Detection apparatus

Abstract

To provide a detection apparatus capable of suppressing occurrence of abnormal detection values of a detection element located directly under, or in the vicinity of a normal LED due to a failure of an LED in a configuration in which the plurality of LEDs are arranged to face a detection region.SOLUTION: A detection apparatus 1 includes: an optical sensor 10 having a detection region AA in which a plurality of sensor pixels 3 are arranged in a planar manner; a light source 80 in which a plurality of light-emitting diodes (LEDs) are arranged in a plane parallel to the detection region AA; and a control circuit 70 which controls the optical sensor 10 and the light source 80. Each of the plurality of sensor pixels 3 is associated with the light-emitting diode (LED) that is located closest among the plurality of light-emitting diodes (LEDs). The control circuit 70 acquires detection values of the plurality of sensor pixels 3 in a state in which a detection object body is not disposed in the detection region AA, and uniformly sets current setting values of the plurality of light-emitting diodes (LEDs) such that an average value of detection values of the plurality of sensor pixels 3 associated with light-emitting diodes (LEDs) that are not failed among the plurality of light-emitting diodes (LEDs) falls within a target range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A method has been disclosed for acquiring images of a culture medium in a culture vessel and a microbial colony (detectable substance) such as bacteria on the culture medium over time using a lensless imaging system with a photosensor (for example, Patent Document 1). In the lensless imaging system of Patent Document 1, light emitted from a light source passes through the microbial colony (detectable substance) and enters the photosensor. The photosensor acquires an image of the microbial colony formation (scattered light pattern) as pixel data. In such a lensless imaging system, in order to acquire the growth process of the microbial colony over time, the light intensity of the light-emitting element is adjusted so that the detection value acquired in the absence of the detectable substance falls within a predetermined range. [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 lensless imaging systems, a configuration in which multiple light-emitting diodes (LEDs) are arranged facing each other in the detection area is sometimes adopted to maintain a uniform in-plane luminance distribution in the detection area. In such a configuration, if one of the multiple LEDs fails, the detection value of the detection element located directly below or nearby the normal LED may deviate from the target value.

[0005] The present invention aims to provide a detection device that can prevent abnormalities in the detection value of a detection element located directly below or near a normal LED due to a failure of an LED in a configuration in which multiple LEDs are arranged opposite each other in a detection area. [Means for solving the problem]

[0006] A detection device according to one aspect of the present invention comprises an optical sensor having a detection area in which a plurality of sensor pixels are arranged in a plane, a light source in which a plurality of light-emitting diodes are arranged in a plane parallel to the detection area, and a control circuit that controls the optical sensor and the light source, acquires detection values ​​of the plurality of sensor pixels, and generates an image of a detectable object arranged in the detection area, wherein each of the plurality of sensor pixels is associated with a light-emitting diode that is closest to the plurality of light-emitting diodes, and the control circuit acquires detection values ​​of the plurality of sensor pixels when no detectable object is arranged in the detection area, and uniformly sets current setting values ​​for the plurality of light-emitting diodes so that the average value of detection values ​​of the plurality of sensor pixels associated with light-emitting diodes that are not faulty among the plurality of light-emitting diodes is within a target range. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a block configuration of a detection device according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the detection device according to the embodiment. [Figure 3] FIG. 3 is a circuit diagram showing an optical sensor of the detection device according to the embodiment. [Figure 4] FIG. 4 is a block diagram showing an example of the configuration of a control circuit according to the embodiment. [Figure 5] FIG. 5 is a plan view showing the correspondence between partial regions and light-emitting elements of the detection device according to the embodiment. [Figure 6] FIG. 6 is a conceptual diagram showing an example of the correspondence between photodiodes and light-emitting diodes. [Figure 7]FIG. 7 is a circuit diagram showing an example of the configuration of the light emitting element and the light emitting element drive circuit of the detection device according to the embodiment. [Figure 8] FIG. 8 is a conceptual diagram showing the relationship between the cathode current setting value and the cathode current setting potential. [Figure 9] FIG. 9 is a timing waveform diagram showing an example of a lighting operation in the detection device according to the embodiment. [Figure 10] FIG. 10 is a flowchart illustrating an example of an initial setting process in the detection device according to the embodiment. [Figure 11] FIG. 11 is a sub-flowchart illustrating an example of the LED failure detection process. [Figure 12A] FIG. 12A is a schematic diagram showing a specific example of a failure determination process for a light-emitting element. [Figure 12B] FIG. 12B is a schematic diagram showing a specific example of a failure determination process for a light-emitting element. [Figure 12C] FIG. 12C is a schematic diagram showing a specific example of a failure determination process for a light-emitting element. [Figure 13] FIG. 13 is a sub-flowchart showing an example of the light-emitting current setting process. [Figure 14] FIG. 14 is a sub-flowchart illustrating an example of the average value calculation process. DETAILED DESCRIPTION OF THE INVENTION

[0008] 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 make 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 previously described with reference to the preceding 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] Fig. 1 is a schematic diagram showing an example of a block configuration of a detection device according to an embodiment. Fig. 2 is a cross-sectional view showing a typical detection device according to an embodiment. In the present disclosure, the detection device 1 is a so-called biosensor that detects minute objects such as bacteria as detection targets 100. The detection device 1 includes an optical sensor 10, a control circuit 70, and a light source 80.

[0011] The optical sensor 10 has a plurality of sensor pixels 3 provided on an array substrate 2 formed using a substrate 21 as a base. A detection area AA is an area on the array substrate 2 where the plurality of sensor pixels 3 are arranged in a plane.

[0012] The first direction Dx is a direction in a plane parallel to the substrate 21. 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 third direction Dz is a direction perpendicular to the first direction Dx and the second direction Dy and is a normal direction to the main surface of the substrate 21.

[0013] Specifically, the plurality of sensor pixels 3 are arranged in a matrix in the first direction Dx and the second direction Dy in the detection area AA. However, the present invention is not limited to this, and the plurality of sensor pixels 3 may be arranged in a staggered pattern in the detection area AA.

[0014] Each of the sensor pixels 3 has a photodiode PD. The photodiode PD outputs a potential corresponding to the light irradiated thereon. More specifically, the photodiode PD is an OPD (Organic Photodiode) or a PIN (Positive Intrinsic Negative) photodiode using an organic semiconductor.

[0015] The light source 80 has a plurality of light-emitting elements 82 provided on a light source substrate 81 that is provided opposite the array substrate 2 of the optical sensor 10 in the third direction Dz. The light source 80 also has a light-emitting element drive circuit 83 that drives the plurality of light-emitting elements 82 mounted on the light source substrate 81. The light-emitting elements 82 are formed, for example, from light-emitting diodes (LEDs: Light Emitting Diodes).

[0016] As shown in FIG. 1, the light source 80 has a plurality of light emitting elements 82 (light emitting diodes LED) arranged in a plane parallel to the detection area AA of the optical sensor 10.

[0017] Specifically, the light source 80 has a plurality of light-emitting elements 82 (light-emitting diodes LED) arranged in a matrix in the first direction Dx and the second direction Dy in an area facing the detection area AA of the optical sensor 10. Without being limited to this, the plurality of light-emitting elements 82 (light-emitting diodes LED) may be arranged in a staggered pattern in the area facing the detection area AA of the optical sensor 10.

[0018] 1, the detection area AA is divided into a plurality of partial areas PAA, and light-emitting elements 82 (light-emitting diodes LED) are provided corresponding to the plurality of partial areas PAA, respectively. In addition, a light-emitting element drive circuit 83 for driving the light-emitting elements 82 (light-emitting diodes LED) provided corresponding to the plurality of partial areas PAA is provided in an area facing the peripheral area GA outside the detection area AA of the optical sensor 10.

[0019] Figure 1 illustrates an example in which a detection area AA, in which 16 sensor pixels 3 (photodiodes PD) are arranged in each of the first direction Dx and the second direction Dy, is divided into four parts in each of the first direction Dx and the second direction Dy, to provide 16 divided areas PAA.

[0020] 1, each partial area PAA has four sensor pixels 3 (photodiodes PD) arranged in each of the first direction Dx and the second direction Dy. When the detection area AA is viewed in the third direction Dz, the light source 80 has a light-emitting element 82 (light-emitting diode LED) provided at a position corresponding to the center of each partial area PAA. In other words, each of the multiple sensor pixels 3 (photodiodes PD) is associated with the light-emitting element 82 (light-emitting diode LED) that is closest when the detection area AA is viewed in a plan view. This associates one light-emitting element 82 (light-emitting diode LED) with multiple sensor pixels 3 (photodiodes PD).

[0021] In the present disclosure, the detection device 1 includes a mounting substrate 101 and a cover member 103 for mounting the detection object 100. The mounting substrate 101 and the cover member 103 are light-transmitting plate-like members made of, for example, glass. Specifically, the mounting substrate 101 and the cover member 103 are, for example, petri dishes.

[0022] The object to be detected 100 is cultured in a culture medium 102 provided on a mounting substrate 101. A cover member 103 is provided on the mounting substrate 101, and the object to be detected 100 is disposed between the optical sensor 10 and the light source 80. More specifically, the detection device 1 is configured such that the mounting substrate 101, the cover member 103 (object to be detected 100), and the light source 80 are disposed above the optical sensor 10 in this order.

[0023] Light L emitted from the light emitting element 82 passes through the mounting substrate 101, the culture medium 102, and the cover member 103 and is irradiated onto the detection area AA. The intensity of light received by the sensor pixels 3 (hereinafter also referred to as "received light intensity") differs between the area overlapping with the detection object 100 and the area not overlapping with the detection object 100. The optical sensor 10 can capture an image of the colony (detection object 100) on the culture medium 102 based on the difference in the received light intensity for each sensor pixel 3.

[0024] In a peripheral area GA outside the detection area AA of the substrate 21, a first gate line driving circuit 15 and a second gate line driving circuit 16 are provided.

[0025] The first gate line driving circuit 15 and the second gate line driving circuit 16 are arranged on either side of the detection area AA in the first direction Dx. The arrangement of the first gate line driving circuit 15 and the second gate line driving circuit 16 is not limited to this. Specifically, for example, the first gate line driving circuit 15 and the second gate line driving circuit 16 may be configured as a single gate line driving circuit.

[0026] 3 is a circuit diagram showing an optical sensor according to an embodiment. As shown in FIG. 3, the sensor pixel 3 includes a photodiode PD, a reset transistor Mrst, a readout transistor Mrd, and a source follower transistor Msf. The sensor pixel 3 also includes a reset control scanning line GLrst, a readout control scanning line GLrd, and a signal line SL.

[0027] The reset control scanning line GLrst, the readout control scanning line GLrd, and the signal line SL are each connected to a plurality of sensor pixels 3 in the detection area AA. Specifically, the reset control scanning line GLrst and the readout control scanning line GLrd extend in a first direction Dx and are connected to a plurality of sensor pixels 3 arranged in the first direction Dx. The signal line SL extends in a second direction Dy and is connected to a plurality of sensor pixels 3 arranged in the second direction Dy. The signal line SL is a wiring through which signals from a plurality of transistors (readout transistors Mrd and source follower transistors Msf) are output.

[0028] The reset transistor Mrst, the readout transistor Mrd, and the source follower transistor Msf are provided for one photodiode PD. Each of the multiple transistors in the sensor pixel 3 is configured as an n-type TFT (Thin Film Transistor). However, this is not limiting, and each transistor may be configured as a p-type TFT.

[0029] A reference potential Vcom is applied to the anode of the photodiode PD, and the cathode of the photodiode PD is connected to one of the source or drain of the reset transistor Mrst and the gate of the source follower transistor Msf.

[0030] The gate of the reset transistor Mrst is connected to a reset control scanning line GLrst. A reset potential Vrst is supplied to the other of the source or drain of the reset transistor Mrst. When the reset transistor Mrst is turned on (conductive state), the potential of the cathode of the photodiode PD is reset to the reset potential Vrst. The reference potential Vcom has a potential lower than the reset potential Vrst, and the photodiode PD is reverse-bias driven.

[0031] The source follower transistor Msf is connected between a terminal to which a power supply potential Vsf is supplied and the readout transistor Mrd. The gate of the source follower transistor Msf is connected to the cathode of the photodiode PD. A voltage corresponding to the intensity of light received by the photodiode PD is supplied to the gate of the source follower transistor Msf. As a result, the source follower transistor Msf outputs a potential corresponding to the intensity of light received by the photodiode PD to the readout transistor Mrd.

[0032] The readout transistor Mrd is connected between the source of the source follower transistor Msf and the signal line SL. The gate of the readout transistor Mrd is connected to the readout control scanning line GLrd. When the readout transistor Mrd is turned on, the signal output from the source follower transistor Msf, i.e., a potential corresponding to the intensity of light received by the photodiode PD, is output to the output signal line SL.

[0033] 3, the reset transistor Mrst and the readout transistor Mrd each have a single-gate structure, but the reset transistor Mrst and the readout transistor Mrd may each have a so-called double-gate structure in which two transistors are connected in series, or may each have a structure in which three or more transistors are connected in series. Furthermore, the circuit of one sensor pixel 3 is not limited to a structure having three transistors: the reset transistor Mrst, the source-follower transistor Msf, and the readout transistor Mrd. The sensor pixel 3 may have two transistors, or may have four or more transistors.

[0034] The first gate line driving circuit 15 is a circuit that drives the reset control scanning lines GLrst in the detection area AA. The first gate line driving circuit 15 is, for example, a shift register circuit.

[0035] In the present disclosure, the first gate line drive circuit 15 sequentially selects the reset control scanning lines GLrst based on various control signals such as a start pulse signal and a clock pulse signal supplied from the detection circuit 11, and supplies a reset control signal to the selected reset control scanning line GLrst. In other words, the first gate line drive circuit 15 simultaneously supplies a reset control signal to the sensor pixels 3 aligned in the first direction Dx, and sequentially supplies a reset control signal to the sensor pixels 3 aligned in the second direction Dy. This resets the potentials of the photodiodes PD of the multiple sensor pixels 3 connected to the reset control scanning line GLrst selected by the first gate line drive circuit 15 of the sensor pixel 3.

[0036] The second gate line driving circuit 16 is a circuit that drives a plurality of read control scanning lines GLrd in the detection area AA. The second gate line driving circuit 16 is, for example, a shift register circuit.

[0037] In the present disclosure, the second gate line driving circuit 16 sequentially selects the readout control scanning lines GLrd based on various control signals such as a start pulse signal and a clock pulse signal supplied from the detection circuit 11, and supplies a readout control signal to the selected readout control scanning line GLrd. In other words, the second gate line driving circuit 16 simultaneously supplies a readout control signal to the sensor pixels 3 arranged in the first direction Dx, and sequentially supplies a readout control signal to the sensor pixels 3 arranged in the second direction Dy. In this way, the potentials of the multiple sensor pixels 3 connected to the readout control scanning line GLrd selected by the second gate line driving circuit 16 are read out.

[0038] The detection circuit 11 is a ROIC (Readout Integrated Circuit) that includes an analog front end (AFE) circuit.

[0039] A constant current source 43 for supplying a bias current Ib to the read transistor Mrd is connected to the detection circuit 11. This constant current source 43 may be provided within the detection circuit 11 or within the substrate 21.

[0040] The detection circuit 11 converts the output potential of each sensor pixel 3 into a digital signal and outputs it to the control circuit 70 as a detection value Raw for each sensor pixel 3. More specifically, the detection circuit 11 A / D converts the difference value between the output potential of the sensor pixel 3 in the reset period and the output potential of the sensor pixel 3 in the readout period, and generates the detection value Raw for each sensor pixel 3.

[0041] 4 is a block diagram showing an example of the configuration of a control circuit according to the embodiment. The control circuit 70 synchronizes and controls the detection operation of the optical sensor 10 and the lighting operation of the light source 80. The control circuit 70 is composed of, for example, an MCU (Micro Control Unit), RAM, EEPROM, ROM, etc.

[0042] Signal transmission between the control circuit 70 and the detection circuit 11 and light source 80 is performed via a clock-synchronized serial interface. More specifically, signal transmission between the control circuit 70 and the detection circuit 11 is performed via, for example, SPI (Serial Peripheral Interface). Furthermore, signal transmission between the control circuit 70 and the light-emitting element drive circuit 83 is performed via, for example, I2C (Inter-Integrated Circuit). The present disclosure is not limited by the signal transmission method between the control circuit 70 and the optical sensor 10 and light source 80.

[0043] As shown in FIG. 4, the control circuit 70 includes a data acquisition circuit 71, a storage circuit 72, and a processing circuit 73.

[0044] The data acquisition circuit 71 acquires the raw detection value for each sensor pixel 3 from the detection circuit 11 and stores it in the memory circuit 72 .

[0045] The processing circuitry 73, for example, binarizes the raw detection values ​​for each sensor pixel 3 stored in the memory circuitry 72 to generate an image of colony formation on the culture medium 102. The process of generating an image of colony formation on the culture medium 102 is not limited to binarization processing.

[0046] In the present disclosure, the control circuit 70 has a function of initially setting the light-emitting current ICS flowing through the light-emitting element 82 (light-emitting diode LED) so that the detection value Raw of the sensor pixel 3 associated with the non-faulty light-emitting element 82 (light-emitting diode LED) is within a target range (for example, “200” ±5% in the case of an 8-bit digital value) when no detection object 100 is present within the detection area AA. Specifically, the data acquisition circuit 71 acquires a fault detection flag BD of the light-emitting element 82 (light-emitting diode LED) from the light-emitting element drive circuit 83 and stores it in the memory circuit 72. Furthermore, when the detection device 1 is started up, the processing circuit 73 sets the light-emitting current ICS flowing through the light-emitting element 82 (light-emitting diode LED) based on the fault detection flag BD stored in the memory circuit 72. The fault detection flag BD of the light-emitting element 82 (light-emitting diode LED) and the initial setting process of the detection device 1 will be described later.

[0047] Fig. 5 is a plan view showing the correspondence between partial regions and light-emitting elements of the detection device according to the embodiment. Fig. 5 illustrates an example in which the detection region AA, in which 16 sensor pixels 3 (photodiodes PD) are arranged in each of the first direction Dx and the second direction Dy as shown in Fig. 1, is divided into four in each of the first direction Dx and the second direction Dy to provide 16 divided regions PAA.

[0048] In other words, the partial areas PAA are areas where the pth block Bp (p is a natural number from 1 to P, and P is the total number of partial areas PAA lined up in the first direction Dx) obtained by dividing the detection area AA into four in the first direction Dx overlaps with the qth zone Zq (q is a natural number from 1 to Q, and Q is the total number of partial areas PAA lined up in the second direction Dy) obtained by dividing the detection area AA into four in the second direction Dy. Each divided area PAA is provided with one light-emitting element 82 (light-emitting diode LED).

[0049] The total number M of sensor pixels 3 (photodiodes PD) arranged in the first direction Dx is not limited to 16. The total number N of sensor pixels 3 (photodiodes PD) arranged in the second direction Dy is not limited to 16. The total number of light-emitting elements 82 arranged in the first direction Dx, in other words, the total number P of partial areas PAA arranged in the first direction Dx (total number of p-th blocks Bp), is not limited to 4. The total number of light-emitting elements 82 arranged in the second direction Dy, in other words, the total number Q of partial areas PAA arranged in the second direction Dy (total number of q-th blocks Zq), is not limited to 4. Furthermore, the number of divisions of the detection area AA, in other words, the total number (P × Q) of partial areas PAA, is not limited to 16. Furthermore, it is not limited to an embodiment in which the number of sensor pixels 3 (photodiodes PD) included in each partial area PAA is the same.

[0050] Hereinafter, the sensor pixel 3 (photodiode PD) will also be referred to as a “photodiode PD(m,n).” The detection value Raw for each photodiode PD(m,n) will also be referred to as a “detection value Raw(m,n).”

[0051] Furthermore, the partial area PAA where the pth block Bp and the qth block Zq overlap is also referred to as the “partial area PAA(p, q).” Furthermore, the light-emitting element 82 (light-emitting diode LED) corresponding to the partial area PAA(p, q) is also referred to as the “light-emitting diode LED(p, q).”

[0052] In the present disclosure, it is assumed that the correspondence between the photodiodes PD(m, n) and the light-emitting diodes LED(p, q) is stored in advance in the memory circuit 72. Fig. 6 is a conceptual diagram showing an example of the correspondence between the photodiodes and the light-emitting diodes.

[0053] In the present disclosure, an emission control scan line ANLq is connected to the anode of each light-emitting diode LED(p, q). The Q emission control scan lines ANLq extend in the first direction Dx and are arranged in the second direction Dy. That is, the anodes of the P light-emitting diodes LED(p, q) arranged in the first direction Dx are connected to a common emission control scan line ANLq.

[0054] In addition, in the present disclosure, the cathodes of the light-emitting diodes LED(p, q) are connected to light-emitting current control lines CSL(p, q), respectively. The P×Q light-emitting current control lines CSL(p, q) extend in the second direction Dy and are arranged in the first direction Dx. That is, the cathodes of the Q light-emitting elements 82 arranged in the second direction Dy are each connected to a separate light-emitting current control line CSL(p, q).

[0055] The light-emitting element drive circuit 83 sequentially supplies a light-emitting element drive voltage VLED (for example, 5 V) to the light-emitting diodes LED(p, q) arranged in the second direction Dy via Q light-emitting control scanning lines ANLq based on a control signal supplied from the control circuit 70. This causes the plurality of light-emitting elements 82 to be driven sequentially along the second direction Dy. Note that the wiring patterns of the light-emitting control scanning lines ANLq and the light-emitting current control lines CSL(p, q) are not limited to the embodiment shown in FIG. 5. The wiring patterns of the light-emitting control scanning lines ANLq and the light-emitting current control lines CSL(p, q) may be any pattern as long as they can sequentially drive the light-emitting diodes LED(p, q) arranged in the second direction Dy.

[0056] Fig. 7 is a circuit diagram showing an example of the configuration of a light-emitting element and a light-emitting element drive circuit of a detection device according to an embodiment. For ease of explanation, Fig. 7 shows only the configuration of a light-emitting element drive circuit 83 corresponding to one light-emitting diode LED(p, q).

[0057] As shown in FIG. 7, the light emitting element drive circuit 83 includes a light emitting control scanning line drive circuit 831 and a light emitting current control circuit 832.

[0058] The light-emission control scanning line driving circuit 831 is a circuit that supplies a light-emitting element driving voltage VLED to the anode of the light-emitting diode LED(p, q).

[0059] Specifically, the light-emission control scanning line drive circuit 831 is supplied with a high potential from the shift register circuit SR to turn on the TFT, and the output potential of the light-emission control scanning line drive circuit 831 becomes the light-emitting element drive voltage VLED. As a result, the light-emitting element drive voltage VLED is supplied to the anode of the light-emitting diode LED(p, q) via the light-emission control scan line ANLq.

[0060] The light-emitting current control circuit 832 is a circuit that controls the current (hereinafter also referred to as "light-emitting current") ICS that flows through the light-emitting diode LED(p, q) to which the light-emitting element drive voltage VLED is supplied from the light-emitting control scanning line drive circuit 831.

[0061] Specifically, the light-emitting current control circuit 832 includes a current-drawing constant current circuit configured by combining, for example, an operational amplifier circuit and a TFT. A cathode current setting potential VSET set by a cathode current setting circuit SC is input to the non-inverting input (+) of the operational amplifier circuit. This sets the light-emitting current ICS (=VSET / Rs) that flows through the light-emitting diodes LED(p, q) via the TFT and source resistor Rs.

[0062] The cathode current setting potential VSET can be set in stages, for example, by selecting the node voltage between a plurality of cathode current adjustment resistors connected in series between the light-emitting element drive voltage VLED (e.g., 5 V) and the GND potential. The cathode current setting circuit SC outputs the cathode current setting potential VSET according to the cathode current setting value ISV set by the processing circuit 73 of the control circuit 70. Figure 8 is a conceptual diagram showing the relationship between the cathode current setting value and the cathode current setting potential.

[0063] 9 is a timing waveform diagram showing an example of lighting operation in the detection device according to the embodiment. In the example of lighting operation shown in FIG. 9, a q-th period Tq is a light emission period of each light-emitting diode LED(p, q) in a q-th zone Zq arranged in the q-th row in one frame period F.

[0064] During the qth period Tq, the light-emitting element drive circuit 83 supplies the light-emitting element drive voltage VLED to the anode of each light-emitting element 82 in the qth zone Zq via the light-emitting control scanning line ANLq, thereby lighting up each light-emitting element 82 in the qth zone Zq.

[0065] The light-emitting element drive circuit 83 increments the value of q from 1 to Q and repeatedly executes the above-described process. During the qth period Tq, the optical sensor 10 sequentially acquires the detection value Raw(m, n) of each photodiode PD(m, n) in the qth zone Zq arranged in the second direction Dy.

[0066] In other words, the light-emitting elements 82 (light-emitting diodes LED) aligned in the second direction Dy are sequentially driven, and during the drive periods (light-emitting periods) of the light-emitting elements 82 (light-emitting diodes LED) aligned in the first direction Dx, the sensor pixels 3 (photodiodes PD) aligned in the second direction Dy in the partial area PAA associated with the light-emitting elements 82 (light-emitting diodes LED) are sequentially driven, thereby acquiring detection values ​​Raw(m, n) for one frame in the detection area AA.

[0067] In the configuration of the detection device 1 according to the embodiment described above, when one or more of the light-emitting diodes LED(p,q) fails and becomes unlit, the output potential of the sensor pixel 3 in the partial area PAA(p,q) corresponding to the failed light-emitting diode LED(p,q) becomes relatively smaller than the output potential of the sensor pixel 3 in the partial area PAA(p,q) corresponding to the normal light-emitting diode LED(p,q).

[0068] In a mode in which the light-emitting current ICS flowing through the light-emitting element 82 (light-emitting diode LED) is initially set so that the average value of the detection value Raw(m,n) across the entire detection area AA falls within a target range, a failure of the light-emitting element 82 (light-emitting diode LED) causes the output potential of the sensor pixel 3 in the partial area PAA(p,q) corresponding to the normal light-emitting diode LED(p,q) to become relatively large. As a result, the detection value Raw(m,n) of the photodiode PD(m,n) in the partial area PAA(p,q) corresponding to the normal light-emitting diode LED(p,q) may deviate from the target value.

[0069] A specific example of the initial setting process in the detection device 1 according to the embodiment will be described below. Fig. 10 is a flowchart showing an example of the initial setting process in the detection device according to the embodiment. The initial setting process shown in Fig. 10 is executed when the detection device 1 is started up. More specifically, the initial setting process in the detection device 1 according to the embodiment is executed in a state where the object to be detected 100 is not present in the detection area AA.

[0070] When the detecting device 1 according to the embodiment is started up, the control circuit 70 first controls the light-emitting element drive circuit 83 to execute a fault determination process for the light-emitting element 82 (light-emitting diode LED) (hereinafter also referred to as "LED fault detection process") (step S100). Fig. 11 is a sub-flowchart showing an example of the LED fault detection process.

[0071] In the LED failure detection process, the light-emitting element drive circuit 83 acquires the cathode voltage VCS(p,q) when the light-emitting element drive voltage VLED is applied for each light-emitting diode LED(p,q), and performs threshold determination processing on the acquired cathode voltage VCS(p,q).

[0072] Specifically, when the process shifts to the LED failure detection process shown in FIG. 11, the light-emitting element drive circuit 83 resets the zone number q, the normal LED counter NDC, and the failed LED counter BDC (q=0, NDC=0, BDC=0, step S101), then increments the zone number q (q=q+1, step S102), and supplies the light-emitting element drive voltage VLED to the anode of the light-emitting diode LED(p, q) in the qth zone Zq via the light-emitting control scanning line ANLq (step S103).

[0073] The normal LED counter NDC is a counter value indicating the number of light-emitting diodes LED(p,q). The faulty LED counter BDC is a counter value indicating the number of faulty light-emitting diodes LED(p,q). In the present disclosure, a threshold value BDCth is set for the number of faulty light-emitting diodes LED(p,q) (the value of the faulty LED counter BDC), and if the number of faulty light-emitting diodes LED(p,q) (the value of the faulty LED counter BDC) is equal to or greater than a predetermined number (the threshold value BDCth), the initial setting process is terminated and the detection device 1 is made unusable. In the present disclosure, the threshold value BDCth of the faulty LED counter BDC is assumed to be stored in advance in, for example, the memory circuit 72 of the control circuit 70.

[0074] Next, the light-emitting element driving circuit 83 resets the block number p (q = 0, step S104), then increments the block number p (p = p + 1, step S105), acquires the cathode voltage VCS(p, q) of the light-emitting diode LED(p, q) corresponding to the partial area PAA(p, q) (step S106), and determines whether the acquired cathode voltage VCS(p, q) is within the range of the low-level threshold VthL or more and the high-level threshold VthH or less (VthL≦VCS≦VthH) (step S107).

[0075] 12A, 12B, and 12C are schematic diagrams showing specific examples of the failure determination process for a light-emitting element. The low-level threshold VthL is set to, for example, 0.25 V. The high-level threshold VthH is set to, for example, (VLED-1) V.

[0076] When the light-emitting diode LED(p,q) is normal, as shown in FIG. 12A, the cathode voltage VCS(p,q) is within the range of the low-level threshold VthL or more and the high-level threshold VthH or less (VthL≦VCS(p,q)≦VthH).

[0077] When the light-emitting diode LED(p,q) has an open circuit fault, the cathode of the light-emitting diode LED(p,q) with the open circuit fault, indicated by the broken line, becomes high impedance (HiZ), as shown in FIG. 12B. As a result, the cathode voltage VCS(p,q) is within the range of the GND potential or more and less than the low-level threshold VthL (GND≦VCS(p,q) <VthL)となる。

[0078] When the light-emitting diode LED(p,q) is short-circuited, the cathode of the short-circuited light-emitting diode LED(p,q) shown by the broken line is connected to the light-emitting control scanning line ANLq through a low resistance (for example, about 1Ω) in a layer short-circuit state, as shown in FIG. 12C. As a result, the cathode voltage VCS(p,q) is in a range (VthH) that is greater than the high-level threshold VthH and less than the light-emitting element drive voltage VLED. <VCS(p,q)≦VLED)となる。

[0079] If the acquired cathode voltage VCS(p,q) is within the range of the low-level threshold VthL or more and the high-level threshold VthH or less (VthL≦VCS≦VthH) (step S107; Yes), the light-emitting element drive circuit 83 sets the failure detection flag BD(p,q) of the light-emitting diode LED(p,q) to “0” and increments the normal LED counter NDC (BD(p,q)=0, NDC=NDC+1, step S108). The data acquisition circuit 71 of the control circuit 70 acquires the value (=0) of the failure detection flag BD(p,q) of the light-emitting diode LED(p,q) and the value of the normal LED counter NDC output from the light-emitting element drive circuit 83, and stores them in the memory circuit 72.

[0080] If the obtained cathode voltage VCS(p,q) is not within the range of the low-level threshold VthL or higher and the high-level threshold VthH or lower (VthL ≦ VCS ≦ VthH), in other words, if the obtained cathode voltage VCS(p,q) is within the range of the GND potential or higher and less than the low-level threshold VthL (GND ≦ VCS(p,q) < VthL), or if the obtained cathode voltage VCS(p,q) is greater than the high-level threshold VthH and within the range of the light-emitting element drive voltage VLED or lower (VthH < VCS(p,q) ≦ VLED), the light-emitting element drive circuit 83 sets the failure detection flag BD(p,q) of the light-emitting diode LED(p,q) to "1" and increments the failed LED counter BDC (BD(p,q) = 1, BDC = BDC + 1, step S109). The data acquisition circuit 71 of the control circuit 70 acquires the value (=1) of the failure detection flag BD(p,q) of the light-emitting diode LED(p,q) output from the light-emitting element drive circuit 83 and the value of the failed LED counter BDC, and stores them in the storage circuit 72.

[0081] Then, the light-emitting element drive circuit 83 determines whether the block number p is "P" (p = P, step S110). In other words, the light-emitting element drive circuit 83 determines whether the failure determination process for all the light-emitting diodes LED(p,q) within the q-th zone Zq has been executed. If the failure determination process for all the light-emitting diodes LED(p,q) within the q-th zone Zq has not been executed (step S110; No), the processes after step S105 are repeatedly executed.

[0082] If the failure determination process for all the light-emitting diodes LED(p,q) within the q-th zone Zq has been executed (step S110; Yes), then, the light-emitting element drive circuit 83 determines whether the zone number q is "Q" (q = Q, step S111). In other words, the light-emitting element drive circuit 83 determines whether the failure determination process for all the light-emitting diodes LED(p,q) within the detection area AA has been executed. If the failure determination process for all the light-emitting diodes LED(p,q) within the detection area AA has not been executed (step S111; No), the processes after step S102 are repeatedly executed.

[0083] When the failure determination process has been performed for all light emitting diodes LED(p, q) within the detection area AA (step S111; Yes), the process returns to the initial setting process shown in FIG.

[0084] 10, the control circuit 70 determines whether the number of failed light emitting diodes LED(p, q) (value of the failed LED counter BDC) is less than a predetermined number (threshold value BDCth) (step S200). If the number of failed light emitting diodes LED(p, q) (value of the failed LED counter BDC) is equal to or greater than the predetermined number (threshold value BDCth) (step S200; No), the control circuit 70 ends the initial setting process and disables the detection device 1.

[0085] If the number of failed light emitting diodes LED(p, q) (value of the failed LED counter BDC) is less than a predetermined number (threshold value BDCth) (step S200; Yes), the control circuit 70 executes a light emitting current setting process (step S300). Fig. 13 is a sub-flowchart showing an example of the light emitting current setting process.

[0086] When the process proceeds to the light emitting current setting process, the control circuit 70 calculates the average value of the detection values ​​Raw(m,n) of the photodiodes PD(m,n) in the partial area PAA(p,q) corresponding to the normal light emitting diodes LED(p,q), and uniformly sets the cathode current setting value ISV so that the calculated average value is within the target range.

[0087] In the present disclosure, the term "target range" refers to a predetermined range (for example, "200" ±5% in the case of an 8-bit digital value) with the target value (for example, "200" in the case of an 8-bit digital value) of the detection value Raw(m,n) of the photodiode PD(m,n) when no object to be detected 100 is present in the detection area AA as the center value. The lower limit value (hereinafter also referred to as "target lower limit value") Rawth1 and the upper limit value (hereinafter also referred to as "target upper limit value") Rawth2 of the target range are assumed to be stored in advance in, for example, the memory circuit 72 of the control circuit 70.

[0088] Specifically, in the light-emitting current setting process shown in Fig. 13, the control circuit 70 controls the optical sensor 10 to acquire the detection values ​​Raw(m,n) for one frame. The data acquisition circuit 71 of the control circuit 70 acquires the detection values ​​Raw(m,n) for one frame output from the detection circuit 11 of the optical sensor 10 (step S301) and stores them in the memory circuit 72. The processing circuit 73 of the control circuit 70 executes the average value calculation process shown in Fig. 14 (step S400) to calculate the average value of the detection values ​​Raw(m,n) of the photodiodes PD(m,n) in the partial area PAA(p,q) corresponding to the normal light-emitting diodes LED(p,q). Fig. 14 is a sub-flowchart showing an example of the average value calculation process.

[0089] Specifically, when the process proceeds to the average value calculation process shown in FIG. 14, the processing circuit 73 of the control circuit 70 resets the zone number q (q=0, step S401), then increments the zone number q (q=q+1, step S402), and then resets the block number p (q=0, step S403), then increments the block number p (p=p+1, step S404), and determines whether the fault detection flag BD(p,q) of the light-emitting diode LED(p,q) is "0" (step S405).

[0090] If the fault detection flag BD(p,q) of the light-emitting diode LED(p,q) is "0" (step S405; Yes), it indicates that the light-emitting diode LED(p,q) corresponding to the partial area PAA(p,q) is normal. At this time, the processing circuit 73 of the control circuit 70 calculates the average value Raw(p,q)ave of the detection values ​​Raw(m,n) of the photodiodes PD(m,n) in the partial area PAA(p,q) (step S406), stores this in the memory circuit 72, and proceeds to the processing of step S407.

[0091] If the failure detection flag BD(p,q) of the light-emitting diode LED(p,q) is "1" (step S405; No), it indicates that the light-emitting diode LED(p,q) corresponding to the partial area PAA(p,q) is faulty. In this case, the processing circuit 73 of the control circuit 70 does not calculate the average value Raw(p,q)ave, and proceeds to the processing of step S407.

[0092] Then, the processing circuit 73 of the control circuit 70 determines whether the block number p is "P" (p=P, step S407). In other words, the processing circuit 73 of the control circuit 70 determines whether the calculation process for the average value Raw(p,q)ave of all partial areas PAA(p,q) corresponding to normal light emitting diodes LED(p,q) in the qth zone Zq has been executed. If the calculation process for the average value Raw(p,q)ave of all partial areas PAA(p,q) corresponding to normal light emitting diodes LED(p,q) in the qth zone Zq has not been executed (step S407; No), the processing from step S404 onwards is repeatedly executed.

[0093] If the calculation process for the average value Raw(p,q)ave of all partial areas PAA(p,q) corresponding to normal light-emitting diodes LED(p,q) in the q-th zone Zq has been performed (step S407; Yes), the processing circuit 73 of the control circuit 70 then determines whether the zone number q is "Q" (q=Q, step S408). In other words, the processing circuit 73 of the control circuit 70 determines whether the calculation process for the average value Raw(p,q)ave of all partial areas PAA(p,q) corresponding to normal light-emitting diodes LED(p,q) in the detection area AA has been performed. If the calculation process for the average value Raw(p,q)ave of all partial areas PAA(p,q) corresponding to normal light-emitting diodes LED(p,q) in the detection area AA has not been performed (step S408; No), the processing from step S402 onwards is repeated.

[0094] When the calculation process of the average value Raw(p,q)ave of all partial regions PAA(p,q) corresponding to normal light-emitting diodes LED(p,q) within the detection region AA is executed (step S408; Yes), the processing circuit 73 of the control circuit 70 reads the average value Raw(p,q)ave stored in the storage circuit 72 and the value of the normal LED counter NDC, and uses the following formula (1) to calculate the average value Rawave of all partial regions PAA(p,q) corresponding to normal light-emitting diodes LED(p,q) (step S409), and returns to the light emission current setting process shown in FIG. 13.

[0095] Rawave = (ΣRaw(p,q)ave) / NDC ··· (1)

[0096] When returning to the light emission current setting process shown in FIG. 13, the processing circuit 73 of the control circuit 70 determines whether the average value Rawave calculated in the average value calculation process shown in FIG. 14 is equal to or greater than the target lower limit value Rawth1 (step S302).

[0097] When the average value Rawave is less than the target lower limit value Rawth1 (Rawave < Rawth1, step S302; No), the processing circuit 73 of the control circuit 70 increases the cathode current setting value ISV by one step (ISV = ISV + 1, step S303), returns to the process of step S301, and executes the processes after step S301.

[0098] When the average value Rawave is equal to or greater than the target lower limit value Rawth1 (Rawave ≧ Rawth1, step S302; Yes), subsequently, the processing circuit 73 of the control circuit 70 determines whether the average value Rawave is equal to or less than the target upper limit value Rawth2 (step S304).

[0099] When the average value Rawave is greater than the target upper limit value Rawth2 (Rawave > Rawth2, step S304; No), the processing circuit 73 of the control circuit 70 decreases the cathode current setting value ISV by one step (ISV = ISV - 1, step S305), returns to the process of step S301, and executes the processes after step S301.

[0100] If the average value Rawave is equal to or less than the target upper limit Rawth2 (Rawave≦Rawth2, step S304; Yes), the process returns to FIG. 10 and the initial setting process ends.

[0101] By the initial setting process of the detection device 1 according to the embodiment described above, the light-emitting current ICS flowing through each light-emitting diode LED(p,q) is initially set so that the average value Raw of the detection values ​​Raw(m,n) of the photodiodes PD(m,n) in the partial area PAA(p,q) corresponding to the normal light-emitting diodes LED(p,q) is within a target range (Rawth1≦Rawave≦Rawth2). This makes it possible to prevent the detection values ​​Raw(m,n) of the photodiodes PD(m,n) in the partial area PAA(p,q) corresponding to the normal light-emitting diodes LED(p,q) from becoming relatively large after the initial setting.

[0102] 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 spirit of each of the above-described embodiments and modifications. [Explanation of symbols]

[0103] 1. Detection device 2 Array board 3 sensor pixels 10 Optical Sensor 11 Detection circuit 15 First gate line driving circuit 16 Second gate line driving circuit 21 PCB 70 Control circuit 71 Data acquisition circuit 72 Memory circuit 73 Processing Circuit 80 light source 81 Light source board 82 Light-emitting element 83 Light-emitting element drive circuit 100 Object to be detected 101 Mounting board 102 Culture medium 103 Cover member AA detection area PD photodiode LED Light Emitting Diode

Claims

1. an optical sensor having a detection area in which a plurality of sensor pixels are arranged in a plane; a light source in which a plurality of light emitting diodes are arranged in a plane parallel to the detection area; a control circuit that controls the optical sensor and the light source, acquires detection values ​​of the plurality of sensor pixels, and generates an image of the object to be detected that is disposed in the detection area; Equipped with each of the plurality of sensor pixels is associated with a light emitting diode that is located closest to the plurality of light emitting diodes; The control circuit obtaining detection values ​​of the plurality of sensor pixels in a state where no object to be detected is disposed in the detection area, and uniformly setting current setting values ​​for the plurality of light-emitting diodes so that an average value of detection values ​​of the plurality of sensor pixels associated with light-emitting diodes that are not faulty among the plurality of light-emitting diodes falls within a target range; Detection device.

2. One light emitting diode is associated with a plurality of sensor pixels; The detection device according to claim 1 .

3. the plurality of sensor pixels are arranged in a matrix in a first direction and a second direction intersecting the first direction; Among the plurality of sensor pixels, the sensor pixels arranged in the first direction are connected to a common scanning line, and the sensor pixels arranged in the second direction are sequentially driven. The detection device according to claim 2 .

4. the plurality of light-emitting diodes are arranged in a matrix in the first direction and the second direction, Among the plurality of light emitting diodes, the light emitting diodes arranged in the first direction are connected to a common scanning line, and the light emitting diodes arranged in the second direction are sequentially driven. The detection device according to claim 3 .

5. During a driving period of the light emitting diodes arranged in the first direction, the sensor pixels arranged in the second direction in an area including the sensor pixels associated with the light emitting diodes are sequentially driven. The detection device according to claim 4 .

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