US Patent 10514481 Annular optical element, imaging lens module and electronic device

An annular optical element having an optical axis includes an outer diameter surface, an inner annular surface, an object-side surface and an image-side surface. The object-side surface includes an annular reflecting surface, an annular auxiliary surface and a connecting surface. The annular reflecting surface is inclined with the optical axis. The annular auxiliary surface is closer to the optical axis than the annular reflecting surface is to the optical axis. The connecting surface is for connecting to an optical element, wherein the connecting surface is closer to the optical axis than the annular auxiliary surface is to the optical axis. The image-side surface is located opposite to the object-side surface and includes an annular optical surface. A V-shaped groove is formed by the annular auxiliary surface and the annular reflecting surface of the object-side surface.