JP5697957B2 - Electronic cassette and electronic cassette set - Google Patents

Description

  The present invention relates to an electronic cassette and an electronic cassette set that detect a radiation image by receiving radiation that has passed through a subject.

  In the medical field, an X-ray imaging apparatus using radiation, for example, X-rays, is known for performing image diagnosis. The X-ray imaging apparatus includes an X-ray source that generates X-rays and an X-ray image detection apparatus that detects an X-ray image by receiving X-rays generated by the X-ray source and transmitted through a subject. As an X-ray image detection apparatus, an X-ray sensitive layer is arranged on a TFT (Thin film transistor) active matrix substrate, and irradiated X-rays representing image information of a subject (patient, etc.) undergoing an X-ray examination. Those using an FPD (flat panel detector) that converts the intensity distribution of the image into digital image data have been put into practical use. The X-ray image detection apparatus is a stationary type in which an FPD is built in an upright photographing stand for photographing a subject in a standing posture or a standing photographing stand for photographing a subject in a prone posture. In addition to the above, a portable X-ray image detection apparatus (hereinafter also referred to as “electronic cassette”) in which an FPD is built in a flat, substantially rectangular parallelepiped cassette type casing has been developed.

  Since the electronic cassette has a high degree of freedom in positioning (positioning of the subject's imaging part and the electronic cassette), it is used for imaging parts that are difficult to shoot with the stationary type, such as extremity imaging for elbows and knee joints. In many cases, some users set an electronic cassette on the existing imaging stand instead of the X-ray film or IP in order to effectively use the existing imaging stand for X-ray film and IP (imaging plate). Some users use the electronic cassette as a stationary type.

  In order to further improve the degree of freedom in positioning the electronic cassette, an internal power supply and wireless communication unit are provided in the housing, so that cables for communication and power supply can be used for shooting without connecting to the housing (wireless use). There is also known a wireless type electronic cassette (see, for example, Patent Document 1). The electronic cassette described in Patent Document 1 is also provided with a connector for connecting a cable to the housing, and can be charged with an internal power supply by connecting to an external power supply with a cable, and the cable is connected while charging It can also be used for shooting (wired use), and can be adapted to users who are stationary users.

  In an electronic cassette that can be used while being charged, such as an electronic cassette described in Patent Document 1, an internal power source is connected to a power supply path that supplies power from an external power source to a power circuit in the housing. Power is supplied simultaneously from an external power supply to the internal power supply and the power supply circuit. As an internal power source of the electronic cassette, a rechargeable secondary battery such as a lithium ion battery is often used. However, in Patent Document 1, it is possible to use a capacitor such as an electric double layer capacitor. Have been described.

JP 2010-154897 A

  By the way, paying attention to the portability of the electronic cassette, there is a demand for using the electronic cassette in a mass examination car in which an X-ray source and an imaging stand are mounted in the vehicle based on a vehicle such as a bus. However, when the electronic cassette is used in a vehicle such as a mass examination car, there are the following problems.

  In other words, the vehicle is less air-conditioned than the in-hospital photography room, tends to be hot, and the environmental conditions are severe. Lithium ion batteries have low heat resistance, and if exposed to a high temperature environment for a long time, there are concerns about liquid leakage, ignition, rupture, etc. There is a problem that it is not suitable for long-time use in a high temperature environment.

As a countermeasure, when the electronic cassette is used in a vehicle, it is conceivable to remove the lithium ion battery from the housing and use it by power supply from an external power source via a cable. However, in the case of electronic cassettes that can be wired while charging the battery, the battery is connected to the power supply path from the external power supply to the power supply circuit in the chassis, so the battery compensates for voltage fluctuations of the external power supply. Thus, the voltage supplied to the power supply circuit is stabilized. In addition, the power supply path is connected to the TFT and its peripheral analog function unit and the digital function unit that drives them, and voltage fluctuations occur when the digital function unit operates, but the battery compensates for the voltage variation. It also functions to prevent noise intrusion into the analog function section. Therefore, from the viewpoint of stabilizing the voltage fluctuation of the external power supply, it is not preferable to remove the battery from the housing even in the case of wired use. When using the electronic cassette in a vehicle, for use a generator having an engine as a power source as an external power source, since the voltage fluctuation larger than when the commercial power supply and external power supply, if the vehicle is battery The function of stabilizing the voltage fluctuation is particularly necessary.

  Another possible countermeasure is to use a capacitor having higher heat resistance than the lithium ion battery, such as an electric double layer capacitor, as the internal power supply as described in Patent Document 1. If a capacitor is used, the voltage fluctuation of an external power supply can be stabilized like a battery. However, a capacitor has a drawback that it has a smaller capacity than a battery and cannot be used for a long time when used wirelessly.

  As described above, since there are various ways of using electronic cassettes, it is preferable that one electronic cassette can be used properly according to user demands such as wired use, wireless use, and in-vehicle use. Although Patent Document 1 describes the use of a battery or a capacitor as an internal power source of an electronic cassette, the battery and the capacitor each have their merits and demerits. It is difficult to use properly according to demand. In addition, it is conceivable that both the battery and the capacitor are built in the casing as an internal power supply, but this leads to an increase in the size and weight of the casing and impairs portability, and is difficult to employ in an electronic cassette. Patent Document 1 did not disclose or suggest such problems or solutions.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic cassette and an electronic cassette set that can be used in various ways according to a user's request without impairing portability.

An electronic cassette according to the present invention is a portable type housing an image detection unit that receives radiation transmitted through a subject and detects a radiographic image of the subject, the image detection unit, and a power supply circuit that supplies power to the image detection unit. A case and a power supply path provided in the case and connected to a power supply path for supplying power from an external power supply to the power supply circuit. Even when there is no power supply from the external power supply, power is supplied to the power supply circuit through the power supply path. An internal power supply capable of supplying a battery is detachably mounted. The internal power supply includes a mounting section capable of selectively mounting a battery and a capacitor, and the image detection section functions as the power supply circuit. Power to the analog function unit that handles analog signals in order to function, and power to the digital function unit that handles digital signals to function the image detection unit And a sheet for digital power supply circuit, the said power supply path, wherein the noise filter to the input side of the analog power supply circuit is provided.

  The power supply path is provided with a charging circuit, and when the internal power supply is mounted on the mounting portion, the internal power supply is preferably connected to the output side of the charging circuit.

  In the power supply path, a noise filter is preferably provided on the input side of the digital power supply circuit.

  The battery is preferably a lithium ion battery.

  The capacitor is preferably an electric double layer capacitor.

  It is preferable to have a wireless communication unit capable of wireless communication with an external device. Furthermore, it is preferable to have a wired communication unit capable of wired communication with the external device.

  The electronic cassette set of the present invention comprises the electronic cassette and the battery or capacitor. It is preferable that the battery or the capacitor is integrally provided with a cover that covers the opening of the mounting portion when the battery or the capacitor is mounted on the mounting portion.

According to the present invention, the portable device is provided in a portable housing that houses the image detection unit and the power supply circuit, and is connected to a power supply path that supplies power from an external power supply to the power supply circuit. relative to the mounting portion internal power capable of supplying electric power to the power supply circuit through the power supply path, even if there is no is detachably mounted, as the internal power supply, and a battery and a capacitor selectively attachable, as a power supply circuit Since it has an analog power supply circuit and a digital power supply circuit, and a noise filter is provided on the input side of the analog power supply circuit , the electronic cassette and the electronic cassette set can be adapted to the user's request without impairing the portability of the electronic cassette set. Can be used in various ways.

It is the schematic which shows the structure of a X-ray imaging system. It is a perspective view of an electronic cassette and a 1st and 2nd internal power supply unit. It is a block diagram which shows the electrical constitution of the 1st and 2nd internal power supply unit. It is a block diagram which shows the electric constitution of an electronic cassette. It is a block diagram which shows the structure of the electric power supply circuit of an electronic cassette. It is a perspective view which shows an example which uses an electronic cassette by a stationary type. It is a top view which shows an example which uses an electronic cassette wirelessly.

  As shown in FIG. 1, the X-ray imaging system 10 of the present invention includes an X-ray generator 11, an electronic cassette 12 that is a radiation image detection device, a console 13, a monitor 14, and an external power supply 15. Based on the control of the console 13, the electronic cassette 12 detects the X-rays that are transmitted through the subject H from the X-ray generator 11 and generates an X-ray image. The console 13 performs various types of image processing on the X-ray image transmitted from the electronic cassette 12 and displays the image on the monitor 14.

  As shown in FIG. 2, the electronic cassette 12 includes an FPD 20 (detection unit) and a casing 21 that houses the FPD 20. A lead plate that absorbs X-ray backscattered rays is disposed on the back side of the FPD 20, and a circuit board (both not shown) is disposed on the back side of the lead plate.

  The casing 21 has a flat and substantially rectangular parallelepiped shape, and transmits X-rays with a case main body of a stainless or aluminum casing having an opening corresponding to the detection surface (surface on which X-rays are incident) of the FPD 20. It is formed of a possible material (carbon or the like), and is composed of a flat plate that is fitted into the opening of the case body and constitutes the irradiation surface. The casing 21 has, for example, an external size conforming to the international standard ISO 4090: 2001 similar to a cassette for a half-cut size (383.5 mm × 459.5 mm) or an IP cassette. It can be used by attaching to a photographing stand used for a cassette. The external size of the electronic cassette 12 includes a four-cut size, a six-cut size, etc. in addition to the half-cut size described above, and is appropriately selected according to the imaging region.

  The casing 21 has an irradiation surface 21a and a back surface 21b irradiated with X-rays that are substantially rectangular, and has four side surfaces 21c to 21f along each of the four sides of the irradiation surface 21a and the back surface 21b. ing. The housing 21 is provided with a mounting portion 24 that can selectively mount any one of the first and second internal power supply units 22 and 23. The mounting portion 24 is provided along one side surface 21 d arranged along the short side direction of the housing 21.

  The housing 21 is provided with an external power supply socket 25. The external power supply socket 25 is provided on the side surface 21c adjacent to the side surface 21d on which the mounting portion 24 is provided. The connector 17 of the power cable 16 is engaged with the external power socket 25. The housing 21 is provided with a communication socket (not shown) for connecting a communication cable for wired communication.

  The mounting portion 24 includes a storage chamber 26 that stores one of the unit main bodies 31 and 36 (described later) of the first and second internal power supply units 22 and 23, and a contact group 27. An opening 28 for exposing the storage chamber 26 is formed in the housing 21.

  The storage chamber 26 has a substantially rectangular frame shape in which the side facing the side surface 21d and the irradiation surface 21a of the housing 21 is open, and is formed in a bottomed recess. The opening 28 is formed by cutting out the side surface 21 d and the irradiation surface 21 a in accordance with the opened surface of the storage chamber 26.

  In the first internal power supply unit 22, a unit body 31 having a flat and substantially rectangular parallelepiped shape and a lid member 32 are integrally formed. The lid member 32 is formed in an outer shape that matches the opening 28. When the first internal power supply unit 22 is attached to the attachment portion 24, the lid member 32 covers the opening of the attachment portion 24, that is, the open surface of the storage chamber 26.

  The lid member 32 is integrally formed with engaging claws 32a to 32c. The engaging claws 32a and 32b protrude along the irradiation surface 21a, and the engaging claws 32c protrude along the side surface 21d. When the first internal power supply unit 22 is mounted on the mounting portion 24, the engaging claws 32 a to 32 c are engaged with the inner periphery of the opening 28. Accordingly, the position of the lid member 32 is regulated in a state where the lid member 32 is fitted in the opening 28, and is fixed to the housing 21.

  By fixing the lid member 32 to the housing 21, the unit main body 31 is stored in the storage chamber 26, and the first internal power supply unit 22 is detachably attached to the electronic cassette 12. Further, when the lid member 32 is bent to release the engagement between the inner periphery of the opening 28 and the engaging claws 32 a to 32 c, the first internal power supply unit 22 mounted on the mounting portion 24 is removed from the electronic cassette 12. be able to.

  As shown in FIG. 3A, the first internal power supply unit 22 has a plurality of capacitors 33 disposed inside a unit main body 31. As the capacitor 33, an electric double layer capacitor is used. The capacitor 33 is connected in parallel and in series, with the positive electrode side connected to the contact 34a and the negative electrode side connected to the contact 34b. As a result, a large amount of power can be charged by the inexpensive capacitor 33. The contacts 34 a and 34 b are provided on the bottom surface of the unit main body 31. The contact group 27 provided in the mounting portion 24 constitutes contacts 27a and 27b described later, and is electrically connected to the contacts 34a and 34b when the first internal power supply unit 22 is mounted on the mounting portion 24. .

  In the second internal power supply unit 23, a unit main body 36 and a lid member 37 are integrally formed. The unit main body 36 and the lid member 37 are formed in the same outer shape as the unit main body 31 and the lid member 32 of the first internal power supply unit 22.

  As shown in FIG. 3B, the second internal power supply unit 23 has a battery 38 disposed inside a unit body 36. As the battery 38, for example, a lithium ion battery is used. The battery 38 has a positive side connected to the contact 39a and a negative side connected to the contact 39b. Engaging claws 37 a to 37 c similar to the engaging claws 32 a to 32 c of the lid member 32 are integrally formed on the lid member 37. Similar to the first internal power supply unit 22, the engaging claws 37 a to 37 c are engaged with the inner periphery of the opening 28, whereby the unit main body 36 is accommodated in the accommodating chamber 26 and the lid member 37 is accommodated in the accommodating chamber 26. The second internal power supply unit 23 is mounted on the mounting portion 24 so as to cover the opened surface. When the second internal power supply unit 23 is mounted on the mounting portion 24, the contacts 39a and 39b are electrically connected to the contacts 27a and 27b. Further, as described above, the first internal power supply unit 22 is provided with the unit main body 31 and the lid member 32 integrally, and the second internal power supply unit 23 is provided with the unit main body 36 and the lid member 37 integrally. Therefore, the unit main body and the lid member can be mounted by a single operation when mounted on the mounting portion 24.

  As shown in FIG. 4, the FPD 20 is configured by laminating a charge generation layer that absorbs X-rays and converts them into charges on a TFT active matrix substrate 48. The charge generation layer is made of amorphous a-Se (amorphous selenium) containing, for example, selenium as a main component (for example, a content rate of 50% or more). When X-rays are irradiated, the charge corresponding to the irradiated X-ray dose By generating a certain amount of charge (electron-hole pairs) internally, the irradiated X-rays are converted into charges. Of course, the FPD 20 may be an indirect conversion type in which X-rays are converted into visible light by a scintillator and then converted into electric charges.

  On the TFT active matrix substrate 48, a large number of pixels 49 each having a storage capacitor for storing the charge generated in the charge generation layer and a TFT for reading out the charge stored in the storage capacitor are arranged in a matrix. These pixels 49 constitute a detection surface for detecting incident X-rays. Charges generated in the charge generation layer according to the amount of X-rays incident on the detection surface are stored in the storage capacitors of the individual pixels 49. Thereby, the image information of the subject H carried on the X-rays incident from the irradiation surface 21 a is converted into charge information and held on the TFT active matrix substrate 48.

  The TFT active matrix substrate 48 includes a plurality of gate wirings 50 extending in a certain direction (row direction) for turning on and off the TFT gates of the individual pixels 49, and a direction orthogonal to the gate wiring 50 (column direction). A plurality of data wirings 51 are provided for reading the stored charge from the storage capacitor via the TFT that is extended and turned on. Individual gate lines 50 are connected to a gate driver 52, and individual data lines 51 are connected to a signal processing unit 53. When charges are accumulated in the storage capacitors of the individual pixels 49, the TFTs of the individual pixels 49 are sequentially turned on in units of rows by a signal supplied from the gate driver 52 via the gate wiring 50, and the TFTs are turned on. The charge accumulated in the storage capacitor of the pixel 49 is transmitted as a charge signal through the data wiring 51 and input to the signal processing unit 53.

  The signal processing unit 53 includes an amplifier and a sample hold circuit provided for each data line, and a charge signal transmitted through each data line is amplified by the amplifier and then held in the sample hold circuit. In addition, a multiplexer and an A / D converter are connected in order to the output side of the sample and hold circuit, and the charge signals held in the individual sample and hold circuits are input to the multiplexer in order (serially) for A / D conversion. The digital image data is converted by the device. Image data output from the A / D converter of the signal processing unit 53 is sequentially stored in the image memory 54. The image memory 54 has a storage capacity capable of storing a plurality of X-ray images.

  In addition to the FPD 20, a cassette control unit 55, an operation unit 56, and a communication unit 57 are provided in the casing 21 of the electronic cassette 12. The cassette control unit 55 is a CPU that controls the entire electronic cassette 12, a ROM that stores a program that is executed by the CPU, and a work memory that is used for the CPU to execute a process by developing a program loaded from the ROM. It is composed of a microcomputer including a certain RAM and an EEPROM for storing various setting information. The operation unit 56 includes a power button and the like.

  The communication unit 57 includes an antenna and a communication circuit that generate radio waves for communication, and a wireless communication unit that performs wireless communication with the console 13 and a wired communication unit that performs wired communication by connecting to the console 13 via a communication cable. And. The communication unit 57 receives control signals such as an X-ray irradiation start signal and an irradiation time from the console 13 by wireless or wired communication, and transmits image data in the image memory 54 to the console 13. Note that the wireless communication unit may be an optical communication unit such as an infrared ray.

  The electronic cassette 12 can select power supply from the external power supply 15 connected via the power cable 16 and power supply only by the battery 38 as an internal power supply. The first and second internal power supplies The units 22 and 23 are selectively mounted to respond.

  With reference to FIG. 5, a circuit configuration for supplying power to each functional unit including the FPD 20 in the electronic cassette 12 will be described below. The electronic cassette 12 includes an analog power supply circuit 61 that supplies power to an analog function unit, a digital power supply circuit 62 that supplies power to a digital function unit, and power supplied from the external power supply 15 to the analog power supply circuit 61. And a power supply path 63 for supplying the digital power supply circuit 62 respectively.

  In the electronic cassette 12, the analog functional unit to which power is supplied by the analog power supply circuit 61 receives analog signals from the TFT active matrix substrate 48, gate driver 52, amplifier and sample and hold circuit, multiplexer, A / D converter, and the like. It is a functional part to handle. On the other hand, the digital functional units to which power is supplied by the digital power supply circuit 62 are functional units that handle digital signals, such as the cassette control unit 55, the image memory 54, and the wireless communication unit 57.

  The power supply path 63 is provided with an external power connection terminal 64a at one end. The external power supply connection terminal 64a is built in the external power supply socket 25 together with the GND (ground) connection terminal 64b. When the connector 17 is engaged with the external power socket 25, the positive terminal 65a provided at one end of the power cable 16 is connected to the external power connection terminal 64a, and the negative terminal 65b is connected to the GND connection terminal 64b. . As a result, the electric power sent from the external power supply 15 via the power cable 16 is received by the power supply path 63.

  A charging circuit 66 is provided in the middle of the power supply path 63. The charging circuit 66 boosts the electric power sent from the external power supply 15 via the power cable 16 and converts it into a voltage that can charge the capacitor 33 or the battery 38.

  In the power supply path 63, an internal power contact 27 a to which the capacitor 33 or the battery 38 as an internal power source is connected is provided at a position on the output side of the charging circuit 66. As described above, the internal power contact 27a is provided in the mounting portion 24 together with the GND contact 27b, and when any one of the first and second internal power supply units 22 and 23 is mounted on the mounting portion 24. The contacts 34a and 34b or the contacts 39a and 39b are connected to the contacts 27a and 27b, and the capacitor 33 or the battery 38 is connected to the power supply path 63. As a result, when any one of the first and second internal power supply units 22 and 23 is mounted on the mounting portion 24, the power from the external power supply 15 is supplied to the analog power supply circuit 61 and the digital power supply through the power supply path 63. In addition to being supplied to the circuit 62, the capacitor 33 or the battery 38 is supplied to charge the capacitor 33 or the battery 38, and even when there is no power supply from the external power supply 15, the power supply path 63 from the capacitor 33 or the battery 38. Through this, power is supplied to the analog power supply circuit 61 and the digital power supply circuit 62.

  In the power supply path 63, a noise filter 67 is provided at a position on the output side of the internal power contact 27 a and the charging circuit 66 and on the input side of the analog power supply circuit 61. The noise filter 67 removes high frequency component noise from the input signal and prevents the noise from entering the analog power supply circuit 61 side. The analog power supply circuit 61 includes a DC / DC converter, a capacitor, and the like, and converts the power supplied from the power supply path 63 and noise-removed by the noise filter 67 into a voltage corresponding to each analog function unit. In the power supply path 63, a noise filter 68 is provided at a position on the output side of the internal power contact 27 a and the charging circuit 66 and on the input side of the digital power supply circuit 62. The digital power supply circuit 62 converts the power supplied from the power supply path 63 into a voltage corresponding to each digital functional unit. The noise filter 68 removes high frequency component noise generated by the operation of each digital functional unit, and prevents the noise from leaking to the input side of the noise filter 68. As a result, the noise generated by the operation of each digital function unit is prevented from entering the analog power supply circuit 61 and thus the analog function units from the input side of the noise filter 68.

  When the X-ray imaging system 10 is mounted on a vehicle and used for mass examination or the like, the electronic cassette 12 is connected to an in-vehicle power supply unit as an external power supply 15 via a power cable 16, One internal power supply unit 22 is mounted.

  A power cable 16 of about 10 m is connected to the in-vehicle power supply unit, and is connected to the electronic cassette 12 via a connector 17 provided at one end of the power cable 16. The in-vehicle power supply unit is mounted on a vehicle such as a collective examination car, and includes a generator that generates electricity using an engine as a power source. The in-vehicle power supply unit as the external power supply 15 has a built-in step-down DC / DC converter (not shown), and supplies power after being converted to a voltage that can be transmitted by the power cable 16.

  When the first internal power supply unit 22 is attached to the attachment portion 24, the capacitor 33 is connected to the position on the output side of the charging circuit 66 in the middle of the power supply path 63. The power supplied from the power supply 15 is charged, and power is supplied from the external power supply 15 and the capacitor 33 to the analog power supply circuit 61 and the digital power supply circuit 62, respectively. The analog power supply circuit 61 and the digital power supply circuit 62 supply power to each functional unit.

  As described above, power is supplied from the external power supply 15 to the electronic cassette 12, and the capacitor 33 is used as an internal power supply connected in the middle of the power supply path 63. Therefore, the voltage supplied to the analog power supply circuit 61 and the digital power supply circuit 62 can be stabilized. Therefore, it is possible to prevent image quality deterioration of X-ray imaging due to a voltage drop of the electronic cassette 12. Further, since the capacitor 33 has the negative contact 34b connected to the GND contact 27b, the capacitor 33 has a low impedance and is hardly affected by external noise. Therefore, image quality deterioration can be further prevented. In addition, since the capacitor 33 is connected in the middle of the power supply path 63, it compensates for voltage fluctuations generated by the operation of each digital function unit, and the analog power supply circuit 61, and consequently, each function unit of the analog system. Prevent noise from propagating. For this reason as well, it is possible to prevent deterioration in image quality of X-ray imaging.

  Furthermore, the capacitor 33 is excellent in heat resistance, and there is no fear of damage even if it is used for a long time, and a commercial product corresponding to a high temperature environment is also sold at a low price. Therefore, the electronic cassette 12 can be used for a long time even in a vehicle that tends to be in a high temperature environment.

  On the other hand, it is also possible to always set the electronic cassette 12 on the photographing stand and use the electronic cassette 12 as a stationary type. Even if the electronic cassette 12 is set on the standing photographing stand 70 as shown in FIG. Good. The standing photographing stand 70 includes a support 71 installed on the floor and a cassette holder 72 to which the electronic cassette 12 is attached. The cassette holder 72 is provided with a slot 73 communicating from the side to the inside, and holds the electronic cassette 12 inserted into the slot 73. The electronic cassette 12 is mounted with the first internal power supply unit 22 in the mounting portion 24 and connected to an external power source via the power cable 16 and to the console 13 via a communication cable. Thereby, the electronic cassette 12 can be always used as a stationary type.

  The electronic cassette 12 is set on the upright photographing stand 70 and used as a stationary type mainly in a place where air conditioning equipment is well-equipped such as a photographing room in the hospital. Therefore, since the heat resistance of the internal power supply need not be considered, as shown in FIG. 6, the combination with the electronic cassette 12 is not limited to the first internal power supply unit 22 including the capacitor 33, You may combine the 2nd internal power supply unit 23 provided with the battery 38. FIG. In the above example, the example in which the electronic cassette 12 is set on the standing photographing table 70 has been described. However, the electronic cassette 12 may be used by being set on a photographing table other than the standing photographing table such as a standing photographing table.

  In addition, the electronic cassette 12 can be used in a hospital room, and the electronic cassette 12 may be used for photographing a limb in the hospital room. As shown in FIG. 7, when photographing the joint of the elbow, for example, the subject H and the electronic cassette 12 are positioned on the bed 80. The electronic cassette 12 is not connected to an external power supply, and the mounting unit 24 is mounted with the second internal power supply unit 23, and only power from the battery 38 is supplied to each functional unit. The electronic cassette 12 and the console 13 communicate wirelessly. Thereby, the electronic cassette 12 can be used wirelessly and can be positioned freely. Furthermore, since the lithium ion battery used as the battery 38 is a secondary battery having a high energy density, sufficient power can be supplied even when a plurality of images are taken.

  As described above, one of the first and second internal power supply units 22 and 23 is selectively mounted on the mounting portion 24 of the electronic cassette 12, so that one electronic cassette 12 can be wired. It can be properly used according to the user's request such as use, wireless use, and on-vehicle use. In particular, when selling electronic cassettes for wired use and in-vehicle use, the second internal power supply unit 23 is omitted, and the electronic cassette 12 and the first internal power supply unit 22 are combined into a set. However, since the capacitor cost is low, it can be provided to the user at a lower price than before. Moreover, if both a capacitor and a battery are provided as the internal power supply of the electronic cassette 12, the portability is impaired. However, in the electronic cassette 12, any one of the first and second internal power supply units 22 and 23 is selectively used. Since it is a configuration to be mounted, it does not impair portability.

  Further, in the conventional electronic cassette, in order to meet the user's request as described above, the manufacturer has to manufacture each electronic cassette configuration in which a capacitor and a battery are provided in advance as an internal power source. In this case, the electronic cassettes with different specifications, that is, the electronic cassettes with different types of internal power supplies are manufactured and stocked, or the customer orders the manufacturer to customize the one with different internal power supply types for each customer. Need a system to do. Therefore, although the manufacturer costs distribution costs or manufacturing costs, this is not the case with the present invention.

  In the electronic cassette 12, noise is removed by the noise filters 67 and 68 while supplying power from the single power supply path 63 to the analog power supply circuit 61 and the digital power supply circuit 62. Noise can be reduced to prevent deterioration of the image quality for analog function units that are likely to be mixed with power supplied from the power source. Furthermore, as with conventional noise countermeasures, the digital function unit supplies power from an external power supply, and the analog function unit supplies power only from the internal power supply. Since it is not necessary to provide a switching circuit for switching the connection with the functional unit, it is possible to prevent the cost of the electronic cassette 12 from increasing.

  The analog and digital functional units in the electronic cassette 12 are not limited to the configurations described in the above embodiment, and may be functional units that handle analog signals and digital signals and function the image detection unit.

  In the above embodiment, an electric double layer capacitor is used as the capacitor 33 built in the first internal power supply unit 22, but the present invention is not limited to this, and other capacitors such as a ceramic capacitor and an electrolytic capacitor may be used. The battery 38 built in the second internal power supply unit 23 may be a battery other than a lithium ion battery, such as a nickel cadmium battery or a nickel metal hydride battery.

  In the above embodiment, X-rays have been described as an example of radiation. However, the present invention may use radiation other than X-rays, such as γ-rays. The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

10 X-ray imaging system 12 Electronic cassette 15 External power supply 20 FPD
21 Housing 22 First internal power supply unit 23 Second internal power supply unit 24 Mounting portion 33 Capacitor 34 Battery

Claims (9)

An image detection unit that receives radiation transmitted through the subject and detects a radiation image of the subject;
A portable housing that houses a power circuit for supplying power to the image detection unit, and the image detection unit;
Provided in the housing and connected to a power supply path for supplying power from an external power supply to the power supply circuit, and can supply power to the power supply circuit through the power supply path even when there is no power supply from the external power supply An internal power supply is a detachable mounting portion, and the internal power supply includes a mounting portion that can selectively mount a battery and a capacitor .
As the power supply circuit, an analog power supply circuit that supplies power to an analog system function unit that handles an analog signal to cause the image detection unit to function, and a digital system function unit that handles a digital signal to function the image detection unit A digital power supply circuit for supplying power,
An electronic cassette according to claim 1, wherein a noise filter is provided on the input side of the analog power supply circuit in the power supply path .   The power supply path is provided with a charging circuit,
  The electronic cassette according to claim 1, wherein when the internal power source is attached to the attachment portion, the internal power source is connected to an output side of the charging circuit.   3. The electronic cassette according to claim 1, wherein a noise filter is provided on the input side of the digital power supply circuit in the power supply path.   The electronic cassette according to claim 1, wherein the battery is a lithium ion battery.   The electronic cassette according to any one of claims 1 to 4, wherein the capacitor is an electric double layer capacitor.   The electronic cassette according to claim 1, further comprising a wireless communication unit capable of wireless communication with an external device.   The electronic cassette according to claim 6, further comprising a wired communication unit capable of wired communication with the external device.   An electronic cassette set comprising the electronic cassette according to claim 1 and the battery or capacitor.   9. The electronic cassette according to claim 8, wherein the battery or the capacitor is integrally provided with a cover that covers an opening of the mounting portion when the battery or the capacitor is mounted on the mounting portion. set.

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