Probe position detection device and automatic analyzer

Abstract

The present invention can accurately detect the position of a probe including an offset from a target stop position in a depth direction. Illumination light is emitted from the light source to the probe, and an image around the probe is captured by the imaging unit. The calculation unit calculates the position of the probe on the basis of an optical image which is formed by reflected light from the probe of the illumination light and which is captured by the imaging unit. The light source emits illumination light to the tip of the probe from an inclined direction in a state where the tip of the probe is located above the target stop position of the probe. The imaging unit captures an optical image of a plane formed in the vicinity of the target stop position by reflecting the illumination light on the surface of the tip of the probe. The calculation unit acquires the optical image from the imaging unit, and calculates the position of the tip of the probe when the tip of the probe is lowered to the same height as the target stop position.

Description

TECHNICAL FIELD

[0001] The present application relates to a probe position detection device that detects a position of a probe used for dispensing of a specimen, a reagent, or the like in an automatic analysis device or the like, and an automatic analysis device including the probe position detection device. BACKGROUND

[0002] From the viewpoint of maintaining the dispensing accuracy, the probe used for dispensing of a specimen, a reagent, or the like in an automatic analysis device is periodically replaced. At the time of dispensing, the tip of the probe is inserted into a plurality of narrow spaces such as a specimen container, a reagent container, or a washing hole. Thus, whenever the probe is replaced in the automatic analysis device, an adjustment work of the tip position of the probe set to a target stop position of the specimen container, the reagent container, the washing hole, or the like is required.

[0003] In the specimen processing device disclosed in Patent Literature 1, the position adjustment of the moving part is easily and accurately performed regardless of the complexity of the moving path of the moving part, and thus, when the specimen analysis device is abnormal, a test tube is photographed with a camera provided in the specimen analysis device. Based on the photographed image, an adjustment amount of the reagent dispensing unit is detected, and adjustment of the reagent dispensing unit is performed according to the detected adjustment amount.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2012-32310 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the specimen processing device described in Patent Literature 1, the tip of the probe is photographed at the target stop position, and the shift of the center line of the obtained image from the target stop position in the left-right direction is detected as an adjustment amount. However, in this device, the shift amount in the depth direction of the image cannot be detected. Thus, even in the case where the tip of the probe coincides with the target stop position on the photographed image, the tip of the probe can be adjusted to a position shifted from the target stop position in the depth direction.

[0009] The present application provides a probe position detection device and an automatic analysis device including the probe position detection device, which can accurately detect the position of the probe including the shift from the target stop position in the depth direction.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] To solve the above problems, a probe position detection device according to the present application detects a position of a probe, the probe position detection device including: a light source that emits illumination light toward the probe; a photographing section that photographs an image of a vicinity of the probe; and a calculation section that calculates the position of the probe based on an optical image formed due to reflection of the illumination light on the probe and photographed by the photographing section. The light source irradiates the illumination light toward a tip end of the probe in an inclined direction from a position above the tip end of the probe, when viewed from the tip end of the probe, toward a lower side, in a state in which the tip end of the probe is positioned above a target stop position of the probe. The photographing section photographs the optical image formed on a plane in the vicinity of the target stop position by reflection of the illumination light on a surface of the tip end section of the probe. The calculation section acquires the optical image from the photographing section and calculates the position of the tip end of the probe when the tip end of the probe is lowered to the same height as the target stop position.

[0012] Effects of Invention

[0013] According to the present application, it is possible to provide a probe position detection device that can accurately detect a position of a probe including a shift in a depth direction from a target stop position. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic configuration view of an automatic analysis device 10 according to a first embodiment.

[0015] Figure 2 is a side view of a reagent dispensing device 14 on which a photographing section 32 is mounted.

[0016] Figure 3 is a rear view of the reagent dispensing device 14 on which the photographing section 32 is mounted.

[0017] Figure 4 is a side view for explaining an optical path of illumination light projected toward a device surface S at the same height as a target stop position 4.

[0018] Figure 5 is a rear view for explaining an optical path of illumination light projected toward a device surface S at the same height as a target stop position 4.

[0019] Figure 6 is a schematic view showing an example of an image photographed by the photographing section 32 (camera 321).

[0020] Figure 7 is a schematic view showing an example of an image photographed by the photographing section 32 (camera 321).

[0021] Figure 8is a side view showing a state in which the photographing section 32 is fixed to a support device separate from the dispensing device in the automatic analysis device 10 of the second embodiment.

[0022] Figure 9 is a schematic view showing an example of an image photographed by the photographing section 32 (the camera 321) in the automatic analysis device 10 of the third embodiment.

[0023] Figure 10 is a schematic view showing an example of an image photographed by the photographing section 32 (the camera 321). DETAILED DESCRIPTION

[0024] Hereinafter, the present embodiment will be described with reference to the drawings. In the drawings, functionally identical elements are sometimes shown with the same reference numerals. Furthermore, the drawings show embodiments and implementation examples that follow the principles of the present disclosure, but they are by no means intended to limit the present disclosure. The description in this specification is merely typical examples, and in no way limits the scope or applications of the claims of the present disclosure.

[0025] In the present embodiment, the description is made sufficiently in detail for those skilled in the art to implement the present disclosure, but it can be other embodiments, and it is to be understood that the structure, configuration, and substitution of various elements can be changed without departing from the scope and spirit of the technical idea of the present disclosure. Therefore, the description hereinafter is not limited to the explanation.

[0026] [First Embodiment]

[0027] First, the structure of the automatic analysis device 10 of the first embodiment will be described with reference to Figure 1 and the like. As shown in Figure 1 , the automatic analysis device 10 is provided with, for example, a reagent tray 12, a reaction tray 13, a plurality of reagent dispensing devices 14, a plurality of specimen dispensing devices 15, a conveyance line 16, a cleaning bath 17, and a control device 100.

[0028] The reagent tray 12 is configured to be rotatable about a rotation axis, and holds a plurality of reagent containers 11 inside. The reaction tray 13 is also configured to be rotatable about a rotation axis, and holds a plurality of reaction units 20 arranged in the circumferential direction.

[0029] The cleaning bath 17 cleans the probe 151 of the specimen dispensing device 15. The conveyance line 16 conveys the shelf 18. The shelf 18 holds a specimen container 19 that accommodates a specimen. The specimen is, for example, a biological sample of a blood source such as serum or whole blood, or a urine source.

[0030] The reagent dispensing device 14 has a probe 141 for dispensing the reagent accommodated in the reagent container 11, and is configured to be able to move the probe 141 in the horizontal direction and the vertical direction. The reagent dispensing device 14 sucks the reagent to the probe 141 and discharges it to the reaction unit 20.

[0031] The specimen dispensing device 15 has a probe 151 for dispensing the specimen accommodated in the specimen container 19, and is configured to be able to move the probe 151 in the horizontal direction and the vertical direction. The specimen dispensing device 15 sucks the specimen to the probe 151 and discharges it to the reaction unit 20. The reagent and the specimen dispensed to the reaction unit 20 are stirred by a stirring device not shown, whereby a reaction solution is obtained.

[0032] The reagent dispensing device 14 is configured to be able to move the probe 141 horizontally to above each of a stop position for sucking the reagent from the reagent container 11, a stop position for discharging the reagent to the reaction unit 20, and a stop position for washing the reagent adhering to the probe 141 in a washing tank not shown, and then to lower (vertically move) the probe 141 to the height of each stop position. Similarly, the specimen dispensing device 15 is configured to be able to lower the probe 151 to each stop position after moving the probe 151 horizontally to above each of a stop position for sucking the specimen from the specimen container 19, a stop position for discharging the specimen to the reaction unit 20, and a stop position for washing the specimen adhering to the tip of the probe 151 in the washing tank 17.

[0033] The control device 100 can be configured by a general computer device, and as an example, has a processor 101, a storage device 102, an input device 103, and an output device 104.

[0034] The processor 101 controls the operation of the automatic analysis device 10 according to a program stored in the storage device 102. The storage device 102 can be configured by, for example, an internal memory or an external storage device, and stores a program and parameters required for the processing of the processor 101. The input device 103 can be configured by, for example, a mouse, a keyboard, a touch panel, or the like. The output device 104 can be configured by, for example, a display, a speaker, a touch panel, or the like.

[0035] Reference Figure 2 The structure of the reagent dispensing device 14 will be described with reference to a schematic view of FIG. 13. In addition, the specimen dispensing device 15 also has substantially the same structure.

[0036] The reagent dispensing device 14 has a probe 141, and is configured to be able to hold and move the probe 141 by arms 142, 143, and a shaft 144. In addition, the reagent dispensing device 14 has a photographing unit 32 for photographing the probe 141. Figure 2indicates a state in which the probe 141 is stopped above the target stop position 4. The imaging section 32 constitutes a probe position detection device for detecting the position of the probe 141.

[0037] In order to avoid collision of the front end of the probe 141 of the first embodiment with the device, adjustment of the position of the front end of the probe 141 is performed in a state in which the probe 141 is stopped slightly above the target stop position 4 without lowering the front end of the probe 141 to the height of the target stop position 4 (the surface S of the device).

[0038] The base end portion (upper end) of the probe 141 is held to one end of the arm 142. The arm 142 is rotatably linked with respect to the arm 143. Also, the arm 143 is rotatably linked with respect to the shaft 144. In Figure 2 In the figure, a state in which the arm 142 and the arm 143 are arranged in a straight line is shown. The shaft 144 is configured to be rotatable and vertically movable by a not-shown motor. In addition, the arm 143 can not be provided, in which case the arm 142 is connected with the shaft 144.

[0039] As one example, the imaging section 32 is provided with a camera 321 and a light source 322. The camera 321 can be a single-lens reflex camera having a photographing element and a lens. The camera 321 is disposed in a manner in which its optical axis becomes the same plane as the central axis of the probe 141. In addition, the camera 321 is disposed in a manner in which its optical axis is slightly directed downward from the front end of the probe 141, and the front end of the probe 141 and the periphery of the target stop position 4 are imaged when the position of the front end of the probe 141 is adjusted.

[0040] The light source 322 irradiates collimated illumination light at least in the direction of the central axis of the probe 141, and illuminates the front end portion of the probe 141 disposed above the target stop position 4 from a direction inclined thereto (a direction from a position above, as viewed from the front end of the probe 141, toward the lower side). The imaging section 32 is mounted to the lower side of the bottom surface of the arm 142 and the rear side of the probe 141 (a position farther from the probe 141, as viewed from the target stop position 4, when the probe 141 approaches the target stop position 4) by a mounting member 320.

[0041] Figure 3 is a rear view of the periphery of the imaging section 32 as viewed from the rear side (the camera 321 side). In Figure 3 In the figure, the arm 143 and the shaft 144 are omitted. In addition, a plane including the optical axis of the camera 321 and the central axis of the probe 141 is described as a plane P (indicated by a double-dotted line).

[0042] It is preferable that the light source 322 be disposed symmetrically with respect to the plane P (in a position not biased to one side of the plane P). That is, it is preferable that the central axis of the probe 141, the optical axis of the camera 321, and the optical axis of the light source 322 all be disposed in the plane P. In addition, it is preferable that the light rays of the illumination light emitted from the light source 322 not intersect the plane P. The arithmetic unit 31 can be constituted by, for example, a computer device, and has, as an example, a processor 311, a storage device 312, an input device 313, and an output device 314. The arithmetic unit 31 calculates the position of the probe 141 from the optical image formed by the reflected light of the illumination light from the light source 322 in the probe 141 and captured by the camera 321.

[0043] The processor 311 controls the operation of the imaging unit 32 in accordance with a program stored in the storage device 312. The storage device 312 can be constituted by, for example, an internal memory or an external storage device, and stores a program and parameters required for the processing of the processor 311. The input device 313 can be constituted by, for example, a keyboard, a numeric keypad, a touch panel, or the like. The output device 314 can be constituted by, for example, a display, a speaker, a touch panel, or the like. The arithmetic unit 31 communicates with the imaging unit 32 by wire or wirelessly, and receives the image captured by the camera 321. The arithmetic unit 31 can be constituted by the same computer device as the control device 100, or can be constituted by a separate computer device.

[0044] Figure 4 and Figure 5 are side and rear views for explaining the optical path of the illumination light emitted from the light source 322. As shown in Figure 4 , in the case where the front end portion of the probe 141 is made of metal and has a mirror-like surface, the illumination light from the light source 322 is specularly reflected on the surface of the front end portion of the probe 141, and is incident on the device surface S located at the same height as the target stop position 4 below.

[0045] Referring to Figure 6 , an example of an image obtained in the case where the light emitted from the light source 322 and specularly reflected on the surface of the probe 141 is incident on the device surface S will be described. The light reflected on the surface of the front end portion of the probe 141 forms an optical image E caused by the reflected light on the device surface S. This optical image E is an optical image of an elliptical arc curve having a higher pixel value than its surroundings. The optical image E is caused by the reflected light emitted from the light source 322 located on one side of the probe 141 and reflected by the probe 141, and thus its shape is not an elliptical shape, but an elliptical arc shape with a part missing (open).

[0046] The operation section 31 extracts the optical image E projected onto the device surface S from the image captured and received by the camera 321, approximates an elliptical arc curve based on the optical image E, calculates the center position C of the approximated elliptical arc, and calculates the center position O of the tip of the probe 141 in the device surface S based on the calculation result. Based on the shift amount of the calculated center position O of the tip of the probe 141 from the target stop position 4 (the center of the cleaning hole 171), the operation amount of the motor in the reagent dispensing device 14 that moves the probe 141 in the horizontal direction is adjusted, and the value of the parameter stored in the storage device 102 is updated.

[0047] As an example of the target stop position 4 of the probe 141, the cleaning hole 171 provided in the cleaning tank 17 can be given. Since the probe 141 is cleaned after being inserted into the cleaning hole 171, it is necessary to control the position of the probe 141 so that the probe 141 moves to the center of the cleaning hole 171.

[0048] The elliptical arc curve approximated based on the optical image E varies in curvature due to the angle and position of the illumination light incident to the surface 141t of the tip of the probe 141. However, the center position C of the elliptical arc varies little. In addition, the distance L between the center position O of the probe 141 and the center position C is a constant value determined based on the outer diameter of the probe 141. In the example shown in FIG. 6, the center position O of the probe 141 is determined as a point obtained by moving the center position C of the elliptical arc curve in the vertical direction by a distance L corresponding to the outer diameter of the probe 141. Figure 2 In the arrangement of the light source 322 shown in FIG. 5, the incident direction of the illumination light is on the center line J (double-dot chain line) of the left and right of the image.

[0049] Further, in the example described above, the optical image E is approximated by an elliptical arc, but instead of or in addition to this, a point D2 halfway between a point Dl, which is the point of the pixel having a coordinate of the horizontal axis that is the smallest among the pixels having a pixel value of a certain threshold value or more in the captured image, and a point D3, which is the point of the pixel having a coordinate of the horizontal axis that is the largest, can be detected as the center position C. The coordinate of the pixel obtained by moving the coordinate of the center position C upward by a number of pixels corresponding to a certain distance L becomes the center position O of the probe 141.

[0050] If the tip of the probe 141 is captured in such a manner that the tip is included in the capturing range of the camera 321, it is possible to prevent a decrease in detection accuracy caused by assembly error or mounting error of the capturing section 32. Specifically, by detecting the tip of the probe 141, it is possible to estimate the center axis A (single-dot chain line) of the probe 141. Figure 7). Thus, even in the case where the central axis of the probe 141 is arranged so as to deviate from the same plane as the optical axis of the camera 321 and the optical axis of the light source 322, the intersection of the circle M (dotted line) with the central axis A of the probe 141, which is centered at the position C of the elliptical arc of the optical image E and has a radius of the distance L, can be found. This intersection can be more accurately detected as the center position O of the front end of the probe 141 when the front end of the probe 141 descends to the same height as the cleaning hole 171.

[0051] In the case where the front end portion of the probe 141 is composed of a metal or the like having high regular reflectance, when the illumination light is reflected at the front end of the probe 141, the regular reflection light component becomes more prominent, and the outline of the optical image E projected onto the device surface S becomes clear, so the optical image E can be easily detected clearly on the image. Further, the directivity of the light regularly reflected from the surface 141t of the front end portion of the probe 141 becomes high, so the approximation accuracy of the optical image E based on the elliptical arc increases.

[0052] The illumination light emitted from the light source 132 can be parallel light. In this case, the directivity of the regular reflection light at the surface 141t of the front end of the probe 141 becomes high, so the approximation accuracy of the elliptical arc of the optical image E projected onto the device surface S increases.

[0053] As described above, according to the first embodiment, the coordinates of the center position C of the optical image E formed on the device surface S at the same height as the target stop position 4 can be detected using the elliptical arc, and the intersection of the center line J of the probe 141 and the device surface S, that is, the center position O of the front end of the probe 141 when the front end of the probe 141 descends to the same height as the target stop position 4, can be found using the coordinates of the center position C. The found center position O of the front end of the probe 141 is located on the same plane as the target stop position 4, so the distance between the two ultimately becomes the shift of the center position O of the front end of the probe 141 and the target stop position 4 in the in-plane direction.

[0054] Further, the photographing section 32 can also be similarly installed to the specimen dispensing device 15, and the position of the probe 151 installed to the specimen dispensing device 15 can also be detected. That is, by photographing the periphery of the target stop position while irradiating the front end of the probe 151 of the specimen dispensing device 15 with illumination light, the center position of the front end of the probe 151 and the shift amount from the position of the target stop position can be detected. In addition, the photographing section 32 can also be installed to other devices instead of being installed to the dispensing device.

[0055] Further, the photographing section 32 can be configured to be attachable to and detachable from the dispensing device or the like. By being configured to be attachable and detachable, the photographing section 32 can be attached to the dispensing device only when the position of the probe is adjusted, and detached from the dispensing device or the like when the normal analysis operation is performed. By being configured to be attachable and detachable, the mass of the photographing section 32 is removed when the analysis operation is performed, and thus the load on the motor that drives the dispensing device can be reduced. As a result, the throughput of the analysis can be improved. Further, for example, if a magnet is attached to the photographing section 32 so that a magnetic body protrudes from the bottom surface of the arm 142, the positioning and detaching operation of the photographing section 32 becomes easy.

[0056] [Second Embodiment]

[0057] Referring to Figure 8 , a second embodiment of the automatic analysis device 10 will be described. Figure 8 is a side view of the photographing section 32 of the automatic analysis device 10 of the second embodiment. The overall structure of the automatic analysis device 10 of the second embodiment can be the same as that of the first embodiment ( Figure 1 ), and thus the repeated description is omitted.

[0058] In the automatic analysis device 10 of the first embodiment, the photographing section 32 is attachable to the bottom surface of the arm 142 of the dispensing device. In contrast, in the second embodiment, as shown in Figure 8 , the photographing section 32 is fixed to a support device 400 that is provided separately from the dispensing devices 14 and 15 in the vicinity of the dispensing devices 14 and 15. The orientation of the optical axes of the camera 321 and the light source 322, the arrangement relationship, and the like can be the same as those of the first embodiment. The separate support device 400 can be provided for each of the plurality of reagent dispensing devices 14 and the specimen dispensing device 15. Alternatively, the support device 400 itself can be moved and fixed in the vicinity of the dispensing device 14 or 15 in which the probe 141 or 151 needs to be replaced.

[0059] According to the second embodiment, the same effects as those of the first embodiment can be obtained. Further, by providing the separate support device 400, the structure of the dispensing device 14 or 15 can be simplified.

[0060] [Third Embodiment]

[0061] Referring to Figure 9 , a third embodiment of the automatic analysis device 10 will be described. Figure 9 shows an example of an image photographed in the photographing section 32 of the automatic analysis device 10 of the third embodiment. The overall structure of the automatic analysis device 10 of the third embodiment can be the same as that of the first embodiment ( Figure 1 ), and thus the repeated description is omitted.

[0062] In the above embodiment, the central axis of the probe 141, the optical axis of the camera 321, and the optical axis of the light source 322 are described as an example in which the central axis of the probe 141, the optical axis of the camera 321, and the optical axis of the light source 322 are located on the same plane P. On the other hand, in this third embodiment, the optical axis of the camera 321 may not be located on the same plane P, but may be set in a direction in which the optical axis of the camera 321 and the plane P intersect.

[0063] Even when the optical axes of the cameras 321 are not on the same plane P but intersect at a predetermined angle, the image captured by the camera 321 is an optical image E in the shape of an elliptical arc with a portion open, similar to the first embodiment.

[0064] The opening of the elliptical arc curve is formed in an area where the illumination light is blocked by the probe 141 and the illumination light reflected by the surface 141t of the front end of the probe 141 is not projected. In other words, the opening of the elliptical arc curve is generated on the opposite side of the incident direction of the illumination light from the light source 322 with respect to the central axis of the probe 141. That is, Figure 9 As shown, the extended direction of line segment l (dashed line) extending from the midpoint E2 of the opening ends E1 and E3 of the optical image E (elliptical curve) toward the center position C of the elliptical curve becomes the incident direction of the illumination light. Therefore, by using the elliptical curve to approximate the optical image E formed on the device surface (plane) S at the same height as the cleaning hole 171, the coordinates of its center C are detected. The coordinates of center C are shifted a certain distance L along line segment l toward point E2, thereby determining the intersection point between the central axis of probe 141 and device surface S. This intersection point corresponds to the center position O of the tip of probe 141 when the tip of probe 141 is lowered to the height of cleaning hole 171.

[0065] If the camera 321 captures the tip of the probe 141 so that it is within the range of the camera 321, it is possible to prevent the reduction in detection accuracy caused by assembly errors and installation errors of the imaging unit 32. Specifically, by detecting the tip of the probe 141, the central axis A (single-dot chain line) of the probe 141 can be estimated ( Figure 10 ). The intersection of a circle M (dashed line) with a certain distance L as radius and the center position C of the elliptical arc curve approximating the optical image E as the center and the central axis A of the probe 141 can be obtained. This intersection can be more accurately detected as the center position O of the front end of the probe 141 when the front end of the probe 141 is lowered to the same height as the cleaning hole 171. Figure 9 and Figure 10 In any case, the distance between the center position O of the front end of the probe 141 and the cleaning hole 171 is the offset in the in-plane direction between the center position of the front end of the probe 141 and the target stop position.

[0066] The present application is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are described in detail in order to easily understand the present application, and it is not necessary to have all the structures described. In addition, a part of one embodiment can be replaced with a structure of another embodiment. In addition, a structure of another embodiment can be added to a structure of one embodiment. In addition, a part of a structure of each embodiment can be added, deleted, or replaced with a part of a structure of another embodiment.

[0067] Symbol explanation

[0068] 10 automatic analysis device

[0069] 11 reagent container

[0070] 12 reagent disk

[0071] 13 reaction disk

[0072] 14 reagent dispensing device

[0073] 15 specimen dispensing device

[0074] 16 transport line

[0075] 17 washing tank

[0076] 18 shelf

[0077] 19 specimen container

[0078] 20 reaction unit

[0079] 5 optical path

[0080] 141 probe

[0081] 142, 143 arm

[0082] 144 shaft

[0083] 151 probe

[0084] 171 washing hole

[0085] 32 imaging section

[0086] 320 mounting member

[0087] 321 camera

[0088] 322 light source

[0089] 31 arithmetic section

[0090] 4 target stop position

[0091] S device surface

[0092] L certain distance

[0093] E optical image.

Claims

1. A probe position detection device for detecting the position of a probe, characterized in that: The probe position detection device comprises: a light source emitting illumination light toward the probe; an imaging unit that captures an image of the area surrounding the probe; and a calculation unit that calculates the position of the probe based on an optical image formed by the reflection of the illumination light on the probe and captured by the imaging unit, When the front end of the probe is located above the target stop position of the probe, the light source irradiates the illumination light toward the front end of the probe in an oblique direction from an upper position toward a lower position when viewed from the front end of the probe. The imaging unit captures the optical image formed on a plane near the target stop position by the illumination light reflected from the surface of the distal end portion of the probe. The calculation unit acquires the optical image from the imaging unit and calculates the position of the tip of the probe when the tip of the probe descends to the same height as the target stop position.

2. The probe position detection device according to claim 1, wherein: The illumination light is parallel light.

3. The probe position detection device according to claim 2, wherein: The imaging unit is set so as to include the tip of the probe within its imaging range.

4. The probe position detection device according to claim 1, wherein: The light source and the imaging unit are arranged so that an optical axis of the imaging unit, an optical axis of the light source, and a central axis of the probe are located on the same plane.

5. The probe position detection device according to claim 1, wherein: The front end portion of the probe is made of metal.

6. The probe position detection device according to claim 1, wherein: The imaging unit is attached to the bottom surface of an arm constituting the dispensing device to which the probe is attached.

7. The probe position detection device according to claim 1, wherein: The imaging unit is configured to be detachable from the dispensing device to which the probe is attached or from a support device provided in the vicinity thereof.

8. An automatic analyzer comprising a dispensing device equipped with a probe for sucking and discharging a specimen or a reagent, characterized in that: The automatic analyzer further includes a probe position detection device for detecting the position of the probe. The probe position detection device comprises: a light source emitting illumination light toward the probe; an imaging unit that captures an image of the area surrounding the probe; and a calculation unit that calculates the position of the probe based on an optical image formed by the reflection of the illumination light on the probe and captured by the imaging unit, When the front end of the probe is located above the target stop position of the probe, the light source irradiates the illumination light toward the front end of the probe in an oblique direction from an upper position toward a lower position when viewed from the front end of the probe. The imaging unit captures the optical image formed on a plane near the target stop position by the illumination light reflected from the surface of the distal end portion of the probe. The calculation unit acquires the optical image from the imaging unit and calculates the position of the tip of the probe when the tip of the probe descends to the same height as the target stop position.

Images