JP3560120B2 - Confocal microscope - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a confocal optical scanner device applied to a confocal microscope, and more particularly to a confocal optical scanner device using an optical fiber bundle.
[0002]
[Prior art]
Conventionally, a confocal optical scanner used for a confocal microscope is well known. For example, Japanese Patent Application Laid-Open No. 5-60980 filed by the present applicant discloses a confocal optical scanner as shown in FIG. A confocal optical scanner having a configuration is described.
[0003]
In the illustrated confocal optical scanner 1, a condensing disk 2 and a pinhole disk 3 are connected in parallel with a drum 4 interposed therebetween, and are formed so as to be rotated by a motor 5. Further, a beam splitter 6 is fixedly arranged between the two disks 2 and 3.
[0004]
A plurality of microlenses (for example, Fresnel lenses) are formed on the condensing disk 2, and a plurality of pinholes are formed on the pinhole disk 3 (for example, such a pinhole disk is a Nipkow disk type). The two disks are connected so that each pinhole is located at the focal position of each microlens.
[0005]
A large number of pinholes on a pinhole disk are spaced apart from each other by about 5 to 10 times the pinhole diameter in order to obtain a confocal effect. Do).
[0006]
The laser beam incident on the focusing disk 2 is focused by a microlens, passes through the beam splitter 6, and is focused on a pinhole. The light passing through the pinhole is condensed by the objective lens 7 and is irradiated on the sample 8. The return light from the sample 8 passes through the objective lens 7 and the pinhole disk 3 again, is reflected by the beam splitter 6, and enters the camera 10 via the condenser lens 9. An image of the sample 8 is formed on an image receiving surface (not shown) of the camera 10.
[0007]
In such a configuration, the surface image of the sample 8 can be observed by the camera 10 by rotating the condenser disk 2 and the pinhole disk 3 and optically scanning the surface of the sample 8 with a plurality of pinholes.
[0008]
[Problems to be solved by the invention]
By the way, in such a conventional confocal microscope, the positional relationship between the optical scanner and the sample 8 is always fixed, and a structure that can observe a sample at an arbitrary position such as an endoscope or a handy microscope is not provided. is not. It would be very convenient if a confocal microscope could observe a sample at any position.
[0009]
In view of the foregoing, an object of the present invention is to realize a confocal microscope capable of observing a sample at an arbitrary position using an optical fiber bundle.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, a confocal microscope in which a sample surface is scanned with a light beam using a confocal optical scanner so that an image of the sample surface can be observed. And a flexible optical fiber bundle that optically couples between the confocal optical scanner and an objective lens, wherein a core diameter of an optical fiber constituting the optical fiber bundle is determined by the confocal optical scanner. while more than half and less than twice the optical beam diameter emitted from the minute opening on the end face of the optical fiber bundle in the pitch between the cores of the optical fibers greater than the light beam diameter, and between the light beam Is made larger than the core diameter of the optical fiber .
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of a confocal microscope according to the present invention. In FIG. 1, the same parts as those in FIG. 11 are denoted by the same reference numerals, and the description thereof will be omitted.
[0012]
1 differs from the configuration in FIG. 11 in that the confocal optical scanner 1 and the objective lens 7 are optically coupled by optical means using an optical fiber bundle. That is, the relay lens 11 and the optical fiber bundle 12 are interposed between the pinhole disk 3 and the objective lens 7.
[0013]
The details are as follows. The optical fiber bundle 12 is a bundle of a plurality of optical fibers (each of these optical fibers is composed of a core and a clad surrounding the core). It is bundled to become. Further, this optical fiber is a so-called flexible fiber whose intermediate portion is deformable and can be flexed appropriately.
[0014]
This optical fiber 12 is fixedly arranged at a position where the end face thereof coincides with a surface (image forming surface) on which light emitted from the pinhole disk 3 forms an image by the relay lens 11.
Further, the lower end surface of the optical fiber 12 is also fixedly arranged so as to come to the focal position of the objective lens 7.
[0015]
When the pinhole disk 3 is rotated and the light beam is scanned, a light beam which is transmitted along the optical fiber bundle 12 and is similarly scanned is emitted from the lower end face. The emitted light beam passes through the objective lens 7 and scans the surface of the sample 8.
[0016]
It is necessary that the core diameter c of the optical fiber bundle is substantially equal to the beam diameter a of the light irradiated on the end face of the optical fiber bundle. The reason is described below.
[0017]
If a> c, a plurality of cores are simultaneously irradiated with light beams as shown in FIG. Considering that the end face of the optical fiber bundle always becomes divergent light as shown in FIG. 3, even when the sample 8 is in the focal plane as shown in FIG. However, since the confocal optical scanner has a confocal slicing effect only on the end surface α, an image can be obtained similarly. That is, a confocal slice image cannot be obtained for the sample 8.
[0018]
If the light beam diameter a is substantially equal to the core diameter c, as shown in FIG. 6, light is applied only to the core separated by the pitch P to the optical fiber, and does not return to the light receiving side. That is, the core of the optical fiber performs the same function as the pinhole.
If the core diameter c is much larger than the light beam diameter a, a plurality of light beams enter the same core as shown in FIG. 7, so that the confocal effect cannot be obtained.
After all, in order to obtain the confocal effect, the limit is about 0.5a ≦ c ≦ 2a. Further, in order to prevent the same core from being irradiated with a plurality of light beams and to prevent one beam from simultaneously irradiating a plurality of cores, the pitch between the cores is larger than the light beam diameter a. And the pitch between the light beams needs to be larger than the core diameter c.
[0019]
In such a configuration, the laser light incident on the light-collecting disk 2 is converged by a microlens and transmitted through the beam splitter 6 to be condensed on a pinhole as in the conventional case. Light emitted from the pinhole is focused on the end face of the optical fiber 12 via the relay lens 11. A light beam equivalent to that from the pinhole is emitted from the lower surface of the optical fiber 12 and enters the objective lens 7.
[0020]
The light beam passing through the objective lens 7 is focused on the surface of the sample 8. The return light from the surface of the sample 8 forms an image on the lower surface of the optical fiber 12 through the objective lens 7, and the image is transmitted to the upper end of the optical fiber 12. That is, the image of the sample 8 surface appears on the upper end surface of the optical fiber 12, and this image is formed on the pinhole surface via the relay lens 11.
[0021]
Thereafter, as before, the light is reflected by the beam splitter 6 and enters the camera 10 via the condenser lens 9.
According to such a configuration, since the optical fiber 12 can be freely deformed, the sample 8 can be observed with an arbitrary positional relationship with respect to the optical scanner.
[0022]
It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of explanation and illustration of the present invention. Therefore, the present invention is not limited to the above-described embodiment, but includes many more changes and modifications without departing from the spirit thereof.
[0023]
For example, the minute opening on the scanner side may be a slit instead of a pinhole. At this time, the limitation on the core diameter is the minimum dimension of the opening, which is a necessary condition for the slit width b at which the confocal effect occurs.
[0024]
In addition, for example, as shown in FIG. 8, for example, as shown in FIG. 8, a cylindrical holder 21 is attached to the lower end of the optical fiber bundle 12, and the objective lens 7 is placed in the holder 21. Means for moving in the optical axis direction, for example, providing an actuator 22 is useful. According to such a mechanism, a site where a slice image is obtained can be finely changed easily.
[0025]
The actuator may be a piezo element or an electromagnetic type, and it is preferable that the drive signal is supplied by an electric wire incorporated coaxially with the optical fiber.
When high-magnification observation is performed with a confocal point, a window 23 made of a material such as glass through which light can pass is provided at the tip of the holder 21 as shown in FIG. Stable measurement can be performed by performing optical scanning while touching.
[0026]
In addition, fluorescent reagents tend to concentrate on cancer and the like, and the affected part is burned with laser light. For this purpose, in addition to the observation laser light, a treatment laser light 24 as shown in FIG. 9 can be introduced coaxially with the optical fiber bundle. If both wavelengths are changed and the laser beam for treatment is cut by a filter on the observation side, observation can be performed while treatment is being performed.
Note that cancer cells may be inside the surface layer to several layers, and confocal slices are very effective.
[0027]
Further, the present invention is useful not only for endoscopes but also for portable microscopes. In addition, when the numerical aperture (NA) for illuminating the fiber is closer to the fiber NA, the irradiation efficiency and the emission efficiency are improved. Further, as shown in FIG. 10, the relay lens between the pinhole disk 3 and the optical fiber 12 is eliminated, and the optical fiber bundle is brought close to the pinhole. It is good also as a structure which makes it enter. There is an advantage that the cost is reduced because the relay lens is not required.
[0028]
It should be noted that the foregoing description has been directed to specific preferred embodiments for the purpose of explanation and illustration of the present invention. Therefore, the present invention is not limited to the above-described embodiment, but includes many more changes and modifications without departing from the spirit thereof.
[0029]
【The invention's effect】
(1) According to the first aspect of the present invention, first, the confocal optical scanner and the objective lens are optically coupled to each other with a flexible optical fiber bundle. The sample at the position can be easily observed. Further, the core diameter of the optical fibers constituting the optical fiber bundle is set to be not less than half and not more than twice the diameter of the light beam , and the pitch between the cores of the optical fibers is larger than the light beam diameter, and the pitch between the light beams is reduced. By making the diameter larger than the core diameter of the optical fiber, a confocal effect can be obtained, and a confocal slice image of the sample can be easily obtained .
[0030]
(2) According to the second aspect of the present invention, light beam scanning can be easily realized by rotating a disk having a large number of minute openings by a confocal optical scanner.
(3) According to the third aspect of the present invention, the minute opening according to the second aspect is limited to a pinhole or a slit, and the resolution of the image on the sample surface is increased.
[0031]
(4) According to the fourth aspect of the present invention, a microlens is disposed on the light-collecting disk to converge light incident on the minute opening, thereby improving light use efficiency.
(5) In the invention described in claim 5, the objective lens between the optical fiber bundle and the sample is formed so as to be movable in the optical axis direction, and the focal position in the optical axis direction is variable. As a result, the adjustment of the slice direction of the sample in the depth direction, which has been difficult by the position adjustment using the optical fiber bundle, is facilitated and can be finely adjusted.
[0032]
(6) In the invention according to claim 6, an optical window that can be in close contact with the sample is provided at the tip of the holder that holds the objective lens placed between the optical fiber bundle and the sample, thereby ensuring stable observation in close contact with the sample. are doing.
(7) In the invention according to claims 7 and 8, light other than for observation (for example, treatment laser light having a wavelength different from the observation light) is simultaneously incident on the optical fiber bundle, so that the treatment and Observation can be performed simultaneously.
[0033]
(8) According to the ninth aspect, a relay lens is provided between the confocal optical scanner and the optical fiber bundle, and the numerical aperture of the relay lens and the optical fiber are made substantially equal. Thereby, irradiation efficiency and emission efficiency are improved.
(9) In the invention according to claim 10, the end face of the optical fiber is disposed close to the minute opening of the confocal optical scanner, and the relay lens according to claim 1 is not required. A less expensive confocal microscope can be realized as compared with the first aspect.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing one embodiment of a confocal microscope according to the present invention.
FIG. 2 is a diagram for explaining a relationship between a core diameter and a light beam diameter.
FIG. 3 is an exemplary illustration of divergent light at the end face of the optical fiber bundle.
FIG. 4 is an explanatory diagram when a sample is on a focal plane.
FIG. 5 is an explanatory diagram when a sample is out of a focal plane.
FIG. 6 is another explanatory diagram for explaining a relationship between a light beam diameter and a core diameter.
FIG. 7 is still another explanatory diagram for explaining a relationship between a light beam diameter and a core diameter.
FIG. 8 is a configuration diagram illustrating an example of a lower end portion of the optical fiber bundle.
FIG. 9 is an explanatory diagram when two lights are coaxially introduced into an optical fiber bundle.
FIG. 10 is a configuration diagram showing one embodiment when an optical fiber bundle is brought close to a pinhole.
FIG. 11 is a configuration diagram illustrating an example of a conventional confocal optical scanner.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 confocal optical scanner 2 focusing disk 3 pinhole disk 4 drum 6 beam splitter 7 objective lens 8 sample 9 focusing lens 10 camera 11 relay lens 12 optical fiber bundle 21 holder 22 actuator 23 window

Claims (10)

In a confocal microscope that was able to scan the sample surface with a light beam using a confocal optical scanner and observe the image of the sample surface,
A flexible optical fiber bundle that optically couples between the confocal optical scanner and the objective lens,
The core diameter of the optical fiber constituting the optical fiber bundle is set to be not less than half and not more than twice the diameter of the light beam irradiated on the end face of the optical fiber bundle from the minute opening in the confocal optical scanner , and A confocal microscope wherein a pitch between optical fiber cores is larger than the light beam diameter and a pitch between the light beams is larger than the core diameter of the optical fiber . 2. The confocal microscope according to claim 1, wherein the confocal optical scanner is configured to scan a light beam by rotating a disk having a large number of minute openings. 3. The confocal microscope according to claim 1, wherein the minute opening is a pinhole or a slit. 3. The confocal microscope according to claim 2, wherein the confocal optical scanner includes a light-collecting disk provided with a microlens for focusing light incident on a minute opening of the disk. 2. The confocal microscope according to claim 1, further comprising an objective lens accommodated in a holder and movable in an optical axis direction, between the optical fiber bundle and the sample. 2. The confocal microscope according to claim 1, wherein the holder has an optical window between the sample and the objective lens, the optical window being capable of being in close contact with the sample. 2. The confocal microscope according to claim 1, wherein light other than for observation is also incident on the optical fiber bundle. The confocal microscope according to claim 7, wherein the light other than the light for observation is light having a different wavelength from the light for observation. 2. A confocal microscope according to claim 1, wherein a relay lens is provided between the confocal optical scanner and the optical fiber bundle, and the numerical apertures of the relay lens and the optical fibers constituting the optical fiber bundle are made substantially equal. . 2. The confocal microscope according to claim 1, wherein an end face of the optical fiber is arranged close to a minute opening of the confocal optical scanner.

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