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:
Dec. 21, 1993
Filed:
Aug. 28, 1992
Yuji Maruyama, Tokyo, JP;
Atsuharu Yamamoto, Kawasaki, JP;
Hidemi Takahashi, Zama, JP;
Hidehiko Kawakami, Tokyo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An inspection apparatus for inspecting a wiring pattern on a printed board by illuminating the printed board with light to photoelectrically convert light reflected from the printed board into an optical grey level image corresponding to the wiring pattern thereon, the grey level image being converted into a bi-level image. The inspection apparatus includes a thinning circuit to perform a thinning process for removing the bi-level image by one picture element from the background side of the wiring pattern, the thinning process being repeatedly performed predetermined times with respect to all of picture elements of the wiring pattern to output the number of repetitions of the thinning process and further to output a skeleton image. Also included is a distance image converter to output a distance conversion image where the number of repetitions is given as a distance value from the background of the wiring pattern. The inspection apparatus compares the distance value of the distance conversion image with one or more thresholds along the skeleton image. This arrangement allows direct detection of the wiring pattern width, thereby permitting the wiring pattern inspection with a simple structure.