1.  Field of the Invention
The present invention relates to an apparatus and related method of winding optical fiber onto a bobbin.  More particularly, the invention relates to an apparatus and related method of winding optical fiber onto a bobbin which permits free streaming out of the fiber from the bobbin without clumping or knotting and which minimizes the effect on the optical signal passing through the fiber. 
2.  Description of the Prior Art
A number of weapons and communications systems have been developed or are under development which use an optical fiber for two-way data communication between two or more moving bodies or between a moving body and a fixed station.  A typical optical fiber application involves packaging a continuous strand of optical fiber inside a vehicle with one end of the fiber being attached to operational devices in the vehicle, attaching the other end of the fiber to a control or communication station at the launch site, launching the vehicle, and conducting two-way communication with the vehicle during its flight. 
It is important to provide a reliable and compact means for packaging the optical fiber in the vehicle which will minimize stresses on the fiber to preclude adverse effects on communication performance and which will permit reliable deployment of the fiber during flight of the vehicle.  Thus, it is important that the optical fiber be smoothly wound onto the supply bobbin and that the windings be free of gaps or overwinds. 
Many different methods and systems having been proposed for winding bobbins.  For example, it has been attempted to ensure fiber optic bobbins free of irregularities by providing a high magnification closed circuit TV monitor continuously monitored by an operator to view the winding process.  This has the disadvantages of high labor costs, and operator fatigue can result in winding flaws.  It has also been attempted to measure laser energy which is reflected from the junction between turns of a plastic coated optical fiber.  Although adequate for the purposes intended, in such a system false signals and reflectance changes may occur because of variations in the plastic coating.  Further, because such a system measures the energy reflected from the junction between turns of the optical fiber, it is incapable of effectively handling fiber turns with deliberately broad gaps between them.  It has also been proposed to provide an open loop system for winding bobbins with no flaw detection.  This would require excessively high precision equipment and it would be difficult to achieve flexibility for a variety of bobbin configurations.  In addition, such a system would not be fail safe. 
Accordingly, it is an object of this invention to provide an improved method and apparatus to ensure accurate positioning of an optical fiber on a bobbin as the fiber is being wound onto the bobbin. 
It is a further object of the present invention to provide a method and apparatus that senses the gap, overwind, and lead angle of an optic fiber being wound onto a bobbin. 
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention.  The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.