Detection device

Abstract

To provide a detection device that allows enhancement of detection precision.SOLUTION: A detection device comprises: an optical sensor comprising a plurality of photodetection elements arranged in a planar configuration; a light source configured to emit light to the plurality of photodetection elements; and a translucent object placement member for placing a plurality of objects to be detected. The light source, the object placement member, and the optical sensor are arranged in the order as listed. The optical sensor is configured to obtain baseline data in an initial state after power-on, and at intervals of a predetermined period of time, obtain difference data based on a difference between the baseline data and sensor values obtained from the plurality of photodetection elements. The detection device is configured to output, when the difference data has exceeded a first threshold, either an alert indicating detection of the objects to be detected in an initial moisture region indicating presence of moisture in the initial state, or an alert indicating detection of the objects to be detected.SELECTED DRAWING: Figure 19

Description

[Technical Field]

[0001] The present invention relates to a detection device. [Background technology]

[0002] Patent Document 1 discloses an image acquisition device that includes an optical sensor, a container containing microorganisms and a culture medium, and a light source, and that acquires images over time that show the growth of the microorganisms in the container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-033430 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a detection device, if moisture adheres to the container, it may become difficult to properly detect the target substance to be detected.

[0005] An object of the present invention is to provide a detection device that can improve detection accuracy. [Means for solving the problem]

[0006] A detection device according to one embodiment of the present disclosure includes an optical sensor including a plurality of photodetector elements arranged in a planar manner, a light source that irradiates the plurality of photodetector elements with light, and a translucent object-to-be-detected mounting section for mounting a plurality of objects to be detected, the light source, the object-to-be-detected mounting section, and the optical sensor being arranged in this order. The optical sensor acquires baseline data in an initial state after power-on, and acquires differential data at predetermined intervals based on the difference between the sensor values ​​acquired from the plurality of photodetector elements and the baseline data. When the differential data exceeds a first threshold, the detection device outputs either an alert indicating the detection of the object to be detected within an initial moisture region, which indicates the presence of moisture in the initial state, or an alert indicating the detection of the object to be detected. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a detection device according to an embodiment. [Figure 2] FIG. 2 is a block diagram illustrating an example of the configuration of the detection device according to the embodiment. [Figure 3] FIG. 3 is a circuit diagram showing a sensor pixel. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of the detection circuit according to the embodiment. [Figure 5] FIG. 5 is a block diagram showing an example of the configuration of the sensor control circuit according to the embodiment. [Figure 6] FIG. 6 is a schematic diagram showing the growth of the object to be detected. [Figure 7] FIG. 7 is a graph schematically showing the relationship between the sensor value and time in the detection of a detection target. [Figure 8] FIG. 8 is a graph showing a schematic relationship between the difference data and time in the detection of a detectable substance. [Figure 9] FIG. 9 is an explanatory diagram for explaining the sensor value, the difference data, and the detected object in the detection of the object. [Figure 10] FIG. 10 is a schematic diagram showing the evaporation of water. [Figure 11]FIG. 11 is a graph showing a schematic relationship between the sensor value and time in the detection of moisture. [Figure 12] FIG. 12 is a graph showing a schematic relationship between difference data and time in moisture detection. [Figure 13] FIG. 13 is an explanatory diagram for explaining the sensor value, difference data, and detected initial moisture region in moisture detection. [Figure 14] FIG. 14 is a graph schematically showing the relationship between the sensor value and time in the detection of moisture according to the modified example. [Figure 15] FIG. 15 is a graph schematically showing the relationship between difference data and time in moisture detection according to a modified example. [Figure 16] FIG. 16 is an explanatory diagram for explaining the sensor value, the difference data, and the detected initial moisture region in moisture detection according to the modified example. [Figure 17] FIG. 17 is a graph that schematically shows the relationship between the sensor value and time in the detection of a detection object and moisture. [Figure 18] FIG. 18 is a graph showing a schematic relationship between difference data and time in the detection of a detection object and moisture. [Figure 19] FIG. 19 is a schematic diagram showing the growth of the detection object and the evaporation of water. [Figure 20] FIG. 20 is an explanatory diagram for explaining the sensor value, difference data, and the detected detectable substance and initial moisture region in the detection of the detectable substance and moisture. [Figure 21] FIG. 21 is a flowchart illustrating a method for acquiring baseline data. [Figure 22] FIG. 22 is a flowchart for explaining a method for acquiring differential data. [Figure 23] FIG. 23 is a flowchart for explaining a method for detecting a detectable substance and outputting an alert. [Figure 24] FIG. 24 is a flowchart illustrating a method for detecting moisture. DETAILED DESCRIPTION OF THE INVENTION

[0008] Modes (embodiments) for carrying out the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and any appropriate modifications that a person skilled in the art can easily conceive while maintaining the gist of the present disclosure are naturally included within the scope of the present disclosure. Furthermore, for clarity of explanation, the drawings may schematically depict the width, thickness, shape, etc. of each part compared to the actual embodiment. However, these are merely examples and are not intended to limit the interpretation of the present disclosure. Furthermore, in this disclosure and each figure, elements similar to those described above with reference to the previous figures may be designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0009] In the present disclosure, when expressing an aspect of placing another structure on top of a certain structure, the term "on top" is used, unless otherwise specified, to include both a case in which another structure is placed directly on top of a certain structure so as to be in contact with the certain structure, and a case in which another structure is placed above a certain structure via yet another structure.

[0010] (Embodiment) Fig. 1 is a cross-sectional view schematically showing a detection device according to an embodiment. As shown in Fig. 1, the detection device 1 includes an optical sensor 10, an optical filter layer 50, a container 110 for accommodating a detection target 100, and a light source 80. In the detection device 1, the light source 80, the container 110 (detection target 100), the optical filter layer 50, and the optical sensor 10 are arranged in this order.

[0011] The detection object 100 is a minute object such as bacteria. When bacteria or the like are cultured on a culture medium 102 and grow into a visible mass, this mass may be referred to as a colony. The detection device 1 is a biosensor that detects minute objects such as bacteria. Note that the detection object 100 is not limited to bacteria, and may be other minute objects such as cells.

[0012] The container 110 includes a container body 111 and a cover member 112. The container 110 is, for example, a petri dish. The container 110 is translucent. A culture medium 102 is accommodated in the container body 111, and the detectable substances 100 are cultured in the culture medium 102. In other words, the container 110 (at least the container body 111 of the container body 111 and the cover member 112) is a translucent detectable substance installation portion for mounting multiple detectable substances 100 thereon.

[0013] In this embodiment, the container 110 is arranged upside down compared to a normal container. That is, in a normal container, the container body is arranged on the bottom and the cover member is arranged on the top. In contrast, in the container 110 according to this embodiment, the container body 111 is arranged on the top and the cover member 112 is arranged on the bottom. Specifically, a detectable substance 100 such as bacteria is placed on top of a culture medium 102 to be cultured, and when an image of the detectable substance 100 is to be taken, the container 110 is arranged upside down so that the detectable substance 100 is arranged on the bottom of the culture medium 102. The detectable substance 100 and the culture medium 102 to be detected are contained in the container 110 and arranged between the optical sensor 10 and the light source 80.

[0014] In the container 110, water vapor may be generated from the culture medium 102, causing moisture 103 to adhere to the culture medium 102 or the cover member 112 inside the container 110. Alternatively, the moisture 103 may adhere to the outside of the container 110 (the upper surface of the container body 111 in FIG. 1). In this case, the amount of light from the light source 80 changes when it passes through the moisture 103, which may make it difficult to distinguish between the moisture 103 and the detectable substance 100 in the sensor value So detected by the optical sensor 10. Alternatively, if the detectable substance 100 is arranged so as to overlap the moisture 103, it may be difficult to properly detect the detectable substance 100. A detailed method for detecting the detectable substance 100 and the moisture 103 will be described later with reference to FIG. 6 and subsequent figures.

[0015] The optical sensor 10 is a detection device including a plurality of photodetection elements 30 arranged in a plane. The photodetection elements 30 are, for example, photodiodes. More specifically, the photodetection elements 30 are PIN (Positive Intrinsic Negative) photodiodes using inorganic semiconductors or OPDs (Organic Photodiodes) using organic semiconductors.

[0016] The optical filter layer 50 is a light directivity control element disposed between a plurality of light-emitting elements 82 (light source 80) and a plurality of light-detecting elements 30 (light sensors 10). More specifically, the optical filter layer 50 is provided between the plurality of light-detecting elements 30 of the light sensor 10 and the container 110. The optical filter layer 50 is disposed opposite the plurality of light-detecting elements 30 of the light sensor 10. The optical filter layer 50 is an optical element that transmits, toward the light-detecting elements 30, components of the light irradiated from the plurality of light-emitting elements 82 that travel in a direction perpendicular to the light sensor 10. The optical filter layer 50 is also called a collimating aperture or a collimator.

[0017] The light source 80 includes a light source substrate 81 and a plurality of light-emitting elements 82. The plurality of light-emitting elements 82 are point light sources provided corresponding to the plurality of light-detecting elements 30 of the optical sensor 10. The plurality of light-emitting elements 82 are provided on the light source substrate 81 and arranged opposite the plurality of light-detecting elements 30 of the optical sensor 10. Each of the plurality of light-emitting elements 82 is formed, for example, by a light-emitting diode (LED: Light Emitting Diode).

[0018] Light emitted from the light-emitting element 82 passes through the cover member 112, the culture medium 102, the container body 111, and the optical filter layer 50, and is irradiated toward the multiple light detection elements 30 of the optical sensor 10. The amount of light irradiated onto the multiple light detection elements 30 differs between the area overlapping with the detection target 100 and the area not overlapping with the detection target 100. This allows the optical sensor 10 to capture an image of the detection target 100. Alternatively, when moisture 103 is present, the amount of light irradiated onto the multiple light detection elements 30 differs between the area overlapping with the moisture 103 and the area not overlapping with the moisture 103. This allows the optical sensor 10 to detect the presence or absence of moisture 103.

[0019] Fig. 2 is a block diagram showing an example of the configuration of a detection device according to an embodiment. As shown in Fig. 2, the detection device 1 further includes a control circuit 70 that controls the optical sensor 10 and the light source 80. The control circuit 70 controls the detection operation of the object 100 by the optical sensor 10 in synchronization (or asynchronously) with the lighting operation of the light emitting element 82 by the light source 80. The control circuit 70 is configured with, for example, an MCU (Micro Control Unit), RAM, EEPROM, ROM, etc.

[0020] The optical sensor 10 includes an array substrate 2, a plurality of sensor pixels 3 (photodetection elements 30) formed on the array substrate 2, gate line driving circuits 15A and 15B, a signal line driving circuit 16A, and a detection circuit 11.

[0021] The array substrate 2 is formed using a substrate 21 as a base. Each of the sensor pixels 3 is configured to have a photodetector element 30, a plurality of transistors, and various wirings. The array substrate 2 on which the photodetector elements 30 are formed is a drive circuit substrate that drives sensors for each predetermined detection area, and is also called a backplane or active matrix substrate.

[0022] The substrate 21 has a detection area AA and a peripheral area GA. A plurality of sensor pixels 3 (a plurality of photodetection elements 30) are arranged in a matrix in the detection area AA. The gate line driving circuits 15A and 15B, the signal line driving circuit 16A, and the detection circuit 11 are provided in the peripheral area GA.

[0023] The detection circuit 11 is a circuit that supplies control signals Sa, Sb, and Sc to the gate line drive circuits 15A, 15B and the signal line drive circuit 16A, respectively, and controls their operations. Specifically, the gate line drive circuits 15A and 15B output gate drive signals to the gate lines GLS (see FIG. 3) based on the control signals Sa and Sb. The signal line drive circuit 16A electrically connects the detection circuit 11 to a signal line SLS (see FIG. 3) selected based on the control signal Sc. The detection circuit 11 also includes a signal processing circuit that processes the detection signals Vdet from the multiple photodetector elements 30. The detection circuit 11 includes a readout integrated circuit (ROIC).

[0024] The photodetection elements 30 included in the plurality of sensor pixels 3 perform detection in accordance with gate drive signals supplied from the gate line drive circuits 15A and 15B. The plurality of photodetection elements 30 output electrical signals corresponding to the light irradiated thereon as detection signals Vdet to the signal line drive circuit 16A. The detection circuit 11 is electrically connected to the plurality of photodetection elements 30 via the signal line drive circuit 16A. The detection circuit 11 processes the detection signals Vdet from the plurality of photodetection elements 30 and outputs a sensor value So based on the detection signals Vdet to the control circuit 70. In this way, the detection device 1 detects information related to the object 100 to be detected.

[0025] 3 is a circuit diagram showing a sensor pixel. As shown in FIG. 3, the sensor pixel 3 includes a photodetection element 30, a capacitance element Ca, and a transistor TrS. The transistor TrS is provided corresponding to the photodetection element 30. The transistor TrS is configured by a thin film transistor, and in this example, is configured by an n-channel MOS (Metal Oxide Semiconductor) TFT (Thin Film Transistor). The gate of the transistor TrS is connected to a gate line GLS. The source of the transistor TrS is connected to a signal line SLS. The drain of the transistor TrS is connected to the anode of the photodetection element 30 and the capacitance element Ca.

[0026] A power supply potential SVS is supplied to the cathode of the photodetector element 30 from the detection circuit 11. Furthermore, a reference potential VR1, which is the initial potential of the capacitive element Ca, is supplied from the detection circuit 11 to the capacitive element Ca.

[0027] When light is irradiated onto the sensor pixel 3, a current corresponding to the amount of light flows through the photodetection element 30, causing charge to accumulate in the capacitance element Ca. When the transistor TrS is turned on, a current corresponding to the charge accumulated in the capacitance element Ca flows through the signal line SLS. The signal line SLS is connected to the detection circuit 11 via the signal line drive circuit 16A. This allows the photosensor 10 of the detection device 1 to detect a signal corresponding to the amount of light irradiated onto the photodetection element 30 for each sensor pixel 3.

[0028] The transistor TrS is not limited to an n-type TFT, and may be a p-type TFT. The pixel circuit of the sensor pixel 3 shown in FIG. 3 is merely an example, and the sensor pixel 3 may be provided with multiple transistors corresponding to one photodetector element 30.

[0029] Fig. 4 is a block diagram showing an example of the configuration of a detection circuit according to an embodiment. As shown in Fig. 4, the detection circuit 11 includes a detection signal amplitude adjustment circuit 41, an A / D conversion circuit 42, a signal processing circuit 43, and a detection timing control circuit 44. In the detection circuit 11, the detection timing control circuit 44 controls the detection signal amplitude adjustment circuit 41, the A / D conversion circuit 42, and the signal processing circuit 43 to operate synchronously based on a control signal supplied from the control circuit 70 (see Fig. 2).

[0030] The detection signal amplitude adjustment circuit 41 is a circuit that adjusts the amplitude of the detection signal Vdet output from the photodetector element 30, and is configured to include, for example, an amplifier. The A / D conversion circuit 42 converts the analog signal output from the detection signal amplitude adjustment circuit 41 into a digital signal. The signal processing circuit 43 processes the digital signal from the A / D conversion circuit 42 and transmits the sensor value So to the control circuit 70.

[0031] Returning to FIG. 2, the light source 80 has a light source drive circuit 12 that drives a plurality of light-emitting elements 82 mounted on a light source substrate 81. The plurality of light-emitting elements 82 are arranged in a matrix in an area that overlaps with the detection area AA of the light source substrate 81. The light source drive circuit 12 supplies power supply voltages (anode power supply potential, cathode power supply potential) to the plurality of light-emitting elements 82 based on a control signal Sd from the control circuit 70 (light source control circuit 72). This switches the plurality of light-emitting elements 82 between on (lighted state) and off (non-lighted state).

[0032] The number and arrangement of the multiple light-emitting elements 82 can be changed as appropriate. The multiple light-emitting elements 82 may emit monochromatic light, or may be configured to emit light of multiple different wavelengths. The lighting pattern of the multiple light-emitting elements 82 can also be changed as appropriate depending on the state of the detection target 100 that is the detection object. The multiple light-emitting elements 82 may be lit simultaneously, or may be lit in a time-division manner for each predetermined region.

[0033] The control circuit 70 includes a sensor control circuit 71 that controls the optical sensor 10, a light source control circuit 72 that controls the light source 80, and a communication circuit 73. The sensor control circuit 71 and the light source control circuit 72 control the optical sensor 10 and the light source 80, respectively, so that the detection operation of the optical sensor 10 and the lighting operation of the light source 80 are performed in synchronization.

[0034] The communication circuit 73 connects the control circuit 70 and an external circuit 85 by wire or wirelessly. The external circuit 85 is, for example, a personal computer (PC). However, the external circuit 85 is not limited to this and may be a mobile terminal such as a tablet or a smartphone. As a result, information about the object 100 or moisture 103 detected by the detection device 1 is output to the external circuit 85 through the communication circuit 73. Furthermore, the user operates the external circuit 85 to input various conditions used in detection, such as the timing of starting and ending detection by the detection device 1, or the first threshold value Th_c and second threshold value Th_w.

[0035] 5 is a block diagram showing an example of the configuration of a sensor control circuit according to an embodiment. As shown in FIG. 5, the sensor control circuit 71 includes an arithmetic circuit 74, an image generation circuit 75, a determination circuit 76, an alert output circuit 77, and a memory circuit 78.

[0036] The arithmetic circuit 74 calculates difference data Diff based on the baseline data (sensor value So(T0)) and the sensor value So(Ti) data received from the optical sensor 10. The baseline data is data of the sensor value So obtained by scanning the multiple light detection elements 30 of the optical sensor 10 in an initial state (for example, at time T0 after power-on). The difference data Diff will be described later with reference to FIGS. 8 and 9.

[0037] The image generating circuit 75 generates an image based on the difference data Diff or the sensor value So.

[0038] The determination circuit 76 determines the presence or absence of the object to be detected 100 or the presence or absence of moisture 103 based on the image data of the image generation circuit 75 and the first threshold value Th_c and the second threshold value Th_w previously stored in the memory circuit 78. The determination circuit 76 also determines each region, such as an initial moisture region R1 indicating that moisture 103 was present in the initial state and a moisture evaporated region R2 indicating that the moisture 103 has evaporated, and their positional relationships.

[0039] When the detectable substance 100 is detected, the alert output circuit 77 outputs an alert indicating the detection of the detectable substance 100. Alternatively, the alert output circuit 77 outputs an alert indicating the positional relationship between the detectable substance 100 and the moisture 103. The display device 86 of the external circuit 85 receives the alert from the alert output circuit 77 and displays an image indicating the detected location of the detectable substance 100.

[0040] The memory circuit 78 stores various conditions such as the sensor value So and baseline data detected by the optical sensor 10, the difference data Diff calculated by the calculation circuit 74, and the preset first threshold value Th_c and second threshold value Th_w.

[0041] 5 is a schematic diagram for ease of understanding. The circuits included in the sensor control circuit 71 are not limited to being configured as separate circuits, and may be configured as a single circuit (IC: Integrated Circuit).

[0042] Next, a detection method of the detection device 1 will be described. As described above, the detection device 1 detects the target object 100 cultured in the culture medium 102. However, if moisture 103 adheres to the container 110 or the culture medium 102, the detection device 1 may detect the moisture 103. In detecting the target object 100 cultured in the culture medium 102, there is a demand to suppress erroneous detection of the moisture 103. Alternatively, there is a demand to allow the user to visually confirm the image when the target object 100 is positioned overlapping the moisture 103.

[0043] Below, we will explain in order the method for detecting the object to be detected 100 when there is no moisture 103, the method for detecting moisture 103 when there is no object to be detected 100 (or when it has not grown sufficiently), and the method for detecting when the object to be detected 100 is positioned overlapping with the moisture 103.

[0044] Fig. 6 is a schematic diagram showing the growth of a detectable substance. Fig. 7 is a graph showing the relationship between sensor values ​​and time in the detection of a detectable substance. Fig. 8 is a graph showing the relationship between differential data and time in the detection of a detectable substance. Fig. 9 is an explanatory diagram for explaining sensor values, differential data, and detected detectable substances in the detection of a detectable substance.

[0045] 6, the intensity of light that passes through the container 110 and the culture medium 102 and is irradiated onto the optical sensor 10 (hereinafter referred to as the transmitted light intensity) is shown schematically in different shades. That is, the shades shown in FIG. 6 correspond to the magnitude of the sensor value So detected by the optical sensor 10. The greater the transmitted light intensity (sensor value So), the whiter the hatching will be, and the smaller the transmitted light intensity (sensor value So), the blacker the hatching will be. Also, FIGS. 7 and 8 show the sensor value So and difference data Diff in the area overlapping with the detection object 100 in FIG. 6.

[0046] 6 and 7, the detection device 1 scans the multiple light detection elements 30 of the optical sensor 10 at predetermined intervals to detect changes over time in the detectable substance 100 cultured in the culture medium 102. FIG. 6 schematically shows the detection results of the detectable substance 100 at three times T0, T1, and Ti. However, the detection device 1 repeatedly detects the detectable substance 100 at predetermined intervals (for example, a period of about 5 to 10 minutes), not limited to three times.

[0047] As shown in Fig. 6, at time T0 in the initial state, the detectable substance 100 has not grown, and therefore the transmitted light intensity of the culture medium 102 in the container 110 is substantially constant. In the following explanation, the sensor value So in the initial state (time T0) is represented as baseline data (sensor value So(T0)). At times T1 and Ti, when a predetermined time has elapsed from time T0, the detectable substance 100 grows, and the transmitted light intensity in the region overlapping with the detectable substance 100 gradually decreases. For ease of understanding, the explanation will be given assuming that the transmitted light intensity of the culture medium 102 is constant within the container 110 and does not change over time (or is negligibly small).

[0048] 7, for a predetermined period from time T0, the sensor value So remains substantially constant because the object 100 does not grow. As the object 100 grows, the sensor value So tends to decrease as the transmitted light intensity decreases.

[0049] As shown in Fig. 8, the difference data Diff shows a tendency that is the inverse of the sensor value So shown in Fig. 7. That is, for a predetermined period from time T0, during which the detectable object 100 is not growing, the difference data Diff shows a substantially constant value (Diff = 0). When the detectable object 100 grows, the difference data Diff shows a tendency to increase as the sensor value So decreases.

[0050] 8 and 9, the calculation circuit 74 (see FIG. 5) calculates difference data Diff based on the baseline data (sensor value So(T0)) received from the optical sensor 10 and the sensor value So(Ti) data at time Ti. The difference data Diff is expressed as Diff=So(T0)-So(Ti). In addition, in FIG. 7, the baseline data is the sensor value So at time 0h (T0).

[0051] 9, the smaller the difference data Diff, the darker the hatching, and the larger the difference data Diff, the lighter the hatching. The black areas in FIG. 9 indicate that the difference data Diff is substantially zero.

[0052] As shown in FIG. 9, in the region overlapping with the detected object 100, the difference data Diff becomes large (white display). In the region not overlapping with the detected object 100 (culture medium 102), the difference data Diff becomes small (black display).

[0053] The determination circuit 76 (see FIG. 5) compares the difference data Diff with a first threshold value Th_c stored in the storage circuit 78 in advance. The first threshold value Th_c is a reference value indicating that the detected object 100 has been detected. In the region overlapping with the detected object 100, the difference data Diff becomes larger than the first threshold value Th_c (Th_c < Diff). Also, in the region not overlapping with the detected object 100, the difference data Diff becomes smaller than the first threshold value Th_c (Diff < Th_c). The determination circuit 76 determines that the detected object 100 has been detected when the difference data Diff exceeds the first threshold value Th_c.<了

[0054] In the examples shown in FIGS. 6 to 9, the moisture 103 is not present at time Ti, and a region (initial moisture region R1, described later) indicating that the moisture 103 was present in the initial state (time T0) is also not detected. Therefore, the determination circuit 76 determines that the detected object 100 has been detected without the moisture 103. The alert output circuit 77 outputs an alert indicating the detection of the detected object 100. The display device 86 of the external circuit 85 displays an image indicating the detection location of the detected object 100 together with the alert indicating the detection of the detected object 100.

[0055] [[ID=I1]] Next, a method for detecting the moisture 103 when the detected object 100 is not present (or has not grown sufficiently) will be described. FIG. 10 is a schematic diagram schematically showing the state of evaporation of moisture. FIG. 11 is a graph schematically showing the relationship between the sensor value and time in the detection of moisture. FIG. 1Z is a graph schematically showing the relationship between the difference data and time in the detection of moisture. FIG. 13 is an explanatory diagram for explaining the sensor value, difference data, and detected initial moisture region in the detection of moisture.

[0056] <着 As shown in Figure 10, at time T0 in the initial state, the transmitted light intensity in the region overlapping with the water 103 in the container 110 is greater than the transmitted light intensity in the region without the water 103 (i.e., the culture medium 102). This is because, according to Fresnel reflectance, the light path through the water exhibits higher transmittance in the order air (refractive index n = 1) → container 110 (acrylic: refractive index n = 1.49) → water (n = 1.33) → air (n = 1) compared to the light passing through air (refractive index n = 1) → container 110 (acrylic: refractive index n = 1.49) → air (n = 1). Here, the region indicating the presence of water in the initial state (time T0) is referred to as the initial water region R1.

[0057] At times T1 and Ti, when a predetermined time has passed since time T0, the water 103 gradually evaporates, and the area of ​​the water 103 becomes smaller. At time T1, the intensity of transmitted light in the area where the water 103 has evaporated decreases and becomes equal to the intensity of transmitted light through the culture medium 102. Here, the area where the water 103 has evaporated is referred to as a water evaporation area R2. The water evaporation area R2 at time T1 is the area between the periphery of the water 103 and the periphery of the initial water area R1. As the area of ​​the water 103 becomes smaller, the water evaporation area R2 becomes larger.

[0058] At time Ti, when all the water 103 has evaporated, the entire initial water region R1 becomes the water evaporated region R2, and the transmitted light intensity of the initial water region R1 becomes equal to the transmitted light intensity of the culture medium 102.

[0059] Fig. 11 shows the relationship between the sensor value So and time in the region overlapping with the moisture 103 in Fig. 10. As shown in Fig. 11, the sensor value So at time T0 is the highest. As the moisture 103 evaporates over time, the sensor value So tends to decrease as the transmitted light intensity decreases.

[0060] As shown in Fig. 12, the difference data Diff shows a tendency that is the inverse of the sensor value So shown in Fig. 11. That is, as the moisture 103 evaporates from time T0, the difference data Diff increases, and after a predetermined period of time has passed and the moisture 103 has evaporated, the difference data Diff shows an almost constant value.

[0061] As shown in FIG. 13, the differential data Diff in the region overlapping with the moisture 103 at time Ti is 0 (black display). At time Ti, in the region overlapping with the initial moisture region R1 and not overlapping with the moisture 103 is the moisture evaporation region R2. The differential data Diff in the moisture evaporation region R2 is larger than that of the moisture 103. The differential data Diff in the region not overlapping with the initial moisture region R1 (the region outside the initial moisture region R1) is 0 (black display).

[0062] More specifically, the determination circuit 76 (see FIG. 5) compares the differential data Diff with the first threshold Th_c and the second threshold Th_w stored in the storage circuit 78 in advance. The second threshold Th_w is set to a value smaller than the first threshold Th_c and is a reference value indicating that the moisture 103 has been detected.

[0063] The determination circuit 76 extracts a first region (Th_w < Diff) in which the differential data Diff is larger than the second threshold Th_w in the distribution of the differential data Diff. The determination circuit 76 sets the first region as the moisture evaporation region R2. Next, when there is a region (Diff < Th_w) in which the differential data Diff is smaller than the second threshold Th_w in the region inside the outer periphery of the first region (the region including the moisture evaporation region R2 and the moisture 103), the region (Diff < Th_w) is determined as the moisture 103. Also, when the moisture 103 is detected in the first region (Th_w < Diff), the region surrounded by the outer periphery of the first region is determined as the initial moisture region R1.

[0064] As described above, the determination circuit 76 detects the presence of the moisture 103 (Diff < Th_w) in the region where the differential data Diff exceeds the second threshold Th_w and does not exceed the first threshold Th_c (Th_w < Diff < Th_c).

[0065] As shown in FIGS. 6 to 13, the temporal changes in the sensor value So and the differential data Diff due to the growth of the detected object 100 show the same tendency as the temporal changes in the sensor value So and the differential data Diff due to the evaporation of the moisture 103. Even in this case, the detection device 1 of the present embodiment can determine whether it is the moisture 103 or the detected object 100 by comparing with the first threshold Th_c and the second threshold Th_w in the distribution of the differential data Diff.

[0066] FIG. 14 is a graph schematically showing the relationship between the sensor value and time in the detection of moisture according to the modification. FIG. 15 is a graph schematically showing the relationship between the differential data and time in the detection of moisture according to the modification. FIG. 16 is an explanatory diagram for explaining the sensor value, the differential data, and the detected initial moisture region in the detection of moisture according to the modification.

[0067] FIGS. 14 to 16 show an example in which the transmitted light intensity in a partial region 103a of the moisture 103 is large at the time T0 in the initial state. As shown in FIGS. 14 and 15, in the region 103a, the change in the sensor value So due to the evaporation of moisture becomes large, and the differential data Diff may exceed the first threshold Th_c.

[0068] As shown in FIG. 16, the determination circuit 76 detects the region 103a where the differential data Diff exceeds the first threshold Th_c in the initial moisture region R1 (Th_w < Diff < Th_c) where the differential data Diff is larger than the second threshold Th_w. In this case, it is difficult to determine whether the region 103a is a part of the moisture 103 or the detected object 100 only from the differential data Diff. The alert output circuit 77 outputs an alert indicating the detection of the detected object 100 within the initial moisture region R1 based on the determination result from the determination circuit 76. Thereby, the user can confirm that a part of the moisture 103 rather than the detected object 100 has been detected by visually checking the inside of the container 110.

[0069] Next, a detection method when the detectable object 100 is positioned overlapping with moisture 103 will be described. Fig. 17 is a graph showing a relationship between the sensor value and time in the detection of the detectable object and moisture. Fig. 18 is a graph showing a relationship between the difference data and time in the detection of the detectable object and moisture. Fig. 19 is a schematic diagram showing the growth of the detectable object and the evaporation of moisture. Fig. 20 is an explanatory diagram for explaining the sensor value, difference data, and the detected detectable object and initial moisture region in the detection of the detectable object and moisture.

[0070] When the detectable object 100 is positioned overlapping with the moisture 103, we will explain an example in which the detectable object 100 grows in the area overlapping with the initial moisture area R1 after the moisture 103 evaporates, and an example in which the growth of the detectable object 100 is faster than the evaporation of the moisture 103 (the detectable object 100 and the moisture 103 exist simultaneously).

[0071] 17 and 18 show an example in which the detectable object 100 grows after the evaporation of the moisture 103. As shown in FIG. 17, the sensor value So is highest at time T0. As the moisture 103 evaporates over time, the sensor value So tends to decrease in accordance with a decrease in the transmitted light intensity. As the detectable object 100 grows after the evaporation of the moisture 103, the sensor value So tends to decrease further in accordance with a further decrease in the transmitted light intensity.

[0072] 18, the difference data Diff becomes larger than the second threshold value Th_w and smaller than the first threshold value Th_c due to evaporation of the water 103. If the detectable object 100 grows after evaporation of the water 103, the difference data Diff becomes larger than the first threshold value Th_c.

[0073] In this way, when the detectable object 100 grows after evaporation of the moisture 103, the sensor value So and the difference data Diff show two-stage changes. In the change in the sensor value So and the difference data Diff due to evaporation of the moisture 103, the initial moisture region R1 and the moisture evaporated region R2 can be determined by the same methods as those shown in Figures 10 to 13 above. In addition, in the change in the sensor value So and the difference data Diff due to growth of the detectable object 100, the detectable object 100 can be determined by the same methods as those shown in Figures 6 to 9 above.

[0074] The determination circuit 76 compares the initial moisture region R1 detected by evaporation of the moisture 103 with the position of the detectable object 100 detected by growth of the detectable object 100. The determination circuit 76 determines that the detectable object 100 is located at a position overlapping the initial moisture region R1. The alert output circuit 77 then outputs an alert indicating that the detectable object 100 has been detected within the initial moisture region R1.

[0075] 19 and 20 illustrate an example in which the growth of the detectable object 100 is faster than the evaporation of the moisture 103. As shown in FIG. 19, the moisture 103 gradually evaporates as time passes from time T0. In a region overlapping with the initial moisture region R1, the detectable object 100 gradually grows as time passes from time T0. At time Ti before the moisture 103 evaporates, the detectable object 100 and the moisture 103 exist simultaneously, and the detectable object 100 is positioned overlapping the moisture 103. At time Tj, a predetermined period after time Ti, the moisture 103 evaporates, and the detectable object 100 exists within the initial moisture region R1 (moisture evaporation region R2). The following explanation will be given for a case in which the detectable object 100 and the moisture 103 exist simultaneously at time Ti.

[0076] As shown in FIG. 20, the determination circuit 76 compares the differential data Diff with the first threshold value Th_c and the second threshold value Th_w. That is, the determination circuit 76 extracts, in the distribution of the differential data Diff, a region where the differential data Diff is larger than the first threshold value Th_c (hereinafter referred to as the white region). When the white region (Th_c < Diff) has a predetermined area or more, the determination circuit 76 determines that the white region (Th_c < Diff) is a detected object region indicating the detection of the detected object 100.

[0077] Furthermore, the determination circuit 76 compares the differential data Diff with the first threshold value Th_c and the second threshold value Th_w, and determines the initial moisture region R1, the moisture evaporation region R2, and the moisture 103, in the same manner as the example described in FIG. 13. The determination method for the initial moisture region R1, the moisture evaporation region R2, and the moisture 103 is the same as that described in FIG. 13, and repeated description is omitted.

[0078] The determination circuit 76 compares the position of the initial moisture region R1 with the position of the detected object 100 (white region (Th_c < Diff)), and determines that the detected object 100 overlaps with the initial moisture region R1. Then, the alert output circuit 77 outputs an alert indicating the detection of the detected object 100 within the initial moisture region R1. Thereby, the user can confirm whether it is the detection of the detected object 100 or the false detection of the moisture 103 by visually checking the inside of the container 110 based on the alert.

[0079] Next, referring to FIGS. 21 to 24, a detailed detection method for the detected object 100 and the moisture 103 will be described. FIG. 21 is a flowchart for explaining a method of acquiring baseline data. As shown in FIG. 21, in the initial state after power-on, the control circuit 70 (light source control circuit 72) lights the light source 80 (step ST11).

[0080] The control circuit 70 (sensor control circuit 71) scans the plurality of photodetection elements 30 to perform detection by the optical sensor 10 (step ST12). The plurality of photodetection elements 30 output a sensor value So in response to light that is irradiated from the light source 80 and transmitted through the container 110 (at least one of the detection target 100, the culture medium 102, and the water 103).

[0081] The sensor control circuit 71 acquires the sensor values ​​So in the initial state from the plurality of light detection elements 30, and stores the detected sensor values ​​So in the storage circuit 78 as baseline data (step ST13).

[0082] 22 is a flowchart illustrating a method for acquiring the difference data. As shown in FIG. 22, after a predetermined period of time has elapsed from the initial state (for example, at time Ti), the control circuit 70 (light source control circuit 72) turns on the light source 80 (step ST21).

[0083] The control circuit 70 (sensor control circuit 71) scans the plurality of photodetection elements 30 to perform detection by the optical sensor 10 (step ST22). The plurality of photodetection elements 30 output a sensor value So in response to light transmitted through at least one of the detection target 100, the culture medium 102, and the water 103 at time Ti.

[0084] The arithmetic circuit 74 calculates the difference data Diff based on the sensor value So received from the optical sensor 10 and the baseline data received from the storage circuit 78 (step ST23). The calculation of the difference data Diff is performed for each sensor pixel PX.

[0085] Fig. 23 is a flowchart for explaining a method for detecting a detectable substance and outputting an alert. As shown in Fig. 23, the calculation circuit 74 calculates difference data Diff at a predetermined time (for example, time Ti) (step ST31). The calculation of the difference data Diff in step ST31 is the same as in flow 2 shown in Fig. 22. However, steps ST21 and ST22 of flow 2 are omitted in Fig. 23.

[0086] The image generation circuit 75 generates a binary image based on the differential data Diff (step ST32). The image generation circuit 75 compares the differential data Diff with the first threshold Th_c, and sets the sensor pixels PX where the differential data Diff is greater than or equal to the first threshold Th_c (Th_c ≤ Diff) as the white area (detected object area), and sets the sensor pixels PX where the differential data Diff is less than the first threshold Th_c (Diff < Th_c) as the black area (see FIG. 9).

[0087] The determination circuit 76 receives the binary image from the image generation circuit 75 and determines whether the cluster of sensor pixels PX in the white area (Th_c ≤ Diff) is equal to or greater than N×N pixels (step ST33). Here, N is the number of pixels indicating that the detected object 100 has grown as a colony, and is set based on the detection data of past colonies (detected objects 100). The number of pixels N is stored in the storage circuit 78 in advance.

[0088] When the white area is less than N×N pixels (step ST33, No), the determination circuit 76 determines that the detected object 100 has not grown, and ends the detection flow of the detected object 100. At this time, the alert output circuit 77 does not output an alert indicating the detection of the colony (detected object 100).

[0089] When the white area is equal to or greater than N×N pixels (step ST33, Yes), the determination circuit 76 determines that the detected object 100 has grown as a colony, and executes the detection process of the initial moisture area R1 (step ST34).

[0090] FIG. 24 is a flowchart for explaining the method of detecting moisture. As shown in FIG. 24, the determination circuit 76 compares the differential data Diff acquired in step ST31 with the second threshold Th_w, and extracts the area where the differential data Diff is greater than the second threshold Th_w (first area: Th_w < Diff) and the area where the differential data Diff is less than or equal to the second threshold Th_w (Diff ≤ Th_w), respectively (step ST41).

[0091] The determination circuit 76 determines whether there is another region where the differential data Diff is greater than the second threshold Th_w (Th_w < Diff) inside the region where the differential data Diff is greater than the second threshold Th_w (the first region (Th_w < Diff)) (step ST42).

[0092] If there is another region (Th_w < Diff) inside the outermost first region (Th_w < Diff) (step ST42, Yes), the determination circuit 76 sets the outermost first region (Th_w < Diff) as region A (step ST43). In step ST43, the case where there is another region (Th_w < Diff) inside the outermost first region (Th_w < Diff) means that in the distribution of the differential data Diff, a ring-shaped bright → dark → bright is repeatedly arranged from the outer periphery to the inner periphery (see FIG. 20).

[0093] If there is no other region (Th_w < Diff) inside the outermost first region (Th_w < Diff) (step ST42, No), the determination circuit 76 sets the region (Th_w < Diff) as region A (step ST44). In step ST44, the case where there is no other region (Th_w < Diff) inside the outermost first region (Th_w < Diff) means that in the distribution of the differential data Diff, a ring-shaped bright → dark is arranged from the outer periphery to the inner periphery (see FIG. 13), or there is no region indicating darkness (Diff ≦ Th_w) inside the first region (Th_w < Diff).

[0094] Next, the determination circuit 76 determines whether there is a second region (Diff ≦ Th_w) where the differential data Diff is less than or equal to the second threshold Th_w inside region A (step ST45). If there is a second region (Diff ≦ Th_w) inside region A (step ST45, Yes), the determination circuit 76 determines that region A (that is, the outermost first region (Th_w < Diff)) is the initial moisture region R1 (step ST46). Also, the second region (Diff ≦ Th_w) inside region A is determined as the region where moisture 103 is detected, and the region between the outer periphery of the second region (Diff ≦ Th_w) and the outer periphery of region A is set as the moisture evaporation region R2.

[0095] If there is no second region (Diff≦Th_w) inside region A (No in step ST45), it is determined that there is no moisture 103, and moisture detection is terminated. At this time, the determination circuit 76 determines region A as a moisture evaporation region R2 (=initial moisture region R1).

[0096] 23, the determination circuit 76 determines whether the white region (detectable substance region) overlaps with the initial moisture region R1 (step ST35). More specifically, the determination circuit 76 compares the position of the sensor pixel PX indicating the white region acquired in step ST32 with the initial moisture region R1 acquired in step ST46.

[0097] If the white region (detectable substance region) overlaps with the initial moisture region R1 (step ST35, Yes), the determination circuit 76 outputs the determination result to the alert output circuit 77. Based on the determination result from the determination circuit 76, the alert output circuit 77 outputs an alert indicating the detection of a colony (detectable substance 100) in the initial moisture region R1 (step ST36).

[0098] If the white region (detectable object 100) does not overlap with the initial moisture region R1 (step ST35, No), the determination circuit 76 outputs the determination result to the alert output circuit 77. That is, the determination circuit 76 determines that the detectable object 100 has been detected outside the initial moisture region R1. Based on the determination result from the determination circuit 76, the alert output circuit 77 outputs an alert indicating that a colony (detectable object 100) has been detected (step ST37).

[0099] The display device 86 of the external circuit 85 displays an alert and also displays an image showing the test object 100 and the initial moisture region R1, or an image showing the detected location of the test object 100 (step ST38).

[0100] As described above, the detection device 1 of this embodiment can determine whether the detection object 100 has been detected or whether the detection object 100 has been detected within the initial moisture region R1 based on the light / dark pattern of the difference data Diff by comparing the distribution of the difference data Diff with the first threshold value Th_c and the second threshold value Th_w.

[0101] 22 and 23 are repeatedly executed multiple times at predetermined intervals from time T0 in the initial state. This allows the detection device 1 to observe changes over time in the growth of the detection object 100 and the evaporation of the water 103. Note that each of the above-described flows can be modified as appropriate. For example, in the detection flow for the detection object 100 shown in FIG. 23, the detection of the initial water region R1 shown in step ST34 may be executed before the detection flow in FIG. 23.

[0102] Although preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible within the scope of the present disclosure. Appropriate modifications made within the scope of the present disclosure naturally fall within the technical scope of the present disclosure. At least one of various omissions, substitutions, and modifications of components can be made within the scope of the gist of each of the above-described embodiments and modifications. [Explanation of symbols]

[0103] 1. Detection device 10. Optical Sensor 30 Photodetector element 70 Control circuit 74 Arithmetic circuit 75 Image generation circuit 76 Judgment circuit 77 Alert output circuit 78 Memory circuit 80 light source 82 Light-emitting element 100 Object to be detected 102 Culture medium 103 Moisture 110 Container Diff differential data R1 initial moisture region R2 Water evaporation region So sensor value Th_c First threshold Th_w Second threshold

Claims

1. an optical sensor including a plurality of photodetection elements arranged in a plane; a light source that irradiates the plurality of photodetector elements with light; a light-transmitting detection target installation portion for mounting a plurality of detection targets; the light source, the detection object installation portion, and the optical sensor are arranged in this order, The optical sensor acquires baseline data in an initial state after power-on; acquiring difference data based on a difference between the sensor values ​​acquired from the plurality of light detection elements and the baseline data for each predetermined period; When the difference data exceeds a first threshold, an alert is output indicating that the detectable substance has been detected inside an initial moisture region, which indicates that moisture was present in the initial state, or an alert is output indicating that the detectable substance has been detected. Detection device.

2. a second threshold value that is less than the first threshold value; extracting a first region in which the difference data is greater than the second threshold value from the distribution of the difference data; When a second region in which the difference data is smaller than the second threshold exists in a region inside the periphery of the first region, the first region is determined to be the initial moisture region. The detection device according to claim 1 .

3. The area between the initial moisture area and the second area is determined to be a moisture evaporation area indicating that moisture has evaporated during a predetermined period from the initial state until the difference data is acquired. The detection device according to claim 2 .

4. The second region is determined to be a region in which moisture was detected during the predetermined period in which the difference data was acquired. The detection device according to claim 2 .

5. extracting a detectable object region in which the difference data is greater than the first threshold value from the distribution of the difference data; When the detection target region overlaps with the initial moisture region, an alert is output indicating the detection of the detection target in the initial moisture region. The detection device according to claim 1 .

6. extracting a detectable object region in which the difference data is greater than the first threshold value from the distribution of the difference data; When the detection target region does not overlap with the initial moisture region, an alert indicating the detection of the detection target is output. The detection device according to claim 1 .

7. The plurality of photodetecting elements are photodiodes. The detection device according to claim 1 .

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