JPH11109247A - Ultraviolet laser microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet laser microscope capable of secure observation while a harmful ultraviolet laser beam does not reach an observing eye through an eyepiece lens. SOLUTION: This microscope is provided with an optical path splitting means 7 having wavelength selectivity; for introducing a visible light beam from a sample 6 through a visible light objective lens 5 along a first optical path and introducing an ultraviolet laser beam from the sample 6 through an ultraviolet objective lens 25 along a second optical path different from the first optical path; and an ultraviolet laser beam shielding means 8; arranged between the optical path splitting means 7 and an observing eye for observing the image 10 of the sample 6 by visible light in the first optical path and for shielding propagation of the ultraviolet laser beam entered into the first optical path through the optical path splitting means 7 to the observing eye.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ultraviolet laser microscope, and more particularly to a microscope provided with a visible light source and an ultraviolet laser light source as illumination light sources.

[0002]

2. Description of the Related Art The resolution R of an optical microscope is R = k1.lambda.
/ NA. Here, k1 is a proportionality constant, and λ
Is the working wavelength, and NA is the numerical aperture of the objective lens.
As can be seen from the equation representing the resolution R, there are a method of increasing the numerical aperture NA of the objective lens and a method of shortening the used wavelength λ in order to improve the resolution of the optical microscope. Although the numerical aperture of the objective lens can be increased to a maximum of 1.0 with respect to a sample (specimen) in the air, the numerical aperture of the objective lens is about 0.95 at the maximum in practical use.

On the other hand, the depth of focus FD of an optical microscope is FD
= K2R / λ. Here, k2 is a proportionality constant. As can be seen from the equation representing the depth of focus FD, if the resolution R is the same, the shorter the wavelength λ used is, the deeper the depth of focus FD is, which is advantageous in use. Therefore, in order to improve the resolving power of an optical microscope while securing a certain depth of focus, the wavelength of illumination light has been shortened. Particularly, an ultraviolet microscope using i-line (365 nm) light having a shorter wavelength than visible light (400 nm to 700 nm) is disclosed in, for example, Japanese Patent Application Laid-Open No. H5-127096.

[0004]

In an ultraviolet microscope, the resolution is increased by shortening the wavelength of illumination light, but it is harmful if ultraviolet light reaches an observation eye through an eyepiece. The ultraviolet microscope disclosed in the above-mentioned publication uses an ultra-high pressure mercury lamp as an illumination light source, and separates visible light and ultraviolet light through a dichroic mirror, for example, so that harmful ultraviolet light reaches an observation eye. Have been around.

[0005] In particular, in an ultraviolet laser microscope using an ultraviolet laser light source as an illumination light source, since the ultraviolet laser light condensing property is good and the eye has no sensitivity to the ultraviolet laser light, it is very difficult for the ultraviolet laser light to reach the observation eye. Dangerous. For example, in the configuration of the ultraviolet microscope disclosed in Japanese Patent Application Laid-Open No. 5-127096, when an ultraviolet laser light source is used as an illumination light source and the laser output is increased, the dichroic mirror alone can sufficiently separate visible light and ultraviolet laser light. It is not possible to perform safe microscopy because harmful ultraviolet laser light reaches the observation eye.

The present invention has been made in view of the above problems, and provides an ultraviolet laser microscope capable of performing a safe microscopic examination without causing harmful ultraviolet laser light to reach an observation eye through an eyepiece. The purpose is to do.

[0007]

In order to solve the above-mentioned problems, the present invention provides a method for forming a visible light image on a specimen based on light from the specimen illuminated by the visible light. An objective lens, an ultraviolet laser light objective lens for forming an image of the sample with ultraviolet laser light based on light from the sample illuminated by ultraviolet laser light, the visible light objective lens and the ultraviolet laser Setting means for selectively setting any one of the objective lenses for light in the optical path, and transmitting the visible light from the sample through the objective lens for visible light along the first optical path. Optical path splitting means having wavelength selectivity for guiding ultraviolet laser light from the sample through the ultraviolet laser light objective lens along a second optical path different from the first optical path. An ultraviolet laser disposed between the optical path splitting unit and an observation eye for observing an image of the sample with visible light in the first optical path, and having entered the first optical path via the optical path splitting unit; An ultraviolet laser microscope comprising: an ultraviolet laser light shielding unit for shielding propagation of light to the observation eye.

According to a preferred aspect of the present invention, the optical path dividing means has a dichroic film for reflecting or transmitting visible light and transmitting or reflecting ultraviolet laser light. The ultraviolet laser light shielding means is disposed between the optical path splitting means and a position where an image of the specimen is formed by visible light, and is an ultraviolet cut filter for transmitting visible light and blocking passage of ultraviolet laser light. It is preferable to have

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In an ultraviolet laser microscope, since an ultraviolet laser light source used as an illumination light source is substantially a monochromatic light source, color information of the specimen is obtained from an image formed based on the ultraviolet laser light from the specimen. It is not possible. In the present invention, the objective lens for visible light and the objective lens for ultraviolet laser light are the same in order to improve the resolution by using ultraviolet laser light and obtain the color information of the sample, which is an advantage of the conventional visible light observation. A configuration is adopted in which the lens is attached to a revolver and one of the objective lenses is selectively set in a predetermined optical path as needed.

According to the structure of the present invention, an image of the sample is formed by the visible light by illuminating the sample with the visible light by setting the objective lens for the visible light in the optical path, and the objective lens for the ultraviolet laser light is connected to the optical path. By illuminating the sample with the ultraviolet laser light with the setting being made inside, an image of the sample with the ultraviolet laser light is formed. Then, for example, by visually observing an image with visible light through an eyepiece, color information of the sample can be obtained. Further, for example, a sample image by an ultraviolet laser beam can be detected with high resolution via an ultraviolet television camera.

In the present invention, in order to guide the visible light from the specimen through the objective lens for visible light and the ultraviolet laser light from the specimen through the objective lens for ultraviolet laser light, respectively, along different optical paths, For example, a wavelength-selective optical path dividing unit such as a dichroic mirror is provided. However, as described above, the dichroic mirror alone cannot sufficiently separate visible light and ultraviolet laser light, for example, a part of the ultraviolet laser light to be reflected by the dichroic mirror passes through the dichroic mirror,
It is conceivable to reach the observation eye via an eyepiece.

Therefore, according to the present invention, for example, an ultraviolet laser light shielding means such as an ultraviolet cut filter or a dichroic mirror is disposed in an observation optical path between an optical path dividing means such as a dichroic mirror and an observation eye, and It blocks the propagation of ultraviolet laser light that has penetrated into the observation eye. As a result, in the ultraviolet laser microscope of the present invention, a harmful ultraviolet laser beam does not reach an observation eye through an eyepiece, and a sample image is detected with high resolution by a safe speculum and color information of the sample is obtained. Can be.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a view schematically showing a configuration of an ultraviolet laser microscope according to a first embodiment of the present invention. The ultraviolet laser microscope of FIG. 1 includes, for example, a halogen lamp 1 as an illumination light source for supplying visible light. The illumination light emitted from the halogen lamp 1 enters the visible light half mirror 3 via the visible light illumination optical system 2. The visible light half mirror 3 is configured to be insertable into and removable from the optical path, is retracted from the optical path when using ultraviolet laser light, and is set in the optical path when using visible light. The illumination light reflected by the visible light half mirror 3 illuminates the sample 6 via the visible light objective lens 5 set in the optical path by the action of the revolver 4.

The light from the sample 6 illuminated with visible light passes through the objective lens 5 for visible light and the half mirror 3 for visible light, and then reaches the dichroic mirror 7. The dichroic mirror 7 has a property of transmitting visible light and reflecting ultraviolet laser light. Therefore, light from the specimen 6 illuminated with visible light is transmitted to the dichroic mirror 7
And enters the ultraviolet cut filter 8. The ultraviolet cut filter 8 has characteristics of transmitting visible light and blocking passage of ultraviolet laser light. Therefore, the visible light transmitted through the ultraviolet cut filter 8 is reflected by the mirror 9 and then forms a sample image 10 of the visible light. Light from the sample image 10 due to visible light reaches the observation eye 12 via the eyepiece 11. Thus, the eyepiece 11
The sample image 10 by visible light is magnified and observed through the
Color information can be obtained.

The ultraviolet laser microscope shown in FIG. 1 includes an ultraviolet laser light source 21 such as a fourth-harmonic YAG laser (output wavelength: 266 nm). UV laser light source 2
The ultraviolet laser light emitted from 1 is shaped into a beam having a predetermined cross-sectional shape via a beam expander 22 and then enters a half mirror 24 for ultraviolet laser light via a collector lens 23. The ultraviolet laser light half mirror 24 is configured to be insertable into and removable from the optical path, is retracted from the optical path when using visible light, and is set in the optical path when using ultraviolet laser light. Half mirror 2 for ultraviolet laser light
The ultraviolet laser light reflected by the laser beam 4 is applied to the ultraviolet laser light objective lens 25 set in the optical path by the action of the revolver 4.
Illuminate the specimen 6 via.

The light from the sample 6 illuminated with the ultraviolet laser light passes through the ultraviolet laser light objective lens 25 and the ultraviolet laser light half mirror 24 and then reaches the dichroic mirror 7. As described above, the dichroic mirror 7
Has the property of transmitting visible light and reflecting ultraviolet laser light. Therefore, the light from the sample 6 illuminated with the ultraviolet laser light is reflected by the dichroic mirror 7 and, after being reflected by the mirror 26, forms a sample image 27 by the ultraviolet laser light. Sample image 2 by ultraviolet laser light
Numeral 7 is detected at a high resolution through a detector (not shown) having sensitivity to light in an ultraviolet region such as an image pickup device (for example, a CCD) of an ultraviolet television camera. In order to prevent the ultraviolet laser light scattered from the specimen 6 illuminated by the ultraviolet laser light from entering the observation eye, an ultraviolet cover (not shown) having a predetermined shape covers the specimen 6 according to a conventional technique. Needless to say, it is provided as follows.

Although the dichroic mirror 7 is configured to transmit visible light and reflect ultraviolet laser light, the dichroic mirror 7 alone can sufficiently separate visible light and ultraviolet laser light. Instead, it is conceivable that part of the ultraviolet laser light to be reflected by the dichroic mirror 7 passes through the dichroic mirror 7 and enters the observation optical path. Therefore, in the first embodiment, most of the ultraviolet laser light that has entered the observation optical path is blocked by the ultraviolet cut filter 8 so that the ultraviolet laser light is inadvertently brought closer to the eyepiece when the ultraviolet laser light is used. To avoid reaching. Therefore, in the first embodiment, a harmful ultraviolet laser beam does not reach the observation eye via the eyepiece, and a sample image can be detected with high resolution by a safe speculum and color information of the sample can be obtained.

FIG. 2 is a view schematically showing a configuration of an ultraviolet laser microscope according to a second embodiment of the present invention. The second embodiment has a configuration similar to that of the first embodiment. However, the second embodiment differs from the first embodiment only in that the ultraviolet cut filter 8 is omitted and the dichroic mirror 28 is used instead of the mirror 9. Therefore, in FIG. 2, elements having the same functions as those in the first embodiment of FIG. 1 are denoted by the same reference numerals as in FIG. Hereinafter, the second embodiment will be described focusing on the difference from the first embodiment.

In the second embodiment, the dichroic mirror 28 has a characteristic of reflecting visible light and transmitting ultraviolet laser light. Therefore, most of the ultraviolet laser light transmitted through the dichroic mirror 7 and entering the observation optical path passes through the dichroic mirror 28 and deviates from the observation optical path. No ultraviolet laser light reaches the observation eye. Therefore, in the second embodiment, similarly to the first embodiment, a harmful ultraviolet laser beam does not reach the observation eye via the eyepiece, the sample image is detected with a high resolution by a safe microscope, and the sample Color information can be obtained.

In the first embodiment, one ultraviolet cut filter 8 is provided as the ultraviolet laser light shielding means, but a plurality of ultraviolet cut filters may be used according to the output of the ultraviolet laser light. it can. Further, in the first embodiment, the ultraviolet cut filter 8 is arranged in the optical path between the dichroic mirror 7 and the mirror 9, but the arrangement is not limited to this. One or a plurality of ultraviolet cut filters can be arranged at an arbitrary position in the observation optical path.

Further, as the ultraviolet laser light shielding means, the ultraviolet cut filter 8 is used in the first embodiment and the dichroic mirror 28 is used in the second embodiment, but one or more ultraviolet cut filters and a dichroic mirror are used. The ultraviolet laser light shielding means can be configured in combination. In each of the above-described embodiments, the dichroic mirror 7 as an optical path dividing unit has a characteristic of transmitting visible light and reflecting ultraviolet laser light. However, the dichroic mirror 7 may be configured to reflect visible light and transmit ultraviolet laser light.

Further, in each of the above-mentioned embodiments, the half mirror 3 for visible light and the half mirror 24 for ultraviolet laser light are configured to be insertable into and removable from the optical path, and the half mirror 3 for visible light is used when ultraviolet laser light is used. Is retracted from the optical path, and when visible light is used, the ultraviolet laser half mirror 24 is retracted from the optical path. However, by configuring the visible light half mirror 3 to transmit the ultraviolet laser light and the ultraviolet laser light half mirror 24 to transmit the visible light, the visible light half mirror 3 and the ultraviolet laser light half mirror 24 are formed. Can be permanently installed in the optical path.

[0023]

As described above, according to the present invention,
In the observation optical path between the optical path splitting means and the observation eye, for example, an ultraviolet laser light shielding means such as an ultraviolet cut filter is arranged to block the propagation of the ultraviolet laser light entering the observation optical path to the observation eye. As a result, in the ultraviolet laser microscope of the present invention, a harmful ultraviolet laser beam does not reach an observation eye through an eyepiece, and a sample image is detected with high resolution by a safe speculum and color information of the sample is obtained. Can be.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a configuration of an ultraviolet laser microscope according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a configuration of an ultraviolet laser microscope according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 halogen lamp (visible light source) 2 visible light illumination optical system 3 visible light half mirror 4 revolver 5 visible light objective lens 5 6 sample 7, 28 dichroic mirror 8 ultraviolet cut filter 9, 26 mirror 10 sample image by visible light DESCRIPTION OF SYMBOLS 11 Eyepiece 11 12 Observation eye 21 Ultraviolet laser light source 22 Beam expander 23 Collector lens 24 Half mirror for ultraviolet laser light 25 Objective lens for ultraviolet laser light 27 Sample image by ultraviolet laser light

Claims (4)

[Claims] A visible light objective lens for forming an image of the sample by visible light based on light from the sample illuminated by visible light; and a light from the sample illuminated by ultraviolet laser light. An objective lens for ultraviolet laser light for forming an image of the sample based on ultraviolet laser light, and any one of the objective lens for visible light and the objective lens for ultraviolet laser light in the optical path. Setting means for selectively setting, and guiding visible light from the sample through the visible light objective lens along a first optical path and from the sample through the ultraviolet laser light objective lens. An optical path splitting unit having a wavelength selectivity for guiding the ultraviolet laser light along a second optical path different from the first optical path; and the optical path splitting unit and the specimen in the first optical path. Is disposed between the observing eye to observe the image by visual light,
An ultraviolet laser microscope, comprising: ultraviolet laser light shielding means for shielding propagation of the ultraviolet laser light, which has entered the first optical path via the optical path splitting means, to the observation eye. 2. An ultraviolet laser microscope according to claim 1, wherein said optical path splitting means has a dichroic film for reflecting or transmitting visible light and transmitting or reflecting ultraviolet laser light. 3. The ultraviolet laser light shielding means is disposed between the optical path splitting means and a position where an image of the specimen is formed by visible light, and transmits the visible light and blocks the passage of the ultraviolet laser light. The ultraviolet laser microscope according to claim 1, further comprising an ultraviolet cut filter. 4. The ultraviolet laser light shielding means is disposed between the optical path dividing means and a position where an image of the specimen is formed by visible light, and is a dichroic for reflecting visible light and transmitting ultraviolet laser light. The ultraviolet laser microscope according to any one of claims 1 to 3, further comprising a film.