Cooling module for portable computer

[0002] This invention relates generally to methods and apparatus for cooling computer devices, and more particularly to cooling portable computer devices.

[0003] This invention addresses the problem of how to achieve cooling for increasingly smaller portable computers having increasingly larger power needs. Providing cooling solutions for increasingly powerful, yet smaller and more portable, computers is a challenge. The difficulties arise from the decreased form factor of portable computers, the more densely packaged environment within the portable computer case, and the need for an increased amount of power to be delivered.

[0004] Advances in technology enable smaller computers to include increasingly more features. Portable computers including notebook computers, sub-notebook computers, palm-top computers and handheld computers are exemplary portable computers which are receiving increasing features. Accompanying this increase in features is an increase in the need for power. Associated with the increased power is an increased generation of heat. Specifically, there is a need to dissipate the heat generated by computing devices so that the computing devices operate safely within optimal temperature limits.

[0005] According to an aspect of the invention, an external cooling module is removably coupled to a portable computer. Heat flows from within the portable computer to the external cooling module where it is dissipated to the external environment.

[0006] In embodiments where the cooling module requires power, the power is provided by either a resident source, the portable computer, or an AC adapter, according to a specific embodiment.

[0007] One aspect of the invention is that the increased cooling ability is achieved when desired (i.e., when the cooling module is attached and operated). Another aspect is that the cooling module is configured in some embodiments with the AC adapter. The AC adapter provides power to both the computer and the cooling module in such embodiment. This allows the computer to have increased cooling ability while it is operated in an increased power mode. Another aspect is that the cooling module in some embodiments provides a resident power source which can serve as a back-up power source for the portable computer.

[0008] Another aspect of this invention is that the cooling module in some embodiments receives power from the portable computer. This allows the operator the flexibility to decide whether to use the cooling module only when in high power mode or also in low power mode. Aspects of the invention will be better understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

[0009] FIG. 1 is a perspective view of a portable computer with an external cooling module;

[0010] FIG. 2 is a functional block diagram of an embodiment of the cooling module;

[0011] FIG. 3 is a block diagram of a general purpose portable computer;

[0012] FIG. 4 is a partial diagram of a heat sink within the portable computer case and a heat pipe of the cooling module forming a thermal interface;

[0013] FIG. 5 is a partial diagram of the heat pipe, heat exchanger and fan of the cooling module;

[0014] FIG. 6 is a partial planar diagram of a power connection between the portable computer and the cooling module;

[0015] FIG. 7 is a partial planar diagram of an alternative power connection between the portable computer and cooling module;

[0016] FIG. 8 is a partial diagram of a cooling module and portable computer, in which the cooling module has a resident power source; and

[0017] FIG. 9 is a partial diagram of a cooling module and portable computer, in which an AC adapter provides a power signal to the cooling module for use by the cooling module alone, or both the cooling module and the portable computer.

[0018] Referring to FIG. 1, a portable computer 10 includes a microcomputer 12 with a display 14 and keyboard 16 housed in a computer case 18 which forms an external surface of the computer 10. An external cooling module 20 plugs into the portable computer to provide a thermal interface 21. Heat generated by the microcomputer 12 and other electrical components housed within the computer case 18 generate heat. The external cooling module 20 receives a portion of the heat through the thermal interface 21. Referring to FIG. 2, the cooling module 20 includes a heat exchanger 22 (e.g., a heat sink) with a large surface area and a fan 24. The fan 24 moves ambient air from the external environment into the cooling module 20 intake vents 26 across the heat exchanger 22. The thermal exchanger 22 receives heat from the portable computer 10 through the thermal interface 21. As the fan 24 moves air across the heat exchanger 22, and the heat received from the portable computer 10 is dissipated, the passing air is warmed. The warmed air continues in motion passing from the cooling module 20 at exit vents 28.

[0019] In various embodiments the portable computer 10 is a notebook computer, sub-notebook computer, palmtop computer, hand-held computer, or another type of mobile or portable computing device. In each embodiment, the portable computer includes a processor and storage (referred to herein as a ‘microcomputer’), a display and an input mechanism. Referring to FIG. 3 an exemplary general purpose portable computer, such as a notebook computer 10 includes a display 14, a keyboard 16, a pointing device 30, a clicking device 32, a processor 34, a hard disk drive with hard disk 36, random access memory 38, and optionally—one or more network interfaces 40 (e.g., modem, ethernet adapter, infrared adapter), one or more transportable storage media drives 42 and media (e.g., CD-ROM drive, DVD-ROM drive, floppy disk drive, zip drive, bernoulli drive). The various components interface and exchange data and commands through one or more busses 44. The portable computer 10 receives information by entry through the keyboard 16, pointing/clicking devices 30/32, the network interface 40, or another input device or input port.

[0020] Referring to FIG. 4, the portable computer 10 also includes a heat sink 50 situated within the computer case 18. Although the heat sink 50 is illustrated in the shape of a bar, in various embodiments the heat sink 50 has a varied shape. Preferably the heat sink is shaped to provide a high capacity efficient heat sink function. The heat sink 50 preferably is positioned adjacent to an edge of the computer case 18. Heat generated by the microcomputer and other electrical components housed within the case 18 is absorbed by the heat sink 50 to keep the electrical components from overheating. In some embodiments the case 18 includes vented openings 52 adjacent to the heat sink allowing heat absorbed by the heat sink 50 to be dissipated to the external environment.

[0021] The case 18 includes a port 54 into which the cooling module 20 detachably connects. Although the port 54 is illustrated in FIG. 1 as being along a side edge of the case 18, in other embodiments, the port is located along the rear edge or another edge of the case 18. The port 54 is situated adjacent to the heat sink 50. In a preferred embodiment the heat sink 50 includes a corresponding opening 56 aligned with the port 54. In some embodiments the cooling module 20 also includes a heat pipe 60. The heat pipe 60 includes a portion 62 which extends arm-like from the cooling module 20. Such portion 62 is inserted into the port 54 to connect the cooling module 20 to the portable computer 10, and more specifically to the heat sink 50.

[0022] The heat pipe 60 extends into the opening 56 of the heat sink 50 to a depth sufficient to define the thermal interface 21 (see FIG. 1) between the cooling module 20 and portable computer 10. Heat is dissipated from the heat sink 50 into the heat pipe 60. In one embodiment the heat pipe 60 includes a thermally conductive fluid which absorbs heat and is moved from an area of high temperature to an area of low temperature. In some embodiments thermal currents cause the movement. In other embodiments the fluid is actively circulated. Whether by passive or active phenomenon, the fluid moves within the heat pipe carrying heat from a hotter region adjacent to the heat sink 50 to a cooler region adjacent to the heat exchanger 22. In various embodiments different heat transfer substances and mediums are used. As shown in FIG. 5, the heat pipe 60 extends substantially through the heat exchanger 22 providing an efficient transfer of heat from the heat pipe 60. Preferably the heat exchanger 22 has a large surface area (e.g. fins) to maximize heat dissipation to the external environment.

[0023] In various embodiments the fan 24 is powered by varying sources. Referring to FIG. 6, in one embodiment, the cooling module 20 includes a power input connector 70. Correspondingly, the computer 10 includes a power output port 72. The power input 70 receives a power signal from the computer 10 through the power output port 72. In an exemplary embodiment, the power output port 72 is located adjacent to the heat interface port 54. When the cooling module 20 is detachably connected to the portable computer 10, such connection is established by the heat pipe 60 and a power input pin 74. In another embodiment (see FIG. 7) a wire connection 75 is implemented allowing the power input 70 and power output port 72 to be situated according to design without regard for the location of the thermal interface 21 (see FIG. 1). Where the computer is capable of providing the power to the cooling module, such power output port 72 alternatively is used for powering other devices, such as a light, external speakers or other electrical and peripheral devices.

[0024] Referring to FIG. 8, in another embodiment the cooling module 20 includes a resident power source 74, e.g., a battery. The battery 74 is replaceable and/or rechargeable, and supplies power to the cooling module 20. In a further variation, the cooling module 20 further includes a power output port 76 which couples to a power input port 78 of the portable computer 10. When the battery 74 is active, and the module power output port 76 is coupled to the computer 10, the battery 74 serves as a back-up power source for the portable computer 10.

[0025] Referring to FIG. 9, in other embodiments the cooling module 20 includes or is coupled to an AC adapter 80 that plugs into a wall outlet to receive AC line voltage. The AC adapter connects to an AC adapter inlet port 82 of the cooling module. The AC adapter 80 converts the signal into a DC signal for use by the fan 24. In a further variation, the AC adapter 80 also powers the portable computer 10. Specifically, the AC adapter 80 plugs into the inlet 82 of the cooling module 20. The cooling module 20 includes a pin 84 which plugs into the AC adapter port 86 of the portable computer 10. The power signal is received from the AC adapter 80 into the cooling module 20 which routes the signal to the fan 24 and to the computer 10, in series or in parallel. In a variation of this, a wire connection provides the power link between the cooling module power outlet pin 84 and the portable computer AC adapter port 86. This allows the power outlet 84 and AC adapter port 86 to be situated according to design with regard for location of the thermal interface 21.

[0026] In another embodiment, portable computer 10 supplies power to by way of a power supply port accessible from the case. Preferably, the port is capable of providing power to a variety of external devices such as a light, an audio speaker, and a cooling module that includes an integral fan, and numerous other external devices.

[0027] One effect of the invention is that the increased cooling ability is achieved when desired (i.e., when the cooling module is attached and operated). Another effect is that the cooling module is configured in some embodiments with the AC adapter. The AC adapter provides power to both the computer and the cooling module in such embodiment. This allows the computer to have increased cooling ability while it is operated in an increased power mode. Another effect is that the cooling module in some embodiments provides a resident power source which can serve as a back-up power source for the portable computer. Another effect is that the cooling module in some embodiments receives power from the portable computer. This allows the operator the flexibility to decide whether to use the cooling module only when in high power mode or also in low power mode.

[0028] To conserve battery life, some processor manufacturers have adopted a high-speed (high power) mode which is in effect while the computer is coupled to an AC power source. When the computer is coupled to a battery source, the processor instead operates in a lower-speed (lower power) mode. Another effect of this invention is that the computer can operate in high power mode while coupled to a battery source, when the cooling module is attached. Another effect of the invention is that in some embodiments the computer is designed to normally run in low power mode. The thermal cooling ability built into the computer is designed to provide cooling at this thermal load. As a result, the computer weighs less as the required heat sink or other cooling mechanism is smaller and lighter in weight. When operating in the high power mode, the operator attaches the external cooling apparatus. This is done while operating on AC power or on a battery source at the operator's discretion.

[0029] Although a preferred embodiment of the invention has been illustrated and described, various alternatives, modifications and equivalents may be used. Therefore, the foregoing description should not be taken as limiting the scope of the inventions which are defined by the appended claims.