Browse Prior Art Database

Programmable Window Orthogonal Reduction Camera

IP.com Disclosure Number: IPCOM000110168D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 2 page(s) / 196K

Publishing Venue

IBM

Related People

Arldt, BD: AUTHOR [+4]

Abstract

Disclosed is a method to locate and inspect fine pitch component leads precisely and quickly. This method provides capability to examine any window of a component image. The window is programmable in position, height and length. The portion of the image admitted through the programmable window is orthogonally reduced to the axis of interest. To reduce the image orthogonal to the y-axis, light admitted along the x-axis is summed and collapsed into a single line in the y-dimension. Likewise, to reduce the image orthogonal to the x-axis, light along the y-axis is summed to a line in the x-dimension. To inspect and locate the leads of a component, the component is placed in front of the camera and each component side containing leads is sequentially inspected.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Programmable Window Orthogonal Reduction Camera

       Disclosed is a method to locate and inspect fine pitch
component leads precisely and quickly.  This method provides
capability to examine any window of a component image.  The window is
programmable in position, height and length.  The portion of the
image admitted through the programmable window is orthogonally
reduced to the axis of interest.  To reduce the image orthogonal to
the y-axis, light admitted along the x-axis is summed and collapsed
into a single line in the y-dimension.  Likewise, to reduce the image
orthogonal to the x-axis, light along the y-axis is summed to a line
in the x-dimension.  To inspect and locate the leads of a component,
the component is placed in front of the camera and each component
side containing leads is sequentially inspected.  To examine leads on
any side of the component, the camera is told to create a window at
and around the expected position of the leads.

      The figure depicts a cross-sectional view of optical flow
through the camera.  Component 1, which contains vertical leads 2 and
horizontal leads 3, is positioned and illuminated in front of the
camera.  An image reflected from Component 1 passes through infrared
filter 4, linear polarizer 5, Liquid Crystal Display (LCD) panel with
optical flats 6 and linear polarizer (analyzer) 7.  The LCD Panel 6
is a high contrast ratio row and column addressable LCD, similar to
that used in portable computer displays.  The purpose of LCD panel 6
is to allow windows of the image to be selected so that each set of
component side leads may be sequentially examined.  For example,
given a component with leads on all four sides (as depicted in the
figure), the first of the two horizontal lead sets may be examined,
followed by the second horizontal lead set.  Vertical leads are
examined in similar fashion.

      Once the image has passed through parts 4, 5, 6 and 7...