JPH09145477A - Spectroscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely select and adjust a wave length range and a spectral condition such as resolution. SOLUTION: A spectroscope is provided with a spectral means 2 on which the measuring light object is made incident and a light receiving element 4 on which the light spectrally dispersed by the spectral means 2 is made incident. The light receiving element 4 is an area image sensor such as a CCD to capture the incident light as a two-dimensional image, and for example, the spectral means 2 is composed of two diffraction gratings 21 and 22 or the like being independently driven, and makes the light under a different spectral condition incident on at least two different light, receiving parts 41 and 42 among a light receiving surface of the light receiving element 4. A detecting means independently detects intensity of the light under a different spectral condition from a light receiving result of the light receiving parts 41 and 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention of the present application relates to intensity measurement, that is, spectroscopic measurement for each wavelength of light.

[0002]

2. Description of the Related Art A spectroscope using a spectroscopic means such as a diffraction grating has long been used as a means for measuring a spectroscopic spectrum. Among these, recently, a multi-channel type spectroscope using a linear light receiving element has been actively used.

FIG. 8 is a diagram for explaining a schematic configuration of such a multi-channel type conventional spectroscope. FIG.
The conventional spectroscope shown in FIG. 1 is provided in a box (not shown) that houses the entire instrument, and an entrance slit 1 on which the light to be measured is incident, and a spectroscopic means 2 arranged at a position where the light passing through the entrance slit 1 is incident. And a linear light receiving element 3 arranged at an image forming position of the light dispersed by the spectral means 2, and a detection means (not shown) for detecting a spectral spectrum from the light reception result of the linear light receiving element 3. ing.

A reflection type diffraction grating or the like is typically used as the spectroscopic means 2. As the linear light-receiving element 3, a semiconductor light-receiving element such as a photodiode array is used as an example, and a plurality of segments for performing photoelectric conversion are arranged in a linear shape. The light from the spectroscopic means 2 is dispersed in a predetermined direction, and the dispersion angle changes for each wavelength. Therefore, if the linear light receiving elements 3 are arranged so as to match the dispersion direction, the light intensity for each wavelength can be measured.

In such a spectroscope, it is possible to simultaneously perform spectroscopic measurement of a plurality of wavelengths according to the number of each segment of the linear light receiving element 3 without changing the direction of the diffraction grating. From this, the spectroscope as shown in FIG. 8 is called a multi-channel type. In such a multi-channel type spectroscope, spectroscopic measurement of a plurality of wavelengths can be performed instantaneously without changing the direction of the diffraction grating that constitutes the spectroscopic means 2, and thus is effective for spectroscopic measurement of transient light such as a flash lamp. Is said to be.

[0006]

However, as can be seen from the above description, in the conventional spectroscope, the spectroscopic measurement conditions, that is, the wavelength range, the resolution, etc., depend on the groove width of the diffraction grating used in the spectroscopic means and the diffraction grating. Is a fixed one that is determined by the arrangement angle, the segment width of the linear light receiving element, and the like. In order to change the spectroscopic conditions, it is necessary to rotate the diffraction grating to change the arrangement angle, and the advantage of using the multi-channel type configuration is lost. The invention of the present application has been made to solve the above problems,
An object of the present invention is to provide a spectroscope capable of freely selecting and adjusting spectroscopic conditions such as wavelength range and resolution.

[0007]

In order to achieve the above object, the invention according to claim 1 of the present application provides a spectroscopic means arranged at a position where the light to be measured is incident, and light which is spectroscopically dispersed by the spectroscopic means. In the spectroscope having a light receiving element arranged at a position, the light receiving element is an area image sensor that captures incident light as a two-dimensional image, and the spectroscopic means is at least one of the light receiving surfaces of the area image sensor. It is possible to make light of different spectral conditions incident on two different light receiving portions, and further, it is possible to independently detect the intensity of light of the different spectral conditions from the light receiving result of the light receiving portion. Equipped with means.
Similarly, in order to achieve the above object, the invention according to claim 2 is the area image sensor according to claim 1, wherein the light receiving element is a charge coupled element. Similarly, in order to achieve the above object, the invention according to claim 3 includes a spectroscopic unit arranged at a position where the measured light is incident, and a light receiving element arranged at a position where the light dispersed by the spectroscopic unit is incident. In the spectroscope having, at least two photomultiplier tubes are arranged at the light receiving position as the light receiving element, and the spectroscopic means can make light of different spectroscopic conditions incident on the respective photomultiplier tubes. In addition, a detection unit capable of independently detecting the intensities of the light under the different spectral conditions from the light reception results of the photomultiplier tubes is provided. Similarly, in order to achieve the above object, the invention according to claim 4 is the structure according to claim 1, 2 or 3, wherein the spectroscopic means performs spectroscopic analysis under different conditions by two diffraction gratings having different spectroscopic conditions. Is. Similarly, in order to achieve the above object, the invention according to claim 5 is the structure according to claim 1, 2 or 3, wherein the spectroscopic means has one diffraction grating and at least two different diffraction gratings for the one diffraction grating. And a splitting optical element capable of splitting and inputting the light to be measured at an incident angle, and corresponding to light having different incident angles, different light receiving portions of the light receiving element or the photomultiplier tubes The incident surface is set. Similarly, in order to achieve the above purpose,
According to a sixth aspect of the present invention, in the structure of the first, second, third, fourth or fifth aspect, different spectral conditions are wavelength ranges, and the spectroscopic means causes light having different wavelength ranges to be incident on the light receiving surface of the area image sensor. It is configured to enter the different light receiving portions of them or the incident surfaces of the photomultiplier tubes.
Similarly, in order to achieve the above-mentioned object, the invention according to claim 7 is the structure according to claim 1, 2, 3, 4 or 5, wherein different spectral conditions are resolutions, and the spectroscopic means is configured such that light having different resolutions is used in an area. The light-receiving surfaces of the image sensor are configured to be incident on different light-receiving portions or the incident surfaces of the photomultiplier tubes.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a diagram illustrating a schematic configuration of a spectroscope according to a first embodiment of the present invention. The spectroscope shown in FIG. 1 has a spectroscopic unit 2 arranged at a position where the measured light is incident, and a light receiving element 4 arranged at a position where the light dispersed by the spectroscopic unit 2 is incident.

First, in the spectroscope of the present embodiment, as with the conventional one shown in FIG. 7, a box body (not shown) accommodating the entire instrument is provided with an entrance slit 1 through which the light to be measured enters. The width of the entrance slit 1 is, for example, 5 μm to 5 mm.
It is about. The spectroscopic means 2 arranged at the position where the light that has passed through the entrance slit 1 is incident is a major feature of the measuring instrument of this embodiment, and is composed of two diffraction elements arranged in a direction perpendicular to the optical axis direction. It is composed of gratings 21 and 22.

The two diffraction gratings 21 and 22 are both reflection type. The two diffraction gratings 21 and 22 are arranged so that the incident surface (which is also the emitting surface because of the reflection type) intersects with the optical axis at different angles, as shown in FIG. The grating constants of the two diffraction gratings 21 and 22 may be the same or different. Also, diffraction grating 2
Both 1 and 22 are arranged such that their grooves are in the vertical direction, and are configured so that diffracted light is dispersed in the horizontal direction.

Further, each of the two diffraction gratings 21 and 22 is provided with a drive motor (not shown) for changing the arrangement angle with respect to the optical axis to disperse an arbitrary wavelength. As the drive motor, an AC or DC servo motor or the like is used, and each can be controlled independently.
It is also possible to manually change the arrangement angles of the diffraction gratings 21 and 22.

On the other hand, the configuration of the light-receiving element 4 arranged at the position where the light split by the splitting means 2 is incident is also a major feature of the spectroscope of the present embodiment, and the incident light is two-dimensional. An area image sensor is used as an image. As the light receiving element 4, typically, an area image sensor including a solid-state image sensor such as a charge coupled device (CCD) is adopted. However, not limited to the CCD system, the XY address system and the CID (Charge Injection Depth)
vice) method, CPD (Charge Priming Device) method, CS
Other types such as the D (Charge Sweep Device) method may be used.

Further, the light passing through the entrance slit 1 is configured to reach the above-mentioned spectroscopic means 2 via the plane mirror 5 and the concave mirror 6. The concave mirror 6 is configured to connect the image of the entrance slit 1 to the entrance surfaces of the two diffraction gratings 21 and 22.

Further, the light emitted from the two diffraction gratings 21 and 22 constituting the spectroscopic means 2 is configured to form an image on the light receiving surface of the light receiving element 4 by the two toroidal mirrors 71 and 72. That is, the light emitted from the upper diffraction grating (hereinafter referred to as the first diffraction grating) 21 forms an image on the light receiving surface of the light receiving element 4 by the upper toroidal mirror (hereinafter referred to as the first toroidal mirror) 71, and the light at the lower side. The light emitted from the diffraction grating (hereinafter, second diffraction grating) 22 is configured to form an image on the light receiving surface of the light receiving element 4 by the lower toroidal mirror (hereinafter, second toroidal mirror) 72.

The image forming positions of the first toroidal mirror 71 and the second toroidal mirror 72 are formed so as to form images at different positions on the light receiving surface of the light receiving element 4. That is, the first toroidal mirror 71 forms an image of the first diffraction grating 21 on the upper light receiving portion (hereinafter, first light receiving portion) 41, and the second toroidal mirror 72 forms the lower light receiving portion (hereinafter, second light receiving portion). Part) 4
2 is formed so as to form an image of the second diffraction grating 22.

The light reception result of the light receiving element 4 is configured to be detected by a detection means (not shown). Specifically, the detection means is composed of a read circuit that reads the light reception result of the light receiving element 4 as an electric signal, a signal processing unit that processes the signal read by the read circuit, and obtains a spectrum.

As described above, the light receiving element 4 in this embodiment employs the area image sensor which captures the incident light as a two-dimensional image. An area image sensor that captures incident light as a two-dimensional image can function as if two linear image sensors are arranged side by side. That is, by reading out photoelectric signals of the first light receiving portion 41 and the second light receiving portion 42 of the light receiving surface of the area image sensor by a reading method called binning, two independent linear image sensors are provided by one area image sensor. The function of can be achieved.

The configuration of the read circuit of the detecting means will be described in detail below, including the above binning point. FIG. 2 is a diagram for explaining the configuration of the readout circuit of the detection means in the spectroscope of FIG. First, a CCD area image sensor (hereinafter referred to as a CCD sensor) is a device for obtaining image information by transferring and reading charges generated by the photoelectromotive force of a photodiode by a CCD. A frame transfer type is known. Of these, in the present embodiment that performs spectroscopic measurement, a frame transfer type readout circuit having a high signal-to-noise ratio is adopted.

The frame transfer type readout circuit includes a storage CCD 81 for accumulating electric charges generated by a light receiving CCD (not shown) constituting a light receiving surface, and a shift register for sequentially transferring the electric charges accumulated in the accumulation CCD 81. 82, and a take-out amplifier 83 that sequentially takes out signals from the shift register 82.

First, the charges accumulated under the gate electrode of each pixel of the light receiving CCD are transferred to the storage CCD 81 at high speed using the light receiving CCD. CCD81 for storage
Then, the charges are sequentially transferred in the vertical direction. That is, C for storage
If the pixels of the CD 81 are arranged in the first, second, third, and fourth columns from the upper side, the charge of the pixels in the first column becomes the pixel of the second column and the charge of the pixels in the second column becomes the third. The charges of the pixels of the third column, the charges of the pixels of the third column and the charges of the pixels of the fourth column are shifted to shift register 8
2 are simultaneously transferred to each of the two.

Normally, every time the charges of the pixels in the fourth column are transferred to the shift register 82, the reading amplifier 83 is used.
Operates to read the data in the shift register 82 one by one. When all the data has been read, the charge transfer of each pixel is performed again. That is, the charges of the pixels of the second column are transferred to the pixels of the third column, the charges of the pixels of the third column are transferred to the pixels of the fourth column, and the charges of the pixels of the fourth column are transferred to shift register 82 at the same time. Then, similarly, the data in the shift register 82 is read by the read amplifier 83, and the charge transfer is repeated. In this way, when all the charges initially accumulated in each pixel are transferred and read, one read of the photoelectric signal is completed.

If the data in the shift register 82 is not read every time charge is transferred once, but after the data is transferred several times, the binning can be performed.
That is, as shown in FIG. 2, for example, the charges of the pixels in the first column are assigned to the pixels of the second column, the charges of the pixels of the second column are assigned to the pixels of the third column, and the charges of the pixels of the third column are assigned to the pixel. The charges of the pixels in the fourth column are simultaneously transferred to the pixels in the fourth column to the shift register 82, and then the shift register 8
The charges of the pixels in the second column are shifted to the pixels of the third column, the charges of the pixels of the third column are shifted to the pixels of the fourth column, and the charges of the pixels of the fourth column are shifted without reading the data in 2. When the data is simultaneously transferred to the registers 82 and then the data in the shift register 82 is read out, the charges of the pixels in the third column and the charges of the pixels in the fourth column are added and read out. When the photoelectric signal is read out in this manner, it is equivalent to using the light-receiving CCD pixel group corresponding to the pixels in the third column and the light-receiving CCD pixel group corresponding to the pixels in the fourth column as one line image sensor. Become.

By thus performing binning for reading by adding charges of pixels in a plurality of columns, it is possible to set a plurality of light receiving portions for which signal reading is independently performed for one area image sensor. . Then, as described above, it is possible to simultaneously perform measurement under different spectroscopic conditions by making light under different spectroscopic conditions incident on the plurality of light receiving portions.

The above points will be described in more detail with reference to FIG. FIG. 3 is a view for explaining the light receiving portion of the light receiving element 4 in the embodiment of FIG. 1, and schematically shows the surface of the CCD area image sensor used as the light receiving element 4.

As shown in FIG. 3, CCD pixels forming a light receiving surface are laid in a matrix on the surface of the CCD area image sensor. These CCD pixels are shown in FIG.
If P (1,1) to P (M, N) as shown in
(X1, y1) to P (x1 + m1, y1 + n1) are set as the first light receiving portion 41, and P (x1, y2) to P (x
1 + m1, y2 + n1) is set as the second light receiving portion 42. Then, P (x1, y1) to P (x1 + m1, y
1 + n1) CCD pixel groups and P (x1, y2) to P (x
1 + m1 and y2 + n1) CCD pixel groups are collectively read out by the above-mentioned binning. That is, the charges are added in the vertical direction and read out collectively. In the horizontal direction, the position of each CCD pixel in the horizontal direction corresponds to the wavelength of the diffracted light.
The distribution of the photoelectric signal of the pixel shows the spectrum in the wavelength range.

Further, with respect to the CCD pixel group which is not set in the light receiving portion, the signal is not read out, or even if the signal is read out, it is removed from the measurement result by the subsequent arithmetic processing.

Next, the operation of the spectroscope of this embodiment having the above configuration will be described. First, the light that has passed through the entrance slit 1 enters the first diffraction grating 21 and the second diffraction grating 22 via the plane mirror 5 and the concave mirror 6. Then, the light reflected by the first diffraction grating 21 and the second diffraction grating 22 enters the light receiving element 4 via the first toroidal mirror 71 and the second toroidal mirror 72, respectively, while generating a predetermined spectrum. At this time, the light dispersed by the first diffraction grating 21 passes through the first toroidal mirror 71 and then the first light receiving portion 4 of the light receiving element 4.
The light which is incident on the first diffraction grating 1 and is dispersed by the second diffraction grating 22 passes through the second toroidal mirror 72 and then the second light receiving portion 4 of the light receiving element 4.
2 is incident. Then, the detecting means independently reads the photoelectric signal generated in each light receiving portion as described above.

Here, as described above, the two diffraction gratings 21,
No. 22 has a different arrangement angle with respect to the optical axis. Therefore, the diffraction gratings 21 and 22 have different wavelength ranges of diffracted light. That is, spectroscopy can be performed in two different wavelength ranges. For example, depending on the first diffraction grating 21,
While performing multi-channel spectroscopic measurement in the wavelength range of about 400 nm, the second diffraction grating 22 allows 400 nm-
It is possible to simultaneously perform multichannel spectroscopic measurement in the wavelength range of about 600 nm. In this case, 200
The result of the spectroscopic measurement in the wavelength range of nm to 400 nm is performed by signal readout of each pixel corresponding to the first light receiving portion, and the spectroscopic measurement in the wavelength range of 400 nm to 600 nm is performed for each pixel corresponding to the second light receiving portion. This can be done by reading the signal.

Although the above example is an example in which the wavelength range is different, it is also possible to make the resolution different. For example, the grating constant or the number of engraved lines (the number of grooves per unit length) of the first diffraction grating 21 and the grating constant or the number of engraved lines of the second diffraction grating 22 are made different, and the first diffraction grating 21 sets
The measurement is performed with a low resolution of about 0 nm width, and the second diffraction grating 22 measures with a high resolution of about 30 nm width. By doing this, for example, first, measurement is performed at a low resolution over a wide range of wavelengths to observe the entire spectrum, and then a specific narrow wavelength range is selected and measurement is performed at a high resolution. The detailed spectrum of can be observed.

As described above, when the two diffraction gratings 21 and 22 having different spectral conditions such as wavelength range and resolution are used as in this embodiment, the multi-channel spectroscopic measurement under different spectral conditions can be performed at the same time. Therefore, the degree of freedom in selecting and adjusting the spectral conditions is dramatically improved, and the measuring instrument is extremely easy to use.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram illustrating a schematic configuration of a spectroscope according to the second embodiment of the present invention. The spectroscope shown in FIG. 4 is, similar to that shown in FIG. 1, a spectroscopic unit 2 arranged at a position where the measured light is incident, and a light receiving element arranged at a position where the light dispersed by the spectroscopic unit 2 is incident. 4 and.

The measuring instrument of this embodiment differs from that of FIG. 1 in that the spectroscopic means 2 is constituted by one diffraction grating 23. The diffraction grating 23 is also arranged so that the groove extends vertically, as in the first embodiment. Also, diffraction grating 2
The concave mirrors 61, 62, 6 having three incident angles
3, the predetermined angle is different. In this case, unlike the first embodiment, the diffraction grating 23 is fixed and used.

More specifically, the concave mirror 6 as a splitting optical element that connects the light passing through the entrance slit 1 to the entrance surface of the diffraction grating 23 is formed by combining three concave mirrors 61, 62 and 63. . Three concave mirrors 61, 62, 6
3 are arranged side by side in the vertical direction so that the lights reflected by the respective concave mirrors 61, 62, 63 are incident on the diffraction grating 23 at different incident angles. As a result, the diffraction grating 23 is adapted to split light in three different wavelength ranges.

The light dispersed by the diffraction grating 23 is incident on the light receiving element 4 by the troy dile mirror 7 and forms an image. A CCD area image sensor is used as the light-receiving element 4 as in the above-described embodiment, but the light-receiving surface of the light-receiving element 4 corresponds to the three concave mirrors 61, 62, 63 in the horizontal direction. Three long light receiving parts 43, 44,
45 is set. That is, for example, the right concave mirror 61
An incident portion (hereinafter referred to as a first light receiving portion) 43 on the upper side of the light receiving element 4 is set corresponding to (hereinafter, a right concave mirror), and a middle portion of the light receiving element 4 is corresponding to a concave mirror 62 at a center (hereinafter, a middle concave mirror). The incident portion (hereinafter, second light receiving portion) 44 is set, and the lower incident portion (hereinafter, third light receiving portion) 45 of the light receiving element 4 corresponding to the left concave mirror 63 (hereinafter, left concave mirror) 45.
Is set.

The light emitted from the diffraction grating 23 and having a different wavelength range is transmitted by the toroidal mirror 7 to the light receiving element 4
Three horizontally long light receiving parts 43, 4 lined up and down
It is configured to form an image on each of 4, 45. That is, as shown in FIG. 4, the toroidal mirror 7 has a curvature not only in the horizontal direction but also in the vertical direction, and due to the difference in the wavelength of the diffracted light, the first reflected light reflected by the right concave mirror 61 is received. The light which is connected to the portion 43 and reflected by the middle concave mirror 62 to be dispersed is connected to the second light receiving portion 44, and the light which is reflected to the left concave mirror 63 and dispersed is connected to the third light receiving portion 45.

Further, the light receiving result of the light receiving element 4 is configured to be detected by a detecting means (not shown) as in the above-described embodiment, and the detecting means reads out the light receiving result of the light receiving element 4 as an electric signal. It is composed of a circuit and a signal processing unit for processing the signal read by the reading circuit to obtain a spectrum. Then, the detection means has the same configuration as the readout circuit of FIG. 2 described above, and performs readout while performing binning.

FIG. 5 is a view for explaining the light receiving portion of the light receiving element 4 in the embodiment of FIG. 4, and similarly to FIG. 3, the surface of the CCD area image sensor used as the light receiving element 4 is schematically shown. It is a thing.

As described above, in this embodiment, three vertically long light receiving portions 43, 44, 45 are set in the horizontal direction. Therefore, three CCD pixel groups are set as light receiving portions on the surface of the CCD area image sensor used as the light receiving element 4, as shown in FIG. That is, P (x2, y3) to P (x2 + m2, y3 +
n2) is set as the first light receiving portion 43, and P (x2,
y4) to P (x2 + m2, y4 + n2) are set as the second light receiving portion 44, and P (x2, y5) to P (x2 + m).
2, y5 + n2) is set as the third light receiving portion 45. Then, batch reading by binning is performed on each of the CCD pixel groups as described above.

The operation of the spectroscope of this embodiment having the above structure will be described below. Similar to the above-described embodiment, the light to be measured that has passed through the entrance slit 1 is reflected by the concave mirrors 61, 62, 63.
To reach the diffraction grating 23. At this time, the light is diffracted by the concave mirrors 61, 62 and 63 at different angles.
It is incident on 3. Each incident light is reflected by the surface of the diffraction grating 23 to generate a predetermined diffracted light. The diffracted light is reflected by the toroidal mirror 7 and reaches the light receiving element 4.

At this time, since the incident angle of the light incident on the diffraction grating 23 is different, the wavelength range of the diffracted light generated is also different for each incident angle. Therefore, lights having different wavelengths are dispersed from the diffraction grating 23, and the lights having different wavelengths are imaged on the respective light receiving portions 43, 44, 45 of the light receiving element 4. That is, the light from the right concave mirror 61 is connected to the first light receiving portion 43, the light from the middle concave mirror 62 is connected to the second light receiving portion 44, and the left concave mirror 63 is connected.
The light from is coupled to the third light receiving portion 45. Then, the photoelectric signals of the CCD pixel groups set in the light receiving portions 43, 44, and 45 are read out as described above, so that the spectral spectrum of the measured light is obtained.

As can be seen from the above description, the light receiving element 4 receives diffracted light of different wavelength ranges for each of the three light receiving portions 43, 44 and 45. Therefore, the spectrums obtained from the light receiving portions 43, 44 and 45 also have different wavelength ranges. For example, assuming that the incident optical axes to the diffraction grating 23 are different by about 10 degrees and the number of engraved lines of the diffraction grating 23 is about 400 grooves / mm, 200n
m-400 nm, 400 nm-600 nm, and 60
It becomes possible to perform spectroscopic measurement in three wavelength ranges of 0 nm to 800 nm.

Conventionally, as described above, multi-channel spectroscopic measurement in one wavelength range determined by the total length of the diffraction grating and the like cannot be performed, and in order to change the wavelength range, it is complicated to change the arrangement angle of the diffraction grating. Work was needed. However, according to the second embodiment, spectroscopic measurement can be performed in a plurality of different wavelength ranges without changing the arrangement angle of the diffraction grating 23. Therefore, a spectroscope that can easily perform spectroscopic measurement in a wide wavelength range is provided. Although light is incident on the diffraction grating 23 at three different incident angles in the above embodiment, it is sufficient if the light is incident at at least two different incident angles. It will be clear from the explanation.

Next, a third embodiment of the present invention will be described. FIG. 6 is a partial schematic diagram for explaining the configuration of the spectroscope of the third embodiment of the present invention. The third embodiment belongs to the invention of claim 3, and the light receiving element 4
It is an embodiment using a photomultiplier tube as.

In the third embodiment, in addition to the configuration of the optical system of the first embodiment, the switching mirror 91 and the slits 921 and 922 arranged at the positions where the light reflected by the switching mirror 91 is incident. Slit plate 92 with
And two photomultiplier tubes 931 and 932, which are arranged at positions where the light passing through the slits 921 and 922 are incident.

First, the switching mirror 91 is disposed on the optical path between the first and second toroidal mirrors 71 and 72 and the light receiving element 4 in the optical system shown in FIG. , 72 to reflect the light toward the slits 931 and 932. That is, as described above, the light dispersed by the two diffraction gratings 21 and 22 under different spectral conditions is reflected by the first and second toroidal mirrors 71 and 72, and then reflected by the switching mirror to enter the slits 921 and 922. After that, the light enters the photomultiplier tubes 931 and 932.

The switching mirror 91 can be retracted from the optical path by a driving mechanism using a solenoid or the like or a mechanism such as a manual lever. Whether the light receiving element 4 such as a CCD area image sensor is used. Whether to use the photomultiplier tubes 931 and 932 can be selected. In addition, with respect to the first and second toroidal mirrors 71 and 72, the light receiving surface of the light receiving element 4 and the slits 921 and 922 are in an optically conjugate relationship, and the light from the diffraction gratings 21 and 22 is a switching mirror 91. Depending on the arrangement state of, the light receiving element 4 or the slits 921, 922 is connected.

The photomultiplier tubes 931 and 93
2 is equipped with a detection means (not shown) that detects the intensity of each photocurrent and enables measurement of different spectral conditions. This detecting means is provided for each of the photomultiplier tubes 931 and 93.
It has an amplifier that amplifies the photocurrent from 2 and an arithmetic processing unit that processes the signal from the amplifier to calculate the intensity of a predetermined wavelength.

As can be seen from the above description, in the third embodiment using the slit plate 91 and the photomultiplier tubes 931 and 932, the number of wavelengths that can be simultaneously measured is limited to two. That is, only the light having a specific wavelength width out of the diffracted light dispersed from the diffraction gratings 21 and 22 is divided into photomultiplier tubes 931 and 932.
The photomultiplier tubes 931 and 932 detect the total intensity of light of this wavelength width.

Therefore, in the third embodiment, it is important to drive the two diffraction gratings 21 and 22 independently. That is, spectroscopic measurement of different wavelengths can be performed simultaneously by setting the two diffraction gratings 21 and 22 at different arrangement angles. By freely changing the arrangement angle of each of the diffraction gratings 21 and 22, it is possible to freely perform simultaneous spectroscopic measurement of two different wavelengths. For example, while measuring the spectral intensity of a specific wavelength of a certain light to be measured by the first diffraction grating 21, the spectral intensity of other various wavelengths is obtained by the second diffraction grating 22 and the intensity ratio is calculated. You can freely perform operations such as doing.

Also in this embodiment, it is possible to simultaneously perform spectroscopic measurements with different resolutions by preparing two diffraction gratings 21 and 22 having different numbers of engraved lines. That is,
It is possible to measure the light of the same wavelength with different resolutions by setting the two diffraction gratings 21 and 22 at the same arrangement angle, or measure the light of different wavelengths with different resolution by setting different arrangement angles.

Although not explicitly stated in the claims, a semiconductor light receiving element such as CdS or a photodiode is used instead of the photomultiplier tubes 931 and 932, and the slit 91 and the photomultiplier tubes 931 and 932 are used. Two C instead
A CD line image sensor or the like can be used.
Further, the CCD line image sensor can be used as a substitute for the light receiving element 4 of the embodiment shown in FIG. In this case, the two CCD line image sensors are arranged so as to be equivalent to the two light receiving portions 41 and 42 of the light receiving element 4 of FIG.

Next, the configuration of the toroidal mirror used in each of the above embodiments will be supplementarily described. FIG. 7 is a schematic perspective view illustrating the configuration of the toroidal mirror. The toroidal mirror is a special concave mirror having a curvature in two directions as described above, and is a kind of aspherical mirror. As shown in FIG. 8, the toroidal mirrors 7, 71, 72 are obtained by grinding the surface of a rectangular plate-shaped member and processing it into a curved surface like the side surface of a barrel or drum. Such a curved surface is also called a toric surface, but by using this curved surface as a reflecting surface, light converges or diverges in two orthogonal directions to form an image.

[0053]

EXAMPLES Next, examples belonging to the first and second embodiments will be described. First, as the first embodiment, the following examples can be considered when the focal length of the spectroscope is set to 23 cm. When the optical system is configured with a design in which the number of engraved lines of the first diffraction grating 21 is 1200 grooves / mm and the number of engraved line of the second diffraction grating 22 is 300 grooves / mm 2, the light receiving element 4 is 650
When using a CCD area image sensor with a pixel width of 27 μm in pixels, the resolution of the first light receiving portion 41: 2.7 nm The half-value width resolution of the first light receiving portion 41: 0.2 nm Simultaneous with the first light receiving portion 41 Detection width: 50 nm / 18 mm Wavelength range of the first light receiving portion 41: 200 nm to 1100
nm Resolution of the second light receiving portion 42: 12.5 nm Half-width resolution of the second light receiving portion 42: 0.9 nm Simultaneous detection width of the second light receiving portion 42: 200 nm / 18 m
m Wavelength range of the second light receiving portion 42: 200 nm to 1100
It becomes possible to perform spectroscopic measurement under the condition of nm.

Similarly, as the second embodiment, the following examples can be considered when the focal length of the spectroscope is 23 cm. Number of lines of the diffraction grating 23: 400 grooves / mm Incident angle of light from the right concave mirror 61 to the diffraction grating 23: 2.
Angle of incidence of light from the 5 degree medium concave mirror 62 on the diffraction grating 23: 4.
Angle of incidence of light from the right concave mirror 63 on the diffraction grating 23: 5.
When an optical system is configured with a design of 5 degrees, when a CCD area image sensor with a pixel width of 27 μm and 650 pixels is similarly used as the light receiving element 4, the wavelength range of the first light receiving portion 43: 200-400 nm, the second light receiving portion 44 wavelength range: 400-600 nm Third light receiving portion 45 wavelength range: 600-800 nm Resolution: 13 nm / mm Half-value resolution: 0.98 nm Simultaneous detection width: It is possible to perform spectroscopic measurement under the conditions of 50 nm / 18 mm. .

In the above description, the "simultaneous detection width" means a wavelength width per a predetermined length that can be simultaneously detected by the light receiving portions when the diffraction grating is fixed. That is, the simultaneous detection width of 50 nm / 18 mm means the light receiving portion 1
A width of 50 nm per 8 mm (for example, 200-250 n
m) can be detected at the same time. The “wavelength range” is an absolute value of a measurable wavelength region regardless of whether the diffraction grating is fixed or rotated. In the above description, resolution and wavelength range are taken as examples of different spectroscopic conditions, but other spectroscopic conditions such as dispersive power and polarization intensity may be used instead.

[0056]

As described above, according to the inventions of the claims of the present application, it becomes possible to freely select and adjust the spectral conditions such as the wavelength range and the resolution, which facilitates various spectroscopic measurements. Can be done.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a spectroscope according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a readout circuit of a detection unit in the spectroscope of FIG.

FIG. 3 is a diagram illustrating a light receiving portion of a light receiving element in the embodiment of FIG.

FIG. 4 is a diagram illustrating a schematic configuration of a spectroscope according to a second embodiment of the present invention.

5 is a diagram illustrating a light receiving portion of a light receiving element in the embodiment of FIG.

FIG. 6 is a partial schematic diagram illustrating a configuration of a spectroscope according to a third embodiment of the present invention.

FIG. 7 is a schematic perspective view illustrating the configuration of a toroidal mirror.

FIG. 8 is a diagram illustrating a schematic configuration of a conventional spectroscope.

[Explanation of symbols]

 1 entrance slit 2 spectroscopic means 21 first diffraction grating 22 second diffraction grating 23 diffraction grating 4 light receiving element 41 first light receiving portion 42 second light receiving portion 43 first light receiving portion 44 second light receiving portion 45 third light receiving portion 6 concave mirror 61 Right concave mirror 62 Middle concave mirror 63 Left concave mirror 7 Toroidal mirror 71 First toroidal mirror 72 Second toroidal mirror

Claims (7)

[Claims] 1. In a spectroscope having a spectroscopic means arranged at a position where the light to be measured is incident and a light receiving element arranged at a position where the light dispersed by the spectroscopic means is incident, the light receiving element is incident. It is an area image sensor that captures light as a two-dimensional image, and the spectroscopic means can make light of different spectroscopic conditions incident on at least two different light receiving portions of the light receiving surface of the area image sensor. A spectroscope further comprising a detection means capable of independently detecting the intensities of light under the different spectral conditions from the light reception result of the light receiving portion. 2. The light receiving element is an area image sensor including a charge coupled element.
The spectroscope described. 3. A spectroscope having a spectroscopic unit arranged at a position where the light to be measured is incident and a light receiving element arranged at a position where the light dispersed by the spectroscopic unit is incident, wherein at least two light receiving elements are provided. Two photomultiplier tubes are arranged at the light receiving position, the spectroscopic means is capable of injecting light of different spectroscopic conditions into each photomultiplier tube, and further, the light receiving result of each photomultiplier tube. In addition, the spectroscope is provided with a detection unit capable of independently detecting the intensities of light under the different spectral conditions. 4. The spectroscope according to claim 1, wherein the spectroscopic unit performs spectroscopic analysis under different conditions by two or more diffraction gratings having different spectroscopic conditions. 5. The spectroscopic means includes one diffraction grating and a splitting optical element capable of splitting and inputting the measured light into the one diffraction grating at at least two different incident angles. And corresponding to the light of different incident angles,
2. A different light receiving part of the light receiving element or an incident surface of each of the photomultiplier tubes is set.
2. The spectroscope according to 2 or 3. 6. The different spectral condition is a wavelength range,
2. The light splitting means is configured such that lights having different wavelength ranges are made incident on different light receiving portions of the light receiving surfaces of the area image sensor or the incident surfaces of the photomultiplier tubes, respectively. , 2, 3, 4 or 5 spectroscope. 7. The different spectroscopic conditions are resolutions, and the spectroscopic means causes light having different resolutions to respectively enter different light-receiving portions of the light-receiving surfaces of the area image sensor or incident surfaces of the photomultiplier tubes. The spectroscope according to claim 1, 2, 3, 4, or 5, wherein the spectroscope is configured as described above.