| 摘要 |
<p>Four light-transmitting mono filaments (2) each having an almost circular cross section and surface substantially being mirror surface are arranged in a single layer and in parallel, and a flat yarn (3) formed by fusing or melt-bonding adjacent mono filaments (2) to each other and fixing them is twisted. Twisting is imparted over a full length of a light diffusing yarn (1) continuously at a frequency of more than one time with a length five times as long as the width of the flat yarn (3). The twisting cyclically reverses the front and rear surfaces of the flat yarn (3) along the longitudinal direction of the light diffusing yarn (1) to continuously change the longitudinal-axis direction of each mono filament (2) along the longitudinal direction of the light diffusing yarn (1). Therefore, when parallel lights enter the light diffusing yarn (1), the center axis directions of conical-surface-like diffused lights differ from each other according to individual portions in the longitudinal direction of the light diffusing yarn (1) even if the incident angle of the parallel lights is constant to produce wide-range diffusion light at one cycle of twisting.</p> |
