Abstract: A Passive Bi-Directional Off-Axis Fiber Optic Rotary Joint (FORJ) with a center bore has been invented in which an optical signal can be transmitted across a rotating boundary without using the centerline or axis of rotation of the FORJ. Rather a fiber bundle is used to transmit the optical signal across a single mechanical rotational interface.

Abstract: An active off-axis optic slip ring system is disclosed. The invention eliminates the huge number of fiber bundles and photodiodes in most published patents. A couple of conventional optical components such as mirrors and prisms are used to transmit optical signals with high, quality and low optic losses. The optical signal pick-up is realized through a pair of prisms mounted on the rotor of motors. It is an active, hi-directional rotational optical transmission device which could be used for multi-mode, or single mode fibers without the limitation to the through bore diameters.

Abstract: A multi-channel electro-magnetic rotary joint has been invented in which one or more electro-magnetic signals can be transmitted simultaneously from a rotating collimator array and a stationary collimator array in air and in other fluids. A metamaterial de-rotating mechanism is positioned in the path between said rotating collimator array and said stationary collimator array, and arranged tier rotation relative to each collimator arrays at a rotary speed equal to one-hall the relative rotational rate between said rotating and stationary collimator arrays.

Abstract: The multiple channel fiber optic rotary joint of this invention can transmit an increased number of optical signals simultaneously through the de-rotating mechanism without increasing the size of the de-rotating mechanism. It also allows for the recapturing of the signals with relative ease. This is accomplished through the use of an optical condenser and/or an optical expander that reduces or expands the overall all beam structure without significantly altering the relative structure. The expanders and condensers are inverse structures in that if an optical signal is condensed when passing from right to light through the condenser it is expanded when passing left to right through the same condenser.

Abstract: A simple planetary or epicyclic gear mechanism consists of a sun gear in the center, an internal or ring gear with a common axis with sun gear, and at least one planet gear. The planet gear is located between the sun gear and ring gear, and meshes with both the sun gear and the ring gear. If the ring gear is stationary, when sun gear rotates, the planet gear not only rotates about its axis, its axis also rotate around the axis of sun gear. In stead of employing the sliding motion between the ring and the brush in electrical slip ring, the current invention makes use of a plurality of conductive gears, particularly a planetary gear mechanism, to transfer electrical power, and/or signal(s) between relatively rotatable objects.

Abstract: The present invention is a limited rotation through-bore optical slip ring. This will enable one or more optical signals to pass across a rotational interface while leaving a center bore free. The present invention is passive, unlike many off axis or through bore optical slip rings and is low loss by nature.