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:
Jan. 11, 1994
Filed:
Oct. 01, 1992
Roman E Popil, White Rock, CA;
Kevin C Houston, New Westminister, CA;
MacMillan Bloedel Limited, Vancouver, CA;
Abstract
A method and apparatus for detecting residual ink in a sample by illuminating by diffused infra-red light a series of spots on a sample and examining a small area on each spot by collecting light in a video camera to form a frame for each spot, digitizing each of the frame and detecting areas in the frames having a brightness below a selected level to determine the total dark area of each frame. The number of such frames processed in a set of frames used to categorize the sample is defined when a certain minimum number of frames have been processed and when a selected degree of convergence of the data collected for the set and the data from the frame currently being processed is obtained, or after a preset maximum number of frames have been processed. The sample is characterised on the basis of the ratio of the dark area to the total area processed.