JPH10186242A - Member for illuminating dark field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize such illumination that the transmission efficiency and the illumination efficiency of illumination light are high and the loss of light quantity is reduced and to illuminate a wide range by providing a member with a light transmission part consisting of a hollow cylindrical transparent material, a tapered ring-like light inner deflection surface and a ring-like emitting end surface. SOLUTION: Divergent luminous flux emitted from a zonal light source 13 is propagated in the light transmission part 15 including an almost pyramid-like side surface and consisting of the hollow cylindrical transparent member while spreading in a radial direction. Since the divergent luminous flux is propagated without spreading over the restriction area of the side surface 15a, it is propagated without waste. Then, the luminous flux is deflected in the direction of a sample surface 14 by the ring-like inner deflection surface 16 tapered toward the sample surface 14 and emitted toward the sample surface 14 from the ring-like emitting end surface 17 by an illumination angle becoming the perfect dark field illumination in a whole observation area. Since the end surface 17 is positioned on the more sample surface 14 side than a middle position between the light source 13 and the sample surface 14, the percentage of the illumination area with respect to the visual field area of the sample surface 14 is made high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dark field illumination member used in a magnifying observation system such as a microscope TV observation system.

[0002]

2. Description of the Related Art As a magnifying observation apparatus for macroscopically observing hair, skin, various small industrial products, and the like, for example, a video microscope disclosed in Japanese Patent Application Laid-Open No. Hei 5-303042 is known. ing. FIG.
FIG. 1 is a diagram schematically showing the configuration of a video microscope of this type. As shown here, a control box 1 provided with a light source and an image processing unit is connected to an observation head unit 4 via a light guide 2 made of an optical fiber and a video signal cable 3. This observation head 4
Indicates that the objective lens 1 is attached to the probe 5 having the built-in image sensor 11.
0 is connected to the cylindrical objective lens section 6 where
Further, a transparent light guide 7 is provided at the tip of the objective lens 6. A monitor 8 is connected to the control box 1.

[0003] Illumination light emitted from the light source of the control box 1 is transmitted through a light guide 2 to an observation head unit 4.
Then, the light passes through the light guide 7 and is emitted toward the sample 9. At this time, the light guide 7 is in a state of being close to or in contact with the sample 9. The reflected light from the sample 9 is again transmitted to the image pickup device 1 by the objective lens 10 through the light guide 7.
1, and a sample image is formed. The sample image is converted into a video signal by the image sensor 11 and then transmitted to the control box 1 via the video signal cable 3. The video signal is subjected to image processing in the image processing section of the control box 1, and an enlarged image of the sample 9 is displayed on the monitor 8.

By the way, in such a video microscope, it is necessary to appropriately illuminate a sample in order to obtain an enlarged image with good contrast. In this case, the illumination means includes a coaxial epi-illumination method for irradiating illumination light to the sample vertically from the optical axis of the optical system, and a vertical epi-illumination for illuminating illumination light from outside the optical axis of the optical system almost directly above the sample. There is an illumination method, and an epi-illumination dark-field illumination method in which illumination light is applied to the sample from the side at an angle greater than the numerical aperture of the objective lens. FIGS. 12A to 12C show schematic diagrams of a coaxial epi-illumination system, a vertical epi-illumination system, and an epi-illumination dark-field illumination system, respectively.

The coaxial epi-illumination system and the vertical epi-illumination system are excellent in overall stereoscopic observation. However, when observing a flat sample having a high reflectance such as a metal surface, an image of the light source and an image of the sample are not observed. Are seen overlapping, causing inconveniences such as a reduction in image contrast and difficulty in observing the color of the sample. On the other hand, the epi-illumination dark-field illumination method has a disadvantage that if there is a concave portion such as a hole, the illumination light does not reach the inside of the concave portion and it is difficult to observe. However, it is possible to observe even scratches and slight irregularities on the surface of the reflective sample, which are difficult to detect by ordinary observation.In addition, since the reflected light from the sample does not directly enter the image sensor, the contrast is low. There is an advantage that ghosts are not generated. For this reason, in a video microscope, in order to avoid a decrease in contrast when observing a reflection sample, an epi-illumination dark field illumination is often used.

In general, as an epi-illumination dark-field illumination method used for a video microscope, illumination light emitted from an annular light source provided at the end of a main body portion containing an objective lens is applied to a sample via a transparent light guide member. There is a known light condensing device. For the transparent light guide member, a transparent resin material such as acrylic is mainly used, so that it is inexpensive and has good workability. In addition, since the light is basically guided by total reflection, the light transmission efficiency is good. There is the advantage that there is no need to apply.

A conventional illumination device used for such a video microscope is disclosed in Japanese Patent Application Laid-Open No. HEI 1-308852.
7 and JP-A-8-36133.

[0008] The technique disclosed in Japanese Patent Application Laid-Open No. 1-308527 uses a light guide cap having a hemispherical front portion and having an illumination hole (small hole) formed at the tip thereof for illuminating a sample. ing. That is, a light guide is configured such that light passing through the light guide cap repeats total reflection and is emitted as substantially horizontal light from the inner peripheral surface of the small hole toward the sample. Optimal observation is made possible by appropriately combining the incident light that leaks from the light guide and the transmitted light to the sample, with mainly the light that is emitted.

The technique disclosed in Japanese Patent Application Laid-Open No. 8-36133 discloses a light guide in which an illumination hole having a tapered inner peripheral surface is provided at the center of the tip of a light guide cap made of a transparent synthetic resin. The light guided into the light guide cap from the light source is reflected once by the tip of the light guide cap, passes through the illumination hole at a right angle, and is emitted toward the sample. That is, the light that has entered the light guide is 1 in the light guide.
Since the light is reflected twice and reaches the sample without being refracted almost even when the light guide is emitted, it is possible to project light inclined to a certain degree to the sample, and even if the sample has a concave portion, the inside of the concave portion is sufficiently brightly illuminated. can do.

The illumination method described above is often used mainly when a very large illumination field is not required. However, it is often necessary to observe a very wide range at a low magnification, such as inspection of a scratch on a painted surface or observation of a living body.
In particular, when observing a wide range of the sample at low magnification, the observation range of the sample tends to be equal to or slightly wider than the diameter of the light source arranged in an annular shape. When the above-described illumination method is used in such a state, complete dark field illumination is not achieved, and a problem occurs in that an image of a light source directly reflected by the sample is received by the image sensor. To avoid this, a slightly complicated illumination system is required, but it is necessary to irradiate the sample after the luminous flux diameter of the illumination light emitted from the light source has been expanded to some extent to the outside in the radial direction.

Means for performing such illumination are disclosed in Japanese Patent Publication No. Hei 5-79139, Japanese Utility Model Laid-Open No. Hei 7-23208 and Japanese Patent Laid-Open No. Hei 6-180427.

According to the technique disclosed in Japanese Patent Publication No. 5-79139, a light beam from an annular light source is deflected radially outward of the light beam by a first optical element, and the light beam is further deflected by a second optical device.
By re-deflecting the optical element inward in the radial direction, the direction of the illumination light can be freely set according to the size and shape of the sample.

The technique disclosed in Japanese Utility Model Laid-Open Publication No. Hei 7-23208 discloses a method in which a divergent light beam emitted from an annular light source is converted into parallel light by using a converging ring lens, and then a ring integrated with the converging ring lens is used. The light beam is deflected radially outward by a mirror, and the light beam is condensed at a fixed position on the optical axis by a condensing mirror. This illumination system is inexpensive and easy to manufacture because the member that converts the diffused light into a parallel light beam is not a mirror but a ring lens.

The technique disclosed in Japanese Patent Application Laid-Open No. 6-180427 discloses a deflecting member composed of a ring-shaped outer deflecting member, a ring-shaped inner deflecting member, and a ring-shaped condensing member. By moving the deflecting member appropriately in conjunction with each other, the incident angle of the illumination light to the sample is changed, so that an optimal dark field illumination can be supplied to the sample.

[0015]

However, when a very wide observation range of a sample is illuminated by the conventional illumination method, the following problems occur.

First, Japanese Patent Publication No. 5-79139,
The technique disclosed in JP-A-6-18042 is effective when the illumination light is a parallel light flux. However, no consideration is given to the illuminating light that diffuses out of the light flux emitted from the tip of the fiber connected to the light source. Therefore, when an optical system in which the optical path from the light source to the sample is formed to be very long with respect to the divergence angle of the illumination light is used, a large light amount loss is caused, and even if a divergent light beam is used using a large deflection member. Even if the light is picked up, the illumination range becomes too wide than desired for the observation range, and the illumination efficiency deteriorates. Further, in the technique disclosed in Japanese Utility Model Laid-Open Publication No. 7-23208, the second optical element (condensing mirror) cannot be reduced in size, so that its use is limited. Further, there is a problem in the low reflectance of the used reflecting member.

Another problem common to the techniques disclosed in Japanese Patent Publication No. 5-79139, Japanese Utility Model Laid-Open No. 7-23208, and Japanese Patent Application Laid-Open No. 6-180427 is that a plurality of deflecting members are independent of each other. Because of this, the structure is complicated. Further, there is no suggestion about a dark-field illumination method for illuminating a wide range equal to or more than the annular light source.
In addition, when observing a flat sample having a high reflectance, the image of the light source reflected by the sample is taken together with the image of the sample using the technology disclosed in those publications, so that the target sample can be clearly identified. This may lead to a situation that cannot be observed.

Further, the techniques disclosed in JP-A-1-308527 and JP-A-8-36133 both illuminate only the observation region located radially inward of the annular light source. It is difficult to illuminate a wide area and obtain an image with good contrast.

Accordingly, the present invention has been made in view of the above-mentioned problems of the prior art, and its object is to
It is an object of the present invention to provide a dark-field illumination member capable of illuminating a wide observation range by improving the transmission efficiency and illumination efficiency of illumination light while having a simple configuration. In addition, another object of the present invention is to provide a compact dark-field illumination member that can be easily focused while maintaining the performance of the illumination device when attached to the illumination device.

[0020]

In order to achieve the above object, a dark-field illumination member according to the present invention has the following features.

According to the first aspect of the present invention, there is provided an illumination member for illuminating a range equivalent to or wider than the annular light source, which is used together with the illumination device having the annular light source. A light guide portion made of a hollow cylindrical transparent material including a substantially truncated cone extending at least partially from the light source side toward the sample side; and a ring-shaped light inwardly deflecting surface tapered toward the sample. And a ring-shaped emission end face located closer to the sample side than an intermediate position between the light source and the sample.

According to a second aspect of the present invention, in the member for dark field illumination of the first aspect, the divergent light emitted from the annular light source is totally reflected by a side surface of the light guide portion to guide the light. Things.

The invention described in claim 3 is the first or second invention.
In the dark field illumination member, the light guide portion is formed so as to be sandwiched between two substantially frustum-shaped side surfaces extending from the light source side to the sample side.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A dark-field illuminating member according to the present invention is an illuminating member for illuminating an area equivalent to or wider than the annular light source, which is used together with an illuminating device having an annular light source. A light guide portion made of a hollow cylindrical transparent material including a substantially frustum-shaped side surface extending from at least the light source side to the sample side in a part of the external shape, and a tapered portion toward the sample. It comprises a ring-shaped light inwardly deflecting surface and a ring-shaped emission end face located closer to the sample than an intermediate position between the light source and the sample.

FIG. 1 is a sectional view taken along the optical axis showing the structure of a dark field illumination member according to the present invention. The dark-field illumination member 12 of the present invention is used by being attached to an emission end of an annular light source 13 of an illumination device. The divergent luminous flux emitted from the annular light source 13 is incident on the dark-field illumination member 12 of the present invention, and then partially expands at least a substantially frustoconical side surface extending from the light source 13 side toward the sample surface 14 side. The light is propagated in the light guide portion 15 formed of a hollow cylindrical transparent member including the radially outer portion. At this time, the divergent light beam is
While the light is repeatedly reflected on the side surface 15a of the No. 5, the light is propagated without expanding beyond the area limited by the side surface 15a. The light beam propagated through the light guide 15 is deflected toward the sample surface 14 by the inwardly deflecting ring-shaped light-deflecting surface 16 toward the sample surface 14, and is completely reflected in the entire observation area of the sample surface 14. The light is emitted from the ring-shaped emission end face 17 toward the sample surface 14 at an irradiation angle serving as dark field illumination. Since the ring-shaped emission end face 17 is located closer to the sample surface 14 than the intermediate position between the light source 13 and the sample surface 14, the ratio of the illumination area to the visual field area of the sample surface 14 can be increased.

Here, the reason why the ring-shaped light inwardly deflecting surface 16 is tapered toward the sample surface 14 is, first, to reduce the luminous flux diverging out of the visual field and to improve the illumination efficiency. It is. Conventionally, it has been often confirmed that when a reflection sample is observed, illumination light reflected outside the field of view enters the observation optical system and lowers the contrast of an image. This is to reduce this. This is the second reason. Needless to say, the shape of the ring-shaped light inward deflecting surface 16 can be freely set in order to obtain a desired illuminance distribution on the sample surface 14.

In addition, in the dark-field illumination member 12 of the present invention, if the divergent light beam emitted from the annular light source 13 is transmitted while being totally reflected between the side surfaces 15a of the light guide portion 15, The light amount loss in the optical path up to the ring-shaped emission end face 17 is very small. In particular, when the distance from the annular light source 13 to the sample surface 14 is very long, the divergent light beam propagates by repeating total reflection many times. It is possible to obtain a high transmission efficiency that cannot be obtained at all. Further, since the dark-field illumination member 12 of the present invention is formed of a transparent material, observation and inspection can be performed while visually confirming the position of the sample surface 14, which is the target of illumination. Further, the dark-field illumination member 12 of the present invention has a very simple configuration in which the illumination light from the light source 13 is guided to the sample surface 14 by an integral transparent member. Therefore, it can be said that there is a great advantage in assembling.

The light guide section 15 of the dark field illumination member 12 of the present invention is composed of two substantially frustum-shaped side surfaces 15a extending from the light source 13 toward the sample surface 14.

In the dark-field illumination member 12, the light source 13
The light flux emitted from the light source monotonously monotonically outwards in the radial direction of the light guide portion 15 while totally reflecting inside the light guide portion 15 formed by the two substantially frustum-shaped side surfaces 15a spread to the sample surface 14 side. The light beam is propagated to the inwardly deflecting surface 16 while the beam diameter is expanded. Since the propagation optical path to the ring-shaped light inward deflection surface 16 has a very simple shape and is not accompanied by extreme bending, the number of rays leaking without total reflection is extremely small, and the light quantity loss can be further reduced. it can. In addition, since the workability is good and the side surface 15a of the light guide portion 15 can be easily mirror-finished, the reflectance of the total reflection surface can be increased. Further, the inner side surface 15 a of the light guide section 15 can also serve as the ring-shaped emission end face 17. When the dark-field illumination member is configured as described above, it is possible to achieve both low light loss and good workability.

Further, the dark-field illumination member 12 of the present invention is configured such that the thickness of the light guide 15 increases as it approaches the ring-shaped emission end face 17.

It is important to suppress the divergence of the light emitted from the illumination member and increase the illumination efficiency in obtaining a bright image. The light source 13 of the illumination device used together with the dark-field illumination member 12 of the present invention has an annular shape having a certain width. Therefore, if light is unnecessarily condensed by a lens or the like, the light source 13 is enlarged and projected, and so on the contrary, the illumination range is widened, and illumination unevenness is liable to occur. Therefore, the dark field illumination member 1 of the present invention
In No. 2, the thickness of the light guide portion 15 was configured to be larger as approaching the ring-shaped emission end face 17. Since the light propagating in the light guide unit 15 configured as described above has a smaller reflection angle every time it is totally reflected by the side surface 15 a of the light guide unit 15, the first reflection occurs. As long as the total reflection occurs, the divergent light beam thereafter has the directivity finally increased to the extent of the spread angle of the thickness of the light guide portion 15. Therefore, the divergence of light is reliably suppressed without particularly configuring the light guide section 15 in a complicated manner, and the range necessary for observation can be efficiently illuminated.

It is generally well known that the total reflection is much higher in reflectivity than the reflection using a mirror, but on the other hand, the total reflection has a critical angle of incidence. It is a well-known fact that there is an angle limitation of the light beam. Therefore, usually, if the total reflection surface is used to largely deflect the divergent light beam, a large light amount loss is caused. However, as described above, the use of the dark-field illumination member 12 of the present invention can greatly enhance the directivity of the divergent light beam. In addition, if the ring-shaped light inward deflecting surface 16 is constituted by a total reflection surface, it is possible to perform deflection with less loss of light amount. As a result, in the entire dark-field illumination member 12 of the present invention, the loss of light amount can be suppressed more reliably.

Further, the dark-field illumination member 12 of the present invention is configured such that the thickness of the light guide portion 15 has a spread angle smaller than the numerical aperture of the illumination light emitted from the annular light source 13. Have been.

The thickness of the light guide section 15 is the ring-shaped emission end face 17.
As described above, it is possible to easily suppress the divergence of light if the structure becomes thicker as approaching.
However, if the spread angle of the thickness is not small to some extent with respect to the divergence angle of the divergent light, sufficient light-collecting performance cannot be obtained. Therefore, the light guide unit 1 is adjusted according to the divergence angle of the illumination light.
It is necessary to set the size of the spread angle of the thickness of No. 5. In order to suppress the spread of divergent light more effectively,
It is necessary that the divergence angle of the thickness of the light guide portion 15 is set to a half of the divergence angle of the illumination light, that is, a size equal to or smaller than the numerical aperture of the illumination light emitted from the annular light source 13. If the spread angle of the thickness is not smaller than this, the outer shape of the lighting member will be large although the obtained light divergence is slightly suppressed.

Further, in the dark-field illumination member 12 of the present invention, it is preferable that the angle θ between the ring-shaped light inwardly deflecting surface 16 and the ring-shaped emission end face 17 satisfies the following conditional expression. . θ ≧ sin ⁻¹ (0.7 / n) (1) where n indicates the refractive index of the material of the transparent member forming the dark-field illumination member 12 of the present invention.

Light guide 1 of dark field illumination member 12 of the present invention
5 is directed toward the sample surface 14 by the ring-shaped light inwardly deflecting surface 16, and then the ring-shaped light-emitting end surface 1.
The light is emitted from the sample 7 toward the sample surface 14, but if total reflection occurs again at the ring-shaped emission end face 17, illumination light cannot be guided to the target area, and the illumination efficiency is reduced. Therefore, the angle of incidence of the light beam on the ring-shaped emission end face 17 is limited, and almost all the light flux reflected on the ring-shaped light inward deflecting face 16 is reflected on the sample surface 14 without being totally reflected on the ring-shaped emission end face 17. If you make it possible to reach
Such a problem is solved.

The incident angle of light rays that can be totally reflected by the ring-shaped emission end face 17 to the ring-shaped emission end face 17 is sin ^-1 (1/1).
n). The incident angle of the light beam that reaches the ring-shaped emission end face 17 from the ring-shaped light inner deflection face 16 is determined by the angle θ formed between the ring-shaped light inner deflection face 16 and the ring-shaped emission end face 17. Since the light that reaches the inner deflecting surface 16 is a light beam having good directivity as described above, even if the angle θ is slightly smaller than the value of sin ⁻¹ (1 / n), a large light amount loss occurs. Does not occur. However, when the angle θ is much smaller than the value of sin ⁻¹ (0.7 / n),
Light rays that cause total reflection at the ring-shaped emission end face 17 gradually increase, which causes a decrease in illumination efficiency.

As described above, according to the dark-field illumination member 12 of the present invention, bright illumination with reduced light divergence and improved illumination efficiency is possible, while the position of the exit end face of the illumination light is reduced. Illumination unevenness accompanied by a sharp intensity change is likely to occur due to reasons such as being close to the sample surface and an extremely wide illumination field. Particularly, when a light source in which optical fibers are arranged in a ring shape is used, extremely unsightly illumination unevenness which spreads in a radial direction around the optical axis may occur. It is difficult to eliminate these illumination irregularities only by changing the shape of the illumination member.

Therefore, in the dark-field illumination member 12 of the present invention, the above-mentioned problem is solved by providing a light diffusing surface on the ring-shaped emission end face 17. Even if a diffusion surface having relatively low power is applied to the emission end face, the intensity change of the illumination light on the sample surface 14 due to the illumination unevenness becomes gentle, and the band-like unevenness extending radially is also eliminated. In addition, almost no light quantity loss occurs at the ring-shaped emission end face 17. Such a light diffusing surface may be formed directly on the ring-shaped emitting end face 17, or the light diffusing surface formed separately may be formed on the ring-shaped emitting end face 1.
7 may be attached. Further, it is not necessary to cover the entire surface of the ring-shaped emission end face 17 with such a diffusion surface. Even if the light diffusion surface is provided only in a part of the area, the above-mentioned effect can be sufficiently obtained.

By the way, the video microscope can easily observe various parts by holding the observation head part in a hand.
Can be inspected. However, unless a part of the observation head portion is brought into contact with somewhere to focus, a satisfactory image cannot be obtained due to camera shake. Conversely, there is an observation sample that can be brought into contact like a precision base. In this case, the observation head is fixed to a dedicated frame to perform focusing. In order to perform such two kinds of observations, in the dark field illumination member 12 of the present invention, it is possible to attach and detach a cylindrical transparent member for focusing, which is in contact at a substantially focused position and surrounds at least the observation range. .

More specifically, the cylindrical transparent member for focusing can be mounted near the ring-shaped light inward deflecting surface 16. When illuminating a wide range equal to or more than the annular light source 13,
It has already been described that the illuminating light flux must be once expanded radially outward so that the image of the light source 13 reflected by the sample surface 14 does not overlap the sample image. Inevitably, the lighting member also becomes large in the radial direction. However, in the present invention, since the cylindrical transparent member for focusing can be attached near the tip near the ring-shaped light inward deflecting surface 16, the entire area from the vicinity of the annular light source to the sample surface 14 is thick. There is no need to cover with a cylindrical transparent member, and the observation head can be made compact. Therefore, the weight of the dark-field illumination member 12 can be made sufficiently small.
Even when the observer uses the illuminating device equipped with the dark-field illuminating member 12 in his hand, the observer does not get tired and the adjustment of the observation position is facilitated. The cylindrical transparent member for focusing is provided on the light guide portion 1 near the ring-shaped light inward deflecting surface 16.
5 may be detachably attached.

In the dark-field illumination member 12 of the present invention,
It is preferable that the cylindrical transparent member for focusing is mounted at a position satisfying the following conditional expression. L / T <1.5 (2) where L is the length along the optical axis from the annular light source 13 to the ring-shaped light inward deflecting surface 16, and T is the annular light source 13. 4 shows the length along the optical axis from the position to the mounting position of the cylindrical transparent member for focusing. When the cylindrical transparent member for focusing is attached to the light guide section 15 near the ring-shaped light inward deflecting surface 16, the attachment portion satisfies the following conditional expression. preferable. 4 <L / S <40 (3) where S is the length in the direction along the optical axis of the mounting portion of the light-guiding section 15 to which the cylindrical transparent member for focusing is attached, and L is the annular shape The length from the light source 13 to the ring-shaped light inward deflection surface 16 along the optical axis is shown.

In the illumination member for transmitting the illumination light by totally reflecting the light in the transparent light guide portion, when a cylindrical transparent member for focusing is mounted on the light guide portion, the light is totally transmitted at the mounting portion. There is a possibility that the reflection is interrupted and a large light amount loss occurs. Therefore, light leakage prevention measures must be taken by adding components such as mirrors. However, if the dark-field illumination member 12 of the present invention is used, the loss of light quantity can be minimized without adding extra components. This is because in the dark-field illumination member 12 of the present invention, the directivity increases each time the divergent light beam emitted from the light source 13 is repeatedly totally reflected between the two side surfaces 15a of the light guide unit 15, and the light guide unit The longer the number 15 is, the more the divergence of the light beam can be suppressed. As a result, the illuminating light incident on the ring-shaped inward deflecting surface 16 has only a divergence angle of about the size of the spread angle of the thickness of the light guide portion 15, and the illuminating light near the ring-shaped inward deflecting surface 16 is guided. This is because the amount of light reflected on the outer surface 15a of the light section 15 is extremely small. That is, if the cylindrical transparent member for focusing is attached to such a portion, the light amount loss can be suppressed.

In addition, if a cylindrical transparent member for focusing is mounted at a position that satisfies the conditional expression (2), it is possible to further reduce light leakage from the portion where the cylindrical transparent member is mounted. If the value of L / T exceeds the upper limit of the range of possible values of the conditional expression (2), the focus is placed at a position where the directivity of the light beam propagated in the light guide unit 15 has not been sufficiently increased. There is a high possibility that a cylindrical transparent member for alignment is attached, and the light amount loss naturally increases.

Further, the dark-field illumination member 12 of the present invention
By satisfying the conditional expression (3), it is possible to perform a firm attachment that can withstand frequent attachment and detachment while minimizing light leakage from the attachment portion of the tubular transparent member. But,
If the value of L / S is below the lower limit of the range of possible values of the conditional expression (3), the loss of the light amount increases because the mounting portion of the tubular transparent member is too large compared to the size of the light guide 15. I do. On the other hand, if the value of L / S exceeds the upper limit of the range of values that conditional expression (3) can take, the strength of the mounting portion of the cylindrical transparent member cannot be maintained, and the mounting and dismounting of the cylindrical transparent member and the sample surface There is also a risk that the mounting portion may be damaged in the process of repeatedly contacting the mounting portion 14.

It is very convenient if the video microscope can be easily carried like a home-use TV camera. However, unlike the TV camera, the video microscope always requires a lighting device. When importance is placed on portability, the most demanding requirements are a light weight of the entire system and a long usable time. In order to reduce the weight, the capacity of the battery as the power source cannot be increased. In order to use the battery for a long time with a small battery capacity, the power consumption of the light source must be reduced. As a result, the lamp that is the light source can use only a fraction of the output of a commonly used lamp. As described above, the absolute amount of light is inevitably limited in a portable video microscope, so how to improve the transmission efficiency of illumination light and the illumination efficiency is a condition for obtaining a clear image with less noise. I can say

The dark field illumination member 12 of the present invention has been proposed for this purpose. The dark field illumination member 12 of the present invention
Can be used together with a microscope TV observation system including an electronic imaging device, an optical system for projecting an image from a sample onto the electronic imaging device, a power supply battery, and a light source powered by the battery. To be able to do so, it is simple and compact as described above. Furthermore, T for microscope
Although the brightness of the illumination light is pursued to the utmost in the V observation system, the most suitable for use in such a system is the dark field illumination member 12 according to the present invention.
This is as described above. In addition, since the dark-field illumination member 12 of the present invention used for such a purpose needs to have both good workability and lightweight, it is highly transparent and lightweight such as acrylic resin. It is preferable to be made of a resin.

Hereinafter, a specific configuration of the present invention will be described based on the illustrated embodiment.

First Embodiment FIG. 2 is a cross-sectional view (although only the upper part is shown) of an arrangement of a dark-field illumination member according to this embodiment, taken along the optical axis. Dark field illumination member 21 of this embodiment includes a light guide 22 having an outer surface a ₁ formed by the side surface of the respective truncated cone-shaped inner surface a _2, a ring-shaped light inward deflection surface a ₃ , it consists formed on the extension of the inner surface a ₂ of the optical beam 22 ring emitting end face a ₄ Prefecture.

First, a light beam (hereinafter, referred to as a ring light beam) emitted from the annular light source 20 in parallel with the optical axis is guided while repeating the total reflection between the outer surface a ₁ and the inner surface a _2. the middle section 22 is propagated guided to ring light inward deflection surface a _3. The outer surface a ₁ and the inner surface a ₂ has a gradually expanding shape toward the ring-shaped light inward deflection surface a _3,
It has a function of suppressing the spread of the divergent light propagated during this time. The light beam reaching the ring-shaped light in the inner deflection surface a ₃ is totally reflected by the deflected towards the ring-shaped exit end face a _4, and is emitted toward the sample surface 23 via a ring-shaped exit end face a _4.

Hereinafter, numerical data of the dark field illumination member 21 according to the present embodiment will be shown. a ₁ = 49.9 mm, a ₂ = 61.6 mm, a ₃ = 49.6
mm, a ₄ = 14.1 mm a ₅ = 137.5 °, a ₆ (θ) = 36.0 ° The divergence angle of the thickness of the light guide 22 (the outer surface a ₁ and the inner surface a ₂
Angle = 64 °

[0052]Second embodiment FIG. 3 shows a configuration of a dark field illumination member according to the present embodiment.
FIG. 3 is a cross-sectional view along the optical axis (however, only the upper part is shown
There). The dark-field illumination member 31 of the present embodiment has a truncated cone shape.
Outer surface b formed on the side surface₁And formed from a substantially frustoconical side
The cross-sectional shape along the optical axis is half that of the dark-field illumination member 31.
Inner surface that has a curved surface with a center of curvature on the outside in the radial direction
b_TwoAnd a ring-shaped light inward
Deflection surface b _ThreeAnd the inner surface b forming the light guide portion 32_Twoof
Ring-shaped emission end face b formed on extension_FourConsisting of
I have.

First, the ring-shaped light beam from the annular light source 20 propagates through the light guide portion 32 while repeating total reflection between the outer side surface b ₁ and the inner side surface b _2, and the ring-shaped light inwardly deflecting surface to b ₃ is derived. The outer surface b ₁ and the inner surface b ₂ has a gradually expanding shape toward the ring-shaped light inward deflection surface b _3, and a function of suppressing the spread of divergent light to be propagated between this. Moreover, the divergence of the light beam by the inner surface b ₂ to the shape of the cross section along the optical axis and has a curved surface having a center of curvature radially outside of the dark field illumination member 31 is Osaeraru. The light beam that has reached the ring-shaped in-light deflection surface b ₃ is deflected toward the ring-shaped emission end surface b ₄ by total reflection, and is emitted toward the sample surface 23 via the ring-shaped emission end surface b ₄ .
Incidentally, b ₅ shows the connecting ends pedestal conical surface of the inner side surface b ₂ a ring-shaped exit end face b ₄ formed on its extension.
b ₆ shows the angle formed by the ring-shaped exit surface b ₃ and the base cone b _5.

In the dark-field illumination member 31 of this embodiment,
The light portion 32 has a ring-shaped light inward deflection surface b. _ThreeGradually approaching
The inner surface of the light guide 32 is thicker
b_TwoThe cross-sectional shape along the optical axis of the
Be a curved surface with a center of curvature outside in the radial direction
From this, the divergence of the luminous flux that is double propagated in the light guide section 32 is suppressed.
The light-collecting property can be greatly improved.

Hereinafter, numerical data of the dark-field illumination member 31 according to the present embodiment will be shown. b ₁ = 48 mm, b ₃ = 16 mm, b ₅ = 61.6 mm, b _{6
= 33.3 °, b 7 = 166.5} ° divergence angle of the thickness of the light guide portion 32 (the outer surface b ₁ and the inner surface b ₂
Angle = approximately 7.2 ° The angle θ ≧ 33.3 ° between the ring-shaped light inward deflecting surface b ₃ and the ring-shaped emission end surface b ₄ .

Third Embodiment FIG. 4 is a cross-sectional view (although only the upper part is shown) of the structure of a dark field illumination member according to this embodiment along the optical axis. The dark-field illumination member 41 of the present embodiment is formed from a substantially frustum-shaped side surface and has a cross-section along the optical axis having a curved surface having a center of curvature on a radially outer side of the dark-field illumination member 41. It formed from the side surface c ₁ and truncated cone-shaped side surface and the inner surface c ₂ and the light guide portion 42 constituted by a ring-shaped light inward deflection surface c _3, has a ring-shaped exit end face c ₄ Metropolitan .

First, a ring-shaped light beam from the annular light source 20
Is the outer surface c₁And inner surface c_TwoRepeats total reflection between
The ring-shaped light inwardly deflecting surface c propagated through the light guide portion 42
_ThreeLed to. Outer surface c₁And inner surface c_TwoIs a ring
Light inward deflection surface c_ThreeWith a shape that gradually expands toward
Work to suppress the spread of divergent light propagating between them
It has. Also, the outer surface c₁Is the optical axis, as described above.
The cross-sectional shape along is outside the dark field illumination member 41 in the radial direction.
Since the curved surface has a center of curvature on the side, the luminous flux
Has the property of slightly diverging. Ring-shaped light inward polarization
Facing c_ThreeThe light beam that has arrived at the ring is emitted by total reflection
End face c_FourDeflected toward the ring-shaped emission end face c_FourThrough
And is emitted toward the sample surface 23. Ring-shaped emission end face c
_FourA fine crease is formed on the lathe by lathing,
Plays the role of diffusion surface. Note that c_FiveIs the outer surface c₁of
Frustum surface connecting both ends, c₈Is a ring-shaped emission end face c_ThreeAnd stand
Cone surface c_FiveAnd the angle between them. c₉Is relative to the optical axis
Inner surface c_TwoSlope, c _TenIs a lighting device having a light source 20
Outgoing end face and outer face c of illumination light beam₁Shows the angle between
You.

The dark-field illuminating member 41 of the present embodiment can be set on the sample surface 23 by appropriately setting the light-condensing action due to the expansion of the thickness of the light guide section 42 and the diverging action due to the curvature of the outer surface c _1. The balance between the brightness at the center and the amount of peripheral light in the illuminated field can be set freely. Further, by providing the diffusing surface of the light in a ring-shaped exit end face c _4, it is to eliminate the uneven illumination with abrupt intensity change.

Hereinafter, numerical data of the dark-field illumination member 41 according to the present embodiment will be shown. c ₂ = 47.3 mm, c ₃ = 18 mm, c ₄ = 13.5 mm,
c ₅ = 46.1 mm, c ₆ = 2.8 mm c ₇ (θ) = 34.5 °, c ₈ = 139.3 °, c ₉ =
13.3 °, c ₁₀ = 21.2 ° The spread angle of the thickness of the light guide portion 42 (the outer side surface c ₁ and the inner side surface c ₂
Angle) = average about 7.9 °

Fourth Embodiment FIG. 5 is a cross-sectional view (although only the upper part is shown) of an arrangement of a dark-field illumination member according to this embodiment, taken along the optical axis. The dark-field illuminating member 51 of this embodiment is formed from a substantially frustum-shaped side surface and has a cross-section along the optical axis having a curved surface having a center of curvature on the radially outer side of the dark-field illuminating member 51. side d ₁ and the light guide portion 52 constituted by this outer surface d ₁ inner surface d ₂ which is formed similarly to a ring-shaped light inward deflection surface d ₃ which is formed by the mirror surface, the inner surface d consist formed on _second extension ring emitting end face d ₄ Prefecture.

First, the ring-shaped light beam from the annular light source 20 is propagated through the light guide portion 52 while repeating total reflection between the outer surface d ₁ and the inner surface d _2, and the ring-shaped light is deflected inward. It is led up to d _3. The outer surface d ₁ and the inner surface d ₂ has a gradually expanding shape toward the ring-shaped light inward deflection surface d _3, and a function of suppressing the spread of divergent light to be propagated between this. Furthermore, the outer surface d ₁ has the property of slightly divergent light flux, the inner surface d ₂ has a property of slightly condensing a light beam. The light beam reaching the ring-shaped light inward deflection surface d ₃ is deflected toward the ring-shaped exit end face d _4, it is emitted toward via a ring-shaped exit end face d ₄ to the sample surface 23. Incidentally, d ₅ is tied I base conical surfaces of both ends of the outer surface d ₁ of the light guide 52, d ₇ is ring-shaped exit end face d ₃ and the base conical surface d
_The angle formed with ₅ is shown. d ₆ is the angle between the inner surface d ₂ thereof connecting both ends of the extension ring exit end face formed on the d ₄ base conical surfaces, d ₈ is a ring-shaped exit end face d ₃ and Taitsumu surface d ₆ Is shown.

[0062] dark field illumination member 51 of this embodiment, a condensing action by the extent of the thickness of the light guide portion 52, and the focusing action of the curved surface of the diverging effect and the inner surface d ₂ by the curved outer surface d ₁ Is set appropriately, it is possible to freely set the balance between the brightness on the sample surface 23 and the illumination unevenness.

Hereinafter, numerical data of the dark field illumination member 51 according to the present embodiment will be shown. _{d 3 = 15.2mm, d 5 =} 52.4mm, d 6 = 65.2
mm d ₇ = 139.4 °, d ₈ = 34.25 ° The divergence angle of the thickness of the light guide 52 (the outer surface d ₁ and the inner surface d ₂
Angle = about 6.9 ° on average, ring-shaped light inward deflection surface d
₃ and the ring-shaped exit end face d _{4 make} an angle θ ≧ 34.5 °

Here, the first to fourth embodiments described so far are described.
The dark-field illumination member shown in the example is actually shared with the illumination device.
Shows the state used. FIG. 6 shows such a dark-field illumination member.
FIG. 3 is a cross-sectional view along an optical axis showing a state where the lighting device is mounted.
(However, only the upper part is shown). This darkfield illumination
Member e₁Is a lighting device in which the annular light source 20 is arranged.
Objective lens section e_FourAnd dark-field illumination
Member e₁And objective lens section e _FourConnection adapter on the outside surface of
Puta e_ThreeAre screwed on. In addition, this connection
Dapta e_ThreeThe outside is a cylindrical transparent for focus alignment
Member e_TwoIs the mounting screw e_FiveDetachable mounting by
Be killed. In addition, a cylindrical transparent member e for focus alignment_Two
Is the connection adapter e_ThreeThrough the dark field illumination member e₁And solid
A length that can almost contact the sample surface 23 in a fixed state
have.

FIG. 7 is also shown in the first to fourth embodiments.
Optical axis showing the state where the dark-field illumination member is mounted on the illumination device
FIG. 2 is a cross-sectional view taken along the line (however, only the upper part is shown).
You. ) This dark-field illumination member f₁Is the adapter f₇By
Objective lens of a lighting device in which an annular light source 20 is disposed
Part f_FourAttached to the light exit surface. Also, the light inward deflection surface
Cylindrical mirror for focus alignment with a mirror surface
Light member connection adapter f _ThreeIs the fixing member f_FiveBy dark field
Lighting member f₁Is fixed by sandwiching the apex angle. Connection
Dapta f_ThreeThe sample 23 has a cylindrical shape for focusing.
Transparent member f_TwoAre detachably attached. It is shown here
Dark field illumination member f₁At the light incident end of the adapter
f₇Through the objective lens unit f_FourTo the exit end face of
Projections are provided. Also for focus alignment
Cylindrical transparent member f_TwoIs the connection adapter f_ThreeMounted on
Length enough to contact the sample surface 23 in the
You.

The numerical data shown in FIG. 7 is shown below. L = 47 mm, T = 41 mm, S = 2 mm L / T = 1.15, L / S = 23.5

Fifth Embodiment FIG. 8 is a cross-sectional view (although only the upper portion is shown) of the structure of a dark field illumination member according to this embodiment along the optical axis. Dark field illumination member 61 of this embodiment includes a light guide portion 62 having an outer surface g ₁ formed by the side surface of the respective truncated cone-shaped inner surface g _2, a ring-shaped light inward deflection surface g ₃ It is constituted by the inner surface g ring emitting facet g ₄ formed on the extension of _2.

First, a ring-shaped light beam from the annular light source 20
Is the outer surface g₁And inner surface g_TwoRepeats total reflection between
While the ring-shaped light inward deflection surface g_ThreeLed to. Outer surface
g₁And inner surface g_TwoIs the ring-shaped light inward deflection surface g_ThreeToward
Has a shape that gradually spreads,
It has the function of suppressing the spread of divergent light. Ring shape
Light inward deflection surface g_ThreeThe light flux that has reached
Ring-shaped emitting end face g _FourDeflected toward
G end face_FourThen, the light is emitted toward the sample surface 23.

The dark-field illumination member 61 of the present embodiment is
Is the outer surface g₁And ring-shaped light inward deflection surface g_ThreeBetween
Reflection surface angle adjustment part g_FiveAre formed. This reflective surface
Angle adjustment part g_FiveIs the outer surface g₁And ring-shaped light deflection surface
g_ThreeIs set to a desired size, and the sample surface 23
Adjust the lighting angle, light collecting property and illumination unevenness to the light in a well-balanced manner
It is for doing. It should be noted that the dark field illumination unit of the present embodiment
In the material 61, the light beam propagated in the light guide section 62 emits light.
Since the scattering is suppressed, the reflection surface angle adjustment portion g _FiveAt
The light loss is very small. Furthermore, the reflection surface angle
Adjustment part g_FiveOutside the adapter g₆Focus through
Cylindrical transparent member g for alignment₇Is detachably attached
Can be Reflection surface angle adjustment part g_Five, Adapter g₆And tube
Transparent member g₇Grooves are formed on the connection surfaces of
These three members can be strongly fixed. In addition, this
Cylindrical transparent member g for focus adjustment₇Is a dark field illumination
Almost in contact with the sample surface 23 while being fixed to the bright member 61.
It is long enough to obtain. G₉Is relative to the optical axis
Inner surface e_TwoSlope, g_TenIs a lighting device having a light source 20
Outgoing end face and outer face g of illumination light beam₁Shows the angle between
You.

Hereinafter, numerical data of the dark field illumination member 61 according to the present embodiment will be shown. g ₁ = 42.1 mm, g ₂ (including g ₄ ) = 61.8 mm, g
₃ = 41.1 mm, g ₈ = 2.7 mm g ₉ = 14.0 °, g ₁₀ = 72 °, g ₁₁ (θ) = 30.
5 ° spread angle of the thickness of the light guide portion 62 (the outer surface g ₁ and the inner surface g ₂
Angle = 4.9 ° L = 46.5 mm, T = 40 mm, S = 6.5 mm L / T = 1.16, L / S = 7.15

Sixth Embodiment FIG. 9 is a cross-sectional view (although only the upper part is shown) of an arrangement of a member for dark field illumination according to the present embodiment, taken along an optical axis. Dark field illumination member 71 of this embodiment includes a light guide portion 72 having an outer surface h ₁ formed in the side surface of the respective truncated cone-shaped inner surface h _2, a ring-shaped light inward deflection surface h ₃ It is constituted by a ring-shaped exit end face h _4.

[0072] First, the ring-shaped light flux from the annular light source 20 is guided to the outer surface h ₁ and the ring-shaped light inward deflection surface h ₃ while repeating total reflection between the inner surface h _2. The outer surface h ₁ and the inner surface h ₂ has a gradually expanding shape toward the ring-shaped light inward deflection surface h _3, and a function of suppressing the spread of divergent light to be propagated between this. The light beam reaching the ring-shaped light inward deflection surface h ₃ is deflected toward the ring-shaped exit end face h ₄ by total reflection, and is emitted toward via a ring-shaped exit end face h ₄ to the sample surface 23.

Further, the dark-field illumination member 71 of the present embodiment is positioned at a position radially inward of the dark-field illumination member 71 slightly above the extension of the inner surface h ₂ of the light guide 72. cylindrical transparent member h ₅ of use are formed integrally with the dark field illumination member 71. The cylindrical transparent member h ₅ are dark field illumination member 71 has a length that may be in contact with the sample surface 23 in a state mounted on the lighting device. Also, dark field illumination member 71 of this embodiment, for the reasons described above, since the divergence of the light beam propagating in the light guide portion 72 can be satisfactorily suppressed, in the cylindrical transparent member h ₅ for focusing alignment Is very small. Incidentally, h ₁₀ is the slope of the inner surface h ₂ with respect to the optical axis, h ₁₁ represents the angle of the emission end face and the outer face h ₁ of the illumination light beam of the illumination device having a light source 20.

Hereinafter, numerical data of the dark field illumination member 71 according to the present embodiment will be shown. h ₁ = 48.4 mm, h ₂ = 49.6 mm, h ₃ = 18 mm,
_{h 4 = 16.8mm, h 6 =} 5.4mm, h 7 = 2.8mm,
h ₈ = 139.1 °, h ₉ = 97.2 mm, h ₁₀ = 14.
6 °, h ₁₁ = 68.5 °, h ₁₂ = 94.5 ° The divergence angle of the thickness of the light guide 71 (the outer surface h ₁ and the inner surface h
₂ ) = 6.9 ° Angle θ = 36.8 ° between ring-shaped light inward deflecting surface h ₃ and ring-shaped emission end surface h ₄ .

FIG. 10 is a diagram showing the configuration of a microscope TV observation system using the dark-field illumination members shown in the first to fifth embodiments. In this system, a light source unit i ₁ containing a battery as a power source and a halogen lamp for a light source, a CCD control unit i
_2, and the output TV monitor i _3, and the observation head i ₄ having a CCD and an objective lens, dark field illumination member i ₅
When, and an optical fiber bundle i ₆ Tokyo.

In this microscope TV observation system, first,
Illumination light emitted from the light source unit i ₁ inside the lamp is guided to the observation head unit i ₄ through the optical fiber bundle i _6. Illumination light guided to the observation head i ₄ is converted into a light flux annularly observation head unit i _4, and is emitted from the exit end of the sample i ₇ side. The annular beam through a dark field illumination member i ₅ for illuminating the sample i _7. Illuminated image of the sample i ₇ is C by the objective lens in the observation head i ₄
After being projected onto a CD, it is converted into an electrical signal. The electrical signal is converted into an image signal by the CCD control unit i _2, it is displayed on the TV monitor i _3. Since the power supply of the TV observation system shown in FIG. 10 uses a battery, the user can easily carry it around his shoulder.

As described above, the dark field illumination member according to the present invention has the following features (1) to (10) in addition to the features described in the claims.

(1) The thickness of the light guide portion increases as it approaches the light emitting end.
The member for dark field illumination according to any one of the above.

(2) The dark field illumination member according to the above (1), wherein the spread angle of the thickness of the light guide portion is equal to or smaller than the numerical aperture of the annular light source.

(3) The angle (θ) formed between the ring-shaped light inwardly deflecting surface and the ring-shaped emission end face satisfies the following conditional expression: (1) or (2). Dark field illumination member. θ ≧ sin ⁻¹ (0.7 / n) where n indicates the refractive index of the material of the transparent member constituting the dark field illumination member.

(4) The member for dark field illumination according to any one of (1) to (3) or (1) to (3), wherein the ring-shaped emitting end face is a light diffusing surface.

(5) The dark field illumination according to any one of (1) to (3) or (1) to (4), further comprising a detachable cylindrical transparent member for focusing. Parts.

(6) The cylindrical transparent member for focusing is detachably mounted near the inward deflecting surface of the ring-shaped light, or the above (1) to (3). The member for dark field illumination according to any one of (5).

(7) The cylindrical transparent member for focusing is detachably attached to the light guide near the inwardly deflecting surface of the ring light.
Alternatively, the dark-field illumination member according to any one of the above (1) to (5).

(8) In any one of the above (1) to (4) or (7), wherein the cylindrical transparent member for focusing is mounted at a position satisfying the following conditional expression. A member for dark field illumination as described in the above. L / T <1.5 where L is the length along the optical axis from the light source to the ring-shaped light inward deflecting surface, and T is the distance from the light source to the mounting position of the cylindrical transparent member for focusing. Shows the length in the direction along the optical axis.

(9) The above-mentioned cylindrical transparent member for focusing is mounted at a position satisfying the following conditional expression (1) to (4) or (7) to (8). The member for dark field illumination according to any one of the above. 4 <L / S <40, where L is the length along the optical axis from the light source to the ring-shaped light inwardly deflecting surface, and S is the length of the cylindrical transparent member for focusing on the light guide. The length of the mounting portion in the direction along the optical axis is shown.

(10) The above-mentioned optical system of a TV imaging apparatus comprising an electronic image pickup device, an optical system for projecting an image of a sample onto the electronic image pickup device, a battery for power supply, and a light source using the battery as a power supply. The darkness according to any one of claims 1 to 3, or (1) to (9), wherein the microscope TV observation device by dark field illumination can be configured by being arranged on the system side. Field lighting member.

[0088]

As described above, according to the present invention, it is possible to perform illumination with high transmission efficiency and high illumination efficiency and low light loss while having a simple structure, and to provide a small-sized light source capable of illuminating a wide range. A member for field illumination can be provided.
In addition, when the dark-field illumination member of the present invention is used together with an illumination device, focusing can be easily performed without impairing the optical performance of the illumination device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view along an optical axis showing a configuration of a member for dark field illumination according to the present invention.

FIG. 2 is a cross-sectional view along the optical axis showing a configuration of a dark field illumination member according to the first example.

FIG. 3 is a cross-sectional view taken along an optical axis showing a configuration of a dark field illumination member according to a second example.

FIG. 4 is a sectional view along an optical axis showing a configuration of a dark field illumination member according to a third example.

FIG. 5 is a sectional view along an optical axis showing a configuration of a dark field illumination member according to a fourth example.

FIG. 6 is a diagram showing a state where the dark field illumination member shown in the first to fourth embodiments is mounted on an illumination device.

FIG. 7 is a view showing a state where the dark field illumination member shown in the first to fourth embodiments is mounted on an illumination device.

FIG. 8 is a sectional view along an optical axis showing a configuration of a dark-field illumination member according to a fifth example.

FIG. 9 is a cross-sectional view along the optical axis showing a configuration of a dark-field illumination member according to a sixth example.

FIG. 10 is a microscope T using the dark-field illumination member of the present invention.
It is a figure showing composition of a V observation system.

FIG. 11 is a diagram showing a system configuration of a conventional video microscope.

12A to 12C are schematic diagrams for explaining a coaxial epi-illumination system, a vertical epi-illumination system, and an epi-illumination dark-field illumination system, respectively.

[Explanation of symbols]

1 control box 2 light guide 3 video signal cable 4, i ₄ observation head unit 5 probe 6, e _4, f ₄ the objective lens unit 7,15,22,32,42,52,62,72 light guide portion 8, i ₃ monitor 9, i ₇ sample 10 objective lens 11 imaging element 12,21,31,41,51,61,71, e _1, f
_1, i ₅ side 16 of the dark field illumination members 13,20 orbicular light source 14, 23 sample surface 15a light guide _{portion, a 3, b 3, c} 3, d 3, g 3, h 3 in the ring-shaped light destination deflection surface _{17, a 4, b 4,} c 4, d 4, g 4, h 4 ring emitting end face _{a 1, b 1, c 1} , d 1, g 1, h 1 outer surface a _2, b _{2, c 2, d 2, g 2} , h 2 inner surface _{e 2, f 2, g 7} , h 5 cylindrical transparent member e _3, f _7, g ₆ adapter e ₅ screws f ₅ fixing member i ₁ source unit i ₂ control unit i ₆ fiber bundle

Claims (3)

[Claims] 1. An illumination member for illuminating an area equal to or wider than the annular light source, which is used together with an illuminating device provided with the annular light source, wherein at least a part of the external shape has the light source side. A light guide portion made of a hollow cylindrical transparent material including a substantially frustum-shaped side surface extending toward the sample side, a ring-shaped light inwardly deflecting surface tapered toward the sample, and the light source. A dark-field illumination member comprising: a ring-shaped emission end face located closer to the sample side than an intermediate position with respect to the sample. 2. The dark field illumination member according to claim 1, wherein the divergent light emitted from the annular light source is totally reflected by a side surface of the light guide portion to guide the light. 3. The light guide section according to claim 1, wherein the light guide section has a shape sandwiched between two substantially frustoconical side surfaces extending from the light source side toward the sample side. Dark field illumination member.