用于投影机的发光二极管照明单元

目前的投影机光源——高压汞灯存在寿命短、色温高、存在有害光线、发热集中等缺点，严重制约了投影机进入家庭应用领域。发光二极管的最近发展为其作为高压汞灯的替代光源提供了可能性。提出了一种由一个发光二极管、一个准直镜、一个前蝇眼透镜和一个后蝇眼透镜组成的用于投影机的发光二极管照明单元，由数个照明单元加上会聚透镜则构成一个基本的照明系统。发光二极管的发光经准直镜压缩光束发散角后被前蝇眼透镜分割为多个细光束，会聚透镜将每个细光束都叠加会聚到显示芯片上，实现光能量的会聚和光场再分布．以满足投影机对光通量和光场均匀性等方面的要求，后蝇眼透镜用于与后续光路的匹配。作为照明单元的一个应用实例，文中分析了一种单片式硅上液晶投影机。

A LED Light Unit for the Projector

For current light source of projectorUHP lamp, the disadvantages of short lifetime, high colour temperature, having harmful light, high heat density etc., restrict the application of projector in home entertainment. Recent development of LED provides the possibility of LED being a substitute light source of UHP lamp. A LED-based lighting unit composed of a LED, a collimating lens, a front fly-lens and a back fly-lens is brought forward. Several such lighting units make a basic lighting system of projector. The divergence angle of light beam from LED is compressed by collimator lens. Then the light beam is divided into several tiny light beams by the front fly-lens, and each tiny light beam will be converged to micro-display panel by converging lens. So, the light energy is gathered and the light field is redistributed. The requirements of projector on light flux and homogeneity could be met. The back fly-lens is used to match with following optical elements. As an application of the lighting unit, a signal panel liquid crystal on silicon projector is analyzed.