Input/output access shield member for computer housing

A shield member for installation on a computer housing includes a generally planar plastic body. The plastic body has at least one opening formed therein to accommodate insertion through the body of at least one computer input/output cable. The shield member also includes a plurality of attachment members integrally formed with the plastic body to attach the shield member to the computer housing. In addition, the shield member includes an electrically-conductive film molded into the plastic body.

BACKGROUND

In the case of many personal computers, electronic components are contained within a housing. The rear wall of the housing is typically constituted by a thin metal shield, sometimes referred to as an “I/O shield”. This term may be considered short-hand for an input/output access shield. The I/O shield typically has openings formed therein to allow input/output cables to be inserted through the I/O shield to allow the cables to be interfaced to the electronic components within the housing. Because the shield is metal it may function to inhibit electromagnetic interference (EMI) signals from passing through the shield.

The cost of manufacturing conventional I/O shields may be higher than is desirable. Furthermore, it may be inconvenient to mount conventional I/O shields to the balance of the housing.

DETAILED DESCRIPTION

FIG. 1is an elevational view of an I/O shield member10as provided in accordance with some embodiments. For convenience of presentation, the shield member10is shown inFIG. 1with its longest dimension oriented horizontally. However, in at least some cases, the longest dimension of the shield member10may be oriented vertically, so that the shield member10may be suitable for closing the rear of a conventional personal computer “tower” housing.FIGS. 2 and 3are other views of the shield member10, withFIG. 2being a top view andFIG. 3being a view of an end of the shield member10.

As seen fromFIGS. 1–3, the shield member10is in the general form of a planar body with a rectangular profile. The shield member10has a number of openings formed therethrough, including openings12,14and16(seen inFIG. 1) for accommodating computer input/output cables (not shown) to be inserted through the openings and thus through the shield member10to allow the cables to be interfaced to internal electronic components (not shown) housed within a computer housing (not shown inFIGS. 1–3) to which the shield member10may be installed. For example, openings12,14,16may accommodate plugs from devices such as printers or scanners. The openings formed through the shield member10further include openings18,20,22,24,26,28,30,32,34,36,38and40for accommodating connections to devices such as mice, keypads and USB ports. In other embodiments, the numbers, shapes and/or locations of the openings may be different from those shown inFIG. 1.

The shield member10further includes a flange42(best seen inFIGS. 2 and 3) which runs around the periphery of the shield member10and which extends normal to the plane of the shield member in a direction that is inward relative to a computer housing (not shown inFIGS. 1–3) to which the shield member10may be installed. The extent of the flange42in the inward direction may be on the order of 1 to 2 mm, in some embodiments. The flange42, and indeed all other features of the shield member10illustrated inFIGS. 1–3, may be integrally formed with shield member10.

The shield member10may also include snap members44formed at respective points along the flange44. The snap members44are six in number in the embodiment shown, though there may be more or fewer in other embodiments, and the locations thereof may be changed. The snap members44extend normal to the plane of the shield member10in the above-mentioned inward direction relative to the computer housing (not shown inFIGS. 1–3) to which the shield member10may be installed. The snap members44may operate as attachment members by which the shield member10may be attached and/or secured to the computer housing. In other embodiments, some or all of the snap members may be dispensed with in favor of small spherical domes (not shown) which may be formed on the flange42extending radially outwardly from the flange42to allow the shield member10to be attached/secured to the computer housing via the spherical domes.

The shield member10may also include contact members46located at various locations across the planar extent of the shield member10. The contact members46may be rounded and may extend in the above-mentioned inward direction normal to the plane of the shield member10. In some cases the contact members46may be associated with some of the openings (e.g., openings12,14,16) formed in the shield member10. A purpose of the contact members46is to be in electrically conductive contact with one or more circuit boards (not shown inFIGS. 1–3) installed within the computer housing (not shown inFIGS. 1–3) to which the shield member10may be installed. For that purpose, as will be explained below, at least the inward-facing surfaces (inward direction indicated by arrows48,50inFIGS. 2 and 3respectively) of the contact members46may be electrically conductive.

As indicated by the above description of the shield member10and the accompanying drawings, the shield member10may be configured to be attached to a computer housing (FIG. 6) from outside the computer housing.

The composition of the shield member10will now be discussed.FIG. 4is a schematic partial cross-sectional view taken normal to the plane of the shield member10at a location (e.g., location52,FIG. 1) that is without features. According to some embodiments, the shield member10is formed as a molded plastic body into which an electrically-conductive film54(FIG. 4) has been molded. It will be noted that the electrically-conductive film54is at an inner surface56(relative to the above-mentioned computer housing) of the plastic body which makes up the shield member10. Thus the inner surface56of the shield member10may be considered to correspond to the electrically-conductive film54. The extent of the electrically-conductive film54in the plane of the shield member10may be substantially the same as (i.e., may substantially match) the planar extent of the shield member10. Thus the surface area of the electrically conductive film54may be substantially the same as, and thus may substantially match, the surface area of the inner surface56of the shield member10. The electrically conductive film54may be suitable for blocking electromagnetic interference from entering or leaving a computer housing (not shown inFIG. 4) of which the shield member10may be a part. Hence, the electrically conductive film54may be referred to as an “EMI film”.

The shield member10may be molded out of conventional plastic resin. The electrically conductive film54may be, for example, a metallized Lexan (polycarbonate) sheet available from General Electric plastics division. It will be noted thatFIG. 4is not necessarily drawn to scale, and that the electrically-conductive sheet may be much thinner than is suggested by the drawing. In some embodiments, the typical over-all thickness of the shield member10(e.g., at a featureless location such as location52,FIG. 1) may be on the order of about 0.5 to 1.0 mm.

FIG. 5is a block diagram that illustrates a process that may be performed in the course of manufacturing the shield member10. At80inFIG. 5, the electrically-conductive film (previously indicated as54inFIG. 4) is placed in a suitable mold (not shown). Then, at82inFIG. 5, a plastic resin or the like is molded in the mold with the electrically-conductive film to form the plastic body84partially indicated inFIG. 4, so that the electrically conductive film54is molded into the plastic body84. The mold may be suitably sized and shaped to form the shield member10described above. In some embodiments, the molding performed at82may be injection molding.

FIG. 6is a schematic side view of a computer system100provided in accordance with some embodiments. (To simplify the drawing, many components of the computer system are omitted.) The computer system100may include a housing102and a circuit board104mounted in the housing102. The circuit board104may include at least one integrated circuit, such as microprocessor106mounted on the circuit board104. The circuit board may also include a chipset108in communication with the microprocessor106.

The computer system100may further include an I/O shield member10like that described above. The shield member10may be installed on the housing102and may form the rear wall thereof. The shield member10may be in electrically-conductive contact with the circuit board104via, e.g., its contact members46(FIGS. 2 and 3) and its electrically conductive film54which forms a surface of the contact members46. Other components that may, but need not, be included in the computer system100, and which are not shown, include (a) I/O cables inserted through the shield member10to be in electrically conductive contact with the circuit board104and/or other internal components of the computer system100; and/or (b) peripheral components of the computer system100coupled to the circuit board104via the I/O cables.

The shield member as described hereinabove, made largely of plastic with an electrically-conductive film molded therein, may be manufactured more economically than a conventional metal I/O shield. Moreover, the shield member may be configured so as to be installable on the computer housing from the outside of the housing rather than from the inside, the latter being the case with respect to at least some conventional I/O shields. This feature of the shield member described herein may make assembly of the computer more convenient. Furthermore, the shield member as described herein may be more resistant to vibration than a conventional metal I/O shield and thus may be more reliably retained in place on the computer housing. Because of the presence of the electrically-conductive film in the shield member described herein, the shield member may be substantially as effective as a metal I/O shield in preventing transmission of electromagnetic interference to/from the interior of the computer housing.

The several embodiments described herein are solely for the purpose of illustration. The various features described herein need not all be used together, and any one or more of those features may be incorporated in a single embodiment. Therefore, persons skilled in the art will recognize from this description that other embodiments may be practiced with various modifications and alterations.