JP2001091842A - Confocal microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of the constitution of a complicated optical system and post processing, to easily switch the obtaining of an image including at least a confocal image and the obtaining of a non-confocal image and to make the structure compact. SOLUTION: This confocal microscope is provided with a light source 1 emitting light, a polarized light set part 20 which can switch the polarizing direction of the light from the light source 1 by 90 deg., a PBS 6 branching the light to a 1st optical path A for obtaining the non-confocal image and a 2nd optical path B interposing a member for obtaining the image including at least the confocal image, a 1st and a 2nd optical system members 21 and 22 respectively arranged at the 1st and the 2nd optical paths A and B so as to polarize the light in the optical paths, a PBS 8 branching light from a sample 10 to either of the optical path A or the optical path B, a measurement lens for obtaining image information from the optical paths A and B, and a CCD 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a confocal microscope for obtaining a confocal image using light transmitted through, for example, a pinhole formed on a rotating disk.

[0002]

2. Description of the Related Art Recently, a disk-rotating confocal microscope capable of obtaining a high-resolution observation image in real time has been commercialized.

[0003] This is to insert and rotate a disk provided with a light-passing portion such as a pinhole into a normal microscope optical path, remove the image on the out-of-focus surface, and remove the image on the in-focus surface. Only images can be extracted. Thereby, a confocal image having a very high contrast can be obtained.

Due to the nature of such a confocal microscope, it is usually used for the purpose of obtaining a further emphasized image at the time of high-magnification observation. In general, it is necessary to perform sample positioning and focusing before image observation.However, since confocal images can be obtained only from the image of the focused surface as described above, positioning and focusing are required. It is very difficult to use in matching work.

[0005] Therefore, in general, in a confocal microscope, the above-mentioned disc is retracted from the optical path so as to obtain a non-confocal image which does not pass through the disc, especially for performing positioning and focusing.

In Japanese Utility Model Laid-Open No. 5-96816 and Japanese Patent Application Laid-Open No. 9-325279, an optical member for branching using a mirror or a beam splitter is used instead of retracting a disk from the optical path as described above. Is inserted into and removed from the optical path to switch between a confocal image and a non-confocal image.

Further, Japanese Patent Application Laid-Open No. 11-40629 discloses that an optical system member for synthesizing two images is added so that an image obtained by dividing a confocal image and a non-confocal image into two images can be obtained on a monitor. .

[0008]

However, in the above-mentioned conventional method, it is necessary to provide extra space for an optical system member to be inserted and removed from the optical path, and a high magnification is required by inserting and removing the optical system member. The required tolerance of the structure of the movable part is strict, so that the image focus position and lateral displacement do not occur,
In addition, it is necessary to accurately adjust the branch optical system member.

In addition, in Japanese Patent Application Laid-Open No. H11-40629, in particular, a complicated optical system and image processing in a subsequent stage are required for synthesizing the image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to eliminate the need for complicated optical system configuration and post-processing, and at least to obtain an image including a confocal image. It is possible to easily switch between acquisition of a confocal image and
Another object of the present invention is to provide a confocal microscope that can have a compact structure.

[0011]

According to the first aspect of the present invention,
A light source for emitting light, and a polarization direction of light from the light source of 9
A polarization setting unit capable of switching by 0 °, and a first polarization setting unit for obtaining a non-confocal image according to the polarization direction of the light switched by the polarization setting unit.
A first branching optical element for branching light into an optical path and a second optical path interposed with a member for obtaining an image including at least a confocal image, and arranged on the first and second optical paths, respectively; First and second optical system members for polarizing light in the optical path, a second optical branching element for branching light from the sample into one of the first and second optical paths, And an image pickup unit for obtaining image information from the second optical path.

With such a configuration, a complicated optical system is not required, and an optical path for easily obtaining a non-confocal image and an optical path for interposing a member for obtaining an image including at least a confocal image. Can be switched, and the entire microscope can have a compact structure.

According to a second aspect of the present invention, in the first aspect of the invention, at least one of the first and second optical members is constituted by a Faraday element and a half-wave plate. It is characterized by.

With this configuration, in addition to the operation of the first aspect of the present invention, the first and second optical system members can provide a brighter image without losing the amount of light. Obtainable.

According to a third aspect of the present invention, in the first aspect of the present invention, at least one of the first and second optical system members is constituted by a quarter-wave plate. .

With this configuration, in addition to the operation of the first aspect of the present invention, the overall configuration of the microscope can be made more compact.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A confocal microscope according to a first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure. Light emitted from a light source 1 is converted into parallel light by a collimating lens 2, passes through a stop 3, and then forms a polarizing plate 4 constituting a polarization setting unit 20.
Is transmitted, the light becomes a light having a uniform polarization direction.

Here, the polarizing plate 4 can change the polarization direction of the outgoing light by 90 ° by the motor 5 which constitutes the polarization setting section 20, and the P plate disposed on the downstream side of the optical path.
The ratio between the amount of light transmitted through the BS (polarizing beam splitter) 6 and the amount of light reflected therefrom can be changed from almost 100% to 0%.

When almost 100% of the light is transmitted through the PBS 6, the emitted light is transmitted to the first optical system member 2 disposed at the subsequent stage.
The polarization direction of the Faraday element 100 constituting 45 is 45 °.
The light is rotated, and the polarization direction is reversed by a half-wave plate (λ / 2 plate) 101 which also forms the first optical system member 21.
After being rotated by 5 ° and returned to the original polarization direction, it is totally reflected by the mirror 7, subsequently passes through the PBS 8, and irradiates the sample 10 through the objective lens 9.

The reflected light from the sample 10 passes through the PBS 8 again through the objective lens 9 and is totally reflected by the mirror 7. After being rotated by 45% in the polarization direction by the half-wave plate 101, the Faraday element 100 and the polarization direction is 45 °
Since the light is rotated, it is reflected without being transmitted at the next PBS 6. The light reflected by the PBS 6 forms a non-confocal image by the imaging lens 14 and is projected on the CCD 15. The above optical path is an optical path (non-confocal optical path) A for acquiring a non-confocal image.

On the other hand, the light after passing through the polarizing plate 4 is
When the light is reflected by the PBS 6 and transmitted by the PBS 6, the light reflected by the PBS 6 irradiates the disk 11 provided with a plurality of light passing portions such as pinholes which are constantly rotating by driving the motor 12.

The light that has passed through the disk 11 is reflected by a mirror 13
The light enters the Faraday element 102 constituting the second optical member 22 and is rotated by 45 ° in the polarization direction. Then, the half-wave plate (λ) also forms the second optical member 22. / 2 plate) 103, the light is again rotated in the original polarization direction, then reflected by the PBS 8 and passed through the objective lens 9 to the sample 1.
It is irradiated to 0.

Then, the reflected light from the sample 10 is reflected by the PBS 8 via the objective lens 9, then the polarization direction is again rotated by 45 ° by the half-wave plate 103, and further 45 ° by the Faraday element 102. Rotated. Then, sample 1
The reflected light from 0 is totally reflected by the mirror 13 and
A confocal image formed by passing through the disk 11 through the imaging lens 14 is formed on the CCD 15 by the imaging lens 14.
The above optical path is an optical path (confocal optical path) B for acquiring a confocal image.

Next, the operation of the microscope as described above includes the case where the light from the light source 1 is irradiated on the sample 10 in each of the non-confocal optical path A and the confocal optical path B, and
With reference to FIG. 2, a description will be given of the state of the polarized light when the reflected light from the CCD is focused on the CCD 15. FIG.

Here, the Faraday element 10
Reference numerals 0 and 102 rotate the polarization direction by 45 ° to the left in the direction on the paper when incident from the light source 1, and conversely, rotate by 45 ° to the right in the direction on the paper when reflected from the sample 10. Shall be.

FIG. 2A shows the polarization when the sample 10 is irradiated with light from the light source 1 with the non-confocal optical path A selected. The light transmitted through the PBS 6 is polarized by the Faraday element 100. The direction is rotated to the left.

Since the crystal axis of the half-wave plate 101 is set to have an inclination of 22.5 ° with respect to the polarization direction of the incident light as shown in FIG.
Will change the polarization direction by (2 × 22.5 ° =) 45 °. Here, the inclination of the crystal axis of the half-wave plate 101 is set so as to return the amount of light that has been rotated by the Faraday element 100.

FIG. 2B shows the polarized light when the reflected light from the sample 10 is imaged on the CCD 15 with the non-confocal optical path A selected, and the reflected light from the sample 10 is the same as that shown in FIG. One half of the polarization direction shown in (a)
The wave enters the wave plate 101 and is similarly rotated to the left by 45 °. In the Faraday element 100, the light is rotated leftward in the opposite direction to the case of FIG.
90 ° with respect to the polarization direction of the incident light from the light source 1
The light is rotated and enters the PBS 6.

As described above, the Faraday element 100 and the half-wave plate 101 maintain the polarization state at the time of incidence from the light source 1, and rotate by 90 ° when reflecting from the sample 10. , An optical path to the imaging system composed of the CCD 15 is formed.

On the other hand, FIG. 2C shows the polarization when the sample 10 is irradiated with the light from the light source 1 via the disk 11 with the confocal optical path B selected.
The light reflected in S6 is rotated left by the Faraday element 102 in the polarization direction.

Since the crystal axis of the half-wave plate 103 is also set to have an inclination of 22.5 ° with respect to the polarization direction of the incident light as shown in the figure, the half-wave plate 103 1
The light transmitted through 03 changes the polarization direction by (2 × 22.5 ° =) 45 °. Here, the half-wave plate 103
The inclination of the crystal axis is set so as to return the amount of light that has been rotated by the Faraday element 102.

FIG. 2D shows a sample 1 on the confocal optical path B.
FIG. 2 shows the polarization when the reflected light from 0 is imaged on the CCD 15.
The light enters the half-wave plate 103 with the polarization direction shown in (c), and is similarly rotated to the left by 45 °. Faraday element 10
In FIG. 2, light is rotated leftward in the opposite direction to the case of FIG. 2C, and after all, the light source 1 shown in FIG.
The light enters the PBS 6 as light that is rotated by 90 degrees with respect to the polarization direction of the incident light from the.

As described above, the crystal axis directions of the half-wave plate 101 and the half-wave plate 103 differ depending on whether the light transmitted through the PBS 6 or the light reflected by the PBS 6 is used. In the optical path B, basically, as shown in FIG.
As in the case of the non-confocal optical path A in (a) and (b), the Faraday element 102 and the half-wave plate 103 maintain the polarization state at the time of incidence from the light source 1 and the reflection state at the time of reflection from the sample 10. By rotating by 90 °, an optical path to an imaging system including the imaging lens 14 and the CCD 15 is formed.

As described above, in the first embodiment of the present invention, the polarization direction of the incident light is changed by 90 ° by the polarizing plate 4 constituting the polarization setting unit 20, and the branching optical element is changed by the polarizing direction of the polarizing plate 4. The optical path is branched by the PBSs 6 and 8 as Faraday elements 10 constituting the first optical member 21 in two optical paths between the PBSs 6 and 8, respectively.
A half-wave plate 101, a Faraday element 102 constituting the second optical system member 22, and a half-wave plate 103
Is arranged so that the non-confocal optical path A and the confocal optical path B can be switched only by the rotation of the polarizing plate 4, so that an extra space is not required due to insertion / removal of members of the optical system. In addition, the microscope itself can have a compact configuration, and a Faraday element with low light loss is used as an optical system member, so that a very bright image can be obtained regardless of whether the image is a confocal image or a non-confocal image. can get.

(Second Embodiment) A confocal microscope according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows the structure, which is basically the same as FIG. 1, so that the same parts are denoted by the same reference numerals and description thereof will be omitted.

In FIG. 1, the Faraday element 10 is used as the first optical member 21 and the second optical member 22.
0 (102) and the half-wave plate 101 (103) are arranged on each of the non-confocal optical path A and the confocal optical path B, but here, instead, the quarter-wave plate (λ / 4 boards) 20
1,202 is used.

With this configuration, the light passing through the quarter-wave plate 201 (202) is circularly polarized.
Half of it is transmitted in BS8 (or PBS6),
The other half will be reflected.

However, the light from the two optical paths, that is, the non-confocal optical path A and the confocal optical path B, is not mixed, and the CCD 15 rotates only the non-confocal image or only the confocal image. An image can be selectively formed corresponding to the position.

In the second embodiment, when the light passing through the quarter-wave plate 201 (202) passes through the PBS 8, the amount of the light becomes と な り, and the reflected light from the sample 10 is reflected by the PB
Quarter-wave plate 2 transmitted (or reflected) in S8 and again
01 (202), when passing through the PBS 6, the light amount is further reduced to １ ／ and an image is formed by the CCD 15. As a result, the light amount is reduced to one fourth, but the first light amount is reduced. First optical system member 2 compared to the embodiment
The first and second optical system members 22 can be inexpensive and have a more compact configuration.

In the first and second embodiments, the polarizing plate 4 may be replaced by a prism, and the rotation of the polarizing plate 4 is performed by the motor 5.
Instead, it is naturally possible to rotate manually.

Further, the same effect is obtained not only when the observation image is photographed by the CCD 15 but also when the naked eye is observed with an eyepiece.

Further, as the disk 11 used in the first and second embodiments described above, a disk obtained as an image, such as a Nipkow disk, is described as a confocal image as it is, but is not limited thereto. Instead, a confocal image may be obtained by performing post-processing by image calculation using a disc called, for example, a Tony Wilson disc.

The Tony Wilson type disc is composed of a transparent portion for transmitting light, a pattern portion having a plurality of lines or a plurality of pinholes, and a light-shielding portion for separating the transparent portion from the pattern portion. Things are often used.

Next, when a confocal image is obtained by a Tony Wilson-type disc, the Tony Wilson-type disc is always rotated at a constant rotation speed, an image is taken in synchronization with the rotation of the disc, and a confocal image is formed at a pattern portion. An image in which the non-confocal image is superimposed is obtained, and only the non-confocal image is obtained in the transparent portion.

Since the obtained image from the pattern portion is an image in which the confocal image and the non-confocal image are superimposed, the non-confocal image obtained in the transparent portion is image-calculated (subtracted) from the superimposed image. By doing so, a confocal image can be displayed on a monitor.

As described above, the optical paths A and B can be switched and used in the Tony Wilson type disk as in the first and second embodiments.

Further, the present invention is not limited to a disc divided into a transparent portion, a pattern portion, and a light-shielding portion as a modification of obtaining a confocal image by the above-described image calculation (subtraction). Can also be used.

In this case, a non-confocal image is obtained from the optical path A, and an image in which the confocal image and the non-confocal image are superimposed is obtained from the optical path B.

That is, instead of performing the image pickup in synchronization with the rotation of the disk, the image pickup is performed in synchronization with the switching by the rotation of the polarizing plate 4, whereby the first and second embodiments described above are performed. In addition to the same effects as above, image calculation (subtraction) is performed from an image obtained by superimposing a confocal image and a non-confocal image.
The brightness of the non-confocal image and the superimposed image can be adjusted separately, and the brightness and contrast of the confocal image can be finely adjusted according to the sample.

Since a Tony Wilson disk is used, a brighter image can be obtained as compared with a confocal image obtained by a Nipkow disk.

The above-mentioned disc is not limited to the above-mentioned disc. For example, a disc for controlling a portion corresponding to a plurality of pinholes on a liquid crystal substrate and a disc-shaped disc other than the disc may be used. it can.

Further, for example, the second optical system member 21 can be arranged at a position immediately before entering the disk 11.

In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0056]

According to the first aspect of the present invention, an optical path for easily obtaining a non-confocal image and a member for obtaining an image including at least a confocal image do not require a complicated optical system. Can be switched with the optical path interposed therebetween, and the entire microscope can have a compact structure.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the first and second optical system members are brighter without losing the amount of light. Images can be obtained.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the present invention, the configuration of the entire microscope can be made more compact.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a confocal microscope according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation according to the embodiment;

FIG. 3 is a diagram showing a configuration of a confocal microscope according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Collimate lens 3 ... Aperture 4 ... Polarizer 5 ... Motor 6 ... PBS 7 ... Mirror 8 ... PBS 9 ... Objective lens 10 ... Sample 11 ... Disk 12 ... Motor 13 ... Mirror 14 ... Imaging lens 15 ... CCD DESCRIPTION OF SYMBOLS 20 ... Polarization setting part 21 ... First optical system member 22 ... Second optical system member 100 ... Faraday element 101 ... 1/2 wavelength plate 102 ... Faraday element 103 ... 1/2 wavelength plate 201,202 ... 4 1 / wave plate

Continued on the front page F term (reference) 2F064 MM04 MM45 MM47 2F065 AA01 AA54 DD00 DD02 DD06 FF04 FF49 GG02 JJ03 JJ26 LL12 LL30 LL32 LL36 LL37 LL53 PP24 2H052 AA08 AB14 AB24 AB25 AC04 AC15 CA17 CA02 A

Claims (3)

[Claims] 1. A light source for emitting light, a polarization setting unit capable of switching the polarization direction of light from the light source by 90 °, and a non-confocal image according to the polarization direction of the light switched by the polarization setting unit A first optical element for splitting light into a first optical path for obtaining light and a second optical path interposed with a member for obtaining an image including at least a confocal image; and the first and second optical elements. First and second optical system members respectively disposed in the optical path and polarizing light in the optical path; and a second optical branching element for branching light from the sample into one of the first and second optical paths. A confocal microscope comprising: an imaging unit for obtaining image information from the first and second optical paths. 2. A confocal microscope according to claim 1, wherein at least one of said first and second optical system members comprises a Faraday element and a half-wave plate. 3. The confocal microscope according to claim 1, wherein at least one of said first and second optical members is constituted by a quarter-wave plate.