JPH09127420A - Confocal scanning microscope scanning device - Google Patents

Abstract

(57) Abstract: The confocal scanning type confocal scanning microscope by Nipkow disk does not have sufficient light quantity.
There is a problem that the reflected light from the disk cannot be completely removed. To solve the problem, a condensing lens arranging surface having a plurality of condensing lenses arranged and a pinhole arranging surface having pinholes arranged coaxially with each condensing lens are provided. An optical path branching optical element, an imaging lens which is inserted into an optical path branched by the optical path branching optical element in a direction perpendicular to the optical axis of a condenser lens to form an image of a pinhole array surface, and an imaging lens of the imaging lens. The deflection optical element that deflects the image-forming light beam in the direction perpendicular to the pinhole array surface, the condenser lens array surface, the pinhole array surface, the optical path branching optical system, the imaging lens and the deflection optical element are fixed and rotated by a motor. The scanning device of the confocal scanning microscope is constituted by the rotating body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning device for a confocal scanning microscope.

[0002]

2. Description of the Related Art Confocal scanning microscopes are known to be able to achieve a resolution exceeding that of a general optical microscope and to observe the three-dimensional shape of an object. The confocal scanning method of the confocal scanning microscope uses a laser beam as an optical deflection element (A
There is a method of scanning with an O element, an EO element, a galvano mirror, a polygon mirror, etc.) and a method of rotating a disk called Nipkow disk for scanning. Of these two types of scanning methods, the Nipkow disk method has a much simpler structure than the laser beam method, and has the advantage that a color image can be obtained by using white light as a light source. There is.

FIG. 4 shows the structure of a confocal scanning confocal microscope according to Nipkow disk. The illumination light passes through the optical path branching optical element 1 and is projected onto the Nipkow disk 41. The Nipkow disk 41 has a large number of spirally arranged pinholes as shown in FIG. 5, and light passes through the pinholes and is condensed by the objective lens 11 to be projected on the object 12. The reflected light from the object is condensed by the same objective lens 11 and Nipkow
It converges on the disk 41. Nipkowdisk
The reflected light that has passed through the pinhole 41 again is condensed by the imaging lens 4 via the optical path branching optical element 1 and converges so that the image of the pinhole is formed on the two-dimensional photoelectric sensor 6. Each pinhole of the Nipkow disk 41 and the objective lens 11 form a confocal optical system, and by rotating the Nipkow disk 41 by the motor 8, the pinhole scans the image plane of the objective lens 11 in two dimensions. A confocal image of the object 12 is obtained on the photoelectric sensor 6.

The above is the basic structure, but in reality N
The illumination light projected on the ipkow disk 41 is Ni.
The light is reflected on the pkow disk 41 and reaches the two-dimensional photoelectric sensor 6 via the optical path branching optical element 1 (hereinafter, such light will be referred to as disk reflected light).
Since a problem occurs, it is necessary to take measures to remove this reflected light from the disk. For this purpose, some polarizing optical components are inserted in FIG. 4 to remove the disk reflected light.
That is, first, the illumination light is linearly polarized and made incident on the optical path branching optical element 1 (polarization beam splitter). And
The reflected light from the disk is cut by the polarizing plate 10.
The light that has passed through the pinhole is circularly polarized by the quarter-wave plate 9, and when it is reflected by the object 12 and passes through the quarter-wave plate 9 again, it becomes linearly polarized light orthogonal to the illumination light. Since the light that has passed through the pinhole again has a parallel Nicol relationship with the polarizing plate 10, it passes through the polarizing plate 10 as it is and the two-dimensional photoelectric sensor 6
To reach. In this way, the reflected light from the object 12 has N
This prevents the reflected light from the ipkow disk 41 from being mixed.

[0005]

The above is Nipkow.
The structure of the confocal scanning confocal microscope according to the disk has two problems related to each other in this scanning mechanism. One is the amount of light. Nipkow disk4
Since the pinholes on 1 are separated from each other and their diameters are small, only a small amount of illumination light can pass through the pinholes. The illumination light that can pass through the pinhole is generally only about 1%. Therefore, the light reflected by the object 12, passing through the pinhole again, and reaching the two-dimensional photoelectric sensor 6 becomes very faint (especially when the reflectance of the object 12 is low). Another is the removal of the reflected light on the disk. di
Since the sk reflected light is quite strong, and conversely, the reflected light from the object 12 is faint as described above, the disk reflected light is not completely cut even if measures are taken by using polarized light. It's not enough because it's not there.

Therefore, an object of the present invention is to provide a scanning device of a confocal scanning microscope which can increase the amount of light passing through a pinhole and has a small amount of disk reflected light.

[0007]

To achieve the object, a condensing lens array surface on which a plurality of condensing lenses are arrayed, and a pin optically coaxial with each arrayed condensing lens are arranged. A pinhole array surface having holes, located between the condenser lens array surface and the pinhole array surface, in the optical axis direction of the condenser lens and in the direction perpendicular to the optical axis of the condenser lens. An optical path branching optical element for branching the optical path; and an imaging lens for forming an image of the pinhole array surface by being inserted into the optical path branched by the optical path branching optical element in a direction perpendicular to the optical axis of the condenser lens. A deflection optical element for deflecting the image-forming light flux of the image-forming lens in a direction perpendicular to the pinhole array surface, the condenser lens array surface, the pinhole array surface, the optical path branching optical system, and the image-forming lens. And the deflection optical element are fixed. Constituting a scanning device for a rotary body more confocal scanning microscope which is rotated by coater. By doing so, the illumination light can be condensed by the condenser lens and converged on the pinhole, so that the amount of illumination light passing through the pinhole can be increased. In addition, since the illumination light that does not pass through the pinhole is significantly reduced, it is possible to reduce the light reflected by the disk.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a confocal scanning microscope according to the present invention. Reference numeral 1 denotes a polarization prism type optical path branching optical element (polarization beam splitter). The top surface of the microlens 2 has a spiral shape as shown in FIG.
2a is a condensing lens array surface 2 and pinholes are arrayed on the lower surface in the same array as the microlenses 2a of the condensing lens array surface 2 as shown in FIG. 2B. It has a pinhole array surface 3. Areas other than the microlenses 2a on the condenser lens array surface 2 are covered with a light shielding mask 2b. When the illumination light linearly polarized in the direction of transmission through the polarizing prism type optical path branching optical element 1 (parallel Nicol) enters the condenser lens array surface 2 as parallel light as shown in FIG. It converges on the focal position of 2a. The pinhole array surface 3 is installed at this position (arranged so that the center of each pinhole is located on the optical axis of each microlens 2a).
Therefore, most of the light incident on each microlens 2a passes through the pinhole. Further, of the illumination light that has entered the condenser lens array surface 2, that which does not enter the microlens 2a is shielded by the light blocking mask 2b and does not reach the pinhole array surface 3, so pinholes are created on the pinhole array surface 3. There is almost no light that reflects without passing through (light equivalent to disk reflected light).

Illumination light that has passed through the pinhole is circularly polarized by the quarter-wave plate 9 and is subjected to an image forming action by the objective lens 11 to form an image of the pinhole on the surface of the object 12.
The reflected light from the object 12 is focused by the same objective lens 11 to become convergent light, and becomes a linearly polarized light orthogonal to the illumination light by the quarter-wave plate 9 and passes through the pinhole again (in this way). The reflected light that has passed through the pinhole is called return light). The return light is deflected by the optical path branching optical element 1 and subjected to the image forming action of the image forming lens 4 to form an image of the pinhole array surface 3 on the two-dimensional photoelectric sensor 6.
The deflection optical element 5 is provided for deflecting the image-forming light flux of the image-forming lens 4 to make the pinhole array surface 3 and its image parallel. The polarizing plate 10 on the deflecting optical element 5 has a parallel Nicol relationship with the return light, and the return light is transmitted as it is.

Optical path branching optical element 1 (condensing lens array surface 2
And the pinhole array surface 3), the imaging lens 4 and the deflection optical element 5 (including the polarizing plate 10) are fixed on a transparent parallel plate-shaped rotating body 7 (for example, parallel plate glass). , Rotates with the rotating body 7 by the rotation of the motor 8. As shown in FIG. 3, the deflection optical element 5 is located on the side opposite to the optical path branching optical element 1 with respect to the rotation center of the rotating body 7, and is arranged on the condenser lens array surface 2 and the pinhole array surface 3.
The center of the spiral pattern of the upper pinhole (see Figure 2),
The center of the spiral pattern of the image of the pinhole and the rotation center of the rotating body 7 coincide with each other. FIG. 3 shows an example when the magnification of the imaging lens 4 is 0.75.

The two-dimensional photoelectric sensor 6 is installed and fixed at a position on the opposite side of the rotation center of the rotating body 7 from the position where the illumination light is emitted (it does not rotate together with the rotating body 7). . As a result, when the rotating body 7 rotates, the image of the pinhole is scanned on the two-dimensional photoelectric sensor 6, and the exposure time of the two-dimensional photoelectric sensor 6 is set to at least the time required for all the images of the pinhole to pass. A confocal image can be obtained by setting it. The rotation cycle of the rotating body 7 is equal to the imaging cycle of the two-dimensional photoelectric sensor 6 (the time from the start of exposure to the start of exposure of the next image, and the exposure time is less than the imaging cycle). In the case of a TV camera of NTSC standard, the image pickup cycle is 1/60 second, so the image is rotated at a rotation speed of 60 times / second.

The exposure of the two-dimensional photoelectric sensor 6 is performed only by the image of the pinhole, and the illumination light or the return light is not incident on the two-dimensional photoelectric sensor 6 in other portions (the deflection optical element 5 is located at the irradiation position of the illumination light). When the illuminating light comes, the illuminating light and the polarizing plate 10 on the deflecting optical element 5 have an orthogonal Nicol relationship, so that the illuminating light does not enter the deflecting optical element 5. Therefore, the illuminating light or the returning light enters the two-dimensional photoelectric sensor 6. Never reach).

In the above example, the polarized light is used for the purpose of cutting unnecessary light (stray light) as much as possible by the linearly polarized illumination, the polarization prism type optical path branching optical element 1, the deflection optical element 5, the quarter wavelength plate 9 and the like. However, it is not always necessary to use polarized light. A point that obviously becomes a problem when the polarized light is not used is the processing of light when the deflection optical element 5 comes to the irradiation position of the illumination light, but this can be solved by using the shutter function of the two-dimensional photoelectric sensor 6. Further, in this example, the condensing lens array surface 2 and the pinhole array surface 3 are formed directly on the surface of the optical path branching optical element 1, but they are formed on parallel plate glass, optical resin, optical crystal, etc. It may be attached to the element 1 or may be formed on the rotating body 7. Further, in this example, a transparent body is used as the rotating body 7, but a non-transparent body having only a spiral pattern portion may be used.

[0014]

The amount of illumination light passing through the pinhole can be increased by condensing the illumination light by the microlens 2a, and the amount of illumination light that does not pass through the pinhole is greatly reduced, so that the amount of the disk reflection light is also small. can do. In addition, all the optical components around the rotating body 7 (the condensing lens array surface 2, the pinhole array surface 3, the optical path branching optical element 1, the imaging lens 4, the deflecting optical element 5, the polarizing plate 10, etc.) should be integrated. Since it is possible, the whole becomes compact and is less susceptible to the influence of vibration.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a condenser lens array surface and a pinhole array surface.

FIG. 3 is a diagram showing an upper surface of a rotating body.

FIG. 4 is a diagram for explaining a conventional technique.

FIG. 5 is a diagram for explaining a Nipkow disk.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical path branching optical element 2 Condensing lens array surface 3 Pinhole array surface 4 Imaging lens 5 Deflection optical element 6 Two-dimensional photoelectric sensor 7 Rotating body 8 Motor 9 1/4 Wave plate 10 Polarizing plate 11 Objective lens 12 Object 41 Nipkow disk

Claims (1)

[Claims] 1. In a confocal scanning microscope having a two-dimensional scanning device inside for obtaining a confocal image, a condensing lens array surface on which a plurality of condensing lenses are arrayed, and each of the arrayed individual condensing lenses. A pinhole array surface having pinholes arranged coaxially with the condenser lens, and an optical axis direction of the condenser lens located between the condenser lens arrangement surface and the pinhole arrangement surface. An optical path branching optical element for branching an optical path in a direction perpendicular to the optical axis of the condenser lens, and the pin inserted in an optical path branched by the optical path branching optical element in a direction perpendicular to the optical axis of the condenser lens. An image forming lens for forming an image on the hole array surface, a deflection optical element for deflecting the image forming light flux of the image forming lens in a direction perpendicular to the pinhole array surface, the condensing lens array surface and the pinhole. Array surface and the optical path branching optical system A scanning device for a confocal scanning microscope, characterized in that the imaging lens and the deflection optical element are fixed and are constituted by a rotating body that is rotated by a motor.