JPH03129311A - Light beam scanning mechanism and scanning type microscope - Google Patents

Abstract

PURPOSE:To simplify the constitution and realize low-cost formation by moving a 2nd slit plate, which has one slit crossing at one place to the slit of a 1st slit plate having one snaking slit passing part of a light beam, relatively to the 1st slit plate. CONSTITUTION:The 1st slit plate 15 has the snaking slit 15a where V-shaped parts connect with one another as shown by an arrow Y. The 2nd slit plate 16, on the other hand, has one linear slit 16a extending almost at right angles to the direction of the arrow Y. Those slits 15a and 16a cross each other only at one position while the slit plates 15 and 16 are put one over the other. Therefore, illumination light 11 is projected only from the intersection of the slits 15a and 16a. Consequently, the light beam makes a two-dimensional scan only by the movement of the two slit plates. Further, a function which stopping down the light beam is obtained. Consequently, the constitution is simple and the low-cost formation is possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scanning microscope with improved light beam scanning mechanism and light spot scanning mechanism.

(Prior Art) Conventionally, illumination light is converged into a minute light spot, and this light spot is scanned two-dimensionally on a sample, and at that time, the light that has passed through the sample or the light that has been reflected there is detected by a photodetector. Optical scanning microscopes are known that detect electrical signals that carry an enlarged image of a sample.

In particular, it is configured to generate illumination light from a light source and image it into a light spot on the sample, and then re-image the light flux from the sample into a point image, which is then detected by a photodetector. Confocal scanning microscopes do not require a pinhole on the sample surface (and are easy to implement).

This confocal scanning microscope basically consists of a sample stage on which a sample is placed, a light source that emits illumination light, a light transmission optical system that images this illumination light as a minute light spot on the sample, and the above-mentioned. It consists of a light receiving optical system that condenses the light beam from the sample and forms it into a point image, a photodetector that detects this point image, and a scanning mechanism that scans the light spot two-dimensionally on the sample. It is something that Furthermore, Japanese Patent Application Publication No. 82-21
An example of this scanning microscope is shown in Japanese Patent No. 7218 and Japanese Patent No. B5-306414.

(Problems to be Solved by the Invention) In conventional scanning microscopes, the above-mentioned scanning mechanism is: (1) a mechanism for moving the sample stage two-dimensionally, or (2) a mechanism for two-dimensionally deflecting the illumination light beam by an optical deflector. mechanism was used.

However, when the mechanism (2) was adopted, there was a problem that the sample would fly away when high-speed scanning was performed. on the other hand,
In the mechanism of ■, galvanometer mirror and AOD
The disadvantage is that an expensive optical deflector such as an acousto-optic optical deflector (acousto-optic optical deflector) is required.

In addition, many conventional light beam scanning mechanisms, not only those used in the above-mentioned scanning microscopes, require that the light beam incident thereon be narrowed in advance.
Providing an optical system for this purpose tends to make the structure even more complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a scanning microscope whose scanning mechanism has a simple configuration and can be manufactured at low cost.

Further, the present invention can realize such a scanning microscope.
It is an object of the present invention to provide a light beam scanning mechanism that has a simple configuration and can be formed at low cost.

(Means and Effects for Solving the Problems) The light beam scanning mechanism according to the present invention includes a first slit plate that is disposed in the optical path of the light beam and has one meandering slit through which a part of the light beam passes. and a second slit plate that is overlapped with the first slit plate and has one slit that extends in a direction intersecting the meandering slit and intersects the slit at one point, and the first slit plate. , a driving means for moving the meandering portion of the slit in the direction in which the meandering portion of the slit is continuous, and for moving the second slit plate relative to the first slit plate in a direction substantially parallel to the above-mentioned moving direction. It is characterized by:

The light beam incident on the first and second slit plates overlapped as described above passes only through the intersection of the slits of both slit plates, and is therefore narrowly focused. By moving the first slit plate as described above, the intersection of both slits moves back and forth along the slit of the second slit plate. Thereby, main scanning of the light beam passing through both slit plates is performed.

Furthermore, when the second slit plate is moved relative to the first slit plate, the intersection of the two slits also changes position in the direction of this movement, which causes the light beam to perform sub-scanning. That will happen.

- The scanning microscope invented by Rikiki consists of the above-mentioned sample stage, a light source that emits illumination light, a light transmitting optical system, a light receiving optical system, a photodetector, and a two-dimensional scanning mechanism for a light spot. In a scanning microscope equipped with the above-mentioned light beam scanning mechanism, the above-mentioned light beam scanning mechanism is placed at a position that receives the illumination light, and the illumination light that has passed through both slit plates of the light beam scanning mechanism is scanned two-dimensionally on the sample. It is configured as follows.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 shows a transmission type confocal scanning microscope according to an embodiment of the present invention. As shown in the figure, a laser beam (illumination light) 11, which is parallel light emitted from a laser light source IO, has a beam diameter expanded by a beam expander 12 and passes through a first slit plate I5 and a second slit plate superimposed thereon. The light enters the slit plate 16 of No. 2.

FIG. 2 shows the shape of these slit plates 15, 18 in detail. As shown in the figure, the first slit plate I5 made of, for example, a steel plate has a slit 15a in which V-shaped portions meander in a row in the direction of the arrow Y. On the other hand, the second slit plate 1B, which is also made of a steel plate or the like, has one linear slit 16a extending in a direction substantially perpendicular to the direction of the arrow Y. Both slits 15aStea having such a shape are connected to the slit plate 15.18.
are superimposed and intersect with each other only at point III.

Therefore, the illumination light 11 is transmitted through these slits 15a, lea
The light is emitted only from the intersection of the two.

The illumination light 11 narrowed down in this way is passed through the second slit plate 16
is diffused by the lens 17 held at the objective lens 1.
8 and is imaged by the objective lens 18 into a minute light spot P on the sample 20 (on the surface or inside). Note that the lens barrel 28 that holds the lens 17 is
is movable in the optical axis direction with respect to the slit plate 16 of
The imaging position of the light spot P in the optical axis direction is adjustable. Further, the sample stage 19 on which the sample 20 is placed is moved by the vertical movement mechanism 2.
1, it is moved in the two directions of arrows, that is, in the optical axis direction of the objective lens 18.

The beam of transmitted light 11' that has passed through the sample 20 is focused into a point image Q by the objective lens 22. A liquid crystal panel 23 is disposed on the surface on which the point image Q is formed. This liquid crystal panel 23 has a large number of liquid crystal cells 23a arranged in a matrix, and has a liquid crystal panel drive circuit 2.
4, one of these liquid crystal cells 23a is sequentially and selectively driven to a light passing state.

Below the liquid crystal panel 23, there is a photodetector 25, such as a photomultiplier tube, which has a light-receiving surface 25a facing the entire surface thereof.
are arranged. The transmitted light 11' forming the point image Q passes through the liquid crystal cell 23a, which is in a light-transmitting state, and enters the light-receiving surface 25a. Therefore, the photodetector 25 outputs a signal S indicating the brightness of the point image Q.

Next, two-dimensional scanning of the light spot P will be explained.

Both ends of the first slit plate 15 are connected to the winding shaft 30, respectively.
, 31. The first slit plate 15 is held between a driven roller 32 and a driving roller 33, and when the driving roller 33 is rotated clockwise in FIG. It is moved in the opposite direction at a relatively fast constant speed. Further, the winding shaft 30 is rotated in the same direction as the drive roller 33 by a drive device (not shown), and the first slit plate 1 is unwound.
Wind up 5. The other winding shaft 31 is rotated by a drive device (not shown) before the next light beam scan, and the first slit plate 15 is wound around the winding shaft 20.
Rewind.

On the other hand, the second slit plate 16 is fixed to the moving member 3B of a reciprocating drive device 85, and is moved by the drive device 35 to
direction, at a lower speed than the first slit plate 15. By moving the second slit plate 16 in this manner, the intersection of the slits 15a and 16a moves in the direction of arrow Y. At the same time, the first slit plate 15 moves relative to the second slit plate 1B, so that the intersection portion moves at high speed in the direction of arrow X along the slit 18A of the second slit plate 16. Thereby, the light spot P scans the sample 20 in the X direction in the main direction, and sub-scans in the Y direction which is substantially orthogonal to the main scanning direction.

As is clear from the above description, in this embodiment, in addition to the first slit plate 15 and the second slit plate 1B,
Drive roller 33 and drive device 34.3 for moving these
5. The moving member 36 constitutes a light beam scanning mechanism. Note that a synchronizing signal is input from the control circuit 37 to the drive devices 34 and 35, and while the second slit plate 16 is moved by one sub-scanning pitch, the slit 15
The movement of both slit plates 15.1B is controlled so that the half pitch ΔY (see FIG. 2) of the meandering portion of a is moved.

When the light spot P is two-dimensionally scanned as described above, the imaging position of the point image Q moves two-dimensionally in accordance with this scan. In order to cope with this, the liquid crystal panel drive circuit 24 synchronizes the movement of both slit plates 15 and 16 based on the synchronization signal input from the control circuit 37, and sequentially moves the liquid crystal cell 23a located at the imaging position of the point image Q. The liquid crystal panel 23 is driven so as to be in a light passing state. In this way, the photodetector 25 outputs a time-series signal S carrying a two-dimensional image of the sample 20. This signal S is converted into a pixel-divided signal Sp by, for example, integrating the signal S at predetermined intervals in synchronization with the movement of both slit plates 15, 16 in the signal processing circuit 26.

Furthermore, in this embodiment, the sample stage 19 is
1, it is moved in the direction of arrow Z perpendicular to the main and sub-scanning directions X, , Y. If the light spot P is two-dimensionally scanned every time the sample 20 is moved a predetermined distance in the Z direction in this manner, only information on the focused plane is detected by the photodetector 25.

Therefore, by importing the output S of the photodetector 25 into the frame memory, it becomes possible to obtain a signal that represents an image that is focused on all surfaces within the range in which the sample 20 is moved in the Z direction. .

Note that the slit 15 formed on the first slit plate 15
The shape a is not limited to the shape in the above embodiment, but may be in the shape of a sinusoidal curve, for example. However, the slit 15a having the shape of the above embodiment is particularly preferable because the light spot P can be main-scanned at a constant speed by moving the first slit plate 15 at a constant speed.

Further, although the scanning microscope of the embodiment described above is for obtaining monochrome microscopic images, the present invention can of course be applied to conventionally known scanning microscopes for obtaining color images. It is. Furthermore, the scanning microscope of the present invention is of a reflection type.

It is also possible to form it by

(Effects of the Invention) As explained in detail above, the light beam scanning mechanism of the present invention has the following features:
It is constructed so that the light beam can be scanned two-dimensionally by simply moving two slit plates1, and at the same time it also has the function of narrowing down the light beam, so it is simple in construction and can be formed at low cost. can. Further, since the scanning microscope according to the present invention employs the above-described light beam scanning mechanism, the structure is simple and can be formed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a scanning microscope according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the slit plate portion of the scanning microscope in detail. lO... Laser light source 11... Illumination light 11
'...Transmitted light 15...First slit plate 15a, 16a...Slit 16...Second slit plate 18.22...Objective lens 19...
- Sample stage 20... Sample 21... Vertical movement mechanism 23... Liquid crystal panel 23a...
・Liquid crystal cell 24...Liquid crystal panel drive circuit 25...
Photodetector 25a... Light receiving surface 26... Signal processing circuit 30.31... Winding shaft 33...
・Drive roller 34.35...drive device 36・
...Moving member 37...Control circuit

Claims (2)

[Claims] (1) A first slit plate having a meandering slit arranged in the optical path of the light beam and allowing a part of the light beam to pass; a second slit plate having one slit extending in intersecting directions and intersecting the slit at one point; and moving the first slit plate in the direction in which the meandering portions of the slits are continuous; A light beam scanning mechanism comprising driving means for moving the second slit plate relative to the first slit plate in a direction substantially parallel to the direction of movement. (2) A sample stage on which a sample is placed, a light source that emits illumination light, a light transmission optical system that images this illumination light as a minute light spot on the sample, and a light transmission system that focuses the light flux from the sample. a light-receiving optical system that forms a point image using a light-receiving optical system; a photodetector that detects the point image; and a photodetector that is placed at a position that receives the illumination light and scans the light spot of the illumination light two-dimensionally on the sample. A scanning microscope comprising a light beam scanning mechanism according to claim 1.