Linescan Detector Interface
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2005-Apr-04
This disclosure relates to a tester specifically aimed to gather time -to-failure data of monochrome and colour CRT displays in a thermal stress environment at a manufacturing plant. It provides a method of interfacing and controlling 16 linescan detectors simultaneously. The next two articles are related to this article.
Linescan Detector Interface
disclosure relates to a tester specifically aimed to
gather time -to-failure data of monochrome and colour CRT displays in
a thermal stress environment at a manufacturing plant. It provides a
method of interfacing and controlling 16 linescan detectors
simultaneously. The next two articles are related to this article.
prediction on display products requires time-to-failure
data during accelerated ageing. Such data are not currently
collectable due to the harsh environment in which the tests take
place. This system allows the required data collection and
predictions for life and fallout rate in the field over the duration
of the life of the product.
testing of display products can take from 24 to 48
hours to complete. Due to the unpleasant environment which exists in
the test chambers (-5 degrees C to +60 degrees C), the quantity of
displays tested simultaneously, testing overnight and during
weekends, it is not possible to manually collect the time-to-failure
data. Also, opening the door of the test chamber has an adverse
effect on the quality and repeatability of the test due to cold or
warm temperature zones in the vicinity of the door, depending on the
prevailing test conditions.
Accurate time-to-failure data is required
for two main reasons.
First the test is conducted under thermal stress conditions with
rapid acceleration of the product ageing process if accurate
predictions are to be calculated for field-return patterns. Also,
these data will allow the optimization of the reliability test and
the quality of the predictions to be improved.
implemented test system exists to provide such data. It
consists of four major parts - the detectors used in the test
chambers, 16-channel receiver cards to which this disclosure relates,
a bus interface and control card and software to drive the tester.
The software is written in 'C' and runs on an IBM PS/2* mod 70.
There are six
16-channel input cards required in the system,
one for each bank of 16 displays being tested. The inputs to this
card come from the detectors. The function of this card is to reduce
the amount of hardware in the PS/2 required to obtain the
time-to-failure data. The card consists of 16 discrete input
channels, the self-test drive circuitry, status display, bank
selection logic and backplane buffer circuits. In the case of a
large system where many displays require to be monitored, without
multiplexing it would become physically impossible to fit the
required I/O cards in the PS/2 due to a shortage of expansion slots.
Each input c...