JP2016138749A - Spectrometric device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectrometric device with which it is possible to acquire with high accuracy an equivalent measurement result to colorimetry using natural light in even a light-shaded space, and also to carry out a fluorescence inspection in the whole of a measurement object.SOLUTION: A spectrometric device 100 comprises: a first light source 161 for emitting a first light including a visible light region; a second light source 162 for emitting a second light of less than 400 nm; a light diffusion unit 150 for diffusing incident light and irradiating a measurement object with the diffused incident light; and an optical module 10 having a wavelength variable interference filter 5 for separating light of a prescribed wavelength from the light reflected by a measurement object X and an image-capturing element 12 for receiving the separated light. The first light source 161 emits a first light at a prescribed angle at which the regular reflection component of the first light reflected by the measurement object X does not enter the optical module 10, and the second light source 162 emits a second light toward the light diffusion unit 150 so that the measurement object X is evenly irradiated with the second light diffused by the light diffusion unit 150.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spectrometer.

2. Description of the Related Art Conventionally, a spectroscopic measurement apparatus that measures a spectroscopic spectrum to be measured is known (for example, see Patent Document 1).
The apparatus described in Patent Document 1 irradiates a measurement object with light or external light from a light source unit, disperses the reflected light with a spectroscopic element, and receives the dispersed light with a detector. The amount of light is acquired, and the color measurement process of the measurement target is performed.

JP 2013-96883 A

By the way, when performing colorimetry of a measurement target, Patent Document 1 uses outside light in addition to light from a light source unit. However, the external light varies greatly depending on the measurement environment such as the measurement position and time. For this reason, it is desired to perform spectroscopic measurement of a measurement object after shielding external light.
On the other hand, in colorimetric processing, it is desired to measure the color appearance of a measurement target in a natural state. For this reason, even when performing colorimetry in a light-shielding space, it is preferable to use a light source (D50 light source) having characteristics standardized in colorimetry. Also, in colorimetry, if the light regularly reflected by the measurement object is received by the light receiving unit, an accurate measurement result cannot be obtained. For example, 45 ° light is incident on the measurement object, and the measurement object It is necessary that the light reflected at 90 ° is received by the light receiving unit so that the regular reflection component is received by the light receiving unit.
Further, for example, when a paper surface or the like is a measurement target, fluorescence detection may be performed by irradiating ultraviolet light in order to inspect a fluorescent component included in the measurement target. Since the D50 light source as described above can perform colorimetry with components equivalent to natural light, and includes ultraviolet light, fluorescence detection can be performed simultaneously. However, in the fluorescence inspection for the measurement target, it is desired to detect the distribution of the fluorescence component in the entire measurement target by irradiating the entire measurement target with the ultraviolet light instead of irradiating the ultraviolet light as a spot light in part. . Therefore, when the D50 light source is irradiated so as to avoid regular reflection, it becomes spot light, so that there is a problem that fluorescence detection of the entire measurement target as described above cannot be performed.

  An object of the present invention is to provide a spectroscopic measurement apparatus that can obtain a measurement result equivalent to colorimetry using natural light with high accuracy even in a light-shielding space and can also perform a fluorescence test on the entire measurement object. .

  A spectroscopic measurement apparatus according to one application example of the present invention is a measurement using a first light source that emits first light including a visible light region, a second light source that emits second light of less than 400 nm, and diffuses incident light. A light diffusing unit that irradiates the target, a spectroscopic element that splits light of a predetermined wavelength from the light reflected by the measurement target, and an optical module that has a light receiving unit that receives the light split by the spectroscopic element, The first light source emits the first light toward the measurement object at a predetermined angle at which the specular reflection component of the first light reflected by the measurement object does not enter the optical module, and the second light source Is characterized in that the second light is emitted toward the light diffusing unit so that the second light diffused by the light diffusing unit is irradiated onto the measurement object.

In this application example, first light including visible light is emitted from the first light source, and light having a wavelength of less than 400 nm is emitted from the second light source. Then, the first light is directly irradiated onto the measurement target, the reflected light is incident on the optical module, the light having a predetermined wavelength is dispersed by the spectroscopic element, and then the dispersed light is received by the light receiving unit. On the other hand, the second light is diffused by the light diffusing unit and then irradiated to the measurement object, and the reflected light is incident on the optical module.
In such a configuration, the measurement result equivalent to the color measurement process using natural light can be obtained by irradiating the measurement target with the light of the first light source and the second light source. In addition, the first light is spot-irradiated on the measurement object at an angle at which the regular reflection component does not enter the optical module, and an accurate color measurement result for the measurement position can be obtained. Furthermore, since the second light from the second light source is diffused by the light diffusing unit and is uniformly irradiated to the measurement target, even when performing fluorescence analysis of the measurement target, the entire measurement target A fluorescence component distribution can be detected.

In the spectroscopic measurement apparatus according to this application example, the light amount ratio between the light having a wavelength of less than 400 nm and the light having the wavelength of 400 nm or more in the light obtained by combining the first light and the second light is a wavelength of 400 nm in a standardized standard light source. It is preferable that the light amount ratio of the light of less than that and the light of wavelength 400 nm or more is the same.
In this application example, the light amount ratio between the light amount of light having a wavelength of less than 400 nm and the light amount of light having a wavelength of 400 nm or more is the same as that of a standardized light source standardized in colorimetry such as a D50 light source. Therefore, a color measurement result according to the color measurement standard can be obtained.

In the spectroscopic measurement device of this application example, the observation light source that emits observation light for performing appearance observation of the measurement target is provided, and the observation light source includes the observation light diffused by the light diffusion unit. It is preferable to emit the observation light so as to irradiate the measurement object.
In this application example, the observation light from the observation light source is diffused by the light diffusing unit, and the measurement target is uniformly irradiated. Thereby, even when the measurement target is in the light-shielding space, the measurement location on the measurement target can be easily selected prior to the color measurement process.

In the spectroscopic measurement apparatus according to this application example, the mounting unit on which the measurement target is mounted is provided to face the mounting unit, the first light source is held at the predetermined angle, and the first light source A light source holding unit that holds the second light source at a position where the second light is irradiated in a direction away from the mounting unit, and the light diffusion unit faces the mounting unit with the light source holding unit interposed therebetween. It is preferable that the concave mirror is provided at a position where the second light from the second light source is diffusely reflected.
In this application example, a concave mirror is provided facing the placement unit on which the measurement target is placed, and a light source holding unit is provided between the concave mirror and the placement unit, facing the placement unit. The light source holding unit holds the first light source at a predetermined angle at which the specular reflection component of the first light does not enter the optical module, and holds the second light source at an angle at which the second light is emitted toward the concave mirror. Yes.
A configuration is also possible in which a diffuser plate is used as the light diffusing unit, and the second light (diffused light) transmitted through the diffuser plate is irradiated onto the measurement target. In this case, the second light source is arranged at a position away from the first light source. The size of the device increases due to the necessity to do so. On the other hand, in the said structure, both a 1st light source and a 2nd light source can be arrange | positioned in one light source holding part, and simplification of a structure and size reduction of a spectrometer can be achieved.

The spectroscopic measurement apparatus according to this application example includes a cylindrical light-shielding unit that surrounds the measurement target placed on the placement unit, and the light source holding unit and the light diffusion unit are arranged in a cylinder of the cylindrical light-shielding unit. It is preferable to arrange | position along a surrounding surface.
In this application example, the light source holding part is arranged along the cylinder inner peripheral surface of the cylindrical light shielding part. For this reason, the light source holding part can be easily positioned at a predetermined position of the spectrometer.

1 is a perspective view showing a schematic configuration of a spectrometer according to an embodiment of the present invention. The figure which shows the outline of the internal structure of the spectrometry apparatus of this embodiment. The top view which looked at the light source holding part of this embodiment from the mounting part side. The top view which looked at the light source holding part of this embodiment from the light-diffusion part side. The figure which shows the spectral characteristics of the 1st light from the 1st light source of this embodiment, and the 2nd light from a 2nd light source. The figure which shows the spectral characteristic of D50 light (standard light) radiate | emitted from a general D50 light source. The figure which shows the spectral characteristic of the observation light of this embodiment. The block diagram which shows the outline of the optical module and control part of this embodiment. FIG. 3 is a cross-sectional view illustrating a schematic configuration of a wavelength tunable interference filter according to the present embodiment. The flowchart which shows the spectrometry method in this embodiment. The figure which shows the paper surface which is an example of the measuring object in this embodiment.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a schematic configuration of a spectroscopic measurement apparatus 100 of the present embodiment. FIG. 2 is a diagram showing an outline of the internal configuration of the spectroscopic measurement apparatus 100.
As shown in FIGS. 1 and 2, the spectroscopic measurement apparatus 100 includes a housing 110, an optical module 10 and a control unit 20 provided in the housing 110, and a mounting unit on which the measurement target X is mounted. 120, a light shielding wall 130 extending from the housing 110 toward the placement unit 120, a light source holding unit 140 provided in the light shielding wall 130, and a light diffusion unit 150 provided in the light shielding wall 130. ing.
In the spectroscopic measurement apparatus 100 of the present embodiment, the measurement target X is placed on the placement unit 120 so that external light does not enter the light shielding space A surrounded by the light shielding wall 130 and the placement unit 120. Thereafter, when the measurement target X is irradiated onto the measurement target X using the observation light emitted from the observation light source, and the measurement range B in the measurement target X is set, the measurement target X is measured using the measurement light. And the colorimetric processing for the measurement range B is performed. Further, in the present embodiment, ultraviolet light is included as measurement light, and fluorescence included in a wide area including the measurement range B in the measurement target X (for example, the entire surface of the measurement target X facing the optical module 10). Perform component detection.
Hereinafter, a detailed configuration of each unit will be described.

(Configuration of housing 110)
As shown in FIGS. 1 and 2, the housing 110 is provided in a box shape, for example, and an opening window 112 (see FIG. 2) is provided on the first surface 111 surrounded by the light shielding wall 130. In addition, a display 114, an operation unit 115, and the like are provided on the second surface 113 that is not surrounded by the light shielding wall 130 of the housing 110. In FIG. 1, the upper surface (surface opposite to the first surface 111) of the housing 110 is illustrated as the second surface 113 on which the display 114 and the operation unit 115 are provided. It may be.
Further, a translucent member 116 is provided on the first surface 111 of the casing 110 so as to face the opening window 112, and the optical module 10 that processes light incident from the opening window 112 is provided inside the casing 110. Is arranged.

(Configuration of placement unit 120)
The placement unit 120 is a stage on which the measurement target X is placed, and is formed in a plate shape, for example. The surface of the mounting unit 120 facing the light shielding space A preferably has a light reflectance of, for example, black or other ultraviolet light and visible light of a predetermined value or less.

(Configurations of the light shielding wall 130 and the light diffusion unit 150)
The light shielding wall 130 is a cylindrical light shielding portion in the present invention, and is formed in a cylindrical shape in which the direction from the first surface 111 of the housing 110 toward the placement portion 120 is the axial direction. One end portion of the light shielding wall 130 is in contact with the first surface 111 and the other end portion is in contact with the mounting portion 120, and is formed of an opaque material that shields external light. Therefore, as described above, the space surrounded by the light shielding wall 130, the mounting portion 120, and the first surface 111 is a light shielding space A in which no external light enters.

In the light shielding space A, a light source holding unit 140 and a light diffusion unit 150 are provided.
The light diffusing unit 150 is a concave mirror having a concave surface facing the mounting unit 120, and is fixed to one end of the light shielding wall 130 on the housing 110 side, as shown in FIG. A light passage hole 151 is provided at a position facing the opening window 112 of the light diffusing unit 150.

(Configuration of the light source holding unit 140)
The light source holder 140 has an outer peripheral surface having the same shape as the inner peripheral shape of the cylinder when the light shielding wall 130 is cut in a direction orthogonal to the axial direction, and is fixed along the circumferential direction of the inner peripheral surface of the light shielding wall 130. ing. For example, when the light shielding wall 130 has a cylindrical shape, the light source holding part 140 is formed in a ring shape whose outer diameter is substantially the same as the inner diameter of the light shielding wall 130, and is fixed along the inner circumferential surface of the light shielding wall 130. Has been.

FIG. 3 is a plan view of the light source holding unit 140 viewed from the placement unit 120 side, and FIG. 4 is a plan view of the light source holding unit 140 viewed from the light diffusion unit 150 side.
As shown in FIGS. 2 and 3, an annular tapered surface having a predetermined angle (45 °) with respect to the mounting portion 120 is provided on the inner peripheral side of the surface facing the mounting portion 120 of the light source holding portion 140. 141 is provided. A plurality of first light sources 161 for emitting the first light are arranged on the tapered surface 141 at a predetermined interval (equal angular interval with respect to the central axis) along the circumferential direction.
On the other hand, a surface 142 of the light source holding unit 140 on the housing 110 side (light diffusion unit 150 side) is a plane orthogonal to the axial direction of the light shielding wall 130 and emits second light as shown in FIG. A plurality of (two in the present embodiment) second light sources 162 are arranged at a predetermined interval. Further, one observation light source 163 that emits observation light is disposed on the surface 142 at an intermediate position between the two second light sources 162.

In the above configuration, the first light source 161 held on the tapered surface 141 emits the first light at 45 ° with respect to the measurement target X placed on the placement unit 120. Thereby, 1st light is irradiated to the measurement range B (measurement location of this invention) as spot light.
On the other hand, the second light source 162 and the observation light source 163 held on the surface 142 emit the second light and the observation light toward the light diffusion unit 150. Since the second light and the observation light are uniformly diffused by the light diffusion unit 150, the mounting unit 120 is irradiated with a uniform light amount regardless of the position.
The light source holding unit 140 is provided with a light source driving circuit 164 (see FIG. 8). The light source driving circuit 164 is constituted by, for example, a switching circuit, and controls lighting driving of the first light source 161, the second light source 162, and the observation light source 163. Further, the light source driving circuit 164 may be configured to be able to control the light emission amount by controlling the driving currents of the light sources 161, 162, and 163. In addition, although the example provided in the light source holding | maintenance part 140 is shown as the light source drive circuit 164, it is not limited to this, For example, you may provide in the housing | casing 110 etc.

(Characteristics of first light, second light, and observation light)
Here, spectral characteristics of light emitted from the first light source 161, the second light source 162, and the observation light source 163 will be described.
FIG. 5 is a diagram illustrating spectral characteristics of the first light (solid line) emitted from the first light source 161 and the second light (broken line) emitted from the second light source 162. FIG. 6 is a diagram showing the spectral characteristics of the D50 light source (standard light source).
The first light source 161 and the second light source 162 are, for example, LEDs, and emit first light and second light having spectral characteristics as shown in FIG. That is, the first light source 161 is composed of a white LED, and has a peak wavelength in the visible light region (in the example of FIG. 5, near 420 nm and near 600 nm) as shown by the broken line in FIG. First light having spectral characteristics indicating light intensity over a wide wavelength range including the infrared region to the infrared region is emitted.
On the other hand, the second light source 162 is constituted by an ultraviolet LED, and emits second light having a peak wavelength in an ultraviolet region with a wavelength of less than 400 nm and almost no light in a wavelength region of 400 nm or more.

In this embodiment, the ratio of the light intensity of the light component having a wavelength of less than 400 nm to the light intensity of the light component having a wavelength of 400 nm or more in the combined light of the first light and the second light is less than the wavelength of 400 nm of the D50 light source. The ratio between the light intensity of the light component and the light intensity of the light component having a wavelength of 400 nm or more is the same (or substantially the same).
That is, the area obtained by adding the area of the first light having a wavelength of less than 400 nm and the area of the second light in FIG. 5 is a, the area of the area of the first light having a wavelength of 400 nm or more is b, and D50 from the D50 light source in FIG. If the area of the standard light having a wavelength of less than 400 nm is c and the area of the wavelength of 400 nm or more is d, a / b = c / d (or a / b≈c / d) is established.
Accordingly, when the first light source 161 and the second light source 162 are simultaneously turned on, light corresponding to D50 standard light is irradiated onto the measurement range B.

FIG. 7 is a diagram illustrating spectral characteristics of observation light.
The observation light source 163 is composed of, for example, a halogen lamp such as a tungsten lamp. As shown in FIG. 7, the observation light source 163 emits, for example, observation light having a spectral characteristic that includes a visible light region and whose light intensity increases as the wavelength increases.

(Configuration of optical module 10)
FIG. 8 is a block diagram showing an outline of the light source (first light source 161, second light source 162, observation light source 163), optical module 10, and control unit 20.
As shown in FIGS. 2 and 8, the optical module 10 includes an incident optical system 11, a variable wavelength interference filter 5, an image sensor 12 (light receiving element), a filter control circuit 13, and a signal processing circuit 14. It is configured to include.

(Configuration of the incident optical system 11)
The incident optical system 11 forms incident light (image of the measurement target X) incident from the aperture window 112 on the image sensor 12. Examples of the incident optical system 11 include a telecentric optical system that guides incident light so that the principal ray of light is parallel (or substantially parallel) to the wavelength variable interference filter 5. 2 and 8, only one lens is illustrated, but actually, it may be constituted by a plurality of lenses. In the present embodiment, a telecentric optical system is exemplified, but the present invention is not limited to this. For example, an LCF (Light Control Film: registered trademark), a Selfoc (registered trademark) lens, or the like is provided in the front stage of the wavelength variable interference filter 5. It may be inserted.
In addition, the angle of view of the incident optical system 11 is set so that an area within the light shielding space A (inside the light shielding wall 130) of the mounting unit 120 is an imaging target of the image sensor 12. It should be noted that an enlargement / reduction mechanism or the like may be provided so that only the image of the measurement range B or a predetermined range centered on the measurement range B is received by the image sensor 12 during color measurement.

(Configuration of wavelength variable interference filter 5)
The wavelength variable interference filter 5 is a spectroscopic element, and transmits light having a predetermined wavelength from incident light incident from the aperture window 112.
FIG. 9 is a cross-sectional view showing a schematic configuration of the wavelength variable interference filter 5.
The wavelength variable interference filter 5 includes a translucent fixed substrate 51 and a movable substrate 52, and the fixed substrate 51 and the movable substrate 52 are composed of, for example, a plasma polymerized film mainly composed of siloxane. By being joined by 53, it is comprised integrally. Such a wavelength tunable interference filter 5 can be reduced in size compared to, for example, a case where an AOTF (Acousto-Optic Tunable Filter) or an LCTF (Liquid crystal tunable filter) is used as a spectroscopic element. Can be planned.

The fixed substrate 51 includes an electrode arrangement groove 511 and a reflective film installation part 512 formed by etching. A fixed electrode 561 is provided in the electrode arrangement groove 511, and a fixed reflective film 54 is provided in the reflective film installation portion 512.
The fixed electrode 561 is formed in an annular shape surrounding the reflective film installation portion 512 in the electrode arrangement groove 511, for example.
As the fixed reflective film 54, for example, a metal film such as Ag or an alloy film such as an Ag alloy can be used. For example, a dielectric multilayer film in which the high refractive layer is TiO ₂ and the low refractive layer is SiO ₂ may be used. Further, a reflective film in which a metal film (or alloy film) is laminated on a dielectric multilayer film, a reflective film in which a dielectric multilayer film is laminated on a metal film (or alloy film), a single refractive layer (TiO ₂ , SiO ₂₎ and a metal film (or alloy film) and the like may be used reflective film formed by laminating a.

As shown in FIG. 9, the movable substrate 52 includes a movable portion 521 and a holding portion 522 that is provided outside the movable portion 521 and holds the movable portion 521.
The movable part 521 is formed to have a thickness dimension larger than that of the holding part 522. For example, in this embodiment, the movable part 521 is formed to have the same dimension as the thickness dimension of the movable substrate 52. The movable portion 521 is formed to have a diameter that is larger than at least the diameter of the outer peripheral edge of the reflective film installation portion 512 in the filter plan view. The movable part 521 is provided with a movable electrode 562 and a movable reflective film 55.

  The movable electrode 562 is provided at a position facing the fixed electrode 561. In addition, the movable reflective film 55 is disposed at a position facing the fixed reflective film 54 via a gap G1. As the movable reflective film 55, a reflective film having the same configuration as that of the fixed reflective film 54 described above is used.

The holding part 522 is a diaphragm that surrounds the periphery of the movable part 521, and has a thickness dimension smaller than that of the movable part 521. Such a holding part 522 is easier to bend than the movable part 521, and the movable part 521 can be displaced toward the fixed substrate 51 by a slight electrostatic attraction. Accordingly, it is possible to change the gap dimension of the gap G1 while maintaining the parallelism of the fixed reflection film 54 and the movable reflection film 55.
In the present embodiment, the diaphragm-like holding part 522 is illustrated, but the present invention is not limited to this. For example, a configuration in which beam-like holding parts arranged at equiangular intervals around the plane center point are provided. It is good.

  In the wavelength variable interference filter 5 as described above, the electrostatic actuator 56 is configured by the fixed electrode 561 and the movable electrode 562, and these electrodes 561 and 562 are connected to the control unit 20 via the filter control circuit 13. Yes. Then, a voltage is applied from the filter control circuit 13 to the electrostatic actuator 56 under the control of the control unit 20, whereby an electrostatic attractive force corresponding to the voltage acts between the electrodes 561 and 562, and the gap G1 between the reflection films is applied. The gap dimension is changed. As a result, the wavelength of light transmitted through the wavelength variable interference filter 5 can be changed.

(Configuration of Image Sensor 12)
Returning to FIGS. 2 and 8, the image sensor 12 receives the light transmitted through the wavelength variable interference filter 5, and outputs a detection signal corresponding to the received light amount to the control unit 20 via the signal processing circuit 14. For example, an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) can be used as the imaging element 12, and an image signal is output to the control unit 20 as a detection signal.

(Configuration of filter control circuit 13 and signal processing circuit 14)
As described above, the filter control circuit 13 applies a drive voltage to the electrostatic actuator 56 of the variable wavelength interference filter 5 under the control of the control unit 20.
For example, the signal processing circuit 14 amplifies the input detection signal (analog signal), converts the detection signal into a digital signal, and outputs the digital signal to the control unit 20. For example, when the detection signal is a current value, the signal processing circuit 14 is an IV converter that converts the detected current value into a voltage value, an amplifier that amplifies the detection signal, and an A that converts an analog signal into a digital signal. / D converter and the like.

(Configuration of control unit 20)
As shown in FIG. 8, the control unit 20 includes a storage unit 21 and a processing unit 22.
The storage unit 21 is configured by, for example, a memory or a hard disk drive. The storage unit 21 stores an OS (Operating System) for controlling the overall operation of the spectrometer 100, various programs, and various data.
And the memory | storage part 21 memorize | stores the V-lambda data etc. for driving the electrostatic actuator 56 of the wavelength variable interference filter 5 as said data.

  The processing unit 22 includes an arithmetic circuit such as a CPU (Central Processing Unit) and a storage circuit. The processing unit 22 reads and executes various programs stored in the storage unit 21, thereby, as shown in FIG. 8, a mode setting unit 221, a light source driving unit 222, a filter driving unit 223, a fluorescence analysis unit 224, It functions as a color measurement unit 225 and a display control unit 226.

The mode setting unit 221 sets the operation mode of the spectrometer 100. That is, based on the operation of the operation unit 115 by the operator, the observation mode for setting the measurement range B in the measurement target X and the color measurement mode for performing the color measurement processing on the measurement range B are switched.
The light source driving unit 222 drives light sources (first light source 161, second light source 162, and observation light source 163) corresponding to the operation mode of the spectroscopic measurement apparatus 100.
Based on the V-λ data stored in the storage unit 21, the filter drive unit 223 outputs a control signal to the filter control circuit and switches the drive voltage applied to the electrostatic actuator 56 of the wavelength variable interference filter 5. That is, the wavelength of the light transmitted through the wavelength variable interference filter 5 is switched.

The fluorescence analysis unit 224 analyzes the fluorescence component included in the measurement target X based on the captured image (each spectral image with respect to the ultraviolet region) captured by the image sensor 12.
The color measurement unit 225 measures the spectral spectrum in the measurement range B of the measurement target X based on the captured image (each spectral image with respect to the visible light range) captured by the image sensor 12, that is, performs color measurement processing.
The display control unit 226 controls the display 114 to display, for example, a color measurement result, a fluorescence analysis result, an observation image to be measured, and the like.

(Spectroscopic measurement method using the spectroscopic measurement apparatus 100)
Next, a spectroscopic measurement method using the spectroscopic measurement apparatus 100 as described above will be described.
In the following description, a method for measuring the color pattern printed on the paper using the spectroscopic measurement apparatus 100 will be described. The color of the color pattern printed on the paper surface may change depending on the fluorescent component included in the paper surface. Therefore, for example, in a printing machine that performs color printing, after performing fluorescence analysis processing on the paper surface that is the measurement target X, color measurement processing is performed on each color of the color pattern, and color reproducibility of the color pattern is improved. It is necessary to judge. The spectroscopic measurement apparatus 100 according to the present embodiment can suitably perform color measurement processing on the paper surface on which the color pattern as described above is printed.

FIG. 10 is a flowchart showing the spectroscopic measurement method of the present embodiment.
In the spectroscopic measurement method using the spectroscopic measurement apparatus 100 of the present embodiment, first, the paper surface that is the measurement target X is placed on the placement unit 120, the measurement target X is surrounded by the light shielding wall 130, and the measurement is performed in the light shielding space A. Arrange the target X.
FIG. 11 is a diagram illustrating an example of a paper surface arranged as the measurement target X in the present embodiment.
As shown in FIG. 11, in this embodiment, a paper surface 170 on which a plurality of types of color patches 171 (color patterns) are printed in the row direction and the column direction, for example, is arranged as the measurement target X.
Thereafter, the mode setting unit 221 sets the operation mode of the spectrometer 100 to the observation mode (Step S1).
When the observation mode is set in step S1, the light source driving unit 222 turns off the first light source 161 and the second light source 162 and drives the observation light source 163 to turn on (step S2). As a result, the observation light is emitted from the observation light source 163 (tungsten lamp), and the observation light is diffusely reflected by the light diffusing unit 150 (concave mirror) and uniformly irradiated on the entire paper surface 170. That is, the observation light with a uniform light amount is irradiated on the paper surface 170 regardless of the position.

Next, the spectroscopic measurement apparatus 100 acquires color images (spectral images) of R, G, and B colors in order to display a real-time image (step S3). In the present embodiment, the wavelengths (for example, a red wavelength 680 nm, a green wavelength 550 nm, and a blue wavelength 450 nm) of each color image for synthesizing a real-time image are set in advance. Then, the filter driving unit 223 reads out the driving voltages corresponding to the respective wavelengths from the V-λ data stored in the storage unit 21 and sequentially applies them to the electrostatic actuator 56. Thereby, the spectral image corresponding to each color of RGB is acquired by the image sensor 12. Then, the display control unit 226 combines these RGB spectral images and displays them on the display 114 as a real-time image (step S4).
In the present embodiment, an example is shown in which a real-time image is displayed by synthesizing spectral images of respective colors that have passed through the wavelength variable interference filter 5, but the present invention is not limited to this. For example, when displaying a real-time image, the wavelength variable interference filter 5 may be retracted from the optical axis of the image sensor 12 and RGB color filters may be sequentially inserted to obtain RGB spectral images. In addition, the wavelength variable interference filter 5 and the image sensor 12 are retracted, and a color image is acquired by inserting a color image capturing image sensor in which one of R, G, and B color filters is arranged in each pixel. May be.

  Thereafter, it is determined whether or not the measurement range B on the paper surface 170 has been determined (step S5). That is, the control unit 20 determines whether or not the operation unit 115 is operated by the operator and an input operation for determining the measurement range B is performed. If “No” is determined in step S5, it is determined whether or not to end the spectroscopic measurement process (step S6). In step S6, for example, when an input operation for ending the measurement is performed by the operator, the control unit 20 determines “Yes” and ends the spectroscopic measurement process. On the other hand, if “No” is determined in step S6, the operation in the observation mode is continued, the real-time image is continuously displayed on the display 114, and the process returns to step S5.

If it is determined as “Yes” in step S5, the mode setting unit 221 of the control unit 20 sets the operation mode of the spectroscopic measurement apparatus 100 to the color measurement mode (step S7). In the example of FIG. 11, among the nine color patches 171 arranged in 3 rows and 3 columns, the center color patch 171 is determined as the measurement range B.
In the color measurement mode, the light source driving unit 222 turns off the observation light source 163 and turns on the first light source 161 and the second light source 162 (step S8). Thereby, the first light including the visible light from the first light source 161 is irradiated at an angle of 45 ° with respect to the measurement range B. On the other hand, the ultraviolet light (second light) from the second light source 162 is diffused by the light diffusing unit 150 and is uniformly applied to the entire paper surface 170 including the measurement range B. That is, the measurement range B is irradiated with both the first light and the second light. Here, as described above, the ratio of the light amount of the light component with a wavelength less than 400 nm and the light amount of the measurement range B light component with a wavelength of 400 nm or more in the combined light of the first light and the second light is the same ratio as the D50 standard light. Become. Visible light used for color measurement is incident on the measurement plane B at 45 ° with respect to the paper surface 170, and among these, light reflected at 90 ° with respect to the paper surface 170 is transmitted from the aperture window 112 to the optical module 10. Incident. Therefore, of the first light from the first light source 161, the light component that is regularly reflected by the paper surface 170 is not incident on the optical module 10. On the other hand, the second light, which is ultraviolet light, is uniformly irradiated on the entire paper surface 170 by the light diffusion unit 150.

  Next, the spectroscopic measurement apparatus 100 sequentially acquires spectral images in a predetermined measurement target wavelength range including the visible light range from the ultraviolet range. That is, the filter driving unit 223 reads out the driving voltage corresponding to each wavelength of a predetermined interval (for example, 5 nm interval) in the measurement target wavelength region from the V-λ data stored in the storage unit 21, and the electrostatic actuator 56. Are sequentially applied. Thereby, the spectral image for every predetermined interval in a measuring object wavelength range is acquired (Step S9).

  After step S9, the fluorescence analysis unit 224 analyzes the fluorescence component included in the paper surface 170 based on each spectral image for the ultraviolet region among the spectral images acquired in step S9 (step S10). Here, as described above, the second light is diffused over the entire paper surface 170 by the light diffusing unit 150, and the incident optical system 11 of the optical module 10 has the entire image of the paper surface 170 reflected by the reflection film of the wavelength tunable interference filter 5. Each lens group is configured to pass through 54 and 55 and be imaged by the image sensor 12. Therefore, it is possible to acquire spectral images of each wavelength in the ultraviolet region with respect to the entire paper surface 170, and the fluorescence analysis unit 224 uses the fluorescence wavelengths and fluorescence excited by the ultraviolet light based on the acquired spectral images in the ultraviolet region. It becomes possible to analyze the fluorescent component corresponding to the wavelength and the distribution of the fluorescent component on the paper surface 170.

In addition, the color measurement unit 225 performs color measurement processing on the measurement range B based on each spectral image for the visible light region among the spectral images acquired in step S9 (step S11).
For example, the color measurement unit 225 detects the target pixel region of the color patch 171 included in the measurement range B from each spectral image by edge detection or the like. Then, the light amount of each pixel included in the target pixel region in the spectral image is detected, and the average value is acquired as the light amount value of the wavelength corresponding to the spectral image. The same processing is performed for each spectral image, the light quantity value of each wavelength is calculated, and the spectral spectrum of the color patch 171 is calculated from the light quantity value of each wavelength. In the above example, an example is shown in which the light amount of each pixel of the detected target pixel region is averaged for one spectral image. For example, the spectral corresponding to each pixel is based on the light amount for each pixel. A spectrum may be acquired.
Here, in the measurement range B described above, the first light irradiated as the spot light and the second light diffused and irradiated by the light diffusion unit 150 are irradiated at the same light amount ratio as the D50 standard light. Therefore, the color measurement result measured by the color measurement unit 225 obtains a color measurement result equivalent to the color measurement result using natural light, similarly to the color measurement result obtained by performing the color measurement processing using the D50 standard light. Can do.
Thereafter, the display control unit 226 causes the display 114 to display the fluorescence analysis result and the color measurement result obtained in steps S10 and S11 (step S12).

(Operational effect of this embodiment)
In the spectroscopic measurement apparatus 100 according to the present embodiment, the first light source 161 that emits the first light including the visible light region has the light source holding unit 140 such that the first light is incident on the measurement target X at 45 °. Is provided. Further, the second light source 162 that emits the second light of less than 400 nm is held by the light source holding unit 140 so as to be emitted toward the light diffusion unit 150, and the second light is diffused by the light diffusion unit 150. The measurement object X is irradiated. In addition, light reflected from the measurement target X at 90 ° is incident on the optical module 10 provided at a position facing the measurement target X, and the wavelength variable interference filter 5 converts the incident light to light having a predetermined wavelength. Spectroscopic light is captured, and the imaged light is captured by the image sensor 12.
In such a configuration, since the combined light of the first light including visible light and the second light that is ultraviolet light is applied to the measurement range B in the measurement target X, natural light is obtained even in the light shielding space A. It is possible to obtain a measurement result equivalent to the colorimetric processing when using. Further, the first light is irradiated at 45 ° with respect to the measurement range B of the measurement target X, and among them, the light reflected at 90 ° from the measurement target X is incident on the optical module. Reflective components are not incident on the optical module, and high-precision colorimetric processing can be performed. Furthermore, since the second light is diffused by the light diffusing unit 150 and uniformly irradiated to the measurement target X, the distribution of the fluorescent component that emits fluorescence using the second light as excitation light is detected in the entire measurement target X. can do. In particular, since the color appearance may change depending on the fluorescent component on the paper used in a printing apparatus or the like, not only a part of the paper (for example, only the measurement range B) but also the fluorescence distribution of the entire paper is analyzed. Is effective. On the other hand, in the present embodiment, the incident optical system 11 causes the image of the region in the light shielding wall 130 (in the light shielding space A) of the placement unit 120 to pass through the reflective films 54 and 55 of the wavelength variable interference filter 5. Thus, the image pickup device 12 is configured to be able to pick up an image. Therefore, the fluorescence analysis of the entire paper surface can be easily performed.
As described above, in the present embodiment, a color measurement result equivalent to the case where color measurement is performed with natural light with respect to the measurement range B of the measurement target X can be obtained with high accuracy, and the entire measurement target X can be obtained. The fluorescent component can be detected appropriately.

In the present embodiment, the light quantity ratio between the light component having a wavelength of less than 400 nm and the light component having a wavelength of 400 nm or more in the combined light of the first light and the second light is the light component having a wavelength of less than 400 nm in the D50 standard light, and the wavelength of 400 nm. A first light source 161 and a second light source 162 having the same light quantity ratio as the above light components are used.
Thereby, the color measurement result according to the standard of color measurement can be obtained. Thereby, for example, when controlling the color balance or the like in an apparatus such as a printing apparatus based on the color measurement result, it is possible to perform highly accurate control based on accurate color information.

In the spectroscopic measurement apparatus 100 of the present embodiment, an observation light source 163 is further provided, and observation light emitted from the observation light source 163 is emitted toward the light diffusion unit 150 and diffused by the light diffusion unit 150. Then, the measurement object X is uniformly irradiated.
Thereby, even when the measurement space is shielded by the light shielding wall 130, the measurement range B in the measurement target X is easily set by observing the reflected light of the observation light that is uniformly irradiated on the measurement target X. can do.

In the present embodiment, a concave mirror is used as the light diffusion unit 150, and the light source holding unit 140 is provided between the placement unit 120 and the light diffusion unit 150. For this reason, the 1st light source 161 for irradiating the measurement object X on the mounting part 120 directly with 1st light, and the 2nd light source for irradiating the 2nd light diffused by the light-diffusion part 150 indirectly. 162 can be provided in one light source holding part 140, and the configuration can be simplified.
Moreover, the light source holding part 140 is provided along the cylinder inner peripheral surface of the light shielding wall 130 formed in a cylindrical shape. For this reason, the positioning of the light source holding part 140 is easy, and the configuration can be simplified.

[Modification of Embodiment]
Note that the present invention is not limited to the above-described embodiments, and the present invention includes configurations obtained by modifying, improving, and appropriately combining the embodiments as long as the object of the present invention can be achieved. Is.

  For example, in the above-described embodiment, an example in which a concave mirror is used as the light diffusion unit 150 has been described, but the present invention is not limited to this. For example, a diffuser plate that diffuses and transmits incident light may be used. In this case, the second light source 162 and the observation light source 163 may be provided on the surface of the light diffusing unit 150 opposite to the mounting unit 120.

  In the said embodiment, although the example using white LED was shown as the 1st light source 161, for example, you may be comprised combining the light source of multiple colors. For example, it is good also as a structure etc. which each color LED of R, G, B is arrange | positioned along the taper surface 141 in the circumferential direction. Moreover, it is not limited to LED, For example, you may use a halogen lamp, a laser light source, etc.

  In the above embodiment, an example in which the observation light source 163 is provided has been described, but the present invention is not limited to this. For example, when observation by the operator is unnecessary, such as when the measurement range B is set in advance, the observation light source 163 may not be provided.

In the above embodiment, an example in which the optical module 10 and the control unit 20 are provided in the housing 110 has been described, but the present invention is not limited to this. For example, the probe having the optical module 10 and the control unit 20 may be separated and connected so as to be communicable by a cable line or wireless.
In the above embodiment, an example in which the light shielding wall 130 of the housing 110 is provided has been described, but the present invention is not limited to this. For example, if the measurement environment is a light shielding space, the light shielding wall 130 may not be provided.
Furthermore, although the example in which the first light source 161, the second light source 162, and the observation light source 163 are provided in the light source holding unit 140 is shown, a configuration in which each light source is held by a separate member may be used.

  In the above-described embodiment, the first light source 161 has been described as being held such that the first light is incident on the measurement target X at 45 °, but is not limited thereto. The first light source 161 only needs to be held at an angle at which the specular reflection component of the first light does not enter the optical module 10. For example, the first light is incident on the measurement target X at 30 °. A configuration in which light reflected in the normal direction (90 °) is incident on the optical module 10 may be employed.

  In the above embodiment, as shown in FIG. 5, the first light source 161 includes an example including a part of ultraviolet light having a wavelength of less than 400 nm. However, the first light source 161 is not limited thereto, and is configured only by light having a wavelength of 400 nm or more. It may be.

  In the above embodiment, the variable wavelength interference filter 5 is exemplified as the spectroscopic element. However, for example, AOTF or LCTF may be used, and any spectroscopic element capable of obtaining a spectroscopic image of a predetermined wavelength by performing surface spectroscopy of incident light. It may be used.

  In addition, the specific structure for carrying out the present invention may be configured by appropriately combining the above-described embodiments and modifications within the scope that can achieve the object of the present invention, and may be appropriately changed to other structures and the like. May be.

  DESCRIPTION OF SYMBOLS 5 ... Wavelength variable interference filter (spectral element), 10 ... Optical module, 11 ... Incident optical system, 12 ... Imaging element (light receiving part), 20 ... Control part, 54 ... Fixed reflection film, 55 ... Movable reflection film, 56 ... Electrostatic actuator, 100: Spectrometer, 120: Placement unit, 130: Light shielding wall (cylindrical light shielding unit), 140: Light source holding unit, 141 ... Tapered surface, 142 ... Surface, 150 ... Light diffusion unit, 161 ... 1st light source 162 ... 2nd light source 163 ... Light source for observation, 170 ... Paper surface (measuring object), 221 ... Mode setting part, 222 ... Light source drive part, 223 ... Filter drive part, 224 ... Fluorescence analysis part, 225 ... Colorimetric part, A ... light-shielding space, B ... measuring range, X ... measuring object.

Claims (5)

A first light source that emits first light including a visible light region;
A second light source that emits second light of less than 400 nm;
A light diffusing unit that diffuses incident light and irradiates a measurement target; and
A spectroscopic element that splits light of a predetermined wavelength from light reflected by a measurement target, and an optical module that has a light receiving unit that receives light split by the spectroscopic element,
The first light source emits the first light toward the measurement target at a predetermined angle at which the regular reflection component of the first light reflected by the measurement target is not incident on the optical module;
The second light source emits the second light toward the light diffusion unit so that the second light diffused by the light diffusion unit is irradiated onto the measurement object. . The spectroscopic measurement device according to claim 1,
The light quantity ratio between the light having a wavelength of less than 400 nm and the light having a wavelength of 400 nm or more in the combined light of the first light and the second light is a light having a wavelength of less than 400 nm and a wavelength of 400 nm or more in a standardized standard light source. A spectroscopic measurement device characterized by having the same light quantity ratio as light. The spectroscopic measurement device according to claim 1 or 2,
An observation light source that emits observation light for carrying out appearance observation of the measurement object;
The spectroscopic measurement apparatus, wherein the observation light source emits the observation light so that the observation light diffused by the light diffusion unit is irradiated on the measurement target. In the spectroscopic measurement device according to any one of claims 1 to 3,
A placement unit on which the measurement object is placed; and
Provided facing the mounting portion, holding the first light source at the predetermined angle, and holding the second light source at a position where the second light is emitted in a direction away from the mounting portion. A light source holding unit
The light diffusing unit is a concave mirror that is provided at a position facing the mounting unit with the light source holding unit interposed therebetween, and diffuses and reflects the second light from the second light source. . The spectrometer according to claim 4, wherein
It has a cylindrical light-shielding portion that surrounds the measurement object placed on the placement portion,
The said light source holding | maintenance part and the said light-diffusion part are arrange | positioned along the cylinder internal peripheral surface of the said cylindrical light-shielding part. The spectrometry apparatus characterized by the above-mentioned.

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