Thermal management of a mobile device with ventless housing

• US 8,595,517 B2
• Filed: 09/01/2010
• Issued: 11/26/2013
• Est. Priority Date: 09/01/2010
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Riechel, Patrick S., Austin, Timothy B., Wulff, Thomas E.
• Primary Examiner(s): WANG, ALBERT C
• Application Number:
  US12/873,541
• Publication Number:
  US 20120049933A1
• Time in Patent Office: 1,182 Days
• Field of Search: 702/132, 361/714, 361/718, 361/679.54, 361/679.56, 713/300
• US Class Current: 713/300
• CPC Class Codes: G06F 1/206 comprising thermal management
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A mobile device includes a housing having a plurality of surfaces. A processor is located within the housing. The processor heats a portion of one or more of the surfaces of the housing. A temperature sensor detects a temperature of the portion of the surface. The rate of energy consumption by the processor is adjusted based on the temperature of the portion of the surface of the housing.

Claims

1. A mobile device comprising:

a housing having a plurality of surfaces, the housing being fabricated without vent holes;

a processor located within the housing, a portion of at least one of the plurality of surfaces of the housing conducting heat away from the processor, wherein the portion corresponds to an area of the at least one surface having the highest temperature;

a first temperature sensor thermally coupled to the processor for detecting a temperature of the processor;

a battery located within the housing and electrically coupled to the processor;

a second temperature sensor thermally coupled to the battery for detecting a temperature of the battery; and

a third temperature sensor thermally coupled to the portion, the third temperature sensor detecting a temperature of the portion, the rate of energy consumption by the processor being adjusted based on the temperatures of the processor, the battery and the portion.

2. The mobile device of claim 1 wherein the rate of energy consumption by the processor is adjusted by modifying at least one of a duty cycle of the processor, a clock speed of the processor and a voltage supplied to the processor.

3. The mobile device of claim 1 further comprising a control loop for continually adjusting the rate of energy consumption by the processor based on a thermal characterization of the mobile device.

4. The mobile device of claim 1 wherein at least one of the plurality of surfaces is thermally conductive.

5. The mobile device of claim 4 wherein the thermally conductive surface conducts heat from the processor.

6. A method comprising:

positioning a processor within a housing of a mobile device having a plurality of surfaces, the housing being fabricated without vent holes;

detecting a temperature of the processor;

positioning a battery within the housing and electrically coupling the battery to the processor;

detecting a temperature of the battery;

conducting heat away from the processor to a portion of at least one of the plurality of surfaces of the housing, wherein the portion corresponds to an area of the at least one surface having the highest temperature;

detecting a temperature of the portion; and

adjusting the rate of energy consumption by the processor based on the temperatures of the processor, the battery and the portion.

7. The method of claim 6 wherein the rate of energy consumption by the processor is adjusted by modifying at least one of a duty cycle of the processor, a clock speed of the processor and a voltage supplied to the processor.

8. The method of claim 6 further comprising continually adjusting the rate of energy consumption by the processor based on a thermal characterization of the mobile device.

9. The method of claim 6 further comprising conducting heat from the processor with at least one of the plurality of surfaces.

10. A mobile device comprising:

a housing having a surface, the housing being fabricated without vent holes;

a processor located within the housing, a portion of surface of the housing conducting heat away from the processor, wherein the portion corresponds to an area of the surface having the highest temperature;

means for activating the processor;

means for detecting a temperature of the processor;

a battery located within the housing and electrically coupled to the processor;

means for detecting a temperature of the battery; and

means for detecting a temperature of the portion of the surface, the rate of energy consumption by the processor being adjusted based on the detected temperatures of the processor, the battery and the portion.

11. The mobile device of claim 10 wherein the rate of energy consumption by the processor is adjusted by modifying at least one of a duty cycle of the processor, a clock speed of the processor and a voltage supplied to the processor.