A shielding film is formed on the surface of a substrate and a pair of aperture patterns for light transmission with substantially the same line width are formed in the above shielding film so as to run parallel to each other with a gap and to be isolated from other aperture patterns for light transmission. One embodiment of the method may have the steps of: coupling a thermally conductive cover to the component via a single interface; and applying a cooling liquid to the thermally conductive cover to cool the component . The housing attaches directly to the return air duct so that the air inlet and outlet openings connect with complementary openings in the return air duct. 2) Vibrating each screen to expedite separation of the fibrous material and the fluid from the wet fibrous matter on each screen such that the fluid separated from the wet fibrous matter on each screen passes through the perforations and the fibrous material conveys along the screen. A crypt key system used for encrypting data uses a secret-key cryptosystem, a public-key cryptosystem or a cryptosystem combining a secret-key and a public-key and further uses a copyright control program to control data copyrights. In response to the scan information, entries associated with the machine-readable codes scanned by the end-user are retrieved from the database.