The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 26, 1985
Filed:
Jun. 02, 1982
Joseph J Crane, Woodbridge, VA (US);
Daniel T Beasley, Springfield, VA (US);
Crosfield Data Systems, Inc., Springfield, VA (US);
Abstract
A scanning system using at least one mirror for scanning material to read (or alternatively to be written upon) with a laser beam is provided. Air under pressure is fed into a hollow shaft and escapes through a turbine on the shaft to rotate the shaft. The shaft is supported by air bearings. The shaft rotates the mirror during scanning. Air pressure escaping from the air bearings is vented to the ambient atmosphere. Two special thrust bearings are provided to improve the stability of the shaft. Each thrust bearing applies a force on the shaft in a direction parallel to the axis of the shaft and opposite to the force applied by the other thrust bearing. Each thrust bearing comprises a cavity in the housing, a flat plate attached to the shaft, and a porous bronze plate between the cavity and the flat plate. The air pressures in the two cavities are separately adjustable to enable the operator to select pressures that provide the system with maximum stability. The air under pressure in each cavity passes through the porous bronze plate associated with the cavity to apply pressure to the flat plate (that is attached to the shaft) associated with the cavity.