便携式电子设备中的ALS应用

　　便携式电子设备中的ALS应用

　　高分辨率彩色手机显示器渲染美丽的图片，但他们的权力饥饿。使用环境光传感器可以导致相当长的电池寿命。

　　在便携式电子产品中，为用户提供提高电池寿命的降低功耗是当今重要的设计考虑之一。LCD（液晶显示器）及其相关背光是便携式产品中耗电量最多的一种。其结果是，在各种环境照明情况下，使用ALS（环境光传感器）优化背光LED操作正在增加。与此同时，设计者对传感的首选技术选择已经转向更全面的解决方案。

　　环境光传感器是如何使用？

　　环境光传感器也被称为照度或照明传感器，光学传感器，亮度传感器，或简单的光传感器。ALS技术的一个非常重要的应用是手机。在这里，ALS可以在较宽的照明条件下自动控制显示背光亮度，从黑暗环境到直射阳光。使用ALS输入，MCU或基带处理器根据环境增加或减小显示器的亮度。这种控制极大地提高可视性和降低功耗，因为LCD背光可以吸引多达51%的功率在输入待机电源模式。此外，ALS信号可用于指示键盘驱动器，以最小化键盘背光，降低高达30%的功率消耗在输入待机电源模式。在明亮的环境中，LED键盘亮度降低，功耗最小。

　　In addition to cell phones， ambient light sensors can be used in a variety of LCD-equipped portable products including PDAs， notebook PCs， digital cameras， video players， and GPS-based navigation systems. Any portable product with an LCD is a candidate for ALS technology to reduce power consumption. In automobiles， the use of LCDs is increasing for navigation， entertainment， and comfort systems， as well as control monitoring and dimming mirrors. Any product with an LCD that requires supplemental light for proper viewing can benefit from using an ALS to reduce power consumption and improve visibility under varying lighting conditions. This includes televisions and home appliances， especially those with increased electronic control and user-driven menus that require larger LCD panels.

　　The market research firm Databeans， Inc. estimates the current total available market for ambient light sensors to be seven percent of LED revenue， or roughly $327 million worldwide. According to Susie Inouye， research director and principal analyst at Databeans， “Due to the large number of feature-rich phone products that will drive demand， we expect this revenue to grow at a compound annual growth rate of 21 percent each year over the next five years to reach close to $860 million by 2014.”