Abstract: A flat optical-interference-functional fiber formed by alternately laminating individually independent layers of polymers having different refractive indices in parallel with the major axis direction of its flat cross section, characterized in that (a) the ratio (SP ratio) of the solubility parameter value (SP1) of high refractive index polymer to the solubility parameter value (SP2) of low refractive index polymer is in the range of 0.8≦SP1/SP2≦1.1, and a fibrous structure using the fiber. According to the present invention, there are provided a fiber which has high color development intensity based on optical interference and forms clear color; and a fibrous structure thereof.

Abstract: A color-developing composite short fiber having a length of 0.01 to 100 mm is obtained by cutting a color-developing short fiber capable of reflecting visible rays and interfering therewith consisting of two or more kinds of polymer compounds having different refractive indices which are laminated alternately, while a color-developing structure is formed by binding particles of the short fiber one another, dispersing the short fiber in or mixing it with other materials to be bound therewith or adhering the short fiber on the surface of a support. Further, a color-developing composite short fiber having a length of 0.

Abstract: A color-developing composite short fiber having a length of 0.01 to 100 mm is obtained by cutting a color-developing short fiber capable of reflecting visible rays and interfering with visible rays consisting of two or more kinds or polymer compounds having different refractive indices which are laminated alternately. A color-developing structure is formed by binding particles of the short fiber to one another, dispersing the short fiber in a mixture with other materials or adhering the short fiber on the surface of a support. Further, a color-developing composite short fiber having a length of 0.01 to 100 mm is obtained by cutting a color-developing composite fiber comprising two or more polymer compounds having different refractive indices which are laminated alternately forming a layer capable of reflecting visible rays and interfering therewith and a layer capable of reflecting invisible rays and interfering therewith.

Abstract: A fiber structure with a cross section having x-axis and y-axis directions includes an alternate lamination including a first portion having a refractive index na and a thickness da and a second portion adjacent to the first portion and having a refractive index nb and a thickness db, wherein when 1.0≦na<1.8, 1.3≦nb≦1.8, and 1.01≦nb/na≦1.80, a primary peak wavelength &lgr;1 which is equal to 2(nada+nbdb) is given by &lgr;1≧0.78 or 1.6 (&mgr;m).

Abstract: A fiber structure includes alternate lamination including a predetermined number of a first portion having a refractive index na and a thickness da, and a second portion adjacent to the first portion and having a refractive index nb and a thickness db, wherein when the refractive index na is given by 1.3≦na, and a ratio nb/na is given by 1.01≦nb/na≦1.20, a reflection peak wavelength &lgr; is equal to 2(nada+nbdb). Such fiber structure is used in a textile.

Abstract: A minute structure for producing a color comprises a first coloring part for producing a color with first wavelengths in the visible light area by physical actions such as reflection and Interference. The first coloring part includes lamellas disposed in layers at predetermined intervals. A second coloring part is disposed adjacent to the first coloring part for absorbing a part of light with second wavelengths in the visible light area and reflecting the rest of light. The second coloring part contains a coloring matter.

Abstract: A fiber with a cross section having x-axis and y-axis directions includes an alternate lamination including a predetermined number of a first portion and a second portion adjacent thereto, which have different optical characteristics, and a clad arranged around the alternate lamination.

Abstract: A composite polymer fiber is produced employing at least two polymer compounds according to a process for producing a composite polymer fiber including the steps of supplying at least two polymer compounds; forming a belt flow by arranging alternately unmixed strips of the polymer compounds supplied; and injecting the belt flow after it is compressed such that the thickness of the belt flow may be longer than the width thereof and that multiple layers of the polymer compounds may be parallel to the longer axis of the fiber. According to this process, there is obtained a fiber having a multilayered structure, in which the thickness of each layer can be controlled with optical accuracy since the multilayered structure is formed in one step, and also having a rectangular cross section in which each layer in the fabric is oriented parallel to the longer axis of the fiber, so that the layers can be easily oriented, when woven into a fabric, in such a direction as to obtain high-intensity coherent beams of light.

Abstract: A method of manufacturing fibers with optical function includes spinning a thermoplastic polymer by a spinneret having an opening with first slits arranged parallel to each other and a second slit arranged perpendicular thereto, the spinneret being formed to satisfy a predetermined relation between the length of the first slits and the width of the second slit.

Abstract: In a fabrication machine of sea island type optical fiber having a plurality of wings by spinning, when a sea part polymer is insufficiently supplied into space between the adjacent wings to cause fusion of the adjacent wings, failing in producing an optical fiber having the desired optical characteristics. The present invention solved this problem. A guide member introduces the sea part polymer supplied from sea part polymer inlets into flow paths or slits between projection wings of a partition wall for a flow path control of an island part. A sufficient amount of sea part polymer is supplied to the space between the adjacent wings of an island part of the obtained optical fiber and an optical fiber having the desired optical characteristics can be obtained.

Abstract: A spinneret for manufacturing modified cross-section fibers with optical function includes tubes arranged to a spinneret for spinning an island portion, and a partition device for enclosing the tubes for leading a melt polymer. The spinneret and the partition device cooperating with each other to define a predetermined space.

Abstract: A spinneret for manufacturing modified cross-section fibers with optical function includes a middle spinneret for spinning an island portion, which has a base and an opening for extruding a melt polymer for forming an island portion. A partition device is mounted to the middle spinneret to partition the opening thereof, the partition device having an opening communicating with the opening of the middle spinneret which protrudes-from the base thereof.