JP2012042302A - Cassette for radiography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the radiation performance without disturbing weight reduction.SOLUTION: In a casing 26 constituting a cassette 13, a heating member such as an IC chip 24 is accommodated. The casing 26 is formed from carbon fibers and has a heat radiation opening 33b. The cassette 13 includes: a heat conductor 27 which is provided in contact with the IC chip 24 and guides heat generated by the IC chip 24 to the opening 33b; and a metal plate 28 which is provided so as to cover the opening 33b from the outside of the casing 26 and in contact with the heat conductor 27 and radiates the heat generated by the IC chip 24 to the outside of the casing 26.

Description

  The present invention relates to a radiographic cassette.

  A radiation imaging system that obtains a radiation image by irradiating radiation such as X-rays from a radiation generator toward a subject is known. The radiation imaging system includes a radiation detector that detects radiation transmitted through a subject. In recent years, a radiation detector using a flat panel detector (FPD) instead of a radiation film or an imaging plate (IP) has become widespread. The FPD is accommodated in a rectangular parallelepiped housing. The FPD accommodated in the housing is called a radiographic FPD cassette (hereinafter simply referred to as a cassette).

  Since the cassette has portability, it has a high degree of freedom in handling, and enables imaging of various parts. For example, the shoulder joint and the elbow joint can be photographed by placing the subject's elbow on a cassette placed on a table. In addition, the chest and abdomen can be photographed by placing the cassette under the subject in the prone position.

  A casing constituting such a cassette contains heat generating members such as a drive circuit and a power supply circuit. When the heat generated by the heat generating member is accumulated inside the casing and becomes high, each member accommodated in the casing is deteriorated or does not function normally. For this reason, various heat dissipation measures have been conventionally taken. For example, in the cassette of Patent Document 1, a heat conductive material that promotes heat dissipation is interposed between the heat generating member and the housing.

JP 09-288184 A

  The cassette of Patent Document 1 uses aluminum, carbon fiber, or the like as a material for forming a casing, as in a general cassette. When the casing is made of aluminum, there is a problem that there is a limit to weight reduction. On the other hand, when the casing is formed of carbon fiber, it is excellent in weight reduction, but the casing itself has a low thermal emissivity and cannot be said to have sufficient heat dissipation performance.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a radiographic cassette having improved heat dissipation performance without inhibiting weight reduction.

  In order to achieve the above object, a radiographic cassette according to the present invention includes a housing formed of a nonmetallic material and having a heat radiation opening, a heat generating member housed in the housing, and the heat generating member. A heat conductive material that guides the heat generated by the heat generating member to the opening, covers the opening from the outside of the housing, and contacts the heat conductive material. And a metal plate that releases heat generated by the heat generating member to the outside of the housing.

  It is preferable that the housing has a transmission surface that transmits radiation, and the opening is formed on a surface opposite to the transmission surface.

  The location where the opening of the casing is formed is a recess recessed inside the casing, and the metal plate is preferably accommodated in the recess.

  The non-metallic material is preferably a carbon fiber.

  It is preferable that the opening is formed at a position where a hand for gripping the casing cannot be reached.

  The metal plate is preferably a name plate displaying a brand name.

  It is preferable that a protective member that is formed of a material having a lower thermal conductivity than the metal plate and covers the metal plate is provided.

  It is preferable that a heat insulating material interposed between the casing and the metal plate is provided.

  The metal plate is preferably an antenna used for wireless communication with an external device.

  According to the present invention, the heat conducting material that guides the heat generated by the heat generating member to the opening formed in the housing formed of the nonmetallic material, the heat conducting material so as to cover the opening from the outside of the housing, and And a metal plate that releases heat generated by the heat generating member to the outside of the housing. Therefore, heat dissipation performance can be enhanced without hindering weight reduction.

It is a figure showing roughly the composition of the radiography system of a 1st embodiment. It is a disassembled perspective view of the cassette of 1st Embodiment. It is sectional drawing of the cassette of 1st Embodiment. It is sectional drawing of the cassette of 2nd Embodiment. It is sectional drawing of the cassette of 3rd Embodiment. It is sectional drawing of the cassette of 4th Embodiment.

[First Embodiment]
As shown in FIG. 1, the radiation imaging system 11 of the first embodiment detects a radiation generator 12 that irradiates a subject H with radiation (X-rays) X, and radiation X that has passed through the subject H. A cassette 13, a system controller 14 that controls the radiation generator 12 and the cassette 13, and a console for inputting imaging conditions such as tube voltage, tube current, exposure time, and operation instructions such as imaging instructions to the system controller 14. 15.

  The radiation generator 12 includes a radiation tube 12a that generates radiation X, and a collimator 12b that limits an irradiation range of the radiation X. The radiation generator 12 is movably supported by a support device (not shown). For example, the radiation generator 12 is moved by a support device (not shown) so as to face the cassette 13, and the irradiation range of the radiation X is changed according to the imaging region set by the system controller 14.

  The cassette 13 is a box shape that is large enough to cover the chest of the subject H, and has high handleability and portability. The cassette 13 is disposed under the subject H lying on a bed when used in an examination room, a hospital room, or the like. The cassette 13 performs wireless communication with the system controller 14 and is controlled based on a signal from the system controller 14.

  The system controller 14 controls the radiation generator 12 and the cassette 13 to operate synchronously based on the imaging conditions and imaging instructions received from the console 15. The radiation image data output from the cassette 13 is transferred to the console 15 via the system controller 14.

  The console 15 outputs the received radiation image data to a monitor or a data storage device (such as an image server connected via a local hard disk or a communication network).

  As shown in FIGS. 2 and 3, the cassette 13 includes a detection panel 16 that functions as a radiation detection unit, various circuit boards 17, 18, 19, and 20, and a detection panel 16 and various circuit boards 17 to 20. A base plate 21 serving as a base, flexible cables 22 and 23 for connecting the circuit boards 17 and 18 to the detection panel 16, IC chips 24 and 25 mounted on the flexible cables 22 and 23, and a casing 26 for housing these. And a heat conductive material 27 that guides the heat generated by the IC chip 24 to the outside of the housing 26, and a metal plate 28 that releases the heat guided by the heat conductive material 27 to the outside of the housing 26.

  The detection panel 16 is a flat panel detector (FPD) in which a glass substrate 29, a detection element array 30, and a scintillator 31 are stacked in this order. The detection panel 16 is fixed to the base plate 21 from the scintillator 31 side.

  The glass substrate 29 has radiation transparency and insulating properties. The detection element array 30 is configured such that detection elements including thin film transistors (TFTs) as switching elements and photodiodes as photoelectric conversion elements are arranged in a matrix on a glass substrate 29. The glass substrate 29 and the detection element array 30 constitute a so-called active matrix substrate.

  The photodiode is made of, for example, amorphous silicon (a-Si), and generates electric charges in response to visible light emitted from the scintillator 31. When the TFT is turned on, the electric charges generated by the photodiode are read out to a signal line (not shown) provided for each column of the detection element array 30.

  The scintillator 31 is made of a phosphor such as cesium iodide (CsI) or gadolinium oxysulfide (GOS), and emits visible light corresponding to the amount of incident radiation. The scintillator 31 is formed by adhering a sheet coated with a phosphor to the detection element array 30 or depositing a phosphor on the detection element array 30.

  The detection panel 16 is a so-called back-illuminated type in which radiation is incident on the scintillator 31 through the glass substrate 29 and the detection element array 30. The light detection surface of the detection element array 30 is arranged to face the scintillator 31. The light emission amount of the scintillator 31 is the largest on the side where the radiation is incident, but since the detection element array 30 is arranged on the side where the light emission amount is large, high detection efficiency can be obtained.

  A circuit for driving the TFTs of the detection element array 30 is formed on the circuit board 17. The circuit board 17 and the IC chip 24 functioning as a shift register constitute a drive circuit.

  An A / D conversion circuit is formed on the circuit board 18. The A / D conversion circuit converts an analog signal output from the IC chip 25 into a digital signal. The IC chip 25 is an ASIC that constitutes a readout circuit, and selects a charge amplifier that converts the signal charge read from the detection panel 16 into a voltage signal, and a signal line formed for each column of the detection element array 30 in order. And a multiplexer that outputs voltage signals to the A / D conversion circuit one column at a time.

  A control circuit is formed on the circuit board 19. The control circuit controls each part of the cassette 13 and controls communication with an external device.

  A power supply circuit is formed on the circuit board 20. The power supply circuit is composed of circuit elements such as an AC / DC converter that converts alternating current into direct current and a DC / DC converter that converts direct current voltage into a voltage necessary for the operation of each circuit, and supplies power to each section.

  The various circuit boards 17 to 20 are fixed on the side of the base plate 21 opposite to the side on which the detection panel 16 is fixed. The base plate 21 is made of a metal having a relatively low radiation transmittance, such as stainless steel, and reduces the influence of the radiation on the various circuit boards 17 to 20.

  The housing 26 includes a front surface portion 32 that covers the detection panel 16 from the side of the glass substrate 29 on which radiation is incident, and a back surface portion 33 that covers the detection panel 16 from the side of the scintillator 31. The housing 26 is made of a non-metallic material having a relatively high radiation transmittance and a relatively light weight. As such a non-metallic material, a carbon fiber is preferable. The front surface portion 32 functions as a transmission surface that transmits radiation. The front panel 32 functions as a transmission surface, so that the detection panel 16 can detect radiation efficiently.

  The back surface portion 33 has a recessed portion 33 a that is recessed inside the housing 26. An opening 33b for heat dissipation is formed in the recess 33a. The heat conductive material 27 is provided so as to be in contact with the IC chip 24 and through the opening 33b. The metal plate 28 is accommodated in the recess 33 a so as to cover the opening 33 b from the outside of the housing 26 and in contact with the heat conductive material 27.

  As described above, since the casing 26 is made of carbon fiber, the weight reduction of the cassette 13 is not hindered. In addition, since the opening 33b is provided in the housing 26 and a heat dissipation path is secured by the heat conducting material 27 and the metal plate 28, the heat generated by the IC chip 24 can be efficiently released to the outside of the housing 26.

  Since the metal plate 28 is disposed on the back surface portion 33 side opposite to the front surface portion 32 facing the subject H at the time of photographing, the subject H does not touch the metal plate 28 and is safe. It is. Further, since the metal plate 28 is accommodated in the concave portion 33a and does not protrude from the outer surface of the back surface portion 33, the metal plate 28 does not get in the way when adjusting the position and posture of the cassette 13.

[Second Embodiment]
The cassette 13 of the second embodiment is different from the first embodiment in the position of the metal plate 28. As shown in FIG. 4, the recess 33 a in which the metal plate 28 is accommodated is formed at a position away from the end portion (upper end in the drawing) of the housing 26 as compared with the first embodiment. Specifically, the concave portion 33 a is formed at a position where a hand for gripping the end portion of the housing 26 cannot reach. The heat conductive material 27 is formed so as to be in contact with the IC chip 24 and penetrate the opening 33b. Since the metal plate 28 is arranged in this way, the hand holding the casing 26 does not touch the metal plate 28 and is safe.

  In addition, description about the same structure, an effect | action, and effect as the said 1st Embodiment is abbreviate | omitted. Further, in each of the following embodiments, description of the same configuration, operation, and effect as in the other embodiments is omitted.

  In each of the above embodiments, the metal plate 28 may be used as a name plate displaying the brand name (product name, model number, etc.) of the cassette 13.

[Third Embodiment]
The cassette 13 of the third embodiment is different from the first embodiment in that the metal plate 28 is prevented from being contacted from the outside. As shown in FIG. 5, the cassette 13 includes a heat insulating material 34 interposed between the housing 26 and the metal plate 28, and a plate-like protection member 35 that covers the back surface portion 33.

  The heat insulating material 34 prevents heat transmitted from the inside of the housing 26 to the metal plate 28 from returning to the inside of the housing 26. The protective member 35 is formed of a material having a lower thermal conductivity than the metal plate 28. The protection member 35 has a plurality of small holes 35a for heat dissipation at locations where it contacts the metal plate 28. The small hole 35a has an outer diameter that a finger cannot enter. The small holes 35a are preferably large and large in number from the viewpoint of heat dissipation performance.

[Fourth Embodiment]
As shown in FIG. 6, the cassette 13 of the fourth embodiment includes a sheet-like protection member 36 instead of the plate-like protection member 35, and completely covers the metal plate 28 in the third embodiment. Different from form. The protection member 36 is preferably made of carbon fiber.

  The protective members 35 and 36 of the third and fourth embodiments may be applied to the cassette of the second embodiment.

  In each of the above embodiments, the heat dissipation path is provided in the IC chip 24. However, the present invention is not limited to the IC chip 24, and the heat dissipation path can be provided for all members that generate heat.

  In each of the above embodiments, the metal plate 28 may be used as an antenna used for wireless communication with an external device.

  In each of the above embodiments, the indirect conversion type FPD that converts radiation into visible light using a phosphor and converts the visible light into electric charge using a photoelectric conversion element has been described as an example of the detection panel 16. Instead of the type FPD, a direct conversion type FPD that directly converts radiation into charges by a photoconductive layer such as amorphous selenium (a-Se) may be used.

13 cassette 24 IC chip 26 housing 27 heat conducting material 28 metal plate 33a recess 33b opening 34 heat insulating material 35, 36 protective member X radiation

Claims (9)

A housing formed of a non-metallic material and having an opening for heat dissipation;
A heating member housed inside the housing;
A heat conducting material that is provided in contact with the heat generating member and guides the heat generated by the heat generating member to the opening;
A metal plate provided so as to cover the opening from the outside of the housing and in contact with the heat conducting material, and to release heat generated by the heat generating member to the outside of the housing. Characteristic cassette for radiography. The housing has a transmission surface that transmits radiation,
The radiographic cassette according to claim 1, wherein the opening is formed on a surface opposite to the transmission surface. The location where the opening of the housing is formed is a recess recessed inside the housing,
The radiographic cassette according to claim 1, wherein the metal plate is accommodated in the recess.   The radiographic cassette according to claim 1, wherein the non-metallic material is a carbon fiber.   The radiographic cassette according to any one of claims 1 to 4, wherein the opening is formed at a position where a hand that holds the casing does not reach.   The radiographic cassette according to claim 1, wherein the metal plate is a name plate displaying a name.   The radiographic cassette according to any one of claims 1 to 5, further comprising a protective member that is formed of a material having a lower thermal conductivity than the metal plate and covers the metal plate. .   The radiographic cassette according to claim 7, further comprising a heat insulating material interposed between the casing and the metal plate.   The radiographic cassette according to claim 1, wherein the metal plate is an antenna used for wireless communication with an external device.

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