JP2001117009A - Inverted microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverted microscope where an ocular is positioned at height at which an observer can easily observe and a stage is low in height while the inverted microscope is a simple optical system. SOLUTION: This microscope is provided with the stage 150 on which a sample is mounted, an objective lens 104 arranged under the stage 150, and an image-formation lens 106 and relay lenses 113 and 115 arranged in order on an optical axis 114. An optical path deflecting means 108 is arranged between the lens 106 and the lenses 113 and 115, and bends the optical axis 114 obliquely upward. The size of an intermediate image 111 formed by the lens 106 is made smaller than relay images 117a and 117b formed by the lenses 113 and 115.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverted microscope used for observing a biological specimen or the like in a culture bottle.

[0002]

2. Description of the Related Art An inverted microscope has an objective lens at a lower portion of a stage and is used for observing an enlarged image of a biological specimen in a container such as a culture bottle mounted on the stage. . Inverted microscopes are, for example,
No. 30,565 discloses an optical system and the like. The optical system disclosed in this publication uses an optical system from an objective lens to an eyepiece,
It is shaped like a letter and has an optical path for photography.

[0003]

In the conventional inverted microscope, the size and complexity of the apparatus have been increased due to the necessity of photographing and multi-purpose ports, which has led to an increase in price.

In addition, in the case of an inverted microscope, considering the ease of observation by an observer, it is easier to observe the position of the eyepiece having the eyepiece at a certain height from the desk. Specifically, the eye level of the eyepiece (the height of the observer's eyes at the time of observation) is preferably about 400 to 450 mm from the desk. On the other hand, it is necessary to confirm the specimen on the stage directly from above with the naked eye from above, so that the lower the height, the better the work efficiency. However, it is difficult to design the configuration of the conventional inverted microscope to a height that satisfies both the eye level and the position of the stage, and the eye level is low and the stage tends to be high.

It is an object of the present invention to provide an inverted microscope having an eyepiece at a height that is easy for an observer to observe and a low stage, even though the optical system is simple.

[0006]

In order to achieve the above object, according to the present application, the following inverted microscope is provided.

In other words, it has a stage for mounting a sample, an objective lens arranged below the stage, an imaging lens and a relay lens arranged in order on the optical axis of the objective lens, An inverted microscope, wherein an optical path deflecting unit is disposed between the imaging lens and the relay lens, and the optical axis is bent obliquely upward.

The imaging lens forms an intermediate image between the imaging lens and the relay lens, and the size of the intermediate image is smaller than that of the relay image formed by the relay lens. can do.

[0009]

An embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1) First, an inverted microscope according to a first embodiment will be described with reference to FIG. 1 includes an illumination optical system 140, a stage 150 for mounting a specimen 153, an objective lens 104, an imaging optical system 160, a relay optical system 170, and an eyepiece optical system 1.
30 are arranged in order along the optical axis 114.

The illumination optical system 140 is an optical system for performing illumination by a so-called critical illumination method, and includes a light source 100 such as a halogen lamp, a collector lens 101, and a diffusion plate 10.
2. An aperture stop 103 and a condenser lens 154 are provided in a lens barrel. This configuration includes the diffuser plate 102 and further arranges the aperture stop 103 near the front focal plane of the condenser lens 154, so that illumination unevenness due to unevenness of the light source 100 can be reduced.

The objective lens 104 includes a stage 15
0.

The image forming optical system 160 includes a stop 105, an image forming lens 106, a mirror 108, stops 109 and 110, and a field stop 112. Among them, the diaphragm 105, the imaging lens 106, and the mirror 108 are arranged between the objective lens 104 and the desk surface 180. The mirror 108
The optical axis 114 is arranged at a position closest to the desk surface 180 and its direction is determined so that the optical axis 114 is bent obliquely upward. Here, the orientation of the mirror 108 is set so that the angle formed by the optical axis 114 is 45 degrees, so that the observer can easily observe. Aperture 109, 1
10. The field stop 112 is disposed on the optical axis 114 bent obliquely upward. Aperture 109, 11
0, the field stop 112 plays a role of blocking light beams outside the field of view and eliminating stray light and flare. The imaging lens 106 forms an intermediate image 111 at the position of the field stop 112. The imaging lens 106 includes a biconvex lens 106a and a concave meniscus lens 106b.

The relay optical system 170 includes the first lens group 11
3, a second lens group 115, a half prism 116, and mirrors 120, 121, and 122. First lens group 11
3 is arranged at a position away from the intermediate image I1 by a distance D1 (= 16 mm). The second lens group 115 is
It is arranged at a position away from the lens group by a distance D2 (= 137 mm). The first lens group 113 includes a biconvex lens 113a and a concave lens 113b. Second
The lens group 115 includes two convex lenses 115a and 115c.
And a bi-concave lens 115b located therebetween.

Half prism 116 and mirror 12
Reference numerals 0, 121, and 122 configure a binocular optical system 190 that divides the optical axis 114 into two optical axes 123 and 124 for observation by both eyes of the observer. This binocular optical system 190
This is a so-called Siddentop optical path configuration. The second lens group 115 forms relay images 117a and 117b on the two optical axes 123 and 124, respectively.

The binocular optical system 190 includes a relay optical system 170.
Can rotate about the optical axis 114 of the
3, 124 can be varied.

The eyepiece optical system 130 has optical axes 123 and 124.
Each has an eyepiece 118 on the top.

In the microscope of the present embodiment, the imaging lens 1
The imaging lens 106 is configured such that the size of the intermediate image 112 formed by 06 is smaller than the image of the specimen 153 at the desired magnification B. That is, the objective lens 1
Reference numeral 04 is designed so that the size of the intermediate image 112 when the imaging lens 106 having a focal length of 200 mm is used becomes the size of the image of the specimen 153 at the desired magnification B as a design criterion. However, in the present embodiment, the design standard (focal length 200 m
Instead of the imaging lens of m), the one having a focal length of 180 mm is used, and the size of the intermediate image 112 is set to be 0.9 times the size of the image of the specimen 153 at the desired magnification B.

On the other hand, the first lens group 113 of the relay optical system
And the second lens group 114 enlarges the intermediate image 111 and adjusts the size of the relay images 117a and 117b to the sample 153.
Of the desired magnification B. Thereby, relay images 117a and 117b of the desired magnification B of the sample 153 are obtained.

In general, a microscope using an objective lens, an image forming lens, and a relay lens has an intermediate image and a relay image.
It is configured to have a one-to-one size. However, in the present embodiment, a lens having a shorter focal length than the design standard is used as the imaging lens 106, and the intermediate image 11
1 is configured to be smaller than the relay images 117a and 117b for the following reason.

That is, in this embodiment, the stage 150 is set low so that an observer can easily check the culture bottle or the like in which the specimen 153 is placed with an inverted microscope by looking up from above. ing. On the other hand, the eyepiece optical system 130
Is preferably set within a certain range according to the height of the observer's eyes. In this embodiment, the eyepiece optical system 1
Approximately 40 eye levels (height for observers to see)
An attempt is being made to set the range between 0 mm and 450 mm. However, if the optical path is bent twice to form a U-shape as in the related art, it is difficult to increase the eye level to 400 mm or more, and the optical system becomes complicated. Therefore,
In this embodiment, the eye level can be set to a height of 400 mm or more by forming the optical path into a V-shape that is bent only once. However, in the case of a V-shaped optical path, if the optical system is designed so that the intermediate image and the relay image have a one-to-one size as in the related art, the optical path length is too long and the eye level is reduced to 450 mm or less. It becomes difficult to do.

Specifically, when the stage is lowered, the imaging lens 106 is arranged at a position close to the desk surface 180, so that in the V-shaped optical path, the position of the intermediate image 111 is the position of the imaging lens 106. Is pushed up toward the eyepiece optical system 130 by the lower amount. Therefore, the position of the eyepiece optical system 130 is set to 4
If the distance is set to 50 mm or less, the distance between the intermediate image 111 and the eyepiece optical system 130 becomes short, and 160 mm, which is the minimum distance required for disposing the binocular optical system 190, is changed to the second distance.
It becomes difficult to secure between the lens group 115 and the eyepiece optical system 130. In order to solve this, it is conceivable to use the second lens group 115 specially designed so that the back focus distance of the second lens group 115 is longer than the front focus distance. It is inevitable that the group 115 becomes complicated and expensive.

Therefore, in the present embodiment, in order to solve this problem with a simple lens group, a lens having a focal length shorter than the design standard is used as the imaging lens 106, so that the position of the intermediate image 111 can be reduced. Is pushed down to the desk surface 180 side. The imaging lens 10 having such a short focal length
6, the size of the intermediate image 112 becomes smaller than the image of the specimen 153 at the desired magnification B. Therefore, the first lens group 113 and the second lens group 115 of the relay optical system 170 are The magnifying optical system is configured so that 111 is enlarged to form relay images 117a and 117b of the sample 153 at a desired magnification B.

With this configuration, as the imaging lens 106, a lens having a shorter focal length than the design standard is used, and the first lens group 1 of the relay optical system 170 is used.
It is only necessary to make the 13 and the second lens group 115 lenses with magnification, and an eye level of 400 mm or more and 450 mm or less can be realized with a simple optical system. Actually, in the present embodiment, the second lens group 115 can be realized with a simple configuration of a perfect symmetric type.

In the present embodiment, the relay optical system 1
Distance D1 between the first lens group 113 of 70 and the intermediate image 111
Are designed to be shorter than the distance D2 between the first lens group 113 and the second lens group 115, that is, D1 <D2. This is for the following reasons.

When the light beam from the imaging lens 106 is made incident on the second lens group 115, the center of the second lens group
When the position (pupil) where the principal rays of the light beam intersect is located, it is easy to correct aberration due to the symmetry of the lens, and it is possible to particularly suppress the occurrence of coma. Therefore, the first lens group 113
However, the light beam is refracted, the diameter of the light beam is reduced, and the light beam is incident on the second lens group. At that time, the first lens group 11
If the distance D2 between the third lens group 115 and the second lens group 115 is very short,
It is necessary to increase the power of the first lens group 113 so that the light beam is refracted greatly and is incident on the second lens group 115. However, if the power of the first lens group 113 is large, field curvature occurs, which is not preferable, and the larger the distance D2, the better. On the other hand, if the distance D2 is increased, the first lens group 113 necessarily comes too close to the intermediate image 111. When the first lens group 113 and the intermediate image 111 overlap, an image of dust or a flaw on the lens surface of the first lens group 113 is formed on the relay images 117a and 117b, making it difficult to observe. Therefore, it is desirable that the distance D1 between the first lens group 113 and the intermediate image 111 be a certain value (D1> 10 mm). Therefore, in the present embodiment, D1 <D2, preferably 10 mm <D1 <D2.

In the present embodiment, the second lens group 1
Reference numeral 15 denotes a configuration of a lens group called a completely symmetric triplet in which a convex lens 115a, a concave lens 115b, and a convex lens 115c are sequentially arranged. At this time, the focal length of the convex lenses 115a and 115c is fA, and the Abbe number is ν.
1. The focal length of the concave lens 115b is fB, and the Abbe number is ν.
When it is set to 2, it is designed to satisfy 0.8 <| ν1 × fB | / | ν2 × fA | <1.0. This is because if these conditions are not met, the convex lenses 115a and 115c and the concave lens 11
This is because the power balance of 5b is lost, and it becomes difficult to correct axial chromatic aberration.

In the present embodiment, the second lens group 115 is designed so as to satisfy 0.45 <| fB | / | fA | <0.55. The reason is that if this condition is not satisfied, it becomes difficult to correct the field curvature.

In the inverted microscope according to the present embodiment having such a configuration, the light beam emitted from the light source 100 is converted into a substantially parallel light beam by the
02, passes through the aperture stop 103, is collected by the condenser lens 154, and is
The upper specimen 153 is illuminated. The luminous flux from the specimen 153 is
The light is collimated by the objective lens 104 into a parallel light beam, condensed by the imaging lens 106a, and
Form one. First lens group 11 of relay optical system 170
Reference numeral 3 refracts the light beam from the imaging lens 106a, narrows the light beam system, and makes the light beam enter the second lens group 115. The light beam that has passed through the second lens group 115 is split by the binocular optical system 190 into two light beams. The second lens group 115
The relay images 117a and 117b are formed on the two light fluxes, respectively.

At this time, the intermediate image 111 is 0.9 times as large as the image of the specimen 153 at the desired magnification B, while the relay images 117a and 117b are at the desired magnification B of the specimen 153. Has become. Therefore, by observing the relay images 117a and 117b with the eyepiece 118 of the eyepiece optical system 130, an image of the desired magnification B can be observed with the binocular.

In the present embodiment, the height of the stage 150 is low and the eyepiece lens 118 is a simple optical system in which the size of the intermediate image 111 is smaller than that of the relay images 117a and 117b. Height is desk top 1
An inverted microscope of 80 to 400 mm or more and 450 mm or less can be realized. Therefore, an inverted microscope with high work efficiency and easy observation can be obtained.

The structure of the first and second lens groups 113 and 115 of the relay optical system 170 is changed to D1 <D2 0.8 <| ν1 × fB | / | ν2 × fA | <1.0 as described above. Since it is designed so as to satisfy the condition of 0.45 <| fB | / | fA | <0.55, it is possible to observe an image in which coma, chromatic aberration and curvature of field are corrected.

Here, Table 1 shows examples of specific configurations of the imaging lens 106 of the first embodiment and the first lens group 113 and the second lens group 115 of the relay optical system 170. Show. However, in Table 1, r: radius of curvature (mm), d: interval (mm), nd: d line (λ = 5)
87.6 nm), and νd: Abbe number. In the example of Table 1, the imaging lens 106 and the first
The lens group 113 is a cemented lens.

[0034]

[Table 1]

In the configuration shown in Table 1, the convex lens 11
The focal length fA of the lenses 5a and 115c is 44.5 mm, and the focal length fB of the concave lens 115b is −23.5 mm.

Therefore, | ν1 × fB | / | ν2 × fA |
= 0.91 and 0.8 <| ν1 × fB | / | ν2 ×
The condition of fA | <1.0 is satisfied. Also, | fB |
/|fA|=0.53 and 0.45 <| fB | / |
The condition of fA | <0.55 is satisfied.

(Embodiment 2) Next, an inverted microscope according to a second embodiment will be described with reference to FIG.

The inverted microscope shown in FIG. 2 has substantially the same configuration as the inverted microscope shown in FIG. 1, except that a mirror 202 is provided on the optical axis 114 between the second lens group 115 of the relay optical system 170 and the binocular optical system 190. Fig. 1 shows that
Is different from When the mirror 202 is inserted on the optical axis 114, the mirror 202 reflects the light beam from the second lens group 115 and guides it to the optical axis 205. On the optical axis 205,
A prism 203 is provided, and an optical axis 205 is bent to form an optical axis 206. The prism 203 has an optical axis 206
Are arranged so as to coincide with each other in the vertical direction. Optical axis 20
An image pickup device 201 such as a video camera such as a CCD or a photographic camera is disposed at the end of 6.

Therefore, when the mirror 202 is located on the optical axis 114, the light beam from the second lens group 115 is reflected by the mirror 202 and further reflected by the prism 203 to form an image 204 on the optical axis 206. I do. Therefore, the image 204 can be captured by the imaging device 201. In the case of visual observation, the mirror 202 is separated from the optical axis 114 by the knob 207, so that the light flux is guided to the binocular optical system 190, and the relay image 11 as in FIG.
7a and 117b can be observed.

In order to arrange the mirror 202 as shown in FIG. 2, not only the space for the binocular optical system 190 but also the mirror 2 between the second lens group 115 and the observation optical system 130 are required.
It is necessary to secure an interval for the intermediate image 111, as described in the first embodiment.
Is smaller than the relay image, the second lens group 11
A large distance between the optical system 5 and the observation optical system 130 can be ensured, and the configuration as shown in FIG. 2 can be realized.

In this configuration, since the imaging device 201 is located above the microscope, a large space for disposing the imaging device 201 can be ensured. Therefore, the imaging device 2
01 as in the case where
There is no possibility that the device 1 will come into contact with the desk surface 180, and a large-sized imaging device can be attached.

Further, as shown in FIG. 2, since the optical axis 206 for mounting the imaging device 201 is oriented vertically, the force applied to the connecting portion 208 between the imaging device 201 and the lens barrel is reduced in the circumferential direction of the lens barrel. Looks like Accordingly, the load on the connecting unit 208 is small, and the large imaging device 201 can be firmly supported.

[0043]

As described above, according to the present invention,
Although the optical system is a simple optical system, it is possible to provide an inverted microscope having an eyepiece at a height that is easy for an observer to observe and a low stage.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an inverted microscope according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration of an inverted microscope according to a second embodiment of the present invention.

[Explanation of symbols]

100 light source, 101 collector lens, 102 diffuser plate, 103 aperture stop, 104 objective lens, 105
Aperture 106, imaging lens 108, mirror 109,
110: stop, 111: intermediate image, 112: field stop, 1
13 first lens group, 114: optical axis, 115: second lens group, 116: half prism, 117a, 117b: relay image, 118: eyepiece, 120, 121, 122
Mirrors 123, 124 Optical axis 130 Eyepiece 140 Illumination optical system 150 Stage 154
Condenser lens, 153 specimen, 160 imaging optical system, 170 relay optical system, 190 binocular optical system, 20
DESCRIPTION OF SYMBOLS 1 ... Imaging device, 202 ... Mirror, 203 ... Prism, 2
04: image, 205, 206: optical axis, 207: movable knob, 208: connecting portion.

Claims (4)

[Claims] 1. A stage for mounting a specimen, an objective lens arranged below the stage, an imaging lens and a relay lens arranged in order on an optical axis of the objective lens, An inverted microscope, wherein an optical path deflecting unit is disposed between the imaging lens and the relay lens, and the optical axis is bent obliquely upward. 2. The inverted microscope according to claim 1, wherein the imaging lens forms an intermediate image formed between the imaging lens and the relay lens, and the size of the intermediate image is An inverted microscope characterized by being smaller than a relay image formed by a relay lens. 3. The inverted microscope according to claim 2, wherein the relay lens has a first lens group arranged on the intermediate image side and a second lens group arranged on the relay image side. The second lens group is a perfect symmetric type in which a convex lens, a concave lens, and a convex lens are sequentially arranged on the optical axis; a distance D1 between the first lens group and an intermediate image; The distance D2 to the second lens group is in a relationship of D1 <D2, and the second lens group has a focal length of the convex lens of fA,
When the Abbe number is ν1, the focal length of the concave lens is fB, and the Abbe number is ν2, 0.8 <| ν1 × fB | / | ν2 × fA | <1.0 0.45 <| fB | / | An inverted microscope characterized by satisfying fA | <0.55. 4. The inverted microscope according to claim 2, wherein a deflection means for separating a light beam from the relay lens from the optical axis is provided between the relay lens and the relay image. An inverted microscope characterized by being detachably mounted on a microscope.