JPH07311089A - Spectral characteristics measuring device - Google Patents

Abstract

(57) [Summary] [Object] To provide a spectral characteristic measuring device having a compact structure capable of accurately analyzing a two-dimensional spectral characteristic of all arbitrary continuous wavelength regions in the visible region of light from a subject. [Structure] A slit means 2 for extracting light from a subject 1 as a slit-shaped section, an optical system 4 for converting the light from the slit into parallel light, and a spectroscopic element 5 for separating the parallel light to generate a spectral image. An area sensor 7 for capturing a spectral image to obtain image data for each slice, and an image sensor for scanning the subject 1 to analyze the image data for each slice scanned to obtain two-dimensional spectral characteristic data. It is composed of means 8 and the like. An imaging element 6 that is replaceable with a spectroscopic element for obtaining an optical image of the subject 1 is provided, and a sensitivity characteristic correction device 9 that corrects the wavelength dependence of the area sensor 7 is additionally provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to light reflected from a subject,
The present invention relates to a spectral characteristic measuring device that analyzes spectral characteristics of an arbitrary continuous wavelength range in the visible region such as scattered light.

[0002]

2. Description of the Related Art The following are examples of methods and devices for analyzing the color tone (spectrum of visible light) of a subject. That is, those disclosed in JP-A-2-226027,
There are a method using a photo diode array, a method using a CCD camera sensitive to the three primary colors of RGB, and a method using a CCD camera using an optical filter that transmits only a specific wavelength.

The "spectroscopic analysis device" disclosed in Japanese Patent Laid-Open No. 2-226027 receives light of an object to be measured (subject) and forms an optical image, and a measurement target area consisting of one line or one point is formed by a lens. After the extraction, a spectral image is created with a diffraction grating, and the light intensity of a predetermined wavelength in this spectral image is detected. The measurement is repeated while moving the measurement target region to obtain a two-dimensional spectroscopic image.

The method using a photodiode array is a method in which light from a subject is guided onto an element in which photodiodes are arranged linearly, that is, a photodiode array to obtain a spectrum.

A method using a CCD camera of three primary colors of RCG is to measure a color tone by a sensitivity ratio of a sensor having peaks at three wavelengths of red, green and blue.

The last one using an optical filter and a CCD camera is one in which light from a subject is imaged and analyzed by a CCD camera using a plurality of optical filters that transmit only specific wavelengths.

[0007]

The above-mentioned conventional techniques have their respective characteristics, but have the following problems. That is, in the "spectroscopic analysis device" of JP-A-2-226027, the image forming position is not constant because the lens of the optical system is a single focus system. In particular, the more obliquely the light is incident on the lens, the more the deviation becomes and the aberration occurs. For this reason, the diffraction grating side is moved and corrected, but this correction operation is extremely difficult, and there is a problem that accurate spectral characteristics cannot be obtained. Also,
In the method using the photo diode array, the light emitted from one point of the subject is the measurement target, so some scanning is required to obtain two-dimensional spectral data, and the optical system is very complicated. It becomes difficult to measure and becomes expensive. The method using a CCD camera of three primary colors of RCG detects the color tone by a sensor having peaks at three wavelengths of red, green, and blue as described above, and the wavelength measured is limited, and the spectrum of any visible light region is limited. Not suitable for analysis. Further, in the case of using an optical filter and a CCD camera, it is necessary to prepare a large number of filters that transmit a wavelength region to be measured, and each time the filter needs to be replaced, which takes time and is troublesome.

The present invention was devised in order to solve the above-mentioned problems of the prior art. The apparatus structure is compactly arranged, and the reflected light from the subject and the scattered light are all continuous in any visible range. It is an object of the present invention to provide a spectral characteristic measuring device capable of accurately analyzing a two-dimensional spectral characteristic in the selected wavelength range.

[0009]

In order to achieve the above object, the present invention provides slit means for cutting out light emitted from a subject into a linear shape and extracting a segment, and a subject relative to the slit means. Scanning means for sequentially selecting and scanning the extracted slices by sequentially moving it, an optical system for converting the cut-out light into parallel light, and a spectroscope for generating a spectral image of the slice extracted from the subject by dispersing the parallel light. Spectral characteristic measurement including an element, an area sensor that captures the spectral image for each slice and outputs corresponding image data, and an analysis unit that performs arithmetic processing on the image data to synthesize a two-dimensional spectral image of a subject It constitutes a device. Further, the spectroscopic element is composed of a direct-viewing prism that can be linearly arranged with respect to the optical system, and is equipped with an image-forming element whose position can be exchanged with the spectroscopic element, so that an optical image of a subject can be taken. It is characterized by becoming.

[0010]

The light from the subject is cut out into slits by the slitting means and becomes a slice. By moving the subject with the scanning mechanism, the slices are continuously scanned and extracted. The light from the section is exchanged into parallel light by an optical system, and a spectroscopic image is obtained by the spectroscopic element. The spectral image for each section is output by the area sensor as image data expressing the position and wavelength distribution. In the present invention, the reflected light or scattered light from the subject is once converted into parallel light, and then spectral processing is performed, so that influences such as aberration of the optical system can be removed. It should be noted that when an optical image of a subject is taken, it becomes possible by using an image-forming element whose position can be exchanged with the spectroscopic element.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing the overall configuration of this embodiment, FIG.
Is a perspective view showing an optical schematic structure of the embodiment, and FIG. 3 is a partial perspective view showing an operation in which imaging elements are combined.

As shown in FIG. 1, the spectral characteristic measuring apparatus of this embodiment is roughly classified into a slit means 2, a scanning mechanism 3 for scanning an object 1, an optical system 4, and a spectroscopic element 5.
The image forming element 6, the area sensor 7, the analyzing unit 8 and the like. Further, a sensitivity characteristic correction device 9 for correcting the image data output from the area sensor 7 based on the correction coefficient 10 is additionally provided.

When light from an illumination light source from a reflection illumination unit or a transmission illumination unit (not shown) is incident on the subject 1, light rays such as reflected light or scattered light are emitted from the subject 1 as shown in FIGS. 1 and 2. Is fired.

The scanning mechanism 3 comprises an X, Y slide stage 3a for moving the subject 1 in the X and Y directions as shown in FIG. 2, and selectively scans the slices of light to the slit means 2 side. Is.

The slit means 2 comprises a plate-like body 2a having a slit 11 as shown in FIG. 2, and the light beam from the subject 1 is extracted as a linear segment by passing through the slit 11. The slits 11 are arranged orthogonal to the one-dimensional movement direction of the X, Y slide stage 3a.

The optical system 4 converts reflected light or scattered light emitted from the extracted slice into parallel light, and for example, a parallel light generation system 4a having a parallel light generation means incorporated in a metal microscope is used.

The spectroscopic element 5 disperses the parallel light from the optical system 4, and an optical element such as a prism or a diffraction grating is adopted. Preferably, the spectroscopic prism 5a shown in FIG. A type prism (Amish type prism) is preferable. This is because the structure is simple and the optical systems can be arranged in a straight line. In the present invention, the light emitted from the subject 1 is converted into parallel light and then spectral processing is performed, so that it is not affected by the aberration of the focusing optical system as in the conventional case. In addition,
As shown in FIG. 3, in order to capture an optical image of the subject 1, the image forming element 6 may be used so that the position thereof can be exchanged with the spectral prism 5a.

The area sensor 7 is for picking up the dispersed light, and is normally used because a monochrome CCD camera 7a is suitable in terms of performance and inexpensive. As a result, image data expressing the position and the frequency on the orthogonal axes can be obtained. That is, assuming that the length direction of the slit 11 of the slit means 2 is the X axis and λ is the wavelength, (Xi, λk) = 5.
Image data indicating the spectral intensity of light like 0 is obtained.
The expression (Xi, λk) = 50 means that the intensity of the light having the wavelength λk at the position Xi on the X axis is 50.

The analysis means 8 is for synthesizing the image data of the slice into a two-dimensional spectral image. By scanning the subject 1 with the scanning mechanism 3, the image data at each scanning position can be obtained. By scanning the subject 1 in the Y-axis direction orthogonal to the X-axis by the scanning mechanism 3, it is possible to obtain image data such as (Xi, Yj, λk) = 22. This data indicates that the intensity of light of wavelength λk at the two-dimensional coordinates Xi, Yj is 22 when the j-th scanning position is Yj. The analysis means obtains the intensity distribution of two-dimensional coordinates of all the wavelengths of the light beam emitted from the subject in an arbitrary visible region. Thereby, the two-dimensional spectral characteristic of the subject 1 can be accurately measured. As described above, by using the image forming element 6 such as a lens instead of the spectroscopic element 5, the optical image of the subject can be confirmed.

The received light intensity of the area sensor 7 has wavelength dependence. Therefore, correction is necessary to obtain accurate image data. A correction coefficient 10 is prepared in advance from the spectral sensitivity characteristic of the area sensor 7. This is the sensitivity characteristic correction device 9
To correct the image data from the area sensor 7. The analysis unit 8 creates corrected image data in which the spectral sensitivity characteristic of the area sensor 7 is added.

[0021]

According to the present invention, the following remarkable effects are obtained. 1) It is possible to accurately obtain a two-dimensional spectroscopic image in an arbitrary continuous wavelength range in the visible region from a subject. 2) The effect of aberration of the optical system can be removed by once converting the light from the subject into parallel light and then dispersing the light. 3) It is also possible to capture an optical image of the subject. 4) Since the spectral sensitivity characteristic of the element of the area sensor is corrected and the image is analyzed, more accurate image data can be obtained. 5) Since each component is arranged linearly optically, it can be compactly assembled. 6) The measurement operation is easy and a two-dimensional spectroscopic image is automatically obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing an optical arrangement of the present embodiment.

FIG. 3 is a partial perspective view showing another operation using an imaging element instead of the spectroscopic element in FIG.

[Explanation of symbols]

 1 subject 2 slit means 2a plate-like body 3 scanning mechanism 3a X, Y slide stage 4 optical system 4a parallel light generation system 5 spectroscopic element 5a spectroscopic prism 6 imaging element 7 area sensor 7a monochrome CCD camera 8 analysis means 9 sensitivity characteristic correction Device 10 Correction factor 11 Slit

Claims (3)

[Claims] 1. The light emitted from a subject is cut out in a line shape,
Slit means for extracting a section, scanning means for sequentially selecting and scanning the extracted sections by moving a subject relative to the slit means, an optical system for converting the cut out light into parallel light, and the parallel light. A spectroscopic element that generates a spectral image of a slice that is obtained by spectrally separating the image from the subject, an area sensor that captures the spectral image for each slice and outputs corresponding image data, and the subject that performs arithmetic processing on the image data An apparatus for analyzing spectral characteristics, characterized by comprising an analyzing means for synthesizing the two-dimensional spectral image of the. 2. The spectral characteristic measuring device according to claim 1, wherein the spectroscopic element is a direct-view prism which can be linearly arranged with respect to the optical system. 3. The spectral characteristic measuring device according to claim 1, further comprising an image-forming element whose position can be exchanged with the spectroscopic element, so that an optical image of a subject can be picked up.