Forming preformed images in organic electroluminescent devices

摘要

A method of making a non-pixelated organic electroluminescent (EL) device with a preformed image includes the steps of forming a light-transmissive anode electrode over a light-transmissive substrate; forming an organic EL medium structure over the anode electrode; forming a cathode electrode over the organic EL medium structure and providing a cover structure over the device; and forming a preformed image in the cathode electrode by using a laser beam to remove cathode material imagewise from the cathode such that when a voltage is applied between the anode and cathode electrodes light will not be emitted from the device in areas corresponding to the preformed image, and the preformed image will be observable by a viewer as a dark image surrounded by a bright field of light emitted through the substrate.