Autofocus system with error compensation

Optics: measuring and testing – Position or displacement – Position transverse to viewing axis

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C356S614000

Reexamination Certificate

active

07982884

ABSTRACT:
An autofocus system (222C) for measuring the position of a work piece (200) along an axis includes a slit light source assembly (236), a slit detector assembly (238), and a control system (224). The slit light source assembly (236) directs a first slit of light (342A) at a first slit area (344A) of the work piece (200). The slit detector assembly (238) detects light reflected off of the first slit area (344A) and generates a first slit signal relating to the amount of light reflected off of the first slit area (344A) at the slit detector assembly (238). The control system (224) uses the first slit signal from the slit detector assembly (238), and first reflectance information of the first slit area (344A) to determine the position of the work piece (200) along the axis. With this design, the autofocus system (222C) can compensate for the changes in reflectivity of the work piece (200). As a result thereof, measurements taken with the autofocus system (222C) are more accurate and the work piece (200) can be positioned with improved accuracy.

REFERENCES:
patent: 5602399 (1997-02-01), Mizutani
patent: 5661548 (1997-08-01), Imai
patent: 6034780 (2000-03-01), Kato
patent: 6333776 (2001-12-01), Taniguchi
patent: 6414743 (2002-07-01), Nishi et al.
patent: 6977728 (2005-12-01), Nakauchi
patent: 2007-192685 (2007-08-01), None
International Search Report and Written Opinion for PCT/US2008/084238 (related to the present application), publication date Feb. 3, 2009, Nikon Corporation.
International Preliminary Report on Patentability for PCT/US2008/084238 (related to the present application), publication date Jun. 10, 2010, Nikon Corporation.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Autofocus system with error compensation does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Autofocus system with error compensation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Autofocus system with error compensation will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2687519

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.