Abstract: An optical pickup apparatus and a laser diode chip which can simplify and miniaturize a construction of the apparatus is provided for using a plurality of laser beams of different wavelengths. The laser diode chip is a chip for the optical pickup apparatus in which a plurality of light emitting portions for emitting the laser beams of the different wavelengths in the same emitting direction are formed on a substrate. Light emitting points of the plurality of light emitting portions are located at positions which are different in the emitting direction.

Abstract: An optical pickup apparatus includes a semiconductor laser device having a plurality of light emitting portions for emitting laser beams having different wavelengths on a substrate for emitting a laser beam from one of the plurality of light emitting portions in response to a light emitter selecting instruction in the same emitting direction. The laser beam emitted from the semiconductor laser device is converged by an objective lens and led to a recording surface of an optical disk, and the objective lens is moved to one of a plurality of different positions in a radial direction of the optical disk, corresponding to the selected light emitting portion.

Abstract: An adhesive composition particularly suitable for adhering polyvinyl chloride and an olefinic polymer comprising 1 to 99% by weight of post-chlorinated polyethylene having a mean molecular weight of about 20,000 to 200,000, a specific gravity of 1.00 to 1.35 and a chlorine content of 5 to 50% by weight and 99 to 1% by weight of polyvinyl chloride having a mean degree of polymerization of about 300 to 2,500.

Abstract: An adhesive composition particularly suitable for adhering polyvinyl chloride and an olefinic polymer comprising 1 to 99% by weight of post-chlorinated polyethylene having a mean molecular weight of about 20,000 to 200,000, a specific gravity of 1.00 to 1.35 and a chlorine content of 5 to 50% by weight and 99 to 1% by weight of polyvinyl chloride having a mean degree of polymerization of about 300 to 2,500.

Abstract: An adhesive composition particularly suitable for adhering polyvinyl chloride and an olefinic polymer comprising 1 to 99% by weight of post-chlorinated polyethylene having a mean molecular weight of about 20,000 to 200,000, a specific gravity of 1.00 to 1.35 and a chlorine content of 5 to 50% by weight and 99 to 1% by weight of polyvinyl chloride having a mean degree of polymerization of about 300 to 2,500.