通過運(yùn)動檢測節(jié)省電池的背光控制

　　通過運(yùn)動檢測節(jié)省電池的背光控制

　　關(guān)閉便攜式產(chǎn)品上的LCD背光，如智能手機(jī)、相機(jī)、平板電腦和筆記本電腦，可以提供可觀的節(jié)電和延長寶貴的電池壽命。運(yùn)動檢測是確定設(shè)備是否真正空閑或需要保持發(fā)光的幾種方法之一。例如，如果有人靠近，很可能該設(shè)備正在使用中，例如。

　　近距離和環(huán)境光傳感器的結(jié)合正在成為一種流行的技術(shù)選擇。如果環(huán)境光很高，則顯示器不需要處于滿功率狀態(tài)。一個創(chuàng)新的消費(fèi)應(yīng)用程序是無線藍(lán)牙激活的羅技鍵盤（見圖1）。輕松連接到PC，筆記本電腦或智能手機(jī)，背光鍵的設(shè)計(jì)是易于閱讀在任何光線水平。環(huán)境光傳感器可以根據(jù)房間光線的大小自動調(diào)節(jié)照明水平。內(nèi)置的接近傳感器檢測用戶的手接近鍵盤和打開照明。

　　Figure 1： Backlit displays on smartphones， tablets， notebooks， and even this illuminated keyboard from Logitech， can be controlled through the combination of motion/proximity sensors and ambient light sensors.

　　Another approach is the use of smart accelerometers to detect linear motion to determine whether a portable device is simply being transported， or is about to be activated. A digital camera， for example， could turn off the display when motion is detected indicating it is no longer in use. While in a smartphone， motion detected after inactivity could indicate the device is about to be used.

　　This article will highlight some of the integration and user-interface issues associated with these technologies. It will also review some recently introduced devices such as theTSL2772 family of light and proximity sensors from TAOS， the MAX44000 combined sensors from Maxim Integrated and the SFH 7773 hybrid sensor from OSRAM Opto Semiconductors， as well as the iNEMO range of LIS331 3-axis accelerometers with embedded microcontroller， from STMicroelectronics.