Browse Prior Art Database

Video Waveform Generator for Functional Tester

IP.com Disclosure Number: IPCOM000121768D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Grant, DA: AUTHOR [+2]

Abstract

An adaptation of a commercial functional tester of VDU analog cards to permit fast mass testing of video amplifiers with consequent improvement in manufacturing throughput.

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

Video Waveform Generator for Functional Tester

      An adaptation of a commercial functional tester of VDU
analog cards to permit fast mass testing of video amplifiers with
consequent improvement in manufacturing throughput.

      A functional tester built using commercial instrumentation and
custom-built electronic devices has the purpose of testing
mass-produced analog cards for visual display monitors.  The tester
is general- purpose in that specific card types are catered for by
the fixtures which connect to the test system.  During functional
testing of the monitor analog card, it is necessary to check the
switching speed and gain linearity of the video amplifliers.
Traditionally, this has been accomplished by taking many different
measurements on the output of the amplifier, each concerned with some
specific aspect of the waveform. Because each analog measurement
takes a significant period of time, several different measurements
are required to verify each output, and each output must be checked
at different gain levels.  For color monitors there are also three
outputs: RED, GREEN and BLUE.  Thus, for color displays much test
time is spent in comprehensively checking only three outputs of the
card under test.

      A circuit has been designed and incorporated in the described
tester which generates a video graphics adapter (VGA) level signal
that is used to drive the video amplifiers of the card under test.  A
crystal is used to feed a TTL counter which drives part of the
address bus of a bipolar PROM.  The remainder of the PROM...