JP2005043517A - Microscope lighting device and microscope equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microscope lighting device capable of securing wide and bright illuminating light, irrespective of magnification of an objective lens, and to provide a microscope equipped with the microscope lighting device. <P>SOLUTION: The device is provided with a light source S for supplying the illuminating light, a collector lens CL for converting the diverging light emitted from the light source S to nearly collimated luminous flux, a fly eye lens F arranged on the back focus position of the collector lens CL, relay optical systems RL1 and RL2 for relaying a pseudo surface light source formed on the exit end face of the fly eye lens F to an aperture diaphragm AS or a plane conjugate to the aperture diaphragm, and the device satisfies a prescribed condition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device for a microscope.
[0002]
[Prior art]
Conventionally, in a microscope illumination apparatus, Koehler illumination that hardly causes uneven illumination is used. However, with the spread of digital cameras in recent years, taking micrographs with a digital camera instead of the conventional silver halide photography is increasing. An imaging device (for example, a CCD) used in a digital camera is visualized as a slight difference in brightness as a difference in gradation, and therefore, uneven illumination tends to be more conspicuous than a silver salt photograph. A microscope illumination device that improves such illumination unevenness has been proposed (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-6225
[Problems to be solved by the invention]
In a microscope, observation is performed by switching objective lenses of various magnifications. For this reason, the required illumination range and illumination conditions differ between a low-magnification objective lens and a high-magnification objective lens. For example, when observing with a low-magnification objective lens, it is necessary to illuminate a wide field of view, and when observing with a high-magnification objective lens, the illuminating field of view may be narrow. On the other hand, with respect to the illumination numerical aperture, in the case of an objective lens with a low magnification, the numerical aperture of the objective lens is small, so that the illumination numerical aperture may be small. However, a large illumination numerical aperture is required with an objective lens with a high magnification. When illumination with a large illumination numerical aperture is to be performed, the light source image to be formed needs to be sufficiently large with respect to the aperture stop of the condenser lens, and a large light source magnification is used.
[0005]
However, if the light source magnification is increased, the range that can be illuminated is narrowed, and the problem that the observation area cannot be illuminated uniformly with a low-magnification objective lens (field loss) occurs. Usually, in order to avoid the above problems, the microscope illumination device must be designed with a low light source magnification, and the ratio of the light source image to the area of the aperture stop (satisfaction rate) becomes low, so observation with a high magnification objective lens In this case, there is a problem that the illumination numerical aperture is insufficient and the brightness is insufficient.
[0006]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a microscope illuminating device that can ensure bright illumination light with a wide field of view regardless of the magnification of the objective lens, and a microscope having the same.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a light source for supplying illumination light, a collector lens for converting divergent light emitted from the light source into a substantially parallel light beam, and a rear focal point of the collector lens A fly-eye lens disposed at a position, and a relay optical system for relaying a pseudo-surface light source formed on the exit end face of the fly-eye lens to an aperture stop or a surface conjugated to the aperture stop, and W The width dimension of the light source, D1 is the height dimension of the light source, fc is the focal length of the collector lens, fe is the focal length of one element constituting the fly-eye lens, and d is one element constituting the fly-eye lens. Where the light source, the collector lens and the fly-eye lens are
d / 2 <(W ² + D1 ² ) ^1/2 × (fe / fc) <d
A microscope illumination apparatus characterized by satisfying the above is provided.
[0008]
Further, in another aspect of the present invention, a concave mirror having the position of the light source as a substantially focal position is provided on the side facing the collector lens side with respect to the position of the light source, and W is the width of the light source. D2 is a height dimension of the light source, fc is a focal length of the collector lens, fe is a focal length of one element constituting the fly-eye lens, and d is an inscribed circle of one element constituting the fly-eye lens. The light source, the collector lens, and the fly-eye lens are
d / 2 <(W ² + (2 × D2) ² ) ^1/2 × (fe / fc) <d
A microscope illumination apparatus characterized by satisfying the above is provided.
[0009]
In another aspect of the present invention, there is provided a microscope illuminating device characterized in that the fly-eye lens has a hexagonal shape as one element, and a flange portion to be attached to the microscope body is integrally formed. .
[0010]
In another aspect of the present invention, there is provided a microscope illumination device, wherein the light source is made of a filament.
[0011]
The present invention also provides a microscope having the microscope illumination device.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 is a schematic configuration diagram of a microscope equipped with a microscope illumination device according to the present invention. 2A and 2B are schematic views of the microscope illumination apparatus according to the first embodiment of the present invention, FIG. 2A is a schematic view of an illumination optical system, and FIG. 2B is a diagram of a light source image on one element of a fly-eye lens. An example is shown, and (c) shows an inscribed circle of one element of the fly-eye lens. 3A and 3B are schematic views of a microscope illuminating device according to a second embodiment of the present invention, FIG. 3A is a schematic view of an illumination optical system, and FIG. 3B is a light source image on one element of a fly-eye lens. An example is shown, (c) shows the inscribed circle of one element of the fly-eye lens, and (d) shows the image forming positional relationship of the filament by the concave mirror. FIG. 4 shows an example of a fly-eye lens in which a mount portion used in the embodiment of the present invention is integrally molded.
[0014]
In FIG. 1, a divergent light beam emitted from a light source S is converted into a substantially parallel light beam by a collector lens CL. At this time, a surface conjugate with the field stop FS is formed at the rear focal position of the collector lens CL. When the fly-eye lens F is arranged at this position, light source images are formed on the exit end face of the fly-eye lens F by the number of fly-eye lens elements (hereinafter referred to as cells). Since divergent light beams emitted from each cell of the fly-eye lens F overlap each other on the field stop FS, for example, even if the light source has a light distribution characteristic, uniform illumination without unevenness is possible. The divergent light beam emitted from the exit surface of the fly-eye lens F is projected onto the aperture stop AS through the relay lens systems RL1 and RL2, and illuminates the specimen 12 placed on the stage 10 via the condenser lens CND. The light from the sample 12 is collected by the objective lens 14 and observed through an imaging optical system and an eyepiece 16 (not shown). In this manner, the transmission microscope 20 equipped with the microscope illumination device 1 according to the embodiment of the present invention is configured.
[0015]
(First embodiment)
Hereinafter, the microscope illumination device according to the first embodiment of the present invention will be described in detail.
[0016]
2A to 2C, the divergent light beam emitted from the light source S is converted into a substantially parallel light beam by the collector lens CL. At this time, a surface conjugate with the field stop FS is formed at the rear focal position of the collector lens CL. The fly-eye lens F is disposed at this position so as to overlap the incident end surface ENT of the fly-eye lens F. At this time, as many light source images as the number of cells Se are formed on the exit end face EXT of the fly-eye lens. Since divergent light beams emitted from the hexagonal cells Se of the fly-eye lens F overlap each other on the field stop FS, for example, even if the light source has a light distribution characteristic, uniform illumination without unevenness is possible. The divergent light beam emitted from the exit surface EXT of the fly-eye lens F is projected onto the aperture stop AS through the relay lens systems RL1 and RL2. The relay magnification is determined by the diameter of the entire fly-eye lens F, the size of the light source S, and the desired light source magnification. A pseudo surface light source is projected onto the aperture stop AS, and illuminates the specimen 12 via the condenser lens CND shown in FIG.
[0017]
In the first embodiment, the area Si of the light source image formed in the cell Se is determined by the ratio of the light source area So, the focal length fc of the collector lens CL, and the focal length fe of the cell Se, and has the following relationship: It is expressed by a formula.
Si = So × (fe / fc)
[0018]
Accordingly, the area Si of the light source image decreases as the focal length fc of the collector lens CL increases, and the area Si of the light source image increases as the focal distance fe of the cell Se increases. When the ratio of the area Si of the formed light source image to the area of the cell Se is expressed as a fullness rate, the fullness rate is expressed by the light source area So, the focal length fc of the collector lens CL, and the cell Se of the fly-eye lens F. It is uniquely determined by the focal length fe.
[0019]
In the present embodiment, as shown in FIG. 2C, the area of the cell Se is approximated by the area of the inscribed circle Ce, the radius of the inscribed circle Ce is d, the light source S has a width W and a height D1. When formed with a rectangular filament fl, the filament image fl satisfies the following conditional expression (1).
(1) d / 2 <(W ² + D1 ² ) ^1/2 × (fe / fc) <d
[0020]
Conditional expression (1) defines the sufficiency of the light source image (filament image) on the cell Se. (W ² + D 1 ² ) ^1/2 indicates the area of the light source, and (W ² + D 1 ² ) ^1/2 × (fe / fc) indicates the area of the light source image. If the lower limit of conditional expression (1) is not reached, the area of the filament image fl on the cell Se becomes too small (the filling rate becomes too small), and a desired light quantity cannot be obtained, which is not preferable. If the upper limit value of conditional expression (1) is exceeded, the area of the filament image fl projected onto the cell Se becomes too larger than the area of the cell Se, and the amount of light of the filament portion protruding from the cell Se is wasted, which is preferable. Absent.
[0021]
As described above, in this embodiment, by adjusting the size of the cell Se of the fly-eye lens F and the size of the filament of the light source S, bright illumination with a wide field of view can be realized regardless of the magnification of the objective lens. As the adjustment procedure, the type of condenser lens CND to be used is determined, the focal lengths of the field lens and collimating lens are determined according to the number of fields of the microscope, and then the focal length of the fly-eye lens F and the size of the cell Se. Decide And finally, it is preferable to adjust the size of the light source S and install the light source S having a suitable size.
[0022]
Table 1 below lists specification values of numerical examples of the microscope illumination apparatus according to the first embodiment. In the specification values, W is the width dimension of the actual filament, D1 is the height dimension of the actual filament, fc is the focal length of the collector lens CL, fe is the focal length of the cell Se of the fly-eye lens F, and d is the cell Se. Is the radius of the inscribed circle Ce. In addition, the focal length and other length units in the specification table are generally "mm", but the optical system can be obtained with the same optical performance even when proportionally enlarged or reduced. is not.
[0023]
[Table 1]
W = 3.2
D1 = 4.8
fc = 26
fe = 7.5
d = 2
Conditional expression (1) corresponding value = 1.64
Good illumination light characteristics can be obtained in the microscope illumination device of the above numerical example.
[0024]
(Second Embodiment)
Hereinafter, the microscope illumination apparatus according to the second embodiment of the present invention will be described in detail with reference to FIG. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0025]
3A to 3D are diagrams showing a schematic configuration of the microscope illumination device. The main difference between the second embodiment and the first embodiment is that the concave surface has the focal position at the position of the light source S on the side facing the collector lens CL side (the rear side of the light source S) with respect to the position of the light source S. The mirror Mi is disposed, and the filament fa that is the light source S is smaller than the height dimension of the filament of the light source of the first embodiment.
[0026]
The divergent light beam emitted backward from the filament fa arranged below the optical axis I in the figure is reflected by the concave mirror Mi, and the filament image fb above the optical axis I in the figure at the position of the filament fa. Is imaged. The filament fa and the filament image fb are axisymmetric with respect to the optical axis. This state is shown in FIG. The filament fa is arranged at a position shifted from the optical axis I by an axis shift amount L (L is approximately half the height of the filament fa). Light from the combined filament FL of the filament fa and the filament image fb is converted into a substantially parallel light beam by the collector lens CL. At this time, a surface conjugate with the field stop FS is formed at the rear focal position of the collector lens CL. The fly-eye lens F is disposed at this position so as to overlap the incident end surface ENT of the fly-eye lens F. At this time, as shown in FIG. 3B, two light source images (filament images) are formed in one cell Se on the exit end face EXT of the fly-eye lens. The filament images are a filament fa filament image far and a first filament image fbm of the filament image fb. Since divergent light beams emitted from the hexagonal cells Se of the fly-eye lens F overlap each other on the field stop FS, for example, even if the light source has a light distribution characteristic, uniform illumination without unevenness is possible. The divergent light beam emitted from the exit surface EXT of the fly-eye lens F is projected onto the aperture stop AS through the relay lens systems RL1 and RL2. The relay magnification is determined by the diameter of the entire fly-eye lens F, the size of the light source S, and the desired light source magnification. A pseudo surface light source is projected onto the aperture stop AS, and illuminates the specimen 12 via the condenser lens CND shown in FIG.
[0027]
In the second embodiment, the total area Si of the light source images formed in the cell Se is the total area So of the light sources (So = 2 × Sf; Sf is the area of the filament fa) and the focal length of the collector lens CL. It is determined by the ratio between fc and the focal length fe of the cell Se, and is expressed by the following relational expression.
Si = So × (fe / fc)
[0028]
Accordingly, the total area Si of the light source image decreases as the focal length fc of the collector lens CL increases, and the area Si of the light source image increases as the focal distance fe of the cell Se increases. When the ratio of the area Si of the formed light source image to the area of the cell Se is expressed as a fullness rate, the fullness rate is expressed by the light source area So, the focal length fc of the collector lens CL, and the cell Se of the fly-eye lens F. It is uniquely determined by the focal length fe.
[0029]
In this embodiment, as shown in FIG. 3C, the area of the cell Se is approximated by the area of the inscribed circle Ce, the radius of the inscribed circle Ce is d, and the shape of the filament fa is the width W and the height. Assuming that the rectangular shape is D2, the composite filament image FL satisfies the following conditional expression (2).
(2) d / 2 <(W ² + (2 × D2) ² ) ^1/2 × (fe / fc) <d
[0030]
Conditional expression (2) defines the sufficiency of the light source on the cell Se. If the lower limit of conditional expression (2) is not reached, the area of the synthetic filament FL image on the cell Se becomes too small (the filling rate becomes too small), and a desired light quantity cannot be obtained. When the upper limit value of conditional expression (2) is exceeded, the area of the synthetic filament FL image projected onto the cell Se becomes too larger than the area of the cell Se, and the amount of light of the synthetic filament FL portion protruding from the cell Se is wasted. Therefore, it is not preferable.
[0031]
In the second embodiment, the height D2 of the filament fa is substantially half of the height D1 of the filament of the first embodiment, and a sufficient filling rate as in the first embodiment can be achieved. For this reason, the power consumption of the light source S can be reduced as compared with the first embodiment.
[0032]
Table 2 below lists specifications of numerical examples of the microscope illumination apparatus according to the second embodiment. In the specification values, W is the width dimension of the filament fa, D2 is the height dimension of the filament fa, fc is the focal length of the collector lens, fe is the focal length of the cell Se of the fly-eye lens F, and d is the inscription of the cell Se. The radius, L, of the circle Ce is the amount of axis shift from the optical axis of the filament fa. In addition, the focal length and other length units in the specification table are generally "mm", but the optical system can be obtained with the same optical performance even when proportionally enlarged or reduced. is not.
[0033]
[Table 2]
W = 4.7
D2 = 2.2
fc = 26
fe = 7.5
d = 1
L = 1.2
Conditional expression (2) corresponding value = 1.85
Good illumination light characteristics can be obtained in the microscope illumination device of the above numerical example.
[0034]
In all the embodiments, as shown in FIG. 4, in the fly-eye lens F, the mount portion Mo attached to the attachment portion of the microscope main body is manufactured by integral injection molding of the cell Se and plastic or glass. Accordingly, it is possible to easily mount the illumination optical system, and to provide the fly-eye lens F with a certain quality and at a low cost.
[0035]
A field stop FS surface is formed between the relay optical systems RL1 and RL2. Here, if the chromatic aberration remains in the relay optical systems RL1 and RL2, the diaphragm appears to be colored during observation. Therefore, it is desirable that the relay optical system uses a cemented lens for correcting chromatic aberration.
[0036]
The cross-sectional shape of the cell Se of the fly-eye lens F is not limited to a hexagon, but may be a polygonal shape or a circular shape. In addition to the filament, a high-intensity lamp such as a halogen lamp or a mercury lamp, an LED, an LD, an LED array, an LD array, or the like may be used as the light source. What is formed is preferred.
[0037]
The above-described embodiment is merely an example, and is not limited to the above-described configuration and shape, and can be appropriately modified and changed within the scope of the present invention.
[0038]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a microscope illumination apparatus that can secure bright illumination light with a wide field of view and a microscope having the same, regardless of the magnification of the objective lens.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a microscope equipped with a microscope illumination device according to the present invention.
2A and 2B are schematic views of the microscope illumination apparatus according to the first embodiment of the present invention, FIG. 2A is a schematic view of an illumination optical system, and FIG. 2B is a diagram of a light source image on one element of a fly-eye lens. An example is shown, and (c) shows an inscribed circle of one element of the fly-eye lens.
3A and 3B are schematic views of a microscope illumination apparatus according to a second embodiment of the present invention, FIG. 3A is a schematic view of an illumination optical system, and FIG. 3B is a diagram of a light source image on one element of a fly-eye lens. An example is shown, (c) shows the inscribed circle of one element of the fly-eye lens, and (d) shows the image forming positional relationship of the filament by the concave mirror.
FIG. 4 shows an example of a fly-eye lens in which a mount portion used in an embodiment of the present invention is integrally molded.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Microscope illumination apparatus 10 Stage 12 Sample 14 Objective lens 16 Eyepiece 20 Transmission microscope S Light source CL Collector lens F Fly eye lens FS Field stop AS Aperture stop RL1, RL2 Relay lens Se Cell (one element)
d Radius Ce Inscribed circle fa Filament W Filament width D1, D2 Filament height Mi Concave mirror fl, fb, far, fbm Filament image I Optical axis FL Synthetic filament

Claims (5)

A light source for supplying illumination light;
A collector lens for converting divergent light emitted from the light source into a substantially parallel light beam;
A fly-eye lens disposed at the rear focal position of the collector lens;
A relay optical system for relaying a pseudo surface light source formed on the exit end face of the fly-eye lens to an aperture stop or a surface conjugated to the aperture stop,
W is the width dimension of the light source, D1 is the height dimension of the light source, fc is the focal length of the collector lens, fe is the focal length of one element constituting the fly-eye lens, and d is the fly-eye lens. When the radius of the inscribed circle of one element is used,
The light source, the collector lens, and the fly eye lens are
d / 2 <(W ² + D1 ² ) ^1/2 × (fe / fc) <d
Microscope illumination device characterized by satisfying On the side facing the collector lens side with respect to the position of the light source, a concave mirror having the light source position as a substantially focal position,
W is the width dimension of the light source, D2 is the height dimension of the light source, fc is the focal length of the collector lens, fe is the focal length of one element constituting the fly-eye lens, and d is the fly-eye lens. When the radius of the inscribed circle of one element is used,
The light source, the collector lens, and the fly eye lens are
d / 2 <(W ² + (2 × D2) ² ) ^1/2 × (fe / fc) <d
The microscope illumination device according to claim 1, wherein: The microscope illumination apparatus according to claim 1, wherein the fly-eye lens has a hexagonal shape as one element, and a flange portion to be attached to the microscope main body is integrally formed. The microscope illumination apparatus according to claim 1, wherein the light source is made of a filament. A microscope comprising the microscope illumination device according to claim 1.

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