US 5,325,443 A · Vision system for inspecting a part having a substantially flat reflective surface

Abstract

The two sides of a flat panel are inspected in successive inspection stations each of which includes a camera having a linear array of CCD elements which generates an image line-by-line from a stripe of light reflected by one flat surface of the panel as the panel is conveyed through the inspection station. The signals representing images of the two faces of the panel are independently digitized and stored in separate pixel arrays of gray-scale values. The images are queued for filtering followed by processing by a single image processing board which generates a table of hits, identified as pixels having gray-scale values which breach preselected thresholds. Sections of the stored pixel array are transmitted sequentially to the image processing board which has a frame size smaller than the stored array, with the frame sized sections overlapping as required to confine the pixels processed to those inside the edges of the panel image. A microprocessor analyzes the hits identified by the image processing board and generates a reject signal if the density of hits exceeds a limit. The microprocessor also associates hits by proximity into blobs and rejects the panel if a weighted count of hits in any blob exceeds predetermined criteria.

Claims17

Dependent claims

A vision system for inspecting a part having a substantially flat reflective surface, said system comprising:

optical data acquisition means including:
light source means directing light at the substantially flat reflective surface, and
camera means generating pixel gray-scale values for light from said light source means reflected from said flat reflective surface;
and
vision processor means comprising:
storage means storing a pixel array of gray-scale values generated by said camera means;
an image processing board processing said pixel gray-scale values to identify from said gray-scale values pixels meeting preselected criteria, said image processing board having a frame size covering an array of pixels smaller than the pixel array stored in said storage means;
transfer means successively transferring to said image processing board for processing, gray-scale values for successive frame sized sections of the pixel array of the storage means until the gray-scale values for all of the pixels of said pixel array have been processed by the image processing board, and wherein said transfer means includes means transferring to said image processing board gray-scale values only for sections of the pixel array of said storage means corresponding to a portion of the substantially flat reflective surface which is more than a predetermined distance inside the edges of said part;
and
processing means evaluating said identified pixels and generating an output based thereon.

7 more elements

Dependencies are inferred from the claim text.

Vision system for inspecting a part having a substantially flat reflective surface

Life of this patent

Vision system for inspecting a part having a substantially flat reflective surface

Life of this patent

Abstract

Claims17