JP2020020606A - Spectrometer and spectral measurement unit - Google Patents

Abstract

To measure spectral characteristics with accuracy and high wave length resolution without a high volume device.SOLUTION: The spectrometer according to the present invention includes a detector 20, an interference optical system, and a processing unit 30. The detector has a photosensitive surface 21, and detects the intensity distribution of light on the photosensitive surface. The interference optical system includes a parallel light flux converging part and a light dividing part, which are integrally configured. The parallel light flux converting part converts light emitted from a measurement point of the measurement object S into a parallel light flux. The light dividing part is configured to emit light toward the photosensitive surface while providing an optical path length difference between a first light flux and a second light flux, and to allow the first light flux and the second light flux to be incident on the photosensitive surface so as to at least partially overlap each other. The processing unit acquires the interferogram of the measurement point based on the intensity distribution of light on the photosensitive surface 21 of the portion where the first light flux and the second light flux overlap, and performs Fourier transform on the interferogram to obtain a spectrum.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for qualitatively or quantitatively measuring the physical properties of a measurement object using the spectral characteristics of the measurement object.

  In various diseases such as diabetes and hyperlipidemia, management of biological components such as glucose and cholesterol contained in blood is important for prevention and treatment of diseases. Blood must be collected to measure biological components in blood. However, since collecting blood requires cumbersome treatment such as disinfection of the blood collection site and disposal of the blood collection device, it is not possible to routinely collect blood to measure biological components for the purpose of preventing disease. Shunned. Therefore, a non-invasive measuring device capable of measuring a biological component without collecting blood has been proposed.

For example, in Patent Literature 1 and Patent Literature 2, light is irradiated to a test site of a living body, and thereby, spectral characteristics of light (object light) emitted from a biological component inside the test site are obtained. A spectrometer for qualitatively and quantitatively measuring a biological component is described.
In the device described in Patent Literature 1, object light such as transmitted light and scattered light emitted from each bright spot optically constituting a biological component is converted into a parallel light flux (object light flux) by an objective lens, and then arranged side by side. Are guided to a fixed mirror and a movable mirror having reflecting surfaces parallel to each other. The object light flux reflected by each of the fixed mirror and the movable mirror is condensed by the imaging lens on an imaging point corresponding to each bright spot on the imaging surface. The movable mirror is moved in the normal direction of the reflection surface by a piezo element or the like, and the optical path length difference according to the amount of movement of the movable mirror determines the difference between the object light beam reflected by the fixed mirror and the movable mirror. Occurs between object beams reflected by Therefore, the fixed mirror and the movable mirror constitute a phase shifter, and the light reflected by these and condensed at each focal point on the image plane is an interference light whose intensity changes with the movement of the movable mirror, a so-called interferometer. It becomes a ferogram. By performing Fourier transform on the interferogram, the spectral characteristics (spectrum) of the object light can be obtained.

  In the device described in Patent Literature 2, the phase shifter includes two mirrors (a reference mirror and an inclined mirror) that are arranged side by side and have different reflection surface inclinations. In this device, an object light beam emitted from each luminescent spot and converted into a parallel light beam by an objective lens is guided to a reference mirror and an inclined mirror, and then reflected by a reflection surface of each mirror. The light reflected by the reference mirror (reference reflected light) and the light reflected by the inclined mirror (inclined reflected light) pass through a cylindrical lens and are on the same straight line extending in directions different from the optical axes of the reference reflected light and the inclined reflected light. To form a linear interference image. Since the inclination of the reflection surface of the reference mirror and the inclination of the reflection surface of the inclined mirror are different, the reference reflected light and the inclined reflected light according to the difference in the angle between the optical axis of the object light beam and each reflection surface of the reference mirror and the inclined mirror The optical path length difference occurs continuously along the longitudinal direction of the linear interference image. Therefore, a change in light intensity along the linear interference image becomes an interferogram. By subjecting this interferogram to Fourier transform, the spectral characteristics of the object light can be obtained.

JP 2008-309706 A JP 2012-058068 A

  Since the spectral characteristics of the object light reflect the properties of the biological components, it is possible to qualitatively and quantitatively determine the biological components non-invasively by using the devices described in Patent Documents 1 and 2. However, in the apparatus described in Patent Document 1, it is necessary to drive the movable mirror with high accuracy and high straightness of motion in order to obtain accurate spectral characteristics. An expensive drive mechanism is required. In addition, the size of the apparatus is increased due to the provision of the drive mechanism for the movable mirror.

  On the other hand, the device described in Patent Literature 2 does not require a mechanism for driving a mirror, and thus does not have the problem as seen in the device described in Patent Literature 1. However, in the device described in Patent Document 2, one linear interference image is formed from the object light emitted from each bright spot, and a spectral characteristic is obtained by detecting a light intensity change along the interference image. I have. Therefore, in order to increase the wavelength resolution, it is necessary to increase the number of elements for detecting a change in the light intensity of the interference image. In addition, in order to increase the number of elements, it is necessary to increase the size of the light receiving surface of the detector, the phase shifter, the objective lens, and the like.

  An object of the present invention is to enable accurate and high-resolution spectral characteristics to be measured without increasing the size of the apparatus.

The spectrometer according to the present invention has been made to solve the above problems,
a) a detector having a light receiving surface and detecting an intensity distribution of light on the light receiving surface;
b) a parallel beam forming unit that converts the light emitted from the measurement point of the object to be measured into a parallel beam, and divides the parallel beam into a first beam and a second beam, between the first beam and the second beam. An interference optical system having a light splitting unit that emits light toward the light receiving surface while providing an optical path length difference, and causes the first light flux and the second light flux to be incident on the light receiving surface so as to overlap each other at least in part; ,
c) Obtaining an interferogram at the measurement point based on the intensity distribution of light on the light receiving surface in a portion where the first light beam and the second light beam overlap, and obtaining a spectrum by Fourier transforming the interferogram. And a processing unit.
The parallel light beam splitting unit and the light splitting unit are integrally formed so that their optical axes coincide with each other.

  In the spectrometer having the above configuration, light emitted from the measurement point of the measurement object (which is located at the focal point of the interference optical system) enters the interference optical system, and is parallelized by the interference optical system. The light beam is converted into a parallel light beam by the light beam forming unit. Subsequently, the parallel light beam is split into a first light beam and a second light beam by the light splitting unit, and then enters the light receiving surface of the detector with the light receiving surface overlapping at least partially. At this time, since a predetermined optical path length difference is provided between the first light beam and the second light beam, an interference image of the first light beam and the second light beam is provided in a portion (overlapping area) where the two light beams overlap on the light receiving surface. Is formed. Therefore, by detecting the intensity distribution of light in the overlapping region, the intensity distribution of the interference image, that is, the interferogram of the measurement point is obtained, and the spectral characteristic of the measurement point is obtained by Fourier transforming the interferogram. can do. In the above-mentioned spectrometer, since the parallel beam forming unit and the light splitting unit of the interference optical system are integrally formed so that their respective optical axes coincide, the spectral characteristics of the optical wavelength resolution can be measured accurately. And the interference optical system can be downsized. Therefore, the size of the spectrometer can be reduced by using such an interference optical system.

In the above-mentioned spectrometer, the parallel beam forming part of the interference optical system is composed of a plate-shaped first transmission optical element having a convex light incident surface and a flat light exit surface located on the back side thereof. The light splitting section is composed of a plate-shaped second transmission type optical element having a planar light incident surface and a light exit surface composed of two inclined surfaces which are located on the back side and have different inclinations from each other. Preferably, the interference optical system further includes a holding member that integrally holds the first transmission type optical element and the second transmission type optical element so that their optical axes coincide. . In the above configuration, the light-emitting surface of the first transmission-type optical element and the light-incident surface of the second transmission-type optical element face each other so as to be parallel to each other, and the first transmission-type optical element and the second transmission-type optical element are opposed to each other. It is held by the holding member so that the optical axes of the mold optical elements coincide.
In the above configuration, the light incident from the light incident surface of the first transmission optical element becomes a parallel light beam, exits from the light exit surface, and enters the light incident surface of the second transmission optical element. Then, the parallel luminous flux incident on the second transmission type optical element is emitted as a first luminous flux and a second luminous flux from the two inclined surfaces constituting the light emitting surface, respectively.

  Further, in the above-described spectrometer, the interference optical system includes a convex light incident surface and a light exit surface, which is a surface located on the back side thereof and includes two inclined surfaces having different inclinations from each other. It can be composed of two plate-shaped transmission optical elements. This transmission optical element has a shape such that the light exit surface of the first transmission optical element and the light entrance surface of the second transmission optical element are joined. In this configuration, a portion from the light incident surface to the light emitting surface of the transmission optical element corresponds to a parallel light beam forming unit, and two inclined surfaces forming the light emitting surface correspond to a light splitting unit. With this configuration, even if some external force acts on the spectrometer, the optical axes of the parallel beam splitting unit and the light splitting unit do not shift, and the spectral characteristics of the measurement point of the measurement object can be stably measured. it can.

  Further, in the above-described spectrometer, the parallel beam forming unit of the interference optical system is formed of a Cassegrain optical system including a convex mirror and a concave mirror, and the light splitting unit is located on the plane light incident surface and the back side thereof. A transmission type optical element having a plate-like shape having a light emission surface composed of two inclined surfaces having different inclinations, wherein the interference optical system further includes the Cassegrain optical system and the transmission type optical element having optical axes thereof. It is preferable to provide a holding member that integrally holds them so as to coincide with each other.

In the spectrometer having the above configuration, as the light emitted from the measurement point of the measurement target, for example, scattered light or fluorescence emitted from the measurement point by irradiating the measurement target with light emitted from the light source, or from the light source Light emitted to the object to be measured, light transmitted through the object to be measured, light reflected from the surface of the object to be measured, or the like can be used.
The light source may be incorporated in a spectrometer, but a general-purpose light source device different from the spectrometer may be used. In addition, sunlight can be used as “light from a light source”.

  Furthermore, infrared rays emitted from the measurement point SP of the measurement target object by ultrasonically heating the measurement target object can be used. That is, a spectrometry unit according to the present invention includes the above-described spectrometry device and an ultrasonic heating device that emits infrared light from a measurement point of the measurement target by ultrasonically heating the measurement target. It is characterized by the following.

  In the spectrometry unit, the ultrasonic heating device and the spectrometry device are respectively attached to the measurement object so that the ultrasonic heating device and the parallel beam forming unit of the spectrometry device face each other across the measurement object. After being mounted, the spectral characteristics of the measurement point of the measurement object are measured. Therefore, it is preferable to provide a mounting member for mounting the ultrasonic heating device and the spectroscopic measurement device on the measurement object in the above-described arrangement.

  For example, a clip or a magnet can be used as the mounting member. That is, the ultrasonic heating device and the spectrometer are attached to both ends of the clip, and the object to be measured is sandwiched between the clips so that the ultrasonic heater and the spectrometer are attached to the object in the above-described arrangement. Can be It is also possible to attach magnets to the ultrasonic heating device and the spectrometer, respectively, and attach the ultrasonic heating device and the spectrometer to the object to be measured by using the attraction of the magnets. The configuration using a magnet as the mounting member is suitable for a spectral characteristic unit used for measuring spectral characteristics of a measurement object having a relatively small thickness such as an earlobe.

  In the above-mentioned spectrometry unit, the ultrasonic heating device includes an ultrasonic vibrator and an ultrasonic vibration changing unit configured to change a frequency and / or an amplitude of ultrasonic vibration generated by the ultrasonic vibrator. It is good to

  When the ultrasonic vibration generated by the ultrasonic vibrator is applied to the measurement target, a standing wave may be formed in the measurement target depending on the frequency and / or amplitude of the ultrasonic vibration. In the standing wave, the energy of the node concentrates on the node, so that the node is heated more than other parts. Therefore, when a standing wave of ultrasonic vibration is formed such that a node is located near the measurement point, light (infrared rays) emitted from the measurement point becomes stronger than light emitted from other places. In order to form a standing wave of ultrasonic vibration such that a node is located near the measurement point, the frequency and / or frequency of ultrasonic vibration generated by the ultrasonic vibrator depends on the size and shape of the measurement object. The amplitude needs to be adjusted. Since the above-mentioned spectrometer includes the ultrasonic vibration changing unit, the frequency and / or the amplitude of the ultrasonic vibration generated by the ultrasonic vibrator can be changed to an appropriate value.

Further, the transmission type optical element according to the present invention is an optical element having a convex light incident surface and a light exit surface formed of two inclined surfaces having different inclinations located on the back side thereof.
The light incident on the light incident surface from the focal point of the light incident surface is converted into a parallel light beam, the parallel light beam is divided into a first light beam and a second light beam, and an optical path length difference between the first light beam and the second light beam. And the first light flux and the second light flux are combined with each other so that the first light flux and the second light flux at least partially overlap each other on a surface located at a predetermined distance from the light emission surface. The light is emitted from the emission surface.

  In the spectrometry device and the spectrometry unit according to the present invention, after the light emitted from the measurement point and incident on the interference optical system is converted into a parallel light beam by the parallel light beam forming unit, the parallel light beam is converted into the first light beam by the light splitting unit. The light beam is divided into two light beams, and an interferogram at the measurement point is obtained by using the interference phenomenon between the first light beam and the second light beam. In the present invention, since the parallel light beam splitting unit and the light splitting unit are integrally formed so that their optical axes coincide with each other, it is possible to measure the spectral characteristics with high accuracy and high wavelength resolution, and furthermore, the interference optical system is used. The device can be miniaturized, and further, the entire device can be miniaturized. Further, since optical members such as an imaging lens used for obtaining an interference image in the conventional spectrometer are not required, the size of the device can be reduced in this respect.

  In addition, the transmission optical element according to the present invention is a single optical element that functions to convert light from the focal point into a parallel light beam, divides the parallel light beam into a first light beam and a second light beam, and that is provided between the two light beams. An optical path length difference is provided, and a function of emitting both light beams to a surface located at a predetermined distance from the light projection surface so that both light beams at least partially overlap each other is provided. Therefore, by using such a transmission type optical element as an interference optical system of the above-described spectrometer and spectrometer, the spectrometer and nighttime high-speed boat unit can be downsized.

FIG. 1 is a schematic configuration diagram of a first embodiment of a spectrometer according to the present invention. (A)-(d) which shows the structure of a transmission type optical element, and (e) which shows a mode that the light which passed the transmission type optical element is incident on the light receiving surface of a detector. FIG. 2 is a schematic configuration diagram of a spectrometer in which a transmission optical element and a detector are housed in a container. FIG. 4 is a schematic configuration diagram of a second embodiment of the spectrometer according to the present invention. FIG. 6 is a schematic configuration diagram of a third embodiment of the spectrometer according to the present invention. FIG. 1 is a schematic configuration diagram of a spectroscopic measurement unit according to a first embodiment of the present invention. FIG. 5 is a schematic configuration diagram of a spectroscopic measurement unit according to a second embodiment of the present invention. FIG. 9 is a schematic configuration diagram of a spectrometry unit according to a third embodiment of the present invention.

Hereinafter, the spectrometer according to the present invention will be specifically described.
[First Embodiment]
FIG. 1 shows a schematic configuration of a first embodiment of the spectrometer according to the present invention. The spectrometer 1 includes a transmission optical element 10, a detector 20 having a light receiving surface 21, and a processing unit 30 for processing a detection signal of the detector 20. The detector 20 includes a two-dimensional area sensor such as a CCD camera in which a plurality of pixels are two-dimensionally arranged. The transmission type optical element 10 has a light incident surface 11 and a light exit surface 12 on the back side thereof. The light incident surface 11 is on the sample (measurement object) S side, and the light exit surface 12 is a light receiving surface of the detector 20. It is arranged between the sample S and the light receiving surface 21 so as to face the 21 side.

  2A is a view of the transmission optical element 10 viewed from the light emitting surface 12 side, FIG. 2B is a cross-sectional view taken along the line bb ′ of FIG. 2A, and FIG. FIG. 2A is a diagram of a cross section taken along line cc ′ of FIG. 2A viewed from above the paper surface, and FIG. 2D is a diagram of a cross section taken along line dd ′ line of FIG. FIG. 2E is a view showing a state in which light emitted from the light emitting surface 12 of the transmission optical element 10 is incident on the light receiving surface 21. Here, the upper, lower, left and right in FIG.

  As apparent from FIGS. 2A to 2D, the transmission optical element 10 is a circular optical element viewed from the light incident surface 11 side (or the light output surface 12 side). Reference numeral 11 denotes a substantially spherical shape which is convex outward. On the other hand, the light emitting surface 12 is composed of a planar first light emitting surface 12A and a second light emitting surface 12B arranged side by side. It is inclined toward the light incident surface 11 side downward and upward.

  Also, the first light emitting surface 12A is not inclined in the cc 'direction (that is, the left-right direction) of FIG. 2A, while the second light emitting surface 12B is denoted by the reference numerals in FIG. It is inclined by an angle θ from c toward the sign c ′ toward the light incident surface 11 side. That is, the second light emitting surface 12B is inclined upward from the center line CL toward the light incident surface 11, and is inclined from right to left toward the light incident surface 11. For this reason, the first light exit surface 12A and the second light exit surface 12B are not symmetrical with respect to the center line CL.

  With the above-described configuration, when the sample S is irradiated with light from the light source 40, a group of light beams (object light) such as scattered light and fluorescent light is generated from the measurement point SP located at the focal point of the transmission optical element 10. When the object light is incident on the light incident surface 11 of the transmission optical element 10, the object light becomes a parallel light flux (hereinafter referred to as “object light flux”) and travels toward the light emission surface 12 of the transmission optical element 10. Then, when refracted and emitted from each of the first light emitting surface 12A and the second light emitting surface 12B, the light is divided into a first light beam and a second light beam, and each light beam enters the light receiving surface 21 of the detector 20. At this time, the traveling directions of the first light beam and the second light beam are the inclination angles of the first light exit surface 12A and the second light exit surface 12B, the wavelength of the object light beam, and the refraction between the transmission optical element 10 and the outside (air). Determined according to the rate difference.

  Accordingly, the material of the transmission optical element 10, the angle φ between the first light exit surface 12A and the second light exit surface 12B (see FIG. 2B), and the distance from the transmission optical element 10 to the light receiving surface 21 of the detector 20. By appropriately selecting the distance L and the like, the first light beam and the second light beam emitted from each of the first light emitting surface 12A and the second light emitting surface 12B are overlapped with each other at least in part. Can be incident. Further, since the second light exit surface 12B is inclined at an angle θ (see FIG. 2D) with respect to the first light exit surface 12A, an optical path length difference occurs between the first light beam and the second light beam. In an area where the first light beam and the second light beam overlap on the light receiving surface 21, an interference image of the first light beam and the second light beam is formed. Therefore, the interferogram of the measurement point SP can be obtained by detecting the light intensity distribution of the interference image by the detector 20, and the interferogram is subjected to the Fourier transform by the processing unit 30 to obtain the measurement point SP. Spectral characteristics can be obtained.

  Thus, in the present embodiment, the transmission optical element 10 functions as an interference optical system. Further, a portion from the light incident surface 11 to the light emitting surface 12 of the transmission optical element 10 forms a parallel light beam forming unit, and the light emitting surface 12 forms a light splitting unit.

When the first light beam and the second light beam are incident on the light receiving surface 21 in an overlapping manner, the inclination angle of the second light exit surface 12B with respect to the first light exit surface 12A is based on optical conditions such as a measurement wavelength range and wavelength resolution. Can be designed.
For example, the diameter D of the transmission optical element 10 is 6 mm, the distance L from the transmission optical element 10 to the light receiving surface 21 of the detector 20 is 20 mm, the number of pixels of the detector 20 is 80 × 80, and the vertical and horizontal directions are different. The pixel pitch is both 34 μm, the measurement wavelength range is 8 to 14 μm, the inclination angle (horizontal inclination angle) of the second light exit surface 12B with respect to the first light exit surface 12A is θ, and the first light exit surface 12A and the second Assuming that the angle formed by the light exit surface 12B (the inclination angle in the vertical direction) is φ, setting the angle θ to 1.12 deg and setting the angle φ to 177.15 deg causes the first light flux and the second light flux to at least partially overlap. Incident on the light receiving surface 21.

  For example, as shown in FIG. 3, when the transmission optical element 10 and the detector 20 are configured to be housed in one container 50, the light emission surface 12 of the transmission optical element 10 to the light receiving surface 21 of the detector 20 are arranged. Can be fixed to a predetermined distance. Further, the distance L can be adjusted according to the measurement wavelength range and the like by making the transmission optical element 10 relatively movable with respect to the detector 20 in the container 50.

  Further, the distance from the end of the container 50 opposite to the detector 20 to the light incident surface 11 of the transmission optical element 10 is defined as the focal length of the transmission optical element 10 on the light incident surface 11 side or the focal length −α. By contacting the end of the container 50 with the surface of the sample S, the measurement point SP located on the surface of the sample S or the measurement point SP located inside the surface by a distance α from the surface is set. The object light can be converted into a parallel light beam by the transmission optical element 10.

[Second embodiment]
FIG. 4 is a schematic configuration diagram of a second embodiment of the spectrometer according to the present invention. In the spectrometer 1A of this embodiment, the interference optical system is composed of two transmission optical elements (hereinafter, referred to as a parallelizing optical element 110 and a split optical element 120).

  The collimating optical element 110 has a convex light incident surface 111 and a planar light emitting surface 112 on the back side. Further, the split optical element 120 has a planar light incident surface 121 and a convex light exit surface 122 on the back side thereof.

  The light exit surface 122 of the split optical element 120 is composed of a planar first light exit surface 122A and a second light exit surface 122B arranged side by side. The first light emitting surface 122A and the second light emitting surface 122B correspond to the first light emitting surface 12A and the second light emitting surface 12B of the first embodiment, and the first light emitting surface 122A and the second light emitting surface 122B. The angle of inclination of the surface 122B and the angle between them are the same as those of the first light emitting surface 12A and the second light emitting surface 12B of the first embodiment. Therefore, detailed description is omitted here.

  The collimating optical element 110 and the split optical element 120 are housed in one cylindrical container 50. In the container 50, the collimating optical element 110 and the split optical element 120 are arranged such that the light emitting surface 112 and the light incident surface 121 are parallel and opposed, and that the optical axes of both optical elements coincide with each other. I have. The detector 20 is attached to an end of the container 50. Thereby, the distance from the light emitting surface 122 of the split optical element 120 to the light receiving surface 21 of the detector 20 is determined. In this example, the container 50 functions as the holding member of the present invention.

  Since the configuration of the spectrometer 1A is substantially the same as that of the spectrometer 1 except for the above, the same or corresponding parts as those of the spectrometer 1 are denoted by the same reference numerals, and description thereof will be omitted.

  With the above configuration, when the object light generated at the measurement point SP of the sample S by irradiating the sample S with light from the light source 40 is incident on the light incident surface 111 of the collimating optical element 110, the object light becomes a parallel light beam. Then, the light exits from the light exit surface 112 of the collimating optical element 110. This parallel light beam travels straight through the space between the collimating optical element 110 and the split optical element 120 and enters the light incident surface 121 of the split optical element 120. When the light is refracted and emitted from each of the first light emitting surface 122A and the second light emitting surface 122B of the splitting optical element 120, the light is split into a first light beam and a second light beam, and each light beam at least partially overlaps. Incident on the light receiving surface 21 of the detector 20. In addition, since an optical path length difference occurs between the first light beam and the second light beam, an interference image of the first light beam and the second light beam is formed in a region where the first light beam and the second light beam overlap on the light receiving surface 21. Is done. Therefore, the interferogram of the measurement point SP can be obtained by detecting the light intensity distribution of the interference image by the detector 20, and the interferogram is subjected to the Fourier transform by the processing unit 30 to obtain the measurement point SP. Spectral characteristics can be obtained.

[Third embodiment]
FIG. 5 is a schematic configuration diagram of a third embodiment of the spectrometer according to the present invention. In the spectrometer 1B, the interference optical system 200 includes a Cassegrain optical system 210 housed in a container 201 as a holding member, an enlargement optical element 220, and a split optical element 230. The container 201 is fixed to the detector 20.

  The Cassegrain optical system 210 includes a primary mirror 211 that is a concave mirror and a secondary mirror 212 that is a convex mirror. Each of the primary mirror 211 and the secondary mirror 212 has a circular outer shape when viewed from above. The primary mirror 211 is held in the container 201 with its concave surface facing down. The secondary mirror 212 is disposed below the primary mirror 211 with the convex surface facing upward. In addition, an upper opening 213 and a lower opening 214 for allowing light to pass therethrough are provided in an upper portion of the main mirror 211 and a bottom surface of the container 201, respectively.

  In the space above the main mirror 211 in the container 201, the magnifying optical element 220 and the split optical element 230 are held in order from the main mirror 211 side. The magnifying optical element 220 has a concave light incident surface 221 and a convex light emitting surface 222, and is housed in the container 201 in a state where the light incident surface 221 is in close contact with the upper surface of the main mirror 211. . Further, the split optical element 230 has a planar light incident surface 231 and a convex light exit surface 232. The shape of the split optical element 230 is the same as the shape of the split optical element 120 of the second embodiment, and the light exit surface 232 is composed of a first light exit surface 232A and a second light exit surface 232B. The split optical element 230 is arranged in the container 201 such that the light incident surface 231 is in contact with the light exit surface 222 of the magnifying optical element 220. The Cassegrain optical system 210, the magnifying optical element 220, and the split optical element 230 are housed in the container 201 with their optical axes aligned.

  When acquiring the spectral characteristics of the sample S using the spectrometer 1B of the present embodiment, the spectrometer 1B is installed so that the bottom surface of the container 201 contacts the surface of the sample S. In this state, light from a light source (not shown) is applied to the sample S, and object light is emitted from the measurement point SP in the sample S in various directions. After being integrated into one parallel light beam through the main mirror 211 and the sub-mirror 212, the light enters the light incident surface 221 of the magnifying optical element 220 from the upper opening 213. The parallel light beam incident on the light incident surface 221 gradually increases in outer diameter when passing through the inside of the magnifying optical element 220, and becomes a parallel light beam having an outer diameter larger than that when the light beam enters the light incident surface 221. The light exits from the exit surface 222. Then, the parallel light beam emitted from the light exit surface 222 enters the light incident surface 231 of the split optical element 230, proceeds inside the split optical element 230 toward the light exit surface 232, and travels through the first light exit surface 232A and the second light. When the light is refracted and emitted from each of the emission surfaces 232 </ b> B, it is split into a first light beam and a second light beam, and each light beam is incident on the light receiving surface 21 of the detector 20 with at least a part thereof overlapping.

  Therefore, the interferogram of the measurement point SP can be obtained by detecting the light intensity distribution in the region where the first light beam and the second light beam overlap on the light receiving surface 21 (that is, the interference image) by the detector 20. By performing the Fourier transform on the interferogram in the processing unit 30, the spectral characteristics of the measurement point SP can be obtained.

Next, an embodiment in which the present invention is applied to a spectrometry unit will be described.
[Example 1]
The spectrometer 300 shown in FIG. 6 includes the spectrometer 1 of the first embodiment (see FIG. 3), the light source 40, and a casing 301 that houses these components. A window plate 302 made of a translucent member is attached to the casing 301. Light from the light source 40 is emitted to the outside of the casing 301 through the window plate 302, and light from the outside enters the casing 301 through the window plate 302. The spectrometer 1 is arranged in the casing 301 so that the transmission optical element 10 faces the window plate 302 side.

  In this embodiment, light from the light source 40 is incident on the measurement target S from the window plate 302 in a state where the window plate 302 is in contact with the surface of the measurement target S. Then, light emitted from within the measurement object S near the window plate 302 enters the casing 301 through the window plate 302, and the incident light is introduced into the spectrometer 1. At this time, when light emitted from the focal point of the transmission type optical element 10 (this is the measurement point SP) enters the transmission type optical element 10 of the spectrometer 1, the incident light becomes a parallel light flux and becomes light. The light beam is split into a first light beam and a second light beam and exits from the light exit surface 12 toward the exit surface 12. The first light beam and the second light beam emitted from the light emitting surface 12 enter the light receiving surface 21 of the detector 20 in a partially overlapping state, and form an interference image of the first light beam and the second light beam. Therefore, the interferogram of the measurement point SP is obtained by measuring the light intensity distribution of the interference image with the detector 20, and the spectral characteristic of the measurement point SP is obtained by performing the Fourier transform on the interferogram in the processing unit 30. Can be obtained.

[Example 2]
The spectrometry unit 400 shown in FIG. 7 includes a spectrometer 1C including a cylindrical casing 401, a transmission optical element 410 and a detector 420 housed therein, and an ultrasonic heating device 450. I have. The transmission optical element 410 has the same configuration as the transmission optical element 10 included in the spectrometer 1 of the first embodiment, and includes a light incident surface 411 and a light emission surface including a first and a second light emission surface. Surface 412. The detector 420 is connected to the processing device 430 via a signal line, and outputs a detection signal to the processing device 430. A window plate 402 made of a translucent member is attached to the casing 401, the window plate 402 faces the light incident surface 411 of the transmission optical element 410, and the optical axis of the transmission optical element 410 is a window. The transmission optical element 410 is arranged in the casing 401 so as to be perpendicular to the plate 402.

  The ultrasonic heating device 450 includes a plate member 451, an ultrasonic vibrator 452 attached to the plate member 451, and a driving device 453 for driving the ultrasonic vibrator 452.

A method for using the spectrometer 400 will be described. Here, an object having a small thickness, such as an earlobe, is assumed to be the measurement target S.
First, the spectrometer 1C and the ultrasonic heating device 450 are arranged on both sides of the measurement target S with the measurement target S interposed therebetween, and the window plate 402 of the casing 401 is brought into contact with the surface of the measurement target S to perform measurement. The plate 451 is brought into contact with the measurement target S so as to face the window plate 402 with the target S interposed therebetween.

  When AC power is supplied to the ultrasonic vibrator 452 by operating the driving device 453 in this state, ultrasonic vibration is generated in a region (measurement region) between the plate 451 and the window plate 402 in the measurement target S. The measurement area is ultrasonically heated. Thereby, infrared rays are emitted from the measurement area, and the infrared rays enter the transmission optical element 410 in the casing 401 through the window plate 402. Of the infrared light incident on the transmission optical element 410, the infrared light emitted from the measurement point SP, which is the focal point of the transmission optical element 410, becomes a parallel light flux toward the light emission surface 412, and from the light emission surface 412, The light beam is split into one light beam and the second light beam and emitted. Then, the first light beam and the second light beam emitted from the light emitting surface 412 are incident on the light receiving surface 421 of the detector 420 in a partially overlapped state, and form an interference image of the first light beam and the second light beam. Therefore, the interferogram of the measurement point SP is obtained by measuring the light intensity distribution of the interference image with the detector 420, and the spectral characteristic of the measurement point SP is obtained by Fourier transforming the interferogram with the processing device 430. Can be obtained.

  In the spectrometry unit 400 of this embodiment, a spectrometer 1C and an ultrasonic heating device 450 functioning as a light source are separately provided. Therefore, the spectrometer 1C can be downsized.

[Example 3]
The spectrometer 400A shown in FIG. 8 is a vibration device that adjusts the frequency of the AC power supplied to the ultrasonic vibrator 452 by the driving device 453 of the ultrasonic heating device 450 and the amplitude of the ultrasonic vibration generated by the ultrasonic vibrator 452. An adjustment unit 455 and an operation unit 456 operated by a user are provided. The vibration adjusting unit 455 and the operation unit 456 correspond to a vibration changing unit of the present invention. Further, the spectrometry unit 400A includes a mounting member 460 for mounting the spectrometer 1C and the ultrasonic heating device 450 to the measurement target S. The mounting member 460 is made of, for example, a clip, and the plate 451, the ultrasonic vibrator 452, and the casing 401 are attached to both ends of the clip, respectively. When the measurement object S is sandwiched by the mounting member 460, the plate material 451, the ultrasonic vibrator 452, and the casing 401 are fixed to the measurement object S such that the plate member 451 and the window member 402 face each other with the measurement object S interposed therebetween. You.
Since the configuration of the spectrometry unit 400A other than that described above is the same as that of the spectrometry unit 400 shown in FIG. 7, the same parts are denoted by the same reference numerals and description thereof will be omitted.

A method of using the above-described spectrometry unit 400A will be described. Here, an object having a small thickness such as an earlobe is assumed to be the measurement target S.
First, the measuring object S is sandwiched between the mounting members 460, and the casing 401 of the spectrometer 1C, the plate member 451 of the ultrasonic heating device 450, and the ultrasonic transducer 451 are fixed to both sides of the measuring object S.

  When AC power is supplied to the ultrasonic vibrator 452 by operating the driving device 453 in this state, ultrasonic vibration is generated in a measurement area between the plate 451 and the window plate 402 in the measurement target S, and the measurement area Is ultrasonically heated. At this time, the frequency of the AC power supplied to the ultrasonic vibrator 452 and the amplitude of the ultrasonic vibration generated by the ultrasonic vibrator 452 are appropriately adjusted by operating the operation unit 456, and the measurement point SP is perpendicular to the plate 451. A standing wave where a node is located is formed in the measurement area.

  FIG. 8 schematically illustrates a state in which a standing wave Sw is formed inside the measurement target S. In the standing wave Sw, energy concentrates on the nodes, so that the nodes are heated more strongly than the other portions and emit high-energy infrared rays. The high-energy infrared rays emitted from the measurement point SP enter the transmission optical element 410 in the casing 401 through the window plate 402. The infrared light from the measurement point SP that has entered the transmission optical element 410 is converted into a parallel light flux toward the light emission surface 412, and is emitted from the light emission surface 412 as a first light flux and a second light flux. The first light beam and the second light beam emitted from the light exit surface 412 are incident on the light receiving surface 421 of the detector 420 in a partially overlapped state, and form an interference image of the first light beam and the second light beam. Therefore, the interferogram of the measurement point SP is obtained by measuring the light intensity distribution of the interference image with the detector 420, and the spectral characteristic of the measurement point SP is obtained by Fourier transforming the interferogram with the processing device 430. Can be obtained.

  Further, in the present embodiment, a standing wave Sw of ultrasonic vibration is formed so as to be located at the measurement point SP, and high-energy infrared rays are generated from the measurement point SP. Accordingly, infrared rays emitted from portions other than the measurement point SP, which do not contribute to the formation of an interference image on the light receiving surface 421 of the detector 420, can be suppressed to a small value, so that the SN ratio can be increased.

  By using the spectrometry units 300, 400, and 400A of the above-described first to third embodiments, it is possible to easily measure the spectral characteristics of the measurement object. In addition, since the spectrometer 1 uses the transmission optical elements 10 and 410 as the interference optical system, and the interference optical system can be downsized, the spectrometry units 300, 400 and 400A can also be downsized. Therefore, the spectrometry units 300, 400, and 400A measure, for example, the spectral characteristics of blood flowing in a relatively small area such as an earlobe or a fingertip as a measurement target, and measure the concentration of a biological component such as glucose or cholesterol from the result. It is suitable as a device that performs

Note that the present invention is not limited to the configuration of the above-described embodiment or example, and can be appropriately changed.
For example, the spectrometry units 300 and 400 of the first and second embodiments may also include a casing 301 or a mounting member for fixing the casing 401 and the ultrasonic heating device 450 to the measurement object.
The spectrometers constituting the spectrometers 300, 400 and 400A may be the spectrometer 1A of the second embodiment or the spectrometer 1B of the third embodiment.
In the spectrometer of the third embodiment, the magnifying optical element is arranged between the Cassegrain optical system and the split optical element, but this magnifying optical element may be omitted.

1, 1A, 1B, 1C Spectrometer 10, 410 Transmission optical element 11, 411 Light incidence surface 12, 412 Light emission surface 12A First light emission surface 12B Second light emission surface 110 Parallel Optical element 111: light incident surface 112: light emitting surface 120: split optical element 121: light incident surface 122: light emitting surface 122A: first light emitting surface 122B: second light emitting surface 20, 420: detector 21 Light receiving surface 200: Interfering optical system 201: Container 210: Cassegrain optical system 211: Primary mirror 212: Secondary mirror 220: Magnifying optical element 221: Light incident surface 222: Light emitting surface 230: Split optical element 231: Light incident surface 232 Light emitting surface 232A First light emitting surface 232B Second light emitting surface 30 Processing units 300, 400, 400A Spectrometer 301, 401 Casing 302, 402 Window plates 40 ... Light source 450 ... Ultrasonic heating device 452 ... Ultrasonic vibrator 453 ... Drive device 455 ... Vibration adjustment unit 456 ... Operation unit 460 ... Mounting member 50 ... Container

Claims (8)

a) a detector having a light receiving surface and detecting an intensity distribution of light on the light receiving surface;
b) a parallel beam forming unit that converts the light emitted from the measurement point of the object to be measured into a parallel beam, and divides the parallel beam into a first beam and a second beam, between the first beam and the second beam. An interference optical system having a light splitting unit that emits light toward the light receiving surface while providing an optical path length difference, and causes the first light flux and the second light flux to be incident on the light receiving surface so as to overlap each other at least in part; ,
c) Obtaining an interferogram at the measurement point based on the intensity distribution of light on the light receiving surface in a portion where the first light beam and the second light beam overlap, and obtaining a spectrum by Fourier transforming the interferogram. And a processing unit.
The spectrometer according to claim 1, wherein the parallel light beam splitting unit and the light splitting unit are integrally formed such that their optical axes coincide with each other. The parallel beam forming unit of the interference optical system is configured by a plate-shaped first transmission optical element having a convex light incident surface and a planar light emitting surface located on the back side thereof, and the light splitting unit. Is constituted by a plate-shaped second transmission optical element having a planar light incident surface and a light exit surface composed of two inclined surfaces that are different from each other and located on the back side,
The interference optical system further comprises a holding member that integrally holds the first transmission type optical element and the second transmission type optical element so that their optical axes coincide. 2. The spectrometer according to 1.   The interference optical system has a convex light incident surface and a light exit surface, which is a surface located on the back side, and is formed of two inclined surfaces having different inclinations from each other. The part up to a surface becomes a parallel light beam forming part, and the two inclined surfaces constituting the light emitting surface are constituted by one transmission type optical element serving as the light dividing part. 2. The spectrometer according to 1. The parallel beam forming unit of the interference optical system is formed of a Cassegrain optical system including a convex mirror and a concave mirror, and the light splitting unit is a plane light incident surface and a surface located on the back side thereof, and the inclination is different from each other. And a plate-shaped transmission optical element having a light emission surface composed of two inclined surfaces,
2. The spectroscopy according to claim 1, wherein the interference optical system further includes a holding member that integrally holds the Cassegrain optical system and the transmission optical element so that their optical axes coincide. measuring device. A spectrometer according to any one of claims 1 to 4,
An ultrasonic heating device that emits infrared light from a measurement point of the measurement target by ultrasonically heating the measurement target.   The said ultrasonic heating device is provided with the ultrasonic vibrator and the ultrasonic vibration change part which changes the frequency and / or the amplitude of the ultrasonic vibration which this ultrasonic vibrator emits, The Claims 5 characterized by the above-mentioned. Spectrometry unit.   A mounting member is provided for mounting the ultrasonic heating device and the spectroscopic measurement device on the measurement object such that the ultrasonic heating device and the parallel beam forming unit of the spectrometry device face each other across the measurement object. The spectrometry unit according to claim 5 or 6, wherein: A transmissive optical element having a convex light incident surface and a light exit surface formed of two inclined surfaces having different inclinations located on the back side thereof,
The light incident on the light incident surface from the focal point of the light incident surface is converted into a parallel light beam, the parallel light beam is divided into a first light beam and a second light beam, and an optical path length difference between the first light beam and the second light beam. And the first light flux and the second light flux are combined with each other so that the first light flux and the second light flux at least partially overlap each other on a surface located at a predetermined distance from the light emission surface. A transmission type optical element that emits light from an emission surface.

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