JP2000310736A - Ultraviolet microscopic optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical system for an ultraviolet microscope using the wavelength of the deep ultraviolet region and capable of observing a bright image excellent in resolution and contrast by using a light source emitting light in a wavelength range from ultraviolet to infrared. SOLUTION: Light outgoing from the mercury lamp of a light source device 9 passes through a wavelength selection means 12, an illumination relay optical system 13, an optical path coupling means 14, a mirror 15, an image-formation lens 16, a wavelength selection means 17, a 1/4 wavelength plate 18, a half mirror 4, and an objective lens 5 and illuminates a sample. The light reflected on the sample traces the path backward, is guided from the means 14 to a relay optical system 19 and picked up by a TV camera 10. The means 12 satisfies a conditional expression (To.δ)/(Tm.Δ)>2 the center transmissivity of a selected wavelength region is To, the half value width is δ nm, the average transmissivity in the wavelength region longer than 300 nm is Tm, and the felt sensitivity wavelength maintenance in the wavelength region longer than 300 nm in the TV camera 10 is Δ nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet microscope optical system mainly using a deep ultraviolet wavelength shorter than 300 nm, and also to an ultraviolet microscope optical system which can be combined with a conventional visible region observation microscope optical system. About the system.

[0002]

2. Description of the Related Art As wiring patterns have been miniaturized rapidly along with high integration of ICs and the like, the demand for higher resolution has been further increased for optical microscopes used for observation and inspection thereof. Is growing. As is well known, there are two methods for achieving high resolution in an optical microscope, one of which is to increase the numerical aperture of an objective lens, and the other is to shorten the wavelength used. However, since it is the present state that the numerical aperture has already reached the limit value of 0.95, it is very difficult to desire a higher numerical aperture. For this reason, it is necessary to adopt a method of shortening the wavelength. However, it is difficult to respond to recent miniaturization of ICs at wavelengths in the visible region, and it is difficult to respond to wavelengths shorter than the visible region. It becomes necessary to use ultraviolet light.

Therefore, various ultraviolet microscopes have been proposed so far. Examples of the ultraviolet microscope using a light source such as a mercury lamp are disclosed in JP-A-64-62609 and JP-A-5-127096. It is described in. Of these, the one disclosed in JP-A-64-62609 is one in which the lenses arranged in the optical path of the ultraviolet light are all made of quartz glass. In addition, Japanese Patent Application Laid-Open
Japanese Unexamined Patent Application Publication No. 6-204, discloses an illumination lens, an objective lens system, and the like, in which chromatic aberration is corrected in a wavelength range from a visible region to a near-ultraviolet region. Is provided. Further, as a means for increasing the transmittance at the time of selecting a wavelength in the ultraviolet region, an example in which a transmission element and a reflection element are combined is disclosed in JP-A-8-313.
No. 728.

[0004]

However, Japanese Patent Application Laid-Open No.
In the case of using the technology disclosed in -62609, the glass to be used is limited to quartz,
Correction of chromatic aberration is not possible. Therefore, there is a problem that the wavelength that can be used is substantially limited to one wavelength. In addition, since chromatic aberration cannot be corrected, if the light other than one wavelength to be used is not cut by a filter or the like, the resolution of an image and the contrast may deteriorate due to aberration. In the illumination optical system, illumination unevenness also occurs due to the influence of aberration. Further, since only one wavelength can be used, only a dark image can be observed.
Further, since this publication does not describe a combination with a conventional visible-range observation microscope, it is unknown whether this is possible, and specific means or conditions for selecting a wavelength in the ultraviolet region shorter than 300 nm are considered. Is not described, so that the optimum resolution, contrast, and brightness cannot be obtained immediately even if the processing is performed as it is.

On the other hand, when the technique disclosed in Japanese Patent Application Laid-Open No. 5-127096 is used, chromatic aberration is corrected from the visible region to the near ultraviolet region, so that visible image observation and ultraviolet image observation are performed. Can be combined. However, since the chromatic aberration is not corrected in a wavelength range shorter than 300 nm, the resolving power and contrast in this wavelength range are significantly deteriorated, and illumination unevenness occurs. Also,
Although the publication discloses means for separating a visible image and an ultraviolet image, it does not show specific means or conditions for selecting an ultraviolet wavelength shorter than 300 nm. Even if it does, it is not possible to immediately obtain the optimum resolution, contrast, and brightness.

The technique disclosed in Japanese Patent Application Laid-Open No. 8-313728 is intended to be used for semiconductor exposure, in which the transmittance at the wavelength used is increased while the transmittance at other wavelengths is reduced. I am trying to do it. However, since it is not intended for imaging / observation using a TV camera, this gazette describes to what extent it is necessary to suppress the transmittance other than the wavelengths used, and discusses the transmittance for infrared wavelengths. There is no mention of consideration. Also, no specific illumination optical system or imaging optical system is described.

Further, when ultraviolet rays are used, it is necessary to use a TV camera or the like to perform observation and inspection, but the image obtained thereby is a black and white image and contains color information. Absent. However, in actual inspections, inspection is also performed using color information using light in the visible range, and it is desired that both ultraviolet range observation with high resolution and visible range observation with color information can be used together. However, there is no specific description in the above publications about enabling such a thing.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a light source that emits light in a wide wavelength range from ultraviolet to infrared. It is possible to observe an image with good resolution and contrast, and it can be used in combination with an optical system of a conventional visible-range observation microscope.
An object of the present invention is to provide an optical system for an ultraviolet microscope using a wavelength in the deep ultraviolet region shorter than nm.

[0009]

In order to achieve the above object, an ultraviolet microscope optical system according to the present invention uses an illumination optical system and an optical path coupling means for emitting light emitted from a light source having light in a wavelength range shorter than 300 nm. A microscope optical system that irradiates a sample through an objective lens system and reflects light reflected by the sample through the objective lens system, the optical path coupling unit, and the imaging optical system, and captures an image by an imaging unit; A wavelength selecting means is disposed in the system, and the illuminating optical system, the objective lens system, the optical path coupling means, and the imaging lens system have chromatic aberration corrected in the wavelength range selected by the wavelength selecting means. The wavelength selecting means has a center transmittance of the selected wavelength range of To, a half-width of δ nm, an average transmittance in a wavelength range longer than 300 nm of Tm, and a wavelength of 300 nm of the imaging means.
Assuming that the sensitive wavelength region in a longer wavelength region is Δnm, the conditional expression (To · δ) / (Tm · Δ)> 2 is satisfied.

[0010] In order to achieve the above object, the ultraviolet microscope optical system of the present invention uses the light emitted from the first light source,
A first illumination optical system irradiates a sample through a first objective lens system, and reflects light reflected by the sample into a first objective lens system.
The first imaging lens system and the observation optical system allow observation through an observation optical system. Between the first objective lens system and the first imaging lens system, light having a wavelength shorter than 300 nm is reflected,
A first microscope optical system in which first wavelength selection means capable of transmitting light having a wavelength longer than 400 nm and shorter than 700 nm is disposed, and light emitted from a second light source having light in a wavelength range shorter than 300 nm A second illumination optical system,
An optical path coupling unit, the first wavelength selection unit, and a second objective lens system are illuminated on the sample through the objective lens system.
An image is formed through a second objective lens system, a first wavelength selection unit, the optical path coupling unit, and a second imaging lens system, and is imaged by an imaging unit. Second wavelength selecting means is arranged between the means, and the second illumination optical system, the second objective lens system, the optical path coupling means, and the second imaging lens system are provided with a second wavelength selecting means. The chromatic aberration is corrected in the wavelength range selected by the means, and the second wavelength selecting means sets the central transmittance of the selected wavelength range to To, the half width at δ nm, and the average transmittance in the wavelength range longer than 300 nm. Is Tm, and Δnm is the sensitive wavelength range in the wavelength range longer than 300 nm of the imaging means, and a second formula (To · δ) / (Tm · Δ)> 2 is satisfied. A microscope optical system, and a first light Source and First
By selectively using the objective lens system or the second light source and the second objective lens system, a visible image and an ultraviolet image can be selectively observed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In practicing the first aspect of the present invention, it is preferable that the wavelength selecting means is disposed between the light source and the illumination optical system, and the imaging means is a TV camera.
Further, the illumination optical system, the objective lens system, the optical path coupling means, the relay optical system, and the like are configured so that the chromatic aberration is corrected in the wavelength range selected by the wavelength selection means, and the wavelength selection means satisfies the condition described later. By satisfying the expression, it is possible to display an image that is bright and has good resolution and contrast on the TV screen.

As is well known, when light having a wavelength other than the wavelength range in which chromatic aberration is corrected reaches a TV camera, an image having deteriorated image quality is formed due to the influence of the aberration of the optical system. It will be superimposed on the surface. This is a factor that significantly lowers the image contrast, as in the case of noise components such as flare. Therefore, it is desirable to cut as much as possible the light in the wavelength range in which chromatic aberration has not been corrected. However, in this case, since the wavelength range to be cut is much wider than the wavelength range in which the chromatic aberration is corrected, it is necessary to consider the wavelength width and the transmittance. . That is, if the wavelength width becomes wider,
That is, the transmittance must be reduced accordingly, and the total amount of light must be reduced.

Therefore, the noise component has an average transmittance in a wavelength range longer than 300 nm of Tm, and a noise component of 300 n of the TV camera.
When the sensitive wavelength range in the wavelength range longer than m is Δnm, it can be expressed by (Tm · Δ). In addition, the observed image component can be expressed as To at the center transmittance in the selected wavelength region and as δ nm at half width. Therefore, when the wavelength selection means satisfies the condition of (To · δ) / (Tm · Δ)> 2 (1), it is possible to observe with good contrast, and (To · δ) δ) / (Tm ·
If the value of Δ) is 2 or less, the resolving power and the contrast deteriorate due to the influence of chromatic aberration.

Further, according to the present invention, the above-mentioned wavelength selecting means comprises:
At least one transmissive element and at least two reflective elements whose reflective surfaces are arranged in parallel to each other, and at least one of the reflective elements reflects light multiple times. Then, it becomes suitable.
That is, the illumination optical system, the objective lens system, the optical path coupling means,
In the relay optical system, the chromatic aberration is corrected in the wavelength range selected by the wavelength selection means, so that the relay optical system can be observed with a wavelength width compared to an optical system in which the aberration is corrected only at one wavelength. , So that bright observations can be made. Therefore, if the wavelength selecting means is constituted by at least one transmissive element and at least two reflective elements, the center transmittance in the selected wavelength region can be increased. The reason will be described below.

When wavelength selection is performed by one transmission element as in a conventional bandpass filter, it is practically necessary to cut off all wavelengths other than the selected wavelength in order to secure image quality. However, since the sensitivity of a TV camera is in the visible range and the infrared range, if it is attempted to cut into these wavelength ranges, the center transmittance in the selected wavelength range of ultraviolet light becomes low,
It becomes difficult to secure the brightness. This is due to the fact that one element must bear the characteristics in a wide wavelength range from ultraviolet to infrared.

Incidentally, the reflective element has a characteristic that it is relatively difficult to obtain wavelength selection characteristics as compared with the transmissive element, but it is relatively easy to cut light on the long wavelength side. However, this reflection element cannot sufficiently cut unnecessary light by itself, and it is necessary to use a combination of a plurality of elements in order to sufficiently cut the unnecessary light.
Therefore, by using at least two reflective elements to cut the wavelength from the near ultraviolet to infrared,
After reducing the load on the transmissive element, if the wavelength is selected by at least one transmissive element, the center transmittance in the selected wavelength region can be increased,
As a result, it is possible to secure a suitable brightness.

However, in this case, if too many reflective elements are used, adjustment of the optical axis and the like becomes very troublesome. Therefore, it is desirable that at least one of the plurality of reflective elements whose reflective surfaces are arranged in parallel to each other can reflect light a plurality of times. With such a configuration, when manufacturing a component to which the reflective element is attached, it is only necessary to make the reflective surface parallel, so that it is easy to secure accuracy and reduce the number of reflective elements. Therefore, adjustment between elements can be easily performed.

Further, according to the present invention, the above-mentioned illumination optical system comprises a collector optical system and an illumination relay optical system arranged in a light source device together with a light source, and the light source is a front focal point of the collector optical system. The distance D between the light source device mounting position and the lens disposed closest to the light source in the illumination relay optical system and the light beam diameter φ of the light incident on the lens are: φ ≧ 4 It becomes more effective if the conditional expression (2) is satisfied.

That is, by disposing the light source in the vicinity of the front focal point of the collector optical system, the light beam between the collector optical system and the illumination relay optical system can be made substantially parallel light. Can be made less susceptible to the angular characteristics of the interference filter and the like arranged in the first position. Further, by making the light substantially parallel, the distance D can be set to some extent arbitrarily according to the number and size of the optical elements and the like arranged here. In particular, in the case where the wavelength selecting means having the above-mentioned configuration is arranged, the light flux coming out of the collector optical system will be blocked unless the interval between the reflecting surfaces is made a certain distance. If the system is configured in this manner, a suitable arrangement can be adopted, so that the light beam is not blocked.

By the way, in the wavelength selecting means having the above configuration, at least one reflection is performed at least once on one reflection surface and at least two times on the other reflection surface. It is necessary to secure a distance of at least three times the beam diameter. In addition, since a transmissive element is also disposed, a distance of about four times the diameter of the light beam must be secured at least in consideration of the space. The above conditional expression 2 is determined in consideration of such a situation. When the value of D / φ is less than 4, it becomes difficult to arrange at least the wavelength selecting unit having the above configuration.

Further, in the present invention, it is preferable that the glass material of the lens constituting the illumination optical system is fluorite and quartz, and at least one of the lenses having a positive focal length is fluorite. In order to correct the chromatic aberration of the optical system, it is necessary to combine at least two types of glass materials.
Glass materials that favorably transmit light having a wavelength shorter than 300 nm are substantially limited to fluorite and quartz. Of these, fluorite has a smaller wavelength dispersion than quartz, and if it is used for a lens having a positive focal length, the occurrence of chromatic aberration can be effectively suppressed. However, since fluorite is a soft glass material and has poor workability,
It is desirable to keep the number to the minimum required.

Next, the invention according to claim 2 will be described. This invention combines the optical system of the microscope for ultraviolet region observation of the invention according to claim 1 with the optical system of the conventional microscope for visible region observation so that both ultraviolet region observation and visible region observation can be performed. Related to a microscope optical system. Therefore, most of the description regarding the optical system of the microscope for ultraviolet region observation overlaps with the above description, so that the above description is referred to, and the optical system of the visible region observation microscope is particularly specific. It is not necessary to give a basic explanation,
Only the connecting components of the two will be described.

According to the present invention, another wavelength selecting means is disposed between the objective lens system and the imaging lens system in the conventional visible range observation microscope optical system, separately from the above-described wavelength selecting means. I have. And the latter wavelength selecting means,
Reflects light of wavelengths shorter than 300 nm and has at least 40
Since light having a wavelength longer than 0 nm and shorter than 700 nm is transmitted, by selecting an objective lens and light from a light source, the light in the ultraviolet region reflected by the wavelength selecting means can be displayed on a TV or the like. Can be observed by means,
The light in the visible region transmitted through the wavelength selecting means can be observed through a conventional observation optical system for visible light.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to FIGS. 1 to 7. Prior to that, a general configuration of a conventional visible range observation microscope will be described with reference to FIG. The microscope body 1 has
A visible light source device 2 in which a visible light source is disposed is attached. Light emitted from the light source passes through a visible illumination relay optical system 3 and is reflected by a half mirror 4 to illuminate a sample through an objective lens 5. It is supposed to.
The observation optical system unit 6 is detachable from the microscope main body 1, and an observation optical system including an imaging lens 7 is disposed inside. The light reflected from the sample passes through the objective lens 5 and passes through the half mirror 4 to be guided into the observation optical system unit 6 so that it can be observed by eyes.

In the embodiment shown in FIG. 1, an ultraviolet microscope unit 8 is disposed between the microscope main body 1 and the observation optical system unit 6 in the above-mentioned conventional visible-range observation microscope. It is shown that the ultraviolet microscope unit 8 can be easily attached to the visible region observation microscope, and that one unit can perform both the visible region observation and the ultraviolet region observation. Therefore, the components described in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.
As is well known, when observing the ultraviolet region, the objective lens 5 must be replaced. However, when the ultraviolet region observation is described below, for convenience, the replaced objective lens 5 is used. Will be described with the same reference numeral 5.

First, an ultraviolet light source device 9 is attached to the ultraviolet microscope unit 8, and a mercury lamp and a collector lens are arranged inside the ultraviolet light source device 9. Further, a TV camera 10 as an image pickup means is also attached so that the picked-up sample image can be observed on the display means 11. For the light emitted from the mercury lamp, only the ultraviolet light to be used is selected by the wavelength selection means 12, and the ultraviolet illumination relay optical system 13, the optical path coupling means 14, and the mirror 1 are selected.
5, ultraviolet imaging lens 16, wavelength selecting means 17, 1/4
The sample is illuminated via the wave plate 18, the half mirror 4, and the objective lens 5.

The light reflected by the sample is supplied to the objective lens 5, half mirror 4, quarter-wave plate 18, wavelength selecting means 17, ultraviolet imaging lens 16, mirror 15, optical path coupling means 14, and ultraviolet relay. An image is formed via the optical system 19 and the TV
The image is taken by the camera 10. still,
When the objective lens 5 is visible, the visual light source device 2 is used to perform observation with the eyes along the dotted optical path, and when the objective lens 5 is ultraviolet, it is observed by the display means 11 according to the optical path of the dashed line. . Further, in the case of the present embodiment, since a deflecting beam splitter is used as the optical path coupling means 14, the 波長 wavelength plate 18 is arranged in the optical path. With this configuration, it is possible to obtain about twice the brightness as compared with the case where the half prism is used. Further, the quarter-wave plate 18 is preferably disposed inside the ultraviolet microscope unit 8, but if it is disposed in the microscope main body 1 as in this embodiment, there is no problem in function.

Here, the wavelength selecting means 12 has the characteristics shown in FIG. 2, and first, the center transmittance (T
Although o) is about 95% as shown in FIG. 2A, it is safe to assume that it is about 70% because there is some absorption by the film substance. The half-width (δ) is 10 nm, and the average transmittance (Tm) in a wavelength range longer than 300 nm is about 0.1% as shown in FIG.
It is. Further, the spectral sensitivity characteristics of the TV camera 10 are shown in FIG.
As shown in the figure, it can be seen that the film has sensitivity up to a wavelength of about 1100 nm. Therefore, 300 of the TV camera 10
The sensitive wavelength range (Δ) in the wavelength range longer than nm is 800
nm. Then, when these values are substituted into the above conditional expression 1 and calculated, (70 × 10) / (0.1 × 800) = 8.75> 2, and it is possible to observe with a sufficiently high contrast. I have.

FIG. 4 shows a specific configuration of the wavelength selecting means 12 used in this embodiment. In this case, the luminous flux is transmitted between the two reflective elements 20 and 21 arranged with the reflective surfaces parallel to each other.
, And is reflected once by the reflective element 21 and then transmitted through the transmissive element 22. However, the configuration shown in FIG. 5 may be adopted, and the light may be reflected three times by the reflective element 20 'and twice by the reflective element 21'. On the other hand,
Another wavelength selecting means 17 has the characteristics shown in FIG. 6 and reflects light having a wavelength shorter than 300 nm,
Since light having a wavelength longer than 700 nm and shorter than 700 nm is transmitted, the microscope of this embodiment can perform both ultraviolet region observation and visible region observation.

FIG. 7 is for explaining the configuration of the illumination optical system of the present embodiment. In this case, the ultraviolet light source device 9
Since the collector lens 9a is disposed inside the lens unit, if the collector optical system is provided up to the mounting unit 23 for the ultraviolet illumination unit 8, the ultraviolet illumination relay optical system disposed closest to the light source from the mounting unit 23 The distance (D) between the lens 13 and the lens 13a is 70 mm,
The light beam diameter (φ) incident on a is 12 mm. Therefore,
When these values are substituted into the above conditional expression 2 and calculated, 5.8 is obtained.
3, which is larger than 4. Incidentally, reference numeral 24 in FIG. 7 denotes a specimen image plane.

The numerical data of the optical system shown in FIG. 7 is as shown in the following table. As can be seen from this data, each of the convex lenses in the lenses 13a and 13b constituting the ultraviolet illumination relay optical system 13 is made of fluorite glass material. [Table] Surface number Curvature radius r (mm) Distance d (mm) Glass material 0 16.5 1 -46.9489 2.0 Quartz 2 -13.4361 1.0 3 53.0428 2.5 Quartz 4 -30.0294 71.5 5 ５ 70.0 6 24.2628 3.5 Fluorite 7 -56.7007 3.85 8 -29.0452 2.5 Quartz 9 -499.4109 147.3177 10 -19.7665 1.25 Quartz 11 7.9280 5.45 Fluorite 12 -13.2213 33.0 13 ∞ 10.0 Quartz 14 ∞ 12.0 15 ∞ (sample image surface) 174.4749 16 826.6658 3.0 Quartz 17 33.9959 5.0 Fluorite 18 -76.3841 198.4119

This embodiment has been described as an embodiment of the invention according to claim 2. However, if the observation optical system unit 6 in this embodiment is eliminated and the wavelength selection means 17 is replaced with a mirror, the invention will be described. Needless to say, this embodiment is an embodiment of the invention according to item 1.

As described above, the present invention has the following features in addition to the features described in the claims. (1) The wavelength selecting means is composed of at least one transmissive element and at least two reflective elements whose reflective surfaces are arranged in parallel with each other. At least one of the reflective elements reflects light a plurality of times. 2. The ultraviolet microscope optical system according to claim 1, wherein the optical system is configured to perform the following. (2) The illumination optical system includes a collector optical system arranged in the light source device together with the light source, and an illumination relay optical system, and the light source is arranged near the front focal position of the collector optical system. Distance D between the light source device mounting position and the lens located closest to the light source in the illumination relay optical system
The ultraviolet microscope optical system according to claim 1 or (1), wherein the relationship between the light flux diameter φ of light incident on the lens and the lens satisfies the following condition: D / φ ≧ 4. (3) The lens material of the lens constituting the illumination optical system is fluorite and quartz, and at least one of the lenses having a positive focal length is fluorite.
The ultraviolet microscope optical system according to any one of (2). (4) The second wavelength selecting means is composed of at least one transmissive element and at least two reflective elements whose reflective surfaces are arranged in parallel with each other. 3. The ultraviolet microscope optical system according to claim 2, wherein the optical system is configured to reflect a plurality of times. (5) The second illumination optical system includes a collector optical system arranged in the light source device together with the second light source, and an illumination relay optical system, and the second light source is a front focal point of the collector optical system. And a distance D between the light source device mounting position and the lens disposed closest to the light source in the illumination relay optical system, and a light beam diameter φ of light incident on the lens.
The ultraviolet microscope optical system according to claim 2 or (4), wherein the relationship with the following condition is satisfied: D / φ ≧ 4. (6) The glass material of the lens constituting the second illumination optical system is fluorite and quartz, and at least one of the lenses having a positive focal length is fluorite. The ultraviolet microscope optical system according to any one of 4) and 5).

[0034]

As is apparent from the above description, when the microscope optical system of the present invention is provided, an ultraviolet microscope mainly using a wavelength in the deep ultraviolet region shorter than 300 nm, particularly in a wavelength region from ultraviolet to infrared. When a light source that emits light is used, observation that is brighter and has better contrast than before can be performed. Further, it can be easily combined with a conventional visible range observation microscope, and particularly greatly contributes to an industrial microscope. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a microscope to which the present invention is applied.

2A and 2B are characteristic diagrams of the wavelength selecting unit 12 shown in FIG. 1, wherein FIG. 2A shows transmittance in a selected wavelength range, and FIG. 2B shows a wavelength range longer than 300 nm. Is a graph showing the transmittance at a time.

FIG. 3 is a spectral sensitivity characteristic diagram of the TV camera 10 shown in FIG.

FIG. 4 is a diagram showing a specific configuration of a wavelength selection unit 12 shown in FIG.

FIG. 5 is a diagram showing another specific configuration of the wavelength selection means 12 shown in FIG.

FIG. 6 is a characteristic diagram of another wavelength selection unit 17 shown in FIG.

FIG. 7 is a diagram illustrating a configuration of an illumination optical system according to an embodiment.

FIG. 8 is a configuration diagram of a general visible range observation microscope.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microscope main body 2 Visible light source device 3 Visible illumination optical system 4, 15 mirror 5 Objective lens 6 Observation optical system unit 7 Imaging lens 8 Ultraviolet microscope unit 9 Ultraviolet light source device 9a Collector lens 10 TV camera 11 Display means 12, 17 wavelength selection means 13 ultraviolet illumination relay optical system 13a, 13b lens 14 optical path coupling means 16 ultraviolet imaging lens 18 quarter wave plate 19 ultraviolet relay optical system 20, 20 ', 21, 21' reflection type Element 22 Transmissive element 23 Mounting part 24 Sample image plane

Claims (2)

[Claims] 1. A sample which is irradiated with light emitted from a light source having light in a wavelength range shorter than 300 nm through an illumination optical system, an optical path coupling means, and an objective lens system, and reflects light reflected by the sample.
A microscope optical system that forms an image through the objective lens system, the optical path coupling unit, and the imaging optical system and captures an image with an imaging unit, wherein a wavelength selection unit is arranged in the microscope optical system, and the illumination optical system , Objective lens system, optical path coupling means,
In the imaging lens system, the chromatic aberration is corrected in the wavelength range selected by the wavelength selecting unit, and the wavelength selecting unit sets the center transmittance of the selected wavelength range to To, the half-value width to δ nm,
When the average transmittance in the wavelength range longer than 300 nm is Tm and the sensitive wavelength range in the wavelength range longer than 300 nm of the imaging means is Δnm, the following conditional expression is satisfied: (To · δ) / (Tm · Δ)> 2 An ultraviolet microscope optical system characterized by satisfying the following. 2. A light emitted from a first light source is applied to a sample through a first illumination optical system and a first objective lens system, and light reflected by the sample is applied to the first objective lens system and a second objective lens system. 1 through an imaging lens system and an observation optical system, and between the first objective lens system and the first imaging lens system, light having a wavelength shorter than 300 nm is reflected and at least 400 nm A first microscope optical system in which a first wavelength selection means capable of transmitting light having a longer wavelength shorter than 700 nm is disposed, and light emitted from a second light source having light in a wavelength range shorter than 300 nm. A second illumination optical system, an optical path coupling unit, and the first illumination optical system;
Irradiates the sample through the second objective lens system and the second objective lens system, and reflects the light reflected by the sample on the second objective lens system, the first wavelength selection unit, the optical path coupling unit, and the second imaging lens. An image is formed through the system, and an image is taken by an image pickup unit. A second wavelength selection unit is disposed between the second light source and the optical path coupling unit, and a second illumination optical system, The second objective lens system, the optical path coupling unit, and the second imaging lens system have chromatic aberrations corrected in the wavelength range selected by the second wavelength selection unit, and the second wavelength selection unit includes: The center transmittance of the selected wavelength region is To and the half width is δ
The average transmittance in the wavelength range longer than 300 nm
m, when the sensitive wavelength region in the wavelength region longer than 300 nm of the image pickup means is Δnm, the second microscope satisfying the conditional expression of (To · δ) / (Tm · Δ)> 2 And an optical system, wherein the first light source and the first objective lens system, or the second light source and the second objective lens system are selectively used to obtain a visible light. An ultraviolet microscope optical system characterized in that an image and an ultraviolet image can be selectively observed.