Radiographic system

Abstract

To reliably prevent a risk that imaging is started in a state where a frame rate not compatible with at least one of a radiation imaging apparatus and a radiation generating apparatus is set when the radiation generating apparatus performs imaging irradiation of radiation a smaller number of times than a predetermined number of times while the radiation imaging apparatus repeats storage and reading of electric charge a predetermined number of times.SOLUTION: A radiation imaging system: first acquisition means capable of acquiring an irradiation frame rate; second acquisition means capable of acquiring an imaging frame rate; determination means for determining whether or not the irradiation frame rate acquired by the first acquisition means is N times (N is an integer of 1 or more) the imaging frame rate acquired by the second acquisition means; and indication means for indicating a determination result given by the determination means in a form that can be identified by a photographer, or output means for outputting the determination result.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to , release a radiation imaging system into .

Background Art

[0002] In a radiation imaging system including a radiation generator capable of generating radiation and a radiation image capturing device capable of generating a radiation image based on the received radiation, and capable of capturing a dynamic image with a series of a plurality of radiation images as each frame, in recent years, there has emerged a device that can switch to a desired frame rate for imaging from among a plurality of different frame rates. For example, Patent Document 1 describes a technique for performing imaging in a state where the frame rate is lowered compared to normal by irradiating radiation a smaller number of times than a predetermined number (skipping some radiation) while the radiation image capturing device repeats charge accumulation and readout a predetermined number of times. Patent Document 1 also describes performing control of radiation irradiation and accumulation / readout by a control unit and using an interpolated image generated at a timing when radiation was not irradiated for correction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, before starting radiography, a radiation image capturing apparatus needs to perform reset, warm-up, etc. Therefore, in order to obtain a stable image by sufficiently performing reset, warm-up, etc., it is required to set the time from when an instruction to start radiography (irradiation of radiation) is given until the imaging operation starts to a time suitable for the imaging mode of radiography.

[0005] The present invention aims to Set the time from when the irradiation of radiation is instructed until the imaging operation starts to a more suitable time achieve the following.

Means for Solving the Problems

[0006] To solve the above problems, the radiation imaging system according to the present invention is capable of still image shooting and dynamic shooting for repeatedly shooting a plurality of still images, and a delay time, which is the time from pressing an irradiation instruction switch for instructing irradiation of radiation until the shooting operation starts, is different between the still image shooting and the dynamic shooting Moreover, the delay time during the dynamic imaging, which requires more time for warm-up and / or reset operation in the imaging apparatus than during the still image imaging, is longer than the delay time during the still image imaging. .

Advantages of the Invention

[0007] According to the present invention, Set the time from when the irradiation of radiation is instructed until the imaging operation starts to a more suitable time this can be achieved.

Brief Description of the Drawings

[0008] [Figure 1] It is a block diagram showing a radiation imaging system according to the prior art 1. [Figure 2] It is a block diagram of a radiation imaging system according to the first embodiment of the present invention. [Figure 3] It is a block diagram of a radiation image capturing device included in the radiation imaging system of FIG. 2. [Figure 4] It is a ladder chart showing the initial stage of the operation of the radiation imaging system of FIG. 2. [Figure 5] It is a ladder chart showing the middle stage of the operation of the radiation imaging system of FIG. 2. [Figure 6] It is a ladder chart showing the later stage of the operation of the radiation imaging system of FIG. 2. [Figure 7] It is a table showing the correspondence between a radiation image capturing device and a radiation generating device connectable to the radiation imaging system of FIG. 2 and the frame rates corresponding thereto. [Figure 8] It is an example of a display screen of a display unit of a console included in the radiation imaging system of FIG. 2. [Figure 9] It is an example of a display screen of a display unit of a console included in the radiation imaging system of FIG. 2. [Figure 10] It is an example of a display screen of a display unit of a console included in the radiation imaging system of FIG. 2. [Figure 11] It is a timing chart showing the operation of the radiographic system of FIG. 2. [Figure 12] It is a block diagram showing a radiographic system according to the prior art 2. [Figure 13] It is a block diagram showing a radiographic system according to the second embodiment of the present invention. [Figure 14] It is a ladder chart showing the initial stage of the operation of the radiographic system of FIG. 13. [Figure 15] It is a ladder chart showing the middle stage of the operation of the radiographic system of FIG. 13. [Figure 16] It is a ladder chart showing the latter stage of the operation of the radiographic system of FIG. 13. [Figure 17] It is a state transition diagram for explaining the state transition of the radiographic system of FIG. 2 or FIG. 13. [Figure 18] It is a timing chart showing the operation of the radiographic system of FIG. 2 or FIG. 13. [Figure 19] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 20] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 21] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 22] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 23] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 24] It is a timing chart showing the operation of the radiographic system according to the examples of the first and second embodiments. [Figure 25] It is a schematic diagram showing a imaging method using the radiographic system according to the examples of the first and second embodiments. [Figure 26] A table showing the steady-state values after performing recursive processing on a dynamic image captured using the radiation imaging system according to the examples of the first and second embodiments. [Figure 27] A block diagram showing a configuration example in the case of including a plurality of constituent devices in the radiation imaging system according to the first and second embodiments. [Embodiments for Carrying Out the Invention]

[0009] Hereinafter, embodiments of the present invention and the conventional technology on which they are based will be described with reference to the drawings. However, the technical scope of the present invention is not limited to what is illustrated in the following description of the embodiments and the drawings. Here, the conventional technology 1 on which the first embodiment is based, the first embodiment, the conventional technology 2 on which the second embodiment is based, and the second embodiment will be described in this order.

[0010] [Conventional Technology 1] First, the conventional technology 1 on which the system 100 (details will be described later) according to the first embodiment of the present invention is based will be described with reference to FIG. 1.

[0011] [System Configuration] First, the schematic configuration of the radiation imaging system according to the conventional technology 1 (hereinafter referred to as the conventional system 100A) will be described. FIG. 1 is a block diagram showing the conventional system 100A.

[0012] The conventional system 100A includes, for example, as shown in FIG. 1, a radiation control unit 11, a high voltage generation unit 12, a radiation generation unit 2, a cassette 3A, a radiation control console 41, and an irradiation instruction switch 5, and is configured to be able to perform static image shooting in which the radiation irradiation timing and the shooting timing are not interlocked, such as a radiation imaging film or CR. In FIG. 1, the case where the radiation control unit 11 and the high voltage generation unit 12 both constitute the radiation control device 1 (for example, stored in one housing) is illustrated, but the radiation control unit 11 and the high voltage generation unit 12 can also have an independent configuration, for example, arranged in different housings. The radiation control unit 11, the high voltage generation unit 12, and the radiation generation unit 2 constitute a radiation generation device (hereinafter referred to as the generation device) in the present invention.

[0013] The radiation control unit 11 is for controlling radiation irradiation. Specifically, based on detecting that the irradiation preparation signal from the radiation control console 41 has become ON, the radiation control unit 11 can turn ON the irradiation preparation signal output to the high voltage generation unit 12 or make it in a state where it can be output to other external devices. Also, based on detecting that the irradiation instruction signal (the first signal in the present invention) for instructing radiation irradiation from the radiation control console 41 has become ON, the radiation control unit 11 can make this irradiation instruction signal in a state where it can be output to external devices, and can transmit an irradiation signal corresponding to the imaging conditions set by the radiation control console 41 to the high voltage generation unit 12.

[0014] The irradiation preparation signal and irradiation instruction signal that can be output from this radiation control unit 11 to external devices are used, for example, when an external device is connected to the radiation control unit 11. With this irradiation preparation signal and irradiation instruction signal, in imaging that requires preparation of external devices other than the cassette 3A during radiation irradiation, the external devices can perform imaging preparation based on the irradiation preparation signal and irradiation instruction signal output from the radiation control unit 11. Examples of such external devices include a grid swing device provided on the radiation incident surface of the cassette 3A and used to swing the grid during imaging.

[0015] Among the above-described external devices, some are configured to transmit an irradiation permission signal to the radiation control unit 11 after completion of imaging preparation. Therefore, the radiation control unit 11 can be provided with a connection part for inputting the irradiation permission signal from the external device, and can be configured to transmit the irradiation signal to the high voltage generation unit 12 only when both the irradiation instruction signal from the radiation control console 41 and the irradiation permission signal from the external device are ON. In this way, since the irradiation permission signal is not input to the radiation control unit 11 until the imaging preparation of the external device is completed, it is possible to prevent radiation from being irradiated before the imaging preparation of the external device is completed.

[0016] For example, when the external device is the aforementioned grid swing device, the grid swing device can be configured to start swinging and, after reaching the specified swing speed, an irradiation permission signal is input from the grid swing device to the radiation control unit 11. In this way, the radiation control unit 11 outputs the irradiation signal only when both the irradiation instruction signal from the irradiation instruction switch 5 based on the operator's operation and the irradiation permission signal from the external device are available, so it is possible to prevent radiation from being irradiated before the preparation of the external device is completed.

[0017] On the other hand, when it is not desired to use the irradiation permission signal from the external device in the radiation control unit 11, for example, it is necessary to invalidate the irradiation permission signal or keep the irradiation permission signal in the ON or OFF state continuously. For example, when the radiation control unit 11 is configured to be able to switch whether to use the irradiation permission signal from the external device in determining whether to output the irradiation signal, it can also be invalidated by switching so as not to use it in the determination. On the other hand, when such switching is not possible, for example, when the irradiation permission signal is configured to be indicated by the open or close of two signal lines, the two signal lines are always kept open or closed, so that the irradiation permission signal is always kept in the ON or OFF state.

[0018] Also, the radiation control unit 11 can be configured not to transmit the irradiation signal even when it detects that the irradiation instruction signal has become ON until a predetermined waiting time has elapsed after detecting that the irradiation preparation signal has become ON. In this way, in the case where the high-voltage generation unit 12 and the radiation generation unit are configured such that it takes a certain amount of time to prepare after detecting that the irradiation preparation signal has become ON, it is possible to prevent radiation from being irradiated when the irradiation preparation is not yet complete.

[0019] The high-voltage generation unit 12 is configured to be able to output an irradiation preparation output to the radiation generation unit 2 based on detecting that the irradiation preparation signal from the radiation control unit 11 has become ON. Further, the high-voltage generation unit 12 is configured to be able to apply, as an irradiation output, a high voltage (corresponding to the input irradiation signal) necessary for the radiation generation unit 2 to generate radiation to the radiation generation unit 2 based on receiving an irradiation signal from the radiation control unit 11. In FIG. 1, an example of a configuration is illustrated in which when the high-voltage generation unit 12 detects that the irradiation preparation signal from the radiation control unit 11 has become ON, the high-voltage generation unit 12 outputs an irradiation preparation output to the radiation generation unit 2. However, a configuration may also be adopted in which the radiation control unit 11 directly outputs an irradiation preparation signal to the radiation generation unit 2, and the radiation generation unit 2 converts it into an irradiation preparation output to perform irradiation preparation.

[0020] The radiation generation unit 2 (radiation tube) is configured to be able to generate radiation (for example, X-rays) corresponding to the high voltage applied from the high-voltage generation unit 12, and includes, for example, an electron gun and an anode. Specifically, when a high voltage is applied, the electron gun irradiates the anode with an electron beam, and the anode generates radiation by receiving the electron beam. Note that when radiation is being generated, the part of the anode that receives the electron beam generates heat and becomes high in temperature. Therefore, in order to stably irradiate radiation, it is necessary to continuously change the position on the anode where the electron beam is irradiated. Thus, in some cases, a configuration using a rotating anode that irradiates the electron beam while rotating the anode is adopted. The above-described irradiation preparation output from the high-voltage generation unit 12 can be used, for example, as an instruction to start the rotation of the rotating anode.

[0021] Cassette 3A stores a radiation film or a fluorescent plate, and when the radiation that has passed through the subject is incident, it is capable of forming a radiation image of the subject.

[0022] The radiation control console 41 is configured to be able to set information about the subject and imaging conditions (tube voltage, tube current, irradiation time, etc.) in the radiation control unit 11 using an information signal connection. Note that the radiation control console 41 may be able to communicate with a higher-level system 7 (such as a Radiology Information System (RIS), a Picture Archiving and Communication System (PACS), etc., see FIGS. 4 and 14) via an external communication network N such as a hospital LAN.

[0023] The irradiation instruction switch 5 is for the operator to instruct radiation irradiation. The irradiation instruction switch 5 in this embodiment is configured to enable two-step operation. Specifically, when the first stage is pressed, the irradiation preparation signal output to the radiation control console 41 is turned on, and when the second stage is pressed, the irradiation instruction signal output to the radiation control console 41 can be turned on. In FIG. 1, an example is shown in which the irradiation instruction switch 5 is connected to the radiation control console 41, and the irradiation preparation signal and irradiation instruction signal output by the irradiation instruction switch 5 are input to the radiation control unit 11 via the radiation control console 41. However, the irradiation instruction switch 5 may be connected to the radiation control unit 11 so that the irradiation preparation signal and irradiation instruction signal are directly input to the radiation control unit 11.

[0024] [Operation] Next, the operation of the above conventional system 100A will be described.

[0025] (Irradiation preparation operation) When the first stage of the irradiation instruction switch 5 is pressed by the photographer, the irradiation instruction switch 5 turns on the irradiation preparation signal output to the radiation control unit 11 via the radiation control console 41. When the radiation control unit 11 detects that the irradiation preparation signal has turned on, it turns on the irradiation preparation signal output to the high-voltage generation unit 12 and makes it possible to output the irradiation preparation signal to external devices. When the high-voltage generation unit 12 detects that the irradiation preparation signal has turned on, it outputs the irradiation preparation output to the radiation generation unit 2.

[0026] When the irradiation preparation output is input to the radiation generation unit 2, the radiation generation unit 2 starts preparations for generating radiation. This preparation for generating radiation refers to operations such as rotating the rotating anode when the anode is a rotating anode.

[0027] (Irradiation operation) Subsequently, when the second stage of the irradiation instruction switch is pressed by the photographer, the irradiation instruction switch 5 turns on the irradiation instruction signal output to the radiation control unit 11 via the radiation control console 41. When the radiation control unit 11 detects that the irradiation instruction signal has turned on, it makes it possible to output this irradiation instruction signal to external devices and transmits the irradiation signal to the high-voltage generation unit 12. When the radiation control unit 11 is configured to determine the permissibility of radiation irradiation based on the irradiation permission signal from the external device, the irradiation instruction signal from the irradiation instruction switch 5 or the radiation control console 41 is ON, and when the irradiation permission signal is received from the external device, the irradiation signal is transmitted to the high-voltage generation unit 12.

[0028] When the high-voltage generation unit 12 receives the irradiation signal, it applies the high voltage required for radiation irradiation in the radiation generation unit 2 to the radiation generation unit 2 (performs irradiation output). When a high voltage is applied to the radiation generation unit 2 from the high-voltage generation unit 12, the radiation generation unit 2 generates radiation corresponding to the applied voltage. The generated radiation is adjusted in terms of the irradiation direction, area, beam quality, etc. by a controller such as a collimator (not shown) and is irradiated onto the subject and the cassette 3A behind it. A part of the radiation passes through the subject and enters the cassette 3A. When radiation enters the cassette 3A, a radiation image is formed on the stored film or fluorescent plate.

[0029] Here, if the timing to turn on the above-described irradiation preparation signal and irradiation instruction signal is close, for example, irradiation may be performed before the rotation of the rotating anode of the radiation generation unit 2 reaches a sufficient speed, and a local part of the rotating anode may be overheated, resulting in damage to the rotating anode or instability of the radiation dose to be irradiated (insufficient or excessive with respect to the irradiation intensity of the electron beam, etc.). However, if the radiation control unit 11 is configured not to transmit the irradiation signal even when it detects that the irradiation instruction signal has become ON until a predetermined waiting time has elapsed after detecting that the irradiation preparation signal has become ON as described above, such problems can be prevented.

[0030] Thus, in the radiation imaging using the conventional system 100A, only one radiation image (still image) of the subject is taken based on one imaging operation.

[0031] <First Embodiment> Next, the first embodiment of the present invention will be described with reference to FIGS. 2 to 11. The same reference numerals are given to the configurations equivalent to the above-described prior art 1, and the description thereof will be omitted.

[0032] [System Configuration] First, the system configuration of the radiation imaging system (hereinafter, system 100) according to the present embodiment will be described. FIG. 2 is a block diagram showing the system 100, and FIG. 3 is a block diagram of the imaging device 3.

[0033] As shown in FIG. 2 for example, the system 100 according to this embodiment replaces the cassette 3A of the conventional system 100A with a radiation imaging device (hereinafter referred to as imaging device 3), and further includes an imaging device control console 42 and an additional device 6. Note that a plurality of generating devices may be connected to the system 100. In such a case, any one of them may be selected and used. Similarly, a plurality of imaging devices 3 may be connected to the system 100. In such a case, any one of them may be selected and used.

[0034] An example of the system 100 in which such a plurality of generating devices and a plurality of imaging devices 3 are installed is shown in FIG. 27. In the example of the system 100 shown in FIG. 27, a lying position imaging table 8A and a standing position imaging table 8B are installed one by one in an imaging room (not shown), and a generating device (A) and a generating device (B) are installed mainly to correspond to those imaging. The imaging device (A) is mainly installed on the lying position imaging table 8A, and the imaging device (B) is installed on the standing position imaging table 8B. The lying position imaging table 8A and the standing position imaging table 8B are each configured to be able to accommodate the imaging device 3 in a changeable manner. Separately from them, in the imaging room, an imaging device (C) for performing partial imaging of, for example, hands and feet without using an imaging table is installed. When using the imaging device (C), for example, it may be placed on the lying position imaging table 8A and imaging may be performed using the generating device (A), or imaging may be performed by changing the irradiation direction of the radiation generating unit (B). Also, the console 4 and each of the plurality of devices (radiation control devices 1, 1A and additional devices 6, 6A) may be connected via a communication device 9 as shown in FIG. 27, or may be connected via a communication network N.

[0035] With such a configuration, for example, in the shooting of still images, when there are no restrictions on the shootable size in particular, it is possible to suppress the replacement of the imaging device 3 and the movement of the radiation generating unit 2 to a minimum and perform shooting efficiently. However, for example, when the shooting size or shooting resolution of each imaging device 3 does not match the shooting technique to be performed, the imaging devices (A), (B), and (C) will be replaced and shooting will be performed respectively.

[0036] The imaging device 3 according to this embodiment includes, in addition to a housing and a scintillator (not shown), as shown in FIG. 3, a shooting control unit 31, a radiation detection unit 32, a scanning drive unit 33, a reading unit 34, a storage unit 35, a communication unit 36, etc. And each of the units 31 to 36 is adapted to receive power supply from the battery 37.

[0037] The housing is provided with a power switch, a changeover switch, an indicator (not shown), a connector 36b of the communication unit 36 to be described later, etc. The scintillator is adapted to emit an electromagnetic wave having a longer wavelength than radiation such as visible light when receiving radiation.

[0038] The shooting control unit 31 is composed of a computer in which a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output interface, etc. (not shown) are connected to a bus, an FPGA (Field Programmable Gate Array), etc. Note that it may be composed of a dedicated control circuit.

[0039] The radiation detection unit 32 is for generating charges by receiving radiation, and is composed of a substrate 32a, a plurality of scanning lines 32b, a plurality of signal lines 32c, a plurality of radiation detection elements 32d, a plurality of switch elements 32e, a plurality of bias lines 32f, a power supply circuit 32g, etc. The substrate 32a is formed in a plate shape and arranged to face the scintillator in parallel. The plurality of scanning lines 32b are provided so as to extend parallel to each other at a predetermined interval. The plurality of signal lines 32c are provided so as to extend orthogonal to the scanning lines 32b, extend parallel to each other at a predetermined interval, and not conduct with each scanning line. That is, a plurality of scanning lines 32b and signal lines 32c are provided so as to form a grid.

[0040] The radiation detection element 32d generates an electrical signal (current, charge) corresponding to the dose of radiation (or the amount of light of the electromagnetic wave converted by the scintillator) irradiated to the radiation detection element, and is composed of, for example, a photodiode, a phototransistor, etc. The plurality of radiation detection elements 32d are provided on the surface of the substrate 32a, respectively, within a plurality of regions partitioned by the plurality of scanning lines 32b and signal lines 32c. That is, the plurality of radiation detection elements 32d are arranged in a matrix (row and column) form. For this reason, each radiation detection element 32d will face the scintillator respectively. To one terminal of each radiation detection element 32d, the drain terminal of the switch element 32e which is a switch element is connected, and to the other terminal, a bias line is connected respectively.

[0041] The plurality of switch elements 32e are provided in the plurality of regions partitioned by the plurality of scanning lines 32b and signal lines 32c respectively, similar to the radiation detection element 32d. Each switch element 32e is connected to the scanning line 32b close to the gate electrode, the signal line 32c close to the source electrode, and one terminal of the radiation detection element 32d in the same region for the drain electrode respectively.

[0042] The plurality of bias lines 32f are connected to the other terminal of each radiation detection element 32d. The power supply circuit 32g generates a reverse bias voltage and applies the reverse bias voltage to each radiation detection element via the bias line 32f.

[0043] The scanning drive unit 33 is composed of a power supply circuit 33a, a gate driver 33b, etc. The power supply circuit 33a generates an on voltage and an off voltage with different voltages respectively, and supplies them to the gate driver 33b. The gate driver 33b is configured to switch the voltage applied to each scanning line 32b between an on voltage and an off voltage.

[0044] The readout unit 34 includes a plurality of readout circuits 34a, an analog multiplexer 34b, an A / D converter 34c, and the like. The plurality of readout circuits 34a are each connected to each signal line 32c of the radiation detection unit 32 and are configured to apply a reference voltage to each signal line 32c. Each readout circuit 34a is composed of an integration circuit 34d, a correlated double sampling circuit (hereinafter referred to as a CDS circuit) 34e, and the like.

[0045] The integration circuit 34d integrates the charge released to the signal line 32c and outputs a voltage value corresponding to the integrated charge amount to the CDS circuit 34e. The CDS circuit 34e samples and holds the output voltage of the integration circuit 34d before applying an on voltage to the scanning line 32b to which the radiation detection element 32d to be read is connected (while an off voltage is applied), reads the signal charge of the radiation detection element by applying an on voltage to the corresponding scanning line 32b, and outputs the difference between the output voltage of the integration circuit 34d after applying an off voltage to the corresponding scanning line 32b.

[0046] The analog multiplexer 34b is configured to output the plurality of differential signals output from the CDS circuit 34e to the A / D converter 34c one by one. The A / D converter 34c is configured to sequentially convert the input analog voltage value of the image data into digital value image data.

[0047] The storage unit 35 is composed of an SRAM (Static RAM), an SDRAM (Synchronous DRAM), a NAND type flash memory, an HDD (Hard Disk Drive), and the like.

[0048] The communication unit 36 includes an antenna 36a and a connector 36b for communicating with the outside. In addition, the communication unit 36 can select whether to perform wireless communication or wired communication based on an external control signal. That is, when wireless communication is selected, wireless communication using the antenna 36a is performed, and when wired communication is selected, information can be transmitted and received by using a wired LAN or the like. Further, when it is desired to perform synchronization using wired communication, for example, synchronization can be performed by using a protocol such as NTP (Network Time Protocol) or a method defined in the international standard IEEE1588.

[0049] When the power of the imaging device 3 configured as described above is turned on, it takes one of the states of "initialization state", "accumulation state", and "readout / transfer state". The timing for switching the state will be described later. The "initialization state" is a state in which an on-voltage is applied to each switch element 32e, and the charges generated by the radiation detection element 32d are not accumulated in each pixel (the charges are discharged to the signal line 32c). The "accumulation state" is a state in which an off-voltage is applied to each switch element 32e, and the charges generated by the radiation detection element 32d can be accumulated in the pixel (the charges are not discharged to the signal line 32c). The "readout / transfer state" is a state in which an on-voltage is applied to each switch element 32e, and the readout unit 34 is driven to read out image data based on the flowing-in charges and transmit it to another device. Note that depending on the configuration of the element and the device, since the charges accumulated by the readout are cleared, there may be a case where "readout" and "initialization" are not distinguished as separate operations, and "readout" and "initialization" are performed simultaneously as the same operation.

[0050] Here, a so-called indirect type that converts the emitted radiation into electromagnetic waves of other wavelengths such as visible light to obtain an electrical signal is described as an example, but the present invention may be a so-called direct type imaging device that directly converts radiation into an electrical signal by a detection element. Moreover, regarding other configurations of the imaging device 3, as long as it is possible to generate image data of a radiation image, it is not necessary to be limited to those illustrated in FIG. 3.

[0051] As shown in FIG. 2, the imaging device control console 42 is configured to be able to transmit and receive information signals with the radiation control console 41 and set information about the subject, imaging conditions, etc. to the imaging device 3. Note that the radiation control console 41 sets the settings of the radiation control unit 11, and the imaging device control console 42 sets the settings of the imaging device 3. Since both of these perform settings related to the same imaging, in the following description, these may be collectively referred to as the console 4 in a broad sense. Also, the console 4, together with the additional device 6, constitutes the radiation generation control system in the present invention.

[0052] Also, in FIG. 2, when settings such as imaging conditions are set by the imaging device control console 42, it is illustrated that the settings are made to the radiation control unit 11 via the radiation control console 41 (the radiation control console 41 and the imaging device control console 42 transmit and receive information signals). However, it is also possible to configure to directly set the radiation control unit 11 from the imaging device control console 42. Also, it is possible to configure to set the imaging device 3 from the radiation control console 41. Also, in FIG. 2, a configuration in which the console 4 is connected to the imaging device 3 via the additional device 6 is illustrated. However, the console 4 can be directly connected to the imaging device 3 or can also be connected to the imaging device 3 via a communication network N, for example, as shown in FIG. 2.

[0053] Also, the console 4 can set the operation of the additional device 6. Specifically, it is possible to set the additional device 6 with the number of output times (maximum number of imaging) of the irradiation permission signal or the output time for repeating the output of the irradiation permission signal until the additional device 6 outputs the irradiation permission signal (the third signal in the present invention).

[0054] In addition, the console 4 may be provided with a display unit 43, and the output frequency or output time set for the additional device 6 may be displayed on the display unit 43. Further, when the imaging start signal (the second signal in the present invention, details will be described later) input to the additional device 6 becomes ON, the console 4 may be configured to display on the display unit 43 that irradiation is possible. Further, while the additional device 6 is outputting an irradiation permission signal, the console 4 may be configured to display on the display unit 43 that radiation is being irradiated.

[0055] The additional device 6 is a radiation generation control device in the present invention, and includes an additional control unit 61 having a first acquisition unit 62, a second acquisition unit 63, a first connection unit 64, and a second connection unit 65.

[0056] The additional control unit 61 can be configured to comprehensively control the operations of the respective parts of the additional device 6 using a CPU, RAM, etc. In this case, various processing programs stored in a storage unit (not shown) are read out and expanded in the RAM, and various processes are executed according to the processing programs.

[0057] The first acquisition unit 62 forms a contact point (for example, a connector) with the radiation control unit 11, and in the present embodiment, is configured to acquire the irradiation preparation signal output by the irradiation instruction switch 5 via the radiation control unit 11 (the generator).

[0058] The second acquisition unit 63 forms a contact point (for example, a connector) with the radiation control unit 11, and in the present embodiment, is configured to acquire the irradiation instruction signal output by the irradiation instruction switch 5 via the radiation control unit 11 (the generator). As described above, since the irradiation instruction signal corresponds to the first signal in the present invention, the second acquisition unit 63 forms the acquisition unit in the present invention.

[0059] The first connection unit 64 forms a contact point (for example, a connector) with the imaging device 3, and is capable of inputting an irradiation start signal. Note that since the irradiation start signal turns ON when the imaging device 3 becomes capable of imaging and turns OFF when it becomes incapable of imaging, it is a signal indicating the driving state of the imaging device 3 in the present invention.

[0060] In the present embodiment, the second connection portion 65 is a connector, and it can be connected to the radiation control portion 11 (generating device) by inserting the other end of a cable whose one end is connected to the radiation control portion 11 (generating device). And it is possible to output an irradiation permission signal to the radiation control portion 11.

[0061] In FIG. 2, a configuration is illustrated in which the first acquisition portion 62, the second acquisition portion 63, the first connection portion 64, and the second connection portion 65 directly transmit and receive information and signals with other devices (the second acquisition portion 63 and the second connection portion 65 are the radiation control device 1, and the first connection portion 64 is the imaging device 3). However, at least any one of the first acquisition portion 62, the second acquisition portion 63, the first connection portion 64, and the second connection portion 65 may be connectable to other devices via a relay portion (not shown) capable of relaying signals. Also, in FIG. 2, a case where the first acquisition portion 62, the second acquisition portion 63, the first connection portion 64, and the second connection portion 65 are provided separately is illustrated. However, at least two of the first acquisition portion 62, the second acquisition portion 63, the first connection portion 64, and the second connection portion 65 may be integrally configured (each of the portions 62 to 65 may be used in common).

[0062] Based on the irradiation instruction signal acquired from the radiation control portion 11 via the second acquisition portion 63 and the irradiation start signal input from the imaging device 3 via the first connection portion 64, the additional control portion 61 of the additional device 6 configured as described above can repeatedly output a pulsed irradiation permission signal for instructing radiation irradiation from the second connection portion 65 to the radiation control portion 11 at a predetermined cycle. Note that the additional control portion 61 may be configured not to output an irradiation permission signal even if it detects that the imaging start signal has become ON until a predetermined standby time has elapsed after detecting that the irradiation start signal has become ON.

[0063] Further, the additional control unit 61 is configured to output a timing signal (the fourth signal in the present invention) for instructing the imaging timing of the radiation image from the first connection unit 64 to the imaging device 3 based on the timing when the irradiation permission signal is output. The imaging timing is, for example, the timing to start the charge accumulation operation of the radiation image. That is, the imaging device 3 according to the present embodiment starts the charge accumulation in accordance with the timing signal, and sequentially performs operations such as the end of the accumulation, the reading of the charge of each pixel, the imaging of the charge of each pixel, and the storage and transfer of the image by the timing means of the imaging device 3. By such control, the additional control unit 61 can control both the timing of radiation irradiation by the irradiation permission signal and the accumulation timing for accumulating charges during radiation irradiation by the timing signal. As a result, the charges due to radiation irradiation can be reliably accumulated, and thus an image due to radiation irradiation can be reliably acquired.

[0064] When the start of the charge accumulation operation is set to the above imaging timing in this way, the imaging device 3 may wait in a state where it can shift to the accumulation timing corresponding to the imaging operation by radiation irradiation, and start the accumulation operation in accordance with the timing signal. By such control, the additional control unit 61 can reliably acquire an image due to radiation irradiation as in the above case.

[0065] Further, the imaging timing triggered by the input of this timing signal can be set to the timing to start any of various operations repeatedly performed by the imaging device 3 other than the above charge accumulation operation. For example, when it is necessary to reset the charges accumulated in each pixel before the accumulation operation, the timing to start the reset may be set to the above imaging timing. In this case, the imaging device 3 may be configured to sequentially shift to the accumulation operation after the reset is completed. By performing such control, it becomes possible to enter the accumulation operation of accumulating charges by radiation irradiation in a state where dark charges, which are noise components accumulated over time before the accumulation of charges by radiation irradiation in each pixel, are released by reset, and it becomes possible to acquire an image with less noise.

[0066] Alternatively, the timing to end the accumulation operation may be set as the above-described shooting timing. Alternatively, the timing to start reading the charges accumulated by the timing signal may be set as the above-described shooting timing. By performing such control, the additional control unit 61 can control both the timing of radiation irradiation by the irradiation permission signal and the timing to end the accumulation of charges by radiation irradiation or the timing to read the charges accumulated by radiation irradiation by the timing signal. As a result, it is possible to surely accumulate the charges by radiation irradiation, and thus it is possible to surely acquire an image by radiation irradiation.

[0067] Note that the timing signal may be used at the end of each operation instead of the start. For example, the accumulation operation may be started in accordance with the timing when the timing signal changes from OFF to ON, and the accumulation operation may be ended in accordance with the timing when the timing signal changes from ON to OFF. By performing such control, the additional control unit 61 can surely acquire an image by radiation irradiation in the same manner as in each of the above cases.

[0068] In this embodiment, the timing signal is repeatedly output with the same period as the irradiation permission signal. In this embodiment, the additional control unit 61 repeatedly outputs the irradiation permission signal until a predetermined number of output times is reached or until a predetermined output time has elapsed since the first output.

[0069] Note that the timing signal may be output with a delay or earlier than a predetermined time after the irradiation permission signal is output. In addition, the additional control unit 61 can be configured to have a timing means for controlling the timing, since it repeatedly transmits a timing signal and an irradiation permission signal at a predetermined period. In addition, the additional control unit 61 can be configured to have a counting means for counting the number of outputs, in order to repeatedly output the timing signal and the irradiation permission signal until a predetermined number of outputs is reached. Alternatively, it can be configured to have a timing means in order to repeatedly output the timing signal and the irradiation permission signal from when they are first output until a predetermined output time has elapsed.

[0070] Also, the timing signal can be configured to be output from a stage before the second stage of the irradiation instruction switch 5 is pressed (when the irradiation instruction signal is acquired). Specifically, for example, it can be configured to output during the period from when a sequence start signal (the fifth signal in the present invention) is acquired (when it is detected that it has become ON) until the irradiation instruction signal is acquired, or during the period from when an irradiation preparation signal (the sixth signal in the present invention) is acquired (when it is detected that it has become ON) until the irradiation instruction signal is acquired.

[0071] [Operation] Next, the operation of the above system 100 will be described. FIGS. 4 to 6 are ladder charts showing the operation of the system 100 according to the present embodiment, FIG. 7 is a table showing the correspondence between the generator and the imaging device 3 connectable to the system 100 and the frame rates corresponding to them, FIGS. 8 to 10 are examples of the display screens of the display unit 43 of the console 4, and FIG. 11 is a timing chart showing the operation of the system 100.

[0072] (A: When installing equipment, starting up the device, changing connected devices, periodically checking connected devices) First, the console 4, particularly the imaging device control console 42, as shown in FIG. 4, checks the imaging device 3 and the additional device 6 connected to the imaging environment controlled by the console 4 when installing equipment, starting up the imaging system, changing connected devices, or performing other periodic connected device checks (step S1), and displays the device configuration and connection configuration on the display unit 43 of the console 4 (step S2). To confirm the imaging device 3 and the additional device 6 connected to the imaging environment controlled by the console 4, for example, the console 4 requests the imaging device 3 and the additional device 6 for the presence or absence of connection and the ID, and the imaging device 3 and the additional device 6 return the presence or absence of connection and the ID, making it possible to confirm. As the ID, for example, a device-specific ID such as a MAC address set uniquely for the device, a BSSID unique to the device, or a serial number set uniquely for the device can be used, or an ID set later such as a set IP address or a set ESSID can also be used.

[0073] (B: Imaging Preparation) After that, when the console 4 receives an imaging order from an upper-level system 7 such as a RIS or HIS (step S3), it displays the received imaging order on the screen of the console 4 (step S4). At that time, it may be configured to notify the operator using light or sound that a new imaging order has been received. The imager changes the imaging order or performs other operations from the displayed imaging order and selects the imaging order to be imaged next (step S5).

[0074] By the way, in the system 100 according to the present embodiment, unlike a fluoroscopic device in which the combination of the radiation generating means and the radiation image capturing means is fixedly configured, imaging can be performed even if the combination of the generating device and the imaging device 3 is changed. For this reason, it is possible to select a suitable one from a plurality of cassette-type imaging devices 3 having different sizes and performances according to the imaging order and imaging technique and perform imaging. In that case, for example, as shown in FIG. 7, an imaging device 3 suitable for the current imaging (for example, imaging device (A) or (C)) is selected from among a plurality of imaging devices 3 that can be connected to the console 4 and can be used for imaging, and imaging is performed. Although not shown, in the case of the system 100 in which a plurality of generating devices are connected to one console 4, the generating device to be used for imaging (for example, generating device (A) or (B)) is selected and imaging is performed.

[0075] When selecting at least one of the generator and the imaging device 3, the addition control unit 61 or the console 4 according to the present embodiment can acquire the irradiation frame rate or the imaging frame rate. Note that the acquired irradiation frame rate or imaging frame rate may be input (selected) by the photographer to the console 4, or may be received from the generator or the imaging device 3. Also, when receiving from the generator or the imaging device 3, it may receive one frame rate selected in each device, or may receive all of the plurality of frame rates corresponding to each device. The addition control unit 61 or the console 4 having such a function constitutes the first and second acquisition means in the present invention.

[0076] In order for imaging to be performed without problems, it is necessary to satisfy all of the following discrimination conditions (1) to (3). Therefore, the addition control unit 61 or the console 4 discriminates whether or not all of these discrimination conditions are satisfied. (1) The acquired irradiation frame rate is a value corresponding to the generator. (2) The acquired imaging frame rate is a value corresponding to the imaging device 3. (3) Irradiation frame rate: imaging frame rate = 1:N (where N is an integer of 1 or more) (the imaging frame rate is N times the irradiation frame rate). Here, the "irradiation frame rate" refers to the number of times the radiation is generated by the generator per unit time, and corresponds to the transmission cycle of the irradiation permission signal by the addition control unit 61. On the other hand, the "imaging frame rate" refers to the number of times the radiation image is generated by the imaging device 3 per unit time, and corresponds to the transmission cycle of the timing signal by the addition control unit 61. Note that when there are a plurality of at least one of the irradiation frame rate and the imaging frame rate, there are a plurality of combinations of the irradiation frame rate and the imaging frame rate, so the discrimination may be performed a plurality of times accordingly. Also, here, N is an integer of 1 or more. However, for example, when taking pictures while thinning out the irradiation of radiation at predetermined intervals, it is preferable that N be an integer of 2 or more. By executing this process, the addition control unit 61 or the console 4 forms the discrimination means in the present invention.

[0077] In addition, when there are a plurality of at least one of the imaging frame rate received from the imaging device 3 and the irradiation frame rate received from the generating device, since there can be a plurality of combinations of the imaging frame rate and the irradiation frame rate, it may be possible to previously determine whether or not all of the above discrimination conditions are satisfied for each of them. Also, when the generating device, the imaging device 3, and the console 4 are configured such that only the irradiation frame rate and the imaging frame rate corresponding to the generating device and the imaging device can be selected, the determination as to whether or not the discrimination conditions (1) and (2) are satisfied can be omitted.

[0078] As a result of confirming whether or not all of the above discrimination conditions are satisfied, if any one of the above discrimination conditions is not satisfied, it is preferable to take at least one of the following corresponding actions (4) to (6). (4) With respect to the imaging device 3 to be used, the generating device to be used, the imaging frame rate of the imaging device 3, and the radiation emission rate of the generating device, prevent selections that do not satisfy the above relationship or do not accept (do not set) the input numerical values. (5) Gray down the setting candidates that do not satisfy the above relationship (perform a display for notifying the discrimination result), etc., so that they are removed from the selection targets and cannot be selected. (6) Even if it can be selected, do not allow it to proceed to the next sequence. Or do not permit imaging. In addition, when performing the above corresponding actions, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied. The warning can be given by voice or by a display for notifying the discrimination result using the display unit 43.

[0079] That is, the additional control unit 61 or the console 4 has the function as the notification means in the present invention for notifying the determined determination result in a manner recognizable by the photographer, or the function as the output means in the present invention for outputting the determination result. Further, when all of the determination conditions (1) to (3) are satisfied, the additional control unit 61 or the console 4 permits the irradiation of radiation to the generating device. That is, the additional control unit 61 or the console 4 forms the irradiation permission means in the present invention. By doing so, it is possible to reliably prevent the imaging from being performed in a state where a selection that does not satisfy the above relationship is made.

[0080] Here, the operation when setting the irradiation frame rate and the imaging frame rate will be described by taking as an example the case in an imaging room where there are combinations of the imaging devices (A) and (C) shown in FIG. 7 and other combinations, and combinations of the generating devices (A) and (B). First, assume that the photographer selects the generating device (A) as the generating device to be used as shown in FIG. 8 (the generating device (A) is displayed in the display column 43a of the selected generating device). The irradiation frame rates corresponding to the generating device (A) (irradiation is possible) are, for example, three types: 15, 10, and 5 frames / s (Hz). Although FIG. 8 illustrates the case where only the information of the generating device (A) is displayed in the display column 43a in the state where the generating device (A) is selected, the display column 43a may be configured to display the information of a plurality of generating devices in the form of options, and the information of the selected generating device (A) may be displayed in a display mode different from the information of other generating devices.

[0081] Subsequently, the imaging device 3 to be used is selected. Here, since the imaging devices (A) and (C) include numerical values that are N times (N is an integer of 1 or more) the irradiation frame rates (15, 10, 5) that can be corresponded to by the previously selected generating device (A) among the corresponding imaging frame rates, they can be selected. Therefore, when the imaging device (A) is selected (the corresponding icon 43b is shown in solid line), due to the relationship with the combination of the irradiation frame rate corresponding to the generating device (A), the selectable imaging frame rate is 15 Hz (three times the irradiation frame rate of 5 Hz). Among such selectable imaging frame rates, it is possible to select the imaging frame rate with a relatively large (fast) value as the basic imaging frame rate. In the procedure of changing the irradiation frame rate for imaging, if the imaging frame rate is changed in accordance with the change of the irradiation frame rate, complicated and time-consuming operations such as restarting the imaging device (A) due to the setting change of the imaging device (A) will be required. However, by fixing the imaging frame rate of the imaging device (A) to the basic imaging frame rate, it is possible to eliminate such switching time. Thus, when 15 Hz is selected as the basic imaging frame rate, as the irradiation frame rate, 15 Hz or 5 Hz, which is 1 / N (where N is an integer of 1 or more) of the basic imaging frame rate among the irradiation frame rates that the generating device (A) can support, can be selected. At this time, when attempting to select 10 Hz as the irradiation frame rate, it can be configured to be non-selectable. In that case, for example, as shown in FIG. 9, a display indicating non-selectability (a display for notifying the discrimination result: for example, the character 43c of "not available") may be made near the displayed irradiation frame rate.

[0082] On the other hand, as another example, as shown in FIG. 10, when the imaging device (C) is selected (the corresponding icon 43d is shown in solid line), it is possible to select 10 Hz as the basic imaging frame rate based on the relationship of the corresponding frame rate of the generating device. Also, as the irradiation frame rate, 10 Hz or 5 Hz can be selected. Here, it is desirable to set the numerical value required according to the imaging procedure for the irradiation frame rate. For example, in order to image the dynamic state of slow changes such as breathing, it is desirable to set the irradiation frame rate to at least 2 Hz or more. Therefore, the additional control unit 61 or the console 4 can be configured to permit radiation irradiation to the generator when the set irradiation frame rate is 2 Hz or more. Alternatively, the minimum required frame rate for each imaging site and procedure can be stored respectively, and when the set irradiation frame rate according to the selected imaging site and procedure is equal to or higher than the minimum required frame rate, the generator can be configured to permit radiation irradiation.

[0083] Also, a configuration may be adopted in which, among the plurality of imaging devices 3 connected, the imaging device 3 recommended according to the imaging technique of the photographer is automatically selected. Also, when there is no particular change, a configuration may be adopted in which the imaging device 3 used in the previous imaging is continuously selected.

[0084] When the imaging device 3 to be used is selected, as shown in FIG. 4, the console 4 makes connection requests to the imaging device 3 and the additional device 6 respectively (step S6). When the imaging device 3 and the additional device 6 receive the connection requests, they connect to the console 4 respectively (step S7). Note that, as shown in FIG. 4, the connection request can also be made from the console 4 to the additional device 6 and then from the additional device 6 to the imaging device 3. The imaging device 3 and the console 4 can be connected via the communication network N as shown in FIG. 2 or directly connected. However, when the console 4 and the imaging device 3 are directly connected, there is a possibility that a connection configuration in a state where the imaging device 3 not connected to the additional device 6 cannot be established while being connected to the additional device 6 and the imaging device 3 are in cooperation. However, by connecting the imaging device 3 and the console 4 via the additional device 6 in this way, it becomes possible to surely connect to the imaging device 3 connected to the additional device 6.

[0085] Alternatively, although not shown, a configuration may be adopted in which a connection request is made from the console 4 to each imaging device 3, and then a connection request is made from each imaging device 3 to the additional device 6. Since the settings of the imaging device 3 used for imaging are made on the console 4, with such a configuration, the imaging device 3 to be used can be surely selected and connected to the additional device 6, and it is possible to establish a state in which the additional device 6 and the imaging device 3 to be used are in cooperation without selecting the wrong imaging device 3. Also, with such a configuration, it becomes possible to select and connect the imaging device 3 not only from the imaging device 3 connected to the additional device 6 as described above, but also from the entire available imaging devices 3. Also, here, when the imaging device 3 is configured to automatically transition its own state from the imaging standby or the aforementioned low-power consumption mode in which imaging is possible to a mode with higher power consumption than the low-power consumption mode when starting the connection.

[0086] Subsequently, when the photographer sets imaging conditions and the like on the console 4 and instructs the console 4 to start imaging, the console 4 turns on a sequence start signal for instructing the start of an imaging sequence for the imaging device 3 and the additional device 6. Then, the sequence start signal is transmitted to the imaging device 3 and the additional device 6 (step S8). The sequence start signal can be transmitted using, for example, an information signal transmitted and received between the console 4 and the additional device 6 and an information signal transmitted and received between the additional device 6 and the imaging device 3. When the imaging device 3 and the additional device 6 detect that the sequence start signal has become ON, they start imaging preparation.

[0087] Here, when the additional device 6 is configured to transmit a timing signal from a stage before the irradiation instruction switch 5 is pressed, after the additional device 6 detects that the sequence start signal has become ON, it may turn on a read instruction signal (see FIG. 18) and control to repeatedly transmit the timing signal to the imaging device 3 at a predetermined interval (step S9). Each time the imaging device 3 receives this timing signal, it repeats the read operation. Then, the temperature of the circuit in the imaging device 3 rises. That is, the read operation repeatedly performed by the imaging device 3 at this stage is the warm-up of the imaging device 3. Also, at the initial stage when the imaging device 3 repeats the read operation, it notifies the console 4 that the warm-up has started (step S10).

[0088] By the way, it is necessary to perform a read operation (reset operation) on the imaging device 3 to remove the charges accumulated immediately before imaging. On the other hand, since the imaging device 3 consumes power when performing the read operation, the temperature of the imaging device 3 rises accordingly. Also, due to this temperature rise, the sensitivity of the light receiving part of the imaging device 3 in particular changes, and the image density output to the radiation incident amount also changes. If it is a single still image capture, the change in the image due to this temperature rise does not pose a problem. However, when performing dynamic imaging (repeated still image capture) like the system 100 according to this embodiment, the change in the image due to the temperature rise during imaging becomes a problem. However, as described above, when configured to perform warm-up, it is possible to reduce the change in image density due to such temperature rise.

[0089] Also, at some timing when step S9 is repeated multiple times, the imaging device 3 may acquire a correction image. For example, when the imaging device 3 is configured to perform warm-up (perform a read operation before pressing the irradiation instruction switch 5), the image read in the latter half of this warm-up may be transmitted to the console 4 as a correction image (step S11). The characteristics of the plurality of pixels of the imaging device 3 are different from each other, and even in a state where no radiation is irradiated, the level of the charge corresponding to the brightness of the image is different for each pixel. Therefore, by acquiring the image read in the latter half of the warm-up as a correction image, and for example, subtracting the signal value of each pixel of the correction image from each signal value of the subsequently obtained captured image, a captured image with the variation between pixels removed can be obtained. Here, as a method of using the correction image, the case of simply subtracting the correction image from the captured image is taken as an example, but it is also possible to remove noise components using various operations.

[0090] Also, during the read operation (reset operation) for removing the charges accumulated immediately before the shooting other than for acquiring the correction image, as an operation similar to normal shooting, at least one of the steps of imaging the removed charges, storing the imaged image data in the storage unit within the imaging device 3, and transferring the imaged data or the image data stored in the storage unit within the imaging device 3 to the console 4 may be performed. Performing the above steps similar to normal shooting results in conditions closer to actual shooting. Thus, in this way, there are fewer differences when shooting in subsequent steps, and for example, it is possible to reduce the influence of the temperature rise. On the other hand, when performing the above steps similar to normal shooting, there are problems such as an increase in power consumption, a reduction in the capacity of the storage unit available during shooting due to the storage of useless images when radiation is not irradiated in the storage unit of the imaging device 3, and the occupation of a part of the communication capacity due to the transmission of useless images when radiation is not irradiated to the console, and a reduction in the capacity of the storage unit available during shooting due to the storage in the storage unit of the console. Therefore, in order to avoid such problems, it is also possible to omit a part of the above steps.

[0091] The imaging device 3 can be configured to complete the warm-up when a preset number of readouts or a read operation period as a warm-up elapses. For example, in step S25 (see FIG. 5) of turning on the irradiation start signal described later, until the preset number of readouts or the read operation period elapses, the irradiation start signal is not turned on, so that it is possible not to start shooting by radiation irradiation until the warm-up is completed.

[0092] Thereafter, the imaging device 3 notifies the console 4 that the shooting preparation is completed (step S12). At that time, the display unit 43 of the console 4 may be set to display "Shooting possible" (step S13).

[0093] (C: Shooting confirmation) The additional device 6 continues to repeatedly transmit the timing signal to the imaging device 3, and each time the imaging device 3 receives this timing signal, the imaging device 3 repeats its read operation. When the photographer finishes positioning the subject and presses the first stage of the irradiation instruction switch 5 (step S14), the irradiation instruction switch 5 turns on the irradiation preparation signal output to the radiation control unit 11 via the console 4 (step S15). When the radiation control unit 11 of the generator detects that this irradiation preparation signal has turned on, it turns on the irradiation preparation signal output to the high voltage generation unit 12 and the additional device 6 (step S16). As a result, the first acquisition unit 62 of the additional device 6 acquires the irradiation preparation signal (which is output after the irradiation instruction signal and before the sequence start signal turns on). In this way, the generator including the radiation control unit 11 starts the irradiation preparation of the radiation according to the irradiation preparation signal.

[0094] When the additional control unit 61 of the additional device 6 detects that the irradiation preparation signal from the radiation control unit 11 has turned on, it transmits the imaging preparation signal to the console 4 (step S17). Also, at this time, the additional control unit 61 or the console 4 may reconfirm the following discrimination conditions (1) to (3). (1) The set irradiation frame rate has a value corresponding to the generator. (2) The set imaging frame rate has a value corresponding to the imaging device 3. (3) Irradiation frame rate: imaging frame rate = 1:N (where N is an integer of 1 or more) (the imaging frame rate is N times the irradiation frame rate). If the above relationship is not satisfied, the console 4 may prohibit the subsequent sequence or not give permission for imaging. Also, when performing the above correspondence, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied.

[0095] When the console 4 receives a shooting preparation signal, it starts the shooting preparation. The shooting preparation on the console 4 is, for example, an operation of confirming that the settings of the shooting device control console 42 constituting the console 4 and the radiation control console 41 for controlling the radiation irradiation are the same, or confirming that the shooting conditions specified for the shooting device 3 are set. When the console 4 completes the shooting preparation, it turns on the shooting preparation completion signal output to the additional device 6 (step S18). At that time, the display unit 43 of the console 4 may be set to display "Shooting" (step S19).

[0096] Also, at the stage when this shooting preparation is completed, it may be configured to lock the input of changing the shooting conditions etc. to the console 4 so that they cannot be changed. In the case of still image shooting, since the shooting ends in a short time, the risk of changing the shooting conditions etc. during shooting is small, and the necessity of such a configuration is low. However, in the case of dynamic shooting, since the shooting period is long, the risk that the photographer or a third party other than the photographer intentionally or unconsciously operates the console screen to change the shooting conditions etc. becomes higher. Therefore, by locking the input of changing the shooting conditions etc. to the console 4 from this stage until the end of the sequence from step S45 and later described, it is possible to surely prevent such a change in the shooting conditions.

[0097] Note that FIG. 4 illustrates the case where the shooting preparation signal is output from the additional device 6 to the console 4. However, there is also a case where the shooting preparation signal is output not to the console 4 but to the shooting device 3, the shooting device 3 is made to perform the shooting preparation, and when the shooting preparation of the shooting device 3 is completed, the shooting preparation completion signal is output from the shooting device 3 to the additional device 6. Also, the shooting preparation signal may be output to both the console 4 and the shooting device 3 respectively, both are made to perform the shooting preparation respectively, and when the shooting preparations of both are completed, the shooting completion signals are transmitted from the console 4 and the shooting device 3 to the additional device 6 respectively, and in some cases, it is determined that the overall shooting preparation is completed at the stage when the additional device 6 receives the shooting completion signals of both.

[0098] Further, although not shown, when the radiation control unit 11 of the generator has a connection unit for inputting a shooting preparation completion signal that can input that the shooting preparation of an external device has been completed, the additional device 6 may be configured to output the shooting preparation completion signal to the radiation control unit 11. By detecting that the shooting preparation completion signal from the additional device 6 has become ON, the radiation control unit 11 can detect that the imaging device 3 is in a state where shooting is possible. Here, by controlling the radiation control device 1 to perform radiation irradiation after detecting that the shooting preparation completion signal has become ON, it is possible to surely eliminate the risk that the imaging device 3 irradiates radiation in a state where shooting is impossible and the subject is exposed needlessly.

[0099] (D: Shooting execution) Subsequently, when the photographer presses the second stage of the irradiation instruction switch 5 (step S20), the irradiation instruction switch 5 turns on the irradiation instruction signal transmitted to the radiation control unit 11 via the console 4 (step S21). At this time, the additional device 6 continues to repeatedly transmit the timing signal to the imaging device 3, and the imaging device 3 repeats the read operation each time it receives this timing signal. Even if an irradiation instruction signal is input from the irradiation instruction switch 5, the radiation control unit 11 of the generator does not transmit the irradiation signal to the high voltage generation unit 12 because the irradiation permission signal from the additional device 6 is OFF at this time.

[0100] On the other hand, the radiation control unit 11 turns on the irradiation instruction signal transmitted to the additional control unit 61 (step S22). When the additional device 6 receives the irradiation instruction signal, it turns on a shooting start signal that notifies whether or not to permit the start of shooting and is output to the imaging device 3 and the console 4 (steps S23, S24). Also, at this time, the additional control unit 61 or the console 4 may re-check the following discrimination conditions (1) to (3). (1) The set irradiation frame rate has a value corresponding to the generator (2) The set shooting frame rate is a value corresponding to the imaging device 3. (3) Irradiation frame rate: shooting frame rate = 1:N (where N is an integer of 1 or more) (the shooting frame rate is N times the irradiation frame rate). If the above relationship is not satisfied, the console 4 may prohibit subsequent steps of the subsequent sequence or may not issue a shooting permission. Also, when performing the above correspondence, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied.

[0101] When the imaging device 3 detects that the shooting start signal has become ON, taking the opportunity that the read operation being performed by itself has ended at that time, for example, as shown in FIG. 5, it turns ON the irradiation start signal output to the additional device 6 (step S25). This is because the read operation of the imaging device 3 is to obtain an image of the entire light receiving surface by sequentially reading the charges accumulated in the pixels arranged two-dimensionally. If the irradiation start signal is turned ON during the read operation and radiation is irradiated, a difference will occur in the signal values between the pixels for which the read has been completed and the pixels for which the read has not been completed, significantly degrading the image quality.

[0102] On the other hand, in the present embodiment, as will be described later, since the radiation irradiation and the image reading of the imaging device 3 are performed based on the irradiation permission signal and the timing signal from the additional device 6, radiation is not irradiated during the read operation in the normal routine. Therefore, the irradiation start signal may be turned ON without considering the read timing of the above-described imaging device 3.

[0103] The imaging device 3 repeats the image read operation even after the irradiation start signal has become ON. The image read after the irradiation start signal has become ON is saved in the memory of the imaging device 3 as a captured image or transferred to the console 4.

[0104] When the additional device 6 detects that the irradiation start signal from the imaging device 3 has become ON, it detects that the imaging device 3 is in a shootable state and repeatedly transmits an irradiation permission signal to the radiation control unit 11 (step S26). When the irradiation frame rate: shooting frame rate is set to 1:N, the additional control unit 61 outputs the shooting permission signal once every time it outputs the timing signal N times (in Fig. 5, the case where N = 2 is shown).

[0105] Each time the radiation control unit 11 of the generating device receives the irradiation permission signal, since the shooting instruction signal and the irradiation permission signal will be aligned, it repeatedly transmits the irradiation signal to the high voltage generating unit 12. Each time the high voltage generating unit 12 receives the irradiation signal, it repeatedly generates the high voltage required for radiation irradiation and repeatedly outputs the high voltage to the radiation generating unit 2 as the irradiation output. Each time the radiation generating unit 2 receives the irradiation output, it repeatedly irradiates the imaging device 3 with radiation (step S27). The irradiated radiation passes through a subject (not shown) disposed between the imaging device 3 and the radiation generating unit 2 and enters the imaging device 3.

[0106] On the other hand, each time the imaging device 3 receives the timing signal, it accumulates an amount of electric charge corresponding to the intensity of the incident radiation (step S28) and repeatedly reads it out as a captured image (step S29). The imaging device 3 continuously repeats the accumulation and reading, but each time the accumulation and reading are repeated N times, it receives radiation irradiation from the generating device once and generates an exposure image. The imaging device 3 transfers the read radiation image to the console 4 (step S30). In the case where the captured image is configured to be transferred to the console 4, if the transfer to the console 4 is not in time due to the data volume or communication environment, a part of the captured images among the plurality of captured images, or a part of one captured image, may be stored in the imaging device 3 and the rest may be transferred to the console 4.

[0107] Here, an example of the operation of the imaging device 3 will be further described. Here, the case where the accumulation of charges is started in accordance with the aforementioned timing signal will be described. <Reset operation / Correction image acquisition operation> In the reset operation performed before imaging, the imaging device 3 repeatedly performs the aforementioned operations in a state where there is no radiation irradiation from the radiation generation device, and discharges the charges (dark charges or dark currents) not based on radiation irradiation accumulated in each pixel, thereby resetting the charges not based on radiation irradiation accumulated in each pixel that become noise components for the image formed by the charges based on radiation irradiation. Note that during this reset operation, it may be controlled that the charges flowing into the aforementioned readout unit 34 are not converted into image data. (Operations before t1)

[0108] Also, in the correction image acquisition operation performed before or after imaging, the imaging device 3 repeatedly performs the aforementioned operations in a state where there is no radiation irradiation from the radiation generation device, and discharges the charges (dark charges or dark currents) not based on radiation irradiation accumulated in each pixel, thereby resetting the charges not based on radiation irradiation accumulated in each pixel that become noise components for the image formed by the charges based on radiation irradiation. Further, during this correction image acquisition operation, by converting the charges flowing into the aforementioned readout unit 34 into image data and storing them, it becomes possible to store the amount of noise components in a state where there is no radiation irradiation, and the noise components can be removed by subtracting them from the image data in a state where radiation irradiation has occurred. Note that this correction image acquisition operation may be performed as a part of the aforementioned reset operation. (Operations before t1)

[0109] <End operation of reset operation / correction image acquisition operation> When the irradiation instruction signal in step S21 becomes ON following the reset operation or the correction image acquisition operation, the imaging start signal input to the imaging device 3 becomes ON (step 23). Then, the imaging device 3 stops the aforementioned reset operation or correction image acquisition operation. On the other hand, even if the shooting start signal is ON, if the correction image acquisition operation has not completed the acquisition of a predetermined number of correction images, the correction image acquisition operation is not stopped, and the correction image acquisition operation is continued until a predetermined number of correction images are acquired, and then the correction image acquisition operation is stopped. When the reset operation or the correction image acquisition operation is stopped, the imaging device 3 stops the reset operation or the correction image acquisition operation, and notifies that it has become in a shootable state by turning on the irradiation start signal in step S25. (t1)

[0110] <Operation> When the imaging device 3 receives a timing signal from the additional control unit 61, it applies an off voltage to each scanning line 32b, so that, as shown in FIG. 11, the charge generated by the radiation detection element 32d transitions to a state where it can be accumulated in the pixel (t2, t6, t10, ···). The additional control unit 61 outputs an irradiation permission signal at a timing linked to the timing when the timing signal is transmitted. The radiation generator irradiates the imaging device 3 with radiation in response to the irradiation permission signal (step S27; t3, t7, t11, ···). When the irradiation frame rate is 1 / N of the shooting frame rate (the case of N = 2 is shown in FIG. 11), the additional control unit 61 outputs the irradiation permission signal once every N times of repeating the output of the timing signal. As a result, in response to the timing signal and the irradiation permission signal, the radiation generator irradiates the radiation once every N times of repeating the accumulation and readout by the imaging device 3 (step S27; t3, t11, ···). At that time, no radiation is irradiated at other timings (t7 ···). The imaging device 3 continues the mode of accumulating charges for a predetermined time by means of the timing means it has. (t2~t4, t6~t8, t10~t12, ···)

[0111] When the imaging device 3 receives radiation while in the mode of accumulating the above charges, each radiation detection element 32d of the radiation detection unit 32 generates charges and accumulates them in each pixel (step S28). Thereafter, the imaging device 3 performs a read operation of discharging the charges accumulated in each pixel to the signal line 32c by applying an on-voltage to each switch element 32e after the elapse of the predetermined time by means of the timing means it has. In the read operation, the imaging device 3 reads out image data based on the charges flowing into the readout unit 34 and converts it into image data. Further, at least a part of the image data converted into image data is transferred to the console 4 (steps S29, S30; t4 to t5, t8 to t9, t12 to t13, ···).

[0112] <Another Embodiment of the Operation Control Method> In the above description, an example in which the imaging device transitions to a state where it can accumulate charges in the pixel in response to the timing signal from the additional control unit 61 has been shown. However, control may be performed so that other operations are performed in response to this timing signal. For example, in another control method, after the imaging device 3 finishes the read operation (t4 to 5, t8 to t9, t12 to t13, ···) of discharging the charges accumulated in each pixel to the signal line 32c, it may be controlled to transition to a state (t6 to t8, t10 to t12, ···) where charges can be accumulated in the pixel without waiting for the timing signal from the additional control unit 61. Thereafter, the additional control unit 61 controls to output a timing signal at a timing linked to the timing when it transmits an irradiation permission signal for controlling the irradiation of radiation from the radiation generator. The imaging device 3 transitions to a read operation of discharging the charges accumulated in each pixel to the signal line 32c in response to the received timing signal. (t4, t8, t12, ···) By repeating such operation control, it is possible to perform imaging while matching the radiation irradiation timing by the radiation generator and the image generation timing by the imaging device.

[0113] (E: End of Imaging) The additional device 6 counts the number of times the irradiation permission signal has been transmitted since the start of the radiation irradiation, and each time, determines whether the preset maximum number of imaging shots has been reached. When it is determined that the counted number of transmissions of the irradiation permission signal (the number of shots taken) has reached the maximum number of imaging shots, as shown in FIG. 6, the imaging start signal is turned off (step S31), and the output of either or all of the aforementioned timing signal and irradiation permission signal is stopped.

[0114] Here, the additional device 6 may be controlled to perform at least once the operation of accumulating (step S28) an amount of charge corresponding to the intensity of the radiation incident on the imaging device 3 after the last output of the irradiation permission signal, and reading it out as an imaging image (step S29). Thereby, the image irradiated with radiation last can be surely read out as an imaging image, and it is possible to surely prevent the subject from being exposed unnecessarily. Also, after the additional device 6 outputs the irradiation permission signal for the last time, the imaging device 3 accumulates charge (step S28), reads it out as an imaging image (step S29), and then the imaging device 3 may be further controlled to perform the operation of accumulating charge and reading it out as an imaging image. Since this imaging image is an image taken in a state where no radiation is irradiated, these images can be used for correcting the imaging image at the time of radiation irradiation in the same manner as the aforementioned correction images.

[0115] That is, as the correction image, an image taken before imaging using radiation as described above may be used as the correction image, or an image taken after imaging using radiation as described above may be used as the correction image. Alternatively, correction images taken before and after imaging using radiation may be used. In this case, by using the correction images before and after imaging using radiation, the change in the correction image during imaging may be predicted and the correction image may be generated. These can be generated, for example, by averaging the correction images taken before and after radiation imaging, or by linearly or curve-complementing the fluctuations. In the case of still image shooting, since the time required for shooting is short, the change in the correction image before and after shooting is small. However, in the case of dynamic shooting, the time required for shooting is much longer than that for still images. Therefore, by using the correction images before and after shooting as described above, it becomes possible to perform correction considering the fluctuations during shooting.

[0116] Also, instead of counting the number of shots based on the number of times the irradiation permission signal is transmitted as described above, it may be counted based on the number of output times of the timing signal after the start of shooting. Also, instead of counting the number of shots based on the number of times the irradiation permission signal is transmitted as described above, it may be counted based on the elapsed time after the start of shooting.

[0117] When the imaging device 3 detects that the imaging start signal has become OFF and further when the imaging after the radiation irradiation and the imaging for obtaining the correction image described above are completed, it turns off the read instruction signal (see FIG. 18) and transfers the remaining image (untransferred captured image) left in the memory of the imaging device 3 to the console 4 (step S32). Then, when the transfer of the remaining image is completed, it transmits a remaining image transfer completion signal to the console 4 (step S33).

[0118] On the other hand, when the console 4 detects that the imaging start signal has become OFF, it starts the operation of checking the transferred captured images. Also, when the console 4 receives the remaining image transfer completion signal, it transmits an image deletion signal instructing image deletion to the imaging device 3 (step S34). Note that the image deletion signal may be controlled to be transmitted after the operation of checking the captured images is completed and it is confirmed that there is no problem with all the transferred images. Also, at that time, "Shooting completed" may be displayed on the display unit 43 of the console 4 (step S35). When the imaging device 3 receives the image deletion signal, it deletes the captured images stored in the memory (step S36). Thereby, a free area in the memory can be secured for the next shooting.

[0119] When the photographer who has confirmed the end of shooting (for example, visually recognized the display of "Shooting Ended" on the console 4) releases the second stage of the irradiation instruction switch 5 (step S37), the irradiation instruction switch 5 turns off the irradiation instruction signal (step S38), and further the radiation control unit 11 also turns off the irradiation instruction signal (step S39). After that, when the photographer releases the first stage of the irradiation instruction switch 5 (step S40), the irradiation instruction switch 5 turns off the irradiation preparation signal (step S41), and further the radiation control unit 11 also turns off the irradiation preparation signal (step S42). When the additional device 6 detects that the irradiation preparation signal has become OFF, it notifies the console 4 to that effect. When the console 4 receives the notification from the additional device 6, it turns off the shooting preparation completion signal and transitions the sequence state to the irradiation preparation state.

[0120] When the additional device 6 detects that the irradiation instruction signal and the irradiation preparation signal have become OFF, it transmits a shooting end signal indicating the end of shooting to the imaging device 3 and the console 4 (steps S43, S44). When the imaging device 3 receives the shooting end signal, it transmits a standby signal to the console 4 (step S45). When the console 4 receives the standby signal, it monitors the presence or absence of reshooting or other shooting for a predetermined period. When the predetermined period has elapsed without reshooting or other shooting, it turns off the sequence start signal and transitions the sequence state to the standby state waiting for a shooting instruction. In this way, a series of shooting operations is completed. The system 100 according to this embodiment operates as described above, whereby dynamic shooting for repeatedly shooting a plurality of still images in a short time is performed.

[0121] [Image Selection after Shooting] After that, on the console 4, from among a plurality of frames including the exposure images taken at the timing of irradiation with radiation for every N sheets that constitute the obtained moving image (with N-1 unexposed images generated without irradiation with radiation sandwiched between the exposure images), only the exposure images are extracted and made into a new moving image, so that it becomes possible to obtain a moving image with a radiation exposure dose of 1 / N. The extraction of the exposure images may be performed based on the set irradiation frame rate, the shooting frame rate, and the frame numbers attached to the moving image, or may be performed by discriminating the pixel values of predetermined pixels of each frame. By such an operation, the console 4 constitutes the selection means and the moving image generation means in the present invention. Also, when extracting the exposure images, if necessary, image correction processing of the exposure images may be performed using the unexposed images generated at timings other than the timings for generating the exposure images.

[0122] [Modification Example 1] Here, in the above example, an example has been described in which all the taken images are sent from the imaging device 3 to the console 4, and the necessary images (exposure images) are extracted at the console 4 to generate a moving image. However, instead of sending all the taken images to the console 4, a configuration may be adopted in which the exposure images or the unexposed images generated at other timings are selected by the imaging device 3 and sent to the console 4. Also, if necessary, the imaging device 3 may perform image correction processing of the exposure images.

[0123] [Modification Example 2: Counting the number of taken images by the imaging device 3] Note that in the above embodiment, an example has been shown in which the additional device 6 counts the number of times the irradiation permission signal is transmitted, and when the output number of the counted irradiation permission signals reaches the maximum number of shooting sheets, it is determined that the maximum number of shooting sheets has been reached. However, the imaging device 3 counts the number of times the timing signal is received after the irradiation start signal is transmitted, or the number of times the timing signal is received and the imaging device 3 is read, or the number of times the imaging device 3 is read and the image is saved or transferred to the console 4, and a device configuration may be adopted in which the determination is made based on whether these reach the preset maximum number of shooting sheets.

[0124] [Modification Example 3: Shooting Permission Based on the State of the Shooting Device] Also, when the shooting device 3, the console 4, and the additional device 6 are connected, or at the start of shooting, a configuration may be adopted in which the remaining battery power and the remaining memory capacity of the shooting device 3 are referred to, and it is determined whether the specified dynamic shooting can be performed until the end. Also, according to the determination result, if shooting is possible, a configuration may be adopted in which it is displayed that shooting is possible. Also, according to the determination result, if shooting is impossible, a configuration may be adopted in which it is displayed that shooting is impossible.

[0125] [Modification Example 4: Operation of the Radiation Control Unit During Dynamic Shooting] In the above-described embodiment, the radiation control unit 11 receives an irradiation instruction signal from the irradiation instruction switch 5 and repeatedly receives an irradiation permission signal from the additional control unit 61. This irradiation permission signal is transmitted to the radiation control unit 11 as, for example, a pulse signal corresponding to radiation irradiation for shooting each frame of a dynamic image. Then, for each of the repeatedly received irradiation permission signals, the radiation control unit 11 transmits an irradiation signal to the high-voltage generation unit 12 on a one-to-one basis to irradiate radiation. Also, when shooting a single still image, it is sufficient for the radiation control unit 11 to transmit an irradiation permission signal once in response to the reception of one irradiation instruction signal.

[0126] Therefore, in order to prevent the irradiation permission signal from being received multiple times for one irradiation instruction signal and the radiation from being accidentally irradiated multiple times when shooting a still image, the radiation control unit 11 can be configured to transmit an irradiation signal only once in response to the input of the first irradiation permission signal even if the irradiation permission signal is received multiple times for one irradiation instruction signal.

[0127] On the other hand, if the radiation control unit 11 is configured to transmit the irradiation signal only once in response to one irradiation permission signal as described above, dynamic imaging cannot be performed by repeating the irradiation of radiation a plurality of times in response to one irradiation instruction signal as in the system 100 according to the present embodiment. Therefore, the radiation control unit 11 may be configured to transmit the irradiation signal to the high voltage generation unit 12 a plurality of times when a plurality of irradiation permission signals are received during one irradiation instruction signal input period, which is the period during which the imaging operator presses the irradiation instruction switch 5. By doing so, it becomes possible to perform dynamic imaging by repeating the irradiation of radiation a plurality of times in response to one irradiation instruction signal.

[0128] Note that the control mode (1) in which the irradiation signal is transmitted only once in response to one irradiation permission signal and the control mode (2) in which the irradiation signal is transmitted to the high voltage generation unit 12 a plurality of times in response to the input of the irradiation permission signal when the irradiation permission signal is input a plurality of times during the irradiation instruction signal input period may be switched according to the type of imaging (still image imaging or dynamic imaging). The switching of the control mode of the radiation control unit 11 according to the type of imaging can be performed by the console 4, and it may be configured to change based on receiving a signal indicating the type of imaging from the console 4. With such a configuration, it is possible to surely prevent the risk of irradiating the subject with radiation a plurality of times by mistake when taking a still image and unnecessarily exposing the subject.

[0129] [Modification Example 5: Timing Limitation of Radiation Control Unit during Dynamic Imaging] For example, if electrical noise is mixed into the irradiation permission signal transmitted from the additional control unit 61 to the radiation control unit 11, and the radiation control unit 11 receives a signal similar to the irradiation permission signal at an unintended timing, the high voltage generation unit 12 may be in a situation similar to that of repeatedly receiving the irradiation permission signal at intervals so short that it cannot generate the high voltage required for radiation irradiation in time. If the radiation control unit 11 forcibly transmits the irradiation signal to the high voltage generation unit 12 in such a case, an excessive current may flow through the high voltage generation unit 12, and the high voltage generation unit 12 may malfunction.

[0130] Therefore, in the above embodiment, when the radiation control unit 11 repeatedly receives the irradiation permission signal from the additional control unit 61 while the irradiation instruction signal input from the irradiation instruction switch 5 is ON, the length of the reception interval between two consecutive irradiation permission signals is compared with a preset minimum reception interval. If it is determined that the interval is shorter than the minimum reception interval, the irradiation signal may not be transmitted to the high voltage generation unit 12. In this way, it is possible to prevent an excessive current from flowing through the high voltage generation unit 12 and the high voltage generation unit 12 from malfunctioning.

[0131] [Effect] As described above, the system 100 according to the present embodiment is obtained by connecting the additional control unit 61 to the radiation control device 1 in the conventional system 100A shown in FIG. 1, which can perform radiation irradiation only once for one radiation irradiation instruction. As a result, the radiation control device 1 can output the irradiation signal a plurality of times for one acquisition (ON detection) of the irradiation instruction signal. That is, the generator can repeatedly generate radiation at a predetermined period. Therefore, it is possible to perform imaging, that is, dynamic imaging, in which frames based on the received radiation are repeatedly generated at a predetermined period using the imaging device 3. In addition, the conventional system 100A shown in FIG. 1 has been widely popularized as being capable of capturing simple still images. For this reason, a medical institution using the conventional system 100A can easily modify the conventional system 100A including the existing generator to support dynamic imaging by simply adding the imaging device 3 and the additional device 6 without updating the expensive generator.

[0132] Further, in the system 100 according to the present embodiment, the determination result for determining whether or not the imaging frame rate acquired by the additional control unit 61 or the console 4 is N times (where N is an integer of 1 or more) the acquired irradiation frame rate is notified to the imager in a distinguishable manner. Therefore, when performing imaging in which the generator irradiates radiation the same number of times as or less than the predetermined number of times while the imaging device 3 repeats charge accumulation and reading a predetermined number of times, it is possible to surely prevent the risk that imaging is started with a frame rate not corresponding to at least one of the imaging device 3 and the generator being set.

[0133] <Prior Art 2> Next, the prior art 2 that is the basis of the system 200 (details will be described later) according to the second embodiment of the present invention will be described with reference to FIG. 12. Note that the same components as those in the above prior art 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[0134] [System Configuration] First, the schematic configuration of a radiation imaging system according to the prior art 2 (hereinafter, the conventional system 200A) will be described. FIG. 12 is a block diagram showing the schematic configuration of the conventional system 200A.

[0135] The conventional system 200A has, for example, as shown in FIG. 12, a configuration of a radiation control unit 11A provided in a radiation control device 1A that is different from that of the conventional system 100A. Specifically, the radiation control unit 11 of the conventional system 100A was configured to be able to output the irradiation preparation signal and irradiation instruction signal from the radiation control console 41 to external devices based on detecting that they had become ON. However, the radiation control unit 11A of the conventional system 200A does not have such a configuration. Also, the radiation control unit 11 of the conventional system 100A was configured to be able to receive an irradiation permission signal from an external device, but the radiation control unit 11A of the conventional system 200A does not have such a configuration either.

[0136] [Operation] Next, the operation of the above-mentioned conventional system 200A will be described.

[0137] (Irradiation Preparation Operation) When the first stage of the irradiation instruction switch 5 is pressed by the photographer, the irradiation instruction switch 5 turns ON the irradiation preparation signal output to the radiation control unit 11A via the radiation control console 41. When the radiation control unit 11A detects that the irradiation preparation signal has become ON, it turns ON the irradiation preparation signal output to the high voltage generation unit 12. In FIG. 12, although the output of the irradiation preparation signal from the radiation control unit 11A to the external device is not shown, when operating in cooperation with the external device, an irradiation preparation signal may be output to the external device. When the high voltage generation unit 12 detects that the irradiation preparation signal has become ON, it outputs an irradiation preparation output to the radiation generation unit 2.

[0138] When the irradiation preparation output is input to the radiation generation unit 2, the radiation generation unit 2 starts preparations for generating radiation. When the anode is a rotating anode, for example, operations such as rotating the rotating anode are performed.

[0139] (Irradiation Operation) Subsequently, when the second stage of the irradiation instruction switch is pressed by the photographer, the irradiation instruction switch 5 turns ON the irradiation instruction signal output to the radiation control unit 11A via the radiation control console 41. In FIG. 12, although the output of the irradiation instruction signal from the radiation control unit 11A to the external device is not shown, when operating in cooperation with the external device, an irradiation instruction signal may be output to the external device.

[0140] In the prior art 2, since it is not configured to receive an irradiation permission signal from the external device, it does not perform control to transmit an irradiation signal when the irradiation instruction signal and the irradiation permission signal are both available. For this reason, the radiation control unit 11A only detects that the irradiation instruction signal has become ON, and transmits the irradiation signal to the high voltage generation unit 12. When the high voltage generation unit 12 receives the irradiation signal, it applies, as an irradiation output, the high voltage required for radiation irradiation in the radiation generation unit 2 to the radiation generation unit 2. When the radiation generation unit 2 is applied with a high voltage from the high voltage generation unit 12, it generates radiation corresponding to the applied voltage. The generated radiation is irradiated to the subject and the cassette 3A behind it after the direction, area, quality, etc. of the irradiation are adjusted by a controller such as a collimator (not shown). Part of the radiation passes through the subject and enters the cassette 3A. When radiation enters the cassette 3A, a radiation image is formed on the stored film or fluorescent plate.

[0141] Here, in order to prevent irradiation from being performed before the rotation of the rotating anode reaches a sufficient speed, similar to the above-described prior art 1, the radiation control unit 11A may be configured not to transmit the irradiation signal even when it detects that the irradiation instruction signal has become ON until a predetermined waiting time has elapsed after detecting that the irradiation preparation signal has become ON as described above.

[0142] Thus, in the radiation imaging using the conventional system 200A, similar to the case of using the above-described conventional system 100A, only one radiation image (still image) of the subject is taken based on one imaging operation.

[0143] <Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 13 to 16. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In addition, the various modification patterns described in the first embodiment are also applicable to this embodiment.

[0144] [Premise, Background, Problem] Among radiation imaging systems, there is a radiation control unit 11 as shown in the above prior art 1, which has an input unit for an irradiation permission signal from the outside, and transmits an irradiation signal in response to an irradiation instruction from a photographer and an irradiation permission from the outside. On the other hand, there is also a radiation control unit 11A as shown in the above prior art 2, which has only an input unit for an irradiation instruction signal from the outside and captures a still image. The radiation imaging system (hereinafter, system 200) according to this embodiment enables continuous imaging by adding an additional device 6A even to such a radiation control unit 11A.

[0145] [System Configuration] First, the system configuration of system 200 will be described. FIG. 13 is a block diagram showing a schematic configuration of system 200 according to the second embodiment.

[0146] The system 200 according to the present invention, for example, as shown in FIG. 13, replaces the cassette 3A of the conventional system 200A shown in FIG. 12 with an imaging device 3, and further includes an imaging device control console 42 and an additional device 6A similar to those in the first embodiment. Note that, similar to system 100 of the first embodiment, in system 200, as shown in FIG. 27, there may be a case where a plurality of generating devices are connected. In such a case, any one of them will be selected and used. Similarly, in system 200, there may be a case where a plurality of imaging devices 3 are connected. In such a case, any one of them will be selected and used.

[0147] The additional device 6A includes an additional control unit 61A and an interface unit (hereinafter referred to as the I / F unit 67). In addition, in FIG. 13, as the additional device 6A, an example is shown in which the additional control unit 61A and the I / F unit 67 are separately configured, but they may be integrally configured.

[0148] The additional control unit 61A has a third connection unit 66 in addition to the first acquisition unit 62, the second acquisition unit 63, the first connection unit 64, and the second connection unit 65, which are the same as those in the first embodiment. The I / F unit 67 includes a first AND circuit 67a and a second AND circuit 67b. The first acquisition unit 62 and the third connection unit 66 are respectively connected to one input unit of the first AND circuit 67a. The second acquisition unit 63 and the second connection unit 65 are respectively connected to one input unit of the second AND circuit 67a and the other input unit of the second AND circuit 67b.

[0149] In the system 100 according to the first embodiment, the irradiation instruction switch 5 is connected to the console 4, and the irradiation instruction switch 5 outputs an irradiation preparation signal and an irradiation instruction signal to the additional device 6 via the radiation control device 1. However, in the system 200 according to this embodiment, the irradiation instruction switch 5 capable of outputting an irradiation preparation signal and an irradiation instruction signal is directly connected to the additional device 6A. The additional device 6A can input the irradiation preparation signal and the irradiation instruction signal from the irradiation instruction switch 5 to one input unit of the first and second AND circuits 67a and 67b of the additional control unit 61A and the I / F unit 67, respectively. That is, the first acquisition unit 62 can directly acquire the irradiation preparation signal from the irradiation instruction switch 5, and the second acquisition unit 63 can directly acquire the irradiation instruction signal from the irradiation instruction switch 5. Note that the substrate or device provided with the irradiation instruction switch 5 may be connected to the I / F unit 67, and the first and second acquisition units 62 and 63 may be configured to acquire the irradiation preparation signal and the irradiation instruction signal output by the irradiation instruction switch 5 via the substrate or device.

[0150] In addition, the third connection part 66 according to the present embodiment outputs a shooting preparation completion signal, and the second connection part 65 outputs an irradiation permission signal to the first and second AND circuits 67a and 67b respectively. When the AND conditions are satisfied between the irradiation preparation signal and the irradiation instruction signal from the irradiation instruction switch 5 in the first and second AND circuits 67a and 67b, the irradiation preparation signal and the irradiation instruction signal can be output to the radiation control unit 11 via the radiation control console 41 respectively. That is, the second connection part 65 according to the present embodiment can be connected to the generator via the I / F part 67. Therefore, the I / F part 67 and the radiation control console 41 of the present embodiment form a relay part in the present invention.

[0151] In FIG. 13, an example is shown in which the irradiation preparation signal from the irradiation instruction switch 5 is also branched so as to be input to the additional control part 61A and the first AND circuit 67a in the I / F part 67, and the irradiation preparation signal is output from the I / F part 67 when the AND condition is satisfied with the shooting preparation completion signal from the additional control part 61A. However, the irradiation preparation signal may not have such a configuration, and may be directly output from the irradiation instruction switch 5 to the radiation control console 41 and the radiation control unit 11A.

[0152] In addition, FIG. 13 illustrates a configuration in which the third connection part 66 directly transmits and receives information and signals to and from the imaging device 3. However, the third connection part 66 may be connected to other devices via a relay part (not shown) capable of relaying signals. In addition, FIG. 13 illustrates a case where the first acquisition part 62, the second acquisition part 63, the first connection part 64, and the second connection part 65 are provided separately. However, at least two of the first acquisition part 62, the second acquisition part 63, the first connection part 64, the second connection part 65, and the third connection part 66 may be integrally configured (each of the parts 62 to 66 may be used in common). In addition, although not shown, a configuration may be adopted in which the irradiation preparation signal and the irradiation instruction signal output from the additional device 6A are directly input to the radiation control unit 11A without passing through the radiation control console 41.

[0153] In addition, the additional control unit 61A executes a program different from the additional control unit 61 according to the first embodiment, and its structure can be the same as that of the additional control unit 61 according to the first embodiment. (Although not shown in FIG. 2, the additional control unit 61 according to the first embodiment also includes the third connection unit 66, but since the program does not include a command using this, it is possible to use the same one as the additional control unit 61). Alternatively, the additional control unit 61A may be separately provided from the additional control unit 61 and use only the necessary functions. When the additional control unit 61A detects that the irradiation preparation signal from the irradiation instruction switch 5 has become ON, it turns ON the imaging preparation signal output to at least one of the imaging device 3 and the console 4. In addition, when the additional control unit 61A detects that the imaging preparation completion signal from at least one of the console 4 and the imaging device 3 has become ON, it turns ON the imaging preparation completion signal output to the other input unit of the first AND circuit 67a of the I / F unit 67.

[0154] When the additional control unit 61A detects that the irradiation instruction signal from the irradiation instruction switch 5 has become ON, it turns ON the imaging start signal output to at least one of the imaging device 3 and the console 4. In addition, when the additional control unit 61A detects that the irradiation start signal from at least one of the console 4 and the imaging device 3 has become ON, it repeatedly outputs the same irradiation permission signal (for example, a pulse-like signal) as in the first embodiment to the other input unit of the second AND circuit 67b of the I / F unit 67 at a predetermined period. In addition, the additional control unit 61A repeatedly outputs the same timing signal (for example, a pulse-like signal) as in the first embodiment to the imaging device 3 at a predetermined period. In this way, in order to control the transmission timing of the irradiation permission signal and the timing signal, the additional control unit 61A can be configured to have the same timing means as in the first embodiment.

[0155] [Operation] Next, the operation of the above system 200 will be described. FIGS. 14 to 16 are ladder charts showing the operation of the system 200 according to the present embodiment.

[0156] A: Operations at the time of equipment installation, device startup, connection device change, and periodic connection device confirmation (steps S1, S2) and B: Operations in preparation for shooting (steps S3 to S13) are the same as those in the first embodiment as shown in FIG. 9. That is, even in the system 200 according to the present embodiment, similar to the system 100 according to the first embodiment, shooting can be performed even when the combination of the generator and the imaging device 3 is changed. Therefore, it is possible to select a cassette-type imaging device 3 suitable for the shooting order and shooting technique from among a plurality of cassette-type imaging devices 3 having different sizes and performances and perform shooting. In that case, for example, as shown in FIG. 7, an imaging device 3 suitable for the current shooting is selected from among a plurality of imaging devices 3 that can be connected to the console 4 and can be used for shooting, and shooting is performed. Although not shown, in the case of the system 100 in which a plurality of generators are connected to one console 4, the generator used for shooting is selected and shooting is performed.

[0157] The addition control unit 61A of the additional device 6A or the console 4 according to the present embodiment can acquire the irradiation frame rate or the imaging frame rate when selecting at least one of the generator and the imaging device 3. In addition, the addition control unit 61A or the console 4 can also acquire the imaging frame rate. The irradiation frame rate and the imaging frame rate to be acquired may be those input (selected) by the photographer to the console 4, or those received from the generator or the imaging device 3. When receiving from the generator or the imaging device 3, it may be configured to receive one frame rate selected in each device, or it may be configured to receive all of the plurality of frame rates corresponding to each device. The additional control unit 61A or the console 4 having such a function constitutes the first and second acquisition means in the present invention.

[0158] In order for imaging to be performed without problems, it is necessary to satisfy all of the following discrimination conditions (1) to (3). Therefore, the additional control unit 61A or the console 4 discriminates whether all of these discrimination conditions are satisfied. (1) The acquired irradiation frame rate has a value corresponding to the generator. (2) The acquired imaging frame rate has a value corresponding to the imaging device 3. (3) Irradiation frame rate: Imaging frame rate = 1:N (where N is an integer of 1 or more) (the imaging frame rate is N times the irradiation frame rate). Here, the "irradiation frame rate" refers to the number of times of radiation generated by the generator per unit time, and corresponds to the transmission cycle of the irradiation permission signal by the additional control unit 61. On the other hand, the "imaging frame rate" refers to the number of times the imaging device 3 generates a radiation image per unit time, and corresponds to the transmission cycle of the timing signal by the additional control unit 61A. In addition, when there are a plurality of at least one of the irradiation frame rate and the imaging frame rate, there are a plurality of combinations of the irradiation frame rate and the imaging frame rate, so the discrimination may be performed a plurality of times accordingly. Also, here, N is an integer of 1 or more. However, for example, when imaging is performed by thinning out radiation irradiation at a predetermined interval, it is preferable to set N as an integer of 2 or more. By executing this process, the additional control unit 61A or the console 4 constitutes the discrimination means in the present invention.

[0159] In addition, when there are a plurality of at least one of the imaging frame rate received from the imaging device 3 and the irradiation frame rate received from the generator, a plurality of combinations of the imaging frame rate and the irradiation frame rate can be obtained. Therefore, it may be discriminated in advance whether all of the above discrimination conditions are satisfied for each of them. Also, when the generating device, the imaging device 3, and the console 4 are configured such that only the irradiation frame rate and the imaging frame rate supported by the generating device and the imaging device can be selected, the determination of whether the above (1) and (2) discrimination conditions are satisfied can be omitted.

[0160] As a result of checking whether all of the above discrimination conditions are satisfied, if any of the above discrimination conditions are not satisfied, it is advisable to take at least one of the following corresponding actions (4) to (6). (4) Do not allow selection that does not satisfy the above relationship or accept (set) the input numerical value for the imaging device 3 to be used, the generating device to be used, the imaging frame rate of the imaging device 3, and the radiation emission rate of the generating device. (5) Gray down the setting candidates that do not satisfy the above relationship (perform a display to notify the discrimination result), etc., so that they are excluded from the selection targets and cannot be selected. (6) Even if it can be selected, do not allow progression to the next sequence. Or do not permit imaging. Note that when performing the above corresponding actions, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied. Also in this embodiment, the warning can be given by voice or by a display that notifies the discrimination result using the display unit 43.

[0161] [C: Imaging confirmation (irradiation preparation)] The additional device 6A continues to repeatedly transmit the timing signal to the imaging device 3, and each time the imaging device 3 receives this timing signal, the imaging device 3 repeats the readout operation. When the photographer finishes positioning the subject and presses the first stage of the irradiation instruction switch 5 (step S14), the irradiation instruction switch 5 turns on the irradiation preparation signal output to the additional device 6A (step S15A).

[0162] The irradiation preparation signal is input to the additional control unit 61A and one input unit of the first AND circuit 67a of the I / F unit 67, respectively. At this time, the additional control unit 61A is connected to the other input part of the first AND circuit 67a. Therefore, even if the irradiation preparation signal input from the irradiation instruction switch 5 to one input part of the first AND circuit 67a is ON, when the imaging preparation completion signal input to the other input part is not ON, the irradiation preparation signal output from the first AND circuit 67a to the radiation control console 41 remains OFF.

[0163] When the additional control unit 61A detects that the irradiation preparation signal from the irradiation instruction switch 5 has become ON, it transmits an imaging preparation signal for instructing imaging preparation to at least one of the console 4 and the imaging device 3 (step S17). At this time, the additional control unit 61A or the console 4 may reconfirm the following discrimination conditions (1) to (3). (1) The set irradiation frame rate has a value corresponding to the generator. (2) The set imaging frame rate has a value corresponding to the imaging device 3. (3) Irradiation frame rate: imaging frame rate = 1:N (where N is an integer of 1 or more) (the imaging frame rate is N times the irradiation frame rate). If the above relationship is not satisfied, the console 4 may prohibit subsequent steps of the subsequent sequence or may not give permission for imaging. Also, when performing the above correspondence, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied.

[0164] When at least one of the console 4 and the imaging device 3 receives the imaging preparation signal, it performs imaging preparation, and when the imaging preparation is completed, it turns ON the imaging preparation completion signal output to the additional device 6A (step S18).

[0165] [Control of Imaging Preparation of External Devices] Also, although illustration is omitted, when at least one of the console 4 and the imaging device 3 has a connection part for inputting a shooting preparation completion signal indicating whether shooting preparation has been completed from an external device, at least one of the console 4 and the imaging device 3 may be configured to turn on the shooting preparation completion signal when it detects that the shooting preparation completion signal from the external device has become ON. Alternatively, although illustration is omitted, a connection part for outputting a shooting preparation signal to an external device or a connection part capable of inputting a shooting preparation completion signal from the external device may be provided in the additional device 6A or the additional control unit 61A. Thereby, it becomes possible to instruct shooting preparation to the external device from the additional device 6A or the additional control unit 61A, or to detect the completion of shooting preparation of the external device, and to output a shooting preparation completion signal to the I / F unit in response to the completion of shooting preparation of the external device.

[0166] By detecting that the shooting preparation completion signal has become ON, the additional device 6A can know that at least one of the console 4 and the imaging device 3 or the external device is in a state where shooting is possible. By controlling to perform radiation irradiation after the shooting preparation completion signal becomes ON, it is possible to surely eliminate the risk of irradiating radiation to the subject when at least one of the console 4 and the imaging device 3 or the external device is in a state where shooting is impossible, causing unnecessary exposure to the subject.

[0167] When at least one of the console 4 and the imaging device 3 detects that the shooting preparation signal has become ON, or enters the shooting preparation operation, or completes the shooting preparation operation, it turns on a signal indicating whether it has received the shooting preparation signal transmitted to the additional device 6A, or a signal indicating whether it has entered the shooting preparation operation, or a shooting preparation completion signal indicating whether the shooting preparation operation has been completed (step S18).

[0168] When the additional device 6A detects that the shooting preparation completion signal has become ON, it turns on the shooting preparation completion signal output to the other input part of the first AND circuit 67a of the I / F unit 67. At this time, since both the irradiation preparation signal from the irradiation instruction switch 5 and the imaging preparation completion signal from the additional control unit 61A input to the first AND circuit 67a of the I / F unit 67 are ON, the first AND circuit 67a turns ON the irradiation preparation signal output to the radiation control console 41.

[0169] When the radiation control console 41 detects that the irradiation preparation signal has become ON, it turns ON the irradiation preparation signal output to the radiation control unit 11A (generator). That is, the additional device 6A turns ON the irradiation preparation signal transmitted to the generator via the radiation control console 41 (step S18A). When the generator (radiation control unit 11A, high voltage generation unit 12, radiation generation unit 2) detects that the irradiation preparation signal has become ON, it performs preparations for radiation irradiation similar to those in the first embodiment.

[0170] Here, the case where the additional device 6A transmits the irradiation preparation signal to the radiation control unit 11A after confirming (receiving the imaging preparation completion signal) that the imaging preparations of the imaging device 3 and the console 4 are completed has been described. However, the configuration may be such that the irradiation preparation signal is transmitted to the radiation control unit 11A simultaneously with being transmitted to the imaging device 3 and the console 4 without confirming the completion of the imaging preparations of the imaging device 3 and the console 4. In this case, the first AND circuit 67a of the I / F unit 67 is unnecessary, and the irradiation preparation signal received from the irradiation instruction switch 5 may be distributed to the console 4, the imaging device 3, the radiation control console 41, and the radiation control unit 11A, respectively.

[0171] [D: Imaging execution] Subsequently, when the photographer presses the second stage of the irradiation instruction switch 5 (step S20), the irradiation instruction switch 5 turns ON the irradiation instruction signal output to the additional device 6A (step S21A). At this time, the additional device 6A continues to repeatedly transmit the timing signal to the imaging device 3, and the imaging device 3 repeats the readout operation each time it receives this timing signal.

[0172] The irradiation instruction signal is input to one input part of the second AND circuit 67b of the additional control unit 61A and the I / F unit 67, respectively. At this time, the additional control unit 61A is connected to the other input part of the second AND circuit 67b. For this reason, even if the irradiation instruction signal input from the irradiation instruction switch 5 to one input part of the second AND circuit 67b is ON, if the irradiation permission signal is not input to the other input part, the irradiation instruction signal output from the second AND circuit 67b to the radiation control console 41 remains OFF.

[0173] When the additional device 6A detects that the irradiation instruction signal from the irradiation instruction switch 5 has become ON, it turns ON the imaging start signal output to at least one of the console 4 and the imaging device 3 (steps S23, S24). At this time, the additional control unit 61A or the console 4 may re-check the following discrimination conditions (1) to (3). (1) The set irradiation frame rate is a value corresponding to the generator. (2) The set imaging frame rate is a value corresponding to the imaging device 3. (3) Irradiation frame rate: Imaging frame rate = 1:N (where N is an integer of 1 or more) (the imaging frame rate is N times the irradiation frame rate). If the above relationship is not satisfied, the console 4 may prohibit the subsequent sequence or may not give imaging permission. Also, when performing the above correspondence, it may be configured to notify the photographer of an error and warn the photographer that the above relationship is not satisfied.

[0174] When the imaging device 3 detects that the imaging start signal has become ON, taking the end of the read operation being performed by itself at that time as an opportunity, it turns ON the irradiation start signal output to the additional device 6A, for example, as shown in FIG. 15 (step S25). When the additional control unit 61A detects that the irradiation start signal from the imaging device 3 has become ON, it determines that the imaging device 3 is in a shootable state, and each time it transmits a timing signal to the imaging device 3, it repeatedly inputs an irradiation permission signal to the other input unit of the second AND circuit 67b of the I / F unit 67. At this time, since both the irradiation instruction signal from the irradiation instruction switch 5 and the irradiation permission signal from the additional control unit 61A input to the second AND circuit 67b of the I / F unit 67 become ON, the second AND circuit 67b repeatedly transmits the irradiation instruction signal to the radiation control unit 11A via the radiation control console 41 (step S26A).

[0175] When the irradiation frame rate: shooting frame rate is set to 1:N, the additional control unit 61 outputs the shooting permission signal once every time it outputs the timing signal N times (in FIG. 5, the case of N = 2 is shown). The imaging device 3 continuously repeats accumulation and readout, but each time it repeats accumulation and readout N times, it receives radiation irradiation from the generating device once and generates an exposure image.

[0176] The latter half of the operation in "D: Shooting execution" (steps S27 to S30) and the first half of the operation in "E: Shooting end" (steps S31 to S36) are the same as those in the first embodiment.

[0177] [Shooting end] When the photographer who has confirmed that shooting has ended releases the second stage of the irradiation instruction switch 5 (step S37), the irradiation instruction switch 5 turns off the irradiation instruction signal (step S38A). Then, the imaging device 3 turns off the shooting start signal.

[0178] After that, when the photographer releases the first stage of the irradiation instruction switch 5 (step S40), the irradiation instruction switch 5 turns off the irradiation preparation signal (step S41A). Steps S43 to S45 are the same as those in the first embodiment. In this way, a series of shooting operations is completed. The system 200 according to this embodiment operates as described above. Thus, similar to the system 100 according to the first embodiment, dynamic imaging is performed in which a plurality of still images are repeatedly captured in a short time.

[0179] [Effect] As described above, the system 200 according to this embodiment connects an additional control unit 61A to the radiation control device 1 in the conventional system 200A shown in FIG. 12, which can only perform radiation irradiation once for one radiation irradiation instruction. As a result, the radiation control device 1 can output irradiation signals a plurality of times for one irradiation instruction (pressing the second stage of the irradiation instruction switch 5). Therefore, it is possible to perform imaging in which still images are repeatedly captured a plurality of times in a short time using the imaging device 3, that is, dynamic imaging. In addition, the conventional system 200A shown in FIG. 12 is widely popular as something that can capture simple still images. Therefore, a medical institution using the conventional system 200A can easily modify the conventional system 200A including the existing generator to support dynamic imaging by simply adding the imaging device 3 and the additional device 6A without updating the expensive generator.

[0180] In addition, the system 200 according to this embodiment divides the additional device 6A into an additional control unit 61A and an I / F unit 67, and the additional control unit 61A can have the same structure as the additional control unit 61 of the first embodiment (only the stored program is different). Therefore, using common parts, it is possible to manufacture both the additional device 6 of the first embodiment and the additional device 6A of the second embodiment (modifying both the conventional system 100A and the conventional system 200A) without increasing the types of devices.

[0181] In addition, since the system 200 according to the present embodiment notifies the determination result of whether the shooting frame rate acquired by the console 4 is N times (where N is an integer of 1 or more) the acquired irradiation frame rate in a manner that can be recognized by the shooter, when the imaging device 3 repeatedly accumulates and reads charges a predetermined number of times and the generating device irradiates radiation a smaller number of times than the predetermined number of times, it is possible to surely prevent the risk that shooting is started with a frame rate not corresponding to at least one of the imaging device 3 and the generating device set.

[0182] Also, in the description of the second embodiment above, the configuration in which the additional device 6A is added to enable dynamic imaging with respect to the conventional system 200A shown in FIG. 12 was described. However, the embodiments of the present invention are not limited to this, and for example, the additional device 6A of the second embodiment can be added to the conventional system 100A shown in FIG. 1 to enable dynamic imaging. This is because, for example, by making the irradiation permission signal input to the radiation control unit 11 of the conventional system 100A shown in FIG. 1 always ON, it is possible to configure the conventional system 100A shown in FIG. 1 as a radiation imaging system according to the present invention. With such a configuration, it is possible to make dynamic imaging possible by adding an additional device to various radiation imaging systems.

[0183] In the description of the first and second embodiments above, the functions as the first acquisition means, second acquisition means, determination means, notification means or output means, irradiation permission means, readout instruction means, and designation means in the present invention, which were described as being possessed by the additional control unit 61 or the console 4, and various functions incidental to these functions may be possessed by the radiation control device 1 or the imaging device 3 instead of the additional control unit 61 or the console 4.

[0184] In addition, as the systems 100 and 200 according to the first and second embodiments, although the conventional systems 100A and 200A are modified using the additional devices 6 and 6A as an example, the present invention is not limited to such a form of a radiation imaging system. A radiation image system may be used in which the imaging device 3 and the radiation control devices 1 and 1A respectively have a dynamic imaging function without including the additional devices 6 and 6A. In this case, the functions as the first acquisition means, the second acquisition means, the determination means, the notification means or the output means, the irradiation permission means, the readout instruction means, and the designation means in the present invention, and various functions incidental to these functions will be possessed by the console 4, the radiation control device 1, or the imaging device 3 or the like.

[0185] <Sequence state transition> Next, the transition operation of the sequence states of the systems 100 and 200 according to the first and second embodiments will be described with reference to FIGS. 17 and 18.

[0186] [Premise, background, problem] In the systems 100 and 200 according to the first and second embodiments, correct imaging cannot be performed unless each connected device operates in the correct order. In addition, even when an error unintended by the imager, such as noise on the signal line or disconnection of the signal line, occurs, it is necessary to safely end the imaging so that unintended radiation irradiation or the like does not occur.

[0187] [Operation] First, the operation of the systems 100 and 200 will be described. FIG. 17 is a state transition diagram of the systems 100 and 200, and FIG. 18 is a timing chart showing the operation of the systems 100 and 200.

[0188] As shown in FIG. 17, the systems 100 and 200 according to the present embodiment are initially in a standby state St1 in which they have not received an imaging start instruction from the imager. After that, when the console 4 receives a shooting order from a higher-level system 7 such as a RIS or HIS, and the shooter selects the shooting order, as shown in FIG. 18, the console 4 turns on the sequence start signal output to the imaging device 3 and the additional devices 6, 6A (t1). Then, the imaging device 3 and the additional devices 6, 6A start the shooting preparation. As a result, the systems 100, 200 transition to the irradiation preparation state St2 as shown in FIG. 17.

[0189] In the irradiation preparation state St2, as shown in FIG. 18, the additional devices 6, 6A repeatedly transmit a timing signal to the imaging device 3 at a predetermined interval, and each time the imaging device 3 receives this timing signal, the imaging device 3 repeatedly performs a reset operation to remove the charge accumulated in the imaging device 3 by repeating a read operation. The read operation performed here is the same as the operation when acquiring a captured image. However, since the image obtained by the reset operation is generated in the irradiation preparation state St2 where no radiation is irradiated, it may be saved in the memory of the imaging device 3 or transferred to the console 4, but it may also be deleted without being saved or transferred.

[0190] On the other hand, at least a part of the image obtained by this reset operation represents the characteristics of individual pixels of the imaging device 3 or the image of the imaging device 3. Therefore, for example, it can be saved in the imaging device 3 or transferred to the console 4 as a correction image for correcting the captured image. As the correction image, at least one of a plurality of images obtained by repeating the reset operation may be used, or the average of the signal values of corresponding pixels in a plurality of images or the complementary predicted value in the time direction may be calculated and used as the correction image. Examples of methods for correcting a captured image include subtracting the signal value of each pixel of the correction image from the image obtained by irradiating radiation.

[0191] Note that it is configured to be able to transmit to the imaging device 3 even when the timing signal is in a state other than the irradiation preparation state St2. When the irradiation preparation state St2 is entered, the reset operation instruction signal is turned on, and the imaging device 3 may be configured to perform a reset operation only when the reset operation instruction signal is on.

[0192] The photographer sets imaging conditions and the like using the imaging device control console 42 or the radiation control console 41, positions the subject, and then starts the imaging operation. Specifically, as shown in FIG. 18, the irradiation instruction switch 5 is operated to turn on the irradiation preparation signal transmitted to the console 4 (t2). Then, the systems 100 and 200 transition to the irradiation activation state St3 as shown in FIG. 17.

[0193] In the irradiation activation state St3, the console 4 checks the states of the radiation control device 1, the imaging device 3, and the additional devices 6 and 6A. When it determines that the imaging is possible, as shown in FIG. 17, it turns on the imaging preparation completion signal transmitted to the additional devices 6 and 6A (t3). Here, the console 4 may be configured to check whether the imaging conditions set in the radiation control console 41 are the same as the imaging conditions set in the imaging device control console 42, and if they are different, display that they are different. Also, when the imaging conditions set in the radiation control console 41 are different from the imaging conditions set in the imaging device control console 42, it may be configured to control so that the subsequent imaging sequence cannot proceed. Also, while the imaging preparation completion signal is on, it may be configured to control so that the imaging conditions set in the imaging device control console 42 and the radiation control console 41 cannot be changed.

[0194] On the other hand, when the radiation control device 1 detects that the imaging preparation completion signal is on, it starts preparing for radiation irradiation (t2). This is, for example, an operation to start the rotation of the rotating anode of the radiation generation unit 2.

[0195] Also, when the additional devices 6, 6A detect that the irradiation preparation signal has become ON, they start counting the set timer (t2). Although details will be described later, this prevents the system from transitioning to the irradiation standby state St4 described later until the count of this timer has elapsed a predetermined standby time even if the photographer presses the second stage of the irradiation instruction switch 5 (turns on the irradiation instruction signal).

[0196] After that, the photographer presses the second stage of the irradiation instruction switch 5 to turn on the irradiation instruction signal (t4). Although FIG. 18 illustrates the case where the irradiation instruction signal becomes ON after the shooting preparation completion signal becomes ON, the irradiation instruction signal may be turned on before the shooting preparation completion signal becomes ON. When the additional control units 61, 61A confirm that the irradiation instruction signal is ON, the shooting preparation completion signal is ON, and the timer has elapsed a predetermined standby time, the systems 100, 200 transition to the irradiation standby state St4 as shown in FIG. 17.

[0197] In the irradiation standby state St4, the additional control units 61, 61A confirm whether the imaging device 3 is in a state where shooting is possible. The imaging device 3 confirms whether it is in a state where shooting is possible, and if it determines that it is in a state where shooting is possible, it transmits an irradiation start signal to the additional control units 61, 61A as shown in FIG. 18 (t5). The confirmation of whether shooting is possible is determined, for example, by whether a predetermined reset operation has been completed, whether the charge in the light receiving unit of the imaging device 3 has been removed, or whether the reset operation has been completed for all pixels on the light receiving surface (since the reset operation is performed by scanning each pixel arranged in a matrix on the light receiving surface one row at a time). When the additional control units 61, 61A detect that the irradiation start signal from the imaging device 3 has become ON, the systems 100, 200 transition to the irradiation permission state St5 as shown in FIG. 17.

[0198] In the irradiation permission state St5, as shown in Fig. 18, the additional control units 61, 61A turn on the imaging start signal, which is an internal interlock (t5), and repeatedly transmit an irradiation permission signal or an irradiation instruction signal to the radiation control units 11, 11A at a timing corresponding to the timing of outputting a timing signal to the imaging device 3. Each time the generating device (radiation control units 11, 11A, high voltage generating unit 12, radiation generating unit 2) receives an irradiation permission signal or an irradiation instruction signal, it generates radiation, enabling the radiation transmitted through the subject to repeatedly enter the imaging device 3.

[0199] In the irradiation permission state St5, after the irradiation start signal is turned on, each time the additional control units 61, 61A transmit a timing signal or an irradiation permission signal, they can be configured to control the counting of the number of images taken. In this case, when the counted number of images taken reaches the set maximum number of images, the imaging start signal is turned off (t6), and the systems 100, 200 transition to the irradiation end state St6 as shown in Fig. 17. When counting the number of images taken by counting the irradiation permission signals, since it is necessary to read out the imaging image obtained by the last radiation irradiation, the timing for turning off the readout instruction signal is delayed, and a configuration can also be adopted in which a timing signal serving as a trigger for the readout operation is further transmitted for one frame. With such a configuration, it is possible to continue imaging beyond the set maximum number of images, perform unnecessary radiation irradiation on the subject, and eliminate the risk of overexposing the subject to radiation.

[0200] Thereafter, when the photographer releases the second stage of the irradiation instruction switch 5, as shown in Fig. 18, the irradiation instruction signal becomes OFF (t7). Thereafter, when the photographer releases the first stage of the irradiation instruction switch 5, the irradiation preparation signal becomes OFF (t8). Then, when the additional control units 61, 61A confirm that all signals input to themselves have been released, the systems 100, 200 transition to the irradiation preparation state St2 as shown in Fig. 17. Here, "all signals" can be an irradiation preparation signal, an irradiation instruction signal, a shooting start signal that is an interlock of the additional control units 61 and 61A, and an irradiation start signal of the imaging device 3.

[0201] After that, if the photographer further performs other shootings or, as a result of checking the captured images, determines that it is necessary to perform reshooting because the obtained captured images are not sufficient for the desired purpose, the state of the subject and the shooting conditions are changed, and shooting is performed again in the flow described above. On the other hand, if it is determined that there is no need to perform shooting, the console 4 turns off the sequence start signal (t9) and ends the shooting sequence. Then, the systems 100 and 200 transition to the standby state St1 as shown in FIG. 17. In addition to the above case (the photographer's determination), it may be configured to transition to the standby state St1 when there is no input from the photographer for a certain period of time.

[0202] [Operation when shooting is not continued] Note that the above-described flow of state transition is the case where shooting is continued until the maximum number of shooting sheets is reached, but there may be cases where shooting cannot be continued until the maximum number of shooting sheets is reached due to various situations.

[0203] For example, when the photographer wants to interrupt shooting before reaching the maximum number of shooting sheets, the irradiation instruction signal is turned off by releasing the second stage of the irradiation instruction switch 5. Then, the systems 100 and 200 transition from the irradiation permission state St5 to the irradiation end state St6. This is because one of the plurality of OR conditions (the irradiation instruction signal from the irradiation instruction switch 5 becomes OFF, the irradiation start signal from the imaging device 3 becomes OFF, the shooting start signal from the additional devices 6 and 6A becomes OFF) for transitioning from the irradiation permission state St5 to the irradiation end state St6 shown in FIG. 17 is satisfied.

[0204] In the irradiation end state St6, the radiation irradiation is stopped, and thereafter, similar to the case where the shooting is performed up to the maximum number of shots, processes such as transferring the remaining images in the imaging device 3 to the console 4 and deleting the images stored in the imaging device 3 after the transfer are performed. This is because even when shooting is not performed up to the previously specified number of shots, the captured images may be available, and in such cases, the photographer can view the captured images in the same way as normal images. On the other hand, it is necessary to manage the fact that shooting was not performed up to the previously specified number of shots in association with the captured images. When shooting is not performed up to the previously specified number of shots, it is possible to adopt a configuration in which the fact that shooting was not performed up to the previously specified number of shots is appended and managed for individual images or an aggregate of images. Also, the console 4 may be configured to display the fact that shooting was not performed up to the previously specified number of shots by transmitting an error signal from the additional devices 6, 6A or the like when shooting is not performed up to the previously specified number of shots.

[0205] [Operation at the time of error occurrence] Also, the connection between the additional devices 6, 6A and the imaging device 3 may be disconnected during shooting. As a cause, for example, when the additional devices 6, 6A and the imaging device 3 are wired-connected, it is conceivable that the cable comes off from the connector, and when the additional devices 6, 6A and the imaging device 3 are wirelessly connected, wireless interference, a failure of the wireless device, a power cut to the wireless device, etc. are conceivable.

[0206] Therefore, the systems 100, 200 may be provided with a function of monitoring the occurrence of errors (error 1, error 2, error 3, error 4) in each sequence state St3 to St6, and when an error is detected, the system may be transitioned to the error state St7 as shown by the broken line in FIG. 17. Also, when transitioning to the error state St7, the display unit 43 of the console 4 or the like may be configured to display what kind of error caused the transition to the error state St7.

[0207] Such error detection may proceed in parallel with an error monitoring sequence that monitors signals in each state, which is different from the imaging sequence shown in FIG. 17, for example. When an error is detected in the error monitoring sequence, the imaging sequence may be configured to transition from the current sequence states St3 to St6 to the error state St7. Alternatively, an operable time may be set for each of the sequence states St3 to St6 shown in FIG. 17, and when transitioning to each of the sequence states St3 to St6, the operation time in each sequence state may be measured by starting the timer. When the time of the timer elapses the operable time in that sequence state, the control may be such that a transition is made to the error state St7. Furthermore, when an error occurs, it may be configured to notify the error to the console 4 from the additional devices 6, 6A or the imaging device 3 that detected the error, and display that an error has occurred on the console 4.

[0208] After transitioning to the error state St7, a transition is made to the irradiation preparation state St2 or the standby state St1 when a specific condition is satisfied (such as error cancellation or cancellation of all signals).

[0209] [Effect] By using such an error detection method, it is possible to surely detect malfunctions of the device and the operation, transition to the error state, and return to the standby state St1 or the irradiation preparation state St2 from the middle of the imaging sequence as necessary, thereby eliminating the risk of radiation irradiation in a state where the device and the operation have malfunctions and needlessly exposing the subject to radiation.

Example

[0210] Next, a specific example of implementing the above systems 100 and 200 will be described. Note that the various techniques described here may also be applicable to the conventional systems 100A and 200A.

[0211] (Example 1) [Commonality of shooting operations at low and high frame rates] When the operation of the imaging device 3 differs depending on the set imaging frame rate, when shooting a moving image, there has been a problem that the captured image obtained after a predetermined time has elapsed since the start of shooting is different between shooting at a high frame rate and shooting at a low frame rate. For example, the number of frames captured until a predetermined time has elapsed since the start of shooting is different between shooting at a high frame rate and shooting at a low frame rate. For this reason, there has been a problem that temperature changes, etc. inside the imaging device 3 accompanying the shooting operation are different between shooting at a high frame rate and shooting at a low frame rate, and as a result, images with different image qualities are obtained. This means that, for example, when observing the change in the size of a region of interest such as a tumor in detail at a high frame rate immediately after surgery and then observing at a low frame rate to reduce the exposure dose when confirming the postoperative course, if the image changes due to the difference in the shooting mode, it becomes difficult to compare the postoperative course with that immediately after surgery, which is a problem.

[0212] In view of such problems, when shooting with a different irradiation frame rate, the imaging frame rate set in the imaging device 3 may not be changed. That is, even if the irradiation cycle of the radiation by the generator expands, the imaging device 3 repeats the imaging operation at the same cycle. At that time, when shooting in the low frame rate mode, unexposed frames are extracted from the captured frames, and a moving image composed of the extracted unexposed frames is generated. By doing so, since the influence of temperature rise, etc. after a predetermined time has elapsed since the start of shooting becomes the same, it is possible to obtain images of the same quality at the same temperature even with different irradiation frame rates.

[0213] (Example 2) [Change of radiation irradiation period] The imaging device 3 forms an image by sequentially reading out the exposure images generated at the timing of radiation irradiation from the pixels at the ends of the radiation detection unit 32. If a part of the radiation irradiation is performed while the reading is being sequentially performed from the pixels at the ends, a part of the radiation image generated by this reading may become a part of the image of the next frame. Therefore, the radiation irradiation time was limited to the period when the imaging device 3 was not being read out. However, since the radiation irradiation window, which is the period during which radiation can be irradiated, becomes short in imaging with a high imaging frame rate, it has been difficult to complete the radiation irradiation within that radiation irradiation window. In particular, in pulsed radiation irradiation, there is a trailing edge where radiation irradiation remains in the latter half of the pulse, and it has been difficult to fit the trailing edge including the radiation irradiation window.

[0214] In view of such problems, for example, as shown in FIG. 19, the length of the radiation irradiation window may be changed according to whether or not decimation irradiation of radiation is performed. In particular, when performing decimation irradiation, as shown in FIG. 19(b), the radiation irradiation window may be made longer than when decimation irradiation is not performed. By doing so, there is a margin in the time from the rise to the fall of the pulsed radiation, so it becomes easier to fit the trailing edge of the radiation within the radiation irradiation window. Note that when performing decimation irradiation, even if the trailing edge does not fit within the radiation irradiation window, it is erased by the reading of the next decimated image. Therefore, even if the radiation irradiation time is lengthened, the influence on the frame for imaging the next radiation irradiation can be eliminated.

[0215] (Example 3) [Change of transfer period] In the imaging of a moving image, there has been a problem that after the image is read out, the transfer of the image may not be completed by the next accumulation. In view of such problems, an image generated at a timing when no radiation is irradiated may not be transferred, but may be stored in the imaging device 3 or deleted from the imaging device 3. Then, for example, as shown in FIG. 20, the transfer of the image generated at the timing of radiation irradiation is performed using at least a part of the accumulation / readout period at the timing when no radiation is irradiated. By doing so, the transfer time of the image generated at the timing of radiation irradiation can be lengthened, and it becomes possible to stably transfer the image. Also, it becomes possible to increase the overall frame rate.

[0216] (Example 4) [Control of shooting timing (1)] When shooting is performed during a partial period of the irradiation instruction signal input period, if the period from when the photographer presses the second stage of the irradiation instruction switch until actual shooting starts is long, there is a problem that the photographer may not be able to shoot the dynamic state he / she wants to shoot. In view of such problems, when shooting is performed during a partial period of the irradiation instruction signal input period, for example, as shown in FIG. 21, shooting (radiation irradiation / accumulation) may be performed at the timing of the first shootable timing after the photographer gives an instruction to shoot. By doing so, since shooting is performed at the earliest possible timing after the photographer gives an instruction to shoot, it becomes possible to start shooting at the timing the photographer wants to shoot, and it becomes possible to reduce the risk of not being able to shoot the dynamic state the photographer wants to shoot.

[0217] (Example 5) [Control of shooting timing (2)] Before starting shooting, the imaging device 3 needs to perform reset, warm-up, etc. In order to obtain a stable image, it may be better to perform shooting at a preferably late timing in some cases. In view of such problems, when shooting is performed during a partial period of the irradiation instruction signal input period, for example, as shown in FIG. 22, shooting may be performed at a shooting timing other than the first shootable timing after the photographer gives an instruction to shoot, but at a timing of the second or later shot. For example, when performing imaging such that the generating device irradiates radiation once every time the imaging device 3 performs N imaging operations (in the case of FIG. 22, N = 2), imaging is performed at the Nth imaging - possible timing after the imager gives an imaging instruction. By doing so, after the imager gives an imaging instruction, by performing imaging at a late timing, the imaging device 3 can sufficiently perform reset, warm - up, etc., and can start imaging in a stable state, making it possible to improve the quality of the captured image.

[0218] (Embodiment 6) [Standby Time Before Imaging Start] Before starting imaging, the imaging device 3 needs to perform reset, warm - up, etc. In order to obtain a stable image, it may be desirable to perform imaging at a timing as late as possible in some cases. In view of such problems, at least one of the imaging device 3, the additional control unit 61, the console 4, and the radiation control unit 11A may set a delay time so as to enter the imaging operation after a predetermined time has elapsed since the first or second stage of the irradiation instruction switch is pressed. Also, when performing imaging in the dynamic imaging mode, the above - mentioned delay time may be made longer than when performing imaging in the still - image imaging mode. Also, it may be possible to start generating an image after irradiating radiation several times at the initial stage of the imaging operation to stabilize it. In this case, the imaging device 3 may not perform imaging during the several times of radiation irradiation at the initial stage.

[0219] Also, during the first few times of radiation exposure, in order to prevent the subject from being irradiated with radiation, the radiation emission may be suppressed by the radiation generation unit, its surroundings, or a collimator attached to the radiation generation unit 2. As a method of suppressing radiation, for example, a suppression plate or the like that is difficult to transmit radiation is movably arranged around the radiation generation unit 2 or its surroundings, or a collimator attached to the radiation generation unit 2. During the first few times of radiation exposure, by moving this suppression plate or the like onto the radiation irradiation axis, the radiation generated from the radiation generation unit 2 is blocked by the suppression plate or the like, and a configuration for suppressing irradiation to the surroundings can be used. After the first few times of radiation exposure, by retracting this suppression plate or the like from the irradiation axis, it becomes possible to irradiate the subject with radiation after the initial stage and perform imaging of the subject. In this way, after the photographer gives an instruction to take a picture, by taking the picture at a slow timing, the imaging device 3 can sufficiently perform resetting, warming up, etc., and it becomes possible to start imaging in a stable state, and it becomes possible to improve the quality of the captured image.

[0220] (Example 7) [Imaging method for change amount] Depending on the imaging technique, there is an imaging method that focuses on the change amount at a certain point in time of dynamic motion. For example, when imaging blood flow, it is not necessary to repeat imaging over a long period of time, and it is sufficient to obtain a plurality of consecutive (two or more) captured images at the moment when blood flow is desired to be imaged. However, if it is not possible to obtain only the images before and after such necessary timings (it is necessary to continuously repeat imaging at the same timing), the subject will be exposed to unnecessary radiation. In view of such problems, only the necessary imaging may be performed at the timing when the change amount is required, or at the timing when only a plurality of consecutive captured images are required. For example, as shown in FIG. 23, the imaging device 3 is made to repeatedly perform accumulation and readout at a fixed cycle, and the generator is made to irradiate radiation only at a plurality of consecutive imaging timings.

[0221] By doing so, it becomes possible to obtain the amount of change in the state of the subject within a predetermined period including the shooting time of a specific captured image by comparing a plurality of consecutive captured images obtained by irradiating this radiation. For example, when photographing blood flow, as shown in FIG. 23, by performing a plurality of consecutive shootings at a specific timing and analyzing their changes, it becomes possible to grasp the blood flow at the shooting timing. Also, by grasping the blood flow state at the shooting timing from the differences between a plurality of consecutive images, it becomes possible to observe the continuous blood flow state. In FIG. 23, the amount of change from the first shooting to the second shooting was obtained by two consecutive shootings, but it may be possible to calculate the amount of change from the first shooting to the plurality of subsequent shootings from three or more shootings as appropriate. By calculating the amount of change from three or more shootings, it becomes possible to suppress noise and the like to a low level. Also, unlike the case shown in FIG. 23, if radiation is irradiated at all timings when the imaging device is in an accumulable state, the subject will be exposed to twice the necessary radiation exposure. However, as shown in FIG. 23, by thinning out the radiation irradiation at unnecessary timings, it becomes possible to reduce the exposure while obtaining necessary information.

[0222] (Example 8) [Variable frame rate] Depending on the imaging technique, the required frame rate may change during imaging. However, in the conventional imaging device 3, it was difficult to change the imaging frame rate during imaging, so accumulation and reading had to be performed at a constant imaging frame rate, and radiation irradiation had to be performed at a constant irradiation frame rate. As a result, radiation irradiation was performed even for unnecessary frames, and the subject was exposed needlessly. In view of such problems, for example, as shown in FIG. 24, imaging may be performed by changing the interval at which thinning is performed at an arbitrary timing of imaging. At that time, the imaging device 3 may be set to perform imaging at a constant imaging frame rate. After that, it is possible to obtain an imaging image with a changed frame rate by selecting only the imaging image at the timing when radiation is irradiated.

[0223] In this way, the conventional imaging device 3 designed according to a specific frame rate can be used. Such an imaging device 3 that performs imaging at a specific frame rate can be started up faster and can continue imaging stably compared to a special imaging device whose frame rate can be changed. Also, by changing the decimation timing of radiation irradiation during imaging, it becomes possible to perform radiation imaging only at the required frame rate, and it is possible to prevent the subject from being exposed to radiation unnecessarily.

[0224] (Example 9) [Control by External Signal] The timing of starting imaging and the timing of changing the frame rate are determined by the dynamics of the subject and the operations of the imaging device and the imaging system. For example, in imaging techniques that require changing the timing of starting imaging and the frame rate according to the operating state of the radiation generation unit such as tomography described later, it is necessary to change according to the operations of the devices in the imaging system. However, it is difficult for the operator to appropriately determine the timing of starting imaging and the timing of changing the frame rate while monitoring the dynamics of the subject and the operations of the imaging device and the imaging system. For this reason, it has been desired to be able to start imaging or change the frame rate by using a measuring device that quantitatively measures the dynamics or a detecting means that detects the start of a predetermined operation of the imaging device 3. In view of such problems, it may be possible to change imaging conditions such as starting imaging and changing the frame rate by an external trigger. As the external trigger, for example, a heart rate monitor attached to the subject, an auto voice that instructs the movement of the subject, a signal from the radiation control device 1 that controls the movement of the tube ball, etc. can be used. By doing so, it is possible to start shooting or change the frame rate at an appropriate timing by using a measuring device that quantitatively measures the dynamics or a detecting means that detects the start of a predetermined operation of the imaging device 3.

[0225] (Example 10) [Application Example to Tomosynthesis, etc.] In a imaging method for generating a tomographic image by performing imaging while moving the radiation generation unit 2 at a constant speed, such as tomosynthesis, an image captured in a state where the inclination of the radiation irradiation axis with respect to the axis orthogonal to the radiation incident surface 3a of the imaging device 3 is large has little influence on the tomographic image. Therefore, in imaging for generating such a tomographic image, it may be desirable to reduce the imaging frame rate and make the imaging interval sparse while the inclination of the radiation irradiation axis is large. On the other hand, when it is desired to obtain a detailed tomographic image, since the influence of an image captured in a state where the inclination of the radiation irradiation axis with respect to the axis orthogonal to the radiation incident surface 3a is large also becomes relatively large, conversely to the above case, it may be desirable to make the imaging interval dense while the inclination of the radiation irradiation axis is large, and reduce the imaging frame rate and make the imaging interval coarse while the inclination of the radiation irradiation axis is small. However, in a conventional radiation imaging control device, since radiation was irradiated and imaging was performed at equal intervals, there was a problem of unnecessarily exposing the subject to radiation. In view of such problems, the irradiation frame rate may be changed according to the inclination of the radiation irradiation axis with respect to the radiation incident surface, that is, thinning of the radiation as shown in FIG. 24 may be performed.

[0226] For example, when the imaging interval is made dense while the inclination of the radiation irradiation axis is large and sparse while the inclination is small, the radiation generation unit 2 has a high irradiation frame rate (in the state of "no decimation (dense)" in FIG. 24) when it is located in the region (A) with a large inclination of the irradiation axis among the regions (A) to (E) shown in FIG. 25, and a low irradiation frame rate (in the state of "decimation 1" in FIG. 24 (for example, decimating every other radiation exposure)) when it is located in the region (B) where the inclination of the irradiation axis is smaller than that in the region (A). Further, when it is located in the region (C) where the inclination of the irradiation axis is smaller than that in the region (B), the irradiation frame rate is further lowered (in the state of "decimation 2" in FIG. 24 (for example, decimating twice every time radiation is irradiated)), and then, in the region (D) where the inclination of the irradiation axis is larger than that in the region (C), the irradiation frame rate is increased (in the state of "decimation 1"), and in the region (E) where the inclination of the irradiation axis is larger than that in the region (D), the irradiation frame rate is further increased (in the state of "no decimation (dense)"), and the like of control is performed.

[0227] On the other hand, depending on the imaging method as described above, it may be desirable to change so that the imaging interval is sparse while the inclination of the radiation irradiation axis is large and dense while the inclination is small. In such a case, when the radiation generation unit 2 is located in the regions (A) or (E) with a large inclination of the irradiation axis among the regions (A) to (E) shown in FIG. 25, it is set to the same state as "decimation 2" in FIG. 24, and when it is located in the regions (B) or (D) where the inclination of the irradiation axis is smaller than that in (A) or (E), the irradiation frame rate is increased (in the state of "decimation 1" in FIG. 24), and when it is located in the region (C) where the inclination of the irradiation axis is smaller than that in (B) or (D), the irradiation frame rate is further increased (in the state of "no decimation (dense)" in FIG. 24). In this way, it becomes possible to perform imaging with the amount of radiation irradiation necessary for generating a tomographic image without unnecessarily exposing the subject, and it becomes possible to reduce the exposure dose of the subject.

[0228] (Example 11) [Application of Additive Readout (1)] Depending on the imaging region and imaging technique, there are cases where the resolution of the image needs to be a certain level or higher, or cases where, instead of a high resolution, high-speed imaging is desired even if the resolution of the image may be low. In view of such problems, when the imaging device 3 reads a radiation image, the imaging frame rate may be changed and imaging may be performed by changing the addition readout (binning) amount for pixels arranged in at least one of the vertical and horizontal directions in the radiation image. Specifically, when selecting the imaging region and imaging technique, set the binning amount, imaging frame rate, and decimation ratio N (where the irradiation frame rate is set to 1 / N of the imaging frame rate) according to the recommended amount of the selected imaging device and perform imaging. In this way, the additional device 6 and the console 4 that give instructions to the imaging device 3 will serve as the readout instruction means in the present invention, and it will be possible to perform imaging with an appropriate resolution and frame rate according to the imaging region and imaging technique. In addition, it becomes possible to increase the number of applicable imaging techniques.

[0229] (Example 12) [Application of addition readout (2)] There are the following methods (a) and (b) for adding and reading the charges accumulated in each pixel of the imaging device. (a) Analog binning that adds and reads on the circuit (b) Digital binning that reads individually on the circuit and adds the read values later To increase the imaging frame rate, it is effective to perform addition readout by analog binning that can shorten the readout time. However, on the other hand, when it is desired to switch the presence or absence of binning after image imaging, or when analog binning is performed and addition is performed on the circuit before readout, and there is a possibility of exceeding the conversion range of the A / D converter 34c of the readout unit 34 of the imaging device 3, etc., it may be appropriate to make at least a part of the addition readout digital binning. In view of such problems, the imaging apparatus 3 may be configured to use analog addition readout for adding and reading out pixels arranged in one of the vertical and horizontal directions in the radiation image, and digital addition readout for adding and reading out pixels arranged in the other direction. In this way, the additional device 6 and the console 4 that give instructions to the imaging apparatus 3 serve as the readout instruction means in the present invention, and it becomes possible to perform imaging at an appropriate resolution and frame rate according to the imaging site and imaging technique.

[0230] In particular, by adjusting the direction and amount of analog binning or digital binning, the frame rate at which the imaging apparatus 3 can perform imaging may be increased, and the combination of frame rates at which imaging can be performed may be increased. For example, in a technique such as tomography in which the radiation generation unit 2 is moved in a certain direction during imaging and the image is reconstructed after imaging, the resolution of the pixels arranged in the direction orthogonal to the moving direction of the radiation generation unit 2 in the imaging apparatus 3 may be more important than the resolution of the pixels arranged in the moving direction of the radiation generation unit 2, or conversely, the resolution of the pixels arranged in the moving direction may be important. In such a case, imaging methods such as adding and reading out pixels arranged in the moving direction of the imaging apparatus 3 by analog binning to speed up the readout, and adjusting the binning amount by digital binning for pixels arranged in the direction orthogonal to the moving direction, or vice versa, become possible.

[0231] (Example 13) [Image correction method (1)] When the switch element 32e provided in each pixel of the imaging apparatus 3 is turned off, each pixel becomes in a state where charge can be accumulated, and when it is turned on, the accumulated charge is discharged. When the imaging frame rate increases, there is a problem that the switch element 32e is turned off before the charge accumulated in each pixel is discharged, and the charge that could not be discharged remains as an afterimage in the next image. In view of such problems, the unexposed image generated at the timing when radiation is not irradiated may be used for correcting (readout efficiency correction) the image with the remaining afterimage. The readout efficiency correction is specifically performed as in the following formula (1). Details are described in, for example, Japanese Patent Application Laid-Open No. 2017-192605 and the like. Image (x, y) after readout efficiency correction = {Image (x, y) after gain correction - Image (x, y) after gain correction one frame before × α(x, y)} / (1 - α(x, y)) ··· (1) (Here, α is a correction coefficient (where 0 < α < 1), and (x, y) indicates coordinates within the image.) For such readout efficiency correction, an image from one frame before is required. By doing so, by using the unexposed image for correction, it is possible to prevent a residual image caused by the operation of the switching element from remaining in the exposed image.

[0232] (Example 14) [Image correction method (2)] Even after performing the above readout efficiency correction on the unexposed image, a residual image may remain. This residual image is often due to the time lag (charge generation delay, lag component) when the photodiode constituting the radiation detection element 32d generates charge. In view of such problems, based on the time interval between the current unexposed image and the next exposed image, the lag component remaining in the next exposed image may be predicted and subtracted from the next exposed image. The unexposed image contains the lag component generated at the timing of generating the exposed image of the previous frame. And the degree to which the lag component is included in the next exposed image can be calculated from the attenuation characteristics. By doing so, it is possible to prevent a residual image caused by the lag component from remaining in the exposed image.

[0233] (Example 15) [Image correction method (3)] For the purpose of suppressing the granularity and line noise of the image, the image may be subjected to a recursive filter process represented by the following formula (2). Image after processing in the current frame = α × Image after processing in the previous frame + (1 - α) × Image before processing in the current frame ··· (2) (Here, α is a correction coefficient (where 0 < α < 1)) However, when photographing a subject with a fast movement speed, there is a problem that the difference in the position of the subject between the pre-exposure frame and the current exposure frame becomes large, and an afterimage of the pre-processed image appears in the processed image. In view of such problems, an unexposed image obtained immediately before the image to be corrected may be used for recursive filter processing. Line noise is noise that is independent of the exposure amount and is included in a certain amount in both the exposed image and the unexposed image. Therefore, by using the unexposed image recursively, it is possible to average and reduce the line noise. In addition, by using the immediately preceding unexposed image, it is possible to suppress granularity and line noise, and even in the case of a fast-moving subject, the blurring becomes less noticeable.

[0234] Note that when the movement of the subject is considerably fast, blurring may still be noticeable even after performing the recursive filter processing using the unexposed image as described above. Therefore, it is preferable to switch the presence or absence of the recursive filter processing according to the decimation rate and the movement of the subject.

[0235] (Example 16) [Image correction method (4)] The steady value X of the image after performing the recursive filter processing (however, when radiation is irradiated every other frame) is represented by the following formula (3). X = 1 / (1 + α) ··· (3) When the above-described recursive filter processing is performed on a dynamic image obtained by photographing without performing decimation irradiation of radiation, for example, as shown in FIG. 26, a decrease in the steady value is observed in the first few frames, but then it returns to the original state. On the other hand, when the above-described recursive filter processing is performed on a dynamic image obtained by photographing with decimation irradiation of radiation, the signal value of the processed image is repeatedly in a low state. For example, when the irradiation frame rate is 1 / 2 of the shooting frame rate (decimating the radiation irradiation every other frame), and the steady value of the pre-processed image is 1 and the correction coefficient α = 0.2, the steady value X becomes 0.83. Also, when the irradiation frame rate is 1 / 4 of the shooting frame rate (skipping radiation irradiation for 3 out of 4 frames), and the steady value of the pre - processed image is 1 and the correction coefficient α = 0.2, the steady value X becomes 0.8. In view of such problems, the steady value of the subsampled image may be divided by the value of X. By doing so, even if the steady value of the post - processed image decreases, it can be restored to 1. Here, although the specific calculation formula is omitted, this embodiment is also applicable to a dynamic image obtained by shooting in which radiation irradiation is performed every N frames (the N - 1 frames in between are not exposed).

[0236] (Example 17) [Image correction method (5)] Even after performing the above - mentioned read - out efficiency correction on the unexposed image and further subtracting the lag component, a signal may remain. This signal is often due to an increase in the offset (offset drift) caused by the temperature rise of the read - out unit 34. In view of such problems, the average value, the mode value, etc. of the offset drift amounts of the unexposed images before and after exposure may be subtracted from the exposed image to reduce the offset drift component. By doing so, it is possible to prevent a signal derived from the offset drift component from remaining in the exposed image.

[0237] In the above - mentioned embodiment, various image corrections using the unexposed image have been described. However, when radiation subsampling irradiation is not performed, for example, image processing is performed using the exposed image. That is, for a radiation image shot in a state where the shooting frame rate set in the shooting device 3 is N times the irradiation frame rate set in the generating device, predetermined image correction is performed, and for a radiation image shot in a state where the shooting frame rate set in the shooting device 3 is equal to the irradiation frame rate set in the generating device, image correction different from the above - mentioned image correction is performed. Therefore, the shooting device 3 and the console 4 in the above - mentioned embodiment constitute the first image correction means and the second image correction means in the present invention.

Explanation of symbols

[0238] 100, 200 Radiographic System 100A, 200A Conventional Radiographic System 1, 1A Radiation Control Device 11, 11A Radiation Control Unit 12 High-Voltage Generation Unit 2 Radiation Generation Unit 3 Radiation Image Acquisition Device 31 Acquisition Control Unit 32 Radiation Detection Unit 32a Substrate 32b Scanning Line 32c Signal Line 32d Radiation Detection Element 32e Switching Element 32f Bias Line 32g Power Supply Circuit 33 Scanning Drive Unit 33a Power Supply Circuit 33b Gate Driver 34 Readout Unit 34a Readout Circuit 34b Analog Multiplexer 34c Converter 34d Integration Circuit 34e Correlated Double Sampling Circuit 35 Storage Unit 36 Communication Unit 36a Antenna 36b Connector 37 Battery 3A Cassette 4 Console 41 Radiation Control Console 42 Acquisition Device Control Console 43 Display Unit 5 Irradiation Indicator Switch 6, 6A Additional Device 61, 61A Additional Control Unit 62 First Acquisition Unit 63 Second Acquisition Unit 64 First Connection Unit 65 Second Connection Unit 66 Third Connection Unit 67 Interface section 67a First AND circuit 67b Second AND circuit 7 Host system 8A Recumbent imaging table 8B Upright imaging table 9 Communication device N Communication network St1 Standby state St2 Irradiation preparation state St3 Irradiation start state St4 Irradiation standby state St5 Irradiation permission state St6 Irradiation end state St7 Error state

Claims

1. It is possible to take still images and dynamic images by repeatedly taking multiple still images. A radiation imaging system in which a delay time, which is the time from pressing an irradiation instruction switch to instruct irradiation of radiation to starting the imaging operation, differs between the still image imaging and the dynamic imaging, and the delay time during dynamic imaging, in which the warm-up and / or reset operation of the imaging device is longer than the delay time during still image imaging.

2. 2. The radiation imaging system according to claim 1, wherein the irradiation instruction switch can be operated in two stages, and pressing the irradiation instruction switch is a first stage press.

3. 2. The radiation imaging system according to claim 1, wherein the irradiation instruction switch can be operated in two stages, and the pressing of the irradiation instruction switch is the second pressing.

4. 2. The radiation imaging system according to claim 1, wherein the delay time is a time from when the irradiation instruction switch is pressed until at least one of an imaging device, an additional control unit, a console, and a radiation control unit starts the imaging operation.

5. The radiography system of claim 1, wherein the dynamic radiography is compatible with a plurality of frame rates, and determines whether all of the following are satisfied: the set irradiation frame rate is a value compatible with the generator, the set imaging frame rate is a value compatible with the imaging device, and the imaging frame rate is N (where N is an integer greater than or equal to 1) times the irradiation frame rate, and controls permission to irradiate radiation based on the determination result.

6. The radiation imaging system according to claim 5 , wherein irradiation of radiation is permitted when the set irradiation frame rate is equal to or higher than a minimum required frame rate stored for each part to be imaged and / or each imaging technique.

7. The radiation imaging system of claim 1, wherein, during the dynamic imaging, the generator irradiates radiation only at a portion of the time while the imaging device is repeatedly storing and reading out, the portion being the timing for capturing a series of multiple consecutive images, or the timing for capturing an amount of change during dynamic imaging.

Images