JPH0933819A - Optical unit and vertically downward illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable adaption to light having a wide wavelength range, to maintain an accurate image position, and to make an optical system compact by composing the optical unit and a vertically downward illuminator of a specific mirror element and a specific image forming lens. SOLUTION: When the projection light from an illumination light source 5 is made incident from one opening of the through hole 1b of a unit main body 1, light of, for example, >=400nm in wavelength is reflected by the surface of the mirror element 2 and projected from the other opening of the through hole of the main body 1 to irradiate a dyed sample 7 through an objective 6. Fluorescent light in the visible wavelength range which is excited on the sample 7 travels through a reverse optical path to enter the other opening of the through hole of the main body 1, and is transmitted through the element 2 and made incident on the image forming lens 3 incorporated in one opening part of the through hole to form an image of the sample 7 at an image formation position. In this case, the maximum remaining chromatic aberration of visible light wavelength that the lens 3 corresponding to the light in the visible wavelength range is about 0.13mm and becomes small as compared with the focal length of the lens 3, so that the image which is in focus can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical unit and an epi-illumination device used in an epi-illumination microscope.

[0002]

2. Description of the Related Art Conventionally, an epi-illumination microscope reflects light of a desired wavelength contained in illumination light and irradiates a sample through an objective lens to collect fluorescence or reflected light excited by the sample. An optical unit is used to create an image of the specimen.

FIGS. 10 (a) and 10 (b) show an example of such an optical unit, and show a schematic structure of a dichroic mirror device disclosed in Japanese Utility Model Laid-Open No. 63-70502.

Such a dichroic mirror device reflects light in a specific wavelength range included in illumination light, and
A plurality of mirror elements 14 to 17 that transmit light in the remaining wavelength range are attached to a rotatable support 18, and the plurality of mirror elements 14 to 17 respectively separate light in a specific wavelength range. By doing so, the support 18 is rotated so that light in a wide wavelength range can be dispersed.

FIG. 11 shows a Japanese Patent Publication Sho 56-19605.
An example of an epi-fluorescent illumination device using the above optical unit disclosed in Japanese Patent Publication No.
And a dichroic separation mirror 20 and a suppression filter 21 having the same structure but different physical characteristics 22
There is a structure in which two or more of them are prepared and these structure single bodies 22 are replaceably incorporated into a support body 24 rotatably supported with respect to the optical axis 23. According to such an epi-illumination device, if the structural unit 22 optimal for fluorescence in each wavelength range is prepared and appropriately attached to the support 24, the illumination device can handle fluorescence in a wide wavelength range. It becomes possible to expand the use range of the fluorescence microscope.

[0006]

However, when these conventional techniques are actually applied to the epi-illumination microscope, the light emitted from these devices is guided to the optical system for forming the image of the specimen. However, the following drawbacks occur.

(1) Generally, the optical system of an epi-illumination microscope includes an imaging lens for forming an image of a sample,
Fluorescence or reflected light from the sample is transmitted by this imaging lens to form an image of the sample, but the wavelength range of the light transmitted through the imaging lens is wide due to the difference in the refractive index depending on the wavelength. In this case, chromatic aberration occurs in which the positions of the images are separated for each wavelength.

The chromatic aberration of such an imaging lens can be corrected for light of a certain wavelength range, but light of a wide wavelength range,
For example, in the case of light including a wavelength range from ultraviolet to infrared, residual chromatic aberration (± m) for each wavelength at each position in the lens radial direction of the imaging lens 3 targeted for these lights.
The vertical spherical surface and chromatic aberration curve diagram showing m) are given as shown in FIG. 12, and as is clear from the figure, the residual chromatic aberration is as large as 4 mm, so that the imaging lens produces a blurred image. Will end up.

The vertical axis shown in FIG. 12 represents the incident position of light on the lens, where the lens center is 0 and the outermost circumference is 1.
The horizontal axis represents the amount of deviation of the actual imaging position from the focus position. Further, the lens having such a chromatic aberration curve is configured as shown in FIG. 8, and the data shown in FIG. 9 (d) is given.

Therefore, if the above-mentioned two conventional techniques are directly applied to the epi-illumination microscope, it is possible to deal with light having a wide wavelength range, but the light of each wavelength range enters the optical system for image formation. After that, since light passes through the same imaging lens, chromatic aberration appears due to light in the uncorrected wavelength range, and a blurred image is formed.

(2) In the above-mentioned two conventional techniques, the surface precision of each of the mirror elements 14 to 17 or the dichroic separation mirror 20 and the variation in the angle after incorporating each mirror are taken into consideration. When replacing the
As shown in FIG. 3, centering adjustment for aligning the imaging lens 25 with the optical axis is required, and unless the centering adjustment is performed, the image position changes. However, since the above-mentioned two conventional techniques do not have such a centering adjustment mechanism, these centering adjustments cannot be performed. For this reason, it is necessary to install the mirrors so that the image position does not shift. However, it is extremely difficult and costly to reduce the surface accuracy of these mirrors and the variation in the angle after the mirrors are mounted.

(3) When applying the above-mentioned two prior arts, as shown in FIG. 13, an imaging lens 25 and a mirror 14 are provided.
Since the image position becomes distant by a distance of ˜17 (20), the optical system of the microscope lacks compactness.

The present invention has been made in view of the above circumstances, and can deal with light having a wide wavelength range, can maintain an accurate image position, and can make the optical system compact and epi-illumination. The purpose is to provide a device.

[0014]

According to the first aspect of the present invention,
A unit main body, a mirror element provided in the unit main body for reflecting light irradiating a sample and transmitting fluorescence or reflected light from the sample, and the unit main body provided corresponding to the mirror element, and the mirror It is composed of an imaging lens in which aberration is corrected in a target wavelength range with respect to light transmitted through the element.

According to a second aspect of the invention, there is provided a unit main body,
A mirror element that is provided in the unit main body and that reflects light that illuminates the sample and transmits fluorescence or reflected light from the sample; and a mirror element that is provided in the unit main body in correspondence with the mirror element and that transmits the mirror element An imaging lens in which aberration is corrected in a target wavelength range for light, and at least two optical units having different characteristics of the mirror element and the imaging lens are provided on an optical path corresponding to an illumination light source. I try to position it selectively.

According to a third aspect of the present invention, in the second aspect, the at least two optical units are mounted on a support base that is movable in a linear direction, and the movement of the support base is operated by operating means. I am trying to do it.

As a result, according to the first aspect of the present invention,
Along with the mirror element in the same optical unit, since the imaging lens that has been chromatic aberration corrected for the target wavelength range for the light transmitted through the mirror element is integrally incorporated, the optical system can be made compact, and Even if the units are switched or replaced, the image forming position does not change, and a blur-free image can always be formed.

According to the second or third aspect of the present invention, further, two or more optical units having the same configuration but different mirror element and imaging lens characteristics are selectively provided on the optical path corresponding to the illumination light source. Since it is possible to position the image, the image-forming position does not change even when the wavelength range of light is wide, and an image without blur can be always formed.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a schematic structure of an optical unit to which the present invention is applied and which corresponds to visible light. In the figure, 1 is a unit main body, and this unit main body 1 has a through hole 1a along a central portion in a longitudinal direction and a through hole 1b orthogonal to the through hole 1a in a central portion in a width direction, The mirror element 2 is provided so as to be inclined at a portion orthogonal to the through holes 1a and 1b. This mirror element 2 has a wavelength of 400
It transmits light having a wavelength of not less than nm and reflects light having a wavelength of less than that.

Further, an imaging lens 3 is provided corresponding to the mirror element 2 in one opening of the through hole 1a of the unit main body 1. The imaging lens 3 in this case has a focal length of 200 m.
m. Also, this imaging lens 3
With the screw 4, the centering of the mirror element 2 on the optical path can be adjusted.

In this case, as the image forming lens 3, an aberration-corrected one for the light in the visible wavelength range is used, and each position in the lens radial direction in the image forming lens 3 for the light in the visible wavelength range is used. Chromatic aberration for each wavelength at ± (mm)
A vertical spherical surface and chromatic aberration curve diagram representing is given as shown in FIG. 2, and as is clear from the figure, the maximum residual chromatic aberration of light of the visible light wavelength is about 0.3 mm.

The vertical axis shown in FIG. 2 represents the incident position of light on the lens, where the center of the lens is 0 and the outermost circumference is 1.
The horizontal axis represents the amount of deviation of the actual imaging position from the focus position. A lens having such a chromatic aberration curve is configured as shown in FIG. 8 and is given the data shown in FIG. 9 (a).

In the optical unit thus constructed, the light emitted from the illumination light source 5 is transmitted through the through hole 1 of the unit body 1.
When incident from one opening of b, wavelength of 400n
Light of m or more is reflected by the surface of the mirror element 2, emitted from the other opening of the through hole 1a of the unit main body 1, and irradiated on the stained specimen 7 through the objective lens 6.

Then, the fluorescence in the visible wavelength range excited on the sample 7 enters the other opening of the through hole 1a of the unit main body 1 through the optical path opposite to the above, passes through the mirror element 2, and is transmitted. Imaging lens 3 incorporated in one opening of hole 1a
The image of the sample 7 is formed at the image forming position 8 of the image forming lens 3.

In this case, the image forming lens 3 for the light in the visible wavelength range is provided as shown in FIG. 2, and as is clear from the figure, the maximum residual chromatic aberration of the light in the visible wavelength is , About 0.3 mm, the focal length of the imaging lens 3 (2
Since the value is significantly smaller than that of (00 mm), the optical unit having such a configuration can form a blur-free image by using visible light as a target.

Further, such an image forming lens 3 can be adjusted with a screw 4 with respect to the mirror element 2.
Moreover, since it is incorporated in the same unit body 1 as the mirror element 2, the distance between the image forming position 8 of the sample 7 and the optical unit can be shortened, and the optical system can be made compact and
Even if the optical unit is replaced with another one, the image forming position 8 does not change, and from this point as well, a blur-free image can be formed.

The optical unit according to this embodiment may use reflected light of the sample as a target in addition to the fluorescence of the sample. Therefore, according to the first embodiment as described above, the mirror element 2 is provided in the same optical unit 1.
In addition, since the imaging lens 3 in which aberration is corrected in the target visible wavelength range is integrally incorporated into the light transmitted through the mirror element 2, the optical system can be made compact. Even if the units are switched or replaced, the image-forming position does not change, and a blur-free image can always be formed. (Second Embodiment) The second embodiment shows an example of an optical unit corresponding to infrared rays as the optical unit having the same configuration as that of the first embodiment described with reference to FIG.

In this case, in FIG. 1, the mirror element 2
Is to transmit light having a wavelength of 780 nm or more and reflect light having a wavelength of less than 780 nm. Further, as the imaging lens 3, the one whose aberration is corrected for the light in the infrared wavelength range is used, and the imaging lens 3 for the light in the infrared wavelength range is used at each position in the lens radial direction. A vertical spherical surface and chromatic aberration curve diagram showing residual chromatic aberration (± mm) with respect to wavelength are shown in FIG.
And the maximum residual chromatic aberration of visible light wavelength is about 0.4 mm as shown in FIG.

The vertical axis shown in FIG. 3 represents the incident position of light on the lens, where the center of the lens is 0 and the outermost circumference is 1.
The horizontal axis represents the amount of deviation of the actual imaging position from the focus position. Further, the lens having such a chromatic aberration curve is configured as shown in FIG. 8, and the data shown in FIG. 9B is given.

Even with the optical unit thus constructed, however, the fluorescence in the visible wavelength range excited on the sample 7 passes through the optical path opposite to that described above and passes through the through hole 1 of the unit body 1.
The image of the sample 7 is incident on the image-forming position 8 of the image-forming lens 3 by being incident on the image-forming lens 3 which is incorporated in the one opening of the through hole 1a after passing through the other opening of the a. An image is formed, but in this case, the image forming lens 3 for the light in the infrared wavelength region is provided as shown in FIG. Has a residual chromatic aberration of about 0.4 mm, and the focal length (2
00 mm), the optical unit having such a configuration can form a blur-free image by using visible light as a target. Further, the optical unit of the first embodiment Similarly, the optical system can be made compact.

The optical unit according to the present embodiment may also use the reflected light of the sample as a target in addition to the fluorescence of the sample. Therefore, according to the second embodiment as described above, the same effect as that of the above-described first embodiment can be expected. (Third Embodiment) The third embodiment shows an example of an optical unit corresponding to ultraviolet rays as the optical unit having the same configuration as that of the first embodiment described with reference to FIG. .

In this case, in FIG. 1, the mirror element 2
Is used that transmits light having a wavelength of 351 nm or more and reflects light having a wavelength of 351 nm or less. Also, the imaging lens 3
Is the one in which aberration is corrected for light in the ultraviolet wavelength range, and residual chromatic aberration (± mm) for each wavelength at each position in the lens radial direction of the imaging lens 3 for light in the ultraviolet wavelength range is used. A vertical spherical and chromatic aberration curve diagram representing is given as shown in FIG. 4, and as is clear from the figure, the maximum residual chromatic aberration of visible light wavelength is about 0.02 m.
m.

The vertical axis shown in FIG. 4 represents the incident position of light on the lens, where the lens center is 0 and the outermost circumference is 1.
The horizontal axis represents the amount of deviation of the actual imaging position from the focus position. Further, the lens having such a chromatic aberration curve is configured as shown in FIG. 8 and the data shown in FIG. 9C is given.

Even with the optical unit thus constructed, however, the fluorescence in the visible wavelength range excited on the sample 7 passes through the optical path opposite to that described above and passes through the through hole 1 of the unit body 1.
The image of the sample 7 is incident on the image-forming position 8 of the image-forming lens 3 by being incident on the image-forming lens 3 which is incorporated in the one opening of the through hole 1a after passing through the other opening of the a. An image is formed, but in this case, the image forming lens 3 for the light in the ultraviolet wavelength range is provided as shown in FIG. 4, and as is clear from the figure, the maximum remaining of the light of the ultraviolet wavelength remains. The chromatic aberration is about 0.02 mm, which is significantly smaller than the focal length (200 mm) of the imaging lens 3,
If the optical unit having such a configuration is used for visible light as an object, it becomes possible to form a blur-free image, and further, the optical system can be made compact as in the first embodiment.

The optical unit according to the present embodiment may also use the reflected light of the sample as a target in addition to the fluorescence of the sample. Therefore, according to the third embodiment as described above, the same effect as that of the above-described first embodiment can be expected. (Fourth Embodiment) The fourth embodiment shows a case where the optical unit having the configuration described in FIG. 1 is applied to an epi-illumination device, and FIG. 5 and FIG. In FIG. 6, the same parts as those in FIG. 1 are designated by the same reference numerals.

In this case, the epi-illumination device has, for example, a wavelength of 4
It is used for a scanning laser microscope for observing a double-stained sample of 56 nm DAPI and 520 nm wavelength FITC. In FIGS. 5 and 6, 11 is a box-shaped device body, and inside this device body 11 A support base 12 is provided.

The support base 12 penetrates the apparatus main body 11 and connects the operation knob 13, and the operation knob 13 can be operated to reciprocate in the linear direction inside the apparatus main body 11.

Then, the optical units 10, 10 'having the same structure as those described in the first embodiment, which can cope with lights of different wavelength regions, are placed on the support 12 and the support 1
By locating the desired optical unit 10 or 10 ′ in the optical path corresponding to the illumination light source 5 by moving in the linear direction of 2, the sample observation corresponding to DAPI of wavelength 456 nm or FITC of wavelength 520 nm can be executed.

Reference numerals 2'and 6'in the drawing denote a mirror element and an imaging lens having different characteristics from the mirror element 2 and the imaging lens 6 in the optical unit 10 ', respectively. Therefore, the optical unit 10 capable of handling light of different wavelength ranges,
If the support base 12 on which the 10 'is mounted is linearly moved by the operation of the operation knob 13 and the optical unit 10 or 10' is selectively positioned in the optical path corresponding to the illumination light source 5 according to the wavelength, these The image forming lenses 6 and 6 ′ of the optical unit 10 or 10 ′ are centered on the mirrors 2 and 2 ′, respectively, and correct the chromatic aberration for the target wavelength. Alternatively, by 10 ', the fluorescent image of each wavelength from the sample 7 can be imaged without blurring at the image forming position 8 without changing the image forming position.

It should be noted that the support base 12 is not limited to a slidable one, but may be rotatable as shown in FIG. In this case, the support base 12 is the turret 14
It is rotatably provided, and by rotating the turret 14, the desired optical unit 10 or 10 ′ can be positioned in the optical path corresponding to the illumination light source 5.

Although the above-described examples shown in FIGS. 5, 6 and 7 show the case where two optical units are used, the number of optical units and the wavelength range of fluorescence are not limited, and In addition to fluorescence, the specimen can be used with the reflected light of the specimen as a target.

Therefore, according to the fourth embodiment as described above, the optical units 10, 10 'having the same configuration of two or more but different characteristics of the mirror element 2 and the imaging lens 3 correspond to the illumination light source 5. Since it can be selectively positioned on the optical path by moving the support base 11, even if the wavelength range of light is wide, the image-forming position does not change and a blur-free image can always be formed.

Although the above description has been given based on the embodiments, the present invention includes the following inventions. (1) a unit main body, a mirror element that is provided in the unit main body and that reflects light that illuminates a sample and that transmits fluorescence or reflected light from the sample; and the unit main body that is provided corresponding to the mirror element, An optical unit comprising: an image forming lens in which aberration of light transmitted through the mirror element is corrected in a target wavelength range.

With this arrangement, the mirror element is incorporated in the same optical unit, and the imaging lens, in which the aberration transmitted through the mirror element is corrected in the target wavelength range, is integrally incorporated. In addition, the optical system can be made compact, and even if the unit is switched or replaced, the image forming position does not change, and an image without blur can always be formed.

(2) A unit main body, a mirror element provided in the unit main body for reflecting light irradiating a sample and transmitting fluorescence or reflected light from the sample, and the unit main body corresponding to the mirror element. At least two optics, each of which is provided with an imaging lens in which aberration is corrected in a target wavelength range for light transmitted through the mirror element, and the characteristics of the mirror element and the imaging lens are different from each other. An epi-illumination device, wherein the unit is selectively positioned on an optical path corresponding to an illumination light source.

With this arrangement, two or more optical units having the same structure but different mirror element and imaging lens characteristics can be selectively positioned on the optical path corresponding to the illumination light source. Even if the wavelength range of is wide, the image-forming position does not change and an image without blur can be always formed.

(3) In the epi-illumination device described in (2), the at least two optical units are mounted on a support base that is movable in a linear direction, and the movement of the support base is operated by an operating means. I am trying. With this configuration, the operation of moving the optical unit can be realized with a simple configuration.

[0048]

As described above, according to the present invention, the optical system can be made compact, and the image position does not change even if the optical unit is switched or replaced, and an image without blurring is always formed. Can be made.

Further, since the optical units having different characteristics can be selectively positioned on the optical path corresponding to the illumination light source, even if the wavelength range of light is wide, the image forming position does not change and a blur-free image is formed. You can

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention.

FIG. 2 is a vertical spherical surface and chromatic aberration curve diagram of the imaging lens used in the first embodiment.

FIG. 3 is a vertical spherical surface and chromatic aberration curve diagram of the imaging lens used in the second embodiment of the present invention.

FIG. 4 is a vertical spherical surface and chromatic aberration curve diagram of the imaging lens used in the third embodiment of the invention.

FIG. 5 is a front view showing a schematic configuration of a fourth embodiment of the present invention.

FIG. 6 is a sectional view showing a schematic configuration of a fourth embodiment.

FIG. 7 is a diagram showing a schematic configuration of a modified example of the fourth embodiment.

FIG. 8 is a schematic configuration diagram of a lens having a chromatic aberration curve used in the present invention.

9 is a diagram showing an example of data of the lens in FIG.

FIG. 10 is a diagram showing a schematic configuration of an example of a conventional optical unit.

FIG. 11 is a diagram showing a schematic configuration of an example of a conventional epi-illumination fluorescent lighting device.

FIG. 12 is a vertical spherical surface and chromatic aberration curve diagram of a conventional imaging lens.

FIG. 13 is a diagram for explaining a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Unit main body, 1a, 1b ... Through hole, 2 ... Mirror element, 3 ... Imaging lens, 4 ... Screw, 5 ... Illumination light source, 6 ... Objective lens, 7 ... Specimen, 8 ... Imaging position, 10 and 10 ′ ... Optical unit, 11 ... Device body, 12 ... Support base, 13 ... Operation knob, 14 ... Turret.

Claims (3)

[Claims] 1. A unit main body, a mirror element provided in the unit main body for reflecting light illuminating a sample and transmitting fluorescent light or reflected light from the sample, and the unit main body provided corresponding to the mirror element. And an imaging lens in which aberration is corrected in a target wavelength range for the light transmitted through the mirror element. 2. A unit main body, a mirror element provided in the unit main body for reflecting light irradiating a sample and transmitting fluorescence or reflected light from the sample, and the unit main body provided corresponding to the mirror element. And an imaging lens in which aberration is corrected in a target wavelength range for the light transmitted through the mirror element, and the characteristics of the mirror element and the imaging lens are different from each other. An epi-illumination device, characterized in that it is selectively positioned on the optical path corresponding to the illumination light source. 3. The at least two optical units are:
The epi-illumination device according to claim 2, wherein the epi-illumination device is mounted on a support base that is movable in a linear direction, and the movement of the support base is operated by an operating unit.