JP2013148651A - Microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and quickly perform observation when magnification is changed.SOLUTION: A microscope 1 comprises: an objective optical system 2 that collects light from a sample A; imaging optical systems 3a and 3b that form the light collected by the objective optical system 2 into an image; and an imaging device 4 that photographs the light formed into an image by the imaging optical systems 3a and 3b. The imaging optical systems 3a and 3b can be set to different multiple magnifications; and the imaging device 4 forms the light formed into an image by the imaging optical systems 3a and 3b into an image in a range with a different size according to the magnification of the imaging optical systems 3a and 3b.

Description

  The present invention relates to a microscope.

  Conventionally, the light from the specimen is collected by the objective lens, the observation optical system is replaced, or the magnification is changed by the variable magnification optical system, and the image pickup device is adapted to the size of the image circle that changes by changing the magnification. There is known a microscope for exchanging (see, for example, Patent Document 1).

International Publication No. 2006/088109

  However, the microscope of Patent Document 1 is to replace the image sensor that captures a rectangular area inscribed in the image circle so that vignetting does not occur when the magnification in the observation optical system is changed. In order to perform the observation, it is necessary to replace the image pickup device, which is troublesome and takes time for the replacement operation.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a microscope that can perform observation with the magnification switched easily and quickly.

In order to achieve the above object, the present invention provides the following means.
In one embodiment of the present invention, an objective optical system that collects light from a specimen, an imaging optical system that forms an image of light collected by the objective optical system, and an image formed by the imaging optical system An imaging device for photographing light, and the imaging optical system can be set to a plurality of different magnifications, and the imaging device transmits light imaged by the imaging optical system to the imaging optical system. Provided is a microscope that forms an image in a range of different sizes according to magnification.

  According to this aspect, the light emitted from the specimen is condensed by the objective optical system, then imaged on the image sensor by the imaging optical system, and photographed by the image sensor. By setting the magnification of the imaging optical system to a different magnification, the size of the image circle in which aberration is guaranteed changes, but the image sensor emits light in a range of different sizes according to the magnification of the imaging optical system. Since the image is formed, it is not necessary to replace the image sensor. That is, it is possible to eliminate the trouble of replacing the image sensor and perform quick observation.

  In particular, when the intensity of light emitted from a specimen is extremely low, such as a fluorescence microscope or a light emission microscope, a brighter image can be obtained by narrowing the light imaging range in the image sensor. As a result, in the case of a fluorescence microscope, the intensity of the excitation light applied to the specimen can be reduced, the specimen can be prevented from fading, and a light source having a low excitation light intensity can be used as a light source. It is possible to reduce the size and weight and reduce the cost.

In the above aspect, the number of pixels of the image sensor may be 4 million pixels or more.
In this way, even if the magnification of the imaging optical system is changed to 0.5, the number of pixels in the imaging range can be secured at 1 million pixels or more, and high magnification observation with high resolution can be performed. it can.

In the above aspect, the imaging element may have an effective imaging range inscribed in an image circle at a magnification that provides the longest focal length of the imaging optical system.
By doing so, the image circle becomes the largest in the state where the focal length of the imaging optical system is the longest, so that the effective imaging range of the image sensor is inscribed in the image circle, and the maximum guaranteed aberration is achieved. If the magnification of the imaging optical system is low, the image circle is reduced, so light that is imaged in a narrower range than the effective imaging range without replacing the imaging device Can be taken.

In the above aspect, the imaging optical system may include a plurality of optical systems having different magnifications or a zoom optical system capable of continuously changing the magnifications, which are arranged in an interchangeable manner.
In this way, by doing so, the magnification of the imaging optical system is continuously changed by the operation of the zoom optical system, and the image pickup element is connected within the effective image pickup range without replacing the image pickup element. An imaged image can be acquired.

In the above aspect, the imaging optical system may include a field stop that forms an intermediate image and circumscribes the intermediate image at the position of the intermediate image.
In this way, the light outside the image circle is shielded by the field stop, so even if the image circle becomes smaller and falls within the effective imaging range of the image sensor, an image outside the image circle for which no aberration is guaranteed. Can be prevented from being acquired.

  According to the present invention, it is possible to easily and quickly perform observation with the magnification changed.

It is a figure which shows the lens arrangement | sequence of the microscope which concerns on one Embodiment of this invention, (a) When the imaging optical system of 1 time magnification is inserted, (b) Imaging optical system of 0.5 time magnification It is a figure which shows the case where each is inserted. FIG. 1 is a relationship between an image circle and an image pickup device by the microscope of FIG. 1, and (a) when an imaging optical system with a magnification of 1 × is inserted, (b) an imaging optical system with a magnification of 0.5 × It is a figure which shows the case where it inserted, respectively. FIG. 7 is a diagram showing a lens arrangement of a modification of the microscope of FIG. 1, wherein (a) the zoom optical system has a magnification of 1 ×, (b) the zoom optical system has a magnification of 0.77 ×, and (c) the zoom optical system has a magnification. It is a figure which respectively shows the case where is 0.5 times. FIG. 3 shows the relationship between an image circle and an image pickup device by the microscope of FIG. 3, where (a) the zoom optical system has a magnification of 1 ×, (b) the zoom optical system has a magnification of 0.77 ×, and It is a figure which respectively shows the case where a magnification is 0.5 time. FIG. 2 is a diagram illustrating a lens arrangement in an embodiment of the microscope of FIG. 1, and (a) when an imaging optical system having a magnification of 1 × is inserted, (b) an imaging optical system having a magnification of 0.5 × It is a figure which shows the case where it inserted, respectively. FIGS. 6A and 6B are aberration diagrams when an imaging optical system having a magnification of 1 is inserted in the microscope of FIG. 5, where (a) shows spherical aberration, (b) shows field curvature, and (c) shows distortion aberration. Yes. 6A and 6B are aberration diagrams when an imaging optical system having a magnification of 0.5 times is inserted into the microscope of FIG. 5, where (a) shows spherical aberration, (b) shows field curvature, and (c) shows distortion. Show. It is a figure which shows the lens arrangement | sequence in one Example of the microscope of FIG. FIGS. 9A and 9B are aberration diagrams when the magnification of the zoom optical system of the microscope in FIG. 8 is set to 1. FIG. 9A shows spherical aberration, FIG. 8B shows field curvature, and FIG. 9C shows distortion. FIGS. 9A and 9B are aberration diagrams in the case where the magnification of the zoom optical system of the microscope of FIG. 8 is 0.77 times, in which FIG. 8A shows spherical aberration, FIG. 8B shows field curvature, and FIG. . FIGS. 9A and 9B are aberration diagrams when the magnification of the zoom optical system of the microscope of FIG. 8 is set to 0.5. FIG. 9A illustrates spherical aberration, FIG. 8B illustrates field curvature, and FIG. 9C illustrates distortion. .

A microscope 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1A, the microscope 1 according to the present embodiment condenses light from a stage (not shown) on which the specimen A is placed and the specimen A placed on the stage. The objective optical system 2, the imaging optical systems 3a and 3b that image the light condensed by the objective optical system 2, and the imaging element 4 that captures the light imaged by the imaging optical systems 3a and 3b And.

As shown in FIG. 1A, the objective optical system 2 and the imaging device 4 are fixed at positions spaced apart from each other. The objective optical system 2 has, for example, a magnification of 4 times.
As shown in FIGS. 1A and 1B, the imaging optical systems 3a and 3b are inserted and removed with different magnifications on the optical axis between the objective optical system 2 and the image sensor 4. By doing so, the magnification can be changed. Arbitrary methods, such as a turret and a slider, may be employed for inserting and removing the imaging optical systems 3a and 3b.

In the example shown in FIG. 1, an imaging optical system 3a having a magnification of 1 is inserted in FIG. 1A and an imaging optical system 3b having a magnification of 0.5 is inserted in the optical axis in FIG. Each state is shown.
As shown in FIG. 2A, the imaging element 4 has an aberration on the imaging surface of a predetermined value or less when the imaging optical system 3a having a magnification of 1 times that in FIG. 1A is inserted on the optical axis. The effective imaging range 4a having a size that circumscribes the image circle B, which is a limited range, is provided.

Further, as shown in FIG. 2B, in the state where the imaging optical system 3b having a magnification of 0.5 times that in FIG. 1B is inserted on the optical axis, the image circle B is effective for the image sensor 4. It is arranged within the imaging range 4a.
In the present embodiment, the number of pixels of the image sensor 4 is 12 million pixels.

The operation of the microscope 1 according to this embodiment configured as described above will be described below.
In order to perform fluorescence observation of the specimen A using the microscope 1 according to the present embodiment, when the specimen A is placed on the stage and the specimen A is irradiated with excitation light, the fluorescent substance contained in the specimen A is excited. Fluorescence is emitted, and the emitted fluorescence is condensed by the objective optical system 2, and then imaged on the imaging surface of the imaging device 4 by the imaging optical systems 3 a and 3 b and photographed by the imaging device 4.

  In this case, as shown in FIG. 1 (a), if the imaging optical system 3a having a magnification of 1 is inserted on the optical axis, the fluorescence from the specimen A is shown in FIG. 2 (a). An image with a guaranteed aberration is formed in the image circle B shown. At this time, since the image circle B circumscribes the effective imaging range 4a of the imaging device 4, the acquired image is a clear image in which aberration is suppressed in all pixels.

  Next, as shown in FIG. 1 (b), when the imaging optical system 3b is replaced with one having a magnification of 0.5, the fluorescence from the specimen A is as shown in FIG. 2 (b). The image circle B in which the aberration is guaranteed is arranged in the effective imaging range 4a of the imaging device 4. As a result, in the pixels arranged outside the image circle B, the aberration is not guaranteed, and the sharpness is reduced, but a clear image in which the aberration is suppressed is acquired in the image circle B.

  That is, if only the image in the image circle B is cut out from the image acquired by the image sensor 4, a clear image can be acquired. Alternatively, as shown in FIG. 2B, all rectangular regions C inscribed in the image circle B can be cut out from the images in the image circle B arranged in the effective imaging range 4a of the image sensor 4. It is possible to obtain a clear image with guaranteed aberration at the pixel.

  In this case, if the imaging optical system 3b having a low magnification is used as shown in FIG. 1B, the fluorescence from the specimen A is imaged in a narrower range of the image sensor 4. As a result, in the case of fluorescence with low intensity, the intensity per unit area can be improved by collecting the fluorescence in a narrower range. That is, there is an advantage that a bright fluorescent image can be obtained by lowering the magnification of the imaging optical system 3b even when light with low intensity such as fluorescence is emitted from the specimen A.

  In this embodiment, since the image sensor 4 having 12 million pixels is used as the image sensor 4, a rectangle inscribed in the image circle B even when the magnification of the imaging optical system 3b is reduced to 0.5 times. When the region C is cut out, a fluorescence image of 3 million pixels can be obtained. That is, observation with a high-resolution bright fluorescent image can be performed.

  Further, when a sufficiently bright image can be obtained by reducing the magnification of the imaging optical system 3b, the exposure time can be reduced by increasing the shutter speed. As a result, the movement of the specimen A moving at a high speed can also be photographed. On the contrary, when the shutter speed is not increased, the intensity of the excitation light applied to the specimen A can be decreased. As a result, there is an advantage that a light source having a small size, light weight and low cost can be adopted.

  In the present embodiment, the image sensor 4 having 12 million pixels is used, but an image sensor 4 having 4 million pixels or more may be used instead. If it is 4 million pixels, an image of 1 million pixels can be obtained even if the imaging optical system 3b with a magnification of 0.5 times is used.

  In this embodiment, the case where two types of imaging optical systems 3a and 3b having different magnifications are exchanged has been described. However, the present invention is not limited to two types, and a plurality of types of imaging optical systems 3a and 3b are exchanged. You may decide to do it. In addition, as shown in FIGS. 3 and 4, an imaging optical system 6 having a zoom optical system 5 may be employed instead of the exchangeable imaging optical systems 3a and 3b. FIG. 4 shows the relationship between the image circle and the imageable range at each zoom magnification of the zoom optical system 5. According to the zoom optical system 5, the magnification can be switched continuously.

As shown in FIG. 3, when the imaging optical system 6 forms an intermediate image, a field stop 7 circumscribing the intermediate image may be provided at the image forming position of the intermediate image.
By doing so, the light does not reach the outside of the image circle B (the hatched area shown in FIG. 4) formed on the imaging surface of the imaging device 4 by being blocked by the field stop 7. It is possible to prevent the generation of an image whose aberration is not guaranteed.

Example 1
Next, an example of the microscope 1 according to the above-described embodiment of FIG. 1 will be described.
FIG. 5 is a diagram showing the arrangement of the optical system of the microscope 1 according to the present embodiment. FIG. 5A shows a case where the imaging optical system 3a having a magnification of 1 is inserted, and FIG. Each shows a case where an imaging optical system 3b having a magnification of 5 times is inserted. Table 1 shows lens data when the imaging optical system 3a having a magnification of 1 is inserted, and Table 2 shows lens data when the imaging optical system 3b having a magnification of 0.5 is inserted.

  6 is an aberration diagram when the imaging optical system 3a having a magnification of 1 is inserted, and FIG. 7 is an aberration diagram when the imaging optical system 3b having a magnification of 0.5 is inserted. ) Indicates spherical aberration, (b) indicates field curvature, and (c) indicates distortion. In the figure, NA is the numerical aperture.

(Table 1)
Surface number Curvature radius r Surface spacing d Refractive index Ne Abbe number νd
1 ∞ 8.33
2 72.47 2.8 1.8348 42.7
3-11.34 5.99
4-7.06 3.42 1.6477 33.8
5 34.82 10.13
6-17.47 3.42 1.834 37.2
7 39.42 3.84 1.4875 70.2
8-15.32 0.42
9 92.37 3.73 1.6031 60.6
10-18.36 55
11 68.62 8.26 1.4875 70.2
12-37.4 3.44 1.8061 40.9
13-102.56 0.74
14 84.38 5.56 1.834 37.2
15-50.62 3.3 1.6445 40.8
16 40.65 156.7
17 ∞

(Table 2)
Surface number Curvature radius r Surface spacing d Refractive index Ne Abbe number νd
1 ∞ 8.33
2 72.47 2.8 1.8348 42.7
3-11.34 5.99
4-7.06 3.42 1.6477 33.8
5 34.82 10.13
6-17.47 3.42 1.834 37.2
7 39.42 3.84 1.4875 70.2
8-15.32 0.42
9 92.37 3.73 1.6031 60.6
10-18.36 109.5
11-25.32 3.75 1.5163 64.1
12 146.15 8.71 1.6679 55.3
13-32.65 2.48
14 92.33 8.89 1.497 81.5
15-30.95 3.75 1.673 38.1
16-111.39 95.75
17 ∞

(Example 2)
Next, an example of the microscope 1 according to the embodiment of FIG. 3 described above will be described.
FIG. 8 is a diagram showing the arrangement of the optical system of the microscope 1 according to the present embodiment. Table 3 shows lens data of the optical system having the zoom optical system 5, and Table 4 shows the magnification of the zoom optical system 5 and the distance between lenses. This is data indicating the relationship between d ₁₈ , dd ₂₁ , and d ₂₃ .

  FIG. 9 is an aberration diagram when the zoom optical system 5 has a magnification of 1. FIG. 10 is an aberration diagram when the zoom optical system 5 has a magnification of 0.77. FIG. 11 shows the zoom optical system 5 with a magnification. It is an aberration diagram in the case of 0.5 times, (a) shows spherical aberration, (b) shows field curvature, and (c) shows distortion.

(Table 3)
Surface number Curvature radius r Surface spacing d Refractive index Ne Abbe number νd
1 ∞ 8.33
2 72.47 2.8 1.8348 42.7
3-11.34 5.99
4-7.06 3.42 1.6477 33.8
5 34.82 10.13
6-17.47 3.42 1.834 37.2
7 39.42 3.84 1.4875 70.2
8-15.32 0.42
9 92.37 3.73 1.6031 60.6
10-18.36 55
11 176.52 6.1 1.4875 70.2
12-64.22 4 1.7185 33.5
13-112.13 85.6
14 22.24 9.09 1.4875 70.2
15 -68.62 0.7
16 -44.38 3 1.6684 50.9
17 89.11 33.6
18 ∞ d ₁₈
19 45.5 1.8 1.74 28.3
20 19.74 4 1.5596 61.2
21-36.01 d ₂₁
22 36.01 4 1.5596 61.2
23 -19.74 1.8 1.74 28.3
24-45.5 d ₂₄
25 ∞

(Table 4)
Magnification of imaging optical system Surface interval d ₁₈ surface interval d ₂₁ surface interval d ₂₃
1x 24.3 27.4 42.8
0.77 times 32.1 40.5 48.8
0.5 times 79.7 66.5 42.8

A specimen B image circle 1 microscope 2 objective optical system 3a, 3b, 6 imaging optical system 4 imaging element 4a effective imaging range 5 zoom optical system 7 field stop

Claims (5)

An objective optical system for condensing the light from the sample, an imaging optical system for imaging the light collected by the objective optical system, and an imaging device for photographing the light imaged by the imaging optical system; With
The imaging optical system can be set to a plurality of different magnifications,
The imaging device is a microscope that forms an image of light imaged by the imaging optical system in a range of different sizes according to the magnification of the imaging optical system.   The microscope according to claim 1, wherein the number of pixels of the image sensor is 4 million pixels or more.   3. The microscope according to claim 1, wherein the imaging element has an effective imaging range inscribed in an image circle at a magnification that is a longest focal length of the imaging optical system.   The microscope according to any one of claims 1 to 3, wherein the imaging optical system includes a plurality of optical systems having different magnifications arranged in an interchangeable manner or a zoom optical system capable of continuously changing magnifications.   The microscope according to claim 4, wherein the imaging optical system includes a field stop that forms an intermediate image and circumscribes the intermediate image.

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