Image acquisition device

Abstract

This image acquisition device operates in a state of being connected to an external device. The image acquisition device comprises: an imaging unit that acquires an imaging signal by detecting light; and a control unit that generates image data on the basis of the imaging signal. The imaging unit is configured to automatically transition to a detection-capable state in which light can be detected, in response to power supply from an external device. The imaging unit has an image sensor and a fiber optic plate disposed on the image sensor. The control unit has: a processor that executes a program for generating image data, which is data in a file format processable by the external device, on the basis of the imaging signal; a memory in which the program is expanded; and an external connection unit that outputs the image data to the external device.

Description

Image acquisition device

[0001] This disclosure relates to an image acquisition device.

[0002] Image acquisition devices that generate image data by detecting light (for example, intraoral imaging devices that generate image data about an object by detecting radiation that has passed through the object) are known (see, for example, Patent Document 1). In the intraoral imaging device described in Patent Document 1, the acquisition of radiation images is started based on instructions from an external computer device connected to the intraoral imaging device. Furthermore, the radiation images acquired by the intraoral imaging device are usually sent to an external computer device and then converted into data in a predetermined file format (an image file in a format that can be displayed and processed on the computer device).

[0003] Japanese Patent Publication No. 2021-78110

[0004] In the mechanism as described above, in order to execute various processes such as the imaging start process of an image by an image acquisition device and the conversion process of the image captured by the image acquisition device, a device driver provided by a sensor manufacturer or the like that manufactures the image acquisition device needs to be installed in advance in an external computer device connected to the image acquisition device, and necessary settings need to be completed on the computer device. Further, the computer device also requires a control program for executing the various processes described above using the functions of the device driver. Since device drivers usually differ for each manufacturer or model of a sensor (image acquisition device), the control program needs to be developed individually for each image acquisition device (device driver). For example, in industrial applications or academic applications, etc., it may be required to image a small object or a narrow area with high precision. In that case, it is common for a control program to be developed for each image acquisition device, and for the customer to install and use the control program on an external device such as a PC. Therefore, the burden of software development for the user who provides the control program to end users (such as dentists, engineers, researchers, and quality control personnel, etc.) is large. The above user is, for example, a device manufacturer (such as a medical device manufacturer) that provides an end user with a system including an image acquisition device and a set of software for handling it.

[0005] Therefore, one aspect of the present disclosure aims to provide an image acquisition device capable of reducing the development burden of software for using the image acquisition device.

[0006] The present disclosure includes the image acquisition devices of the following [1] to

[15] .

[0007] [1] An image acquisition device that operates in connection with an external device, comprising: an imaging unit that acquires an imaging signal by detecting light; and a control unit that generates image data based on the imaging signal, wherein the imaging unit is configured to automatically transition to a detectable state in which it is capable of detecting light in response to power supply from the external device, the imaging unit comprises an image sensor and a fiber optic plate disposed on the image sensor, the control unit comprises a first processing unit that generates the image data based on the imaging signal, and a second processing unit that relays data communication between each of the imaging unit and the external device and the first processing unit, the first processing unit comprises a processor that executes a program that generates the image data, which is data in a file format that can be processed by the external device, based on the imaging signal, and a memory in which the program is expanded, and the second processing unit receives power supply from the external device and has an external connection unit that outputs the image data generated by the first processing unit to the external device.

[0008] In the image acquisition device described in [1] above, the imaging unit is configured to automatically transition to a detectable state in which it can detect light in response to power supply from an external device. With this configuration, the imaging unit can automatically start the process of acquiring an imaging signal in response to the detection of light. In addition, the first processing unit of the control unit generates image data in a file format that can be processed by the external device based on the imaging signal acquired by the imaging unit. With this image acquisition device, the imaging start process (transition to a detectable state) and the image data generation process (generation of image data) can be performed autonomously without requiring detailed control from an external device. As a result, it is not necessary to install a device driver provided by the sensor manufacturer or the like that manufactures the image acquisition device on the external device, and a control program for executing the imaging start process and image data generation process described above using the functions of the device driver is also unnecessary. As a result, the development burden of software for using the image acquisition device can be reduced. Furthermore, in this image acquisition device, the imaging unit has an image sensor and a fiber optic plate. With this configuration, the image acquisition device can perform high-precision imaging of small objects or narrow areas. Therefore, with this image acquisition device, high-precision imaging of small objects or narrow areas can be automatically started.

[0009] [2] The image acquisition device according to [1], wherein the imaging unit includes a light detection unit that detects the light and outputs a detection signal, and a detection signal processing unit that generates the imaging signal based on the detection signal.

[0010] [3] The image acquisition apparatus according to [2], wherein the detection signal processing unit includes a single control circuit configured to generate the imaging signal based on the detection signal and output the imaging signal to the control unit.

[0011] According to the configuration described in [3] above, by having a single control circuit handle the operation control of the imaging unit, detailed operation control of the imaging unit can be achieved through that single control circuit.

[0012] [4] The image acquisition apparatus according to [2], wherein the detection signal processing unit includes a plurality of control circuits configured to generate the imaging signal based on the detection signal and output the imaging signal to the control unit.

[0013] According to the configuration described in [4] above, the degree of freedom in the physical configuration of the image acquisition device can be improved by dividing the control circuit that controls the operation of the imaging unit into multiple units.

[0014] [5] The image acquisition device according to any one of [2] to [4], wherein the light detection unit has an image sensor that includes an imaging pixel for detecting the light and outputting the detection signal, and a monitoring pixel for outputting a monitoring signal relating to the intensity of the light.

[0015] According to the configuration described in [5] above, charge accumulation by the imaging pixels can be automatically started at an appropriate timing based on the monitor signal. Furthermore, the exposure time of the imaging pixels can be automatically adjusted based on the monitor signal, and the total amount of light detected by the imaging pixels can be automatically adjusted. As a result, the imaging signal can be acquired automatically and accurately.

[0016] [6] The image acquisition device according to any one of [2] to [5], wherein the detection signal processing unit is connected to the second processing unit via USB communication.

[0017] According to the configuration described in [6] above, by connecting the control unit (second processing unit) and the imaging unit (detection signal processing unit) via USB communication, the independence of the circuits constituting the control unit (second processing unit) and the circuits constituting the imaging unit (detection signal processing unit) can be increased. As a result, the circuit configuration of the control unit can be flexibly changed without affecting the circuit configuration of the imaging unit.

[0018] [7] The image acquisition device according to any one of [2] to [5], wherein the detection signal processing unit is connected to the second processing unit via a data bus in a manner that enables communication.

[0019] According to the configuration described in [7] above, the control unit (second processing unit) and the detection signal processing unit can be formed on the same printed circuit board by data bus connection. This reduces the total number of components in the control unit and detection signal processing unit circuits, and also reduces the overall size of these circuits, compared to the case where the detection signal processing unit is connected to the second processing unit via USB communication.

[0020] [8] The image acquisition apparatus according to any one of [1] to [7], further comprising a non-volatile memory for storing the image data generated by the first processing unit, the second processing unit.

[0021] According to the configuration described in [8] above, it becomes possible to store the image data generated by the first processing unit in the non-volatile memory of the second processing unit. This makes it possible to acquire the image data on the image acquisition device from an external device at any time.

[0022] [9] The image acquisition device according to any one of [1] to [7], wherein the image data generated by the first processing unit is stored in the memory.

[0023] According to the configuration described in [9] above, by temporarily storing the image data generated by the first processing unit in high-speed memory (memory in which the program executed by the processor in the first processing unit is deployed), it becomes possible to access (read) the image data on the image acquisition device at high speed from an external device.

[0024]

[10] The image acquisition device according to any one of [1] to [9], wherein, in response to the commencement of power supply from the external device, the imaging unit transitions to the detectable state by executing a predetermined program that has been pre-installed.

[0025] According to the configuration described in

[10] above, the imaging unit autonomously starts processing to transition to a detectable state in response to power supply from an external device, thereby enabling a rapid transition to a detectable state.

[0026]

[11] The image acquisition apparatus according to

[10] , wherein the imaging unit operates based on power supplied to the imaging unit from the external device and then supplied to the second processing unit without being stored in the second processing unit.

[0027] According to the configuration described in

[11] above, the process of transitioning the imaging unit to a detectable state in response to power supply from an external device can be reliably executed. Furthermore, since the imaging unit automatically transitions to a detectable state in response to power supply from an external device, the image acquisition device can start imaging immediately when connected to the external device.

[0028]

[12] The image acquisition apparatus according to any one of [1] to

[11] , wherein the control unit moves the imaging unit to the detectable state in response to the commencement of power supply from the external device.

[0029] According to the configuration described in

[12] above, the reliability of the transition process can be improved by using the operation control from the control unit as the trigger for starting the transition process to a detectable state.

[0030]

[13] The image acquisition apparatus according to any one of [1] to

[12] , wherein the image sensor has a light-receiving surface, and the fiber optic plate includes an optical input surface formed by one end face of a plurality of optical fibers extending in a direction perpendicular to the light-receiving surface, and an optical output surface formed by the other end faces of the plurality of optical fibers, and the fiber optic plate is arranged on the image sensor such that the optical output surface faces the light-receiving surface.

[0031] According to the configuration described in

[13] above, compared to the case where each of the multiple optical fibers extends in a direction inclined with respect to the direction perpendicular to the light-receiving surface, the fiber optic plate can receive incident light at a wider angle, thereby increasing the amount of light incident on the light-receiving surface of the image sensor.

[0032]

[14] The image acquisition apparatus according to any one of [1] to

[12] , wherein the image sensor has a light-receiving surface, and the fiber optic plate includes an optical input surface formed by one end face of a plurality of optical fibers extending in a direction inclined with respect to the direction perpendicular to the light-receiving surface, and an optical output surface formed by the other end faces of the plurality of optical fibers, and the fiber optic plate is arranged on the image sensor such that the optical output surface faces the light-receiving surface.

[0033] According to the configuration described in

[14] above, each of the multiple optical fibers extends in a direction inclined with respect to the direction perpendicular to the light-receiving surface, thereby enabling the acquisition of image data in which information in a specific direction of the object being imaged is enhanced. This makes it easier to perform image processing on the image data (e.g., edge detection or pattern recognition). As a result, user convenience can be improved.

[0034]

[15] The image acquisition apparatus according to

[13] or

[14] , wherein the imaging unit further comprises a resin layer located between the light-receiving surface of the image sensor and the light-output surface of the fiber optic plate.

[0035] First, when the temperature changes in the image acquisition device, stress may occur between the image sensor and the fiber optic plate due to the difference in thermal expansion coefficients between the image sensor and the fiber optic plate. In this case, according to the configuration of

[15] above, the stress between the image sensor and the fiber optic plate can be relieved by the resin layer. This makes it possible to suppress the delamination of the fiber optic plate from the image sensor.

[0036] According to one aspect of this disclosure, the development burden for software used with the image acquisition device can be reduced.

[0037] This is a diagram illustrating the configuration of an intraoral imaging system equipped with an image acquisition device according to the first embodiment. This is a cross-sectional view of the imaging device shown in Figure 1. This is a diagram showing an example of the physical configuration of the intraoral imaging system shown in Figure 1. This is a diagram showing an example of the hardware configuration of the intraoral imaging system shown in Figure 1. This is a diagram showing an example of the hardware configuration of the image sensor and FPGA shown in Figure 4. This is a sequence diagram showing an example of the operation of the intraoral imaging device according to the first embodiment. This is a sequence diagram showing an example of the operation of the intraoral imaging device according to the first modified example. This is a diagram showing an example of the physical configuration of an intraoral imaging system equipped with an intraoral imaging device according to the second modified example. This is a diagram showing an example of the physical configuration of an intraoral imaging system equipped with an intraoral imaging device according to the third modified example. This is a diagram showing an example of the hardware configuration of the intraoral imaging system shown in Figure 9. This is a diagram showing an example of the hardware configuration of an intraoral imaging system equipped with an intraoral imaging device according to the fourth modified example. This is a diagram illustrating the configuration of an imaging system equipped with an image acquisition device according to the second embodiment. (a) is a diagram showing an example of the image sensor and fiber optic plate of the imaging unit shown in Figure 12, and (b) is a diagram showing another example of the image sensor and fiber optic plate of the imaging unit shown in Figure 12. This is a diagram showing an example of a part of the hardware configuration of the imaging system shown in Figure 12.

[0038] The first and second embodiments of this disclosure will be described in detail below with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference numerals, and redundant descriptions will be omitted. [Configuration of the intraoral imaging system of the first embodiment]

[0039] As shown in Figure 1, the intraoral imaging system 100 comprises an intraoral imaging device 1 (image acquisition device) and an external device 10. The intraoral imaging device 1 operates in connection with the external device 10. In the first embodiment, the intraoral imaging device 1 is electrically connected to the external device 10 and operates using power supplied from the external device 10. The intraoral imaging device 1 is used, for example, by an end user such as a dentist to obtain radiographic images of the oral cavity of a patient who is the subject of imaging. As an example, the end user can view and confirm the radiographic images (image data) retrieved from the intraoral imaging device 1 to the external device 10 on a display or the like provided by the external device 10, or link them with an application installed on the external device 10 (for example, an electronic medical record application).

[0040] The intraoral imaging device 1 comprises an imaging device 2, a control device 3, and two cables 4 and 5. The imaging device 2, when placed inside the patient's oral cavity, detects radiation (e.g., X-rays) that has passed through objects such as teeth. The control device 3, when placed outside the patient's oral cavity, controls the imaging device 2. The imaging device 2 is electrically connected to the control device 3 by cable 4. The imaging device 2 and the control device 3 transmit and receive signals (i.e., communicate) via cable 4. The control device 3 is electrically connected to an external device 10 by cable 5. The control device 3 and the external device 10 transmit and receive signals (i.e., communicate) via cable 5. Cables 4 and 5 are wired cables, for example, USB (Universal Serial Bus) cables. The external device 10 consists of devices such as a PC, tablet terminal, and smartphone. In the intraoral imaging system 100, when radiation transmitted through an object is detected by the imaging device 2, the control device 3 generates image data showing an image of the object (radiation-transmitted image) based on the resulting electrical signal, and this image data is output to the external device 10. The end user of the intraoral imaging device 1 (for example, a dentist) can perform diagnoses on patients by checking the image data extracted to the external device 10 in this way.

[0041] As shown in Figure 2, as an example, the imaging device 2 includes a wiring board 21, an image sensor 63, an FOP (Fiber Optic Plate) 23, a scintillator 24, and a case 25. The image sensor 63 is mounted on the wiring board 21. The image sensor 63 is a solid-state image sensor, such as a CMOS image sensor. The FOP 23 is placed on the image sensor 63. The scintillator 24 is placed on the FOP 23. A resin layer is provided between the image sensor 63 and the FOP 23. The case 25 houses the wiring board 21, the image sensor 63, the FOP 23, and the scintillator 24. Of the walls of the case 25, the wall portion 25a along the scintillator 24 is the wall portion where radiation is expected to be incident. The end of a cable 4 that penetrates the wall portion of the case 25 opposite to the wall portion 25a is electrically connected to the wiring board 21.

[0042] In the imaging device 2 configured as described above, when the case 25 is placed inside the oral cavity, radiation that has passed through the object passes through the wall portion 25a of the case 25 and enters the scintillator 24, fluorescence (scintillation light) corresponding to the intensity of the incident radiation is emitted from the scintillator 24. When this fluorescence is guided by the FOP 23 and enters the image sensor 63, a detection signal corresponding to the intensity of the incident fluorescence is generated in the image sensor 63, and this detection signal is transmitted to the control device 3 via the cable 4. In other words, the scintillator 24 converts radiation into scintillation light, and the image sensor 63 detects the scintillation light emitted from the scintillator 24 and outputs a detection signal. The image sensor 63 and the scintillator 24 correspond to the radiation conversion unit 6A, which will be described later.

[0043] As shown in Figures 3 and 4, the imaging device 2 and the control device 3 are composed of an imaging unit 6 and a control unit 7. The imaging unit 6 has a first unit 61 and a second unit 62. The imaging device 2 is composed of the first unit 61 of the imaging unit 6. The control device 3 is composed of the second unit 62 of the imaging unit 6 and the control unit 7. That is, the entire control unit 7 is located outside the patient's oral cavity. The first unit 61 and the second unit 62 of the imaging unit 6 are connected to each other so as to be able to communicate by a plurality of wires 81. The number of wires 81 is, for example, 2 to 8 (Figure 3 shows an example with 8 wires). The plurality of wires 81 are provided on a cable 4. The second unit 62 of the imaging unit 6 and the control unit 7 are connected to each other so as to be able to communicate by the wires 82. The control unit 7 and the external device 10 are connected to each other so as to be able to communicate by the wires 83. The wires 83 are provided on a cable 5. The imaging unit 6 and the control unit 7 operate on power supplied from the external device 10. Power from the external device 10 is supplied to the control unit 7 via wiring 83, and then supplied to the imaging unit 6 via wiring 82 and 81.

[0044] As shown in Figure 4, the imaging unit 6 includes a radiation conversion unit 6A (photodetection unit) that detects radiation (light) and outputs a detection signal, and a detection signal processing unit 6B that generates an imaging signal based on the detection signal. The first unit 61 of the imaging unit 6 includes an image sensor 63 (part of the radiation conversion unit 6A) and an FPGA 64 (first control circuit). The second unit 62 of the imaging unit 6 includes an FPGA 65 (second control circuit), a USB transceiver 66, and a frame memory 67. FPGAs 64 and 65, the USB transceiver 66, and the frame memory 67 correspond to the detection signal processing unit 6B. In other words, in the first embodiment, the detection signal processing unit 6B has multiple FPGAs 64 and 65 (multiple control circuits). Furthermore, the detection signal processing unit 6B includes a first part (FPGA 64 included in the first unit 61) that is placed inside the patient's oral cavity when the intraoral imaging device 1 is in use, and a second part (FPGA 65, USB transceiver 66, and frame memory 67 included in the second unit 62) that is placed outside the patient's oral cavity when the intraoral imaging device 1 is in use.

[0045] The FPGA 64 is connected to the image sensor 63 so as to be able to input and output signals via, for example, two sets of signal lines for transmitting an input differential signal and two sets of signal lines for transmitting an output differential signal (a total of eight signal lines). The FPGA 64 is connected to the FPGA 65 so as to be able to input and output information via, for example, two signal lines (wiring 81). Here, when the first unit 61 has only the image sensor 63 and the second unit 62 has a single FPGA, the number of wirings included in the cable 4 is, for example, eight, whereas when connecting the two FPGAs 64 and 65 as in the first embodiment, unnecessary wirings (for example, wirings for transmitting a clock signal for synchronization, etc.) when connecting the two FPGAs 64 and 65 can be omitted in the cable 4, so the number of wirings included in the cable 4 is, for example, two. Thus, according to the configuration of the first embodiment, the number of wirings included in the cable 4 can be reduced compared to the former case, so the cable 4 can be made thinner.

[0046] The FPGA 65 is connected to the FPGA 64, the frame memory 67, and the USB transceiver 66 so as to be able to input and output information. The USB transceiver 66 is a USB device configured to be able to communicate with the USB transceiver 77 of the second processing unit 7B (described later) in the control unit 7. That is, the detection signal processing unit 6B is connected to the second processing unit 7B so as to be able to communicate via USB communication.

[0047] The image sensor 63 executes a preset operation based on the digital signal and the clock input from the FPGA 64. The image sensor 63 outputs the detection signal generated as described above to the FPGA 64. For example, the image sensor 63 has an AD converter (not shown). The image sensor 63 converts the analog data read from the imaging pixel 63A or the monitor pixel 63B described later into a detection signal (digital data) using the AD converter, and outputs the detection signal to the FPGA 64. Note that the image sensor 63 may include, for example, an LVDS (Low Voltage Differential Signaling) unit, convert the detection signal into a differential voltage signal, and output it to the FPGA 64.

[0048] The FPGA 64 has a function of executing a program pre - incorporated therein. The FPGA 64 controls the image sensor 63 by inputting a digital signal (such as a signal indicating the start or end of imaging detection) and a clock to the image sensor 63 based on a program pre - incorporated in the FPGA 64 or a signal acquired from the FPGA 65. The FPGA 64 outputs the detection signal output from the image sensor 63 to the FPGA 65. For example, the FPGA 64 includes an LVDS (Low Voltage Differential Signaling) unit, converts the detection signal output from the image sensor 63 into a differential voltage signal, and outputs it to the FPGA 65.

[0049] The FPGA 65 has a function of executing a program pre - incorporated therein. As an example, the FPGA 65 may be mainly configured to execute a process of receiving data (imaging signal) from the FPGA 64 and not input data to the FPGA 64. The FPGA 65 outputs the imaging signal acquired from the FPGA 64 to the second processing unit 7B of the control unit 7 via the USB transceiver 66. The imaging signal transmitted from the FPGA 65 to the control unit 7 may be the same signal data as the detection signal output from the FPGA 64 to the FPGA 65, or may be signal data obtained by converting the detection signal in the FPGA 65.

[0050] The USB transceiver 66 has the function of sending and receiving information to and from the USB transceiver 77. The USB transceiver 66 is composed of at least one IC (Integrated Circuit).

[0051] The frame memory 67 has the function of acquiring imaging signals from the FPGA 65 and storing them temporarily. For example, if there is a delay in communication between the USB transceiver 66 and the USB transceiver 77, the frame memory 67 acquires imaging signals from the FPGA 65 and stores them temporarily. The frame memory 67 is, for example, a volatile memory.

[0052] As described above, the image sensor 63 generates a detection signal by detecting radiation that has passed through the object. The multiple FPGAs 64 and 65 are configured to generate imaging signals based on the detection signal and output the imaging signals to the control unit 7. In other words, the imaging unit 6 acquires imaging signals related to the object by detecting radiation that has passed through the object and outputs them to the control unit 7.

[0053] As shown in Figure 5, the image sensor 63 has a plurality of imaging pixels 63A and one or more monitoring pixels 63B. The plurality of imaging pixels 63A are pixels for detecting scintillation light and outputting a detection signal. The plurality of imaging pixels 63A are arranged, for example, in a two-dimensional manner and constitute a light detection area. The one or more monitoring pixels 63B are pixels for outputting a monitor signal regarding the intensity of the scintillation light. The one or more monitoring pixels 63B are arranged, for example, in a one-dimensional manner along the outer periphery of the plurality of imaging pixels 63A. Note that the one or more monitoring pixels 63B may be composed of a single pixel.

[0054] The FPGA 64 uses multiple imaging pixels 63A to perform imaging detection to detect radiation in order to acquire an image of an object, and obtains a detection signal. Specifically, when the FPGA 64 controls the image sensor 63 to perform imaging detection, each imaging pixel 63A converts the fluorescence emitted by the scintillator 24 due to the incidence of radiation into an electric charge and accumulates the charge. More specifically, the ASIC (Application Specific Integrated Circuit) (not shown) of the image sensor 63 outputs the charge accumulated in each imaging pixel 63A as a detection signal by switching the ON / OFF of switch SW1. Switch SW1 is a switch of the image sensor 63 and is connected to the imaging pixels 63A and the FPGA 64. Switch SW1 is composed of, for example, a transistor.

[0055] The FPGA 64 uses multiple monitor pixels 63B to perform monitoring detection to monitor the radiation dose and outputs a monitor signal. Specifically, when the FPGA 64 controls the image sensor 63 to perform monitoring detection, each monitor pixel 63B converts the fluorescence emitted by the scintillator 24 due to the incidence of radiation into an electric charge and accumulates the charge. More specifically, the ASIC of the image sensor 63 outputs the charge accumulated in each monitor pixel 63B as a monitor signal by switching the ON / OFF of switch SW2. Switch SW2 is a switch on the image sensor 63 and is connected to the monitor pixels 63B and the FPGA 64. Switch SW2 is composed of, for example, a transistor. As shown in Figure 5, in the first embodiment, as an example, the imaging pixel 63A and the monitor pixels 63B share an output line to the FPGA 64. In this case, the ASIC of the image sensor 63 can output an imaging signal from the imaging pixel 63A to the FPGA 64 by turning switch SW1 ON and switch SW2 OFF. On the other hand, the ASIC of the image sensor 63 can output a monitor signal from the monitor pixel 63B to the FPGA 64 by turning switch SW1 OFF and switch SW2 ON.

[0056] As shown in Figure 4, the control unit 7 generates image data of an object based on the imaging signal. The control unit 7 has a first processing unit 7A and a second processing unit 7B. The first processing unit 7A generates image data based on the imaging signal. The second processing unit 7B relays data communication between the imaging unit 6 and the external device 10 and the first processing unit 7A. The first processing unit 7A is the part that performs relatively high-speed data input / output processing, and the second processing unit 7B is the part that performs relatively low-speed data input / output processing. The first processing unit 7A and the second processing unit 7B are mounted on the same circuit board (printed circuit board). The first processing unit 7A has a processor 71 and a main memory 72 (memory). The second processing unit 7B has a southbridge 73, storage 74 (non-volatile memory), an RTC device 75, a battery 76, and a USB transceiver 77 (external connection part).

[0057] The processor 71, main memory 72, and southbridge 73 are connected to each other via a data bus so as to be able to communicate with one another. The storage 74 and USB transceiver 77 are connected to the southbridge 73 via a data bus so as to be able to communicate with one another. The USB transceiver 77 is connected to the USB transceiver 66 and the external device 10 so as to be able to communicate with each of them via USB communication. That is, the detection signal processing unit 6B (in the first embodiment, FPGA 64, FPGA 65, frame memory 67, and USB transceiver 66) is connected to the second processing unit 7B so as to be able to communicate with one another via USB communication. The RTC device 75 is connected to the southbridge 73 so as to be able to communicate with one another via a serial bus (for example, I2C (Inter-Integrated Circuit)). The battery 76 is configured to supply power to the RTC (Real Time Clock) device 75.

[0058] The processor 71 has the function of executing a predetermined program. For example, the processor 71 executes a predetermined program, such as a program for generating image data based on an imaging signal. The processor 71 may be composed of a CPU (Central Processing Unit), such as an x86 processor or an ARM processor. The processor 71 reads and executes a predetermined program loaded into the main memory 72. The processor 71 also temporarily stores the imaging signal that forms the basis of the image data, the image data generated from the imaging signal, etc., in the main memory 72. The main memory 72 is a volatile memory such as RAM (Random Access Memory).

[0059] Image data is data in a file format that can be processed by the external device 10. For example, image data is data expressed in one of several general-purpose image file formats predetermined for image information. Therefore, without performing any special conversion processing on the image data in the external device 10, the image represented by the image data can be displayed on a display or the like simply by performing a file execution operation on the image data in the external device 10. The file format of the image data is not limited to a specific format, but it is preferable, for example, to be an uncompressed format or a lossless compressed format so that processing by general imaging software can be easily performed. Specific examples of image data file formats include raster format data such as BMP (Bitmap), PNG (Portable Network Graphics), and TIFF (Tagged Image File Format). Alternatively, the image data may be data in a format other than raster format, such as vector format (for example, data with extensions such as SVG, AI, etc.). The file format of the image data generated by the first processing unit 7A may be set to a specific file format (for example, BMP, etc.), or it may be configured to be selectable from a plurality of file formats prepared in advance as compatible file formats.

[0060] The southbridge 73 has the function of controlling input / output that is slower than the input / output between the processor 71 and the main memory 72. For example, the southbridge 73 controls the input / output of information to the storage 74, the RTC device 75, and the USB transceiver 77.

[0061] Storage 74 is the part where data for permanent storage is stored. For example, storage 74 stores an operating system such as Linux®, imaging signals acquired from the imaging unit 6, image data generated by the processor 71, etc. Storage 74 is a non-volatile memory such as a general-purpose external memory card (e.g., microSD®).

[0062] The RTC device 75 holds time information indicating the current time. For example, the RTC device 75 can retain time information even when there is no power supply from the external device 10 by receiving power from the battery 76. This allows the processor 71 to assign an accurate timestamp to the generated image data.

[0063] The USB transceiver 77 has the function of sending and receiving information to and from the USB transceiver 66 and the external device 10. The USB transceiver 77 receives power from the external device 10 by being communicated with, for example, the external device 10. Based on instructions from the external device 10, the USB transceiver 77 outputs image data generated by the processor 71 to the external device 10. The USB transceiver 77 is composed of, for example, at least one or more ICs.

[0064] The control unit 7 (USB transceiver 77) operates as a USB host from the perspective of the imaging unit 6. The USB transceiver 77 acquires the imaging signal from the USB transceiver 66. Subsequently, the USB transceiver 77 outputs the imaging signal to the main memory 72 via the southbridge 73. Next, the processor 71 generates image data based on the imaging signal by loading a predetermined program into the main memory 72. Finally, the processor 71 stores the generated image data in the storage 74. In this way, the control unit 7 generates image data related to the object based on the imaging signal. On the other hand, the control unit 7 operates as a USB device (slave) from the perspective of the external device 10. For example, the external device 10 acquires image data from the storage 74 by recognizing the intraoral imaging device 1 as a single USB device (USB mass storage). [Imaging Process]

[0065] Referring to Figure 6, an example of the operation (imaging process) of the intraoral imaging device 1 will be described. As a premise, the imaging unit 6 is configured to automatically transition to a detectable state in which it is capable of detecting radiation that has passed through an object, in response to the power supply from the external device 10. As an example, the imaging unit 6 transitions to the detectable state by executing a predetermined program that has been pre-installed in response to the start of power supply from the external device 10. In the first embodiment, as an example, after the FPGA 64 has finished starting up with the power supplied from the external device 10, it starts the process of step S101 in Figure 6 by executing a pre-installed program. Thus, in the first embodiment, the predetermined program is composed of a program installed in the FPGA 64. In another form, a control signal instructing the FPGA 64 to execute the imaging start process may be transmitted from the FPGA 65 to the FPGA 64, and the FPGA 64, upon receiving the control signal, may start the process of step S101 in Figure 6. In this case, the predetermined program is composed of a plurality of programs installed in each of the FPGAs 64 and 65.

[0066] In step S101, the FPGA 64 (imaging unit 6) acquires information regarding the background of the monitor pixel 63B of the image sensor 63. The background is the charge accumulated and output in the monitor pixel 63B regardless of radiation emission, due to dark current, etc. In other words, the background is the charge output from the monitor pixel 63B even when no radiation is emitted. As an example, the ASIC of the image sensor 63 controls the monitor pixel 63B to periodically read the monitor signal with switch SW2 always set to ON during a predetermined period when no radiation is emitted, so that the FPGA 64 periodically acquires the monitor signal (i.e., the background described above) output from the monitor pixel 63B. The FPGA 64 calculates the statistical values ​​(e.g., mean, mode, etc.) and the standard deviation σ of each monitor signal (charge amount) acquired at multiple time points. In this way, the FPGA 64 grasps the background of the monitoring pixels 63B at the start of imaging (i.e., after the imaging unit 6 has finished starting up due to power supply from the external device 10, but before radiation is emitted), thereby preventing the accumulation of charge in the imaging pixels 63A from starting at the wrong timing (in a state where radiation that has actually passed through the object is not detected) due to fluctuations in the power supplied to the intraoral imaging device 1 and the afterglow of the scintillator 24 during processing from step S102 onward. As a result, the imaging unit 6 can detect radiation with greater accuracy.

[0067] In step S102, FPGA 64 sets a first threshold to prevent imaging from starting at the wrong timing due to the background effects described above. As an example, FPGA 64 determines the first threshold based on the statistical value and standard deviation σ calculated in step S101. For example, assuming that the intensity of the monitor signal output from monitor pixel 63B fluctuates according to a Gaussian distribution, FPGA 64 may set the first threshold to a value obtained by adding a predetermined value based on the standard deviation σ (for example, 6σ, which is six times the standard deviation σ) to the above statistical value.

[0068] In step S103, FPGA 64 determines whether or not to start accumulating charge in the imaging pixel 63A. For example, FPGA 64 acquires a monitor signal output from the monitoring pixel 63B at a predetermined period and determines whether or not the value of the monitor signal exceeds a first threshold. If the determination result in step S103 is "YES", FPGA 64 starts accumulating charge in the imaging pixel 63A (step S104). On the other hand, as long as the determination result in step S103 is "NO", FPGA 64 repeatedly executes the determination process in step S103 at a predetermined period.

[0069] The determination process in step S103 may be modified as follows. For example, FPGA 64 may determine the determination result in step S103 as "YES" if the monitor signal output from monitor pixel 63B exceeds the first threshold for a predetermined number of consecutive times (a predetermined period). In this case, it is possible to more reliably prevent the accumulation of charge in imaging pixel 63A from starting when the monitor signal temporarily exceeds the first threshold due to the sudden occurrence of electromagnetic noise, an unstable output value of the monitor signal immediately after the start of operation, etc.

[0070] In step S105, FPGA 64 determines whether or not to terminate the charge accumulation in the imaging pixel 63A. For example, FPGA 64 integrates the values ​​obtained by subtracting the background statistics calculated in step S101 from the monitor signals output from the monitoring pixel 63B after a certain point in time. FPGA 64 determines whether or not the integrated value (total dose of radiation) exceeds a preset second threshold. If the determination result in step S105 is "YES", FPGA 64 terminates the charge accumulation in the imaging pixel 63A (step S106). On the other hand, as long as the determination result in step S105 is "NO", FPGA 64 repeatedly executes the determination process in step S105 at a predetermined cycle.

[0071] In step S107, the ASIC of the image sensor 63 switches switches SW1 and SW2 (see Figure 5) so that switch SW1 is ON and switch SW2 is OFF, causing the FPGA 64 to read the detection signal (accumulated charge) from the imaging pixels 63A. The FPGA 64 generates an imaging signal based on the read detection signal. The imaging signal is signal data corresponding to the detection signal, which is an electrical signal corresponding to the charge accumulated in each imaging pixel 63A. In other words, the imaging signal is raw data (RAW data) relating to the radiographic image of the object. That is, the imaging signal is data in a preliminary stage to image data in a predetermined file format, and is data that cannot be handled as an image file by an external device 10 such as a PC in its current state.

[0072] In step S108, the imaging unit 6 transfers the imaging signal to the control unit 7. In the first embodiment, the imaging signal is transmitted from FPGA 64 to FPGA 65, and then from FPGA 65 to the control unit 7 (USB transceiver 77) via USB transceiver 66. As described above, if there is a delay in communication between USB transceivers 66 and 77, the imaging signal that was to be transmitted from FPGA 65 to the control unit 7 is temporarily stored in the frame memory 67. The imaging signal transmitted to the USB transceiver 77 is temporarily stored, for example, in the main memory 72.

[0073] In step S109, the control unit 7 (processor 71) corrects the imaging signal. As an example, the processor 71 corrects the imaging signal using correction information that has been stored in advance. Specific examples of such corrections include reversible corrections to the imaging signal (e.g., corrections for point defects, line defects, dark current, bias components, sensitivity non-uniformity, and linearity) or irreversible corrections (e.g., processing that irreversibly changes the image content, such as convolution processing like filtering (enhancement processing)). Although the correction processing in step S109 may be omitted, performing the correction processing is expected to result in clearer and lower-noise image data.

[0074] In step S110, the control unit 7 (processor 71) converts the imaging signal (or the corrected imaging signal if the correction process in step S109 is performed) into image data in a file format (for example, bitmap format) that can be processed by the external device 10. For example, the control unit 7 converts the imaging signal into image data in uncompressed or lossless compressed format. In step S111, the control unit 7 (processor 71) stores the generated image data in the storage 74. This makes it possible to access the storage 74 from the external device 10 and retrieve the image data. [Effects of the First Embodiment]

[0075] In the intraoral imaging device 1 described above, the imaging unit 6 is configured to automatically transition to a detectable state in response to power supply from the external device 10, enabling it to detect radiation transmitted through an object. With this configuration, the imaging unit 6 can automatically start the process of acquiring imaging signals related to the object (for example, the processes in steps S101 to S107 in Figure 6) in response to the detection of radiation transmitted through the object. Furthermore, the first processing unit 7A of the control unit 7 generates image data in a file format that can be processed by the external device 10 based on the imaging signals acquired by the imaging unit 6. The intraoral imaging device 1 can autonomously perform the imaging start process (transition to detectable state) and the image data generation process (generation of image data related to the object) without requiring detailed control from the external device 10. As a result, it is not necessary to install a device driver provided by the sensor manufacturer or the like that manufactures the intraoral imaging device 1 on the external device 10, nor is a control program required to execute the imaging start process and image data generation process described above using the functions of the device driver. Consequently, the development burden of software for using the intraoral imaging device 1 can be reduced. As a result of reducing the development burden on users (medical device manufacturers, etc.), users can focus on software development such as improving the user interface (user-friendliness, screen layout, etc.) and expanding the functionality of applications in order to enhance the convenience of end users (e.g., dentists, etc.). For example, users can focus on development related to image data processing (e.g., additional image processing, integration with electronic medical records, etc.) and display processing. Furthermore, by simply connecting the intraoral imaging device 1 to the external device 10, the intraoral imaging device 1 can perform imaging processing, and image data in a predetermined file format can be easily acquired from the external device 10. In this way, the intraoral imaging device 1 also enhances the convenience of end users.

[0076] Furthermore, with the intraoral imaging device 1, end users can easily obtain image data captured under appropriate imaging conditions (e.g., exposure conditions) without having to be concerned with the technical details and control of the hardware of the intraoral imaging system 100. In other words, end users can treat the intraoral imaging device 1 as if it were a smartphone camera.

[0077] In the intraoral imaging device 1, the imaging unit 6 includes a radiation conversion unit 6A that detects radiation and outputs a detection signal, and a detection signal processing unit 6B that generates an imaging signal based on the detection signal. In the first embodiment, the radiation conversion unit 6A includes a scintillator 24 that converts radiation into scintillation light, and an image sensor 63 that detects the scintillation light emitted from the scintillator 24 and outputs a detection signal. With the above configuration, when the image sensor 63 is an indirect conversion type image sensor, the development burden of software for using the intraoral imaging device 1 can be reduced.

[0078] In the intraoral imaging device 1, the image sensor 63 includes an imaging pixel 63A for detecting scintillation light and outputting a detection signal, and a monitoring pixel 63B for outputting a monitoring signal regarding the intensity of the scintillation light. With this configuration, the accumulation of charge by the imaging pixel 63A can be automatically started at an appropriate timing based on the monitoring signal. Furthermore, the exposure time of the imaging pixel 63A can be automatically adjusted based on the monitoring signal, and the total dose of radiation detected by the imaging pixel 63A can be automatically adjusted. As a result, imaging signals related to the target object can be acquired automatically and accurately.

[0079] In the intraoral imaging device 1, the detection signal processing unit 6B includes a plurality of control circuits (FPGA 64, 65) configured to generate an imaging signal based on the detection signal and output the imaging signal to the control unit 7. With the above configuration, by dividing the control circuits that control the operation of the imaging unit 6 into a plurality, the degree of freedom in the physical configuration of the intraoral imaging device 1 can be improved. For example, as in the first embodiment, by storing one control circuit (FPGA 64) in a first unit 61 located inside the oral cavity and the other control circuit (FPGA 65) in a second unit 62 located outside the oral cavity, it becomes possible to reduce the size of the part located inside the oral cavity (first unit 61).

[0080] In the intraoral imaging device 1, the detection signal processing unit 6B (USB transceiver 66) is connected to the second processing unit 7B (USB transceiver 77) via USB communication. With this configuration, by connecting the control unit 7 (second processing unit 7B) and the imaging unit 6 (detection signal processing unit 6B) via USB communication, the independence of the circuits constituting the control unit 7 (second processing unit 7B) and the circuits constituting the imaging unit 6 (detection signal processing unit 6B) can be increased. As a result, the circuit configuration of the control unit 7 can be flexibly changed without affecting the circuit configuration of the imaging unit 6. This reduces the cost of changing the circuit configuration of the control unit 7.

[0081] In the intraoral imaging device 1, the detection signal processing unit 6B has a first part (in the first embodiment, an FPGA 64 housed in the first unit 61) that is placed inside the patient's oral cavity when in use, and a second part (in the first embodiment, a second unit 62) that is placed outside the patient's oral cavity when in use. With this configuration, the size (thickness) of the first part of the detection signal processing unit 6B that is placed inside the oral cavity can be reduced compared to the case where the entire detection signal processing unit 6B is placed inside the oral cavity (see Figure 8). As a result, the burden on the patient who has to place a part of the intraoral imaging device 1 (in the first embodiment, the imaging device 2 shown in Figure 3) inside their oral cavity can be reduced. Furthermore, with this configuration, the number of circuit components mounted on the imaging device 2 can be reduced, so heat generation in the imaging device 2 can also be suppressed.

[0082] In the intraoral imaging device 1, the multiple control circuits in the detection signal processing unit 6B include an FPGA 64 and an FPGA 65 connected to FPGA 64. As described above, the detection signal processing unit 6B has a first part that is placed inside the patient's oral cavity during use and includes FPGA 64, and a second part that is placed outside the patient's oral cavity during use and includes FPGA 65. With the above configuration, by arranging FPGAs 64 and 65 in the first and second parts, the size of the first part placed inside the patient's oral cavity can be reduced compared to the case where both FPGAs 64 and 65 are housed in the first part. In addition, the cable 4 connecting the control circuits (FPGAs 64 and 65) can be made thinner than the cable required when a single control circuit is provided in the detection signal processing unit 6B and that control circuit is connected to the radiation conversion unit (the cable connecting the image sensor 63 and FPGA 68 in the example in Figure 11). For example, as described above, the cable 4, which includes two wires connecting the two FPGAs 64 and 65, is thinner than the cable, which includes eight wires connecting the image sensor 63 and a single FPGA. Therefore, by making the cable connecting the first part inside the oral cavity and the second part outside the oral cavity relatively thin, it becomes possible to easily position the first part inside the patient's oral cavity. In addition, the size of the first part placed inside the patient's oral cavity can be reduced, and the cable extending from inside to outside the patient's oral cavity can be made relatively thin, thus reducing the burden on the patient when using the intraoral imaging device 1.

[0083] In the intraoral imaging device 1, the entire control unit 7 is positioned outside the patient's oral cavity during use. With this configuration, the size of the portion of the intraoral imaging device 1 that is positioned inside the patient's oral cavity can be reduced.

[0084] In the intraoral imaging device 1, the second processing unit 7B includes a storage 74, which is a non-volatile memory for storing image data generated by the first processing unit 7A. With this configuration, it is possible to store the image data generated by the first processing unit 7A in the storage 74. This makes it possible to acquire image data from the intraoral imaging device 1 from an external device 10 at any time. For example, since the external device 10 can recognize the storage 74 as mass storage, the end user can easily acquire image data by recognizing the storage area of ​​the storage 74 as a folder and selecting the file (image data) stored in that folder. The process of transferring image data from the intraoral imaging device 1 (storage 74) to the external device 10 may be explicitly performed by the end user as described above, or it may be executed by a function of an application installed on the external device 10.

[0085] In the intraoral imaging device 1, when power is supplied from the external device 10, the imaging unit 6 (FPGA 64 in the first embodiment) executes a predetermined program that has been pre-programmed, thereby transitioning to a detectable state (for example, the state in which the processing from step S101 onwards in Figure 6 is executed). With the above configuration, since the imaging unit 6 autonomously starts the processing to transition to the detectable state in response to power supply from the external device 10, a rapid transition to the detectable state can be achieved. [Modified Example]

[0086] The first embodiment of this disclosure has been described above, but this disclosure is not limited to the configuration shown in the first embodiment. Furthermore, some of the configurations or processing details included in the first embodiment may be omitted or modified as appropriate, and other configurations or processing details may be added. Several modifications are described below. Note that the configurations of the first embodiment and the modifications described below may be combined as appropriate. (First Modification)

[0087] In the first embodiment described above, the imaging unit 6 autonomously performs a process to transition to a detectable state in response to power supply from the external device 10 (for example, the process from step S101 onwards in Figure 6). However, this process may also be triggered by operation control (control signal) from the control unit 7. That is, in response to the start of power supply from the external device 10, the control unit 7 (for example, the processor 71) may transition the imaging unit 6 to a detectable state. Referring to Figure 7, an example of the operation of the intraoral imaging device 1 according to the first modified example will be described.

[0088] In step S201, the control unit 7 (processor 71) transmits a control signal (monitor signal request) to the imaging unit 6 (FPGA 65) to request the imaging unit 6 to acquire a monitor signal, in response to the power supply from the external device 10. Upon receiving the monitor signal request, FPGA 65 instructs FPGA 64 to acquire the monitor signal by, for example, forwarding the monitor signal request as is to FPGA 64. Upon receiving this instruction, FPGA 64 acquires the monitor signal at a predetermined interval and transmits it to the control unit 7 via FPGA 65 (step S202). FPGA 64 repeatedly performs the monitor signal transmission process in step S202 at a predetermined interval until it receives a control signal (monitor signal acquisition stop request) transmitted from the control unit 7 in step S209, which will be described later.

[0089] In step S203, the control unit 7 calculates background statistics (e.g., mean, mode, etc.) and standard deviation σ by performing the same processing as in step S101 based on the monitor signal (information about the background) acquired from the imaging unit 6. Subsequently, in step S204, the control unit 7 determines the first threshold by performing the same processing as in step S102. Subsequently, in step S205, the control unit 7 performs the same determination processing as in step S103. If the determination result in step S205 is "YES", the control unit 7 transmits an instruction to the imaging unit 6 to start charge accumulation in the imaging pixel 63A (step S206). The above start instruction is transmitted to FPGA 64 via FPGA 65. Upon receiving the above start instruction, FPGA 64 starts charge accumulation by the imaging pixel 63A in the same manner as in step S104 (step S207). If the result of step S205 is "NO", the control unit 7 repeatedly executes the determination process of step S205 based on the monitor signal acquired from the imaging unit 6 at a predetermined interval.

[0090] In step S208, the control unit 7 determines whether or not to terminate the charge accumulation in the imaging pixel 63A by performing the same processing as in step S105 described above. If the determination result in step S208 is "YES", the control unit 7 sends a stop instruction to the imaging unit 6 to stop acquiring the monitor signal (step S209), and also sends an imaging signal request to the imaging unit 6 requesting that the charge accumulation by the imaging pixel 63A be terminated and an imaging signal be transmitted (step S210). In response to receiving the stop instruction in step S209, the FPGA 64 terminates the monitor signal transmission process (the process of acquiring a monitor signal at a predetermined period and transmitting it to the control unit 7). Also, in response to receiving the imaging signal request in step S210, the FPGA 64 terminates the charge accumulation in the imaging pixel 63A in the same way as in step S106 described above (step S211). Subsequently, in step S212, the FPGA 64 transmits an imaging signal to the control unit 7 by performing the same processing as in step S108 described above.

[0091] In steps S213 to S215, the control unit 7 performs the same processing as in steps S109 to S111 described above. As a result, similar to the first embodiment (Figure 6), image data in a file format that can be processed by the external device 10 is ultimately stored in the storage 74.

[0092] As described above, in the first modified example, when power supply from the external device 10 is started, the control unit 7 transmits an explicit control signal to the imaging unit 6, thereby transitioning the imaging unit 6 to a detectable state. With the above configuration, the reliability of the transition process can be increased by using the operation control from the control unit 7 (for example, step S201 in Figure 7) as the trigger for starting the transition process to the detectable state. Furthermore, by having the control unit 7 (processor 71) execute the detailed operation control for imaging (for example, steps S203, S204, S205, S206, S208, S209, S210, etc. in Figure 7) instead of the control circuit (FPGA 64, 65) of the detection signal processing unit 6B, the processing by the control circuit can be simplified. (Second Modified Example)

[0093] As shown in the second modified example in Figure 8, the entire detection signal processing unit 6B may be placed inside the patient's oral cavity during use. In the example shown in Figure 8, both the first unit 61 and the second unit 62 are provided on the imaging device 2. With this configuration, the entire detection signal processing unit 6B is incorporated into the module (imaging device 2) of the intraoral imaging device 1 that is placed inside the patient's oral cavity, thereby enabling the module to be configured as an independent intraoral sensor module. As a result, a flexible usage mode can be realized, such as using the module separately from the intraoral imaging device 1. For example, the imaging device 2 shown in Figure 8 can also be used as a USB-connected sensor module by being connected via a USB cable (cable 4) to a single computer device (for example, a computer device incorporating a device driver and control program for controlling the imaging device 2, as in the conventional method) that incorporates a processing program similar to that of the control unit 7 in the first embodiment. (Third Modified Example)

[0094] As shown in the third modified example in Figures 9 and 10, the second unit 62 and the control unit 7 of the imaging unit 6 may be configured by a single processing unit 9 (for example, a group of circuits mounted on the same printed circuit board). For example, the detection signal processing unit 6B (FPGA 65) may be connected to the second processing unit 7B (Southbridge 73) of the control unit 7 via a data bus 84 in a communicative manner.

[0095] According to the third modification, the control unit 7 (second processing unit 7B) and the detection signal processing unit 6B can be formed on the same printed circuit board by data bus connection. This reduces the total number of components in the control unit 7 and the detection signal processing unit 6B circuits, and also reduces the overall size of these circuits, compared to the case where the detection signal processing unit 6B (USB transceiver 66) is connected to the second processing unit 7B (USB transceiver 77) via USB communication (wiring 82) as in the first embodiment (see Figures 3 and 4) (i.e., the circuit board for the control unit 7 and the circuit board for the detection signal processing unit 6B are provided separately). (Fourth modification)

[0096] As shown in the fourth modified example in Figure 11, the detection signal processing unit 6B may have a single control circuit (FPGA 68). That is, in the first embodiment described above, the detection signal processing unit 6B had multiple (two) FPGAs 64 and 65, whereas in the example in Figure 11, the detection signal processing unit 6B has a single FPGA 68 that includes the functions of these FPGAs 64 and 65. The FPGA 68, like the FPGA 65, is connected to the USB transceiver 66 and the frame memory 67 so that information can be input and output. Also, like the FPGA 64, the FPGA 68 is connected to the image sensor 63 so that signals can be input and output, for example, via two sets of signal lines for transmitting input differential signals and two sets of signal lines for transmitting output differential signals.

[0097] According to the fourth modification, by assigning the operation control of the imaging unit 6 to a single control circuit (FPGA 68), detailed operation control of the imaging unit 6 can be realized via this single control circuit (FPGA 68). More specifically, in the first embodiment, FPGA 64, which executes specific imaging control in the imaging unit 6, was configured as a separate control circuit from FPGA 65, which receives direct commands from the processor 71. Therefore, in the first embodiment, it was difficult to flexibly change the processing content based on a program pre-installed in FPGA 64 through control from the processor 71. In contrast, as shown in Figure 11, by replacing the multiple FPGAs 64 and 65 of the first embodiment with a single FPGA 68, detailed control of FPGA 68 from the processor 71 (for example, changing shooting conditions, adding or modifying control content, etc.) becomes easily possible. (Other modifications)

[0098] In the first embodiment described above, the image data generated by the control unit 7 was stored in the storage 74. However, the image data only needs to be stored in a storage area accessible from the external device 10, and may be stored in a storage area other than the storage 74. For example, the image data may be stored in the main memory 72. As an example, the control unit 7 may make a part of the main memory 72 a virtual storage so that it can be accessed from the external device 10, and then store the image data in the virtual storage (which is actually the main memory 72). With the above configuration, by temporarily storing the image data generated by the first processing unit 7A in a high-speed memory (the main memory 72 where the program executed by the processor 71 in the first processing unit 7A is deployed), it becomes possible to access (read) the image data on the intraoral imaging device 1 at high speed from the external device 10.

[0099] Alternatively, the control unit 7 may, triggered by an instruction from the external device 10, transfer the generated image data (data temporarily stored in the main memory 72) to a storage area on the external device 10 (for example, a pre-specified folder).

[0100] In the first embodiment described above, the entire control unit 7 was located outside the oral cavity, but a part of the control unit 7 may be located inside the oral cavity. For example, in the second modified example shown in Figure 8, a part of the control unit 7 (i.e., a circuit configured to perform the functions of the part of the control unit 7 described above) may be stored inside the imaging device 2, which is placed inside the patient's oral cavity when in use.

[0101] In the first embodiment described above, the radiation conversion unit 6A included a scintillator 24 and an image sensor 63 that detects scintillation light emitted from the scintillator 24 and outputs a detection signal. However, the configuration of the radiation conversion unit 6A is not limited to this. For example, the radiation conversion unit 6A may include a radiation conversion member that converts radiation into electric charge and a pixel circuit that reads out the electric charge generated by the radiation conversion member as a detection signal. With the above configuration, in a configuration where the imaging unit 6 is a direct conversion type image sensor, the development burden of software for using the intraoral imaging device 1 can be reduced.

[0102] In the first embodiment described above, the intraoral imaging device 1 was configured to perform two processes, an imaging start process (automatic transition to a detectable state in response to power supply from the external device 10) and an image data generation process (a process that generates image data in a file format that can be processed by the external device 10), without requiring specific control from the external device 10. However, the intraoral imaging device 1 may be configured to perform only one of the imaging start process or the image data generation process.

[0103] For example, the intraoral imaging device 1 may be configured to perform an imaging start process, but not to perform an image data generation process. For instance, the intraoral imaging device 1 may not generate image data, and after the imaging signal is output to the external device 10, the external device 10 may perform a conversion process from the imaging signal to image data. In this case, although it is necessary to prepare a processing program for generating image data in the external device 10, it is not necessary to prepare a processing program for the imaging start process in the external device 10, thereby reducing the development burden of the software used to operate the intraoral imaging device 1.

[0104] Furthermore, the intraoral imaging device 1 may be configured to perform image data generation processing but not to perform imaging start processing. For example, the intraoral imaging device 1 may perform imaging start processing based on a control signal from an external device 10 (a control signal transmitted to the intraoral imaging device 1 when a processing program for performing imaging start processing is executed in the external device 10). In this case, although it is necessary to prepare a processing program for imaging start processing in the external device 10, it is not necessary to prepare a processing program for generating image data in the external device 10, thereby reducing the development burden of software for using the intraoral imaging device 1.

[0105] In the first embodiment described above, as shown in Figure 5, the imaging pixel 63A and the monitoring pixel 63B shared an output line to the FPGA 64. However, the output line of the imaging pixel 63A and the output line of the monitoring pixel 63B may each be configured as separate, independent output lines. In this case, the ASIC of the image sensor 63 can simultaneously output the imaging signal from the imaging pixel 63A and the monitoring signal from the monitoring pixel 63B.

[0106] In the first embodiment described above, the ASIC of the image sensor 63 controlled the monitor pixel 63B to periodically read the monitor signal with the switch SW2 always set to ON during a predetermined period when no radiation was being emitted. However, the monitor signal may be periodically output from the monitor pixel 63B by setting the switch SW2 to ON at a predetermined interval (i.e., periodically switching the switch SW2 between the ON state and the OFF state).

[0107] In the first embodiment and its various modifications described above, the second processing unit 7B has a southbridge 73, and the storage 74, RTC device 75, USB transceiver 77, and FPGA 65 are connected to the processor 71 via the southbridge 73, but this is not limited to this. For example, the second processing unit 7B does not have a southbridge 73. In this case, the storage 74, RTC device 75, USB transceiver 77, and FPGA 65 may be directly connected to the processor 71 via a serial bus.

[0108] In the first embodiment and its various modifications described above, the storage 74 stored the operating system, but it does not need to store the operating system.

[0109] In the third modified example described above, the processor 71, main memory 72, southbridge 73, storage 74, RTC device 75, and USB transceiver 77 were provided as separate components on a printed circuit board, but the invention is not limited to this. For example, a microcontroller having the functions of the processor 71, main memory 72, southbridge 73, storage 74, RTC device 75, and USB transceiver 77 may be provided on a printed circuit board. In this case, some of the blocks constituting the control unit 7 (processor 71, main memory 72, southbridge 73, storage 74, RTC device 75, and USB transceiver 77) are coupled together as a microcontroller. [Configuration of the imaging system in the second embodiment]

[0110] As shown in Figure 12, the imaging system 200 of the second embodiment comprises a plurality of image acquisition devices 201 and an external device 10. The plurality of image acquisition devices 201 are connected to and operate with the external device 10. In the second embodiment, the image acquisition devices 201 are electrically connected to the external device 10 and operate using power supplied from the external device 10. The image acquisition devices 201 generate an imaging signal by detecting light and generate image data based on the imaging signal. The image acquisition devices 201 transmit the image data to the external device 10. In the first embodiment, the light was, for example, radiation such as X-rays or gamma rays, but in the second embodiment, it is, for example, electromagnetic waves such as visible light, ultraviolet rays or infrared rays.

[0111] For example, the image acquisition device 201 is an optical encoder, and one example is a reflective encoder or a transmissive encoder. Also, for example, the image acquisition device 201 is a biosensing device, and one example is a nanohole array biosensing device, a monitoring device for imaging microorganisms, or a plant sensing device for imaging plants. Furthermore, for example, the image acquisition device 201 is a device for biometric authentication, and one example is a device for collecting palm prints or a device for measuring wrist vein patterns.

[0112] The image acquisition device 201 includes an imaging device 202, a control device 203, and two cables 4 and 5. The imaging device 202, like the imaging device 2 in the first embodiment, includes a wiring board 21, an image sensor 63, an FOP 23, and a case 25. However, unlike the imaging device 2 in the first embodiment, the imaging device 202 does not have a scintillator 24. The imaging device 202, like the imaging device 2 in the first embodiment, has a resin layer 26 located between the image sensor 63 and the FOP 23. Unlike the first embodiment, the wall portion 25a of the case 25 along the FOP 23 (see Figure 2) is a wall portion into which light is intended to enter. For example, the wall portion 25a is provided with a window portion through which light can pass (not shown). The control device 203 includes, for example, a microcontroller provided on a printed circuit board. The external device 10 recognizes a plurality of control devices 203 as existing USB class devices.

[0113] Figures 13(a) and 13(b) show an example of the image sensor 63, FOP 23, and resin layer 26 in the imaging device 202 of the second embodiment. The FOP 23, resin layer 26, and image sensor 63 are arranged in this order along direction A, starting from one side in direction A. Hereinafter, one side in direction A (the upper side in Figures 13(a) and 13(b)) will be simply referred to as "one side," and the other side in direction A (the lower side in Figures 13(a) and 13(b)) will be simply referred to as "the other side."

[0114] In the example shown in Figures 13(a) and 13(b), the image sensor 63 has a light-receiving surface 63a that extends in a direction perpendicular to direction A. That is, direction A is the direction perpendicular to the light-receiving surface 63a. Multiple pixels 63b are arranged on the light-receiving surface 63a along a direction B perpendicular to direction A. The FOP 23 is placed on the light-receiving surface 63a of the image sensor 63. For example, the FOP 23 is bonded to the light-receiving surface 63a of the image sensor 63 by an adhesive made of a resin-containing material. The resin layer 26 is formed when the adhesive hardens. The thickness of the image sensor 63 along direction A is greater than the thickness of the resin layer 26 along direction A, and less than the thickness of the FOP 23 along direction A. The thickness of the FOP 23 along direction A is greater than the sum of the thickness of the image sensor 63 along direction A and the thickness of the resin layer 26 along direction A.

[0115] The FOP 23 is composed of a bundle of multiple optical fibers 27. The multiple optical fibers 27 extend parallel to each other. The FOP 23 has an optical input surface 23a and an optical output surface 23b. The optical input surface 23a is one side surface of the FOP 23 and is composed of multiple end faces 27a of the multiple optical fibers 27. Light is incident on the optical input surface 23a of the FOP 23 along direction A. That is, direction A is the direction in which the light is incident. The optical output surface 23b is the other side surface of the FOP 23 and is composed of multiple other end faces 27b of the multiple optical fibers 27. The optical output surface 23b faces the light-receiving surface 63a of the image sensor 63 in direction A. The FOP 23 is formed, for example, in a rectangular prism shape or cylindrical shape having a center line parallel to direction A.

[0116] In the example shown in Figure 13(a), the multiple optical fibers 27 extend in direction A. The multiple optical fibers 27 extend parallel to each other. For example, one end face 27a of an optical fiber 27 overlaps with the other end face 27b of the optical fiber 27 when viewed from direction A. In the example shown in Figure 13(b), the multiple optical fibers 27 extend in a direction inclined with respect to direction A. The multiple optical fibers 27 are inclined to one side in a direction parallel to the plane of the paper with respect to direction A. For example, one end face 27a and the other end face 27b of an optical fiber 27 are aligned along a direction perpendicular to direction A (a direction perpendicular to direction A and parallel to the plane of the paper in Figure 13(b)) when viewed from direction A. The outer diameter of the optical fiber 27 in a cross section perpendicular to the direction of extension of the optical fiber 27 is smaller than the width of the pixels 63b along direction B, which is the arrangement direction of the multiple pixels 63b. For example, the outer diameter of the optical fiber 27 in a cross section perpendicular to the direction of extension of the optical fiber 27 is less than or equal to half the width of the pixels 63b along direction B. Furthermore, the maximum outer diameter of the other end face 27b of the optical fiber 27 is smaller than the width of the pixel 63b along direction B. For example, the maximum outer diameter of the other end face 27b is less than or equal to half the width of the pixel 63b along direction B.

[0117] In the imaging device 202 configured as described above, light passes through a window provided in the wall portion 25a of the case 25 and enters the FOP 23 (see Figure 2). When the light is guided by the FOP 23 and enters the image sensor 63, a detection signal corresponding to the intensity of the incident light is generated in the image sensor 63, and this detection signal is transmitted to the control device 203 via the cable 4. In other words, the image sensor 63 detects the light and outputs a detection signal. The image sensor 63 corresponds to the light detection unit 206A, which will be described later.

[0118] Figure 14 shows an example of a part of the hardware configuration of the imaging system 200. The imaging device 202 and control device 203 shown in Figure 12 are composed of the imaging unit 206 and control unit 7 shown in Figure 14. The imaging unit 206 generates an imaging signal by detecting light. The control unit 7 generates image data based on the imaging signal. As shown in Figure 14, unlike the imaging unit 6 of the first embodiment, the imaging unit 206 has a light detection unit 206A that detects light and outputs a detection signal instead of a radiation conversion unit 6A. The light detection unit 206A is an image sensor 63. The image sensor 63 has a plurality of imaging pixels 63A and one or more monitoring pixels 63B (see Figure 5). The plurality of imaging pixels 63A are pixels for detecting light and outputting a detection signal. The one or more monitoring pixels 63B are pixels for outputting a monitoring signal related to the intensity of light.

[0119] The first unit 261 of the imaging unit 206 includes an image sensor 63 (light detection unit 206A) and an FPGA 64. The second unit 62 of the imaging unit 206 includes an FPGA 65, a USB transceiver 66, and a frame memory 67. In other words, in the second embodiment, the detection signal processing unit 6B has a plurality of FPGAs 64, 65 (a plurality of control circuits). The detection signal processing unit 6B (in the second embodiment, FPGAs 64, 65, frame memory 67, and USB transceiver 66) is connected to the second processing unit 7B via USB communication.

[0120] The control unit 7, like in the first embodiment, has a first processing unit 7A and a second processing unit 7B. Each block constituting the control unit 7 (processor 71, main memory 72, southbridge 73, storage 74, RTC device 75, and USB transceiver 77) is coupled together as a microcontroller.

[0121] An example of the operation (imaging process) of the image acquisition device 201 will be described. The imaging unit 206 is configured to automatically transition to a detectable state in which it is capable of detecting light in response to the power supply from the external device 10. As an example, the imaging unit 206, similar to the imaging unit 6 of the first embodiment, transitions to a detectable state by executing a predetermined program that is pre-installed in response to the start of power supply from the external device 10. For example, the image acquisition device 201 performs the processing of steps S101 to S110 shown in Figure 6, similar to the intraoral imaging device 1 of the first embodiment.

[0122] Furthermore, similar to the imaging unit 6 in the first modified example, the process for the imaging unit 206 to transition to a detectable state may be triggered by operation control (control signal) from the control unit 7. That is, in response to the start of power supply from the external device 10, the control unit 7 (for example, the processor 71) may transition the imaging unit 206 to a detectable state. For example, the image acquisition device 201 may perform the processes of steps S201 to S215 shown in Figure 7, similar to the intraoral imaging device 1 in the first modified example. [Effects of the second embodiment]

[0123] In the image acquisition device 201 according to the second embodiment, the device is configured to automatically transition to a detectable state in which light can be detected in response to power supply from the external device 10. With this configuration, the imaging unit 206 can automatically start the process of acquiring an imaging signal in response to the detection of light (for example, the same process as steps S101 to S107 in Figure 6). In addition, the first processing unit 7A of the control unit 7 generates image data in a file format that can be processed by the external device 10 based on the imaging signal acquired by the imaging unit 206. The image acquisition device 201 can autonomously execute the imaging start process (transition to a detectable state) and the image data generation process (generation of image data related to the target object) without requiring detailed control from the external device 10. As a result, it is not necessary to install a device driver provided by a sensor manufacturer or the like that manufactures the image acquisition device 201 on the external device 10, and a control program for executing the above-mentioned imaging start process and image data generation process using the functions of the device driver is also not required. As a result, the development burden of software for using the image acquisition device 201 can be reduced. As a result of reducing the development burden on users (equipment manufacturers, etc.), users can focus on software development such as improving the user interface (user-friendliness, screen layout, etc.) and expanding the functionality of applications in order to enhance the convenience of end users (e.g., engineers, researchers, and quality control personnel, etc.). For example, users can focus on development related to image data processing (e.g., additional image processing) and display processing. Furthermore, by simply connecting the image acquisition device 201 to the external device 10, the image acquisition device 201 can be made to perform imaging processing, and image data in a predetermined file format can be easily acquired from the external device 10. In this way, the image acquisition device 201 also enhances the convenience of end users. Moreover, in the image acquisition device 201, the imaging unit 206 has an image sensor 63 and an FOP 23. With this configuration, the image acquisition device 201 can perform high-precision imaging of small objects or narrow areas. Therefore, the image acquisition device 201 can automatically start high-precision imaging of small objects or narrow areas.

[0124] The above effects will be explained in detail. First, in industrial or academic applications, it is sometimes necessary to image small objects or narrow areas with high precision. In this case, it is common practice to develop a control program for each image acquisition device and for the customer to install and use this control program on an external device such as a PC. If not only the control program but also the external device such as a PC is developed as a dedicated product for the image acquisition device, then the external device becomes a device specialized for industrial or academic applications. However, such an external device often lacks user-friendliness, unlike products used by general consumers (for example, digital cameras developed for general consumers). In contrast, according to one aspect of this disclosure, it is possible to provide an image acquisition device that can improve user-friendliness while being specialized for industrial or academic applications.

[0125] In the image acquisition device 201, the imaging unit 206 operates using power supplied in real time from the external device 10, without relying on energy storage by a storage element (such as a battery, secondary battery, or supercapacitor) in the second processing unit. More specifically, the imaging unit 206 operates based on power supplied from the external device 10 to the second processing unit 7B, and then supplied to the imaging unit 206 without being stored in the second processing unit 7B. Therefore, the imaging unit 206 operates solely on power supplied from the external device 10, without receiving power from the battery of the image acquisition device 201. With this configuration, the process of transitioning the imaging unit 206 to a detectable state in response to power supply from the external device 10 can be reliably executed. Furthermore, since the imaging unit 206 automatically transitions to a detectable state in response to power supply from the external device 10, the image acquisition device 201 can immediately start imaging when connected to the external device 10.

[0126] In the image acquisition device 201, the light detection unit 206A has an image sensor 63 that includes an imaging pixel 63A for detecting light and outputting a detection signal, and a monitor pixel 63B for outputting a monitor signal related to the intensity of light. In this case, the accumulation of charge by the imaging pixel 63A can be automatically started at an appropriate timing based on the monitor signal. Furthermore, the exposure time of the imaging pixel 63A can be automatically adjusted based on the monitor signal, and the total amount of light detected by the imaging pixel 63A can be automatically adjusted. As a result, the imaging signal can be acquired automatically and accurately.

[0127] In the image acquisition device 201, the image sensor 63 has a light-receiving surface 63a, and the FOP 23 includes an optical input surface 23a formed by one end face 27a of a plurality of optical fibers 27 extending in direction A (a direction perpendicular to the light-receiving surface 63a), and an optical output surface 23b formed by the other end faces 27b of the plurality of optical fibers 27, and the optical output surface 23b is positioned on the image sensor 63 so as to face the light-receiving surface 63a. In this case, compared to the case where each of the plurality of optical fibers 27 extends in a direction inclined with respect to direction A (as shown in Figure 13(b)), the FOP 23 can receive incident light at a wider angle, so that the amount of light incident on the light-receiving surface 63a of the image sensor 63 can be increased. In addition, the sensitivity of the imaging unit 206 to light propagating along direction A is improved, so the effect of stray light on the imaging unit 206 can be suppressed.

[0128] In the image acquisition device 201, the image sensor 63 has a light-receiving surface 63a, and the FOP 23 includes an optical input surface 23a formed by one end face 27a of a plurality of optical fibers 27 extending in a direction inclined with respect to direction A (a direction perpendicular to the light-receiving surface 63a), and an optical output surface 23b formed by the other end faces 27b of the plurality of optical fibers 27, and the optical output surface 23b may be arranged on the image sensor 63 so as to face the light-receiving surface 63a. In this case, since each of the plurality of optical fibers 27 extends in a direction inclined with respect to direction A, it is possible to obtain image data in which information in a specific direction of the object to be imaged is emphasized. This makes it easier to perform image processing (e.g., edge detection or pattern recognition) on the image data. As a result, user convenience can be improved.

[0129] In the image acquisition device 201, the imaging unit 206 further includes a resin layer 26 located between the light-receiving surface 63a of the image sensor 63 and the light-output surface 23b of the FOP 23. First, when the temperature changes in the image acquisition device 201, stress may be generated between the image sensor 63 and the FOP 23 due to the difference in thermal expansion coefficients between them. In this case, the stress between the image sensor 63 and the FOP 23 can be relieved by the resin layer 26. This suppresses the peeling of the FOP 23 from the image sensor 63. Also, in the above case, since there is no air layer between the light-output surface 23b of the FOP 23 and the light-receiving surface 63a of the image sensor 63, it is possible to suppress the reflection of light incident from the FOP 23 to the imaging unit 206 between the FOP 23 and the imaging unit 206.

[0130] In the image acquisition device 201, when power supply from the external device 10 is initiated, the imaging unit 206 (FPGA 64 in the second embodiment) executes a predetermined program that has been pre-installed, thereby transitioning to a detectable state (for example, a state in which processing similar to the processing from step S101 onwards in Figure 6 is performed). With the above configuration, since the imaging unit 206 autonomously starts processing to transition to the detectable state in response to power supply from the external device 10, a rapid transition to the detectable state can be achieved.

[0131] In the image acquisition device 201, the control unit 7 may transmit an explicit control signal to the imaging unit 206 in response to the start of power supply from the external device 10, thereby transitioning the imaging unit 206 to a detectable state. With the above configuration, the reliability of the transition process can be increased by using the operation control from the control unit 7 (for example, step S201 in Figure 7) as the trigger for starting the transition process to the detectable state. Furthermore, by having the control unit 7 (processor 71) execute detailed operation controls for imaging (for example, steps S203, S204, S205, S206, S208, S209, S210, etc. in Figure 7) instead of the control circuits (FPGA 64, 65) of the detection signal processing unit 6B, the processing by the control circuits can be simplified.

[0132] In the second embodiment, the image acquisition device 201 performed the processes of steps S101 to S110 shown in Figure 6, or the processes of steps S201 to S215 shown in Figure 7, but is not limited thereto. The image acquisition device 201 may perform various known imaging processes.

[0133] In the second embodiment, the imaging unit 206 and the control unit 7 are configured as separate modules. This allows the imaging unit 206 to be easily positioned in a confined space (for example, inside a patient's oral cavity), thereby improving user convenience. On the other hand, unlike the second embodiment, the imaging unit 206 and the control unit 7 may be integrated as a single module.

[0134] In the second embodiment, similar to the example shown in Figure 10, the second unit 62 and the control unit 7 of the imaging unit 206 may be configured by a single processing unit 9 (for example, a group of circuits mounted on the same printed circuit board). For example, the detection signal processing unit 6B (FPGA 65) may be connected to the second processing unit 7B (Southbridge 73) of the control unit 7 via a data bus 84 in a communicative manner.

[0135] In the second embodiment, similar to the example shown in Figure 11, the detection signal processing unit 6B may have a single control circuit (FPGA 68). That is, in the second embodiment, the detection signal processing unit 6B had multiple (two) FPGAs 64 and 65, but as shown in Figure 11, the detection signal processing unit 6B may have a single FPGA 68 that includes the functions of these FPGAs 64 and 65.

[0136] In the second embodiment, the image data generated by the control unit 7 was stored in the storage 74 (non-volatile memory). However, the image data only needs to be stored in a storage area accessible from the external device 10, and may be stored in a storage area other than the storage 74. For example, the image data may be stored in the main memory 72.

[0137] In the second embodiment, the external device 10 is composed of, for example, a PC, a tablet terminal, and a smartphone, but is not limited thereto. The external device 10 can be any device capable of supplying power to the image acquisition device 201. For example, the external device 10 may be a device other than a PC, a tablet terminal, and a smartphone, and may be an electronic device equipped with a computer.

[0138] In the second embodiment, the image sensor 63 had a plurality of imaging pixels 63A and one or more monitoring pixels 63B, but is not limited to this. For example, the image sensor 63 may have only a plurality of imaging pixels 63A. In this case, the image acquisition device 201 may not perform the processes of steps S101 to S103 shown in Figure 6, but instead perform the processes of steps S104 to S111. Also, the image acquisition device 201 may not perform the processes of steps S201 to S205 and S209 shown in Figure 7, but instead perform the processes of S206 to S208 and S210 to S215. In these cases, the image acquisition device 201 may terminate the charge accumulation in the imaging pixels 63A if it determines in steps S105 and S106 or steps S208 and S211 that a predetermined time has elapsed since the start of charge accumulation in the imaging pixels 63A. This allows the image acquisition device 201 to capture images at a predetermined cycle.

[0139] In the first and second embodiments, the imaging unit 6,206 had a resin layer 26 located between the image sensor 63 and the FOP 23, but is not limited to this. For example, the imaging unit 6,206 may have an optical film material located between the image sensor 63 and the FOP 23.

[0140] 1...Intraoral imaging device (image acquisition device), 6, 206...Imaging unit, 6A...Radiation conversion unit, 6B...Detection signal processing unit, 7...Control unit, 7A...First processing unit, 7B...Second processing unit, 10...External device, 23...FOP, 23a...Optical input surface, 23b...Optical output surface, 24...Scintillator, 26...Resin layer, 27...Multiple optical fibers, 27a...One end surface, 27b...Other end surface, 63...Image sensor, 63a...Light receiving surface, 63A...Imaging pixel, 63B...Monitor pixel, 64...FPGA (First control circuit), 65...FPGA (Second control circuit), 71...Processor, 72...Main memory (memory), 74...Storage (non-volatile memory), 77...USB transceiver (external connection unit), 201...Image acquisition device, 206A...Light detection unit, A...Direction (direction perpendicular to the light receiving surface).

Claims

1. An image acquisition device that operates in connection with an external device, comprising: an imaging unit that acquires an imaging signal by detecting light; and a control unit that generates image data based on the imaging signal, wherein the imaging unit is configured to automatically transition to a detectable state in which it is capable of detecting light in response to power supply from the external device, the imaging unit comprises an image sensor and a fiber optic plate disposed on the image sensor, the control unit comprises a first processing unit that generates the image data based on the imaging signal, and a second processing unit that relays data communication between the imaging unit and the external device and the first processing unit, the first processing unit comprises a processor that executes a program that generates the image data, which is data in a file format that can be processed by the external device, based on the imaging signal, and a memory in which the program is expanded, and the second processing unit receives power supply from the external device and has an external connection unit that outputs the image data generated by the first processing unit to the external device.

2. The image acquisition apparatus according to claim 1, wherein the imaging unit comprises a light detection unit that detects the light and outputs a detection signal, and a detection signal processing unit that generates the imaging signal based on the detection signal.

3. The image acquisition apparatus according to claim 2, wherein the detection signal processing unit includes a single control circuit configured to generate the imaging signal based on the detection signal and output the imaging signal to the control unit.

4. The image acquisition apparatus according to claim 2, wherein the detection signal processing unit includes a plurality of control circuits configured to generate the imaging signal based on the detection signal and output the imaging signal to the control unit.

5. The image acquisition apparatus according to any one of claims 2 to 4, wherein the light detection unit has an image sensor including an imaging pixel for detecting the light and outputting the detection signal, and a monitoring pixel for outputting a monitoring signal relating to the intensity of the light.

6. The image acquisition apparatus according to any one of claims 2 to 5, wherein the detection signal processing unit is communicated with the second processing unit via USB communication.

7. The image acquisition apparatus according to any one of claims 2 to 5, wherein the detection signal processing unit is communicated with the second processing unit via a data bus.

8. The image acquisition apparatus according to any one of claims 1 to 7, wherein the second processing unit further includes a non-volatile memory for storing the image data generated by the first processing unit.

9. The image acquisition apparatus according to any one of claims 1 to 7, wherein the image data generated by the first processing unit is stored in the memory.

10. The image acquisition apparatus according to any one of claims 1 to 9, wherein, in response to the commencement of power supply from the external device, the imaging unit transitions to the detectable state by executing a predetermined program that has been pre-installed.

11. The image acquisition apparatus according to claim 10, wherein the imaging unit operates based on power supplied to the imaging unit from the external device and then not stored in the second processing unit.

12. The image acquisition apparatus according to any one of claims 1 to 11, wherein the control unit moves the imaging unit to the detectable state in response to the commencement of power supply from the external device.

13. The image acquisition apparatus according to any one of claims 1 to 12, wherein the image sensor has a light-receiving surface, and the fiber optic plate includes an optical input surface formed by one end face of a plurality of optical fibers extending in a direction perpendicular to the light-receiving surface, and an optical output surface formed by the other end faces of the plurality of optical fibers, and the optical output surface is arranged on the image sensor such that it faces the light-receiving surface.

14. The image acquisition apparatus according to any one of claims 1 to 12, wherein the image sensor has a light-receiving surface, and the fiber optic plate includes an optical input surface formed by one end face of a plurality of optical fibers extending in a direction inclined with respect to the direction perpendicular to the light-receiving surface, and an optical output surface formed by the other end faces of the plurality of optical fibers, and the optical output surface is arranged on the image sensor such that it faces the light-receiving surface.

15. The image acquisition apparatus according to claim 13 or 14, wherein the imaging unit further comprises a resin layer located between the light-receiving surface of the image sensor and the light-output surface of the fiber optic plate.

Images