Abstract: An example optical alignment target includes a translucent or transparent substrate having a bottom surface; an opaque material formed over the bottom surface in a pattern; an enclosed channel disposed below the bottom surface; and a fluid suspension contained in the enclosed channel. The pattern has an opaque portion of an opaque material and has a gap portion devoid of the opaque material. The fluid suspension includes a carrier liquid and a light emitting material suspended in the carrier liquid. The light emitting material is selected from the group consisting of quantum dots and cerium powder.

Abstract: A device is provided for mechanically coupling two parallel shafts together allowing rotation thereof in a 2/1 ratio in an angular sector defined, by producing a very rigid connection without lost motion, with a minimum of parasite torque and insensitive to environmental vibrations. It includes a first piece mounted on a shaft and having two guide elements and a second piece mounted on a shaft having two arms provided with flat surfaces on which the guide elements move. The center of these latter, as well as the axis of rotation of the second shaft, are on a circle centered on the axis of rotation of the first shaft. Preferably, one of the pieces is made in two parts, one being integral with the associated shaft and the other freely mounted on this shaft, and a return spring holds said guide elements against the flat surfaces, these elements being formed by ball bearings.