Automatic analysis device, and method for manufacturing protective cover for automatic analysis device

Abstract

In order to provide an automatic analysis device having a cover that has high visibility and is provided with electromagnetic wave shielding properties, and a method for manufacturing a protective cover for the automatic analysis device, the configuration indicated below is adopted.　This automatic analysis device comprises a liquid-dispensing mechanism that is provided on the upper surface of a body housing, and a protective cover that is provided above the body housing and covers at least the dispensing mechanism, the automatic analysis device being characterized in that: the protective cover has an electromagnetic wave shield layer having an opening through which light can be transmitted, and a transparent substrate supporting the electromagnetic wave shield layer; and the protective cover is integrally formed via a curved part.

Description

Automatic Analyzer and Method for Manufacturing a Protective Cover of an Automatic Analyzer

[0001] The present invention relates to an automatic analyzer and a method for manufacturing a protective cover of an automatic analyzer.

[0002] Automatic analyzers for qualitative and quantitative analysis of biological components such as blood and urine are used in clinical tests in hospitals, testing centers, and many other medical research institutions. Inside an automatic analyzer, there is a dispensing mechanism for sucking a predetermined amount of sample and reagent from a sample container containing the sample and a reagent container containing the reagent, respectively, and discharging them into a reaction container.

[0003] The dispensing mechanism is required to have extremely high dispensing accuracy. Also, since the sample and reagent are mechanically moved to the dispensing position at high speed to a large number of containers, dispensed with high precision, and analyzed, it is necessary to appropriately confirm visually whether the analyzer is operating properly. Therefore, a transparent cover is provided on the upper part of the analyzer so that the movement of the dispensing mechanism, incubator disk, etc. inside the automatic analyzer can be visually observed.

[0004] The transparent cover needs to suppress the intrusion of dust, etc. from the outside into the apparatus and also enable visual recognition of the operating status of the internal devices. It also has the effect of preventing injuries to the user and damage to the sample container, reagent container, apparatus, etc. caused by accidental contact with the operating part.

[0005] In addition, since the dispensing mechanism has not only horizontal movement visible from above but also vertical movement, lateral visibility is also required. Therefore, it is common to have a structure that curves from the upper part to the side part so that the upper part and the side part can be continuously visually observed.

[0006] On the other hand, in recent years, with the increased use of electronic devices, various electromagnetic waves are entering automated analyzers from the outside, becoming noise in the analyzer's measurement information and increasing the likelihood of malfunctions. Therefore, the housing of automated analyzers is made of metal such as stainless steel, which has high electromagnetic shielding properties, to suppress the intrusion of electromagnetic waves. However, the transparent cover mentioned above is made of a transparent resin material or glass for ease of opening and closing, and for durability so as not to be damaged by impact during opening and closing (for example, paragraph

[0043] of Patent Document 1). For this reason, under certain conditions, there was a non-zero possibility that electromagnetic waves could enter from the outside and affect the measurement.

[0007] On the other hand, as a general technique for adding electromagnetic wave shielding functionality to a transparent flat plate, the techniques described in Patent Documents 2 and 3 are known.

[0008] Japanese Patent Publication No. 2010-256345, U.S. Patent Application Publication No. 2016 / 0113161, Japanese Patent Publication No. 2003-318595

[0009] The technology described in Patent Document 2 achieves both visibility and electromagnetic shielding by attaching a metal mesh to a transparent flat plate. Furthermore, the technology described in Patent Document 3 achieves both visibility and electromagnetic shielding by etching a conductive metal film, formed by vapor-depositing copper, aluminum, etc., or by adhering copper foil, etc., onto a transparent substrate, to create a grid-like shielding pattern. When these transparent flat plates are applied to the protective cover of an automated analyzer, it is envisioned that the protective cover will consist of multiple transparent flat plates (for example, one top cover and four side covers) joined together by a frame or similar means. On the other hand, as can be seen from Figure 1 of Patent Document 1, the protective cover is required to have high visibility (for example, visibility from diagonally above) by curving the corners to form a single cover. The technologies described in Patent Documents 2 and 3 do not anticipate bending the transparent flat plate. If the transparent flat plates described in Patent Documents 2 and 3 were to bend, there is a high possibility that wrinkles would form in the shielding film at the curved portion, or that the shielding film would peel off, reducing visibility.

[0010] The present disclosure provides an automated analyzer having a cover that has high visibility and electromagnetic shielding properties, and a method for manufacturing a protective cover for an automated analyzer.

[0011] The present invention provides the following configuration for achieving the above objectives: An automatic analyzer comprising a liquid dispensing mechanism provided on the upper surface of a main body housing, and a protective cover provided above the main body housing that covers at least the dispensing mechanism, wherein the protective cover comprises an electromagnetic wave shielding layer having light-transmitting openings and a transparent substrate supporting the electromagnetic wave shielding layer, and the protective cover is integrally formed via a curved portion.

[0012] Furthermore, a method for manufacturing a protective cover for an automatic analyzer comprising a liquid dispensing mechanism provided on the upper surface of the main body housing and a protective cover provided above the main body housing that covers at least the dispensing mechanism, characterized in that an electromagnetic wave shielding layer having light-transmitting openings is formed on the transparent substrate while the transparent substrate is in a planar state, and the transparent substrate is curved on the surface where the electromagnetic wave shielding layer is formed.

[0013] The present invention provides an automated analyzer having a cover that has high visibility and electromagnetic shielding properties, and a method for manufacturing a protective cover for an automated analyzer.

[0014] A side view of an automated analyzer according to an embodiment of the present invention. A top view of an automated analyzer according to an embodiment of the present invention. A front view of an automated analyzer according to an embodiment of the present invention. A perspective view of an automated analyzer according to an embodiment of the present invention. A schematic diagram of a dispensing mechanism according to an embodiment of the present invention. A diagram showing an example of the manufacturing process of a protective cover according to an embodiment of the present invention. A top view of a protective cover according to an embodiment of the present invention. A cross-sectional view of a protective cover according to an embodiment of the present invention. A diagram showing an example of the bonding portion between a protective cover and a housing according to an embodiment of the present invention.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0016] (1) Automatic analyzer Figures 1 to 4 show the overall configuration of an automatic analyzer according to an embodiment of the present invention. The automatic analyzer 1 reacts a sample with a reagent to analyze a specific component in the sample. Its general configuration includes a reagent container loading section 3 into which reagent containers 2 filled with reagents are loaded, a reagent refrigerator 4 enclosing the reagent container loading section 3, and a rack transport line 7 which is a transport line for racks 6 on which sample containers 5 holding samples are mounted. The rack transport line 7 is provided on an upper panel parallel to the floor surface on which the automatic analyzer 1 is installed.

[0017] Furthermore, the automated analyzer 1 is equipped with a disc-shaped incubator disk 9 on which many reaction vessels 8 can be installed, a sample dispensing nozzle 10 which is a nozzle for dispensing samples, a reagent dispensing nozzle 11 which is a nozzle for dispensing reagents, and a reaction vessel transport mechanism 12 which is a mechanism for transporting reaction vessels 8.

[0018] As described above, multiple reaction vessels 8 can be installed on the incubator disk 9, and the incubator disk 9 is attached in such a way that the reaction vessels 8, which are installed in the circumferential direction, can be moved to their respective predetermined positions by rotation.

[0019] In the automated analyzer 1, sample containers 5 for holding samples are mounted on rack 6 as described above, and the rack transport line 7 moves the sample containers 5 to a sample dispensing position near the sample dispensing nozzle 10.

[0020] The sample dispensing nozzle 10 rotates and moves up and down. The sample dispensing nozzle 10 moves above the sample container 5 held in the rack 6, then descends to aspirate a predetermined amount of the sample held in the sample container 5.

[0021] Next, the sample dispensing nozzle 10, which has aspirated the sample, moves above the incubator disc 9, then descends to dispense the sample into an unused reaction vessel 8 held on the incubator disc 9. Once the dispensing of the sample is complete, the tip of the sample dispensing nozzle 10 is placed in the nozzle cleaning mechanism 25 for cleaning.

[0022] Furthermore, multiple reagent containers 2 are loaded into the reagent container loading section 3 located inside the reagent cooler 4. In addition, a lid 19 of the reagent cooler 4 is provided on top of the reagent container loading section 3, and the inside of the reagent cooler 4 can be kept at a predetermined temperature.

[0023] The lid 19 does not cover part of the cooler, but there is a loader there for lifting and inserting the reagent container loading section 3.

[0024] Furthermore, a reagent suction hole 20, which is a through-hole for aspirating reagents, is provided in a part of the lid 19. The reagent dispensing nozzle 11 rotates and moves up and down. It rotates and moves above the reagent suction hole 20 provided in the lid 19 of the reagent cooler 4, then descends and passes through the reagent suction hole 20. After that, the tip of the reagent dispensing nozzle 11 that has passed through the reagent suction hole 20 is placed into the reagent in the predetermined reagent container 2 and a predetermined amount of reagent is aspirated. After that, the reagent dispensing nozzle 11 rises and rotates to move above the predetermined position on the incubator disk 9, and then discharges the reagent into the reaction vessel 8 installed on the incubator disk 9. Once the discharge of the reagent is complete, the tip of the reagent dispensing nozzle 11 is placed in the nozzle cleaning mechanism 25 and cleaned.

[0025] The reaction vessel transport mechanism 12 rotates and moves up and down. After the dispensing and stirring of the sample and reagents are completed and a predetermined reaction time has elapsed in the incubator disc 9, it moves above the reaction vessel 8, then descends to hold the reaction vessel 8. Subsequently, the reaction vessel 8 is transported to the measurement unit 26 by the rotational movement of the reaction vessel transport mechanism 12, and the color intensity, turbidity, etc. of the sample and reagent mixture in the reaction vessel are quantified by the measurement unit 26.

[0026] Furthermore, the driving and timing of the various components described above are controlled by a control mechanism, such as a personal computer, of the automatic analysis device 1, which is not shown in the diagram.

[0027] (2) Dispensing Mechanism Next, the dispensing mechanism will be explained using Figure 5. Figure 5 shows a schematic diagram of the dispensing mechanism.

[0028] The dispensing mechanism 114 includes a dispensing nozzle 115 for dispensing samples or reagents, which moves as described in Figures 1 to 4. The dispensing nozzle 115 is connected to a syringe 105 via a flow path 104, and the inside of both is filled with system water 106. The syringe 105 has a cylinder 107 and a plunger 108. The plunger 108 moves vertically relative to the syringe 105, thereby aspirating and dispensing liquid samples or liquid reagents from the dispensing nozzle 115. The syringe 105 has a flow path that leads to a water supply tank 109, and a solenoid valve 110 and a water supply pump 111 are provided in this flow path.

[0029] The water supply tank 109 stores system water 106, and the water supply pump 111 drives the system water 106 out of the dispensing nozzle 115, which allows the inside of the dispensing nozzle 115 to be cleaned. This cleaning is performed before dispensing the sample or reagent, thereby minimizing contamination of the sample or reagent with contaminants from the dispensing nozzle during dispensing.

[0030] The pressure sensor unit 112 is located between the flow path 104 and the syringe 105. It measures the pressure in the flow path 104 with the pressure sensor 113 and sends the result to the control unit 103.

[0031] After the sample and reagent have been aspirated and discharged using these nozzles, the nozzle tip is immersed in a nozzle cleaning mechanism 117 containing cleaning water 116 to clean it.

[0032] As described above, automated analyzers have many mechanically moving parts, and it is necessary to visually check the movement of these moving parts as needed while conducting the analysis.

[0033] (3) Protective cover with electromagnetic shielding layer (a) A protective cover with an electromagnetic shielding layer (also called a "transparent cover" due to its function) relating to the present invention will be explained using the shape diagrams 1 and 4. The protective cover 118 with the electromagnetic shielding layer is attached to the housing to prevent dust and other particles from entering the measuring section of the automatic analyzer, and because it is transparent, the internal conditions can be visually observed. The electromagnetic shielding layer is formed on the side with the dispensing mechanism (inner surface) so as not to peel off due to contact with human hands or objects.

[0034] As shown in Figure 4, when viewed from diagonally above, the protective cover 118 with the electromagnetic shielding layer has a curved section that curves approximately 90° with a gentle curvature. It consists of a first surface 119 with the electromagnetic shielding layer, whose upper surface is almost parallel to the top panel of the automatic analyzer, and a second surface 120 with the electromagnetic shielding layer, whose side surface is almost perpendicular to the top panel (vertical surface). The first surface 119 and the second surface 120 are such that the upper surface is almost parallel to the top panel of the automatic analyzer, and the side surface is almost perpendicular to the top panel (vertical surface), respectively, so as not to obstruct the visibility of the operation of the dispensing mechanism from above and from the side. The first surface 119 and the second surface 120 do not necessarily have to be flat and may have a certain degree of curvature. If the side on which the cover of the automatic analyzer opens and closes is considered the front, the dispensing mechanism moves in three dimensions, horizontally and vertically, when viewed from the front. Since the first surface 119 and the second surface 120 are connected by a curved section, the three-dimensional operation of the dispensing mechanism can be continuously observed.

[0035] The curved portion involves light scattering, resulting in reduced visibility. Therefore, a smaller inner diameter of the curved portion is preferable as it reduces the area with poor visibility. However, if the inner diameter is made too small, the conductive grid of the electromagnetic shielding layer may deform, potentially reducing its electromagnetic shielding performance. As will be described later, the electromagnetic shielding layer is formed on a flat transparent plate and then bent. Therefore, it is desirable to make the inner diameter as small as possible within a range where deformation is difficult even when bent. According to the inventors' experiments, it was found that if the curvature of the curved portion is 5 mm or more, the dispensing device and the like, which are installed on the top panel of the automatic analyzer, can be observed simultaneously through both the first surface 119 and the second surface 120 of the protective cover 118.

[0036] Furthermore, the inventors found that, when L is the length of the side where the first surface, second surface, and curved section of the protective cover are continuously connected, it is desirable for the inner diameter of the curved section to be between 0.02 and 0.2L. This is because if the inner diameter is less than 0.02L, it will affect the shape of the electromagnetic shielding layer and reduce its electromagnetic shielding performance. On the other hand, if it is 0.2L or more, the space inside the protective cover will be reduced too much, making it impossible to arrange the equipment necessary for analysis.

[0037] (b) Material of the protective cover The protective cover is preferably made of a material with a visible light transmittance of 30% or more. This is because if it is less than 30%, the operation of the internal dispensing mechanism will be difficult to see from the outside. It is required to be lightweight so that it can be easily opened and closed. It is also desirable that the material not break due to vibration when opening and closing it be used. Considering these factors, a transparent resin is preferable to glass, and specifically, general-purpose resins such as amorphous resins such as acrylic resin, polycarbonate resin, and polyethylene terephthalate resin are preferred. Of these, acrylic resin is more preferable because it is less likely to yellow under the lighting of the room where the measuring device is installed, and has a pencil hardness of H to 2H, which is higher than that of polycarbonate resin and polyethylene terephthalate resin, as it is less likely to be damaged by contact and friction from hands, fingers, nails, etc. when opening and closing the protective cover.

[0038] Furthermore, when forming an electromagnetic shielding layer with a paste containing organic solvents, as described later, acrylic resin is preferable because it readily dissolves and swells in organic solvents such as ketones, esters, and ethers that may be present in the paste. After formation, the acrylic resin partially swells and dissolves, roughening the surface and contributing to improved adhesion of the electromagnetic shielding layer to the cover.

[0039] (c) Material and Formation Method of Electromagnetic Shielding Layer The electromagnetic shielding layer consists of a conductive material and a resin mainly composed of organic materials that holds it. The conductive material can be a mixture of metal powder such as silver, copper, or iron and resin. Examples of metals include silver (conductivity: 10⁸ × 10⁻⁸). ６ S / m) is the most preferred because it has the highest conductivity. In addition, copper (conductivity: 44-71 x 10) is also preferred. ６S / m), Aluminum (electrical conductivity: 33 x 10 ６ S / m can also be used. Furthermore, conductive particles (metal powders) can be made not only from a single material, but also from a mixture of multiple metals, such as copper powder coated with silver. For the organic resin, a thermosetting resin is preferred, as it has excellent heat resistance, high adhesion, and is resistant to moisture.

[0040] To improve electromagnetic shielding performance, it is necessary to form an electromagnetic shielding layer continuously on the first surface, the second surface, and the curved portion of the protective cover. For this reason, it is desirable to form it in a flat state using methods such as screen printing. The mixture of conductive material and resin used in this process is preferably a paste-like mixture of the conductive material and resin with a small amount of organic solvent.

[0041] Next, the flat plate with the electromagnetic shielding layer is bent using the bending member 127 shown in Figure 6. At this time, the flat plate is heated to a degree that it can be bent when pressed against the bending member 127. If the plate is bent so that the side with the electromagnetic shielding layer is on the outside, there is a concern that the electromagnetic shielding performance will decrease due to deformation of the electromagnetic shielding layer, so it is bent so that the side with the electromagnetic shielding layer is on the inside.

[0042] Furthermore, when a metal mesh, as described in Patent Document 2, is bonded to a flat transparent substrate and then bent, wrinkles may form in the curved portion, reducing visibility in that portion, making it difficult to apply to a protective cover for an automated analyzer. Additionally, the wrinkles may detract from the appearance, potentially reducing the marketability of the automated analyzer. Moreover, while the method of forming a metal film on a transparent substrate and creating openings by etching, as described in Patent Document 3, is suitable for providing electromagnetic shielding on large-area flat plates such as plasma displays, it is unsuitable for application to components with curved portions, such as the protective cover for an automated analyzer targeted by the present invention, as it may wrinkle in the curved portion, similar to the metal mesh described in Patent Document 2. Additionally, the manufacturing cost is higher compared to the conductive paste mesh printing method of the present invention, raising concerns about increased costs for the automated analyzer.

[0043] (d) Shape of the electromagnetic shielding layer, etc. Since the electromagnetic shielding property deteriorates if the electromagnetic shielding layer 121 is discontinuous, it is continuously formed in a lattice pattern on the transparent base material 124 and has regular openings 130 shown in FIG. 7. The openings 130 are not limited to squares and may have various geometric patterns such as polygons, circles, or combinations thereof. The electromagnetic shielding layer 121 enables electromagnetic shielding by absorbing and reflecting electromagnetic waves, and since visible light passes through the openings 130, the operating status of dispensing devices etc. inside the device can be observed. The size of the openings 130 is determined by the line width and the pitch of the lattice, and the larger the line width of the lattice and the smaller the pitch, the larger the openings 130.

[0044] When the electromagnetic shielding layer 121 is formed on the transparent base material by a printing method using the above mixture of the paste-like conductive particles 123 and the resin 131, the paste spreads slightly after printing. Therefore, when the integrated area of the electromagnetic shielding layer in a plane parallel to the transparent base material is taken as the cross-sectional area and the adhesion surface between the transparent base material and the electromagnetic shielding layer is taken as the bottom, the cross-sectional area at the bottom is larger than that at the top. As a result, as shown in FIG. 8, the visibility when visually recognizing the inside of the analyzer through the protective cover obliquely with the human eye 122 is improved.

[0045] In order to prevent deterioration of the electromagnetic shielding layer 121, the electromagnetic shielding layer 121 may be coated from above with a transparent resin 126.

[0046] Since the conductive particles 123 such as silver and copper have a higher density than the resin 131, they settle near the transparent base material after printing. As a result, the conductive particles are localized, the conductivity of the electromagnetic shielding layer increases, and the shielding property is improved, which is preferable. As the conductive particles, silver, which has a high bulk conductivity and a larger density than copper, iron, etc., is most suitable.

[0047] The protective cover, which has an electromagnetic shielding layer formed on it, has a visible portion that allows the interior to be seen and an adhesive portion that is not visible because it is bonded to the housing 125. The protective cover is bonded to the housing 125 at the adhesive portion with conductive tape 128. The electromagnetic shielding layer 121 is formed up to the connection portion 129 with the ground and is electrically connected to the ground. This improves the electromagnetic shielding performance and reduces noise. To facilitate electrical connection with the ground, the electromagnetic shielding layer has a wider line width at the adhesive portion of the protective cover than the line width of the visible portion. This also makes it easier to test the conductivity of the electromagnetic shielding layer before bonding it to the housing 125, as the measurement terminal can be easily placed on the grid with the wider line width.

[0048] The following provides a detailed explanation of how the electromagnetic shielding layer is formed.

[0049] (4) Formation of electromagnetic wave shielding layer (Part 1) A silver-containing paste is prepared by kneading 92% by weight of silver particles with an average particle diameter of 1 μm, 5% by weight of resin components, and 3% by weight of cyclohexanone. Using this, silver-containing lines are printed onto a blue acrylic plate measuring 0.8 m in length, 0.6 m in width, and 3 mm in thickness via a screen printing plate with a screen thickness of 45 μm and a grid line width / grid spacing of 100 μm / 500 μm. After that, the plate is heated at 100°C for 30 minutes to almost completely volatilize the cyclohexanone, forming a grid-like electromagnetic wave shielding layer made of a conductor with a layer thickness of 30 μm and a grid line width / grid spacing of 150 μm / 450 μm.

[0050] After placing the acrylic plate with the electromagnetic shielding layer in a 180°C constant temperature bath for 5 minutes, immediately bend it 90° from the center with the electromagnetic shielding layer facing inward using the bending member shown in Figure 7.

[0051] (5) Evaluation: When the inside of the device was observed visually, the three-dimensional operation of the dispensing mechanism was easily observed. Next, the total light transmittance of this acrylic plate at wavelengths of 380 to 780 nm was measured using a spectrophotometer V770 manufactured by JASCO Corporation. Next, the visible light transmittance was calculated by multiplying it by the weighting coefficient obtained from the wavelength distribution of the CIE (International Commission on Illumination) daylight D65 spectrum and the CIE light-adapted relative luminous efficiency in accordance with the JIS R3106 standard, and taking a weighted average, which was 41.4%.

[0052] Similarly, the visible light transmittance of a blue acrylic sheet without an electromagnetic shielding layer was also determined to be 59.6%. Therefore, it was found that when an electromagnetic shielding layer is formed, approximately 70% of the visible light transmittance when it is not formed is secured.

[0053] Next, to investigate the electromagnetic shielding performance, the electromagnetic shielding performance in the range of 100 kHz to 1 GHz was measured using the JSE-KEC electromagnetic shielding effect measuring device manufactured by Nippon Shield Enclosure Co., Ltd. The electromagnetic shielding performance at the most critical frequency of 400 MHz was 5 dB for the acrylic plate alone, but improved to 42 dB for the acrylic plate with the electromagnetic shielding layer formed on it. The EMC standard required for medical analytical equipment (IEC 60601-1-2:2014) states that an electromagnetic shielding performance of 30 dB or more at 400 MHz is desirable, and it was found that the electromagnetic shielding layer formed in this embodiment clears this standard.

[0054] Next, we used a tester to check the conductivity between the edge of the electromagnetic shielding layer furthest from the bent portion of the folded surface and the edge of the electromagnetic shielding layer furthest from the bent portion of the unfolded surface. It was confirmed that the formed electromagnetic shielding layer maintained conductivity even with a bent portion in the middle.

[0055] Formation of an electromagnetic wave shielding layer (Part 2) A copper-containing paste is prepared in the same manner as in Example 1, except that 92% by weight of copper particles with an average particle size of 5 μm is used instead of 92% by weight of silver particles with an average particle size of 1 μm.

[0056] Using this method, an electromagnetic shielding layer was printed onto an acrylic sheet, and then heated at 100°C for 30 minutes to almost completely volatilize the cyclohexanone, thereby forming an electromagnetic shielding layer on the acrylic sheet consisting of a conductor with a layer thickness of 30 μm and a grid line width / grid spacing of 150 μm / 450 μm. After that, this acrylic sheet was bent using the same procedure as in Example 1.

[0057] Next, the same evaluation as in Example 1 was performed. When the visible light transmittance was determined, it was 41.0% for both the folded and unfolded surfaces.

[0058] Therefore, it was found that even without forming an electromagnetic shielding layer using copper particles instead of silver particles, a transmittance of approximately 70% was achieved.

[0059] Next, to investigate the electromagnetic shielding performance, we examined the shielding performance in the range of 100 kHz to 1 GHz. The acrylic sheet alone showed a shielding level of 5 dB. With the acrylic sheet having an electromagnetic shielding layer formed on it, both the bent and unbent surfaces showed a shielding level of 42 dB. This confirmed that forming an electromagnetic shielding layer using copper particles instead of silver particles resulted in the same improvement in electromagnetic shielding performance as with silver particles.

[0060] Based on the inventors' experimental results, it was found that the optimal volume fraction of conductive particles for the electromagnetic shield used in the protective cover of the automated analyzer in this embodiment is 60% or more and 95% or less. If the volume fraction of conductive particles is less than 60%, the opportunities for contact between conductive particles decrease, the volume resistivity decreases, and the performance as an electromagnetic shield deteriorates. On the other hand, if the total volume fraction of conductive particles exceeds 95%, the viscosity becomes high, making it difficult to handle as a paste material, which may hinder the formation of the electromagnetic shield pattern. For this reason, it is desirable that the total volume fraction of conductive particles be 95% or less. Within this range, conductive particles other than silver, such as copper, may be added as conductive particles. Copper has high electrical conductivity, so it is desirable as a particle to mix with silver. In addition, the average particle size of the conductive particles is preferably 0.5 μm to 5 μm. Since the thickness of the electromagnetic shield layer used in the protective cover of the automated analyzer in this embodiment is about 45 μm before heating and about 30 μm after heating, if the average particle size of the conductive particles is greater than 5 μm, it becomes difficult to handle as a paste material. Furthermore, if the particles are smaller than 0.5 μm, they will aggregate and form clumps, making dispersion in the paste difficult.

[0061] Formation of Electromagnetic Shielding Layer (Part 3) The pencil hardness of the electromagnetic shielding layer of the acrylic protective cover formed with the electromagnetic shielding layer prepared in Examples 1 and 2 was measured and found to be 2B. Furthermore, when rubbed with a pencil of hardness B or higher at the same load and sweeping speed as in the pencil hardness measurement, the grid of the electromagnetic shielding layer prepared in Examples 1 and 2 peeled off in all cases. Since the electromagnetic shielding layer is formed on the inside of the protective cover, it is not rubbed against anything during normal measurements, but it may be rubbed with a cloth or the like during cleaning, so a certain degree of abrasion resistance is desirable. Therefore, the following studies were conducted to improve abrasion resistance.

[0062] A flat acrylic plate with an electromagnetic shielding layer was prepared using the same procedure as in Example 1. Next, acrylic resin pellets (2 parts by weight) were dissolved in 2-butanone (98 parts by weight). This solution was designated as coating solution A. Coating solution A was spin-coated onto the flat acrylic plate with the electromagnetic shielding layer at a rotation speed of 3000 rpm for 1 minute. After rotation, almost all of the 2-butanone in the coated coating solution A had evaporated. The coated acrylic plate was placed in an 80°C constant temperature bath for 30 minutes to almost completely evaporate the 2-butanone. In this way, a thin film of acrylic resin was formed on top of the electromagnetic shielding layer.

[0063] After bending this acrylic sheet using the same procedure as in Example 1, the same evaluation as in Example 1 was performed. The average transmittance in the visible region was found to be 41.4% for both the bent and unbent surfaces.

[0064] It was found that even when an acrylic resin thin film is formed on top of the electromagnetic wave shielding layer, approximately 70% of the transmittance of a layer without an electromagnetic wave shielding layer is maintained.

[0065] Next, to investigate the electromagnetic shielding properties, we examined the shielding performance in the range of 100 kHz to 1 GHz. For acrylic plates with a thin film of acrylic resin formed on top of the electromagnetic shielding layer, the level was 42 dB on both the bent and unbent surfaces, confirming sufficient electromagnetic shielding performance.

[0066] Next, the pencil hardness of the electromagnetic shielding layer of the acrylic protective cover was measured, and the result was B. Furthermore, when rubbed with a B-hardness pencil using the same load and sweeping speed as the pencil hardness measurement, the grid of the electromagnetic shielding layer did not peel off.

[0067] Based on the above, the abrasion resistance was improved by forming a thin film of acrylic resin on the electromagnetic wave shielding layer. Furthermore, no decrease in visible light transmittance, i.e., visibility, or electromagnetic wave shielding performance was observed even with the formation of the thin film of acrylic resin.

[0068] [Comparative Example] Prepare and mix an 8% by weight sodium hydroxide aqueous solution (10 parts by weight) and a 3.3% by weight glucose aqueous solution (10 parts by weight). This mixture will be called Mixture B. Next, mix a 3.4% by weight silver nitrate aqueous solution (10 parts by weight) and 2,2'-thiodiethanol (0.4 parts by weight). This mixture will be called Mixture C.

[0069] A blue acrylic sheet measuring 0.8 m in length, 0.8 m in width, and 3 mm in thickness is left in an ozone gas atmosphere until the contact angle with water on the surface is 10° or less. Mixture C is spin-coated onto this blue acrylic sheet at a rotation speed of 1000 rpm for 30 seconds. The coated acrylic sheet is then placed in an 80°C constant temperature bath for 5 minutes to allow the water to almost completely evaporate. Next, mixture B is spin-coated onto this blue acrylic sheet at a rotation speed of 1000 rpm for 30 seconds. The coated acrylic sheet is then placed in an 80°C constant temperature bath for 5 minutes to allow the water to almost completely evaporate. In this way, a uniform silver film with a thickness of 14 μm is formed on the surface of the blue acrylic sheet using the silver mirror reaction.

[0070] When this was evaluated in the same manner as in Example 1, the electromagnetic wave shielding performance was good at 44 dB, but the visible light transmittance was low at 12.6%. Due to the low visible light transmittance, it was difficult to visually observe the operation of the dispensing mechanism inside the device.

[0071] 1...Automatic analyzer 2...Reagent container 3...Reagent container loading unit 4...Reagent refrigerator 5...Sample container 6...Rack 7...Rack transport line 8...Reaction vessel 9...Incubator disc 10...Sample dispensing nozzle 11...Reagent dispensing nozzle 12...Reaction vessel transport mechanism 19...Lid 20...Reagent suction port 25...Nozzle cleaning mechanism 26...Measurement unit 104...Flow path 105...Syringe 106...System water 107...Cylinder 108...Plunger 109...Water tank 110...Solenoid valve 111...Water pump 112...Pressure sensor unit 113...Pressure sensor 114...Dispensing mechanism 115...Dispensing nozzle 116...Washing water 117...Nozzle cleaning mechanism 118...Protective cover with electromagnetic shielding layer 119...First surface of protective cover with electromagnetic shielding layer 120...Second surface of protective cover with electromagnetic shielding layer formed thereon 121...Electromagnetic shielding layer 122...Human eye 123...Conductive particles 124...Transparent substrate 125...Housing 126...Transparent resin 127...Bending member 128...Conductive tape 129...Connection part to ground 130...Opening 131...Resin

Claims

1. An automatic analyzer comprising a liquid dispensing mechanism provided on the upper surface of a main body housing, and a protective cover provided above the main body housing that covers at least the dispensing mechanism, wherein the protective cover comprises an electromagnetic wave shielding layer having an opening that allows light to pass through, and a transparent substrate that supports the electromagnetic wave shielding layer, and the protective cover is integrally formed via a curved portion.

2. An automatic analyzer according to claim 1, characterized in that the radius of curvature of the curved portion is 5 mm or more.

3. An automatic analyzer according to claim 1, characterized in that the protective cover is integrally formed with a first surface which is at least partially parallel to the upper surface of the main body housing and a second surface which is at least partially perpendicular to the upper surface of the main body housing, via the curved portion.

4. An automatic analyzer according to claim 3, characterized in that when the length of the side on which the first surface, the second surface, and the curved portion are continuously connected is L, the inner diameter of the curved portion is 0.02 to 0.2L.

5. An automatic analyzer according to claim 3, characterized in that the electromagnetic wave shielding layer is continuously configured on the side where the dispensing mechanism is located, extending across the first surface, the second surface, and the curved portion.

6. An automatic analyzer according to claim 1, characterized in that the electromagnetic wave shielding layer has a continuous grid shape and has the openings in the gaps between the grid.

7. An automatic analyzer according to claim 1, characterized in that at least a portion of the electromagnetic wave shielding layer is covered with a resin film.

8. An automated analyzer according to claim 1, characterized in that the electromagnetic wave shielding layer is composed of at least a resin and conductive particles.

9. An automated analyzer according to claim 8, characterized in that at least the surface of the conductive particles is mainly composed of silver.

10. An automatic analyzer according to claim 9, characterized in that the volume fraction of conductive particles in the electromagnetic wave shielding layer is 60% or more and 95% or less.

11. An automatic analyzer according to claim 1, characterized in that, when the electromagnetic wave shielding layer has its contact surface with the protective cover at the bottom and the opposite direction from the contact surface at the top, the cross-sectional area of ​​the plane parallel to the transparent substrate at the top is greater than the cross-sectional area of ​​the plane parallel to the transparent substrate at the bottom.

12. An automated analyzer according to claim 1, characterized in that the protective cover has a visible light transmittance of 30% or more.

13. An automatic analyzer according to claim 1, characterized in that the protective cover has a housing for installing the electromagnetic wave shielding layer.

14. An automatic analyzer according to claim 13, wherein the electromagnetic wave shielding layer has a continuous grid shape and has the openings in the gaps between the grid, and the electromagnetic wave shielding layer is characterized in that the area of ​​the openings in the region near the adhesive portion between the protective cover and the housing is smaller than the area of ​​the openings in other regions of the protective cover.

15. A method for manufacturing a protective cover for an automatic analyzer, comprising a liquid dispensing mechanism provided on the upper surface of a main body housing, and a protective cover provided above the main body housing that covers at least the dispensing mechanism, characterized in that an electromagnetic wave shielding layer having light-transmitting openings is formed on a transparent substrate while the transparent substrate is in a planar state, and the transparent substrate is curved on the surface where the electromagnetic wave shielding layer is formed.

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