JPH0540226A - Transmission illuminator for stereo-microscope - Google Patents

Abstract

PURPOSE:To provide the transmission illuminator for a stereo-microscope so as to eliminate illumination nonuniformity and to supply illumination luminous flux with satisfactory illumination efficiency. CONSTITUTION:This transmission illuminator is equipped with a light source 1, collector lens 2, luminous flux splitting prism 13 and capacitor lens 4. The luminous flux splitting prism 13 splits and deflects the luminous flux, which is made almost parallel by the collector lens 2, from the light source 1 into the luminous flux in two directions parallel to optical axes 9a and 9b of a pair of observation optical systems. Therefore, since a sample S is illuminated by the almost parallel luminous flux from the directions along the respective optical axes 9a and 9b, the illumination range is considerably enlarged and the illumination nonuniformity is eliminated for this transmission illuminator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transillumination device for a binocular stereomicroscope.

[0002]

2. Description of the Related Art A conventional binocular stereomicroscope, as shown in FIG. 5, includes an illumination optical system including a light source 1, a collector lens 2, a diffusion plate 3 and a condenser lens 4, a stage 5 for holding a sample S, and an objective. The lens 6 and the zoom lenses 7a and 7b and the eyepieces 8a and 8b are arranged to be symmetrical, and a pair of observation optical systems are arranged. The optical axes 9a and 9b of the pair of observation optical systems are respectively inclined by an angle α / 2 with respect to the optical axis 10 of the illumination optical system. That is, the optical axes 9a and 9b are symmetrically positioned with the extension line of the optical axis 10 as the axis of symmetry.

In the transmission illumination optical system of such a binocular stereomicroscope, the illumination light flux from the light source 1 is made into a substantially parallel light flux by the collector lens 2, the light flux from the collector lens 2 is diffused by the diffuser plate 3, and the condenser lens 4 is set. The sample S is transmitted and illuminated via the light. Further, the pair of observation optical systems stereoscopically observes the sample illuminated by the illumination optical system.

[0004]

However, since the diffusing plate 3 of the illumination optical system has the directivity as shown in FIG. 6, as shown in FIG. Illumination unevenness occurs in which the outside of each field of view becomes dark. This is because the directivity of the diffusing plate exhibits a strong directivity in the optical axis direction of the illumination optical system, and the light intensity is significantly reduced as the deflection angle of the diffusing light beam is not large. In order to solve this uneven illumination, it is good to use a diffuser with a high diffusivity, that is, a diffuser with a small directivity. The field of view of the system becomes dark as a whole.

Further, it is disclosed in Japanese Patent Laid-Open No. 60-111201 that a pair of lenses is used instead of a diffusion plate to divide the observation optical system into two directions along the optical axis. However, if a pair of lenses is used, only a part of the light flux from the condenser lens can be split in two directions, and the illumination efficiency will be reduced. In view of such a problem, an object of the present invention is to provide a transillumination device for a binocular stereomicroscope having no illumination unevenness and good illumination efficiency.

[0006]

According to a first aspect of the present invention, there is provided a transmissive illumination device which comprises an illumination light source (1) and a sample held by a sample holding means (5) which makes a light beam from the light source substantially parallel. An illumination optical system having a condensing lens (2) for transmitting illumination, and a pair of observation optical systems (6, 7a, 7) in which respective optical axes are symmetrically arranged and the sample is substantially observed.
b, 8a, 8b), and the optical axis (10) of the illumination optical system is the optical axis (9) of each of the pair of observation optical systems.
a, 9b), a binocular stereomicroscope that is substantially coincident with the symmetry axis (9), is provided between the condenser lens and the sample holding means, and transmits the light flux from the condenser lens to the pair of observation optics. It has a single beam splitting and deflecting means (13) for splitting and deflecting in a direction substantially parallel to each optical axis of the system.

According to a second aspect of the present invention, there is provided a transillumination device in which the light beam splitting / deflecting means is provided with an inclined surface (1) having a predetermined inclination angle.
1a, 11b) is a beam splitting prism (13) having a plurality of parallel chevron rows (11), the ridgeline (12) of each chevron row of the pair of observing optical systems. It is arranged so as to extend in a direction perpendicular to the plane including the optical axis.

According to a third aspect of the present invention, there is provided a transillumination device in which the light beam splitting / deflecting means is detachable from an installation position between the condenser lens and the sample holding means, and a plurality of deflection angles are different. Beam splitting means is provided, and the pair of observation optical systems have the objective lens (6) having a certain magnification and a pair of eyepieces (8a, 8b), and the objective lenses have different magnifications. When the objective lens (8 ') is replaced, the luminous flux splitting / deflecting means is replaced with an objective lens (13') corresponding to the magnification of the objective lens.

[0009]

In the transillumination device of the present invention, the light flux from the light source that has passed through the condenser lens is split and deflected by the light flux splitting and deflecting means in the directions substantially parallel to the respective optical axes of the pair of observation optical systems. Therefore, the light beams split and deflected by the light beam splitting and deflecting means travel in the directions along the respective optical axes of the pair of observation optical systems, and illuminate the sample from the same directions.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a transillumination device for a binocular stereomicroscope of the present invention will be described in detail by giving the same numbers to the same members used in the conventional example. As shown in FIG. 1, the transillumination device of the embodiment includes an illumination light source 1, a collector lens 2, a light beam splitting prism 13 and a condenser lens 4. Further, the binocular stereomicroscope includes the transillumination device, the stage 5 holding the sample S, and a pair of observation optical systems. This pair of observation optical systems includes a common objective lens 6 arranged on the respective optical axes 9a and 9b set at an opening angle α, a pair of zoom lenses 7a and 7b, and a pair of eyepieces 8a and 8b. Therefore, the optical axes 9a and 9b are located symmetrically with respect to the symmetry axis 9 which is an extension of the optical axis 10 of the transillumination device.

As shown in FIG. 2, the light beam splitting prism 13 of the transillumination device has a front surface on which a plurality of mountain-shaped rows 11 are engraved and a back surface formed on a plane, and the plurality of mountain-shaped rows 11 is formed. Have the same shape and are arranged in parallel with each other. Each chevron array 11 is composed of a pair of slanted surfaces 11a and 11b, and the line of intersection between these slanted surfaces 11a and 11b is the ridgeline 12 of the chevron array. The light beam splitting prism 13 is
It is arranged between the collector lens lens 2 and the condenser lens 4 of the transillumination device so that the ridgeline 12 of the chevron array 11 is perpendicular to the plane including the optical axes 9a and 9b, and as shown in FIG. When the parallel light flux enters, the outgoing light flux is deflected by the deflection angle θ.

Next, the operation of this binocular stereomicroscope will be described. The illumination light flux from the light source 1 is condensed by the collector lens 2 and becomes a substantially parallel light flux. The light beam splitting prism 13 is
The substantially parallel light flux from the collector lens 2 is split, and is deflected to a light flux in a direction substantially along the optical axes 9a and 9b of the pair of observation optical systems. The light beam thus divided and deflected illuminates the sample S from the direction along the optical axes of the pair of observation optical systems via the condenser lens 4. In this way, the image of the sample illuminated by the transillumination device is stereoscopically observed by the pair of observation optical systems provided on the respective optical axes 9a and 9b.

The split deflection in the light beam splitting prism 13 is a plane (paper surface) including the optical axes 9a and 9b of the observation optical system.
And is deflected in a plane parallel to the plane of the drawing, and in the vertical plane including the optical axis 9a and orthogonal to the plane of the paper, or in the vertical plane including the optical axis 9b and orthogonal to the plane of the paper, division or There is no bias. Therefore, the conventional transillumination device using the diffusion plate 3 diffuses in all directions, and the transillumination device using a pair of lenses divides and deflects only part of the light beam from the condenser lens. While the illumination efficiency is poor, the transmissive illumination device of the embodiment using the light beam splitting prism 13 allows almost all of the light beams from the condenser lens 2 to be in a direction substantially parallel to the optical axes 9a and 9b. Since it is deflected, the illumination efficiency is extremely good, and since the deflected illumination light flux becomes the illumination light flux substantially along the optical axes 9a and 9b, there is no illumination unevenness. Further, in consideration of the overall configuration of the binocular stereomicroscope, the diffuser plate 3 can be manufactured at a low cost because it has a simple configuration in which only the light beam splitting prism 13 is changed.

In the above-mentioned embodiment, the beam splitting prism consisting of a plurality of chevron rows is used, but each chevron row may be formed in a V-shaped row, and the surface of the prism has at least a pair of slopes. It is only necessary to form one, but if a pair of slopes is used, the illumination area on the sample becomes narrow. In addition, the inclination angle of each inclined surface of the light beam splitting prism 13 is determined by considering the opening angle α between the optical axes 9a and 9b and the refractive index of the material so that the deviation angle θ of the prism 13 becomes θ = α / 2. To set.

Next, in the above embodiment, the case where the observation magnification of the observation optical system is changed by changing the magnification of the objective lens will be described. As shown in FIG. 4, the magnification of the objective lens 6 is changed by adding an auxiliary lens 6 ′ to the objective lens 6. However, in this case, since the distance between the sample S and the objective lens 6 changes with the observation magnification,
The opening angle α between the optical axes 9a and 9b changes before and after exchanging the observation magnification. Therefore, the optical axes 9a and 9b before the magnification change
The illumination light flux along the line is displaced from the direction of the optical axis after the magnification is changed, and uneven illumination occurs. If the opening angle α between the optical axes 9a and 9b changes by exchanging the observation magnification in this way, the light beam splitting prism 13 is moved to the optical axis 9a after the magnification is changed.
And 9b are replaced with prisms 13 'having a deflection angle .theta. =. Alpha.' / 2 according to the opening angle .alpha. ', And the illumination light fluxes are changed in the respective optical axis directions after the magnification is changed. Specifically, the light beam splitting prisms 13 and 13 'are connected by a slider (not shown), and the slider is replaced by sliding it in the direction of the arrow. For this exchange, a plurality of prisms may be housed in a turret-shaped metal object and the turret may be rotated. Further, as a matter of course, when the observation magnification is changed by removing the objective lens 6 and exchanging it with another objective lens having a different magnification, similarly, the prism is changed according to the opening angle α ′ after the magnification is changed. Exchange.

In this way, the plurality of prisms having different deflection angles can be exchanged in advance so that the objective lens is exchanged and the illumination unevenness is eliminated when the opening angle of the pair of observation optical systems changes. be able to.

[0017]

As described above, the transillumination device of the binocular stereomicroscope of the present invention divides and deflects the illumination light beam from the light source in the directions along the optical axes of the pair of observation optical systems. Therefore, compared with the conventional transillumination device using the diffusion plate, since it does not diffuse in a wasteful direction, the illumination efficiency is good,
Moreover, it is possible to perform illumination without uneven illumination.

[Brief description of drawings]

FIG. 1 is an optical path diagram showing a main configuration of a binocular stereomicroscope using a transillumination device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a light beam splitting prism of an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the operation of the light beam splitting prism of the present invention.

FIG. 4 is an explanatory diagram when the objective lens of the binocular stereomicroscope using the transillumination device of the embodiment of the present invention is exchanged.

FIG. 5 is an optical path diagram showing a main configuration of a conventional binocular stereomicroscope.

FIG. 6 is a diagram showing the directivity of a diffusion plate of a conventional binocular stereomicroscope.

FIG. 7 is a schematic diagram showing illumination unevenness of a conventional binocular stereomicroscope.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Collector lens (condensing lens) 5 ... Stage (sample holding means) 6, 7a, 7b, 8a, 8b ... A pair of observation optical systems (6 is an objective lens, 7a, 7b is a zoom lens, 8 respectively)
a and 8b are eyepieces) 9a, 9b ... Optical axis of pair of observation optical system 9 ... Symmetrical axis of optical axes 9a and 9b 10 ... Optical axis of illumination optical system 11 ... Angle array 11a, 11b ... Inclined surface 12 ... ridge lines of chevron array 13, 13 '... light beam splitting prism (light beam splitting and deflecting means) S ... sample

Claims (3)

[Claims] 1. An illuminating optical system having an illuminating light source and a condenser lens for converting a light beam from the light source into a substantially parallel light beam and transmitting and illuminating a sample held by a sample holding means, and optical axes thereof are symmetrically arranged. In a binocular stereomicroscope, which comprises a pair of observation optical systems for stereoscopically observing the sample, and the optical axis of the illumination optical system is substantially coincident with the symmetry axis of each optical axis of the pair of observation optical systems. Provided between the condenser lens and the sample holding means,
A transillumination device for a binocular stereomicroscope, comprising a single light beam splitting / deflecting means for splitting and deflecting a light beam from the condenser lens in a direction substantially parallel to each optical axis of the pair of observation optical systems. 2. The light beam splitting / deflecting means comprises a light beam splitting prism having a plurality of parallel chevron rows formed by inclined surfaces having a predetermined tilt angle, and in the light flux dividing prism, the ridge line of each chevron row is The pair of observation optical systems are arranged so as to extend in a direction perpendicular to a plane including an optical axis of the pair of observation optical systems.
A transillumination device for the binocular stereomicroscope described. 3. The light beam splitting / deflecting means is configured to be attachable / detachable from an installation position between the condenser lens and the sample holding means, and a plurality of light beam splitting means having different deflection angles are prepared. The pair of observation optical systems has an objective lens having a certain magnification and a pair of eyepieces, and when the objective lens is replaced with an objective lens having a different magnification, the light beam splitting / deflecting means is The transillumination device for a binocular stereomicroscope according to claim 1, wherein the transmissive illumination device is replaced with a light beam splitting prism having a deflection angle according to a magnification.