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:
Jun. 10, 1997
Filed:
Dec. 07, 1994
Yasuhiro Oomura, Tokyo, JP;
Nikon Corporation, , JP;
Abstract
Illumination light having passed a pattern formed on a first surface enters a beam splitter directly or through a refracting system. On this occasion, inside the beam splitter, at least part of the illumination light having passed through an entrance surface is transmitted or reflected by a direction changing surface and then passes through an exit/entrance surface. Subsequently, the illumination light first leaving the beam splitter is reflected by a reflective surface of a concave mirror and then again enters the beam splitter. On this occasion, inside the beam splitter, at least part of the illumination light having passed through the exit/entrance surface is reflected or transmitted by the direction changing surface then to pass through an exit surface. The illumination light thus again leaving the beam splitter is projected directly or through a refracting system onto a second surface to form an image of the pattern thereon. Here, an orthogonal projection area of the direction changing surface on the exit/entrance surface is made different from an area of the exit/entrance surface, whereby the beam splitter is constructed in a decreased size.