Laptop Power Management via Display Angle Detection

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Solution Overview

Problem

Existing power management techniques for portable information processing devices, such as laptops, fail to effectively reduce heat and extend battery life by not considering the ergonomic relationship between the device and the user, leading to user discomfort and inefficient power consumption.

Innovation Solution

The implementation of an information processing apparatus that detects the relative arrangement between the user and the device using an angle sensor and acceleration sensor to determine if the device is being used on a lap, switching to a laptop mode that reduces CPU clock rate and video clock rate, thereby managing power consumption based on the detected position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the CPU operates at full power, then processing performance is improved, but the bottom of the housing gets hotter causing user discomfort

Engineering Contradiction:

Improveprocessing performanceVSAvoidheat to user

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts CPU operating mode based on detected usage scenario. When laptop mode is detected (display angle between 0-45 degrees), the CPU automatically switches to a low-power state with reduced frequency, thereby reducing heat generation while maintaining full performance capability when needed

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the display angle is small (laptop mode), then portability is improved, but heat accumulation at the bottom increases

Engineering Contradiction:

ImproveportabilityVSAvoidhousing temperature

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The angle sensor continuously monitors the display angle and provides feedback to the control unit. When the display angle falls within the predetermined range (0-45 degrees), the control unit automatically activates power management measures including CPU frequency reduction and cooling fan operation to control temperature

Inventive Principle:

Principle #23Feedback

3Temperature

If power management is implemented by reducing video clock rate, then temperature control is improved, but processing speed decreases

Engineering Contradiction:

Improvehousing temperatureVSAvoidprocessing speed

Core Design Contradiction:

TemperatureVSSpeed

Solution Approach 1:

The system changes multiple parameters simultaneously when laptop mode is detected: CPU operating frequency is reduced to a predetermined lower frequency, display brightness is adjusted, and cooling fan speed is modified. This multi-parameter coordination allows temperature control while maintaining acceptable processing performance through balanced system-wide adjustments

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7707436B2Managing laptop power based on display angle

Publication Date: 2010.04.27 LENOVO SWITZERLAND INTERNATIONAL GMBH

AI summary

A notebook type of computer of one embodiment includes a display unit, a housing to which the display unit is pivotally attached, an angle sensor which detects an opening angle between the display unit and the housing, a sensor driver which A/D converts an output from the angle sensor and passes the result to a power management driver, and an angle comparison module which reads a setting value as to the opening angle and determines whether the opening angle is within a range of a predetermined angle. If the opening angle is within the predetermined range, a user is presumed to be using the notebook computer on a lap and the power management operation is performed per that presumption.