汽车显示器需要更明亮的背光

　　汽车显示器需要更明亮的背光

　　介绍

　　到2012，高亮度（HB）发光二极管的市场规模预计将达到120亿美元，并以30.6%的复合年增长率增长到2015美元，根据战略的限制（见图1）。用于背光显示器的LED是目前这种空前增长的主要驱动力。应用范围从电视到汽车显示无数其他的手持设备。为了保持这种令人印象深刻的增长率，LED不仅必须提供更高的可靠性、更低的功耗和更小/更平坦的外形，而且还必须在对比度、图像清晰度和颜色精度方面提供明显的改进。此外，汽车、航空、海洋显示必须最大化所有这些改进而受到各种各样的环境照明条件从耀眼的阳光，没有月亮的夜晚。这些晶体管液晶显示器（TFT-LCD）显示应用范围从信息娱乐系统到仪表集群和广泛的仪表显示器。这些LED背光显示创造了一些独特的LED驱动程序设计挑战，以优化显示器的可读性，在广泛的环境照明条件下。这就要求LED驱动器能够提供非常宽的调光比和高的转换效率而承受的相对腐蚀汽车的电气和物理环境的严酷。最后，这些解决方案必须提供低姿态、紧凑的脚印，同时提高成本效益。

　　How can such an impressive growth potential in automotive lighting be supported？ First of all， LEDs are ten times more efficient at producing light than incandescent bulbs， and almost twice as efficient as fluorescent lamps， including cold cathode fluorescent lamps （CCFL）， thereby reducing the amount of electrical power required to deliver a given amount of light output （measured in lumens）。 As LEDs are further developed， their efficacy， or ability to produce lumens of light from electrical power， will only continue to increase. Secondly， in our environmentally conscientious world， LED lighting does not require the handling， exposure， and disposal of the toxic mercury vapor commonly found in CCFL/fluorescent bulbs. Finally， incandescent bulbs need to be replaced about every 1，000 hours， while fluorescent bulbs last up to 10，000 hours compared to a 100，000+ hour lifetime for LEDs. In most applications， this allows the LEDs to be permanently embedded into the final application. This is especially important for backlighting automotive instrument/navigation/infotainment panels， which are embedded into a car’s interior as they will never require replacement during the life of the car. Additionally， LEDs are orders of magnitude smaller and flatter than their counterparts， so the LCD panels can be very thin， thereby requiring minimal space in the interior of the car. Furthermore， by using a configuration of red， green， and blue LEDs， an infinite number of colors can be delivered. LEDs also have the ability to dim and turn on/off much faster than the human eye can detect， enabling dramatic improvements in backlighting of LCD displays while simultaneously allowing dramatic contrast ratios and high resolution.