JP7205190B2 - Optical measuring instrument - Google Patents

Description

The present invention relates to a compact optical measuring instrument capable of high-performance measurement.

In recent years, there has been an increasing demand for a compact and portable optical measuring instrument capable of short inspection time and high-precision evaluation analysis at sites where analysis is required, such as POCT (Point Of Care Test). In addition, especially using such an optical measuring instrument, it is possible to perform optical measurements using optical measurement methods such as absorbance and fluorometry (for example, laser induced fluorescence (LIF)) at the site of analysis. Demand is high.
LIF uses resonance transitions of atoms and molecules to be measured to irradiate laser light that matches the excitation level (tuned wavelength) to excite the measurement target, and emit light (fluorescence) caused by it. is a method of measuring The concentration of the object to be measured is calculated from the intensity of the fluorescence, and the temperature of the object to be measured is calculated from the spectral distribution of the fluorescence.

As such a LIF device, there is a technique described in Patent Document 1, for example. In this LIF device, at least part of the optical path through which the excitation light emitted from the light source and the observation light emitted from the measurement sample pass is made of a resin (silicone resin) transparent to the excitation light and the observation light. , the optical path is surrounded by a pigment-containing resin containing a light-absorbing material (pigment such as carbon black). Here, by using the same material for the transparent resin and the pigment-containing resin, the following advantages can be obtained.

First, reflection and scattering at the interface between both resins are suppressed. Next, the stray light incident on the pigment-containing resin is absorbed by the resin and hardly returns to the light guide path, and complicated multiple reflection of the stray light hardly occurs. Therefore, it is not necessary to configure the optical system to deal with complicated multiple reflections, and the size and simplification of the optical system can be achieved. As a result, the device itself can also be miniaturized. The technology of an optical system constructed with silicone resin as described above is called SOT (Silicone Optical Technologies).
According to the optical measuring instrument having the optical path of such an SOT structure, stray light such as reflected light and scattered light emitted from the light source enters the measuring instrument for measuring the observation light emitted from the sample. It is possible to suppress Therefore, it is possible to provide an optical measuring instrument that is compact, easy to carry, and capable of simple, high-speed, and high-performance measurement that can meet the demands of POCT.

Japanese Patent No. 5665811 JP 2016-191707 A

The technique described in Patent Document 1 uses a green laser device that emits a laser beam with a wavelength of 532 nm as a laser light source. The sample includes an antibody light chain variable region polypeptide and an antibody heavy chain variable region polypeptide, and either the antibody light chain variable region polypeptide or the antibody heavy chain variable region polypeptide is labeled with a fluorescent dye. I'm using the same kit.
On the other hand, for example, ethidium bromide, which is known as a fluorescent reagent for DNA detection, is excited by ultraviolet light (UV light: eg 300-350 nm).
Further, as described in Patent Document 2, for example, optical measurement with an excitation wavelength of 260 to 300 nm is performed in order to measure blood indoxyl sulfate concentration, which increases during renal dysfunction.

Thus, there is a demand for an optical measuring instrument using an ultraviolet light source. Ultraviolet light sources include UV-LDs (Laser Diodes) and UV-LEDs (Light Emitting Diodes), but UV-LDs are relatively large and expensive. Therefore, it is desirable to use a compact and relatively inexpensive UV-LED as an ultraviolet light source for irradiating a sample with excitation light.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a compact optical measuring instrument that uses an LED light source that emits ultraviolet light and is capable of highly sensitive measurement.

In order to solve the above problems, one aspect of the optical measuring instrument according to the present invention includes: a housing; a light source unit disposed in the housing for irradiating a measurement sample accommodated in a sample case with excitation light; a light receiving unit arranged in a housing for measuring observation light emitted from the measurement sample irradiated with the excitation light, wherein the light source unit is an LED light source that emits ultraviolet light that is the excitation light; a light collecting unit for collecting light emitted from the LED light source; a first light guide for guiding the light collected by the light collecting unit to the measurement sample; and surrounding the first light guide. and a first light guide unit having a first light shielding member that controls the observation light, and the light receiving unit guides the light emitted from the measurement sample to the light receiving sensor for measuring the observation light. a second light guide unit having a second light guide path and a second light shielding member surrounding the second light guide path, wherein the optical axis of the light source unit and the optical axis of the light receiving unit An angle is formed, and both optical axes are not parallel.

In this way, since the optical measuring instrument has a configuration in which the diffused light emitted from the LED light source is condensed and guided to the measurement sample, it is possible to irradiate the measurement sample with the UV light by narrowing the optical path along which the UV light travels. can be done. Therefore, it is possible to suppress the UV light emitted from the LED light source from irradiating a wide range other than the sample case, and to suppress secondary light emission (autofluorescence) due to the UV light. Also, the optical measuring instrument has a configuration in which the light source unit and the light receiving unit are arranged such that the optical axis of the light source unit and the optical axis of the light receiving unit form a predetermined angle and the two optical axes are not parallel. Therefore, it is possible to prevent the excitation light emitted from the light source unit from directly entering the light receiving unit.
Therefore, it is possible to suppress the UV light emitted from the LED light source and the secondary light emitted by the UV light from becoming noise light and affecting the light measurement, and highly sensitive light measurement becomes possible. .

Further, in the optical measuring instrument described above, the excitation light and the observation light have different wavelengths, and the light source unit emits light emitted from the LED light source with at least the same wavelength component as that of the observation light. may be further provided with a first filter section that blocks the excitation light and transmits the excitation light.
In this case, even when an LED light source with a wide spectral width is used, it is possible to appropriately extract light of a desired excitation light wavelength and irradiate the measurement sample. In other words, even if the LED light source emits not only the excitation light wavelength but also the light with the same wavelength as the observation light wavelength, the light with the same wavelength as the observation light wavelength becomes noise light and cannot be used for optical measurement. Influence is suppressed, and highly sensitive optical measurement becomes possible.

Furthermore, in the above optical measuring instrument, the first filter section may be arranged on the light exit side of the first light guide unit.
In this case, secondary light emission generated by the UV light in the optical path through which the UV light passes from the LED light source to the sample case can be appropriately blocked by the first filter section.

Further, in the optical measuring instrument described above, the excitation light and the observation light have different wavelengths, and the light receiving unit detects at least the same wavelength component as the excitation light in the light emitted from the measurement sample. may be further provided with a second filter unit that blocks the observation light and transmits the observation light.
In this case, even if the UV light emitted from the LED light source enters the light receiving unit as stray light, it is possible to prevent the stray light from reaching the light receiving sensor. In this way, the UV light emitted from the LED light source can be prevented from becoming noise light and affecting the optical measurement, thereby enabling highly sensitive optical measurement.

Furthermore, in the above optical measuring instrument, the second filter section may be arranged on the light incident side of the second light guide unit.
In this case, UV light can be blocked on the light incident side of the second light guide unit. Therefore, secondary light emission due to UV light can be suppressed in the optical path to the light-receiving sensor including the second light guide path after the second filter section.

Further, in the optical measuring instrument described above, the predetermined angle may be an angle at which excitation light emitted from the light source unit does not enter the second light guide path of the light receiving unit. In this case, it is possible to appropriately suppress the excitation light emitted from the light source unit from becoming noise light and affecting light measurement.
Furthermore, in the above optical measuring instrument, the predetermined angle may be 90 degrees or more and 170 degrees or less. Thus, by setting the angle to 170 degrees or less, it is possible to prevent the excitation light emitted from the light source unit from directly entering the second light guide path of the light receiving unit. Further, by setting the angle to 90 degrees or more, physical interference between the first light guide unit and the second light guide unit can be avoided while keeping the optical path length short.

Further, in the optical measuring instrument described above, the second light guide path is made of a resin transparent to the observation light, the second light shielding member contains a pigment that is a light absorbing material, and the transparent It may be a pigment-containing resin made of the same material as the other resin.
In this way, by surrounding the second light guide path with the pigment-containing resin capable of absorbing external light and scattered light, the external light, scattered light, and the like become stray light (noise light) and enter the light receiving sensor. can be suppressed. Therefore, measurement errors due to the stray light can be reduced, and highly accurate measurement is possible.

Furthermore, in the above optical measuring instrument, the first light guide path may be hollow, and the first light shielding member may be a pigment-containing resin made of a resin containing a pigment, which is a light-absorbing material. .
In this way, by making the first light guide path for guiding UV light to the sample case hollow, it is possible to suppress secondary light emission (autofluorescence) due to UV light in the first light guide path. Therefore, in order to suppress the self-fluorescence, it is not necessary to fill the first light guide path with expensive high-purity transparent silicone or the like, and the cost can be reduced.

In the optical measuring instrument described above, the condensing unit may have a hemispherical lens and a ball lens arranged in this order from the light incident side. In this case, the emitted light from the LED light source, which is diffused light, can be appropriately collected and made incident on the first light guide unit.

Further, the above optical measuring instrument further includes a light damper section on the optical axis of the light source unit, into which the excitation light emitted from the light source unit and transmitted through the sample case is incident, wherein the light damper section A space may be provided in which the incident excitation light is multiple-reflected between a plurality of reflecting surfaces and attenuated.
In this case, the UV light transmitted through the sample case can be appropriately attenuated, and the UV light can be prevented from becoming stray light and entering the light receiving unit.

In the above optical measuring instrument, at least part of an optical path through which light emitted from the LED light source passes may be made of at least one of quartz glass and high-purity transparent silicone.
Quartz glass and high-purity transparent silicone are materials that generate little autofluorescence when UV light passes through them. By forming at least part of the optical path through which UV light passes with such a material, it is possible to suppress the generation of autofluorescence and noise light that may enter the light-receiving sensor.

The optical measuring instrument of the present invention can be a compact optical measuring instrument that uses an LED light source that emits ultraviolet light and is capable of highly sensitive measurement.

It is a figure showing the whole optical measuring instrument composition in this embodiment. It is a figure explaining the external light which penetrate|invades into a light guide path. It is a figure which shows another example of the optical measuring device in this embodiment. It is a figure which shows the whole structure of the conventional optical measuring instrument.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing the overall configuration of an optical measuring instrument 100 according to this embodiment.
The optical measuring instrument 100 in the present embodiment is a light-induced fluorescence measuring instrument that irradiates a measurement sample with ultraviolet light (excitation light) and measures observation light (fluorescence) emitted from the measurement sample irradiated with the excitation light. be. This optical measuring instrument 100 is an apparatus that detects physical properties of a measurement sample by irradiating the measurement sample with ultraviolet light to excite the measurement sample and measuring the degree of fluorescence caused thereby.
The optical measuring instrument 100 in this embodiment includes a light source unit 110, a light receiving unit 120, and a sample case holding housing 130, as shown in FIG. The sample case 200 accommodates the measurement sample 210 and is detachably held by the sample case holding housing 130 .

(light source unit)
The light source unit 110 is arranged in the first housing 111 and irradiates the measurement sample 210 housed in the sample case 200 with excitation light. The light source unit 110 includes an LED light source 112 , a condensing unit 113 , a first light guide unit 114 and a first filter section 115 . The first light guide unit 114 includes a first light guide path 114a and a first light shielding member 114b surrounding the first light guide path 114a.
The first housing 111 encloses the LED light source 112 , the condensing unit 113 , the first light guide unit 114 and the first filter section 115 .
The LED light source 112 emits ultraviolet light (UV light) with a peak wavelength of 340 nm, for example. This LED light source 112 can be mounted, for example, on an aluminum substrate in order to ensure heat dissipation.

The light collecting unit 113 is arranged on the light emitting side of the LED light source 112 . The condensing unit 113 includes, for example, a hemispherical lens 113a and a ball lens 113b in order from the side closer to the LED light source 112 . The light collecting unit 113 has a function of collecting diffused light emitted from the LED light source 112 onto a first light guide path 114a, which will be described later.
It should be noted that the condensing unit 113 is not limited to the configuration consisting of the hemispherical lens 113a and the ball lens 113b. For example, the condensing unit 113 may have a configuration in which a plurality of hemispherical lenses are arranged. In other words, the condensing unit 113 only needs to have at least one hemispherical lens.

The first filter section 115 can be arranged on the light exit side of the condensing unit 113 . In this embodiment, the first filter section 115 is arranged between the light collecting unit 113 and the light incident side of the first light guiding unit 114 . The first filter unit 115 has a function of transmitting light of the excitation light wavelength to be irradiated to the measurement sample 210 and cutting (blocking) transmission of at least light of the same wavelength as the observation light wavelength emitted from the measurement sample 210 . have.
Here, the observation light emitted from the measurement sample 210 is light having a longer wavelength than the excitation light wavelength, and can be visible light with a wavelength of 450 nm to 500 nm, for example.

Since the LED light source 112 emits light with a relatively broad spectrum, it emits not only the excitation light wavelength but also the light having the same wavelength as the observation light wavelength emitted from the measurement sample, albeit weakly. The first filter section 115 can block light having the same wavelength as the observation light wavelength contained in the light emitted from the LED light source 112 .
In addition, the first filter unit 115 can also block secondary emission (autofluorescence) light that may be generated by the UV light emitted from the LED light source 112 . Here, the secondary light emission (autofluorescence) is light that has a wavelength equivalent to the observation light wavelength and can become noise light in optical measurement. For example, even if autofluorescence occurs when the UV light emitted from the LED light source 112 passes through the condensing unit 114 or the like, the first filter unit 115 appropriately blocks the autofluorescence. can be done.

The first light guiding unit 114 is arranged between the light emitting side of the light collecting unit 113 and the sample case 200 in which the measurement sample 210 is accommodated. In this embodiment, the first light guide unit 114 is arranged between the light exit side of the first filter section 115 and the sample case 200 .
A first light guide path 114 a provided in the first light guide unit 114 is a light guide path for guiding excitation light emitted from the LED light source 112 to the sample case 200 . The first light guide path 114 a is made of resin (for example, silicone resin) transparent to excitation light emitted from the LED light source 112 and transmitted through the first filter section 115 .

Also, the first light shielding member 114b surrounding the first light guide path 114a is made of pigment-containing resin. The pigment-containing resin is obtained by adding a pigment having a property of absorbing stray light to a resin having a light transmission property (for example, a silicone resin). For example, carbon black, which is a black pigment, can be used as the pigment.
Here, it is preferable that the material of the transparent resin constituting the first light guide path 114a and the material of the resin containing the pigment-containing resin be the same. With this configuration, both resins have the same refractive index, so reflection and scattering at the interface between the two resins is suppressed. The stray light incident on the pigment-containing resin is absorbed by the pigment-containing resin and hardly returns to the first light guide path 114a, so that complicated multiple reflection of stray light hardly occurs.

As shown in FIG. 2, of the noise light L11 such as external light entering the first light guide path 114a, the component traveling in the same direction as the optical axis of the first light guide path 114a is very small, and most of it is The light enters the pigment-containing resin from the interface between the first light guide path 114a and the first light shielding member 114b made of the pigment-containing resin, and is absorbed by the pigment. At this time, reflection at the interface does not occur by using the same material for the transparent resin forming the first light guide path 114a and the pigment-containing resin forming the first light blocking member 114b.
The external light incident on the pigment and its scattered light are mostly absorbed by the pigment, but are slightly scattered on the surface of the pigment. However, the scattered light often re-enters the first light shielding member 114b made of pigment-containing resin and is absorbed by the pigment of the pigment-containing resin.
Therefore, as shown in FIG. 2, most of the light extracted from the first light guide path 114a becomes straight light L1 along the optical axis of the first light guide path 114a.

Here, the first light guide path 114a can also be configured as a cavity provided in the first light shielding member 114b made of pigment-containing resin. In this case, reflection and scattering occur at the interface between the first light guide path 114a made of a cavity and the first light shielding member 114b, and a part of the reflected light and scattered light travels through the first light guide path 114a as noise light. Emitted from the output end. However, the amount of noise light emitted from the output end is very small, and even in this case, most of the light extracted from the first light guide path 114a is light traveling straight along the optical axis of the first light guide path 114a. becomes.

According to the light source unit 110 of this embodiment, straight light can be extracted from the LED light source 112 that emits diffused light and the measurement sample 210 can be appropriately irradiated with the light without using a complicated collimating optical system. The light source unit 110 has an excitation light wavelength to irradiate the measurement sample 210, and extracts light from which at least the light having the same wavelength as the observation light wavelength emitted from the measurement sample 210 is cut as straight traveling light. 210 can be irradiated.

(Sample case holding housing)
The sample case holding housing 130 holds the sample case 200 containing the measurement sample 210 . Here, the sample case 200 is a container for accommodating the measurement sample 210 inside, and is made of a light transmissive material through which the excitation light that excites the measurement sample 210 and the observation light emitted from the measurement sample 210 are transmitted. Configured. The sample case 200 is preferably made of a material that generates little autofluorescence due to UV light, such as quartz glass or high-purity transparent silicone.
The sample case holding housing 130 is connected to the first housing 111 of the light source unit 110 and the second housing 121 of the light receiving unit 120, which will be described later. The sample case holding housing 130 has a first opening 131 through which the excitation light emitted from the light source unit 110 passes and reaches the sample case 200, and an opening 131 through which the observation light emitted from the sample case 200 passes. and a second opening 132 for reaching a second light guide path 123a of the light receiving unit 120, which will be described later.

(Light receiving unit)
The light receiving unit 120 is arranged in the second housing 121 and measures observation light emitted from the measurement sample 210 irradiated with the excitation light. The light receiving unit 120 includes a light receiving sensor 122 , a second light guide unit 123 and a second filter section 124 . The second light guide unit 123 includes a second light guide path 123a and a second light shielding member 123b surrounding the second light guide path 123a.
The second housing 121 includes the light receiving sensor 122, the second light guide unit 123 and the second filter section 124. As shown in FIG.

The light receiving sensor 122 is an optical sensor that measures the degree of fluorescence emitted from the measurement sample 210 .
A second light guiding unit 123 is provided on the side of the light receiving unit 120 facing the sample case 200 . The second light guide unit 123 has the same configuration as the first light guide unit 114 included in the light source unit 110 . A second light guide path 123 a provided in the second light guide unit 123 is a light guide path for guiding observation light emitted from the measurement sample 210 housed in the sample case 200 to the light receiving sensor 122 . The second light guide path 123a is made of resin (for example, silicone resin) transparent to the observation light emitted from the measurement sample 210 . A second light shielding member 123b surrounding the second light guide path 123a is made of pigment-containing resin, like the first light shielding member 114b.

Here, it is preferable to use the same materials for the transparent resin that constitutes the second light guide path 123a and the resin that contains the pigment-containing resin.
Thus, the second light guide unit 123 has the same configuration as the first light guide unit 114 described above, and has the same function as the first light guide unit 114 . That is, most of the light extracted from the second light guide path 123a becomes straight light along the optical axis of the second light guide path 123a.

The second filter section 124 can be arranged on the light incident side of the light receiving sensor 122 . In this embodiment, the second filter section 124 can be arranged on the light exit side of the second light guiding unit 123 . The second filter section 124 has a function of transmitting light of the observation light wavelength emitted from the measurement sample 210 and cutting (blocking) transmission of light of at least the same wavelength as the excitation light wavelength emitted from the light source unit 110 . have.

In FIG. 1, the first filter section 115 and the second filter section 124 can be configured by interference filter members. The interference filter member may be composed of a bandpass filter, or may be composed of a combination of a highpass filter and a lowpass filter.
For example, the second filter section 124 can be configured as a bandpass filter that transmits only the wavelength region of the observation light. The second filter unit 124 includes a first interference filter member configured as a high-pass filter that transmits light on the longer wavelength side than the shorter wavelength side of the observation light wavelength region, and a long wavelength region of the observation light. It may be configured in combination with a second interference filter member configured as a low-pass filter that transmits light on the shorter wavelength side than on the wavelength side. Here, as described above, the light emitted from the second light guide unit 123 is substantially straight light. Therefore, the second filter section 124 configured by an interference filter member having incident angle dependency can efficiently perform a wavelength selection function.
Also, the interference filter that constitutes the first filter section 115 can be made of quartz glass. As a result, autofluorescence generated when UV light passes through the interference filter can be suppressed, and an effect of suppressing noise light can be obtained.

In FIG. 1, the first housing 111, the second housing 121 and the sample case holding housing 130 can be made of aluminum, for example. Since the LED light source 112 generates a large amount of heat, a heat sink function can be provided by configuring each housing with aluminum. Further, if each housing is made of resin or the like, UV light emitted from the LED light source 112 may cause UV deterioration. The UV deterioration can be suppressed by configuring each housing with aluminum. In addition, it is possible to suppress the generation of self-fluorescence due to UV light in each housing.
As described above, from the viewpoint of heat dissipation and UV resistance, each housing is preferably made of aluminum. The material forming each housing may be an aluminum alloy such as duralumin. However, the material forming each housing is not limited to the above. For example, a separate heat sink may be provided to ensure heat dissipation.
Furthermore, in this embodiment, each housing is described as a separate body, but each housing may be integrally formed.

(Arrangement of light source unit and light receiving unit)
As shown in FIG. 1, the light source unit 110 and the light receiving unit 120 are arranged such that a first optical axis (optical axis of the first light guide path 114a) 116 of the light source unit 110 and a second optical axis of the light receiving unit 120 ( and the optical axis 125 of the second light guide path 123a are arranged to form a predetermined angle θ. That is, the first optical axis 116 and the second optical axis 125 are not parallel.
This predetermined angle θ is an angle set so that straight light emitted from the light source unit 110 along the first optical axis 116 does not enter the second light guide path 123a of the light receiving unit 120. For example, it can be 170 degrees or less (135 degrees in FIG. 1).
Also, the predetermined angle θ is preferably 90 degrees or more. If the angle θ becomes narrower than 90 degrees, the first light guide unit 114 and the second light guide unit 123 interfere with each other. In order to avoid the interference, the distance between the first light guide unit 114 and the sample case 200 and the distance between the second light guide unit 123 and the sample case 200 must be long. become longer. Therefore, the size of the apparatus is increased.
Therefore, the predetermined angle θ is preferably 90 degrees or more and 170 degrees or less.

The light emitted from the light source unit 110 has a relatively high light intensity, but is straight light as described above. Therefore, by arranging the light source unit 110 and the light receiving unit 120 so that the angle formed by the first optical axis 116 and the second optical axis 125 is the above angle θ, it is possible to easily move straight from the light source unit 110 . It is possible to significantly reduce the incidence of light entering the second light guide path 123 a of the light receiving unit 120 .
That is, the light passing through the second light guide path 123 a of the light receiving unit 120 is almost the observation light emitted from the measurement sample 210 . Therefore, it is possible to perform highly accurate fluorescence measurement.

In order to arrange the light source unit 110 and the light receiving unit 120 as described above, the first housing 111 of the light source unit 110, the second housing 121 of the light receiving unit 120, and the sample case holding housing 130 are arranged as follows. is configured as
As shown in FIG. 1, the surface of the first housing 111 on the light output side forms a plane, and the plane on the light output side of the first light guide unit 114 is included in the plane. The surface of the second housing 121 on the light incident side also forms a plane, and the plane on the light incident side of the second light guide unit 123 is included in this plane.
The sample case holding housing 130 is formed with a first opening 131, a light incident plane 133 on which light (excitation light) emitted from the light source unit 110 is incident, and a second opening 132. , and a light exit plane 134 through which light (observation light) emitted from the measurement sample 210 is emitted. Here, the angle between the light incident side plane 133 and the light emitting side plane 134 of the sample case holding housing 130 is (180−θ) degrees.

Then, the light incident side plane 133 of the sample case holding housing 130 and the light emitting side plane of the light source unit 110 are brought into contact with each other, and the light emitting side plane 134 of the sample case holding housing 130 and the light incident side of the light source unit 120 are brought into contact with each other. Each housing is placed in contact with the plane. As a result, the first optical axis 116 and the second optical axis 125 form a predetermined angle θ, and the two optical axes are not parallel.

Note that the first opening 131 of the sample case holding housing 130 is arranged so that the light incident side plane 133 of the sample case holding housing 130 and the light emitting side plane of the light source unit 110 are in contact with each other. It is provided at a position where the optical axis of first opening 131 of holding housing 130 and first optical axis 116 substantially coincide. Similarly, when the second opening 132 of the sample case holding housing 130 is arranged such that the light emitting side plane 134 of the sample case holding housing 130 and the light incident side plane of the light receiving unit 120 are in contact with each other, the sample It is provided at a position where the optical axis of the second opening 132 of the case holding housing 130 and the second optical axis 125 substantially coincide.

In addition, the sample case holding housing 130 receives the excitation light emitted from the light source unit 110 onto the optical axis 116 of the light source unit 110, traveling straight along the first optical axis 116, and passing through the sample case 200. An optical damper section 135 may be provided. The light damper section 135 has a light damper section space into which light is incident, and the surfaces forming the light damper section space are configured to multiple-reflect and attenuate the incident light.
Specifically, the inner surface of the light damper section 135 is made into a scattering surface composed of a plurality of reflecting surfaces that scatter incident light, and the scattering surface is blackened by, for example, black alumite treatment, so that the scattered light is gradually attenuated. Here, there should be no plane perpendicular to the traveling direction of the excitation light traveling straight from the light source unit 110 in the planes forming the light damper section space. By configuring in this way, it is possible to prevent the regular reflection component of the incident light from returning to the sample case 200 .
By providing the light damper section 135 in the sample case holding housing 130, straight light emitted from the light source unit 110 and transmitted through the sample case 200 becomes stray light and enters the second light guide path 123a of the light receiving unit 120. It is possible to suppress

A configuration example of a conventional optical measuring instrument (LIF device) will be described below with reference to FIG.
The LIF apparatus 1000 shown in FIG. 4 includes a laser light source 1103, a sample case 1105 for holding a measurement sample, a fluorescence collecting optical system 1107 including lenses, optical filters, and the like, and a fluorometer 1109 such as a photomultiplier tube.
The LIF apparatus 1000 employs an optical system with an SOT structure, and is at least partially filled with a transparent resin 1113 such as PDMS for observation light (fluorescence) emitted from a measurement sample held in a sample case 1105 . and a pigment-containing resin 1111 surrounding the light guide. The sample case 1105 and fluorescence collection optical system 1107 are embedded in transparent resin 1113 .

A fluorescence collecting optical system 1107 in the above optical system guides observation light emitted from a measurement sample to a fluorometer (optical sensor) 1109 .
The fluorescence collection optics 1107 has notch filters (1119, 1121), a first lens 1115, colored glass filters (1123, 1125, 1127), and a second lens 1117.
Here, the notch filter reduces noise light such as stray light of the excitation light, autofluorescence from the sample case 1105, and Raman light emitted when the excitation light passes through the transparent resin 1113, and transmits observation light. placed in In particular, the noise light other than the observation light is turned into parallel light (incidence angle 0°) by the first lens 1115 and is effectively attenuated by the notch filter 1121 . The colored glass filter is arranged to absorb the noise light that has slightly passed through the notch filter 1121 and to pass the observation light.
Moreover, the resin 1111 substantially uniformly contains a pigment having a wavelength characteristic of absorbing the noise light.
Note that the notch filter 1119 can be omitted depending on the intensity of the noise light. Also, the number of colored glass filters may be one.

When the present inventors adopted a UV-LED instead of the laser light source 1103 shown in FIG. 4 and prototyped an optical measuring instrument (light-induced fluorescence measuring instrument) equivalent to that shown in FIG. 4, the following effects occurred. There was found.
According to the configuration shown in FIG. 4, the optical path until the sample case 1105 is irradiated with the UV light emitted from the light source (UV-LED) is filled with a transparent resin. The present inventors adopted PDMS as a transparent resin, and attempted to pass UV light emitted from UV-LEDs through PDMS manufactured by a plurality of resin manufacturers. As a result, in the case of PDMS manufactured by a certain manufacturer, secondary luminescence (autofluorescence) was significantly observed from PDMS.

Unlike the light emitted from UV-LD, the light emitted from UV-LED is diffuse light and thus travels a relatively wide area of the PDMS optical path. Therefore, the emission region of this secondary light emission is wide and the intensity is relatively high.
Autofluorescence generated by this UV light enters the notch filter 1119 as stray light. However, since the wavelength of this autofluorescence overlaps with the wavelength of the observation light (fluorescence) emitted from the measurement sample, the notch filter 1119 and the subsequent colored glass filter or the like cannot cut off the autofluorescence. Therefore, the autofluorescence reaches the fluorometer 1109 as noise light and adversely affects the measurement result.

On the other hand, the light source unit 110 of the optical measuring instrument 100 in this embodiment includes a light collecting unit 113 that collects the light emitted from the LED light source 112 and the light collected by the light collecting unit 113 to the measurement sample. a first light guiding unit 114 for guiding light to 210;
In this manner, the diffused light emitted from the LED light source 112 is condensed and guided to the measurement sample 210, so the optical path along which the UV light travels can be narrowed. Therefore, it is possible to suppress the UV light emitted from the LED light source 112 from being irradiated in a wide range, and to suppress secondary light emission (autofluorescence) due to the UV light.
Here, the condensing unit 113 can have a configuration in which a hemispherical lens 113a and a ball lens 113b are arranged in order from the light incident side. In this case, the emitted light from the LED light source 112, which is diffused light, can be appropriately collected. Further, each lens constituting the light collecting unit 113 can be a quartz lens. In this case, self-fluorescence generated when the UV light emitted from the LED light source 112 travels through the condensing unit 113 can be suppressed, and an effect of suppressing noise light can be obtained.

In addition, the optical measuring instrument 100 is arranged such that the first optical axis 116 of the light source unit 110 and the second optical axis 125 of the light receiving unit 120 form a predetermined angle θ and are not parallel to each other. It has a configuration in which a unit 110 and a light receiving unit 120 are arranged. Therefore, the excitation light emitted from the light source unit 110 can be prevented from being directly incident on the light receiving unit 120, and the influence of the excitation light on the optical measurement can be suppressed.
In this way, it is possible to suppress the influence of the UV light emitted from the LED light source and the secondary light emitted by the UV light from becoming noise light and affecting the light measurement, enabling highly sensitive light measurement. becomes.

When a laser light source is used as the light source of the optical measuring instrument, it is better to measure the observation light from the direction of travel of the laser beam from the side (90 degrees direction) so that the observation light emission region can be effectively viewed from the optical axis direction. Therefore, the intensity of the observation light is high and the measurement sensitivity is high. That is, as shown in FIG. 4, the light guide path for guiding the observation light (fluorescence) from the measurement sample is preferably arranged at 90 degrees with respect to the light path from the light source to the sample case.
On the other hand, the optical measuring instrument 100 in this embodiment uses an LED light source as the light source. Since the LED light source emits diffused light, even if the light emitted from the LED light source is condensed and irradiated onto the sample case, the entire sample case is irradiated with the light, and the intensity of fluorescence emitted from the measurement sample is Equivalent when measured from any direction of the case.
Therefore, the second light guide path 123a, which guides the observation light (fluorescence) from the measurement sample, should be arranged at 90 degrees to the first light guide path 114a, which guides the excitation light from the light source to the sample case. Even if the angle θ between the first optical axis 116 and the second optical axis 125 is not 90 degrees, highly sensitive optical measurement is possible.

The light source unit 110 of the optical measuring instrument 100 further includes a first filter section 115 that blocks at least the same wavelength component as the wavelength of the observation light from the light emitted from the LED light source 112 and transmits the excitation light. be prepared.
By arranging the first filter unit 115, even when a light source with a wide spectrum width such as an LED is used, it is possible to appropriately extract light of a desired excitation light wavelength and irradiate the measurement sample 210. can. Moreover, even if autofluorescence having the same wavelength as the observation light wavelength is generated by the UV light in the optical path through which the UV light emitted from the LED light source 112 passes, the autofluorescence can be blocked. Further, by using an interference filter made of quartz glass as the first filter section 115 , it is possible to suppress self-fluorescence generated when UV light passes through the first filter section 115 .
Therefore, it is possible to suppress the influence of noise light and improve the light measurement accuracy.

Further, the light-receiving unit 120 of the optical measuring instrument 100 blocks at least the wavelength component of the light emitted from the measurement sample 210 housed in the sample case 200, and transmits the observation light. Two filter sections 124 may further be provided.
By arranging the second filter section 124, even if the UV light emitted from the LED light source 112 enters the light receiving unit 120 as stray light, the stray light is prevented from reaching the light receiving sensor 122. can be suppressed. Moreover, since the UV light incident on the light receiving unit 120 can be cut, it is possible to suppress the generation of self-fluorescence due to the UV light within the light receiving unit 120 .

Also, the optical measuring instrument 100 can have an optical path of an SOT structure. That is, the first light guide path 114a of the first light guide unit 114 is made of a resin transparent to excitation light, the first light shielding member 114b contains a pigment that is a light absorbing material, and the first A pigment-containing resin made of the same material as the transparent resin forming the light guide path 114a can be used. Further, the second light guide path 123a of the second light guide unit 123 is made of a resin transparent to observation light, the second light shielding member 123b contains a pigment that is a light absorbing material, and the second A pigment-containing resin made of the same material as the transparent resin forming the light guide path 123a can be used.
In this way, by having the optical path of the SOT structure, it is possible to suppress stray light such as reflected light and scattered light emitted from the LED light source 112 from entering the light receiving sensor 122 with a simple configuration. In other words, compact and highly sensitive light measurement is possible.

Here, the first light guide path 114a of the first light guide unit 114 can also be hollow. When the first light guide path 114a is filled with a silicone resin, if the silicone resin is not, for example, high-purity transparent silicone, there is a risk that significant autofluorescence will occur. By making the first light guide path 114a hollow, it is possible to suppress the generation of self-fluorescence in the first light guide path 114a.

In addition, the optical measuring instrument 100 may further include an optical damper section 135 on the optical axis of the light source unit 110 into which the excitation light emitted from the light source unit 110 and transmitted through the sample case 200 is incident. Here, the optical damper unit 135 may have a space for multiple reflection of incident excitation light between a plurality of reflecting surfaces to attenuate the excitation light.
Thereby, the UV light transmitted through the sample case 200 can be appropriately attenuated, and the UV light can be prevented from becoming stray light and entering the light receiving unit 120 .

Furthermore, the sample case 200 can be made of quartz glass or high-purity transparent silicone. Thereby, it is possible to suppress the generation of autofluorescence when the UV light passes through the sample case 200 .
In this way, at least part of the optical path (the light collecting unit 113, the first light guide path 114a, the first filter section 115, the sample case 200) through which the light emitted from the LED light source 112 passes is composed of quartz glass and high It can be composed of at least one of pure transparent silicone. Further, the housing (the first housing 111, the second housing 121, the sample case holding housing 130) containing the optical path can be made of aluminum or an aluminum alloy. As a result, secondary light emission (autofluorescence) due to UV light in the optical path or the like can be appropriately suppressed.

As described above, the optical measuring instrument 100 according to the present embodiment can appropriately irradiate the measurement sample 200 with UV light, which is the excitation light, and appropriately measure only the fluorescence caused thereby by the light receiving sensor 122. . As described above, the optical measuring instrument 100 according to the present embodiment uses a UV-LED light source that emits diffused light, and even when secondary light emission (noise light) can occur remarkably in the optical path or the like, noise light can be generated. It is possible to appropriately suppress the influence and provide a compact optical measuring instrument capable of high-sensitivity measurement.

(Modification)
In the above embodiment, the first filter section 115 is arranged on the light incident side of the first light guide unit 114, but as shown in FIG. may be arranged on the light exit side of the light guiding unit 114 .
When first light guide path 114a is filled with silicone resin, if the silicone resin is not high-purity transparent silicone, excitation light (UV light) passing through first light guide path 114a may cause self-fluorescence. be. By arranging the first filter section 115 on the light emitting side of the first light guide unit 114, even if autofluorescence is generated in the first light guide path 114a, it can be blocked appropriately. , the influence of noise light on optical measurement can be suppressed. In other words, if the first filter section 115 is arranged on the light emitting side of the first light guide unit 114, the resin filling the first light guide path 114a can be high-purity transparent silicone for suppressing self-fluorescence. You don't have to, and you can save costs.

Further, in the above embodiment, the case where the second filter section 124 is arranged on the light emitting side of the second light guide unit 123 has been described, but as shown in FIG. It may be arranged on the light incident side of the second light guiding unit 123 .
By arranging the second filter section 124 on the light incident side of the second light guide unit 123 , UV light can be blocked on the light incident side of the second light guide unit 123 . Therefore, in the optical path to the light receiving sensor 122 including the second light guide path 123a after the second filter section 124, it is possible to suppress the generation of autofluorescence due to UV light. Thus, an effect of suppressing noise light is obtained.

Furthermore, in the above embodiment, the angle θ between the first optical axis 116 and the second optical axis 125 can theoretically be 180 degrees.
In this case, the UV light emitted from the light source unit 110 passes through the sample case 200 and directly enters the light receiving unit 120 . Therefore, it is not necessary to provide the optical damper section 135 in this case. However, before the UV light reaches the light receiving sensor 122, it is necessary to cut the UV light to the extent that it does not affect the light measurement result. Is required. In addition, since the interference filter has an incident angle dependency, UV light whose incident angle is not 0 degrees cannot be blocked appropriately, and enters the light receiving sensor 122 as noise light. Therefore, it is necessary to take measures such as separately providing a collimating optical system for making the UV light perpendicularly incident on the interference filter at an incident angle of 0 degree.
Therefore, for example, in the case of an optical measuring instrument that performs highly sensitive measurements in which even UV light of several μW affects the light measurement result, the angle θ It is preferable to set the angle at which the received UV light does not enter the light receiving unit 120 .

Further, in the above embodiments, the light-induced fluorescence measuring device was described as an optical measuring device, but the present invention can also be applied to a turbidity measuring device that measures the turbidity of a measurement sample. In this case, the turbidimeter irradiates a measurement sample with UV light emitted from a UV-LED light source, and measures scattered light (UV light) emitted from the measurement sample irradiated with UV light. That is, the observation light becomes scattered light emitted from the measurement sample. In this case, the first filter section 115 and the second filter section 124 shown in FIG. 1 are unnecessary.

DESCRIPTION OF SYMBOLS 100... Optical measuring instrument, 110... Light source unit, 111... 1st housing|casing, 112... LED light source, 113... Light collection unit, 114... Light guide unit, 115... 1st filter part, 116... 1st light Axes 120 Light receiving unit 121 Second housing 122 Light receiving sensor 123 Light guiding unit 124 Second filter 125 Second optical axis 130 Sample case holding housing 135 ... optical damper part, 200 ... sample case, 210 ... measurement sample

Claims (12)

a housing;
a light source unit arranged in the housing for irradiating excitation light onto the measurement sample housed in the sample case;
a light receiving unit that is arranged in the housing and measures observation light emitted from the measurement sample irradiated with the excitation light;
The light source unit
an LED light source that emits ultraviolet light as the excitation light;
a light collecting unit for collecting light emitted from the LED light source;
a first light guide unit having a first light guide path for guiding the light condensed by the light condensing unit to the measurement sample and a first light shielding member surrounding the first light guide path; ,
The light receiving unit is
a light receiving sensor that measures the observation light;
a second light guide unit having a second light guide path for guiding light emitted from the measurement sample to the light receiving sensor and a second light shielding member surrounding the second light guide path;
An optical measuring instrument, wherein the optical axis of the light source unit and the optical axis of the light receiving unit form a predetermined angle and are not parallel to each other. The excitation light and the observation light have different wavelengths,
The light source unit
2. The apparatus according to claim 1, further comprising a first filter section that blocks at least a wavelength component of the light emitted from the LED light source that is the same as the wavelength of the observation light and that transmits the excitation light. optical measuring instrument. The first filter unit is
3. The optical measuring instrument according to claim 2, arranged on the light exit side of said first light guide unit. The excitation light and the observation light have different wavelengths,
The light receiving unit is
4. The apparatus further comprises a second filter section for blocking at least the same wavelength component as the excitation light in the light emitted from the measurement sample and for transmitting the observation light. The optical measuring instrument according to any one of . The second filter section is
5. An optical measuring instrument according to claim 4, arranged on the light incident side of said second light guiding unit. 6. The predetermined angle according to any one of claims 1 to 5, wherein the predetermined angle is an angle at which excitation light emitted from the light source unit does not enter the second light guide path of the light receiving unit. Optical measuring instrument. 7. The optical measuring instrument according to claim 6, wherein the predetermined angle is 90 degrees or more and 170 degrees or less. the second light guide path is made of a resin transparent to the observation light,
8. The second light shielding member is a pigment-containing resin containing a pigment, which is a light-absorbing material, and made of the same material as the transparent resin. The optical measuring instrument described in . the first light guide path is hollow,
9. The optical measuring instrument according to any one of claims 1 to 8, wherein the first light shielding member is a pigment-containing resin made of a resin containing a pigment, which is a light-absorbing material. 10. The optical measuring instrument according to any one of claims 1 to 9, wherein the condensing unit comprises a hemispherical lens and a ball lens arranged in order from the light incident side. further comprising a light damper unit on the optical axis of the light source unit, into which the excitation light emitted from the light source unit and transmitted through the sample case is incident;
11. The optical measuring instrument according to any one of claims 1 to 10, wherein the optical damper section has a space that multiple-reflects and attenuates the incident excitation light between a plurality of reflecting surfaces. . 12. The method according to any one of claims 1 to 11, wherein at least part of an optical path through which light emitted from said LED light source passes is made of at least one of quartz glass and high-purity transparent silicone. optical measuring instrument.

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