Image analysis – Histogram processing – For setting a threshold
Patent
1988-03-25
1991-03-19
Boudreau, Leo H.
Image analysis
Histogram processing
For setting a threshold
382 22, 358106, G06K 900, G06K 948, H04N 718
Patent
active
050017640
ABSTRACT:
A laser pattern inspection and/or writing system which writes or inspects a pattern on a target on a stage, by raster scanning the target pixels. Inspection can also be done by substage illumination with non-laser light. A database, organized into frames and strips, represents an ideal pattern as one or more polygons. Each polygon's data description is contained within a single data frame. The database is transformed into a turnpoint polygon representation, then a left and right vector representation, then an addressed pixel representation, then a bit-mapped representation of the entire target. Most of the transformations are carried out in parallel pipelines. Guardbands around polygon sides are used for error filtering during inspection. Guardbands are polygons, and frames containing only guardband information are sent down dedicated pipelines. Error filtering also is done at the time of pixel comparisons of ideal with real patterns, and subsequently during defect area consolidation. Defect areas are viewed as color overlays of ideal and actual target areas, from data generated during real time. Defect areas can be de-zoomed to allow larger target areas to be viewed. An autofocus keeps the scanning laser beam in focus on the target. The inspection system is used to find fiducial marks to orient the target prior to raster scanning. IC bars are provided with alignment marks for locating each IC bar. Interferometers or glass scale encoders allow the stage position to be known.
REFERENCES:
patent: 3851951 (1974-12-01), Eveleth
patent: 4408342 (1983-10-01), Grabowski et al.
patent: 4541712 (1985-09-01), Whitney
patent: 4620288 (1986-10-01), Welmers
patent: 4776023 (1988-10-01), Hamada et al.
patent: 4783829 (1988-11-01), Miyakawa et al.
patent: 4837447 (1989-06-01), Pierce et al.
patent: 4853971 (1989-08-01), Nonura
Bademian, "Acousto-Optic Laser Recording", Optical Engineering, Jan./Feb. 1981, vol. 20, No. 1, pp. 143-149, (147).
Hammer, "In-Line Anamorphic Beam Expanders", Aug. 1982, vol. 21, No. 15, Applied Optics, p. 2861.
Bademian, "Acousto-Optic Laser Recording", SPIE, vol. 175, Airborne Reconnaissance IV, (1979), pp. 111-123, (117).
Merry, "Acousto-Optic Laser Scanning", SPIE, vol. 169, Laser Printing, (1979), pp. 56-59.
Manns William G.
Norwood David A.
Sheng Chyi N.
Weeks Don J.
Wood Anthony B.
Barndt B. Peter
Boudreau Leo H.
Comfort James T.
Cummarata Michael R.
Sharp Melvin
LandOfFree
Guardbands for pattern inspector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Guardbands for pattern inspector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Guardbands for pattern inspector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2016766