Patent Application
20060087809
Embodiments of the present invention relate to the field of computer system housings. Specifically, embodiments of the present invention relate to a drive bay cover for reducing high frequency electromagnetic interference (EMI) emissions.
Electromagnetic interference (EMI) is an electrical disturbance that causes the disruption of operation of an electronic device when it is in the vicinity of an electromagnetic (EM) field. The electrical disturbance may be caused by high frequency waves in the radio frequency (RF) range from microchips or other electronic devices. For example, the internal circuits and electronic components of personal computer systems can generate EM fields in the RF range that may disrupt the operation of neighboring electronic devices.
There are a number of electronic devices that can fail to function properly in the presence of EMI, such as cordless telephones, computers, consumer electronics devices, and even certain medical devices. In order to reduce EMI emissions from personal computer systems, the electronic componentry of a typical computer system is housed within a metal chassis. The metal chassis blocks a large percentage of EMI emissions. The metal chassis may include a number of openings (e.g., vents, connector holes, etc.). However, these openings are typically small enough such that only EMI emissions having very short wavelengths may escape the chassis. These short wavelength EMI emissions are typically less disruptive to electronic devices proximate the computer system.
However, a metal chassis typically has a number of openings for drive bays (e.g., 3.5 inch drive bays and 5.25 inch drive bays) for holding various types of drives. These drive bay openings are often big enough to allow larger wavelength EMI emissions that are more disruptive to electronic devices to escape the metal chassis. In order to reduce these EMI emissions, drive bay covers, also referred to as knockout plates and knockout shield, are placed over the drive bay opening to block a portion of the EMI emissions. However, there are typically gaps between edges of adjacent drive bay covers or a drive bay cover and an adjacent edge of the metal chassis. For example, there is typically a gap between the drive bay cover of an unused bay and the drive of an adjacent drive bay, so as to not interfere with the placement and installation of the drive. This gap is typically long enough so that large wavelength EMI emissions can escape the metal chassis, and interfere with the operation of neighboring electronic devices.
Another prior solution for reducing EMI emissions escaping through drive bay openings is to use permanently attached knockout shields as drive bay covers. These knockout shields are manufactured into the chassis. For example, the knockout shields may be molded into the chassis using perforations in the metal of the chassis. However, these knockout shields are very difficult to remove. Typically, they can only be removed at the time the computer system is assembled. At any time after assembly, removing the knockout shield may damage the electronic componentry of the computer system. Furthermore, once the knockout shield is removed, it cannot be reconnected to the chassis, requiring the use of a conventional drive bay cover, and thus allowing for large wavelength EMI emissions to escape the chassis, as described above.
Various embodiments of the present invention, drive bay cover for reducing high frequency electromagnetic interference (EMI) emissions, are described. The drive bay cover is for covering a bay of a computer system chassis by coupling to the computer system chassis. A at least one edge of the drive bay cover is a serrated edge such that a gap between the serrated edge and a second edge is less than a wavelength of an EMI emission.
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention:
Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.
Computer system housing 100 of
In one embodiment, computer system 200 comprises an optional user output device such as display device 205 coupled to bus 210 for displaying information to the computer user, an optional user input device such as alphanumeric input device 206 including alphanumeric and function keys coupled to bus 210 for communicating information and command selections to processor 201, and an optional user input device such as cursor control device 207 coupled to bus 210 for communicating user input information and command selections to processor 201. Furthermore, an optional input/output (I/O) device 208 is used to couple computer system 200 onto, for example, a network.
Display device 205 utilized with computer system 200 may be a liquid crystal device, cathode ray tube, or other display device suitable for creating graphic images and alphanumeric characters recognizable to the user. Cursor control device 207 allows the computer user to dynamically signal the two-dimensional movement of a visible symbol (pointer) on a display screen of display device 205. Many implementations of the cursor control device are known in the art including a trackball, mouse, joystick or special keys on alphanumeric input device 206 capable of signaling movement of a given direction or manner of displacement. It is to be appreciated that the cursor control 207 also may be directed and/or activated via input from the keyboard using special keys and key sequence commands. Alternatively, the cursor may be directed and/or activated via input from a number of specially adapted cursor directing devices.
Drive bay covers 422 and 424 are configured to be connected to chassis 410 for covering portions of drive bay opening 420. In one embodiment, drive bay covers 422 and 424 are configured to be connected to chassis 410 by a connector, such as a screw, a rivet, a locking tab, or any other connector means. Edge 432 is adjacent to edge 434, such that a gap between edge 432 and 434 is less than a wavelength of a high frequency EMI emission. For example, double-sided arrow 440 represents the longest straight length of the gap between edges 432 and 434. The length of double-sided arrow 440 is less than a wavelength of a high frequency EMI emission. Therefore, high frequency EMI emissions are not able to escape through chassis 410 through drive bay opening 420.
In one embodiment, chassis 410 also includes drive bay opening 450. In one embodiment, drive bay opening 450 is configured to provide access to two 3.5 inch drive bays. Drive bay cover 452 covers an upper portion of drive bay opening 450 and drive bay cover 454 covers a lower portion of drive bay opening 450. Edge 462 of drive bay cover 452 is a serrated edge with trapezoidal serrations and edge 464 of drive bay cover 454 is a serrated edge with trapezoidal serrations. It should be appreciated that edges 462 and 464 may include serrations of other geometries, as described below in conjunction with
Drive bay covers 452 and 454 are configured to be connected to chassis 410 for covering portions of drive bay opening 450. In one embodiment, drive bay covers 452 and 454 are configured to be connected to chassis 410 by a connector, such as a screw, a rivet, a locking tab, or any other connector means. Edge 462 is adjacent to edge 464, such that a gap between edge 462 and 464 is less than a wavelength of a high frequency EMI emission. Therefore, high frequency EMI emissions are not able to escape through chassis 410 through drive bay opening 450.
While the embodiments described in
Various embodiments of the present invention provide a computer system housing, a computer system chassis, and a drive bay cover for reducing high frequency EMI emissions. The drive bay cover is configured to cover a drive bay opening and includes a serrated edge that, in conjunction with a second edge, provides that a gap between the serrated edge and the second edge is less than a wavelength of a high frequency EMI emission. Since the wavelength is longer than the length of the gap, the EMI emission is not able to escape the drive bay opening. Thus, the present invention provides a drive bay cover for reducing high frequency EMI emissions, thereby reducing RF interference with electronic devices proximate to the computer system.
Embodiments of the present invention, a drive bay cover for reducing high frequency EMI emissions, are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the following claims.
