摘要:
In an aperture stop mechanism, two aperture blades are arranged so as to overlap each other and form a single light passage opening into which light utilized in imaging is introduced with the respective edge portions of the two aperture blades. A drive mechanism drives the two aperture blades in directions different from each other, whereby the aperture area of the light passage opening is changed within a predetermined range. When the two aperture blades are located at a minimum aperture position where the aperture area of the light passage opening is minimum within the predetermined range, the two aperture blades are provided so that the single light passage opening surrounded by boundaries including eight straight lines is constituted of the respective edge portions of the two aperture blades.
摘要:
In an aperture stop mechanism, two aperture blades are arranged so as to overlap each other and form a single light passage opening into which light utilized in imaging is introduced with the respective edge portions of the two aperture blades. A drive mechanism drives the two aperture blades in directions different from each other, whereby the aperture area of the light passage opening is changed within a predetermined range. When the two aperture blades are located at a minimum aperture position where the aperture area of the light passage opening is minimum within the predetermined range, the two aperture blades are provided so that the single light passage opening surrounded by boundaries including eight straight lines is constituted of the respective edge portions of the two aperture blades.
摘要:
Nitrous oxide contained in a gas is directly decomposed by contacting the gas with a catalyst layer composed mainly of tin (IV) oxide at a reaction temperature of not less than 250.degree. C., preferably not less than 300.degree. C. Particularly when a cobalt (II) compound is added to the catalyst layer, nitrous oxide can be effectively removed to a low concentration by contacting the gas with the catalyst layer at the reaction temperature of not less than 200.degree. C., preferably not less than 300.degree. C. By the present process, nitrous oxide which has not conventionally effectively removed can be reliably removed at a low cost. The present process can be applied for the removal of nitrous oxide in exhaust gases discharged from a sludge-incinerating furnace, a boiler fine powder coal combustion furnace, etc.