JPH0980312A - Confocal microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make lights from all fine apertures possible to be incident on the pupil center of an objective, to eliminate the loss of the quantity of light at the marginal part, and to increase light utilization efficiency and increase the resolution of the marginal part by arranging a lens which has focal length equal to the rear-side focal length of an objective between the fine aperture part and objective. SOLUTION: A field lens 60 has a focal length equal to the rear-side focal length (a) of the objective 30 of a finite microscope and is arranged nearby a pinhole array 11. Laser lights are converged on pinholes PH through microlenses ML and the laser lights having passed through the pinholes PH have their optical axes bent to the pupil center of the objective 30 by the field lens 60 arranged right below. Therefore, laser lights from all the pinholes PH are made incident on the pupil center of the objective 30. Consequently, the loss of the quantity of light at the marginal part is eliminated and the resolution at the marginal part is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a confocal microscope using a minute aperture (hereinafter also referred to as a pinhole array) having a plurality of minute apertures (eg pinholes), and more specifically, a confocal optical scanner is combined. The present invention relates to an improvement for improving light use efficiency and resolution in the peripheral part of the visual field in a finite optical microscope.

[0002]

2. Description of the Related Art FIG. 4 shows an example of an essential part of an optical system when an optical scanner is attached to a conventional finite microscope. In the figure, 10 is an optical scanner and 30 is an objective lens. Although the details of the optical scanner 10 will be described later, the laser light focused by the microlens ML in the optical scanner is pinhole P.
The light source becomes a point light source at H (a point light source by three pinholes is representatively shown in the figure), and the light of this point light source enters the objective lens 30.

Regarding an optical scanner in which a micro aperture having a plurality of micro apertures is rotatably incorporated, for example, US Pat. No. 3,926,500 and US Pat.
No. 7,254, U.S. Pat. No. 5,067,805 and the like. FIG. 6 shows an example of an optical scanner in which a microlens is further added to this type of optical scanner, which is a patent application filed by the applicant of the present application, Japanese Patent Application No. 4-15411 (Japanese Patent Application Laid-Open No. 5-60980) “Optical Scanner for Confocal Focus”. Shows a confocal optical scanner described in ". This confocal optical scanner comprises a disk unit 11, a beam splitter 12, and a motor 13 that rotates the disk unit 11 at a constant speed.

In the disk unit 11, a plurality of Fresnel lenses (corresponding to the microlenses ML in FIG. 4) formed on one surface of the glass substrate 141 shown in FIG. _The condensing disk 14 formed by sequentially shifting by _r and the plurality of pinholes PH formed on the substrate 151 as shown in FIG. 7B are sequentially displaced by P _{r in the} radial direction (P _{θ in the} circumferential direction). Pinhole disk 15 and the condensing disk 14 formed by
And a drum 16 connecting the pinhole disk 15 so that the pinhole PH is arranged at the focal position of the Fresnel lens. The beam splitter 12 is held between the condensing disk 14 and the pinhole disk 15 by means not shown.

The configuration shown in FIG. 6 is an example of a configuration in which the confocal optical scanner 10 is attached to a finite optical system microscope. The laser light emitted from the confocal optical scanner is focused by the objective lens 41 and irradiated on the sample 42. The light returned from the sample 42 passes through the objective lens 41 again, and is focused on the pinhole PH of the confocal optical scanner 10, where a real image of the sample surface is obtained. The light passing through the pinhole PH is reflected by the beam splitter 12, passes through the condenser lens 43, and is applied to the image receiving surface of the camera 44. By driving the motor 13 to rotate the disk unit 11, the sample 42
The surface of the sample is optically scanned, and an image of the sample surface can be observed with a camera.

[0006]

In the finite optical system microscope shown in FIG. 4, the distance between the pinhole PH and the objective lens 30 is the back focal length a of the objective lens. Therefore, all the light from the pinhole PH is incident on the objective lens 30 with the optical axes parallel to each other, and the peripheral light is shifted to the position of the pupil of the objective lens 30 as shown in FIG. Incident. This causes the following problem.

(1) Depending on the type of the objective lens 30, the pupil diameter is small, and the amount of light from the peripheral pinhole is eclipsed, and the amount of illumination light decreases in the periphery (illumination unevenness occurs). (2) Since the light from the peripheral pinhole cannot sufficiently fill the pupil of the objective lens and cannot utilize the numerical aperture (NA) of the objective lens 30, the resolution is reduced in the peripheral portion. (3) The return light (reflected light or fluorescence) from the sample is obliquely incident on the pinhole PH, the transmission efficiency is reduced, and it is obliquely incident on the optical system after that, which is affected by the shading of the light quantity and aberration. .

In view of the above, an object of the present invention is to dispose a lens having the same focal length as the rear focal length of the objective lens between the minute aperture and the objective lens so that the objective lens has the same focal length. The light from the small aperture of
It is an object of the present invention to provide a confocal microscope capable of eliminating the loss of light amount in the peripheral portion, improving the light utilization efficiency, and increasing the resolution of the peripheral portion.

[0009]

In order to achieve such an object, in the present invention, a confocal optical scanner having a minute aperture is attached to a microscope of finite optical system, and laser light from the minute aperture is passed through an objective lens. The sample was irradiated, and the return light from the sample was configured to return to the minute aperture through the objective lens, and the minute aperture was rotated to optically scan the sample surface and observe the image of the sample surface. The confocal microscope is characterized in that a lens having a focal length equal to a rear focal length of the objective lens is arranged between the minute aperture and the objective lens.

[0010]

In a structure in which an optical scanner is combined with a finite optical system microscope, a lens having a focal length equal to the back focal length of the objective lens is arranged between the pinhole array and the objective lens. As a result, the light from the pinhole in the peripheral portion is also made incident on the center of the pupil of the objective lens, the light amount loss in the peripheral portion is eliminated, and the resolution in the peripheral portion is improved.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the drawings. FIG. 1 is a main part configuration diagram showing an embodiment of a confocal microscope according to the present invention. The same parts as those in FIG. 3 are denoted by the same reference numerals, and the description of those parts will be omitted. 1 is different from FIG. 4 in that a field lens 60 is arranged immediately below the pinhole array.

The field lens 60 has the same focal length as the back focal length a of the objective lens 30 of the finite microscope,
It is arranged close to the pinhole array 11 (in other words, immediately below the pinhole array 11). The laser light is narrowed down to the pinhole PH by the microlens ML, and the laser light that has passed through the pinhole PH is bent by the field lens 60 disposed directly below the optical axis to the center of the pupil of the objective lens 30. Therefore, the laser light from all the pinholes PH is incident on the center of the pupil of the objective lens 30 as shown in FIG.

The optical axis of the return light from the sample (not shown) is bent by the field lens 60 so as to be incident on the pinhole PH at 0 degree. Thereby, the light utilization efficiency of the signal light is improved. Aberrations and the like occur in the field lens 60 when it is far away from the pinhole PH surface, but in general, the focal length a can be designed to be 200 mm, and the distance between the pinhole PH and the field lens 60 can be designed to be about 10 mm, so aberration is a practical problem. do not become.

FIG. 3 is a block diagram showing another embodiment of the present invention. In the figure, 71 is a relay lens and 72 is a lens. The relay lens 71 is a lens that forms the image plane of the pinhole PH at the position of the rear focal length a of the objective lens 30, and is arranged between the pinhole PH and the objective lens 30. The lens 72 has the same focal length as the rear focal length a of the objective lens 30, and is arranged at the position of the image plane of the pinhole formed by the relay lens 71. With such a configuration, all the light from the pinhole enters the center of the pupil of the objective lens 30.

The present invention is not limited to the above embodiment, but can be appropriately modified and modified. For example, the microlens ML may be omitted. Further, the shape of the minute opening is not limited to a circular shape such as a pinhole. Other shapes may be used as long as the same purpose can be achieved.

[0016]

As described above, according to the present invention, since the laser light from the minute aperture in the peripheral portion can be incident on the center of the pupil of the objective lens, the following effects can be obtained, which is extremely useful. (1) Due to the pupil diameter of the objective lens, the amount of light from the minute aperture in the peripheral portion is not obstructed, the loss of light amount is eliminated, the light utilization efficiency is improved, and uneven illumination does not occur. (2) The small aperture in the peripheral portion can effectively use the pupil of the objective lens like the small aperture in the central portion, the numerical aperture does not decrease, and the resolution only in the peripheral portion does not decrease. (3) In the configuration shown in FIG. 3, the return light from the sample is passed through the lens 72.
Thus, the light can be incident on the minute aperture at 0 degree, the transmission efficiency of the minute aperture can be improved, the influence of the vignetting and the aberration in the subsequent optical system can be reduced, and the peripheral image can be bright and the resolution can be improved.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing an embodiment of a confocal microscope according to the present invention.

FIG. 2 is a diagram showing a relationship between a pupil of an objective lens and a laser light incident position.

FIG. 3 is a main part configuration diagram showing another embodiment of the confocal microscope according to the present invention.

FIG. 4 is a configuration diagram of main parts when an optical scanner is attached to a conventional finite optical system microscope.

5 is a diagram showing the relationship between the pupil of the objective lens in FIG. 4 and the laser light incident position.

FIG. 6 is a configuration diagram showing an example of a confocal optical scanner.

FIG. 7 is a diagram illustrating the details of the condensing disc and the pinhole disc shown in FIG. 6;

[Explanation of symbols]

 10 Optical Scanner 30 Objective Lens 60 Field Lens 71 Relay Lens 72 Lens PH Pinhole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takeo Tanaami 2-39 Nakamachi, Musashino-shi, Tokyo Yokogawa Electric Co., Ltd.

Claims (4)

[Claims] 1. A finite optical system microscope is equipped with a confocal optical scanner having a plurality of minute apertures having a plurality of minute apertures, and laser light from the minute apertures is applied to a sample through an objective lens so that return light from the sample is emitted. A confocal microscope configured to return to the minute aperture through the objective lens, and to rotate the minute aperture to optically scan the sample surface to observe an image of the sample surface. And a lens having a focal length equal to the focal length on the rear side of the objective lens between the objective lens and the objective lens. 2. The field lens, wherein the lens is arranged between the minute aperture and the objective lens in the vicinity of the minute aperture, and all the light from the minute aperture is the center of the pupil of the objective lens. The confocal microscope according to claim 1, wherein the confocal microscope is configured to be incident on. 3. A relay lens, wherein the lens forms an image plane of the minute aperture at a position of a rear focal length of the objective lens, and a minute aperture of the relay lens having a rear focal length of the objective lens. The confocal microscope according to claim 1, wherein the confocal microscope is composed of a lens arranged at a position of an image plane, and all the light from the minute aperture is incident on the center of the pupil of the objective lens. 4. The confocal optical scanner has a plurality of microlenses for narrowing laser light incident on the minute apertures into the respective minute apertures. The confocal microscope described.