Detection device and detection system

Abstract

This detection device comprises: an optical sensor that includes a plurality of photodiodes arranged on a substrate; a light source device that has a plurality of light sources and that is arranged so as to face the optical sensor; a translucent container that is arranged between the optical sensor and the light source device and that houses an object to be detected and a culture medium; and a detection circuit that is electrically connected to the plurality of photodiodes and that outputs a sensor value corresponding to the light irradiated on each of the plurality of photodiodes. The detection device calculates gradation, on the basis of the rate of change of a second sensor value with respect to a first sensor value obtained in a first period, the second sensor value being obtained in a second period which is after the elapse of a predetermined period from the first period.

Description

Detection device and detection system

[0001] The present invention relates to a detection device and a detection system.

[0002] There is a known method for detecting and identifying microorganisms by monitoring their growth on a culture medium. One known method for identifying and detecting microorganisms involves monitoring the state of the culture medium by placing a lensless optical sensor facing the culture medium, without using a camera with a lens (see, for example, Patent Document 1). 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 of the growth of the microorganisms in the container over time.

[0003] JP 2018-33430 A

[0004] In such a detection device, there are differences in the type (color) of culture medium, the in-plane luminance distribution of the light irradiated onto the sensor from each light source, and variations in the light receiving sensitivity of the sensor at each wavelength. Therefore, if the sensor value detected by the sensor is used as is, there will be a deviation from the gradation of the actual culture medium and the detected substance, which may make it difficult to capture a good image.

[0005] An object of the present invention is to provide a detection device and a detection system that are capable of capturing good images.

[0006] A detection device of one embodiment of the present invention comprises an optical sensor including a plurality of photodiodes arranged on a substrate, a light source device having a plurality of light sources and arranged opposite the optical sensor, a light-transmitting container arranged between the optical sensor and the light source device for containing a detectable substance and a culture medium, and a detection circuit electrically connected to the plurality of photodiodes and outputting a sensor value corresponding to the light irradiated to each of the plurality of photodiodes, and calculates a gradation based on the rate of change of a second sensor value acquired in a second period after a predetermined period has elapsed since the first period relative to a first sensor value acquired in the first period.

[0007] A detection system of one embodiment of the present invention comprises a detection device and a host IC that controls the detection device, wherein the detection device comprises an optical sensor including a plurality of photodiodes arranged on a substrate, a light source device having a plurality of light sources and arranged opposite the optical sensor, a light-transmitting container arranged between the optical sensor and the light source device for containing a detectable substance and a culture medium, and a detection circuit that is electrically connected to the plurality of photodiodes and outputs a sensor value corresponding to light irradiated onto each of the plurality of photodiodes, wherein the host IC acquires a first sensor value from the detection circuit during a first period, acquires a second sensor value from the detection circuit during a second period after a predetermined period has elapsed from the first period, and calculates a gradation based on the rate of change of the second sensor value relative to the first sensor value.

[0008] FIG. 1 is a cross-sectional view schematically showing a detection device according to a first embodiment. FIG. 2 is a block diagram showing an example of the configuration of a detection device and a detection system according to the first embodiment. FIG. 3 is a block diagram showing an example of the configuration of a detection control circuit according to the first embodiment. FIG. 4 is a plan view schematically showing an example of the configuration of a plurality of light sources according to the first embodiment. FIG. 5 is a circuit diagram showing a sensor pixel. FIG. 6 is a plan view schematically showing a sensor pixel according to the first embodiment. FIG. 7 is a cross-sectional view taken along line VII-VII′ of FIG. 6. FIG. 8 is an explanatory diagram for schematically explaining the relationship between a detection target, a container, a culture medium, and a sensor value. FIG. 9 is a table showing the relationship between the gradation of the culture medium and the sensor value for each of RGB. FIG. 10 is a flowchart showing the detection operation of a first period of the detection device and detection system according to the first embodiment. FIG. 11 is a flowchart showing the detection operation of a second period of the detection device and detection system according to the first embodiment. FIG. 12 is a timing waveform diagram for explaining an example of the operation of the detection device and detection system according to the first embodiment. FIG. 13 is a block diagram showing an example of the configuration of a detection control circuit of a detection device according to a second embodiment. Fig. 14 is a flowchart showing the detection operation of the detection device and detection system according to the second embodiment in a first period. Fig. 15 is a flowchart showing the detection operation of the detection device and detection system according to the second embodiment in a second period. Fig. 16 is a schematic diagram showing an example of the configuration of the detection system. Fig. 17 is a cross-sectional view showing an inspection unit included in the detection system.

[0009] Modes (embodiments) for carrying out the present invention 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.

[0010] In this specification and claims, 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.

[0011] 1 is a cross-sectional view schematically illustrating a detection device according to a first 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, a light source device 80, and a spring (elastic member) 51. The light source device 80, the container 110 (detection target 100), the optical filter layer 50, and the optical sensor 10 are arranged in this order.

[0012] The detection object 100 is a minute object such as a bacterium. 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.

[0013] 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. 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, the container 110 according to this embodiment has the container body 111 on the top and the cover member 112 on the bottom. The container body 111 contains a culture medium 102, and a micro-object (subject to be detected 100) is cultured in the culture medium 102. Specifically, a micro-object such as bacteria is placed on top of the culture medium 102 and cultured. When imaging the micro-object, the container 110 is placed upside down so that the micro-object, i.e., the subject to be detected 100, is placed below the culture medium 102. The subject to be detected 100 and the culture medium 102 are contained in the container 110 and arranged between the optical sensor 10 and the light source device 80.

[0014] In a typical container arrangement, water vapor is generated from the culture medium and moves upward, which can cause water droplets to adhere to the cover member. In this case, when light from the light source passes through the water droplets, noise can occur, potentially distorting the image obtained via the optical sensor. However, in the container 110 according to this embodiment, the cover member 112 is arranged on the lower side, making it difficult for water droplets to adhere to the cover member 112, thereby suppressing the generation of noise. The container 110 is lifted upward by a spring 51 via a holding member (not shown).

[0015] The optical sensor 10 is a detection device including a plurality of photodiodes 30 (photodetection elements) arranged in a plane. The detailed configuration of the optical sensor 10 will be described later with reference to FIGS.

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

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

[0018] Light L emitted from the light source 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 photodiodes 30 of the optical sensor 10. The amount of light irradiated onto the multiple photodiodes 30 differs between the area overlapping with the object to be detected 100 and the area not overlapping with the object to be detected 100. This allows the optical sensor 10 to capture an image of the object to be detected 100.

[0019] In this embodiment, the plurality of light sources 82 are arranged at a predetermined pitch as point light sources. Therefore, compared to when a surface light source is provided, variation in the direction of the light L is suppressed, enabling better imaging. In other words, in this embodiment, variation in the angle of incidence of the light L incident on the object 100 and the plurality of photodiodes 30 is suppressed even when the positions within the detection area AA (see FIG. 2 ) are different. The arrangement pitch of the plurality of light sources 82 is set to suppress interference between the light L emitted from adjacent light sources 82. Furthermore, the light L, whose viewing angle is limited by the optical filter layer 50, is irradiated onto the optical sensor 10, and the arrangement pitches PS1 and PS2 of the plurality of photodiodes 30 are set to ensure a sufficient light-receiving area at the optical sensor 10.

[0020] FIG. 2 is a block diagram showing an example configuration of a detection device and a detection system according to the first embodiment. As shown in FIG. 2, the detection system 5 includes a detection device 1 (optical sensor 10 and light source device 80) and a host IC 70. The host IC 70 is a control circuit that controls the optical sensor 10 and the light source device 80, and is configured, for example, by an FPGA (Field Programmable Gate Array). For ease of understanding, FIG. 2 shows an example in which one detection device 1 (optical sensor 10 and light source device 80) is connected to one host IC 70. However, this is not limiting, and multiple detection devices 1 (optical sensors 10 and light source devices 80) may be connected in parallel to one host IC 70 (see FIG. 16 ).

[0021] The optical sensor 10 includes an array substrate 2, a plurality of sensor pixels 3 (photodiodes 30) formed on the array substrate 2, gate line driving circuits 15A and 15B, a signal line driving circuit 16A, and a detection control circuit 11.

[0022] The array substrate 2 is formed using a substrate 21 as a base. Each of the sensor pixels 3 includes a photodiode 30, a plurality of transistors, and various wirings. The array substrate 2 on which the photodiodes 30 are formed is a drive circuit substrate that drives the sensors for each predetermined detection area, and is also called a backplane or active matrix substrate.

[0023] The substrate 21 has a detection area AA and a peripheral area GA. The detection area AA is an area in which a plurality of sensor pixels 3 (a plurality of photodiodes 30) are provided. The peripheral area GA is an area between the periphery of the detection area AA and the outer edge of the substrate 21, and is an area in which a plurality of sensor pixels 3 are not provided. The gate line driving circuits 15A and 15B, the signal line driving circuit 16A, and the detection control circuit 11 are provided in the peripheral area GA.

[0024] Each of the sensor pixels 3 is an optical sensor having a photodiode 30 as a sensor element. The photodiode 30 outputs an electrical signal corresponding to the light irradiated thereon. More specifically, the photodiode 30 is a PIN (Positive Intrinsic Negative) photodiode or an OPD (Organic Photodiode) using an organic semiconductor. The sensor pixels 3 (the photodiodes 30) are arranged in a matrix in the detection area AA.

[0025] The detection control circuit 11 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 operation. Specifically, the gate line drive circuits 15A and 15B output gate drive signals to the gate lines GLS (see FIG. 4) based on the control signals Sa and Sb. The signal line drive circuit 16A electrically connects the signal line SLS selected based on the control signal Sc to the detection control circuit 11. The detection control circuit 11 also includes a signal processing circuit that processes the detection signals Vdet from the multiple photodiodes 30.

[0026] The photodiodes 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 photodiodes 30 output electrical signals corresponding to the light irradiated thereon as detection signals Vdet to the signal line drive circuit 16A. The detection control circuit 11 (detection circuit) is electrically connected to the plurality of photodiodes 30 via the signal line drive circuit 16A. The detection control circuit 11 processes the detection signals Vdet from the plurality of photodiodes 30 and outputs a sensor value So based on the detection signals Vdet to the host IC 70. In this way, the detection device 1 detects information related to the object 100 to be detected.

[0027] 3 is a block diagram showing an example of the configuration of the detection control circuit according to the first embodiment. As shown in Fig. 3, the detection control 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 control 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 host IC 70 (see Fig. 2).

[0028] The detection signal amplitude adjustment circuit 41 is a circuit that adjusts the amplitude of the detection signal Vdet output from the photodiode 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 is a circuit that processes the digital signal from the A / D conversion circuit 42 and transmits the sensor value So to the host IC 70.

[0029] 2 , the light source device 80 has a light source substrate 81, a plurality of light sources 82 formed on the light source substrate 81, and a light source control circuit 12. The plurality of light sources 82 are arranged in a matrix in an area overlapping with the detection area AA of the light source substrate 81. The plurality of light sources 82 are switched on (lit state) and off (non-lit state) based on a control signal from the light source control circuit 12.

[0030] FIG. 4 is a plan view schematically illustrating an example configuration of multiple light sources according to the first embodiment. As shown in FIG. 4, in the light source device 80, the multiple light sources 82 include a first light source 82-R, a second light source 82-G, and a third light source 82-B. The first light source 82-R emits red light. The second light source 82-G emits green light. The third light source 82-B emits blue light. The first light source 82-R, the second light source 82-G, and the third light source 82-B are arranged side by side in this order. However, this is not limited thereto, and the arrangement of the first light source 82-R, the second light source 82-G, and the third light source 82-B can be changed as appropriate. Furthermore, the multiple light sources 82 may be configured with four or more colors.

[0031] 2, the light source control circuit 12 includes a first light source control circuit 12-R, a second light source control circuit 12-G, and a third light source control circuit 12-B. The first light source control circuit 12-R, the second light source control circuit 12-G, and the third light source control circuit 12-B output drive signals based on control signals Sd-R, Sd-G, and Sd-B from the host IC 70, respectively, and control the lighting (on) and non-lighting (off) of the first light source 82-R, the second light source 82-G, and the third light source 82-B.

[0032] Note that any method may be used to control the on / off of the plurality of light sources 82. For example, the light source control circuit 12 may individually control each of the plurality of light sources 82. Furthermore, the light source substrate 81 of the light source device 80 may be a so-called active matrix substrate.

[0033] The host IC 70 controls the optical sensor 10 and the light source device 80 to acquire a first sensor value So-1 and a second sensor value So-2 over multiple detection periods. The host IC 70 then calculates a gradation based on the rate of change of the second sensor value So-2 relative to the first sensor value So-1. The host IC 70 also turns on the first light source 82-R, the second light source 82-G, and the third light source 82-B in a time-division manner during each detection period. This allows the host IC 70 to acquire sensor values ​​So corresponding to the red light emitted from the first light source 82-R, the green light emitted from the second light source 82-G, and the blue light emitted from the third light source 82-B, respectively. The host IC 70 then calculates gradations corresponding to the red light, the green light, and the blue light, respectively, to generate a color image.

[0034] The host IC 70 has a sensor value storage circuit 71, an arithmetic circuit 72, and a reference gradation storage circuit 73 as control circuits on the optical sensor 10 side. The sensor value storage circuit 71 stores the sensor value So (first sensor value So-1 and second sensor value So-2) output from the detection control circuit 11 of the optical sensor 10. The arithmetic circuit 72 performs a predetermined arithmetic process on the sensor value So of the photodiode 30. For example, the arithmetic circuit 72 calculates the rate of change So-C of the second sensor value So-2 relative to the first sensor value So-1, i.e., So-C=((So-2 / So-1)×100(%)).

[0035] The reference gradation storage circuit 73 stores a reference gradation Gd-1 that is preset for each of a plurality of different types of culture media 102. The reference gradation Gd-1 is the gradation of the culture medium 102 in its initial state (i.e., the state before the culture of the test object 100 begins). The reference gradation Gd-1 is preset for each of red (R), green (G), and blue (B). The calculation circuit 72 calculates the gradation by multiplying the reference gradation Gd-1 by the above-mentioned rate of change So-C. The method of calculating the gradation based on the reference gradation Gd-1 and the rate of change So-C will be described later with reference to FIG. 8 and subsequent figures.

[0036] The host IC 70 has a lighting control circuit 74 and a lighting pattern memory circuit 75 as control circuits on the light source device 80 side. The lighting pattern memory circuit 75 stores the light intensity of each of the multiple light sources 82, the lighting order of the first light source 82-R, the second light source 82-G, and the third light source 82-B, or, as necessary, the on (lit state) and off (non-lit state) arrangement pattern of the multiple light sources 82. The lighting control circuit 74 outputs control signals Sd-R, Sd-G, and Sd-B to the light source control circuit 12 based on various information from the lighting pattern memory circuit 75.

[0037] The host IC 70 further includes an image generation circuit 76. The image generation circuit 76 generates an image based on the gradation calculated by multiplying the reference gradation Gd-1 by the rate of change So-C in the calculation circuit 72. The image generation circuit 76 also generates a color image by combining the gradations calculated for red (R), green (G), and blue (B).

[0038] Although not shown, the host IC 70 has a control circuit that synchronously controls the detection control circuit 11 and the light source control circuit 12. That is, based on a control signal from the host IC 70, the switching between on and off of the plurality of light sources 82 (first light source 82-R, second light source 82-G, and third light source 82-B) on the light source device 80 side and the detection of the plurality of photodiodes 30 on the optical sensor 10 side are synchronously controlled.

[0039] Although the optical sensor 10 has two gate line drive circuits 15A and 15B, it may have one gate line drive circuit. The light source device 80 has a light source control circuit 12, but the light source control circuit 12 may be provided as a common circuit with the lighting control circuit 74 of the host IC 70.

[0040] Next, an example configuration of the optical sensor 10 will be described. FIG. 5 is a circuit diagram showing a sensor pixel. As shown in FIG. 5, the sensor pixel 3 includes a photodiode 30, a capacitance element Ca, and a transistor TrS. The transistor TrS is provided corresponding to the photodiode 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 photodiode 30 and the capacitance element Ca.

[0041] The detection control circuit 11 supplies a power supply potential SVS to the cathode of the photodiode 30. The detection control circuit 11 also supplies a reference potential VR1, which serves as the initial potential of the capacitance element Ca, to the capacitance element Ca.

[0042] When light is irradiated onto the sensor pixel 3, a current corresponding to the amount of light flows through the photodiode 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 control circuit 11 via the signal line drive circuit 16A. This allows the optical sensor 10 of the detection device 1 to detect a signal corresponding to the amount of light irradiated onto the photodiode 30 for each sensor pixel 3.

[0043] 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. 5 is merely an example, and the sensor pixel 3 may be provided with multiple transistors corresponding to one photodiode 30.

[0044] Next, a detailed configuration of the optical sensor 10 will be described. Fig. 6 is a plan view schematically showing a sensor pixel according to the first embodiment.

[0045] In the following description, the first direction Dx is a direction in a plane parallel to the substrate 21 (see FIG. 7). The second direction Dy is a direction in a plane parallel to the substrate 21, and is a direction perpendicular to the first direction Dx. The second direction Dy may intersect the first direction Dx without being perpendicular thereto. The third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy, and is the normal direction to the main surface of the substrate 21. Furthermore, "planar view" refers to the positional relationship when viewed from a direction perpendicular to the substrate 21.

[0046] As shown in FIG. 6 , the sensor pixel 3 is an area surrounded by the gate line GLS and the signal line SLS. In this embodiment, the gate line GLS includes a first gate line GLA and a second gate line GLB. The first gate line GLA is provided to overlap the second gate line GLB. The first gate line GLA and the second gate line GLB are provided in different layers with insulating layers 22c and 22d (see FIG. 7 ) interposed therebetween. The first gate line GLA and the second gate line GLB are electrically connected at an arbitrary location and are supplied with gate drive signals having the same potential. At least one of the first gate line GLA and the second gate line GLB is connected to the gate line drive circuits 15A and 15B. Note that, although the first gate line GLA and the second gate line GLB have different widths in FIG. 6 , they may also have the same width.

[0047] The photodiodes 30 are provided in an area surrounded by the gate lines GLS and the signal lines SLS. An upper electrode 34 and a lower electrode 35 are provided corresponding to each photodiode 30. The photodiodes 30 are, for example, PIN photodiodes. The lower electrode 35 is, for example, an anode electrode of the photodiode 30. The upper electrode 34 is, for example, a cathode electrode of the photodiode 30.

[0048] The upper electrode 34 is connected to a power supply signal line Lvs via a connection wiring 36. The power supply signal line Lvs is a wiring that supplies a power supply potential SVS to the photodiode 30. In this embodiment, the power supply signal line Lvs extends in the second direction Dy, overlapping with the signal line SLS. A plurality of sensor pixels 3 arranged in the second direction Dy are connected to a common power supply signal line Lvs. This configuration allows the aperture of the sensor pixel 3 to be large. The lower electrode 35, the photodiode 30, and the upper electrode 34 are each substantially rectangular in plan view. However, this is not limited thereto, and the shapes of the lower electrode 35, the photodiode 30, and the upper electrode 34 can be changed as appropriate.

[0049] The transistor TrS is provided near the intersection of the gate line GLS and the signal line SLS, and includes a semiconductor layer 61, a source electrode 62, a drain electrode 63, a first gate electrode 64A, and a second gate electrode 64B.

[0050] The semiconductor layer 61 is an oxide semiconductor. More preferably, the semiconductor layer 61 is a transparent amorphous oxide semiconductor (TAOS) among oxide semiconductors. By using an oxide semiconductor for the transistor TrS, the leakage current of the transistor TrS can be suppressed. That is, the transistor TrS can reduce the leakage current from unselected sensor pixels 3. This allows the optical sensor 10 to improve the S / N ratio. However, the semiconductor layer 61 is not limited thereto, and may be a microcrystalline oxide semiconductor, an amorphous oxide semiconductor, polysilicon, low temperature polycrystalline silicon (LTPS), or the like.

[0051] The semiconductor layer 61 is disposed along the first direction Dx and intersects with the first gate electrode 64A and the second gate electrode 64B in a plan view. The first gate electrode 64A and the second gate electrode 64B are disposed branching off from the first gate line GLA and the second gate line GLB, respectively. In other words, the portions of the first gate line GLA and the second gate line GLB that overlap with the semiconductor layer 61 function as the first gate electrode 64A and the second gate electrode 64B. The first gate electrode 64A and the second gate electrode 64B are made of aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), or an alloy thereof. Furthermore, a channel region is formed in the portion of the semiconductor layer 61 that overlaps with the first gate electrode 64A and the second gate electrode 64B.

[0052] One end of the semiconductor layer 61 is connected to the source electrode 62 via a contact hole H1. The other end of the semiconductor layer 61 is connected to the drain electrode 63 via a contact hole H2. The portion of the signal line SLS that overlaps with the semiconductor layer 61 serves as the source electrode 62. The portion of the third conductive layer 67 that overlaps with the semiconductor layer 61 functions as the drain electrode 63. The third conductive layer 67 is connected to the lower electrode 35 via a contact hole H3. With this configuration, the transistor TrS can switch between connecting and disconnecting the photodiode 30 and the signal line SLS.

[0053] Next, the layer structure of the optical sensor 10 will be described with reference to Fig. 7, which is a cross-sectional view taken along line VII-VII' in Fig. 6 .

[0054] In the description of the detection device 1 including the optical sensor 10, the direction from the substrate 21 toward the photodiode 30 in the direction perpendicular to the surface of the substrate 21 (third direction Dz) will be referred to as the "upper side" or "top." The direction from the photodiode 30 toward the substrate 21 will be referred to as the "lower side" or "bottom."

[0055] 7, the substrate 21 is an insulating substrate, and may be, for example, a glass substrate such as quartz or alkali-free glass. Transistors TrS, various wirings (gate lines GLS and signal lines SLS), and an insulating layer are provided on one surface of the substrate 21 to form the array substrate 2. A plurality of photodiodes 30 are arranged on the array substrate 2, i.e., on one surface of the substrate 21. The substrate 21 may be a resin substrate or a resin film made of a resin such as polyimide.

[0056] The insulating layers 22a and 22b are provided on the substrate 21. The insulating layers 22a, 22b, 22c, 22d, 22e, 22f, and 22g are inorganic insulating films, and are made of, for example, silicon oxide (SiO ２ ), silicon nitride (SiN), etc. Furthermore, each inorganic insulating layer is not limited to a single layer, and may be a laminated film.

[0057] The first gate electrode 64A is provided on the insulating layer 22b. The insulating layer 22c is provided on the insulating layer 22b, covering the first gate electrode 64A. The semiconductor layer 61, the first conductive layer 65, and the second conductive layer 66 are provided on the insulating layer 22c. The first conductive layer 65 is provided to cover the end of the semiconductor layer 61 that is connected to the source electrode 62. The second conductive layer 66 is provided to cover the end of the semiconductor layer 61 that is connected to the drain electrode 63.

[0058] The insulating layer 22d is provided on the insulating layer 22c, covering the semiconductor layer 61, the first conductive layer 65, and the second conductive layer 66. The second gate electrode 64B is provided on the insulating layer 22d. The semiconductor layer 61 is provided between the first gate electrode 64A and the second gate electrode 64B in the direction perpendicular to the substrate 21. In other words, the transistor TrS has a so-called dual-gate structure. However, the transistor TrS may have a bottom-gate structure in which the first gate electrode 64A is provided but the second gate electrode 64B is not provided, or a top-gate structure in which the first gate electrode 64A is not provided but only the second gate electrode 64B is provided.

[0059] The insulating layer 22e is provided on the insulating layer 22d, covering the second gate electrode 64B. The source electrode 62 (signal line SLS) and the drain electrode 63 (third conductive layer 67) are provided on the insulating layer 22e. In this embodiment, the drain electrode 63 is the third conductive layer 67 provided on the semiconductor layer 61 via the insulating layers 22d and 22e. The source electrode 62 is electrically connected to the semiconductor layer 61 via a contact hole H1 and a first conductive layer 65. The drain electrode 63 is electrically connected to the semiconductor layer 61 via a contact hole H2 and a second conductive layer 66.

[0060] The third conductive layer 67 is provided in a region overlapping with the photodiode 30 in plan view. The third conductive layer 67 is also provided above the semiconductor layer 61, the first gate electrode 64A, and the second gate electrode 64B. That is, the third conductive layer 67 is provided between the second gate electrode 64B and the lower electrode 35 in the direction perpendicular to the substrate 21. As a result, the third conductive layer 67 functions as a protective layer that protects the transistor TrS.

[0061] The second conductive layer 66 extends opposite the third conductive layer 67 in a region not overlapping with the semiconductor layer 61. Furthermore, a fourth conductive layer 68 is provided on the insulating layer 22d in a region not overlapping with the semiconductor layer 61. The fourth conductive layer 68 is provided between the second conductive layer 66 and the third conductive layer 67. As a result, a capacitance is formed between the second conductive layer 66 and the fourth conductive layer 68, and a capacitance is formed between the third conductive layer 67 and the fourth conductive layer 68. The capacitance formed by the second conductive layer 66, the third conductive layer 67, and the fourth conductive layer 68 is the capacitance of the capacitive element Ca shown in FIG. 5 .

[0062] The first organic insulating layer 23a is provided on the insulating layer 22e, covering the source electrode 62 (signal line SLS) and the drain electrode 63 (third conductive layer 67). The first organic insulating layer 23a is a planarizing layer that flattens irregularities formed by the transistor TrS and various conductive layers.

[0063] Next, a description will be given of the cross-sectional structure of the photodiode 30. The photodiode 30 is formed by stacking a lower electrode 35, the photodiode 30, and an upper electrode 34 in this order on the first organic insulating layer 23a of the array substrate 2.

[0064] The lower electrode 35 is provided on the first organic insulating layer 23a and is electrically connected to the third conductive layer 67 through a contact hole H3. The lower electrode 35 is the anode of the photodiode 30 and is an electrode for reading out the detection signal Vdet. The lower electrode 35 is made of a metal material such as molybdenum (Mo) or aluminum (Al). Alternatively, the lower electrode 35 may be a laminated film in which a plurality of these metal materials are stacked. The lower electrode 35 may also be made of a light-transmitting conductive material such as ITO (indium tin oxide) or IZO (indium zinc oxide).

[0065] The photodiode 30 includes semiconductor layers such as an i-type semiconductor layer 31, an n-type semiconductor layer 32, and a p-type semiconductor layer 33. The i-type semiconductor layer 31, the n-type semiconductor layer 32, and the p-type semiconductor layer 33 are formed of, for example, amorphous silicon (a-Si). In FIG. 7, the p-type semiconductor layer 33, the i-type semiconductor layer 31, and the n-type semiconductor layer 32 are stacked in this order in the direction perpendicular to the surface of the substrate 21. However, the opposite configuration, that is, the n-type semiconductor layer 32, the i-type semiconductor layer 31, and the p-type semiconductor layer 33 may also be used. Each semiconductor layer may also be a photoelectric conversion element made of an organic semiconductor.

[0066] The n-type semiconductor layer 32 is formed by doping impurities into a-Si to form an n+ region. The p-type semiconductor layer 33 is formed by doping impurities into a-Si to form a p+ region. The i-type semiconductor layer 31 is, for example, an undoped intrinsic semiconductor, and has lower conductivity than the n-type semiconductor layer 32 and the p-type semiconductor layer 33.

[0067] The upper electrode 34 is a cathode of the photodiode 30 and is an electrode for supplying the power supply potential SVS to the photoelectric conversion layer. The upper electrode 34 is a light-transmitting conductive layer made of, for example, ITO, and a plurality of upper electrodes 34 are provided for each photodiode 30.

[0068] Insulating layers 22f and 22g are provided on the first organic insulating layer 23a. The insulating layer 22f covers the periphery of the upper electrode 34 and has an opening at a position overlapping the upper electrode 34. The connection wiring 36 is connected to the upper electrode 34 at a portion of the upper electrode 34 where the insulating layer 22f is not provided. The insulating layer 22g is provided on the insulating layer 22f, covering the upper electrode 34 and the connection wiring 36. A second organic insulating layer 23b, which is a planarizing layer, is provided on the insulating layer 22g. In the case of an organic semiconductor photodiode 30, an insulating layer 22h may be further provided thereon.

[0069] Next, an example of a detection method of the detection device 1 and detection system 5 of this embodiment will be described. FIG. 8 is an explanatory diagram for schematically explaining the relationship between the sensor value and the target object, container, and culture medium. FIG. 9 is a table showing the relationship between the gradation of the culture medium and the sensor value for each RGB. Note that each graph shown in the lower diagram of FIG. 8 schematically shows values ​​normalized using the first sensor values ​​So-1(R), So-1(G), and So-1(B) in the initial state as the reference (100%). Furthermore, the sensor values ​​So shown in FIG. 8 and the magnitudes and rates of change of the gradations Gd and sensor values ​​So shown in the table of FIG. 9 are merely examples and are exaggerated for ease of understanding.

[0070] The left diagram of Fig. 8 schematically shows the detectable substance 100 (not shown in the left diagram of Fig. 8 ), the container 110, and the culture medium 102 in an initial state (hereinafter referred to as a first period) when the detectable substance 100 is not in the culture medium 102 or before the detectable substance 100 is cultured in the culture medium 102. The right diagram of Fig. 8 schematically shows the detectable substance 100, the container 110, and the culture medium 102 after a predetermined period has elapsed since the first period (hereinafter referred to as a second period).

[0071] First, the detection of the detection target 100 will be described. As shown in the left diagram of Fig. 8, during a first period, light L emitted from the multiple light sources 82 passes through the culture medium 102 and the container 110 and is incident on the photodiode 30. The photodiode 30 outputs a first sensor value So-1 corresponding to the amount of light emitted. The first sensor values ​​So-1(R), So-1(G), and So-1(B) during the first period are the sensor values ​​So corresponding to red light, green light, and blue light, respectively.

[0072] Next, as shown in the right diagram of Figure 8, in a second period after a predetermined period has elapsed since the first period (initial state), the detectable substance 100 (e.g., bacteria) grows in the culture medium 102. Furthermore, the turbidity (color) of the culture medium 102 changes in the second period compared to the first period. The amount and distribution of light incident on the photodiode 30 in the second period differs depending on the turbidity (color) of the culture medium 102 and the presence or absence of the detectable substance 100. The amount of light incident on the photodiode 30 at position x1, where the photodiode 30 overlaps with the detectable substance 100, is reduced compared to position x2, where the photodiode 30 does not overlap with the detectable substance 100.

[0073] The second sensor values ​​So-2(R), So-2(G), and So-2(B) at position x1 overlapping with the detectable object 100 are, for example, approximately 5% of the first sensor values ​​So-1(R), So-1(G), and So-1(B) in the first period. Also, the second sensor values ​​So-2(R), So-2(G), and So-2(B) at position x1 overlapping with the detectable object 100 are smaller than the second sensor values ​​So-2(R), So-2(G), and So-2(B) at position x2 not overlapping with the detectable object 100. In other words, in the second period, the light transmittance at position x1 overlapping with the detectable object 100 is smaller than the light transmittance (light transmittance of the culture medium 102) at position x2 not overlapping with the detectable object 100.

[0074] The host IC 70 can detect the presence or absence, position, shape, etc. of the detection target 100 based on the distribution of the second sensor values ​​So-2(R), So-2(G), and So-2(B). The light intensity of the light L irradiated from the plurality of light sources 82 is appropriately set in advance so that the second sensor value So-2 is equal to or greater than a predetermined value, i.e., so that the second sensor value So-2 falls within the detection range of the photodiode 30 and the detection control circuit 11, even if the state of the detection target 100, the culture medium 102, etc. changes.

[0075] Next, detection of the culture medium 102 will be described. The table shown in FIG. 9 shows the gradation Gd of the culture medium 102 during a first period (hereinafter referred to as the reference gradation Gd-1) and the gradation Gd during a second period after a predetermined period has elapsed since the first period (hereinafter referred to as the gradation Gd-2). The table also shows the first sensor value So-1 detected by the photodiode 30 during the first period and the second sensor value So-2 detected by the photodiode 30 during the second period. In FIG. 9, the gradation Gd of the culture medium 102 is a predetermined theoretical value, and the sensor value So is a measurement value of the photodiode 30. The sensor values ​​So (first sensor value So-1 and second sensor value So-2) shown in FIG. 9 correspond to the sensor values ​​So (first sensor value So-1 and second sensor value So-2) at position x2 in FIG. 8 that do not overlap with the detection object 100.

[0076] As shown in FIG. 9 , the reference gradation Gd-1 (theoretical value) of the culture medium 102 during the first period is (Gd-1(R), Gd-1(G), Gd-1(B)) = (20, 20, 100) for red, green, and blue, respectively. In FIG. 9 , the reference gradation Gd-1 of the culture medium 102 is a value set in advance according to the type of culture medium 102. A plurality of reference gradations Gd-1 are stored in a library in the reference gradation storage circuit 73 (see FIG. 2 ) for each type of culture medium 102. The reference gradations Gd-1 of the plurality of types of culture medium 102 stored in the reference gradation storage circuit 73 are the reference gradation Gd-0 of each culture medium 102 at a predetermined thickness (e.g., 1 mm), and the reference gradation Gd-1 for the culture medium 102 used at the time may be further calculated using the reference gradation Gd-0 and the thickness of the culture medium 102 used at the time.

[0077] The first sensor value So-1 detected by the photodiode 30 in the first period is (So-1(R), So-1(G), So-1(B)) = (50, 40, 30). The first sensor value So-1 (measured value) is different from the reference gradation Gd-1 (theoretical value) of the culture medium 102 in the first period. Also, in the table of FIG. 9, the RGB ratio of the first sensor value So-1 is different from the RGB ratio of the reference gradation Gd-1 in the first period, but may be the same.

[0078] As shown in FIG. 9, the gradation Gd-2 (theoretical value) of the culture medium 102 in the second period is (Gd-2(R), Gd-2(G), Gd-2(B)) = (100, 100, 20) for red, green, and blue, respectively. This indicates that the turbidity (color) of the culture medium 102 changes over a predetermined period. Note that in the table of FIG. 9, the value of the gradation Gd-2 and the ratio of RGB in the second period are both different from the value of the reference gradation Gd-1 and the ratio of RGB in the first period, but there are cases where the ratio is the same even though the gradation value is different.

[0079] The second sensor value So-2 detected by the photodiode 30 in the second period is (So-2(R), So-2(G), So-2(B)) = (250, 200, 6). In the second period after a predetermined period has elapsed since the first period, the second sensor value So-2 (measured value) differs from the gradation Gd-2 (theoretical value) of the culture medium 102 in the second period. Also, in the table of FIG. 9, the RGB ratio of the second sensor value So-2 differs from the RGB ratio of the gradation Gd-2 in the second period, but may be the same.

[0080] In this embodiment, as described above, the photodiode 30 is irradiated with light transmitted through the culture medium 102 and outputs a signal corresponding to the irradiated light. Because the state of light transmitted through or reflected by the culture medium 102 differs depending on the state (color, turbidity, etc.) of the culture medium 102, as shown in FIG. 9 , the sensor value So (measured value) detected by the photodiode 30 may deviate from the reference gradation Gd-1 and gradation Gd-2 (theoretical value) of the culture medium 102. Furthermore, if the light sensitivity of the photodiode 30 varies among the sensor pixels 3, an error in the sensor value So may occur, for example, with each sensor pixel 3 having a high red light sensitivity and a low green light sensitivity. If the sensor value So (first sensor value So-1 and second sensor value So-2) detected by the photodiode 30 were used directly as the gradation of an image, an image with a color that deviates from the theoretical value of the gradation Gd of the culture medium 102 and the object to be detected 100 may be generated.

[0081] On the other hand, as shown in FIG. 9, when the rate of change of each sensor value So in the first period and the second period is compared, the rate of change of the sensor value So (measured value) in the first period and the second period is equal to the rate of change of the theoretical value in the first period and the second period.

[0082] In view of this, in this embodiment, the host IC 70 of the detection system 5 calculates the gradation based on the rate of change of the second sensor value So-2 acquired in a second period, which is a predetermined period after the first period, relative to the first sensor value So-1 acquired in a first period (initial state).

[0083] 9, regarding the gradation Gd (theoretical value) of the culture medium 102, the rate of change of the gradation Gd-2 in the second period after a predetermined period has elapsed relative to the reference gradation Gd-1 in the first period differs for each color. The rate of change of the red gradation Gd-2(R) in the second period relative to the red reference gradation Gd-1(R) in the first period is (Gd-2(R)) / (Gd-1(R)) = 100 / 20 = 5 (times). The rate of change of the green gradation Gd-2(G) in the second period relative to the green reference gradation Gd-1(G) in the first period is (Gd-2(G)) / (Gd-1(G)) = 100 / 20 = 5 (times). The rate of change of the blue gradation Gd-2(B) in the second period relative to the blue reference gradation Gd-1(B) in the first period is (Gd-2(B)) / (Gd-1(B)) = 20 / 100 = 1 / 5 (times).

[0084] On the other hand, the rate of change of the second sensor value So-2 in the second period after the predetermined period has elapsed relative to the first sensor value So-1 detected in the first period for the sensor value So detected by the photodiode 30 differs for each color. Here, when viewed for each color, the rate of change of the sensor value So is equivalent to the rate of change of the gradation Gd of the culture medium 102 in the theoretical value.

[0085] 8 and 9, the rate of change SoC(R) of the second sensor value So-2(R) corresponding to the red light in the second period relative to the first sensor value So-1(R) corresponding to the red light in the first period is (So-2(R)) / (So-1(R)) = 250 / 50 = 5 (times). The rate of change SoC(G) of the second sensor value So-2(G) corresponding to the green light in the second period relative to the first sensor value So-1(G) corresponding to the green light in the first period is (So-2(G)) / (So-1(G)) = 200 / 40 = 5 (times). The rate of change SoC(B) of the second sensor value So-2(B) corresponding to blue light in the second period relative to the first sensor value So-1(B) corresponding to blue light in the first period is (So-2(B)) / (So-1(B)) = 6 / 30 = 1 / 5 (times).

[0086] As shown in the graphs in the lower part of Figure 8, the first sensor values ​​So-1(R), So-1(G), and So-1(B) in the first period are set as the reference (100%), and the second sensor values ​​So-2(R) and So-2(G) are 500%, and the second sensor value So-2(B) is 20%.

[0087] The arithmetic circuit 72 of the host IC 70 (see FIG. 2) calculates the rate of change SoC of the sensor value So described above for each color. The arithmetic circuit 72 then calculates the gradation Gd-a of the culture medium 102 using the following equation (1). That is, the arithmetic circuit 72 calculates the actual gradation Gd-a of the culture medium 102 during the second period based on the value obtained by multiplying the reference gradation Gd-1 (gradation Gd during the first period) of the culture medium 102 stored in the reference gradation storage circuit 73 by the rate of change SoC of the second sensor value So-2 relative to the first sensor value So-1. The arithmetic circuit 72 calculates the gradation Gd-a for each sensor pixel 3.

[0088] (Gd-a)=(Gd-1)×((So-2) / (So-1))... (1)

[0089] In the example shown in FIG. 9, the arithmetic circuit 72 calculates the red gradation Gd-a(R) as follows: Gd-a(R)=(Gd-1(R))×((So-2(R)) / (So-1(R)))=20×250 / 50=100. The arithmetic circuit 72 calculates the green gradation Gd-a(G) as follows: Gd-a(G)=(Gd-1(G))×((So-2(G)) / (So-1(G)))=20×200 / 40=100. The arithmetic circuit 72 calculates the blue gradation Gd-a(B) as follows: Gd-a(B)=(Gd-1(B))×((So-2(B)) / (So-1(B)))=100×6 / 30=20.

[0090] As described above, the gradation Gd-a calculated based on the rate of change of the second sensor value So-2 relative to the first sensor value So-1 is (100, 100, 20) for each of R, G, and B. The calculated gradation Gd-a = (100, 100, 20) matches the gradation Gd-2 (theoretical value) = (100, 100, 20) of the culture medium 102 in the second period.

[0091] Therefore, even if the magnitude and RGB ratio of the sensor value So detected by the photodiode 30 differ from the gradation Gd (theoretical value) of the object to be detected 100 and the culture medium 102, the detection device 1 and detection system 5 of this embodiment can suppress the deviation between the gradation Gd (theoretical value) of the object to be detected 100 and the culture medium 102 and the calculated gradation Gd-a by calculating the gradation Gd-a based on the rate of change of the second sensor value So-2 relative to the first sensor value So-1. The image generation circuit 76 generates a color image using the calculated gradation Gd-a. This allows the detection device 1 and detection system 5 to capture images well.

[0092] Next, the detection flow of the detection device 1 and the detection system 5 will be described with reference to Fig. 10 to Fig. 12. Fig. 10 is a flowchart showing the detection operation of the detection device and detection system according to the first embodiment in a first period. Fig. 11 is a flowchart showing the detection operation of the detection device and detection system according to the first embodiment in a second period. Fig. 12 is a timing waveform diagram for explaining an example of the operation of the detection device and detection system according to the first embodiment.

[0093] 10 , the detection system 5 (detection device 1) according to the embodiment selects RGB reference gradations (step ST1). Specifically, an operator operates an input device such as a PC (personal computer) to input the type of culture medium 102 to the host IC 70. The arithmetic circuit 72 of the host IC 70 selects and acquires the reference gradation Gd-1 corresponding to the type of culture medium 102 from the reference gradation storage circuit 73.

[0094] Next, the operator places the container 110 containing the test object 100 and the culture medium 102 (step ST2). The container 110 is disposed between the optical sensor 10 (plurality of photodiodes 30) and the light source device 80 (plurality of light sources 82).

[0095] Next, the host IC 70 sets the number of measurements n to n=1 (step ST3) and starts detecting the detection target 100. In the detection for the first period, the culture medium 102 is detected in the initial state, i.e., the state before the start of culturing the detection target 100, and the first sensor values ​​So-1(R), So-1(G), and So-1(B) are obtained.

[0096] Next, the first light source 82-R is turned on based on a control signal from the host IC 70 (step ST4). As shown in FIG. 12, during the first period T1, the first light source 82-R, the second light source 82-G, and the third light source 82-B are turned on in a time-division manner. More specifically, the first period T1 is divided into a plurality of periods T1-1, T1-2, and T1-3, and during each of the periods T1-1, T1-2, and T1-3, the first light source 82-R, the second light source 82-G, and the third light source 82-B are turned on in a time-division manner. During the period T1-1, the first light source 82-R is turned on, and the second light source 82-G and the third light source 82-B are not turned on.

[0097] As shown in FIGS. 10 and 12, the optical sensor 10 scans the plurality of photodiodes 30 to detect the detection target 100 and the culture medium 102 (step ST5).

[0098] Specifically, the gate line driving circuits 15A and 15B of the optical sensor 10 sequentially scan the first gate line GLS-1 to the last gate line GLS-m based on a control signal from the host IC 70. This causes the optical sensor 10 to fully scan the multiple photodiodes 30 in the detection area AA. The multiple photodiodes 30 output detection signals Vdet corresponding to red light irradiated from the first light source 82-R and transmitted through the culture medium 102. The detection control circuit 11 performs signal processing on the detection signals Vdet from the multiple photodiodes 30 to generate a first sensor value So-1(R) corresponding to the red light.

[0099] The detection control circuit 11 transmits the first sensor value So-1(R) corresponding to the red light to the host IC 70 (step ST6). The sensor value storage circuit 71 of the host IC 70 stores the first sensor value So-1(R).

[0100] 10 and 12, the second light source 82-G is turned on based on a control signal from the host IC 70 (step ST7). During a period T1-2, the second light source 82-G is turned on, and the first light source 82-R and the third light source 82-B are turned off.

[0101] As shown in FIGS. 10 and 12, the optical sensor 10 scans the plurality of photodiodes 30 to detect the detection target 100 and the culture medium 102 (step ST8).

[0102] Specifically, the optical sensor 10 scans the entire surface of the multiple photodiodes 30 in the detection area AA. The multiple photodiodes 30 output detection signals Vdet corresponding to green light irradiated from the second light source 82-G and transmitted through the culture medium 102. The detection control circuit 11 performs signal processing on the detection signals Vdet from the multiple photodiodes 30 to generate a first sensor value So-1(G) corresponding to the green light.

[0103] The detection control circuit 11 transmits the first sensor value So-1(G) corresponding to the green light to the host IC 70 (step ST9). The sensor value storage circuit 71 of the host IC 70 stores the first sensor value So-1(G).

[0104] 10 and 12, the third light source 82-B is turned on based on a control signal from the host IC 70 (step ST10). During a period T1-3, the third light source 82-B is turned on, and the first light source 82-R and the second light source 82-G are turned off.

[0105] As shown in FIGS. 10 and 12, the optical sensor 10 scans the plurality of photodiodes 30 to detect the detection target 100 and the culture medium 102 (step ST11).

[0106] Specifically, the optical sensor 10 scans the entire surface of the multiple photodiodes 30 in the detection area AA. The multiple photodiodes 30 output detection signals Vdet corresponding to blue light irradiated from the third light source 82-B and transmitted through the culture medium 102. The detection control circuit 11 performs signal processing on the detection signals Vdet from the multiple photodiodes 30 to generate a first sensor value So-1(B) corresponding to the blue light.

[0107] The detection control circuit 11 transmits the first sensor value So-1(B) corresponding to blue light to the host IC 70 (step ST12). The sensor value storage circuit 71 of the host IC 70 stores the first sensor value So-1(B).

[0108] 11 , the host IC 70 updates the number of measurements n to n=n+1 (step ST13) and starts detecting the object to be detected 100 and the culture medium 102. In this embodiment, when one frame of detection is performed by scanning the multiple photodiodes 30 in the detection area AA for each of RGB, the number of measurements n increases by 1. In the detection when the number of measurements n=2, the object to be detected 100 and the culture medium 102 are detected in a second period T2 after a predetermined period has elapsed (for example, after about 5 to 10 minutes have elapsed) from a first period T1 (initial state).

[0109] Next, the detection device 1 and the detection system 5 perform detection during the second period T2 in steps ST14 to ST22, and acquire second sensor values ​​So-2(R), So-2(G), and So-2(B). Note that steps ST14 to ST22 shown in FIG. 11 are similar to steps ST4 to ST12 in FIG. 10, and therefore, repeated explanations will be omitted.

[0110] The arithmetic circuit 72 of the host IC 70 calculates the gradation Gd-a of each color (RGB) based on the rate of change of the second sensor value So-2 relative to the first sensor value So-1 (step ST23).

[0111] More specifically, the calculation circuit 72 calculates the red gradation Gd-a(R) based on the reference gradation Gd-1(R) selected in step ST1, the first sensor value So-1(R) acquired in step ST6, and the second sensor value So-2(R) acquired in step ST16. The red gradation Gd-a(R) is calculated by Gd-a(R)=(Gd-1(R))×((So-2(R)) / (So-1(R))) based on the above-mentioned formula (1).

[0112] The calculation circuit 72 calculates the green gradation Gd-a(G) based on the reference gradation Gd-1(G) selected in step ST1, the first sensor value So-1(G) acquired in step ST9, and the second sensor value So-2(G) acquired in step ST19. The green gradation Gd-a(G) is calculated based on the above-mentioned formula (1) by Gd-a(G)=(Gd-1(G))×((So-2(G)) / (So-1(G))).

[0113] The arithmetic circuit 72 calculates the blue gradation Gd-a(B) based on the reference gradation Gd-1(B) selected in step ST1, the first sensor value So-1(B) acquired in step ST12, and the second sensor value So-2(B) acquired in step ST22. The blue gradation Gd-a(B) is calculated by Gd-a(B) = (Gd-1(B)) × ((So-2(B))) / (So-1(B))) based on the above-mentioned formula (1). The arithmetic circuit 72 calculates the gradations Gd-a(R), Gd-a(G), and Gd-a(B) for each sensor pixel 3.

[0114] The image generating circuit 76 of the host IC 70 generates an image based on the gradations Gda(R), Gda(G), and Gda(B) calculated by the arithmetic circuit 72 (step ST24).

[0115] The host IC 70 determines whether the number of measurements n is the final value (step ST25). If the number of measurements n is not the final value (No in step ST25), the host IC 70 returns to step ST13, updates the number of measurements n to n=n+1, and executes the detection and image generation from step ST14 to step ST23.

[0116] If the number of measurements n is the final value (Yes in step ST25), the host IC 70 ends the detection of the test object 100 and the culture medium 102 and the image generation.

[0117] 10 to 12, for ease of understanding, the final value of the number of measurements n is set to 2. However, this is not limited to this, and the number of detections and the detection interval (time) can be changed as appropriate depending on the type of the test object 100 and the culture medium 102, the content of the detection, etc. For example, while FIG. 12 shows the first period T1 and the second period T2 consecutively, there may be a predetermined period between the end of detection in the first period T1 and the start of detection in the second period T2. Furthermore, when the final value of the number of measurements n is 3 or greater, the calculation circuit 72 calculates the gradation Gd-a by substituting the nth sensor values ​​So-n(R), So-n(G), and So-n(B) acquired in the nth period Tn for the second sensor value So-2 in the above-described formula (1).

[0118] (Second embodiment) Fig. 13 is a block diagram showing an example of the configuration of a detection control circuit of a detection device according to a second embodiment. Fig. 14 is a flowchart showing the detection operation of a detection device and detection system according to the second embodiment in a first period. Fig. 15 is a flowchart showing the detection operation of a detection device and detection system according to the second embodiment in a second period. In the following description, the same components as those described in the above-mentioned embodiments are assigned the same reference numerals, and duplicate description will be omitted.

[0119] In the first embodiment described above, an example was shown in which the optical sensor 10 detects the sensor value So, the host IC 70 receives the sensor value So, and calculates the gradation Gd-a based on the rate of change of the sensor value So, but this is not limiting. In the detection device according to the second embodiment, the detection control circuit 11A included in the optical sensor 10 calculates the gradation Gd-a based on the rate of change of the sensor value So, and transmits an image generated based on the calculated gradation Gd-a to the host IC 70.

[0120] 13, the detection control circuit 11A according to the second embodiment has a sensor value storage circuit 71A, an arithmetic circuit 72A, a reference gradation storage circuit 73A, and an image generation circuit 76A, in addition to 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. The sensor value storage circuit 71A, the arithmetic circuit 72A, the reference gradation storage circuit 73A, and the image generation circuit 76A have the same configurations as the sensor value storage circuit 71, the arithmetic circuit 72, the reference gradation storage circuit 73, and the image generation circuit 76 (see FIG. 2) of the host IC 70 according to the first embodiment.

[0121] That is, in the second embodiment, in the detection control circuit 11A of the detection device 1 (optical sensor 10), the sensor value storage circuit 71A stores the sensor value So (first sensor value So-1 and second sensor value So-2). The reference gradation storage circuit 73A stores the reference gradation Gd-1 that is set in advance for each of the plurality of culture media 102.

[0122] The arithmetic circuit 72A calculates the gradation Gd-a based on the rate of change of the second sensor value So-2 acquired during the second period T2 relative to the first sensor value So-1 acquired during the first period T1. The arithmetic circuit 72A calculates the gradation Gd-a for each of RGB based on equation (1), as in the first embodiment. The arithmetic circuit 72A transmits the gradation Gd-a to the image generation circuit 76A. The image generation circuit 76A generates an image based on the gradation Gd-a received from the arithmetic circuit 72A and transmits the generated image to the host IC 70.

[0123] As shown in Figures 14 and 15, in the second embodiment, similar to the first embodiment, the first sensor value So-1 is detected during the first period T1, and the second sensor value So-2 is detected during the second period T2, a predetermined period after the first period T1. However, unlike the first embodiment, in the second embodiment, the detection control circuit 11A stores the first sensor values ​​So-1(R), So-1(G), and So-1(B) in the sensor value storage circuit 71A in steps ST6A, ST9A, and ST12A shown in Figure 14. Furthermore, in steps ST16A, ST19A, and ST22A shown in Figure 15, the detection control circuit 11A stores the second sensor values ​​So-2(R), So-2(G), and So-2(B) in the sensor value storage circuit 71A.

[0124] In the second embodiment, in step ST23, the detection control circuit 11A of the optical sensor 10 calculates the gradation Gd-a based on the rate of change of the sensor value So. In step ST24, the detection control circuit 11A of the optical sensor 10 generates an image based on the gradation Gd-a. Then, the detection control circuit 11A transmits the image generated based on the gradation Gd-a to the host IC 70 (step ST25A).

[0125] The host IC 70 determines whether the number of measurements n is the final value (step ST26). If the number of measurements n is not the final value (step ST26, No), the host IC 70 returns to step ST13, updates the number of measurements n to n = n + 1, and executes detection and image generation from step ST14 to step ST25A. If the number of measurements n is the final value (step ST26, Yes), the host IC 70 ends detection and image generation of the test object 100 and the culture medium 102.

[0126] Fig. 16 is a schematic diagram showing an example of the configuration of a detection system. Fig. 17 is a cross-sectional view showing an inspection unit included in the detection system. As shown in Fig. 16, the detection system 5 includes a plurality of detection units 121 (detection devices 1), a host IC 70, and a connection circuit 125 that connects the plurality of detection units 121 (detection devices 1) to the host IC 70. The plurality of detection units 121 (detection devices 1) are electrically connected to the common host IC 70 via the connection circuit 125.

[0127] 17 , the detection unit 121 includes a detection device 1 (optical sensor 10, optical filter layer 50, light source device 80, and control board 13) and a housing 122. The detection device 1 (optical sensor 10, optical filter layer 50, light source device 80, and control board 13) is disposed within the housing 122. A container 110 containing a detection target 100 and a culture medium 102 is disposed between the optical sensor 10 (optical filter layer 50) and the light source device 80. The detection device 1 is stacked in the housing 122 in the order of the light source device 80, the container 110, and the optical sensor 10 (optical filter layer 50). However, this is not limiting, and the stacking order of the detection device 1 may be reversed.

[0128] The control board 13 is mounted with a detection control circuit 11A (see FIG. 13) that controls the optical sensor 10. The control board 13 may also be mounted with a light source control circuit 12 (see FIG. 2) that controls the light source device 80.

[0129] 16, with its door closed, the incubator 120 is maintained in an environment (temperature, humidity, etc.) suitable for culturing the test object 100. A plurality of detection units 121 (detection devices 1) are arranged inside the incubator 120, and detect the test object 100 multiple times at preset timings (times). A connection circuit 125, not shown, is connected to the plurality of detection units 121 (detection devices 1) by wire or wirelessly. The plurality of detection units 121 (detection devices 1) transmit the gradation Gd-a calculated by the detection control circuit 11A to the host IC 70 via the connection circuit 125.

[0130] The detection system 5 has a plurality of detection units 121 (detection devices 1) and a host IC 70, and therefore can easily perform parallel detection (image capture) of a plurality of different objects to be detected 100. Furthermore, in this embodiment, the rate of change of the sensor value So and the gradation Gd-a are calculated in each of the plurality of detection units 121 (detection devices 1), so even in a configuration in which a plurality of detection units 121 (detection devices 1) are connected to one host IC 70, the load of calculation processing on the host IC 70 can be reduced.

[0131] 16 and 17 is not limited to the second embodiment, but can also be applied to the first embodiment. That is, each of the multiple detection units 121 (detection devices 1) transmits the sensor value So detected by the detection control circuit 11 to the host IC 70 via the connection circuit 125. The host IC 70 can be configured to calculate the gradation Gd-a based on the rate of change of the sensor value So.

[0132] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible without departing from the spirit of the present invention. Appropriate modifications made without departing from the spirit of the present invention naturally fall within the technical scope of the present invention. At least one of various omissions, substitutions, and modifications of components can be made without departing from the gist of each of the above-described embodiments and modifications.

[0133] REFERENCE SIGNS LIST 1 detection device 2 array substrate 3 sensor pixel 5 detection system 10 optical sensor 11, 11A detection control circuit 12 light source control circuit 21 substrate 30 photodiode 50 optical filter layer 70 host IC 71, 71A sensor value storage circuit 72, 72A arithmetic circuit 73 reference gradation storage circuit 80 light source device 81 light source substrate 82 light source 82-R first light source 82-G second light source 82-B third light source 100 detection target 102 culture medium 110 container 111 container body 112 cover member 120 incubator 121 detection unit

Claims

1. A detection device comprising: an optical sensor including a plurality of photodiodes arranged on a substrate; a light source device having a plurality of light sources and arranged opposite the optical sensor; a light-transmitting container arranged between the optical sensor and the light source device for containing a detection target and a culture medium; and a detection circuit electrically connected to the plurality of photodiodes and outputting a sensor value corresponding to light irradiated to each of the plurality of photodiodes, wherein the detection device calculates a gradation based on the rate of change of a second sensor value acquired in a second period after a predetermined period has elapsed since the first period, relative to a first sensor value acquired in a first period.

2. The detection device according to claim 1, further comprising: a reference gradation memory circuit that stores a reference gradation in the initial state of the culture medium; and a calculation circuit that calculates the gradation by multiplying the reference gradation by the rate of change of the second sensor value relative to the first sensor value.

3. The detection device according to claim 1, wherein the plurality of light sources include a first light source that irradiates red light, a second light source that irradiates green light, and a third light source that irradiates blue light, the first light source, the second light source, and the third light source are turned on in a time-division manner during each of the first period and the second period, and the detection circuit outputs the first sensor value corresponding to each of the red light, the green light, and the blue light, and the second sensor value corresponding to each of the red light, the green light, and the blue light, and calculates the gradation of each color based on the rate of change of the second sensor value relative to the first sensor value.

4. A detection system comprising: a detection device; and a host IC for controlling the detection device, wherein the detection device comprises: an optical sensor including a plurality of photodiodes arranged on a substrate; a light source device having a plurality of light sources and arranged opposite the optical sensor; a light-transmitting container arranged between the optical sensor and the light source device for containing a detection target and a culture medium; and a detection circuit electrically connected to the plurality of photodiodes and outputting a sensor value corresponding to light irradiated to each of the plurality of photodiodes, wherein the host IC acquires a first sensor value from the detection circuit during a first period, acquires a second sensor value from the detection circuit during a second period after a predetermined period has elapsed from the first period, and calculates a gradation based on a rate of change of the second sensor value relative to the first sensor value.

5. The detection system according to claim 4, wherein the host IC comprises: a sensor value memory circuit that stores the sensor value acquired from the detection device; a reference gradation memory circuit that stores a reference gradation in the initial state of the culture medium; and a calculation circuit that calculates the gradation of the object to be detected and the culture medium based on a value obtained by multiplying the reference gradation by the rate of change of the second sensor value relative to the first sensor value.

6. The detection system according to claim 4, wherein the plurality of light sources include a first light source that irradiates red light, a second light source that irradiates green light, and a third light source that irradiates blue light; the light source device turns on the first light source, the second light source, and the third light source in a time-division manner during each of the first period and the second period based on a control signal from the host IC; the detection circuit outputs the first sensor value corresponding to each of the red light, the green light, and the blue light, and the second sensor value corresponding to each of the red light, the green light, and the blue light, based on a control signal from the host IC; and the host IC calculates the gradation of each color based on a rate of change of the second sensor value relative to the first sensor value.

7. The detection system according to claim 4, comprising a plurality of said detection devices, said plurality of detection devices being electrically connected to a common said host IC.

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