JPH03168713A - Scanning type microscope - Google Patents

Abstract

PURPOSE:To increase the scanning speed of illumination light by providing a mechanism which holds a member moving for relative movement and a guide member for guiding and supporting the member not in contact with each other between the both. CONSTITUTION:When a two-dimensional scan is made with a light spot, a solenoid valve 49 is opened to send compressed air into guide pipes 40 and 45. This compressed air is discharged from air blow-off holes 40a and 45a, so jet air layers are formed between a guide pipe 40 and a guide hole 41, and a guide pipe 45 and a guide hole 46. Consequently, a moving base 15 moves reciprocally without contacting the guide pipe 40 and a sample base 22 also moves reciprocally without contacting the guide pipe 45. Therefore, when the moving base 15 and sample base 22 move, the friction resistance becomes small. Consequently, laminate piezoelectric elements 33 and 47 can vibrate fast and the fast scan can be made with the light spot.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a scanning microscope, and more particularly to a scanning microscope with an improved illumination light scanning mechanism.

(Prior art) Conventionally, illumination light is converged into a minute light spot, and this light spot is scanned two-dimensionally on a sample, and at that time, the light that has passed through the sample or the light that has been reflected there is detected by a detector. Optical scanning microscopes are known that detect electrical signals that carry an enlarged image of a sample. In addition, Japanese Patent Application Publication No. 8
An example of this scanning microscope is disclosed in Japanese Patent No. 2-217218.

(Problems to be Solved by the Invention) In conventional optical scanning microscopes, a mechanism in which an illumination light beam is two-dimensionally deflected by an optical deflector has often been used as the scanning mechanism.

However, in this mechanism, galvanometer mirrors and
A disadvantage is that an expensive optical deflector such as an OD (acousto-optic optical deflector) is required. In addition, in this mechanism, the illumination light beam is deflected by an optical deflector, so this light beam enters the objective lens of the light transmission optical system at different angles from time to time, and the resulting aberrations are corrected. It has also been recognized that this makes it difficult to design the objective lens. In particular, when an AOD is used, a special correction lens is required in addition to the objective lens because astigmatism occurs in the light beam emitted from the AOD, making the optical system more complicated.

In view of the above points, it has been conventionally considered to scan the illumination light spot by moving the sample stage two-dimensionally without deflecting the illumination light beam.

Furthermore, as shown in the specification of Japanese Patent Application No. 1-24694Ei filed by the present applicant, the light transmitting optical system and the light receiving optical system are mounted on a common moving stage, and this moving stage is moved relative to the sample stage. It has also been considered to scan the illumination light spot by

When scanning the illumination light spot by moving the optical system and sample stand relatively as described above, it is necessary to move the optical system or the sample stand at high speed in order to shorten the time required for imaging. It will be done. Therefore, it is conceivable to use piezo elements, ultrasonic vibrators, etc. as a drive source for this movement, but such elements are generally unable to vibrate at high speed when a large load is applied. . For example, a reciprocating mechanism using a motor or the like as a driving source can operate normally even under high loads, but such a mechanism has difficulty operating at high speed.

Therefore, an object of the present invention is to provide a scanning microscope that can move a moving stage equipped with the above-mentioned optical system or a sample stage at high speed, and can therefore sufficiently increase the scanning speed of illumination light. It is something.

(Means for Solving the Problems) As described above, the first scanning microscope according to the present invention is a scanning microscope in which illumination light is scanned over a sample by relatively moving the sample stage and the optical system. The microscope is characterized by being provided with a mechanism that keeps the member moved for the relative movement (i.e., the above-mentioned moving stage, etc.) and the guide member that guides and supports the member in a non-contact state. It is something to do.

Specifically, for example, a mechanism for ejecting gas between the moved member and the guide member can be used as the above mechanism.

Also, instead of the mechanism that blows out gas as described above,
It is also possible to use a mechanism that magnetically repels the moving member and the guide member to keep them in a non-contact state.

(Function) When the movable member and the guide member are in a non-contact state as described above, the frictional resistance when the movable member moves is reduced, so that the movable member can be moved with a small force. It becomes like this. Therefore, as a driving source for this moving member,
The piezo elements and ultrasonic transducers mentioned above can now be used.
High speed movement of the moving member is achieved.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 shows a transmission type confocal scanning microscope according to a first embodiment of the present invention, and FIG. 2 shows in detail the scanning mechanism used therein. As shown in FIG. 1, the RGB laser 10 emits illumination light 11 consisting of red light, green light, and blue light. The beam diameter of this illumination light 1l is reduced by a beam compressor 12, condensed by a gradient index lens 13, and made to enter a single mode optical fiber 14.

One end of this optical fiber 14 is fixed to a moving table 15, and the illumination light 1l propagated within the optical fiber 14 is emitted from this one end. At this time, one end of the optical fiber 14 emits illumination light 1l in the form of a point light source. Mobile platform l
5 includes a collimator lens 16 and an objective lens 17.
A light transmitting optical system 18 consisting of a light transmitting optical system 18 and a light receiving optical system 2l consisting of an objective lens 19 and a condensing lens 20 are fixed with their optical axes aligned with each other.

Further, a sample stage 22, which is separate from the moving stage l5, is arranged between both optical systems 18 and 2l.

The above illumination light 1l is made into parallel light by a collimator lens l6, and then condensed by an objective lens 17,
The light converges into a minute light spot P on the sample 28 placed on the sample stage 22. The luminous flux of the transmitted light 11' that has passed through the sample 23 is made into parallel light by the objective lens l9 of the light receiving optical system 2l,
Next, the light is condensed by the condenser lens 20 and is made to enter the single mode optical fiber 24 from one end thereof. One end of the optical fiber 24 is fixed to the movable table 15, and a gradient index lens 25 is connected to the other end. optical fiber 24
The transmitted light 1F that has propagated inside is emitted from the other end and is converted into parallel light by the gradient index lens 25.

This transmitted light 11' enters the dichroic mirror 26, and only the blue light 11B is reflected there.
1B is detected by the first photodetector 27.

The transmitted light lV transmitted through the dichroic mirror 26 enters another dichroic mirror 28, and its green light 11
Only G is reflected there. This green light 11G is detected by the second photodetector 29. The transmitted light lr (ie, red light 11R) transmitted through the dichroic mirror 28 is reflected by the mirror 30 and detected by the third photodetector 31. Note that the photodetectors 27, 2
9. For example, a photodiode or the like is used as 31, and from these, the blue component of the enlarged image of the sample 23,
Signals SB, SG, and SR carrying green color and red color are output.

Next, two-dimensional scanning of the light spot P of the illumination light U will be explained with reference to FIG. The moving platform i5 is relative to the pedestal 32,
It is supported movably in the direction of arrow X.

That is, one end portions of two hollow guide vibes 40, 40 with both ends closed are fixed to the stand 32, and the movable stand l5
Two guide holes 41. These guide pipes 40, 40 are loosely fitted into the inside 41.

Incidentally, FIG. 3 shows a longitudinal cross-sectional shape of a portion taken along the line ■-■ in FIG. 2. As shown in the figure, a large number of small air outlets 40a are provided in the portion of the guide vibe 40 that slides on the guide hole 4l. Further, the inside of this guide vibe 40 is communicated with an air chamber 43 via a compressed air supply pipe 42 in which a solenoid valve 49 is interposed. Compressed air is supplied to this air chamber 43 from an air compressor 44 .

A laminated viezo element 33 is interposed between the movable table l5 and the pedestal 32. This laminated piezo element 33 receives drive power from a piezo element drive circuit 34, and the movable base 15
is moved back and forth at high speed in the direction of arrow X.

The frequency of this reciprocating movement is, for example, lokHz.

In that case, if the main scanning width is 100 μm, the main scanning speed will be 10XIO" While allowing the vibration to propagate, the vibration of the movable table 15 is allowed.

On the other hand, the sample stand 22 is held with respect to the pedestal 32 so as to be movable in the direction of the arrow Y, which is perpendicular to the direction of the arrow X. That is, one end portions of two guide vibes 45, 45 similar to the guide pipes 40, 40 are fixed to the mount 32, and these guide vibes are inserted into the two guide holes 4B, 46 provided in the sample stand 22. 45, 45 are loosely fitted. As shown in FIG. 3, each guide pipe 45 is also provided with an air outlet 45a like the guide pipe 40, and the compressed air supply pipe 42 is connected to these guide pipes 45.

A laminated viezo element 47 is interposed between the sample stage 22 and the pedestal 32. This laminated Viezo element 47 receives drive power from the Viezo element drive circuit 48, and
is moved back and forth at high speed in the direction of arrow Y.

Thereby, the sample stage 22 is moved relative to the moving stage l5, and the light spot P sub-scans the sample 23 in the Y direction perpendicular to the main scanning direction X. The time required for this sub-scanning is, for example, 1/20 second, and in that case, the sub-scanning width is set to 100μ.
m, the sub-scanning speed is 20X100XIO'
-0.002 m/s 2 mm/s, which is sufficiently lower than the main scanning speed. With this level of sub-scanning speed, it is possible to prevent the sample 23 from flying away even if the sample stage 22 is moved.

By scanning the light spot P two-dimensionally over the sample 23 as described above, a series of signals SB, SG, and SR carrying a two-dimensional image of the sample 23 is obtained.

These signals SB, SG, and SR are made into pixel-divided signals by, for example, sampling at predetermined intervals.

When the light spot P is two-dimensionally scanned as described above, the electromagnetic valve 49 is opened and compressed air is sent into the guide vibes 40 and 45. This compressed air is air outlet 40a
and 45a, jet air layers are generated between the guide pipe 40 and the guide hole 4l and between the guide vibe 45 and the guide hole 46.

As a result, the movable stage 15 reciprocates with respect to the guide pipe 40 without contacting it, and the sample stage 22 also reciprocates with respect to the guide vibe 45 without contacting it.

Therefore, the frictional resistance when the moving stage l5 and the sample stage 22 move becomes extremely small, and the laminated vieso element 3
3 and 47 become extremely small. Therefore, these laminated piezo elements 33 and 47 can vibrate at extremely high speed as described above, and high-speed scanning of the light spot P is realized.

Note that a synchronizing signal is input from the control circuit 35 to the vieso element drive circuits 34 and 48, thereby synchronizing the main and sub-scanning of the light spot P.

Although not particularly shown in the figure, the main and sub-scanning directions
The sample stage 22 can also be moved in the direction of arrow Z (see FIG. 1) perpendicular to Y, that is, in the direction of the optical axes of the optical systems 18 and 2l. If the light spot P is two-dimensionally scanned each time the sample stage 22 is moved a predetermined distance in the Z direction, only information on the focused plane is detected by the photodetectors 27, 29, and 3l. Therefore, by importing the outputs SB, SG, and SR of these photodetectors 27, 29, and 3l into the frame memory, it is possible to create an image in focus on all surfaces within the range in which the sample 23 is moved in two directions. It becomes possible to obtain the signal that is to be carried.

In the embodiments described above, occasional changes are possible. For example, by moving the sample stage 22, the light point P
Instead of sub-scanning the light spot P, the light spot P may be sub-scanned by moving the movable stage l5.

Further, the movement of the moving stage 15 and the sample stage 22 can be carried out by using a laminated piezo probe or by using a scanning method using, for example, the natural vibration of a solid body caused by a voice coil or ultrasonic waves.

Next, another embodiment of the present invention will be described. In the following figures, elements that are equivalent to those in Figures 1, 2, or 3 are given the same numbers, and explanations thereof will be omitted unless particularly necessary.

Further, in the following, only the scanning mechanism of the illumination light spot will be explained.

In the second embodiment shown in FIGS. 4 and 5, the moving platform 1
Two guide grooves 60 and 60 are formed at the lower part of the movable table 15 in the direction of the arrow It is guided and supported so that it can be moved freely. Each guide rail 6l is shaped to have an internal space B2, and a compressed air supply pipe 4 is provided in this internal space 62.
2 are connected. A large number of small air outlets 61a are formed in each guide rail 6l.

When the moving table 15 is moved for main scanning of the light spot, the compressed air sent from the compressed air supply pipe 42 is discharged from the air outlet 61g, and the same effect of reducing frictional resistance as described above is obtained. It will be done.

Next, in the third embodiment shown in FIGS. 6 and 7, a guide rail 65 is formed at the lower part of the moving table 15, and this guide rail 65 is loosely fitted into a guide groove 66 formed in the guide block 64. By doing so, the moving table 15 moves in the direction of arrow
It is guided and supported so that it can move freely in the direction. A hollow portion 67 is formed in the guide block 64 in a portion along the guide groove 66, and the compressed air supply pipe 42 is communicated with the hollow portion 67.

Further, the guide block 64 is provided with a number of air outlets 84a that communicate with the hollow portion 67 at positions facing the lower surface of the movable table l5 and positions facing the side surface of the guide rail 65 in the guide groove 66. There is.

When the movable stage 15 is moved for main scanning of the light spot, the compressed air sent from the compressed air supply pipe 42 is discharged from the air outlet 64a, and the same effect of reducing frictional resistance as described above can be obtained. .

Next, in the fourth embodiment shown in FIGS. 8 and 9, guide rail receivers 70, 70 are fixed to the pedestal 32 across the sub-scanning direction (arrow Y direction). Guide rails 71 on the top surface,
71 is attached. Each guide rail 71 is
Like the guide rail 61 shown in FIGS. 4 and 5, it has an internal space 72, and the compressed air supply pipe 42 is located in this internal space 72.
(They are in communication with each other.) Each guide rail 71 has a large number of small air outlet ports 7La.

On the other hand, guide blocks 73, 73 are fixed to the lower part of the sample stage 22, and guide grooves 74, 74 formed in these guide blocks 73, 73, respectively, are connected to the guide rail 71,
It is combined with 71. As a result, the sample stage 22
It is guided and supported so as to be movable in the sub-scanning direction. Furthermore, the laminated Viezo element 47 in this embodiment is attached to the guide rail receivers 7G and 70 via a bracket 75, and reciprocates the sample stage 22 via a connecting member 7B.

When the sample stage 22 is moved for light spot sub-scanning, compressed air sent from the compressed air supply pipe 42 is discharged from the air outlet 71a, and the same effect of reducing frictional resistance as described above is obtained. .

Next, in the fifth embodiment shown in FIGS. 10 and 11, the guide rails 80, 80 are
The guide grooves 81, 81 formed in the lower part of the moving table 15 are disposed so as to extend into the guide rails 80, 8.
0, the movable table l5 is guided and supported so as to be movable in the main scanning direction.

A running element 82 and a stator 83, which constitute a linear motor, are attached to the moving table l5 and the guide rail 80, respectively.

In this device, the reciprocating movement of the movable table 15 for main scanning of the illumination light is performed by driving the linear motor. At that time, the moving table 15 is connected to the guide rail 80
, 80, the frictional resistance between the moving table l5 and the guide rails 80, 80 is kept small,
The movable table 15 becomes capable of reciprocating at extremely high speed.

Note that it is of course possible to use the near motor as described above for reciprocating the sample stage 22.

Moreover, such a near motor is not particularly used as a drive source for main scanning or sub-scanning, and means may be provided to achieve only the above-mentioned magnetic levitation using magnetic repulsion. Even in such a case, the frictional resistance during reciprocating movement of the moving stage 15 or the sample stage 22 is reduced, making high-speed scanning possible.

Although the embodiments applied to a transmission type confocal scanning microscope have been described above, the present invention can also be applied to a reflection type confocal scanning microscope and furthermore, to scanning microscopes other than the confocal type. be.

(Effects of the Invention) As explained in detail above, the scanning microscope of the present invention blows out gas between the member that is moved for scanning the illumination light spot and the guide member that guides and supports this member. The movable member is configured to be movable without contacting the guide member by moving the movable member or by magnetically repelling both of them, thereby reducing frictional resistance during movement of the movable member. It becomes possible to keep the load on the drive source small.

Therefore, in the device of the present invention, an element capable of high-speed driving even with a small driving force can be used as the driving source, and high-speed scanning can be achieved. Therefore, according to the apparatus of the present invention, it becomes possible to significantly shorten the time required to take a microscope image.

Furthermore, in the apparatus of the present invention, since the movable member moves without contacting the guide member, vibrations during this movement can be suppressed to a small level, and image quality can be improved by improving scanning accuracy. Since heat generation due to friction between the moving member and the guide member is suppressed, deformation and wear of the scanning mechanism due to frictional heat are also prevented, and the reliability and durability of the apparatus are improved.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a scanning microscope according to a first embodiment of the present invention, and FIGS. 2 and 3 are a perspective view and a partially cutaway schematic front view showing the main parts of the scanning microscope, respectively. , FIG. 4 and FIG. 5 are respectively a front view and a partially cutaway side view showing the main parts of a scanning microscope according to a second embodiment of the present invention, and FIGS. A front view and a partially cutaway side view showing the main parts of a scanning microscope according to the third embodiment, and FIGS. 8 and 9 are a front view and a partially cutaway side view showing the main parts of a scanning microscope according to the fourth embodiment of the present invention, Partially Cutaway Side View FIG. 10 and FIG. 11 are a front view and a partially cutaway side view, respectively, showing essential parts of a scanning microscope according to a fifth embodiment of the present invention. IO...RGB laser 11...Illumination light 11'
...Transmitted light 12...Beam compressor l3...
・Refractive index gradient lens l4, 24...Optical fiber 15...Moving table 1B...Collimator lens l7, l9...Objective lens l8...Light transmission optical system 20...Condensing lens 2l ... Light receiving optical system 22 ... Sample stage 23 ... Sample 26
, 2B... Dichroic mirror 27, 29, 31.
... Photodetector 30 ... Mirror 32 ... Mount
33, 47... Laminated piezo elements 34, 48...
...Viezo element drive circuit 35...Control circuit 40, 45...Guide pipes 40a, 45as alas 84as 71a
-... Air outlet 41, 4G... Guide hole 4
2...Compressed air supply pipe 43...Air chamber
44... Air compressor 60, 66, 74, 8l.
...Guide grooves 01, 65, 7, 80...Guide rails 64, 73...Guide block 82...Linear motor running element 83...Linear motor stator 1 Fig. 3 Fig. 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 1':) Figure 10 Figure 11

Claims (3)

[Claims] (1) In a scanning microscope in which illumination light is scanned over a sample by relatively moving a sample stage on which a sample is placed and an optical system that irradiates illumination light onto the sample, the relative A scanning microscope characterized in that a mechanism is provided between a member that is moved for movement and a guide member that guides and supports the member to keep them in a non-contact state. (2) In a scanning microscope that scans the illumination light over the sample by relatively moving a sample stage on which the sample is placed and an optical system that irradiates the illumination light onto the sample, the relative A scanning microscope characterized in that a mechanism is provided for ejecting gas between a member that is moved for movement and a guide member that guides and supports the member to keep them in a non-contact state. . (3) In a scanning microscope that scans the illumination light over the sample by relatively moving a sample stage on which the sample is placed and an optical system that irradiates the sample with illumination light, the relative A scanning microscope characterized by being provided with a mechanism for magnetically repelling a member to be moved and a guide member for guiding and supporting the member to keep them in a non-contact state.