JP2011099794A - Radiation image detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable radiation image detector which senses the start of irradiation of radiation by itself, and timely switches the drive state of a detection section. <P>SOLUTION: The radiation image detector includes a rectangular sensor panel section 34; the detecting section 45 for reading a charge from the sensor panel section 34, and converting the charge into an electrical signal; a housing 3 for incorporating the sensor panel section 34 and the detecting section 45, and having at least one surface for transmitting a radiation; a rectangular conversion layer 270, having a fluorescent material layer 271 disposed on the radiation-incident side from the sensor panel section 34, and a first glass substrate 214 for guiding a light generated by the fluorescent material layer 271; a light-sensing section 275 for sensing the light guided by the first glass substrate 214; and a control section 30 for determining whether the radiation irradiation of the sensor panel section 34 is started, based on a sensed result by the light-sensing section 275, and for controlling the detection section 45 so as to switch the drive state, based on this determination result. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a radiological image detection apparatus.

  2. Description of the Related Art Conventionally, as a means for acquiring a medical radiation image, a radiation image detection device in which a solid-state imaging device called a so-called flat panel detector (FPD) is two-dimensionally arranged is known. In such a radiation image detection apparatus, radiation energy is directly converted into charges using a photoconductive material such as a-Se (amorphous selenium) as a radiation detection element, and the charges are arranged two-dimensionally. A direct readout method that reads out electrical signals in pixel units by switching elements for signal readout, such as TFT (Thin Film Transistor), or radiation energy is converted into light by a scintillator, and this light is arranged two-dimensionally. It is known that there is an indirect type that is converted into electric charge by a photoelectric conversion element such as a photodiode and read out as an electric signal by a TFT or the like.

  In recent years, a cassette-type radiation image detection apparatus configured to be portable and can be driven without a cable has been developed. When the radiation image detection apparatus is configured to be portable as described above, it is possible to perform imaging with a high degree of freedom including portable imaging on the patient's bedside or the like.

  By the way, in the case of a radiographic image detection apparatus configured to be built in and driven by this battery, in order to suppress the power consumption of the battery, a sleep state in which power supply to each functional unit is stopped during non-imaging is performed. When radiation is emitted from the radiation generation apparatus and imaging is started, the system is activated and transitions to a charge accumulation state (imaging possible state) that generates a signal corresponding to the irradiated radiation dose.

  However, there is a possibility that the portable radiographic image detection apparatus performs imaging together with various manufacturers and types of radiation generating apparatuses in imaging. For this reason, it is not always possible to link the radiation generation device and the radiation image detection device through an I / F connection or the like, and in order to improve the degree of freedom of imaging by taking advantage of the portable characteristics, It is required that the connection is not required, and that the radiation image detection device itself detects that radiation has been emitted from the radiation generation device, and that the drive state can be switched.

In this regard, conventionally, the following methods have been proposed as methods for detecting the start of radiation irradiation with a radiation image detection apparatus.
That is, Patent Document 1 proposes a method of detecting a radiation irradiation start by providing a detection unit that detects radiation irradiation outside the imaging region of the radiation image detection apparatus.
Patent Document 2 proposes a configuration in which a sensor that detects irradiation of radiation is provided on the back surface of a solid-state imaging device that is two-dimensionally arranged in a photographic area.
Patent Document 3 proposes a method of randomly embedding radiation start detection pixels in each pixel in the two-dimensional imaging region and detecting the irradiation start based on these read values.
Further, Patent Document 4 proposes a method of repeatedly reading using a sensor array having a special structure called non-destructive reading and detecting the irradiation start based on a difference between frames. According to this, the sensor does not go out of the irradiation field, and even when the irradiation field is narrowed down, irradiation of radiation can be detected.
Patent Document 5 proposes a method of detecting the leakage current in each reverse bias line of the two-dimensional detection element and determining the start of irradiation.

Japanese Patent Laid-Open No. 06-342099 JP-A-11-151233 US Pat. No. 6,307,915 JP 2003-126072 A US Pat. No. 7,211,803

  However, in the methods described in Patent Document 1 and Patent Document 2, if the detection unit (sensor) is disposed outside the irradiation range (irradiation field) where no radiation is irradiated, the start of radiation irradiation cannot be detected. For this reason, in order to perform detection appropriately, there is a restriction that the radiological image detection apparatus must be arranged on the subject so that the detection unit is within the irradiation field, and the degree of freedom of imaging is narrowed, and cableless The advantages of the cassette-type radiation image detection device driven by this could not be utilized. Moreover, when there is only one detection part (sensor), since the dose itself which reaches | attains a detection part (sensor) is weak, there also exists a problem that detectability is low.

In this respect, the methods described in Patent Documents 3 to 5 are excellent in that the start of radiation irradiation can be detected regardless of where the irradiation field is set.
However, according to the method described in Patent Document 3, if the output value of the randomly assigned detection pixel is read in a short time, the circuit configuration becomes complicated and it is difficult to implement in terms of wiring and the like. There's a problem. On the other hand, if the number of detection pixels is reduced in order to simplify the circuit configuration, the detection pixels may be outside the irradiation field and radiation may not be detected.

  Further, the technique described in Patent Document 4 uses a special sensor array. However, if the sensor array radiation image detection apparatus is mounted on such a technique, the cost becomes high, and it is necessary to perform repeated reading. , Power consumption becomes large. For this reason, it can be said that adoption is difficult in the case of the radiographic image detection apparatus driven by a built-in battery.

  Furthermore, in the method described in Patent Document 5, there are many noise factors that affect radiation irradiation start detection, and in particular, since it is difficult to detect irradiation start at the time of radiation irradiation at a low dose, it is difficult to put it to practical use. There is a problem with.

  The present invention has been made in view of the circumstances as described above, and provides a radiographic image detection apparatus capable of detecting the start of radiation irradiation and switching the driving state as appropriate in a portable radiographic image detection apparatus. It is intended to do.

In order to solve the above-mentioned problem, the radiological image detection apparatus of the present invention is
A plurality of radiation detection elements constituting the pixels arranged in a two-dimensional matrix, and a rectangular sensor panel unit for detecting radiation;
A detection unit that reads out the electric charge accumulated in the radiation detection element and converts it into an electrical signal;
A housing in which the sensor panel unit and the detection unit are incorporated, and at least one surface of which is capable of transmitting radiation;
A phosphor layer that is disposed on the radiation incident side of the sensor panel unit and converts a part of incident radiation into light, and a light guide member that guides light generated by the phosphor layer in a predetermined direction. A rectangular conversion layer;
A light detection unit that is disposed on at least one side of the rectangular conversion layer and detects light generated in the phosphor layer and guided by the light guide member;
A control unit that determines whether or not radiation irradiation to the sensor panel unit is started based on a detection result of the light detection unit, and that controls switching of a driving state of the detection unit based on the determination result. It is characterized by being.

According to this invention, radiation is irradiated to the sensor panel unit by converting the radiation into light in the phosphor layer arranged on the radiation incident side of the sensor panel unit, and detecting this light by the light detection unit. Determine whether it has started. For this reason, even when the irradiation field is narrowed down, it is possible to appropriately determine the start of radiation irradiation.
In addition, it is possible to determine the start of radiation irradiation with high accuracy without being easily influenced by electrical noise.
And since the drive state of a detection part is switched based on this determination result, there exists an effect that it can transfer to imaging | photography operation | work rapidly, when irradiation of a radiation is started, suppressing useless power consumption.

It is a perspective view which shows the external appearance of the radiographic image detection apparatus which concerns on this embodiment. It is the schematic which shows the internal structure of the cassette type detector shown in FIG. It is the sectional view on the AA line in FIG. It is a top view which shows the detection panel in this embodiment. FIG. 5 is a cross-sectional view of the detection panel shown in FIG. 4 taken along line BB. It is a top view which shows the irradiation detection unit in this embodiment. It is an equivalent circuit diagram which shows the structure of a sensor panel part, a detection part, etc. of the radiographic image detection apparatus shown in FIG. It is a top view which shows the modification of the irradiation detection unit in this embodiment. It is sectional drawing of the detection panel to which the irradiation detection unit shown in FIG. 8 is applied. It is a top view which shows the modification of the irradiation detection unit in this embodiment. It is a step view which shows the modification of the irradiation detection unit in this embodiment. It is a step view which shows the modification of the detection panel in this embodiment. It is a step view which shows the modification of the detection panel in this embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that embodiments to which the present invention is applicable are not limited to this.

  First, an embodiment of a radiological image detection apparatus according to the present invention will be described with reference to FIGS. However, the present invention is not limited to the illustrated example.

FIG. 1 is a perspective view of a radiation image detection apparatus 1 in the present embodiment.
In this embodiment, the radiological image detection apparatus 1 is a cassette type FPD in which a so-called flat panel detector (hereinafter referred to as “FPD”) is configured to be portable, and is used for radiographic imaging to detect radiation. Thus, radiation image data corresponding to the radiation dose (hereinafter simply referred to as “image data”) is generated and acquired.
In the present embodiment, the radiation image detection apparatus 1 includes a scintillator layer 211 (see FIG. 3 and the like) and the like, so-called electric signals are obtained by converting emitted radiation into electromagnetic waves of other wavelengths such as visible light. The indirect radiation image detection apparatus 1 will be described, but the present invention is also applicable to a so-called direct radiation image detection apparatus that directly detects radiation with a radiation detection element without using the scintillator layer 211 or the like. Can do.

As shown in FIG. 1, the radiation image detection apparatus 1 includes a housing 3 that protects the inside. In the housing 3, at least a surface X on which radiation is received (hereinafter referred to as a radiation incident surface X) is formed of a material such as a carbon plate or plastic that transmits radiation. FIG. 1 shows a case where the housing 3 is formed of the front member 5 and the back member 4, but the shape and configuration are not particularly limited. It is also possible to form a cylindrical so-called monocoque shape.
Inside the housing 3, as will be described later, a sensor panel section 34, an irradiation detection unit, and the like constituting the detection panel 21 are arranged.

  As shown in FIG. 1, in the present embodiment, a power switch 54, an indicator 56, a connection unit 55, and the like are disposed on the side surface portion of the radiation image detection apparatus 1.

  The power switch 54 switches ON / OFF of the power supply of the radiation image detection apparatus 1, and the power to each functional unit of the radiation image detection apparatus 1 by the battery 25 (see FIG. 2) is operated by operating the power switch 54. A signal instructing the start and stop of the supply is output to the control unit 30 (see FIG. 7) described later. When the radiographic image detection apparatus 1 is not used for imaging, the power consumption of the battery 25 can be suppressed by turning off the power (that is, stopping the power supply to each functional unit by the battery 25).

The indicator 56 is composed of, for example, an LED or the like, and displays the remaining amount of charge of the battery 25 and various operation statuses.
In the present embodiment, for example, it performs a function of notifying the operator of the completion of the reset operation by blinking when the reset is completed.

Further, the radiological image detection apparatus 1 is provided with a battery 25 (see FIG. 2) that supplies power to each functional unit of the radiographic image detection apparatus 1.
The battery 25 is rechargeable, for example, a rechargeable secondary battery such as a nickel cadmium battery, a nickel metal hydride battery, a lithium ion battery, a small sealed lead battery, a lead storage battery, an electric double layer capacitor, a lithium ion capacitor (LIC). ) And the like can be applied.

  In addition, a lid member 8 that is opened and closed for replacement of the battery 25 built in the housing 3 is provided on the side surface portion of the radiation image detection apparatus 1. An antenna device 9 is embedded for the image detection device 1 to transmit and receive information to and from the outside via a wireless access point (not shown).

  The connection unit 55 is a connection unit for connecting a power supply cable (not shown) for charging the battery 25 and an external power supply terminal. The connection unit 55 may be connected to a communication cable (not shown) when performing communication by a wired method in addition to a power feeding cable or the like.

  2 is a plan view of the state in which the detection unit 2 is housed in the housing 3 as viewed from the lower side (the side opposite to the radiation incident side during imaging), and FIG. 3 is a line AA in FIG. It is sectional drawing. In FIG. 2, for convenience, the internal state of the housing 3 is illustrated without the bottom surface portion of the back member 4.

  As shown in FIGS. 2 and 3, the detection unit 2 includes a detection panel 21, a circuit board 23 on which various electronic components 22 are mounted, and the like. In the present embodiment, the circuit board 23 is fixed to a base 24 made of resin or the like, and the circuit board 23 is attached via the base 24 by bonding and fixing the base 24 to the detection panel 21. It is fixed to the detection panel 21. The base 24 is not an essential component of the present invention, and the circuit board 23 or the like may be directly fixed to the detection panel 21 without the base 24 being interposed.

As shown in FIG. 2, in this embodiment, the circuit board 23 on which the electronic component 22 is mounted is divided into four parts, which are arranged close to each corner of the detection panel 21. The electronic component 22 is disposed on the circuit board 23 along the outer periphery of the detection panel 21. The electronic component 22 is preferably disposed at a position as close to each corner of the detection panel 21 as possible. By arranging the electronic component 22 on the circuit board 23 in this way, when the detection unit 2 is housed in the housing 3, the electronic component 22 is near the corner of the housing 3 and the flat portion 51 ( It is arranged along the ridgeline of the rectangular portion.
The configuration and arrangement of the circuit board 23, the electronic component 22, and the like are not limited to those exemplified here.

  In the present embodiment, as the electronic component 22 arranged on the circuit board 23, for example, a central processing unit (CPU) (not shown) that constitutes a control unit 30 (see FIG. 7) that controls each unit, a ROM ( There are a storage unit 31 including a read only memory), a RAM (Random Access Memory), a scan driving circuit 32 (see FIG. 7), a signal reading circuit 33 (see FIG. 7), and the like. In addition to the ROM and RAM, an image storage unit that includes a rewritable read-only memory such as a flash memory or the like and that stores an image signal output from the detection panel 21 may be provided.

  The detection unit 2 is provided with a communication unit (not shown) that transmits and receives various signals to and from an external device. The communication unit, for example, transfers image signals accumulated as electric charges in the sensor panel unit 34, which will be described later, and output as electric signals to the external device via the antenna device 9 described above, or starts photographing that is transmitted from the external device. A signal or the like is received via the antenna device 9.

  Further, on the base 24, when the detection unit 2 is housed in the housing 3, a position corresponding to the lid member 8 is provided with a plurality of drive units (for example, described later) constituting the radiographic image detection apparatus 1. As a power supply unit that supplies power to the scanning drive circuit 32 (see FIG. 7), the signal readout circuit 33 (see FIG. 7), the communication unit (not shown), the storage unit 31, the indicator 56, the detection panel 21, etc. A battery 25 is provided.

  As the battery 25, for example, a rechargeable battery such as a nickel cadmium battery, a nickel metal hydride battery, a lithium ion battery, a small sealed lead battery, or a lead storage battery can be used. Further, a fuel cell or the like may be applied instead of the battery 25. Note that the shape, size, number, arrangement, and the like of the battery 25 as the power supply unit are not limited to those illustrated in FIG.

  As shown in FIG. 2, a buffer member 26 is provided between the electronic components 22 and the battery 25 to protect these components from being damaged by interference with the housing 3. In addition, the number, arrangement | positioning, etc. of the buffer member 26 and the electronic component 22 are not limited to what was illustrated here. The material of the buffer member 26 is not particularly limited, and for example, an elastic resin such as polyurethane can be applied.

4 is a plan view of the detection panel 21, and FIG. 5 is a cross-sectional view of the detection panel 21 taken along line BB in FIG.
The detection panel 21 is sandwiched between the first glass substrate 214 and the second glass substrate 213 and the two glass substrates 214 and 213, and converts radiation incident on the detection panel 21 into light, for example, CsI. It has a laminated structure in which a scintillator layer (light emitting layer) 211 composed of a columnar crystal such as is laminated. A glass protective film 216 is further laminated on the lower side of the second glass substrate 213.
On one surface of the second glass substrate 213, there is a sensor panel section 34 (see FIG. 7) in which photodiodes and TFTs are formed that detect light converted by the scintillator layer 211 and convert it into an electrical signal. Is formed.

In the present embodiment, the first glass substrate 214 is a substrate that constitutes the rectangular conversion layer 270 that constitutes the irradiation detection unit 27. That is, a part of the radiation incident on the detection panel 21 is converted into light on the upper surface of the first glass substrate 214 (that is, on the radiation incident side of the sensor panel unit 34, upper side in FIG. 5), for example, A phosphor layer 271 formed by a coating method such as GOS (rare earth phosphor) is formed, and an upper side (radiation incident side) of the phosphor layer 271 and a lower side (anti-radiation incidence) of the first glass substrate 214. A reflective layer 272 made of a reflective material such as aluminum (Al) or silver (Ag) is formed on the peripheral surface including the side.
The first glass substrate 214 has a function as a light guide member that guides the light generated by the phosphor layer 271 in a predetermined direction, and the light generated by the phosphor layer 271 and irregularly reflected by the reflection layer 272 is the first. One glass substrate 214 is guided to one side.

On one side of the first glass substrate 214 where light is guided, a light detector 275 that detects light generated in the phosphor layer 271 and guided by the light guide member is provided. The light detection unit 275 is an optical sensor including, for example, a phototransistor, a photodiode, a photo IC, a CdS cell, or the like. Note that the configuration of the light detection unit 275 is not limited to that illustrated here.
The light detection unit 275 is connected to the circuit board 23, and the detection result is output to the control unit 30 described later.

  As described above, the phosphor layer 271 is made of, for example, GOS (rare earth phosphor) and is formed by a so-called coating method. Note that the method for forming the phosphor layer 271 on the first glass substrate 214 is not limited to the coating method, and for example, a film forming method (PVD) by a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method. ), Electroplating, dry plating, chemical vapor deposition (CVD), or the like.

As shown in FIGS. 5 and 6, in the present embodiment, a rectangular conversion layer 270 is configured by the phosphor layer 271, the reflection layer 272, and the first glass substrate 214 as a light guide member.
The rectangular conversion layer 270 and the light detection unit 275 constitute an irradiation detection unit 27 that detects the start of radiation irradiation.
As shown in FIG. 6, in this embodiment, since the phosphor layer 271 is provided over almost the entire area of the rectangular conversion layer 270, the radiation irradiation range (irradiation field) is as shown in FIG. Even when the light is focused only on the center portion, it can be converted into light and guided to the light detection portion 275, and the start of radiation irradiation can be appropriately detected regardless of the radiation irradiation range.

The conversion layer 270 is required to be such that the radiation incident on the scintillator layer 211 and the sensor panel unit 34 does not decrease to such an extent that it affects image formation. Preferably, 3% to 5% of radiation is converted to light. The thickness of the phosphor layer 271 is required to be such that radiation irradiation can be detected and that radiation reaching the scintillator layer 211 and the sensor panel unit 34 is not blocked more than necessary.
Further, the range and size in which the phosphor layer 271 is formed are not particularly limited, but the phosphor layer 271 is preferably provided so as to correspond to almost the entire detectable range of the sensor panel unit 34. By providing in such a range, it is possible to reliably detect the radiation no matter how the radiation irradiation range is set.

The scintillator layer (light emitting layer) 211 has a reflective layer 272 on the lower surface of the first glass substrate 214 (that is, the surface opposite to the surface on which the phosphor layer is provided, the lower side in FIG. 5). Is formed through.
Note that when the first glass substrate 214 and the second glass substrate 213 are stacked, a sealing member 212 is provided so as to surround the scintillator layer (light emitting layer) 211. The sealing member 212 is formed of, for example, resin, and secures a certain space between the first glass substrate 214 and the second glass substrate 213 so that the scintillator layer 211 is not pressed and damaged. , Prevent moisture and the like from entering.

  The scintillator layer 211 has, for example, a phosphor as a main component and outputs an electromagnetic wave having a wavelength of 300 nm to 800 nm, that is, an electromagnetic wave (light) ranging from ultraviolet light to infrared light centering on visible light, based on incident radiation. It is like that.

The phosphor used in the scintillator layer 211 is, for example, a material using CaWO ₄ or the like as a base material, or a luminescent center substance activated in a host body such as CsI: Tl, Gd ₂ O ₂ S: Tb, or ZnS: Ag. What was formed using the made fluorescent substance can be used. Further, when the rare earth element is M, a phosphor represented by a general formula of (Gd, M, Eu) ₂ O ₃ can be used. In particular, CsI: Tl or Cd ₂ O ₂ S: Tb having a columnar crystal formed by a vapor phase growth method or the like is preferable because of high radiation absorption and emission efficiency. By using these, high image quality with low noise can be obtained. Images can be obtained.

  The scintillator layer 211 is formed, for example, on a support (not shown) formed of various polymer materials (polymers) such as a cellulose acetate film, a polyester film, and a polyethylene terephthalate film by, for example, vapor deposition using a phosphor. The phosphor layer is formed of a columnar crystal of the phosphor. As the vapor deposition method, a vapor deposition method, a sputtering method, a chemical vapor deposition (CVD) method or the like is preferably used. In any of the methods, the phosphor layer can be vapor-grown into independent elongated columnar crystals on the support.

  The scintillator layer 211 is attached to the first glass substrate 214 via a support (not shown), and the surface side opposite to the surface on which the radiation of the scintillator layer 211 is incident (the lower side in FIG. 5). ) Is provided with a sensor panel section 34 as a detection section in which a plurality of photoelectric conversion elements 35 (see FIG. 7) for converting the light output from the scintillator layer 211 into an electric signal are two-dimensionally arranged. Yes. The photoelectric conversion element 35 is, for example, a photodiode or the like, and constitutes a radiation detection element that converts the radiation transmitted through the subject into an electric signal together with the scintillator layer 211 and the like.

  In the present embodiment, the detection unit 45 (see FIG. 7) is a reading unit that reads the output value of each photoelectric conversion element 35 of the sensor panel unit 34 by the control unit 30, the scanning drive circuit 32, the signal readout circuit 33, and the like. Is configured.

  Further, a buffer member 218 for protecting the detection panel 21 from an external impact or the like is provided near each corner of the detection panel 21 and between the corners.

The configurations of the sensor panel unit 34 and the detection unit 45 will be further described with reference to the equivalent circuit diagram of FIG.
As shown in FIG. 7, one electrode of each photoelectric conversion element 35 of the sensor panel section 34 is connected to the source electrode of a TFT 46 that is a signal reading switch element. In addition, a bias line Lb is connected to the other electrode of each photoelectric conversion element 35, and the bias line Lb is connected to a bias power supply 36, and a reverse bias voltage is applied from the bias power supply 36 to each photoelectric conversion element 35. It has come to be.

  The gate electrode of each TFT 46 is connected to a scanning line Ll extending from the scanning drive circuit 32, and a read voltage (ON voltage) or OFF voltage is applied to the gate electrode of the TFT 46 from a TFT power source (not shown) via the scanning line Ll. Is applied. The drain electrode of each TFT 46 is connected to the signal line Lr. Each signal line Lr is connected to an amplifier circuit 37 in the signal readout circuit 33, and an output line of each amplifier circuit 37 is connected to an analog multiplexer 39 via a sample hold circuit 38. The signal readout circuit 33 is provided with a capacitor (not shown) corresponding to each amplifier circuit 37. The signal readout circuit 33 is connected to an A / D converter 40 as processing means for converting the signal into a digital signal. The analog image signal sent from the analog multiplexer 39 is an A / D converter. 40 is converted into a digital image signal. The signal readout circuit 33 is connected to the control unit 30 via the A / D conversion unit 40, and a digital image signal is output to the control unit 30. A storage unit 31 is connected to the control unit 30, and the control unit 30 stores the digital image signal sent from the A / D conversion unit 40 in the storage unit 31 as image data.

  The control unit 30 is a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and comprehensively controls the entire radiation image detection apparatus 1.

The ROM stores a program for performing various processes in the radiation image detection apparatus 1 such as an image data generation process and an image correction process, various control programs, parameters, and the like.
The control unit 30 reads a predetermined program stored in the ROM, develops it in a work area of the RAM, and the CPU executes various processes according to the program.

In the present embodiment, the detection result is sent from the light detection unit 275 to the control unit 30, and the control unit 30 has started radiation irradiation to the sensor panel unit 34 based on the detection result. It is determined whether or not, and based on the determination result, the drive state of the detection unit is switched and controlled.
In other words, in the present embodiment, the radiographic image detection apparatus 1 has a driving state that includes an imaging enabled state and a sleep state that consumes less power than the imaging enabled state. When the control unit 30 determines from the detection result of the light detection unit 275 that radiation irradiation has been started from a radiation generator (not shown), the control unit 30 supplies power from the battery 25 to each functional unit constituting the detection unit 45. Then, the driving of the detection unit 45 is controlled, the detection unit 45 is started from the sleep state, and the driving state is switched so that the photographing can be performed.

  For example, a predetermined threshold value is stored in advance in the storage unit 31 or the like for determining what kind of result the detection result from the light detection unit 275 is to start radiation irradiation. And the control part 30 always monitors the detection result from the light detection part 275, and when this detection result exceeds a fixed threshold value, it judges that irradiation is started. Note that the threshold for determining whether or not radiation irradiation has started may be set by the user according to the usage environment or the like.

In the present embodiment, the control unit 30 controls a communication unit (not shown) so as to communicate with an external device such as a console (not shown).
When the reset process of the radiation image detection apparatus 1 is completed, the control unit 30 transmits a reset completion signal to that effect to the corresponding console.
In addition, when the driving state is switched from the sleep state to the photographing enabled state, a signal to that effect is transmitted to the corresponding console.

  The storage unit 31 includes, for example, an HDD (Hard Disk Drive), a flash memory, or the like, and the storage unit 31 includes real image data (radiation transmitted through the subject) generated by the detection unit 45 (see FIG. 7). Based image data), dark read values (image data of dark images acquired without radiation), and the like are stored.

  The storage unit 31 may be a built-in memory or a removable memory such as a memory card. Further, the capacity is not particularly limited, but preferably has a capacity capable of storing a plurality of pieces of image data. By providing such a storage means, it is possible to continuously irradiate a subject with radiation, and to record and accumulate image data each time, enabling continuous shooting and moving image shooting. Become.

The communication unit is connected to the antenna device 9 and transmits / receives various signals to / from an external device such as a console under the control of the control unit 30.
The communication unit transmits image data based on the image signal read by the detection unit 45 and converted from an analog signal to a digital signal in the A / D conversion unit 40 to a console (not shown) that is an external device and the console. It is possible to receive shooting order information and the like.

  Next, the operation of the radiation image detection apparatus 1 in this embodiment will be described.

In the present embodiment, the radiological image detection apparatus 1 automatically enters a sleep state in which power supply from a battery 25 to a predetermined functional unit is stopped when imaging is not performed for a certain period of time.
The control unit 30 constantly monitors the detection result from the light detection unit 275, and determines that radiation irradiation has started when the detection result exceeds a certain threshold. When it is determined that radiation irradiation has started, power is supplied from the battery 25 to the detection unit 45 such as the scanning drive circuit 32 and the signal readout circuit 33, and the state is changed from the sleep state to the imageable state.
When the driving state is switched, a signal to that effect is sent from the radiation image detection apparatus 1 to the console. In addition, electric charges are accumulated in the sensor panel unit 34 of the radiological image detection apparatus 1, and the detection unit reads out this and converts it into an electrical signal to generate image data.

As described above, according to the present embodiment, it is determined whether or not radiation irradiation has started based on the detection result from the light detection unit 275 of the irradiation detection unit 27, regardless of the position of the irradiation field or the like. Can make an appropriate decision. Based on this determination, the radiological image detection apparatus 1 is shifted from the sleep state to the radiographable state, so that it is possible to reliably enter the radiographable state when radiation is irradiated.
For this reason, even in the radiographic image detection apparatus 1 that is in a sleep state when not in use in order to suppress the power consumption of the battery 25, it is possible to perform smooth imaging without performing unnecessary radiation irradiation without being ready for imaging. Can do.

  In the present embodiment, the configuration in which the light detection unit 275 is provided on the entire surface of one side of the first glass substrate 213 as the light guide member is shown. However, the light detection unit 275 is the first glass substrate 213. It is not necessary to be provided on the entire surface of one side. As shown in FIG. 8, an overhanging portion 277 whose width decreases toward the outer side is provided on one side of the first glass substrate 213, and a light detection unit is provided at the end. 275 may be provided. Also in this case, the portion other than the portion where the light detection unit 275 is provided is covered with the reflection layer 272 so that the light generated by the phosphor layer 271 collects in the light detection unit 275 without leaking to the outside.

The substrate on which the phosphor layer 271 is provided is not limited to glass. For example, the phosphor layer 271 may be formed on a substrate formed of a flexible material such as a transparent resin.
In this case, as described above, an overhanging portion 277 that projects outward from the position corresponding to the sensor panel portion 34 may be provided on the substrate, and the light detection portion 275 may be provided at the tip thereof (see FIG. 8). Then, as shown in FIG. 9, the light detection unit 275 can be disposed on the back side of the detection panel 21 by folding the overhanging portion 277 on the back side of the detection panel 21. With such a configuration, the arrangement of the light detection unit 275 can be changed according to the mounting state inside the radiological image detection apparatus 1, which is convenient.

Further, as shown in FIG. 10, a plurality of light detection units 275a, 275b, 275c,... 275n may be provided on one side of the first glass substrate 213. In this manner, by providing a plurality of the light detection units 275a, 275b, 275c,... 275n, radiation is emitted only to a part of the radiation image detection apparatus 1 as when any one of the end portions is an irradiation field. Even when the irradiation is not performed, the start of irradiation can be appropriately detected.
In this case, the detection results of all the light detection units 275a, 275b, 275c,... 275n may be averaged, and it may be determined whether or not radiation irradiation has started depending on whether the value exceeds a predetermined threshold. The detection results of all the light detection units 275a, 275b, 275c,... 275n may be added and compared with a threshold value, or the highest value among all the light detection units 275a, 275b, 275c,. It may be determined by whether or not the value of what is exceeding the threshold value.

  In the present embodiment, an example in which the reflective layer 272 of the conversion layer 270 is formed by coating the surface of the first glass substrate 213 is shown, but the method of providing the reflective layer 272 is not limited to this. For example, as shown in FIG. 10, the phosphor layer 271 formed on the first glass substrate 213 is accommodated in a bag-like reflecting member 280 formed of a reflective material such as aluminum. The conversion layer 270 having a reflective layer may be formed later by sealing the opening side.

  In this embodiment, the light detection unit 275 is provided only on one side of the first glass substrate 213. However, the light detection unit 275 may be provided on a plurality of sides such as two opposite sides. For example, when the radiation image detection apparatus 1 is large, light can be detected more reliably by providing the light detection units 275 on a plurality of sides as described above.

  Furthermore, in the present embodiment, the indirect radiation image detection apparatus 1 including the scintillator layer 211 has been described as an example. However, radiation energy is directly converted into charges using a photoconductive substance such as a-Se (amorphous selenium). Even if the present invention is applied to a direct type radiological image detection apparatus that reads out this electric charge as an electric signal for each pixel by a signal reading switch element such as a TFT (Thin Film Transistor) arranged two-dimensionally. Good.

In this case, for example, as shown in FIG. 12, a reflective layer 272 made of a reflective material such as aluminum is formed on the direct sensor panel unit 290 by a technique such as vapor deposition, and the phosphor layer 271 is formed thereon. Alternatively, the first glass substrate 213 on which the reflective layer 272 is formed may be stacked.
Further, after forming the reflective layer 272 on the entire peripheral surface of the first glass substrate 213, it may be laminated on the direct sensor panel 34.
Further, a substrate serving as a light guide member constituting the conversion layer 270 is formed of a transparent resin or the like, and, for example, as shown in FIG. The light detection unit may be arranged on the back side of the sensor panel unit 34 by bending the back side.

  Further, the conversion layer 270 and the sensor panel unit may be laminated and fixed by adhesion or the like, or may be arranged with a slight gap between them.

In the present embodiment, the first glass substrate 213 on which the columnar crystals of the scintillator layer 211 are grown also serves as the substrate of the conversion layer 270 in the indirect sensor panel unit 34. Although the case where the scintillator layer 211 and the phosphor layer 271 are formed on the front and back is described as an example, the substrate on which the phosphor layer 271 of the conversion layer 270 is formed separately from the first glass substrate 213 that forms the scintillator layer 211 May be provided. In this case, the conversion layer 270 may be laminated on the sensor panel portion as in the case of using the direct sensor panel portion 290 (see FIGS. 12 and 13). In this case, it may be bonded and fixed, or simply placed.
The scintillator layer 211 is formed by growing a columnar crystal in a high temperature furnace. After forming the columnar crystal on one surface of the first glass substrate 213, the phosphor on the opposite surface is formed. When the layer is formed, the columnar crystal may be damaged when the phosphor layer is formed. Therefore, it is conceivable to form columnar crystals after forming the phosphor layer first, but in that case, there is a possibility that the phosphor layer 271 may peel off when placed in a high-temperature furnace. is there.
Therefore, by providing a substrate on which the phosphor layer 271 of the conversion layer 270 is formed separately from the first glass substrate 213 on which the scintillator layer 211 is formed, each of the substrates is made separately and then laminated. The above problem can be solved.

Further, in the present embodiment, the driving state includes a photographing enabled state and a sleep state, and when the control unit 30 determines that radiation irradiation has been started from the radiation generation device based on the detection result by the light detection unit 275, Although the case where the detection unit 45 is activated from the sleep state and the driving state is switched so as to be in a state where photographing can be performed has been described as an example, the control unit 30 performs radiation detection based on the detection result by the light detection unit 275. The control of the driving state when it is determined that the irradiation has started is not limited to the one exemplified here.
For example, in an energized state in which power is already supplied from the sleep state and power is supplied to the detection unit 45 and the like, a standby state in which charge accumulation and erasure (reset) are repeated, and photographing for accumulating charge to generate image data If the control unit 30 determines that radiation irradiation has started when the drive state is in the standby state, the detection state of the detection unit 45 is changed from the standby state to the imaging state (charge storage state). ) May be controlled so as to make a transition.
In this case, in the standby state, charge accumulation and erasure (reset) are repeated periodically so that imaging may be started at any time. However, the control unit 30 generates radiation based on the detection result by the light detection unit 275. When it is determined that radiation irradiation has started from the apparatus, the charge is accumulated for a certain period of time, or the charge is accumulated until the detection of the irradiation stop based on the detection result by the light detection unit 275, and this is read as an image signal to read the image data. The control unit 30 controls the detection unit 45 and the like so as to generate them.

  In addition, it goes without saying that the present invention is not limited to the present embodiment and can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 Radiation image detection apparatus 2 Detection unit 21 Detection panel 27 Irradiation detection unit 30 Control part 32 Scan drive circuit 33 Signal read-out circuit 34 Sensor panel part 211 Scintillator layer 213 2nd glass substrate 214 1st glass substrate 270 Conversion layer 271 Fluorescence Body layer 272 Reflective layer 275 Photodetector

Claims (6)

A plurality of radiation detection elements constituting the pixels arranged in a two-dimensional matrix, and a rectangular sensor panel unit for detecting radiation;
A detection unit that reads out the electric charge accumulated in the radiation detection element and converts it into an electrical signal;
A housing in which the sensor panel unit and the detection unit are incorporated, and at least one surface of which is capable of transmitting radiation;
A phosphor layer that is disposed on the radiation incident side of the sensor panel unit and converts a part of incident radiation into light, and a light guide member that guides light generated by the phosphor layer in a predetermined direction. A rectangular conversion layer;
A light detection unit that is disposed on at least one side of the rectangular conversion layer and detects light generated in the phosphor layer and guided by the light guide member;
A control unit that determines whether or not radiation irradiation to the sensor panel unit has been started based on a detection result by the light detection unit, and that controls switching of a driving state of the detection unit based on the determination result;
A radiological image detection apparatus comprising: A scintillator layer that converts the radiation irradiated on the sensor panel unit into light is converted into light, and the sensor panel unit is an indirect method that converts the light generated in the scintillator layer into electric charge and reads it as an electric signal,
The radiographic image detection apparatus according to claim 1, wherein the rectangular conversion layer is disposed closer to a radiation incident side than the scintillator layer. The scintillator layer is made of CSI,
The radiographic image detection apparatus according to claim 2, wherein the phosphor layer is made of GOS.   The rectangular conversion layer converts 3% to 5% of the radiation incident on the sensor panel unit into light, and the conversion layer according to any one of claims 1 to 3. The radiographic image detection apparatus described. As a driving state, it has a photographing enabled state and a sleep state with less power consumption than this photographing enabled state,
The said control part switches the said drive state by controlling the drive of the said detection part based on the detection result by the said light detection part, The Claim 1 characterized by the above-mentioned. Radiation image detection device.   6. The battery according to claim 1, wherein a battery that supplies power to each functional unit is built in the housing, and can be driven by power supply from the battery. Radiation image detection device.

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