JPH1195110A - Confocal optical scanner having multi-pinhole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a confocal optical scanner capable of preventing deterioration of the S/N ratio. SOLUTION: In a confocal optical scanner having a multi-pinhole for obtaining the image of a sample by rotating a pinhole disk having plural pinholes, scanning the irradiating light beam passed through the pinhole on the sample and detecting the reflected light beam from the sample, an image forming optical system IL connecting a pinhole plane to an image forming plane with a conjugate relation is provided in the rear of the pinhole disk and a light shielding plate 13, having an aperture for passing the light beam from the sample surface through it, is provided in the image forming optical system IL.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanner for a confocal microscope in which a sample surface is optically scanned using a plurality of pinholes to obtain an image of the sample surface, that is, a so-called multi-pinhole confocal scanner. The present invention relates to an optical scanner, and particularly to an improvement in an SN ratio.

[0002]

2. Description of the Related Art A confocal optical scanner of this type has been well known. For example, Japanese Unexamined Patent Application Publication No. Hei. A confocal optical scanner having a simple configuration is described.

[0003] In the illustrated confocal optical scanner 1, a condensing disk 2 and a pinhole disk 3 are connected in parallel with a drum 4 interposed therebetween, and are formed so as to be rotated by a motor 5. Further, a beam splitter 6 is fixedly arranged between the two disks 2 and 3.

A plurality of microlenses (for example, Fresnel lenses) are formed on the condensing disk 2, and a plurality of pinholes are formed on the pinhole disk 3, and each pinhole is located at the focal position of each microlens. The two discs are connected to each other.

[0005] The laser beam incident on the condensing disk 2 is converged by a microlens, passes through a beam splitter 6 and condenses on a pinhole. The light passing through the pinhole is condensed by the objective lens 7 and is irradiated on the sample 8. The return light from the sample 8 passes through the objective lens 7 and the pinhole disk 3 again, is reflected by the beam splitter 6, and enters the camera 10 via the condenser lens 9. An image of the sample 8 is formed on an image receiving surface (not shown) of the camera 10.

In such a configuration, the condensing disk 2
And the pinhole disk 3 is rotated, and the surface of the sample 8 is optically scanned by a plurality of pinholes, thereby obtaining the camera 10.
Thereby, a surface image of the sample 8 can be observed.

FIG. 3 shows a specific example of a main part of an optical scanner of a confocal microscope based on such a principle.
Only the optical system from to the binhole disk is shown. In the sample surface by an objective lens (also referred to as object plane) O and the pinhole disk surface P are in conjugate relationship confocal microscope optical system, the light beam R _K emitted from the object point O _K passes through the pinhole P _K The light beam R _{K + 1} emitted from the object point O _{K + 1} passes through the pinhole P _{K + 1} , and transmits information on the object plane to the rear of the pinhole P.

[0008] In this case, 'light flux R _K exiting the' object point O _K at a position deviated from the object point O _K is pinhole is diffused
The disk surface P is reached. Small enough information from the object point O _K 'negligible with respect to the pinhole P _K information of the object point O _K is transmitted.

[0009]

The object of the invention is to be Solved by the way, although the impact on the pinhole P _K of the light beam R _K 'diffused small,
Diffused light beam R _K 'is also mixed into the plurality of pin holes adjacent to the pin hole P _K. This phenomenon is caused by light beams emitted from all object points other than the object plane O, so that light from other than the object plane O is superimposed on each pinhole. As a result, in the conventional optical scanner, the S / N ratio of the image of the object plane O transmitted behind the pinhole is inferior,
There is a drawback that the image is observed as a poor contrast image.

In view of the above, an object of the present invention is to provide an S
An object of the present invention is to provide a confocal optical scanner that blocks background light that causes the deterioration of the N ratio and allows only the light flux from the sample surface to pass, thereby preventing the deterioration of the S / N ratio.

[0011]

In order to achieve the above object, according to the present invention, a pinhole disk having a plurality of pinholes is rotated, and irradiation light passing through the pinholes is scanned on a sample. A multi-pinhole confocal optical scanner that obtains an image of the sample by detecting reflected light from the sample, wherein a pinhole surface and an imaging surface are connected in a conjugate relationship behind the pinhole disk. An image optical system is provided, and a light shielding plate having an opening through which the light beam from the sample surface passes is provided in the image forming optical system.

[0012]

An image forming optical system is provided behind the pinhole disk for connecting the pinhole surface and the image forming surface in a conjugate relationship, and the image forming optical system has an opening through which the light beam from the sample surface passes. Arrange a light shielding plate. As a result, the background light that causes the SN ratio to deteriorate is shielded, and only the light beam from the sample surface passes through the aperture. As a result, a confocal image with an excellent SN ratio is obtained. Further, by providing the light shielding plate, the optical aberration of the imaging optical system can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a multi-pinhole confocal optical scanner according to the present invention. In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals.

In the present invention, the beam splitter and the condensing disk are not shown in the drawing, since the condensing disk and the beam splitter having the structure as shown in the conventional example are not necessarily required, and in order to avoid complexity. I have.

IL is an imaging optical system IL for connecting the pinhole surface P and the imaging surface I in a conjugate relationship behind the pinhole disk P. This imaging optical system IL includes a lens 1
1 and 12 and a light shielding plate 13 inserted therebetween. The light-shielding plate 13 has an opening 14 for transmitting a light beam.

In such a configuration, the light beam from the object plane O passes through the pinhole, and then becomes parallel light by the lens 11, passes through the opening 14 of the light shielding plate 13, and enters the lens 12. The parallel light is focused by the lens 12 and is focused on the image plane I. The aperture 14 of the light-shielding plate 13 is desirably a hole large enough to allow the light from the object plane O passing through the pinhole to pass through the light flux of parallel light when entering the lens 12 from the lens 11.

[0017] This light shielding plate, (light causing the SN ratio degradation) 'light flux R _K exiting the' object point O _K at a position deviated from the object point O _K is the majority is blocked as shown Therefore, an image having a good SN ratio can be obtained on the image plane I. At the same time, since the light shielding plate 13 is used, the imaging optical system IL
Can be reduced.

It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of illustration and illustration of the invention. Therefore, the present invention is not limited to the above-described embodiments, and includes many more modifications without departing from the spirit thereof.
This includes deformation.

[0019]

As described above, according to the present invention, the use of the imaging optical system and the light-shielding plate having the opening for shielding the background light and allowing only the light flux from the sample surface to pass therethrough,
There is an effect that a confocal image with an excellent S / N ratio can be obtained, and at the same time, the optical aberration of the imaging optical system can be reduced by the light shielding plate.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a multi-pinhole confocal optical scanner according to the present invention.

FIG. 2 is a configuration diagram illustrating an example of a conventional confocal optical scanner.

FIG. 3 is a diagram showing a specific example of a main part of a conventional optical scanner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Confocal optical scanner 2 Condensing disk 3 Pinhole disk 4 Drum 5 Motor 6 Beam splitter 7 Objective lens 8 Sample 9 Condensing lens 10 Camera 11, 12 Lens 13 Shielding plate 14 Opening O Object surface P Pinhole disk surface _{O K, O K ', O} K + 1 object point P _K, P _{K + 1} pinhole _{R K, R K + 1,} R K' light beam IL imaging optical system I imaging plane

Claims (4)

[Claims] 1. A method according to claim 1, further comprising: rotating a pinhole disk having a plurality of pinholes, scanning a sample with irradiation light passing through the pinhole, detecting reflected light from the sample, and forming an image of the sample. In the obtained multi-pinhole confocal optical scanner, an imaging optical system for connecting a pinhole surface and an imaging surface in a conjugate relationship is provided behind the pinhole disk, and the sample is provided in the imaging optical system. A multi-pinhole confocal optical scanner comprising a light-shielding plate having an opening through which a light beam from a surface passes. 2. An optical scanner for a multi-pinhole confocal according to claim 1, wherein said imaging optical system includes two lenses, and said light shielding plate is disposed between said two lenses. . 3. The multi-pinhole confocal optical scanner according to claim 2, wherein said light shielding plate is arranged such that the center of the opening is located on the optical axis. 4. The multi-pinhole confocal optical scanner according to claim 1, wherein the aperture of the light-shielding plate is formed to have a size that allows only a light beam from the sample plane to pass.