Abstract: An optical recording medium which comprises an organic thin film layer containing at least one of phthalocyanine compounds, due to which high light absorptivity to laser beams and high recording sensitivity can be obtained. The optical recording medium provided by the present invention has high chemical and physical stability. There is also disclosed a process for the production of the optical recording medium.

Abstract: A pigment composition consisting of 100 parts by weight of a pigment, and from 0.1 to 30 parts by weight of a pigment dispersant of formula ##STR1## in which Q is (a) an anthraquinone dye or pigment radical, (b) an azo dye or pigment radical, (c) a benzimidazolone dye or pigment radical, (d) a phthalocyanine dye or pigment radical, (e) a quinacridone dye or pigment radical, (f) a dioxazine dye or pigment radical, (g) an anthrapyrimidine dye or pigment radical, (h) an anthanthrone dye or pigment radical, (i) an indanthrone dye or pigment radical, (j) a falvanthrone dye or pigment radical, (k) a pyranthrone dye or pigment radical, (l) a perinone dye or pigment radical, (m) a perylene dye or pigment or (n) a thioindigo dye or pigment radical; X is a direct bonds, --CH.sub.2 --; ##STR2## Y.sub.1 is NH or --O--; Z is in which Y.sub.2 is --NH-- or --O--, or --NH--X--Q when n is 1; R.sub.1 and R.sub.

Abstract: A heat roller fixing device for use in an electrophotographic copying apparatus and the like, which includes a heating roller constituted by laminating a fluorine resin layer on an electrically conductive core member through a primer layer and driven for rotation, and a pressure roller constituted by forming an electrically insulative layer on another electrically conductive core member and held in contact with the heating roller for simultaneous rotation with the heating roller so as to fix a positively charged toner image formed on copy paper onto the copy paper by causing the copy paper to pass between the heating roller and the pressure roller. The primer layer is composed of an offset prevention agent containing carbon black by a predetermined amount, preferably 0.4 to 3.0% by weight.

Abstract: An optical semiconductor device includes a light emitting element disposed on a silicon sub-mount having a light receiving element formed in a surface region. By virtue of integral arrangement of the light emitting element and the light receiving element, a single lens can be used for both optical transmission and optical reception, whereby an optical communication system can be manufactured very inexpensively. Further, transmission and reception can be carried out simultaneously.