JP2002131650A - Microscope illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microscope illuminator which is dealable respectively with the case a microscope having a wide visual field free of illumination unevenness and the case the microscope of a low cost is required without requiring so much wide visual field. SOLUTION: The Koehler illuminator constituted to irradiate an object surface 20 by condensing the divergent illumination luminous flux from a light source 10 through a collector lens 12 to a field stop FS, condensing the illumination luminous flux condensed to this field stop FS through a field lens 16a to an aperture-stop AS and converting the illumination luminous flux condensed to this aperture-stop AS to parallel luminous fluxes through a condenser lens 18, in which a field lens section 26a housing the field lens 16a of a relatively small diameter is attachably and detachably mounted at a device body and a field lens section 26b housing the field lens 16b of a relatively large diameter as its option is separately prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microscope illumination device, and more particularly to a microscope illumination device having a Koehler illumination system.

[0002]

2. Description of the Related Art A performance required for a microscope illumination device is that illumination is not uneven. For this reason, a Koehler illumination system, which is an ideal illumination system, is generally used for a microscope illumination device. Since the Koehler illumination system is not affected by the shape of the light source, since the light source image is located at the optically farthest position from the object surface to be irradiated,
It has the property that unevenness hardly occurs.

[0003] Hereinafter, a microscope illuminator equipped with a conventional Koehler illumination system (hereinafter referred to as "Koehler illuminator" as appropriate)
Will be described with reference to FIG. As shown in FIG. 3, the divergent illumination light beam emitted from the light source 10 is condensed on the field stop FS by the collector lens 12 and further condensed on the aperture stop AS via the field lens 16. Has become. That is, the light source 10 is a collector lens 12
And the field lens 16 forms an image on the aperture stop AS. The illumination light flux from the light source image formed on the aperture stop AS is
The light is converted into a parallel light beam through the light source 8 and irradiates the object surface 20 to be irradiated.

As described above, in the Koehler illumination system, the light source image formed on the aperture stop AS is projected onto the object surface 20 to be irradiated.
From the object plane 20 because it is optically furthest from
Irradiation is not affected by the shape of the light source 10, so that illumination unevenness is less likely to occur.

[0005]

By the way, with the spread of digital cameras in recent years, digital cameras have been increasingly used in place of conventional silver halide photography when taking photographs under a microscope. However, in the case of a digital camera, slight illumination unevenness appears on an image as a gradation change, so that even if there is slight illumination unevenness that is not conspicuous in a conventional silver halide photograph, it becomes conspicuous.

This is particularly noticeable when a low-magnification objective lens having a large field of view is used. For example, when a high-magnification condenser lens having a focal length of about 10 mm is used as the condenser lens 18 and a low-magnification objective lens of about 10 times is used as a finder, the amount of light at the periphery of the field of view decreases and the image becomes dark. There are cases. Such illumination unevenness is mostly due to the small diameter of the field lens 16.

That is, as shown in FIG. 4, when the diameter of the field lens 16 is small, the field lens 1
A part (illustrated by broken lines in the figure) of the illumination light beam from the light source 10 that irradiates the object surface 20 through the light source 6 deviates from the field lens 16 and does not reach the object surface 20. For this reason, the amount of light in the peripheral portion of the visual field decreases and the image becomes dark.

In a microscope, an objective lens is replaced according to an observation object, or a condenser lens 1 is used.
The field lens 16 is generally fixedly installed in the microscope illuminating device, and the diameter of the field lens 16 is determined by the focal length of the condenser lens 18 and the objective lens. The size is set to an appropriate size so as to be able to cope with a change in magnification in general.

However, for special applications, the condenser lens 18 having a short focal length as described above may be used,
If a large illumination field without illumination unevenness is required by using a lens having a large back aperture such as a low-magnification objective lens, the diameter of the ordinary field lens 16 is not sufficient, In some cases, the amount of light in the peripheral portion is reduced to darken, and the required illumination field may be insufficient.

To cope with this, the diameter of the field lens 16 may be increased, but if the large-diameter field lens 16 is uniformly installed in the microscope illuminating device,
This leads to an increase in the price of the device.

That is, for example, a condenser lens 18 having a long focal length is used as in the case of manipulating an object with a manipulator while observing with a microscope, or a lens having a small back aperture such as a high-magnification objective lens is used. For a user who does not need a large illumination field, it is not necessary to make the diameter of the field lens 16 larger than usual. Instead, a low-cost field lens having a smaller field lens 16 than usual is installed. A device is desirable.

Therefore, even for a user who needs a microscope having a wide illumination field without illumination unevenness that can be used for special applications, a user who does not need a very large illumination field and who wants a low-cost microscope is desirable. However, it is an issue to realize a microscope illumination device that can meet each requirement.

Further, when changing from a normal use mode to a use mode for a special use requiring a wide illumination field with more uniform illumination than usual, the microscope in use can be used without purchasing a new expensive microscope. If this can be dealt with by the system upgrade, there will be a great cost advantage for the user.

Accordingly, the present invention has been made to solve the above-mentioned problems, and even when a microscope having a wide illumination field without illumination unevenness is required, a low-cost illumination can be achieved without requiring such a wide illumination field. It is an object of the present invention to provide a microscope illuminating device capable of coping with a case where a microscope is required.

[0015]

The above object is achieved by the following microscope illumination device according to the present invention. That is, the microscope illumination device according to claim 1 is a microscope illumination device including a Koehler illumination system that forms an image of a light source on an aperture stop using a collector lens and a field lens, and further illuminates an object surface via a condenser lens. In addition, the field lens is exchangeably installed.

In the microscope illuminating device according to the first aspect of the present invention, since the field lenses are exchangeably installed, the field lenses having different diameters are arranged as needed, so that the illumination unevenness is increased. The unlit illuminated field is adjusted to the desired size. That is, for example, when a lens having a small back aperture such as a high-magnification objective lens is used, a field lens having a not so large diameter may be arranged. When a lens having a large back aperture, such as a lens, is used, by replacing the field lens with a larger diameter, an illuminated field having a necessary and sufficient area without illumination unevenness is secured.

Further, even if the use of the microscope is changed to a special use requiring a wide illumination field without illumination unevenness due to the optional field lens in such a microscope illumination device, an expensive microscope is required. Can be dealt with by upgrading the system by replacing the field lens of the microscope in use without purchasing a new one.

In the microscope illumination device according to the first aspect, it is preferable that the condenser lens is also exchangeably installed. In this case, the condenser lens is replaced with another type of condenser lens corresponding to the observation object, for example, another condenser lens having a different focal length. It becomes possible to exchange for another different field lens.

That is, for example, when a condenser lens having a long focal length is used, a field lens having a not so large diameter may be disposed, but a condenser lens having a short focal length is used for special purposes. In such a case, by replacing the field lens with a larger diameter, an illuminated field having a necessary and sufficient area without illumination unevenness is secured. Thus, by replacing the condenser lens and the field lens with each other, it becomes possible to perform Koehler illumination of the observation target with an appropriate illumination field corresponding to various uses of the microscope.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. FIG. 1 is an optical path diagram showing a microscope illumination device including a Koehler illumination system according to one embodiment of the present invention.

As shown in FIG. 1, in the Koehler illumination device according to the present embodiment, a light source 10 for emitting illumination light is provided.
And the divergent illumination light beam emitted from the light source 10
, A reflector 14 for reflecting the illumination light beam condensed on the field stop FS, and a predetermined diameter for condensing the illumination light beam from the reflector 14 on the aperture stop AS. And a condenser lens 18 for converting the illumination light beam condensed on the aperture stop AS into a parallel light beam, and the parallel light beam from the condenser lens 18 is applied to the object surface 20 to be irradiated.
Is illuminated.

That is, the light source 10 forms an image on the aperture stop AS via the collector lens 12, the reflecting mirror 14, and the field lens 16a, and the illuminating light beam from this light source image becomes a parallel light beam via the condenser lens 18 to be irradiated. The Koehler illumination system irradiates the object plane 20 of the object. Therefore, the light source image formed on the aperture stop AS is located at a position optically farthest from the object surface 20 to be irradiated, and is not affected by the shape of the light source 10 when the object surface 20 is irradiated. And uneven illumination is less likely to occur.

And, in this Koehler lighting device,
A lamp house 22 that houses the light source 10 and the collector lens 12 and a microscope illumination unit 24 that houses the field stop FS and the reflecting mirror 14 are both fixed to the apparatus body.

On the other hand, a feature of the present embodiment is that the field lens portion 26a for accommodating the field lens 16a is detachably attached to the apparatus main body. Here, it is assumed that, for example, a field lens 16a having a relatively small diameter is housed in the field lens unit 26a attached to the apparatus main body. Then, as an option of the field lens portion 26a housing the relatively small diameter field lens 16a,
A field lens portion 26b accommodating the field lens 16b having a relatively large diameter is separately prepared.

Further, the condenser lens section 28 for accommodating the aperture stop AS and the condenser lens 18 is detachably attached to the apparatus main body as in the conventional case.

Next, a method of using the Koehler illumination device shown in FIG. 1 will be described. For example, a field lens having a relatively small diameter is used for a user who uses a condenser lens 18 having a long focal length or a lens having a small back aperture such as a high-magnification objective lens corresponding to an observation target. The field lens unit 26a housing the 16a is attached to the apparatus body for use.

In this case, the illuminated field having no illumination unevenness is relatively narrow due to the size of the diameter of the field lens 16a. However, a very wide illuminated field is not required for this user. It does not interfere with the observation of the subject. In addition, in this Koehler illumination device, since the field lens 16a having a relatively small diameter is used, there is an advantage that the device is inexpensive.

Further, the user changes the use of the microscope from a normal use to a special use. For example, the condenser lens unit 28 is replaced to use the condenser lens 18 having a short focal length, or a low magnification objective is used. When a lens having a large back aperture such as a lens is used, the field lens portion 26a accommodating the field lens 16a having a relatively small diameter is removed, and a relatively large diameter lens is separately prepared as an option. Lens unit 2 containing a large field lens 16b
6b is attached.

In this case, since the diameter of the field lens 16 becomes sufficiently large, the illumination field free from unevenness of illumination by the Koehler illumination device becomes sufficiently large, and the object can be favorably observed with a microscope even in special applications. Etc. are performed.

As described above, according to the present embodiment, the field lens unit 2 accommodating, for example, the relatively small-diameter field lens 16a constituting the Koehler illumination device.
6a are exchangeably installed, and a field lens portion 26b accommodating a field lens 16b having a relatively large diameter is separately prepared as an option. Since it becomes possible to arrange the 16a, 16b, it is possible to adjust the illumination field without illumination unevenness to a desired size according to the diameter of the field lenses 16a, 16b.

Therefore, it is necessary to use a condenser lens 18 having a long focal length, a lens having a small back aperture such as a high-magnification objective lens, and a microscope having a wide illumination field without illumination unevenness. In this case, a condenser lens 18 having a short focal length or a lens having a large back aperture such as a low-magnification objective lens is used, so that a low-cost microscope can be used without requiring a large illumination field. It is possible to provide a Koehler lighting device that can cope with each case even when it is required.

When this is viewed from the user side, for example, the condenser lens 18 having a short focal length is used exclusively,
A user who exclusively uses a lens with a small back aperture such as a high-magnification objective lens has a field lens unit 26a that houses a relatively small-diameter field lens 16a when purchasing a microscope. It is only necessary to purchase a relatively low-priced one equipped with a Koehler lighting device.

In special applications, for example, a condenser lens 18 having a long focal length or a lens having a large back aperture such as a low-magnification objective lens is used to provide a wide illumination field without illumination unevenness. When purchasing a microscope equipped with the above-mentioned Koehler illumination device, a user who may need it may purchase an optional field lens unit 26b containing a relatively large-diameter field lens 16b. .

If the normal use is changed to a special use requiring a sufficiently wide illumination field without illumination unevenness, the field lens housing the field lens 16a having a relatively small diameter is used. By replacing the section 26a with the field lens section 26b containing the field lens 16b having a relatively large diameter, the system of the microscope in use is improved, and it is possible to cope with a special use. Therefore, it is not necessary to newly purchase an expensive microscope for a special use, and a great advantage in cost can be obtained.

Further, since the condenser lens section 28 for accommodating the aperture stop AS and the condenser lens 18 is exchangeably installed together with the field lens section 26a for accommodating the field lens 16a, the condenser according to the observation object is provided. The lens 18 is replaced with another condenser lens 18 having a different focal length, and in response to the replacement of the condenser lens 18, for example, a field lens 16a having a relatively small diameter is replaced with a field lens 16b having a relatively large diameter. This makes it possible to perform Koehler illumination on the observation target with an appropriate illumination field corresponding to each of various uses of the microscope.

In the above-described embodiment, when the field lens 16a having a relatively small diameter and the field lens 16b having a relatively large diameter are exchanged, for example, a field lens having a relatively small diameter which is initially installed is replaced. Although the field lens portion 26a containing the lens 16a is removed, and a field lens portion 26b containing a relatively large-diameter field lens 16b separately provided as an option is attached instead. The method of replacing the field lenses 16a and 16b is not limited to the method of attaching and detaching the field lens portions 26a and 26b containing the field lenses 16a and 16b.

For example, as shown in FIG. 2, a turret 30 incorporating both a relatively small-diameter field lens 16a and a relatively large-diameter field lens 16b is installed, and the turret 30 is rotated. , Field lens 1 arranged in Koehler lighting device
Exchange of 6a and 16b may be performed. In this case, there is an advantage that the field lenses 16a and 16b can be easily and quickly replaced.

Further, the number of field lenses separately prepared as an option is not limited to one. In the above embodiment, the case where two types of field lenses 16a and 16b having different diameters are used has been described. However, three or more types of field lenses having different diameters may be used. . In this case, it is possible to perform Koehler illumination with an illumination field having an optimal size and no illumination unevenness for various applications of the microscope including extremely special applications. The turret 30 in FIG. 2 can be configured to be electrically driven by a motor, and the field lenses 16a and 16b can be configured to be electrically driven according to replacement of the condenser lens unit 28.

[0039]

As described in detail above, according to the microscope illumination device of the present invention, the following effects can be obtained. That is, according to the microscope illumination device of the first aspect, the field lenses constituting the Koehler illumination system are exchangeably installed, so that field lenses having different diameters are arranged as necessary. Therefore, an illumination field free from uneven illumination can be adjusted to a desired size.

Accordingly, even when a microscope having a wide illumination field without illumination unevenness is required by using a lens having a small back aperture, such as a high-magnification objective lens,
A microscope illuminator that can handle low-priced microscopes without using a large illumination field by using a lens with a large back aperture, such as a low-magnification objective lens. Can be provided.

That is, by making the field lens optional in such a microscope illuminating device, even in a special use requiring a sufficiently wide illumination field without illumination unevenness,
This can be dealt with by upgrading the microscope by replacing the field lens, so that it is not necessary to purchase a new expensive microscope, and a great cost advantage can be obtained.

According to the microscope illuminating device of the second aspect, since the condenser lens is exchangeable together with the field lens, the condenser lens can be replaced with another condenser lens having a different focal length according to the observation object. It is possible to replace the field lens with another field lens having a different diameter according to the replacement of the condenser lens. It is possible to perform Koehler illumination with an illumination field that has no uneven illumination.

[Brief description of the drawings]

FIG. 1 is an optical path diagram illustrating a microscope illumination device including a Koehler illumination system according to an embodiment of the present invention.

FIG. 2 is an optical path diagram illustrating a microscope illumination device including a Koehler illumination system according to a modification of the embodiment of the present invention.

FIG. 3 is an optical path diagram showing a microscope illumination device including a conventional Koehler illumination system.

FIG. 4 is an optical path diagram for explaining a problem of a microscope illumination device having a conventional Koehler illumination system.

[Explanation of symbols]

 Reference Signs List 10 Light source 12 Collector lens 14 Reflector 16a Field lens with relatively small diameter 16b Field lens with relatively large diameter 16 Field lens 18 Condenser lens 20 Object Surface 22 Lamp house 24 Microscope illumination unit 26a, 26b, 26 Field lens unit 28 Condenser lens unit 30 Turret FS Field stop AS ... Aperture stop

Claims (2)

[Claims] 1. A microscope illumination device comprising a Koehler illumination system that forms an image of a light source on an aperture stop using a collector lens and a field lens, and further illuminates an object surface via a condenser lens, wherein the field lens is A microscope illumination device, which is installed so as to be exchangeable. 2. The microscope illuminating device according to claim 1, wherein the condenser lens is exchangeably installed.