US 4677531

Patent Overview: US 4,677,531 — "Inspection Illumination Device"

Bibliographic data (from supplied text): U.S. Patent 4,677,531 A; application US06/824,895; inventor Donald M. Szeles; assignee Applied Intelligent Systems, Inc. (original and current assignee listed); priority/filing date 1986-01-31; granted and published 1987-06-30; anticipated expiration 2006-01-31; status "Expired - Lifetime."

Purpose: The device supplies specialized illumination for automated inspection—particularly printed circuit boards at an intermediate fabrication step, where component leads are inserted through board holes and must be imaged by video cameras for "artificial vision" inspection. The stated goal is to illuminate as wide an area as possible, at relatively low cost, while accommodating different board sizes, attitudes, and lead configurations.

Plain-language scope: A rectangular housing connects to a remote light source via elongate bundles of optical fibers. A clamping assembly holds the bundles in a linear array at a point spaced from their ends; between the clamp and the housing the bundles fan out, with their ends entering a rectangular opening in one end wall arranged in rows (about three rows) to provide substantially uniform illumination across the opening's cross-section. At the opposite end, a rectangular glass lens is flat on its inner face and convex about a single axis. Inside the housing, between the fiber ends and the lens, an apertured plate masks dispersing light so all light passing the aperture strikes the lens's inner flat face; this partially collimates the light and reduces scattered and reflected light. A linear polarizer may be mounted immediately behind the apertured plate. The aperture is placed approximately midway between the end wall and lens. The output is described as a substantially rectangular beam of uniform intensity, substantially focused in one dimension over a substantial depth. The described components may be metal, with interior surfaces coated black and non-reflective.

What the excerpt does not establish: It does not give the full text of the claims or dependent-claim structure; complete description text (the excerpt is expressly partial); any prior-art references, comparisons, or examination history; the exact number, ordering, or scope of claims; or details of Figures 3–6 beyond their captions.

Source: https://patents.google.com/patent/US4677531/en