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:
May. 31, 1988
Filed:
Jun. 17, 1986
Applicant:
Inventors:
Peter de Zoeten, Eindhoven, NL;
Albert Smid, Eindhoven, NL;
Assignee:
U.S. Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; H01J / ;
U.S. Cl.
CPC ...
350-68 ;
Abstract
A scanning device is described which comprises a rotationally symmetrical rotating reflecting facet disc (3) in which a scanning beam (2, 2') is focussed on a face (5, 6) of the facet elements (4). The sensitivity of the device to surface defects or dust particles on the faces of the facet elements can be reduced by means of a first astigmatic element (20) which widens the beam (2') issuing from the detector (10) at the location of the facet disc in a direction transverse to the scanning direction (18), while a second astigmatic element (21) cancels the astigmatism of the first element.