Abstract:
A portable computer system has heat transfer mechanisms incorporated therein for transfer of heat to a docking station with active cooling capacity. A portable computer case has openings placed in alignment with mating openings in the docking station to provide additional active cooling capacity. The portable computer system case also has further openings and a defined air flow path to enhance airflow across a processor to cool it more effectively. A fan in the docking station pulls or pushes air from or into the portable computer system case. The mating openings and further openings in the computer system case are positioned to optimize the cooling effectiveness of the air flow with respect to the processor and other heat producing components. Other devices such as refrigeration coils, heat slugs, and heat pipes are also described. A switch detects when the portable computer is connected to the docking station and causes deactivation of processor slowing power management routines.

Description:
RELATED APPLICATION 
     This application is a continuation under 37 CFR 1.53(b) of U.S. application Ser. No. 09/212,614, filed Dec. 16, 1998 is now U.S. Pat. No. 6,453,378, which application is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to portable computer systems, and in particular to the management of performance and power consumption in a portable computer. 
     BACKGROUND OF THE INVENTION 
     Portable computer systems have always lagged their desktop counterpart personal computers in speed and overall performance due to the limited power available in current batteries. Because the latest and fastest computer components, such as processors consume more power and generate more heat than lower speed components, they are not normally used in portable computer systems such as laptop computers. The use of high speed central processing units (CPUs) requires higher clock speed and higher voltages than current CPUs used for portable computer systems because the higher clock speed and higher operating voltage results in more power being consumed and thus heat being generated. The cooling of such components requires greater power, or larger heat sinks, which is readily available in larger desktop type computer systems. 
     Due to space constraints, thermal considerations and limited battery life, some portable computers employ various power management methods to reduce generation of heat while operating on battery power such that fans are not activated. Such methods include the reduction of the speed of the processor. When AC power is provided, the processor may run at higher speed and/or higher voltage, however, the cooling capability may not be sufficient to properly cool a portable computer using the current fastest processors and other components. Either there is not sufficient room for a large enough heat sink for the processor, or a large enough fan would consume so much power that the battery would not last long enough to meet current user expectations. 
     There is a need for a portable computer which can utilize the faster processors that generate more heat than can currently be dissipated by portable computers. There is a further need to operate such processors at higher speed at selected times. There is yet a further need to provide such abilities without using larger heat sinks or other solutions that would increase the size and or weight of such portable computers. 
     SUMMARY OF THE INVENTION 
     A portable computer receives additional cooling capabilities from an external docking station. The portable computer detects such cooling capacity and modifies its performance. In one embodiment, the portable computer system has a case with openings placed in alignment with mating openings in a docking station which provides additional active cooling capacity. The portable computer system case also has further openings and a defined air flow path to enhance airflow across a processor to cool it more effectively. 
     In one embodiment, the active cooling provided by the docking station is a fan, or other device which pulls or pushes air from or into the portable computer system case. The mating openings and further openings in the computer system case are positioned to optimize the cooling effectiveness of the air flow with respect to the processor and other heat producing components. Further active cooling apparatus include a compressor coupled to refrigeration coils positioned beneath the portable computer, and other devices which provide active cooling such as by refrigeration or sound and diaphragm combinations. Still further embodiments utilize heat pipes positioned proximate the processor of the portable computer and functioning to transfer heat to the docking station where active heat transfer is provided. Yet further embodiments utilize extruded aluminum slugs to transfer heat from the bottom of the portable computer to the active cooling mechanism provided in the docking station. 
     In one embodiment, power management functions of the computer system are alerted that the portable computer has been docked with the docking station. Once alerted, the power management functions allow the processor to operate at higher speed, relying on the extra cooling capacity provided by the docking station to properly cool the processor. In a further embodiment, the power management functions simply rely on temperature sensing to control the processor speed. 
     The extra cooling capacity provided by the docking station then allows the processor to run indefinitely at higher speed. The extra cooling capacity may also provide the ability to utilize faster, more expensive processors which generate more heat without sacrificing the power of the processor when docked. It further enhances the ability to obtain desktop performance from a docked portable computer, while retaining the ability to slow the CPU speed, and/or operating voltage to obtain longer battery life when undocked. 
    
    
     DESCRIPTION OF THE FIGURES 
     FIG. 1 is a cut away perspective of a portable computer docked with a docking station. 
     FIG. 2 is a rear perspective representation of the portable computer of FIG.  1 . 
     FIG. 3 is a front perspective representation of the docking station of FIG.  1 . 
     FIG. 4 is a rear perspective representation of an alternative embodiment of the portable computer of FIG.  1 . 
     FIG. 5 is a rear perspective representation of an alternative embodiment of the docking station for mating with the alternative embodiment of the portable computer of FIG.  4 . 
     FIG. 6 is rear perspective representation of an embodiment of the portable computer of FIG.  1 . 
     FIG. 7 is a flow chart of power management performed by a portable computer. 
     FIG. 8 is a front perspective cutaway representation of an alternative docking station for mating with a portable computer. 
     FIG. 9 is a side cross sectional cut away block representation of a combined docking station and portable computer showing a further embodiment of the present invention. 
     FIG. 10 is a side cross sectional cut away block representation of a combined docking station and portable computer showing a yet a further alternative embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims. 
     A portable computer system is indicated generally at  110  coupled to a docking station  112 . The portable computer system has a display device  114  (indicated in broken line form) rotatably coupled to one end of a portable computer system case  116 . In one embodiment, the portable computer system  110  is a Gateway 2000, Inc Solo® having a keyboard  118 , a touchpad  120 , speakers  122  and  124  and other commonly provided accessibly computer peripheral and connectors. The case  116  is shown in cutaway form to expose a processor  130 . In one embodiment, the processor  130  as a heat sink  132  mounted thereon with fins  134  to help dissipate heat when cooling is effected in both a passive mode, or an active mode. Thus, the need for a fan located within the computer system case  116  is either eliminated, or a smaller fan may be employed as desired. 
     The processor  130  is mounted in the case  116  proximate a plurality of mating openings  140 . The mating openings  140  mate with counterpart openings in a case of the docking station  112  which contains a fan  150  mounted therein for drawing or moving air from the computer system case  116  through mating openings  140  to help cool the processor  130 . The docking station  112  also contains a power supply for providing additional power to allow the portable computer system  110  to operate at higher voltages and/or amperages. 
     Air intake openings  155  are indicated in the top of case  116  and positioned to one side of the processor  130 . Air is drawn in through intake openings  155  as represented by lines  156 . The air is then drawn through the fins  134  of heat sink  132  as represented by line  157  and out through the mating openings  140 , through the docking station as represented by lines  158  and out of the docking station past the fan  150  as indicated by lines  159 . 
     Processor  130  in the past has been mounted on an aluminum backing plate for keyboard  118 , which acts as a heat sink. In the present invention, the processor is mounted in such a manner as to enable outside air to be drawn past it and then into the docking station through the mating openings  140 . While shown in the embodiment of FIG. 1 as residing near the back of the case, proximate the docking station, and between the air intake openings  155  and mating openings  140 , it will be recognized that it could be positioned otherwise within the portable computer case  116  while still obtaining the same cooling effects, provided that the air intake and mating openings are also repositioned proximate the processor, or in a position to help create a well defined airflow past the processor heat sink. 
     Further air intake openings are optionally provided on a front edge of the computer case as indicated at  170  for drawing in air as represented by lines  172 . Air intake openings may be positioned wherever desired, resulting in airflow operating to cool other components which generate undesired heat, as represented by airflow line  174 . 
     In FIG. 2, a rear elevation view of portable computer  110  is shown with a first set of mating openings  210  and second set of mating openings  212  located on either side of a docking electrical connector  214  which comprises a PCI bus in one embodiment, but may also be infrared or other electromagnetic communication device. A separate switch  216  is also located in a position on the rear of the portable computer to come into contact with a corresponding switch contact  316  shown in FIG. 3 on the docking station  112 . These switches are well known in the art, and may take many different forms, from mechanically actuated to electrically actuated. The switch  216  is coupled in a known manner to provide an indication to power management software running on processor  130  that the portable computer is docked, and receiving additional cooling capacity. The switch or contact  316  is coupled to the docking station power supply and may be used to automatically initiate the provision of AC power and turn on fan  150  to provide cooling. It may also just be a plastic projection that actuates switch  216  to indicate that the docking station has been successfully coupled to the portable computer. 
     A front view of docking station  112  in FIG. 3 also comprises mating openings  310  formed in the docking station case which mate with openings  210  on the computer case  116 , and also comprises openings  312  which mate with openings  212 . A further plurality of openings  320  are provided proximate the fan  150  to provide for the exit of air drawn in from the portable computer. Further, a female connector  314  mates with a male connector  214  on the computer case to provide communications between the computer and the docking station. Docking station  112  further comprises a switch  316  to indicate successful coupling to the portable computer. Many docking stations or docking bars provide AC power and further peripheral devices such as disk drives and network cards, all as represented by docking station  112 . 
     FIG. 4 shows a portable computer  410  having an alternative positioning of mating openings indicated at  412  and  414 . Openings  412  comprise circular holes formed in the case, either as the case is molded, or after the case is formed the openings are formed as by drilling. Further openings  414  are oval or elongated circles as shown to provide for even greater airflow. Openings  414  and  412  are located near the bottom of the back side of the computer case. Since the processor is also located near the bottom of the computer case, more air is likely to be directed through the fins of the heat sink, providing even better cooling. While these openings are shown off to one side of the case, they could be located anywhere along the back side of the case depending on the placement of the processor and the air intake holes. Both of these sets of openings are designed to mate with similar openings shown at  514  and  516  of and alternative docking station indicated at  512  in FIG.  5 . Further, larger, elongated openings are shown at  520  for the exhaustion of air from the docking station  512 . It should be noted that the types of openings may easily be modified by one of average skill in the art to many different shapes to obtain desired airflow characteristics. With the openings located toward one side of the computer as shown in FIG. 4, the placement of the air intake openings and the processor heat sink will also need to modified. In one embodiment, the fins of the heat sink may be placed so that the run from the front to the back of the computer, at right angles from that shown in FIG.  1 . The fins could also be placed to encourage direct airflow between the intake and exhaust (mating) openings. In this case, the fins may be placed at any angle relative to the case of the computer. The placement of openings and the processor may be dictated by the need to place many components inside of a limited space case. Thus, the freedom to modify the angle or orientation of the fins provides more design freedom in locating such other components while still maintain the advantages provided by the present invention. 
     FIG. 6 represents yet a further embodiment of the invention wherein air intake openings  612  are provided on a side of a computer case  610 . This placement of intake openings provides more freedom in the use of the portable computer when docked. Many times, a display  414  of the portable computer does not have the quality and ease of viewing associated with large screen CRT displays which are often provided by with docking stations. In the event that such a CRT display is being used, the display  414  of the portable may be in a locked down position, which could block the flow of air in through intake openings  155  in FIG.  1 . Providing air intake openings  612  on the side of the computer case  610  reduces such a problem. It may also allow for more air to flow evenly across the fins of the heat sink, since the air will be following more of a straight path from the side rather than from the top. 
     As mentioned above, present power management systems of portable computers slow down the processor to avoid excess generation of heat by the processor which cannot be effectively dissipated. An improved power management system is represented by the flowchart represented in FIG.  7 . The flowchart is representative of code modules or a module running on the processor  130 , or other electronic device or machine as desired, and may be hardcoded, hardwired, or written in software and stored on machine readable media such as RAM, CDROM, or disk drive to name but a few. It may also be received via network and run directly from the network. The flowchart is entered at  710  upon power up of the portable computer. At  712 , the normal power management functions are run, which result in processor speeds being cut and hence performance reduced. At decision block  714 , an interrupt resulting from the docking switch  216  being triggered indicates that docking as been detected. In one embodiment, the docking switch is sensitive to only a docking station which provides additional cooling functionality. If no docking has been detected, the normal standalone power management is continued. However, if docking is detected, the power management system runs the processor at higher speed or cycle time at  720  relying of sufficient cooling being provided by the docking station or docking bar. If undocking is detected at  730 , again as indicated by the switch  216 , standalone power management is reentered at  712 . In further embodiments, the power management systems also decrease the operating voltage with decreases in operating speed. This further decreases the power consumed in power conservation modes. 
     In FIG. 8, a further alternative embodiment of a docking station  810  provides active cooling by means of refrigerative cooling. In a cutaway portion of a base support  812  of the docking station  810  corresponding to where a portable computer would rest when engaged with the docking station, a cooling coil is shown at  814 . The cooling coil may be filled with any type of fluid, such as water or gas, or common refrigerant to provide cooling for the portable computer. A compressor is shown at  816  which is coupled to the coil  814  in a common manner. The compressor  816  may be a common compressor used in refrigeration systems, or may be just a fan which provides cooling of the portion of the coil  814  proximate to it. 
     In FIG. 9, yet a further alternative embodiment shows how active cooling of a portable computer  912  is provided by a docking station  910 . The portable computer  912  comprises two cooling blocks  914  and  916  which may be heat sinks coupled to one or more processors or other heat producing elements within the portable computer. Cooling blocks  914  and  916  are coupled through heat transfer pads  920  and  922  to a heat transfer rod  926  with corresponding projections  928  and  930  contacting the heat transfer pads  920  and  922 . The pads may reside on the bottom of the portable computer, or on a docking station base  932 , placed to contact the blocks  914  and  916  when the computer is operatively coupled to the docking station  910 . Heat transfer rod  926  comprises an extruded aluminum slug in one embodiment, but could be made of any other material having desired heat transfer characteristics. The heat transfer rod  926  is then formed in the shape of fins  934  spaced a suitable distance from the portable computer. The fins are then actively cooled by fan or other cooling device  936 . 
     In a still further alternative embodiment shown in FIG. 10, a docking station  1010  provides active cooling for a portable computer  1012  by the use of heat pipes. A central processing unit CPU  1014  is located in the portable computer thermally coupled proximate a first heat pipe  1016 . The first heat pipe is coupled via an aluminum collar  1018  mounted on the docking station  1010  to second heat pipe  1020  which may be fanned out into cooling fins at  1022  for cooling by an active cooling mechanism such as a fan  1026  positioned proximate the heat pipe within the docking station. In a variation, the heat pipe  1016  is coupled to a heat sink or other heat transfer mechanism in the docking station in place of the heat pipe and actively cooled by any of the previous methods described. 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. For instance, the location of mating holes or openings along with the placement of the processor and the placement or orientation of the heat sink on the processor may be modified as desired or needed due to design constraints. Further, temperature sensors may be used to determine the speed at which the processor runs as opposed to the use of switches or other means. Further, the switches may be incorporated into the electrical connector, or simply be coupled to one of the connectors to determine if the impedance or other detectable characteristic of the connector has changed, indicating that the portable computer is coupled to a docking station or other type of device which provides both more power and active cooling capabilities. Moreover, the air flow may be modified such that the docking station moves air into the portable computer as opposed to only drawing air from it. The docking station also provides a common power supply, which when combined with the increased cooling abilities enables the computer to operate at higher voltages and/or amperages, which can increase the performance of the computer system. While a docking station is described, it should be clear that other types of devices that provide cooling may also be used although not normally referred to as a docking station. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.