Patent ID: 6032490
Filing Date: 2000-03-07
Classification: B29C,B29D,G02B

Abstract:
A mold for fabricating optical fiber guide blocks, for the purpose of molding, by press-molding process, at least the optical fiber engagement portions of optical fiber guide blocks comprising optical fiber engagement portions for the purpose of positioning and aligning optical fibers at a fixed pitch; comprising:a plurality of concavities that extend in one direction in the forming surface; wherein the tangent lines at the points where the portions that are to support said optical fibers at the two sloping surfaces which configure said concavities, in a cross-section that is perpendicular to the longitudinal dimension of said concavities, subtend an angle .theta. that is equal to or smaller than .theta.c which satisfies the relationship noted below;the perpendicular cross-sectional shape of said concavities is such that the contour thereof is contained within an area bounded by two tangent lines that touch the sloping surfaces and by a line that is tangent to an imaginary circle and perpendicular to the straight line connecting the intersection of said two tangent lines with the center of said imaginary circle, and that passes between said intersection and said center of said imaginary circle, when said imaginary circle, of radius Rmin as defined below, is inscribed in the area that is in the bight of said two tangent lines;the depth of said concavities is such that said intersection of said two tangent lines is at a position deeper than dmin, as defined below; andsaid forming surfaces between said concavities are what form said optical fiber engagement portions:.theta.c=2 tan.sup.-1 {S.sup.2 -1)/2S},where:S=YO/RO;Rmin=[RO+{RO/sin(.theta./2)}-{YO/tan (.theta./2)}]/[1-{1/sin(.theta./2)}];dmin=[YO-RO.multidot.tan{(.pi.-.theta.)/4}]/tan(.theta./2);RO is the optical fiber radius; andYO is half the pitch length of the optical fiber engagement portion.