JP2009008701A - Illuminator and zoom microscope with this illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator having a means for coping with pupil face movement caused by zooming, without requiring a zoom system in which a conjugated relation between an image and a pupil, complicating the configuration, is maintained, and to provide a zoom microscope that has this illuminator. <P>SOLUTION: The illuminator 20 is disposed in the zoom microscope 30 having, in order from a specimen face 10a, an objective lens 11, aperture diaphragm 12, and afocal zoom system 13, and is used to emit illuminating light to the specimen face 10a via the afocal zoom system 13, aperture diaphragm 12 and objective lens 11. The illuminator 20 includes, in order from the afocal zoom system 13 toward the light source, an imaging lens 15, a pupil position correcting optical system 16, and the light source 18. The pupil position correcting optical system 16 corrects an emission pupil position change, which arises on the light source side of an illuminating optical system as a result of zooming of the afocal zoom system 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coaxial epi-illumination device and a zoom microscope equipped with the illumination device.

In general, a zoom optical system maintains a conjugate relationship between a sample plane and an image plane position (hereinafter referred to as “image plane conjugate relationship”) during zooming, but a phenomenon occurs in which the conjugate relationship between pupil positions changes. For example, in the case of a zoom microscope having an aperture stop on the sample side of the afocal zoom system on the image side of the objective lens, the conjugate relation of the image plane is naturally maintained, but at the same time, the conjugate relation of the pupil plane is also maintained. This is extremely difficult in terms of configuration, and it is an unavoidable phenomenon that the conjugate relationship of the pupil plane changes (for example, see Patent Document 1).
JP 2006-178440 A

  As described above, in the zoom system, it is natural that the conjugate relationship of the image plane is maintained during zooming, but the conjugate relationship of the pupil plane, which is another important factor in constructing the optical system, moves. It is common to do. In the case of a reflective illumination device disposed between the zoom system and the observation barrel, movement of the pupil due to zooming affects the illumination state, which is not preferable. That is, in configuring an apparatus including a zoom system, it is ideal that the conjugate relationship between the pupil plane and the image plane is maintained by zooming, and neither the entrance pupil position nor the exit pupil position is changed. However, when it is intended to construct a zoom system that maintains the conjugate relationship between the image plane and the pupil plane, there is a problem that a large space and a complicated mechanism and optical system are required. In particular, in the case of a microscope having a fixed aperture stop on the sample plane side of the zoom system, the movement of the exit pupil plane tends to be larger than when the aperture stop is in the zoom system.

  The present invention has been made in view of such problems, and provided means for dealing with movement of the pupil plane due to zooming without using a zoom system that maintains a conjugate relationship between the image and the pupil having a complicated configuration. It aims at providing an illuminating device, and also aims at providing the zoom microscope provided with this illuminating device.

  In order to solve the above-described problem, an illumination apparatus according to the present invention includes an objective lens and an afocal zoom system in order from the sample plane, and a pupil (for example, a pupil of the objective lens on the sample plane side of the afocal zoom system) An illumination apparatus that is provided in a zoom microscope in which an aperture stop 12) in the embodiment is located and irradiates a specimen surface with illumination light via an afocal zoom system and an objective lens, and is directed from the afocal zoom system toward the light source side. The imaging lens, the pupil position correction optical system, and the light source are sequentially provided so that the pupil position correction optical system corrects the position change of the exit pupil formed on the light source side of the illumination optical system caused by zooming. Configured.

  In such an illuminating device according to the present invention, the pupil position correcting optical system includes, in order from the sample surface side, a first lens having a negative refractive power, and a first lens having a positive refractive power that is movable along the optical axis. The second lens and the third lens move along the optical axis according to the zooming of the afocal zoom system. It is preferably configured to correct the position change of the exit pupil.

  Alternatively, the pupil position correcting optical system is composed of a movable lens having a positive refractive power that can move along the optical axis in order from the sample surface side, and a diffusion plate, and according to zooming of the afocal zoom system It is preferable that the movable lens is moved to correct the position change of the exit pupil.

  The zoom microscope according to the present invention includes an objective lens, an afocal zoom system, an imaging lens, any one of the above-described pupil position correction optical systems, and a light source in order from the sample surface. Is positioned on the sample plane side of the afocal zoom system, and the pupil position correcting optical system is configured to correct the position change of the exit pupil formed on the light source side of the illumination optical system caused by zooming.

  In such a zoom microscope according to the present invention, the pupil of the objective lens can be matched with the aperture stop provided on the specimen side of the afocal zoom system.

  When the illumination device and the zoom microscope according to the present invention are configured as described above, the pupil position correction optics can move the pupil plane by zooming without using a zoom system that simultaneously maintains the conjugate relationship between the image and the pupil having a complicated configuration. By correcting by the system, Koehler illumination can be realized regardless of the zoom magnification, and the sample surface can be efficiently illuminated.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the configuration of a zoom microscope provided with a reflective illumination device will be described with reference to FIG. The zoom microscope 30 includes an objective lens 11, an aperture stop 12, an afocal zoom system 13, and an imaging lens (second objective lens) 14 arranged in order on the optical axis from the sample surface 10a. A reflective illumination device 20 is disposed between the afocal zoom system 13 and the second objective lens 14. Here, the reflective illumination device 20 includes a light source 18 composed of an optical fiber or the like, a pupil position correcting optical system 16 including a diffusion plate G6 and a movable lens G5, a field stop (field stop surface 10c), an imaging lens 15, and The half mirrors 19 are arranged in this order on the optical axis, and the optical axis of the optical system of the zoom microscope 30 and the optical axis of the optical system of the reflective illumination device 20 are orthogonal, and these optical axes are orthogonal. The half mirror 19 is disposed so as to be positioned. In the zoom microscope 30 having such a configuration, the pupil surface is moved by the zooming of the afocal zoom system 13, so that the situation close to the critical illumination state, that is, only the movable lens G5 of the pupil position correcting optical system is used. Since the situation where the position cannot be completely corrected occurs, the diffusion plate G6 is provided to make the structure of the fiber surface of the light source 18 invisible.

  The light emitted from the light source 18 is diffused by the diffusion plate G6 of the pupil position correcting optical system 16, is uniformly passed through the field stop surface 10c by the movable lens G5, and is converted into a parallel light beam by the imaging lens 15, and is a half mirror. 19 enters. The half mirror 19 is an optical member that reflects a part of the light and transmits the remaining light. The light reflected by the half mirror 19 passes through the afocal zoom system 13 and the aperture stop 12 and is an objective lens. 11 is condensed and irradiated onto the specimen surface 10a. Then, the light reflected by the specimen surface 10a passes through the objective lens 11, the aperture stop 12 and the afocal zoom system 13, becomes a parallel light beam, enters the half mirror 19, and a part of the light is reflected, and the rest. The transmitted light is collected by the second objective lens 14, and an image of the specimen surface 10a is formed on the image surface 10b.

  In such a zoom microscope 30, consider the conjugate relationship of the aperture stop 12 by the afocal zoom system 13 and the imaging lens 15. At this time, if the image position by the afocal zoom system 13 and the imaging lens 15 of the aperture stop 12 is at the same position from the field stop surface 10c regardless of the zoom magnification of the afocal zoom system 13, the light source is transmitted through the movable lens G5. It coincides with the 18 light source surfaces (optical fiber surface or diffuser plate surface), and so-called Koehler illumination can be obtained and good illumination can be performed. However, the image position of the aperture stop 12 generally moves due to zooming. For example, in the case of a zoom microscope having a zoom ratio of 1 × on the low magnification side and 8 ×, the image position of the aperture stop 12 when the zoom magnification is 1 × is 40 mm in the light source direction starting from the field stop surface 10c. In some cases, the zoom magnification is 400 mm when the zoom magnification is 8 times. Therefore, when the movable lens G5 is fixed, the image position of the aperture stop 12 changes as the zoom magnification changes, as can be seen from the way of the light beam shown in FIG. The position (size direction) of LS and the exit pupil position of the illumination optical system that is an image by the optical system from the afocal zoom system 13 of the aperture stop 12 to the movable lens G5 are greatly different.

  As described above, in designing the optical system constituting the illumination apparatus, it is necessary to cope with the change in the exit pupil position. Due to the influence of the change in the exit pupil position due to zooming, the illumination device changes including an intermediate state that can be said to be neither from a case close to Kohler illumination to a case close to critical illumination. Therefore, the light source is required to have both uniformity of the light distribution angle characteristic and uniformity of the light emitting surface. In the Koehler illumination, the uniformity of the light emitting surface is not necessarily required, and in the critical illumination, the uniformity of the angle characteristic is not necessarily required. However, depending on the zooming state, the situation is intermediate, and both are necessary.

  Therefore, the reflection illumination device 20 used in the zoom microscope 30 moves the movable lens (movable lens G5 in FIG. 1) of the pupil position correcting optical system 16 along the optical axis according to the magnification of the afocal zoom system 13. By moving, the correction is performed so that the pupil position becomes substantially constant. Specifically, a controller 40 is provided, and the controller 40 sets the magnification of the afocal zoom system 13 and moves the movable lens G5 of the pupil position correcting optical system 16 according to the magnification. .

  Hereinafter, specific examples of the pupil position correcting optical system will be described. Before that, the afocal zoom system 13 in which the pupil position is corrected by the pupil position correcting optical system will be described. As shown in FIG. 3, for example, the afocal zoom system 13 includes a negative meniscus lens L1 and a biconvex lens L2 having a convex surface facing the object side in order from the aperture stop surface SP (corresponding to the aperture stop 12 described above). A first lens group G1 composed of a lens to which the lens is bonded and a positive meniscus lens L3 having a convex surface facing the object side, a biconcave lens L4, a lens to which a biconvex lens L5 and a biconcave lens L6 are bonded, and a biconcave lens L7. A second lens group G2, a third lens group G3 comprising a lens in which a biconvex lens L8 and a biconvex lens L9 and a negative meniscus lens L10 having a concave surface facing the object side are bonded together; and a positive meniscus lens having a concave surface facing the object side A fourth lens group G4 comprising a lens in which L11 and a negative meniscus lens L12 having a concave surface directed toward the object side are bonded, and a lens barrel; Consists PL, by moving along the second lens group G2 and the third lens group G3 in the optical axis and is capable of changing the zoom magnification (a focal magnification).

  Table 1 shows the specifications of each lens in the afocal zoom system 13. In Table 1, m represents the surface number, r represents the radius of curvature of the lens surface, d represents the distance between the lens surfaces, νd represents the Abbe number of each lens glass material, and nd represents the refractive index with respect to the d-line. The same applies to the specifications of the pupil position correcting optical system described later. F indicates the focal length of the entire afocal zoom system 13. Here, 1 to 26 shown in the surface number m in Table 1 relate to the afocal zoom system 13 and correspond to reference numerals 1 to 22 in FIG. The table 1 also includes specification values of the imaging lens 15 and the field stop surface FS (corresponding to the field stop surface 10c in FIG. 1) not shown in FIG. Corresponds to the imaging lens 15, and the surface number 26 corresponds to the field stop surface FS.

  In addition, unless otherwise specified, “mm” is generally used as the focal length f, radius of curvature r, surface spacing d, and other length units listed in all the following specifications, but the optical system is proportional. Since the same optical performance can be obtained even when the magnification or reduction is performed, the unit is not limited to “mm”, and other appropriate units can be used.

(Table 1)
m r d νd nd
d0
1 ∞ 15.0000 SP
2 120.1967 2.0000 39.57 1.80440 L1
3 48.7980 3.0000 82.56 1.49782 L2
4 -509.0866 0.5000
5 50.4610 3.0000 82.56 1.49782 L3
6 3179.8129 d1
7 -108.0082 1.5000 35.71 1.90265 L4
8 25.8194 2.0000
9 32.8474 3.5000 23.78 1.84666 L5
10 -19.0003 1.0000 60.29 1.62041 L6
11 31.8448 1.5000
12 -25.9839 1.5000 35.71 1.90265 L7
13 228.2515 d2
14 838.2380 6.0000 82.56 1.49782 L8
15 -31.9728 0.2000
16 136.9685 6.0000 82.56 1.49782 L9
17 -39.2120 2.0000 28.55 1.79504 L10
18 -92.0449 d3
19 -339.8016 5.5000 36.24 1.62004 L11
20 -40.8020 1.5000 39.57 1.80440 L12
21 -124.4210 8.017
22 ∞ 50.0000 PL
23 93.0000 8.0000 60.29 1.62041 Imaging lens 15
24 -39.0000 3.0000 35.28 1.74950
25 -110.0000 96.0000
26 ∞ Bf FS

(Variable data)
When zoom is 1x When zoom is 7.5x f 100.0000 750.0000
d0 0.0000 0.0000
d1 2.6024 60.3676
d2 22.8372 2.5051
d3 43.3588 5.9257
Bf 37.5000 476.0000

  As shown in Table 1, when the aperture stop surface SP is arranged at a position 15 mm on the object side of the afocal zoom optical system 13, an image formed by the afocal zoom optical system 13 and the imaging lens 15 of this aperture stop. The position is formed at a position 37.5 mm (Bf) behind the field stop FS when the focal length f of the afocal zoom optical system 13 is 100 mm (corresponding to 1 time), and the focal length of the afocal zoom optical system 13 is When f is 750 mm (equivalent to 7.5 times), it is formed at a position 476.0 mm (Bf) behind the field stop FS.

(First embodiment)
FIG. 4 shows the pupil position correcting optical system 16 according to the first example. This configuration enables the movable lens G5 in FIG. 1 to move in the optical axis direction according to the zoom magnification of the afocal zoom system 13. The exit pupil position is made to coincide with or be as close as possible to the light source surface LS of the light source 18. The base end side of the arrow shown in FIG. 4 indicates the position of the movable lens G5 when the afocal zoom system 13 is at the low magnification end (for example, 1 ×), and the tip side of this arrow is the end of the afocal zoom system 13 at the high magnification end. The position of the movable lens G5 when it is (for example, 7.5 times) is shown. Table 2 below shows the specification values of each lens in the pupil position correcting optical system 16, and 1 to 4 indicated by the surface number m correspond to reference numerals 1 to 4 shown in FIG. 4. Table 2 shows the specifications when the magnification of the afocal zoom system 13 is 1 and 7.5.

(Table 2)
When zoomed 1x, m r d νd nd
d0 = -37.500
1 ∞ 39.0000 FS
2 21.0000 3.0000 64.10 1.51680 G5
3 -21.0000 4.0000
4 ∞ -10.0000 LS

M r d νd nd at zoom 7.5 times
d0 = -476.000
1 ∞ 24.0000 FS
2 21.0000 3.0000 64.10 1.51680 G5
3 -21.0000 19.0000
4 ∞ 0.0000 LS

  As shown in Table 2, when the zoom magnification of the afocal zoom optical system 13 is 1, the movable lens G5 (surface numbers 2 and 3) is positioned 39 mm behind the field stop surface FS (surface number 1). An image of the aperture stop 12, that is, an exit pupil is formed at a position 10 mm ahead (−10 mm from LS) of the light source surface LS (surface number 4). On the other hand, when the zoom magnification is 7.5 times, the movable lens G5 is disposed at a position 24 mm behind the field stop surface FS, and the light source surface LS and the image of the aperture stop 12 (exit pupil) completely overlap. Yes. FIG. 5 shows the state of the light flux of the pupil position correcting optical system 16 when the zoom magnification is 1 × and when the zoom magnification is 7.5 ×. As is apparent from FIG. 5, when the zoom magnification of the afocal zoom optical system 13 is 1, the light source surface LS and the exit pupil position are deviated by 10 mm, and the zoom is not completely corrected. When the magnification is 7.5, the light source surface LS and the exit pupil position are completely overlapped and corrected by the pupil position correcting optical system 16. For this reason, when the pupil position correcting optical system 16 according to the first embodiment is used, it becomes almost Koehler illumination state regardless of the zoom magnification of the afocal zoom optical system 13, and does not depend on the luminance distribution of the light source surface LS (fiber surface). Good illumination can be obtained. In the first embodiment, as described above, the pupil position cannot be completely corrected when the zoom magnification is 1, so that it is preferable to provide the diffusion plate G6.

(Second embodiment)
FIG. 6 shows the pupil position correcting optical system 17 according to the second example. In order from the object side, the first lens G7 composed of a biconcave lens, the second lens G8 composed of a biconvex lens, and the biconvex lens. The third lens G9 is composed of three groups. The pupil position correcting optical system 17 is also disposed between the field stop surface 10c and the light source 18 in the same manner as in the first embodiment. The first lens G7 is fixed and the afocal zoom optical system 13 is fixed. According to the zoom magnification, the second lens G8 and the third lens G9 are moved in the opposite directions along the optical axis so that the exit pupil position coincides with the light source surface LS. In FIG. 6, the base end side of the arrow indicates the position of the second and third lenses G8 and G9 when the afocal zoom system 13 is at the low magnification end (for example, 1 ×). The side shows the positions of the second and third lenses G8 and G9 when the afocal zoom system 13 is at the high magnification end (for example, 7.5 times). Table 3 below shows the specification values of each lens in the pupil position correcting optical system 17, and 1 to 8 shown in the surface number m correspond to reference numerals 1 to 8 shown in FIG. Table 3 also shows the specifications when the magnification of the afocal zoom system 13 is 1 × and 7.5 ×.

(Table 3)
When zoomed 1x, m r d νd nd
d0 = -37.500
1 ∞ 10.0000 FS
2 -24.0000 2.0000 53.88 1.71300 G7
3 24.0000 1.0000
4 370.0000 3.0000 53.88 1.71300 G8
5 -27.0000 35.5000
6 27.0000 3.0000 53.88 1.71300 G9
7 -370.0000 22.5000
8 ∞ 0.0000 LS

M r d νd nd at zoom 7.5 times
d0 = -476.000
1 ∞ 10.0000 FS
2 -24.0000 2.0000 53.88 1.71300 G7
3 24.0000 8.0000
4 370.0000 3.0000 53.88 1.71300 G8
5 -27.0000 3.0000
6 27.0000 3.0000 53.88 1.71300 G9
7 -370.0000 48.0000
8 ∞ 0.0000 LS

  As shown in Table 3, when the zoom magnification of the afocal zoom optical system 13 is 1, the first lens G7 (surface numbers 2 and 3) is positioned 10 mm behind the field stop surface FS (surface number 1). Is disposed, a second lens G8 (surface number 4, 5) is disposed at a position 1 mm behind the first lens G7, and a third lens G9 (surface is disposed at a position 35.5 mm behind the second lens G8. Numbers 6, 7) are arranged. On the other hand, when the zoom magnification is 7.5 times, similarly, the first lens G7 is disposed at a position 10 mm behind the field stop surface FS, and the second lens G8 is disposed at a position 8 mm behind the first lens G7. Further, the third lens G9 is disposed at a position 3 mm behind the second lens G8. In both zoom positions, the light source surface LS (surface number 8) and the exit pupil position completely overlap with the pupil conjugate position. FIG. 7 shows the state of the light flux of the pupil position correcting optical system 17 when the zoom magnification is 1 and 7.5. As is apparent from FIG. 5, when the pupil position correcting optical system 17 according to the second embodiment is used, a Koehler illumination state is obtained regardless of the zoom magnification of the afocal zoom optical system 13, and the light source surface LS (fiber surface) Good illumination can be obtained regardless of the luminance distribution of

It is explanatory drawing which shows the structure of a zoom microscope. It is explanatory drawing which shows the change of the exit pupil position by the change of the magnification of an afocal zoom optical system, (a) shows the time of zoom 1 time, (b) shows the time of zoom 7.5 times. It is sectional drawing which shows the lens structure of an afocal zoom optical system. It is sectional drawing which shows the lens structure of the pupil position correction | amendment optical system which concerns on 1st Example. FIG. 4 is an explanatory diagram showing a state of an exit pupil position by the pupil position correcting optical system according to the first embodiment, where (a) shows when the zoom is 1 × and (b) shows when the zoom is 7.5 ×. . It is sectional drawing which shows the lens structure of the pupil position correction | amendment optical system which concerns on 2nd Example. It is explanatory drawing which shows the state of the exit pupil position by the pupil position correction | amendment optical system which concerns on the said 2nd Example, (a) shows the time of zoom 1 time, (b) shows the time of zoom 7.5 times. .

Explanation of symbols

10a Sample surface 10c Field stop surface 11 Objective lens 12 Aperture stop (pupil of objective lens) 13 Afocal zoom system 15 Reflection illumination system imaging lens 16, 17 Pupil position correcting optical system 18 Light source 20 Illumination device 30 Zoom microscope G5 Movable lens G6 Diffuser G7 First lens G8 Second lens G9 Third lens

Claims (5)

The objective lens and the afocal zoom system are provided in order from the sample plane, and are provided in a zoom microscope in which the pupil of the objective lens is located on the sample plane side of the afocal zoom system, and the afocal zoom system and the objective lens An illumination device for illuminating the specimen surface with illumination light through a lens,
In order from the afocal zoom system toward the light source side,
An imaging lens;
A pupil position correcting optical system;
A light source,
An illumination device configured to correct a position change of an exit pupil formed on the light source side of the illumination optical system, which is generated by zooming of the afocal zoom system, wherein the pupil position correction optical system is. The pupil position correcting optical system is
In order from the specimen surface side,
A first lens having negative refractive power;
A second lens having a positive refractive power that is movable along the optical axis;
A third lens having a positive refractive power movable along the optical axis,
2. The illumination device according to claim 1, wherein the second lens and the third lens are moved along an optical axis in accordance with zooming of the afocal zoom system to correct a position change of the exit pupil. The pupil position correcting optical system is
In order from the specimen surface side,
A movable lens having a positive refractive power movable along the optical axis;
A diffusion plate, and
The illumination device according to claim 1, wherein the movable lens is moved in accordance with zooming of the afocal zoom system to correct a change in position of the exit pupil. Objective lens in order from the sample surface,
An afocal zoom system,
An imaging lens;
The pupil position correcting optical system according to any one of claims 1 to 3,
A light source,
The pupil of the objective lens is located on the specimen surface side of the afocal zoom system;
A zoom microscope configured such that the pupil position correcting optical system corrects a position change of an exit pupil formed on a light source side of an illumination optical system caused by zooming.   The zoom microscope according to claim 4, wherein a pupil of the objective lens is an aperture stop provided on a specimen surface side of the afocal zoom system.

Images