1. Field of the Invention
The present invention relates to computer equipment and peripherals. More specifically, the present invention relates to temperature control mechanisms for peripheral devices and the like for computer equipment.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
Heat generated by computers and associated devices may be problematic under certain environmental and operational conditions. As a result, heat dissipation is an important design consideration in the properly engineered system.
Heat is generated in the typical personal computer system by the computer and the associated peripheral devices. Packaging constraints and unique operating conditions make the heat generated by one peripheral, the optical drive, particularly problematic.
Recent technological advances have opened the door to widespread use of optical drives as attractive alternatives for off-line information storage and retrieval. For example, rewritable optical drives have recently been introduced which offer substantially increased storage capacity, 128 and 325 Megabytes per side for the 31/2 and 51/4 inch drives, respectively, as compared to conventional hard disk drive systems which offer up to 80 to 100 Mbytes per side.
Rewritable optical drive systems typically include an optical media consisting of a magneto-optic material, e.g., a thin film layer of ferrous-oxide or other suitable material, vapor deposited on a substrate of plastic or glass. A laser beam is directed onto the media for read, write, erase and verify operations. The media is driven by a motor and spindle arrangement. For write and erase operations, a high intensity beam is directed onto the media at storage locations determined by a carriage and a fine tracking and focus lens mounted in a deflection coil. The carriage is driven by an actuator coil.
An electromagnetic or bias coil is positioned by the carriage below the media at a storage location at which a write or erase operation is desired. As the beam heats the media above the Currie point, the magnetic orientation of the area illuminated by the beam is set in accordance with the orientation of a magnetic field generated by the bias coil. When the high intensity beam is removed, the spot cools below the Currie point and the magnetic field orientation thereof is fixed.
During subsequent read and verification operations, a low intensity beam is directed on a given storage location and is reflected in accordance with the magnetic field orientation thereof. This causes a slight rotation in the polarization of the reflected beam which is detected and output as the information stored at the addressed location.
It is well known in the art that a considerable amount of heat is generated in the bias and actuator coils during the high intensity write and erase operations. In addition, heat is generated by the illumination of the media by the high intensity laser beam. Heat is also generated by driver circuits for the laser and the bias and actuator coils as well as other electronic circuitry in the system.
Unfortunately, operation of the drive media is typically adversely affected by high temperatures, i.e., temperatures in excess of 55.degree. C. Thus, although the other components may operate at temperatures up to 100.degree. C., there has been an ongoing effort in the art to address the heat issue.
One conventional approach to the heat problem involved the separation of the drive components and the location of the separated components at a spacing sufficient to allow for adequate cooling. However, this approach became impractical as the form factor (packaging) constraints became more demanding. That is, it has been recognized as desirable to have an optical drive and associated circuitry that fit into the space allocated in a personal system for conventional disk drive systems. This minimizes the spacing between components and inhibits cooling for the form factor for the 51/4 inch drive and is especially acute for the form factor for the 31/2 inch drive.
Some systems use fans to force increased airflow through the drive. Unfortunately, fans also contaminate the drive with dust and other debris.
Heat conduction mechanisms have been used, but have been found to be limited by low energy transfer rates due to silicon thermal isolation between components.
Other conventional approaches to the heat problem have included: 1) the use of components with greater temperature margins, 2) a decrease in the current demands of the system with a greater circuit integration and/or use of more efficient components, and 3) a decrease in the performance of the system to reduce energy demands. The first option adds to the cost of the system and places that cost on all users regardless of the environmental conditions in which their systems operate. The second option also adds to the cost of the system and the third option is generally considered to be undesirable.
Thus, a need remains in the art for an inexpensive system and/or technique for addressing the heat generation problem associated with computer peripherals in general and tightly packaged optical drives in particular.