US Patent 7535646 Light emitting device with microlens array

A light-emitting device, comprising: a light emitting element on a first side of a transparent substrate or cover through which light is emitted; and a microlens array on a second side, opposite to the first side, of the transparent substrate or cover though which light is emitted; wherein the microlens array comprises individual hemispherical shaped microlenses having a mean diameter of less than 20 micrometers and a mean microlens height to diameter ratio of greater than 0.30, and has a microlens area fill factor greater than 0.8.