Apparatus and method for detecting defect in optical fiber, and plastic optical fiber manufacturing apparatus
AssigneeFUJIFILM Corporation
InventorsShinsuke Aoshima, Shinji Higaki, Yoshiaki Shibano
Life of this patent
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Abstract
While a plastic optical fiber (POF) strand is guided by guide pulleys toward a winding machine, an internal defect in the POF strand is detected by a defect detection apparatus. The defect detection apparatus includes at least one light illumination device, at least one imaging device and at least one defect detection unit. The light illumination device illuminates the POF strand, and the imaging device takes an image of the POF strand and outputs signal to the detection unit.
Claims13
An apparatus for detecting an internal defect in an optical fiber, the apparatus comprising:
- a detection light illumination device for illuminating detection light to the optical fiber from a direction that crosses the axis of the optical fiber;
- an imaging device that takes an image of the optical fiber illuminated by the detection light from a direction that crosses the optical axis of the detection light, and outputs light intensity distribution signals in the radial direction perpendicular to the axis of the optical fiber;
- and
- a defect detection section that obtains the light intensity distribution signals continuously in the axial direction of the optical fiber, and detects the internal defect based on the level of the light intensity distribution signals in the radial direction and the axial direction,
- wherein the imaging device is a line sensor camera having plural imaging elements in line, and the detection light illumination device is offset from a center axial line of the optical fiber such that the light axis of the illumination is only in the opposite side of the line sensor camera with respect to the center axial line of the optical fiber.
A method for detecting an internal defect in an optical fiber, the method comprising the steps of:
- (a) illuminating detection light to the optical fiber from a direction that crosses the axis of the optical fiber;
- (b) taking an image, using an imaging device, of the optical fiber illuminated by the detecting light from a direction that crosses the optical axis of the detection light and outputting light intensity distribution signals over the radial direction perpendicular to the axis of the optical fiber;
- (c) obtaining the light intensity distribution signals continuously in the axial direction of the optical fiber;
- and
- (d) detecting the internal defect based on the level of the light intensity distribution signals in the radial direction and the axial direction,
- wherein the imaging device is a line sensor camera having plural imaging elements in line, and the detection light illumination device is offset from a center axial line of the optical fiber such that the light axis of the illumination light is only in the opposite side of the line sensor camera with respect to the center axial line of the optical fiber.
Dependencies are inferred from the claim text.