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Presented
at the SID Display Applications Conference, October 24,2007
Click
here to view slide show on Resized LCD's.
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Resized LCDs, A Proven Alternative
by
Lawrence E. Tannas, Jr.
President
Tannas Electronic Displays, Inc.
Orange, California
for
SID Display Applications Conference
October 24, 2007
Abstract: Since the first publications of resized LCDs
in May of 1999 (Ref 1 & 2), they have been used in simulators, avionics
and as replacements for custom LCDs, CRTs, ELDs and Plasma Panels. Resized
LCDs have been qualified to aerospace requirements by three independent
companies (Ref 3, 4 & 5). The COTS LCD glass is literally cut, or
resized, to a new and smaller size and resealed without diminishing its
performance.
Introduction: A new generation of LCD glass has been
developed using the TANNAS-SIZED™ LCD process. New commercial-off-the-shelf
(COTS) LCDs have been resized for many applications.
TED has been resizing LCDs for eight years. TED, a wholly-owned company
of Tannas Electronics, has licensed the technology and is selling product
to the industry at large. Custom-sized and custom-shaped LCDs never considered
possible before have been demonstrated at SID, SPIE and other Symposia.
The technology consists of taking a COTS LCD and physically cutting the
glass, polarizer and circuit boards to a new size and resealing it without
diminishing its original performance as specified by the LCD manufacturer.
The TANNAS-SIZED™LCD process opens up a vast source of custom sizes
for avionics, vehicular electronics, aerospace and industry at a fraction
of the cost and lead time of custom-made displays. The resized LCDs are
being used to replace custom-made LC, EL, PDP and CRT displays.
The cost of making a resized LCD by patented and proprietary methods is
low and, typically, there is no NRE or minimum order. Nominal lead-time
is six weeks.
Resizing Design Rules: The primary objective is to make
the sizes needed to fit the task in a cost-effective manner. The first
principle is to use as much of the original LCD as possible; secondly,
be minimally invasive with all remaining parts. In the TANNAS-SIZED™
LCD process, the polarizers, TABs and LC material are preserved. Many
other things could be changed but, thus far, this has not been found necessary.
The organization of the TABs, where used, dictates the most cost-effective
way for resizing as shown in Slide 4.
The glass does not need to be cut at the edges of a TAB, but the remaining
TABs dictate the remaining number of active lines available for an image.
Some LCDs use in-situ row drivers. In such cases, the horizontal cut can
be made at any row. The LCD can be cut in either the horizontal or vertical
direction or in both on the same display. Further, the corner away from
the row and column drivers can be cut off in any manner without affecting
the performance of the balance of the display as shown in Slide
5. This cut is preferably in a straight, diagonal line at any angle.
The other corners can be diminished; but if cut into the active area of
the display, the cut row or column lines will be lost.
The row and column circuit boards and circuits are primarily shift registers
and can be cut off at the ends opposite the input with no consequence
on the performance of the shift register or LCD. The input sync signals
retain the same timing and the software remains the same. Obviously, the
part of the image that would have been in the removed portion of glass
is not displayed. The remaining viewable image is dictated by the remaining
row- and column-driven lines and LCD glass. There may be other components
on the circuit boards that will need to be moved before the down-stream
ends of the circuit boards can be removed. However, this is most often
not the case and the circuit boards can usually be cut along the same
line as the LCD glass. This leads to a neat and cost-effective resized
LCD. It is sometimes necessary to reorganize the column circuit board
and reattach it to the TABs. If possible, this should be done without
removing the TABs from the glass.
After resizing, the new seal is made narrower than the original seal.
The detailed dimensions of the seal are shown in Slide
6. However, a seal narrower than 0.050” (1.27mm) has been found
to be difficult to achieve.
Qualification Testing: The TANNAS-SIZED™ LCDs have
been tested and they have successfully passed the commercial avionics
ARINC FTCA/DO-160 Section Category B,
Severe Humidity Environmental test. This is a non-operating, ten-day,
24-hour cycle between 65°C and 38°C at 95% RH.
TANNAS-SIZED™ LCDs have been tested by J. Thomas
and P. Lynes of General Dynamics, Canada, to the harsh land-military environment
of the M1A2-SEP tank (Ref. 4). The resized LCD was made by Symbolic Displays,
Inc., a Licensee of the TANNAS-SIZED™ LCD process to replace an
EL display. It successfully passed a series of Mil Qualification tests.
TED has life-tested several resized LCDs. The longest test has been on
a Sharp 13.3” LQ13x023 resized (on Feb. 04, 2003) to an 8”x8”
display for the SID International Symposium of May 2003. Except during
power outage and disconnection for travel, it has operated continuously
ever since with no significant degradation. Ten resized NEC NL10276BC16-01s
have been continually operated approximately one year each with no significant
degradation.
TED has tested the resized seal in a very severe temperature cycle. Seals
are tested from immersion in boiling water to wrapping in dry ice for
five cycles over a ten-hour period. Everything fails except the LC material
between the glass, the original manufacturer’s seal and the TED
reseal.
As reported in a technical paper by David Craig, BAE Systems, (Ref. 3),
under his direction, extensive testing was done on BAE-remanufactured
LCDs. In Mr. Craig’s conclusion he states: “Our general conclusion
from all the testing to date is that the resealed panel is as robust as
the original; and that environment difficulties are more likely to be
experienced with the other aspects of the remanufacturing process, for
example protection of polarizers from UV and humidity.” Today, modern
polarizers are much more resistant to UV and humidity than in the year
2000 at the time of the testing.
Size and Shape Options: LCDs can be resized in many ways
and in a cost-effective way, as summarized in Slide 13. Resized cuts of
0.200 inches to 30 inches have been performed by TED and any one LCD can
be resized many ways. The example of an LCD resized several ways as shown
in Slide 12 is made from an NEC NL10276BC16-01 display. The advantages
of multiple sizes made from the same COTS LCD is that one LCD model can
be inventoried at the COTS cost for several end items. Further, they would
all have the same interface electronics. The resizing can be done at the
time the display is needed. Thus, the inventory cost is very low. This
cost is in the realm of hundreds of dollars each compared to the inventory
cost for custom displays that is in the range of thousands of dollars
each.
The resizing of a 30-inch LCD is shown in Slides
14, 15 and 16. The resized 30-inch LCD is to replace an obsolete plasma
panel in neon orange, Slide 16.
The first application of a resized LCD was performed by Symbolic Displays,
Inc., for an Apache Longbow Cockpit simulator, Slide
18. Of particular note is the F-35 8”x20” simulator display
made by Driven Technologies, Inc., Slide
20. Inertial Aerospace Services, Inc., is developing a replacement
D-size LCD using resized glass, Slide
21.
Summary: In every way, resized LCDs are proving to be
viable, versatile, rugged and cost-effective. Further, they are significantly
less expensive than custom LCD sizes presently made for the aerospace
industry.
References:
1. Lawrence E Tannas, Jr. “ Resizing COTS AMLCDs for Avionics Application”,
SID International Symposium, San Jose, May 1999;
2. Lawrence E Tannas, Jr., “AMLCD Resizing”, Presented at
SPIE Conference 4362, 19 April 2001, Cockpit Displays VIII, Orlando, FL.
3. David M. Craig, “LCD cutting process: remanufacture of 4:3 aspect
commercial into 1:1 avionic display”, Pro SPIE Vol. 4022 (2000)
pp313-320
4. J. Thomas, P. Lynes, “Concept Validation for a Resized AMLCD
Used in a Land- Mobile”, SPIE, Aug. 29, 2000;
5. Dr. Priya R. Brendale, Manager R&D, Interface Displays & Controls,
SPIE Symposium on Defense & Security Display Technologies & Applications
for Defense, Security and Avioinics, 12 April, 2007, Orlando, FL;
;
TED Tannas
Electronic Displays, Inc. ///
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