WO2014199885A1 - Multi-angle colorimeter - Google Patents

Abstract

A selection unit drives a second light guiding section and variably selects a selected optical path. More specifically, the selection unit switches an upstream optical path in a second optical path so that a downstream optical path in the selected optical path and the upstream optical path in the second optical path are optically connected, and a single optical path is selected from among a plurality of first optical paths as the selected optical path. Thus, light obtained at a plurality of light reception angles can be guided to a single spectroscopy unit without the use of a fiber bundle. As a result, it is possible to make a colorimeter more compact and inexpensive, eliminate the drawback of fiber bundles of high loss of light during light guiding, and achieve colorimetry having a high signal-to-noise ratio.

Description

Multi-angle colorimeter

The present invention relates to a multi-angle colorimeter that receives light emitted from a sample at multiple angles and performs spectral colorimetry.

Metallic paint and pearl color paint used for automobile paintings, etc. may appear to vary in color depending on the direction of the observer due to the effect of the internal glittering material, so the paint evaluation (evaluation of paint color) A multi-angle colorimeter that illuminates or receives light at multiple angles is used.

In a multi-angle colorimeter, light emitted from a sample is generally guided to a spectroscopic unit, and the spectrum of the light is measured in the spectroscopic unit. However, spectroscopic elements such as a diffraction grating and a linear variable filter are not used. It is expensive and has a certain size. For this reason, in a multi-angle colorimeter that receives light at a plurality of angles with respect to a sample, providing a spectroscopic unit for each light reception angle causes an increase in manufacturing cost and an increase in size of the apparatus.

In order to solve this problem, in the multi-angle colorimeter disclosed in Patent Document 1, as a configuration for guiding the reflected light on the surface of the sample to be colorimetric to the spectroscopic unit, the sample side (upstream in the progress of light) A bifurcated bundle fiber having two openings on the side) and one opening on the spectroscopic unit side (downstream side in the travel of light) is used. Also in Patent Document 2, a bundle fiber is used as a configuration for guiding a plurality of measurement lights guided by separate light guide members to one spectroscopic unit.

International Publication No. 2012/147488 JP 2011-64676 A

However, the bundle fiber has a drawback that the effective area of the core portion is small with respect to the total area of the fiber end face and the loss of the light amount is large. There was a problem that it was reduced. In addition, the bundle fiber is more expensive than other light guide members, and there is a problem that the manufacturing cost of the colorimeter increases when this is used.

The present invention has been made in view of such circumstances, and provides a multi-angle colorimeter that receives light at a plurality of angles with respect to a sample while suppressing an increase in manufacturing cost and a decrease in SN ratio. With the goal.

In order to solve the above-mentioned problem, the invention according to the first aspect of the present invention includes: (a) an irradiation unit that irradiates a sample with irradiation light; and (b) a surface of the sample in response to irradiation with the irradiation light. (C) a first light guide unit that receives emitted measurement light at a plurality of different angles with respect to the surface and guides the measurement light through a plurality of first optical paths corresponding to the plurality of angles; A second light guide that receives the measurement light guided through the selected optical path, which is one of the plurality of first optical paths, and guides the measurement light through the second optical path; and (d) the second light guide. A selection unit that drives and variably selects the selected optical path; and (e) a spectroscopic unit that receives and separates the measurement light guided through the second optical path, and the selection unit includes the selected optical path. In order for the downstream optical path in the selection optical path and the upstream optical path in the second optical path to be optically connected, The optical path on the upstream side of the second optical path is switched to select the selected optical path, and any one of the plurality of first optical paths is selected as the selected optical path as the downstream optical path in the second optical path. This is also the same, and by switching the selected optical path for the plurality of first optical paths, multi-angle measurement that performs colorimetry using spectral results for the plurality of measurement lights corresponding to the plurality of angles. It is a color meter.

The invention according to a second aspect of the present invention is the multi-angle colorimeter according to the first aspect of the present invention, wherein the second light guide part reflects light incident from the selected optical path. An optical element having a reflective surface, and the selection unit has a drive unit that rotates the optical element about one axis, and is in accordance with a rotation stop position of the optical element rotated by the drive unit. Thus, the upstream optical path in the second optical path is selectively switched, and the selected optical path is selected from the plurality of first optical paths.

The invention according to a third aspect of the present invention is the multi-angle colorimeter according to the second aspect of the present invention, wherein the optical element reflects the light incident from the selected optical path. A reflective surface; and a second reflective surface that is formed to face the first reflective surface and reflects the reflected light emitted from the first reflective surface. The surface is rotated around one axis by the common drive unit.

The invention according to a fourth aspect of the present invention is the multi-angle colorimeter according to the third aspect of the present invention, wherein the first and second reflecting surfaces maintain an angular relationship with each other in the optical element. In the state of rotation, the first and second reflecting surfaces are maintained at a constant angle with respect to a plane perpendicular to the one axis.

The invention according to a fifth aspect of the present invention is the multi-angle colorimeter according to the first aspect of the present invention, wherein the second light guide part reflects light incident from the selected optical path. An optical element having a reflecting surface, and the selection unit includes a drive unit that displaces the optical element in a linear bidirectional manner, and is in accordance with a drive stop position of the optical element displaced by the drive unit. The upstream optical path in the second optical path is selectively switched, and the selected optical path is selected from the plurality of first optical paths.

The invention according to a sixth aspect of the present invention is the multi-angle colorimeter according to the fifth aspect of the present invention, wherein the reflecting surface is constant with respect to the direction of the linear displacement of the optical element. Is maintained at an angle of

The invention according to a seventh aspect of the present invention is the multi-angle colorimeter according to the first aspect of the present invention, wherein the second light guide portion includes an optical fiber, and the selection portion is the A drive unit that displaces the position or angle of the light incident part that is an opening on the upstream side of the optical fiber, and the upstream of the second optical path according to the position or angle of the light incident part displaced by the drive part The optical path on the side is selectively switched, and the selected optical path is selected from the plurality of first optical paths.

The invention according to an eighth aspect of the present invention is the multi-angle colorimeter according to any one of the first to seventh aspects of the present invention, wherein the measurement light is guided through the plurality of first optical paths. Are spectrally measured by a single spectroscopic unit.

In the multi-angle colorimeter according to the first aspect to the eighth aspect of the present invention, the light obtained at different angles with respect to the measurement point is spectroscopically switched by switching the selected optical path for the plurality of first optical paths. Lead to color measurement. Therefore, compared to a multi-angle colorimeter with a configuration in which a spectroscopic unit is provided for each light receiving angle, measurement errors due to individual differences among a plurality of spectroscopic units are reduced. There is an advantage that the apparatus is reduced and the apparatus can be made compact.

In the multi-angle colorimeter according to the first to eighth aspects of the present invention, the selection optical path is selected by the selection unit driving the second light guide unit. Specifically, the optical path on the upstream side of the second optical path is switched by the selection unit so that the downstream optical path in the selected optical path and the upstream optical path in the second optical path are optically connected, and a plurality of first optical paths are switched. One optical path is selected as the selected optical path from one optical path. For this reason, it is possible to guide light obtained at a plurality of light receiving angles to one spectroscopic unit without using a bundle fiber. Therefore, the point that there is a large amount of light loss in the light guide, which was a defect of the bundle fiber, is solved, and color measurement with a high SN ratio can be realized. Furthermore, a multi-angle colorimeter can be manufactured at a lower cost than when a bundle fiber is used.

In the multi-angle colorimeter according to the first to eighth aspects of the present invention, even if a different first optical path is selected as the selected optical path, the downstream optical path in the second optical path is Identical. As a result, the light guided through the second optical path is incident on the spectroscopic unit at the same position and angle. Therefore, compared to a multi-angle colorimeter with a configuration in which the position and angle of light incident on the spectroscopic unit are different for each guided light path, the measurement error due to the non-identity of the light receiving position and the light receiving angle at the spectroscopic unit There is an advantage that is reduced.

It is a perspective view which shows the external appearance of the multi-angle colorimeter which concerns on 1st Embodiment. In 1st Embodiment, it is a schematic diagram explaining the positional relationship of a measuring device main body and the measurement surface of a to-be-measured object. It is a figure which shows the functional structural example of the multi-angle colorimeter 100 which concerns on 1st Embodiment. In 1st Embodiment, it is a figure which shows the positional relationship of the optical system of the 2nd light guide part 27 periphery. It is a schematic diagram which shows a mode that a to-be-selected optical path is switched in 1st Embodiment. It is a schematic diagram which shows a mode that a to-be-selected optical path is switched in 1st Embodiment. It is a schematic diagram which shows a mode that a to-be-selected optical path is switched in 1st Embodiment. It is a schematic diagram which shows a mode that a to-be-selected optical path is switched in 1st Embodiment. It is a figure which shows the operation | movement flow of the multi-angle colorimeter 100 which concerns on 1st Embodiment. In 2nd Embodiment, it is a figure which shows the positional relationship of the optical system of the 2nd light guide part 27 periphery. In 3rd Embodiment, it is a figure which shows the positional relationship of the optical system of the 2nd light guide part 27 periphery. In 1st Embodiment, it is the figure which showed the relationship between the drive stop position of the mirror MR, and the optical path of measurement light. In 1st Embodiment, it is the figure which showed the relationship between the drive stop position of the mirror MR, and the optical path of measurement light. In 3rd Embodiment, it is the figure which showed the relationship between the drive stop position of the mirror MR, and the optical path of measurement light. In 3rd Embodiment, it is the figure which showed the relationship between the drive stop position of the mirror MR, and the optical path of measurement light. In 4th Embodiment, it is a figure which shows the positional relationship of the optical system of the 2nd light guide part 27 periphery. In 4th Embodiment, it is the figure which showed the relationship between the rotation stop position of the prism PR, and the optical path of measurement light. In 4th Embodiment, it is the figure which showed the relationship between the rotation stop position of the prism PR, and the optical path of measurement light. In 5th Embodiment, it is a figure which shows the positional relationship of the optical system of the 2nd light guide part 27 periphery. It is a functional block diagram of a multi-angle colorimeter in each embodiment. It is a functional block diagram of a multi-angle colorimeter in a modification.

<1 First Embodiment>
<1.1 Appearance and usage>
FIG. 1 is a perspective view showing an appearance of a multi-angle colorimeter 100 according to the first embodiment. FIG. 2 is a schematic diagram for explaining the positional relationship between the measuring instrument main body and the measurement surface of the object to be measured.

As shown in FIG. 1, the multi-angle colorimeter 100 is composed of a box-shaped measuring instrument body 2 in which constituent elements (see FIG. 3) described later are accommodated. The measuring instrument main body 2 includes a measurement opening 3 drilled in the bottom wall and an operation display panel 4 which is disposed at a suitable surface and includes a display showing the measurement results, an operation switch, and the like, and is portable. Configures a portable colorimeter.

FIG. 2 is a schematic diagram for explaining the angle between the central axis of the measuring instrument main body of the multi-angle colorimeter and the measurement surface of the measurement sample. As shown in FIG. 2, the measurement by the multi-angle colorimeter 100 is performed with the measurement opening 3 facing the measurement object 5 (sample), and the surface of the measurement object 5 facing the measurement opening 3 is the measurement surface. 5a.

Then, in a state where the measuring instrument body 2 is in contact with the object to be measured 5 so that the central axis 2n of the measuring instrument body 2 (normal line of the measurement opening 3) and the normal line 5n of the measuring surface 5a coincide with each other, The measurement operation of the multi-angle colorimeter 100 is performed.

<1.2 Configuration of Multi-angle Colorimeter 100>
FIG. 3 is a diagram showing a basic functional configuration of the unidirectional illumination multidirectional light receiving type multi-angle colorimeter 100 according to the first embodiment of the present invention. Hereinafter, the configuration and functions of the multi-angle colorimeter 100 will be described with reference to FIG. Further, in each of the drawings after FIG. 3, right-handed XYZ coordinates are attached as necessary for the purpose of clarifying the arrangement relationship of each part.

The multi-angle colorimeter 100 generally irradiates a predetermined measurement point P on the object to be measured 5 with light, and spectrally decomposes the reflected light from the measurement point P to convert it into an electrical signal. A detection unit 40 and a control unit 70 that controls each unit of the multi-angle colorimeter 100 and processes a signal about the reflected light acquired by the light detection unit 40 are provided.

<1.2.1 Photodetector 40>
As shown in FIG. 3, the light detection unit 40 irradiates a predetermined measurement point P on the object to be measured 5 with the first light r1 (irradiation light) and the first light r1. In response, the second light r2 (measurement light) emitted from the measurement surface 5a of the sample is received at a plurality of different angles with respect to the measurement surface 5a, and a plurality of first optical paths corresponding to the plurality of angles. A first light guide 20 for guiding the second light r2 through the second light r2 guided through the second optical path and the second light r2 guided through the selected optical path which is one of the plurality of first optical paths. 2 light guide section 27, selection section 29 that drives second light guide section 27 to variably select the selected optical path, and spectroscopic section that receives and splits second light r2 guided through the second optical path 30.

Hereinafter, each part of the light detection unit 40 will be described in detail. In the present specification, the irradiation unit 10 side is referred to as “upstream side” and the spectroscopy unit 30 side in the progression of light from the irradiation unit 10 until the first light r1 is emitted and incident on the spectroscopy unit 30. Is expressed as “downstream”.

The irradiation unit 10 includes, for example, a light source composed of a xenon flash lamp, a restriction plate that restricts light from the light source, and a collimator lens (none of which are shown). The light emitting circuit 11 that emits light from the light source is provided in the vicinity of the irradiation unit 10.

The light emitting circuit 11 is, for example, a main capacitor for applying a DC high voltage of several hundred volts to the electrode of the light source, a charging circuit for charging the main capacitor, and a trigger composed of a metal wire wound in close contact with the light source. A trigger generation circuit for applying an alternating high voltage of tens of thousands of volts to the electrode, for example, a semiconductor switch element made of IGBT, and a drive circuit for applying a drive voltage to the semiconductor switch element are provided.

FIG. 4 shows the second light guide unit 27 (mirror MR), the downstream side of the first light guide unit 20 (the emission ports B21 to B26 side of the optical fibers 21 to 26), and the spectrum in the multi-angle colorimeter 100. 4 is a schematic diagram showing a positional relationship with a unit 30. FIG.

The first light guide 20 has a plurality of optical fibers 21 to 26 (six in this embodiment). The optical fibers 21 to 26 are single-core optical fibers having incident ports B11 to B16 at one end and emitting ports B21 to B26 at the other end.

In each of the optical fibers 21 to 26, the entrances B11 to B16 are arranged at positions where the second light r2 emitted from the measurement point P of the object to be measured 5 is received at different angles with respect to the surface (FIG. 3). ), And the emission ports B21 to B26 are arranged at positions optically opposed to the second light guide unit 27 (mirror MR) operated by the selection unit 29 (FIG. 4). In the following description, the light guided by the optical fibers 21 to 26 in the second light r2 is referred to as light r21 to r26, respectively.

Between the measurement point P of the object to be measured 5 and the entrances B11 to B16, a light receiving window for focusing the second light r2 emitted from the measurement point P (typically constituted by an aperture and a convex lens). ), And entrances B11 to B16 are provided at the image forming positions of the light receiving windows. Therefore, the light r21 to r26 emitted from the measurement point P can be guided to the emission ports B21 to B26 through the optical fibers 21 to 26.

The second light guide unit 27 receives one light (light guided through the selected optical path) of the light r21 to r26 emitted from the emission ports B21 to B26 of the optical fibers 21 to 26, and splits the light. This is an optical system that guides to the entrance slit 31 of the unit 30, and includes various known mirrors such as a mirror MR (FIGS. 4 to 8, 10 to 15), a prism PR (FIGS. 16 to 18), and an optical fiber FB (FIG. 19). These optical elements can be used. In the following, first, a mode in which the mirror MR is used as the second light guide unit 27 in the present embodiment will be described, and modes (FIGS. 16 to 18) in which the prism PR is used in the fourth embodiment to be described later will be described in the fifth embodiment. An embodiment (FIG. 19) using a fiber in the form will be described.

The selection unit 29 is a part that variably selects a selected optical path that is one of the plurality of first optical paths (each optical path corresponding to the optical fibers 21 to 26) of the first light guide unit 20.

As an example of the selection unit 29, the selection unit 29 includes a support shaft 291 that rotatably supports the mirror MR, and a drive unit 292 (typically a motor) that rotates the support shaft 291 around the Y axis. A case will be described in which a configuration in which the mirror MR of the optical unit 27 is rotated about the Y axis (about one axis) is employed (FIG. 4). In this case, the selected optical path is selected according to the rotation stop position of the mirror MR (optical element) rotated by the drive unit 292.

Between the exit ports B21 to B26 and the mirror MR, mechanical or optical shutters T1 to T6 are provided. Further, between the shutters T1 to T6 and the mirror MR and between the mirror MR and the spectroscopic unit 30, the optical element 28 for guiding the light r21 to r26 emitted from the respective exit ports B21 to B26 to the spectroscopic unit 30. (Typically a lens) is provided.

With this configuration, while one shutter is open, the other shutter is closed, and the mirror MR is rotated by a predetermined angle by the selection unit 29, so that it can be obtained from one light receiving angle. Only light (light r24 in FIG. 4) can be guided to the mirror MR. Then, the opening and closing of the shutters T1 to T6 and the rotation of the mirror MR are controlled, and one of the lights r21 to r26 incident from the incident ports B11 to B16 is sequentially switched over time. Thus, the time division light reception of the measurement light in the spectroscopic unit 30 is realized, and a configuration in which the light corresponding to each light receiving angle is received by the single spectroscopic unit 30 becomes possible.

As described above, since the multi-angle colorimeter 100 according to the present embodiment is configured to receive the measurement light at a plurality of angles by the single spectroscopic unit 30, the multi-angle colorimetry having a configuration in which the spectroscopic unit is provided for each light receiving angle. Compared to a meter, there are advantages such as a reduction in measurement error due to individual differences among a plurality of spectroscopic units, a reduction in manufacturing cost by reducing the number of spectroscopic units, and a compact colorimeter.

Here, the terms “first optical path”, “selected optical path”, and “second optical path”, which are the optical paths of the second light r2 used in this specification, mean the meaning of the configuration of this embodiment as an example. To organize. That is,
(a) First optical path; an optical path defined by the first light guide 20 (in the present embodiment, for each of the optical fibers 21 to 26). After the lights r21 to r26 are emitted from the sample surface, the optical fibers 21 to 26 are used. Optical paths from the exit ports B21 to B26
(b) optical path to be selected; one optical path guided by the selection unit 29 toward the second light guide unit 27 among the plurality of first optical paths;
(c) Second optical path; an optical path that can switch the downstream side of the optical path by the selector 29, and the light guided through the selected optical path is emitted from the exit ports B21 to B26 and then incident on the entrance slit 31. Optical path to,
It becomes the correspondence relationship.

In the following description, the first optical path corresponding to the light r21 to r26 may be particularly referred to as “first optical path L11 to L16”, and the second optical path may be particularly referred to as “second optical path L21 to L26”.

FIG. 5 to FIG. 8 are schematic diagrams showing how the selection unit 29 selects the selected optical path. To simplify the explanation, two optical fibers 21 and 26 out of the six optical fibers 21 to 26 are shown. Only shown. In addition, for the purpose of simplifying the drawing, the lights r21 and r26 are drawn as light rays, but in reality they may be light beams.

5 to 8, the optical axes of the light beams r21 and r26 emitted from the emission ports B21 and B26 exist in the same XZ plane, and the mirror MR has a reflection surface RS1 of 45 relative to the XZ plane. The support shaft 291 is supported by the support shaft 291 so as to be rotatable around the Y axis.

When light emitted from the emission ports B21 and B26 of the two optical fibers 21 and 26 is incident on the reflection surface RS1 of the mirror MR at an incident angle of 45 degrees, the optical axis of the light and the reflection of the mirror MR A point where the surface RS intersects is called a point PT (FIGS. 5 to 8). The relative positional relationship between the mirror MR and the optical fibers 21 and 26 is adjusted so that the points PT are the same in the two optical fibers 21 and 26. Further, the spectroscopic unit 30 is disposed at a position where the reflected light from the mirror MR of the light guided through the optical fibers 21 and 26 enters the entrance slit 31. The point PT is a point through which the axial center line of the support shaft 291 passes in the reflecting surface RS1, and is a point that does not move due to the rotation of the mirror MR.

Since the arrangement relationship is as described above, as shown in FIG. 5, when the shutter T1 is closed, the shutter T6 is opened, and the reflecting surface RS1 of the mirror MR faces the optical fiber 26, the light r21. Is guided by the first optical path L11 and then blocked by the shutter T1, and the light r26 is guided by the first optical path L16 and then by the second optical path L26 and enters the entrance slit 31. Thus, in the state shown in FIG. 5, the first optical path L16 is selected as the selected optical path.

When the light guided to the entrance slit 31 is switched from the light r26 to the light r21, in other words, when the selected optical path is switched from the first optical path L16 to the first optical path L11, the shutters T1 and T6 are once closed, and the drive unit The support shaft 291 that supports the mirror MR is rotated about the Y-axis by 292 (FIGS. 6 and 7).

At this time, the optical path upstream of the second optical path is selected by the selector 29 so that the downstream optical path in the first optical path L11, which is the selected optical path, and the upstream optical path in the second optical path are optically connected. It is switched (switched from the second optical path L26 to the second optical path L21). This switching is performed by stopping the rotation at the timing when the reflecting surface RS1 of the mirror MR optically opposes the emission port B21.

When the shutter T1 is opened, as shown in FIG. 8, the light r26 is guided by the first optical path L16 and then blocked by the shutter T6, and the light r21 is guided by the first optical path L11 (selected optical path). After that, the light is guided through the second optical path L21 and enters the entrance slit 31.

Further, as can be seen from the arrangement relationship of the above-described units (emission ports B21 to B26, mirror MR, spectroscopic unit 30, etc.), in the multi-angle colorimeter 100 of this embodiment, different first optical paths L11 and L16 are selected. Even when the optical paths are selected, the downstream optical paths in the second optical paths L21 and L26 are the same (FIGS. 5 and 8).

Therefore, the lights r21 and r26 are incident on the incident slit 31 of the spectroscopic unit 30 at the same position and angle. As a result, in the multi-angle colorimeter shown in FIG. 5 to FIG. 8, the spectroscopic unit 30 is compared with the multi-angle colorimeter having a configuration in which the position and angle of light incident on the spectroscopic unit are different for each of the guided light paths. There is an advantage that the measurement error due to the non-identity of the light receiving position and the light receiving angle is reduced.

Up to this point, the procedure for switching the selected optical paths for the two optical fibers 21 and 26 has been described with reference to FIGS. 5 to 8. This is for the six optical fibers 21 to 26 (FIG. 4). But the same is true. Hereinafter, a procedure for switching the selected optical path in the multi-angle colorimeter 100 of the present embodiment will be described with reference to FIG. Note that the arrangement relationship of each part in FIG. 4 is the same as that described in FIGS. 5 to 8 in a simplified manner.

Specifically, the optical paths of the six optical fibers 21 to 26 on the exit B21 to B26 side (downstream side) exist in the same XZ plane, and the mirror MR has a reflection surface RS1 with respect to the XZ plane. The drive unit 292 and the support shaft 291 are supported so as to be rotatable around the Y axis so as to have an inclination of 45 degrees.

Further, when the light r21 to r26 emitted from the emission ports B21 to B26 of the optical fibers 21 to 26 are incident on the reflecting surface RS1 of the mirror MR at an incident angle of 45 degrees, the optical axis of the light and the mirror MR The point at which the reflecting surface RS1 intersects is called a point PT. The relative positional relationship between the mirror MR and the optical fibers 21 to 26 is adjusted so that the point PT is the same among the six optical fibers 21 to 26. In other words, downstream of the optical fibers 21 to 26 (a fixed length including the exit ports B21 to B26) so that the light r21 to r26 can be irradiated at the same angle (45 degrees) toward the point PT of the mirror MR. Are arranged in a plane (XZ plane) radially expanding from the point PT (FIG. 4). The spectroscopic unit 30 is arranged at a position where the reflected light from the mirror MR of the light r21 to r26 guided through the optical fibers 21 to 26 enters the incident slit 31.

Accordingly, as in the case described with reference to FIGS. 5 to 8, the opening and closing of the shutters T1 to T6 is controlled, and the downstream optical path in the selected optical path and the upstream optical path in the second optical path are optically connected. Thus, by switching the upstream optical path of the second optical path by the selection unit 29, one optical path can be selected as the selected optical path from among the plurality of first optical paths L11 to L16.

At the time of colorimetry of the object 5 to be measured, one light guided to the spectroscopic unit 30 among the light r21 to r26 incident from each of the entrances B11 to B16 is performed by sequentially switching the selected optical path. And the time division light reception of the measurement light in the spectroscopic unit 30 is realized. FIG. 4 illustrates the case where the first optical path L14 is selected as the selected optical path.

As described above, even when different first optical paths L11 to L16 are selected as the selected optical paths, the downstream optical paths (optical paths on the spectroscopic unit 30 side) in the second optical paths L21 to L26 are the same. (FIGS. 5 and 8). For this reason, the lights r21 to r26 are incident on the incident slit 31 of the spectroscopic unit 30 at the same position and angle.

The spectroscopic unit 30 (FIG. 3) separates incident light beams incident through the second optical paths L21 to L26 by the second light guide unit 27 for each wavelength and outputs spectroscopic data corresponding to the light intensity. The spectroscopic unit 30 includes a concave diffraction grating 32 and a line sensor 33 (one-dimensional photoelectric conversion element).

Therefore, in the multi-angle colorimeter 100 of the present embodiment, the emitted lights r21 to r26 from the optical fibers 21 to 26 are incident on the spectroscopic unit 30 in time sequence in accordance with the switching operation of the selected optical path described above. It is diffracted and reflected by the concave diffraction grating 32 and received by the line sensor 33. The line sensor 33 converts the incident light into an electrical signal.

As the spectroscopic unit 30, in addition to the mode of performing the spectrum using the reflection type diffraction grating as in the present embodiment, the mode of using the transmission type diffraction grating, or an optical element having a spatially different bandpass ( Various known spectroscopic sections such as an embodiment that typically uses a filter) can be employed.

<1.2.2 Control Unit 70, Operation Display Panel 4, Memory Unit 60>
Hereinafter, the control unit 70, the operation display panel 4, and the memory unit 60 will be described as electrical configurations in the multi-angle colorimeter 100.

The control unit 70 has a measurement control unit 71 and a calculation unit 72 as functional blocks, and controls the operation of each unit of the multi-angle colorimeter 100 according to a control program stored in the memory unit 60. It is configured by an electronic circuit such as an A / D converter.

The measurement control unit 71 causes the light source of the irradiation unit 10 to emit light by the operator of the multi-angle colorimeter 100 operating the measurement switch 65 to perform color measurement in the light detection unit 40. In addition, the measurement control unit 71 displays the calculation result by the calculation unit 72 on the display unit 66 as the measurement result.

The calculation unit 72 obtains a light detection value (spectral reflection characteristic) based on the electrical signal output from the light detection unit 40, and color information at the measurement point P of the object 5 to be measured based on the detection value. (E.g., tristimulus values).

The operation display panel 4 includes a measurement switch 65 for a user of the multi-angle colorimeter 100 to instruct measurement start, a display unit 66 (typically a liquid crystal panel) for displaying a measurement result, and the like.

The memory unit 60 includes a RAM, an EEPROM, etc., and temporarily stores measurement results and stores a control program for operating the control unit 70.

<1.3 Example of control of multi-angle colorimeter 100>
Next, a control example of the multi-angle colorimeter will be described with reference to FIG. The following operation is automatically executed by the control unit 70 according to a program stored in the memory unit 60.

FIG. 9 is a flowchart illustrating the flow of the color measurement operation realized in the multi-angle colorimeter 100. Since the individual functions of each unit have already been described, only the overall flow will be described here. The measuring instrument body 2 is opposed to the surface of the object to be measured 5 so that the central axis 2n of the measuring instrument body 2 (normal line of the measurement aperture 3) and the normal line 5n of the measuring surface 5a coincide with each other, and the irradiation unit It is assumed that the process proceeds to step ST1 (at the start of measurement) with 10 turned off.

In step ST1, the irradiation controller 10 is turned on by the measurement controller 71.

In step ST2, the measurement control unit 71 opens the shutter T1, closes the shutters T2 to T6, and the selection unit 29 detects the light r21 using the first optical path L11 as the selected optical path, by the spectroscopic unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST3, the measurement control unit 71 opens the shutter T2, closes the shutters T1 and T3 to T6, and the selection unit 29 detects the light r22 with the first optical path L12 as the selected optical path by the spectroscopic unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST4, the measurement control unit 71 opens the shutter T3, closes the shutters T1, T2, and T4 to T6, and the selection unit 29 detects the light r23 with the first optical path L13 as the selected optical path and the spectral unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST5, the measurement control unit 71 opens the shutter T4, closes the shutters T1 to T3, T5, and T6, and the selection unit 29 detects the light r24 using the first optical path L14 as the selected optical path and the light splitting unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST6, the measurement control unit 71 opens the shutter T5, closes the shutters T1 to T4, and T6, and the selection unit 29 detects the light r25 using the first optical path L15 as the selected optical path by the spectroscopic unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST7, the measurement control unit 71 opens the shutter T6, closes the shutters T1 to T5, and the selection unit 29 detects the light r26 using the first optical path L16 as the selected optical path, by the spectroscopic unit 30. Then, based on the detection result, the detection value is acquired by the calculation unit 72 and stored in the memory unit 60.

In step ST8, the measurement control unit 71 turns off the irradiation unit 10.

In step ST9, the computing unit 72 calculates the color information of the DUT 5 at the measurement point P based on the six light detection values corresponding to the lights r21 to r26 stored in the memory unit 60.

In step ST10, the measurement control unit 71 displays the color information of the device under test 5 at the measurement point P calculated by the calculation unit 72 on the display unit 66 as a measurement result, whereby the operation flow is completed.

<1.4 Effects of the multi-angle colorimeter 100>
Hereinafter, the main effects of the multi-angle colorimeter 100 according to the present embodiment will be summarized.

(1) In the multi-angle colorimeter 100 according to the present embodiment, the selected optical paths are sequentially switched for the plurality of first optical paths L11 to L16 (FIGS. 5 to 8), so that different angles with respect to the measurement point P are obtained. The light r21 to r26 obtained in step 1 can be guided to a single spectroscopic unit 30 to perform spectroscopic colorimetry.

Therefore, the colorimeter can be reduced in size and cost. In addition, since the internal parts can be shared by using a single spectroscopic unit 30 in common, it is not necessary to consider individual differences between spectroscopic units that occur when using a plurality of spectroscopic units.

(2) In the multi-angle colorimeter 100 of the present embodiment, the second optical path is selected by the selector 29 so that the downstream optical path in the selected optical path and the upstream optical path in the second optical path are optically connected. Is switched, and one optical path is selected as the selected optical path from among the plurality of first optical paths L11 to L16 (FIGS. 5 to 8). The selection of the selected optical path is performed by driving the second light guide unit 27 (rotating the mirror MR).

For this reason, for example, as in a multi-angle colorimeter that uses a bundle fiber as the second light guide unit, the upstream side of the second optical path is branched, and the optical path downstream of the plurality of first optical paths and the upstream of the second optical path The multi-angle colorimeter (that is, the first optical path) selects one light to be guided to the spectroscopic unit by selecting one optical path pair from a plurality of corresponding optical path pairs. 2) The multi-angle colorimeter in which the light guide is not driven) and the multi-angle colorimeter 100 in the present embodiment are different in technical characteristics in optical path selection.

As described above, the multi-angle colorimeter 100 of the present embodiment can guide the light r21 to r26 obtained at a plurality of light receiving angles to the single spectroscopic unit 30 without using a bundle fiber. For this reason, the point that there is much light quantity loss in the light guide which was a defect of the bundle fiber is solved, and colorimetry with a high SN ratio can be realized. Furthermore, a multi-angle colorimeter can be manufactured at a lower cost than when a bundle fiber is used.

(3) In the multi-angle colorimeter 100 of the present embodiment, even if different first optical paths L11 to L16 are selected as the selected optical paths, the downstream optical path (on the spectroscopic unit 30 side) in the second optical path. Are the same. Therefore, the lights r21 to r26 guided through the second optical paths L21 to L26 are incident on the spectroscopic unit 30 at the same position and angle.

Therefore, in the multi-angle colorimeter 100 according to the present embodiment, the light received by the spectroscopic unit 30 is compared with the multi-angle colorimeter having a configuration in which the position and angle of light incident on the spectroscopic unit are different for each of the guided light paths. There is an advantage that the measurement error due to the non-identity of the position and the light receiving angle is reduced.

<2 Other Embodiments>
In the first embodiment,
(Condition 1) The selection unit 29 optically connects the downstream optical path in one optical path (selected optical path) of the plurality of first optical paths L11 to L16 and the upstream optical path in the second optical paths L21 to L26. As described above, the optical path on the upstream side of the second optical paths L21 to L26 can be switched,
(Condition 2) The downstream optical paths in the second optical paths L21 to L26 are the same even when any of the plurality of first optical paths L11 to L16 is selected as the selected optical path.
The multi-angle colorimeter 100 has been described as an example of the multi-angle colorimeter that satisfies both conditions.

Hereinafter, other embodiments of the multi-angle colorimeters 100A to 100D that satisfy the conditions 1 and 2 will be described. In each of the following embodiments, redundant description of the same configuration and effects as those of the multi-angle colorimeter 100 of the first embodiment will be omitted.

<2.1 Multi-angle Colorimeter 100A of Second Embodiment>
FIG. 10 is a schematic diagram illustrating configurations of the first light guide unit 20, the second light guide unit 27, the selection unit 29, and the spectroscopic unit 30 of the multi-angle colorimeter 100A according to the second embodiment. Further, in FIG. 10 and the subsequent drawings, the same reference numerals are given to the same elements as those in the first embodiment.

In FIG. 10, as in FIGS. 5 to 8, only two optical fibers 21 and 26 among the six optical fibers 21 to 26 are illustrated for the purpose of simplifying the description. Similarly to the multi-angle colorimeter 100, 100A also has optical fibers 21 to 26.

The multi-angle colorimeter 100A differs from the above-mentioned multi-angle colorimeter 100 in that the angles of the exits B21 to B26 with respect to the XZ plane (in FIG. 10, the angles of the exits B21 and B26) and the mirror with respect to the XZ plane Only the angle of the MR reflection surface RS1 is used, and the remaining configuration is the same as that of the multi-angle colorimeter 100.

That is, as long as the above-described conditions 1 and 2 are satisfied, as shown in FIG. 10 shown in the second embodiment, an arrangement relationship in which the incident angle and the reflection angle to the mirror MR are larger than 45 degrees may be used. . Similarly, as long as the above conditions 1 and 2 are satisfied, a multi-angle colorimeter in which the incident angle and the reflection angle on the mirror MR are smaller than 45 degrees may be used.

When the light beams r21 to r26 are irradiated onto the mirror MR at an incident angle other than 45 degrees as in the multi-angle colorimeter 100A of the second embodiment, for example, downstream of the optical fibers 21 to 26 (emission ports B21 to B26) Can be employed in a plane corresponding to the conical side surface when viewed from the point PT toward the point PT.

<2.2 Multi-angle Colorimeter 100B of Third Embodiment>
FIG. 11 is a schematic diagram illustrating configurations of the first light guide unit 20, the second light guide unit 27, the selection unit 29, and the spectroscopic unit 30 of the multi-angle colorimeter 100B according to the third embodiment.

In FIG. 11, only three optical fibers 21, 22, and 23 among the six optical fibers 21 to 26 are shown for the purpose of simplifying the explanation, but the multi-angle colorimeter 100 B is also multi-angle colorimetry. Similar to the total 100, it has six optical fibers 21-26.

The multi-angle colorimeter 100B is different from the above-mentioned multi-angle colorimeter 100 in the arrangement relationship of the optical fibers 21 to 26 and the switching operation of the second optical paths L21 to L26, and the remaining configuration is the multi-angle colorimetry. The total is the same as 100.

Specifically, in the multi-angle colorimeter 100B, the emission ports B21 to B26 of the optical fibers 21 to 26 are emitted in the Y direction so that the lights r21 to r26 are emitted in the −X direction at predetermined intervals in the Y direction. Arranged along. The mirror MR is supported by the support shaft 291 in a state where the reflection surface RS1 is inclined by 45 degrees with respect to the XZ plane and perpendicular to the XY plane, and the support shaft 291 and the mirror MR supported by the support shaft 291 are driven by the drive unit 292b. (For example, a linear motor) is displaced in the ± Y direction (linear bidirectional). Further, the upstream optical path and the downstream optical path in the second optical paths L21 to L26 are selectively switched according to the driving stop position of the mirror MR driven by the driving unit 292b.

For this reason, when the mirror MR is displaced in the ± Y direction by the drive unit 292b, the displacement amount is made to correspond to the predetermined interval, so that the irradiation position of the optical axis when the light beams r21 to r26 are irradiated onto the mirror MR. Can be the same. The spectroscopic unit 30 is arranged at a position where the reflected light from the mirror MR of the light r21 to r26 guided through the optical fibers 21 to 26 enters the incident slit 31. Because of such a configuration, the multi-angle colorimeter 100B of the third embodiment can satisfy the above conditions 1 and 2.

<2.2.1 Effect of Multi-angle Colorimeter 100B of Third Embodiment>
The effect of the multi-angle colorimeter 100B of the third embodiment will be described with reference to FIGS.

FIG. 12 shows the relationship between the rotation stop position of the mirror MR and the optical path of the measurement light when the drive unit 292 (FIG. 4) is ideally controlled in the multi-angle colorimeter 100 of the first embodiment. FIG. FIG. 13 shows the rotation stop position of the mirror MR when the drive unit 292 is controlled to stop rotating at a certain angle from the ideal rotation stop position in the multi-angle colorimeter 100 of the first embodiment. It is the figure which showed the relationship with the optical path of measurement light.

FIG. 14 shows the drive stop position (Y-direction displacement amount) of the mirror MR and the optical path of the measurement light when the drive unit 292b (FIG. 11) is ideally controlled in the multi-angle colorimeter 100B of the third embodiment. It is the figure which showed the relationship. FIG. 15 shows the drive stop position (Y of the mirror MR when the drive unit 292b is controlled to stop driving with a certain distance in the Y direction from the ideal drive stop position in the multi-angle colorimeter 100B of the third embodiment. It is the figure which showed the relationship between (direction displacement amount) and the optical path of measurement light.

Also, in common with FIGS. 12 to 15 and FIGS. 17 and 18 to be described later, the optical path when the drive units 292 and 292b are ideally controlled is indicated by dotted arrows, and the drive units 292 and 292b have a certain level from the ideal control. The optical path in the case of being controlled by shifting is indicated by a solid arrow.

In the following description, among the light incident on the mirror MR (second light guide unit 27), the light incident at the ideal position and angle is shifted from the “incident light IL1”, the ideal position and angle. The incident light is referred to as “incident light IL2”. Similarly, the light emitted from the mirror MR (second light guide unit 27) is referred to as “emitted light RL1” and “emitted light RL2”.

The incident light IL1 and the incident light IL2 are actually light that follows the same optical path in the spectrometer 30. However, the incident light IL1 and the incident light IL2 enter the mirror MR (second light guide unit 27) due to the presence or absence of the drive control deviation. The light has a different incident angle or incident position. Due to this, the outgoing light RL1 and the outgoing light RL2 become light that follows different optical paths in the spectrometer 30.

As described above, in the multi-angle colorimeter 100 of the first embodiment, the selection unit 29 switches the second optical paths L21 to L26 by rotating the mirror MR about the Y axis. For this reason, the incident light IL2 (FIG. 13) in the case where the mirror MR is rotated and stopped at a certain angle from the ideal rotation stop position is different from the incident light IL1 (FIG. 12) that is ideal in design. It is incident on the mirror MR at an angle. As a result, the emitted light RL2 is also emitted at a different angle from the emitted light RL1.

On the other hand, in the multi-angle colorimeter 100B of the third embodiment, the switching of the second optical paths L21 to L26 by the selection unit 29 is performed by the direct movement of the mirror MR. The reflecting surface RS1 is maintained at a constant angle with respect to the linear displacement direction of the mirror MR (optical element). Thus, since the reflecting surface RS1 maintained at a constant angle with respect to the linear displacement direction (Y direction) of the mirror MR is used, even if the mirror MR is displaced linearly (Y direction), The traveling direction of the light reflected from the reflecting surface (emitted light RL) does not vary. Specifically, even if the incident light IL2 (FIG. 15) is generated when a position shift occurs at the drive stop position of the mirror MR, the mirror has the same incident angle as the incident light IL1 (FIG. 14) that is ideal in design. The light enters the MR, and the outgoing light RL2 is also emitted at the same angle as the outgoing light RL1.

Therefore, in the multi-angle colorimeter 100B according to the third embodiment, the angular deviation of the emitted light RL that can occur in the multi-angle colorimeter 100 according to the first embodiment (the angular deviation in the downstream optical path of the second optical path) is generated. It does not occur, and the light guided from the selected optical path can be guided to the entrance slit 31 at a certain angle.

Note that the positional deviation and angular deviation (FIG. 13) of the light applied to the spectroscopic unit 30 that can occur in the multi-angle colorimeter 100 of the first embodiment are not so much as to impair the essence of the present invention. (The downstream side of the second optical paths L21 to L26 is the same).

However, it is preferable to reduce or eliminate such a slight error (displacement) as much as possible in order to further improve the measurement accuracy. Therefore, the measurement accuracy is further improved if the configuration does not cause an angular shift of the light irradiated to the spectroscopic unit 30 as in the multi-angle colorimeter 100B of the third embodiment (FIGS. 14 and 15). .

Further, when the second optical paths L21 to L26 are switched by the rotation of the mirror MR as in the multi-angle colorimeter 100 of the first embodiment, the distance between the second optical paths L21 to L26 is shortened so that the mirror The positional deviation of the incident position on the incident slit 31 due to the positional deviation of the MR rotation stop position can be reduced, and the measurement error can be reduced.

<2.3 Multi-angle Colorimeter 100C of Fourth Embodiment>
FIG. 16 is a schematic diagram illustrating configurations of the first light guide unit 20, the second light guide unit 27 (prism PR), the selection unit 29, and the spectroscopic unit 30 of the multi-angle colorimeter 100C according to the fourth embodiment. It is.

In FIG. 16, only two optical fibers 21 and 26 of the six optical fibers 21 to 26 are shown for the purpose of simplifying the description. However, the multi-angle colorimeter 100C is also the multi-angle colorimeter 100C. Similarly to the above, six optical fibers 21 to 26 are provided.

The multi-angle colorimeter 100C is different from the multi-angle colorimeter 100 of the first embodiment in that a prism PR is used as the second light guide 27 instead of the mirror MR, and the remaining configuration is a multi-colorimeter. This is the same as the angle colorimeter 100. As the prism PR, for example, a rhombus prism (FIGS. 16 to 18) having reflection surfaces RS2 and RS3 that cause internal reflection parallel to two opposing surfaces can be used.

As shown in FIG. 16, the light r21 to r26 guided through one optical path (selected optical path) among the plurality of first optical paths L11 to L16 is the first reflection surface RS2 and the second reflection in the prism PR. The light is reflected by the surface RS3 and guided to the entrance slit 31 of the spectroscopic unit 30.

Further, the upstream optical path in the second optical paths L21 to L26 is selectively switched according to the rotation stop position of the prism PR rotated by the driving unit 292, and the plurality of first optical paths L11 to L16 are selected. The selected optical path is selected.

Thus, the main role of the prism PR (the role as the second light guide 27) is the same as that of the mirror MR in the multi-angle colorimeter 100. That is, the prism PR is rotated by the drive unit 292 to switch the upstream optical path of the second optical paths L21 to L26 and guided through one of the first optical paths L11 to L16 (selected optical path). The light is guided to the entrance slit 31 of the spectroscopic unit 30. Further, the downstream optical paths in the second optical paths L21 to L26 are the same even when any of the plurality of first optical paths L11 to L16 is selected as the selected optical path.

<2.3.1 Effect of Multi-angle Colorimeter 100C of Fourth Embodiment>
The effect of the multi-angle colorimeter 100C of the fourth embodiment will be described with reference to FIGS.

17 and 18 are diagrams showing the relationship between the rotation stop position of the prism PR and the optical path of the measurement light in the multi-angle colorimeter 100C of the fourth embodiment.

FIG. 17 is a diagram showing the relationship between the rotation stop position of the prism PR and the optical path of the measurement light when the drive unit 292 is ideally controlled in the multi-angle colorimeter 100C. FIG. 18 shows the relationship between the rotation stop position of the prism PR and the optical path of the measurement light when the drive unit 292 is controlled to stop rotation by deviating from the ideal rotation stop position in the multi-angle colorimeter 100C. It is the figure which showed the relationship.

As described above, the optical path when the drive unit 292 (FIG. 16) is ideally controlled is indicated by a dotted arrow (FIG. 17), and the optical path when the drive unit 292 is controlled by a certain degree of deviation from the ideal control is indicated by a solid arrow. (FIG. 18).

Similarly to FIGS. 12 to 15, the incident light IL1 and the incident light IL2 are actually light that follows the same optical path in the spectroscope 30. However, the prism PR ( The incident light or the incident position on the second light guide 27) is different. Due to this, the outgoing light RL1 and the outgoing light RL2 become light that follows different optical paths in the spectrometer 30.

In the multi-angle colorimeter 100C of the fourth embodiment, the first reflecting surface RS2 and the second reflecting surface RS3 are fixedly formed in parallel with each other in a prism PR (optical element). The first reflecting surface RS2 and the second reflecting surface RS3 are rotated while being maintained at a constant angle with respect to the plane XZ perpendicular to the Y axis, which is the rotation axis.

For this reason, even if the incident light IL2 (FIG. 18) when the mirror MR is rotated and deviated from the ideal rotation stop angle by a certain angle, the incident light IL1 (FIG. 17) that is ideal in design. Is incident on the prism PR at the same incident angle. As a result, the emitted light RL2 emitted through the reflecting surfaces RS2 and RS3 fixedly formed parallel to each other in the prism PR is also emitted at the same angle as the emitted light RL1. That is, even if the posture of the prism PR slightly varies due to the shift in the rotation stop angle, the shift in the reflection direction that occurs on the first reflection surface RS2 is offset by the shift in the reflection direction on the second reflection surface RS3. 2 The traveling direction of the light emitted from the light guide unit (the angle of the emitted light RL) is maintained constant.

Therefore, in the multi-angle colorimeter 100C according to the fourth embodiment, the angular deviation of the emitted light RL (the angular deviation in the downstream optical path of the second optical path) that can occur in the multi-angle colorimeter 100 according to the first embodiment described above. It does not occur, and the light guided from the selected optical path can be guided to the entrance slit 31 at a certain angle. As a result, the measurement accuracy is further improved as in the multi-angle colorimeter 100B of the third embodiment.

<2.4 Multi-angle Colorimeter 100D of Fifth Embodiment>
FIG. 19 is a schematic diagram illustrating configurations of the first light guide unit 20, the second light guide unit 27 (optical fiber FB), the selection unit 29, and the spectroscopic unit 30 of the multi-angle colorimeter 100D according to the fifth embodiment. FIG.

In FIG. 19, only two optical fibers 21 and 26 of the six optical fibers 21 to 26 are illustrated for the purpose of simplifying the explanation, but the multi-angle colorimeter 100D is also shown in FIG. Similarly to the above, six optical fibers 21 to 26 are provided.

The multi-angle colorimeter 100D is different from the multi-angle colorimeter 100 of the first embodiment in that an optical fiber FB is used as the second light guide 27 instead of the mirror MR, and the remaining configuration is as follows. The same as the multi-angle colorimeter 100.

As the optical fiber FB, for example, a single-core fiber (FIG. 19) having a large core diameter on the incident side as compared with the exit numerical apertures of the optical fibers 21 to 26 of the first light guide unit 20 can be used.

Further, the multi-angle colorimeter 100D includes a drive unit 292 that displaces the position or angle of the light incident unit B17 that is the opening on the upstream side of the optical fiber FB as the selection unit 29. For this reason, the upstream optical path in the second optical paths L21 to L26 is selectively switched according to the position or angle of the light incident section B17 displaced by the driving section 292, and the plurality of first optical paths L11 to L16 are changed. The selected optical path is selected. In addition, as the drive part 292, the rotation mechanism using a motor etc. can be utilized similarly to 1st Embodiment.

The lights r21 to r26 guided through one optical path (selected optical path) among the plurality of first optical paths L11 to L16 are guided to the entrance slit 31 of the spectroscopic unit 30 through the optical fiber FB.

Thus, the main role of the optical fiber FB (the role as the second light guide 27) is the same as that of the mirror MR in the multi-angle colorimeter 100. That is, the optical fiber FB is driven by the drive unit 292 to switch the position and angle of the light incident part B17 of the optical fiber FB (switch the optical path on the upstream side of the second optical paths L21 to L26), and the first optical path The light guided through one optical path (selected optical path) among L11 to L16 is guided to the entrance slit 31 of the spectroscopic unit 30. Further, the downstream optical paths in the second optical paths L21 to L26 are the same even when any of the plurality of first optical paths L11 to L16 is selected as the selected optical path.

<2.4.1 Effect of Multi-Angle Colorimeter 100D of Fifth Embodiment>
As described above, in the multi-angle colorimeter 100D of the fifth embodiment, the optical fiber FB having a large core diameter on the incident side as compared with the exit numerical apertures of the optical fibers 21 to 26 of the first light guide unit 20 (FIG. 19). ) Can be used.

For this reason, even if the rotation stop position by the drive unit 292 is slightly deviated from the ideal design position, the light guided through the selected optical path can be incident from the incident side end of the optical fiber FB. It becomes.

Further, if an optical fiber having a low correlation between the incident position and incident angle of the incident light IL and the outgoing position and angle of the emitted light RL, that is, an optical fiber having high mixing properties, is used as the optical fiber FB. Even if a deviation occurs, the influence of the deviation hardly occurs when the outgoing light RL enters the spectroscopic unit 30. In addition, the improvement of the mixing property of the optical fiber FB can be realized by an aspect in which the light guide distance of the optical fiber FB is increased in addition to an aspect in which components having high mixing properties are used for fiber formation.

<3 Types of multi-angle colorimeter 100, 100A-100D>
The multi-angle colorimeters 100 and 100A to 100D described above are classified into the following types from the viewpoint of optical path selection by the second light guide unit 27 and the selection unit 29.

<3.1 Multi-angle colorimeter of the same position incidence type>
In the multi-angle colorimeter of the same position incidence type, when the first optical paths L11 to L16 guided by the first light guide 20 are virtually extended downstream from the exit ports B21 to B26 of the optical fibers 21 to 26, The extension lines of the optical paths L11 to L16 intersect at one point.

Therefore, in this type of multi-angle colorimeter, the second light guide 27 can receive the light r21 to r26 guided through the first optical paths L11 to L16 at the one point, and the light r21 to r26. Can be emitted in the same direction, the above conditions 1 and 2 can be satisfied.

The multi-angle colorimeters 100 and 100A of the first and second embodiments belong to this type. That is, as a typical example of this type, a plurality of optical fibers 21 to 21 are arranged in a radial plane centered at one point (point PT in the above embodiment) or in a plane corresponding to a side surface of a cone having one point as a vertex. 26 (the downstream side of the first optical paths L11 to L16) is directed to the one point, and the optical element (mirror MR, etc.) of the second light guide unit 27 is rotated around one axis by the selection unit 29. Thus, there is a multi-angle colorimeter in which the light r21 to r26 received at the one point is emitted in the same direction (direction in which the spectroscopic unit 30 is arranged).

<3.2 Multi-angle colorimeter of the same angle incidence type>
In the same angle incident type multi-angle colorimeter, when the first optical paths L11 to L16 guided by the first light guide unit 20 are virtually extended downstream from the emission ports B21 to B26 of the optical fibers 21 to 26, Each optical path is parallel.

Therefore, in this type of multi-angle colorimeter, the second light guide 27 can receive the parallel lights r21 to r26 guided through the first optical paths L11 to L16, and the parallel lights r21 to r26. If it is possible to emit light from the same position while maintaining the directional relationship (parallel), the above condition 1 and condition 2 can be satisfied.

The multi-angle colorimeters 100B and 100C of the third and fourth embodiments belong to this type. That is, as a typical example of this type, the downstream sides of the plurality of optical fibers 21 to 26 (downstream sides of the first optical paths L11 to L16) are arranged in parallel, and the optical element of the second light guide unit 27 is selected by the selection unit 29. (Mirror MR, prism PR, etc.) are displaced along one axis or rotated around one axis, so that the light r21 to r26 is directed from the same position of the second light guide 27 in the same direction (toward the spectroscopic unit 30). E) An emitted multi-angle colorimeter.

<3.3 Mixing type multi-angle colorimeter>
In the mixing-type multi-angle colorimeter, a light guide having high optical mixing property is used as the second light guide 27, so that the incident positions and incident angles of the lights r21 to r26 to the second light guide 27 are determined. The emission position and the emission angle from the second light guide unit 27 do not depend on (or the dependency ratio is sufficiently small).

The multi-angle colorimeter 100D of the fifth embodiment belongs to this type. That is, as a typical example of this type, the upstream optical path is the downstream side of the selected optical path while the downstream optical path of the optical element (such as the optical fiber FB) of the second light guide unit 27 is kept constant. By being switched by the selection unit 29 so as to be optically connected to the optical path, the light guided through the selected optical path is mixed by the second light guide unit 27 and emitted in the same direction (toward the spectroscopic unit 30). Multi-angle colorimeter.

<3.4 Other types of multi-angle colorimeter>
The three types of multi-angle colorimeters have been described above. In these types, as described above, the selection unit 29 has a drive mechanism (one-axis rotation mechanism, one-axis displacement mechanism, etc.) for one degree of freedom. If it is possible, it is enough. Note that the present invention can be implemented even if these conditions are not satisfied. In this case, a necessary optical path is selected by combination driving with two or more degrees of freedom such as a combination of displacement and rotation.

<4 Modification>
As mentioned above, although embodiment of this invention has been described, this invention is not limited to said each embodiment, A various deformation | transformation is possible.

FIG. 20 is a functional block diagram of the multi-angle colorimeter 100, 100A to 100D of each of the above embodiments, and FIG. 21 is a functional block diagram of a multi-angle colorimeter 100E as a modification. 20 shows a state in which the light r21 is guided to the single spectroscopic unit 30 in the multi-angle colorimeters 100, 100A to 100D. In FIG. 21, the light r21 in the multi-angle colorimeter 100E is a spectroscopic unit 30A. The light r24 is guided to the spectroscopic unit 30B.

As shown in FIG. 20, in the multi-angle colorimeters 100, 100A to 100D of each of the above embodiments, the mode in which all of the lights r21 to r26 are guided to the single spectroscopic unit 30 has been described. The embodiment is not limited to this. For example, as shown in FIG. 21, a plurality of spectroscopic units 30A and 30B (two in this modification) may be provided, and the light r21 to r26 may be guided to any of the spectroscopic units.

In the case of the multi-angle colorimeter 100E of this modification, the above-described spectral colorimetry operation is performed in parallel on the light beams r21 to r23 guided to the spectroscopic unit 30A and the light beams r24 to r26 guided to the spectroscopic unit 30B. Therefore, the time required for the color measurement can be shortened. On the other hand, in the case of the multi-angle colorimeter 100, 100A to 100D of the above embodiment, since the spectral colorimetry is performed by the single spectroscopic unit 30, a plurality of spectroscopic units 30A, 30B are used like the multi-angle colorimeter 100E. Compared with the configuration in which the apparatus is provided, the manufacturing cost can be reduced and the apparatus can be downsized. In addition, it is not necessary to consider measurement errors due to individual differences between the spectroscopic units 30.

In each of the above-described embodiments, the aspect in which the optical fibers 21 to 26 are used as the first light guide unit 20 has been described. However, the present invention is not limited to this. That is, the first light guide unit 20 only needs to be configured to be able to guide the second light r2 through the plurality of first optical paths corresponding to the light reception angles, and is in positions corresponding to the plurality of light reception angles. Various known optical elements such as a configuration in which a mirror is arranged can be substituted.

In each of the above-described embodiments, the configuration in which the shutters T1 to T6 are provided around the exit ports B21 to B26 of the optical fibers 21 to 26 has been described. It may be provided. In the configuration in which the shutters T1 to T6 are provided around the exit ports B21 to B26 as in the first embodiment, the opening / closing control of the shutters T1 to T6 and the rotation control of the mirror MR are mechanically integrated. It may be broken.

In the multi-angle colorimeter 100C of the fourth embodiment, a rhombus prism PR (FIGS. 16 to 18) having reflection surfaces RS2 and RS3 that cause internal reflection on two opposing surfaces is used as the second light guide unit 27. Although the aspect which performs is demonstrated, it is not restricted to this. For example, the two reflecting surfaces RS2 and RS3 need only be opposed to each other while maintaining a certain angular relationship during rotation, and need not necessarily be in a parallel relationship. Further, the same effect can be obtained by using two mirrors that are formed to face each other while maintaining the angular relationship between the reflecting surfaces instead of the prism PR.

Even when two mirrors MR are used, it is desirable that the first and second reflecting surfaces are fixedly formed and driven by a common drive unit 292, as in the prism PR of the fourth embodiment. . As a result, it is possible to prevent a displacement difference due to the drive unit between the two mirrors MR.

The multi-angle colorimeters 100 and 100A to 100D of the above-described embodiments have been described as configuration examples that satisfy the conditions 1 and 2. However, as long as the conditions 1 and 2 are satisfied, the optical fibers 21 to 26 are used. Change in the incident ports B11 to B16 (change of the light receiving angle of the measurement light), change of the arrangement of the optical fibers 21 to 26 at the exit ports B21 to B26, change of the number of light guide paths of the first light guide unit 20, etc. You may change the design.

Also, within the scope of the present invention, the present invention can be freely combined with each embodiment, modified with any component in each embodiment, or omitted with any component in each embodiment.

DESCRIPTION OF SYMBOLS 100,100A-100E Multi-angle colorimeter 2 Measuring device main body 3 Measurement opening 5 Measured object 10 Irradiation part 20 1st light guide part 21-26 Optical fiber 27 2nd light guide part 29 Selection part 30 Spectroscopic part 40 Light Detection unit 60 Memory unit 70 Control unit 71 Measurement control unit 72 Calculation unit FB Optical fiber L11 to L16 First optical path L21 to L26 Second optical path MR mirror (an optical element having a reflection surface)
PR prism (optical element having first and second reflecting surfaces)
RS1-3 reflective surface

Claims (8)

1. (a) an irradiation unit for irradiating the sample with irradiation light;
   (b) The measurement light emitted from the surface of the sample in response to the irradiation of the irradiation light is received at a plurality of different angles with respect to the surface, and through a plurality of first optical paths corresponding to the plurality of angles. A first light guide for guiding the measurement light;
   (c) a second light guide unit that receives the measurement light guided through the selected optical path, which is one of the plurality of first optical paths, and guides the measurement light through the second optical path;
   (d) a selection unit that drives the second light guide unit to variably select the selected optical path;
   (e) a spectroscopic unit that receives and separates the measurement light guided through the second optical path;
   With
   The selection unit switches the optical path on the upstream side of the second optical path so that the downstream optical path on the selected optical path and the upstream optical path on the second optical path are optically connected to each other. Select the optical path,
   The downstream optical path in the second optical path is the same even when any of the plurality of first optical paths is selected as the selected optical path,
   A multi-angle colorimeter that performs colorimetry using spectral results for a plurality of measurement lights corresponding to the plurality of angles by switching the selected optical paths for the plurality of first optical paths.
2. The multi-angle colorimeter according to claim 1,
   The second light guide unit includes an optical element having a reflection surface that reflects light incident from the selected optical path,
   The selection unit has a drive unit that rotates the optical element around one axis,
   The upstream optical path in the second optical path is selectively switched according to the rotation stop position of the optical element rotated by the drive unit, and the selected optical path is selected from the plurality of first optical paths. Multi-angle colorimeter characterized by being selected.
3. The multi-angle colorimeter according to claim 2,
   The optical element includes a first reflecting surface that reflects light incident from the selected optical path;
   A second reflecting surface that is formed opposite to the first reflecting surface and reflects the reflected light emitted from the first reflecting surface;
   The multi-angle colorimeter, wherein the first and second reflecting surfaces are rotated about one axis by the common driving unit.
4. The multi-angle colorimeter according to claim 3,
   The first and second reflecting surfaces are fixedly formed while maintaining an angular relationship with each other in the optical element,
   In the rotation, the first and second reflecting surfaces are maintained at a fixed angle with respect to a plane perpendicular to the one axis.
5. The multi-angle colorimeter according to claim 1,
   The second light guide unit includes an optical element having a reflection surface that reflects light incident from the selected optical path,
   The selection unit has a drive unit that displaces the optical element in a linear bidirectional manner,
   The upstream optical path in the second optical path is selectively switched according to the driving stop position of the optical element displaced by the driving unit, and the selected optical path is selected from the plurality of first optical paths. Multi-angle colorimeter characterized by that.
6. The multi-angle colorimeter according to claim 5,
   The multi-angle colorimeter, wherein the reflecting surface is maintained at a constant angle with respect to the linear displacement direction of the optical element.
7. The multi-angle colorimeter according to claim 1,
   The second light guide has an optical fiber,
   The selection unit includes a drive unit that displaces a position or an angle of a light incident unit that is an opening on the upstream side of the optical fiber,
   The upstream optical path in the second optical path is selectively switched according to the position or angle of the light incident section displaced by the drive section, and the selected optical path is selected from the plurality of first optical paths. A multi-angle colorimeter characterized by
8. The multi-angle colorimeter according to any one of claims 1 to 7,
   A multi-angle colorimeter, wherein all of the measurement light guided through the plurality of first optical paths is spectrally measured by a single spectroscopic unit.

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