JP5667894B2 - Diffraction grating, capillary array electrophoresis device, liquid chromatograph, spectrophotometer, biochemical automatic analyzer - Google Patents

Description

  The present invention relates to a diffraction grating and an analyzer provided with the diffraction grating. As an analyzer provided with a diffraction grating, it relates to a capillary array electrophoresis apparatus, a liquid chromatograph, a spectrophotometer, a biochemical automatic analyzer, and the like.

  A diffraction grating is an optical element in which a plurality of serrated shapes (irregular grooves) are formed on the surface of a substrate, and an optical analyzer (capillary array electrophoresis apparatus, liquid chromatograph, spectrophotometer, biochemical automatic analyzer, etc.) And is used as an element for wavelength dispersion.

  In a general configuration of a diffraction grating, a metal film and a substrate are fixed via an adhesive (for example, epoxy resin), and a sawtooth shape is formed on the surface of the metal film at an interval of about 1 μm.

  A general manufacturing method of the diffraction grating is as follows. First, a metal film (for example, aluminum) is vapor-deposited on a glass substrate (master substrate), and a diffraction grating (master diffraction grating) is produced by processing a sawtooth shape on the surface of the metal film. Next, after the metal film surface of the master diffraction grating with the sawtooth shape formed is coated with a release agent (silicon or fluorine), a metal vapor deposition film is formed on the release agent coating surface, and an adhesive is used. A glass substrate (replica substrate) is bonded and pressure is applied. After the adhesive is cured, when the master diffraction grating and the glass substrate are peeled off, it is separated from the release agent coating surface, and the metal vapor deposition film is transferred to the glass substrate (replica substrate) side, so that a sawtooth shape is formed on the metal film surface A diffraction grating (replica diffraction grating) in which is formed can be produced. Next, the replica diffraction grating (that is, a replica of the master diffraction grating) can be manufactured by repeating the above process using the replica diffraction grating as the master diffraction grating.

  Here, as the metal film, generally, an Al vapor deposition film having a high reflectivity and small deterioration with time (decrease in reflectivity with time) is used. As the thickness of the metal film increases, the surface roughness increases, so that the amount of surface reflected light (scattered light on the surface of the metal film) increases. On the contrary, the metal film decreases as the film thickness decreases. Since the film quality is incomplete (a minute hole in which the metal film is not formed is partially generated), the internally reflected light of the light transmitted through the metal film (for example, at the interface between the metal film and the adhesive) (Reflected light) increases. Since the surface reflection light and the internal reflection light are detected as stray light together with the diffracted light, the analysis accuracy is lowered. As a solution to this problem, by using a tar epoxy resin in which tar pitch and swollen charcoal are mixed as a light absorbing material with an epoxy resin (adhesive), the light transmitted through the metal film is absorbed to reduce the reflected light. Some have been proposed to prevent the occurrence. Thus, it is possible to provide a diffraction grating in which stray light does not increase due to internally reflected light even if the thickness of the metal film is reduced in order to reduce surface reflected light. As a thing relevant to this patent, there exists Unexamined-Japanese-Patent No. 2007-199540 (patent document 1), for example.

JP 2007-199540 A

  The sawtooth shape of the diffraction grating is a fine shape having a width of about 0.1 to 1 μm and a depth of about 0.1 to 1 μm. The diffraction grating is formed by coating the master diffraction grating with a release agent, forming a sawtooth-shaped metal film, and curing the adhesive in a state where the replica substrate is bonded through the adhesive. After the adhesive is cured, the master diffraction grating and the replica substrate are peeled off at the release agent coating surface, and a sawtooth-shaped metal film is transferred to the replica substrate, thereby producing a replica diffraction grating. At this time, in order to completely transfer the metal film formed on the master diffraction grating to the replica substrate, the width formed by the metal film is about 0.1 to 1 μm and the depth is about 0.1 to 1 μm. It is necessary to completely fill in every corner of the fine groove with an adhesive.

  When the light-absorbing substance is mixed with the adhesive, the viscosity of the adhesive increases. However, the greater the viscosity of the adhesive, the more the adhesive can be completely filled in the fine groove, and the master diffraction through the adhesive When bonding the lattice and the replica substrate, higher pressure must be applied. In order to prevent the generation of surface scattered light, the flatness and surface roughness of the metal film must be reduced. However, the higher the pressure at which the master diffraction grating and the replica substrate are bonded, the more the microfabricated grooves are formed. Since the applied pressure increases, the deformation of the fine groove increases. This is an increase in the flatness and surface roughness of the metal film, which causes generation of surface scattered light, that is, generation of stray light.

  In addition, the volume of the adhesive shrinks when it is cured, but when the light absorbing material is mixed with the adhesive, the volume of the light absorbing material does not shrink. Therefore, the shrinkage rate of the adhesive in the direction perpendicular to the metal film is in-plane. Since it becomes non-uniform | heterogenous, a wave | undulation will generate | occur | produce on the adhesive agent surface (surface which contacts a metal film). Since the thickness of the metal film is generally about 0.1 to 1 μm and has low rigidity, it is affected by the volume shrinkage of the adhesive. That is, since the surface of the metal film undulates along the undulation of the adhesive surface, the surface roughness of the metal film increases. This causes generation of surface scattered light, that is, generation of stray light.

  Furthermore, when the light absorbing material is mixed with the adhesive, the light absorbing material is in a state of being dispersed in the adhesive. Therefore, the metal film and the light absorbing material are in contact with the metal film. And a portion having an adhesive layer between the two. At this time, in the portion where the metal film and the light absorbing material are in contact, the light transmitted through the metal film reaches the light absorbing material directly and is absorbed by the light absorbing material, so that no light scattering occurs. However, in the portion where the adhesive is filled between the metal film and the light absorbing material, the light transmitted through the metal film reaches the adhesive and passes through the adhesive, and then reaches the light absorbing material and is absorbed by the light absorbing material. Light is absorbed, but part of the light that has passed through the metal film is reflected by the adhesive surface, or part of the light that has passed through the adhesive and reached the light absorbing material is because the surface of the light absorbing material is not flat. I do diffuse reflection. Among these reflected lights, those that coincide with the radiation direction of the diffracted light become stray light.

  An object of the present invention is to provide a diffraction grating having excellent optical characteristics with reduced stray light and an analyzer equipped with a diffraction grating having excellent optical characteristics with reduced stray light.

  According to a first aspect of the present invention, there is provided a diffraction grating having a substrate and a light reflecting film, wherein the light reflecting film is provided with a plurality of sawtooth-shaped grooves, between the substrate and the light reflecting film. Is provided with a light absorption film, and the reflection film is an Ag alloy, Al, or a titanium oxide-based metal, and the light absorption film is carbon, black chrome, black nickel, or black. It is characterized by being quartz.

  A second feature of the present invention is a diffraction grating comprising a substrate and a light reflecting film provided on the substrate, wherein the light reflecting film is provided with a plurality of sawtooth-shaped grooves. It is an alloy or a titanium oxide-based metal.

  A third feature of the present invention is that the substrate includes a light reflecting film provided on the substrate, the light reflecting film being a diffraction grating having a sawtooth groove, wherein the reflecting film is an Ag alloy, or It is made of Al or a titanium oxide-based metal, and is at least one of a side surface perpendicular to the surface on which the light reflecting film is provided on the substrate and a surface on the opposite side of the light reflecting film from the substrate. On the other hand, a light absorption film is provided, and the light absorption film is carbon, black chrome, black nickel, or black quartz.

  A fourth feature of the present invention is a capillary array electrophoresis apparatus having any one of the first to fourth diffraction gratings, a liquid chromatograph, a spectrophotometer, or a biochemical automatic analyzer. To do.

Of the inventions disclosed in this application, effects obtained by typical ones will be briefly described as follows.
(1) It is possible to provide a diffraction grating having excellent optical characteristics with reduced stray light.
(2) It is possible to provide an optical analyzer (capillary array electrophoresis apparatus, liquid chromatograph, spectrophotometer, biochemical automatic analyzer, etc.) equipped with a diffraction grating having excellent optical characteristics with reduced stray light. .

It is explanatory drawing of the diffraction grating which is the 1st Embodiment of this invention. It is a figure explaining the manufacturing method of the diffraction grating which is the 1st Embodiment of this invention. It is the elements on larger scale explaining the conventional diffraction grating and the diffraction grating which is the 1st embodiment of the present invention. It is a figure explaining the stray light intensity of the conventional diffraction grating and the diffraction grating which is the 1st embodiment of the present invention. It is explanatory drawing of the diffraction grating which is the 2nd Embodiment of this invention. It is explanatory drawing of the diffraction grating which is the 3rd Embodiment of this invention. It is a figure explaining the manufacturing method of the diffraction grating which is the 3rd Embodiment of this invention. It is explanatory drawing of the diffraction grating which is the 4th Embodiment of this invention. It is a figure explaining the manufacturing method of the diffraction grating which is the 4th Embodiment of this invention. It is the elements on larger scale explaining the diffraction grating which is the 4th Embodiment of this invention. It is a figure explaining the outline of the capillary array electrophoresis apparatus which is the 5th Embodiment of this invention. It is the elements on larger scale explaining the capillary array electrophoresis apparatus which is the 5th Embodiment of this invention. It is a figure explaining the outline of the liquid chromatograph which is the 6th Embodiment of this invention. It is the elements on larger scale explaining the liquid chromatograph which is the 6th Embodiment of this invention. It is a figure explaining the outline of the spectrophotometer which is the 7th Embodiment of this invention. It is a figure explaining the outline of the biochemical automatic analyzer which is the 8th Embodiment of this invention. It is the elements on larger scale explaining the biochemical automatic analyzer which is the 8th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, these examples do not limit the present invention.

(First embodiment)
The configuration of the diffraction grating according to this embodiment is shown in FIG.

  The diffraction grating of the first embodiment is composed of a substrate 1, a resin 2, a light absorbing film 3, and a highly reflective film 4, and is composed of a substrate 1 made of a glass material (size: 20 mm × 20 mm × 5 mm) and a carbon film. The light absorption film 3 (film thickness: about 0.1 to 1 μm) is fixed by the resin 2 (thickness: about 20 to 100 μm) made of an adhesive. A high reflection film 4 (film thickness: about 0.1 to 1 μm) made of an Ag alloy is provided on the surface of the light absorption film 3 opposite to the resin 2, and the high reflection film 4 has a width of 0. A sawtooth-shaped groove having a depth of about 0.1 to 1 μm and a depth of about 0.1 to 1 μm is formed. The sawtooth-shaped groove is generally formed of an Al film. However, in the present invention, the reflectivity is higher than that of the Al film (90% reflectance at a wavelength of 500 nm) and the Ag film (99% reflectance at a wavelength of 500 nm). ) And an Ag alloy film (Ag—Pt, Ag—Au, etc.) having the same degree of reflectivity as that of the above. In FIG. 1, only five sawtooth-shaped grooves are shown, but in actuality, about tens of thousands to hundreds of thousands are formed. Here, the reason why the Ag alloy film is used instead of the Ag film is that the Ag alloy film has a smaller reflectance drop due to the change with time than the Ag film.

  A method for manufacturing the diffraction grating of the present invention will be described. FIG. 2 shows a side view of the diffraction grating. First, a master diffraction grating including a substrate 1, a resin 2 and a metal film 5 is prepared (FIG. 2A). Although not shown, the sawtooth shape provided on the metal film 5 of the master diffraction grating is formed by machining or etching. Next, a silicon-based or fluorine-based release agent 6 is coated on the metal film 5 of the master diffraction grating by vapor deposition or coating, and then the light absorption film 3 is formed on the mold release agent 6 by vapor deposition. A certain resin 7 is applied (FIG. 2B). Subsequently, after covering the master diffraction grating with a guide 8 provided with a square hole, the substrate 9 is placed on the resin 7, and a pressure is applied by placing a weight (not shown) on the substrate 9. Covers the serrated groove surface of the light absorption film 3 and the surface of the substrate 9 (FIG. 2C). The weight of the weight is set to an optimum weight depending on the area of the diffraction grating, the viscosity of the adhesive forming the resin 7, and the like. After the adhesive forming the resin 7 is cured, the guide 8 is removed from the master diffraction grating, and the substrate 9 is separated from the master diffraction grating, so that it peels off with the release agent 6 (not shown) as a boundary. A replica diffraction grating in which 3 and the resin 7 are fixed to the substrate 9 is manufactured (FIG. 2D). Since the light-absorbing film 3 of the replica diffraction grating is formed with the same sawtooth shape as the sawtooth shape provided on the metal film 5 of the master diffraction grating, a replica of the master diffraction grating is manufactured. After removing the release agent 6 adhering to the surface of the light absorption film 3 of this replica diffraction grating by cleaning (not shown), a high reflection film 4 is formed on the light absorption film 3 by vapor deposition, thereby replica diffraction. A lattice (complete) is produced (FIG. 2 (e)). Note that mass production can be achieved by using, as a master, a replica diffraction grating composed of the substrate 9, the resin 7, and the light absorption film 3 instead of the master diffraction grating composed of the substrate 1, the resin 2, and the metal film 5.

  The effect of the diffraction grating of the present invention will be described. 3A and 3B show how diffracted light and stray light are generated in the diffraction grating. FIG. 3A shows a conventional diffraction grating, and FIG. 3B shows the diffraction grating of the present embodiment. FIG. 4 shows the measurement result of detection light having a wavelength of 500 nm when incident light (white light having a wavelength of 400 to 700 nm) is irradiated onto the diffraction grating. FIG. 4A shows the conventional diffraction. FIG. 4B shows the diffraction grating of this embodiment. The numerical value of the result is the relative intensity of stray light with respect to the diffracted light intensity (= stray light intensity / diffracted light intensity).

As shown in FIG. 3A, when incident light 10 is irradiated onto a conventional diffraction grating composed of a substrate 1, a resin 2, and a metal film 5 (for example, an Al film), the diffracted light 11 is emitted according to the theory of diffraction. Is done. As the film thickness of the metal film 5 increases, the surface roughness increases and the generation of surface scattered light increases. Therefore, the film thickness of the metal film 5 is set to be thin. However, as the film thickness decreases, the film quality of the metal film 5 becomes incomplete, so that internally scattered light, that is, stray light 12 due to light transmitted through the metal film 5 is generated. The relative intensity of the stray light with respect to the diffracted light intensity at this time was 1.0 × 10 ⁻⁵ (FIG. 4A). On the other hand, also in FIG. 3B, when the incident light 10 is irradiated on the diffraction grating of this embodiment composed of the substrate 1, the resin 2, the light absorption film 3, and the high reflection film 4, the diffracted light 13 is obtained according to the theory of diffraction. However, since the transmitted light 14 that passes through the highly reflective film 4 and reaches the resin 3 is absorbed by the light absorbing film 3, the transmitted light 14 does not become stray light.

Here, the line widths of the incident light 10 and the diffracted lights 11 and 13 in FIGS. 3A and 3B indicate the intensity of the light intensity, and the larger the line width, the stronger the light intensity. The reflectance at a wavelength of 500 nm is 90% for the metal film 5, and 99% for the high reflection film 4, so that the diffracted light 13 from the high reflection film 4 is more than the diffracted light 11 from the metal film 5. The diffracted light intensity is also increased (the diffracted light 13 is shown by a thicker line than the diffracted light 11). Since the surface roughness of the high reflection film 4 and the metal film 5 is not zero, stray light due to surface scattering is actually generated slightly, and the film thickness of the high reflection film 4 is approximately the same as the film thickness of the metal film 5. The stray light intensity of the stray light due to the surface scattering is the same. However, the diffracted light intensity of the diffracted light 13 is stronger than that of the diffracted light 11, and as a result, FIG. 3B shows stray light (stray light due to surface scattering) with respect to the diffracted light intensity as compared with FIG. The relative intensity is reduced. As a result, the relative intensity of the stray light with respect to the diffracted light intensity in FIG. 3B was 0.9 × 10 ⁻⁵ (10% reduction compared to the prior art) (FIG. 4B).

  Further, as a conventional diffraction grating that replaces FIG. 3A, a proposal has been proposed in which a light absorbing material is mixed with resin 2 (not shown), but a light absorbing material is mixed with resin 2 as an adhesive. The resin 2 cures and shrinks, whereas the light-absorbing substance does not shrink in volume, so that the surface roughness of the resin 2 on which the sawtooth shape is formed increases, and as a result, the surface roughness of the metal film 5 also increases. . When the surface roughness of the metal film 5 increases, the generation of surface scattered light, that is, stray light increases. On the other hand, in the present embodiment, since the resin 2 that is an adhesive and the light absorption film 3 are separated, the surface of the resin 2 on which the sawtooth shape is formed does not change before and after the resin 2 is cured. Therefore, since the surface roughness of the light absorption film 3 and the high reflection film 4 is reduced, stray light due to surface scattered light is reduced. Further, when the resin 2 mixed with the light absorbing material is used, there are a portion where the metal film 5 and the light absorbing material are in direct contact and a portion where the resin film 2 is located between the metal film 5 and the light absorbing material. However, in the portion where there is a layer of the resin 2 between the latter metal film 5 and the light absorbing material, the light passing through the metal film 5 passes through the resin 2 before reaching the light absorbing material. At this time, a part of the transmitted light becomes scattered light on the surface of the resin 2 or becomes scattered light due to the non-planar surface of the light absorbing material, which causes stray light. On the other hand, in the present embodiment, since the high reflection film 4 and the light absorption film 3 are adjacent to each other, all the light transmitted through the high reflection film 4 is absorbed by the light absorption film 3, so that stray light is generated. do not do.

  Although only the planar diffraction grating is shown in the present embodiment, the configuration of the present invention may be applied to a concave diffraction grating. Further, the sawtooth shape formed in the diffraction grating is not limited to the triangular shape, and any shape that satisfies the diffraction theory may be used. Furthermore, the member that forms the light absorption film 3 is not necessarily limited to the carbon film, and any member that absorbs the wavelength of incident light may be used. For example, black chrome, black nickel, black quartz, or the like may be used. Absent. Also in the high reflection film, it is not necessary to be limited to the Ag alloy, and similarly to the Ag alloy, titanium oxide or a titanium oxide-based metal having a higher reflectance than Al may be used. Also in the substrate 1, a light absorbing member such as black quartz may be used.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.

  Compared with the first embodiment, the diffraction grating of the present embodiment is different in that a metal film 5 made of Al is provided instead of the highly reflective film 4, and is a diagram for explaining the first embodiment. 2, the metal film 5 made of Al can be used instead of the highly reflective film 4.

  Since the Ag alloy forming the highly reflective film 4 makes use of the high reflectance characteristics of Ag, the element added to improve durability is about several percent by weight. The characteristics are similar to Ag. That is, in a wavelength region shorter than about 400 nm, the reflectance of the Ag alloy is lower than that of an Al film generally used as a metal film of a diffraction grating, and is 90% or less. Therefore, the diffraction grating of the present embodiment is desirable when light having a wavelength shorter than about 400 nm is wavelength-dispersed by the diffraction grating.

  According to this embodiment, substantially the same effect as the first embodiment can be obtained.

  Although only the planar diffraction grating is shown in the present embodiment, the configuration of the present invention may be applied to a concave diffraction grating. Further, the sawtooth shape formed in the diffraction grating is not limited to the triangular shape, and any shape that satisfies the diffraction theory may be used. Furthermore, the member that forms the light absorption film 3 is not necessarily limited to the carbon film, and any member that absorbs the wavelength of incident light may be used. For example, black chrome, black nickel, black quartz, or the like may be used. Absent. Also in the substrate 1, a light absorbing member such as black quartz may be used.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.

  Compared with the first embodiment, the diffraction grating of the present embodiment is different in that the light absorption film 3 between the highly reflective film 4 and the resin 2 is removed, and the others are the same.

  A method for manufacturing the diffraction grating of the present invention will be described. FIG. 7 shows a side view of the diffraction grating. First, a master diffraction grating composed of a substrate 1, a resin 2, and a highly reflective film 4 is prepared (FIG. 7A). Although not shown, the sawtooth shape provided on the high reflection film 4 of the master diffraction grating is formed by machining or etching. Next, a high-reflection film 15 of the master diffraction grating is coated with a silicon-based or fluorine-based release agent 6 by vapor deposition or coating, and then a high-reflection film 15 is formed on the release agent 6 by vapor deposition. The resin 7 is applied (FIG. 7B). Subsequently, after covering the master diffraction grating with a guide 8 provided with a square hole, the substrate 9 is placed on the resin 7, and a pressure is applied by placing a weight (not shown) on the substrate 9. Covers the serrated groove surface of the highly reflective film 15 and the surface of the substrate 9 (FIG. 7C). The weight of the weight is set to an optimum weight depending on the area of the diffraction grating, the viscosity of the adhesive forming the resin 7, and the like. After the adhesive forming the resin 7 is cured, the guide 8 is removed from the master diffraction grating, and the substrate 9 is separated from the master diffraction grating. A replica diffraction grating in which 15 and the resin 7 are fixed to the substrate 9 is manufactured (FIG. 7D). The high reflection film 15 of the replica diffraction grating is formed with the same sawtooth shape as the sawtooth shape provided on the high reflection film 4 of the master diffraction grating, so that a replica of the master diffraction grating is manufactured.

  According to the present embodiment, there is no stray light reduction effect by the light absorption film 3 in the first embodiment, so the effect is lower than in the first embodiment. However, compared with the manufacturing method of the first embodiment, the surface forming film of the diffraction grating of this embodiment may be one layer so that the manufacturing cost can be reduced, so that it is selected in consideration of cost and optical characteristics. desirable.

  Although only the planar diffraction grating is shown in the present embodiment, the configuration of the present invention may be applied to a concave diffraction grating. Further, the sawtooth shape formed in the diffraction grating is not limited to the triangular shape, and any shape that satisfies the diffraction theory may be used. Also in the high reflection film 4, it is not necessary to be limited to the Ag alloy. Like the Ag alloy, titanium oxide or a titanium oxide-based metal having a higher reflectance than Al may be used. Also in the substrate 1, a light absorbing member such as black quartz may be used.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG.

  When the diffraction grating of this embodiment is compared with the first embodiment, the substrate 1 is removed, and the light absorption film 3 provided between the resin (support base material) 2 and the highly reflective film 4 is removed. The difference is that the light absorption film 3 is provided on the side surface of the resin 2 (the surface perpendicular to the surface provided with the highly reflective film 4 on which the sawtooth shape is formed). In the figure, the light absorbing film 3 is not shown on a part of the side surface of the resin 2, but this is for explaining the configuration of the diffraction grating of the present embodiment. The entire side surface is covered with the light absorption film 3.

  A method for manufacturing the diffraction grating of the present invention will be described. FIG. 9 shows a side view of the diffraction grating. First, a master diffraction grating composed of resin 2 and highly reflective film 4 is prepared (FIG. 9A). Although not shown, the sawtooth shape provided on the high reflection film 4 of the master diffraction grating is formed by machining or etching. Next, after coating the high reflection film 4 of the master diffraction grating with a silicon-based or fluorine-based release agent 6 by vapor deposition or coating, a high reflection film 15 made of an Ag alloy is formed on the mold release agent 6 by vapor deposition. Then, a resin 7 as an adhesive is applied (FIG. 9B). Subsequently, after covering the master diffraction grating with a guide 8 provided with a square hole, the pressing plate 16 is placed on the resin 7 and pressurized by placing a weight (not shown) on the pressing plate 16, The resin 7 covers the surface of the sawtooth groove of the highly reflective film 15 and the surface of the pressing plate 16 (FIG. 9C). The weight of the weight is set to an optimum weight depending on the area of the diffraction grating, the viscosity of the adhesive forming the resin 7, and the like. Further, as the pressing plate 16, optical glass such as a glass substrate is used so that the surface roughness on the side in contact with the resin 7 is small, and the surface is Teflon (registered trademark) or the like so that the resin 7 does not adhere. It is coated with a release agent. After the adhesive forming the resin 7 is cured, the guide 8 and the holding plate 16 are removed from the master diffraction grating, and the resin 7 is separated from the master diffraction grating, and then peeled off with the release agent 6 (not shown) as a boundary. Therefore, a replica diffraction grating in which the highly reflective film 15 is fixed to the resin 7 is manufactured (FIG. 9D). The high reflection film 15 of the replica diffraction grating is formed with the same sawtooth shape as the sawtooth shape provided on the high reflection film 4 of the master diffraction grating, so that a replica of the master diffraction grating is manufactured. By forming the light absorption film 3 made of a carbon film on the side surface of the resin 7 of the replica diffraction grating by vapor deposition, a replica diffraction grating (complete) is manufactured (FIG. 9E).

  The effect of the diffraction grating of the present invention will be described. FIG. 10A shows how diffracted light and stray light are generated in the diffraction grating of the present embodiment. In the diffraction gratings of the first to third embodiments, incident light is irradiated on the surface of the diffraction grating on which the sawtooth shape is formed. As shown in FIG. In the grating, incident light 10 is applied to the surface (resin 2) opposite to the side where the sawtooth shape of the diffraction grating is formed. The incident light 10 is refracted and incident on the surface of the resin 2 and reaches the highly reflective film 4 having a sawtooth shape. When the highly reflective film 4 is irradiated with the incident light 10, the diffracted light 11 is emitted and detected by the photodetector 19 according to the theory of diffraction. Here, since the film thickness of the high reflection film 4 is set to be thin in order to reduce the generation of scattered light, the film quality of the high reflection film 4 becomes incomplete. Although there is no obstacle, the transmitted light 14 goes straight as it is. That is, stray light is not generated by the transmitted light 14 being reflected by the lower surface of the highly reflective film 4. Further, a slight amount of reflected light 17 is generated at the interface between the highly reflective film 4 and the resin 2, but the light is absorbed by the light absorbing film 3 formed on the side surface of the resin 2, so that the reflected light 17 becomes stray light. There is no. Further, when the incident light 10 is irradiated on the surface of the resin 2, the reflected light 18 is slightly generated on the surface of the resin 2, but the photodetector 19 is not provided in the traveling direction of the reflected light 18. The reflected light 18 does not become stray light. Therefore, the diffraction grating of the present embodiment can reduce the relative intensity of stray light with respect to the diffracted light intensity, as in the first embodiment.

  Although only the planar diffraction grating is shown in the present embodiment, the configuration of the present invention may be applied to a concave diffraction grating. Further, the sawtooth shape formed in the diffraction grating is not limited to the triangular shape, and any shape that satisfies the diffraction theory may be used. Furthermore, the member that forms the light absorption film 3 is not necessarily limited to the carbon film, and any member that absorbs the wavelength of incident light may be used. For example, black chrome, black nickel, black quartz, or the like may be used. Absent. The light absorbing film 3 may have a configuration in which the light absorbing film 3 is provided on the surface of the highly reflective film 4 having a sawtooth shape so that the transmitted light 14 is absorbed by the light absorbing film 3 (FIG. 10B). )). Also in the high reflection film 4, it is not necessary to be limited to the Ag alloy, and similarly to the Ag alloy, titanium oxide or a titanium oxide-based alloy having higher reflectance than the Al metal may be used. Furthermore, an Al metal film may be used in place of the highly reflective film 4.

(Fifth embodiment)
With reference to FIG. 11, the overall configuration of a capillary array electrophoresis apparatus according to the fifth embodiment of the present invention will be described. This embodiment is a capillary array electrophoresis apparatus provided with the diffraction grating according to any one of the first to fourth embodiments.

  The capillary array electrophoresis apparatus according to this embodiment includes a capillary (a structure in which a quartz tube having an inner diameter of 50 μm and an outer diameter of 126 μm is covered with a polymer film having a thickness of 12 μm) including a separation medium for separating a test sample. A first buffer container 105 holding a buffer solution 104 for immersing the array 101, the negative electrode 102 of the capillary array 101 and the sample introduction part 103, a gel block 107 having a valve 106, a gel block 107 and a ground electrode 108; A second buffer container 110 holding a buffer solution 109 to be immersed, a syringe 111 for injecting a polymer as a migration medium into the capillary array 101, a detection unit 112 for acquiring information depending on the sample, and coherent light Light that irradiates the light irradiation unit 114 with the laser beam 113 And 115, a detection mechanism 117 for obtaining a fluorescence 116 sample occurs, a constant temperature bath 118 for adjusting the temperature of the capillary array 101, and a high voltage power source 119 for applying a voltage to the separation medium.

  The capillary array 101 has, for example, 48 quartz capillaries, which are tubular members, and a separation for separating a test sample in which a sample such as a DNA molecule is contained in the capillary and a DNA molecule in the test sample. The medium polymer is filled. At one end of the capillary array 101, a sample introduction portion 103 capable of introducing a sample into the capillaries is formed, and a negative electrode 102 capable of applying a negative voltage is disposed. The other end has a capillary head 120 which is connected to the gel block 107 and can move the separation medium between the gel block 107 and the capillary array 101. Between the sample introduction unit 103 and the capillary head 120, a detection unit 112 including a light irradiation unit 114 irradiated with a laser beam 113 is provided.

  The gel block 107 and the syringe 111 are separation medium injection mechanisms that inject a polymer as a separation medium into the capillary. When filling the capillary with the polymer as the separation medium, the valve 106 is closed and the syringe 111 is pushed in, so that the polymer in the syringe 111 is injected into the capillary.

  The capillary array 101, the negative electrode 102, the buffer solution 104, the gel block 107, the buffer solution 109 on the ground electrode side, the ground electrode 108, and the high voltage power source 119 constitute a voltage application mechanism for electrophoresis of the test sample. Accordingly, the negative electrode 102, the buffer solution 104, the capillary array 101 (more precisely, the polymer in the capillary), the gel block 107 (more precisely, the polymer in the gel block), the buffer solution 109 on the ground electrode side, An energization path composed of the ground electrode 108 is formed. A voltage is applied to this energization path by a high voltage power source 119. When a voltage is applied to the current path, the test sample in the polymer is electrophoresed and separated according to properties such as its molecular weight.

  The optical system of the capillary array electrophoresis apparatus includes a light source 115, a detection unit 112 including a light irradiation unit 114, and a detection mechanism 117 that detects fluorescence 116 generated from the detection unit 112. The light source 115 generates laser light 113 (488.0 nm and 514.5 nm light from an argon ion laser) that is coherent light. The laser light 113 generated from the light source 115 is divided into two equal parts by the half mirror 121, and the optical axes of the two equally divided laser lights 122 and 123 are substantially coaxial, and the mirror 124 causes the traveling direction to be opposite. The direction of travel is changed. In the detection unit 112, a light irradiation unit 114 where laser beams 122 and 123 pass through the capillaries is aligned, a plane including the central axes of 48 capillaries constituting the light irradiation unit 114, and a laser The lights 122 and 123 are arranged so as to be substantially in the same plane. The laser beams 122 and 123 are condensed by the condenser lens 125 and irradiate the light irradiation unit 114 from both the upper and lower directions so as to penetrate the light irradiation unit 114 composed of 48 capillaries simultaneously. The laser beams 122 and 123 excite the inspection sample, and the fluorescence 116 is emitted from the inspection sample.

  The detection mechanism 117 will be described with reference to FIG. The detection mechanism 117 includes a diffraction grating 126, a first lens 127, a second lens 128, and a detector 129. The fluorescence 116 emitted from the light irradiation unit 114 is collected by the first lens 127 and is incident on the diffraction grating 126. The fluorescence 116 is wavelength-dispersed by the diffraction grating 126, emitted as diffracted light 130, collected by the second lens 128, and detected by the detector 129. Thereby, information depending on the test sample such as a DNA molecule sequence can be acquired.

  The effect of the capillary array electrophoresis apparatus of the present invention will be described. According to the present embodiment, stray light mixed in the diffracted light 130 that is spectrally separated by the diffraction grating 126 is reduced, so that the background is reduced and the analysis sensitivity is improved. Therefore, a capillary array electrophoresis apparatus with excellent analytical performance can be realized.

  The configuration of the capillary array electrophoresis apparatus is not limited to the configuration of the present embodiment. For example, a planar diffraction grating 126 is replaced with a concave diffraction grating (a planar diffraction grating 126 and a concave diffraction grating). A similar effect can be obtained by replacing the same with the same cross-sectional configuration) and removing the second lens 128.

(Sixth embodiment)
FIG. 13 shows the overall configuration of a liquid chromatograph that is a sixth embodiment of the present invention. The present embodiment is a liquid chromatograph provided with the diffraction grating according to any one of the first to fourth embodiments.

  The liquid chromatograph according to this embodiment includes a pump 201, an autosampler 202, a thermostatic chamber 203, a separation column 204, a detection mechanism 205, and a data processing unit 206.

  The mobile phase 207 is sent to the separation column 204 by the pump 201. The separation column 204 is disposed in the thermostatic chamber 203, and the sample is introduced into the flow path by an autosampler 202 having a switching valve between the pump 201 and the separation column 204. Each separated component separated by the separation column 204 passes through the detection mechanism 205 and is then discharged as a waste liquid 208.

  The detection mechanism 205 will be described with reference to FIG. The detection mechanism 205 includes a diffraction grating 209, a light source 210, a flow cell 211, a first lens 212, a second lens 213, and a detector 214. Incident light 215 emitted from the light source 210 irradiates the flow cell 211. Since the separated components separated in the separation column 204 are fed into the flow cell 211, the incident light 215 emitted from the flow cell 211 is light that has passed through the separated components separated in the separation column 204. It is. Incident light 215 emitted from the flow cell 211 is collected by the first lens 212 and is incident on the diffraction grating 209. The incident light 215 is wavelength-dispersed by the diffraction grating 209, emitted as diffracted light 216, collected by the second lens 213, and detected by the detector 214. Thereby, information of each separated component separated by the separation column 204 can be acquired.

  The effect of the liquid chromatograph of the present invention will be described. According to the present embodiment, stray light mixed into the diffracted light 216 that is wavelength-dispersed by the diffraction grating 209 is reduced, so that the detection accuracy of the detection signal (transmittance) is improved. Therefore, a liquid chromatograph excellent in analytical performance can be realized.

  The detection mechanism 205 is not limited to the optical system of the present embodiment. For example, a planar diffraction grating 209 is replaced with a concave diffraction grating (a cross-sectional configuration of the planar diffraction grating 209 and the concave diffraction grating). The same effect can be obtained even in an optical system in which the second lens 213 is removed.

(Seventh embodiment)
FIG. 15 shows the overall configuration of a spectrophotometer that is a seventh embodiment of the present invention. This embodiment is a spectrophotometer provided with the diffraction grating according to any one of the first to fourth embodiments.

  In the spectrophotometer according to this embodiment, incident light 302 emitted from a light source 301 is collected by a first lens 303 and is incident on a diffraction grating 304. The incident light 302 is wavelength-dispersed by the diffraction grating 304, emitted as diffracted light 305, collected by the second lens 306, and divided into two equal parts by the half mirror 307 into reflected light 311 and transmitted light 312. . The reflected light 311 is detected as reference light by the reflected light detector 310, while the transmitted light 312 passes through the sample 308 and is detected by the transmitted light detector 309. The component of the sample 308 is analyzed by comparing the reflected light 311 and the transmitted light 312.

  The effect of the spectrophotometer of the present invention will be described. According to the present embodiment, stray light mixed into the diffracted light 305 that is wavelength-dispersed by the diffraction grating 304 is reduced, so that the detection accuracy of the detection signal (transmittance) is improved. Therefore, a spectrophotometer excellent in analytical performance can be realized.

  Note that the configuration of the spectrophotometer is not limited to the optical system of the present embodiment. For example, a planar diffraction grating 304 is replaced with a concave diffraction grating (a planar diffraction grating 304 and a concave diffraction grating). The same effect can be obtained with an optical system in which the second lens 306 is removed by replacing the same with the same cross-sectional configuration. Furthermore, the spectrophotometer of this embodiment shows a configuration in which the transmittance is detected by comparing the reflected light 311 and the transmitted light 312. For example, when the sample 308 is irradiated with incident light, the sample 308 is detected. You may use for the spectrophotometer which detects the fluorescence which light-emits.

(Eighth embodiment)
FIG. 16 shows the overall configuration of a biochemical automatic analyzer according to the eighth embodiment of the present invention. This embodiment is a biochemical automatic analyzer provided with the diffraction grating according to any one of the first to fourth embodiments.

  The biochemical automatic analyzer according to this embodiment includes a reaction cell 401, a sample disk 402, a sample dispensing mechanism 403, a reagent disk 404, a reagent dispensing mechanism 405, a light source 406, and a detection device 407.

  The sample in the sample disk 402 is injected into the reaction cell 401 by the sample dispensing mechanism 403. Next, the reagent in the reagent disk 404 is injected into the reaction cell 401 into which the sample has been injected by the reagent dispensing mechanism 405, and is stirred and mixed.

  The detection device 407 will be described with reference to FIG. The detection device 407 includes a diffraction grating 408, a first lens 409, a second lens 412, and a detector 413. Incident light 410 emitted from the light source 406 is collected by the first lens 409, passes through the reaction cell 401, and enters the diffraction grating 408. The incident light 410 is wavelength-dispersed by the diffraction grating 408, emitted as diffracted light 411, collected by the second lens 412, detected by the detector 413, and analyzed.

  The effect of the biochemical automatic analyzer of the present invention will be described. According to the present embodiment, stray light mixed in the diffracted light 411 that is wavelength-dispersed by the diffraction grating 408 can be reduced, so that the detection accuracy of the detection signal (transmittance) is improved. Therefore, a biochemical automatic analyzer excellent in analytical performance can be realized.

  The configuration of the biochemical automatic analyzer is not limited to the configuration of the present embodiment. For example, a planar diffraction grating 408 is replaced with a concave diffraction grating (a planar diffraction grating 408 and a concave diffraction grating). The same effect can be obtained even by replacing the second lens 412 with the same cross-sectional configuration.

1, 9 Substrate 2, 7 Resin 3 Light absorption film 4, 15 High reflection film 5 Metal film 6 Release agent 8 Guide 10, 215, 302, 410 Incident light 11, 13, 130, 216, 305, 411 Diffracted light 12 Stray light 14, 312 Transmitted light 16 Holding plates 17, 18, 311 Reflected light 19 Photo detector 101 Capillary array 102 Negative electrode 103 Sample introduction part 104, 109 Buffer liquid 105 First buffer container 106 Valve 107 Gel block 108 Earth electrode 110 First 2 Buffer container 111 Syringe 112 Detection unit 113, 122, 123 Laser beam 114 Light irradiation unit 115, 210, 301, 406 Light source 116 Fluorescence 117, 205 Detection mechanism 118, 203 Constant temperature bath 119 High voltage power supply 120 Capillary head 121, 307 Half Mirror 124 Mirror 125 Condensing lens 126, 209, 304, 408 Diffraction gratings 127, 212, 303, 409 First lens 128, 213, 306, 412 Second lens 129, 214, 413 Detector 201 Pump 202 Autosampler 204 Separation column 206 Data processing unit 207 Movement Phase 208 Waste liquid 211 Flow cell 308 Sample 309 Transmitted light detector 310 Reflected light detector 401 Reaction cell 402 Sample disk 403 Sample dispensing mechanism 404 Reagent disk 405 Reagent dispensing mechanism 407 Detection device

Claims (7)

In a diffraction grating having a support substrate and a light reflecting member, wherein the light reflecting member is provided with a plurality of grooves,
Between the support substrate and the light reflecting member, a resin layer made of an adhesive and a light absorbing member are provided, and the resin layer and the light absorbing member are laminated independently,
The diffraction grating, wherein the light absorbing member is sandwiched between the light reflecting member and the resin layer . The diffraction grating according to claim 1, wherein
The diffraction grating, wherein the light reflecting member is made of an Ag alloy, Al, or a titanium oxide-based metal. The diffraction grating according to claim 1, wherein
The diffraction grating, wherein the light absorbing member is made of carbon, black chrome, black nickel, or black quartz. In a capillary array electrophoresis apparatus using a diffraction grating having a support substrate and a light reflecting member, and the light reflecting member is provided with a plurality of grooves,
Between the support substrate and the light reflecting member, a resin layer made of an adhesive and a light absorbing member are provided, and the resin layer and the light absorbing member are laminated independently,
The capillary array electrophoresis apparatus, wherein the light absorbing member is sandwiched between the light reflecting member and the resin layer . In a liquid chromatograph using a diffraction grating having a support substrate and a light reflecting member, and the light reflecting member is provided with a plurality of grooves,
Between the support substrate and the light reflecting member, a resin layer made of an adhesive and a light absorbing member are provided, and the resin layer and the light absorbing member are laminated independently,
The liquid chromatograph, wherein the light absorbing member is sandwiched between the light reflecting member and the resin layer . In a spectrophotometer using a diffraction grating having a support substrate and a light reflecting member, the light reflecting member having a plurality of grooves,
Between the support substrate and the light reflecting member, a resin layer made of an adhesive and a light absorbing member are provided, and the resin layer and the light absorbing member are laminated independently,
The spectrophotometer, wherein the light absorbing member is sandwiched between the light reflecting member and the resin layer . In a biochemical automatic analyzer using a diffraction grating having a support substrate and a light reflecting member, wherein the light reflecting member is provided with a plurality of grooves,
Between the support substrate and the light reflecting member, a resin layer made of an adhesive and a light absorbing member are provided, and the resin layer and the light absorbing member are laminated independently,
The biochemical automatic analyzer, wherein the light absorbing member is sandwiched between the light reflecting member and the resin layer .

Images