US Patent 9939721 Integrated light pipe for optical projection

An optical device includes a first plate having a first transparent region defining an exit face of the device, and a second plate having a second transparent region defining an entrance face of the device. At least one lens is formed over at least one of the first and second transparent regions. First and second planar reflectors are spaced apart and fixed between the first and second plates in mutually-parallel orientations diagonal to the first and second plates, thereby defining an optical path through the device from the entrance face, reflecting from the first and second reflectors, through the exit face and passing through the at least one refractive surface.