摘要 |
An apparatus for detecting variations in light output of an electroluminescent (EL) device is described. The EL device includes a transparent substrate having a first edge extending in a first direction and a plurality of EL emitters disposed over the face of the substrate in the first direction, and some of the light emitted by each EL emitter travels through the substrate and out of the first edge. A light sensor physically separated from the first edge senses the light travelling out of the first edge. A controller stored first sensed light at a first time and second sensed light at a later second time and computes a variation in light output of one or more of the EL emitters in the EL device using the stored first sensed light and second sensed light. |