Browse Prior Art Database

Automated Inspection of Card Holes for Inserted Leads

IP.com Disclosure Number: IPCOM000040659D
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 3 page(s) / 58K

Publishing Venue

IBM

Related People

Kishi, GT: AUTHOR [+2]

Abstract

An analysis routine is described that utilizes video grayscale image data and processes the image to determine the presence or absence of leads in a hole of a printed circuit card by analyzing the shape of the hole. The routine is based on the fact that the holes in a printed circuit card are round, and that any lead present in the hole "spoils" the roundness of the hole. The image of a hole at a given threshold is an empty circular area surrounded by a bright region (the copper pad on the printed circuit card.

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Automated Inspection of Card Holes for Inserted Leads

An analysis routine is described that utilizes video grayscale image data and processes the image to determine the presence or absence of leads in a hole of a printed circuit card by analyzing the shape of the hole. The routine is based on the fact that the holes in a printed circuit card are round, and that any lead present in the hole "spoils" the roundness of the hole. The image of a hole at a given threshold is an empty circular area surrounded by a bright region (the copper pad on the printed circuit card.) *******************************

************** **************

********** **********

******** ********

****** ******

***** hole *****

***** *****

****** ******

******** ********

********** **********

************** ******pad*****

******************************* The routine determines the location of a rectangle (of width slightly narrower than the width of the hole) which it fits in the hole. The distance from the top of the rectangle to the top of the hole is measured. The distance from the bottom of the rectangle to the bottom of the hole is also measured. The distances to the top, bottom, left and right sides of the hole are measured (from its theoretical center.) *******************************

************** **************

********** **********

********XXXrectangleXXX********

****** X X ******

***** X hole X *****

***** X X *****

****** X X ******

********XXXXXXXXXXXXXXX********

********** **********

************** ******pad*****

******************************* The distance from the top of the rectangle to the top of the hole is shorter when a lead is present at the top of the hole. *******************************

**************lead***...