WO2008072311A1 - Imaging device - Google Patents

Abstract

When assuming the timing at which a predetermined line is driven to read charge information and a line adjacent to the predetermined line is not driven and the charge information is not read to be a first reading time and assuming the timing from the first reading time to the next reading to be a second reading time, an imaging device performs drive control so that the predetermined line and the line adjacent thereto are simultaneously driven to simultaneously read carriers at the second reading time. This makes it possible to prevent a false image caused by parasitic capacitance because the parasitic capacitance is not formed between the predetermined line and the adjacent line.

Description

 Imaging device

 Technical field

 [0001] The present invention relates to an imaging device used in the medical field, the industrial field, the nuclear field, and the like.

 Background art

 [0002] An imaging device that performs imaging based on detected light or radiation includes a light or radiation detector that detects light or radiation. An X-ray detector will be described as an example. The X-ray detector has an X-ray sensitive X-ray conversion layer (semiconductor layer). When the X-ray is incident, the X-ray conversion layer converts it into carriers (charge information) and reads the converted carriers. so

Detect X-rays. As the X-ray conversion layer, for example, amorphous amorphous selenium (a-Se) film force S is used (for example, see Non-Patent Document 1).

[0003] When radiation imaging is performed by irradiating a subject with X-rays, the radiation image force transmitted through the subject is projected onto the S amorphous selenium film, and carriers proportional to the density of the image are generated in the film. To do. After that, the carriers generated in the film are collected by the two-dimensionally arranged carrier collecting electrodes, integrated for a predetermined time (also called “accumulation time”), and then passed through the thin film transistor. Read out to the outside.

[0004] Around such an X-ray detector, a gate driver circuit for switching ON / OFF of a thin film transistor switch, an amplifier array circuit for reading carriers, and a peripheral circuit are arranged. The drive circuit gives a drive signal to the X-ray detector to drive the X-ray detector, and the amplifier array circuit receives the read carrier based on the read signal related to the carrier reading. These circuits and an X-ray detector are included in the imaging sensor.

[0005] By the way, when reading carriers, there are a method of reading one line at a time via a data line and a method of reading data at a plurality of lines via a data line. In the former method of reading one line at a time, the thin film transistor switches are turned on one by one (or one by one OF F) and driven, and then stored in the capacitor connected to the driven switch. Kiya Read the rear one line at a time via the data line connected to the switch. On the other hand, in the case of the latter method of reading with a plurality of lines, a plurality of thin film transistor switches are simultaneously provided.

Drives ON (or turns OFF simultaneously) and reads the carriers once stored in the capacitors connected to the simultaneously driven switches via the data lines connected to those switches.

 [0006] The former method of reading out one line at a time is because the carrier is read out one line at a time, so it is suitable for low-speed but high-definition mode (for example, still image shooting), and the latter method is used for reading multiple lines. Since it can read faster than the former method of reading line by line, it is suitable for a mode that can read images at a high speed (for example, video shooting). There is also a shooting method in which the operation is switched during moving image shooting to perform still image shooting.

 [0007] Even when X-rays are not irradiated, carriers are accumulated in the capacitor due to the leakage current (also referred to as "dark current" or "dark current") of the amorphous selenium film. Therefore, even when only taking a still image is taken, unnecessary carriers may be simultaneously read out by a plurality of lines and swept out at a high speed in order to release a leakage current at the time of non-irradiation. Also, when the field of view range (image size) is switched during movie shooting, the number of lines to be read at the same time for a large field of view is increased to speed up readout, and movie shooting is switched without reducing the frame rate. There is a shooting method to do. In some cases, unnecessary carriers outside the field of view are simultaneously read out by multiple lines and swept at high speed.

 Non-Patent Literature 1: W. Zhao, et al., A flat panel detector for digital radiology using acti ve matrix readout of amorphous selenium, Proc. SPIE Vol. 2708, pp. 523-531, 19 96.

 Disclosure of the invention

 Problems to be solved by the invention

However, such a conventional method has a problem that it appears as a false image when the above-described thin film transistor is used for reading. For example, the effect of the driving method before switching appears as a false image in the image after switching about several hundred msec after switching by changing the number of lines driven simultaneously. Therefore, when switching from the above-mentioned movie shooting or the process of sweeping out unnecessary carriers to still image shooting that reads out one line at a time, Even in this case, a fake image appears in the still image after switching. The appearance of this fake image causes the problem that image diagnosis cannot be performed for several hundreds of milliseconds after switching.

[0009] In general, in order to maintain the shooting frame rate at a large visual field size, the number of lines driven simultaneously is increased as described above. Even when moving images are shot while switching the visual field size, there is a problem that image diagnosis cannot be performed for several hundred msec after switching because of the appearance of a fake image.

 [0010] Thus, immediately after the moving image shooting or the process of sweeping out unnecessary carriers, still image shooting or moving image shooting after switching the field of view size cannot be performed, causing a problem S in shooting response. Therefore, in the case where the subject is a patient, when performing X-ray irradiation that matches the patient's breathing timing while confirming with a moving image, there is a problem that it is difficult to perform X-ray irradiation that matches the breathing timing.

 [0011] The present invention has been made in view of such circumstances, and an object thereof is to provide an imaging apparatus capable of preventing a fake image.

 Means for solving the problem

[0012] As a result of intensive studies to solve the above problems, the inventors have obtained the following knowledge.

 In other words, the authors focused on the fact that the cause of the false image is a parasitic capacitance that is coupled between a given line and a line adjacent to the given line. This will be described with reference to FIG. 4 and FIG. When the timing of a certain carrier is set to the time of the first reading and the power of the first reading is also set to the timing of the next reading, the timing of the first reading is t as shown in FIGS. And t for the second readout,

 1 2 Let L be a given line and L be a line adjacent to it. The predetermined line

 K K + 1

 In order to distinguish from adjacent lines, hatching is added as shown in Figs. Also, as shown in Fig. 4 and Fig. 5, the line to be driven is separated by a frame F to distinguish it from the line that is not driven.

 [0013] As shown in FIG. 4, a plurality of lines including a predetermined line L are connected at the first reading t.

 1 K

Suppose that it is sometimes driven and the carriers are read simultaneously. At this time, it is assumed that the carrier is not read without driving the adjacent line L. In other words, including the predetermined line L Multiple line groups and multiple line groups including adjacent line L

 K + 1

 Are in different groups. Next, as shown in FIG.

 2) Drive multiple lines at the same time including line L

 K + 1

 Let ’s say that it ’s out. At this time, a group of a plurality of lines including a predetermined line L and adjacent

 K

 Since the group of multiple lines including line L is different from each other,

 K + 1

 Read the carrier without driving the specified line.

 [0014] A line L adjacent to a predetermined line L after the first read time t through the second read time t

 Parasitic capacitance couples with 1 2 K K. In that state, change the number of lines to be driven simultaneously.

+ 1

 When switched, a false image is generated due to parasitic capacitance.

 Therefore, as shown in FIG. 5, at the time of the first reading t, the same driving state as in FIG. 4 is set, and at the time of the second reading, the predetermined line L and the adjacent line L are simultaneously driven to drive the carrier.

 K K + 1

 If they are read at the same time, the parasitic capacitance between a given line L and the adjacent line L

 K K + 1

 We obtained knowledge that false images can be prevented even if the driving method is switched without combining the quantities.

 [0016] The present invention based on such knowledge has the following configuration.

 That is, the imaging apparatus of the present invention is an imaging apparatus that obtains an image by performing imaging with light or radiation, a conversion layer that converts light or radiation information into charge information by the incidence of the light or radiation, and the conversion Charge accumulation information converted in each layer is stored and read out via a plurality of lines arranged in a two-dimensional manner. The accumulation is based on the charge information read out by the readout circuit. The apparatus is configured to obtain the image, and the apparatus further reads the charge information by driving a predetermined line, and the charge information without driving a line adjacent to the predetermined line. When the first reading is performed at the time of the first reading and the timing of the first reading is set at the second reading, the timing at the second reading is And it is characterized in that it comprises a driving control means for driving and controlling so that a constant line and said adjacent lines simultaneously driven to simultaneously read charge information, respectively.

[0017] According to the imaging apparatus of the present invention, the charge information is read by driving a predetermined line, and the charge information is not read without driving a line adjacent to the predetermined line. When the first reading is performed and the first reading force is also set to the second reading, the drive control means sets a predetermined line and an adjacent line during the second reading. Drive control is performed so that the charge information is read out simultaneously by driving simultaneously. As in the prior art, a predetermined line is driven to read the charge information at the time of the first read, and the adjacent line is driven at the time of the second read without reading the charge information without driving the adjacent line. When the charge information is read and the charge information is not read without driving the predetermined line, a parasitic capacitance is coupled between the predetermined line and the adjacent line. In contrast, in the case of the imaging apparatus of the present invention, the charge information is simultaneously read by simultaneously driving a predetermined line and an adjacent line at the time of the first reading, and simultaneously driving a predetermined line and an adjacent line at the time of the second reading. As a result, the parasitic capacitance is not coupled between the predetermined line and the adjacent line. As a result, false images due to parasitic capacitance can be prevented.

 An example of the above-described invention is that the above-described drive control unit drives and controls a plurality of lines including a predetermined line at the same time to read out charge information simultaneously. Therefore, the present invention can be applied to simultaneous driving imaging in which a plurality of lines including a predetermined line are simultaneously driven to simultaneously read out charge information.

 [0019] When applied to such simultaneous driving imaging, for example, there may be provided switching means for changing and switching the number of lines driven simultaneously. By changing the number of lines to be driven at the same time and switching, if parasitic capacitance occurs, it will appear as a fake image in the image after switching. In the present invention, since the parasitic capacitance is not coupled, a false image does not appear in the image after switching by the switching means.

[0020] Examples of switching by the switching means include the following. In other words, the switching means switches the number of lines to be driven simultaneously from a plurality to one to drive one line and simultaneously drive a plurality of lines to simultaneously read out charge information and drive one line. Switch to shooting that reads charge information (for example, still image shooting). Even if it is switched to the shooting to read out the charge information by driving one line like this, since the parasitic capacitance is not coupled in the present invention, the fake image is displayed in the image (for example, still image) after the switching by the powerful switching means. Do not appear. [0021] In another example of the above-described invention, when a plurality of lines including adjacent lines are simultaneously driven at the time of the second reading, among the simultaneously driven lines, the most opposite to the predetermined line is the most. The line to be positioned is set as a new predetermined line, and the second read time is set as the new first read time, the drive control at the first read time, the drive control at the second read time, and the above-mentioned It is to repeat the setting.

 According to another example, the predetermined line is driven at the time of the first reading, and the adjacent line is driven at the same time at the time of the second reading without driving the adjacent line. The drive control can be performed as many times as it is repeated. Therefore, the parasitic capacitance is not coupled between the predetermined line and the adjacent line during the repetition, so that a false image due to the parasitic capacitance can be prevented. In this case, there are a further example as described below and another example.

 That is, as a further example, without changing the number of lines to be driven simultaneously, the drive control at the time of the first reading, the drive control at the time of the second read, and the above setting are repeated. As yet another example, the drive control at the first read time without changing the number of lines to be driven simultaneously at the first read time and the second read time except at the initial first read time, Repeat the drive control at the time of reading and the setting described above, and control the drive by reducing the number of lines described above by 1 only at the time of the initial first reading described above.

[0024] Still another example of the above-described invention is that only a predetermined line is driven at the time of the first reading and also driven at the time of the second reading. Of course, the lines driven during the first reading and also driven during the second reading may be a plurality of lines including a predetermined line.

 The invention's effect

 [0025] According to the imaging apparatus of the present invention, the drive control means performs the drive control so that the predetermined line and the adjacent line are simultaneously driven and the charge information is simultaneously read at the time of the second readout, thereby Since the parasitic capacitance is not coupled between the line and the adjacent line, a false image due to the parasitic capacitance can be prevented.

Brief Description of Drawings FIG. 1 is a block diagram of an X-ray imaging apparatus according to each embodiment.

 FIG. 2 is an equivalent circuit of a flat panel X-ray detector used in an X-ray imaging apparatus as viewed from the side.

 [Fig. 3] Equivalent circuit of flat panel X-ray detector in plan view.

 FIG. 4 is a schematic diagram showing a change over time of driving of a conventional line for comparison with the principle of the present invention.

 FIG. 5 is a schematic diagram showing a change over time of line driving for explaining the principle of the present invention.

 FIG. 6 is a schematic diagram showing a change over time of driving of each conventional line for comparison with Example 1.

 FIG. 7 is a schematic diagram showing a change with time of driving of each line according to the first embodiment.

 FIG. 8 is a schematic diagram showing a change with time of driving of each line according to Example 2.

 Explanation of symbols

 8… AZD strange

 10

 31 .. Semiconductor thick film

 37 · ■-Amplifier array circuit

 Ca · '' · Capacitor

 L · ·

 K-predetermined line

 L… Adjacent line

 K + 1

 S… Imaging sensor

 Example 1

[0028] Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the X-ray imaging apparatus according to each embodiment, and FIG. 2 is an equivalent circuit of a flat panel X-ray detector used in the X-ray imaging apparatus as viewed from the side. Is an equivalent circuit of a flat panel X-ray detector in plan view. In Example 1, including Example 2 described later, a flat panel X-ray detector (hereinafter referred to as “FPD” as appropriate) is taken as an example of an optical or radiation detector, and X-ray imaging is used as an imaging device. The apparatus will be described as an example. In addition, each example The X-ray equipment and FPD have the same configuration as in Figs.

As shown in FIG. 1, the X-ray imaging apparatus according to the first embodiment including the second embodiment described later includes an X-ray tube 2 that irradiates the subject M with X-rays, and a subject. F PD3 that detects X-rays transmitted through M.

 [0030] The X-ray imaging apparatus includes an X-ray tube controller having an FPD controller 5 that controls scanning of the FPD 3 and a high-voltage generator 6 that generates tube voltage and tube current of the X-ray tube 2. 7 or an AZD converter 8 that digitally extracts an X-ray detection signal that is a charge signal from the FPD3, or an image processing unit 9 that performs various processes based on the X-ray detection signal output from the AZD converter 9 A controller 10 that controls these components, a memory unit 11 that stores processed images, an input unit 12 in which an operator makes input settings, and a monitor that displays processed images 13 Etc.

 [0031] The FPD control unit 5 performs control related to scanning by horizontally moving the FPD 3 or rotating it around the body axis of the subject M. The high voltage generator 6 generates a tube voltage and a tube current for irradiating X-rays and applies them to the X-ray tube 2. The X-ray tube controller 7 moves the X-ray tube 2 horizontally, Controls related to scanning by rotating around the body axis of the specimen M, and controls the setting of the irradiation field of the collimator (not shown) on the X-ray tube 3 side. When scanning the X-ray tube 2 or the FPD 3, the X-ray tube 2 and the FPD 3 move while facing each other so that the FPD 3 can detect the X-rays emitted from the X-ray tube 2.

 The controller 10 is composed of a central processing unit (CPU) and the like, and the memory unit 11 is a storage medium represented by ROM (Read-only Memory), RAM (Random-Access Memory), and the like. It is configured. The input unit 12 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, and a touch panel. In the X-ray imaging apparatus, the FPD 3 detects X-rays that have passed through the subject M, and the image processing unit 9 performs image processing based on the detected X-rays to capture the subject M.

[0033] In the first embodiment, the controller 10 reads a carrier by driving a predetermined line at the time of a first read to be described later, and reads a carrier without driving a line adjacent to the predetermined line. Without reading, at the time of the second reading, the specified line and the adjacent line Is also provided with a function of simultaneously driving and reading the carriers simultaneously. The controller 10 also has a function of changing and switching the number of lines to be driven simultaneously, that is, a function of switching a driving method. The controller 10 corresponds to drive control means and switching means in the present invention.

 [0034] Further, the memory unit 11 uses a RAM for writing X-ray detection signals and processed images. For example, when the controller 10 executes the control sequence by reading a program related to the control sequence, ROM is used exclusively for reading the program related to the control sequence. In Example 1, including Example 2 described later, in the first reading, a predetermined line is driven to read out the carrier, and the carrier adjacent to the predetermined line is not driven and the carrier is not read out. During the second reading, a program related to a control sequence for simultaneously reading a carrier by simultaneously driving a predetermined line and adjacent lines is stored in the memory unit 11, and the control sequence is executed by the controller 10 by reading the program.

 As shown in FIG. 2, the FPD 3 includes a radiation-sensitive semiconductor thick film 31 in which carriers are generated by the incidence of radiation such as X-rays, and a voltage mark provided on the surface of the semiconductor thick film 31. An additional electrode 32, a carrier collection electrode 33 provided on the back surface opposite to the radiation incident side of the semiconductor thick film 31, a charge storage capacitor Ca for accumulating collected carriers to the carrier collection electrode 33, and It is provided with a thin film transistor (TFT) Tr, which is a switching element for taking off charges (normally OFF) for taking out the carriers (charges) accumulated in the capacitor Ca. In Example 1, including Example 2 which will be described later, the semiconductor thick film 31 is formed of a radiation-sensitive material in which carriers are generated by the incidence of radiation, such as amorphous selenium. It may be a light-sensitive substance that is produced. The semiconductor thick film 31 corresponds to the conversion layer in this invention.

In addition to this, in Example 1, including Example 2 described later, in Example 1, the data line 34 connected to the source of the thin film transistor Tr and the gate line connected to the gate of the thin film transistor Tr The voltage application electrode 32, the semiconductor thick film 31, the carrier collection electrode 33, the capacitor Ca, the thin film transistor Tr, the data line 34, and the gate line 35 are stacked on the insulating substrate 36. . [0037] As shown in FIG. 2 and FIG. 3, each of the carrier collection electrodes 33 formed in a large number (for example, 1024 × 1024 or 4096 × 4096) in a vertical and horizontal two-dimensional matrix arrangement is described above. Each capacitor Ca and thin film transistor Tr are connected to each other, and the carrier collection electrode 33, the capacitor Ca, and the thin film transistor Tr are separately formed as each detection element DU. In addition, the voltage application electrode 32 is formed over the entire surface as a common electrode of all the detection elements DU. Further, as shown in FIG. 3, the data lines 34 described above are arranged in parallel in the horizontal (X) direction, and the gate lines 35 described above are arranged vertically (Y) as shown in FIG. A plurality of data lines 34 and gate lines 35 are connected in parallel to each detection element DU. The data line 34 is connected to the amplifier array circuit 37, and the gate line 35 is connected to the gate driver circuit 38. Note that the number of detector elements DU arranged can be changed according to the embodiment in which the number of detector elements DU is only 1024 × 1024 or 4096 × 4096. Therefore, it may be in the form of only one detection element DU.

 The detection elements DU are patterned on the insulating substrate 36 in a two-dimensional matrix arrangement, and the insulating substrate 36 on which the detection elements DU are formed is also called an “active matrix substrate”.

 [0039] When the periphery of the detection element DU of the FPD3 is created, the data line 34 and the surface of the insulating substrate 36 are formed on the surface of the insulating substrate 36 using various thin film formation techniques by vacuum deposition and pattern techniques by photolithography. A gate line 35 is provided, and a thin film transistor Tr, a capacitor Ca, a carrier collection electrode 33, a semiconductor thick film 31, a voltage application electrode 32, and the like are sequentially stacked. The semiconductor for forming the semiconductor thick film 31 can be appropriately selected according to the withstand voltage and the like, as exemplified by an amorphous semiconductor, a polycrystalline semiconductor, and the like.

[0040] The amplifier array circuit 37 has a function of receiving a carrier including the AZD variable 8 outside the FPD 3. That is, the AZD conversion 8 and the amplifier array circuit 37 read the carrier converted by the semiconductor thick film 31 through the detection element DU of the FPD 3. Capacitor Ca corresponds to the storage circuit in the present invention, and AZD variable 8 and amplifier circuit 37 correspond to the readout circuit in the present invention. Therefore, capacitor C a. The image sensor S including the AZD converter 8 and the amplifier array circuit 37 corresponds to the storage / readout circuit in the present invention. Note that AZD Transformation 8 may be provided in the FPD3 configuration. The gate driver circuit 38, the amplifier array circuit 37, and the AZD converter 8 are peripheral circuits of the FPD3.

In addition to this, the FPD 3 includes a power source 39. In the first embodiment including the second embodiment described later, the power source 39 supplies power to the readout circuit such as the amplifier array circuit 37 and the AZD converter 8. The image sensor S of FIG. 3 is configured by the FPD 3, the FPD control unit 5, and the AZD converter 8.

 Next, the operation of the X-ray imaging apparatus and flat panel X-ray detector (FPD) according to the first embodiment will be described, including a second embodiment to be described later. With a high voltage (for example, several hundred volts to several tens of kV) applied to the voltage application electrode 32,

 A

 A certain radiation is incident. The FPD controller also controls the application of this bias voltage V.

 A

 Start from 5.

 [0043] Carriers are generated by the incidence of radiation, and the carriers are stored as charge information in a capacitor Ca for charge storage. The gate line 35 is selected by the scanning signal for extracting signals from the gate driver circuit 38 (that is, the gate drive signal), and the detection element DU connected to the selected gate line 35 is selected and designated. The carrier (charge) force accumulated in the capacitor Ca of the specified detection element DU is read out to the data line 34 via the thin film transistor Tr that has been turned on by the signal of the selected gate line 35.

[0044] Further, the address (address) designation of each detection element DU is a scanning signal for extracting signals from the data line 34 and the gate line 35 (in the case of the gate line 35, the gate drive signal, in the case of the data line 34) Based on the amplifier driving signal). When a scanning signal for signal extraction is sent to the amplifier array circuit 37 and the gate driver circuit 38, each detection element DU is selected from the gate driver circuit 38 according to the scanning signal (gate driving signal) in the longitudinal (Y) direction. Then, when the amplifier array circuit 37 is switched in accordance with the scanning signal (amplifier drive signal) in the horizontal (X) direction, the carrier (charge) data line 34 accumulated in the capacitor Ca of the selected detection element DU. To the amplifier array circuit 37. And Anne Amplified by the pre-array circuit 37, output from the amplifier array circuit 37 as an X-ray detection signal, and sent to the AZD converter 8.

[0045] With the above-described operation, for example, when the imaging sensor S including the FP D3 according to the first embodiment is used to detect an X-ray image of the X-ray imaging apparatus, the image is read out via the data line 34. The charge information (X-ray detection signal) is amplified as voltage by the amplifier array circuit 37, converted into image information, and output as an X-ray image. Thus, an X-ray image is obtained based on the charge information (X-ray detection signal) accumulated and read out by the imaging sensor S including the capacitor Ca, the AZD converter 8 and the amplifier array circuit 37. The X-ray equipment is configured.

 [0046] The imaging sensor S including the capacitor Ca, the AZD converter 8 and the amplifier array circuit 37 temporarily accumulates the carriers converted by the semiconductor thick film 31 by the capacitor Ca and arranges them in a two-dimensional form. In other words, it can be read out through the plurality of data lines 34.

 Next, carrier reading according to the first embodiment will be described with reference to FIG. 5 and FIG. For comparison with the prior art, description will be made with reference to FIGS. FIG. 4 is a schematic diagram showing the change over time of the conventional line drive for comparison with the principle of the present invention, and FIG. 5 shows the change over time of the line drive for explaining the principle of the present invention. FIG. 6 is a schematic diagram showing a change over time in driving of each conventional line for comparison with Example 1, and FIG. 6 is a diagram showing each line according to Example 1. FIG. 6 is a schematic diagram showing a change over time in driving.

 [0048] First, the principle of the present invention will be described. As described in the paragraph “Means for Solving the Problems”, the timing of a certain carrier is set to the time of the first reading, and the power of the first reading is set to the timing of the second reading. 4 and 5, the first read time is t, the second read time is t, and the predetermined line is L.

 1 Let L be the line adjacent to 2K. A given line is distinguished from an adjacent line.

 K + 1

 For this purpose, hatching is provided as shown in Figs. Also, as shown in Figs. 4 and 5, the line to be driven is separated by a frame F to distinguish it from the line that is not driven.

[0049] Conventionally, as shown in FIG. 4, at the first reading time t, a plurality of lines including a predetermined line L are included.

 1 K

Are simultaneously driven and carriers are read simultaneously. At this time, next Assume that the carrier L is not read without driving the line L in contact. In other words, the predetermined

K + 1

 Multiple line groups including In L and multiple lines including adjacent Line L

K K + 1

 This group is different from each other. Next, as shown in FIG. 4, at the second read time t, a plurality of lines including the adjacent line L are simultaneously driven to shift the carrier.

2 K + 1

 Assume that the data are read simultaneously. At this time, the group of multiple lines including the predetermined line L

 K

 Loops and groups of lines, including adjacent line L, are different from each other.

 K + 1

 Therefore, the carrier is not read without driving the predetermined line.

 Summarizing the above, in the conventional case, as shown in FIG. 4, at the first read time t, a predetermined line L is driven to read out a carrier and adjacent to the predetermined line L. Rye

 K K

 Do not read carrier without driving L. And at the second reading t

K + 1 2 Line L is driven to read the carrier, and the key is not driven without driving the predetermined line L.

 K + 1 Do not read K area. As a result, after the first reading t to the second reading t

 1 2 Parasitic capacitance is coupled between a constant line L and an adjacent line L. In that state, at the same time

 K K + 1

 If the number of lines to be driven is changed and switched, a false image is generated due to parasitic capacitance.

 [0051] On the other hand, in the present invention, the predetermined line L and the adjacent line are as follows.

 K

 Drive L. That is, as shown in FIG. 5, at the first read time t, the same drive as in FIG.

K + 1 1

 In the second read, the predetermined line L and the adjacent line L are simultaneously

 K K + 1 Drives and reads each carrier simultaneously.

 Summarizing the above, in the case of the present invention, as shown in FIG. 5, at the first read time t, a predetermined line L is driven to read out the carrier and adjacent to the predetermined line L. Shi

 K K

 The carrier L is not read without driving the line L. And at the second reading t

 K + 1 2 Constant line L and adjacent line L are driven at the same time and carriers are simultaneously

 K K + 1

 read out. By reading the carrier in this way, the line L adjacent to the predetermined line L

 Even if the driving method is switched without coupling parasitic capacitance to K K + 1, false images can be prevented.

 [0053] Next, a case where the present invention is applied to the first embodiment will be described. Here, n is the number of lines to be driven simultaneously, r is the number of repetitions described later, and t, t,

 1 2

..., t, t, and L, L, ..., L, L for each line on the river page. Each line L, L,

15 16 1 2 15 16 1 2 ···, L and L indicate gate lines 35 (see Fig. 2 and Fig. 3), respectively. In addition, the repetitive steps described later

15 16

 As a result of the return, the target line of the predetermined line is sequentially changed for each readout, so that only the target line of the predetermined line is distinguished from the adjacent line and other lines in FIG. As shown in Fig. 7, it is painted black. Similarly to FIGS. 4 and 5, as shown in FIGS. 6 and 7, the lines to be driven are separated by a frame to distinguish them from the lines not to be driven.

[0054] t at the initial first read and t at the first read of the first repetition.

 1 2 Hereinafter, if it is repeated in the same way, the number of repetitions is t at the first reading of the 15th time.

 16

. That is, t at the first reading of the repetition count.

 r + 1

 [0055] Conventionally, in the case of the number of lines that are driven simultaneously, the predetermined line at the initial first read time t is n, and the initial first read time t force is the timing of the next read. The predetermined line at the time of reading is 2 X n. When the second read time is set as the new first read time, the initial first read time t force is equal to the second read time, which is the next read timing, and the new first read time t. Therefore, the new first reading

 2

 The predetermined line at t is 2 X n. Hereafter, if you repeat in the same way,

 2

 The predetermined line at the first reading t of the 14th number is 15 Xn. That is, repeat

 15

 The predetermined line at t at the first reading of the number of times is (r + 1) Xn.

 r + 1

 [0056] As shown in FIG. 6, for example, in the case of four-line simultaneous driving, the number of lines to be driven simultaneously is four, so the predetermined line at the initial first read time t is the fourth (in FIG. 6). L)

 14

The predetermined line at the first read t is the 8th (L in FIG.

 When the first read time is 2nd, the predetermined line at t is 12th (in Fig. 6,

 Three

 L). For example, in the case of 2-line simultaneous drive, the number of lines driven simultaneously is 2.

12

 Therefore, the predetermined line at the initial first read t is the second (L in Fig. 6) and repeats.

 1 2

 The predetermined line at the first read time t is the 4th (L in Fig. 6) and repeats.

 2 4 When the first read is the second repeat count The predetermined line at t is the sixth (L in Fig. 6)

 3 6

. Also, for example, in the case of one line drive, the number of lines driven simultaneously is only 1, so the predetermined line at the initial first read t is the first (L in FIG. 6), and the number of repetitions is At the first read of the first time, the predetermined line at t is the second (L in Fig. 6) and repeats

 twenty two

However, the predetermined line at the first read t is the third (L in Fig. 6). [0057] At the time of each first reading, a predetermined line is driven to read a carrier, and a line adjacent to the predetermined line is not driven to read a carrier. In each second read, the adjacent line is driven to read the carrier, and the carrier is not read without driving the predetermined line.

 In contrast, in the first embodiment, when a plurality of lines including a line adjacent to a predetermined line are simultaneously driven at the time of the second reading, the predetermined line among the simultaneously driven lines is Let the line located most on the opposite side be a new predetermined line. Then, the second read time is set as a new first read time. The drive control at the time of the first read, the drive control at the time of the second read and the above setting are repeated.

 [0059] Therefore, in the case of the number of lines driven simultaneously, the predetermined line at the initial first read time t is n, and the nth predetermined line is from the initial first read time t. Even at the second read time t, which is the next read timing, the (n + 1) th neighbor

 2

 Are driven simultaneously with the selected line. At this time, of the simultaneously driven lines, the line located on the opposite side to the nth predetermined line is 2 X n−l, and the (2 X n 1) th line is the new predetermined line. Line. For the above reason, since the second read time t is set as the new first read time t, the number of repetitions is the first (new

twenty two

 The predetermined line at the first read t is 2 X n-l. Repeat the same in the following

 2

 Then, at the first reading of the number of repetitions ^, the predetermined line at t is (r + 1) X n-r r + 1

In FIG. 6, in the case of the number of lines that are driven simultaneously, the force that is increased by n each time it is repeated. In the case of FIG. 7 as in Example 1, (n−l) It moves up one by one. Therefore, in the case of 4-line simultaneous drive as shown in Fig. 6, in Example 1, 5-line simultaneous drive as shown in Fig. 7 is performed, and in the case of 2-line simultaneous drive as shown in Fig. 6, In the first embodiment, three lines are simultaneously driven as shown in FIG. 7, and in the case of one line as shown in FIG. 6, two lines are simultaneously driven as shown in FIG. As described above, in the first embodiment, the number of lines to be driven simultaneously is increased by one as compared with the conventional case, so that the number to be advanced can be made equal.

[0061] As shown in FIG. 7, for example, in the case of 5-line simultaneous drive, the number of lines to be driven simultaneously is Therefore, the predetermined line at the initial first read t is the fifth (L in Fig. 7).

 1 5

When the first reading is the first iteration, the predetermined line at t is 9th (L in Fig. 7).

 2 9 and the number of repetitions for the first read at the second read time is 13th (in Fig. 7,

 Three

 L). For example, if 3 lines are driven simultaneously, the number of lines to be driven simultaneously is 3.

13

 Therefore, the predetermined line at the initial first read t is the third (L in Fig. 7) and repeats.

 13

 The predetermined line at the first read t is the fifth (L in Fig. 7) and the repetition is repeated.

 2 5 When the first read is the second repeat count The predetermined line at t is the seventh (L in Fig. 7)

 3 7

. In addition, for example, in the case of two-line simultaneous driving, the number of lines to be driven simultaneously is 2, so the predetermined line at the initial first read time t is the second (L in FIG. 7), and is repeated repeatedly.

 1 2

 The predetermined line at the first read t at the first time is the third (L in Fig. 7) and repeats.

 twenty three

 However, the predetermined line at time t of the first read for the second time is the fourth (L in FIG. 7).

 3 4

 [0062] At the time of each first reading, a predetermined line is driven to read a carrier, and a carrier adjacent to the predetermined line is not driven and a carrier is not read. Then, at the time of each second reading, a predetermined line and an adjacent line are simultaneously driven to simultaneously read the carriers.

 As described above, in the first embodiment, the number of lines driven simultaneously is changed by the controller 10 (see FIG. 1) and switched. That is, the drive system is switched by the controller 10. Therefore, the drive methods shown in FIG. 7 may be switched to each other, or the drive methods shown in FIG. 7 may be changed to the drive methods shown in FIG.

 [0064] In the case of switching between the respective driving methods in FIG. 7, for example, switching from 5 line simultaneous driving to 3 line simultaneous driving or 2 line simultaneous driving may be performed, or from 3 line simultaneous driving to 2 line simultaneous driving or You can switch to 5-line simultaneous drive, or you can switch from 2-line simultaneous drive to 5-line simultaneous drive or 3-line simultaneous drive.

[0065] In addition, when switching each drive system as shown in FIG. 7 to each drive system as shown in FIG. 6, for example, from the 5-line simultaneous drive in FIG. 7 to the 4-line simultaneous drive in FIG. You can switch to either simultaneous drive or 1-line drive, or switch from 3-line simultaneous drive in Figure 7 to 4-line simultaneous drive, 2-line simultaneous drive, or 1-line drive in Figure 6. You can also use the two-line simultaneous drive in Fig. 7, the four-line simultaneous drive in Fig. 6, the two-line simultaneous drive, Or you can switch to one line drive! /.

 [0066] According to the X-ray imaging apparatus according to the first embodiment described above, the carrier is read by driving a predetermined line, and the carrier is not read without driving a line adjacent to the predetermined line. When the timing is the first read time and the first read power is the second read timing, the controller 10 is connected to a predetermined line and adjacent to the second read time. Drive control is performed so that the lines are simultaneously driven and the carriers are read simultaneously. As in the prior art, the carrier is read by driving a predetermined line at the time of the first read, and the carrier is not read by driving the adjacent line without driving the adjacent line. In the case where the carrier is not read without driving the predetermined line, parasitic capacitance is coupled between the predetermined line and the adjacent line. On the other hand, in the case of the X-ray imaging apparatus according to the first embodiment, the carrier is driven by simultaneously driving a predetermined line and an adjacent line at the time of the first reading in the same driving state as before and at the time of the second reading. By reading each simultaneously, parasitic capacitance is not coupled between a given line and the adjacent line. As a result, false images due to parasitic capacitance can be prevented.

 [0067] In Example 1, including Example 2 described later, the controller 10 described above performs drive control so as to simultaneously drive a plurality of lines including a predetermined line and simultaneously read out the carriers. Yes. Therefore, the present invention can be applied to simultaneous drive photography in which a plurality of lines including a predetermined line are simultaneously driven to simultaneously read out carriers.

 When applied to such simultaneous driving imaging, as described above, the controller 10 has a function of changing and switching the number of lines driven simultaneously. By changing the number of lines driven simultaneously and switching, if parasitic capacitance occurs, it will appear as a false image in the image after switching. In the present invention, as described in the first embodiment, since the parasitic capacitance is not coupled, a false image does not appear in the image after switching by the powerful switching function.

[0069] Further, as described above, when each drive method as shown in FIG. 7 is switched to each drive method as shown in FIG. 6, the 5-line simultaneous drive, 3-line simultaneous drive, or 2-line simultaneous drive shown in FIG. No The case of switching to the one-line drive shown in FIG. 6 will be described. In other words, by switching the number of lines to be driven simultaneously from multiple to one, from simultaneous drive shooting that simultaneously drives multiple lines and simultaneously reads each carrier, shooting that drives one line and reads carriers (for example, Switch to still image shooting. Even if it is switched to the shooting to read the carrier by driving one such line, in this invention, the parasitic capacitance is not coupled as described in the first embodiment. No fake image will appear in later images (eg still images).

[0070] Simultaneous drive imaging in which a plurality of lines are simultaneously driven and the carriers are read simultaneously is suitable for moving image shooting. Even if you switch to still image shooting or movie shooting after switching the field-of-view size immediately after shooting such a movie, a fake image does not appear in the still image z movie image after switching. This can be done immediately and can improve the shooting response. Therefore, in the case where the subject is a patient, even if X-ray irradiation is performed in accordance with the patient's breathing timing while confirming with a moving image, the X-ray irradiation can be performed in accordance with the breathing timing.

 In the first embodiment, when a plurality of lines including a line adjacent to a predetermined line are simultaneously driven at the time of the second reading, among the simultaneously driven lines, the line on the opposite side to the predetermined line is the most. The line located is set as a new predetermined line. The second read time is set as a new first read time. The drive control at the time of the first reading, the drive control at the time of the second read, and the above setting are repeated.

 [0072] According to this case, the drive control is performed such that the predetermined line is driven at the time of the first read and the adjacent line is not driven, and the predetermined line and the adjacent line are simultaneously driven at the time of the second read. This can be done for repeated times. Therefore, during repetition, the parasitic capacitance is not coupled between the predetermined line and the adjacent line, and a false image due to the parasitic capacitance can be prevented.

In the first embodiment, as shown in FIG. 7, in the simultaneous driving of each line, except for the last reading, the number of lines to be driven at the same time is not changed, and the driving control at the first reading is performed. Drive control at the time of reading and setting (when the second reading is the new first reading) are repeated. Example 2

 Next, Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 8 is a schematic diagram illustrating a change over time of driving of each line according to the second embodiment. Since the X-ray imaging apparatus and the FPD of the second embodiment are the same as those of the first embodiment, the description thereof will be omitted and only the differences will be described.

 [0075] The difference from the first embodiment is that the number of lines to be driven simultaneously is not changed at the time of each first reading and at the time of the second reading except for the initial first reading t (see FIG. 8). , Drive control at the time of the first read, drive control at the time of the second read, and the above-described setting (the second read time is set as the new first read time) are repeated, and the initial first read time described above is repeated. Only t is the point where the number of lines mentioned above is reduced by 1 and the drive is controlled. When a plurality of lines including adjacent lines are simultaneously driven at the time of the second reading, the line that is located on the opposite side to the predetermined line among the simultaneously driven lines is set as a new predetermined line. In addition, the second read time is set as the new first read time, and the drive control at the first read time, the drive control at the second read time, and the above settings are repeated. Same as 1.

 Specifically, in the second embodiment, in the case of the number of lines that are driven simultaneously, the number of lines n is reduced by 1 only at the time of initial first reading t. Therefore, the predetermined line at the initial first reading t is n−1, and the (n−1) th predetermined line is the timing of the next reading at the initial first reading t force. At the second read time t

 1 Driven simultaneously with 2 adjacent lines. At this time, of the simultaneously driven lines, the line located closest to the (n-1) th predetermined line is 2 Xn-2, and the (2Xn-2) th line is The line becomes a new predetermined line. For the above reasons, the second read time t is set as a new first read time t, so the number of repetitions is

 twenty two

 At the first (new) first read time, the predetermined line at t is 2 × n−2. same as below

 2

 Then, the predetermined line at t at the first read of the number of repetitions is (r + 1) r + 1

Xn—r—1, and (r + 1) X (n—1). Therefore, in comparison with Example 1 described above, Example 2 is obtained by lowering each corresponding line (predetermined line or adjacent line) one by one. [0077] As shown in FIG. 8, for example, in the case of 5-line simultaneous drive, the number of lines to be driven simultaneously becomes 5, so the predetermined line at the initial first read time t is the fourth (in FIG. 8). L)

 14

When the first reading is the first repetition, the predetermined line at t is 8th (L in Fig. 8).

 When the first read time is 2nd, the predetermined line at t is 12th (in Fig. 8,

 Three

 L). For example, if 3 lines are driven simultaneously, the number of lines to be driven simultaneously is 3.

12

 Therefore, the predetermined line at the initial first read t is the second (L in FIG. 8) and repeats.

 1 2

 The predetermined line at the first read t is the 4th (L in Fig. 8) and the repetition is repeated.

 2 4 When the first read is the second repeat count The predetermined line at t is the sixth (L in Fig. 7)

 3 6

. Also, for example, in the case of two-line simultaneous driving, the number of lines to be driven simultaneously is 2, so the predetermined line at the initial first read time t is the first (L in FIG. 8), and the number of repetitions is At the first read time of the first time, the predetermined line at t is the second (L in Fig. 8) and repeats

 twenty two

 However, the predetermined line at the first read t is the third (L in Fig. 7).

 3 3

 [0078] As in the first embodiment, at the time of each first read, a predetermined line is driven to read a carrier, and a carrier adjacent to the predetermined line is not driven and a carrier is not read out. . At the time of each second reading, a predetermined line and an adjacent line are simultaneously driven to simultaneously read the carriers.

 [0079] Also, in the conventional case, the predetermined line at t at the first read of the number of repetitions ^ is r + 1

 In contrast to (r + 1) X n, in the case of the second embodiment, the predetermined line at t at the first reading of the repetition power ^ is (r + 1) X (n-l) It becomes. Therefore, r + 1 in Fig. 6 as before.

 In FIG. 8, the number of lines that are driven simultaneously is the same as the number of lines that are simultaneously driven in FIG. Therefore, in the case of 4-line simultaneous drive as shown in FIG. 6, in Example 2, 5-line simultaneous drive as shown in FIG. 8 is performed, and in the case of 2-line simultaneous drive as shown in FIG. In Example 2, 3-line simultaneous drive as shown in FIG. 8 is performed, and in the case of 1-line drive as shown in FIG. 6, 2-line simultaneous drive as shown in FIG. 8 is performed in Example 2. As described above, in the second embodiment, by increasing the number of simultaneously driven lines by one as compared with the conventional case, the number of lines to be advanced can be made the same, and the predetermined lines can also be made the same.

[0080] Also in the second embodiment, as in the first embodiment, the driving methods shown in Fig. 8 may be switched to each other. However, each drive system as shown in Fig. 8 can be switched to each drive system as shown in Fig. 6.

Since the operations and effects of the X-ray imaging apparatus according to the second embodiment are the same as those of the first embodiment described above except for the differences, the description thereof will be omitted.

[0082] The present invention is not limited to the above embodiment, and can be modified as follows.

 (1) In each of the above-described embodiments, the force described by taking the X-ray imaging apparatus as shown in FIG. 1 as an example. The present invention also applies to, for example, an X-ray imaging apparatus disposed on a C-type arm. You may apply. The present invention may also be applied to an X-ray fluoroscopic apparatus and an X-ray CT apparatus.

 [0084] (2) In each of the above-described embodiments, the present invention is applied to a “direct conversion type” radiation detector in which incident radiation is directly converted into charge information by the semiconductor thick film 31 (semiconductor layer). The present invention applies an “indirect conversion type” radiation detector that converts incident radiation into light by a conversion layer such as a scintillator and converts the light into charge information by a semiconductor layer formed of a photosensitive material. May be. Photosensitive semiconductor layers may be formed with photodiodes.

 (3) In each of the above-described embodiments, an X-ray detector for detecting X-rays has been described as an example. However, the present invention is not limited to a radioisotope (RI) as in an ECT (Emission Computed Tomography) apparatus. ) Is not particularly limited as long as it is a radiation detector that detects radiation, as exemplified by a γ-ray detector that detects y-rays radiated from a subject administered. Similarly, the present invention is not particularly limited as long as it is an apparatus that detects an image by detecting radiation as exemplified by the ECT apparatus described above.

 (4) In each of the above-described embodiments, the radiation detector typified by X-rays has been described as an example. However, the present invention can also be applied to a photodetector that detects light. Therefore, the device is not particularly limited as long as the device detects light and performs imaging.

 (5) In each of the embodiments described above, the number of lines to be driven simultaneously is changed and switched, but it is not always necessary to switch.

[0088] (6) In the first embodiment described above, except for the last read, the drive control at the first read, the drive control at the second read, and ( (The second read time is the new first read time) In Example 2, the drive control during the first read is performed without changing the number of lines driven simultaneously during the first read and the second read except for the initial first read (see Fig. 8). The drive control at the time of the second read and the setting described above (the second read at the time of the new first read) were repeated, but even if the number of lines to be driven at the same time is changed during the read Good.

 (7) Like the above-described embodiments, the present invention can be applied to the case where the number of lines to be simultaneously driven exceeds two, such as the 5-line simultaneous drive and 3-line simultaneous drive shown in FIGS. Alternatively, the present invention may be applied to the case where the number of lines to be driven simultaneously is two, such as the two-line simultaneous driving shown in FIGS. When the number of lines to be driven simultaneously exceeds 2, as is clear from FIGS. 7 and 8, the lines that are driven during the first reading and that are also driven during the second reading include a plurality of lines including a predetermined line. Indicates a line. On the other hand, when the number of lines to be driven simultaneously is 2, as is clear from FIGS. 7 and 8, the line force that is driven at the time of the first reading and is driven at the time of the second reading is only a predetermined line. It shows that.

 [0090] (8) The present invention can also be applied to a case where unnecessary carriers are simultaneously read out by a plurality of lines and discharged at high speed in order to release a leakage current at the time of non-irradiation. It can also be applied to cases where unnecessary carriers outside the field of view are simultaneously read out by multiple lines and swept out at high speed.

Claims

The scope of the claims  [1] An imaging device that obtains an image by imaging with light or radiation, wherein the light or radiation information is converted into charge information by the incidence of the light or radiation, and is converted by the conversion layer. Accumulation charge information is stored and read out via a plurality of lines arranged in a two-dimensional manner, and the image is obtained based on the charge information read out by the storage read circuit. The apparatus is configured as described above, and the apparatus further reads the charge information by driving a predetermined line and the timing at which the charge information is not read without driving a line adjacent to the predetermined line. In addition to the time of 1 reading, the first reading power is also set to the predetermined line and the adjacent line at the time of the second reading when the timing of the next reading is set to the second reading time. A driving control means for driving and controlling so as to drive the in-time simultaneously read charge information respectively !, imaging apparatus according to claim Rukoto.  [2] In the imaging device according to claim 1, the drive control unit V controls the drive so that the plurality of lines including the predetermined line are simultaneously driven and the charge information is read simultaneously. An imaging apparatus characterized by that.  [3] The imaging apparatus according to claim 2, further comprising switching means for switching by changing the number of lines to be driven simultaneously.  [4] The imaging device according to claim 3, wherein the switching unit simultaneously drives a plurality of lines to simultaneously read out the charge information by switching the number of lines to be simultaneously driven from a plurality to one. An imaging apparatus characterized in that the imaging is switched to imaging that reads out charge information by driving one line.  [5] In the imaging device according to [1], when a plurality of lines including the adjacent line are simultaneously driven at the time of the second reading, the line that is simultaneously driven is opposite to the predetermined line. The line located closest to the side is set as a new predetermined line, and the second read time is set as the new first read time, and the drive control at the first read time and at the second read time are set. An imaging apparatus characterized by repeatedly performing the drive control and the setting. [6] The imaging device according to claim 5, wherein the number of lines to be driven simultaneously is not changed. An image pickup apparatus that repeats the drive control at the time of the first reading, the drive control at the time of the second read, and the setting. [7] In the imaging device according to claim 5, without changing the number of lines to be driven simultaneously in each of the first readout and in the second readout except for the initial first readout. The drive control during the first read, the drive control during the second read, and the setting are repeated, and the drive control is performed by reducing the number of lines by 1 only during the initial first read. An imaging device. [8] The imaging device according to [1], wherein the imaging device is driven at the time of the first readout, and the first 2. An imaging apparatus characterized in that only the predetermined line is driven during reading.