Abstract: A cleaning blade for use in an electrophotographic apparatus, which rubs and eliminates residual toners. The cleaning blade is made up of polyrethane resin sheet controls chipping of a top end of the cleaning blade and reduces an abrasion of a photosensitive drum. The cleaning blade is prepared by mixing and hardening at least a prepolymer, which is obtained from butylene adipate polyester polyol, hexylene adipate polyester polyol and polyisocyanate, and a hardening agent including a low molecular weight polyol and potassium acetate so that a mol ration (&agr; value) of hydroxyl group to isocyanate group becomes not less than 0.7 and not more than 0.9.

Abstract: A cleaning blade mainly has polyurethane resin, which is mainly installed in an electrophotographic apparatus and rubs and eliminates residual toners control chipping of a top end of the cleaning blade and reduces an abrasion of a photosensitive drum. The cleaning blade is prepared by mixing and hardening at least prepolymer which is obtained from butylene adipate polyester polyol, hexylene adipate polyester polyol and polyisocyanate and the hardening agent including low molecular weight polyol and potassium acetate so that a mol ratio (&agr; value) of hydroxyl group to isocyanate group becomes not less than 0.7 and not more than 0.9.

Abstract: A stem for a semiconductor laser device of a terraced substrate structure which has a tilted active layer against flat parts of the substrate, the stem comprises a base plate and a heat sink block, a flat face of the heat sink block for bonding the semiconductor laser device thereonto is tilted with respect to a base face of the base plate; this stem has features that the polarization direction of the lased light from the semiconductor laser device can be set to be parallel to (or perpendicular to) the base face of the base plate, and therefore it becomes much easier to make adjustments related with the polarization direction of the lased light.

Abstract: A terraced semiconductor laser comprising semiconductor layers (10, 11, 12) including an active layer (11) formed on a terraced semiconductor substrate (9) in a manner to have an inclined part (111) ranging from the position above said step to the part shifted to the side of said thinner part,an overriding layer (13) having the opposite conductivity type to that of the uppermost layer (12) of said semiconductor layers (10, 11, 12) and formed on said uppermost layer (12),characterized by further comprising:a last layer (14) having the same conductivity type to that of the overriding layer (13) formed on the latter layer (13),said last layer (14) having a stripe-shaped through-opening (141) at the position which is a shifted position from the part immediately above said inclined part 111, thereby exposing a surface of said overriding layer (13) at the bottom of the through-opening (141),a conduction region (15) formed at least on the bottom and side faces of said stripe-shaped opening, in a manner to reach and