JPH06201997A - Discussion microscope optical system - Google Patents

Abstract

PURPOSE:To insert and detach an intermediate lens barrel on main observer and sub-observer sides, and to obtain a distinct observation image by equalizing each focal distance of image forming lenses of main observation optical axis side and sub-observation optical axis side. CONSTITUTION:A luminous flux which is made incident on an image forming lens TL is condensed temporarily and forms an intermediate image. The luminous flux which is made incident on a first lens group L1 is condensed temporarily, and thereafter, is made incident on a second lens group L2 for constituting an afocal unmagnification relay system together with a first lens group, and the emitted luminous flux is converted to a parallel luminous flux again. Also, the parallel luminous flux emitted from a second lens group 2 is deflected so as to become parallel to a main observation optical axis 7 by a reflecting optical element M2 and guided to an image forming lens L3. Subsequently, the luminous flux which is made incident on the image forming lens L3 is condensed temporarily and forms an intermediate image. In this case, this system is constituted so that an interval between the reflecting optical element M2 on a sub-observation optical axis 8 side and the image forming lens L3 is variable, and also, a focal distance fT1 of an image forming lens TL and a focal distance fT2 of the image forming lens L3 become equal to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discussion microscope optical system in which a plurality of observers can observe the same specimen at the same time, and more particularly to a microscope optical system for infinity correction.

[0002]

2. Description of the Related Art If a microscope optical system is distinguished by a difference in image forming method, a finite distance correction optical system for forming an object image at a finite distance by an objective lens and an infinite distance at which the light emitted from the objective lens becomes a substantially parallel light beam. There are two types of correction optics. FIG. 4 shows a schematic configuration of a finite distance correction optical system. 1 in the figure
Is a sample surface, 2 is an objective lens, 3 is an eyepiece lens, and an intermediate image (arrow A ') of the image (arrow A) of the sample surface 1 is provided between the objective lens 2 and the eyepiece 3 by the objective lens 2. ) Is imaged. In the finite-distance correction optical system having such a configuration, when the intermediate lens barrel is inserted between the objective lens 2 and the eyepiece lens 3, the positional deviation of the image corresponding to the length of the intermediate lens barrel is corrected in the intermediate lens barrel. It was necessary to install a flattening lens for the image.

FIG. 5 shows a configuration in which a discussion lens barrel is inserted into the optical system shown in FIG. In the figure, the light beam emitted from the objective lens 2 enters the light beam splitting element M1 through the image spreading lens 4, and the light beam splitting element M1
As a result, a part of the light flux is deflected to the relay lens 5, and the light flux not deflected is transmitted as it is. The light beam that has passed through the light beam splitting element M1 is once condensed to form an intermediate image, and this image is observed by the main observer via the eyepiece lens 3. On the other hand, the light flux that has entered the relay lens 5 is once condensed by the relay lens 5 and then enters the relay lens 6, and then exits the relay lens 6 and is reflected by the reflective optical element M2.
The light is focused again through to form an intermediate image and is observed by a sub-observer through the eyepiece lens 3. Reference numerals 7 and 8 are the main observation optical axis and the sub-observation optical axis, respectively. According to the above configuration, since the image expanding lens 4 is installed between the objective lens 2 and the light beam splitting element M1, both the main observer and the sub-observer receive the image transmitted through the image expanding lens 4. Is supposed to be observed. However, when the image expanding lens is installed in the intermediate lens barrel as described above, the intermediate magnification of the image may be changed in accordance with the correction of the positional deviation of the image.
Further, in order to suppress the variation of the intermediate magnification, an equal magnification afocal lens having a complicated structure has to be used as an image spreading lens.

[0004]

As described above, when the intermediate lens barrel is inserted in the finite-distance correction optical system, the image expansion lens for correcting the positional deviation of the image is inserted in the optical path. There is a problem in that a problem such as a change in magnification of an observed image, a narrowing of a real visual field, or deterioration of an image occurs.
Especially, when a plurality of intermediate lens barrels are inserted, these problems occur remarkably. Further, in the above-mentioned conventional configuration, even when the intermediate lens barrel is inserted on the side of the sub-observer, an image flattening lens is necessary, and there is a problem that a similar problem occurs.

On the other hand, in the infinity correction optical system, since the light flux between the objective lens and the imaging lens is parallel, the distance between the objective lens and the imaging lens is variable, and when the intermediate lens barrel is inserted. However, no image extension lens is required. However, a discussion microscope optical system that employs an infinity correction optical system has not been proposed.

The present invention has been made in view of the above problems of the prior art, and its object is to make a main observer side and a sub-observer side without using an image expanding lens. The objective of the present invention is to provide a discussion microscope optical system in which the intermediate lens barrel can be freely inserted and removed and a clear observation image can be obtained.

[0007]

Means and Actions for Solving the Problems The means and actions will be described with reference to FIG. 1 showing the configuration of the first embodiment of the present invention. The discussion microscope optical system of the present invention has an objective lens 2 and an imaging lens TL, and is connected to the objective lens 2 in an infinity-corrected microscope optical system in which the distance between the objective lens 2 and the imaging lens TL is variable. The image lens TL constitutes the main observation optical axis 7 and is installed in a parallel light beam between the objective lens 2 and the imaging lens TL to deflect the light beam from the objective lens 2 in a direction different from the main observation optical axis 7. And a first lens group L1 for temporarily converging the deflected light beam and forming an image by the objective lens 2.
A second lens group L2 for converting the light flux condensed by the first lens group L1 into a parallel light flux, and a second lens group L
A reflective optical element M2 that forms a sub-observation optical axis 8 that is parallel to the main observation optical axis 7 by deflecting the parallel light flux from
An imaging lens L3 for condensing the light beam deflected by the reflection optical element M2 to form an image by the objective lens 2, and a distance between the reflection optical element M2 on the side of the sub-observation optical axis 8 and the imaging lens L3. Is variable, and the focal length of the imaging lens TL on the main observation optical axis 7 side and the focal length of the imaging lens L3 on the sub observation optical axis 8 side are equal, in other words, the imaging lens TL. , L3 when the focal lengths are fT1 and fT2, respectively, fT1 = fT2.

The beam splitting element M1 may be a prism block or a half mirror, and the reflective optical element M2 may be a prism or a mirror. The first lens unit L1 and the second lens unit L2 that transmit an image to the sub-observation optical axis 8 side constitute an afocal equal-magnification relay system, and the sub-observation optical axis 8 side also has infinity correction optics. Since it is configured as a system,
The distance between the reflective optical element M2 and the imaging lens L3 is variable, and the intermediate lens barrels can be inserted and removed depending on the purpose of observation. Further, since the image forming lens TL and the image forming lens L3 are arranged so that their focal lengths fT1 and fT2 are equal (fT1 = fT2), the main observation optical axis 7 side and the sub observation optical axis 8 side are arranged. As long as the eyepiece 3 having the same magnification is used, the magnification of the observation image is the same on each side.

Further, when the distance between the main observation optical axis 7 and the sub-observation optical axis 8 is d, in order to keep the distance d at a practically appropriate size, the condition expressed by the following equation (1) is set. It is desirable to satisfy. Formula (1) 0.7fT1 <fL1 <1.4fT1 where fL1 is the focal length of the first lens unit L1.

If the lower limit of the above equation (1) is exceeded, the distance d becomes too small. The microscope is provided with a stage and a frame in order from the front side of the main observer, and a lamp house is provided at a position farthest from the main observer. That is,
When the discussion microscope is configured to face each other, that is, the main observer and the sub-observer face each other, the lamp house is located in front of the sub-observer. Therefore,
If the distance d is too small, the face will come over the lamp house when the sub-observer approaches the eyepiece lens,
The hot airflow generated from the lamp house hits the face, making observation difficult. If the upper limit of the above formula (1) is exceeded, the distance d becomes too large. That is, when the discussion microscopes are arranged in parallel, that is, when the main observer and the sub-observer are arranged in the same direction, if the distance d is unnecessarily large, the width of the microscope becomes large,
The waste of space becomes large.

Imaging lens T of the microscope optical system for infinity correction
Although the focal length fT1 of L is determined by the focal length of the objective lens and the limiting conditions such as the configuration of the entire system, it is approximately 160
~ 200 mm. Therefore, from the above formula (1), the range of the focal length fL1 of the first lens unit L1 is 112 to 280 mm.
Becomes On the other hand, the practical range of the distance d is about 300 mm for the opposed type and about 600 to 700 mm for the parallel type.

Since the first lens unit L1 and the second lens unit L2 constitute an afocal equal-magnification relay system, if the focal length of the second lens unit L2 is fL2, then fL1 = fL2, and both Have the same focal length. Therefore, ignoring the lens thickness, the paraxial thickness of the afocal system formed by combining the first lens unit L1 and the second lens unit L2 is (fL1 + fL2), which is approximately 224 to 560 mm. . In order to provide a plurality of sub-observation optical axes not only in the facing type but also in a parallel type discussion microscope, this numerical value is used in addition to the light beam splitting element M1 and the reflection optical element M2 in FIG. The optical axis may be further bent by combining the split element and the reflective optical element,
Considering that the first lens group L1 and the second lens group L2 are actually composed of a plurality of lenses and have a certain thickness, etc., the practical range of the distance d described above and the first lens group L1 It can be said that the paraxial thickness of the afocal system formed by combining the above and the second lens unit L2 substantially corresponds.

In FIG. 1, only one sub-observation optical axis is formed, but as is well known, when a total of an even number of light beam splitting elements and reflective optical elements are arranged in the optical system. , It is possible to configure a plurality of sub-observation optical axes. Also in this case, the intermediate lens barrel can be inserted / removed on / from each sub-observation optical axis by disposing the image forming lens for each optical axis.

Further, the first lens group L1 and the second lens group L2 are each provided with a light beam splitting element and a reflective optical element depending on the layout of each lens disposed on the sub-observation optical axis or optical path. There is no problem even if it is configured to be included in the lens group.

[0015]

Embodiments will be described with reference to the drawings. First Embodiment FIG. 1 is a diagram showing the configuration of this embodiment. In FIG.
The parallel light flux emitted from the objective lens 2 is incident on the light flux dividing element M1, and a part of the light flux is deflected by the light flux dividing element M1 toward the first lens group L1. Head toward the image lens TL. The light flux incident on the imaging lens TL is once condensed to form an intermediate image, and this image is observed by the main observer through the eyepiece lens 3. On the other hand, the light flux that has entered the first lens unit L1 is once condensed and then enters the second lens unit L2 that constitutes an afocal unity relay system together with the first lens unit L1. It is converted again into a parallel light flux by the two lens unit L2. The parallel light flux emitted from the second lens group L2 is deflected by the reflective optical element M2 so as to be parallel to the main observation optical axis 7, and is guided to the imaging lens L3. Then, the light flux that has entered the imaging lens L3 is once condensed to form an intermediate image, and this image is observed by the sub-main observer via the eyepiece lens 3. The distance between the reflective optical element M2 on the side of the sub-observation optical axis 8 and the imaging lens L3 is variable, and
The focal length fT1 of the imaging lens TL and the focal length fT2 of the imaging lens L3 are configured such that fT1 = fT2.

FIG. 2 is a diagram showing the configuration of an opposed-type discussion microscope constructed based on the optical system shown in FIG. In the figure, 11 is a microscope main body, 12 is a lamp house, 13 is a condenser lens, 14 is a coarse and fine adjustment screw, and 15 is a screw.
Is a stage, 16a and 16b are eyepieces on the main observer side and the sub-observer side, respectively, and 17 is a prism. The light emitted from the lamp house 12 is condensed by the condenser lens 13 and illuminates the sample mounted on the stage 15. The main observer operates the coarse and fine adjustment screw 14 to move the stage 15 up and down to adjust the focus of the image on the specimen surface 1 and to the eyepiece unit 1.
This image is observed from 6a, and the sub-observer observes the image guided to the eyepiece 16b via the first lens unit L1 and the second lens unit L2.

According to this embodiment, the imaging lenses TL and L3
It is possible to freely insert and remove the intermediate lens barrels on both the main observer side and the sub-observer side by integrally configuring the lens barrel on the side of the microscope barrel (eyepieces 16a, 16b).

Second Embodiment FIG. 3 is a diagram showing the configuration of this embodiment. In this embodiment, a plurality of sub-observation optical axes 8 are formed by combining the opposed type and the parallel type, and the imaging lens L3 is arranged for each sub-observation optical axis 8. Further, in the optical system of the present embodiment, a total of an even number of light beam splitting elements M1 and reflective optical elements M2 are provided, and the focus of the imaging lens L3 provided on each sub-observation optical axis 8 is set. The distance and the focal length of the imaging lens TL arranged on the main observation optical axis 7 are equal. In this embodiment, as in the first embodiment, the intermediate lens barrels can be freely inserted and removed on both the main observer side and the sub-observer side.

[0019]

As described above, according to the discussion microscope optical system of the present invention, the intermediate lens barrel can be freely inserted and removed on the main observer side and the sub-observer side without using an image expanding lens. Therefore, since unnecessary intermediate magnification is not applied to the observation, clear observation images can be obtained on both the main observer side and the sub-observer side, and it is effective for expansion of the microscope system. .

[Brief description of drawings]

FIG. 1 is a first discussion microscope optical system of the present invention.
It is a figure which shows the structure of an Example.

FIG. 2 is a diagram showing a configuration of an opposed-type discussion microscope configured based on the optical system shown in FIG.

FIG. 3 is a second discussion microscope optical system of the present invention.
It is a figure which shows the structure of an Example.

FIG. 4 is a diagram showing a schematic configuration of a conventional finite distance correction optical system.

FIG. 5 is a diagram showing a configuration of a conventional discussion microscope optical system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample surface 2 ... Objective lens 3 ... Eyepiece lens 4 ... Image extension lens 7 ... Main observation optical axis 8 ... Sub-observation optical axis 11 ... Microscope main body 16a, 16b ...
Eyepiece M1 ... Beam splitting element M2 ... Reflective optical element TL, L3 ... Imaging lens L1 ... First lens group L2 ... Second lens group

Claims (1)

[Claims] 1. An infinity-corrected microscope optical system having an objective lens and an imaging lens, wherein the distance between the objective lens and the imaging lens is variable, wherein a main observation optical axis is provided by the objective lens and the imaging lens. And a light beam splitting element which is installed in a parallel light beam between the objective lens and the imaging lens and deflects the light beam from the objective lens in a direction different from the main observation optical axis, and the deflected light beam. A first lens group for once condensing and forming an image by the objective lens, and a second lens group for converting the light beam condensed by the first lens group into a parallel light beam.
A parallel optical beam from the second lens group is deflected to form a sub-observation optical axis parallel to the main observation optical axis, and a light beam deflected by the reflective optical element is condensed. An image forming lens for forming an image by the objective lens, wherein the distance between the reflective optical element on the side of the sub-observation optical axis and the image forming lens is variable, and the image on the side of the main observation optical axis is formed. A discussion microscope optical system, wherein the focal length of the lens and the focal length of the imaging lens on the side of the sub-observation optical axis are equal.