Abstract: In a copier or input scanner wherein original documents are manually placed on a platen for scanning, when a platen cover is lowered over the document and approaches a closed position, a control system initiates a scanning operation while locking the platen cover in the closed position. After the scanning operation is completed, the platen cover is automatically pushed into an open position as a visual cue to the user that a new document may be scanned. The system facilitates manual scanning of odd-shaped documents, such as successive pages of bound books.

Abstract: In a copier or input scanner wherein original documents are manually placed on a platen for scanning, when a platen cover is lowered over the document and approaches a closed position, a control system initiates a scanning operation while locking the platen cover in the closed position. After the scanning operation is completed, the platen cover is automatically pushed into an open position as a visual cue to the user that a new document may be scanned. The system facilitates manual scanning of odd-shaped documents, such as successive pages of bound books.

Abstract: Xerographic copying apparatus includes an optical system for forming an optical image of an object to be copied on an electrically charged photoconductive surface, the optical image forming a corresponding electrostatic latent image on the surface, and means to develop the latent image with a particulate toner material. At least part of the optical system is housed in a substantially closed compartment, and imaging rays are directed out of the compartment in a generally horizontal direction through a substantially vertical transparent window in the compartment. A blower is provided to blow a curtain of air generally downwardly over the surface of the window outside the compartment, and to blow air into the optics compartment so as to cause a net outflow of air from the optics compartment.

Abstract: The compound 2,2-bis(4-hydroxyphenyl)propane is recovered in the form of rhombic crystals from an essentially non-crystalline mixture comprising 2,2-bis(4-hydroxyphenyl)propane, organic by-products of the condensation reaction of phenol and acetone, and phenol by lowering the temperature of the mixture from an elevated state to a temperature which is low enough to cause the separation of the phenol and 2,2-bis(4-hydroxyphenyl)propane in equimolar proportions as a crystalline adduct, recovering the adduct, forming a mixture of the adduct and water at an elevated temperature sufficient to completely melt the adduct, and thereafter lowering the temperature of the mixture of water and melted adduct to cause the separation of the 2,2-bis(4-hydroxyphenyl)propane in the form of rhombic crystals substantially free of the phenol. The crystals are easily handled and recovered by means such as filtration or centrifugation, and they can be formed into high quality polycarbonate molding resins.