Specimen imaging device, specimen supply device, and automatic analyzation device

Abstract

A specimen imaging device (11) is provided with: an imaging element (51); an imaging lens (52) which is disposed between the imaging element (51) and a container (3) containing a specimen (4), and which is such that an optical axis (Ai) and the central axis (At) of the container (3) perpendicularly intersect each other; a mirror (9) which is disposed so as to face an opening surface (U) of the container (3); and an objective lens (6) which is disposed on an optical path between the mirror (9) and the imaging lens (52). A straight line (Atm) symmetrical to the central axis (At) of the container (3) with the normal line (9n) of a reflection surface of the mirror (9) serving as the axis of symmetry passes through an object-side focal point (Fi) of the imaging lens (52) and coincides with the optical axis (Ao) of the objective lens (6). The focal length (fo) of the objective lens (6) is longer than the optical path length (Lmo) + (Lmt) from the objective lens (6) to the bottom of the container (3) and is greater than or equal to the distance (Loi) from the object-side focal point (Fi) of the imaging lens (52) to the objective lens (6).

Description

Sample imaging device, sample supply device, and automated analyzer 【0001】 The present invention relates to a sample imaging device, etc., for imaging a sample and container to be placed into an automated analyzer. 【0002】 Automated analyzers measure the amount of components such as sugar and cholesterol, or antigens and antibodies, by reacting samples such as blood and urine with reagents and measuring the absorbance and luminescence intensity of the reaction solution. Mixing the sample and reagent is generally done by aspirating a specified amount using a dispensing probe and dispensing it into the reaction vessel for reaction. When dispensing samples with low serum content, such as centrifuged blood, if the tip of the dispensing probe reaches the separating agent during aspiration and aspirates the separating agent, the dispensing probe may become clogged with the highly viscous separating agent, potentially requiring replacement. Also, when dispensing samples with air bubbles on the liquid surface, the surface of the bubbles may be mistakenly detected as the liquid surface, resulting in the aspiration of air and failure to aspirate the specified amount of sample, potentially leading to abnormal analysis results. Furthermore, if the color of the sample is clearly abnormal, or if the sample contains foreign matter, it is desirable to exclude it from measurement by the automated analyzer. 【0003】To address these challenges, automated analyzers equipped with cameras that image the container holding the sample from the side have been used. Prior art has been disclosed that uses the acquired images to detect the location of the interface between serum and a separating agent, and to determine the presence or absence of clots, air bubbles, and foam in serum or plasma. Patent Document 1 describes a method and apparatus for classifying artifacts in a sample, which acquires lateral images of the sample under multiple illumination conditions with varying wavelengths and exposure times, and generates an image by synthesizing pixels with the optimal exposure time (hereinafter referred to as high dynamic range processing). Pixel classification is performed on this image to detect the location of the interface between liquid and air, and the interface between serum and gel. Patent Document 2 describes a method and apparatus configured to quantify a sample from multiple lateral viewpoints, which calculates statistical data of pixels from the high dynamic range processed image and determines the presence or absence of clots, air bubbles, and foam in serum or plasma based on the statistical data. The bubble detection system and method described in Patent Document 3 involves using a tilted mirror positioned opposite the opening of the container to capture an image of the liquid surface of the sample with a camera positioned on the side of the container, comparing two images taken at different times, and determining the presence or absence of bubbles based on the magnitude of the pattern matching score. 【0004】 Japanese Patent Publication No. 2019-504997, Japanese Patent Publication No. 2019-504996, International Publication No. 2023 / 126745 【0005】 Patent documents 1 and 2 describe an example in which multiple cameras are placed at equal intervals to image a container from multiple different lateral viewpoints. This allows the sample (hereinafter referred to as "sample") to be imaged by at least one camera even if part of its field of view is obstructed by a barcode label attached to the container. However, in the case of long, narrow containers such as test tubes, the label may be attached over a wide area exceeding half the circumference of its side. In such cases, part of the liquid surface may be obscured by the label and appear in the image, potentially leading to insufficient detection of air bubbles or foam. 【0006】Patent Document 3 states that when the imaging lens is a typical single-focus lens, the lower the liquid level, the longer the working distance becomes, resulting in a smaller image. In particular, with elongated containers, the difference in liquid level depending on the amount of sample is large, and if the amount is small, it may not be possible to obtain the resolution necessary for judgment from the image of the liquid surface. 【0007】 The objective of the present invention is to provide a sample imaging device that can acquire high-resolution images of the liquid surface, which is effective for detecting the presence or absence of bubbles on the liquid surface, regardless of the amount of sample in the container. 【0008】 The specimen imaging device according to the present invention images a specimen contained in a container whose top surface is light-transmitting or open, and comprises an image sensor, an imaging lens positioned between the container and the image sensor, the optical axis of which intersects perpendicularly with the central axis of the container positioned at a predetermined imaging position, a mirror positioned opposite the top surface of the container, and an objective lens positioned on the optical path between the top surface of the container and the imaging lens, wherein a straight line symmetric to the central axis of the container passes through the object-side focal point of the imaging lens, with the normal to the reflective surface passing through the intersection of the reflective surface of the mirror and the extension of the central axis of the container as the axis of symmetry, the optical axis of the objective lens coincides with the straight line symmetric to the central axis of the container or the central axis of the container, the focal length of the objective lens is longer than the optical path length from the objective lens to the bottom of the container and is greater than or equal to the distance from the object-side focal point of the imaging lens to the objective lens. 【0009】 The specimen supply device according to the present invention comprises the specimen imaging device and a transport mechanism that moves the container and passes it through the imaging position of the specimen imaging device. 【0010】 According to the present invention, it is possible to provide a sample imaging device that can acquire high-resolution images of the liquid surface, which is effective for detecting the presence or absence of bubbles on the liquid surface, regardless of the amount of sample in the container. 【0011】This is a top view showing an overview of the configuration of an automated analyzer equipped with a sample imaging device according to an embodiment of the present invention. This is a block diagram of an automated analyzer equipped with a sample imaging device according to an embodiment of the present invention. This is a side view showing an overview of the configuration of a sample imaging device according to Embodiment 1 of the present invention. This is a schematic diagram for explaining the formation of a virtual image of the liquid surface of a sample in the sample imaging device shown in Figure 3. This is a schematic diagram for explaining the formation of a real image of the liquid surface of a sample in the sample imaging device shown in Figure 3. This is a side view showing an overview of the configuration of a sample imaging device according to Embodiment 2 of the present invention. This is a schematic diagram for explaining the formation of a real image of the liquid surface of a sample in the sample imaging device shown in Figure 6. This is a side view showing an overview of the configuration of a sample imaging device according to Embodiment 3 of the present invention. 【0012】 The following describes a sample imaging device, a sample supply device, and an automated analyzer to which embodiments of the present invention are applied, with reference to the drawings. The sample imaging device according to the present invention is not limited to an automated analyzer, but can be applied to any device that images a container or the liquid inside it. In the drawings referenced herein, the same or corresponding components are denoted by the same reference numerals, and repeated descriptions of these components may be omitted. 【0013】 [Example 1] (Automated analyzer) Figure 1 is a top view showing an overview of the configuration of an automated analyzer 1 equipped with a sample imaging device according to an embodiment of the present invention. Figure 2 is a block diagram of the automated analyzer 1. The automated analyzer 1 comprises an analysis module 13 that dispenses a fixed amount of sample 4 and performs measurement, a sample supply device 12 that transports the sample 4 and supplies it to the analysis module 13, and a control unit 10 that controls the sample supply device 12 and the analysis module 13. The automated analyzer 1 may further include a storage device 16, an operation unit 17, and a display device 18. In Figure 1, the control unit 10 is installed inside the sample supply device 12, but it can be installed at any position in the automated analyzer 1. Alternatively, the control unit 10 may be installed outside the automated analyzer 1 and control the automated analyzer 1 by communicating with it. 【0014】 Sample 4 is the object to be measured by the automated analyzer 1 and is also the subject of the sample imaging device 11. Sample 4 is a liquid, such as human blood or urine, and is contained in container 3. 【0015】 Container 3 is a container that holds the sample 4 and has an open top. Preferably, it has vertical sides, or tapered sides that widen towards the opening. Furthermore, a container 3 that is elongated vertically, with a height (depth) that is greater than its inner diameter, is preferable for achieving the effects of the present invention. Container 3 is preferably made of a light-transmitting material such as glass, quartz, or transparent plastic. Specifically, container 3 is a test tube or blood collection tube, having cylindrical sides and a hemispherical bottom. Alternatively, container 3 may be a prismatic cuvette. Container 3 may also have a lid made of a transparent (highly light-transmitting) material on its top surface. Container 3 may, if necessary, have a label 31 (see Figure 3) printed with a barcode for sample identification affixed to its side. However, the label 31 covers a portion of the circumferential direction of the side (cylindrical surface) of container 3, leaving the entire vertical direction open, and preferably does not cover more than half the circumference. If the container 3 is a rectangular prism, it is preferable that the label 31 covers one entire side, leaving it blank. The label 31 may have a two-dimensional code or characters printed on it. Alternatively, instead of attaching the label 31, a barcode or the like may be printed directly on the side of the container 3. 【0016】 The sample rack 2 houses the containers 3 containing the samples 4. In the automated analyzer 1, in order to protect the samples 4 and improve work efficiency, the containers 3 containing the samples 4 are transported while stored in the sample rack 2. The sample rack 2 may be a multi-slot sample rack capable of storing multiple containers 3, or a single-slot sample rack capable of storing one container 3. In Figure 1, the sample rack 2 stores five containers 3 in a single row. The sample rack 2 grips the bottom and part of the sides of the containers 3, and is configured so that the containers 3 are exposed on the front and rear surfaces, except for the area near the bottom. In Figure 1, the front surface of the sample rack 2 is the -y direction (downward side), and the rear surface is the +y direction (upward side). This is the same for the sample supply device 12. 【0017】(Sample Supply Device) The sample supply device 12 includes a sample imaging device 11 for imaging the sample 4, a transport mechanism 14 for transporting the sample 4, and a barcode reader 15. The sample supply device 12 is installed adjacent to the -x side (left side in Figure 1) of the analysis module 13 and is provided with an input rack transport path 121, an output rack transport path 122, an input entrance 123, and an output entrance 124. The input rack transport path 121 is a passage for sample racks 2 for transporting the sample 4 in the +x direction (right) to supply it to the analysis module 13. The output rack transport path 122 is a passage for sample racks 2 for transporting the sample 4 that has been output by the analysis module 13 in the -x direction (left), and is arranged parallel to the rear side of the input rack transport path 121. The rack transport paths 121 and 122 are arranged to be continuous with the rack transport paths 131 and 132 of the analysis module 13. As described above, in the sample supply device 12, the sample 4 is contained in a container 3, and the container 3 is stored in a sample rack 2. The entrance 123 is a space for bringing in the sample 4 to be measured by the automatic analyzer 1 from the outside. The exit 124 is a space for removing (recovering) the container 3 containing the sample 4 after measurement by the automatic analyzer 1 (analysis module 13) has been completed. The entrance 123 and exit 124 are located on the front side of the sample supply device 12 and are drawers that can be pulled out to the front of the sample supply device 12, or a lid that opens and closes is provided on the top surface of the sample supply device 12. 【0018】 As shown by the thick arrows in Figure 1, the transport mechanism 14 moves the sample racks 2 stored in the loading port 123 one by one onto the loading rack transport path 121, and moves them along the loading rack transport path 121 to transport them to the analysis module 13. The transport mechanism 14 also moves the sample racks 2 that have been moved from the analysis module 13 onto the unloading rack transport path 122 to the front of the unloading port 124, and then transports them from the unloading rack transport path 122 to the unloading port 124. The transport mechanism 14 can be configured, for example, with belts provided on the rack transport paths 121 and 122 to transport the sample racks 2 in a linear direction in the x or y direction. 【0019】In the sample supply device 12, the sample imaging device 11 is positioned near one side (the rear side in the sample supply device 12) of the rack transport path 121 for loading samples, and the barcode reader 15 is positioned near the other side (the front side). Therefore, the container 3 is stored in the sample rack 2 with the side with the label 31 facing the front (-y side) and the exposed side facing the rear (+y side) (see Figure 3). The sample imaging device 11 images the container 3 at the imaging position 125 on the rack transport path 121 for loading samples. The barcode reader 15 reads the barcode on the label 31 of the container 3 at the barcode reading position 126 on the rack transport path 121 for loading samples. In the sample supply device 12, a barcode reading position 126 and an imaging position 125 correspond to each adjacent container on the sample rack 2 on the transport path 121 for loading. The barcode is read by the barcode reader 15, and then the sample is imaged by the sample imaging device 11. Alternatively, the barcode reading position 126 and the imaging position 125 may be separated by more than the length of one container 3, or they may be in the same position, or their order may be changed. 【0020】 The barcode reader 15 reads the barcode on the label 31 attached to the rear side of the container 3 at the barcode reading position 126. The barcode reader 15 corresponds to the information printed on the label 31 and may be a two-dimensional code reader or an OCR (Optical Character Recognition) reader. 【0021】The sample imaging device 11 simultaneously images the rear surface (+y side) of the container 3 at the imaging position 125 and the liquid surface of the sample 4 inside the container 3. The sample imaging device 11 comprises a camera 5 composed of an image sensor 51 and an imaging lens 52 (see Figure 3) facing its light incidence surface, a light source 7, an objective lens 6, a mirror 9 positioned above the container 3 at the imaging position 125, and a planar mirror 8. The camera 5 is positioned appropriately to image the side surface of the container 3. In the sample supply device 12, the sample imaging device 11 is positioned between the input rack transport path 121 and the output rack transport path 122, and therefore its length in the y direction is limited. Therefore, the sample imaging device 11 places a planar mirror 8 tilted at 45° in the xy plane behind the container 3 (imaging position 125) (+y side) to bend the light path from the container 3 in the +y direction in the +x direction. The camera 5 is positioned on the +x side of the planar mirror 8 so that this light in the +x direction is incident on it. The light source 7 illuminates the container 3 at the imaging position 125, and is not limited to the position shown in Figure 1; one or more light sources may be placed as needed for imaging. The detailed configuration of the specimen imaging device 11 will be described later. 【0022】 The control unit 10 controls the sample imaging device 11 (camera 5), ​​transport mechanism 14, barcode reader 15, and analysis module 13 of the sample supply device 12. When the container 3 stored in the sample rack 2, which is moving on the rack transport path 121 for loading by the transport mechanism 14, reaches the barcode reading position 126, the control unit 10 reads the label 31 attached to the container 3 from the front using the barcode reader 15. Next, when the container 3 reaches the imaging position 125, the control unit 10 images the container 3 with the camera 5. Then, based on the information obtained from the label 31 read by the barcode reader 15, the control unit 10 identifies the sample 4 contained in the container 3. The control unit 10 also analyzes the image captured by the camera 5 to determine whether there are any abnormalities such as bubbles in the sample 4. The information acquired by the control unit 10 is stored in the storage device 16. After that, the sample rack 2 is transported to the transport path 131. 【0023】The control unit 17 is a keyboard, mouse, etc. The display device 18 is a display, speaker, etc. The control unit 17 and the display device 18 may be an integrated touch panel. The automatic analyzer 1 can also connect to an external display device, etc. 【0024】 The automated analyzer 1 may not use a sample rack 2, and the sample supply device 12 may have a configuration in which the transport mechanism 14 directly supports and transports the container 3. Preferably, the transport mechanism 14 is configured so as not to cover the rear surface of the container 3 at the imaging position 125. 【0025】 (Sample Imaging Device) Figure 3 is a side view showing an overview of the configuration of the sample imaging device 11 according to this embodiment. In Figure 3, the light source 7 is omitted. Also, the camera 5 is moved symmetrically with respect to the planar mirror 8, and for convenience, the camera 5 is shown aligned in a straight line from the side of the container 3. The sample imaging device 11 comprises an image sensor 51, an imaging lens 52 positioned between the container 3 and the image sensor 51 at the imaging position 125, with its optical axis Ai intersecting perpendicularly with the central axis At of the container 3, a mirror 9 positioned opposite the aperture surface U of the container 3, and an objective lens 6 positioned in the optical path between the mirror 9 and the imaging lens 52. The sample imaging device 11 can simultaneously image the field of view FOVf on the side of the container 3 and the field of view FOVu on the aperture surface side. 【0026】 The image sensor 51 and the imaging lens 52 constitute the camera 5. The imaging lens 52 faces the light incident surface (imaging surface) of the image sensor 51, and preferably, the optical axis Ai of the imaging lens 52 coincides with the normal to the imaging surface of the image sensor 51. The camera 5 is positioned so that the optical axis Ai of the imaging lens 52 intersects perpendicularly with the central axis At of the container 3, corresponding to imaging the side surface of the container 3. Furthermore, the distance between the image sensor 51 and the imaging lens 52 is adjusted so that light reflected or scattered in the field of view FOVf on the side of the container 3 that has passed through the imaging lens 52 is imaged on the imaging surface of the image sensor 51. In addition, the camera 5 is positioned so that it can image the entire field of view FOVf as well as the entire field of view FOVu on the aperture surface U side of the container 3. 【0027】The mirror 9 and objective lens 6 are provided to image the aperture surface U of the container 3 with the camera 5. The mirror 9 faces the aperture surface U of the container 3 and is positioned at an angle with respect to the central axis At of the container 3. More specifically, the mirror 9 is tilted at an angle such that a straight line Atm, symmetric to the central axis At of the container 3, passes through the object-side focal point Fi of the imaging lens 52, with respect to the axis of symmetry being the normal vector 9n at the intersection point 9p of the mirror 9 with the extension of the central axis At of the container 3. In other words, the straight line Atm connects the intersection point 9p of the mirror 9's reflective surface with the extension of the central axis At of the container 3 and the object-side focal point Fi of the imaging lens 52, and the angle between this straight line Atm and the central axis At of the container 3 is divided into two by the normal vector 9n of the mirror 9. Therefore, the tilt angle of the mirror 9 (the angle between the normal vector 9n and the central axis At of the container 3) is 1 / 2 * tan, with respect to the distance L1 from the object-side focal point Fi of the imaging lens 52 to the central axis At of the container 3, and the distance L2 from the intersection point 9p of the central axis At of the container 3 and the mirror 9 to the optical axis Ai of the imaging lens 52. -1 This can be expressed as (L1 / L2). This straight line Atm is the mirror image of the central axis At of the container 3 by the mirror 9. The objective lens 6 is positioned on the optical path between the aperture surface U of the container 3 and the imaging lens 52, and in this embodiment, it is positioned on the optical path between the mirror 9 and the imaging lens 52. Furthermore, the objective lens 6 is positioned such that its optical axis Ao coincides with the straight line Atm, which is symmetrical with respect to the central axis of the container. That is, the optical axis Ao of the objective lens 6 passes through the object-side focal point Fi of the imaging lens 52 and is symmetric with respect to the central axis At of the container 3 with respect to the normal 9n at the intersection point 9p of the mirror 9 with the optical axis Ao of the objective lens 6. Therefore, when the container 3 is moved symmetrically with respect to the mirror 9's reflective surface, the central axis At (Atm) of the container 3 coincides with the optical axis Ao of the objective lens 6 and passes through the object-side focal point Fi of the imaging lens 52. Furthermore, as will be described later, the objective lens 6 has a predetermined focal length fo and is positioned on the optical path between the mirror 9 and the imaging lens 52 at a location that satisfies the characteristics described later. 【0028】The specimen imaging device 11 according to this embodiment has the following four features for imaging the field of view FOVu on the aperture surface U side of the container 3 with the camera 5. The first feature is that the focal length fo of the objective lens 6 is longer than the optical path length from the objective lens 6 to the bottom of the container 3. The optical path length from the objective lens 6 to the bottom of the container 3 is the sum Lmo + Lmt of the distance Lmo from the intersection point 9p of the optical axis Ao of the objective lens 6 to the objective lens 6 and the distance Lmt from the intersection point 9p of the mirror 9 to the bottom of the container 3, so fo > Lmo + Lmt. The second feature is that the optical axis Ao of the objective lens 6 and the central axis At of the container 3 are symmetrical with respect to the normal 9n at the intersection point 9p of the optical axis Ao of the objective lens 6 on the reflective surface of the mirror 9 as the axis of symmetry. The third feature is that the optical axis Ao of the objective lens 6 passes through the object-side focal point Fi of the imaging lens 52. The fourth characteristic is that the focal length fo of the objective lens 6 is greater than or equal to the distance Loi from the object-side focal point Fi of the imaging lens 52 to the objective lens 6 (fo ≥ Loi). The distance Lmi (= Lmo + Loi) from the intersection point 9p of the optical axis Ao of the objective lens 6 and the mirror 9 to the object-side focal point Fi of the imaging lens 52 is given by Lmi = √(L1 2 +L2 2 Therefore, from the fourth characteristic, the focal length fo of the objective lens 6 is fo ≥ √(L1 2 +L2 2 ) - Lmo. 【0029】 The effects of these features will be explained below using diagrams. First, the effects of the first and second features will be explained using Figure 4. Figure 4 is a schematic diagram for explaining the formation of virtual images of the container 3 and the liquid surface S of the sample in the sample imaging device 11, and shows the positional relationship between the mirror image 3m of the container, obtained by symmetrically moving the container 3 with respect to the reflective surface of the mirror 9, and the objective lens 6. 【0030】The solid lines in the figure represent light rays that originate from the outer diameter of the mirror image Sm of the liquid surface S of the sample, or from the inner diameter of the mirror image Um of the aperture U of the container, and travel parallel to the optical axis Ao of the objective lens 6. These rays enter the objective lens 6, are refracted, and pass through the image-side focal point Fo' of the objective lens 6. The dashed lines represent the straight lines extended from the objective lens 6 toward the object side (the side of the mirror image 3m of the container) after the ray passes through focal point Fo' following refraction in the objective lens 6. The dotted lines (angles) represent light rays that originate from the inner diameter of the mirror image Um of the aperture of the container and enter the center of the objective lens 6; these rays travel in a straight line through the objective lens 6. The dotted lines (circles) represent light rays that originate from the outer diameter of the mirror image Sm of the liquid surface and enter the center of the objective lens 6; these rays also travel in a straight line. The dotted lines (corners, rounds) further include straight lines extending each ray from the emission point toward the object side (mirror image Um, Sm side). On the line segment connecting the intersections of the object-side extensions (dotted lines) of the ray passing through the center of the objective lens 6 and the object-side extensions (dashed lines) of the ray passing through the image-side focal point Fo' of the objective lens 6 (solid lines), enlarged virtual images Ui and Si of the aperture surface mirror image Um and the liquid surface mirror image Sm are formed. In Figure 4, a portion of the aperture surface Ui side of the virtual image 3i of the container mirror image 3m (virtual image of container 3) is shown with a thick dashed line. 【0031】 As described in the first feature, the focal length fo of the objective lens 6 is longer than the optical path length Lmo + Lmt from the objective lens 6 to the bottom of the container 3, and the object-side focal point Fo of the objective lens 6 is below the bottom of the container 3 (see Figure 3). Therefore, regardless of the liquid level of the sample 4, the mirror image Sm of the liquid surface is located in front of the mirror image Fom of the object-side focal point as seen from the objective lens 6. As a result, the camera 5 captures a magnified virtual image Si of the liquid surface. Furthermore, as described in the second feature, the optical axis Ao of the objective lens 6 is collinear with the central axis Atm of the mirror image 3m of the container. Therefore, light emitting from the outer diameter of the mirror image Sm of the liquid surface and traveling parallel to the optical axis Ao of the objective lens 6 travels along the inner wall of the side surface of the mirror image 3m of the container, and thus coincides with light emitting from the inner diameter of the mirror image Um of the open surface of the container, traveling parallel to the optical axis Ao of the objective lens 6, refracted by the objective lens 6, and passing through the image-side focal point Fo' of the objective lens 6. As a result, the virtual images of the inner diameter of the mirror image Um of the open surface of the container and the outer diameter of the mirror image Sm of the liquid surface are always formed on two straight lines (dashed lines) passing through the image-side focal point Fo' of the objective lens 6. 【0032】 Next, the effects of the third and fourth features will be explained using Figure 5. Figure 5 is a schematic diagram illustrating the formation of a real image of the liquid surface of a sample in the sample imaging device 11, showing the positional relationship between the virtual image Ui of the container's aperture, the virtual image Si of the sample's liquid surface, the objective lens 6, and the imaging lens 52. Figure 5 also shows a mirror image 3m of the container. The dotted lines (corners) in the figure indicate light that exits from the inner diameter of the virtual image Ui of the container's aperture and passes through the center of the imaging lens 52 or the object-side focal point Fi of the imaging lens 52. The dotted lines (circles) indicate light that exits from the outer diameter of the virtual image Si of the liquid surface and passes through the center of the imaging lens 52 or the object-side focal point Fi of the imaging lens 52. Light passing through the object-side focal point Fi of the imaging lens 52 is refracted by the imaging lens 52 and travels parallel to the optical axis Ai of the imaging lens 52. Light rays passing through the center of the imaging lens 52 continue to travel in a straight line. Then, on the line segment connecting the intersection points of the two light rays that pass through the center of the imaging lens 52 and the object-side focal point Fi, respectively, a real image of the aperture surface U of the container and a real image of the liquid surface S of the sample are formed. 【0033】 As described in the third feature, the optical axis Ao of the objective lens 6 passes through the object-side focal point Fi of the imaging lens 52. Also, as described in the fourth feature, the focal length fo of the objective lens 6 is greater than or equal to the distance Loi from the object-side focal point Fi of the imaging lens 52 to the objective lens 6, and in this embodiment, the focal length fo is longer (fo > Loi). Due to these two features, and as described as an effect of the second feature, the inner diameter of the virtual image Ui of the container's aperture and the outer diameter of the virtual image Si of the sample's liquid surface are both formed on two straight lines (see Figure 4) passing through the image-side focal point Fo' of the objective lens 6, so that the container's aperture U and the sample's liquid surface S are captured by the camera 5 in a concentric manner. In addition, on the image sensor 51, the virtual image Ui of the container's aperture is closer to the object-side focal point Fi of the imaging lens 52 than the virtual image Si of the sample's liquid surface. Therefore, the inner diameter Du of the real image of the container's aperture U is larger than the outer diameter Ds of the real image of the sample's liquid surface S (Du > Ds), and consequently, the sample's liquid surface S is projected inside the container's aperture U. Furthermore, both the container's aperture U and the sample's liquid surface S are projected as large images by the camera 5, and even if the liquid level of the sample 4 is low, the diameter Ds of the liquid surface S is not projected as small. 【0034】As described above, a sample imaging device can be provided that uses a camera to capture images of the side of a container, which is effective for detecting the interface position of the sample inside the container, and a camera to capture images of the side of the container, which is effective for detecting the presence or absence of bubbles on the liquid surface, to acquire a high-resolution image of the sample's liquid surface without blind spots, by combining the images of the side of the container and the camera into a single image, in a single imaging operation. 【0035】 Furthermore, the sample imaging device 11 can image the sample 4 even if it is contained in a container 3 with low light transmittance. Even if it is difficult to detect the liquid level, etc., from the image of the side of the container 3, it can detect whether or not there are any abnormalities such as bubbles on the liquid surface of the sample 4. 【0036】 [Example 2] Below, the sample imaging device according to Example 2 will be described, mainly using Figures 6 and 7, highlighting the differences from Example 1. 【0037】 Figure 6 is a side view showing an overview of the configuration of the specimen imaging device 11A according to this embodiment. The specimen imaging device 11A differs from the specimen imaging device 11 according to Embodiment 1 in its fourth feature that the focal length fo of the objective lens 6 coincides with the optical path length Loi from the object-side focal point Fi of the imaging lens 52 to the objective lens 6 (fo = Loi). That is, the position of the image-side focal point Fo' of the objective lens 6 and the object-side focal point Fi of the imaging lens 52 coincide. 【0038】 Figure 7 is a schematic diagram illustrating the formation of a real image of the liquid surface S of a sample in the sample imaging device 11A, showing the positional relationship between the virtual image Ui of the container's aperture, the virtual image Si of the sample's liquid surface, the objective lens 6, and the imaging lens 52. Figure 7 also shows a mirror image 3m of the container. The dotted lines (squares and circles) in the figure indicate light emitted from the inner diameter of the virtual image Ui of the container's aperture or the outer diameter of the virtual image Si of the liquid surface, respectively, and passing through the center of the imaging lens 52 or the object-side focal point Fi of the imaging lens 52. 【0039】In this embodiment, both the inner diameter of the virtual image Ui of the opening surface of the container and the outer diameter of the virtual image Si of the liquid surface of the specimen exist on two straight lines passing through the object-side focal point Fi of the imaging lens 52. That is, the light emitted from each of the inner diameter of the virtual image Ui of the opening surface of the container and the outer diameter of the virtual image Si of the liquid surface of the specimen and passing through the object-side focal point Fi of the imaging lens 52 both enter the imaging lens 52 along the above two straight lines, are refracted by the imaging lens 52, and travel parallel to the optical axis Ai of the imaging lens 52. In FIG. 7, this light ray is shown by a dotted line (angle). The real images of the inner diameter of the opening surface U of the container and the outer diameter of the liquid surface S of the specimen are formed at the intersections of the two straight lines parallel to the optical axis Ai of this imaging lens and the straight line passing through the center of the imaging lens 52 and emitted from the inner diameter of the virtual image Ui of the opening surface of the container or the outer diameter of the virtual image Si of the liquid surface. The diameter of the real image is determined by the distance between the two straight lines parallel to the optical axis Ai of the imaging lens 52. Therefore, the real image of the liquid surface S of the specimen is enlarged and imaged to the same diameter as the inner diameter Du of the real image of the opening surface U of the container regardless of the liquid level of the specimen 4. That is, the specimen imaging device 11A can image the inner wall of the side surface of the container 3 with a zero angle of view using the camera 5. 【0040】 In addition, when the focal length fo of the objective lens 6 is shorter than the optical path length Loi from the object-side focal point Fi of the imaging lens 52 to the objective lens 6 (fo < Loi), the inner diameter Du of the real image of the opening surface U of the container becomes smaller than the outer diameter Ds of the real image of the liquid surface S of the specimen (Du < Ds), and the peripheral portion of the liquid surface S of the specimen is covered by the side surface of the container and becomes a blind spot. 【0041】 As described above, similar to Example 1, using a camera for imaging the image of the side surface of the container, a high-resolution image without a blind spot of the liquid surface of the specimen can be aggregated with the image of the side surface of the container into one image and obtained by one imaging. Furthermore, a specimen imaging device can be provided in which the image size of the liquid surface matches the inner diameter of the opening surface of the container regardless of the amount of the specimen. 【0042】 〔Example 3〕Regarding the specimen imaging device according to another Example 3, the differences from Example 2 will be mainly described using FIG. 8. 【0043】FIG. 8 is a side view showing an outline of the configuration of the specimen imaging apparatus 11B according to the present embodiment. The specimen imaging apparatus 11B has a different arrangement of the objective lens 6 from that of the specimen imaging apparatus 11A according to the second embodiment. In the specimen imaging apparatus 11B, the objective lens 6 is disposed between the opening surface U of the container 3 and the mirror 9, and the optical axis Ao coincides with the central axis At of the container 3. 【0044】 Also in the present embodiment, as the first feature, the focal length fo of the objective lens 6 is longer than the optical path length, that is, the distance Lto from the objective lens 6 to the bottom of the container 3 (fo > Lto). Further, as the fourth feature, the focal length fo of the objective lens 6 is not less than the optical path length from the object-side focal point Fi of the imaging lens 52 to the objective lens 6. The optical path length from the object-side focal point Fi of the imaging lens 52 to the objective lens 6 is the sum Lmi + Lmo of the distance Lmi from the intersection 9p of the central axis At of the container 3 and the mirror 9 to the object-side focal point Fi of the imaging lens 52 and the distance Lmo from the intersection 9p of the optical axis Ao of the objective lens 6 and the mirror 9 to the objective lens 6. Therefore, fo ≧ Lmi + Lmo, and here, fo = Lmi + Lmo. Also, since Lmi = √(L1 2 + L2 2 ), fo ≧ √(L1 2 + L2 2 )+ Lmo. On the other hand, in the present embodiment, as the second feature, the optical axis Ao of the objective lens 6 coincides with the central axis At of the container 3. And as the third feature, with the normal line 9n of the reflecting surface of the mirror 9 as the axis of symmetry, a straight line (the optical axis of the mirror image of the objective lens) Aom symmetric to the optical axis Ao of the objective lens 6 passes through the object-side focal point Fi of the imaging lens 52. That is, when the container 3, the specimen 4 therein, and the objective lens 6 are symmetrically moved with respect to the reflecting surface of the mirror 9, on the optical path of the opening surface side view field FOVu of the container, the positional relationship among the opening surface U of the container 3, the liquid surface S of the specimen 4, the objective lens 6, and the imaging lens 52 is the same as that in the previous embodiment. 【0045】 Therefore, similar to the previous embodiment, it is possible to provide a specimen imaging apparatus that can obtain a high-resolution image without dead angles of the liquid surface of the specimen by using a camera for imaging an image of the side surface of the container, aggregating the image of the side surface of the container and the image of the liquid surface of the specimen into one image, and acquiring the image in one imaging. 【0046】It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and the present invention is not necessarily limited to embodiments having all of the described configurations. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations. 【0047】1 Automatic analyzer 10 Control unit 11, 11A, 11B Sample imaging device 12 Sample supply device 13 Analysis module 14 Transport mechanism 15 Barcode reader 123 Inlet 124 Outlet 125 Imaging position 126 Barcode reading position 121 Rack transport path for loading 122 Rack transport path for unloading 2 Sample rack 3 Container 3i Virtual image of container 3m Mirror image of container 31 Label 4 Sample 5 Camera 51 Image sensor 52 Imaging lens 6 Objective lens 7 Light source 8 Planar mirror 9 Mirror 9n Normal to the reflective surface of the mirror S Liquid surface of sample Si Virtual image of the liquid surface of sample Sm Mirror image of the liquid surface of sample U Opening surface of container Ui Virtual image of the opening surface of container Um Mirror image of the opening surface of container At Central axis of container Atm: Center axis of the mirror image of the container Ao: Optical axis of the objective lens Aom: Optical axis of the mirror image of the objective lens Ai: Optical axis of the imaging lens Fi: Object-side focal point of the imaging lens Fo: Object-side focal point of the objective lens Fom: Mirror image of the object-side focal point of the objective lens Fo': Image-side focal point of the objective lens fo: Focal length of the objective lens L1: Distance from the object-side focal point of the imaging lens to the center axis of the container L2: Distance from the intersection of the center axis of the container and the mirror to the optical axis of the imaging lens Lmi: Distance from the intersection of the optical axis of the objective lens and the mirror to the object-side focal point of the imaging lens Lmo: Distance from the intersection of the optical axis of the objective lens and the mirror to the objective lens Lmt: Distance from the intersection of the center axis of the container and the mirror to the bottom of the container Loi: Distance from the object-side focal point of the imaging lens to the objective lens Lto: Distance from the objective lens to the bottom of the container Ds: Diameter of the real image of the liquid surface of the sample Du The diameter of the real image at the opening of the container (Hf), the height of the real image at the side of the container (FOVf), the field of view on the side of the container (FOVs), the field of view at the liquid surface of the sample (FOVu), and the field of view at the opening of the container.

Claims

1. A specimen imaging device for imaging a specimen contained in a container whose top surface transmits light or is open, comprising: an image sensor; an imaging lens disposed between the container and the image sensor, the optical axis of which intersects perpendicularly with the central axis of the container, which is positioned at a predetermined imaging position; a mirror disposed opposite the top surface of the container; and an objective lens disposed in the optical path between the top surface of the container and the imaging lens, wherein a straight line symmetric to the central axis of the container passes through the object-side focal point of the imaging lens, with the normal of the reflective surface passing through the intersection of the reflective surface of the mirror and the extension of the central axis of the container as the axis of symmetry; the optical axis of the objective lens coincides with the straight line symmetric to the central axis of the container or the central axis of the container; and the focal length of the objective lens is longer than the optical path length from the bottom of the container to the objective lens, and greater than or equal to the distance from the object-side focal point of the imaging lens to the objective lens.

2. The specimen imaging apparatus according to claim 1, characterized in that the image-side focal point of the objective lens and the object-side focal point of the imaging lens are at the same position.

3. The specimen imaging device according to claim 1 or 2, wherein at least a portion of the side surface of the container transmits light, and the container is imaged simultaneously from the side and the top surface.

4. The specimen imaging apparatus according to claim 1 or 2, wherein the container has a vertical surface on its side and the distance from the bottom to the top surface is longer than the inner diameter.

5. A sample supply device comprising a sample imaging device according to claim 1 or claim 2, and a transport mechanism that moves the container and passes it through the imaging position.

6. The sample supply device according to claim 5, wherein one or more containers are supported on a rack, the transport mechanism moves the containers by transporting the rack, and the transport mechanism is provided with a control mechanism that moves the rack so that the containers are positioned one by one at the imaging position, and causes the sample imaging device to image the samples in the containers.

7. An automated analyzer that performs automated analysis of a sample, comprising the sample imaging device described in claim 1 or claim 2.

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