JP2001041821A - Slit image detecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a slit image detecting apparatus capable of improving detection precision of a slit image. SOLUTION: This slit image detecting apparatus is provided with a slit image projection optical system projecting a slit image which has passed a first slit plate 2c, on a specimen S. A galvano mirror 3a is so arranged at a focal point position on the rear side of an objective 2f that a telecentric system is constituted. A second slit plate 2h is arranged at a position conjugate with the first slit 2c when viewed from the focal point position. That is, these constitute a confocal optical system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slit image detecting device for detecting a slit image.

[0002]

2. Description of the Related Art A conventional apparatus for obtaining a wavelength-resolved image is described in Japanese Patent No. 2,558,864 of the applicant.
This device illuminates the sample uniformly from the back side, forms the transmitted light image transmitted through the sample uniformly on the slit plate, and scans the transmitted light image projected on the slit plate with a galvanomirror. Cut out the slit image by doing
The slit image is split and the split image is captured by a TV camera. An image captured by the TV camera is synthesized as a sample image for each wavelength.

[0003]

However, in the above-mentioned conventional apparatus, the slit image is cut out by projecting the transmitted light image on the slit plate, so that the brightness of the slit image is weak. It has been desired to improve the detection accuracy of the image projected on the image pickup surface. When imaging a fluorescent image or the like of a semiconductor or a biological sample, it is necessary to irradiate the sample with excitation light to separate the excitation light from the fluorescence generated by the excitation light. Is expected. Of course, if the power of the light source is increased, the luminance of the fluorescent image can be improved. However, the excitation light that becomes background noise also increases, and the image detection accuracy cannot be essentially improved. The present invention has been made in view of such problems,
An object of the present invention is to provide a slit image detection device capable of improving the detection accuracy of a slit image.

[0004]

In order to solve the above problems, a slit image detecting apparatus according to the present invention comprises a slit image projecting optical system for projecting a slit image passing through a first slit onto a sample, and a slit image projecting optical system. Galvano mirror disposed at the rear focal position of the objective lens of the optical system, a second slit disposed at a position conjugate to the first slit when viewed from the focal position, and an imaging device for detecting a slit image passing through the second slit And characterized in that:

[0005] According to this apparatus, the slit image is projected on the sample as illumination light, and is scanned perpendicularly to the longitudinal direction of the slit by a galvanomirror arranged at the rear focal point of the objective lens. Reaction light such as fluorescence from the sample is collected by the objective lens and forms a slit image again on the second slit.

Since the second slit is arranged at a position conjugate with the first slit, they constitute a confocal optical system, which suppresses light other than the slit image illumination light from passing through the second slit, and Improve resolution and contrast.

When the rear focal point of the objective lens is within the objective lens, a conjugate position with the rear focal point may be formed outside the lens by adding a relay lens, and a galvanomirror may be installed there.

If a spectroscope for dispersing the slit image passing through the second slit is provided in the optical path between the second slit and the imaging device, the slit image can be wavelength-resolved.

If the imaging device is provided with a storage device that captures a wavelength-resolved image of the slit image and stores the data of the wavelength-resolved image in synchronization with the scanning drive of the galvanomirror, the storage device is provided for each wavelength. Can be stored in association with the sample position.

[0010] Based on the data stored in the storage device,
If a processing device for synthesizing a sample image for each wavelength and a display for displaying the sample image are provided, a sample image for each wavelength obtained by synthesizing a plurality of slit images can be displayed on the display. it can.

When the second slit forms the entrance surface of the streak tube, and the exit surface of the streak tube faces the imaging device, the slit image can be resolved in time.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a slit image detecting device according to an embodiment will be described. The same elements will be denoted by the same reference symbols, without redundant description.

FIG. 1 is a system configuration diagram of the slit image detecting device. Illumination light emitted from the light source 1 is condensed by an optical unit with a spectroscope 2 that forms a slit image, converted into a substantially parallel light beam in one direction by a cylinder lens, and condensed light in the other direction, and converged on a scanner 3. It is arranged so that the lightized light is focused. The slit image is projected on the sample S via the scanner 3. The sample is placed on the stage 4. The slit image as illumination light scans the surface of the sample S along the X direction by driving the scanner 3 by the scanner driver 5. The scanner controller 6 generates a synchronization signal for driving the scanner driver 5 according to an instruction from the computer 10. Note that the slit image itself has the Y direction as its longitudinal direction.

The reflected light of the sample S illuminated by the slit image or, if the illuminating light is excitation light, self-generated light in the sample is again introduced into the optical unit 2 with a spectroscope via the scanner 3. Is done. The optical unit with a spectroscope 2 splits the slit image from the sample S by inputting the slit image to the spectroscope, and projects the wavelength-resolved slit image along the X direction on a TV camera (imaging device) 7. T
The V camera 7 itself is constituted by a solid-state image pickup device such as a CCD, and a driving signal of the CCD is inputted from a camera controller 8, and a video signal from the CCD is inputted to a frame grabber 9 via the camera controller 8. You.

The frame grabber 9 extracts from a video signal of a specific pixel row on a CCD image pickup surface in which a plurality of pixels are arranged in a matrix. When a video signal from a specific pixel row is output from the CCD t seconds after counting from the reference row on the imaging surface, the frame grabber 9 samples only the video signal t seconds after the reference row and sends it to the computer 10. input.
This pixel row is specified by the computer 10.

The computer 10 includes a CPU 10a, an RA
An M10b and a storage device 10c are provided to control the entire system. The computer 10 controls the scanner controller 6, which controls the swing of the scanner driver 5, the frame grabber 9, and the display 11. Of course, the scanner controller 6 and the frame grabber 9 can be constituted by the computer 10.

While scanning the sample S with the slit image on the sample S, the video signal of a specific pixel row (corresponding to the wavelength) on the CCD image pickup surface is sampled by the frame grabber 9 and taken out. 10c. That is, the angle of the scanner 3 (the position of the slit image in the X direction on the sample S) and the data of the slit image of the specific wavelength λ at this position are stored in the storage device 10c in the computer 10 in association with each other. At time t = 1, 2, 3, 4, 5, the X-direction position of the slit image on the sample S: X = 1, 2, 2
3, 4, and 5. The Y direction position of the slit image on the sample S is Y, and the wavelength is λ. Note that these units are arbitrary constants.

FIG. 2 is an explanatory diagram showing an image on the image pickup surface of the TV camera 7 at time t = 1, 2, 3, 4, and 5 (FIG. 2).
(A) to (e)). FIG. 3 shows that each time t =
Graphs showing spectral distributions obtained by integrating slit images at 1, 2, 3, 4, and 5 in the Y direction (FIGS. 3A to 3E).
It is. For example, when obtaining a sample image with a wavelength λ = 2, the computer 10 instructs the frame grabber 9 to sample the video signal of the pixel column with λ = 2 in FIG. Thereby, the X on the sample S is stored in the storage device 10c.
The data of the slit image with the wavelength λ = 2 at the direction slit image position is obtained along the X direction, and when these are combined, a sample image with the wavelength λ = 2 is obtained.

FIG. 4 is an explanatory diagram showing sample images synthesized at λ = 1, 2, 3, and 4 (FIGS.
(F)). The data shown in FIGS.
Displayed above.

When the scanning of the slit image is repeated, the sample surface S
Since the data (X, Y, λ) can be obtained, the computer 10 can rearrange them and create an image showing the relationship between λ and X.

FIG. 5 is an explanatory diagram showing images on the image pickup surface of the TV camera 7 at the positions Y = 1, 2, 3, and 4 (FIGS. 5A to 5D). FIG. 6 shows that each position Y = 1,
It is a graph which shows the spectrum distribution of the slit image in 2, 3, and 4 (FIGS. 6A to 6D). When the spectrum (luminance I) distribution shown in FIG. 6 is integrated, a graph showing the integrated spectral distribution over the entire sample observation region is obtained as shown in FIG.

Next, an optical system for obtaining the wavelength-resolved image will be described.

FIG. 8 is a perspective view of an optical system applied to the slit image detecting device. This optical system includes a collimator lens 2a that converts light emitted from the light source 1 into parallel light. A plane perpendicular to the optical axis of the collimator lens 2a is defined by a YZ plane including the Y axis and the Z axis.
The light image emitted from the collimator lens 2a is input to a cylindrical lens 2b that focuses only light in the Z-axis direction. At the focal position of the cylindrical lens 2c, Y
A first slit 2c having an opening along the direction is arranged. The slit image that has passed through the first slit 2c is applied to the galvanomirror 3a constituting the scanner 3 by the focusing lens 2d. More specifically, a slit image is formed on the swing axis of the reflection surface of the galvanomirror 3a. Note that a beam splitter 2e is disposed in an optical path between the focusing lens 2d and the galvanometer mirror 3a.

The slit image as illumination light reflected by the galvanometer mirror 3a is focused by the objective lens 2f and forms an image on the surface of the sample S. Galvano mirror 3a
Is rotated with a controlled rotation angle, so that the surface of the sample S is scanned along the X direction by a slit image. The position of the pivot axis of the reflecting surface of the galvanometer mirror 3a is determined by the objective lens 2f.
At the rear focal position, which constitutes a telecentric optical system.

When the reflected light from the sample S or the illumination light is excitation light, self-generated light such as fluorescence is captured by the objective lens and returned to the light source by the galvanometer mirror 3a.
The second through the beam splitter 2e and the focusing lens 2g
An image is formed on the slit 2h. The second slit 2h has an opening along the Y direction, and when viewed from the sample position, the first slit 2h
And the second slits 2c and 2h are arranged at conjugate positions,
These constitute a confocal optical system. 2nd slit 2
The light image emitted from h is condensed by the condenser lens 2i,
The light is irradiated on the transmission diffraction grating 2j. The diffraction grating 2j wavelength-divides the incident slit image along the X direction, that is, splits and emits it. The wavelength-resolved slit image is formed on the imaging surface of the TV camera 7 via the lens 2k.

As described above, the slit image detecting apparatus includes the slit image projecting optical system 2 for projecting the slit image passing through the first slit (slit plate) 2c onto the sample S, and the slit projecting optical system 2 The objective lens 2f passes through a galvanomirror 3a disposed at a rear focal position, a second slit (slit plate) 2h disposed at a position conjugate to the first slit 2c when viewed from the focal position, and a second slit 2h. And an imaging device 2k for detecting the slit image.

According to the present apparatus, the slit image is scanned on the sample S by the galvanometer mirror 3a as illumination light. Self-generated light such as fluorescence from the sample S is captured by the objective lens, returned to the original direction again by the galvanomirror 3a, and forms a slit image on the second slit.

Since the second slit 2h is arranged at a position conjugate with the first slit 2c, they constitute a confocal optical system and suppress the passage of light beams other than the slit image through the second slit 2h, and Improve the resolution.

Here, since the galvanometer mirror 3a is arranged at the rear focal point of the objective lens 2f and functions as an aperture, it constitutes a telecentric optical system and can illuminate the sample S under the same conditions within the entire field of view. Even if the sample is a reflective object, the amount of light does not decrease around the visual field. Note that the rear focal position of the objective lens 2f may be moved to another location by a relay lens or the like.

In this apparatus, a spectroscope 2j for dispersing the slit image passing through the second slit 2h is provided in the optical path between the second slit 2h and the imaging device 7.
The slit image can be wavelength-resolved (spectroscopy).

In the present apparatus, the imaging device 7 includes a storage device 10c which captures an image obtained by wavelength-resolving the slit image and stores data of the wavelength-resolved image in synchronization with the scanning drive of the galvanometer mirror 3a. The storage device 10c can store the slit image for each wavelength in association with the sample position.

The present apparatus includes a processing device 10 for synthesizing a sample image for each wavelength based on the data stored in the storage device 10c, and a display 11 for displaying the sample image. A sample image for each wavelength obtained by synthesizing the images can be displayed on the display 11. In the case of this example, the processing device 10 includes a storage device 10c.

Although the confocal optical system is of the falling-emission type, the light receiving optical system composed of the optical components 2g, 2h, 2i, 2j, 2k and the imaging device 7 is arranged on the back side of the sample S. Alternatively, a transmission type configuration may be adopted. In this case, the objective lens 2g is arranged to face the sample, and the focal position is in the sample. The galvanomirrors 3a are respectively arranged at the rear focal points of the two objective lenses. In this case,
The first and second slits 2c and 2f have a conjugate relationship.
Note that the diffraction grating 2j may be any one that performs spectral separation.
A prism and an acousto-optic device can be provided. As the TV camera 7, a digital camera using a CCD was used.
A device using a MOS image sensor may be used. Also,
The data may be integrated before reading the data from each pixel (pinning). In this case, the reading speed of the video signal is increased, the wavelength resolution and the image resolution are reduced, or the S / N is reduced while the speed is kept constant. The effect of raising can be expected.

Further, the slit (opening) width of the first and second slits 2c and 2f can be adjusted. Since the data of the slit image is the luminance data of each pixel and the data of the position on the sample surface, if all the data is stored in the storage device 10c, the image can be reconstructed and displayed when necessary. Can be.

The present apparatus can be modified from the above-described wavelength-resolved configuration to a time-resolved configuration.

FIG. 9 is a perspective view of an optical system of a slit image detecting device of the type which resolves a slit image in time. The configuration of the apparatus is substantially the same as that shown in FIG. 1. In the above, a plurality of slit images wavelength-resolved using a spectroscope are captured by a TV camera 7, but in the following, a streak is used instead of a A plurality of slit images time-resolved using a camera are captured using a TV camera 7. In other words, in the above-described wavelength-resolving apparatus configuration, the present apparatus adopts a structure in which time-resolving is employed instead of omitting the spectroscope, and the wavelength is read as time. In this apparatus, a streak camera is used as a structure for time resolution. That is, the second slit 2h forms the entrance surface of the streak camera. More specifically, the streak camera has a second
It comprises a streak tube 12 having a slit 2h, a TV camera 7 facing the emission surface of the streak tube 12, and a coupling optical system for coupling an image emitted from the streak tube 12 to the TV camera 7.

The streak tube 12, after photoelectrically converting the incident slit image, periodically deflects the generated photoelectrons by a deflecting device, and time-resolves the light slit image along the deflection direction as an electron slit image in the deflection direction. Then, the electron slit image is made incident on the phosphor screen. Since the phosphor screen emits light in accordance with the electron slit image, a time-resolved slit image is emitted from the streak tube 12 along the deflection direction (X direction), and this slit image is projected on the TV camera 7. It will be.

In the TV camera 7, a slit image at a specific sample position is time-resolved and detected. Computer 1
Since 0 causes the galvanometer mirror 3 to swing so that the slit image as the illumination light scans the entire surface of the sample, time-resolved data of the slit image at all positions is stored in the storage device 10c. If a slit image at a specific time T seconds after the irradiation start or end time of the slit image as illumination light is synthesized at all positions, a sample image T seconds after the light irradiation can be obtained. Can be displayed on the display 11. Such a time-resolved slit image is useful for two-photon time-resolved fluorescence detection. As mentioned above,
In this device, the second slit 2h is connected to the streak tube 1
2 and the exit surface of the streak tube 12 faces the imaging device 7, so that the slit image can be time-resolved.

[0039]

According to the present invention, it is possible to provide a slit image detecting device capable of improving the slit image detecting accuracy.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a slit image detection device.

FIG. 2 is an explanatory diagram showing an image on an imaging surface of a TV camera 7 at times t = 1, 2, 3, 4, and 5;

FIG. 3 is a graph showing a spectral distribution of a slit image at times t = 1, 2, 3, 4, and 5;

FIG. 4 is an explanatory diagram showing a sample image synthesized at λ = 1, 2, 3, and 4;

FIG. 5 shows a TV camera 7 at positions Y = 1, 2, 3, and 4.
FIG. 4 is an explanatory diagram showing an image on the imaging surface of FIG.

FIG. 6 is a graph showing a spectral distribution of a slit image at positions Y = 1, 2, 3, and 4;

FIG. 7 is a graph showing an integrated spectrum distribution over the entire sample observation region.

FIG. 8 is a perspective view of an optical system applied to the slit image detecting device.

FIG. 9 is a perspective view of an optical system of a slit image detection device of a type that time-resolves a slit image.

[Explanation of symbols]

2c: slit plate, S: sample, 2: slit image projection optical system, 2f: objective lens, 3a: galvanometer mirror, 3b ...
Swinging mechanism, 2h ... second slit plate.

Claims (5)

[Claims] 1. A slit image projection optical system for projecting a slit image passing through a first slit onto a sample, a galvano mirror disposed at a rear focal position of an objective lens of the slit image projection optical system, and the focal position A second slit disposed at a position conjugate with the first slit,
An image pickup device for detecting a slit image passing through the slit. 2. A spectroscope for dispersing a slit image passing through the second slit in an optical path between the second slit and the imaging device.
3. The slit image detecting device according to item 1. 3. The image pickup apparatus according to claim 1, further comprising: a storage device for picking up an image obtained by wavelength-resolving the slit image and storing data of the wavelength-resolved image in synchronization with scanning drive of a galvanomirror. The slit image detecting device according to claim 2. 4. The apparatus according to claim 3, further comprising: a processing device for synthesizing a sample image for each wavelength based on the data stored in the storage device; and a display for displaying the sample image. The slit image detecting device according to the above. 5. The slit image according to claim 1, wherein the second slit forms an entrance surface of the streak tube, and an exit surface of the streak tube faces the imaging device. Detection device.