Irradiation apparatus and optical measurement apparatus

Abstract

To provide an illumination optical system, an illumination device, and an optical measuring device capable of casting more uniform light.SOLUTION: An illumination optical system C1 includes: a light source 101 including a surface light emitting element 102 for emitting irradiation light L1 from a light emission surface 102s and a lens part 103b for increasing directivity of the irradiation light L1 emitted from the surface light emitting element 102; a light shaping member 120 for applying the irradiation light L1 emitted from the light source 101 from a light incidence surface 121, shaping the incident irradiation light L1 by a slit 120s and emitting it; and a first lens 111 for forming an image of the slit 120s of the light shaping member 120. Distance H between the light emission surface 102s of the surface light emitting element 102 and the light incidence surface 121 of the light shaping member 120 is equal to or less than 26 times larger than magnitude in one direction of the light emission surface 102s.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an irradiation optical system, an irradiation device, and an optical measurement device.

Background Art

[0002] Patent Documents 1 and 2 describe optical units used in a sample concentration measurement device. These optical units include a semiconductor laser serving as a light source, a collimating lens that converts the beam emitted from the semiconductor laser into a parallel beam, a cylindrical lens that receives the beam that has passed through the collimating lens through an aperture and a beam splitter and guides the beam to an immunochromatography test strip, and an optical bench that houses these components.

[0003] In these sample concentration measurement devices, the beam emitted from the semiconductor laser is made into a parallel beam through the collimating lens. This parallel beam is incident on a polarization beam splitter through an aperture. The beam that has passed through the polarization beam splitter is incident on the cylindrical lens, and the cylindrical lens forms an image only in the length direction of the immunochromatography test strip and irradiates the immunochromatography test strip.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above-described sample concentration measuring apparatus, the beam emitted from the semiconductor laser is made elliptical by a cylindrical lens or rectangular using an aperture, and is irradiated onto an immunochromatography test strip to which a sample is added, thereby reducing the influence of uneven coloring in the width direction on the immunochromatography test strip. However, in the optical units described in Patent Documents 1 and 2, although making the beam elliptical or rectangular is mentioned, there is no mention of the uniformization of the illuminance distribution within the irradiation surface of the elliptical or rectangular beam, nor is there a configuration therefor. Therefore, in the sample concentration measuring apparatuses described in Patent Documents 1 and 2, it is difficult to achieve uniform light irradiation on the immunochromatography test strip.

[0006] An object of the present invention is to provide an irradiation optical system, an irradiation apparatus, and an optical measurement apparatus that enable more uniform light irradiation.

Means for Solving the Problems

[0007] The irradiation optical system according to the present invention is an irradiation optical system for irradiating an object with first light, and includes a light source including a surface-emitting element that emits the first light from a light emission surface, and a lens unit for enhancing the directivity of the first light emitted from the surface-emitting element, a light shaping member that receives the first light emitted from the light source from a light incident surface and shapes and emits the incident first light through a light passage hole, and a first lens for forming an image of the first light emitted from the light shaping member on the object. The distance between the light emission surface of the surface-emitting element and the light incident surface of the light shaping member is 26 times or less the size in one direction of the light emission surface.

[0008] In this irradiation optical system, the first light emitted from the light source is shaped by the light shaping member and then irradiated onto the object through the first lens. The light source includes a surface light emitting element and a lens unit for enhancing the directivity of the first light emitted from the surface light emitting element. And the distance between the light emitting surface of the surface light emitting element and the light incident surface of the light shaping member is 26 times or less the size of the light emitting surface of the surface light emitting element in one direction. According to the findings of the present inventor, in the surface light emitting element used in combination with the lens unit for enhancing the directivity in this way, within a distance range close to within 26 times the size of its light emitting surface, a relatively high light quantity and a uniform illuminance distribution can be obtained. Therefore, by forming an image of the first light on the incident surface of the light shaping member arranged within the above distance range on the object with the first lens, more uniform light irradiation of the object becomes possible. Note that the size of the light emitting surface of the surface light emitting element in one direction is, for example, when the light emitting surface of the surface light emitting element has a longitudinal direction, the size in the longitudinal direction.

[0009] The irradiation optical system according to the present invention may include a second lens disposed between the light source and the first lens for correcting the aberration generated in the first lens. In this case, more uniform light irradiation becomes possible.

[0010] In the irradiation optical system according to the present invention, the second lens is disposed between the light source and the light shaping member or between the light shaping member and the first lens, and may have a function of enhancing the directivity of the first light emitted from the light source. In this case, the loss due to the diffusion of the first light is reduced.

[0011] In the irradiation optical system according to the present invention, the second lens may be fixed to the light shaping member. In this case, a mechanism for separately holding the second lens becomes unnecessary.

[0012] In the irradiation optical system according to the present invention, the light source may include a light transmissive light transmitting portion that seals the surface light emitting element, and the lens unit may be formed on the light transmitting portion and integrated with the surface light emitting element. In this case, handling and positioning of the surface light emitting element and the lens unit become easy.

[0013] The irradiation optical system according to the present invention may be provided between a light source and a first lens, and may include a first wavelength selection filter for selectively transmitting a part of the wavelength components of the first light toward the first lens. In this case, it becomes possible to selectively irradiate an object with a part of the wavelength components of the first light.

[0014] The irradiation device according to the present invention includes the above-described irradiation optical system and a housing that houses the irradiation optical system. The housing includes a first space portion in which an optical path of the first light is formed, and a first inner wall surface that defines the first space portion. According to this irradiation device, it is possible to achieve the same effect as that of the above-described irradiation optical system. Further, according to this irradiation device, since the above-described irradiation optical system is housed in the housing, its handling becomes easy.

[0015] In the irradiation device according to the present invention, a first widened portion widened between the light shaping member and the first lens is formed in the first space portion, and the first inner wall surface may include a first intersecting surface that intersects the optical path of the first light and faces the light shaping member side in the first widened portion. In this case, light traveling obliquely at an angle of a certain degree or more from the light shaping member toward the first lens is trapped by the first intersecting surface, thereby suppressing the generation of stray light.

[0016] The irradiation device according to the present invention may include a first photodetector that is installed on the first inner wall surface so as to face the optical path of the first light, and detects a part of the first light that is emitted from the light source and diffused, thereby detecting the light amount of the first light emitted from the light source. In this case, it becomes possible to monitor the light amount of the first light.

[0017] The irradiation device according to the present invention may include a drive circuit for driving the surface light emitting element so that the light amount becomes constant while inputting a detection signal indicating the light amount of the first light from the first photodetector. In this case, it becomes possible to irradiate light with a stable light amount.

[0018] In the irradiation device according to the present invention, the housing may be made of a material having absorbency with respect to the first light. Alternatively, in the irradiation device according to the present invention, the housing may be made of a material that does not generate autofluorescence by the first light. In these cases, the generation of stray light is more reliably suppressed.

[0019] The optical measurement device according to the present invention includes the above-described irradiation device and a detection optical system for detecting the second light from the object irradiated with the first light. The housing further houses the detection optical system and includes a second space portion in which the optical path of the second light is formed and a second inner wall surface that defines the second space portion. The detection optical system includes a second photodetector for detecting the second light and a third lens for condensing the second light toward the second photodetector. According to this optical measurement device, stable measurement of the object is possible by detecting the second light from the object that has received uniform light irradiation by the above-described irradiation optical system and irradiation device.

[0020] The optical measurement device according to the present invention may include a second wavelength selection filter provided between the third lens and the second photodetector for selectively transmitting a part of the wavelength components of the second light toward the second photodetector. In this case, it is possible to selectively detect a part of the wavelength components of the second light.

[0021] In the optical measurement device according to the present invention, a second widened portion widened between the third lens and the second wavelength selection filter is formed in the second space portion, and the second inner wall surface may include a second intersection surface that intersects the optical path of the second light and faces the third lens side in the second widened portion. In this case, the light traveling obliquely at an angle of a certain degree or more from the third lens toward the second wavelength selection filter is trapped by the second intersection surface, thereby restricting the range of the incident angle of the second light incident on the second wavelength selection filter. As a result, the influence of the incident angle dependency of the characteristics of the second wavelength selection filter is reduced, and high-precision measurement is possible.

[0022] In the optical measurement device according to the present invention, the second wavelength selection filter may include a dielectric multilayer film filter and a color glass filter disposed on the second photodetector side with respect to the dielectric multilayer film filter. In this case, the incident angle dependence of the characteristics of the second wavelength selection filter is reduced.

[0023] The optical measurement device according to the present invention includes a current-voltage converter for converting a current signal output from a second photodetector in response to detection of second light into a voltage signal, and the second photodetector may be mounted on a substrate of the current-voltage converter. In this case, noise is reduced.

[0024] The optical measurement device according to the present invention may include a metal shield provided in a housing so as to cover at least the second photodetector and the current-voltage converter. In this case, noise is reduced.

[0025] In the optical measurement device according to the present invention, the first light may include excitation light for exciting an object, and the second light may include fluorescence emitted by the object in response to irradiation with the excitation light. In this case, stable fluorescence measurement becomes possible.

Advantages of the Invention

[0026] According to the present invention, it is possible to provide an irradiation optical system, an irradiation device, and an optical measurement device that enable more uniform light irradiation.

Brief Description of the Drawings

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0028] Hereinafter, an embodiment will be described in detail with reference to the drawings. In the description of each figure, the same or corresponding elements are denoted by the same reference numerals, and redundant descriptions may be omitted.

[0029] FIG. 1 is a schematic configuration diagram of an optical measurement apparatus according to the present embodiment. The optical measurement apparatus 1 shown in FIG. 1 is an apparatus that detects light generated from a sample in response to light irradiated on the sample. In the present embodiment, the optical measurement apparatus 1 will be described as a fluorescence measurement apparatus that detects fluorescence generated from a sample in response to excitation light irradiated on the sample. The excitation light is light that excites the sample, and the fluorescence is light emitted by the sample in response to the excitation light and having a wavelength different from that of the excitation light. Further, in the present embodiment, the optical measurement apparatus 1 will be described as an apparatus that detects fluorescence related to measurement using the immunochromatography method. The immunochromatography method is an immunoassay method using an antigen-antibody reaction, and is used, for example, for the detection of influenza virus.

[0030] Figure 2 is a diagram showing an example of the test piece and detection result shown in Figure 1. As shown in Figures 1 and 2, in the measurement using the immunochromatography method, an immunochromatography test piece 500 is prepared as a sample. The immunochromatography test piece 500 has, in a reagent holder 500A, a dropping portion 502 where a specimen is dropped, a holding portion 503 that holds a detection antibody labeled with a fluorescent reagent, and a measurement portion (object) 501 in which a capture antibody is fixed to a measurement target portion 504, which are arranged from upstream to downstream. The fluorescent reagent is, for example, europium.

[0031] When a specimen is dropped onto the dropping portion 502 of such an immunochromatography test piece 500, the specimen moves to the downstream side by capillary action. When there is a substance to be detected in the specimen, the detection antibody in the holding portion 503 reacts with the substance to be detected to form a complex, and this complex moves to the downstream side of the measurement portion 501. Then, when the complex reaches the measurement target portion 504 on the measurement portion 501, the complex is captured by the capture antibody in the measurement target portion 504, and a complex of the substance to be detected, the detection antibody, and the capture antibody is formed.

[0032] In this state, by irradiating excitation light while changing the condensing position (measurement position) with respect to the measurement portion 501, which is the measurement region, it is possible to derive the detection light intensity (fluorescent intensity) corresponding to the measurement position. The measurement position where the detection light intensity is larger than others corresponds to the measurement position corresponding to the position of the measurement target portion 504 where the complex is captured.

[0033] The measurement area in the immunochromatography method is on a line, and since fluorescent substances also float in places other than the line (background), if the illuminance distribution of the excitation light is non-uniform within the irradiation surface, stable measurement becomes difficult. Also, the amount of fluorescent substances present in the line itself varies depending on the position, and the distribution of the fluorescence emission may be non-uniform. In that case too, stable measurement becomes difficult. Therefore, for stable measurement, it is desirable to make the illuminance distribution of the excitation light more uniform.

[0034] In addition, the detection light detected by the detection optical system of the optical measurement device 1 may include not only fluorescence but also light caused by the excitation light itself. Such light includes, for example, scattered light of the excitation light. Such scattered light is, for example, a part of the excitation light generated when the excitation light irradiates the immunochromatographic test strip 500 and is scattered. When the immunochromatographic membrane or reagent holder 500A of the immunochromatographic test strip 500 is white, such scattered light is likely to occur. Furthermore, depending on the sample to be measured and the arrangement of the detection optical system, the excitation light itself may be detected. Therefore, it is also desired to suppress stray light other than the fluorescence of the detection target. [Configuration of Optical Measurement Device]

[0035] Subsequently, the configuration of the optical measurement device 1 will be described. FIG. 3 is a schematic side view showing the inside of a part of the optical measurement device shown in FIG. 1, and FIG. 4 is a schematic side view from another direction showing the inside of a part of the optical measurement device shown in FIG. 1. FIG. 5 is a side view showing the light source shown in FIGS. 3 and 4. As shown in FIGS. 1, 3 to 5, the optical measurement device 1 includes an optical head 10. The optical head 10 includes an irradiation optical system C1 and a detection optical system C2. The irradiation optical system C1 is for irradiating irradiation light (first light) L1 toward the immunochromatographic test strip 500. The irradiation light L1 includes excitation light for exciting the fluorescent reagent of the immunochromatographic test strip 500. The irradiation light L1 is, for example, ultraviolet light including a wavelength component of 340 nm. The detection optical system C2 is for detecting detection light (second light) L2 from the immunochromatographic test strip 500. The detection light L2 includes fluorescence from the fluorescent reagent of the immunochromatographic test strip 500.

[0036] First, the irradiation optical system C1 will be described. The irradiation optical system C1 includes a light source 101, a first lens 111, a second lens 112, a light shaping member 120, a first wavelength selection filter 125, and a first photodetector 140. The light source 101, the first lens 111, the second lens 112, the light shaping member 120, the first wavelength selection filter 125, and the first photodetector 140 are housed in and held by a housing 130, and together with the housing 130, they constitute an irradiation device 100.

[0037] The light source 101 includes a surface light emitting element 102 that includes a light emitting surface 102s and emits irradiation light L1 from the light emitting surface 102s, a lens portion 103b for enhancing the directivity of the irradiation light L1 emitted from the surface light emitting element 102, a reflector 104 on which the surface light emitting element 102 is installed and that reflects the irradiation light L1 emitted from the surface light emitting element 102 toward the lens portion 103b, and a sealing portion 103a that seals the surface light emitting element 102 and the reflector 104. The surface light emitting element 102 is, for example, an LED (Light Emitting Diode). The light emitting surface 102s is, for example, an area from which the irradiation light L1 is emitted on one end surface of the surface light emitting element 102 (in the illustrated example, the entire one end surface of the surface light emitting element 102).

[0038] The sealing portion 103a and the lens portion 103b are integrally formed of a light transmissive material having transmissivity with respect to the irradiation light L1, for example, a resin having light transmissivity, and constitute a resin portion (light transmissive portion) 103 that seals the surface light emitting element 102 and the reflector 104. In other words, the lens portion 103b is formed in the light transmissive resin portion 103 so as to be convex on the side opposite to the surface light emitting element 102 and is integrated with the surface light emitting element 102. Thereby, when the surface light emitting element 102 is an LED, the light source 101 is configured as a bullet type LED.

[0039] The light shaping member 120 includes a light incident surface 121 on which the irradiation light L1 emitted from the light source 101 is incident and a slit 120s that is a light passage hole, and shapes and emits the irradiation light L1 incident from the light incident surface 121 by the slit 120s. The slit 120s is open on the light incident surface 121. The shape of the slit 120s when viewed from the direction along the optical axis of the irradiation light L1 is a shape corresponding to the shape of the measurement target portion 504, and is, for example, a rectangular shape having a longitudinal direction.

[0040] The optical shaping member 120 is arranged such that its light incident surface 121 is at a distance H from the light emitting surface 102s of the surface light emitting element 102. The distance H between the light emitting surface 102s and the light incident surface 121 is 26 times or less the size d in one direction of the light emitting surface 102s. The size d in one direction of the light emitting surface 102s is, for example, the size of one side of a square when the light emitting surface 102s is square, or the size in the longitudinal direction when the light emitting surface 102s has a longitudinal direction. In the latter case, the distance H is also less than 26 times the size in the short side direction of the light emitting surface 102s. The size d is, for example, 0.5 mm.

[0041] The irradiation light L1 emitted from the optical shaping member 120 is incident on the first lens 111 via the slit 120s. The first lens 111 is, for example, a spherical lens that is convex on the side of the optical shaping member 120 and on the side opposite to the optical shaping member 120, and is arranged so as to form an image of the slit 120s, which is an image of the irradiation light L1 emitted from the optical shaping member, on the immunochromatographic test strip 500. The second lens 112 is arranged between the light source 101 and the first lens 111. Here, the second lens 112 is arranged between the light source 101 and the optical shaping member 120 and is fixed to the optical shaping member 120. The second lens 112 has at least a function of correcting the aberration (for example, spherical aberration) generated in the first lens 111. Here, the second lens 112 further has a function of enhancing the directivity of the irradiation light L1. The second lens 112 is, for example, a lens that is convex on the side of the light source 101.

[0042] The first wavelength selection filter 125 is provided between the light source 101 and the first lens 111, and is for selectively transmitting a part of the wavelength components of the irradiation light L1 toward the first lens 111. The first wavelength selection filter 125 is configured to selectively transmit, for example, the wavelength components (excitation light) that contribute to the excitation of the fluorescent reagent in the irradiation light L1. The first wavelength selection filter 125 may be configured, for example, by depositing a dielectric multilayer film filter that transmits only a specific wavelength band (the excitation wavelength of the fluorescent reagent) on the first lens 111.

[0043] The housing 130 includes a first spatial portion 131 in which the optical path of the irradiation light L1 is formed, and a first inner wall surface 132 that defines the first spatial portion 131. The housing 130 is solid except for the first spatial portion 131 and a second spatial portion 171 described later. In other words, in the housing 130, the first spatial portion 131 and the second spatial portion 171 are formed in the solid main body portion 130A. Each member of the irradiation optical system C1 is disposed in the first spatial portion 131 and held by the first inner wall surface 132. The housing 130 is made of a material that is at least absorbent to the irradiation light L1. The housing 130 is further made of a material that does not generate autofluorescence by the irradiation light L1. As an example, the material of the housing 130 is black ABS resin or black POM (Polyoxymethylene).

[0044] The first photodetector 140 is installed on the first inner wall surface 132 so as to face the optical path of the irradiation light L1, for example, between the light source 101 and the light shaping member 120. The first photodetector 140 is for detecting the amount of the irradiation light L1 emitted from the light source 101 by detecting a part of the irradiation light L1 that is emitted from the light source 101 and diffuses. The first photodetector 140 is, for example, a photodiode (Si photodiode as an example). The first photodetector 140 outputs a signal indicating the detection result to a drive circuit 50 described later.

[0045] In the first space portion 131, a first widened portion 133 widened between the optical shaping member 120 and the first lens 111 is formed. Here, the first widened portion 133 is provided between the optical shaping member 120 and the first wavelength selection filter 125. The first widened portion 133 is formed by the first inner wall surface 132 being recessed so as to be away from the optical path of the irradiation light L1. Here, the width of the first widened portion 133 is constant. The first widened portion 133 is, for example, in the shape of a rectangular parallelepiped. The first inner wall surface 132 includes a pair of intersecting surfaces 134, 135 that intersect the optical path of the irradiation light L1 (the direction from the optical shaping member 120 toward the first lens 111) in the first widened portion 133. The intersecting surface 134 is the surface facing the first lens 111 side, and the intersecting surface (the first intersecting surface) 135 is the surface facing the optical shaping member 120 side. The intersecting surface 134 and the intersecting surface 135 are surfaces facing each other and are, for example, parallel to each other.

[0046] Subsequently, the detection optical system C2 will be described. The detection optical system C2 includes a second photodetector 150, a third lens 153, and a second wavelength selection filter 160. The second photodetector 150, the third lens 153, and the second wavelength selection filter 160 are housed in the housing 130 and held by the housing 130.

[0047] The second photodetector 150 is for detecting the detection light L2. The second photodetector 150 is, for example, a photodiode (a Si photodiode as an example). The second photodetector 150 may be an avalanche photodiode or a photomultiplier tube, and their multi-pixel arrays. On the outer surface of the housing 130, a substrate 21 of a current-voltage converter 20 described later is attached, and the second photodetector 150 is mounted on the substrate 21. The second photodetector 150 outputs a signal indicating the detection result of the detection light L2 to the current-voltage converter 20.

[0048] The third lens 153 is for condensing the detection light L2 toward the second photodetector 150. The third lens 153 is, for example, a plano-convex lens that is convex on the side opposite to the second photodetector 150.

[0049] The second wavelength selection filter 160 is disposed between the third lens 153 and the second photodetector 150. The second wavelength selection filter 160 is for selectively transmitting some of the wavelength components of the detection light L2 toward the second photodetector 150. The second wavelength selection filter 160 is configured to selectively transmit, for example, fluorescence generated from a fluorescent reagent among the detection light L2. Here, the second wavelength selection filter 160 includes a dielectric multilayer film filter 161 and a colored glass filter 162 that transmit only a specific wavelength band (fluorescence). The second wavelength selection filter 160 is, for example, a band-pass filter that combines the dielectric multilayer film filter 161 and the colored glass filter 162. The colored glass filter 162 is disposed closer to the second photodetector 150 than the dielectric multilayer film filter 161. The colored glass filter 162 is adhered to the dielectric multilayer film filter 161 as an example.

[0050] The housing 130 includes a second space portion 171 in which the optical path of the detection light L2 is formed, and a second inner wall surface 172 that defines the second space portion 171. Each member of the detection optical system C2 is disposed in the second space portion 171 and held by the second inner wall surface 172.

[0051] In the second space portion 171, a second widened portion 173 widened between the third lens 153 and the second wavelength selection filter 160 is formed. The second widened portion 173 is formed by the second inner wall surface 172 being recessed away from the optical path of the detection light L2. Here, the width of the second widened portion 173 is constant. The second widened portion 173 is, for example, in the shape of a rectangular parallelepiped. The second inner wall surface 172 includes a pair of intersecting surfaces 174 and 175 that intersect the optical path of the detection light L2 (the direction from the third lens 153 toward the second photodetector 150) in the second widened portion 173. The intersecting surface (the second intersecting surface) 174 is the surface facing the third lens 153 side, and the intersecting surface 175 is the surface facing the second wavelength selection filter 160 side. The intersecting surface 174 and the intersecting surface 175 are opposing surfaces and are, for example, parallel to each other. Note that when the second space portion 171 does not have the second widened portion 173, the second wavelength selection filter 160 may be configured by vapor-depositing the dielectric multilayer film filter 161 on the third lens 153.

[0052] Here, as shown in FIG. 1, the optical measurement device 1 further includes a current-voltage converter 20, an AD converter 30, a CPU 40, and a drive circuit 50. The current-voltage converter 20 converts the current signal output from the second photodetector 150 into a voltage signal and outputs it to the AD converter 30. As described above, the substrate 21 of the current-voltage converter 20 is attached to the outer surface of the housing 130 (see FIG. 3). The AD converter 30 changes the voltage signal output from the current-voltage converter 20 into a digital signal and outputs it to the CPU 40.

[0053] The CPU 40 performs signal processing on the digital signal output from the AD converter 80, for example, to remove a signal component corresponding to scattered light from the detection signal. The drive circuit 50 receives an input from the CPU 40 and also receives an input from the first photodetector 140. While receiving a detection signal indicating the light quantity of the irradiation light L1 from the first photodetector 140, the drive circuit 50 controls the driving of the surface light emitting element 102 so that the light quantity becomes constant. [Operation and Effect]

[0054] Subsequently, the operation and effect of the optical measurement device 1, the irradiation optical system C1, and the irradiation device 100 according to the present embodiment will be described.

[0055] In the irradiation optical system C1 according to the present embodiment, the irradiation light L1 emitted from the light source 101 is shaped by the light shaping member 120 and then irradiated onto the immunochromatographic test strip 500 through the first lens 111. The light source 101 includes a surface light emitting element 102 and a lens unit 103b for enhancing the directivity of the irradiation light L1 emitted from the surface light emitting element 102. And the distance H between the light emission surface 102s of the surface light emitting element 102 and the light incident surface 121 of the light shaping member 120 is 26 times or less the size d in one direction of the light emission surface 102s of the surface light emitting element 102. Regarding this point, the findings of the present inventor will be described.

[0056] Figures 6 and 7 are graphs LA showing the illuminance distribution of the irradiated light on the irradiation surface at a specific distance from the light emitting surface of the surface light emitting element. Figures 6 and 7 are examples when the size d is 0.5 mm. (a) to (f) of Figure 6 respectively show the cases of distance H = 5 mm (10d), distance H = 7 mm (14d), distance H = 8.5 mm (17d), distance H = 9 mm (18d), distance H = 10 mm (20d), and distance H = 13.5 mm (27d). (a) to (d) of Figure 7 respectively show the cases of distance H = 13 mm (26d), distance H = 15 mm (30d), distance H = 25 mm (50d), and distance H = 35 mm (70d).

[0057] In the cases shown in (a) to (e) of Figure 6, that is, when the distance H is in the range of 10d to 20d, a relatively uniform illuminance distribution is obtained in the central portion, and a relatively high light quantity is achieved. On the other hand, in the case shown in (f) of Figure 6, that is, when the distance H is 27d, although a medium light quantity is obtained, the illuminance distribution becomes non-uniform in the central portion. On the other hand, in the cases shown in (b) to (d) of Figure 7, that is, when the distance H is 30d or more, as a result of being sufficiently away from the light source, a relatively uniform illuminance distribution is obtained, but a sufficient light quantity is not obtained.

[0058] In contrast, in (a) of Figure 7 where the distance H is 26d, compared with (f) of Figure 6, the illuminance distribution in the central portion is uniform, and a high light quantity is obtained. From this, it is found that the illuminance distribution is uniformized and a relatively high light quantity is obtained when the distance H is 26d or less. Thus, in the surface light emitting element 102 used in combination with the lens portion 103b for enhancing directivity, in a distance range close to within 26 times the size d of the light emitting surface 102s, a relatively high light quantity and a uniform illuminance distribution can be obtained.

[0059] Fig. 8(a) is a diagram showing the light quantity of the irradiation light L1 imaged by the irradiation optical system C1 according to the present embodiment. Further, Fig. 8(b) is a diagram showing the simulated light quantity of the irradiation light L1 imaged by the irradiation optical system C1 according to the present embodiment. As shown in Fig. 8, the irradiation light L1 is shaped by the light shaping member 120 installed in the above distance range, and imaged by the first lens 111, so that more uniform light irradiation can be performed on the immunochromatographic test strip 500.

[0060] As described above, in the irradiation optical system C1 according to the present embodiment, an image of the irradiation light L1 (image of the slit 120s) on the light incident surface 121 of the light shaping member 120 arranged within the above distance range is imaged on the immunochromatographic test strip 500 by the first lens 111, so that more uniform light irradiation can be performed on the immunochromatographic test strip 500. The irradiation device 100 including the irradiation optical system C1 and the optical measurement device 1 can also achieve the same effect. In particular, in the optical measurement device 1, stable measurement is possible by detecting the detection light L2 from the immunochromatographic test strip 500 (fluorescent reagent) that has received uniform light irradiation by the above irradiation optical system C1 and irradiation device 100.

[0061] Further, the irradiation optical system C1 according to the present embodiment is arranged between the light source 101 and the first lens 111, and includes a second lens 112 for correcting the aberration generated by the first lens 111. Therefore, more uniform light irradiation becomes possible.

[0062] Further, in the irradiation optical system C1 according to the present embodiment, the second lens 112 is arranged between the light source 101 and the light shaping member 120, and has a function of enhancing the directivity of the irradiation light L1 emitted from the light source 101. Therefore, the loss due to the irradiation light L1 hitting and being absorbed by the first inner wall surface 132 due to the diffusion of the irradiation light L1 is reduced.

[0063] Further, in the irradiation optical system C1 according to the present embodiment, the second lens 112 is fixed to the light shaping member 120. Therefore, there is no need for a mechanism for separately holding the second lens 112 or positioning it.

[0064] In the irradiation optical system C1 according to the present embodiment, the light source 101 includes a light-transmissive resin portion 103 that seals the surface light-emitting element 102, and the lens portion 103b is formed in the resin portion 103 and integrated with the surface light-emitting element 102. Therefore, it is easy to handle and position the surface light-emitting element 102 and the lens portion 103b.

[0065] Further, the irradiation optical system C1 according to the present embodiment includes a first wavelength selection filter 125 that is provided between the light source 101 and the first lens 111 and selectively transmits some wavelength components of the irradiation light L1 toward the first lens 111. Therefore, it is possible to selectively irradiate some wavelength components of the irradiation light L1 onto the immunochromatographic test strip 500.

[0066] The irradiation device 100 according to the present embodiment includes the above-described irradiation optical system C1 and a housing 130 that houses the irradiation optical system C1. The housing 130 includes a first space portion 131 in which the optical path of the irradiation light L1 is formed and a first inner wall surface 132 that defines the first space portion 131. According to this irradiation device 100, as described above, it is possible to achieve the same effects as those of the irradiation optical system C1. Further, according to this irradiation device 100, since the above-described irradiation optical system C1 is housed in the housing, it is easy to handle.

[0067] In the irradiation device 100 according to the present embodiment, a first widened portion 133 that is widened between the light shaping member 120 and the first lens 111 is formed in the first space portion 131, and the first inner wall surface 132 includes an intersection surface 135 that intersects the optical path of the irradiation light L1 and faces the light shaping member 120 side in the first widened portion 133. Therefore, light that travels obliquely from the light shaping member 120 toward the first lens 111 at an angle greater than or equal to a certain angle is trapped by the intersection surface 135, thereby suppressing the generation of stray light. That is, the first widened portion 133 and the intersection surface 135 function as a structure for trapping stray light.

[0068] Here, the first widening portion 133 is provided between the optical shaping member 120 and the first wavelength selection filter 125. In other words, in the present embodiment, the first wavelength selection filter 125 is disposed at the rear stage of the first widening portion 133 in the optical path of the irradiation light L1. Therefore, as a result of the light traveling obliquely toward the first wavelength selection filter 125 at an angle greater than or equal to a certain angle being trapped by the intersection surface 135, the incident angle of the irradiation light L1 on the first wavelength selection filter is restricted.

[0069] As an example, the first wavelength selection filter 125 may include a dielectric multilayer film filter. In this case, when the incident angle of the irradiation light L1 on the dielectric multilayer film filter becomes large, the filtering characteristics may deteriorate. Therefore, by restricting the incident angle on the first wavelength selection filter 125 by the first widening portion 133 and the intersection surface 135 as described above, it is possible to suppress a decrease in the filtering characteristics of the first wavelength selection filter 125 and more surely selectively transmit only some wavelength components of the irradiation light L1 (to suppress the generation of stray light).

[0070] Note that the effect of suppressing stray light by the first widening portion 133 and the intersection surface 135 is particularly effective when the first wavelength selection filter 125 including a dielectric multilayer film filter is provided on the subsequent stage side, but is not limited to that case, and can be exhibited simply by trapping the light traveling obliquely in the first space portion 131 at an angle greater than or equal to a certain angle.

[0071] Further, the irradiation device 100 according to the present embodiment includes a first photodetector 140 that is installed on the first inner wall surface 132 so as to face the optical path of the irradiation light L1 and detects a part of the irradiation light L1 that is emitted from the light source 101 and diffuses, thereby detecting the light quantity of the irradiation light L1 emitted from the light source 101. Therefore, it is possible to monitor the light quantity of the irradiation light L1.

[0072] Further, the irradiation device 100 according to the present embodiment includes a drive circuit 50 for driving the surface light emitting element 102 while inputting a detection signal indicating the light amount of the irradiation light L1 from the first photodetector 140, so that the light amount becomes constant. Therefore, light irradiation with a stable light amount becomes possible.

[0073] Furthermore, in the irradiation device 100 according to the present embodiment, the housing 130 may be made of a material having absorbency with respect to the irradiation light L1. Alternatively, in the irradiation device 100 according to the present embodiment, the housing 130 may be made of a material that does not generate autofluorescence by the irradiation light L1. In these cases, the generation of stray light is more reliably suppressed.

[0074] Here, the optical measurement device 1 according to the present embodiment includes the above-described irradiation device 100 and a detection optical system C2 for detecting the detection light L2 from the immunochromatographic test strip 500 (fluorescent reagent) irradiated with the irradiation light L1. The housing 130 further houses the detection optical system C2 and includes a second space portion 171 in which the optical path of the detection light L2 is formed and a second inner wall surface 172 that defines the second space portion 171. The detection optical system C2 includes a second photodetector 150 for detecting the detection light L2 and a third lens 153 for condensing the detection light L2 toward the second photodetector 150. According to this optical measurement device 1, by detecting the detection light L2 from the immunochromatographic test strip 500 that has received uniform light irradiation by the above-described irradiation optical system C1 and irradiation device 100, stable measurement of the immunochromatographic test strip 500 becomes possible.

[0075] In addition, the optical measurement device 1 according to the present embodiment includes a second wavelength selection filter 160 provided between the third lens 153 and the second photodetector 150 for selectively transmitting a part of the wavelength components of the detection light L2 toward the second photodetector 150. Therefore, it becomes possible to selectively detect a part of the wavelength components of the detection light L2.

[0076] In the optical measurement device 1 according to the present embodiment, a second widened portion 173 widened between the third lens 153 and the second wavelength selection filter 160 is formed in the second space portion 171, and the second inner wall surface 172 includes an intersection surface 174 that intersects the optical path of the detection light L2 and faces the third lens 153 side in the second widened portion 173. For this reason, light traveling obliquely at an angle greater than or equal to a certain angle from the third lens 153 toward the second wavelength selection filter 160 is trapped by the intersection surface 174, thereby restricting the range of the incident angle of the detection light L2 incident on the second wavelength selection filter 160.

[0077] As described above, since the second wavelength selection filter 160 includes the dielectric multilayer film filter 161, it has filtering characteristics that depend on the incident angle. Therefore, by restricting the incident angle to the second wavelength selection filter 160 by the second widened portion 173 and the intersection surface 174 as described above, a decrease in the filtering characteristics of the second wavelength selection filter 160 is suppressed, and only some wavelength components of the detection light L2 can be more surely selectively transmitted (the generation of stray light is suppressed). Therefore, highly accurate measurement becomes possible.

[0078] This can also be understood from the detection results shown in FIG. 9. That is, FIG. 9(a) shows the light amount of the detection light L2 on the light receiving surface of the second photodetector 150 when there is no stray light trapping structure by the second widened portion 173 and the intersection surface 174, and FIG. 9(b) shows the light amount of the detection light L2 on the detection surface of the second photodetector 150 when there is a stray light trapping structure by the second widened portion 173 and the intersection surface 174. As shown in FIG. 9, by using the stray light trapping structure according to the present embodiment, noise due to stray light is reduced and a uniform detection result is obtained.

[0079] Note that the effect of suppressing stray light by the second widened portion 173 and the intersection surface 174 is particularly effective when the second wavelength selection filter 160 including the dielectric multilayer film filter 161 is provided on the subsequent stage side, but is not limited to that case, and can be exhibited simply by trapping light traveling obliquely at an angle greater than or equal to a certain angle within the second space portion 171.

[0080] Further, in the optical measurement device 1 according to the present embodiment, the second wavelength selection filter 160 includes a dielectric multilayer film filter 161 and a colored glass filter 162 disposed closer to the second photodetector 150 side than the dielectric multilayer film filter 161. As described above, the characteristics of the dielectric multilayer film filter have incident angle dependence. On the other hand, by providing the colored glass filter 162, the incident angle dependence of the entire second wavelength selection filter 160 is reduced, and it becomes possible to selectively transmit only some wavelength components more effectively for a wider range of incident angles. In particular, it is more effective to arrange the dielectric multilayer film filter 161 and the colored glass filter 162 in this order toward the second photodetector 150.

[0081] The optical measurement device 1 according to the present embodiment further includes a current-voltage converter 20 for converting a current signal output from the second photodetector 150 in response to the detection of the detection light L2 into a voltage signal, and the second photodetector 150 is mounted on the substrate 21 of the current-voltage converter 20. Therefore, it is possible to avoid noise being added to the detection signal between the second photodetector 150 and the current-voltage converter 20, and the noise is reduced.

[0082] In the optical measurement device according to the present invention, the irradiation light L1 includes excitation light for exciting the immunochromatographic test strip 500 (fluorescent reagent), and the detection light L2 includes fluorescence emitted by the immunochromatographic test strip 500 (fluorescent reagent) in response to the irradiation of the excitation light. Therefore, stable fluorescence measurement becomes possible.

[0083] The above embodiments illustrate one aspect of the present invention. Therefore, the present invention is not limited to the above embodiments, and the irradiation optical system C1, the irradiation device 100, and the optical measurement device 1 described above can be arbitrarily modified.

[0084] For example, the above-described optical measurement device 1 may include a metal shield provided on the housing 130 so as to cover at least the second photodetector 150 and the current-voltage converter 20. As an example, the metal shield can be provided so as to cover the entire side surface of the housing 130. In this case, noise is further reduced.

[0085] Further, the second lens 112 may be disposed between the light shaping member 120 and the first lens 111. Even in this case, the second lens 112 may be fixed to the light shaping member 120. However, the second lens 112 may be fixed to the housing 130 separately from the light shaping member 120. Also, when viewed from the direction along the optical axis of the irradiation light L1, the shape of the light passing hole of the light shaping member 120 is not limited to a rectangular shape having a longitudinal direction such as the slit 120s, as long as it corresponds to the shape of the measurement target portion 504, and may be other shapes (for example, circular, elliptical, etc.).

[0086] Also, the first wavelength selection filter 125 and the second wavelength selection filter 160 are not limited to the above-described configuration and can be arbitrarily changed. For example, the first wavelength selection filter 125 may also include a dielectric multilayer film filter and a color glass filter (for example, disposed closer to the first lens 111 than the dielectric multilayer film filter), or may include only the color glass filter, similar to the second wavelength selection filter 160. Similarly, the second wavelength selection filter 160 may also include only one of the dielectric multilayer film filter 161 and the color glass filter 162.

[0087] Also, the light source 101 is not limited to being configured as a bullet-type LED in which the surface-emitting element 102 and the lens unit 103b are integrated, and the surface-emitting element 102 and the lens unit 103b may be configured separately.

[0088] Furthermore, in the above embodiment, the optical measurement device 1 used in the fluorescence immunochromatography method has been described. However, the optical measurement device 1 can be used for other purposes. In this case, the irradiation light L1 may not include excitation light for exciting the object, or the detection light L2 may not include fluorescence emitted from the object by the irradiation of the excitation light.

Description of Symbols

[0089] 1…Optical measurement device, 20…Current-voltage converter, 50…Drive circuit, 100…Irradiation device, 101…Light source, 102…Surface light-emitting element, 102s…Light-emitting surface, 103…Resin part (light-transmitting part), 103b…Lens part, 111…First lens, 112…Second lens, 120…Light shaping member, 120s…Slit (light passage hole), 121…Light incident surface, 131…First space part, 132…First inner wall surface, 133…First widened part, 135…Intersection surface (first intersection surface), 140…First photodetector, 150…Second photodetector, 160…Second wavelength selection filter, 161…Dielectric multilayer filter, 162…Color glass filter, 171…Second space part, 172…Second inner wall surface, 173…Second widened part, 174…Intersection surface (second intersection surface), C1…Irradiation optical system, C2…Detection optical system, L1…Irradiation light (first light), L2…Detection light (second light).

Claims

1. An irradiation optical system, a housing that houses the irradiation optical system, and the irradiation optical system is an irradiation optical system for irradiating an object with first light, a light source including a surface light emitting element that emits the first light from a light emitting surface, and a lens unit for enhancing the directivity of the first light emitted from the surface light emitting element, a light shaping member that receives the first light emitted from the light source through a light incident surface, and shapes and emits the incident first light through a light passage hole, a first lens for forming an image of the first light emitted from the light shaping member on the object, and includes the distance between the light emitting surface of the surface light emitting element and the light incident surface of the light shaping member is 26 times or less the size in one direction of the light emitting surface, the housing includes a first space portion in which an optical path of the first light is formed, and a first inner wall surface that defines the first space portion, and includes a first photodetector that is installed on the first inner wall surface so as to face the optical path of the first light, and detects a part of the first light that is emitted from the light source and diffuses, thereby detecting the light quantity of the first light emitted from the light source, a drive circuit that drives the surface light emitting element so that the light quantity becomes constant while receiving a detection signal indicating the light quantity of the first light from the first photodetector, and further includes an irradiation device.

2. The irradiation optical system includes a second lens that is disposed between the light source and the first lens and corrects aberration generated by the first lens, The irradiation device according to Claim 1.

3. The second lens is disposed between the light source and the light shaping member or between the light shaping member and the first lens, and has a function of enhancing the directivity of the first light emitted from the light source, The irradiation device according to Claim 2.

4. The second lens is fixed to the light shaping member, The irradiation device according to Claim 2 or 3.

5. The light source includes a light transmissive light transmitting portion that seals the surface light emitting element, The lens unit is formed on the light transmitting portion and is integrated with the surface light emitting element, The irradiation device according to any one of Claims 1 to 4.

6. The irradiation optical system includes a first wavelength selection filter that is provided between the light source and the first lens and selectively transmits a part of the wavelength components of the first light toward the first lens, The irradiation device according to any one of Claims 1 to 5.

7. In the first space portion, a first widened portion widened between the optical shaping member and the first lens is formed. The first inner wall surface includes a first intersecting surface that intersects the optical path of the first light and faces the optical shaping member side in the first widened portion. The irradiation device according to claim 1.

8. The housing is made of a material having absorbability with respect to the first light. The irradiation device according to any one of claims 1 to 7.

9. The housing is made of a material that does not generate autofluorescence by the first light. The irradiation device according to any one of claims 1 to 8.

10. The irradiation device according to any one of claims 1 to 9, and a detection optical system for detecting second light from the object irradiated with the first light, comprising: The housing further houses the detection optical system, and a second space portion in which the optical path of the second light is formed, a second inner wall surface that defines the second space portion, including: The detection optical system is a second photodetector for detecting the second light, a third lens for condensing the second light toward the second photodetector, an optical measurement device comprising.

11. A second wavelength selection filter provided between the third lens and the second photodetector for selectively transmitting a part of the wavelength components of the second light toward the second photodetector is provided. The optical measurement device according to claim 10.

12. In the second space portion, a second widened portion widened between the third lens and the second wavelength selection filter is formed. The second inner wall surface includes a second intersecting surface that intersects the optical path of the second light and faces the third lens side in the second widened portion. The optical measurement device according to claim 11.

13. The second wavelength selection filter includes a dielectric multilayer film filter and a color glass filter disposed closer to the second photodetector side than the dielectric multilayer film filter. The optical measurement device according to claim 11 or 12.

14. A current-voltage converter for converting a current signal output from the second photodetector in response to the detection of the second light into a voltage signal is provided. The second photodetector is mounted on a substrate of the current-voltage converter. The optical measurement device according to any one of claims 10 to 13.

15. A metal shield provided on the housing so as to cover at least the second photodetector and the current-voltage converter is provided. The optical measurement device according to claim 14.

16. The first light includes excitation light for exciting the object, The second light includes fluorescence emitted by the object in response to irradiation with the excitation light, The optical measurement device according to any one of claims 10 to 15.

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