Abstract:
A magnetic latching system selectively couples and releases an information handling system housing and lid by moving a magnet associated with one of the housing or lid relative to a ferrous metal in the other of the housing or lid to selectively apply magnetic attraction between the housing and lid. A latch retainer interfaced with the magnetic latching system retains the magnetic latch in a released position until the lid and housing approach a closed position and then allows the magnetic latch to return to a locked position, thus bringing the lid and housing to a securely closed configuration without slamming together due to the magnetic attraction between the magnet and ferrous metal.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates in general to the field of information handling system housings, and more particularly to a system and method for an information handling system articulated magnetic latch. 
         [0003]    2. Description of the Related Art 
         [0004]    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. 
         [0005]    Active information handling system users have migrated from desktop systems to portable systems. Portable information handling systems generally include an integrated display to present visual information and an integrated power supply to power the system while mobile. A typical portable information handling system display integrates a flat panel liquid crystal display (LCD) in a rotationally hinged lid. The lid rotates between an open position providing access to a keyboard and a closed position providing a compact form for improved end user mobility. Generally, the closed lid is held in place by a latch that articulates to release the lid when desired by the end user. When the end user desires to have increased mobility, rotating the lid to a closed position automatically engages the latch to secure the lid in the closed position. Often, engagement of the latch in the closed position is used as an indicator by the system to enter into an ACPI standby state. A portable information handling system that was placed in a standby state by closing the lid often recovers to “on” when the lid is open. For example, opening and closing the lid is tracked with a Hall effect switch that activates power consumption control states through the chipset and BIOS. 
         [0006]    One difficulty faced by information handling system manufacturers is to secure and release a lid and a portable information handling system housing in an aesthetically pleasing yet reliable manner. One common latching system uses “cobra fangs” that extend outward from the lid and align to enter holes in the housing. A latch biased to a locked position articulates to an unlocked position so that the “fangs” engage and disengage a retaining portion within the housing holes. Although effective and reliable, this arrangement is not generally considered aesthetically pleasing. Another system for selectively engaging a lid to a housing uses detent hinges that lock with detents when the lid is in the closed position. Although detent hinges lock and release without the use of an articulating latch, thus offering a more aesthetically pleasing solution, portable information handling systems having larger displays tend to have reliability problems with detent hinges. Another system for selectively engaging a lid to a housing uses a magnet to hold the lid and housing together. However, magnetic latches have a tendency to use magnets that are either too weak or too strong. Weak magnetic latches can result in display damage if the lid opens inadvertently, such as while stored in a carrying case, to allow objects to lodge between the lid and the housing. Overly strong magnetic latches are annoying where they require two hands to separate the lid and housing or where pulling on a lid results in the lifting of the entire system from a resting position. 
       SUMMARY OF THE INVENTION 
       [0007]    Therefore a need has arisen for a system and method which selectively moderates magnetic attraction between an information handling system lid and housing to secure or release the lid and housing. 
         [0008]    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 selectively securing or releasing an information handling system lid and housing. A latch having a magnet portion and opposing ferrous portion disposed in an information handling system lid and housing selectively secures the lid and housing in a closed position with magnetic attraction or releases the lid and housing for rotation to an open position. In the closed position, the magnet and ferrous portions have a locked position of substantial alignment with sufficient proximity to keep the lid and housing together. For movement to the open position, the magnet and ferrous portion are moved relative to each other to reduce the magnetic attraction and allow movement of the lid relative to the housing. 
         [0009]    More specifically, a magnetic latch has a magnet portion and ferrous portion that move relative to each other to selectively generate magnetic attraction for securing or releasing an information handling system lid and housing. The ferrous portion or magnetic portion is moved by user interaction with a user interface, such as movement perpendicular to the rotation of the lid and housing or movement in the direction of the lid and housing. In order to avoid slamming of the lid to the housing during closing of the lid, a latch retainer maintains the magnetic latch in a released position having minimal magnetic attraction until the lid is substantially closed and then allows the magnetic latch to go to the locked position to secure the lid and housing. A retainer coupled to the user interface maintains the user interface in the released position until the lid approaches closure relative to the housing. As the lid substantially closes relative to the housing, a magnet associated with the retainer interacts with a magnet or ferrous portion disposed in the housing to release the retainer and allow the user interface to move to the locked position. Because movement of the magnetic latch to the locked position is delayed until the lid is substantially closed, the force of the magnetic attraction does not operate to slam the lid to the housing. 
         [0010]    The present invention provides a number of important technical advantages. One example of an important technical advantage is that an aesthetically-pleasing and reliable magnetic latch secures an information handling system lid to a housing in a closed position yet moves to an open position with relatively little force. The magnetic latch automatically secures the lid to the housing without excessive force during closing by maintaining the magnetic latch in a released position until the lid is substantially closed. The articulation latch moves either horizontally or vertically to release the lid from the housing to provide a natural end user interaction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    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. 
           [0012]      FIG. 1  depicts an information handling system having a magnetic latch; 
           [0013]      FIG. 2  depicts an information handling system housing and lid in a closed position secured by a magnetic latch in a locked position; 
           [0014]      FIG. 3A  depicts an information handling system housing and lid in a closed position with a magnetic latch in a vertical released position having a magnet portion moved distal the ferrous portion in the direction of rotation of the lid relative to the housing; 
           [0015]      FIG. 3B  depicts an information handling system housing and lid in a closed position with a magnetic latch in a horizontal released position having a magnet portion moved distal the ferrous portion perpendicular to the direction of rotation of the lid relative to the housing; 
           [0016]      FIG. 3C  depicts an information handling system housing and lid in a closed position with a magnetic latch in a vertical released position so that a magnetic portion and release magnet align to bias the lid from the housing; 
           [0017]      FIG. 4A  depicts a magnetic latch having a latch retainer with opposing magnets; and 
           [0018]      FIG. 4B  depicts a magnetic latch having a latch retainer with a magnet and opposing ferrous portion. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    A magnetic latch selectively secures and releases an information handling system housing and lid. 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. 
         [0020]    Referring now to  FIG. 1 , an information handling system  10  having a magnetic latch  12  is depicted. Information handling system  10  has plural processing components that cooperate to process information, such as a CPU  14 , RAM  16 , a hard disk drive  18 , and chipset  20 . Chipset  20  has graphical processing capability to process information for presentation at an LCD panel  22 . LCD panel  22  is integrated in a lid  24  that is rotationally coupled to a housing  26 . Lid  24  rotates as depicted by rotational coupling arrows  28  between the depicted open position and a closed position in which the lid covers the upper face of housing  12 . Magnetic latch  12  includes a portion in lid  24  and a portion in housing  26  that interact to selectively secure lid  24  to housing  26  in the closed position and selectively release lid  24  to rotate relative to housing  26 . 
         [0021]    Referring now to  FIG. 2 , an information handling system housing  26  and lid  24  are depicted in a closed position secured by a magnetic latch  12  in a locked position. Magnetic latch  12  has a magnetic portion  30  disposed in lid  24  and a ferrous portion  32  disposed in housing  26 . A user interface  34  couples to magnetic portion  30  to allow an end user to move magnetic portion  30  relative to ferrous portion  32 . In alternative embodiments, magnetic portion  30  and/or user interface  34  may be disposed in housing  26  and ferrous portion  32  may be disposed in lid  24 . Magnetic portion  30  and ferrous portion  32  have sufficient magnetic attraction so that, when placed in proximity to each other, lid  24  and housing  26  are securely held together. However, the magnetic attraction decreases logarithmically when magnetic portion  30  and ferrous portion  32  are moved relative to each other to have increased distance between each other so that lid  24  and housing  26  are separated from each other with minimal force. The amount of magnetic attraction is selected based upon the desired securing strength of magnetic latch  12 . In one embodiment, the ferrous portion is a magnet so that two magnets are used instead of a single magnet and ferrous portion. A Hall switch detects a closed position of lid  24  to housing  26 , such as to place information handling system  10  in a standby state. 
         [0022]    Referring now to  FIG. 3A , an information handling system housing  26  and lid  24  are depicted in a closed position with a magnetic latch  12  in a vertical released position  38  having a magnet portion  30  moved distal the ferrous portion  32  in the direction of rotation of the lid relative to the housing. Movement of user interface  34  in the sliding direction  40  that is perpendicular to the direction of rotation of lid  24  activates a lever device  42  that lifts magnetic portion  30  away from ferrous portion  32 , thus reducing the magnetic attraction securing lid  24  and housing  26 . As an alternative, user interface  34  may move in the direction of rotation of lid  24  so that end user inputs to lift user interface  34  also work to separate lid  24  from housing  26 . 
         [0023]    Referring now to  FIG. 3B , an information handling system housing  26  and lid  24  are depicted in a closed position with a magnetic latch  12  in a horizontal released position  44  having a magnet portion  30  moved distal the ferrous portion  32  perpendicular to the direction of rotation of the lid relative to the housing. In order to manage the amount of force needed to slide user interface  34 , materials of varying degrees of friction may be used along the path followed by magnetic portion  30 . The amount of horizontal offset may vary based upon the degree of separation needed to sufficiently reduce the attraction between lid  24  and housing  26  for the desired resistance to the opening of lid  24  by an end user. As is depicted in  FIG. 3C , in addition to moving the magnetic portion  30  and ferrous portion  32  to obtain horizontal offset  44 , user interface  34  might also align magnetic portion  30  with a release magnet  58  to obtain vertical release alignment  60 . Release magnet  58  has a pole that is opposite the pole of magnet portion  30  so that the opposing poles repel each other. The repelling force provided by the opposing poles biases lid  24  away from housing  26  so that the lid rotates more easily from the closed to the open position. 
         [0024]    Referring now to  FIG. 4A , a magnetic latch  12  having a latch retainer  46  with opposing magnets  48  is depicted. User interface  34  has an arm  50  that terminates with a retaining hook  52 . A retaining point  54  is disposed in the lid along a path followed by retaining hook  52  when user interface  34  is slid to a released position in which ferrous portion  32  and magnetic portion  30  are misaligned to reduce their magnetic attraction. Movement of user interface  34  to a release position engages retaining hook  52  at retaining point  54  so that user interface  34  remains in the released position as lid  24  rotates away from housing  26 . With user interface  34  in the released position, magnet portion  30  and ferrous portion  32  are misaligned so that magnetic attraction pulling lid  24  and housing  26  together is minimized. The reduced magnetic attraction prevents lid  24  and housing  26  from slamming shut as lid  24  is rotated to a closed position. However, when lid  24  reaches a predetermined closure, such as a substantially closed position where the remaining movement to full closure is too small to build adequate strength to slam shut, opposing poles of latch retainer magnets  48  forces arm  50  upwards to release retaining hook  52  from retaining point  54 . Once freed from engagement of retaining hook  52 , user interface  34  is biased towards a locked position by the proximity of magnetic portion  30  to ferrous portion  32 . In the locked position, the magnetic attraction of magnetic portion  30  to ferrous portion  32  brings lid  24  and housing  26  together securely. Since the locked position was delayed until lid  24  was substantially closed, lid  24  and housing  26  do not have sufficient room to slam shut. 
         [0025]    Referring now to  FIG. 4B , a magnetic latch  12  having a latch retainer  46  with a magnet  48  and opposing ferrous portion  56  is depicted. In the embodiment depicted by  FIG. 4B , latch retainer  46  activates by the interaction of a magnet  48  and ferrous potion  56  that are attracted towards each other as lid  24  approaches a substantially closed position, such as predetermined distance at which lid  24  and housing  26  will not slam together when magnet portion  30  and ferrous portion  32  move into alignment. As lid  24  approaches housing  26 , magnet  48  is pulled toward ferrous portion  56  to release retaining hook  52  from retaining point  54 . Release of retaining hook  52  allows user interface  34  to bias to a locked position so that magnet portion  30  and ferrous portion  32  secure lid  24  to housing  26 . 
         [0026]    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.