the third embodiment of the present invention. The light emitted from the laser light source 11 is transmitted through the optical fiber 12 and emitted from the end face as a point light source. Then, the collimator lens 13 converts the light into a parallel light beam, reflects it with the beam splitter 14, and changes it into scanning light with the scanner 16. In the present embodiment, the beam splitter switching device 15 is configured so that the beam splitter 14 can be changed according to the wavelength of excitation light (irradiation light) emitted from the laser light source 11 and the fluorescence emitted from the specimen 20. Is provided.

  The light converted into the scanning light by the scanner 16 passes through the relay lens 17, the imaging lens 18, and the objective lens 19, and the image of the point light source is converted into the sample 20 (sample) placed at a position conjugate with the point light source. To form an image. That is, the specimen 20 is point-lit as excitation light. The specimen 20 is placed on the microscope stage 21.

  As a result, reflected light and fluorescence of the excitation light are generated from the specimen 20. These lights pass through the objective lens 19, the imaging lens 18, and the relay lens 17 to become a parallel light flux, and enter the scanner 16 to become a non-scanning parallel light flux. Then, the light enters the beam splitter 14, most of the excitation light is reflected, and only a part of the excitation light and fluorescence is transmitted through the beam splitter 14. The light transmitted through the beam splitter 14 is collected by the imaging lens 22 at the opening of the pinhole plate 23. Since the pinhole plate 23 is placed at a position conjugate with the light condensing point in the sample 20 (a surface conjugate with the point light source), light emitted from above and below the light condensing point in the sample 20. Cannot pass through the opening of the pinhole plate 23. Therefore, it is possible to provide a microscope apparatus having a good function in the depth direction of the specimen 20. That is, the pinhole plate 23 plays a role of generating a resolution in the depth direction of the specimen 20.

  The light that has passed through the opening of the pinhole plate 23 enters the optical fiber 24 and is guided to the variable filter device 1. In this example, since the end face of the optical fiber 24 is substituted for the opening of the incident pinhole plate 2 shown in FIG. 1, the incident pinhole plate 2 is not provided, but of course the incident pinhole plate 2 is provided. The light from the end face of the optical fiber 24 may be incident on the opening of the incident pinhole plate 2.

  In the variable filter device 1, the frequency of the voltage applied to the acousto-optic variable filter 4 is determined so that the excitation light is shielded as diffracted light. Therefore, most of the very little excitation light transmitted through the beam splitter 14 is shielded by the variable filter device 1 and hardly emitted to the outside of the variable filter device 1.

  In the variable filter device 1, a light-shielding / heat-absorbing member made of an oriented graphite sheet that shields and absorbs the excitation light is provided in a region where the excitation light strikes. The light shielding / heat absorbing member is joined to the heat radiating fin by a heat conductive resin. As a heat conductive resin, what disperse | distributed the inorganic filler excellent in heat conductivity in a thermosetting resin can be used. As the inorganic filler, Al 2 O 3, MgO, BN, SiC, Si 3 N 4, AlN and the like excellent in thermal conductivity are preferable. As the thermosetting resin, epoxy resin, phenol resin, cyanate resin and the like can be used.

  Further, the cover member of the variable filter device 1 has an opening that exposes at least a part of the radiating fin.

  The heat generated in the light-shielding / heat-absorbing member due to the light-shielding / heat-absorption of the excitation light is transmitted to the heat radiation fin joined by the heat conductive resin, and is released to the outside from the portion exposed from the opening of the cover member of the heat radiation fin.

  Alternatively, the light-shielding / heat-absorbing member is bonded to the heat pipe with a heat conductive resin, the heat pipe is bonded to the heat radiating fin with a heat conductive resin, and further, a part of the heat radiating fin passes through the opening of the cover member. You may comprise so that it may be exposed outside. In this case, the heat generated in the light-shielding / heat-absorbing member due to the light-shielding / heat-absorption of the excitation light is transferred to the heat pipe and the heat-radiating fin via the heat conductive resin, and is exposed from the opening of the cover member of the heat-radiating fin. To the outside.

  The oriented graphite sheet has a thermal conductivity of 400 to 1700 W / (m · K), and can utilize characteristics exceeding the thermal conductivity (390 W / (m · K)) of copper having excellent thermal conductivity.

  In addition, the oriented graphite sheet has a low reflectance and can utilize light absorption.

  Furthermore, the specific gravity of the oriented graphite sheet is 1/9 that of copper, and weight reduction can be realized.

  On the other hand, the fluorescence becomes zero-order light and is condensed on the end face of the optical fiber 25 by the condenser lens 5. In this example, the end face of the optical fiber 25 is used in place of the opening of the output pinhole plate 6 shown in FIG. 1, and the output pinhole plate 6 is not provided. The light that has passed through the opening of the output pinhole plate 6 may be incident on the end face of the optical fiber 25.

  The light guided by the optical fiber 25 enters the spectroscopic detector 26. Although the spectroscopic detector 26 is as described in Patent Document 1, it has a spectroscope and a one-dimensional linear sensor such as a CCD array, and the light dispersed by the spectroscope is transmitted to each of the one-dimensional linear sensors. The light intensity (spectral intensity) for each wavelength can be measured. In this embodiment, the spectral intensity in the wavelength region corresponding to the fluorescence is measured, and the light intensity in the wavelength corresponding to the excitation light is shielded by the light shielding plate.

  The output of the spectroscopic detector 26 is input to the arithmetic control device 27. The arithmetic and control unit 27 calculates the intensity and driving data of the scanner 16 for each wavelength corresponding to fluorescence, forms a two-dimensional image for each wavelength corresponding to fluorescence, and displays it on a display device (not shown).

  According to the present embodiment, even if the excitation light becomes stray light in the spectroscopic detector 26 and enters the region of the one-dimensional linear sensor for measuring other wavelength regions, before that, the variable filter device Since the intensity of the excitation light is very weak due to the function of 1, the amount of noise (flare) of the excitation light can be made very small as compared with the conventional apparatus.

  In this embodiment, by providing the spectroscopic detector 26, images of fluorescence of a plurality of wavelengths are simultaneously collected. However, when forming an image of fluorescence of a single wavelength range, the spectroscopic detector 26 Instead, an optical sensor may be used.

  When the wavelength of the excitation light is changed by exchanging the laser light source 11, the beam splitter switching device 15 is operated to switch the beam splitter 14 and applied to the acoustooptic variable filter 4 of the variable filter device 1. The frequency of the voltage to be changed is changed so that the excitation light having the changed wavelength becomes diffracted light. Further, a dichroic mirror is generally used as the beam splitter 14, but in the present embodiment, when the variable filter device 1 can efficiently separate excitation light and fluorescence, A half mirror may be used as the beam splitter 14.

  In this embodiment, since the confocal microscope main body from the laser light source 11 to the pinhole plate 23 and the variable filter device 1 can be separated, the degree of freedom of design can be increased by unitizing each. The overall size can be reduced and simplified.

  FIG. 5 is a diagram showing an outline of the configuration of a confocal microscope according to the fourth embodiment of the present invention. In this embodiment, the configuration from the laser light source 11 to the imaging lens 22 is exactly the same as that of the embodiment shown in FIG.

  In this embodiment, the incident pinhole plate 2 of the variable filter device 1 is provided at the condensing point of the imaging lens 22, and the variable filter is provided in the main body of the confocal microscope from the laser light source 11 to the imaging lens 22. The device 1 is directly connected. In this configuration, the incident pinhole plate 2 also serves as the pinhole plate 23 shown in FIG. The configurations and operations of the variable filter device 1, the optical fiber 25, the spectral detector 26, and the arithmetic control device 27 are the same as those shown in FIG.

  FIG. 6 is a diagram showing an outline of the configuration of a confocal microscope according to the fifth embodiment of the present invention. In this embodiment, the configuration from the laser light source 11 to the scanner 16 is exactly the same as the embodiment shown in FIG.

  In this embodiment, the imaging lens 22 is not provided, and the fluorescence converted into a parallel light beam by the relay lens 17 passes through the beam splitter 14, is deflected by the mirror 28, and remains as parallel light. It enters the variable filter device 10 having the configuration shown in FIG. The excitation light slightly mixed in the fluorescence is shielded as diffracted light by the variable filter device 10, and only the fluorescence passes through the opening of the output pinhole plate 6 and enters the end face of the optical fiber 25. The configurations and operations of the optical fiber 25, the spectroscopic detector 26, and the arithmetic control device 27 are the same as those shown in FIG. In this example, the output pinhole plate 6 is provided at a position conjugate with the condensing point in the sample 20 and also serves as the pinhole plate 23 in FIG.

  In the cover member (housing member) of the variable filter device 10, an output pinhole plate 6 made of an oriented graphite sheet that shields and absorbs the excitation light is provided in a region where the excitation light strikes.

  The cover member has an opening that exposes the output pinhole plate 6.

  The heat generated in the output pinhole plate 6 due to the shielding and heat absorption of the excitation light is released to the outside from the portion exposed from the opening of the cover member.

  The oriented graphite sheet has a thermal conductivity of 400 to 1700 W / (m · K), and can utilize characteristics exceeding the thermal conductivity (390 W / (m · K)) of copper having excellent thermal conductivity.

  In addition, the oriented graphite sheet has a low reflectance and can utilize light absorption.

  Furthermore, the specific gravity of the oriented graphite sheet is 1/9 that of copper, and weight reduction can be realized.

It is a figure which shows the outline | summary of the optical system of the variable filter apparatus which is the 1st Embodiment of this invention. It is a figure which shows the example which connected the variable filter apparatus in series. It is a figure which shows the outline | summary of the optical system of the variable filter apparatus which is the 2nd Embodiment of this invention. It is a figure which shows the outline | summary of a structure of the confocal microscope which is the 3rd Embodiment of this invention. It is a figure which shows the outline | summary of a structure of the confocal microscope which is the 4th Embodiment of this invention. It is a figure which shows the outline | summary of a structure of the confocal microscope which is the 5th Embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 ... Variable filter apparatus, 2 ... Incident pinhole board, 3 ... Collimating lens, 4 ... Acousto-optic variable filter, 5 ... Condensing lens, 6 ... Outgoing pinhole board, 7 ... Optical fiber, 10 ... Variable filter apparatus, 11 ... Laser light source, 12 ... optical fiber, 13 ... collimator lens, 14 ... beam splitter, 15 ... beam splitter switching device, 16 ... scanner, 17 ... relay lens, 18 ... imaging lens, 19 ... objective lens, 20 ... sample, 21 DESCRIPTION OF SYMBOLS ... Microscope stage, 22 ... Imaging lens, 23 ... Pinhole plate, 24 ... Optical fiber, 25 ... Optical fiber, 26 ... Spectral detector, 27 ... Calculation control apparatus, 28 ... Mirror

Claims (9)

  An incident pinhole provided on the incident surface of the light beam, a collimator lens that converts the light that has passed through the incident pinhole into parallel light, an acoustooptic variable filter that receives and emits the parallel light, and the acoustooptic variable filter. A light-shielding / heat-dissipating member composed of an oriented graphite sheet that shields the deflected diffracted light, a heat pipe joined with the light-shielding / heat-dissipating member and a heat conductive resin, and a joint between the heat pipe and the heat conductive resin Radiating fins, a cover member having an opening for exposing the radiating fins, a condensing lens for condensing light emitted from the acousto-optic variable filter, and an emission provided at a condensing point of the condensing lens A variable filter device having a pinhole. 2. The variable filter device according to claim 1, wherein the diameter of the incident pinhole is D1, the diameter of the output pinhole is D2, and the wavelengths of diffracted light and zero-order light at the acousto-optic variable filter are λ1, When λ0, the separation angle is θ, the focal length of the collimating lens is f1, the focal length of the condenser lens is f2, and the diameter of the parallel light is D3,
@ 0013

A variable filter device characterized by the above.   The variable filter apparatus which connected the variable filter apparatus of Claim 1 or Claim 2 in series.   An acousto-optic variable filter that receives and emits parallel light, a light-shielding / heat-dissipating member composed of an oriented graphite sheet that shields diffracted light deflected by the acousto-optic variable filter, and the light-shielding / heat-dissipating member and thermal conductivity A heat pipe joined by a resin, a heat radiating fin joined by a heat conductive resin to the heat pipe, a cover member having an opening exposing the heat radiating fin, and condensing light emitted from the acousto-optic variable filter A variable filter device comprising: a condensing lens that performs a focusing operation, and an output pinhole provided at a condensing point of the condensing lens.   The light from the light source is converted into scanning light through the scanner, the sample placed at a position conjugate with the light source is scanned, and the reflected light and fluorescence generated from the sample are passed through the scanner in reverse. 4. A confocal microscope that receives light by a light receiving device through a pinhole placed at a position conjugate with the sample instead of scanning light, wherein the variable filter device according to claim 1. The confocal microscope is characterized in that the pinhole is an incident pinhole of the variable filter device, and the reflected light is shielded by the variable filter device.   The light from the light source is converted into scanning light through the scanner, the sample placed at a position conjugate with the light source is scanned, and the reflected light and fluorescence generated from the sample are passed through the scanner in reverse. 4. A confocal microscope that receives light by a light receiving device through a pinhole placed at a position conjugate with the sample instead of scanning light, wherein the variable filter device according to claim 1. The confocal microscope is characterized in that the pinhole and the incident pinhole of the variable filter device are coupled by an optical fiber, and the reflected light is shielded by the variable filter device.   The confocal microscope according to claim 6, wherein the pinhole is substituted by an end face of the optical fiber.   Light from the light source is converted into scanning light through a scanner, a sample placed at a conjugate position with the light source is scanned, and reflected light and fluorescence generated from the sample are paralleled by passing through the scanner in reverse. The variable filter is changed into non-scanning light of a light beam and incident on the variable filter device according to claim 4, wherein the reflected light is shielded by the variable filter device, and the fluorescence is placed at a position conjugate with the sample. A confocal microscope characterized in that light is received by a light receiving device through an output pinhole of the device. The confocal microscope according to any one of claims 5 to 8, wherein the light receiving device is a spectroscopic detector.