WO2021065348A1

WO2021065348A1 - Spectrometer

Info

Publication number: WO2021065348A1
Application number: PCT/JP2020/033628
Authority: WO
Inventors: 克敏 ▲鶴▼谷
Original assignee: コニカミノルタ株式会社
Priority date: 2019-09-30
Filing date: 2020-09-04
Publication date: 2021-04-08
Also published as: JPWO2021065348A1

Abstract

The present invention comprises: an incident part shaped such that the width thereof varies, in the wavelength dispersion direction, depending on positions in the direction orthogonal to the wavelength dispersion direction; a diffraction means for diffracting light to be measured, which light is incident from the incident part; a two-dimensional light-receiving sensor (506) for receiving the light to be measured, which light has been diffracted by the diffraction means to exhibit received light distribution (507) that corresponds to the shape of the incident part; and a spectral data acquisition means for acquiring two or more different types of spectral data by integrating the received amount of light to be measured in two or more types of integrated pixel ranges of the two-dimensional light-receiving sensor (506).

Description

Spectrometer

The present invention relates to a spectroscopic measuring instrument used for measuring the brightness and chromaticity of a light source, the spectral reflectance of an object, the color value, and the like.

For example, the resolution of display devices such as liquid crystal monitors has increased in recent years, and there is a demand to reduce the half width of the spectral response of the spectroscopic measuring instrument to obtain more detailed measurement data.

Conventionally, as a general method for reducing the half width of the spectral response, it is known to change the size of the incident slit that allows the light to be measured from the object to be measured to enter the spectroscopic portion. Specifically, the size of the incident slit is changed by changing the size of the wavelength dispersion direction in the direction orthogonal to the wavelength dispersion direction.

However, the method of reducing the half width by changing the size of the incident slit has the following problems.
1) Since the half-value width of the spectral response is different for each changed size, the measurement data must be acquired for each changed size, and the measurement data with different half-value widths cannot be acquired at the same time.
2) A drive mechanism is required to change to an incident slit of a different size, which requires extra installation space and is costly.
3) Since the position of the incident slit has high error sensitivity, it is difficult to ensure position reproducibility and reliability.
4) When an incident slit smaller than the optical path of the measurement light is arranged, a part of the measurement light does not enter the spectroscopic part, so that accurate measurement cannot be performed.

It is also known that the light passing through the aperture mirror is guided to the incident slit by a bundle fiber, but if an incident slit smaller than the outlet size of the bundle fiber is arranged, a fiber wire that is not used for measurement is generated. If the positional relationship between the entrance and exit strands is not random, there is also the problem that the characteristics of each strand (unevenness in the measurement area of the object to be measured, directivity, etc.) are affected.

Therefore, Patent Document 1 includes a two-dimensional sensor, two sets of diffraction gratings, and a toroidal mirror, and is characterized by receiving light under two types of spectral conditions (conditions having different wavelength ranges and conditions having different half-value widths). The spectroscope is disclosed. Specifically, the light emitted from one incident slit (rectangular) is divided into two optical paths to receive light, and the diffraction gratings are arranged at different angles to receive light in different wavelength ranges (half-value width is The same), the diffraction gratings with different numbers of grooves receive light with different wavelength resolution and half-value width (the wavelength range is also different).

Japanese Unexamined Patent Publication No. 9-145477

However, the spectroscope described in Patent Document 1 has a problem that different half widths cannot be obtained in the same wavelength range. Moreover, two sets of an expensive diffraction grating and a toroidal mirror are required, which causes a problem that the configuration is complicated and the cost is high.

The present invention has been made in view of such a technical background, and it is possible to simultaneously obtain measurement data in the same wavelength range and different full widths at half maximum without changing the size of the incident slit, and the diffraction grating. It is an object of the present invention to provide a spectroscopic measuring instrument that does not require a plurality of sets of toroidal mirrors.

The above object is achieved by the following means.
(1) An incident portion having a shape in which the width in the wavelength dispersion direction differs depending on a position in a direction orthogonal to the wavelength dispersion direction, a diffraction means for diffracting the light to be measured incident from the incident portion, and the diffraction. By integrating and calculating the amount of light received by the two or more integrated pixel ranges of the two-dimensional light receiving sensor that receives the light to be measured diffracted by the means and the two or more types of the two or more integrated pixel ranges, two or more types are different. A spectroscopic measuring instrument including a spectroscopic data acquisition means for acquiring spectral data.
(2) The spectroscopic measuring instrument according to item 1 above, wherein the incident portion is composed of at least one of an incident slit and an output end of an optical bundle fiber.
(3) The spectroscopic measuring instrument according to

item

1 or 2 above, wherein the incident portion has a stepwise difference in width in the wavelength dispersion direction in a direction orthogonal to the wavelength dispersion direction.
(4) The spectrophotometer according to

item

1 or 2 above, wherein the incident portion has a continuously different width in the wavelength dispersion direction in a direction orthogonal to the wavelength dispersion direction.
(5) The integrated pixel range is described in any one of 1 to 4 above, which is set according to the optical characteristics of at least one optical system component arranged in the optical path from the incident portion to the two-dimensional light receiving sensor. Spectral measuring instrument.
(6) The spectrophotometer according to any one of items 1 to 5 above, wherein the incident portion is an incident slit, and the incident slit is arranged in the vicinity of the outlet of the single-line optical fiber.

According to the invention described in the preceding paragraph (1), the incident portion has a shape in which the width in the wavelength dispersion direction differs depending on the position in the direction orthogonal to the wavelength dispersion direction, and the subject incident from the incident portion. The measurement light is diffracted by the diffracting means, and the diffracted light to be measured is received by the two-dimensional light receiving sensor. Then, two or more different types of spectral data are acquired by performing an integrated calculation of the amount of received light to be measured in two or more types of integrated pixel ranges of the two-dimensional light receiving sensor.

That is, if the amount of received light to be measured is integrated and calculated in two or more types of integrated pixel ranges of the two-dimensional light receiving sensor, spectral data with two or more types of spectral responsiveness having different half-value widths can be obtained. It is not necessary to change the size of the incident slit each time the measurement is performed, and two or more different spectral data can be simultaneously acquired in one measurement in the same wavelength range. Moreover, since it is not necessary to provide a plurality of sets of diffraction gratings and toroidal mirrors, it is possible to suppress the complexity of the configuration and the high cost.

According to the invention described in the previous section (2), by combining at least one shape of the incident slit or the output end of the optical bundle fiber and the integration calculation in two or more types of integration pixel ranges of the two-dimensional light receiving sensor. , The effect of the preceding paragraph (1) can be obtained.

According to the invention described in the preceding paragraph (3), as an example of the shape of the incident portion, a shape in which the width of the wavelength dispersion direction is stepwise different in the direction orthogonal to the wavelength dispersion direction can be mentioned.

According to the invention described in the preceding paragraph (4), as an example of the shape of the incident portion, a shape in which the width in the wavelength dispersion direction is continuously different in the direction orthogonal to the wavelength dispersion direction can be mentioned.

According to the invention described in the preceding paragraph (5), the integrated pixel range is set according to the optical characteristics of at least one optical system component arranged in the optical path from the incident portion to the two-dimensional light receiving sensor, and thus is intended. It is possible to realize a spectral response degree having a half-value width.

According to the invention described in the previous section (6), an incident slit having a shape in which the width in the wavelength dispersion direction differs depending on the position in the direction orthogonal to the wavelength dispersion direction is arranged near the outlet of the single-wire optical fiber. Also, the effect of the preceding paragraph (1) can be obtained.

It is a figure which shows an example of the basic structure of the spectroscopic measuring instrument which concerns on one Embodiment of this invention. It is a perspective view of a bundle fiber. It is a front view of the output end of a bundle fiber. It is explanatory drawing of the two-dimensional light receiving sensor. (A) and (B) are diagrams showing an example of an integration region set for the two-dimensional light receiving sensor when the bundle fiber having the shape of the output end of FIG. 3 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG. It is a graph which added the spectral response degree in another integration region to the spectral response degree of FIG. It is a figure which shows another example of the shape of the output end of a bundle fiber. (A) and (B) are diagrams showing an example of an integration region set for the two-dimensional light receiving sensor when the bundle fiber having the shape of the output end of FIG. 8 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG. It is a figure which shows still another example of the shape of the output end of a bundle fiber. It is a figure which shows still another example of the shape of the output end of a bundle fiber. (A) and (B) are diagrams showing an example of an integration region set for the two-dimensional light receiving sensor when the bundle fiber having the shape of the output end of FIG. 12 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG. (A) to (C) are diagrams showing other examples of the integration region set for the two-dimensional light receiving sensor when the bundle fiber having the shape of the output end of FIG. 12 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG. (A) and (B) are diagrams showing still another example of the integration region set for the two-dimensional light receiving sensor when the bundle fiber having the shape of the output end of FIG. 12 is used. (A) to (D) are diagrams showing still another example of the shape of the output end of the bundle fiber. It is a figure which shows the basic structure of the spectroluminometer which combined the single wire fiber and the incident slit. It is a figure which shows an example of the shape of the incident slit with respect to the outlet end of a single wire fiber. (A) and (B) are diagrams showing an example of an integration region set for the two-dimensional light receiving sensor when the incident slit having the shape of FIG. 20 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG. It is a figure which shows another example of the shape of the incident slit with respect to the outlet end of a single wire fiber. (A) and (B) are diagrams showing an example of an integration region set for the two-dimensional light receiving sensor when the incident slit having the shape of FIG. 23 is used. It is a graph which shows the spectroscopic response degree obtained in each integration region of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a basic configuration of a spectroluminometer, which is a spectrophotometer according to an embodiment of the present invention. As shown in FIG. 1, the spectroscopic measuring instrument 1 includes a light receiving optical system 100, an observation optical system 200, a measurement optical system 300, a signal processing circuit 600, and an arithmetic processing unit 700, and includes a measurement optical system 300. Further includes a light guide unit 400 and a spectroscopic unit 500.

The light receiving optical system 100 receives the light beam 3 from the object 2 to be measured, which is a light source, and guides the light beam 3 to the light guide unit 400 and the observation optical system 200 of the measurement optical system 300, and the light beam from the object 2 to be measured. An objective lens 101 that collects light 3, an aperture diaphragm 102 for regulating the amount of measured light arranged behind the objective lens 101 (front in the traveling direction of the light beam 3), and an aperture mirror further arranged behind the aperture diaphragm 102. It is equipped with 103.

The aperture mirror 103 is a mirror that is arranged in the incident optical path of the light flux 3 to the light guide unit 400 and has an opening through which the light flux 3 focused by the objective lens 101 passes. Of the light beam from the objective lens 101, the light beam from the light measurement area of the object 2 to be measured passes through the aperture of the aperture mirror 103 and goes straight to the light guide portion 400 in the subsequent stage, but the light beam outside the light measurement area is the aperture. It is reflected by the mirror 103 and guided to the pupil of the user through a lens group including the reflection mirror 201 and the observation relay lens 202 in the observation optical system 200. The user visually recognizes the object 2 to be measured and the index circle (the area that is not reflected by the aperture mirror and appears to be black to the user) from the observation optical system 200, and performs measurement positioning and focusing. Focusing focuses on the aperture mirror position by moving all or part of the lens group of the objective lens 101. The aperture angle (F number) of the measurement light does not change even if the aperture diaphragm 102 is focused. The hole size of the aperture mirror 103 may be changed manually or automatically. The measurement angle (measurement size) can be changed by changing the hole size.

The light guide unit 400 in the measurement optical system 300 is a condensing lens 401 that collects the light beam that has passed through the aperture of the aperture mirror 103, and an optical bundle that guides the light beam that has passed through the condensing lens 401 to the spectroscopic unit 500. A fiber (also simply referred to as a bundle fiber) 402 is provided, and in this embodiment, an output end (which is an outlet end face and corresponds to an input portion) of the bundle fiber 402 constitutes an incident slit 501. An incident slit 501 different from the bundle fiber 402 may be arranged on the outlet side of the bundle fiber 402.

The spectroscopic unit 500 in the measurement optical system 300 includes a collimator lens 502 that makes the light beam incident from the output end of the bundle fiber 402 substantially parallel light, and an infrared light cut filter 510 that is sequentially arranged behind the collimator lens 502. An optical member 520, an aperture having a rectangular opening (not shown), a diffraction grid 504 that diffracts parallel light that has passed through the opening of the aperture, an imaging lens 505, and an image of the diffracted light by the diffraction grid 504. It includes a two-dimensional light receiving sensor 506 that receives light through the lens 505, a secondary light cut filter 507 that is partially arranged in front of the two-dimensional light receiving sensor 506, and the like. The dimming member 520 is for adjusting the amount of received light, and is driven by the drive unit 521 so that it can be inserted and exited with respect to the optical path.

The aperture regulates the amount of parallel light from the collimator lens 502 according to the size of the diffraction grating 504, and the imaging lens 505 connects the light rays dispersed in wavelength by the diffraction grating 504 to the two-dimensional light receiving sensor 506. It is an image.

The bundle fiber 402 has a structure in which about 350 fiber strands having a wire diameter of, for example, 0.05 mm are bundled (bundle). Since the circular strands are bundled, light rays do not pass through the entire surface within the bundle diameter. In addition, since the strands are bundled randomly, light loss occurs due to twisting of the strands. Due to the area ratio of the wire core and the light loss, the efficiency of passing light rays is about 50%.
[Embodiment 1]
In this embodiment, as shown in FIG. 2, the shape of the input end 402a of the bundle fiber 402 is circular (φ1.1 mm), and the shape of the output end 402b is dodecagonal. Explaining the shape of the output end 402b in detail, as shown in FIG. 3, the long side is the direction orthogonal to the wavelength dispersion direction (horizontal direction in FIG. 3), and the wavelength dispersion direction (vertical direction in FIG. 3) is short. A rectangular central portion 402b1 as a side and rectangular end region portions 402b2 and 402b2 protruding in the wavelength dispersion direction at the central portion of both short sides of the central portion 402b1 are formed in a dodecagonal shape. The areas of the input end 402a and the output end 402b are the same.

As shown in FIG. 3, the incident slit (indicated by a broken line) 503 having the same area as the output end 402b is used as the conventional incident slit, the size of the conventional incident slit 503 is 0.315 × 3.0 mm, and the bundle fiber 402 is used. Compared with the size of the output end 402b of the above, the width in the wavelength dispersion direction (longitudinal direction) in the direction orthogonal to the wavelength dispersion direction (horizontal direction) is larger in the central portion 402b1 than in the conventional case (0.315 mm). It is set to .4 mm and 0.15 mm, which is smaller than the conventional one in the end regions 402b2 and 402b2 on both sides, and the length in the direction orthogonal to the wavelength dispersion direction is set to 0.4 mm in the central portion 402b1 than the conventional one (3.0 mm). The short length is set to 2.0 mm, and each end region 402b2 is set to 0.5 mm. In the following description, the wavelength dispersion direction is also simply referred to as a vertical direction, and the direction orthogonal to the wavelength dispersion direction is also simply referred to as a horizontal direction.

However, the area of the conventional incident slit 503 and the output end 402b of the bundle fiber 402 are the same, and therefore the total amount of light passing through the bundle fiber 402 is set to be the same.

That is, while it's conventional input slit 503 area = 0.315 × 3.0 = 0.95mm ^2, an area = 0.4 × 2.0 = 0.8mm ² of the central portion 402b1 of the fiber bundle 402 Yes, this corresponds to 84% of the area of the conventional incident slit 503. Further, the area of the end regions 402b2 on both sides of the bundle fiber 402 = 0.15 × 0.5 × 2 = 0.15 mm ² , which corresponds to 16% of the area of the conventional incident slit 503.

Therefore, the area of the central portion 402b1 + the area of the end regions 402b2 on both sides = 0.8 + 0.15 = 0.95 mm ² , which is the same as the area of the conventional incident slit 503.

As shown in FIG. 4, the two-dimensional light receiving sensor 506 has a large number of pixels 506a arranged two-dimensionally in the vertical and horizontal directions, and is, for example, by a CCD (Charge Coupled Device) sensor, a CMOS (Complementary MOS) sensor, or the like. It is configured. The light receiving data for each pixel 506a of the two-dimensional light receiving sensor 506 is transmitted to the signal processing circuit 600 for signal processing, and further transferred to the arithmetic processing unit (corresponding to the spectral data acquisition means) 700 to disperse the object 2 to be measured. Data is obtained. In this embodiment, for example, a sensor 506 with 512 pixels in the effective pixel = wavelength dispersion direction (longitudinal direction) and 122 pixels in the direction orthogonal to the wavelength dispersion direction (horizontal direction) is used. However, the actual calculation range is set to 500 pixels in the vertical direction x 100 pixels in the horizontal direction. The same applies to the two-dimensional light receiving sensor 506 shown in FIGS. 5 and later.

FIG. 4 shows a distribution image diagram of the light receiving data of the emission line (light of a specific wavelength) on the surface of the two-dimensional light receiving sensor 506. The light receiving distribution 507 corresponds to the shape of the output end 402b of the bundle fiber 402.

Next, the integration area of the pixels arranged in the horizontal direction, that is, the integration pixel range will be described. In this embodiment, two or more types of integration areas are set. 5 (A) and 5 (B) show an example of the integration region with a dash-dotted line, and FIG. 6 shows the spectral responsiveness obtained in each integration region. In FIG. 6, the integration area is simply described as an area.

The integration area A and the integration area B shown in FIGS. 5 and 6 are both integration areas when the dodecagonal output end 402b of the bundle fiber 402 shown in FIG. 4 is used, and the integration area A is FIG. 5 ( As shown in A), it is an area for all pixels (100 pixels) in the horizontal direction, and the integration area B is an area on both left and right sides of the output end 402b of the bundle fiber 402 as shown in FIG. 5B. This is an integration area for the pixels corresponding to 402b2 and 402b2 (15 pixels each, for a total of 30 pixels). The arithmetic processing unit 700 integrates and calculates the amount of light received by each pixel in each region.

The spectral responsiveness in FIG. 6 is a measurement result for the central pixel having a light receiving wavelength of 580 nm, and the solid line indicates the spectral responsiveness in the integrated region A and the alternate long and short dash line indicates the spectral responsiveness in the integrated region B. Further, the broken line indicates the spectral response degree when the conventional rectangular incident slit 503 described with reference to FIG. 3 is used.

As shown in the spectral response of FIG. 6, the half-value width of the conventional rectangular incident slit 503 is about 4 nm, the half-value width of the spectral response in the integration region A is also about 4 nm, and the spectral response in the integration region B. The half width of is about 2.5 nm. Further, assuming that the light receiving amount in the case of the conventional rectangular incident slit 503 is 1, the light receiving amount in the integration area A is also substantially the same as 1, and the light receiving amount in the integration area B is 16%.

In this way, by setting each integration region and measuring the received light data, it is possible to acquire different spectral data with two types of half-value width spectral responsiveness. Each integration area is preset, and the user selects one of the integration areas to perform measurement.

FIG. 7 shows the spectral responsiveness when the dodecagonal output end 402b of the bundle fiber 402 is used and only the central 50 pixels in the horizontal direction are used as the integration region, and the spectral response is added to the graph of FIG. 6 by a chain double-dashed line. It was done.

Since the vertical width of the central portion 402b1 at the output end 402b of the bundle fiber 402 is larger than the width of the conventional rectangular incident slit 503, the full width at half maximum is about 5 nm when only the central 50 pixels are integrated.

As described above, in this embodiment, the shape of the output end 402b of the bundle fiber 402 is such that the vertical width of the central portion 402b1 in the horizontal direction is large and the vertical width of the end regions 402b2 on both sides is small. Since two or more different integration areas corresponding to this shape are set for the two-dimensional light receiving sensor 506, two types with different half-value widths are calculated by integrating the received amount of the light to be measured in each integrated image area. Spectral data with the above spectral responsiveness can be acquired. Moreover, since the calculation can be performed by changing the integration area, only one measurement is required. Therefore, in order to change the full width at half maximum, it is not necessary to change the size of the incident slit each time the measurement is performed, and it is possible to simultaneously acquire two or more different spectral data in one measurement in the same wavelength range. it can. Moreover, since it is not necessary to provide a plurality of sets of diffraction gratings and toroidal mirrors, it is possible to suppress the complexity of the configuration and the high cost.
[Embodiment 2]
In this embodiment, the shape of the output end 402b of the bundle fiber 402 is changed. Specifically, as shown in FIG. 8, the output end 402b of the bundle fiber 402 has a rectangular shape having a small vertical width at the central portion 402b3 in the horizontal direction, and the vertical end regions 402b4 and 402b4 on both sides in the horizontal direction. It is set to a rectangle with a large width in the direction. Assuming that the conventional rectangular incident slit 503 shown by the broken line has a size of 0.315 × 3.0 mm, which is the same as the incident slit 503 shown by the broken line in FIG. 3, the central portion 402b3 has a lateral length of 1.0 mm. The width in the vertical direction is set to 0.15 mm, the length of each end region 402b4 is set to 1.0 mm in the horizontal direction, and the width in the vertical direction is set to 0.4 mm, respectively. The area of the output end 402b of the bundle fiber 402 is the same as the area of the conventional rectangular incident slit 503.

Two types of integration regions A and B when the output end 402b of the bundle fiber 402 shown in FIG. 8 is used are shown in FIGS. 9 (A) and 9 (B), and the spectral response is shown in FIG.

The integration area A shown in FIG. 9A is an area for all pixels (100 pixels) in the horizontal direction, and the integration area B shown in FIG. 9B is the central portion 402b3 at the output end 402b of the bundle fiber 402. It is an area about a pixel (30 pixels) corresponding to. The arithmetic processing unit 700 integrates and calculates the amount of light received by each pixel in each region.

The spectral response of FIG. 10 is a measurement result for the central pixel having a light receiving wavelength of 580 nm, and the solid line indicates the spectral response in the integrated region A and the alternate long and short dash line indicates the spectral response in the integrated region B. Further, the broken line indicates the spectral response degree when the conventional rectangular incident slit 503 described with reference to FIG. 3 is used.

As shown in the spectral response of FIG. 10, the half-value width of the conventional rectangular incident slit 503 is about 4 nm, the half-value width of the spectral response in the integration region A is also about 4 nm, and the spectral response in the integration region B. The half width of is about 2.5 nm. Further, assuming that the light receiving amount in the case of the conventional rectangular incident slit 503 is 1, the light receiving amount in the integration area A is also substantially the same as 1, and the light receiving amount in the integration area B is 15%.

As described above, in this embodiment, the shape of the output end 402b of the bundle fiber 402 is such that the vertical width of the central portion 402b3 in the horizontal direction is small and the vertical width of the end regions 402b4 and 402b4 on both sides is large. Since two or more different integration regions corresponding to this shape are set for the two-dimensional light receiving sensor 506, the half-value width is different by integrating the received amount of the light to be measured in each integrated image region. It is possible to acquire spectral data with two or more types of spectral responsiveness. Moreover, since the calculation can be performed by changing the integration area, only one measurement is required. Therefore, in order to change the full width at half maximum, it is not necessary to change the size of the incident slit each time the measurement is performed, and it is possible to simultaneously acquire two or more different spectral data in one measurement in the same wavelength range. it can.
[Embodiment 3]
As shown in FIG. 11, the shape of the output end 402b of the bundle fiber 402 may be set to a shape provided with three or more different regions having a width in the vertical direction in the horizontal direction. That is, the output end 402b of the bundle fiber 402 has the smallest width in the vertical direction at the central portion 402b5 in the horizontal direction, and becomes the first region 402b6, the second region 402b7, and the third region 402b8 as it reaches both ends in the horizontal direction. The width in the vertical direction is set stepwisely in three steps. The area of the output end 402b of the bundle fiber 402 is substantially the same as the area of the conventional rectangular incident slit 503.

Therefore, it is possible to set three or more types of integration areas including an integration area for all pixels in the horizontal direction and an integration area for pixels corresponding to the central portion 402b5, with a spectral response rate of three or more types of half-value widths. Three or more different spectral data can be acquired by calculation.
[Embodiment 4]
FIG. 12 shows an embodiment in which the shape of the output end 402b of the bundle fiber 402 is formed into an elliptical shape by continuously reducing the width in the vertical direction in the horizontal direction from the central portion to both ends. The major axis of the elliptical shape is 3.0 mm and the minor axis is 0.4 mm, and the area is substantially the same as the area of the conventional rectangular incident slit 503.

Two types of integration regions A and B when the output end 402b of the bundle fiber 402 shown in FIG. 12 is used are shown in FIGS. 13 (A) and 13 (B), and the spectral response is shown in FIG.

The integration area A shown in FIG. 13 (A) is an area for all pixels (100 pixels) in the horizontal direction, and the integration area B is a pixel (2) corresponding to both ends in the horizontal direction at the output end 402b of the bundle fiber 402. It is an area about 30 pixels in total with 15 pixels each. The arithmetic processing unit 700 integrates and calculates the amount of light received by each pixel in each integration region.

The spectral response of FIG. 14 is a measurement result for the central pixel having a light receiving wavelength of 580 nm. The solid line indicates the spectral response in the integrated region A, and the alternate long and short dash line indicates the spectral response in the integrated region B. Further, the broken line indicates the spectral response degree when the conventional rectangular incident slit 503 is used.

As shown in the spectral response of FIG. 14, the half-value width of the conventional rectangular incident slit 503 is about 4 nm, the half-value width of the spectral response in the integration region A is also about 4 nm, and the spectral response in the integration region B. The half width of is about 2.5 nm. Further, assuming that the light receiving amount in the case of the conventional rectangular incident slit 503 is 1, the light receiving amount in the integration region A is also 1, which is almost the same. Regarding the integration area B, the area ratio of the calculation area is 15% (15 pixels ÷ 100 pixels), and the light receiving amount is 12% including the elliptical shape and the narrow periphery. Further, the shape of the spectral response of the integration region A is closer to the shape of the conventional rectangular spectral response than the spectral response of the integration region A of the first embodiment shown in FIG. ..

Next, the optimum shape of the spectral response will be described.

The chromaticity value (x, y) is a value calculated from the measured spectral data and the color matching function data. If the shape of the spectral response is different from that of the conventional luminance meter (incident slit is rectangular), the chromaticity value will be different. Therefore, by making the shape of the spectral responsiveness the same as the conventional one, compatibility with the chromaticity measurement value can be obtained. That is, there is no difference between the models of the conventional model.

Next, the fine adjustment of the integration range and the obtained spectral response will be described.

As shown in FIGS. 15A to 15C,
Integration area A: Horizontal integration pixel = 100 pixels Integration area A2: Horizontal integration pixel = 80 pixels (10 pixels at both ends are not included in the range)
Integration area A3: Horizontal integration pixels = 60 pixels (20 pixels at both ends are not included in the range)
The spectral response of each integrated region is shown in FIG.

As can be understood from FIG. 16, the shape of the spectral response is closest to the conventional rectangle in the integration region A2. The integration area A (100 pixels) is thin, and the area A3 (center 60 pixels) is thick.

Since the shape of the output end 402b of the bundle fiber 402 is such that the width in the vertical direction in the horizontal direction continuously changes, the optimum spectral response can be obtained by controlling the integration range.

Since the integration region where the optimum spectral response is obtained depends on the performance of the optical system (lens, stray light of the diffraction grating, etc.), it is desirable to set the integration range for each optical system to be adopted. Further, since the performance of the optical system differs depending on the wavelength, it is desirable to set the integration range for each wavelength in the measurement wavelength range (380 to 780 nm).

As still other integration areas, in addition to the integration areas A and B shown in FIGS. 13 (A) and 13 (B), and the integration areas A1 and A2 shown in FIGS. 15 (B) and 15 (C), FIG. The integration area may be set as shown in 17 (A) and 17 (B). FIG. 17 (A) shows the integration area C for the pixels excluding the pixels at both ends and the center in the horizontal direction, and FIG. 17 (B) shows the pixels in the region asymmetric with respect to the vertical center line in the horizontal direction. When the output end 402b of the bundle fiber 402 has an elliptical shape, it is possible to acquire data in three or more arbitrary half-value widths.

As described above, in this embodiment, since the shape of the output end 402b of the bundle fiber 402 has a shape in which the width in the vertical direction is continuously different in the horizontal direction, it is optimal according to the performance of the optical system. By selecting the integration range, spectral response data of the same shape can be obtained with the same amount of light as the received light data obtained by the conventional rectangular incident slit. Therefore, the chromaticity value is compatible with the conventional rectangular luminance meter, and at the same time, data with different half-value widths can be acquired.

The shape of the output end 402b of the bundle fiber 402, which has a continuously different width in the vertical direction in the horizontal direction, is not limited to the elliptical shape. In addition to the elliptical shape, as shown in FIG. 18A, the vertical width in the horizontal central portion is the largest, and the vertical width is continuously small from the horizontal central portion to both ends. It may be a flat hexagon.

Further, it may have a rhombic shape as shown in FIG. 18 (B), or as shown in FIG. It may be a drum shape in which the width in the vertical direction is continuously increased toward. Alternatively, as shown in FIG. 3D, it is a horizontal triangle in which the vertical width at one end in the horizontal direction is large and the vertical width is continuously reduced toward the other end in the horizontal direction. Is also good.
[Embodiment 5]
In the above embodiment, the case where the output end 402b of the bundle fiber 402 serves as an incident slit and the shape of the output end 402b is set to a shape in which the width in the vertical direction is different in the horizontal direction is shown. However, instead of the bundle fiber 402, the shape of the incident slit may be set in the combination of the single wire fiber and the incident slit.

FIG. 19 is a diagram showing a basic configuration of a spectroluminometer in which such a single wire fiber and an incident slit are combined.

In the spectroluminometer shown in FIG. 19, the light guide portion 400 is provided with a single wire fiber 410, and the output end (outlet end face) of the single wire fiber 410 is in the vicinity of an incident slit (corresponding to an input portion) 530 formed by a slit member 531. Is located in.

The spectroscopic unit 500 includes an infrared light cut filter 510 that receives the light beam incident from the incident slit 530, a dimming member 520, an imaging lens 505 that also serves as an irradiation lens, and diffraction arranged behind the imaging lens. A lattice 504, a two-dimensional light receiving sensor 506 that receives light diffracted by the diffraction grating 504 via an imaging lens 505, a secondary light cut filter 507 that is partially arranged in front of the two-dimensional light receiving sensor 506, and the like are provided. There is. The dimming member 520 is for adjusting the amount of received light, and is driven by the drive unit 521 so that it can be inserted and exited with respect to the optical path. In this embodiment, since the irradiation lens and the imaging lens 505 are composed of one lens, the configuration is inexpensive and compact. Since the other configurations of the spectroluminance meter of FIG. 19 are the same as the configurations of the spectroluminometer shown in FIG. 1, the description thereof will be omitted.

The single wire fiber 410 has a diameter of φ1.0 mm in this embodiment. The purpose of using the single wire fiber 410 is to mix the polarization characteristics of the measurement light, the position characteristics (positional unevenness) of the measurement area, and the light distribution characteristics (directional unevenness). By eliminating it, accurate measurement can be performed even if the incident slit 530 smaller than the outlet diameter is arranged, and accurate measurement can be performed regardless of the position in the incident slit surface.

The longer the single wire fiber 410, the higher the mixing effect, and the less uneven the characteristics at the exit. In this embodiment, a resin fiber having a diameter of φ1.0 mm and a length of 500 mm is used and arranged in a wound state.

In this embodiment, the shape of the incident slit 530 is set to a predetermined shape by arranging a mechanically operating diaphragm (mechanical diaphragm) near the outlet of the single wire fiber 410. Since it is a mechanical diaphragm, it can be inexpensive even if it has a complicated shape.

As shown in FIG. 20, the shape of the incident slit 530 was set as follows with respect to the outlet end 410a of the single wire fiber 410 by a mechanical diaphragm. That is, the incident slit 530 has a rectangular central portion 530a having a vertical width of 0.4 mm and a lateral length of 0.75 mm, and a vertical width formed at both ends of the central portion 530a in the horizontal direction. Is formed into a dodecagon by the

rectangular end regions

530a and 530a having a length of 0.15 mm and a length of 0.125 mm.

The area of the outlet end 410a of the single wire fiber 410 is 0.5 × 0.5 × 3.14 = 0.78 mm ² , and the area of the incident slit 530 is 0.4 × 0.75 + 0.15 × 0.125 ×. 2 = 0.38 mm ² , and the area ratio of the incident slit 530 to the single wire fiber outlet end 410a is 43%, that is, the light loss at the outlet of the single wire fiber 410 is 57%.

Here, when compared with the efficiency of the bundle fiber 402, assuming that the efficiency of the bundle fiber 402 is 50%, the efficiency at the single wire fiber outlet is 43%, and the ratio of the amount of light obtained to the bundle fiber configuration is 43/50 = It becomes 86% (integration area A for all pixels). By this amount, the repeatability (SN) is worse than that of the bundle fiber configuration.

When the single wire fiber 410 and the incident slit 530 shown in FIG. 20 are combined, the light receiving distribution 507 of the light receiving data of the emission line (light of a specific wavelength) on the surface of the two-dimensional light receiving sensor 506 and the two-dimensional light receiving sensor 506 An example of the integration area to be set is shown in FIGS. 21 (A) and 21 (B).

The integration area A shown in FIG. 21 (A) integrates 36 pixels in the central portion in the horizontal direction, and the integration area B shown in FIG. 21 (B) integrates ± 13 to 18 pixels from the center in the horizontal direction. It is a thing.

FIG. 22 shows the spectral responsiveness obtained in each of the integration regions A and B. In FIG. 22, the “rectangle” is a conventional incident slit (0.315 × 3.0 rectangle), and shows a case where the integration is performed in the integration area A.

As shown in FIG. 22, the half width of the conventional rectangular incident slit is about 4 nm, the half width of the spectral response in the integration region A is also about 4 nm, and the half width of the spectral response in the integration region B is about about 4 nm. It is 2.5 nm. Further, assuming that the light receiving amount in the case of the conventional rectangular incident slit 503 is 1, the light receiving amount in the integrated area A is 86% and the light receiving amount in the integrated area B is 8% when the efficiency of the fiber portion is taken into consideration. ..

FIG. 23 is an example of changing the shape of the incident slit 530. Also in this example, the predetermined shape of the incident slit 503 is realized by arranging the mechanical diaphragm near the outlet of the single wire fiber 410.

In the example of FIG. 23, the shape of the incident slit 530 is formed into an elliptical shape having a major axis of 1.0 mm and a minor axis of 0.4 mm. Area of the outlet end 410a of the single line fiber 410 is 0.78 mm ^2, the area of the entrance slit 530 is ^{0.2 × 0.5 × 3.14 = 0.32mm 2} . The area ratio of the incident slit 530 to the single wire fiber outlet end 410a is 40%, that is, the light loss at the outlet of the single wire fiber 410 is 60%.

Compared with the efficiency of the bundle fiber 402, if the efficiency of the bundle fiber 402 is 50%, the efficiency at the single wire fiber outlet is 40%, and the ratio of the amount of light obtained to the bundle fiber configuration is 40/50 = 80%. (Integration area A for all pixels). By this amount, the repeatability (SN) is worse than that of the bundle fiber configuration.

When the single wire fiber 410 and the incident slit 530 shown in FIG. 23 are combined, the light receiving distribution 507 of the light receiving data of the emission line (light of a specific wavelength) on the surface of the two-dimensional light receiving sensor 506 and the two-dimensional light receiving sensor 506 An example of the integration region to be set is shown in FIGS. 24 (A) and 24 (B), and the spectral response degree obtained in each integration region is shown in FIG. 25.

As shown in FIG. 25, it can be seen that the full width at half maximum is also changed by changing the integration area. Therefore, by integrating the amount of received light to be measured in each integrated image region, it is possible to acquire spectral data with two or more types of spectral responsiveness having different half-value widths. Moreover, since the calculation can be performed by changing the integration area, only one measurement is required. Therefore, in order to change the full width at half maximum, it is not necessary to change the size of the incident slit each time the measurement is performed, and it is possible to simultaneously acquire two or more different spectral data in one measurement in the same wavelength range. it can. Moreover, since it is not necessary to provide a plurality of sets of diffraction gratings and toroidal mirrors, it is possible to suppress the complexity of the configuration and the high cost.

Further, by combining the single wire fiber 410 and the incident slit 530 having a shape different in the vertical direction in the horizontal direction, the amount of light is reduced and the repeatability (SN) is deteriorated as compared with the bundle fiber 402. There are also advantages.

That is, by using the single wire fiber 410, sufficient mixing can be performed, so that accurate measurement can be performed regardless of the characteristics (polarization, uneven position, directivity) of the object to be measured, and the single wire fiber 410 is more than the bundle fiber 402. Has the advantage of being inexpensive.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the area of the outlet end 402a of the bundle fiber 402 or the like and the incident slit 503 is set to be the same as that of the conventional rectangular incident slit, but the area may be increased. In this case, the size of the two-dimensional light receiving sensor 506 is also increased if necessary.

The present invention can be used when measuring the brightness and chromaticity of a light source, the spectral reflectance of an object, the color value, and the like.

1 Spectral measuring instrument 2 Object to be measured 3 Light to be measured 100 Light receiving optical system 200 Observation optical system 300 Measuring optical system 400 Light guide unit 402 Bundle fiber 402a Output end 500 Spectroscopic unit 504 Diffraction grid 506 Two-dimensional light receiving sensor 507 Light receiving distribution 530 Incident Slit 700 Arithmetic processing unit (data acquisition means)

Claims

An incident part having a shape in which the width in the wavelength dispersion direction differs depending on the position in the direction orthogonal to the wavelength dispersion direction,
A diffracting means for diffracting the light to be measured incident from the incident portion, and
A two-dimensional light receiving sensor that receives the light to be measured diffracted by the diffracting means, and
A spectroscopic data acquisition means for acquiring two or more different types of spectral data by integrating the amount of received light to be measured in two or more types of integrated pixel ranges of the two-dimensional light receiving sensor.
A spectroscopic measuring instrument equipped with.
The spectroscopic measuring instrument according to claim 1, wherein the incident portion is composed of at least one of an incident slit and an output end of an optical bundle fiber.
The spectrophotometer according to claim 1 or 2, wherein the incident portion has a stepwise difference in width in the wavelength dispersion direction in a direction orthogonal to the wavelength dispersion direction.
The spectrophotometer according to claim 1 or 2, wherein the incident portion has continuously different widths in the wavelength dispersion direction in a direction orthogonal to the wavelength dispersion direction.
The spectroscopic measurement according to any one of claims 1 to 4, wherein the integrated pixel range is set according to the optical characteristics of at least one optical system component arranged in the optical path from the incident portion to the two-dimensional light receiving sensor. vessel.
The spectroscopic measuring instrument according to any one of claims 1 to 5, wherein the incident portion is an incident slit, and the incident slit is arranged in the vicinity of the outlet of the single-line optical fiber.