Abstract
A digital radiographic detector includes a planar multilayer core having a two-dimensional array of photo-sensitive cells. An enclosure having only one open side and upper and lower halves is joined together using a three—sided bumper configured to provide impact absorption for sides of the enclosure. An end cap covers the only one open side of the enclosure.
Claims
1. A digital radiographic (DR) detector comprising: a planar multilayer core comprising a two-dimensional array of photo-sensitive cells; a rectangular shaped housing comprising upper and lower shells which, when joined together, leave only one open side; and an end cap to cover the only one open side of the enclosure.
2. The DR detector of claim 1, wherein the upper and lower shells each comprise flanged edges having adhesive therebetween for being joined together.
3. The DR detector of claim 2, further comprising a U-shaped bumper configured to engage both of the upper and lower shells' flanged edges to hold together the upper and lower shells along their flanged edges, the U-shaped bumper extending around a perimeter of three edges of the rectangular housing, excluding the only one open side.
4. The DR detector of claim 1, wherein the end cap is configured to thermally engage a heat source inside the housing and to provide a thermal path from the heat source to an exterior of the housing.
5. The DR detector of claim I, wherein the housing comprises a width dimension and a length dimension, the width dimension is perpendicular to the length dimension, the length dimension is greater than the width dimension, and wherein the only one open side is open along the width dimension.
6. The DR detector of claim 1, further comprising a conformal adhesive release sheet surrounding at least a portion of the planar multilayer core to prevent adhesive material from contacting said portion of the planar multilayer core and to promote separation of the upper shell from the multilayer core.
7. The DR detector of claim 1, wherein the upper shell is configured to face an x-ray source, and wherein the upper shell is thicker than the lower shell.
8. The DR detector of claim 7, wherein the upper shell includes a. stiffening layer adhered to an interior surface thereof.
9. The DR detector of claim 7, wherein the lower shell includes a concave indentation on an exterior surface thereof for receiving a battery therein.
10. The DR detector of claim 1, further comprising a foam filler within the housing surrounding portions of the multilayer core.
11. A method of making a DR detector comprising: providing a planar multilayer core comprising a two-dimensional array of photo-sensitive cells; enclosing the multilayer core with an upper shell and a corresponding lower shell by positioning together three flanged edges of each of the upper shell and the lower shell, including adhering the flanged edges together; positioning a bumper around the three flanged edges of the upper shell and the lower shell, including adhering the bumper to the flanged edges; positioning an end cap over one remaining opening along a width of the upper shell and the lower shell.
12. The method of claim 11, further comprising using the end cap to thermally engage a heat source enclosed by the upper and lower shells.
13. The method of claim 11, further comprising surrounding at least a portion of the multilayer core using a conformal sheet to prevent adhesive material from contacting said portion of the planar multilayer core and to promote separating the upper shell from the multilayer core.
14, The method of claim 11, further comprising adhering a stiffening member to an interior surface of the upper shell.
15. The method of claim 11, further comprising forming a concave recess in an exterior surface of the lower shell for receiving a battery therein.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which:
[0025] FIG I is a schematic perspective view of an exemplary x-ray system;
[0026] FIG. :2 is a schematic diagram of a photosensor array in a radiographic detector;
[0027] FIG. 3 is a perspective diagram of an exemplary DR detector;
[0028] FIG. is a cross section diagram of an exemplary DR detector;
[0029] FIG. 5 is an exploded view of an exemplary DR detector assembly;
[0030] FIG. 6 is a perspective view of the upper shell having component layers laminated to the upper shell, shown upside down;
[0031] FIG. 7 illustrates a side edge cross section of the DR detector with interlocking bumper design;
[0032] FIG. 8 is an internal detector assembly with foam core base populated with printed circuit board and related electronics;
[0033] FIG. 9 shows a conformal adhesive release layer over portions of the internal detector assembly of FIG. 8;
[0034] FIG. 10 shows a cross-section cut away portion of the multilayer sensor laminate structure;
[0035] FIG. 11 shows a DR detector partial cross-section;
[0036] FIG. 12 shows an exploded view of the DR detect( ) av s in more detail;
[0037] FIG. 13 shows a DR detector partial cross-section with an alternative glass substrate embodiment; and
[0038] FIG. 14 shows an exploded view of the multilayer core with the additional stiffener layer for a glass substrate embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0039] This application claims priority to U.S. Patent Application Ser. No. 62/885,423, filed Aug. 12, 2019, in the name of Bogumil et al., and entitled RADIOGRAPHIC DETECTOR, which is hereby incorporated by reference herein in its entirety.
[0040] Referring to FIG. 5, an exploded view of components of an inventive assembly for a DR detector 500 includes an upper shell 501 secured to a lower shell 502 using a U-shaped, or three-sided, bumper 503. The bumper 503 engages flanged edges (HG. 7) of the upper shell 501 and the lower shell 502 to secure them together. Adhesive is also used between the flanged edges and on an inside surface of the bumper 503. When joined together, the upper shell 501 and the lower shell 502 leave an opening along a width of the shells because upper and lower shell edges 501.a, 502a, respectively, are not folded over and so do not contact each other. The upper and lower shells 501, 502, enclose a multilayer core 505 which includes a two dimensional array of photosensors, a scintillator, a support substrate and supporting electronics for reading out radiographic image data captured by the photosensors. The upper and lower shells 510, 502, may be made from carbon fiber or similar material. As shown in FIG. 5, the multilayer core is embedded. in a core foam base 702 (FIG. 7). The opening along the width of the shells is closed by positioning an end cap 504 therein. Power is supplied to the DR detector by a battery placed in a battery compartment 506 formed in the lower shell 502. A battery compartment 506 is positioned in the lower shell 502 by forming a concave recess in an exterior bottom surface thereof.
[0041] With reference to FIG. 6, a perspective view of the upper shell 501 is shown wherein the upper shell 501 is flipped upside down with the multilayer core 505 and additional components attached thereto. In one embodiment, an L-shaped grounding plate 602 is attached with adhesive either to a lead sheet, if a lead sheet 1003 (FIG. 12) is used; or, in another embodiment, the L-shaped grounding plate 602 is attached with adhesive to a stiffening member with adhesive, if a stiffening member 1302 (FIG. 14) is used; or, in another embodiment, the L-shaped grounding plate 60:2 is attached with adhesive directly to the multilayer core 505 (FIG. 12) if neither a stiffening member 1302 nor a lead sheet 1003 is used. The grounding plate 602 extends along two perpendicular peripheral edges of the DR detector 500, and may be made from aluminum or other suitable conductor. Gate driver integrated circuitry 603 is electrically attached to the grounding plate 602 along one edge thereof and read out integrated circuits (ROICS) 604 are electrically attached thereto along an adjacent perpendicular edge of the L-shaped grounding plate 602. A thermally conductive pad 605 is attached to, and is thermally coupled to, the ROICS 604. The end cap 504, when positioned in the open end of the joined shells 501, 502, thermally engages the thermally conductive pad 605 to act as a thermal sink for heat generated by ROICS 604.
[0042] FIG. 7 illustrates a cross-section view of one edge of DR detector 500 showing the engagement of bumper 503 to flange edge 501b of the upper shell 501 and to flanged edge 502b of the lower shell 502. The vertical sidewall portions of upper and lower shells 501, 502, respectively, in the perspective of FIG. 7, extend horizontally into bumper 503 to form flanged edges 501b, 502b, respectively. The bumper 503 secures together both the upper and lower shells, 501, 502, respectively, by compressive force against flanged edges 501b, 502b, and, in addition, adhesive 701 is disposed between upper and lower flanged edges 501b, 502b, between the bumper 503 and the upper and lower flanged edges 501b, 502b, and between the bumper 503 and the upper and lower shells 501, 502. As will be described herein, the multilayer core 505 is embedded in a core foam base 702 disposed in the interior area of DR detector 500. The bumper 503 may be made of an elastomeric material, plastic, rubber, or other suitable impact tolerant material, to absorb shock but should be suitably rigid to hold together the upper and lower shells 501, 502.
[0043] FIG. 8 is a perspective view of the core foam base 702, and other internal electronic components of DR detector 500, which includes shaped. recesses 806, cutouts 809, pockets 808, and wirelines 802 to receive components of DR detector 500, and which occupies a major volume of the interior of the DR detector 500 between upper and lower shells 501, 502. Recesses 806 may be used to provide space for folds 807 of the ribbon cables 804, which provide for data and electrical communication between ROICS 604 and the PCB main control circuitry 801 via chip-on-film connectors 810, among other communications; pockets 808 may be used for providing space for a battery, for example; wirelines 802 may each be used to press a wire 803 therein in order to secure the wire in position within DR detector 500. Components of the PCB main control circuitry 801 are positioned within the edges of a cutout 809.
[0044] FIG. 9 is a perspective view similar to FIG. 8 but with a conformal adhesive release layer, film, sheet, or tape, 901 place along a periphery of the assembly of FIG. 8. The release layer 901 covers the ROICS 604, chip-on-film connectors 810, and portion of the DR detector interior assembly. The release layer 901 prevents seeping or leaking adhesive from contacting portions of DR detector 500 that are covered by the release layer 901. Release layer 901 also serves as a sacrificial layer that may be peeled off when separating the upper and lower shells 501, 502, during a repair procedure. Release layer 901 also assists in separating the upper and lower shells 501, 502, for repair purposes by preventing excess adhesive or glue from contacting the upper shell 501.
[0045] FIG. 10 is a cross-section cut away view of a portion of DR detector 500 without core foam base 702 to illustrate positioning of certain described components. FIG. 11 is a cross-section view near one edge of assembled DR detector 500 showing relative positioning of the components of FIG. 10 from a view perpendicular to the view of FIG. 10. Adhered to an interior surface of upper shell 501 is a carbon fiber stiffening member 1005 which strengthens upper shell 501 against distortion caused by weight placed thereon. In one embodiment, the upper shell 501 is manufactured to have a thicker structure of about 1.5 mm up to about 2 mm thickness, instead of adhering the stiffening member 1005 thereto. The other portions of upper shell 501, i.e., sidewall area proximate the flanged edges, and lower shell 502 may have half the thickness of the upper shell 501. A buffer layer (foam) 1001 is positioned below the stiffening member 1005. The multilayer core 505 is positioned below the buffer layer 1001, which includes a scintillator layer, photosensor layer, and a substrate, such as a polyimide substrate. An optional, very thin, mylar sheet 1002 and conductive grounding sheet 1006 may be positioned 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 below. An optimal lead (Pb) layer 1003 may be positioned under the substrate layer of the multilayer core 505. The grounding plate 602 is placed below the optional lead (Pb) layer 1003, if the lead layer 1003 is used, otherwise against the substrate layer of the multilayer core 505. The ROICS 604 (FIG. 10) are attached to the ground plate 602 using posts 1007; the gate driver ICs 603 are similarly attached to the ground plate 602. using posts 1007. Foam supports 1004 may be positioned between the multilayer core 505 and the thermal pad 605 (FIG. 10). The thermal pad 605 is in thermal contact with a heat generating IC chip 1008 mounted on chip-on-film conductor 810. Chip-on-film conductor 810 is in electrical communication with both photosensor electronics in the multilayer core 505 and ROICS 604, and wraps around intermediate layers as shown in FIG. 10. The core foam base 702 (FIG. 11) supports portions of the assembly as shown including the ROICS 604 (core foam base 702 not shown in FIG. 10) and gate driver PCB 603 (FIG. 11).
[0046] FIG. 12 shows several of the assembly components described herein in an exploded view. Each individual functional layer, enumerated along the left side of FIG. 12, is attached to an adjacent layer using adhesive 1201, except for the grounding plate 602 and core foam base 702. The upper shell 501 is adhered to carbon fiber stiffener 1005, which is adhered to buffer layer (foam) 1001, which is adhered to an optional, very thin conductive grounding sheet 1002, which is adhered to multi layer core 505, which is adhered to optional lead (Pb) sheet 1003, which is adhered to L-shaped grounding plate 602, which is supported by core foam base 702. As shown in FIG, 12, a carbon fiber bridge structure 1201 is positioned in a recess on the core foam base, to provide stiffness and to prevent excess loads on PCB main control 801 which is positioned directly underneath the carbon fiber bridge 1201, in the perspective of FIG. 12. The core foam base 702. is shaped along one edge 1202 to conform to, and support, gate driver integrated circuitry 603 (not shown) that is attached to an underside of ground plate 602, in the perspective of FIG. 12, as described in relation to FIG. 6.
[0047] FIGS. 13 and 14 correspond substantially to FIGS. II and 12, respectively, and so enumeration of the same components will not be repeated in these figures. FIGS, 13 and 14 illustrate an optional use of a glass substrate 1301 as part of the multilayer core 505, rather than a polyimide substrate as shown in FIG. 11. Due to the glass substrate being more brittle than a polyimide substrate, an additional stiffening member 1302. is positioned beneath the multilayer core 505, however, this stiffening member 1302 may optionally he used with other substrates, such as polyimide. The stiffening member 1302 may he made from a carbon fiber composite, or other sturdy and stiff material. The stiffening member 1302 may also include a grounded, thin conductive layer thereon. The grounding plate 602 is then adhered to this stiffening member 1302.
[0048] As described herein, any foam layer components, including foam core base 702, buffer layer 1005, foam supports 1004, may be made from a lightweight low density foam. Examples of foam materials suitable for use as described herein include ULTEM™ foam which is a polyetherimide thermoplastic foam, having a density of about 60 kg/m.sup.3, that is thermoformable, manufactured by SABIC, based in Riyadh, Saudi Arabia, Another suitable foam is ZOTEK® foam which is a closed cell foam made from poly vinylidene fluoride, having a density of about 74 kg/m.sup.3 is thermoformable, manufactured by Zotefoarns, in Walton, Ky., USA,
[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.
