Brightness control of a status indicator light

Abstract

An apparatus and method for controlling the brightness and luminance of a light, such as an LED. The embodiment may vary the brightness and luminance of the LED in a variety of ways to achieve a variety of effects. The exemplary embodiment may vary the rate at which the LED's luminance changes, such that an observer perceives the change in the LED's brightness to be smooth and linear as a function of time, regardless of the ambient light level. Changes to the LED's luminance may be time-constrained and / or constrained by a maximum or minimum rate of change.

Description

technical field [0001] The present invention relates generally to the field of lighting control, and more particularly to the control of luminance of lamps. Background technique [0002] Electronic devices such as computers, personal digital assistants, monitors, portable DVD players, and portable music players such as MP3s often have multiple power states. Two exemplary power states are "on" when the device is operating at full power and "off" when the device is turned off and uses very little or no power. Another exemplary power state is "sleep" when the device is on but uses less power than the "on" state, typically because one or more features of the device are disabled or suspended. Yet another exemplary power state is "hibernate" when the device's state is saved to non-volatile memory (typically the system's hard disk) and then the device is turned off. Sleep or hibernate states are often used to reduce energy consumption, conserve battery life, and enable devices to...

AI Technical Summary

Problems solved by technology

Other prior art systems may include more complex LED behavior

For example, some prior art systems with built-in monitors only activate the LED when the computer is on and the monitor is off

while other prior art systems that do not have an integrated display may turn on the LED whenever the computer is turned on

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