JP2007121749A - Microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microscope capable of changing the size of annular zonal illumination, without significantly changing the light quantity of illuminating light. <P>SOLUTION: The microscope where a sample 11 is vertically illuminated via an objective lens 9, includes a toric lens 13 for condensing the light emitted from a light source 2 and forming an annular-zonal light source image; a concave axicon lens 14a having a conical concave face; a dark field observation unit 4, including a convex axicon lens 14b having a conical convex face; a reflecting means 8 for guiding the illuminating light emitted from the light source 2 to the objective lens 9 and also transmitting the observation light from the sample 11. By changing an optical-axis distance between the concave axicon lens 14a and the convex axicon lens 14b, the annular zone diameter of the light source image is changed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microscope.

Conventionally, as illumination methods for optical microscopes, annular illumination in which a central portion is shielded and illumination is performed in an annular shape is known, and is used for phase difference observation and dark field illumination. The size of the zonal illumination must be changed according to the pupil diameter when the objective lens is replaced, and a plurality of zonal apertures with different sizes can be replaced, or the diaphragm blades can be moved to change the zonal illumination. The size is changed (for example, refer to Patent Document 1).
Japanese Patent Application No. 11-39227

  However, when changing the size of the annular illumination by exchanging the aperture or moving the aperture blade, the size of the shading part is simply changed, and the amount of light is reduced by the amount of light shielding. Therefore, there is a problem that the illuminance for illuminating the sample is greatly reduced.

  The present invention has been made in view of the above problems, and an object thereof is to provide a microscope capable of changing the size of annular illumination without significantly changing the amount of illumination light.

In order to solve the above problems, the present invention
In a microscope that performs epi-illumination of a specimen through an objective lens,
A toric lens for condensing light from a light source to form a ring-shaped light source image, a concave axicon lens having a conical concave surface, and a convex axicon lens having a conical convex surface A dark field observation unit;
Reflecting means for guiding illumination light from the light source to the objective lens and passing observation light from the specimen;
There is provided a microscope characterized in that a ring zone diameter of the light source image is changed by changing a distance on an optical axis between the concave axicon lens and the convex axicon lens.

The microscope of the present invention is
The reflecting means is preferably a hollow mirror having an opening for allowing observation light from the specimen to pass therethrough.

The microscope of the present invention is
Further comprising a bright field observation unit provided with a condenser lens, the dark field observation unit and the bright field observation unit can be selectively inserted into and removed from the optical path,
The reflecting means is preferably a half mirror.

The microscope of the present invention is
It is desirable to further include a fluorescence observation reflecting means having a dichroic mirror, and the reflection means and the fluorescence observation reflecting means can be selectively inserted into and removed from the optical path.

The microscope of the present invention is
A revolver for holding a plurality of objective lenses and selectively inserting and removing one of the plurality of objective lenses into the optical path;
A discriminating means for discriminating the pupil diameter of the objective lens inserted in the optical path;
It is desirable to have driving means for changing the distance between the axicon lenses according to the pupil diameter of the objective lens determined by the determining means.

  ADVANTAGE OF THE INVENTION According to this invention, the microscope which can change the magnitude | size of annular illumination, without changing the light quantity of illumination light significantly can be provided.

Hereinafter, microscopes according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a diagram showing a configuration of a microscope according to the first embodiment of the present invention.
As shown in FIG. 1, the microscope 1 includes a light source 2, a collector lens 3, a dark field observation unit 4, a lens 5, a field stop 6, a lens 7, a hollow mirror 8, and a hollow mirror 8 in order from the light source 2 side. The objective lens 9 is disposed on the reflection optical path, and the imaging lens 10 is disposed on the transmission optical path of the hollow mirror 8 when viewed from the objective lens 9. In FIG. 1, a specimen 11 is disposed below the objective lens 9, and an imaging surface 12 of the imaging element is disposed above the imaging lens 10.

  The dark field observation unit 4 includes a toric lens 13 and an axicon lens unit 14 in order from the light source 2 side. The toric lens 13 is a donut-shaped condensing lens for forming an annular light source image by forming an image of illumination light from the light source 2. A circular light shielding portion 13a for shielding the central portion of the illumination light beam is provided on the inner portion of the toric lens 13.

The axicon lens unit 14 includes a plano-convex axicon lens 14a having a conical convex surface, and a conical concave surface having the same apex angle as the convex surface of the axicon lens 14a, that is, overlapping the convex surface. It consists of a plano-concave axicon lens 14b. Further, the refractive indexes of the materials constituting these lenses 14a and 14b are the same, and as shown in FIG. 1, the axicon lens 14a is disposed on the light source side so that the conical lens surfaces face each other. Has been.
Further, as shown in FIG. 1, the axicon lens unit 14 has a drive unit 14c for moving the axicon lens 14b in the optical axis direction, whereby light from the axicon lens 14a and the axicon lens 14b is obtained. The spacing on the axis can be adjusted.

  The hollow mirror 8 is disposed with an inclination of 45 degrees with respect to the optical axis from the light source 2, and has an elliptical opening when viewed from the front so as to be circular when viewed from the light source 2 side and the objective lens 9 side. The total reflection mirror 8a is formed. By providing the opening 8a, the observation light from the specimen 11 can be passed.

  In the microscope 1 having such a configuration, the illumination light emitted from the light source 2 is converted into parallel light by the collector lens 3 and enters the toric lens 13 in the dark field observation unit 4. The illumination light incident on the toric lens 13 is condensed by the toric lens 13 so as to form an annular light source image after passing through the axicon lens unit 14. Here, the central light flux of the illumination light incident on the light shielding portion 13a of the toric lens 13 is shielded by the light shielding portion 13a as described above.

  The illumination light condensed by the toric lens 13 passes through the lens 5, the field stop 6, and the lens 7, is reflected by the hollow mirror 8 toward the objective lens 9, and is again reflected on the pupil plane 9 a of the objective lens 9. An annular light source image is formed. Then, the illumination light incident on the objective lens 9 illuminates the sample 11 from an oblique direction as a conical and hollow illumination light through the peripheral portion of the lens 9. Thereby, reflective dark field illumination is achieved.

  Further, a part of the illumination light incident on the specimen 11 is diffracted and scattered by the fine structure of the specimen 11 and becomes observation light necessary for observing the specimen 11. This observation light passes through the central portion of the objective lens 9, further passes through the opening 8 a of the hollow mirror 8, and is imaged on the imaging surface 12 of the imaging element by the imaging lens 10. As a result, a dark field image of the specimen 11 can be obtained, and the dark field observation of the specimen 11 can be performed by the microscope 1.

  Note that most of the illumination light incident on the specimen 11 is reflected by the specimen 11, passes again through the peripheral edge of the objective lens 9 as light unnecessary for observation, and reaches the peripheral area in the pupil plane 9a. Since this light is an annular light beam similar to the illumination light incident on the sample 11, it is reflected to the light source 2 side as unnecessary light by the hollow mirror 9.

  Further, as described above, the microscope 1 according to the present embodiment can adjust the distance on the optical axis between the axicon lens 14a and the axicon lens 14b by the driving unit 14c. When the axicon lens 14b is moved toward the hollow mirror 8 to increase the distance on the optical axis, the ring-shaped illumination light from the toric lens 13 has a ring-shaped diameter as shown in FIG. As a result, the diameter of the annular light source image formed on the pupil plane 9a of the objective lens 9 is reduced.

  On the other hand, when the axicon lens 14b is moved to the light source 2 side and the interval on the optical axis is reduced, the ring-shaped illumination light has a large ring-zone diameter, and the light source image formed on the pupil plane 9a The diameter also increases. When the axicon lens 14b is superimposed on the axicon lens 14a as shown in FIG. 2A and the interval on the optical axis is made zero, the annular illumination light from the toric lens 13 is The axicon lenses 14a and 14b are transmitted as they are without changing the band diameter, and a light source image having the maximum diameter is formed on the pupil plane 9a.

With the above-described configuration, the optical axis between the axicon lenses is driven by the drive unit 14c even when the observation magnification changes, for example, by replacing the objective lens 9 with another objective lens having a different magnification, or when the sample 11 is changed. By adjusting the upper distance, the diameter of the annular light source image formed on the pupil plane 9a can be appropriately adjusted.
As described above, it is possible to realize a microscope configured to perform reflection type dark field illumination using a normal objective lens and capable of performing appropriate dark field illumination according to the observation magnification and the specimen.
In addition, it is possible to irradiate the sample with light from the light source more efficiently than using a light-shielding stop.

In addition, since the microscope 1 according to the present embodiment uses the hollow mirror 8, unnecessary light can travel to the image plane 12 by reflecting unnecessary illumination light to the light source 2 side and eliminating it. Since only the observation light can be guided to the imaging plane 12, an observation image with higher contrast can be obtained.
Moreover, since the self-fluorescence from the lens etc. which comprise an objective lens can be prevented by using the hollow mirror 8, observation of a high S / N ratio can be performed.

(Second Embodiment)
The microscope according to the second embodiment of the present invention is a microscope for switching between dark field observation, bright field observation, and fluorescence observation, and FIGS. 3 and 4 are related to the second embodiment of the present invention. It is a figure which shows the structure of a microscope, and has each shown the structure at the time of dark field observation (FIG. 3) and fluorescence observation (FIG. 4). Note that in the microscope according to the present embodiment, the same reference numerals are given to portions having the same configuration as the microscope according to the first embodiment, and description thereof will be omitted, and characteristic portions will be described in detail.

  As shown in FIG. 3, the microscope 20 according to the present embodiment includes a bright field observation unit 22 for performing bright field observation including a condenser lens 21 in addition to the dark field observation unit 4. These units can be switched and inserted into and removed from the optical path. More specifically, these units can be detachably provided by, for example, a known slide mechanism, and a unit corresponding to an observation method can be selected and inserted into the optical path.

Moreover, the microscope 20 according to the present embodiment includes a half mirror unit 23 and a fluorescence observation unit 24 for fluorescence observation that can be selectively inserted into and removed from the optical path instead of the hollow mirror 8 in the first embodiment. ing.
The half mirror unit 23 is composed only of a half mirror 23 a disposed at an angle of 45 degrees with respect to the optical axis from the light source 2.

Further, the fluorescence observation unit 24 includes a dichroic mirror 24a disposed at an inclination of 45 degrees with respect to the optical axis from the light source 2, a coupling between the excitation filter 24b disposed on the light source 2 side of the dichroic mirror 24a, and the dichroic mirror 24a. And an absorption filter 24c disposed on the image lens 10 side.
As the light source 2 of the microscope 20, it is desirable to use a semiconductor light emitting element such as an LED, a mercury lamp, a halogen lamp, or the like.

(During dark field observation)
When the dark field observation unit 4 and the hollow mirror 8 are arranged in the optical path under the above configuration (FIG. 3), the illumination light from the light source 2 is converted into annular illumination light as in the first embodiment. Then, the light enters the half mirror 23a. The illumination light reflected by the half mirror 23a illuminates the specimen 11 through the objective lens 9 as in the first embodiment. Thereby, reflective dark field illumination is achieved.
The observation light from the specimen 11 enters the half mirror 23a through the objective lens 9, and the observation light transmitted through the half mirror 23a is imaged on the imaging surface of the image sensor by the imaging lens 10 as in the first embodiment. 12 is imaged. As a result, a dark field image of the specimen 11 can be obtained, and the dark field observation of the specimen 11 can be performed by the microscope 20.

(During bright field observation)
On the other hand, when the bright field observation unit 22 and the half mirror unit 23 are arranged in the optical path, the illumination light emitted from the light source 2 is converted into parallel light by the collector lens 3, and further, a condenser lens. The light is condensed by 21 to form a normal spot-like light source image. The illumination light condensed by the condenser lens 21 enters the half mirror 23a via the lens 5, the field stop 6, and the lens 7. Then, the illumination light reflected by the half mirror 23 a forms a light source image again on the pupil plane 9 a of the objective lens 9 and illuminates the specimen 11 through the objective lens 9. Thereby, reflection type bright field illumination is achieved.

  The illumination light reflected by the specimen 11 passes through the objective lens 9 as observation light necessary for observing the specimen 11 and enters the half mirror 23a. The observation light transmitted through the half mirror 23 a is imaged on the imaging surface 12 of the imaging element by the imaging lens 10. Thereby, a bright field image of the sample 11 can be obtained, and the bright field observation (normal epi-illumination observation) of the sample 11 can be performed by the microscope 20.

(At fluorescence observation)
On the other hand, when the dark field observation unit 4 and the fluorescence observation unit 24 are arranged in the optical path (FIG. 4), the illumination light from the light source 2 is annular illumination light as in the first embodiment. The excitation light is further extracted by the excitation filter 24b. This excitation light is reflected by the dichroic mirror 24 a and is applied to the specimen 11 through the objective lens 9. Thereby, fluorescent illumination is achieved.
Then, the fluorescence generated from the excited specimen 11 passes through the objective lens 9 as observation light, passes through the dichroic mirror 24a, and enters the absorption filter 24c. This observation light is imaged on the imaging surface 12 of the imaging element by the imaging lens 10 as in the first embodiment, after unnecessary light other than fluorescence is cut by the absorption filter 24c. Thereby, a sample image by fluorescence can be obtained, and the fluorescence observation of the sample 11 can be performed by the microscope 20.

  As described above, the microscope 20 can perform appropriate dark field illumination in accordance with the observation magnification and the specimen as in the first embodiment. Furthermore, in addition to dark field observation of the specimen 11, bright field observation and fluorescence observation can be switched.

As described above, according to each embodiment of the present invention, it is possible to realize a microscope that can change the size of annular illumination without significantly changing the amount of illumination light.
Although the first embodiment shows a microscope that performs only dark field observation, the present invention is not limited to this. For example, the fluorescence observation described in the second embodiment can be switched to the hollow mirror 8. With the configuration including the unit 24, a configuration capable of performing fluorescence observation can also be provided.

  In addition to the configuration of each of the above embodiments, the revolver that holds a plurality of objective lenses and the type of objective lens in the optical path (specifically, the pupil diameter of the objective lens) are discriminated to control the drive unit of the axicon lens unit. It can also be set as the structure further provided with the control part to perform. Thereby, it is possible to realize a microscope that automatically adjusts the ring diameter of the illumination light when switching the objective lens.

  In each of the above embodiments, a toric lens 13 forms a ring-shaped light source image on the pupil plane 9a of the objective lens 9, thereby forming a dark field microscope using a normal objective lens, and a ring of illumination light. The axicon lens unit 14 for adjusting the band diameter is provided. However, the present invention is not limited to this, and a conventional dark field microscope, that is, a microscope provided with an objective lens for dark field observation is used. Can of course be applied.

It is a figure which shows the structure of the microscope which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the axicon lens unit * in 1st Embodiment of this invention. It is a figure which shows the structure at the time of the dark field observation of the microscope which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure at the time of the fluorescence observation of the microscope which concerns on 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,20 Microscope 2 Light source 4 Dark field observation unit 9 Objective lens 10 Imaging lens 11 Sample 12 Image pick-up surface 13 of an image pick-up element 13 Toric lens 14 Axicon lens unit 22 Bright field observation unit 23 Half mirror unit 24 Fluorescence observation unit

Claims (5)

In a microscope that performs epi-illumination of a specimen through an objective lens,
A toric lens for condensing light from a light source to form a ring-shaped light source image, a concave axicon lens having a conical concave surface, and a convex axicon lens having a conical convex surface A dark field observation unit;
Reflecting means for guiding illumination light from the light source to the objective lens and passing observation light from the specimen;
A microscope, wherein a ring zone diameter of the light source image is changed by changing a distance on an optical axis between the concave axicon lens and the convex axicon lens.   The microscope according to claim 1, wherein the reflection unit includes a hollow mirror having an opening for allowing observation light from the specimen to pass therethrough. Further comprising a bright field observation unit provided with a condenser lens, the dark field observation unit and the bright field observation unit can be selectively inserted into and removed from the optical path,
The microscope according to claim 1, wherein the reflecting means is a half mirror.   4. The fluorescent observation reflecting means further comprising a dichroic mirror, wherein the reflecting means and the fluorescent observation reflecting means can be selectively inserted into and removed from the optical path. The microscope according to any one of the above. A revolver for holding a plurality of objective lenses and selectively inserting and removing one of the plurality of objective lenses into the optical path;
A discriminating means for discriminating the pupil diameter of the objective lens inserted in the optical path;
5. The driving device according to claim 1, further comprising a driving unit configured to change the distance between the axicon lenses in accordance with the pupil diameter of the objective lens determined by the determining unit. The microscope according to item.

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