JPS60118814A - Vertical illuminating type microscope device - Google Patents

Abstract

PURPOSE:To detect a focus by an invisible light with simple constitution, by constituting the titled device so that an image of a slit-shaped opening part on an invisible light shielding plate is projected onto the surface of an object, and its image is formed on a two-divided photodetecting member by its reflected light. CONSTITUTION:The image of a slit-shaped opening part on the first invisible area light shielding plate P1 is projected onto an object surface 8 by infrared rays as an invisible light emitted from a light source 1 as a passing area of the invisible light is shown by oblique lines. Its reflected light passes through the second invisible area light shielding plate P2 which has a transparent area and an opaque area against the invisible light and whose whole surface is transparent, and forms the image of a slit-shaped opening part, on a two-divided photodetecting member 15. Subsequently, output signals of each photodetector 15b, 15c of the two-divided photodetecting member 15 are compared, and the focus is detected. As a result, the stage of which the object 8 is placed is moved in the optical axis direction, a focused state is obtained automatically, and an object observation by a visible light is executed without a trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to an epi-illumination type microscope apparatus, and particularly to a focus detection apparatus therefor.

(Background of the Invention) Conventionally, as a focus detection device used in an epi-illuminated microscope, there is a device that performs focus detection using invisible light (infrared light), as disclosed in US Pat. No. 3,721,827, for example. Are known. According to this device, it is possible to perform focus detection without interfering with visible range observation. However, if a light source separate from that for observation is required for focus detection, or if the illumination light source for observation is shared as a light source for focus detection, the projection system for focus detection is formed by branching off from the observation optical system. Then, it is necessary to synthesize the light into the illumination optical system again, and in either case, the configuration has to be complicated.

(Object of the invention) The object of the present invention is to eliminate the need for a special light source as in the past;
In addition, there is no need to branch the optical path of the illumination optical system.
The purpose of this invention is to provide a mirror device.

(Summary of the Invention) An epi-illumination type UN mirror device according to the present invention includes an epi-illumination optical system having a light source for supplying illumination light to an object surface via a semi-transmissive mirror, and an epi-illumination optical system that supplies illumination light to an object surface via a semi-transmissive mirror. In an epi-illumination microscope having an observation optical system having an objective lens for observing an image of the object, a field of view always arranged at a position conjugate to the object plane in the epi-illumination optical system, that is, a position conjugate to the reference object plane. A first invisible-range light-shielding plate that has a slit-shaped opening for invisible light and is completely transparent for visible light is provided at the aperture position or a position conjugate with the field stop, and the semi-transparent light in the observation optical system is provided. Near the pupil position of the objective lens in the optical path on the image side of the mirror or at a position substantially conjugate with the pupil position of the objective lens, or in the optical path on the light source side of the semi-transparent mirror in the epi-illumination optical system. 011 Near the pupil position of the objective lens or at a position almost conjugate with the pupil position of the objective lens, one side of a predetermined boundary line is transparent to invisible light and the other side is opaque, and 1IJ8+! A second invisible-area light-shielding plate completely transparent to light is provided, and the longitudinal direction of the slit-shaped opening that appears to the invisible light on the first invisible-area light-shielding plate and the second invisible light-shielding plate are provided.
．． 1. A boundary line for invisible light on the JI3i light shielding plate is arranged parallel to the optical path 2, and an optical system is further provided to extract invisible light from the imaging light beam formed by the observation optical system glue and 1-object lens. A light receiving unit set is provided to detect the position of invisible light falling on the imaging plane of the invisible light extraction optical system.

(Example) Hereinafter, the present invention will be explained based on examples.

FIG. 1 is a schematic diagram of a first embodiment of an epi-illumination type microscope apparatus according to the present invention. Illumination light from an illumination light source (1) is focused by a condenser lens (2) at the position of an aperture stop (3). The light is then guided to the objective lens 7) via the first relay lens (4), the second relay lens (5), and the first semi-transmissive mirror (6), and performs coaxial epi-illumination of the object surface (8). The light beam reflected by the object surface (8) is reflected by the objective lens (7).
), the light passes through the first semi-transmitting mirror (6) and the second semi-transmitting mirror (11) and is focused on the image plane (12), where an image of the object is formed. The object image on the image plane (12) is magnified and observed by an eyepiece (13). Here, the first
A field stop (9) is arranged between the relay lens (4) and the second relay lens (5), and this field stop is aligned with the reference object plane with respect to the second relay lens (5) and the objective lens (7). The aperture stop (3) is conjugate with the objective lens (7) with respect to the first and second relay lenses (4, 5).
is conjugate with the pupil position (10) of In FIG. 1, light rays representing a conjugate relationship with the reference object plane (8) are shown by solid lines, and light rays representing a conjugate relationship with the pupil of the objective lens are shown by dotted lines.

As shown in the plan view of FIG.
A light-shielding plate P1 is placed at the central position intersecting the optical axis and is transparent to visible light. 11) There is a third
As shown in the plan view of the figure, a second invisible-area light-shielding plate P2 is arranged, which has a transparent area C and an opaque area d bounded by a boundary line S to invisible light, and is entirely transparent to visible light. has been done.

In the optical path reflected by the second semi-transmissive mirror (11), there are
A filter (14) that transmits J visual light and blocks visible light is arranged, and a two-split light receiving section 44' (15) is arranged at the reference image point position.
) is provided. The two-split light receiving member (15) has a fourth
As shown in the plan view of the figure, two light receiving elements (15b and 15c) are arranged in parallel with a dividing line (15a) in between. The dividing line (15g) of the light receiving part shrine (15) is arranged to intersect perpendicularly to the optical axis of the objective lens. Further, the boundary line of the second invisible area light shielding plate P2 and the dividing line (15a) of the two-part light receiving member (15) are both on the optical path in the longitudinal direction of the slit-shaped opening a on the first invisible area light shielding plate Pl. is placed parallel to.

In such a configuration, an image of the slit-shaped opening on the first invisible region light shielding plate Pl is projected onto the object plane (8>) by infrared light as invisible light emitted from the light source (1),
An image of the slit-shaped opening is formed on the two-part light-receiving member (15) by the reflected light from the object plane (8). When the focus of the objective lens accurately matches the object plane (8), the first invisible J13 provided at the field stop position
i The image of the slit-shaped opening on the light-shielding plate Pl is the object plane (8)
Therefore, an image of the slit-shaped opening is clearly formed also on the two-part light receiving member (15).

FIG. 5 is an optical path diagram showing the state of invisible light (infrared light) when the object plane (8) is in focus.

The shaded area in the figure represents the area through which invisible light passes. Moreover, FIGS. 6(A) to 6(C) are partially enlarged optical path diagrams showing the state of invisible light reaching the two-split light receiving member (15). 6th
Figure (A) shows a state where the object plane (8) is in focus,
FIG. 6(13) and FIG. 6(C) respectively show the state of the front focus and the rear focus being out of focus. As is clear from each figure in FIG. 6, when the focus is on, both light receiving elements (15b and 15C
) Invisible light is incident almost equally on both sides, and when the object is out of focus, invisible light is incident on one side. Therefore, by comparing the output signals of each light-receiving element (15b, 15C), it is possible to perform 6-focus detection.In addition, the invisible light area indicated by diagonal lines in Figs. 5 and 6, respectively. For ease of understanding, only the light flux passing through the center point of the field diaphragm is shown; in reality, a slit-shaped Open l
It has a luminous flux width corresponding to the width of the section.

Then each light receiving element (15b) on the color light receiving section +A (15)
The output signal from 15C) is inputted to the calculation means (16), which determines whether the focus is in focus or not and the front bin and the rear bin based on the difference between the output signals from both light receiving elements, and determines the amount of out-of-focus. Output the corresponding signal. Drive means (17)
moves the stage (18) on which the object is placed in the optical axis direction based on the signal from the calculation means (16). Then, the above operation is repeated until the same amount of light reaches each of the light receiving elements (15b, 15C), and finally, an accurate focusing state is automatically obtained. Therefore, an epi-illumination type microscope device with such a configuration does not cause any trouble in observing objects using visible light (it has a simple configuration that shares a light source and uses a normal epi-illumination optical system as is). This makes it possible to perform automatic focus detection.

In the first embodiment, the second invisible region light shielding plate P2 is arranged between the first semi-transmissive mirror (6) and the second semi-transmissive mirror (11). It is effective to have a position closer to the pupil position, and the first semi-transparent stop (6)
It is desirable that the location be close to . In addition, when relaying the invisible light of the imaging light flux through the 1') lll'j image, the objective lens 11f! It is desirable to provide the second invisible region light shielding 4 and 1) 2 at a position conjugate with position (10). Furthermore, the position of the second invisible area shading treatment 112 is as follows:
It is also possible to install LJ not only on the imaging system side of the first semi-transmissive mirror (6) but also on the illumination system side, and in the optical path of the first semi-transmissive mirror (6) on the light source (1) side. It is also possible to arrange it near the pupil position of the objective lens (7) or at a position conjugate with the pupil position (10) of the objective lens (7). Figure 7 is the second figure.
This is an optical path diagram of the second embodiment in which the JJ viewing area light shielding plate 1) 2 is arranged between the first semi-transmissive mirror (6) and the second relay lens (5), and similarly to FIG. The passage area is indicated by the P1 line. FIG. 8 is an optical path diagram of the third embodiment in which the second invisible region shading JMP2 is opened at the position of the aperture (3) of 1'', and in this way, the second invisible region shading 1'2 is treated as the first According to the present invention, it is arranged closer to the light source than the light-shielding plate 1] 1 in the area 6A. In other words, the position of the second invisible light shielding plate P2, which is used to block invisible light and perform pupil division, can be placed either on the image side of the first semi-transmissive mirror (6) for epi-illumination or on the illumination light source side. It is effective to arrange both at a position close to the pupil position of the objective lens or at a position conjugate with this pupil position.

FIG. 9 is a schematic optical path diagram of a fourth embodiment in which the epi-illumination type microscope apparatus according to the present invention is applied to a dark-field illumination type. In the figure,
Components having the same functions as those shown in FIG. 1 are given the same reference numbers. In order to achieve dark field illumination, a visible range light shielding plate P3 for blocking visible light in the central part including the optical axis is installed in the epi-illumination system by using a first semi-transmissive mirror (6) and a second relay lens. (5). As a result, the visible light illuminates the object (8) from the periphery of the objective lens (7) at a large angle, and the specularly reflected light from the object (8) does not enter the objective lens (7) and illuminates the object (8) at the object surface. Only the scattered (diffraction) light enters the objective lens (7) and contributes to image formation, resulting in good dark field illumination. Here, the visible light shielding plate P3 does not have the same effect on invisible light, and automatic focus detection can be performed in exactly the same manner as in the above embodiment. In this case as well, the illumination system can share the light source with a normal dark-field illumination optical system by using the visible light shielding plate P3, and the equivalent optical path can be branched.
Automatic focus detection is possible with a simple configuration without the need for any maintenance. Also in this case, the second invisible region light blocking treatment 112
The position of 1. is not limited to the image side of the first semi-transmissive mirror as shown in FIG. As shown in Figure 7 or 8, the first semi-transparent mirror (
6) It goes without saying that the light source side may be -1.

In each of the above embodiments, the boundary line on the second invisible area light shielding plate 1) 2 for substantially performing pupil division for invisible light is not necessarily located at the center of the optical path, or at a position where it intersects with the optical axis. For example, as shown in the plan view of FIG. 10, the opaque area d occupies more than half of the second invisible area light shielding plate P2 so that the invisible light passes through the off-axis area. Just configure it. Such a second invisible region shading IEt
The configuration P2 is effective when this UJ viewing area light shielding plate cannot be placed accurately at the pupil position of the objective lens or at a position conjugate with the pupil. In addition, in the configuration of the embodiment illustrated above, epi-illumination is performed by reflection from the first semi-transmissive mirror (6), and an observation system is provided on the optical path passing through this, but the reverse configuration is also possible.
It is J-Noh. The invisible light extraction optical system that extracts invisible light using the second semi-transmissive mirror (11) also includes the second semi-transmissive mirror (11)! (
11) can be provided not only on the optical path on the reflection side but also on the optical path on the transmission side.

Furthermore, a second semi-transparent 1 forming an invisible light extraction optical system
It is also possible to replace (11) and filter (14) with one dichroic mirror.

That is, in the configuration shown in FIG.
) If a dichroic mirror or a gicchroic prism that reflects invisible light (e.g. infrared light) and transmits visible light is provided instead of the filter (14), the number of components will be reduced and it will be simpler. It can be configured as follows. On the other hand, in each of the above embodiments, a two-split light receiving member is used, but a so-called image sensor may be used instead. In this case, substantially two
Since it can be divided, the image of the slit-shaped opening can be located at any position on the sensor during focusing, making it possible to adjust the sensor position relatively easily.

(Effects of the Invention) As described above, according to the epi-illumination type microscope device of the present invention,
Unlike conventional methods, it does not require a special light source or branch the optical path of the illumination optical system, has a simple configuration, and can be used as a focal point using invisible light without causing the same problems as normal object observation using visible light. Detection is I! It is Bif3.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an epi-illumination type microscope apparatus according to the present invention, FIG. 2 is a plan view of a first invisible area light shielding plate, and FIG. 3 is a plan view of a second invisible area light shielding plate. , Fig. 4 is a plan view of the two-divided light-receiving part shrine, Fig. 5 is a plan view of the invisible light passage area in the first embodiment, Fig.
- (C) are partial optical path enlarged views showing the state of invisible light reaching the two-split light-receiving section H, No. 7 and 1 are optical path diagrams showing the passage area of invisible light in the second embodiment, and FIG. FIG. 9 is an optical path diagram showing the passage area of the invisible light beam in the third embodiment, and FIG. The optical path diagram showing the passage area and FIG. 10 are plan views showing other examples of the second invisible area light shielding plate. (Explanation of symbols of main parts) 1... Light source 6, 7... Semi-transparent mirror 7...Objective lens 8...Object 9...Field diaphragm 10...Pupillary position of objective lens 15
...Two-divided light-receiving element Pl...First invisible area light shielding plate a...Slit-shaped opening P2...Second invisible area light shielding plate b...Boundary line Applicant Nippon Kogaku Kogyo Co., Ltd. Agent Takao Watanabe

Claims (1)

[Claims] an epi-illumination optical system having a light source for supplying illumination light to an object surface via a semi-transmissive mirror; and an observation optical system having an objective lens for observing an image of the object via the semi-transmissive mirror. In an epi-illumination type microscope, the epi-illumination optical system includes a first invisible-area light-shielding plate having a slit-shaped opening for invisible light at a position conjugate with the object plane and completely transparent for visible light. near the pupil position of the objective lens in the optical path on the image side of the semi-transmissive mirror in the observation optical system, or at a position substantially conjugate with the pupil position of the objective lens, or in the epi-illumination optical system. At a position near the pupil position of the objective lens or at a position substantially conjugate to the pupil position of the objective lens in the optical path on the light source side of the semi-transparent mirror, one side of a predetermined boundary line is transparent and the other side is transparent to invisible light. A second invisible area light shielding plate is provided which is opaque on its side and entirely transparent to visible light;
The first direction of the slit-shaped opening for invisible light on the invisible light shielding plate and the boundary line for the invisible light on the second invisible light shielding plate are arranged in parallel on the optical path, and , an optical system for extracting invisible light from the imaging light beam formed by the objective lens of the observation optical system is provided, and a light receiving member is provided for detecting the position of the invisible light on the imaging surface of the invisible light extraction optical system. Epi-illumination type microscope device with M7 signature.