JPH07225342A - Illuminator for microscope - Google Patents

Abstract

PURPOSE:To make the blurred image of the minute luminescent point of a sample similar to an original blurred image in the case of illuminating light from a point light source instead of a blurred image having the shape of the light emitting surface of the light source in the defocusing state of a microscope when the sample of the minute luminescent point-like shape is observed under the dark background of the microscope, in the illuminator of a microscope using a light source of the shape of a light emitting surface other than a circle with extremely irregular luminance and almost vertically irradiating the surface of a sample with the illuminating light from the light source from the object side of the microscope. CONSTITUTION:The illuminating light beam from the light emitting surface 4a of an LED 4 is diffused by a diffusing filter 5, converged by a condenser lens 3, reflected by a half mirror 2 and a sample surface 6 is vertically irradiated with the beam along the optical axis of an objective lens l. Since the illuminating beam is diffused by the diffusing filter 5, the shape of the light emitting surface having a hole is blurred as if it were illuminated by a point light source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for illuminating a sample to be observed with a microscope.

[0002]

2. Description of the Related Art In a conventional microscope having a built-in illuminating device for illuminating a sample surface, a halogen lamp, a tungsten lamp, a mercury lamp, a xenon lamp or the like has been used as a light source. Further, when the sample is opaque, the reflection type illumination method is required. FIG. 1 shows the basic configuration of the reflective Koehler illumination method. In FIG. 1, the light source surface 11
The light emitted from is collected by the collector lens 12, is guided to the field lens 15 through the aperture stop 13 and the field stop 14, is reflected by the half mirror 16, and is guided along the optical axis of the objective lens 17. An image is formed in the vicinity of the rear focal point of the objective lens 17, the parallel light flux is made by the objective lens 17, and the sample surface 18 is irradiated.

[0003]

In the above-described microscope illuminator, the lamp of the light source is generally large, and the lamp is provided with a cooling unit to generate heat, which is further increased. Therefore, in order to achieve miniaturization, an LED (light emitting diode) that is a light source that generates a small amount of heat and is easily miniaturized may be used.

In this case, however, when trying to see a minute bright spot-like sample with a dark background, it can be seen clearly in the focused state, but when the focused point is shifted or out of focus. Image does not become an original blurred image corresponding to the bright spot, and a square shape having a hole, that is, a non-light emitting portion (electrode portion), in the center of the light emitting surface of the LED, which is the light source, is directly seen as a blurred image. Sometimes. This is not only difficult to see, but also an obstacle to autofocusing by utilizing the image contrast and the like. That is, it becomes impossible to properly determine whether or not the focus for autofocus is in focus.

This phenomenon is caused by the fact that the minute bright spots of the sample function as an aperture having a small diameter, and in a state where the minute bright spots are out of focus, the illumination light reflected by the minute bright spots has a depth of a cross section having the shape of the light emitting surface of the light source. This is because it becomes a deep light flux.

Therefore, an object of the present invention is to use a light source having a light emitting surface other than a circular shape, such as the above-described LED, or a light source having a non-light emitting portion and having extremely uneven brightness, and illuminating light of a microscope. In a microscope illuminator that irradiates the sample from the objective lens side almost perpendicularly to the sample surface, when focusing on the microscope's focus when observing a minute bright spot sample with a dark background by eliminating the above drawbacks. Illumination is performed so that the blurred image of the minute bright spots of the sample does not become the blurred image of the shape of the light emitting surface of the light source in the state where the light sources do not match, and is the same as the original blurred image of the illumination light from the point light source. It is to provide a configuration that can.

[0007]

In order to solve the above problems, according to the present invention, the light emitting surface has a shape other than a circle.
Or, in a microscope illuminating device that uses a light source having an extremely uneven brightness on its light emitting surface and illuminates the illumination light from the light source from the objective lens side of the microscope almost perpendicularly to the sample surface, diffuses the illumination light from the light source. A structure provided with a diffusing means is adopted.

[0008]

According to such a structure, the illumination light is diffused so that the shape or brightness unevenness of the light source is blurred, and it is as if it were illuminated by a point light source. For this reason, when a sample with a small dark spot and a small bright spot is seen, it can be seen clearly when the subject is in focus. It becomes the same as the original blurred image in the case of light, and the image becomes rounded in proportion to the amount of focus shift.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a microscope illuminator 1 according to the present invention.
The structure of an Example is shown. With this configuration, the field of view of the microscope objective lens is epi-illuminated by the reflection type Koehler method, that is, an illumination light flux parallel to the optical axis of the microscope objective lens side is irradiated almost perpendicularly to the sample surface. is there.

In FIG. 2, reference numeral 1 denotes a microscope objective lens, and 2
Is a half mirror, 3 is an illumination system condenser lens (condensing lens), 4 is a light source LED (light emitting diode),
Reference numeral 5 is a diffusion filter, 6 is a sample surface on which a sample object is arranged, and 7 is an image forming surface of the objective lens 1 of the microscope. The diffusion filter 5 is a diffusion means that uniformly diffuses and scatters the illumination light emitted from the LED 4, and is made of frosted glass, paper, or a semitransparent plastic plate with one or both sides as the diffusion surface, and between the LED 4 and the condenser lens 3. At L
It is arranged near the ED4.

The illumination light emitted from the light emitting surface 4a of the LED 4 is diffused by the diffusion filter 5, condensed by the condenser lens 3, reflected by the half mirror 2 and bent along the path by 90 °, and the objective lens 1 is illuminated. Guided along the optical axis.

Here, in order to carry out epi-illumination of the visual field of the objective lens 1, the condenser lens 3 is arranged so that the image of the light emitting surface 4a of the LED 4 is formed in the vicinity of the rear focus position of the objective lens 1. As a result, the illumination light is made into a parallel light flux by the objective lens and is irradiated perpendicularly to the sample surface 6 along the optical axis of the objective lens 1.

By the way, the light emitting surface 4a of the LΦD4 is generally shaped as shown in FIG. That is, as shown by the hatched portion, it is a square having a circular hole 4b in the center, that is, a non-light emitting portion (electrode portion).

If there is no diffusion filter 5 in the configuration of FIG. 2, the light emitted from the light emitting surface 4a of the LED 4 having the hole 4b passes through the condenser lens 3 as it is,
It is bent by the half mirror 2, passes through the objective lens 1,
The sample surface 6 is irradiated almost perpendicularly, but as described above, when trying to see a minute bright spot-like sample with a dark background, it can be clearly seen in the focused state, but the focus is clear. In the image of the bright spots when the light is shifted or out of focus, the shape of the light emitting surface 4a having the holes 4b appears as a blurred image. This is not only difficult to see, but also an obstacle to autofocusing using contrast and the like.

On the other hand, as shown in FIG.
When the diffusion filter 5 is inserted in the vicinity of, the illumination light from the LED 4 is uniformly diffused, so that the shape of the light emitting surface 4a having the hole 4b is blurred and it is as if illuminated by a point light source.

Therefore, when a sample having a small bright spot with a dark background is seen, it is clearly visible when the subject is in focus, and a minute bright spot when the subject is out of focus or out of focus. The blurred image is similar to the original blurred image in the case of the illumination light from the point light source, and the image becomes rounded in proportion to the focus shift amount.

Therefore, it is easy for the observer to see,
When performing autofocus, it can be properly determined whether or not the focus is achieved, and the autofocus can be favorably performed.

By the way, the diffusion filter 5 may be arranged between the LED 4 and the condenser lens 3 in the vicinity of the LED 4 as shown in FIG. 2, but the diffusion filter 5 may be arranged between the condenser lens 3 and the half mirror 2. good. Further, instead of providing the diffusion filter 5, as a means for diffusing the illumination light of the LED 4, the surface of the condenser lens 3 on the LED 4 side or the half mirror 2 side or both surfaces is formed as a diffusion surface, or the light emitting surface of the LED 4 is formed. There is also a method of forming the surface of the lens portion 4c covering 4a as a diffusion surface.

The shape of the light emitting surface 4a of the LED 4 is shown in FIG.
It is needless to say that the shape is not limited to the shape shown in (1), and may be a surface shape having a hole (non-light emitting portion) other than a circular shape or a surface shape having unevenness. Further, the light source is not limited to the LED, and if the light emitting surface has a shape other than a circular shape, or if the light emitting surface has an extremely uneven brightness, the illumination light is similarly diffused to obtain the same effect.

[0021]

As is apparent from the above description, according to the present invention, a light source having a light emitting surface having a shape other than a circle, or having an extremely uneven brightness on the light emitting surface is used, and illumination light from the light source is used. In the illuminating device of the microscope, which irradiates the sample from the objective lens side of the microscope almost perpendicularly to the sample surface, since the structure is provided with the diffusing means for diffusing the illumination light from the light source, the background is dark in the microscope, When observing a sample in the form of a bright spot, if the image is out of focus, the blurred image of the minute bright spot does not become a blurred image of the shape of the light emitting surface of the light source, and the It is similar to a blurred image and is easy for the observer to see, and when performing autofocus, it is possible to properly determine whether or not focus is achieved, and it is possible to perform good autofocus. Cormorants excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a conventional illumination device for a microscope.

FIG. 2 is a configuration diagram showing a configuration of an embodiment of a microscope illumination device according to the present invention.

FIG. 3 is an explanatory diagram showing a shape of a light emitting surface of an LED of a light source of the device.

[Explanation of symbols]

 1 Objective Lens 2 Half Mirror 3 Condenser Lens 4 LED 5 Diffusion Filter 6 Sample Surface 7 Imaging Surface

Claims (6)

[Claims] 1. A light source whose light emitting surface has a shape other than a circular shape or whose light emitting surface has extremely uneven brightness is used, and the illumination light from the light source is irradiated from the objective lens side of the microscope substantially perpendicularly to the sample surface. The illuminating device for a microscope, wherein the illuminating device for a microscope is provided with a diffusing unit for diffusing the illumination light from the light source. 2. The illumination device for a microscope according to claim 1, wherein a diffusion filter is provided as the diffusion means near the light source. 3. A condensing lens that condenses the illumination light from the light source, and a half mirror that reflects the illumination light condensed by the condensing lens and guides it along the optical axis of the objective lens of the microscope. The illumination device for a microscope according to claim 1, wherein a diffusion filter as the diffusion means is arranged between the condenser lens and a half mirror. 4. The microscope according to claim 1, further comprising a condenser lens that condenses the illumination light from the light source, and a surface of the condenser lens is formed as a diffusion surface as the diffusion means. Lighting equipment. 5. The illumination device for a microscope according to claim 1, wherein a light emitting diode is used as the light source. 6. A light emitting diode is used as the light source,
The illumination device for a microscope according to claim 1, wherein a surface of a lens portion that covers a light emitting surface of the light emitting diode is formed as a diffusion surface as the diffusion means.