便攜式電子設備中的ALS應用

　　便攜式電子設備中的ALS應用

　　高分辨率彩色手機顯示器渲染美麗的圖片，但他們的權力饑餓。使用環(huán)境光傳感器可以導致相當長的電池壽命。

　　在便攜式電子產(chǎn)品中，為用戶提供提高電池壽命的降低功耗是當今重要的設計考慮之一。LCD（液晶顯示器）及其相關背光是便攜式產(chǎn)品中耗電量最多的一種。其結果是，在各種環(huán)境照明情況下，使用ALS（環(huán)境光傳感器）優(yōu)化背光LED操作正在增加。與此同時，設計者對傳感的首選技術選擇已經(jīng)轉向更全面的解決方案。

　　環(huán)境光傳感器是如何使用？

　　環(huán)境光傳感器也被稱為照度或照明傳感器，光學傳感器，亮度傳感器，或簡單的光傳感器。ALS技術的一個非常重要的應用是手機。在這里，ALS可以在較寬的照明條件下自動控制顯示背光亮度，從黑暗環(huán)境到直射陽光。使用ALS輸入，MCU或基帶處理器根據(jù)環(huán)境增加或減小顯示器的亮度。這種控制極大地提高可視性和降低功耗，因為LCD背光可以吸引多達51%的功率在輸入待機電源模式。此外，ALS信號可用于指示鍵盤驅動器，以最小化鍵盤背光，降低高達30%的功率消耗在輸入待機電源模式。在明亮的環(huán)境中，LED鍵盤亮度降低，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.”