JPH01285912A - Illuminating optical device for stereomicroscope - Google Patents

Abstract

PURPOSE:To deal with a change in intersection angles while making effective utilization of the luminous flux of a light source so that Kohler's illumination is always maintained by constituting the optical device in such a manner that the two light source images formed by light source image forming means and beam splitting means are made approximately conjugate with the respective incident pupils of condenser lenses. CONSTITUTION:Two reflecting means 51, 52 having the functions to intersect the optical axes of the respective luminous fluxes bisected by the beam splitting means 4 via the light source image forming lens 3 with each other at the center of the visual field on a sample surface and to reflect and turn the same so as to align the axes to the centers of the respective incident pupils 18 of the stereomicroscope are disposed. The device is so constituted that the two light source images formed by the light source image forming means 3 and the beam splitting means 4 are made approximately conjugate with the respective incident pupils P of the stereomicroscope with respect to the condenser lenses. The Kohler's illumination making the effective utilization of the luminous flux of the light source is thereby executed. The Kohler's illumination can be maintained as well even at the time of exchanging objective lenses.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates in particular to a Köhler illumination optical device for a stereomicroscope.

[Conventional technology]

Conventional lighting devices of this type are disclosed in, for example, Japanese Patent Application Laid-open No. 1986-
This is disclosed in JP-A No. 112011 and the like.

Therefore, the optical system of this illumination device will be explained with reference to FIG. 5, which shows a schematic configuration diagram of the device disclosed in this publication.

The illumination optical system includes a light source 1, a collector lens 2, and a pair of light source image forming lenses 201 and 202, which are arranged symmetrically about the optical axis of the collector lens 2.
and a condenser lens 7 arranged coaxially with the condenser lens 7, respectively.

On the other hand, the observation optical system includes a stage glass 8, an object lens 9, a variable magnification optical system M (101 to 121, 102 to 122) arranged symmetrically about the optical axis of this objective lens 9,
It consists of a configuration in which image loch tabrhythm +3], 132, and eyepiece lenses 141 and 142 are provided in this order.

The illumination optical system and observation optical system constitute an optical system of the stereomicroscope.

In a conventional illumination optical system having such a configuration, the collector lens 2 and the condenser lens 7 are arranged so that the light flux supplied from the light beam 18X1 is imaged on the stereo microscope. An appropriate pair of light rays incident on the center of a pair of entrance pupils P are selected, and light source imaging lenses 201 and 202 are placed on each light ray.

Then, a pair of light source images 1. , ,l,
□ is formed.

Then, this pair of light source image forming lenses 201.2 (12
Let each chief ray pass through the center of - Jigasos 10
With respect to the indenser lens 7 and stage glass 8, this light source image ■
8. By determining the positions of the light source image forming lenses 201 and 202 so that ■1□ and the pair of entrance pupils P of the stereomicroscope are each conjugate, a light source image 1z is formed on each entrance pupil P of the stereomicroscope. , I+□ can be reimaged.

Therefore, Koehler illumination is substantially realized by such a configuration of the illumination optical system.

[Problem to be solved by the invention]

However, the conventional techniques described above do not necessarily aim to effectively utilize the luminous flux of the light source.

That is, as shown in FIG. 6, a pair of light source image forming lenses 201 and 202 are arranged symmetrically about the optical axis of the collector lens 2, and in this case, a portion of the light flux supplied from the light tA1, that is, each Only the light beams incident on the light source image forming lenses 201 and 202 are guided to each observation optical system. Therefore, it is basically impossible to effectively utilize the light source luminous flux.

Furthermore, the effective diameter of the light source image forming lenses 201 and 202 must be smaller than the diameter of the observation field area (hereinafter referred to as observation area) in a low magnification state that is included in the observation optical system. Difficult to do lighting. therefore,
In order to make the illumination optical system somewhat compact while the illumination light beam fills the entire observation area in a low magnification state, the imaging magnification of the light source image forming lenses 201 and 202 is made small, and the F number of the condenser lens 7 is made small. There is a need. As a result, large aberrations occur, causing uneven illumination. In particular, in a stereomicroscope, the light beam from the light source obliquely enters the condenser lens 7, which causes significant aberrations, which causes asymmetric illumination unevenness.

Therefore, in the illumination of a conventional stereoscopic microscope, in principle, illumination unevenness is likely to occur, and there are many problems in that the light ffi+ is often lost.

Also, a pair of light source image forming lenses 201 and 202 provide two
The light source image forming lens 201.2 is configured so that the optical axis of the divided light beam intersects the center of the field of view of the sample surface.
The angle θ (hereinafter abbreviated as the intersection angle) between the optical axis of the light beam divided into two by 02 and the optical axis of the objective lens 9 is determined by the diameter of the collector lens.

Therefore, as shown in FIG. 4 fal, if the focal length of the objective lens 91 is f and the distance between the optical axes of the pair of observation optical systems is l, then the intersection angle is θ, = tan ''(7!/2f )
This intersection angle θ1 depends on the focal length of the objective lens 91, as is clear from this equation. Generally, the intersection angle within the range required in a stereomicroscope is approximately inversely proportional to the focal length of the objective lens.

For example, as shown in FIG. 4 (bl), when changing the magnification by replacing the objective lens 92 with a focal length of f/2 in order to double the observation magnification, the intersection angle θ2 becomes θ2# 2θ1
This is approximately twice as large as the intersection angle of θ1.

Therefore, approximately twice the crossing angle is required to maintain Kohler illumination.

However, in the configuration of the conventional technology shown above,
Since the intersection angle is determined by the diameter of the collector lens, a diffusion filter is placed between the optical paths of the pair of light source image forming lenses 201 and 202 and the objective lens 9 in order to achieve the desired intersection that corresponds to the exchange of the objective lens. It was necessary to perform illumination or replace the source imaging lenses 201, 202.

However, since the light is diffused, there is a problem in that the loss of illumination luminous flux is large and the illumination efficiency is significantly degraded.

Therefore, the present invention solves all these problems and
It is an object of the present invention to provide an illumination optical device for a stereomicroscope that can cope with changes in the intersection angle due to exchange of objective lenses and can always maintain Koehler illumination while effectively utilizing the light source luminous flux.

[Means to solve the problem]

In order to achieve the objects stated in item 2, the present invention provides a light source image of each of the light source beams for illuminating the sample surface in two directions having a predetermined angle, at or near each entrance pupil position of the stereomicroscope. In the illumination optical device of a stereomicroscope that re-images, as shown in FIG. 1A, a light source means 1 for supplying a light source beam
, a collector lens 2 that converts the light source light flux from the light source means 1 into a substantially parallel light flux, a light source image forming means 3 that forms a light source image with the light flux passing through the collector lens 2, and a light flux that forms this light source image. a condenser lens 7 for illuminating the sample surface, and a beam splitting means for splitting the light beam passing through the light source image forming means 3 into two light beams between the optical path of the light source image forming means 3 and the condenser lens 7. 4, and 2 which has the function of reflecting and turning the optical axes of these two light beams so that they intersect at the center of the field of view on the sample surface and match the center of each entrance pupil of the stereomicroscope.
two reflecting means are arranged so that the two light source images formed by the light source image forming means 3 and the light beam splitting means 4 are substantially conjugate with each entrance pupil of the observation optical system with respect to the condenser lens 9. It is constructed.

[For production]

In the present invention, the optical axes of the respective light beams divided into two by the light beam splitting means 4 through the light source image forming lens 3 are made to intersect at the center of the field of view on the sample surface, so that each entrance pupil 1 of the stereomicroscope is divided into two parts.
The two light source images formed by the light source image forming means 3 and the light beam splitting means 4 are formed by a condenser lens. By configuring the stereomicroscope so that each entrance pupil P is approximately conjugate with respect to
It is possible to perform Kohler illumination that aims to effectively utilize the light source luminous flux.

When replacing the objective lens, the two reflecting means are placed at predetermined positions so that the optical axes of the respective beams passing through the beam splitting means intersect at the center of the field of view on the sample surface. , Köhler illumination can be maintained.

Also, between the optical path of the collector lens and the beam splitting means,
By removably configuring the light source image magnification optical system 21 that can change the magnification of the light source image, the light source image can be adjusted to an appropriate size so as to correspond to the change in the size of the entrance pupil due to the magnification change of the variable optical system. The observation area and the illumination area can be made to substantially match each other by changing the magnification of the image. Therefore, it is possible to achieve even and efficient illumination, and at the same time, flare, ghost, etc. can be reduced.

〔Example〕

FIG. 1A shows a schematic configuration diagram of a first embodiment of the present invention, and the present invention will be described in detail below with reference to this figure.

The illumination optical system in the first embodiment includes, in order from the light source side, a light source l as a light source means, a collector lens 2, a light source image forming lens 3 as a light source image forming means, a beam splitter 4 as a light beam splitting means, and a beam splitter 4 as a light beam splitting means. A reflecting member 51 as a reflecting means in the reflection direction of the beam splitter 4, a reflecting member 6 in the transmission direction of the beam splitter 4, a reflecting member 52 as a reflecting means, and a condenser in the reflecting direction of the two reflecting means 51 and 52. The lens 7 is arranged respectively.

On the other hand, in the observation optical system, a stage glass 8 and an objective lens 91 are respectively arranged behind this condenser lens 7, and a variable magnification optical system M is arranged symmetrically to the optical axis of this objective lens 91.
(101-121, 102-122), Image Lochta Bism +31, 132, Eyepiece 141.
142 are arranged respectively.

The light flux supplied from the light source 1 is converted into a substantially parallel light flux by the 2l rectifier lens 2, and after passing through the light source image forming lens 3, the light flux is directed by the beam splitter 4 to a plane direction perpendicular to the optical axis of the collector lens 3. The light beam is divided into two parts: a reflected light beam that is reflected and turned, and a transmitted light beam.

Then, this reflected light beam is reflected and turned by the reflection member 51 at a reflection angle of α so that the light ray traveling along the optical axis of the reflected light beam is guided to the center of the visual field of the sample surface of the stage glass 8.

On the other hand, the transmitted light beam is reflected and turned by the reflecting member 6 at an appropriate angle of about 90 degrees, and this reflected light beam is changed by the reflecting means 52 so that the light = 11- line traveling along the optical axis of this reflected light beam is reflected by the reflecting means 52. It is reflected and turned at a reflection angle of β so as to be guided to the center of the field of view of the sample surface of the cover glass 8.

Here, the light source 1 is conjugate with two light source images 1 and 11 with respect to the collector lens 2 and the light source image forming lens 3, and the light source images 1 and 1 are approximately at the focal position of the light source image forming lens 3. 1□ is formed and serves as a substantial secondary light source.

In this way, the two light beams reflected by the two reflecting means 51 and 52 are guided to the stage glass 8 by the condenser lens 7, and uniformly illuminate the observation area of the sample surface on the stage glass at a predetermined angle. .

The optical axis of each light beam illuminating the sample surface at a predetermined angle enters the objective lens 91 at a predetermined crossing angle θ so that it coincides with the center of the entrance pupil P of the stereomicroscope.

Then, each light beam that has passed through the stage glass 8 passes through the objective lens 91 and is then connected to each variable magnification optical system M (101 to 101).
121, 102 to 122), and forms secondary light source images (2) and (2) in this variable magnification optical system.

Here, the light source image r .12□ are formed at a pair of entrance pupils P of the stereomicroscope.

Then, this variable magnification optical system M (101 to 12+, 1
02 to 122) passes through the image rotor beam 131.132, the eyepiece lens 141.142, and is guided to the eye point (E, P,). Therefore, with this configuration, the light flux is substantially the same as the Kohler beam. Lighting can be done.

Further, the light beam from the sample located at the center of the observation area is converted into a parallel light beam by an objective lens 91 placed at a focal distance position from the stage glass 8, and is converted into a parallel light beam by each variable magnification optical system M.
, the object image I behind it by passing through the image Rocheetahism 131,132. form. Then, the light beam that formed this object image of 1° passes through the eyepiece lens 1.
4], 142 and the eye point (Ii, ++,
), and this object image I at this eye point 1-(E, P,). You can observe the virtual image of By moving the lenses of each variable magnification optical system M along the respective optical axes, it is possible to continuously change the magnification of the object image 1o from the low magnification region to the optical magnification region.

By the way, as described above, for example, if the objective lens is replaced with an objective lens having a focal length of f/2 in order to double the observation magnification, an intersection angle approximately twice as large is required to perform Koehler illumination.

Therefore, in order to take such a measure, first replace the objective lens 92 with a smaller focal length, and move the entire observation optical system up to the position of the objective lens 92 as shown by the dotted line in FIG. 1A along the optical axis of the objective lens 92. along the direction towards the light source. Then, in conjunction with the replacement of the objective lens 92, each of the reflecting means 5I and 52 is displaced by a predetermined displacement amount Δ1 and Δ2, respectively, and each reflecting means 51 is moved to the position shown by the dotted line.
．． 52.

Thereafter, the reflection angles are adjusted so that the optical axis of the beam split into two by the beam splitter 4 intersects the center of the field of view on the sample surface of the stage glass 8 and coincides with the center of the pair of entrance pupils P. Reflection means 51 until Δα, β−Δβ.
．． 52 should be swung.

That is, in order to obtain a desired intersection angle, the reflecting means 51 and 52 are respectively displaced by predetermined displacement positions as necessary, and then the optical axis of the beam split into two by the beam splitter 4 is aligned with the stage glass 8. The reflecting means 51 and 52 may be swung so as to intersect with the center of the field of view on the sample surface and coincide with the center of the pair of input η·1 pupils P.

Therefore, with this configuration, Koehler illumination can always be achieved even when changing the magnification by replacing the objective lens.

Specifically, the system in this first embodiment is '4Jll.
To explain the system, as shown in the block diagram of Figure 1B,
When replacing the objective lens, there is a detection means 25 for detecting the magnification of the objective lens, a calculation means 26 for calculating the necessary movement amount and reflection angle of the reflection means based on this detection signal, and a calculation means 26 for calculating the necessary movement amount and reflection angle of the reflection means based on this detection signal. a driving means 27 for moving each reflecting means to a predetermined position, and a swinging means 28 for swinging each reflecting means to a predetermined reflection angle in response to this calculation signal = 15- The structure has the following.

The signal from the detection means 25 is input to the calculation means 26, where the optical axis of the beam split into two by the beam splinter 4 intersects the center of the field of view on the sample surface of the stage glass 8, and the observation optical system The amount of movement and angle of reflection required to match the centers of a pair of entrance pupils are calculated, and an output signal corresponding to the required amount of movement and angle of reflection is output. This calculating means 26 can be operated by changing the objective lens to reflect the reflecting member 51.5.
It is desirable to have a structure having an element such as a ROM in which the movement amount and reflection angle necessary for 2 are stored in advance. The drive means 27 having two drive motors provided in the reflection means 51.52 of each customer drives the drive motors based on the output signal from the calculation means 23, and
move it to the specified position. Thereafter, the swinging means 28 having two drive motors drives the motors again based on the output signal from the calculation means 23, and swings the reflecting members 51 and 52 until a predetermined reflection angle is reached.

Therefore, with such a configuration, even if the objective lens is replaced, Kohler illumination can always be performed automatically.

Incidentally, since the optical path length between the beam splinter 4 and the condenser lens 7 changes slightly with the movement of the reflecting means described in the first embodiment, the positions of the pair of secondary light source images may vary depending on the position of the pair of secondary light source images in the observation optical system. Although there is a slight movement from the pair of pupil devices, there is virtually no problem in practice, and approximately Koehler illumination can be maintained.

However, this pupil variation can be suppressed by moving the collector lens 2, the light source image forming lens 3, etc. along the optical axis in conjunction with the movement of the reflecting means.

Furthermore, in the second embodiment, as shown in FIG.
Instead of the two reflecting means mentioned in the first embodiment above,
A plurality of reflective members 531 to 53 are provided on the disks 530 and 540.
The structure includes two rotary reflecting means 53 and 54, each having a design number of 3.541 to 543.

The plurality of reflecting members are provided in a number corresponding to the number of objective lenses to be replaced. Then, each of these reflection parts is rotated by the rotation of the disc so that it can be reflected and turned to the intersection angle required for the objective lens to be replaced while it is set in a predetermined position like the reflection members 531 and 541. It is disposed obliquely with respect to the radial direction of the disc at a predetermined distance from the axis O.

In order to ensure that each of these reflecting members is set at a position where the beam split into two by the beam splitter is guided to the sample surface at a predetermined intersection angle,
Although not shown, a click stop or the like is provided.

Therefore, depending on the magnification change by replacing this objective lens,
By rotating each of the discs 530 and 540 about the rotation axis O in the direction of the arrow, a desired reflecting member can be reliably set at a predetermined position.

The control system having the configuration of the second embodiment includes a detection means 25 for detecting the magnification of the objective lens when replacing the objective lens, and a detection means 25 for detecting the magnification of the objective lens, and until a desired reflecting member is set at a predetermined position based on this detection signal. and a rotating means 30 which rotates the disks 530 and 540 respectively around the rotation axis 0 based on the calculation signal and moves the reflecting means to a predetermined position by seven steps. ing.

The signal from the detection means 25 is input to the calculation means 29, where the optical axis of the light beam split into two by the beam splitter 4 intersects the center of the field of view on the sample surface of the stage glass 8, and the observation optical system The amount of rotation required to match the centers of a pair of entrance pupils is calculated, and an output signal corresponding to the required amount of rotation is output.

This calculation means 29 is operated by a disk 23 by exchanging the objective lens.
As in the first embodiment, it is preferable to use a device such as a ROM in which the amount of rotation required for 24 is stored in advance. The rotating means 27 having two drive elements is
The motor is driven based on the output signal from the calculation means 26 until the desired reflective part is set at a predetermined position.
The disks 530 and 540 are each rotated around the rotation axis 0.

Therefore, in the second embodiment, as in the first embodiment, Koehler illumination can always be performed automatically even if the objective lens is replaced.

Note that by rotating a desired reflecting member and placing it in a predetermined position, the optical path length between the beam splitter 4 and the condenser lens 7 changes slightly, as in the first embodiment. Although the position of the secondary light source image moves slightly from the position of the pair of pupils in the observation optical system, there is almost no problem in practice.

However, by providing the reflective surface of each reflective member with an appropriate curvature, it is possible to extremely effectively suppress this variation in pupil position.

In addition, fine adjustment of the intersection angle on the sample surface can be done using the disk 530.5.
40 may be slightly rotated, or each reflecting member may be oscillated so as to achieve a predetermined reflection angle.

In addition, the detection method in each embodiment includes attaching a detection mark to the objective lens and detecting this mark, detecting the magnification number engraved on the objective lens, or manually changing the objective lens to be replaced. There are ways to specify the magnification.

Furthermore, as the magnification of the variable magnification optical system is increased in order to observe the sample at a high observation magnification, the observation area φ becomes smaller. Therefore, if the illumination area φ does not change in accordance with the change in the observation area, the brightness of the observation area will become extremely dark, and flare, ghost I, etc. will occur.

Therefore, It'! When observing a sample at a magnification of 1.1, as shown in FIG. 38, each light source image 1. ■1□Convergent lens group 211 and diverging lens group 212 so that the position remains unchanged.
A light source image magnification changing optical system 21 is disposed.

The principle of this light source image magnification changing optical system 21 will be explained below while comparing tar and fbl in FIG. 3B.

Each light source image 18, ++z
is magnified and the illumination aperture is enlarged accordingly.

Then, the angle of union between the outermost ray of light that has passed through the light source image magnification optical system 21 and the optical axis is reduced to θ4×θ, so that the illumination area φ can be made smaller.

Therefore, even when observing a sample by changing the magnification to a high observation ratio of 1゛τ using the variable magnification optical system M, it is possible to substantially match the illumination area and the observation area, improving the illumination efficiency. Moreover, flare, gose 1, etc. can also be reduced.

In this way, since the light source image magnification optical system 21 is arranged so that the positions of the light source images II+ and ■1□ remain unchanged, even if the light source images r and r12 are magnified, the Kohler Lighting can be maintained.

In addition, the group spacing in the light source image magnification optical system 21 is changed along the optical axis so that the light source image can be continuously variable in magnification.
It is also possible to change the illumination area in conjunction with the change in the observation area due to magnification change, so that the illumination area and the observation area always match.

Further, this variable magnification optical system 21 is also effective in the second embodiment.

Furthermore, it goes without saying that the present invention is not limited to such embodiments.

〔Effect of the invention〕

While changing the objective lens, Koehler illumination can always be achieved even when the objective lens is changed (0), and the variable magnification optical system allows for efficient illumination both at high magnification and during observation. Since it is possible to secure a light intensity of -1 minute, it is sufficient to handle biological samples that require a fast observation speed.Furthermore, in high magnification observation conditions, the brightness of the observation area has traditionally been low. However, since it is now possible to match the illumination area and the observation area by changing the illumination area according to the magnification change using the variable magnification optical system, the fluctuation in brightness has been reduced. In addition, it is possible to reduce flare, ghost, etc. Also, since all the light source light flux including the collector lens can be used effectively, even if the magnification of the light source image is increased, it will remain in a low magnification state. In addition, unlike conventional illumination optical systems, instead of using the peripheral light source light flux that passes through the collector lens as illumination light, the light source light flux that has passed through the collector lens is used as a beam splitter. Since the light beam is divided into two light beams such as -, and the entire divided light beam is used as illumination light, it is advantageous in correcting aberrations and can suppress the occurrence of uneven illumination.

[Brief explanation of the drawing]

FIG. 1A is a schematic block diagram of the first embodiment of the present invention, FIG. 1B is a block diagram of the first embodiment, and FIG. 2A is a schematic block diagram of the reflecting means of the second embodiment of the present invention.
Figure B is a block diagram of the second embodiment, and Figure 3A is the block diagram of the first embodiment.
Figure 38 shows the arrangement of the light source image magnification optical system in the embodiment, Figure 38 (ta+ and (bl) is a diagram showing the principle of the light source image magnification optical system, and Figure 4 shows how the intersection angle changes as the objective lens is replaced. Fig. 5 is a schematic configuration diagram of a conventional stereoscopic microscope, and Fig. 6 is an arrow diagram in Fig. 5. [Explanation of main parts]

Claims (1)

[Claims] 1) A stereomicroscope that re-images each light source image of a light source beam for illuminating a sample surface in two directions with predetermined angles at or near each entrance pupil position of the stereomicroscope. The illumination optical device includes: a light source unit that supplies a light source beam; a collector lens that converts the light source beam from the light source unit into a substantially parallel beam; and a light source image forming unit that forms the light source image using the light beam that has passed through the collector lens. and a condenser lens for illuminating the sample surface with the light beam forming the light source image, and the light beam passing through the light source image forming means is divided into two light beams between the optical path of the light source image forming means and the condenser lens. a beam splitting means for dividing the two beams into two beams, and a function of reflecting and turning the two beams so that the optical axes of the two beams intersect at the center of the field of view on the sample surface and coincide with the center of each entrance pupil of the stereomicroscope. and two reflecting means arranged so that the two light source images formed by the light source image forming means and the light beam splitting means are substantially conjugate with each entrance pupil of the stereomicroscope with respect to the condenser lens. An illumination optical device for a stereomicroscope. 2) The illumination optical device for a stereomicroscope according to claim 1, wherein the two reflecting means are configured to be respectively arranged at predetermined positions in response to replacement of the objective lens. 3) The reflecting means has a plurality of reflecting members that are rotatably provided around a rotation axis and are each provided in a predetermined positional relationship with respect to the rotation axis, and the reflection means is rotatable around a rotation axis, and has a plurality of reflection members that are each provided in a predetermined positional relationship with respect to the rotation axis, and that 2. The illumination optical device for a stereomicroscope according to claim 1, wherein the illumination optical device for a stereomicroscope is configured so that a desired reflecting member is set at a predetermined position by rotating around the rotation axis. 4) The illumination optical device of the stereomicroscope is characterized by having a light source image magnification optical system having a convergent lens group and a diverging lens group between the optical path of the collector lens and the light beam splitting means. An illumination optical device for a stereomicroscope according to claim 1.