Imaging method, imaging device, automatic analyzer, and automatic analyzer position adjustment method

Abstract

To acquire highly accurate three-dimensional information on a measurement object or distance information without relying upon a deviation of an optical axis of an imaging device or a change in optical characteristics of a variable focus lens with respect to the imaging device.SOLUTION: An imaging method comprises: a first step of acquiring a picture-taking image of a first subject by an imaging unit; a second step of selecting two or more reference points from the first subject; a third step of acquiring the coordinate of the reference point; a fourth step of acquiring the focus position of the reference point; a fifth step of determining whether misalignment of the optical axis between the first subject and the imaging unit is equal to or less than a fixed value on the basis of information on a preliminarily stored first subject imaging allowance area, the coordinate and focus position of the reference point obtained in the step; a sixth step of calculating the misalignment amount of the optical axis when the misalignment of the optical axis of the imaging unit is equal to or less than the fixed value; a seventh step of acquiring a picture-taking image of a second subject serving as a measurement object; and an eighth step of correcting the picture-taking image of the second subject on the basis of the misalignment amount of the optical axis to acquire an image of a measurement result.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an imaging method for photographing a measurement object and calculating the relative position with respect to the measurement object, and an imaging device, and particularly relates to an imaging method suitable for an automatic analyzer, an imaging device, an automatic analyzer using the same, and a position adjustment method of the automatic analyzer.

Background Art

[0002] Lenses are used in various optical devices. In addition to general lenses with a fixed focal length, there are variable focal length lenses capable of changing the focal length. Since variable focal length lenses can focus faster than changing the focus by moving the position of the lens itself, for example, their application to automatic equipment, inspection equipment, and medical equipment has been promoted. For example, when using a liquid for the lens, the focus can be changed by electrically controlling the liquid interface that becomes the refractive surface of the lens, so that the speed of focus change can be increased. With the increase in the speed of focus change, the technological development of measuring the three-dimensional information and distance information of a measurement object using lens focal length information has been advanced.

[0003] Here, as technologies for measuring the three-dimensional information and distance information of a measurement object using a variable focal length lens, Patent Document 1 and Patent Document 2 are known. Patent Document 1 discloses "a measuring device comprising: an imaging unit having an imaging lens for photographing a measurement object having a flat surface; a storage unit for storing a distance table showing the relationship between the in-focus position of the imaging lens and the distance from the imaging lens to the measurement object; a focus position measurement unit for measuring the in-focus position of the imaging lens with respect to three or more reference points set on the flat surface; a distance measurement unit for measuring the distance from the imaging lens to each of the reference points based on the collation result between the measured in-focus positions and the distance table; a coordinate calculation unit for calculating the spatial coordinates of each of the reference points based on the planar coordinates of each of the reference points in the captured image obtained by the imaging unit, the measurement result of the distance measurement unit, and the field angle of the imaging lens; and a dimension information calculation unit for determining a reference plane including the flat surface based on the spatial coordinates of each of the reference points and calculating dimension information on the reference plane."

[0004] In Patent Document 2, there is disclosed "a three-dimensional shape measuring apparatus for measuring the three-dimensional shape of an object to be inspected, including a camera for photographing the object to be inspected, the distance to the focusing position being constant, the photographing unit having a variable photographing distance from the camera to the object to be inspected, a photographing control unit for causing the photographing unit to photograph the object to be inspected at a plurality of the photographing distances, a focusing position calculation unit for acquiring each image photographed by the photographing unit and calculating the focusing position based on the degree of focus at each part of each image, a focusing distribution calculation unit for calculating a focusing distribution which is a set of focusing positions based on the focusing position calculated by the focusing position calculation unit, a shape identification unit for identifying the three-dimensional shape of the object to be inspected based on the calculated focusing distribution, and a shape extraction unit for calculating the features at each position of the three-dimensional shape of the object to be inspected identified by the shape identification unit and extracting a predetermined type of shape constituting the three-dimensional shape based on the calculated features."

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the method described in Patent Document 1, the distance from the imaging lens to the measurement object is calculated by the focusing position of the imaging lens and the distance table in the storage unit. However, since the change in the optical characteristics of the imaging lens due to changes over time cannot be corrected, there is a deviation in the calculated distance from the imaging lens to the measurement object, and there is a possibility of misreading the spatial coordinates calculated based on the measurement result of the distance measurement unit and the viewing angle of the imaging lens.

[0007] In addition, in the method described in Patent Document 2, the inspection object is imaged while changing the focus position of the imaging unit, and the three-dimensional shape of the inspection object is specified based on the focus distribution of the inspection object. However, due to the deviation of the optical axis caused by the looseness of the attachment of the imaging unit of the imaged inspection object, the inclination of the surface of the inspection object changes, so there is a possibility of misinterpreting the focus distribution of the inspection object, which may make it difficult to obtain the three-dimensional shape of the inspection object.

[0008] An object of the present invention is to provide an imaging method, an imaging device, an automatic analysis device using the same, and a position adjustment method of the automatic analysis device that can obtain three-dimensional information and distance information of a measurement object with high accuracy without depending on the deviation of the optical axis of the imaging device and the change in the optical characteristics of the variable focal length lens.

Means for Solving the Problems

[0009] One aspect for achieving the above object is as follows. An imaging method including: a first step of obtaining a photographed image of a first subject by an imaging unit; a second step of selecting two or more reference points from the first subject; a third step of obtaining coordinates of the reference points; a fourth step of obtaining a focus position of the reference points; a fifth step of determining whether the deviation of the optical axis between the first subject and the imaging unit is equal to or less than a certain value based on the information of the first subject imaging allowable area stored in advance, the coordinates of the reference points obtained in the step, and the focus position; a sixth step of calculating the amount of deviation of the optical axis when the deviation of the optical axis of the imaging unit is equal to or less than a certain value; a seventh step of obtaining a photographed image of a second subject to be measured; and an eighth step of correcting the photographed image of the second subject based on the amount of deviation of the optical axis to obtain an image of a measurement result.

[0010] An imaging device including a variable focal length lens whose focal length is variable, a control unit that controls the focus of the variable focal length lens, a detection unit that detects a focus position at an imaging position of a subject using the variable focal length lens, and a measurement unit that measures a relative position of the subject based on a difference between the imaging position of the subject and the focus position, the imaging device further including a calculation unit that calculates a deviation of an optical axis between the first subject and the imaging device based on the imaging position and the focus position of the first subject, and a correction unit that corrects a measurement result of the relative position of a second subject to be measured based on information on the deviation of the optical axis between the first subject and the imaging device calculated by the calculation unit.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide an imaging method, an imaging device, an automatic analysis device using the same, and a position adjustment method of the automatic analysis device that can measure the relative positional relationship of a plurality of objects with high accuracy without depending on a deviation of the optical axis of the imaging device or a change in optical characteristics of the variable focal length lens.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0013] Embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, an example of a variable focal length lens is described, but a general lens with a fixed focal length can also be applied.

[0014] FIG. 1 is a configuration diagram of the imaging system according to the first embodiment. The imaging system 1 includes an imaging device 2 and an image output unit 3 connected to the imaging device and outputting an imaging result.

[0015] The imaging device 2 includes an imaging unit 10 and a control unit 20.

[0016] The imaging unit 10 includes an imaging element 11, an imaging lens 12, a lens driving unit 13, and a signal processing unit (hereinafter also referred to as a "video processing unit") 14. The imaging element 11 is composed of a PSD (Position Sensitive Detector), a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, etc., and captures a measurement object to obtain a captured image. Strictly speaking, the reflected light of the measurement object is received through the imaging lens 12 to obtain a captured image.

[0017] The imaging lens 12 is composed of a lens configured to be able to freely change the focal length, and has a variable focal length lens 15 that moves for focusing and a fixed lens 16 that moves for zoom adjustment. Strictly speaking, the variable focal length lens 15 and the fixed lens 16 are each composed of a lens group composed of a plurality of lenses.

[0018] The lens driving unit 13 is composed of a 1-2 phase excitation type or microstep type stepping motor and a driver for the liquid lens, and drives the imaging lens 12. Specifically, the lens driving unit 13 moves the position of the variable focus lens 15 on the optical axis to perform focus adjustment.

[0019] The image processing unit 14 performs image processing on the captured image acquired by the image sensor 11 and detects the contrast value of the captured image. Although details will be described later, this contrast value is used to measure the in-focus position of the variable focus lens 15 with respect to the object to be measured. The control unit 20 includes a storage unit 30, a generation unit 40, and an arithmetic unit 50.

[0020] The storage unit 30 includes a first subject imaging position 31, a first subject in-focus position 32, a first subject imaging allowable area 33, and aberration correction data 34. Here, the first subject 1000 is a subject whose relative position with respect to the imaging lens 12 is known when there is no deviation of the optical axis of the imaging unit 10 or the like. The first subject imaging position 31 is the position of a specific point in the first subject shown in the captured image when there is no deviation of the optical axis of the imaging unit 10 or the like. The first subject in-focus position 32 is the position where the focus of a specific point in the first subject 1000 shown in the captured image coincides when there is no deviation of the optical axis of the imaging unit 10 or the like.

[0021] The first subject imaging allowable area 33 is the area where a specific point of the first subject 1000 exists in the captured image when the deviation of the optical axis of the imaging unit 10 or the like is equal to or less than a predetermined value. When there is no deviation of the optical axis of the imaging unit 10, the specific point in the first subject 1000 shown in the captured image exists at the first subject imaging position 31. However, due to the deviation of the optical axis caused by looseness or the like during the installation of the imaging device, the specific point of the first subject 1000 actually does not exist at the first subject imaging position 31. At this time, if the optical axis deviates greatly and the specific point of the first subject exists outside the first subject imaging allowable area 33, it becomes impossible to measure the relative position with respect to each subject after correcting the deviation of the optical axis or the like to be performed later.

[0022] The aberration correction data 34 is data of correction values for distortion (lens distortion) in the imaging lens 12. That is, it is matrix data consisting of distortion correction values for each XY coordinate in the captured image. This aberration correction data 34 is used when performing lens distortion correction on the captured image. Also for this aberration correction data 34, for each imaging lens 12, correction values for each XY coordinate are measured and created.

[0023] The generation unit 40 includes a distance table 41. The distance table 41 is a table showing the relationship between the focus position of the variable focal length lens 15 and the distance (depth) from the imaging lens 12 to the measurement object in the optical axis direction. This focus position of the variable focal length lens 15 is the lens position of the variable focal length lens 15 at which a focused image is obtained or the voltage value (referred to as the "step number") applied to the lens. This distance table 41 is created by measuring the corresponding distance for each focus position for each imaging lens 12. Also, when there is no deviation in the optical axis of the imaging unit 10, the distance table 41 utilizes the fact that the relative position between the first subject 1000 and the imaging lens 12 is known, and based on the measurement result of the focus position of the first subject 1000, the distance table 41 is generated.

[0024] The arithmetic unit 50 includes an imaging position measurement unit 51, a focus position measurement unit 52, a determination unit 53, an optical axis deviation calculation unit 54, a relative coordinate calculation unit 55, and a coordinate correction unit 56. The imaging position measurement unit 51 measures the position of the measurement object in the captured image by the imaging element 11 and the video processing unit 14. Specifically, the video processing unit 14 detects the contour of each measurement object using the luminance difference. The position of the target measurement object is detected from the detected contours using a matching method or the like.

[0025] The focus position measurement unit 52 measures the focus position of the variable focus lens 15 by means of the imaging device 11, the lens drive unit 13, and the video processing unit 14. Specifically, while driving the variable focus lens 15 by the lens drive unit 13, the imaging device 11 acquires a photographed image in each lens state (step number) of the variable focus lens 15. Then, the video processing unit 14 calculates the degree of focus based on various calculation methods such as the absolute value of the luminance gradient, the variance value of the luminance, or the edge intensity within a certain region of the photographed image as the target region. As a result of the calculation, the lens position at which a photographed image with a high degree of focus within the target region is obtained is set as the focus position. Note that the luminance gradient is calculated based on, for example, the difference between the luminance value of each pixel constituting the image within the target region and the luminance values of one or more adjacent pixels, and there are various calculation methods, and any of them can be appropriately used.

[0026] Based on the measurement result of the imaging position measurement unit 51 and the first subject imaging allowable area 33, the determination unit 53 determines that the deviation of the optical axis of the imaging unit 10 or the like is equal to or less than a certain value.

[0027] Based on the measurement result of the imaging position measurement unit 51, the measurement result of the focus position measurement unit 52, the first subject imaging position 31, and the first subject focus position 32, the optical axis deviation calculation unit 54 calculates the deviation of the relative position between the imaging unit 10 and the first subject 1000, and calculates the deviation of the optical axis of the imaging unit 10 or the like.

[0028] Based on the measurement result of the imaging position measurement unit 51, the measurement result of the focus position measurement unit 52, the aberration correction data 34, and the distance table 41, the relative coordinate calculation unit 55 calculates the relative coordinates from the imaging lens 12 in the optical axis direction to the measured object.

[0029] Based on the measurement result of the relative coordinate calculation unit 55, the measurement result of the optical axis deviation calculation unit 54, and the aberration correction data 34, the coordinate correction unit 56 measures the relative coordinates from the imaging lens 12 in the optical axis direction to the measured object in consideration of the deviation of the optical axis of the imaging unit 10 or the like.

[0030] Figure 2 is a schematic configuration diagram of an automatic analyzer, which is one of the application targets of the imaging system 1 of the present embodiment. The automatic analyzer 100 is a device for measuring a reaction solution obtained by causing a chemical reaction in a reaction vessel 102 and performing component analysis. This automatic analyzer 100 mainly includes a reaction disk 101, a cleaning mechanism 103, a spectrophotometer 104, a stirring mechanism 105, a cleaning tank 106, a reagent dispensing mechanism 107, a cleaning tank 108, a reagent disk 109, a pair of sample dispensing mechanisms 111 (in Fig. 2, the reference numeral 111 is attached only to the sample dispensing mechanism on the left side of the drawing, but the sample dispensing mechanism on the right side of the drawing is the same), a cleaning tank 113, a sample transport mechanism 117, and a controller 118. Further, the reagent dispensing mechanism 107 and the sample dispensing mechanism 111 have a liquid level detection function.

[0031] A plurality of reaction vessels 102 are arranged on the circumference of the reaction disk 101. The reaction vessel 102 is a container for accommodating a mixed solution obtained by mixing a sample and a reagent. Near the reaction disk 101, a sample transport mechanism 117 for transporting a sample rack 116 on which a sample container 115 is mounted is arranged.

[0032] Between the reaction disk 101 and the sample transport mechanism 117, a pair of sample dispensing mechanisms 111 that can rotate and move up and down are arranged. The pair of sample dispensing mechanisms 111 each include a sample dispensing arm 111a and a sample dispensing probe 111b. A sample syringe 122 is connected to each of the sample dispensing probes 111b. The sample dispensing probe 111b horizontally moves while drawing an arc around a rotation axis and moves up and down to dispense a sample from the sample container 115 to the reaction vessel 102. The reagent disk 109 is a storage where a plurality of reagent bottles 110 containing reagents, detergent bottles 112, etc. can be placed on the circumference. The reagent disk 109 is kept cold.

[0033] Between the reaction disk 101 and the reagent disk 109, a pair of reagent dispensing mechanisms 107 capable of rotation and vertical movement are installed, each comprising a reagent dispensing arm 107a and a reagent dispensing probe 120. The reagent dispensing probe 120 is moved vertically and horizontally by the reagent dispensing mechanism 107. Reagent syringes 121 are connected to the reagent dispensing probes 120 respectively. By means of this reagent syringe 121, reagents, detergents, diluents, pretreatment reagents, etc. aspirated from a reagent bottle 110, a detergent bottle 112, a diluent bottle, a pretreatment reagent bottle, etc. are dispensed into the reaction vessel 102 via the reagent dispensing probe 120.

[0034] Around the reaction disk 101, a cleaning mechanism 103 for cleaning the inside of the reaction vessel 102, a spectrophotometer 104 for measuring the absorbance of light passed through the mixed solution in the reaction vessel 102, a stirring mechanism 105 for mixing the sample and the reagent dispensed into the reaction vessel 102, etc. are arranged.

[0035] Also, a cleaning tank 108 for the reagent dispensing probe 120 is arranged above the operating range of the pair of reagent dispensing mechanisms 107, a cleaning tank 113 for the sample dispensing probe 111b is arranged above the operating range of the pair of sample dispensing mechanisms 111, and a cleaning tank 106 for the stirring mechanism 105 is arranged above the operating range of the stirring mechanism 105.

[0036] Each mechanism is connected to a controller 118, and its operation is controlled by the controller 118. The controller 118, which is a control unit, is composed of a computer or the like, controls the operation of each of the above-described mechanisms in the automatic analyzer, and performs arithmetic processing for obtaining the concentration of a predetermined component in a liquid sample such as blood or urine.

[0037] The analysis process of the test sample by the automatic analyzer 100 as described above is executed in the following order. First, the sample in the sample container 115 placed on the sample rack 116 conveyed near the reaction disk 101 by the sample conveyance mechanism 117 is dispensed into the reaction container 102 on the reaction disk 101 by the sample dispensing probe 111b of either one of the pair of sample dispensing mechanisms 111. Next, the reagent used for analysis is dispensed from the reagent bottle 110 on the reagent disk 109 into the reaction container 102 where the sample has been previously dispensed by either one of the pair of reagent dispensing mechanisms 107. Subsequently, the stirrer mechanism 105 stirs the mixture of the sample and the reagent in the reaction container 102.

[0038] Thereafter, the light generated from the light source is irradiated onto and transmitted through the reaction container 102 containing the mixture, and the light intensity of the transmitted light is measured by the spectrophotometer 104. The light intensity measured by the spectrophotometer 104 is transmitted to the controller 118 via an A / D converter and an interface. Then, the controller 118 performs calculations to obtain the concentration of a predetermined component in a liquid sample such as blood or urine, and the result is displayed on a display unit (not shown) or the like. Although an automatic analyzer that uses the spectrophotometer 104 to obtain the concentration of a predetermined component is described as an example, the technology disclosed in the embodiments described later may also be used in an immunoautomatic analyzer or a coagulation automatic analyzer that measures a sample using other photometers.

[0039] FIG. 3(a) is a side view of the sample dispensing mechanism 111 to which the imaging device 2 is attached. The sample dispensing mechanism 111 has an arm 111a, a probe 111b, and a shaft 111c. The proximal end portion of the probe 111b is held at one end portion of the arm 111a. In FIG. 3(a), the arm 111a is supported by the shaft 111c. The shaft 111c is configured to be rotatable and vertically movable by a motor (not shown).

[0040] As shown in Fig. 3(a), in this specification, the longitudinal direction of the shaft 111c is defined as the vertical direction. Also, the direction parallel to the longitudinal direction of the arm 111a is defined as the front-rear direction, with the front represented by F and the rear represented by B. The optical axis of the imaging unit 10, that is, the straight line passing through the center of the imaging element 11 and the principal point of the imaging lens 12 is denoted as O. When there is no deviation of the optical axis due to looseness in the attachment of the imaging device 2 or the like, the optical axis O of the imaging unit 10 exists on the same line as the probe tip.

[0041] Fig. 3(b) is a rear view of the periphery of the imaging device 2 as seen from the rear. As shown in Fig. 3(b), in this embodiment, the short-side direction (the direction perpendicular to the vertical direction and the front-rear direction) of the arm 111a is defined as the left-right direction, with the right represented by R and the left represented by L. The plane including the rotation axis Q of the arm 111a and the central axis of the probe 111b is denoted as A. The plane including the center of the imaging element 11 and the central axis of the probe 111b is denoted as P. When there is no looseness in the attachment of the imaging device 2 or the attachment of the probe 111b or the like, the plane A and the plane P are the same.

[0042] Fig. 4 is a flowchart showing the imaging operation by the imaging system in the first embodiment. When the process starts, first, the imaging device 2 uses the imaging unit 10 to photograph the first subject and acquires a photographed image of the first subject. In this embodiment, the probe 111b shown in Fig. 5 is used as the first subject. (Step S101) In step S102, among the probes 111b existing in the captured image 200, two or more reference points are selected. The reference points can be selected by the operator manually using the captured image 200 or by the imaging device 2 from the captured image 200 output based on conditions set in advance in the imaging device 2. In this embodiment, the tip position FP1 of the probe 111b shown in Fig. 5 and the upper center point FP2 of the probe 111b in the captured image 200 are used as the reference points.

[0043] In step S103, the imaging unit 10 measures the coordinates of the imaging positions of the reference points FP1 and FP2 of the first subject. Specifically, for the captured image 200 in FIG. 5, the signal processing unit 14 detects the contour using the luminance difference. The contour of the first subject is detected from the detected contours using a matching method or the like. The Y-direction coordinates of FP1 and FP2 are obtained by acquiring the upper and lower ends among the detected contours of the first subject. The X-direction coordinates of FP1 and FP2 are obtained by averaging the X coordinates of the contours around the Y coordinates of FP1 and FP2 to specify the center position.

[0044] In step S104, the imaging unit 10 measures the focusing positions of the reference points FP1 and FP2 of the first subject. Specifically, while driving the variable-focus lens 15 by the lens driving unit 13, the imaging element 11 acquires a captured image at each lens position (the number of steps of the stepping motor of the lens driving unit 13 corresponds to each lens position). Then, the video processing unit (signal processing unit) 14 detects the contrast value of each captured image at each lens position. As a result of the detection, the lens position at which the captured image having the maximum contrast value is obtained is set as the focusing position.

[0045] In step S105, the control unit 20 determines whether the deviation of the optical axis of the imaging unit 10 is equal to or less than a certain value based on the first subject imaging allowable area 33 of the storage unit 30, the imaging position measurement unit 51 of the calculation unit 50, the focusing position measurement unit 52, and the determination unit 53. In this embodiment, it is determined whether the tip FP1 of the probe 111b shown in FIG. 5 exists within the first subject imaging allowable area 201. Also, it is determined whether the difference between the focusing position of the tip FP1 of the probe 111b measured in step S104 and the first subject focusing position 32 of the storage unit 30 is equal to or less than a certain value. When the deviation of the optical axis of the imaging unit 10 is equal to or less than a certain value, the process proceeds to step S106. When the deviation of the optical axis of the imaging unit 10 is equal to or greater than a certain value, the image output unit 3 is notified that the imaging environment of the imaging device 2 is abnormal (step S107), and subsequent measurements are aborted.

[0046] In step S106, the control unit 20 calculates the deviation of the optical axis of the imaging unit 10 based on the first subject imaging position 31 of the storage unit 30, the first subject focus position 32, the aberration correction data 34, the imaging position measurement unit 51 of the calculation unit 50, the focus position measurement unit 52, and the optical axis deviation calculation unit 54. In this embodiment, the inclination with respect to the roll direction 300, the yaw direction 400, and the pitch direction 500 of the imaging device 2 with respect to the sample dispensing device 111 shown in FIG. 6 is defined as the deviation of the optical axis of the imaging unit 10. Using the pixel differences in the X direction and the Y direction of the imaging measurement positions of the reference points FP1 and FP2 of the probe 111b shown in FIG. 5, the distances (ΔX, ΔY) in the XY direction of the reference points FP1 and FP2 of the probe 111b are calculated. Using the calculated respective distances, the inclination in the roll direction 300 of the imaging device 2 is calculated. Next, using the pixel difference in the X direction between the reference point FP1 of the probe 111b and the first subject imaging position 202 of the storage unit, the distance in the X direction between the reference point FP1 of the probe 111b and the first subject imaging position 202 is calculated. By using the calculated distance in the X direction and the inclination in the roll direction 300 calculated above, the inclination in the yaw direction 400 is calculated.

[0047] Finally, using the pixel difference in the X direction between the reference point FP1 of the probe 111b and the first subject imaging position 202 of the storage unit, the distance in the Y direction between the reference point FP1 of the probe 111b and the first subject imaging position 202 is calculated. By using the calculated distance in the Y direction and the inclination in the roll direction 300 calculated above, the inclination in the pitch direction 500 is calculated.

[0048] In step S108, the generation unit 40 generates a distance table 41 showing the correlation between the variable focus lens 15 and the distance from the imaging lens based on the focus position measurement unit 52 of the calculation unit 50 and the optical axis deviation calculation unit 54. In this embodiment, the distance table 41 is generated using the difference in the focus measurement positions of the reference points FP1 and FP2 of the probe 111b shown in FIG. 5 and the deviation of the optical axis of the imaging unit 10 calculated in step S106.

[0049] In step S109, the control unit 20 calculates the relative coordinates of the measurement target point of the first subject as seen from the imaging lens 12 based on the aberration correction data 34 of the storage unit 30, the distance table 41 of the generation unit 40, the imaging position measurement unit 51 of the calculation unit 50, the focusing position measurement unit 52, and the relative coordinate calculation unit 55. The measurement target point can be selected from the captured images output by the imaging device 2 based on the conditions manually specified by the operator using the captured images or set in the imaging device 2 in advance. In this embodiment, the tip position of the probe 111b shown in FIG. 5 is set as the measurement target point MP1.

[0050] In step S110, the imaging device 2 captures a second subject by the imaging unit 10 and acquires a captured image of the second subject. In this embodiment, the cylindrical object shown in FIG. 7 is used as the second subject.

[0051] In step S111, the imaging unit 10 and the imaging position measurement unit 51 of the calculation unit 50 of the control unit 20 measure the imaging position of the measurement target point of the second subject. The measurement target point can be selected from the captured images output by the imaging device 2 based on the conditions manually specified by the operator using the captured images or set in the imaging device 2 in advance. In this embodiment, the center MP2 of the upper surface of the cylindrical object is set as the measurement target point of the second subject. Specifically, for the captured image 200 in FIG. 7, the signal processing unit 14 detects the contour using the luminance difference. The contour of the second subject is detected from the detected contours using a matching method or the like. The upper surface of the second subject is detected by detecting a circle from the detected contour of the second subject. The measurement target point of the second subject is obtained by extracting the center of the detected upper surface of the second subject.

[0052] In step S112, the imaging unit 10 and the focusing position measurement unit 52 of the calculation unit 50 of the control unit 20 measure the imaging position of the measurement target point of the second subject. Specifically, while driving the variable focus lens 15 by the lens driving unit 13, the video processing unit 14 acquires the lens position at which a captured image having the maximum contrast value is obtained at the measurement target point of the second subject.

[0053] In step S113, the control unit 20 calculates the relative coordinates of the measurement target point of the second subject as seen from the measurement target point of the first subject based on the aberration correction data 34 in the storage unit 30, the distance table 41 of the generation unit 40, the imaging position measurement unit 51 of the calculation unit 50, the focusing position measurement unit 52, and the relative coordinate calculation unit 55. Specifically, first, based on the aberration correction data 34 in the storage unit 30, the distance table 41 of the generation unit 40, the imaging position measurement unit 51 of the calculation unit 50, the focusing position measurement unit 52, and the relative coordinate calculation unit 55, the relative coordinates of the measurement target point of the second subject as seen from the imaging lens 12 are calculated. Based on the calculated relative coordinates and the relative coordinates of the measurement target point of the first subject as seen from the imaging lens 12 calculated in step S109, the relative coordinates of the measurement target point of the second subject as seen from the measurement target point of the first subject are obtained.

[0054] In step S114, the control unit 20 corrects the relative coordinates of the measurement target point of the second subject as seen from the measurement target point of the first subject calculated in step S113 based on the relative coordinate calculation unit 55 and the coordinate correction unit in the calculation unit 50 by the deviation of the optical axis of the imaging unit 10 calculated in step S106, and calculates the relative coordinates considering the deviation of the optical axis.

[0055] In step S115, the imaging device 2 outputs the result of the relative coordinates of the measurement target point of the first subject and the measurement target point of the second subject calculated by the calculation unit 50 in the control unit 20 to the image output unit 3 as a measurement result. To the image output unit 3, the relative coordinates of the measurement target points of the first subject and the second subject as seen from the imaging lens 12 and the relative coordinates of the measurement target point of the second subject as seen from the measurement target point of the first subject are output. Thereby, this imaging operation is terminated.

[0056] In the first embodiment, the deviation of the optical axis of the imaging unit 10 was measured based on the imaging position and the focusing position of the reference point of the first subject. However, it is also possible to measure the deviation of the optical axis of the imaging unit 10 from the dimensional information of the reference point of the first subject. FIG. 8 is a configuration diagram of an imaging system according to a second embodiment. Only the parts different from the imaging system of the first embodiment will be described. The imaging device 2 in this embodiment includes first subject dimension information 35 in a storage unit 30 within a control unit 20. The first subject dimension information 35 is data regarding the dimensions between two or more reference points of a first subject determined in advance when there is no deviation of the optical axis of the imaging unit 10 with respect to the first subject. Further, the imaging device 2 includes a first subject dimension measurement unit 57 in an arithmetic unit 50 within the control unit 20. The first subject dimension measurement unit 57 measures the dimensions between two or more reference points of the first subject when the imaging device 2 actually images the first subject.

[0057] FIG. 9 is a flowchart showing an imaging operation when measuring the deviation of the optical axis of the imaging unit 10 based on the imaging position and the dimension information of the first subject. Only the parts different from the first embodiment will be described.

[0058] In step S204, the arithmetic unit 50 uses the first subject dimension measurement unit to measure the dimensions between two points of the reference points in the probe 111b existing in the captured image. As shown in FIG. 10, the length L between the two points is measured using the pixel difference between the two reference points FP1 and FP2 of the probe 111b existing in the captured image.

[0059] In step S206, the control unit 20 calculates the deviation of the optical axis of the imaging unit 10 based on the first subject imaging position 31, the first subject focusing position 32, the aberration correction data 34, the first subject dimension information 35, the imaging position measurement unit 51 of the arithmetic unit 50, the first subject dimension measurement unit, and the optical axis deviation calculation unit 54. Using the pixel differences in the X direction and the Y direction of the imaging measurement positions of the reference points FP1 and FP2 of the probe 111b shown in FIG. 10, the distances (ΔX, ΔY) in the XY direction of the reference points FP1 and FP2 of the probe 111b are calculated. Using each calculated distance, the inclination in the roll direction 300 of the imaging device 2 is calculated.

[0060] Next, using the pixel difference in the X direction between the reference point FP1 of the probe 133 and the first subject imaging allowable area 201 of the storage unit, the distance in the X direction between the reference point FP1 of the probe 133 and the first subject imaging allowable area 201 is calculated. By using the calculated distance in the X direction and the inclination in the roll direction 300 calculated above, the inclination in the yaw direction 400 is calculated. Finally, based on the dimensions L regarding the reference points FP1 and FP2 of the probe 111b measured by the first subject dimension measurement unit 57 of the arithmetic unit 50 in the control unit 20, the dimension information of the reference points FP1 and FP2 of the probe 111b stored in the aberration correction data 34 of the storage unit 30, and the inclination in the roll direction 300 calculated above, the inclination in the pitch direction 500 is calculated.

[0061] According to the configurations of the above embodiments, the imaging positions of two reference points set on the probe 111b, which is the first subject whose relative position with the imaging device is known, are calculated, and based on this, information regarding the deviation of the optical axis of the imaging unit 10 with respect to the first subject is calculated. Based on the calculated deviation of the optical axis and the in-focus position of the reference point, a distance table between the value of the variable focal length lens and the depth information of the optical axis is generated. Based on the imaging position measured by the imaging device, the deviation of the optical axis of the imaging unit, and the generated distance table, spatial coordinates are calculated. In this way, when there is no deviation of the optical axis or the like in the imaging device, by utilizing the fact that the relative position between the imaging unit 10 and the first subject is known, the deviation of the optical axis of the imaging unit 10 and information on the optical characteristics of the variable focal length lens are calculated, and spatial coordinates are calculated using the calculated information and the results of the imaging device. Therefore, it is possible to obtain accurate spatial coordinates without depending on the deviation of the optical axis of the imaging unit due to the mounting play of the imaging device. In addition, it is possible to suppress a decrease in the measurement accuracy of the spatial coordinates with respect to changes in the optical characteristics of the variable focal length lens due to changes over time.

[0062] In particular, by attaching an imaging unit to the dispensing arm of an automatic analyzer, the relative positional relationship between the dispensing probe and the containers (such as reagent containers, sample containers, reaction containers, washing tanks, etc.) to which the dispensing probe dispenses reagents, samples, etc. can be accurately measured. As a result, the dispensing probe can accurately dispense various liquids to a predetermined position. Also, the relative positional relationship between the dispensing probe and the containers to which the dispensing probe dispenses reagents, samples, etc. can be adjusted accurately and in a short time.

Explanation of Signs

[0063] 1…Imaging system, 2…Imaging device, 3…Image output unit, 10…Imaging unit, 11…Image sensor, 12…Imaging lens, 13…Lens drive unit, 14…Signal processing unit, 15…Variable focus lens, 16…Fixed lens, 20…Control unit, 30…Storage unit, 31…First subject imaging position, 32…First subject focusing position, 33…First subject imaging allowable area, 34…Aberration correction data, 35…First subject dimension information, 40…Generator, 41…Distance table, 50…Calculation unit, 51…Imaging position measurement unit, 52…Focusing position measurement unit, 53…Determination unit, 54…Optical axis deviation calculation unit, 55…Relative coordinate calculation unit, 56…Coordinate correction unit, 57…First subject dimension measurement unit, 100…Automatic analyzer, 101…Reaction disk, 102…Reaction container, 103…Washing mechanism, 104…Spectrophotometer, 105…Stirring mechanism, 106…Washing tank (for stirring mechanism), 107…Reagent dispensing mechanism, 107a…Reagent dispensing arm, 108…Washing tank (for reagent dispensing mechanism), 109…Reagent disk, 110…Reagent bottle, 111…First sample dispensing mechanism, 111a…Sample dispensing arm, 111b…Sample dispensing probe, 112…Detergent bottle, 113…Washing tank (for sample dispensing mechanism), 115…Sample container, 116…Sample rack, 117…Sample transfer mechanism, 118…Controller, 120…Reagent dispensing probe, 200…Imaged image, 201…First subject imaging allowable area, 210…Second subject.

Claims

1. A first step of obtaining a captured image of a first subject by an imaging unit; A second step of selecting two or more reference points from among the first subjects; A third step of obtaining the coordinates of the reference points; A fourth step of obtaining the focus position of the reference points; A fifth step of determining whether the deviation of the optical axis between the first subject and the imaging unit is equal to or less than a certain value based on the information on the imaging allowable area of the first subject stored in advance, the coordinates of the reference points obtained in the step, and the focus position; A sixth step of calculating the amount of deviation of the optical axis when the deviation of the optical axis of the imaging unit is equal to or less than a certain value; A seventh step of obtaining a captured image of a second subject to be measured; An eighth step of correcting the captured image of the second subject based on the amount of deviation of the optical axis to obtain an image of the measurement result; An imaging method characterized by including the above.

2. In the imaging method according to Claim 1, The lens of the imaging unit is a variable-focus lens. Instead of calculating the amount of deviation of the optical axis in the sixth step, based on the information on the imaging allowable area of the first subject stored in advance, the coordinates of the reference points obtained in the step, and the focus position, the optical characteristics of the variable-focus lens are calculated. In the eighth step, instead of correcting the captured image of the second subject based on the amount of deviation of the optical axis, the captured image of the second subject is corrected based on the optical characteristics of the variable-focus lens. An imaging method characterized by the above.

3. In the imaging method according to Claim 1, When the deviation of the optical axis between the first subject and the imaging unit in the fifth step is greater than a certain value, an imaging method characterized by including a notification step of notifying the same.

4. A variable-focus lens that varies the focal length; A control unit that controls the focus of the variable-focus lens; A detection unit that detects the focus position at the imaging position of a subject using the variable-focus lens; An imaging device including a measurement unit that measures the relative position of the subject based on the difference between the imaging position of the subject and the focus position, wherein: A calculation unit that calculates the deviation of the optical axis between the first subject and the imaging device based on the imaging position and the focus position of the first subject; A correction unit that corrects the measurement result of the relative position of the second subject to be measured based on the information on the deviation of the optical axis between the first subject and the imaging device calculated by the calculation unit; An imaging device characterized by including the above.

5. In the imaging device according to Claim 4, The calculation unit calculates the optical characteristics of the variable focal length lens instead of the deviation of the optical axis, a correction unit that corrects the measurement result of the relative position of the second subject to be measured based on the information on the optical characteristics of the variable focal length lens calculated by the calculation unit; An imaging device characterized by comprising the above.

6. In the imaging device according to claim 4, a determination unit that determines that the first subject exists within a predetermined imaging position and / or in-focus position range; An imaging device characterized by comprising the above.

7. In the imaging device according to claim 4, a notification unit that notifies that the first subject does not exist within a predetermined imaging position and / or in-focus position range when the first subject does not exist within the range; An imaging device characterized by comprising the above.

8. In the imaging device according to claim 4, a storage unit that stores the imaging position and the in-focus position of the first subject when there is no deviation in the optical axis between the first subject and the imaging device; An imaging device characterized by comprising the above.

9. In the imaging device according to claim 4, a generation unit that generates a distance table that holds the correlation between the focal length of the variable focal length lens and the relative distance from the imaging device to the first subject when the imaging device is at the in-focus position of the first subject; An imaging device characterized by comprising the above.

10. In the imaging device according to claim 4, a storage unit that stores aberration correction data that holds the correlation between the imaging position acquired by the imaging device and the relative position between the imaging device and the optical axis based on the optical characteristics of the imaging device; An imaging device characterized by comprising the above.

11. In the imaging device according to claim 4, a storage unit that stores the imaging position and the in-focus position of the first subject when there is no deviation in the optical axis between the first subject and the imaging device; a generation unit that generates a distance table that holds the correlation between the focal length of the variable focal length lens and the relative distance from the imaging device to the first subject when the imaging device is at the in-focus position of the first subject; Comprising a correction unit that corrects the measurement result of the relative position between the imaging device and the subject based on the generation unit, the distance table acquired by the storage unit, and the aberration correction data; An imaging device characterized by comprising the above.

12. An automatic analyzer comprising a dispensing probe for dispensing a liquid, a dispensing arm to which the dispensing probe is attached, and a liquid container for discharging the liquid from the dispensing probe. An automatic analyzer, characterized in that at least the imaging unit among the imaging devices according to any one of claims 4 to 11 is attached to the dispensing arm.

13. A method for adjusting the position of an automatic analyzer, comprising a dispensing probe for dispensing a liquid, a dispensing arm to which the dispensing probe is attached, and a liquid container for discharging the liquid from the dispensing probe. A method for adjusting the position of an automatic analyzer, characterized in that at least the position of the dispensing probe is adjusted based on the result obtained by the imaging method according to any one of claims 1 to 3.

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