Abstract: All operations available on an intranet are securely performed from an outside of the intranet without taking out a file on the intranet from the intranet. A file on the intranet is not taken out, but, instead of this, image information on a target computer 1 is transmitted to an operational computer 4 with the http protocol, the https protocol, or the SSL protocol, and keyboard information, pointing information, or the like are transmitted from an operational computer 4 to the target computer 1. Consequently, the target computer 1 is operated.

Abstract: All operations available on an intranet are securely performed from an outside of the intranet without taking out a file on the intranet from the intranet. A file on the intranet is not taken out, but, instead of this, image information on a target computer 1 is transmitted to an operational computer 4 with the http protocol, the https protocol, or the SSL protocol, and keyboard information, pointing information, or the like are transmitted from an operational computer 4 to the target computer 1. Consequently, the target computer 1 is operated.

Abstract: An optical head for use with an optical disk has a unit packaging an optical path conversion device for converting a light beam path from substantially in parallel to the surface of a rotating optical disk into a direction substantially perpendicular to the surface of the optical disk, a lens system for focusing the light beam onto the recording surface of the optical disk, and a focus controlling mechanism for adjusting the focus of the lens system. A head outer shell supports the unit by one or more diaphragms for movement of the unit in the parallel direction of the optical path. A track control mechanism which includes an electromagnetic actuator adjusts the positional relation of the unit relative to outer shell in that parallel direction without causing unit movement in the perpendicular direction.