Articulated optical coupler

Abstract

An articulated coupler which, when inserted between an endoscope and a suspended television camera, allows all rotations of the endoscope to occur while automatically avoiding image rotation on the television screen. The coupler includes first and second right angle deflectors, first and second rotatable bearings, and a compensation mechanism. Light is incident along a first optical axis (endoscope axis) and ultimately emerges along a second optical axis (camera axis). The first rotatable bearing is disposed between the first and second deflectors to permit relative rotation of the first and second deflectors about the coupler optical axis (horizontal). The second rotatable bearing is disposed between the second deflector and the camera to permit relative rotation of the second deflector and the camera about the camera optical axis. The compensation mechanism rotates the camera about the camera optical axis relative to the second deflector in an amount and direction necessary to compensate for the relative rotation between the first and second deflectors about the coupler optical axis that arises from pitch rotation of the endoscope. The compensation mechanism preferably comprises first and second bevel gears coaxial with the coupler optical axis and the camera optical axis, respectively, which gears are rigidly coupled to the first deflector and to the television camera, respectively, and are carried coaxially on mutually perpendicular hollow sleeve bearings that are rigidly coupled to the second deflector. In an embodiment where the gears mesh directly, the second deflector is configured to cause an even number of reflections.