Radiographic detectors

Abstract

A digital radiographic detector includes a planar multilayer core having a two-dimensional array of photosensitive cells. A housing having a single open side and upper and lower halves is joined together using a three-sided bumper configured to provide impact absorption to the sides of the housing. An end cap covers the single open side of the housing.

Description

Technical Field

[0001] The subject matter disclosed herein relates to digital radiography (DR) detectors for use with x-ray systems in medical imaging facilities. Background Art

[0002] Portable digital radiography detectors have been widely deployed to improve imaging productivity, image quality, and ease of use in diagnostic radiography. In particular, mobile or bedside radiographic imaging can be performed in locations such as intensive care units, eliminating the need to transfer patients from their intensive care environment. This type of imaging procedure is best served by a portable detector that is lightweight and durable, thereby improving ease of use and reliability.

[0003] Current digital radiography detectors typically include an amorphous silicon TFT / photodiode image sensor array fabricated on glass using semiconductor processes similar to those used for flat panel displays. A scintillator is combined with the image sensor array, along with the required electronics for signal readout and processing, on an internal core board contained in a durable housing to create a portable DR detector.

[0004] Figure 1 is a perspective view of a digital radiographic (DR) imaging system 10 according to one embodiment, which may include a generally curved or planar DR detector 40 (shown in a planar embodiment and without a housing for clarity of description), an x-ray source 14 configured to generate radiographic energy (x-ray radiation), and a digital monitor or electronic display 26 configured to display images captured by the DR detector 40. The DR detector 40 may include a two-dimensional array 12 of detector elements 22 (photoelectric sensors) arranged in electronically addressable rows and columns. The DR detector 40 may be arranged to receive x-rays 16 that pass through a subject 20 during a radiographic energy exposure or radiographic energy pulse emitted by the x-ray source 14. Figure 1As shown in FIG, a radiographic imaging system 10 may utilize an x-ray source 14 that emits collimated x-rays 16 (e.g., an x-ray beam) that are selectively aimed at and pass through a preselected region 18 of a subject 20. Depending on the internal structure of the subject 20, the x-ray beam 16 may be attenuated to varying degrees along its multiple rays, which are detected by an array 12 of photosensitive detector elements 22. A curved or planar DR detector 40 is positioned as perpendicular as possible relative to a substantially central ray 17 of the multiple rays 16 emitted by the x-ray source 14. In a curved array embodiment, the source 14 may be centrally positioned so that a greater percentage or all of the photosensitive detector elements are positioned perpendicular to incoming x-rays from the centrally positioned source 14. The array 12 of individual photosensitive elements (pixels) 22 may be electronically addressable (scanned) based on their position in columns and rows. As used herein, the terms "columns" and "rows" refer to the vertical and horizontal arrangements of photosensitive cells 22, and for clarity of description, it will be assumed that the rows extend horizontally and the columns extend vertically. However, the orientation of the columns and rows is arbitrary and does not limit the scope of any embodiment disclosed herein. Furthermore, although Figure 1 The term "subject" may be illustrated in the description of the present invention as a human patient, but when this term is used in this document, the subject of the DR imaging system may be a human, an animal, an inanimate object, or a part thereof.

[0005] In one exemplary embodiment, the rows of photosensitive cells 22 may be scanned one or more times at a time by electronic scanning circuitry 28 so that exposure data from the array 12 may be communicated to electronic readout circuitry 30. Each photosensitive cell 22 may independently store an electrical charge proportional to the intensity or energy level of the attenuated radiographic radiation or x-rays received and absorbed in the cell. Thus, each photosensitive cell, when read out, provides information defining a pixel of the radiographic image 24, such as the brightness level or the amount of energy absorbed by that pixel, which information may be digitally decoded by image processing electronics 34 and communicated for display by the digital monitor 26 for viewing by a user. Electronic bias circuitry 32 is electrically connected to the two-dimensional detector array 12 to provide a bias voltage to each of the photosensitive cells 22.

[0006] Each of the bias circuitry 32, scanning circuitry 28, and readout circuitry 30 can communicate with an acquisition control and image processing unit 34 via a connected cable 33 (wired), or the DR detector 40 and the acquisition control and image processing unit 34 can be equipped with wireless transmitters and receivers to wirelessly transmit 35 radiographic image data to the acquisition control and image processing unit 34. The acquisition control and image processing unit 34 may include a processor and electronic memory (not shown) to control the operation of the DR detector 40 (including control of the circuitry 28, 30, and 32) as described herein, for example, by using programmed instructions, and to store and process image data. The acquisition control and image processing unit 34 may also be used to control activation of the x-ray source 14 during radiographic exposures, to control the x-ray tube current magnitude, and therefore the fluence of x-rays in the x-ray beam 16, and / or to control the x-ray tube voltage, and therefore the energy level of x-rays in the x-ray beam 16. Some or all of the functionality of the acquisition control and image processing unit 34 may reside in the detector 40 within an onboard processing system 36. Similar to the functionality of a separate acquisition control and image processing system 34, the onboard processing system 36 may include a processor and electronic memory to control the operation of the DR detector 40 (including control of the circuits 28, 30, and 32) as described herein, and to store and process image data, using programmed instructions. The image processing system may perform the image acquisition and image manipulation functions described herein. The image processing system 36 may control image transmission, image processing, and image correction on the onboard detector 40 based on instructions or other commands transmitted from the acquisition control and image processing unit 34, and transmit corrected digital image data therefrom. Alternatively, the acquisition control and image processing unit 34 may receive raw image data from the detector 40, process the image data, and store it, or it may store raw, unprocessed image data in local memory or in remotely accessible memory.

[0007] With respect to a direct detection embodiment of the DR detector 40, the photosensitive units 22 may each include a sensing element that is sensitive to x-rays, i.e., it absorbs x-rays and generates an amount of charge carriers that is proportional to the magnitude of the absorbed x-ray energy. The switching element may be configured to be selectively activated to read out the charge level of the corresponding x-ray sensing element. With respect to an indirect detection embodiment of the DR detector 40, the photosensitive units 22 may each include: a sensing element that is sensitive to light rays in the visible spectrum, i.e., it absorbs light rays and generates an amount of charge carriers that is proportional to the magnitude of the absorbed light energy, and a switching element that is selectively activated to read out the charge level of the corresponding sensing element. A scintillator or a wavelength converter may be provided on the photosensitive sensing element to convert the incident x-ray radiographic energy into visible light energy. Therefore, in the embodiments disclosed herein, it should be noted that the DR detector 40 (or Figure 3 DR detector 300 or Figure 4 The DR detector 400 in FIG. 4 may include an indirect or direct type of DR detector.

[0008] Examples of sensing elements used in the sensing array 12 include various types of photoelectric conversion devices (e.g., photosensors), such as photodiodes (PN or PIN diodes), photocapacitors (MIS), phototransistors, or photoconductors. Examples of switching elements used for signal readout include a-Si TFTs, oxide TFTs, MOS transistors, bipolar transistors, and other pn junction components.

[0009] Figure 2 Schematic diagram 240 of a portion of a two-dimensional array 12 of a DR detector 40. The array 212 of photosensor cells may operate in the same manner as the photosensor array 12 described above and may include a plurality of hydrogenated amorphous silicon (a-Si:H) nip photodiodes 270 and thin film transistors (TFTs) 271 formed as field effect transistors (FETs), each TFT 271 having a gate (G), a source (S), and a drain (D) terminal. In a multilayer DR detector ( Figure 4In an embodiment of the DR detector 40 disclosed herein (e.g., FIG400 ), the two-dimensional array of photosensor cells 12 can be formed in a device layer adjacent to adjacent layers of the DR detector structure, which can include a rigid glass layer or a flexible polyimide layer or a layer comprising carbon fiber without any adjacent rigid layers. A plurality of gate driver circuits 228 can be electrically connected to a plurality of gate lines 283 that control the voltage applied to the gates of the TFTs 271; a plurality of readout circuits 230 can be electrically connected to data lines 284; and a plurality of bias lines 285 can be electrically connected to a bias line bus or variable bias reference voltage line 232 that controls the voltage applied to the photodiodes 270. A charge amplifier 286 can be electrically connected to the data lines 284 to receive signals therefrom. The outputs from the charge amplifiers 286 may be electrically connected to a multiplexer 287 (such as an analog multiplexer) and then to an analog-to-digital converter (ADC) 288, or they may be connected directly to the ADC to stream out digital radiographic image data at a desired rate. In one embodiment, Figure 2 The schematic diagram of may represent a portion of a DR detector 40, such as an a-Si:H based indirect flat panel, curved panel, or flexible panel imager.

[0010] Incident x-rays or x-ray photons 16 are converted into optical photons or light rays by the scintillator, which are then converted into electron-hole pairs or charges when striking a-Si:H nip photodiodes 270. In one embodiment, an exemplary detector cell 222, which may equivalently be referred to herein as a pixel, may include a photodiode 270 whose anode is electrically connected to a bias line 285 and whose cathode is electrically connected to the drain (D) of a TFT 271. A bias reference voltage line 232 may control the bias voltage of the photodiode 270 at each detector cell 222. The charge capacity of each photodiode 270 is a function of its bias voltage and its capacitance. Generally, a reverse bias voltage (e.g., a negative voltage) may be applied to the bias line 285 to create an electric field (and therefore a depletion region) across the pn junction of each photodiode 270, thereby enhancing its efficiency in collecting charge generated by incident light rays. Image signals represented by the array of photosensor cells 212 can be integrated via photodiodes while their associated TFTs 272 are kept in a non-conducting (off) state, for example, by maintaining gate lines 283 at a negative voltage via gate driver circuitry 228. Photosensor cell array 212 can be read out by sequentially switching rows of TFTs 271 to a conducting (on) state via gate driver circuitry 228. When a row of pixels 22 is switched to a conducting state, for example, by applying a positive voltage to the corresponding gate line 283, the collected charge from the photodiodes in those pixels can be transferred along data lines 284 and integrated by external charge amplifier circuitry 286. The row can then be switched back to a non-conducting state, and this process is repeated for each row until the entire photosensor cell array 212 has been read out. The integrated signal output from external charge amplifier 286 is transferred to analog-to-digital converter (ADC) 288 using a parallel-to-serial converter, such as multiplexer 287; these devices collectively comprise readout circuitry 230.

[0011] This digital image information may then be processed by the image processing system 34 to obtain a digital image which may then be digitally stored and immediately displayed on the monitor 26 or may be displayed at a later time by accessing a digital electronic memory containing the stored image. Figure 2 The flat panel DR detector 40 of the described imaging array is capable of both single shot (eg, static, radiographic) and continuous (eg, fluoroscopic) image acquisition.

[0012] Figure 3A perspective view of an exemplary prior art, generally rectangular, planar, portable, wireless DR detector 300 is shown, in accordance with an embodiment of the DR detector 40 disclosed herein. The DR detector 300 may include a flexible substrate to allow the DR detector to capture radiographic images in a curved orientation. The flexible substrate may be manufactured in a permanently curved orientation, or it may remain flexible throughout its useful life to provide adjustable curvature in two or three dimensions as desired. The DR detector 300 may include a similarly flexible housing portion 314 surrounding a multilayer structure or core containing the flexible photosensor array portion 22 of the DR detector 300. The housing portion 314 of the DR detector 300 may include a continuous, rigid or flexible, x-ray opaque material, or as used synonymously herein, surrounding the interior volume of the DR detector 300. The housing portion 314 may include four flexible sides 318 extending between a top surface 321 and a bottom surface 322 and arranged substantially orthogonally relative to the top and bottom surfaces 321, 322. The bottom surface 322 can be continuous with the four sides and disposed opposite the top surface 321 of the DR detector 300. The top surface 321 includes a top cover 312 attached to the housing portion 314, which together with the housing portion 314 substantially encloses the core within the interior volume of the DR detector 300. The top cover 312 can be attached to the housing 314 to form a seal therebetween, and it can be made of a material that passes x-rays 16 without significant attenuation thereof, i.e., an x-ray transparent material or, as used synonymously herein, a radiolucent material, such as carbon fiber, carbon fiber embedded in plastic, polymers, elastomers, and other plastic-based materials.

[0013] refer to Figure 4 , a DR detector 300 is shown in a schematic diagram ( Figure 3) is an exemplary cross-sectional view of an exemplary embodiment of the DR detector 400 taken along section 4-4. For spatial reference purposes, as used herein, one major surface or face of the DR detector 400 may be referred to as a top surface 451, and a second major surface or face of the DR detector 400 may be referred to as a bottom surface 452. The core layer or sheet may be disposed within an interior volume 450 enclosed by the housing 314 and the top cover 312 and may include a flexible curved or planar scintillator layer 404 positioned above a curved or planar two-dimensional imaging sensor array 12, schematically shown as a device layer 402. The scintillator layer 404 may be directly positioned (e.g., directly connected) to the substantially planar top cover 312, and the imaging array 402 may be directly positioned below the scintillator 404. Alternatively, a flexible layer 406 may be disposed between the scintillator layer 404 and the top cover 312 as part of the core layered structure, thereby allowing for adjustable curvature of the core layered structure and / or providing shock absorption. The flexible layer 406 may be selected to provide a certain amount of flexible support for both the top cover 312 and the scintillator 404 and may include a foam rubber type material. Each of the layers comprising the multi-layer core structure just described may be formed generally in a rectangular shape and may be defined by sides arranged orthogonally and parallel to the inner face of the side 318 of the housing 314, as shown in FIG. Figure 3 described.

[0014] A substrate layer 420 may be disposed beneath the imaging array 402, such as, in one embodiment, a rigid glass layer or a flexible substrate comprising polyimide or carbon fiber. The array of photosensors 402 may be formed on the flexible substrate to allow for adjustable curvature of the array, and the substrate layer 420 may comprise another layer of the core layered structure. Beneath the substrate layer 420, a radiopaque shielding layer 418, such as lead, may be used as an x-ray blocking layer to help prevent scattering of x-rays that pass through the substrate layer 420 and to block x-rays reflected from other surfaces in the interior volume 450. A system including scanning circuitry 28, readout circuitry 30, bias circuitry 32, and processing system 36 (all as shown) may be formed adjacent to the imaging array 402. Figure 1 ) or, as shown, may be disposed beneath frame support member 416 in the form of an integrated circuit (IC) electrically connected to printed circuit boards (PCBs) 424, 425. Imaging array 402 may be electrically connected to readout electronics 424 (IC) via flexible connector 428, which may include a plurality of flexible, sealed conductors known as chip-on-film (CoF) connectors.

[0015] X-ray flux can pass through the radiolucent top panel cover 312 in a direction indicated by the exemplary x-ray beam 16 and impact the scintillator 404, where the high-energy x-rays 16, or photons, cause the scintillator 404 to emit lower-energy photons as visible light rays, which are then received by the photosensors of the imaging array 402. Frame support members 416 can connect the core layered structure to the housing 314 and can further operate as shock absorbers by providing resilient pads (not shown) between the frame support beams 422 and the housing 314. Fasteners 410 can be used to attach the top cover 312 to the housing 314 and create a seal between the top cover 312 and the housing 314 in the area 430 where they contact. In one embodiment, external bumpers 412 can be attached along the sides 318 of the DR detector 400 to provide additional shock absorption.

[0016] Recently, processes have been developed that enable image sensor arrays to be fabricated onto durable, thin substrates such as polyimide. This highly durable substrate enables the use of alternative housing assemblies that are lighter in weight, as the need for glass protection is reduced.

[0017] The above discussion is provided for general background information only and is not intended to be used as an aid in determining the scope of the claimed subject matter. Summary of the Invention

[0018] A digital radiographic detector includes a planar multilayer core having a two-dimensional array of photosensitive cells. A housing having a single open side and upper and lower halves is joined together using a three-sided bumper configured to provide impact absorption to the sides of the housing or casing. A thermally conductive end cap covers the single open side of the housing.

[0019] In one embodiment, a DR detector includes a planar multilayer core comprising a two-dimensional array of photosensitive elements. A rectangular housing, comprising upper and lower shells joined together, surrounds the multilayer core and leaves a single open side along the width of the DR detector. An end cap covers the single open side of the housing.

[0020] In one embodiment, the carbon fiber housing, in the form of an upper half and a lower half, is joined by a seam around the perimeter, covered and secured together by interlocking bumpers. The upper half is as thick as or thicker than the lower half, which can be achieved with a single upper half or by laminating two or more sections together. A thermally conductive end cap is mounted on the fourth open side of the housing to complete the housing and dissipate heat. Together, the housing forms a protective, fluid-resistant structural enclosure for the detector panel assembly.

[0021] In one embodiment, the detector panel assembly is laminated to the inner surface of the upper half for support. This laminated configuration is more rigid than the individual components. Stiffness can be further increased by adding a lightweight core material between the upper half and the sensor panel assembly to increase the separation distance and / or adding a rigid material below the sensor panel assembly for protection. All or part of the sensor panel electronics can be confined to the laminate structure. Below the laminate structure, a high-strength, lightweight material such as foam is used to support the load applied to the detector. In the area cutout for the electronics, rigid material is integrated with lightweight material to redirect (i.e., bridge) the load from the electronics to the surrounding area. The sides and lower half of the housing are constructed of thinner material to act as shock absorbing elements to further increase durability.

[0022] The present invention is directed to a lightweight, durable DR housing and core board assembly that utilizes the benefits offered by non-glass substrate image sensor panels. Additionally, a method is included that provides electromagnetic compatibility and ease of assembly.

[0023] This brief description of the invention is intended only to provide a brief overview of the subject matter disclosed herein according to one or more illustrative embodiments and is not intended to serve as a guide for interpreting the claims or to define or limit the scope of the invention, which is defined solely by the appended claims. This brief description is provided to introduce in a simplified form an illustrative selection of concepts that will be further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that address any or all of the shortcomings mentioned in the background. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order that the manner in which the features of the present invention can be understood, the present invention may be described in detail with reference to certain embodiments, some of which are illustrated in the accompanying drawings. However, it is to be noted that the drawings illustrate only certain embodiments of the present invention and, therefore, should not be considered as limiting the scope of the present invention, as the scope of the present invention encompasses other equally effective embodiments. The drawings are not necessarily drawn to scale, but generally emphasis is placed on illustrating the features of certain embodiments of the present invention. In the drawings, like numbers are used to indicate like parts throughout the various views. Therefore, for a further understanding of the present invention, read in conjunction with the drawings, reference may be made to the following detailed description, in which:

[0025] Figure 1 is a schematic perspective view of an exemplary x-ray system;

[0026] Figure 2is a schematic diagram of a photoelectric sensor array in a radiographic detector;

[0027] Figure 3 is a perspective view of an exemplary DR detector;

[0028] Figure 4 is a cross-sectional view of an exemplary DR detector;

[0029] Figure 5 is an exploded view of an exemplary DR detector assembly;

[0030] Figure 6 is a perspective view of an upper housing shown inverted with component layers laminated to the upper housing;

[0031] Figure 7 The figure shows a side cross section of a DR detector with an interlocking buffer design;

[0032] Figure 8 An internal detector assembly with a foam core base populated with a printed circuit board and associated electronics;

[0033] Figure 9 Shown Figure 8 a conformal adhesive release layer on a portion of an internal probe assembly;

[0034] Figure 10 shows a cross section of a portion of a multi-layer sensor laminate structure removed;

[0035] Figure 11 A partial cross section of a DR detector is shown;

[0036] Figure 12 An exploded view of the DR detector layer is shown in greater detail;

[0037] Figure 13 shows a partial cross-section of a DR detector having an alternative glass substrate embodiment; and

[0038] Figure 14 An exploded view of a multi-layer core with additional strengthening layers is shown for a glass substrate embodiment. DETAILED DESCRIPTION

[0039] This application claims priority to U.S. patent application serial number 62 / 885,423, filed on August 12, 2019, in the name of Bogumil et al., and entitled RADIOGRAPHIC DETECTOR, which is hereby incorporated by reference in its entirety.

[0040] refer to Figure 5, an exploded view of the components of an inventive assembly for a DR detector 500 includes an upper housing 501 secured to a lower housing 502 using a U-shaped or three-sided bumper 503. The bumper 503 engages the flange edges ( Figure 7 ) to secure them together. Adhesive is also used between the flange edges and on the inner surface of the buffer 503. When joined together, the upper shell 501 and the lower shell 502 leave an opening along the width of the shell because the upper and lower shell edges 501a, 502a, respectively, do not fold over and therefore do not contact each other. The upper and lower shells 501, 502 enclose a multi-layer core 505, which includes a two-dimensional array of photosensors, a scintillator, a support substrate, and supporting electronic devices for reading out radiographic image data captured by the photosensors. The upper and lower shells 510, 502 can be made of carbon fiber or similar materials. As Figure 5 As shown in FIG, the multi-layer core is embedded in the core foam base 702 ( Figure 7 ). An opening along the width of the housing is closed by placing an end cap 504 therein. The DR detector is powered by batteries housed in a battery compartment 506 formed in the lower housing 502. The battery compartment 506 is arranged in the lower housing 502 by forming a groove in the outer bottom surface of the lower housing 502.

[0041] refer to Figure 6 , showing a perspective view of the upper shell 501, wherein the upper shell 501 is flipped upside down with the multi-layer core 505 and additional components attached thereto. In one embodiment, if the lead sheet 1003 ( Figure 12 ), then the L-shaped ground plate 602 is attached to the lead sheet using adhesive; or, in another embodiment, if a reinforcement member 1302 ( Figure 14 ), the L-shaped ground plate 602 is attached to the reinforcing member with adhesive using an adhesive; or, in another embodiment, if neither the reinforcing member 1302 nor the lead sheet 1003 is used, the L-shaped ground plate 602 is attached directly to the multi-layer core 505 using an adhesive ( Figure 12 ) on a shaped surface. A ground plate 602 extends along two vertical outer perimeters of the DR detector 500 and can be made of aluminum or another suitable conductor. A gate driver integrated circuit 603 is electrically attached to the ground plate 602 along one edge thereof, and a readout integrated circuit (ROICS) 604 is electrically attached to the ground plate 602 along an adjacent vertical edge of the L-shaped ground plate 602. A thermal pad 605 is attached to and thermally coupled to the ROICS 604. When placed in the open ends of the joined housings 501 and 502, the end cap 504 thermally engages the thermal pad 605, thereby acting as a heat sink for heat generated by the ROICS 604.

[0042] Figure 7 A cross-sectional view of one edge of the DR detector 500 is illustrated showing the engagement of the bumper 503 to the flange edge 501b of the upper housing 501 and to the flange edge 502b of the lower housing 502. Figure 7 From a perspective, vertical sidewall portions of the upper and lower housings 501 and 502 extend horizontally into the bumper 503 to form flanges 501b and 502b, respectively. The bumper 503 secures the upper and lower housings 501 and 502 together by applying a compressive force to the flanges 501b and 502b. Furthermore, adhesive 701 is provided between the upper and lower flanges 501b and 502b, between the bumper 503 and the flanges 501b and 502b, and between the bumper 503 and the upper and lower housings 501 and 502. As will be described herein, the multi-layer core 505 is embedded in a core foam base 702, which is disposed within the interior region of the DR detector 500. The bumper 503 can be made of an elastomeric material, plastic, rubber, or other suitable impact-resistant material to provide shock absorption, but should be suitably rigid to hold the upper and lower housings 501 and 502 together.

[0043] Figure 8 FIG3 is a perspective view of the core foam base 702 and other internal electronic components of the DR probe 500, which includes shaped recesses 806, cutouts 809, pockets 808, and wired circuits 802 for accommodating the components of the DR probe 500 and occupying the majority of the volume within the DR probe 500 between the upper and lower housings 501, 502. Recesses 806 can be used to provide space for a fold 807 of a ribbon cable 804, thereby providing data and electrical communication between the ROICS 604 and the PCB main control circuitry 801 via a chip-on-film connector 810, as well as other communications; pockets 808 can be used to provide space, for example, for a battery; and wired circuits 802 can each have wires 803 pressed into them to secure them in place within the DR probe 500. Components of the PCB main control circuitry 801 are arranged within the edges of the cutouts 809.

[0044] Figure 9 is with Figure 8 Similar, but along Figure 8FIG2 is a perspective view of a conformal adhesive release layer, film, sheet, or tape 901 positioned around the periphery of the assembly. Release layer 901 covers ROICS 604, chip-on-film connector 810, and a portion of the DR probe's internal assembly. Release layer 901 prevents seepage or leaking adhesive from contacting the portion of DR probe 500 covered by release layer 901. Release layer 901 also serves as a sacrificial layer that can be peeled off when the upper and lower housings 501, 502 are separated during repair procedures. Release layer 901 also facilitates separation of the upper and lower housings 501, 502 for repair purposes by preventing excess adhesive or glue from contacting the upper housing 501.

[0045] Figure 10 is a cross-sectional view of a portion of the DR probe 500 without the core foam base 702 for the purpose of illustrating the arrangement of certain described components. Figure 11 is perpendicular to Figure 10 Angle of view of the view shown Figure 10 A cross-sectional view near one edge of the assembled DR detector 500 shows the relative arrangement of the components. Adhered to the inner surface of the upper housing 501 is a carbon fiber reinforcement 1005, which strengthens the upper housing 501 against deformation caused by the weight placed upon it. In one embodiment, the upper housing 501 is manufactured as a thicker structure, having a thickness of approximately 1.5 mm to approximately 2 mm, rather than adhering the reinforcement 1005 thereto. The remaining portions of the upper housing 501 (i.e., the sidewall areas near the flange edge) and the lower housing 502 can have a thickness half that of the upper housing 501. A buffer layer (foam) 1001 is disposed beneath the reinforcement 1005. A multilayer core 505 is disposed beneath the buffer layer 1001 and includes a scintillator layer, a photosensor layer, and a substrate (such as a polyimide substrate). An optional, very thin Mylar film sheet 1002 and a conductive ground sheet 1006 can be disposed between the buffer layer 1001 and the multilayer core 505. If included, the Mylar sheet 1002 may be adhered to the buffer layer 1001 with the conductive sheet 1006 underneath. An optional lead (Pb) layer 1003 may be disposed beneath the substrate layer of the multilayer core 505. The ground plane 602 is placed beneath the optional lead (Pb) layer 1003 (if used) or otherwise against the substrate layer of the multilayer core 505. Posts 1007 are used to attach the ROICS 604 ( Figure 10 ) is attached to the ground plane 602; the gate driver IC 603 is similarly attached to the ground plane 602 using pillars 1007. The foam support 1004 can be placed between the multi-layer core 505 and the thermal pad 605 ( Figure 10). The thermal pad 605 is in thermal contact with the heat generating IC chip 1008 mounted on the COF conductor 810. The COF conductor 810 is in electrical communication with the photoelectric sensor electronics in both the multilayer core 505 and the ROICS 604 and wraps around the intermediate layer, such as Figure 10 As shown in the core foam base 702 ( Figure 11 ) supports the assembled parts as shown, including ROICS 604 (in Figure 10 The core foam base 702 (not shown) and the gate driver PCB 603 ( Figure 11 ).

[0046] Figure 12 Several assembly components described herein are shown in exploded view. In addition to the ground plate 602 and the core foam base 702, adhesive 1201 is used to secure the base along the Figure 12 Each individual functional layer enumerated on the left side of the diagram is attached to the adjacent layer. The upper shell 501 is adhered to the carbon fiber reinforced plate 1005, the carbon fiber reinforced plate 1005 is adhered to the buffer layer (foam) 1001, the buffer layer (foam) 1001 is adhered to the optional, very thin conductive grounding sheet 1002, the conductive grounding sheet 1002 is adhered to the multi-layer core 505, the multi-layer core 505 is adhered to the optional lead (Pb) sheet 1003, the lead sheet 1003 is adhered to the L-shaped grounding plate 602, and the L-shaped grounding plate 602 is supported by the core foam base 702. Figure 12 As shown in Figure 12 From the perspective of the carbon fiber bridge structure 1201, it is arranged in a recess on the core foam base to provide rigidity and prevent excessive load on the PCB main control 801 arranged directly below the carbon fiber bridge 1201. Figure 6 Described, from Figure 12 The core foam base 702 is shaped along one edge 1202 to conform to and support the gate driver integrated circuit 603 (not shown) attached to the underside of the ground plane 602 , as viewed from the perspective of FIG.

[0047] Figure 13 and Figure 14 Basically corresponding to Figure 11 and Figure 12 , and therefore, the enumeration of the same components will not be repeated in these figures. Figure 13 and Figure 14 The optional use of a glass substrate 1301 as part of the multi-layer core 505 is illustrated, rather than as Figure 11The polyimide substrate shown in FIG. Because glass substrates are more brittle than polyimide substrates, an additional reinforcement member 1302 is placed beneath the multilayer core 505. However, this reinforcement member 1302 can alternatively be used with other substrates, such as polyimide. Reinforcement member 1302 can be made of carbon fiber composite or other strong and rigid materials. Reinforcement member 1302 can also include a thin conductive layer thereon for grounding. Ground plate 602 is then adhered to this reinforcement member 1302.

[0048] As described herein, any foam layer components including the foam core base 702, the cushioning layer 1005, and the foam support 1004 can be made of lightweight, low-density foam. Examples of foam materials suitable for use as described herein include ULTEM manufactured by SABIC headquartered in Riyadh, Saudi Arabia. TM Foam, which is a thermoformable polyetherimide thermoplastic foam with a density of approximately 60 kg / m 3 Another suitable foam is ZOTEK manufactured by Zotefoams of Walton, Kentucky, USA. ® Foam, which is a closed-cell foam made of thermoformable polyvinylidene fluoride with a density of approximately 74 kg / m 3 density.

[0049] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A digital radiography (DR) detector comprising: a planar multilayer core comprising a two-dimensional array of photosensitive elements; a rectangular housing comprising an upper shell and a lower shell, the upper shell and the lower shell leaving only one open side when joined together; as well as an end cap for covering the only open side of the housing, Wherein the end cap is configured to thermally engage a heat source within the housing and provide a thermal path from the heat source to an exterior of the housing. 2 . The DR detector according to claim 1 , wherein the upper housing and the lower housing each include a flange edge with adhesive therebetween for bonding together.

3. The DR detector according to claim 2, further comprising a U-shaped bumper configured to engage both the flange edge of the upper shell and the flange edge of the lower shell to clamp the upper shell and the lower shell together along their flange edges, the U-shaped bumper extending around the periphery of three sides of the rectangular housing excluding the only open side.

4. The DR detector of claim 1, wherein the housing comprises a width dimension and a length dimension, the width dimension being perpendicular to the length dimension, the length dimension being greater than the width dimension, and wherein the only open side is open along the width dimension.

5. The DR detector of claim 1 , further comprising a conformal adhesive release sheet surrounding at least a portion of the planar multi-layer core to prevent adhesive material from contacting the portion of the planar multi-layer core and to facilitate separation of the upper housing from the multi-layer core. 6 . The DR detector according to claim 1 , wherein the upper housing is configured to face an x-ray source, and wherein the upper housing is thicker than the lower housing. 7 . The DR detector of claim 6 , wherein the upper housing includes a reinforcement layer adhered to an inner surface thereof.

8. The DR detector of claim 6, wherein the lower housing includes a recess on an outer surface thereof for receiving a battery therein.

9. The DR detector of claim 1, further comprising a foam filler within the housing surrounding a portion of the multi-layer core.

10. A method for manufacturing a DR detector, comprising: providing a planar multilayer core comprising a two-dimensional array of photosensitive cells; enclosing the multi-layer core with the upper shell and the corresponding lower shell by arranging three flange edges of each of the upper shell and the lower shell together, including adhering the flange edges together; disposing bumpers around the three flange edges of the upper shell and the lower shell, including adhering the bumpers to the flange edges; An end cap is disposed over a remaining opening along the width of the upper and lower shells, and the end cap is used to thermally engage a heat source enclosed by the upper and lower shells.

11. The method of claim 10, further comprising surrounding at least a portion of the multi-layer core with a conformal sheet to prevent adhesive material from contacting the portion of the planar multi-layer core and to facilitate separation of the upper shell from the multi-layer core.

12. The method of claim 10, further comprising adhering a reinforcement member to an inner surface of the upper housing.

13. The method of claim 10, further comprising forming a groove in an outer surface of the lower case for receiving a battery therein.

Images