JPH04125609A - Optical microscope - Google Patents

Abstract

PURPOSE:To realize manifold illumination and easy space coherence control by employing such constitution that the light source of the illumination system of an optical microscope is formed in a LED array, and the shape itself of the light source can be changed by light control. CONSTITUTION:The light source of the illumination system is comprised of high luminance light emitting diodes 2 on each of which the light control can be applied independently, and it is arranged on the front side focal point plane of a condenser lens 4. The illumination strength can be controlled by the number of light of light emitting diodes 1, and also, the shape of the light source itself is changed by selecting the pattern of the light emitting diode to be lit, thereby, zonal illumination, oblique illumination, and dark field illumination can be performed. In such a way, the miniaturization and light weight of a chemical microscope can be attained, and also, the manifold illumination i.e. a various kinds of space coherence control can be easily and quickly performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical microscope, and more particularly to means for illuminating a sample thereof.

(Background) The optical microscope is an optical instrument that has a long history of over three centuries and can be said to be basically perfected. Its performance is close to the theoretical limit. Optical microscopes, which can be said to be the result of many years of optical technology, are undergoing improvements as the times progress.

In recent years, the use of electronics and computers in imaging systems has progressed, and various types of optical microscopes have been proposed. Background to recent developments is the ever-increasing demand for optical microscopes, which are closely related to research in the medical and bioengineering fields in particular, and have the feature of not damaging biological samples and allowing observation of living specimens.

For these reasons, optical microscopes are being actively developed, but the means for illuminating the sample, especially the light source, have not been studied at all, other than the introduction of lasers. However, the drawback is that high coherence is a problem, producing coherent noise such as speckles and interference fringes. In order to avoid coherent noise, the only way to use it is to reduce the coherence by using a diffuser, or to use it only for special purposes such as confocal or sigma scanning microscopes.

(Conventional technology and its problems) As a light source for the general illumination system of optical microscopes, tungsten lamps have been used in the past, and halogen lamps have recently been used because of their higher brightness and color temperature compared to tungsten lamps. is frequently used.

However, since both of these light sources directly convert high power into light, they generate a large amount of heat, which requires an equivalent force f of 7T to dissipate, and also requires considerable distance from the sample surface. It is necessary to provide a lamp house at a distance, and furthermore, a lamp house for shielding and a transformer device (such as a slider) for controlling brightness connected to the lamp house by a cable are also required.

For this reason, optical microscopes that use conventional light sources are generally large and used stationary in locations with commercial power, and it is extremely difficult to make them small and lightweight enough to be portable. Have difficulty.

On the other hand, in terms of usage, in conventional optical microscopes, the spatial coherence of illumination light is controlled by switching the condenser pattern.

That is, in FIG. 2, which shows the illumination system of a conventional optical microscope, light from a light source (21), which has been made uniform by a diffuser plate, is focused by a condenser lens r (22) at the position of a condenser pattern (23). It is configured to form an image and then convert it into a parallel light beam using a condenser lens (24) to illuminate the sample surface (25) in a −-like manner. When irradiation is desired, the condenser pattern (23) is replaced with one with an annular opening to perform spatial coherence control.

The capacitor crest (23) is replaced by replacing it in the removable type, and by rotating it in the revolver type with a turret disc. For example, when performing dark-field illumination, a bright-field condenser unit in which a condenser lens r (24) and its crest (23) are integrated into one housing can be used as a separate dark-field condenser unit. In any case, conventional spatial coherence control involves cumbersome mechanical operations and lacks coordination.

(Object of the Invention) The present invention solves the above-mentioned problems, and makes it possible to reduce the size and weight of an optical microscope, as well as to provide an optical system that can easily and quickly control various types of illumination, i.e., various types of spatial coherence. The purpose is to provide a microscope.

(Means for Achieving the Object) In order to achieve the above object, in the optical microscope of the present invention, the light source of the illumination system is composed of two-dimensionally arranged and independently controllable high-brightness light emitting diodes. The basic feature is that it is structured.

Furthermore, in order to further reduce the size and weight and increase the efficiency of illumination light, the array light source of the high-brightness light emitting diodes is arranged on the front focal plane of the condenser lens.

(Function) When uniformly illuminating the sample surface, it is basically enough to turn on one light emitting diode, and the illumination intensity can be controlled by the number of light emitting diodes lit, and the pattern of the light emitting diodes to be lit can be controlled. If selected, annular illumination, oblique illumination, and dark field illumination can be freely achieved by changing the shape of the light source itself. The two lighting patterns, that is, the lighting pattern can be changed instantly electrically.

When in an imaging relationship with the sample surface, a specific point on the sample surface, the fI region, can be electrically illuminated instantaneously by selecting a light emitting diode that lights up without moving the sample stake.

(Example) An example will be described with reference to the drawings. In FIG. 1, (1) is an LED array in which high-brightness light emitting diodes (2) (hereinafter, light emitting diodes are abbreviated as LED) are arranged in a two-dimensional manner. The microscope (3) has an LED array light source (1) and a condenser lens (4) on its optical axis (3a).
), an objective lens (5), and an eyepiece lens (6), the sample placed on the object plane (7) is uniformly illuminated by lighting the LED (2) of the LED array light source (1). The objective lens (5) magnifies and forms an image of the sample on the pupil plane (8), and the eyepiece lens (6) further magnifies the image to create a virtual image that is visible through the eyeball (9). Obtain a magnified image of the sample on the retina. FIG. 1(A) schematically shows the above optical microscope.

The LED array (1) is formed by arranging a large number of high-intensity LEDs (2) in a square lattice, as shown in FIG. 1(B). LED (2),
(2>,... light spot (21), (2&),...
... forms a discrete light source surface (10), and the LED array (1) is positioned so that this light source surface (10) is at the focal length (f) of the condenser lens (4). ing. Since the condenser lens (4) is fixed at a position away from the object plane (7) by its focal length fi (f), each LED (2), (2),...
The light beams diverging are converted into parallel light beams by the condenser lens (4), and both illuminate the center of the object plane (7).

Each LED (2), (2) that makes up the LED array (1)
, . . . receive power from a DC power source (12) such as a battery, and are each independently controlled to be lit by an LED drive circuit (11). The lighting pattern selector (13) is LE
LEDs (2), (2), etc. that make up D array (1)
・Information regarding which of the lights or groups to light and the lighting time is given to the LED drive circuit (11).This allows the lighting intensity and shape of the light source to be freely set, as well as lighting scanning, etc. Sequential illumination can also be performed freely.

More specifically, the LED array (1) is formed by attaching a plurality of LEDs (2) on a printed circuit board, and as shown in FIG. It is assembled into a body (14) and fixed at a predetermined position to form a unit (referred to as a condenser unit). In addition,
(15) is the sample (16) held between cover glasses.
This is a sample stage on which the sample (16) is placed, and the position of the sample (16) corresponds to the position of the object plane (7).

The LEDs (2) constituting the LED array (1) are of high brightness, and here, high brightness means that the light emission intensity is 150mc.
d or more. However, in relation to the arrangement density of the array, if the LEDs can be arranged relatively densely, 80 to 100 mcd LEDs can be used. Although the arrangement is shown in a square lattice in FIG. 1(B), it may be arranged in a hexagonal lattice.

Further, the directivity of the LED (2) needs to have a certain degree of spread in order to uniformly illuminate the field of view. However, if the directivity spreads too much, the illumination light will irradiate outside the field of view, causing a halo to appear in the image, or increasing stray light due to scattering by a condenser lens holder. When calculated from the field of view obtained with an actual objective lens, the half-value angle of the spread of directivity of each LED is preferably about 5 to 7 (deg).

Furthermore, in practice, the optical axes of the individual LEDs (2) must be arranged as perpendicular to the light source plane (10) as possible. If they are not orthogonal, the spots created by the respective LEDs will shift in the plane direction on the sample surface (7), resulting in uneven illumination. The tolerance range for the deviation of the optical axis of the LED becomes stricter as the magnification of the objective lens becomes lower. Practically, 3-4 (deg)
It is desirable to do the following.

Incidentally, the coherence of illumination light greatly affects image quality and how the image looks. When using illumination with high coherence,
As the depth of focus becomes deeper, interference fringes and ringing appear, making it impossible to accurately represent the object image. On the other hand, if low-coherence illumination is used, no coherence noise will appear, but since the depth of focus will be shallow, when observing a thick sample, the defocused images will overlap, making the image difficult to see. Put it away. Therefore, when using an optical microscope, the coherence of the illumination light is changed to
This means that it is desirable for students to study in the L dormitory and make comprehensive decisions.

When the LED7 ray is used as an illumination light source, the coherence of the light source itself is complicated. Therefore, the present inventors studied this and found out from the analysis below that the degree of coherence, which is a function of the distance between two points on the object plane, has multiple maximum values (peaks) when using an LED array. We have found that the distribution is controlled by the following three factors: ■ The distance between two points at which the degree of coherence is maximum is
Determined by the reciprocal of the array spacing.

■The spread of each peak is determined by the lighting pattern of the LED array.

■The envelope that connects the maximum values is determined by the intensity distribution of the light emitting part of one ED.

Here, we will derive the relationship between the lighting pattern of the LED array and its coherence, and in particular, find the conditions for obtaining a power equivalent to that of an incoherent continuous light source. First, we give specific values to the distance between the LEDs, the lighting pattern of the LED array, and the intensity distribution of the light emitting part, and calculate the actual degree of coherence between two points on the object plane.

FIG. 3 shows the optical system. Each LED is of the same quality, and its emission intensity distribution is given by w(x) with respect to the spatial coordinate x (see figure (a)), and these are the light source planes X.

Suppose that there is only one row of 2m+1 pieces lined up at equal intervals on the glaze (
Figure (b)). When all of these LEDs are lit, the intensity distribution 1s (xs) of the light source is given by: At this time, two points X on the object plane, and
The degree of coherence of the intensity at “(×) is van C1t
According to the tert-Zernike theorem, it is given by the 7-Rier transformation for x5 of l5(xs), and becomes: ・W(yrxzλfc) ・=<2). Here, it is defined as 5inc(x)=si (×/π×), K is a constant, and W(πx/λfc) represents the 7-Lier transform of −(x,). In equation (2), , the degree of coherence r(X> does not depend on the absolute positions of the two points, but is a function of the distance between the two points.

When the LED array is lit in a certain pattern, if this lighting pattern is expressed as p(x=), the intensity distribution of the light source is expressed as l5(x,)''Σp(x,) instead of equation (1).・w(x, -nD)
・-(3) jlt-becomes a sentry. The degree of coherence of light on the object plane is expressed as (
3) Perform 7-lier transformation on the equation to obtain r' (x) = KΣP(x-λre/D)・W(πX
/λfc) −(4).

Next, consider conditions for obtaining an image equivalent to an image obtained by illumination by a continuous light source using an LED array light source. In the case of a continuous linear light source with a length of 2 to D, the degree of coherence of light on the object plane is given by the following equation.

r(x) = sinc(πx/2mD A fc)
-(5) LE illumination system completely equivalent to this continuous light source
In order to realize this with a D array, the degree of coherence must be (5)
must match the expression. However, even if the degrees of coherence at the sample surface are different, it is possible to equivalently make the observed images the same at the image plane.

The degree of coherence of light on the object plane when all LEDs are lit (×) has already been given in equation (2), but
This function has multiple peaks. Among these, consider a two-point object separated by the distance between two adjacent peaks ×=λfc/D. When these two points are imaged on the image plane by the objective lens, the image of each point expands as shown in FIG. 4(a). As shown in FIG. 4(a), when the f value of the objective lens is small,
When the respective point images overlap, the degree of coherence of the distance X between these two points reaches a peak, so the overlap of these two points interferes with each other. On the other hand, when the f-number of the objective lens is large, as shown in FIG. 4(b), if each point image becomes sufficiently small and does not overlap with each other, the two points will not interfere on the image plane. In the case as shown in FIG. 14(b), an image equivalent to an image illuminated by an incoherent continuous light source is provided.

The spread of the point image is determined by the numerical aperture NA and magnification M of the objective lens.
The radius of its expansion is R=0.61・λM
/N A ... is given by (6). ^
The condition that the spreads of the complex amplitudes of light from two points separated by re/D do not overlap is λfc/D > 2R・= (7) If we rewrite this as a condition for D, then D decreases λfc/2R becomes.

Specifically, the focal length of the condenser lens is 15111
When the f1% magnification is 40 times, from equation (8), the value of the LED aperture to obtain an image equivalent to incoherent illumination is D < 0.26 (mm) - (9
). However, currently there are no LEDs as small as this. Or, if the diameter of the LED is 2■, NA=0.8
5. For an objective lens with a magnification of 40 times, the focal length fc of a condenser lens that satisfies equation (8) is fc>11
5 (em) - (10). Furthermore, the diameter of current small high-brightness LEDs is about 4m1m, so the focal distance fc of the condenser lens is fc>230 (m+o) - (1
1). The above were the conditions for giving an image equivalent to the image obtained with completely incoherent illumination, but
The light source of an actual commercially available microscope does not provide completely incoherent illumination, but is a partially coherent illumination system. Therefore, the conditions for an LED array light source that provides an image comparable to that of current microscope illumination systems are (9) to (11).
The conditions are much looser than those in the formula.

(Le×Ding, #White) Based on the above results, the relationship between the intensity distribution on the light source plane and the degree of coherence between two points on the object plane was calculated and determined. When calculating, the actual LED (Toshiba-T
A plan view of LRA 160R) is shown in FIG. The diameter is 3.81 and the central light emitting part or p-n junction (50)
The light emitted from the reflector plate (50') is considered to be a Fheelen F light source, and the LED array is arranged in a hexagonal lattice shape with a lattice interval of 4 mm.

FIG. 6 illustrates an example of the calculation results. Intensity distribution on the light source surface when performing discrete annular illumination (illumination at 18 points on the circumference with a radius of 13.2 mm from the center) (Figure (a)
) and the coherence degree distribution on the object plane ((b) in the same figure).

To contrast with the above example, FIG. 7 shows the case of continuous annular illumination. That is, what is annular illumination in the case where the inner and outer diameters are the same as in the case shown in FIG. 6(a), but where there are continuous light-emitting parts on the circumference? FIG. 7(a) shows the intensity distribution, and FIG. 7(b) shows the degree of coherence on the object plane. Figure 6.

It can be seen from FIG. 7 that in the case of discrete annular illumination, the region of high coherence becomes wider than in the case of continuous annular illumination. Therefore, in the case of discrete annular illumination, it can be assumed that interference fringes are more likely to appear in the actual observed image.

Now, although FIG. 1 above shows the best embodiment, the eighth
Figures 1 to 10 show illumination systems according to other embodiments.

FIG. 8 shows a Kohler illumination system in which a conventional filament light source is replaced by an LED array light source (81). An image of the LED array light source (81) is created on the front focal plane of the condenser lens (83) by the condenser lens (82), and an image of the LED array light source (81) is formed on the sample stage (83) located at the rear focal plane of the condenser lens X' (83). The sample (85) is illuminated with a parallel beam of light, and an enlarged image thereof is obtained using the objective lens (82), but in a case like this example, the field stop (87) has the advantage of facilitating adjustment of the optical system of the microscope.

Note that in an actual microscope, the optical path of the illumination system is L-shaped so as to reduce the height of the entire microscope.

FIG. 9 shows a more realistic embodiment. The optical path of the illumination light is made L-shaped by reflection [(91). FIG. 2B shows a case in which an LED array light source (81) is reduced and projected onto a position (93) where a normal filament light source is located using an imaging lens system (92). Here, the same reference numerals as in FIG. 8 indicate the same or equivalent components, and (94) indicates the condenser diaphragm.

10(A) and 10(B) show a critical illumination system, and in particular, FIG. 10(A) shows a configuration in which a conventional filament light source is replaced with an LED array light source (101). Same figure (B)
shows a configuration in which an LED array light source (108) is provided in front of a condenser lens (107). (104)
is a sample steno, (105) is a sample, and (10B) is an objective lens. This LED array light! (101), (
108) is used for the critical illumination system, the sample (10
5) The specific point, 'WR region, is the sample steno (104)
LED 7 ray light source (101), (1
9) It can be used for microscopic photometry, microspectroscopy, and polarization analysis, which can be illuminated simply by selectively controlling the lighting of the LEDs corresponding to 08).

The LED array shown in the above embodiments may be a two-dimensional arrangement of discrete LEDs or a planar LED array.
Either can be constructed by combining a large number of components, or can be modularized into a predetermined shape and used as is. In the case of a planar LED, since it is integrally molded with resin or the like, this mold acts as a light diffuser and makes the emission intensity distribution uniform, which is preferable.

When using discrete LEDs, Figure 11 (a
In addition to the single-color LED shown in ), two-color and three-color LEDs as shown in FIGS.

Moreover, if it is a monochrome one, any of red, green, and blue may be used. Two colors, red and green.

Any of three combinations of two blue colors may be used. In the case of the three colors shown in FIG. 3(c), when each color is turned on simultaneously, it becomes white light, and when it is turned on selectively, it becomes illumination of a specific wavelength (wavelength range). In such a case, it is possible to dispense with the use of conventionally used interference filters. Note that when configuring an LED array using discrete LEDs, it is not prohibited to mix single-color, two-color, and three-color LEDs. Furthermore, in the case of multicolor LEDs, a total emission intensity of 300 mcd or more per one LED is defined as high brightness.

Disk sheet LEDs can also utilize infrared LEDs. Furthermore, a laser diode can also be used. In the Kohler illumination system, by lighting a large number of laser diodes, it is possible to achieve a nearly spatially incoherent state on the sample surface. It is suitable for using light energy rather than illumination.

When LEDs are arranged two-dimensionally to form an LED array light source, it is preferable to provide a light diffusing plate on the top surface of the array to flatten the overall emission intensity distribution. More preferably, as shown in FIG. 12 (a), diffuser plates (31
), (32), (33), (34), and (35) are preferably combined. In addition, an annular diffuser plate (34
), the annular diffuser plate may be radially divided into a plurality of segments. In addition, in the illustration, L E D (30) is located below the diffuser plate, but is shown as a solid line for explanation. Also,
The diagonally shaded annular zone (33) indicates that it emits light, and since this area is separated by an annular diffuser plate, it is possible to prevent the LED emitted light from diffusing and illuminating the internal and external annular zones. are doing. If a diffuser plate is not provided, the emission intensity distribution of the LED array will be discrete as shown in Figure 12(b), but if a diffuser plate is provided, it will be as shown by ML in Figure 12(c). In addition, the intensity is generally uniform and flattened, making it easier to provide incoherent illumination. Note that when a diffuser plate is provided, the illumination intensity decreases, but a higher brightness LED may be used to compensate for the decrease.

All of the optical microscopes in the examples are shown as transmission type, but it is of course possible to change some of the configurations to make them reflective, and there is also a royal type that provides illumination from below. In addition, the LED array light source can be similarly applied to an inverted type that provides illumination from above.

FIG. 13 partially schematically shows an example of an inverted optical microscope.

An objective lens (42) is provided below the sample stage (41), and a slide glass or petri dish (43) containing a sample (44) such as cultured cells is placed under the LED array light source (
An illumination system consisting of a condenser lens (45) and a condenser lens (46) illuminates from above, and the sample (44) can be manipulated by means of a micromanipulator (47) while observing the image.

In conventional microscopes of this type, the condenser aperture is operated to change the appearance of the sample image, but this operation is mechanical and requires the hands, which is inconvenient as it competes with sample manipulation. , and the static state of the sample from giving mechanical vibration! ! There were also disadvantages in terms of maintenance. On the other hand, in the example, since the illumination system is compact, it is easy to arrange the operating devices etc. around it.
In addition, there is no need to consider any adverse thermal effects, and the way the sample image is viewed can be electrically switched instantly, so there is no mechanical vibration, making micro operations easier, and greatly improving usability and operability. It's a good idea to improve your skills.

Next, an example of a sample image obtained by the LED array light source microscope of the example will be shown.

FIG. 14 schematically shows the microscope system used to obtain the sample image. The LED array (51) was fixed at the aperture position (ie, the front focal plane of the condenser lens) of a condenser lens unit (53) that housed a condenser lens (52). (54) is an LED drive circuit, (55) is a DC voltage source such as a battery or a DC variable voltage power source, and (56) is a lighting pattern selector. (5
7) is a sample stake, (58) is a sample, (59) is an objective lens, (60) is a relay lens, (61) is a CCD camera, and the base of the microscope is BH- manufactured by Olympus.
2. CCD camera (61) is Sony XC-77
and the resulting Il-sensing image TV monitor (62
) and took a photo of the image on the monitor screen. In addition,
The LEDs constituting the LED array (51) have a center wavelength of 6
Ultra-high brightness LED with 60nLm and emission intensity of 700mcd (
Toshiba TLRA160R), and the array arrangement is 37
This is a hexagonal lattice shape shown in FIG.

FIG. 15 shows Aomidoro's i-imaging using a 20x objective lens (NA is 0.65).

(a) is a defocused image when fully lit.

In the case of fully lit illumination, the depth of focus becomes shallow because images from illumination light beams from many directions are superimposed. Furthermore, the object plane is almost incoherent, and even when defocused in this way, interference fringes do not appear conspicuously. (b) is a defocused image when the central LED is lit by 1@. - In the case of illumination from a point, the depth of focus becomes deeper, so even if the image is taken under the same conditions as in (a), a much clearer image is obtained. (e) is a case where only the outermost six lights are turned on as shown in (d). An image based only on the 6L light scattered by the object, that is, a dark field image is obtained. As is clear from this,
There is no need to replace the condenser unit in order to obtain dark-field images, as is the case with conventional methods.

FIG. 16 is an observation image of cultured tobacco cells using 40x magnification (NAo, 85).

(a) shows the focus level when all lights are on. As in the case of Aomidro, the depth of focus is shallow and the sample is a phase object, so the contrast is low and the structure is almost invisible. (b) is an image when only one LED in the center is lit. It is. The part that was almost invisible in (a) (the intersection of arrows p and q) is the arrow @ r in case 2.
, as can be seen at the intersection of s. Also, because the depth of focus is deep, structures in the depth direction can be clearly seen. However, since the coherence is high, the interference fringes are conspicuous as can be seen from the intersection of the arrows r+t. (c) is an image observed with oblique illumination. In this case, only a part of the esso is clearly visible, for example, as seen at the intersection of the arrows ulV.

Therefore, by using a large number of such images, CT, or optical computed tomography (
Optical CT) can be performed.

FIG. 17 shows an observed image of a single mode optical fiber using a 40x objective lens (NA is 0.85).

(a) is a seven-orcus image with full lighting.

Almost no internal structure can be seen. (b) is the central LE
This is an image when one D is lit. As can be seen from this observation image, using this illumination allows the internal structure of the optical fiber to be seen relatively clearly.

This is because highly coherent light also transmits changes in phase. However, due to the high coherence, noticeable interference fringes occur, as seen at the intersections of the arrows and X's. (C) is an image observed with oblique illumination. With this illumination method, the segmented structure can also be seen, similar to that seen in (b). In addition, each structure is shaded by shading, and an image similar to that obtained using differential interference method is obtained.

All of the above observed images show that in the configuration shown in Figure 14,
This is a photograph of the image displayed on the monitor (62). On the other hand, when it is desired to obtain an image by processing it in advance according to a desired shape, that is, when processing the image, the signal of the microscopic fIt image captured by the CCD camera (61) is captured by the image capture device (63), Computer (64
), predetermined processing can be performed, and the processing results can be displayed on the monitor (62).

For example, in order to perform the computer Y tomography (CT) using the light mentioned above, for example, as shown in FIG.
2), (73), . can. The present inventors previously installed a pulse rotation stage at the position of the condenser diaphragm in the Koehler illumination system.
We proposed a system that captures and processes projected images from other directions by rotating an ff-axis aperture under computer control (academic journal "Optics Jvol, 14+n
o, 5 (1985) pp. 333-342), in a microscope having an LED array light source according to the present invention, this optical CT can be performed by a simple method of simply controlling the lighting of the LEDs.

Furthermore, in the embodiment, if a phase contrast objective lens is configured in which the objective lens can be set according to the lighting pattern of the LED array, it can be used not only as a stereoscopic microscope but also as a phase contrast microscope. That is, since the optical microscope according to the present invention can freely change the shape of the light source itself of the illumination system, it can be easily applied to the optical CT or phase contrast microscope described above.

(Effects of the Invention) As described above, the present invention has a structure in which the light source of the illumination system of an optical microscope is an LED array, and the shape of the light source itself can be changed by lighting control. In addition, spatial coherence control can be performed simply and quickly electrically without any mechanical operations.

In addition, LED array light sources have low power dissipation and generate very little heat, so there are no problems with heat dissipation of filament thermal light sources in conventional optical I[@ mirrors, and since batteries can be used as a power source, they can be used in specific locations. This eliminates the restriction of using a stationary device. That is, combined with the fact that it can be made smaller and lighter, it has become possible to make it portable.

When an LED array is incorporated into a condenser unit, the condenser unit itself becomes the illumination system, making it possible to achieve a significant reduction in size and weight compared to conventional optical microscopes.

[Brief explanation of the drawing]

FIG. 1(A), FIG. 1(B), and FIG. 1(C) are explanatory diagrams showing one embodiment of the present invention. FIG. 2 is a diagram showing the optical system of a conventional optical microscope. FIGS. 3(a) and 3(b) are diagrams showing an optical system used for analyzing the degree of coherence. FIGS. 4(a) and 4(b) are explanatory diagrams illustrating the degree of coherence. FIG. 5 is a schematic plan view of the LED used to verify the analysis results. FIGS. 6(a), (b) and FIG. 7(a) are diagrams showing the intensity distribution on the light source plane and the degree of coherence between two points on the object plane. Figure 8, Figure 9 (A>, CB), Figure 10 (A), (B
) is a diagram showing an illumination optical system of another embodiment. FIG. 11 is a plan view of various applicable LEDs, and FIG. 12 is an explanatory diagram illustrating the use of a diffuser plate. FIG. 13 is a partial horizontal view of the inverted microscope. FIG. 14 is a diagram showing a microscope system according to an embodiment of the present invention configured to obtain an example of a sample image. FIGS. 15(a), f(b), and (c) show microscopic photographs of Aomhidoro, and FIG. 15(d) is a diagram showing the LED that was turned on when photographing the same figure (C). FIGS. 16(a), (b), and (C) are micrographs of cultured tobacco cells. Figure 17 (a), (b), and (c) show single mode light 7.
This is a microscopic photograph of Aiva. FIG. 18 is an explanatory diagram of LED lighting control when performing optical CT. 1.81,101,108.51...LED array light source, 2...High brightness light emitting diode (LED), 4,5
2... Condenser lens, 5,59... Objective lens, 7... Object surface, 10... Light source surface, 11.54.
...LED drive circuit, 12.55...Power supply, 14.5
3...Condenser Uni Nod, 16, 85, 105
．． 58...Sample.

Claims (2)

[Claims] (1) In a transmission type optical microscope equipped with an illumination device, the illumination device is a light source consisting of a condenser lens and high-intensity light emitting diodes that are arranged two-dimensionally in the front focal plane of the condenser lens and can each be lit and controlled independently. An optical microscope characterized by comprising: (2) An optical microscope equipped with a Köhler illumination system or a critical illumination system, characterized in that the light source of the illumination system is comprised of high-intensity light-emitting diodes that are arranged two-dimensionally and can each be independently controlled to turn on.