1. Field of the Invention
The present invention relates to portable computing devices and to display module housing units for portable computing devices.
2. Description of the Related Art
Conventional portable computer display units typically utilize a flexible, non-rigid, non-conductive material to hold internal display parts. Such flexible, non-rigid display unit materials do not adequately protect against damage from shocks, drops, or vibration because the fragile internal glass components are not stabilized and are thus vulnerable upon impact. Some manufacturers, in an attempt to strengthen display units, construct an additional enclosure that goes around the existing non-rigid display unit. The additional enclosure is constructed as an outer unit, and the existing non-rigid display unit is a sub-enclosure. This additional outer main enclosure results in a thicker, bulkier display.
Additionally, conventional portable computer display assemblies use a non-conductive material to hold internal display parts. Non-conductive materials typically cannot shield against Electromagnetic Interference (“EMI”) or Radio Frequency Interference (“RFI”) noise. The terms “EMI” and “RFI” both refer to unwanted electromagnetic radiation signals that can potentially interfere with other signals. For purposes of brevity and consistency, this specification will use the term “EMI” when referring to such interference.
Some embodiments improve upon conventional display systems by integrating internal display components directly into a rigid, strong, conductive rear chassis. The conductive rear chassis may be configured such that internal display parts can be secured without using a secondary substructure. The conductive rear chassis may include any, or a combination, of printed circuit board (“PCB”) mounters, hinge mounters, antenna mounters, or other mounters built into the chassis itself. The conductive rear chassis may be configured to provide EMI suppression. The suppression provided by the conductive rear chassis may prevent EMI from interfering with signals sent or received by one or more antennas that may be mounted on or near the conductive rear chassis.
The conductive rear chassis may be constructed of a material that is rigid, strong, and lightweight. The conductive rear chassis may be formed from a titanium alloy. The conductive rear chassis may be formed from an aluminum alloy. The conductive rear chassis may be formed from a carbon fiber material. The conductive rear chassis may be formed from a graphite material. The conductive rear chassis may be formed from a magnesium alloy. The conductive rear chassis may be formed from a zinc alloy. The conductive rear chassis may be formed from a copper alloy. Other materials may also be used.
The conductive rear chassis may be produced by a casting method. The casting method may involve pressure injection. The casting method may involve gravity pressure. A die casting method may be used. The conductive rear chassis may be produced by a molding method. The conductive rear chassis may be produced by a stamping method. Other techniques are contemplated.
The display module may be a Liquid Crystal Display (“LCD”). The display module may be a plasma display panel (“PDP”). The display module may be a Field Emission Display (“FED”).
Purposes and advantages of the exemplary embodiments will be apparent to those of ordinary skill in the art from the following detailed description in conjunction with the appended drawings in which like reference characters are used to indicate like elements, and in which:
Advantages of these and other embodiments will become apparent from the following detailed description, which taken in conjunction with the accompanying drawings, describes by way of example—and not limitation—principles of various exemplary embodiments.
An exemplary, non-limiting portable computing device and a display housing module for a portable computing device will be described in detail with reference to the accompanying figures. The display housing module includes a conductive rear chassis, a display module, an environmental sealer, and a front bezel. The display module may be configured to display images and may include a backlight unit, a display panel, and a touch screen. The conductive rear chassis may be constructed so as to exhibit strong, lightweight, and rigid properties. It may be configured to receive and secure a display module and to protect the display module from shock events, drop events, and vibration. The portable computing device may meet the United States Military standard for shocks, drops, and vibration (MIL STD 810F). The MIL STD 810F is a series of standards issued by the United States Army's Developmental Test Command, to specify various environmental tests to prove that equipment qualified to the standard will survive in the field. The MIL STD 810F standards are set forth in a public document entitled “Department of Defense Test Method Standard For Environmental Engineering Considerations And Laboratory Tests.” To meet the MIL STD 810F for transit drops, the portable computing device must be able to withstand drops on each face, edge and corner. It must be able to withstand 26 of these drops from a height of at least 36 inches. To meet the standard, the portable computing device must retain structural and functional integrity.
The conductive rear chassis may be configured to mount an antenna. The conductive rear chassis may prevent EMI signals from interfering with signals sent or received by an antenna. To this end, the conductive rear chassis may be configured to shield EMI that originates from noisy electronics, internal to the computer, from signals sent or received by an antenna. The conductive rear chassis may be configured to provide a conductive path to a ground connection. The conductive rear chassis may be configured to channel EMI from the noisy electronics to ground, thereby preventing unwanted EMI leakage outside the display module.
The conductive rear chassis may be further configured to receive an environmental sealer around the perimeter of the housing. The conductive rear chassis may be further configured for direct attachment to a front bezel. Attaching the front bezel to the conductive rear chassis may create pressure on the environmental sealer, thereby protecting internal display parts from environmental elements such as rain, dust, sand, chemicals, and other elements.
Certain additional features of the conductive rear chassis, such as the two closely spaced horizontal strips 210 and 212, may be located just above the lower perimeter wall 202 of the conductive rear chassis 100. The horizontal strips 210 and 212 are shown with a close-up view in
In some embodiments the conductive rear chassis may include a cavity portion 220. The cavity portion 220 may allow for a slimmer display by creating additional space to house and shield electronic circuitry. An example of such electronic circuitry is a display driver that helps create the images that appear on the display panel. The display driver may produce EMI.
In some embodiments, the cavity portion may be formed as a depression area in the conductive rear chassis 100. In such embodiments, a slimmer display may be achieved while keeping the continuity of the conductive rear chassis 100 intact. In some embodiments the cavity portion 220 may be formed by cutting out a portion of the conductive rear chassis 100 and then adhering a conductive member back over top of the removed portion. The conductive member may be thin sheet-like metal or a metallized plastic material. It should be appreciated that
EMI may be created when electrical current is driven through a wire, such as a trace on a PCB. The trace may then act as an EMI transmitter, and this may become problematic if the transmitted EMI begins to interfere with signals being sent to or from a nearby antenna. The conductive rear chassis 100 may act as a conductive partition between the electronic circuitry and the antenna, and may consequently act as an EMI shield. When EMI comes in contact with the conductive rear chassis 100, a current may flow on the conductive rear chassis 100 to ground. EMI is thus attenuated by a force called the skin effect. It should be appreciated that an ungrounded EMI shield that completely surrounds a noisy device can provide effective EMI shielding. Such an enclosure is known as a Faraday cage and results in two-way EMI shielding (i.e., EMI can neither enter nor exit the shield). The Faraday cage does not have to be fully enclosed to the extent that there are no gaps, cracks, or holes at all. There can be gaps, cracks, or holes in the enclosure, but they can be no bigger than the EMI's wavelength. If there are gaps, cracks, or holes larger than the EMI's wavelength, the enclosure does not provide the shielding benefits of a true Faraday cage. In some instances, it may be difficult or impractical to surround a device with an enclosure that qualifies as a true Faraday cage. However, EMI can still be effectively shielded without the existence of a true Faraday cage. In this situation, the EMI can be effectively shielded if the shielder lies between the EMI source and the antenna to be shielded, and is grounded or has its voltage potential defined with respect to the source of the EMI. The conductive rear chassis 100 can effectively shield antenna signals from EMI that originates from PCB circuitry, such as a display driver, because (1) it provides a conductive spatial partition between the PCB and the antenna, and (2) it shares a ground connection with the EMI source on the PCB. The at least one PCB mounter 410 may be configured to mount the at least one PCB such that the ground connection of the PCB is in contact—and thus electrically linked—with the conductive rear chassis 100. The connection between the conductive rear chassis 100 and the PCB is not susceptible to physical separation because the conductive rear chassis 100 is constructed of a rigid material. Specifically, the rigidity of the conductive rear chassis 100 may prevent a PCB ground connection from losing connectivity with the conductive rear chassis 100 as a result of a jarring event such as a shock, drop, or vibration. The grounding of the conductive rear chassis 100 may protect from shock hazards by providing a fault-current return path. Further, grounding the conductive rear chassis 100 may prevent the buildup of voltage on the chassis itself.
In some embodiments the conductive rear chassis 100 may include a cavity portion 220. The cavity portion 220 may be formed as a depression area in the conductive rear chassis 100. The cavity portion 220 may also be formed by cutting out a portion of the conductive rear chassis 100 and then adhering a conductive member back over top of the removed portion. The conductive member may be thin insulated sheet-like metal or an insulated metallized plastic material. A PCB may be mounted or adhered in the cavity portion 220. When the cavity portion 220 is a cut-out area, the PCB may be mounted or adhered to the insulated sheet-like metal or the insulated metallized plastic material which may have been adhered back over the top of a removed portion. The PCB may be mounted or adhered on the sides or bottom of the cut-out area. When the cavity portion 220 is a depression, the PCB may be mounted or adhered on the sides or bottom of the depression area.
In some embodiments, hinge mounters 415 may be configured to mount a display housing module to the base of a portable computing device. Hinge mounters 415 may be configured to attach to the base unit of a portable computing device to allow the display module to rotate about the hinge. Hinge mounter 415 may allow for forward and backward rotation and may also allow for the display module to be rotated or twisted to the left or the right with respect to the base unit of a portable computing device. In some embodiments, external cover mounters 420 may be configured to mount a decorative covering. Additionally, external cover mounters 420 may be configured to mount external attachments that may facilitate carrying the portable computing device (e.g. a handle), or docking or attaching the portable computing device.
The lower horizontal and upper horizontal strips 210 and 212, and the wall of the bottom perimeter 202 are both conductive as they are a part of the conductive rear chassis 100. Configuring the conductive rear chassis 100 such that the EMI emitting PCB 510 is sandwiched between two conductive strips allows for effective EMI noise suppression because the emitted electromagnetic radiation follows the conductive path of least resistance to ground, and noise emission is thereby reduced. The EMI suppression effect is further enhanced by the attachment of a front bezel 170, which is illustrated at
In some embodiments, the antenna 1010 may be attached to the conductive rear chassis through antenna mounter 1020. The antenna mounter 1020 may be disposed on the inside or outside surface of the conductive rear chassis 100. An antenna mounter 1020 may be located or positioned to ensure that EMI produced by electronic circuitry used to drive the display of images is shielded from the signals sent and received by the antenna. The conductive rear chassis 100 may provide such shielding.
The preceding specification makes repeated reference to Printed Circuit Boards (“PCB”). It should be appreciated that the term PCB is a generic term that includes both rigid and other types of circuit boards, such as, by way of non-limiting example, Flexible Printed Circuits (“FPC”).
In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.
This application claims priority to provisional U.S. Application Ser. No. 60/976,628 filed Oct. 1, 2007 entitled “SuperStructure,” which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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60976628 | Oct 2007 | US |