Western Electric Company, Inc.

At&t Technologies, Inc.

David H Smithgall, Sr

Ralph E Frazee, Jr

Daryl L Myers

Ralph Edward Frazee, Jr

A technique for dynamically changing from a full, rotating spool (18) of lightguide fiber (10) to an empty spool (19) while maintaining a substantially constant feed velocity is described. The fiber (10) is moved along a tapered transition section (40 or 52) having a continually decreasing cross-sectional diameter as the spools (18 and 19) and the transition section (40 or 52) rotate at the same velocity. The rotational velocity of the spools and the transition section are increased as the fiber is wound therealong. The fiber is transferred from the transition section onto the empty spool.

Lightguide fiber spool changeover technique

A technique for dynamically transferring a lightguide fiber (10) from a full spool (18) to an empty spool (19) as both spools rotate at the same velocity and the input velocity of the fiber is constant. The lightguide fiber (10) is wound onto the rotating spool (18) in such a manner as to form a package of wound material having a conically tapered section (52) when full. The fiber (10) is then wound along the tapered section (52) as the velocity of the spools (18 and 19) are increased. When the fiber (10) is at the diameter of the tapered section (52) which is equal to the diameter of the empty spool, it is transferred to the empty spool without any substantial loss of fiber spooling control.

A technique for automatically centering a lightguide fiber (7) in a transparent plastic coating (6) having a refractive index lower than that of the fiber. The fiber (7) is passed through an applicator (14) having the coating material (6) therein to coat the fiber. Orthogonal laser beams (50 or 52) are directed at the coated fiber (5) resulting in first and second forward scattered light patterns (51 or 53) impinging on first and second screens (36 and 37). The patterns are monitored with a pair of CCTV cameras (38 and 39) and the video output signals therefrom are processed to determine the period (P.sub.1 and P.sub.2) of outboard interference fringes (61 and 62) of each pattern. The period of the interference fringes are compared to determine the difference therebetween which is proportional to the eccentricity of the fiber (7) within the coating. The position of the applicator (14) is then adjusted to center the lightguide fiber (7) in the coating (6).

Technique for automatically centering a lightguide fiber in a coating

The diameter of an optical fiber is continuously measured by directing a laser beam at the fiber to form a light intensity fringe pattern. The pattern is converted to a substantially sinusoidal electrical signal having a period proportional to the fiber diameter. The sinusoidal signal is forwarded to a tapped delay line to form a plurality of delayed replicas thereof having a predetermined delay therebetween. A pulse is generated for each zero crossing of all the sinusoidal signals and the pulses interleaved to form an output train having an interpulse interval proportional to a fraction of the fiber diameter.

Methods and apparatus for improving the resolution of measured parameters

The diameters of successive axial portions of an optical fiber being drawn are monitored and controlled by an optical measuring technique in such manner as to eliminate the effects of occasional, anomalous measurements or 'dropouts'. Measurement validity is tested by comparing, with a maximum allowable value, the difference between each successive diameter measurement and a standard for diameter measurement validity. Some examples of such a standard are provided. In addition, two embodiments of fiber monitoring systems are disclosed, as well as an overall monitoring and control system for fiber diameters.

Growing community of inventors

East Windsor Township, NJ, United States of America

David H Smithgall, Sr