JP2018048980A - Spectrometry device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectrometry device capable of reducing measurement error due to bending an optical fiber and also enhancing an amount of light supplied to a spectral measurement section.SOLUTION: A spectrometry device comprises: a spectral measurement section that performs spectral measurement of light being made incident through a slit thereon; and light diffusion means that diffuses light supplied from a plurality of optical fibers and is physically fixed to the slit so that the diffused light is incident on the slit directly or through a lens or a mirror.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a spectrometer.

  In Patent Document 1, the distribution of light emitted from an optical fiber fluctuates due to bending of the optical fiber, which may cause a measurement error. To solve this problem, a plurality of optical fibers are optically coupled. Using an integrating sphere as a fiber coupler is disclosed.

Japanese Patent No. 5634983

  By the way, in Patent Document 1, light from a light source is guided to an integrating sphere through an incident side fiber, and light emitted from the integrating sphere is guided to a spectrophotometer through the output side fiber. For this reason, even if the measurement error due to the bending of the incident side fiber can be reduced, the measurement error due to the bending of the outgoing side fiber cannot be reduced.

  In addition, since the light guided to the integrating sphere by the plurality of incident side fibers is guided from the integrating sphere to the spectroscopic measuring instrument by one output side fiber, there is a possibility that sufficient light quantity cannot be obtained in the spectroscopic measuring instrument. is there.

  The present invention has been made in view of the above problems, and its object is to reduce a measurement error due to bending of an optical fiber and to improve the amount of light supplied to the spectroscopic measurement unit. Is to provide.

  In order to solve the above-described problems, a spectroscopic measurement apparatus according to the present invention includes a spectroscopic measurement unit that spectroscopically measures light incident through a slit, and a light diffusion unit that diffuses light supplied from a plurality of optical fibers. Light diffusing means that is physically fixed to the slit so that the incident light enters the slit directly or through a lens or a mirror.

  The spectroscopic measurement apparatus may further include a diaphragm that restricts the light flux of the diffused light traveling toward the slit. The spectroscopic measurement apparatus may further include the plurality of optical fibers that supply light to the light diffusing unit. The light diffusing unit may include an emission part that emits the diffused light, and the slit and the emission part may face each other.

  In one aspect of the present invention, the light diffusing means is a diffusing plate, light supplied from the plurality of optical fibers is incident on one surface of the diffusing plate, and the diffusing from the other surface of the diffusing plate. The emitted light may be emitted.

  The output ends of the plurality of optical fibers may be arranged offset from an optical axis passing through the slit. The light emitting ends of the plurality of optical fibers may emit light in a direction toward the slit from a position offset from an optical axis passing through the slit. The output ends of the plurality of optical fibers may be disposed so as to surround an optical axis passing through the slit.

  In one aspect of the present invention, the light diffusing means may be an integrating sphere in which light supplied from the plurality of optical fibers is diffusely reflected by a spherical inner wall surface, and the diffused light is emitted from a detection window. . In the present invention, the term “integrating sphere” is used to mean a wide range of devices that diffusely reflect incident light on a spherical inner wall surface, such as a spherical shape, a hemispherical shape, and a 1/8 spherical shape.

  In one aspect of the present invention, the spectroscopic measurement device supplies light from a part of optical fibers selected from the plurality of optical fibers to the light diffusing unit, and shields light from the remaining optical fibers. A switching means may be further provided.

  In addition, the emission ends of the plurality of optical fibers are arranged offset from the optical axis passing through the slit, and the light shielding switching unit is configured so that the light from the part of the optical fibers passes from above the optical axis passing through the slit. You may provide the direction conversion means which changes the direction of the light from the said one part optical fiber so that it may inject into a light-diffusion means.

  According to the present invention, the light diffusing means is physically fixed with respect to the slit so that the diffused light enters the slit directly or through a lens or mirror, thereby reducing measurement errors due to bending of the optical fiber. In addition, it is possible to improve the amount of light supplied to the spectroscopic measurement unit.

It is a schematic diagram which shows the structural example of the spectrometer which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structural example of a fiber coupling part. It is a schematic diagram which shows the structural example of a fiber coupling part. It is a schematic diagram which shows the structural example of the spectrometer which concerns on the 2nd Embodiment of this invention. It is a schematic diagram which shows the structural example of the spectrometer which concerns on the 3rd Embodiment of this invention. It is a schematic diagram which shows the structural example of the spectrometer which concerns on the 4th Embodiment of this invention. It is a schematic diagram which shows the structural example of a fiber switching part. It is a schematic diagram which shows the structural example of a fiber switching part. It is a schematic diagram which shows the modification of a fiber switching part. It is a schematic diagram which shows the modification of a fiber switching part. It is a schematic diagram which shows the 1st application example of the spectrometer which concerns on embodiment of this invention. It is a schematic diagram which shows the 2nd application example of the spectrometer which concerns on embodiment of this invention. It is a schematic diagram which shows a reference example. It is a schematic diagram which shows the 3rd application example of the spectrometer which concerns on embodiment of this invention. It is a schematic diagram which shows the 4th application example of the spectrometer which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals, and the detailed description may be omitted.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration example of a spectroscopic measurement apparatus 1A according to the first embodiment of the present invention. 2A and 2B are schematic views illustrating a configuration example of the fiber coupling portion 5A. The spectroscopic measurement apparatus 1A includes a spectroscopic measurement unit 3 and a fiber coupling unit 5A.

  The spectroscopic measurement unit 3 spectroscopically measures light incident through the slit 4 a formed in the slit plate 4. The spectroscopic measurement unit 3 includes a diffraction grating 32 that diffracts light incident from the slit 4a and a line sensor 34 that receives light diffracted by the diffraction grating 32, and detects the spectrum of the incident light. The length (height) of the slit 4 a corresponds to the lengths of the diffraction grating 32 and the line sensor 34.

  As the spectroscopic measurement unit 3, various known configurations capable of spectroscopic measurement can be applied. In the example shown in the figure, a concave grating is applied. However, the present invention is not limited to this. For example, a Czerny-turner spectrograph may be applied, or a transmission-type spectrograph may be used. A transmissive spectrograph may be applied. In the illustrated example, a line sensor (multi-sensor) is applied. However, the present invention is not limited to this. For example, a method of detecting a spectrum by rotating a diffraction grating using a single sensor may be applied.

  Based on the spectrum detected by the spectroscopic measurement unit 3, evaluation of characteristics as a light source such as chromaticity, illuminance, luminance, and color rendering, measurement of optical characteristics of a measurement target such as surface characteristics, reflection characteristics, and transmission (absorption) characteristics; Measurement of physical characteristics of a measurement object such as film thickness can be performed.

  The fiber coupling unit 5A optically couples the plurality of optical fibers 91 and 92. The fiber coupling unit 5A includes a diffusion plate 52, a condenser lens 61, and a diaphragm 65, and couples light supplied from the plurality of optical fibers 91 and 92 and guides the light to the slit 4a.

  The housing 2 of the spectroscopic measurement apparatus 1 includes a first housing portion 21 that houses the spectroscopic measurement portion 3 and a second housing portion 23 in which the fiber coupling portion 5A is provided. The second housing part 23 houses the diffusion plate 52, the condenser lens 61 and the diaphragm 65. The first housing portion 21 and the second housing portion 23 may be partitioned by the slit plate 4 to prevent stray light.

  The optical fibers 91 and 92 propagate light incident from the incident ends 911 and 921 and exit from the output ends 913 and 923. The optical fibers 91 and 92 are, for example, fiber bundles in which a plurality of fiber strands are bundled. The emission ends 913 and 923 are introduced into the second accommodating portion 23 that accommodates the fiber coupling portion 5A. The emission ends 913 and 923 may be detachable from the second accommodating portion 23.

  The diffusing plate 52 is an example of a light diffusing means, and is a plate-like light-transmitting member having fine protrusions on the surface, such as polished glass. The light diffusing film may be applied without being limited to the diffusing plate 52. The diffusion plate 52 diffuses light supplied from the plurality of optical fibers 91 and 92. Even if the light supplied from the optical fibers 91 and 92 is polarized, the diffusion plate 52 diffuses the light to cancel the polarization.

  The diffusion plate 52 is disposed between the emission ends 913 and 923 of the plurality of optical fibers 91 and 92 and the slit 4a. One surface of the diffusing plate 52 faces the emission ends 913 and 923, and the other surface of the diffusing plate 52 faces the slit 4a. When light emitted from the emission ends 913 and 923 enters one surface of the diffusion plate 52, diffused light is emitted from the other surface of the diffusion plate 52.

  The condenser lens 61 is disposed between the diffusion plate 52 and the slit 4a, and condenses the diffused light emitted from the diffusion plate 52 toward the slit 4a. The condensing lens 61 is configured to focus at the slit 4a. The diaphragm (aperture) 65 is disposed between the condenser lens 61 and the slit 4a, and restricts the luminous flux (light beam) of the diffused light that travels toward the slit 4a. Note that the condenser lens 61 and the diaphragm 65 are not necessarily provided. In addition, the diaphragm 65 may be installed inside the first housing portion 21.

  The diffuser plate 52 is physically fixed to the slit 4a so that the diffused light emitted from the diffuser plate 52 enters the slit 4a via the condenser lens 61. That is, the light emitted from the diffusion plate 52 is directly incident on the condenser lens 61, and the light emitted from the condenser lens 61 is directly incident on the slit 4a. Thus, in this embodiment, the light emitted from the diffusion plate 52 enters the slit 4a without passing through the optical fiber.

  However, the present invention is not limited to this, and the condensing lens 61 may be omitted, and the diffused light emitted from the diffusion plate 52 may be directly incident on the slit 4a.

  As described above, since the light from the optical fibers 91 and 92 is coupled using the diffusion plate 52, even if the types (numerical aperture (NA) and strand diameter) of the optical fibers 91 and 92 are different from each other, There is no problem in joining. For example, the optical fiber 91 may be an SMA fiber (NA = 0.21, strand diameter = 0.5 mm), and the optical fiber 92 may be an FC fiber (NA = 0.11, strand diameter = 0.2 mm). . Further, since the light from the optical fibers 91 and 92 is diffused by the diffusion plate 52 and then enters the slit 4a, even if the positions of the emission ends 913 and 923 of the optical fibers 91 and 92 are slightly shifted, the spectroscopic measurement unit 3 is less affected by wavelength shift and the like. For this reason, the position adjustment range of the output ends 913 and 923 of the optical fibers 91 and 92 is widened as compared with a spectroscopic measurement apparatus that does not include the light diffusion means.

  The slit plate 4 and the diffusion plate 52 are fixed to the housing 2. Specifically, the slit plate 4 is fixed to the boundary between the first housing portion 21 and the second housing portion 23 of the housing 2 or in the vicinity thereof. The diffusion plate 52 is fixed inside the second housing portion 23 so as to partition the inside of the second housing portion 23 into a space on the optical fibers 91 and 92 side and a space on the slit 4a side. In order to prevent stray light, it is preferable that the two spaces are completely partitioned by the diffusion plate 52 and a member that supports the peripheral edge thereof.

  For example, the diffusion plate 52 may be fixed by being inserted into a guide groove provided on the inner wall of the second housing portion 23, or may be screwed or bonded to a protruding portion provided on the inner wall of the second housing portion 23. It may be fixed using an agent or the like. A method for fixing the diffusion plate 52 is not particularly limited.

  2A is a diagram when the fiber coupling portion 5A is viewed from the side with respect to the optical axis LA passing through the slit 4a, and FIG. 2B is a diagram when the diffusion plate 52 is viewed from the slit 4a side. The optical axis LA that passes through the slit 4a is a virtual axis that is representative of the light beam emitted from the diffusion plate 52 and that passes through the slit 4a, and is an axis that passes through the center of the condenser lens 61 and the center of the stop 65.

  The emission ends 913 to 953 of the plurality of optical fibers 91 to 95 are arranged offset from the optical axis LA passing through the slit 4a. That is, the emission ends 913 to 953 are not on the optical axis LA, but are away from the optical axis LA in the outward direction (radial direction). If the specific emission end is on the optical axis LA, the light from the emission end more easily passes through the slit 4a than the light from the remaining emission end, and there is a possibility that the coupling of light becomes non-uniform. Therefore, it is possible to make the light coupling uniform by arranging all the emission ends 913 to 953 offset from the optical axis LA.

  Moreover, the output ends 913 to 953 of the plurality of optical fibers 91 to 95 are arranged so as to surround the optical axis LA passing through the slit 4a. Here, being arranged so as to surround the optical axis LA also includes being arranged so as to sandwich the optical axis LA when there are two emission ends. The emission ends 913 to 953 are preferably arranged so that the distances from the optical axis LA are equal, and more preferably arranged so as to be rotationally symmetric about the optical axis LA. According to this, it is possible to achieve further uniform light coupling.

  The emission ends 913 to 953 of the plurality of optical fibers 91 to 95 emit light in a direction toward the slit 4a from a position offset from the optical axis LA passing through the slit 4a. That is, the light emitted from the emission ends 913 to 953 is not parallel to the optical axis LA, but is emitted in a direction inclined more toward the side closer to the optical axis LA. According to this, even if the emission ends 913 to 953 are offset from the optical axis LA, the amount of light passing through the slit 4a can be further improved.

  As the diffusion plate 52, it is preferable to use a diffusion plate having a high depolarization function for the purpose of depolarization. In addition, when the purpose is to improve the amount of light supplied to the spectroscopic measurement unit 3, it is preferable to use a diffusion plate having a high transmittance. As described above, the type of the diffusion plate 52 can be selected in accordance with the purpose and application of the measurement.

  In the first embodiment described above, the diffuser plate 52 is physically disposed with respect to the slit 4a so that the diffused light emitted from the diffuser plate 52 enters the slit 4a directly or via the condenser lens 61. It is fixed to. According to this, since there is no exit side fiber as in Patent Document 1, it is possible to reduce measurement errors due to bending of the optical fiber.

  It is also possible to improve the amount of light supplied to the spectroscopic measurement unit 3. In the configuration in which light is guided to the spectrometer through the output side fiber as in Patent Document 1, the amount of light supplied to the spectrometer may not be sufficient. For example, when the exit side fiber includes a plurality of fiber strands, the exit ends of the plurality of fiber strands are arranged and fixed along the slit. In this case, since the strand diameter and number of fiber strands are limited by the length of the slit, the amount of light supplied to the slit may not be sufficient. On the other hand, in this embodiment, if a sufficient amount of light is supplied from the optical fibers 91 and 92 to the diffusion plate 52, the diffused light enters the slit 4a directly or via the condenser lens 61. Even if there is a slight loss of light quantity at 52, it is possible to supply a sufficient quantity of light to the spectroscopic measurement unit 3 (this will be described in detail later with reference to FIGS. 8 to 10).

[Second Embodiment]
FIG. 3 is a schematic diagram showing a configuration example of a spectrometer 1B according to the second embodiment of the present invention. The fiber coupling unit 5B included in the spectroscopic measurement device 1B includes an integrating sphere 7, a collimating lens 62, a condenser lens 63, and a diaphragm 65.

  The integrating sphere 7 is an example of a light diffusing unit, and diffuses and reflects the light supplied from the plurality of optical fibers 91 and 92 by the spherical inner wall surface 714, and emits the diffused light from the detection window 73a. Specifically, the integrating sphere 7 is constituted by a hemispherical shell portion 71 and a circular flat plate portion 73, and has a hollow hemispherical internal space. The inner wall surface 714 of the hemispherical shell portion 71 is a white highly diffuse reflection surface made of barium sulfate, PTFE (polytetrafluoroethylene) sintered product, or the like, and the inner wall surface 734 of the circular flat plate portion 73 is a mirror formed by aluminum vapor deposition or the like.

  The hemispherical shell portion 71 of the integrating sphere 7 is provided with a plurality of attachment portions 711 and 712 to which the emission ends 913 and 923 of the optical fibers 91 and 92 are attached. The emission ends 913 and 923 may be detachable from the attachment portions 711 and 712. The integrating sphere 7 combines the light supplied from the plurality of optical fibers 91 and 92 by diffusing in the internal space. Moreover, even if the light supplied from the optical fibers 91 and 92 is polarized, the polarization is canceled by being diffused in the internal space of the integrating sphere 7.

  In the center of the circular flat plate portion 73, a detection window 73a is provided for taking out the light diffused in the internal space of the integrating sphere 7 to the outside. The detection window 73a is an emission part that emits diffused light, and faces the slit 4a. A light shielding plate 75 is provided around the detection window 73a to prevent light emitted from the emission ends 913 and 923 from directly entering the detection window 73a.

  In the present embodiment, the integrating sphere 7 is hemispherical, but is not limited thereto, and may be a full spherical shape or a 1/8 spherical shape.

  The collimating lens 62 is disposed between the integrating sphere 7 and the slit 4a, and makes light emitted from the detection window 73a of the integrating sphere 7 parallel light. The condensing lens 63 is disposed between the collimating lens 62 and the slit 4a, and condenses the light emitted from the collimating lens 62 toward the slit 4a. The condenser lens 63 is configured to focus at the slit 4a. Note that the collimating lens 62, the condenser lens 63, and the diaphragm 65 are not necessarily provided. Further, the diaphragm 65 may be installed inside the first housing portion 21.

  The integrating sphere 7 is physically fixed to the slit 4a so that the diffused light emitted from the detection window 73a enters the slit 4a via the collimating lens 62 and the condenser lens 63. That is, the light emitted from the detection window 73a is directly incident on the collimator lens 62, the light emitted from the collimator lens 62 is directly incident on the condenser lens 63, and the light emitted from the condenser lens 63 is directly incident on the slit 4a. . Thus, also in this embodiment, the light emitted from the detection window 73a enters the slit 4a without passing through the optical fiber.

  However, the present invention is not limited to this, and the collimator lens 62 and the condenser lens 63 may be omitted, and the diffused light emitted from the detection window 73a may be directly incident on the slit 4a.

  The integrating sphere 7 is attached to the second housing portion 23 of the housing 2. Specifically, the second housing part 23 has an opening facing in the protruding direction, and the integrating sphere 7 is attached so as to close the opening of the second housing part 23. In order to prevent stray light, it is preferable that the integrating sphere 7 completely closes the opening of the second accommodating portion 23. The integrating sphere 7 is fixed to the second housing portion 23 using a fastener such as a bolt, for example. The method for fixing the integrating sphere 7 is not particularly limited.

  According to the second embodiment described above, similarly to the first embodiment, it is possible to reduce the measurement error due to the bending of the optical fiber, and the amount of light supplied to the spectroscopic measurement unit 3 can be reduced. It is possible to improve.

[Third Embodiment]
FIG. 4 is a schematic diagram showing a configuration example of a spectrometer 1C according to the third embodiment of the present invention. The fiber coupling unit 5 </ b> C included in the spectrometer 1 </ b> C includes a diffusion plate 52, a condensing mirror 67, and a diaphragm 65.

  The condensing mirror 67 is disposed between the diffuser plate 52 and the slit 4a, and condenses the diffused light emitted from the diffuser plate 52 toward the slit 4a while reflecting the diffused light. The condensing mirror 67 is configured to focus at the slit 4a. The diaphragm (aperture) 65 is disposed between the condensing mirror 67 and the slit 4a, and restricts the light beam (light bundle) of the diffused light toward the slit 4a. In addition, it is not restricted to the condensing mirror 67, A plane mirror may be provided. In addition, the diaphragm 65 may be installed inside the first housing portion 21.

  The diffusion plate 52 is physically fixed to the slit 4 a so that the diffused light emitted from the diffusion plate 52 enters the slit 4 a via the condenser mirror 67. That is, the light emitted from the diffusion plate 52 is directly incident on the condensing mirror 67, and the light reflected from the condensing mirror 67 is directly incident on the slit 4a. Thus, also in this embodiment, the light emitted from the diffusion plate 52 enters the slit 4a without passing through the optical fiber.

  According to the third embodiment described above, as in the first and second embodiments, it is possible to reduce the measurement error due to the bending of the optical fiber and to be supplied to the spectroscopic measurement unit 3. It is possible to improve the amount of light. Furthermore, since the condensing mirror 67 is used in the third embodiment, the chromatic aberration is less than in the case where a lens is used, and the influence of wavelength shift or the like in the spectroscopic measurement unit 3 is small.

  In the third embodiment, the condensing lens 61 in the first embodiment is replaced with a condensing mirror 67. Similarly, the collimating lens 62 in the second embodiment is used as a collimating mirror. Alternatively, the condenser lens 63 may be replaced with a condenser mirror.

[Fourth Embodiment]
FIG. 5 is a schematic diagram showing a configuration example of the spectrometer 10 according to the fourth embodiment of the present invention. 6A and 6B are schematic diagrams illustrating a configuration example of the fiber switching unit 8. The spectroscopic measurement apparatus 10 includes a spectroscopic measurement unit 3 and a fiber switching unit 8. The fiber switching unit 8 selectively guides light supplied from the plurality of optical fibers 91 to 95 to the slit 4a.

  The fiber switching unit 8 is obtained by adding a light shielding switching plate 82 to the fiber coupling unit 5A of the first embodiment. That is, the fiber switching unit 8 includes a light shielding switching plate 82, a diffusion plate 52, a condenser lens 61, and a diaphragm 65. The light shielding switching plate 82 is disposed between the emission ends 913 to 953 of the plurality of optical fibers 91 to 95 and the diffusion plate 52. The fiber switching unit 8 may be obtained by adding a light shielding switching plate 82 to the fiber coupling unit 5C of the third embodiment.

  The light shielding switching plate 82 is an example of a light shielding switching means, and supplies light from a part (one in the illustrated example) of optical fibers selected from the plurality of optical fibers 91 to 95 to the diffusion plate 52 through the opening 8a. Then, the light from the remaining optical fiber is shielded. The light supplied to the diffusing plate 52 is diffused in the diffusing plate 52 as in the first embodiment, and the diffused light enters the slit 4 a through the condenser lens 61.

  Specifically, as shown in FIG. 6B, the light shielding switching plate 82 has an opening 8 a corresponding to one of the emission ends 913 to 953 of the plurality of optical fibers 91 to 95. Only light emitted from one of the emission ends 913 to 953 is supplied to the diffusion plate 52 through the opening 8 a of the light shielding switching plate 82, while light emitted from the remaining emission ends is blocked by the light shielding switching plate 82. And is not supplied to the diffusion plate 52.

  Further, the light shielding switching plate 82 is configured to be movable or rotatable so that the plurality of emission ends 913 to 953 face the opening 8a in order. Specifically, the light shielding switching plate 82 is configured to be rotatable around an optical axis LA passing through the slit 4a, and the opening 8a is movable on a circumference around the optical axis LA. As a result, the opening 8 a faces one of the emission ends 913 to 953 according to the rotation angle of the light shielding switching plate 82. Further, the spectroscopic measurement apparatus 10 may include an actuator (not shown) that rotationally drives the light shielding switching plate 82 according to a switching command, for example.

  Further, the light shielding switching plate 82 may be configured to be movable between a light shielding position located between the emission ends 913 to 953 and the diffusion plate 52 and a retreat position away from the light shielding position. According to this, it is possible to use the functions of both the fiber coupling unit 5 and the fiber switching unit 8 in the spectrometer 10.

  In addition, in the spectroscopic measurement apparatus 1B according to the second embodiment, the light from a part of the optical fibers selected from the plurality of optical fibers 91 and 92 is supplied to the integrating sphere 7, and the light from the remaining optical fibers is supplied. A light blocking switching unit that blocks light may be provided.

  According to the fourth embodiment described above, even when the light supplied from the plurality of optical fibers 91 to 95 is selectively guided to the slit 4a, the same as in the first, second, and third embodiments. In addition, it is possible to reduce the measurement error due to the bending of the optical fiber, and to improve the amount of light supplied to the spectroscopic measurement unit 3.

  7A and 7B are schematic views showing a modification of the fiber switching unit 8. 7A is a cross-sectional view when the light shielding switching plate 84 is cut so as to pass through the optical axis LA passing through the slit 4a and the opening 8b, and FIG. 7B is a view when the light shielding switching plate 84 is viewed from the slit 4a side. FIG.

  The light shielding switching plate 84 is configured such that light from a part (one in the illustrated example) of optical fibers selected from the plurality of optical fibers 91 to 98 enters the diffusion plate 52 from the optical axis LA passing through the slit 4a. Furthermore, mirrors 86 and 87 for converting the direction of light from the part of the optical fibers are provided as direction changing means.

  Specifically, an opening 8b corresponding to one of the emission ends 913 to 953 of the plurality of optical fibers 91 to 95 is formed on the surface of the light shielding switching plate 84 on the emission ends 913 to 983 side. On the other hand, an opening 8c is formed on the surface of the light shielding switching plate 84 on the slit 4a side on the optical axis LA passing through the slit 4a. Further, a passage 8d connecting the openings 8b and 8c is formed inside the light shielding switching plate 84, and mirrors 86 and 87 are disposed in the passage 8d.

  Of the exit ends 913 to 983 of the plurality of optical fibers 91 to 98, only the light exiting from one exit end facing the opening 8b enters the passage 8d from the opening 8b and the direction is switched by the mirrors 86 and 87. The light is emitted from 8c onto the optical axis LA and supplied to the diffusion plate 52. On the other hand, the light emitted from the remaining emission ends is shielded by the shielding switching plate 84 and is not supplied to the diffusion plate 52.

  Further, the light shielding switching plate 84 is configured to be rotatable around the optical axis LA passing through the slit 4a, and the opening 8b moves on a circumference around the optical axis LA to be one of the emission ends 913 to 983. It is designed to face each other. On the other hand, since the opening 8c is formed on the optical axis LA, the opening 8c emits light on the optical axis LA regardless of which light exits 913 to 918 enters the opening 8b.

  The emission ends 913 to 983 of the plurality of optical fibers 91 to 98 are arranged offset from the optical axis LA passing through the slit 4a, and emit light in parallel with the optical axis LA. A collimator lens 89 is disposed in front of each of the emission ends 913 to 983, and the light emitted from the emission ends 913 to 983 is converted into parallel light by the collimator lens 89 and then enters the opening 8 b of the light shielding switching plate 84. enter in.

  According to the modification of the fourth embodiment described above, in addition to the above effects, the amount of light passing through the slit 4a even if the positions of the mirrors 86 and 87 are slightly changed due to the installation of the diffusion plate 52. Changes are reduced. Note that the number of mirrors as the direction changing means is not limited to two, and may be one or three.

[First application example]
FIG. 8 is a schematic diagram showing a double beam measurement system 100A which is a first application example of the spectrometer according to the embodiment of the present invention. In the figure, an example of a cross-sectional structure of each optical fiber is also shown. The double beam measurement system 100A includes the spectroscopic measurement apparatus 1A according to the first embodiment, and further includes a branch fiber 101, output fibers 102 and 103, and a light shielding switching plate 108.

  The branch fiber 101 divides light from a light source (not shown) into two light beams and irradiates the measurement object Sam and the reference Ref. The light source includes, for example, a tungsten lamp and a deuterium lamp. The output fiber 102 supplies the transmitted light that has passed through the reference Ref to one optical fiber 91 of the spectrometer 1A. The output fiber 103 supplies the transmitted light that has passed through the measurement object Sam to the other optical fiber 92 of the spectrometer 1A.

  The light shielding switching plate 108 supplies only light from one of the output fibers 102 and 103 to the spectroscopic measurement apparatus 1A through the opening, and shields light from the other. By switching the light shielding switching plate 108, the transmitted light transmitted through the measuring object Sam and the transmitted light transmitted through the reference Ref are sequentially spectroscopically measured. Since the operation of the spectrometer 1A has been described above, detailed description will not be repeated.

  Here, as in the example shown in the figure, assuming that four fiber strands 99 are included in each of the two optical fibers 91 and 92 coupled to the fiber coupling portion 5A, there are a total of 8 in the fiber coupling portion 5A. Even if one of the fiber strands 99 is drawn and one side is shielded by the light shielding switching plate 108, light is supplied to the diffusion plate 52 by the four fiber strands 99 that are half of the strands.

[Second application example]
FIG. 9 is a schematic diagram showing a double beam measurement system 100B, which is a second application example of the spectrometer according to the embodiment of the present invention. In the same figure, an example of a cross-sectional structure of each optical fiber is also shown. The double beam measurement system 100B includes the spectroscopic measurement apparatus 10 according to the fourth embodiment, and further includes a branch fiber 101.

  In the double beam measurement system 100B, since the spectroscopic measurement apparatus 10 includes the fiber switching unit 8, the output fibers 102 and 103 and the light shielding switching plate 108 are compared with the double beam measurement system 100A according to the first application example. It is omitted.

  The transmitted light that has passed through the reference Ref is supplied to one optical fiber 91 of the spectrometer 10, and the transmitted light that has passed through the measurement object Sam is supplied to the other optical fiber 92 of the spectrometer 1A.

  By switching the light shielding switching plate 82 included in the fiber switching unit 8, the transmitted light transmitted through the measurement object Sam and the transmitted light transmitted through the reference Ref are sequentially spectroscopically measured. Since the operation of the spectrometer 10 has been described above, detailed description will not be repeated.

  Here, as in the example shown in the figure, if the two optical fibers 91 and 92 connected to the fiber switching unit 8 each include four fiber strands 99, the fiber switching unit 8 has a total of eight. Even if one of the fiber strands 99 is drawn in and one of the fibers is shielded by the light shielding switching plate 82, light is supplied to the diffusion plate 52 by the four fiber strands 99, which are half of the strands.

[Reference example]
FIG. 10 is a schematic diagram showing a double beam measurement system according to a reference example. In the same figure, an example of a cross-sectional structure of each optical fiber is also shown. The double beam measurement system according to the reference example includes a branch fiber 101, output fibers 102 and 103, a light shielding switching plate 108, a branch fiber 104, and a spectroscopic measurement device 106.

  The branch fiber 104 combines the transmitted light that has passed through the reference Ref supplied from the output fiber 102 and the transmitted light that has passed through the measurement object Sam supplied from the output fiber 103 into one light beam, and emits the light from the output end 104 c. . The exit end 104 c of the branch fiber 104 is fixed close to the slit 105 of the spectroscopic measurement device 106, and light emitted from the exit end 104 c enters the spectroscopic measurement device 106 through the slit 105.

  The exit end 104c of the branch fiber 104 includes a plurality of fiber strands 104d. Of these, half of the fiber strands 104d belong to one incident end 104a, and the other half of the fiber strands 104d belong to the other incident end 104b. The plurality of fiber strands 104d included in the emission end 104c are arranged and fixed in a line along the slit 105. For this reason, the number of fiber strands 104 d is limited by the length of the slit 105.

  Here, as in the illustrated example, assuming that the total number of fiber strands 104d arranged in a line along the slit 105 is four in total, there are two at each incident end 104a, 104b of the branch fiber 104. Only the fiber strand 104d is present. For this reason, no matter how many fiber strands of the upstream output fibers 102 and 103 are increased, the branch fiber 104 becomes a bottleneck, and a sufficient amount of light cannot be supplied to the slit 105.

  On the other hand, in the spectrometers 1A and 10 of the present embodiment shown in FIGS. 8 and 9, the fiber strands 99 included in the optical fibers 91 and 92 connected to the fiber coupling unit 5 or the fiber switching unit 8 are used. Since the diameter and number of the strands are not limited by the length of the slits 4a, it is possible to supply light with more fiber strands 99 than when arranged along the slits 4a. Furthermore, it is possible to supply light through a fiber strand 99 having a large strand diameter. In many cases, the use of a fiber having a larger wire diameter results in less light loss as a whole measurement system. For this reason, it is possible to supply a sufficient amount of light to the spectroscopic measurement unit 3 even if there is some loss of the amount of light in the diffusion plate 52.

[Third application example]
FIG. 11 is a schematic diagram showing a reflected light measurement system 200 that is a third application example of the spectrometer according to the embodiment of the present invention. The reflected light measurement system 200 includes the spectroscopic measurement device 10 according to the fourth embodiment, and further includes a light source device 201 and a light distributor 205.

  The reflected light measurement system 200 performs spectroscopic measurement of the reflected light of a substance having a known spectral reflectance (Ref), and then spectroscopically measures the reflected light generated on the surface of the measurement target Sam. Evaluate spectral reflection characteristics and film thickness. The reflected light measurement system 200 is used for applications such as evaluating the film thickness of a film or the like manufactured in the longitudinal direction at a plurality of points in the width direction.

  The light source device 201 generates light having a wavelength band suitable for reflected light generated in the measurement target Sam. The light generated from the light source device 201 is guided to the light distributor 205 through the connection fiber 203. The light distributor 205 distributes the light from the light source device 201 into a plurality. In the illustrated example, the light distributor 205 divides the light from the light source device 201 into five.

  Five Y-branch fibers are connected to the other end of the optical distributor 205, and the divided lights are respectively output to the input fibers 207-1 to 207-1 of the corresponding Y-branch fibers. Output / incident sections 209-1 to 209-5 are connected to the tips of the input fibers 207-1 to 207-5, respectively. And each light divided | segmented by the light divider | distributor 205 is irradiated toward each measuring object Sam from each of the emission / incident part 209-1-5.

  Of the light irradiated to the measurement object Sam, a component corresponding to the surface state of the measurement object Sam is generated as reflected light. Then, the generated reflected light reenters the emission / incident portions 209-1 to 209-5.

  Reflected light incident on each of the exit / incident units 209-1 to 209-5 is guided to the fiber switching unit 8 of the spectrometer 10 through the corresponding output fibers 211-1 to 5 of the Y-branch fiber. Since the operation of the spectrometer 10 has been described above, detailed description will not be repeated.

[Fourth application example]
FIG. 12 is a schematic diagram showing a transmitted light measurement system 300 which is a fourth application example of the spectrometer according to the embodiment of the present invention. The transmitted light measurement system 300 includes the spectroscopic measurement device 10 according to the fourth embodiment, and further includes a light source device 301 and a light distributor 305.

  The transmitted light measurement system 300 performs spectroscopic measurement of transmitted light in a state where there is no measurement target Sam (Ref), and then measures the light transmitted through the measurement target Sam, thereby measuring the spectral transmission of the measurement target Sam ( Absorption) characteristics and chromaticity are evaluated. The transmitted light measurement system 300 is used for applications such as evaluating the chromaticity of a film manufactured in the longitudinal direction at a plurality of points in the width direction.

  The light source device 301 generates light having a wavelength band suitable for transmitted light generated in the measurement object Sam. The light generated from the light source device 301 is guided to the light distributor 305 through the connection fiber 303. The light distributor 305 distributes the light from the light source device 301 into a plurality. In the illustrated example, the light distributor 305 divides the light from the light source device 301 into five.

  Input fibers 307-1 to 307-5 are respectively connected to the other end of the light distributor 305 to guide light to the emission units 309-1 to 309-5 arranged on one side of the measurement object Sam. And each light divided | segmented by the light divider | distributor 305 is irradiated toward each measuring object Sam from each of the output parts 309-1 to 309-5.

  Of the light applied to the measurement object Sam, a component that has passed through the measurement object Sam is generated as transmitted light. Then, the generated transmitted light is incident on the incident portions 311-1 to 311-5 arranged on the other side of the measurement object Sam.

  The transmitted light incident on each of the incident units 311-1 to 511-5 is guided to the fiber switching unit 8 of the spectrometer 10 through the corresponding output fibers 313-1 to 531-5. Since the operation of the spectrometer 10 has been described above, detailed description will not be repeated.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art.

  DESCRIPTION OF SYMBOLS 1 Spectrometer, 2 Case, 3 Spectrometer, 32 Diffraction grating, 34 Line sensor, 4 Slit plate, 4a Slit, 5 Fiber coupling part, 52 Diffusing plate (an example of light diffusing means), 61, 63 Lens, 65 Aperture, 67 Condensing mirror, 7 Integrating sphere (an example of light diffusing means), 714 inner wall surface, 73a detection window, 8 fiber switching unit, 82, 84 Light shielding switching plate (an example of light shielding switching means), 86, 87 mirror (direction changing means), 91, 92 optical fiber, 913, 923 exit end, 100 double beam measurement system, 200 reflected light measurement system, 300 transmitted light measurement system, LA optical axis.

Claims (11)

A spectroscopic measurement unit for spectroscopically measuring light incident through the slit;
A light diffusing means for diffusing light supplied from a plurality of optical fibers, and is physically fixed to the slit so that the diffused light enters the slit directly or through a lens or a mirror. Light diffusing means;
A spectroscopic measurement apparatus. Further comprising a diaphragm for restricting the light flux of the diffused light toward the slit;
The spectroscopic measurement apparatus according to claim 1. Further comprising the plurality of optical fibers for supplying light to the light diffusing means.
The spectroscopic measurement apparatus according to claim 1 or 2. The light diffusing means includes an emitting portion that emits the diffused light,
The slit and the emission part are opposed to each other.
The spectroscopic measurement device according to claim 1. The light diffusion means is a diffusion plate;
The light supplied from the plurality of optical fibers is incident on one surface of the diffusion plate, and the diffused light is emitted from the other surface of the diffusion plate.
The spectroscopic measurement device according to claim 1. Outgoing ends of the plurality of optical fibers are arranged offset from an optical axis passing through the slit,
The spectroscopic measurement apparatus according to claim 5. The emission ends of the plurality of optical fibers emit light in a direction toward the slit from a position offset from an optical axis passing through the slit.
The spectroscopic measurement apparatus according to claim 5 or 6. Outgoing ends of the plurality of optical fibers are arranged so as to surround an optical axis passing through the slit,
The spectroscopic measurement apparatus according to claim 5. The light diffusing means is an integrating sphere in which light supplied from the plurality of optical fibers is diffusely reflected by a spherical inner wall surface, and the diffused light is emitted from a detection window.
The spectroscopic measurement device according to claim 1. A light-blocking switching unit configured to supply light from a part of the optical fibers selected from the plurality of optical fibers to the light diffusion unit and block light from the remaining optical fibers;
The spectroscopic measurement apparatus according to claim 1. Outgoing ends of the plurality of optical fibers are arranged offset from an optical axis passing through the slit,
The light shielding switching means changes the direction of the light from the part of the optical fibers so that the light from the part of the optical fibers enters the light diffusing means from the optical axis passing through the slit. With means,
The spectroscopic measurement apparatus according to claim 10.

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