JPH03146832A - Surface scanning type two-dimensional image spectrographic device - Google Patents

Abstract

PURPOSE:To measure a wide space area without impairing space sharing and to obtain a precise two-dimensional image by correcting the change of an operating distance with a material by combining a turning plane mirror for optical scan with a surface measuring optical system with constant angle of view. CONSTITUTION:A beam 2 of light from a light source is fetched with the turning plane mirror 10, and is turned to a plane beam reduced with objective lenses 20, 25, and a beam 5 of light passing an incident slit 30 image-forms a light source image on a diffraction grating 60 with a collimator mirror 40. In such a case, strict image- forming is not required, but it can be performed in the neighborhood of the 0-order light reflecting plane of a diffraction grating 60. Diffracted light 6 corresponding to wavelength advances a camera mirror 45, and passes an emission slit 80, then, is turned to light with narrow wavelength width. The light is turned to parallel beams 7 of light advancing a collimator mirror 50 with a plane mirror 75, and is made incident on a diffraction grating 65 at the same angle of refraction as that of the diffraction grating 65, then, is parallelized with a camera mirror 55. At this time, a dispersed component by the diffraction grating 60 is negated completely with the diffraction grating 65, thereby, an image without generating bleeding can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-dimensional image spectrometer, and more particularly to a surface scanning two-dimensional image spectrometer suitable for observing a space with a wide angle of view.

[Conventional technology]

The conventional device is Anal Sam 5th volume (1985) 20
pages 4-9 to 2055 (Anal, Chem, 57
(1985), PP 204-9-2055, and U.S. Patent No. 4,705,396 (1987).
It is described in detail in the November 10, 2013 patent).

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the field of view of the target space that can be measured, and has a relatively short working distance and a wide area.
In other words, observation with a wide angle of view was difficult.

Furthermore, the image of the light source emitting a continuous spectrum included image blur due to wavelength dispersion.

An object of the present invention is to provide a two-dimensional image spectroscopy device that compensates for the drawbacks of the prior art and easily enables observation with a wide angle of view.

[Means to solve the problem]

In order to achieve the above object, a light scanning means is combined with a surface observation means having a fixed angle of view using a conventional two-dimensional image spectrometer.

Furthermore, a light scanning means is combined with a surface observation means having a constant angle of view using a zero-dispersion type two-dimensional image spectrometer.

Further, as these optical scanning means, a plane mirror is used which rotates back and forth in a stepwise manner within a certain angle around an axis within its reflecting surface.

Still another optical scanning means uses a polygonal rotating mirror that rotates around an axis that is parallel to the reflecting surface and out of the plane.

Still another optical scanning means uses a rotating plane mirror mounted at an angle that is not perpendicular to the rotation axis.

Still another two-dimensional optical scanning means is a combination of any two of the above optical scanning means at right angles.

Furthermore, focusing means is provided to deal with changes in the working distance between the virtual plane of the target space and the introducing optical system due to optical scanning.

Furthermore, the image processing means automatically corrects distortions in the observation space that occur due to optical scanning.

[Effect]

Unlike the conventional point-to-point method that scans a point two-dimensionally to obtain surface information, the optical scanning means scans a surface of a fixed angle of view one-dimensionally or two-dimensionally to obtain surface information of a fixed angle of view. This provides a field of view as wide as an integer. Therefore, this method is called a surface scanning method to distinguish it from the conventional point scanning method.

In surface scanning, there is no need to continuously vary the scanning angle; instead, two steps are performed for a fixed angle of view corresponding to the solid angle determined by the area of the diffraction grating of the two-dimensional image spectrometer and the focal length of the mirror. All you have to do is scan in the same way.

In addition, by combining continuous scanning means and electronic shutter function,
The capture angles of view may be arranged adjacent to each other in a stepwise manner.

Now, if you scan M screens in the horizontal direction and N screens in the vertical direction,
A total of MXN screens will be divided into MXN times and captured. Let screen capture time ta and optical scanning time ts be,
The total time t is t=M-N (ta+ts), and it takes MXNXN more time than when optical scanning is not performed.

For example, M=5. Considering one-dimensional optical scanning with N=1, five screens in the horizontal direction are sequentially captured.

In FIG. 2, if the angle between the central field of view 83 and the field of view 82 or 84 (the center of the field of view) is 01, then the angle 02 between the field of view 8 or 85 is smaller than 20x. When scanning the acquisition declination in a stepwise manner, corresponding to the field of view number,
It is necessary to optimize the value of the declination angle. Naturally, adjacent fields of view may overlap to some extent.

If the size of the basic screen with a constant angle of view is 10×10an, and the distance Qo from the reference point 89 of the scanning means is 800, then the first
The declination angle θ1 is 7.13", and the distance Q1 to the center of the screen is 80.
6(1). On the other hand, the second declination angle θ2 is 14.04',
The distance Qz increases to 82.5an.

This situation is shown in FIG. 2, where the half angle of view α corresponds to 1/2 of one side of the basic screen, and is α=3.58°. Furthermore, as a result of the distance a increasing at both ends of the scan, the image at the relevant portion is reduced and the field of view is expanded, resulting in overlap between the screens.

In this way, when optical scanning is performed, the working distance changes due to the supplementary angle, so it is necessary to enlarge or reduce the detected image or correct image distortion.

FIG. 3 shows the relative fields of view 91 to 85 when the observation surfaces 81 to 85 on the virtual plane 86 in FIG. 2 are taken in through the optical scanning means.
95 is shown. The distance S between the visual field centers on the horizontal axis 96 is the same. It can be seen that the image of the object on the virtual plane 86 is subjected to image distortion due to the difference in distance from the center of declination 89 to the virtual plane 86 (FIG. 2).

Although the illustration in FIG. 3 is slightly exaggerated, at the end of the optical scan, the field of view expands as the working distance Q increases, and this also differs between the left and right sides of the field of view. 99 is an overlapping part of the visual field. Since objects in the enlarged field of view are observed in a relatively reduced size, if the image is enlarged in proportion to the vertical length (97) of the box 91 of the field of view in Figure 3, a distortion-free image can be reproduced. You can.

However, for example, when the deviation angle 0 is 5 degrees or less and the number M of horizontal scanning screens is 3, the maximum image distortion is about 1% or less, and there is usually no need to perform correction.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. One-dimensional surface scanning is performed with the number of horizontal scans M=3, and the rotating plane mirror 10 for scanning is fixed vertically to a rotary table 18 on which a lever 15 that is in contact with an eccentric cam 12 and slowly moves in a horizontal plane is attached. There is. The objective lens 20° 25 causes the light 4 from the rotating plane mirror 10 to enter the entrance slit 30 of the spectrometer 100 as a parallel beam. The spectrometer 100 includes two collimating mirrors 40.50, two camera mirrors 45.55, a plane diffraction grating 60.65 that rotates as a unit, a polarizing plane mirror 35.70,
75, 9o, and an exit slit 80, and further includes an imaging spherical mirror 105. Image for optical amplification
An intensifier (abbreviated as II) 110, a two-dimensional array camera (abbreviated as CCD camera) 115 using a semiconductor charge-coupled device, an image processing device 1209 and an image monitor 130
It is equipped with

Now, the light ray 2 from the light source is taken in by the rotating plane mirror 10, becomes a reduced plane light beam by the objective lens 20.25, and the light ray 5 passing through the entrance slit 30 is transmitted to the collimating mirror 4.
0, a light source image is formed on the diffraction grating 60. In this case, the image should not be formed strictly, but rather in the vicinity of the O-order light reflection plane of the first diffraction grating. The diffracted light beam 6 corresponding to the wavelength is directed toward the camera mirror 45 and passes through the output slit 80 to become only light having a narrow wavelength width. This is a plane mirror 75 and a collimating mirror 50
The parallel light rays 7 are directed toward the 1st diffraction grating 65, and the diffraction grating 6
It is incident at the same angle as the diffraction angle of 0.

The camera mirror 55 parallelizes the images. At this time, the dispersion component caused by the diffraction grating 60 is completely canceled by the diffraction grating 65, and an image without blur can be obtained.

Therefore, this two-stage spectrometer is of zero dispersion type.

Plane mirror 90. A reduced image is made incident on the photocathode of IIIO by a spherical mirror 105. In step 110, the light quantity weakened by an optical element such as a slit is recovered and incident on a CCD camera 115, where it is converted into a video signal 116 and sent to an image processing device 12.
Incorporated into 0. The three captured images are displayed as three images 131 to 133 on the image monitor 130 in pseudo color or the like in accordance with the light intensity.

Rotation of eccentric cam 12, IIIO, CCD camera 11
The illustration of the drive control No. 5 is omitted.

FIG. 4 shows another mechanism for swinging the rotary plane mirror 10, in which a swing lever 15 is in contact with a rotating cam 16 and pulled by a tension spring 19. Since the rotating cam 6 is formed in a step shape with a cam radius r+ corresponding to the deflection angle θ, the rotating shaft 13
When continuously rotated around the rotating plane mirror 10, the rotating plane mirror 10 can perform step-like optical scanning in which it remains stationary for a certain period of time. This is in contrast to the need to rotate an eccentric cam intermittently.

FIG. 5 is an example of two-dimensional surface scanning, in which a rotating plane mirror 210
The rotating plane mirror 31 swings 217 around the axis 211.
0 swings 317 around an axis 311. At this time, the axes 217 and 317 are at right angles, and the vertical scanning 2
03 and horizontal scanning 202, respectively.

FIG. 6 shows an optical scanning mechanism using a rotating polygon mirror 220, in which a reflecting mirror surface 225 changes direction by rotation 227 about a rotation axis 221 to perform horizontal scanning 202. Can be done.

The incident light rays 201 are extracted in the same exit direction 204.

FIG. 7 shows another optical scanning mechanism, in which a rotating plane mirror 230 is attached to a rotating shaft 231 at an eccentric angle O. This rotation 2
37, the result will be as shown in FIG. 3(b) after, for example, half a rotation. As a result, the first field of view 86 to 89 shown in FIG. 8 can be rotated and scanned along the central trajectory 97.

FIG. 9 is an explanatory diagram of the automatic focusing mechanism, and shows the observation surface 82.
The light rays l from ~84 are selected by the swinging of the rotating plane mirror 10, pass through the movable lens 20, become parallel light rays 4, and enter the input line 1-30 of the spectrometer 100. Lens drive stand 29. The scanning mechanism 19 and spectrometer 100 are connected to an interface circuit 240 connected to a storage/arithmetic device 250 .

Wavelength scanning within the spectrometer 100 is performed using a drive signal 241,
The position of the lens 20 is corrected to correct the change in the refractive index of the lens material due to wavelength, but this is done using the lens drive signal 29.
controlled by On the other hand, the rotating plane mirror 10 receives the optical scanning signal 2.
43, but since this is managed by the storage/arithmetic unit 250, the optimal lens position is calculated according to changes in the wavelength and working distance of the spectrometer by commands 251 to the interface circuit 240 and status reading 252. can be specified.

FIG. 10 shows an example of automatically correcting image distortion, in which the CCD camera 115 receives a capture command signal 244 from the interface circuit 240 and sends a video signal to the image processing device 120. On the other hand, the storage/arithmetic device 250 controls the rotary plane mirror 10 for optical scanning and stores its declination state, so it provides the data 245 to the image processing device 120 .

As a result, coordinate processing is performed in the image memory, and the distorted image 134 on the image monitor 130 is converted into a corrected image 135 and displayed.

〔Effect of the invention〕

According to the invention, I I , CCD with the same spatial resolution
Using cameras and the like, vast spatial regions can be measured without compromising spatial resolution. Moreover, the means for scanning the surface required for this can be achieved using conventional optical scanning technology.

Furthermore, it is possible to obtain an accurate two-dimensional image by correcting changes in the working distance to the object due to surface scanning.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a perspective view of an embodiment of the present invention. Fig. 3 is an explanatory diagram of the principle of surface scanning, Fig. 4 is a diagram showing an example of a mechanical surface scanning mechanism, Fig. 5 is an explanatory diagram of the principle of two-dimensional scanning, and Fig. 6 is a diagram illustrating the principle of two-dimensional scanning.
Fig. 7 is a diagram showing another example of optical scanning, Fig. 8 is an explanatory diagram of the field of view, Fig. 9 is an explanatory diagram of the automatic focusing mechanism, and Fig. 10 is an explanatory diagram of the automatic image distortion correction function. It is.

Claims (1)

[Claims] 1. A spectroscope that monochromates light, an introduction optical system that allows parallel light to enter an input slit of the spectrometer, and a system that forms an image of the parallel light that has passed through an output slit of the spectrometer. In a two-dimensional image spectrometer comprising an imaging optical system and a two-dimensional semiconductor camera or a two-dimensional optical amplifier and a two-dimensional semiconductor camera installed on the imaging plane, one-dimensional or two-dimensional light is introduced into the introduction optical system. A surface scanning two-dimensional image spectrometer comprising a scanning means. 2. In the apparatus described in item 1, the spectrometer for monochromating light is a zero-dispersion type consisting of two Czerny-Turner type spectroscopic optical systems using a plane diffraction grating as a dispersive element. Scanning two-dimensional image spectrometer. 3. In the apparatus described in item 1 or 2, the optical scanning means includes one plane mirror that reciprocates in a stepwise manner within a certain angle around a rotation axis included in its reflection surface, or at right angles to each other. A surface scanning two-dimensional image spectrometer characterized in that a two-dimensional image spectrometer is used in combination. 4. In the apparatus described in item 1 or 2, one polygonal rotating mirror formed around a rotating axis parallel to the reflecting surface of the optical scanning means, or two mirrors combined at right angles to each other. A surface scanning two-dimensional spectrometer characterized by using. 5. Surface scanning in the apparatus according to item 1 or 2, characterized in that a rotating plane mirror is used as the optical scanning means, the maximum deviation angle of the scanning mirror being equal to the deviation angle from the vertical plane of the rotation axis. Two-dimensional image spectrometer. 6. Surface scanning in the apparatus described in item 1 or 2, characterized in that the two-dimensional optical scanning means is a combination of any two of the optical scanning means described in items 3 to 5. Two-dimensional image spectrometer. 7. In the apparatus described in Items 1 to 6, the optical scanning means and the focusing means of the introduced optical system are linked so that the focus at the center of the screen can always be maintained on the virtual plane of the target space. A surface scanning two-dimensional image spectrometer characterized by the following. 8. In the apparatus described in Items 1 to 7, the visual field distortion is corrected by automatically performing enlargement/reduction processing depending on the coordinates of the image for each screen in accordance with the declination angle of the optical scanning means. A surface scanning two-dimensional image spectrometer characterized by: