JPH09264841A - Observation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ease the effect of a speckle pattern when observing a sample using a laser light concerning an observation apparatus for optically observing a microscopic sample, especially in the observation apparatus which can obtain a clear image of a sample using the laser light. SOLUTION: Laser light emitted from a light source is projected onto a sample 100 passing through a diffusion means 3 moving between the light source 1 and the sample 100 and the laser light reflected from or transmitted through the sample 100 is received by an image pickup means to photograph the sample 100. This enables easing of the effect of a speckle pattern as much as possible as generated by the projection of the laser light onto the sample 100 and thus, achieves an observation of a clear picture of the sample even when interfering laser light is used as irradiation light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observation apparatus for optically observing a sample having a fine structure and the like, and more particularly to an observation apparatus capable of obtaining a clear image of a sample by using a laser beam.

[0002]

2. Description of the Related Art Conventionally, there is an observation apparatus of this type shown in FIG. 7 as an observation apparatus for observing magnetic domains of a magnetic material. FIG. 7 is a schematic block diagram of a conventional magnetic domain observation apparatus. In the figure, a conventional magnetic domain observation apparatus is a helium-neon (He-Ne) laser 1 that emits laser light.
0, the synchronizing shutter 8 that transmits / blocks this laser light based on the synchronizing signal from the synchronizing signal generator 81, and the laser light transmitted from this synchronizing shutter 8 as a polarized light in a predetermined vibration direction of a magnetic material. A polarizer 25 that is emitted to the sample 100 side, an analyzer 26 that inspects the polarization degree of the reflected light that is polarized and emitted after the laser light of this polarization is projected on the sample 100, and the reflected light that is transmitted from this analyzer 26. A CCD camera 4 for picking up the image, an image processing device 45 for image-processing the image pickup signal picked up by the CCD camera 4 based on the synchronizing signal, and visually displaying based on the image signal. The display 43 for outputting is provided. In this conventional magnetic domain observation apparatus, a pair of coils 50a and 50b are arranged facing each other between a polarizer 25 and an analyzer 26 near the mounting table 6 on which the sample 100 is mounted, and the pair of coils 50a, The excitation current supplied to 50b is controlled by the excitation controller 51.

Next, the sample observing operation of the conventional apparatus based on the above configuration will be described. First, sample 10 which is a magnetic material
0 is mounted on the mounting table 6, and the mounting table 6 is attached to the x-axis, the y-axis,
The optical axes of the polarizer 25 and the analyzer 26 are made to coincide with each other by finely adjusting in the z-axis direction. After the sample 100 is mounted on the mounting table 6 in this way, the excitation controller 51
The exciting current controlled by the control of the pair of coils 50
It is supplied to a and 50b to be in an excited state.

The laser light generated by the He-Ne laser 10 is made into an intermittent laser light by the synchronizing shutter 8 based on a synchronous signal, and the intermittent laser light is transmitted through the polarizer 25 to the pair of laser lights. It is projected onto the sample 100 magnetized by the magnetic field induced by the excitation of the coils 50a and 50b. The polarized laser light emitted by the polarizer 25 causes a magnetic rotatory phenomenon based on the magneto-optical Kerr effect on the magnetized sample 100 to rotate the plane of polarization by a predetermined angle.

The rotation of the polarization plane changes depending on the degree of magnetization of the sample 100, and the laser light whose polarization plane is rotated by a predetermined angle is imaged by the CCD camera 4 through the analyzer 26. In this way, by changing the magnetic susceptibility of the sample 100 under the control of the excitation control unit 51, it is possible to observe the changed change in the magnetic domain of the sample 100 with the intermittent laser light.

[0006]

Since the conventional magnetic domain observation apparatus is configured as described above, when the surface of the sample 100 is a magnetic material having a surface shape having irregularities such as a rough surface, a laser is used. There is a problem in that a speckle pattern is generated due to the coherence of light, and the speckle pattern is superimposed on the magnetic domain image so that the magnetic domain pattern cannot be observed. Also,
Even when the surface of the sample 100 is a magnetic material having a mirror surface, there is a problem that a clear magnetic domain image cannot be obtained due to the influence of the speckle pattern.

Also, when the sample 100 is for observing microorganisms other than magnetic materials, animals and plant cells, etc., as long as coherent laser light is used as a light source, a speckle pattern is generated, and this speckle pattern is generated. Therefore, a clear image of the sample 100 cannot be obtained. The present invention has been made in order to solve the above problems, and an object of the present invention is to propose an observation apparatus that can alleviate the influence of a speckle pattern when observing a sample using laser light.

[0008]

An observation apparatus according to the present invention is arranged such that it moves between a light source that emits laser light and a light source and a sample, and transmits the laser light to the sample side. It is provided with a diffusing unit that emits light, and a unit that projects a laser beam onto the sample via the diffusing unit and receives the laser beam reflected or transmitted from the sample to image the sample. As described above, in the present invention, the laser light emitted from the light source is transmitted through the diffusing means that moves between the light source and the sample to project the laser light onto the sample, and the laser beam reflected or transmitted from the sample. Since the light is received by the image pickup means to image the sample, the influence of the speckle pattern generated by projecting the laser light on the sample can be reduced as much as possible, and the coherent laser light is used as the irradiation light. Even when used, a clear image of the sample can be observed.

Further, in the observation apparatus according to the present invention, the light source blinks the laser light at a predetermined timing to emit a laser beam as needed, and the imaging means reflects or reflects from the sample in synchronization with the predetermined timing. It receives the transmitted laser beam and images the sample. As described above, in the present invention, since the image pickup unit images the sample at the timing when the laser light is emitted from the light source, the change state of the sample can be observed as a still image at each change stage.

Further, in the observation apparatus according to the present invention, the mobility of the diffusing means can be set to a range in which the imaging sensitivity of the imaging means cannot follow the change in the speckle pattern that changes due to the movement, if necessary. it can. As described above, according to the present invention, since the image pickup unit images the sample with the image pickup sensitivity that cannot follow the speckle pattern that changes with the movement of the diffusion unit, the speckle pattern is picked up by the image pickup unit. Only the stationary sample will be imaged without any observation, and a clearer image of the sample can be observed.

Further, in the observation apparatus according to the present invention, the diffusion means can be moved by vibration or rotation if necessary. As described above, in the present invention, since the diffusing means is moved by vibration or rotation,
In the case of vibration, a simple and compact device configuration is possible, and in the case of rotation, the uniform movement speed allows the laser light to be always diffused under the same conditions and transmitted to the sample side to make the effect of the speckle pattern uniform. Can be removed.

Further, the observation apparatus according to the present invention, if necessary, magnetizes the sample by a magnetizing means when the sample is a magnetic body, and associates the magnetization of the magnetizing means with the image pickup of the image pickup means. You can also do it. As described above, in the present invention, the sample that is a magnetic body is magnetized by the magnetizing means, and the image capturing means images the sample in association with the magnetization of the magnetizing means. Alternatively, changes in magnetic properties can be observed in association with the degree of magnetization.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment of the Invention) An observation apparatus according to a first embodiment of the present invention will be described below with reference to FIG. 1. FIG. 1 is a block diagram of the observation apparatus according to this embodiment. In the drawing, in the observation apparatus according to the present embodiment, a semiconductor laser 1 that emits laser light and a frosted glass plate 31 are interposed in the optical path of this laser light.
Is provided on the rear side of the frosted glass plate 31, and the beam splitter 21 reflects the laser light transmitted through the frosted glass plate 31 to the sample 100 side. The sample 100 is imaged by irradiating an image and irradiating the laser beam reflected from the sample 100 through the beam splitter 21 and the laser beam transmitted through the beam splitter 21 of the optical system. This is a configuration including a CCD camera 4. The optical system is configured as coaxial epi-illumination with respect to the sample 100 by the beam splitter 21. The vibrator 32 of the diffusing means 3 may be formed of a voice coil or the like to vibrate the frosted glass plate 31 in a speaker system.

Next, the operation of observing the sample of this embodiment based on the above configuration will be described. First, the sample 100 is mounted on the mounting table 6, and laser light is emitted from the light source 1. On the optical path of this laser beam, the diffusing means 3 vibrates the ground glass plate 31 by the vibrator 32, and the laser light transmitted through this glass plate 31 is imaged and projected on the sample 100 by the objective lens 22. The laser light projected on the sample 100 is reflected on the sample 100, and the reflected laser light is again reflected by the objective lens 22 and the beam splitter 2.
It is emitted to the CCD camera 4 side via the optical system 1 of 1.
The CCD camera 4 receives the laser light transmitted through the beam splitter 21 and images the sample 100. A printer (not shown) based on the captured image data,
The sample 100 can be observed by outputting in a format that can be visually recognized by an output device such as a CRT.

(Second Embodiment of the Invention) FIG. 2 is a block diagram of an observation apparatus according to the second embodiment. In the figure, the observation apparatus according to the present embodiment is provided with a semiconductor laser 1, an optical system 2, a diffusing means 3, a CCD camera 4 and a mounting table 6 in common, as in the apparatus of the embodiment shown in FIG. In addition, the emission control unit 11 for adjusting and controlling the blinking timing and the light intensity of the semiconductor laser 1, the vibration control unit 33 for adjusting and controlling the vibration of the vibrator 32 in the diffusing means 3, and the imaging timing of the CCD camera 4 are set. The imaging control unit 41 for adjusting and controlling, and the excitation yoke 5 arranged in the mounting unit 6 for magnetizing the magnetic material sample 100.
An excitation control unit 51 for controlling an excitation current supplied to the excitation yoke 5; and an image processing unit 42 for generating image data based on an electric signal output from the CCD camera 4.
And a CRT 43 displayed based on this image data,
This is a configuration including a control calculation unit 7 that controls the entire apparatus.

Next, the operation of observing the magnetic domain pattern of the sample of 3% silicon-iron (3% Si-Fe) having the orientation close to the (110) [001] orientation according to the present embodiment based on the above-mentioned structure will be described. . First, the sample 100 is placed on the mounting table 6.
The magnetic fluid colloidal solution 101 is dripped onto the mounted sample 100, and the sample 100 is covered with a cover glass. In this state, the control calculation unit 7 causes the light emission control unit 11 and the vibration control unit 3 to operate.
3. A start signal is transmitted to the excitation controller 51 and the imaging controller 41, and each control is started in a synchronized state.

The excitation yoke 5 is excited by the excitation current supplied from the excitation controller 51, and this excitation causes 3%.
The Si-Fe sample 100 is magnetized. The magnetic fluid colloidal solution 101 detects the magnetic domain wall position of the magnetic domain wall movement that occurs with the magnetization of the 3% Si-Fe sample 100. As described above, in the state where the magnetic fluid colloidal solution 101 is magnetized by the excitation current having the predetermined value, the vibration control unit 33 controls the vibrator 32 to vibrate the frosted glass plate 31 of the diffusing means 3 to cause the emission control unit 11 to vibrate. Under control, the semiconductor laser 1 is caused to emit light at a predetermined timing, and the emitted laser light is projected onto the magnetic fluid colloidal solution 101 via the vibrating ground glass plate 31 and the optical system 2 by the coaxial epi-illumination method. When this laser light is projected onto the magnetic fluid colloidal solution 101 in which a magnetic domain pattern is formed by magnetization, the reflected laser light enters the optical system 2 through the objective lens 22.

The optical system 2 on which this laser light is incident is guided to the CCD camera 4 by the beam splitter 21, and this CC
The D camera 4 converts the electric signal into an electric signal, and the image processing unit 42 forms an image signal. The image signal is input to the CRT 43 and visually displayed. In this way, the excitation controller 5
The excitation current is controlled by 1 to drive the CCD camera 4 according to the degree of magnetization of the 3% Si-Fe sample 100 and the magnetic fluid colloidal solution 101, and the CCD camera 4 drives the magnetic domains corresponding to each degree of magnetization. The pattern can be displayed on the CRT 43 for observation.

FIGS. 3 to 5 are respective photomicrographs substituted for the drawings showing the magnetic domain patterns of the magnetic fluid colloidal solution 101 observed in this example. In observing each of these micrographs, it is assumed that laser light is emitted from the semiconductor laser 1 with an output light wavelength of 691.1 mm and an emission light output of 12.6 mw. In this FIG. 3, the frequency of the diffusing means 3 is a sine wave of 100 Hz and the ground glass plate 31 is vibrated, and the micrograph of the magnetic fluid colloidal solution 101 shows a surface reflux domain and a 180 ° domain wall, and no speckle pattern. It turns out that it can be observed very well without appearing. In FIG. 4, the diffusion means 3
Is a case where the frosted glass plate 31 is vibrated with a sine wave of 10 Hz, and the microscopic photograph of the magnetic fluid colloidal solution 101 should be observed well with almost no appearance of speckle patterns on the surface reflux domain and 180 ° domain wall. You can see that In the same case as in the prior art in which the diffusing means 3 is not provided in FIG. 5, a high-density speckle pattern appears in the microphotograph of the magnetic fluid colloidal solution 101, and a magnetic domain image is formed by this speckle pattern. It turns out that observation is impossible. That is, in contrast to FIG. 5 in which the vibrated glass plate 31 is not interposed in the optical path of the laser light, in the case of FIGS. 3 and 4 in which the glass plate 31 is interposed in the optical path of the laser light, interference is possible. Of the speckle pattern generated by the reflected light from the sample 100 of the steel sheet, which is a magnetic material, by the characteristic laser light is applied to the CCD.
It can be seen that the camera 4 can image the magnetic domain pattern. As described above, the sample 10 is not affected by the speckle pattern.
A surface shape of 0, for example, in the case of a magnetic material, a magnetic domain pattern can be observed with a clear image.

(Third Embodiment of the Present Invention) FIG. 6 shows a magneto-optical Kerr effect (Kerr Eff) according to a third embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of an observation device that uses ect). In the figure, the observation apparatus according to the present embodiment is similar to the conventional apparatus described in FIG. 7, and includes a He-Ne laser 10 (corresponding to a semiconductor laser in FIG. 6), a polarizer 25, and an analyzer 2.
6, the CCD camera 4, the image processing device 45 (corresponding to the image processing unit 42 and the control calculation unit 7 in FIG. 6), the pair of coils 50a and 50b, the display 43 (corresponding to the CRT 43 in FIG. 6), and the mounting table 6. In addition to this configuration, the diffusing means 3 is interposed between the polarizer 25 and the sample 100. The semiconductor laser 1 is controlled to emit light by the light emission control unit 11, and the pair of coils 50a and 50b is controlled to be excited by the excitation control unit 51.
Further, the CCD camera 4 is driven and controlled by the image pickup control unit 41, and the light emission control unit 11, the excitation control unit 51, and the image pickup control unit 41 are each controlled by the control calculation unit 7.

Next, the sample observing operation of the apparatus of this embodiment based on the above construction will be described. First, the sample 100, which is a magnetic material, is mounted on the mounting table 6, and the mounting table 6 is moved in the x-axis and y
The polarizer 2 is finely adjusted in the axial and z-axis directions.
5 and the optical axis of the analyzer 26. After the sample 100 is mounted on the mounting table 6 as described above, the excitation current controlled by the excitation control unit 51 is applied to the pair of coils 5.
0a, 50b to supply the excited state, and the diffusion means 3
Start to vibrate.

The semiconductor laser 1 is emitted as laser light in an intermittent state with a predetermined cycle by the emission control of the emission controller 11, and the laser beam in the intermittent state is polarized by the polarizer 25 into a polarized light having a predetermined polarization angle. It is transmitted through the diffusing means 3. The polarized laser light transmitted through the diffusing means 3 is projected onto the sample 100 magnetized by the magnetic field induced by the excitation of the pair of coils 50a and 50b. The polarized laser light causes a magnetic rotation phenomenon based on the magneto-optical Kerr effect on the magnetized sample 100 to rotate the plane of polarization by a predetermined angle.

The rotation of the plane of polarization changes depending on the degree of magnetization of the sample 100, and the laser light whose plane of polarization is rotated by a predetermined angle is imaged by the CCD camera 4 via the analyzer 26, and the electrical image obtained by this imaging is obtained. Image processing unit 4
An image signal is generated in 2 and displayed on the CRT 43. In this way, by changing the magnetic susceptibility of the sample 100 under the control of the excitation controller 51, the changed dynamic domain magnetic domain of the sample 100 can be changed by the laser beam in the intermittent state without being affected by the speckle pattern. A clear still image can be observed at each step of the change of the magnetic domain pattern.

(Other Embodiments of the Present Invention) The diffusing means 3 in the observation apparatus of each of the above-mentioned embodiments is a ground glass plate 31.
However, the diffusing means 3 can also be configured by rotating a scattering or diffusing member such as the frosted glass plate 31 at a predetermined peripheral speed. The mobility such as vibration and rotation of the diffusing means 3 can be set within a range in which the image sensing sensitivity of the image sensing means such as the CCD camera 4 cannot follow the change in the speckle pattern that changes due to this mobility. When the image pickup means is the CCD camera 4, the image pickup sensitivity that cannot follow the change of the speckle pattern controls the speed at which the charge accumulated in each potential well is moved by the shift register to a predetermined value in proportion to the light intensity. If the image pickup means is a developed photographic film camera, it can be set according to the exposure time of the camera or the sensitivity of the photographic film.

In the observation apparatus of each of the above-described embodiments, the laser light is projected onto the sample 100 and the sample 100 is observed based on the reflected light. However, the laser light is projected onto the sample 100 and the transmitted light is converted into the transmitted light. It is also possible to adopt a configuration in which the sample 100 is observed based on this. When observing the transmitted light, the magnetic domain pattern of the magnetic substance in the sample 100 as shown in FIG. 6 is to observe the magnetic rotation phenomenon based on the Faraday effect. Further, in the observation apparatus of each of the above-described embodiments, the sample 100 has been described by taking the magnetic domain pattern of a magnetic material as an example, but it is also possible to observe the cell tissue of a microorganism as the sample 100.

[0026]

As described above, according to the present invention, the laser light emitted from the light source is transmitted through the diffusing means which moves between the light source and the sample, and the laser light is projected onto the sample. Since the image of the sample is received by receiving the reflected or transmitted laser beam by the image pickup means, the influence of the speckle pattern generated by projecting the laser beam on the sample can be reduced as much as possible, and the coherence Even if laser light is used as irradiation light, a clear image of the sample can be observed. Further, in the present invention, since the image pickup means images the sample at the timing when the laser light is emitted from the light source, it is possible to observe the change state of the sample as a still image at each stage of the change. Have. Further, in the present invention, since the image pickup device images the sample with the image pickup sensitivity that cannot follow the speckle pattern that changes with the movement of the diffusing device, the image pickup device does not image the speckle pattern. Since only the stationary sample is imaged, there is an effect that a clearer image of the sample can be observed. Further, in the present invention, since the diffusing means is moved by vibration or rotation, a simple and downsized device configuration is possible in the case of vibration, and in the case of rotation, it is always the same due to a uniform moving speed. Depending on the conditions, the laser light can be diffused and transmitted to the sample side, and the effect of the speckle pattern can be uniformly removed. Further, in the present invention, the sample, which is a magnetic body, is magnetized by the magnetizing means, and the imaging means images the sample in association with the magnetization of the magnetizing means. This has the effect that changes in magnetic characteristics can be observed in association with the degree of magnetization.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an observation apparatus according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of an observation device according to a second embodiment of the present invention.

FIG. 3 is a drawing-substitute micrograph showing a magnetic domain pattern imaged by the observation device shown in FIG.

FIG. 4 is a drawing-substitute micrograph showing a magnetic domain pattern imaged by the observation device shown in FIG.

FIG. 5 is a drawing-substitute micrograph showing a magnetic domain pattern imaged by the observation device shown in FIG.

FIG. 6 is a drawing-substitute micrograph showing a magnetic domain pattern imaged by the observation device shown in FIG. 2.

FIG. 7 is a block diagram of a conventional magnetic domain observation apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2 optical system 3 diffusing means 4 CCD camera 5 excitation yoke 6 mounting table 7 control arithmetic unit 8 shutter for synchronization 10 He-Ne laser 11 emission control unit 21 beam splitter 22 objective lens 25 polarizer 26 analyzer 31 ground glass plate 32 vibrator 33 vibration control part 41 imaging control part 42 image processing part 43 display 45 image processing device 50a, 50b coil 51 excitation control part 81 synchronization signal generator 100 sample 101 magnetic fluid colloidal solution

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideaki Uekawa 1-8 Jiyugaoka, Yawatanishi-ku, Kitakyushu, Fukuoka Kyushu Kyoritsu University

Claims (5)

[Claims] 1. A light source that emits laser light, a diffusing means that is interposed between the light source and the sample and moves, and that transmits the laser light to the sample side and emits the laser light, through the diffusing means. A laser beam is projected onto the sample, and means for receiving the laser beam reflected or transmitted from the sample to image the sample is provided. 2. The observation device according to claim 1, wherein the light source blinks at a predetermined timing to emit a laser beam, and the imaging means reflects or reflects the sample in synchronization with the predetermined timing. An observation device, which receives a transmitted laser beam and images a sample. 3. The observation apparatus according to claim 1 or 2, wherein the mobility of the diffusing unit is set to a range in which the imaging sensitivity of the imaging unit cannot follow the change in the speckle pattern that changes due to the movement. An observation device characterized by the above. 4. The observation apparatus according to any one of claims 1 to 3, wherein the diffusion means is moved by vibration or rotation. 5. The observation device according to claim 1, wherein when the sample is a magnetic material, the sample is magnetized by a magnetizing means, and the magnetization of the magnetizing means and the imaging by the imaging means are performed. An observation device characterized by performing the above and the above in association with each other.