Abstract:
An information handling system component contained within an information handling system housing uses the information handling system housing as at least a portion of a safety enclosure for hazardous functions of the component. A lock out device disables the hazardous function if the information handling system housing is moved relative to the component. For example, an optical disc drive laser is disabled if a Hall effect sensor in the chassis of the optical disc drive no longer senses a magnet placed in a portion of the information handling system housing used to enclose the optical disc drive.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates in general to the field of information handling system components, and more particularly to a system and method for enclosing information handling system component devices. 
     2. Description of the Related Art 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     Information handling systems are typically built in portable or stationary configurations. Portable information handling systems have smaller-sized housings that allow use of the system on the go. Integrated power, I/O and display devices support system operation free from permanent connections to external power and peripherals. Stationary information handling systems have housings of a wide variety of shapes and sizes that support use of the system in a fixed location. Desktop, tower and server information handling systems typically interface with external power and I/O devices. Manufacturers generally try to build information handling systems in as small a chassis as possible for the functionality supported by the information handling systems. Smaller sized stationary information handling systems are more convenient because a smaller footprint fits better in space-constrained locations, such as a user desk or a data center. Smaller sized portable information handling systems are more convenient for users since a smaller size and decreased weight make a portable information handling system less awkward to handle and less burdensome to carry. Generally, as an information handling system housing decreases in size, functionality also decreases because less room is available to fit in component devices and smaller space makes thermal transfer more difficult to accomplish. 
     Component devices used to build an information handling system include hard disk drives and optical drives, such as CD, DVD and BD drives, which store information for use in processing by a CPU or other processor. Some component devices are built in their own housing so that the component device housing fits within the information handling system housing. For example, optical drives that include one or more lasers to read and write information typically are built into a class 1 laser enclosed device housing. ANSI standards require that class 1 laser device housings have safety interlocks wherever the housing can be opened so that the laser within the device will not emit laser light that could injure an end user. The safety interlocks prevent emission of a beam of radiant energy above a minimum standard from leaving the laser or laser system. Service adjustments or maintenance work performed on the optical drive must not render the interlocks inoperative or cause exposure levels outside the housing to exceed the minimum standard unless the work is performed in an approved area with limited access and appropriate safeguards, supervision and control. The protective housing and optical drive must have a fail-safe design so that, if a failure occurs, the system will continue to meet the safety requirements for enclosed laser operations. The use of an optical drive housing within an information handling system housing tends to add to the size and weight of the information handling system. 
     SUMMARY OF THE INVENTION 
     Therefore a need has arisen for a system and method which encloses information handling system component devices and information handling systems in a common housing. 
     In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for enclosing information handling system component devices. At least a portion of a safety enclosure for an information handling system component is formed with a portion of the housing of the information handling system. A lock out device detects removal of the shared housing portion to disable one or more functions of the component. 
     More specifically, an information handling system is built from a plurality of electronic components, such as a CPU, RAM, a hard disk drive and chipset, which cooperate to process information. A component disposed in a housing of the information handling system performs one or more functions that call for a safety enclosure, such as an optical disc drive, which uses a laser to read and write information. A safety enclosure for the component is formed at least in part by a portion of the housing that encloses the information handling system, such as a side wall, a keyboard or a palm rest. A lock out device detects a breach of the safety enclosure, such as removal of the information handling system housing relative to a chassis of the optical disc drive. For example, a Hall effect switch disposed in the optical disc drive chassis detects proximity to a magnet integrated in the information handling system housing portion that forms a portion of the optical disc drive safety enclosure. For example, if a keyboard, palm rest or side wall of the information handling system housing proximate the optical disc drive is removed, movement of the magnet in the housing portion distal from the Hall effect sensor in the optical disc drive chassis causes the Hall effect sensor to command disablement of a laser in the optical disc drive. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that the housing of an information handling system also serves as a safety housing of an internal component so that the weight and size of the internal component is reduced. A lock out device detects removal of the information handling system housing to lock out operation of one or more component functions in response to removal of the information handling system housing. In the case of an optical disc drive, a laser device internal to the optical drive is prevented from operation upon removal of a portion of the information handling system housing that also forms the optical disc drive housing. The information handling system housing forms an ANSI Class 1 Enclosure of the laser device. Combining the optical disc drive housing and information handling system housing reduces the size and weight of the information handling system for improved usability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
         FIG. 1  depicts a block diagram of an information handling system having an internal component with a safety enclosure formed at least in part by portions of the information handling system housing; and 
         FIG. 2  depicts a block diagram of an optical disc drive having a safety enclosure formed at least in part by information handling system housing portions. 
     
    
    
     DETAILED DESCRIPTION 
     Forming a safety enclosure around an information handling system component with at least a portion of the housing of the information handling system limits the need for redundant enclosures of the component. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     Referring now to  FIG. 1 , a block diagram depicts an information handling system  10  having an internal component  12  with a safety enclosure formed at least in part by portions of the information handling system housing  14 . In the example embodiment depicted by  FIG. 1 , internal component  12  is an optical disc drive. Information handling system  10  is built from a plurality of electronic components disposed in information handling system housing  14 , such as a CPU  16  that processes information, RAM  18  that stores information for access by CPU  16 , a hard disk drive  18  that provides permanent storage of information and a chipset  20  that coordinates interaction of the electronic components to process information. Information handling system  10  includes an integrated display  24  that presents information as visible images. A keyboard  26  fits over the top of the electronic components and accepts end user inputs. A palm rest  28  near keyboard  26  provides a resting surface for an end user during typing at keyboard  26 . 
     Optical disc drive  12  has a microcontroller  30  that controls a laser  32  for illumination of an optical disc  34  during information reads and writes. Laser  32  is, for example, an infrared laser that reads and writes to CD optical media, a red laser that reads and writes to DVD optical media or a blue laser that reads and writes to BD optical media. Optical disc drive  12  is an ANSI Class 1 Enclosure that must restrict illumination of laser  32  if an end user is at risk of exposure to the illumination. In order to limit end user exposure to illumination by laser  32 , keyboard  26  and palm rest  28  rest across the upper surface of optical disc drive  12  so that information handling system housing  14  includes keyboard  26  and palm rest  28  and forms at least a portion of the safety enclosure around optical disc drive  12  to protect end users from exposure to illumination by laser  32  during operation of optical disc drive  12 . A lock out device  36  detects the presence of keyboard  26  and palm rest  28  to restrict operation of laser  32  in the event of removal of keyboard  26  and palm rest  28 . If keyboard  26  or palm rest  28  are removed, thus breaching the safety enclosure around optical disc drive  12 , disabling of laser  32  maintains optical disc drive  12  within the requirements for ANSI Class 1 enclosures. In alternative embodiments, information handling system housing  14  forms all or other portions of optical disc drive  12 &#39;s safety enclosure. In other alternative embodiments, other types of components having a variety of functions have a safety enclosure defined by information handling system housing  14 , such as hard disk drives. Lock out device  36  disables one or more of the functions as desired to maintain a desired safety standard. Forming a safety enclosure of an internal component with the information handling system housing  14  reduces weight and footprint by limiting or eliminating the need for a separate housing around the component to form the safety enclosure. 
     Referring now to  FIG. 2 , a block diagram depicts an optical disc drive  12  having a safety enclosure formed at least in part by information handling system housing portions  14 ,  26  and  28 . In the example embodiment depicted by  FIG. 2 , lock out device  36  is built from a Hall effect sensor  38  disposed in optical disc drive  12  and a magnet  40  disposed in portions of information handling system housing  14  that form a safety enclosure about optical disc drive  12 . Hall effect sensor  38  detects the presence of a magnet  40  and provides an enable signal to microcontroller  30  when in proximity to a magnet  40 . When microcontroller  30  has an enable signal, microcontroller  30  allows application of power to laser  32 ; when microcontroller  30  loses the enable signal, microcontroller  30  disables one or more functions of optical disc drive  12 . For example, in the absence of an enable signal, microcontroller  30  disables laser  32  but allows operation of other functions, such as spin at spindle  44 . Disabling laser  32  in the absence of an enable signal from Hall effect sensor  38  ensures that laser  32  will not operate if a safety enclosure formed by information handling system housing  14  is breached. Requiring an enable signal by Hall effect sensor  38  fails optical disc drive  12  to a safe condition in the event of a failure of Hall effect sensor  38 . 
     As depicted in the example embodiment of  FIG. 2 , multiple magnets  40  and Hall effect sensors  38  may be used to monitor the enclosure about optical disc drive  12 . Optical disc drive chassis  42  contains the operational components of optical disc drive  12  within a bottom surface  46  and two side surfaces  48 . A portion of information handling system housing  14  forms another side surface of optical disc drive  12  with a magnet  40  aligned with a Hall effect sensor  38 . Removal of the side portion of information handling system housing  14  to remove magnet  40  from proximity to Hall effect sensor  38  will result in disablement of laser  32 . The upper surface of optical disc drive  12  is formed by keyboard  26  and palm rest  28 , each of which have a magnet  40  proximate a Hall effect sensor  38 . If keyboard  26  or palm rest  28  are removed from their assigned positions over optical disc drive  12 , the loss of the enablement signal from Hall effect sensor  38  causes microcontroller  30  to disable laser  32 . In alternative embodiments, the loss of the enablement signal can cause microcontroller  30  to remove power from other functions of optical disc drive  12 . In one alternative embodiment, magnet  40  is placed in optical disc drive chassis  42  and Hall effect sensors are placed in housing portions  14 ,  26  or  28  to command removal of power to optical disc drive  12  by components within information handling system  10 . Optical disc drive chassis  42  can form a portion of the safety enclosure about optical disc drive  12  or, alternatively, the entire safety enclosure can be formed my information handling system housing  14 . In another alternative embodiment, specific portions of information handling system components form the safety enclosure, such as a keyboard deflection plate that rests underneath the keyboard to provide physical support during use of the keyboard. Alternatively, the safety enclosure is formed by components, such as a PCIMCIA card, an Express card, a hard disk drive, a battery or other components that are proximate the laser drive. In other alternative embodiments, other types of lock out devices  36  may be used, such as a physical switch that is engaged by proximity of housing  14  to optical disc drive  12  or other types of proximity sensors. 
     Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.