Technique for automatically centering a lightguide fiber in a coating

Claim 1

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) directing a light beam at the coated fiber to cause a forward scattered light intensity pattern to impinge on a screen, the pattern having a high intensity central peak and a first and second outboard interference fringes; (b) monitoring the forward scattered light pattern to determine the period of each of the first and second outboard interference fringes; and (c) comparing the period of the fringes to determine the eccentricity of the fiber within the coating in a plane normal to the light beam.

Claim 2

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) directing a light beam at the coated fiber to cause a forward scattered light intensity pattern to impinge on a screen, the pattern having a high intensity central peak and a first and second outboard interference fringes; (b) monitoring the forward scattered light pattern to determine the period of each of the first and second outboard interference fringes; and (c) comparing the period of the fringes to determine the eccentricity of the fiber within the coating in a plane normal to the light beam.

Claim 4

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) passing the fiber through an applicator having the coating material therein; (b) directing a light beam at the coated fiber to cause a forward scattered light pattern to impinge on a screen; (c) monitoring the forward scattered light pattern with a TV camera, the camera generating a video output representing the light intensity of said pattern; (d) converting the video output into an envelope signal representative of the intensity amplitude of the scattered light intensity pattern, the envelope signal having first and second outboard interference fringes with a high intensity central peak; (e) determining the period of the first and second outboard fringes associated with the envelope of the video output; (f) comparing periods of the first and second outboard fringes determined in step (e), the difference being the eccentricity of the fiber within the coating in a plane normal to the light beam; (g) generating an analog electrical signal proportional to the fiber eccentricity determined in step (f); and (h) adjusting the position of the applicator in response to the analog signals generated in step (g) to center the fiber in the coating in said plane.

Claim 5

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) passing the fiber through an applicator having the coating material therein; (b) directing a light beam at the coated fiber to cause a forward scattered light pattern to impinge on a screen; (c) monitoring the forward scattered light pattern with a TV camera, the camera generating a video output representing the light intensity of said pattern; (d) converting the video output into an envelope signal representative of the intensity amplitude of the scattered light intensity pattern, the envelope signal having first and second outboard interference fringes with a high intensity central peak; (e) determining the period of the first and second outboard fringes associated with the envelope of the video output; (f) comparing periods of the first and second outboard fringes determined in step (e), the difference being the eccentricity of the fiber within the coating in a plane normal to the light beam; (g) generating an analog electrical signal proportional to the fiber eccentricity determined in step (f); and (h) adjusting the position of the applicator in response to the analog signals generated in step (g) to center the fiber in the coating in said plane.

Claim 6

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) passing the fiber through an applicator having the coating material therein; (b) directing first and second orthogonal light beams at the coated fiber to cause first and second forward scattered light patterns to impinge on a screen; (c) monitoring the first and second forward scattered light patterns with first and second TV cameras, respectively, each camera generating a video output representing the light intensity of said respective patterns; (d) converting each video output into first and second envelope signals representative of the intensity amplitudes of the first and second scattered light intensity patterns, the envelope signals each having first and second outboard interference fringes with a high intensity central peak; (e) determining the period of the first and second outboard fringes associated with the envelope signal of each video output; (f) comparing periods of the first and second outboard fringes determined in step (e), the difference being the eccentricity of the fiber within the coating in a first and second radially orthogonal direction; (g) generating first and second analog electrical signal proportional to the fiber eccentricity determined in step (f); and (h) adjusting the position of the applicator in response to the analog signals generated in step (g) to center the fiber in the coating.

Claim 7

A method of automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising the steps of: (a) passing the fiber through an applicator having the coating material therein; (b) directing first and second orthogonal light beams at the coated fiber to cause first and second forward scattered light patterns to impinge on a screen; (c) monitoring the first and second forward scattered light patterns with first and second TV cameras, respectively, each camera generating a video output representing the light intensity of said respective patterns; (d) converting each video output into first and second envelope signals representative of the intensity amplitudes of the first and second scattered light intensity patterns, the envelope signals each having first and second outboard interference fringes with a high intensity central peak; (e) determining the period of the first and second outboard fringes associated with the envelope signal of each video output; (f) comparing periods of the first and second outboard fringes determined in step (e), the difference being the eccentricity of the fiber within the coating in a first and second radially orthogonal direction; (g) generating first and second analog electrical signal proportional to the fiber eccentricity determined in step (f); and (h) adjusting the position of the applicator in response to the analog signals generated in step (g) to center the fiber in the coating.

Claim 8

An apparatus for automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising: (a) means for directing a light beam at the coated fiber to cause a forward scattered light intensity pattern to impinge on a screen; the pattern having a high intensity central peak and a first and second lower intensity outboard interference fringes; (b) means for monitoring the forward scattered light intensity pattern to determine the period of each of the first and second outboard interference fringes; and (c) means for comparing the period of the first fringe to the period of the second fringe to determine the eccentricity of the fiber within the coating in a plane normal to the light beam.

Claim 9

An apparatus for automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising: (a) means for directing a light beam at the coated fiber to cause a forward scattered light intensity pattern to impinge on a screen; the pattern having a high intensity central peak and a first and second lower intensity outboard interference fringes; (b) means for monitoring the forward scattered light intensity pattern to determine the period of each of the first and second outboard interference fringes; and (c) means for comparing the period of the first fringe to the period of the second fringe to determine the eccentricity of the fiber within the coating in a plane normal to the light beam.

Claim 11

An apparatus for automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising: (a) means for passing the fiber through an applicator having the coating material therein; (b) means for directing a light beam at the coated fiber to cause a forward scattered light pattern to impinge on a screen; (c) means for monitoring the forward scattered light pattern with a TV camera, the camera generating a video output representing the light intensity of said pattern; (d) means for converting the video output into an envelope signal representative of the intensity amplitude of the scattered light intensity pattern, the envelope signal having first and second outboard fringes with a high intensity central peak; (e) means for determining the period of the first and second outboard fringes associated with the envelope signal of the video output; (f) means for comparing periods of the first and second outboard fringes, the difference being the eccentricity of the fiber within the coating in a plane normal to the light beam; (g) generating an analog electrical signal proportional to said fiber eccentricity; and (h) adjusting the position of the applicator in response to said analog signals to center the fiber in the coating in said plane.

Claim 12

An apparatus for automatically centering a lightguide fiber in a light transmissive coating material having an index of refraction lower than that of the fiber, comprising: (a) means for passing the fiber through an applicator having the coating material therein; (b) means for directing a light beam at the coated fiber to cause a forward scattered light pattern to impinge on a screen; (c) means for monitoring the forward scattered light pattern with a TV camera, the camera generating a video output representing the light intensity of said pattern; (d) means for converting the video output into an envelope signal representative of the intensity amplitude of the scattered light intensity pattern, the envelope signal having first and second outboard fringes with a high intensity central peak; (e) means for determining the period of the first and second outboard fringes associated with the envelope signal of the video output; (f) means for comparing periods of the first and second outboard fringes, the difference being the eccentricity of the fiber within the coating in a plane normal to the light beam; (g) generating an analog electrical signal proportional to said fiber eccentricity; and (h) adjusting the position of the applicator in response to said analog signals to center the fiber in the coating in said plane.