Abstract:
A computer system is described having additional cooling capabilities in a docking station for a mobile computer. The docking station includes P- and N-doped semiconductor thermoelectric components. The thermoelectric components are connected in series when the mobile computer engages with the docking station. A current flowing through a doped semiconductor causes heat to be transferred either in a direction of a current through the semiconductor component or in a direction opposite to a current in the thermoelectric components, depending on their doping. The thermoelectric components alternate from being P-doped to N-doped and the direction in which current flows alternates accordingly so that heat is transferred in one direction only. A heat pumping effect is created by the thermoelectric components which does not require high-pressure contact upon engagement of the mobile computer with the docking station.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a computer system and its cooling. 
     2. Discussion of Related Art 
     A mobile computer such as a laptop computer or a notebook computer is often cooled with a computer fan located therein. The computer fan is driven from a battery of the mobile computer and only provides a limited amount of cooling for a processor of the mobile computer. 
     The mobile computer can usually be engaged with a port replicator such as a docking station. Cables are connected to the docking station which provide large amounts of electric power to the docking station. The additional power of the docking station is generally only used for reloading the battery of the mobile computer and for powering of the mobile computer while engaged with the docking station. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is further described by way of example with reference to the accompanying drawings wherein: 
     FIG. 1 is a perspective view of a computer system according to an embodiment of the invention; 
     FIG. 2 is a cross-sectional side view of the computer system shown in FIG. 1; 
     FIG. 3 is a view similar to FIG. 2 after a mobile computer of the computer system is engaged with a docking station of the computer system; 
     FIG. 4 is a cross-sectional side view of a computer system according to another embodiment of the invention; and 
     FIG. 5 is a cross-sectional side view of a computer system according to a further embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 of the accompanying drawings illustrates a computer system  10  according to an embodiment of the invention including a mobile computer  12  and a port replicator in the form of a docking station  14 . 
     Referring to FIG. 1, the mobile computer  12  includes a mobile computer housing  16 , a screen  18 , alphanumeric keys  20 , and a track pad  22 . The screen  18  is mounted to the mobile computer housing  16  by a hinge  24 . The screen  18  is shown in an upright position wherein a person located in front of the mobile computer housing  16  can view a display on the screen  18 . The screen  18  can also be folded down onto the mobile computer housing  16  into a compact arrangement allowing for transportability of the mobile computer  12 . 
     The alphanumeric keys  20  extend out of an upper surface of the mobile computer housing  16  and the track pad  22  is mounted to the mobile computer housing  16  in a position closer to the user than the alphanumeric keys  20 . The mobile computer housing  16  has surfaces  26  on which a user can locate his or her wrists. The user can move a finger across the track pad  22  to control a cursor on the display  18 . The user can also depress on the alphanumeric keys  20  to generate text on the display  18  or otherwise control operation of the mobile computer  12 . The components of the mobile computer  12  thus for described are of course conventional and are not further elaborated on herein. 
     Referring to FIG. 2, the mobile computer  12  further includes a logic board  30 , a logic processor  32 , and a computer heat dissipation arrangement  34 . 
     A logic board  30  is mounted on an internal surface of the mobile computer housing  16 . The processor  32  is mounted to the logic board  30 . Heat is generated by the processor  32  when being operated and it is required to cool the processor  32  in order to maintain its functional integrity. 
     The computer heat dissipation arrangement  34  includes a heat plate  36 , a heat pipe  38 , a cold plate  40 , a computer heat sink  42 , a computer fan  44 , a cold thermoelectric plate  46 , and a first set of metal electric links  48 . 
     The heat plate  36  is located against the processor  32  so that heat generated by the pipe processor  32  is transferred to the heat plate  36 . One end of the heat pipe  38  is attached to the heat plate  36 . 
     The cold thermoelectric plate  46  is mounted in an opening in a lower surface of the mobile computer housing  16 . An upper surface of the cold thermoelectric plate  46  faces into an internal volume in the mobile computer housing  16  and a lower surface of the cold thermoelectric plate  46  faces out of the mobile computer housing  16 . The cold plate  40  is mounted on the cold thermoelectric plate  46  and is thermally connected thereto. 
     An end of the heat pipe  38  opposing the end connected to the heat plate  36  is attached to the cold plate  40 . The heat pipe  36  has a wicking layer on an internal surface thereof. A fluid in the heat pipe  38  condenses on the wicking layer when it is cooled and evaporates from the wicking layer when it is heated. Should the cold plate  40  be cooled, and the heat plate  36  be heated, the fluid will evaporate from the wicking layer in the vicinity of the heat plate  36 . The vaporized fluid will then flow through the heat pipe  38  to the cold plate  40  where the fluid will then be cooled by the cold plate  40  and condense on the wicking layer. The condensed fluid will then flow back through the wicking layer to the heat plate  36 . 
     The computer heat sink  42  includes a spreader plate  50  and fins  52  extending from the spreader plate  50 . The spreader plate  50  is located against the cold plate  40  and is thermally connected thereto. A computer fan  44  is mounted in a position over the fins  52  so that rotation of the computer fan  44  causes movement of air to move over the fins  52 . 
     The electric links  48  are all secured to a lower surface of the cold thermoelectric plate  46 . The cold thermoelectric plate  46  is made of a material such as aluminum oxide which is thermally conductive and electrically insulating. Because the cold thermoelectric plate  46  is thermally conductive, heat can be transferred from the cold plate  40  through the cold thermoelectric plate  46  to the electric links  48 . The processor is thus thermally coupled to the cold thermoelectric plate  46 . 
     The docking station  14  includes a port station engager in the form of a docking station engager  60  and a docking station heat dissipation arrangement  62 . The docking station heat dissipation arrangement  62  includes a hot thermoelectric plate  64 , a second set of metal electric links  66 , a plurality of thermoelectric components  68  made of a semiconductor material, a docking station heat sink  70 , and a docking station fan  72 . 
     The hot thermoelectric plate  64  is made of the same material as the cold thermoelectric plate  46  and is mounted to the docking station engager  60  in an opening of the docking station engager  60 . An upper surface of the hot thermoelectric plate  64  faces upwardly out of the docking station engager  60  and a lower surface of the hot thermoelectric plate  64  faces down into an internal space of the docking station engager  60 . 
     The metal electric links  66  are mounted to an upper surface of the hot thermoelectric plate  64 . The thermoelectric components  68  are secured to upper surfaces of the metal electric links  66 . Each metal electric link  66  has two of the thermoelectric components  68  mounted thereto. The respective metal electric link  68  thereby electrically connects two of the thermoelectric components  68  to one another. Two of the thermoelectric components  68  in a pair are thus electrically connected to one another through one of the metal electric links  66 . Respective pairs of the thermoelectric components  68  are electrically disconnected from one another. 
     The docking station heat sink  70  includes a spreader plate  74  and fins  76  extending from the spreader plate  74 . The spreader plate  74  is mounted to a lower surface of the hot thermoelectric plate  64 . The fins  76  extend down away from the spreader plate  74 . The docking station fan  72  is mounted to the docking station engager  60  in a position wherein air is blown by the docking station fan  72  over the fins  76 . 
     Referring again to FIG. 1, the mobile computer housing  16  has a substantially rectangular outer periphery  80  when viewed from above. The docking station engager  60  has a recessed shape with a substantially rectangular inner periphery  82 . The inner periphery  82  of the docking station engager  60  is complementary to the outer periphery  80  of the mobile computer housing  16 . The mobile computer housing  16  can be engaged with the docking station engager  60  by inserting the mobile computer housing  16  into the inner periphery  82 . Because of the complementary shapes of the inner periphery  82  and the outer periphery  80 , alignment between the mobile computer housing  16  and the docking station engager  60  is provided. Other engagement mechanisms are possible. 
     The docking station heat dissipation arrangement  62  is located within the inner periphery  82 . The docking station  14  also includes other components that are conventional, including a docking port  84  and cables  86  connected to the docking port  84 . The docking port  84  engages with a complementary docking port on the mobile computer housing  16  when the mobile computer housing  16  is moved from a position as shown in FIG. 1 into a position wherein the mobile computer housing  16  engages with the docking station engager  60 . Signals can be provided between the cables  86  and the mobile computer  12  through the docking port  84  and the docking port on the mobile computer housing  16 . Peripheral devices such as a mouse, a disk drive etc. may be connected to the docking station engager  60 . A port replicator alone generally does not have such peripheral devices. Power can also be provided through the cables  86  through the docking port  84  to the mobile computer  12 . It should also be noted that power is provided through the cables  86  to a power lead  88  secured to the docking station engager  60  and that a ground lead  90  secured to the docking station engager  60  is connected to one of the cables  86 . The power lead  88  is connected to one of the metal electric links  66  and the ground lead  90  is connected to another one of the metal electric links  66 . 
     In use, the mobile computer  12  is engaged with the docking station  14  by inserting the mobile computer housing  16  into the inner periphery  82 . Engagement of the mobile computer  10  with the docking station  14  moves the components of the mobile computer from the position shown in FIG. 2 into the position shown in FIG.  3 . Each one of the thermoelectric components  68  is then in contact with one of the metal electric links  48 . As previously mentioned, respective pairs of the thermoelectric components  68  are connected to each respective metal electric link  66 . The metal electric links  48  now connect one thermoelectric link  68  of one pair with one thermoelectric link  68  of another pair. All the thermoelectric components  68  are then connected in series. An electric voltage and current is provided through the power lead  88  to a first of the thermoelectric components  68 . Current flows through that thermoelectric component in a direction from one of the metal electric links  66  to one of the metal electric links  48 . Current then flows through the metal thermoelectric link  48  to another one of the thermoelectric components  68 . The current then flows through that thermoelectric component  68  in a direction from the metal electric link  48  to another one of the metal electric links  66 . The current thus flows in a direction from the hot thermoelectric plate  64  to the cold thermoelectric plate  46  through odd ones of the thermoelectric components  68  located in series and in a direction from the cold thermoelectric plate  46  to the hot thermoelectric plate  64  through even ones of the thermoelectric components  68  located in series. 
     Odd ones of the thermoelectric components  68  located in series are P-doped and even ones of the thermoelectric components  68  located in series are N-doped. Heat is transferred through the N-doped thermoelectric components  68  in a direction in which current flows therethrough and heat is transferred through the P-doped thermoelectric components in a direction opposite to the direction in which current flows therethrough. Heat is thus transferred through both the odd and even thermoelectric components  68  in a direction from the metal electric links  48  to the metal electric links  66  all located thermally in parallel. The metal electric links  48  are thermally connected to the cold thermoelectric plate  46  and the metal electric links  66  are thermally connected to the hot thermoelectric plate  64 . A current through the thermoelectric components  68  thus causes heat to be transferred from the cold thermoelectric plate  46  to the hot thermoelectric plate  64 . 
     Proper heat transfer between a hot and a cold component generally requires high-pressure contact between the two components. High-pressure contact is however not required between the thermoelectric components  64  and the metal electric links  48  because of an active heat pumping effect created when current flows through the thermoelectric components  68 . 
     Heat is transferred from the logic processor  32  to the cold plate  40  and from the cold plate  40  to the heat pipe  38 . The fluid within the heat pipe  38  evaporates and flows to the heat plate  36 . Heat is transferred from the heat plate  36  to the cold thermoelectric plate  46 , causing the fluid within the heat pipe  38  to condense and flow back to the cold plate  40  for recirculation. The heat is then transferred from the cold thermoelectric plate  46  to the hot thermoelectric plate  64  as discussed. The heat then transfers from the hot thermoelectric plate  64  through the spreader plate  74  to the fins  76 . The heat is then convected from the fins  76  to atmosphere. Rotation of the fan  72  blows air over the fins  76  to accelerate transfer of heat from the fins  76  to atmosphere. 
     More heat is transferred from the cold plate  40  to the spreader plate  50  and from the spreader plate  50  to the fins  52 . The heat is then convected from the fins  52  to atmosphere. Rotation of the fan  44  causes air to blow over the fins  52  thus accelerating transfer of heat from the fins  52  to atmosphere. 
     It can thus be seen that additional cooling capability is provided by the docking station  14 . More electric power is available at the docking station  14  through the cables  86  for provision to the power lead  88 . Because of the additional power available at the docking station  14 , the thermoelectric components  68  can easily be powered. 
     When the mobile computer  12  is disengaged from the docking station  14 , the logic processor  32  can still be cooled with the computer heat dissipation arrangement  34  alone. The fan  44  is powered from a battery supply of the mobile computer  12 . The additional cooling capability of the docking station heat dissipation arrangement  62  however allows for more power to be provided to the processor  32  when the mobile computer  12  is engaged with the docking station  14  without danger of overheating of the processor  32 . 
     FIG. 4 illustrates a computer system  10 A according to another embodiment of the invention. The system  10 A is similar to the system  10  of FIG.  2  and like reference numerals indicate like or similar components. No heat sink is attached to the cold plate  40  of the system  10 A. Instead, a separate cooling system  100  is provided for cooling the processor  32  when not engaged with or engaged with the docking station  14 . The cooling system includes a heat pipe  102 , a cold plate  104 , a heat sink  106 , and a fan  108 . The cold plate is secured to the mobile computer housing  16 . The heat pipe  102  has one end structurally secured to an thereby thermally connected to the heat plate  36 . Heat transfers through the heat pipe  102  to the cold plate  104 . The heat sink  106  is secured to the cold plate  106  and the fan  108  blows air over fins of the heat sink  106 . The heat conducts from the cold plate  104  to fins of the heat sink  106  and the fan  108  blows air over the fins of the heat sink  106 . 
     FIG. 5 illustrates a computer system  10 B according to a further embodiment of the invention which is similar to the systems  10  and  10 A, like reference numerals indicating like components. A processor  32  is mounted to a circuit board  30  and the processor is located directly against a cold plate  40 . Heat conducts directly from the processor  32  to the cold plate from where it is transferred to a cold thermoelectric plate  46 . An additional cooling arrangement  200  is provided for cooling of the processor when the mobile computer  12  is engaged with or disengaged from the docking station  14 . The cooling arrangement includes a heat pipe  202 , a cold plate  204 , a heat sink  206  and a fan  208 . The heat pipe  202  has one end structurally and thermally connected to the cold plate  40  and an opposing end structurally and thermally connected to the cold plate  204 . Heat conducts from the cold plate  40  to the heat pipe  202  and from the heat pipe  202  to the cold plate  204 . The heat then conducts from the cold plate  204  to fins of the heat sink  206 . The fan  208  blows air over fins of the heat sink  206  to accelerate cooling. 
     While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described since modifications may occur to those ordinarily skilled in the art. A port replicator other than a docking station may for example be used in a similar manner.