VarTech’s LED-enhancement
– We Engineer Light
An increased number of LCD-based products
are being utilized in high ambient light conditions, typically
outdoors in direct sunlight. The need has become significantly
greater for them to not only be able to withstand extensive
operational temperatures, sometimes down to -40C, but as well
be adequately readable when exposed to extreme optical conditions
such as direct and/or indirect sunlight, glare and reflection.
Most “off-the-shelf” LCD flat
panels are not properly equipped to handle most rigors of
outdoor conditions. The traditional approach has been the
integration of additional CCFL, cold cathode fluorescent lamps,
to increase luminance levels. This method, while producing
the desired readability effect, has five significant drawbacks.
First, the use of added CCFL increases the amount of heat
needed to be dissipated away from the monitor. This is typically
accomplished through the use of an extensive and costly thermal
management system. Second, added backlights will increase
the amount of power required to sufficiently operate the display
system. For example, a non-actively enhanced display might
use 30 watts of power, while an actively enhanced approach
using added CCFL might increase power consumption up to 85
watts. Third, driving the enhanced backlights to optimal potential
will significantly reduce the expected life of the backlights.
This could result in costly repairs when backlights begin
to fail.
Fourth, the use of enhanced wattage CCLF
backlights, as we mentioned, is used to increase the luminance
of an LCD. Imagine, as an example, that a typical LCD monitor
has a white luminance of 200 nits and a contrast ratio of
300:1 (black luminance of 0.66 nits) and the newly integrated
backlights then enhances by ten times the white luminance
to 2,000 nits. A display's brightness, typically referred
to as a Nit (Candela per meter/2) is the amount of light energy
coming out of the display. While the display is unarguably
brighter, the increased brightness will not have much effect
in direct sunlight if the “black luminance” is
correspondingly increased from 0.66 nits to 660 nits (contrast
ratio of 3.03). Finally, added CCFL backlights significantly
increases the amount of electro magnetic interference (EMI).
This can be an important issue if the monitor will be positioned
near other mission critical electronic devices.
VarTech Systems has developed a
ground-breaking LED backlight technology. This new
technology creates an amazingly bright LCD display without
increased heat from higher wattage CCFL integration. LED backlight
technology when coupled with a liquid crystal display (LCD)
provides the best of both worlds – a high brightness
LCD monitor with low power consumption.
VarTech’s LED backlighting was developed
for displays requiring a luminance level of at least 700 nits
as required for outside viewing. When compared to the practice
of adding higher wattage backlights to achieve a high brightness
LCD (CCFL), LED backlight technology increases the reliability
of the high bright monitor and extends the lifetime of the
display system. This new technology by VarTech creates a sunlight
readable monitor with inherit protections against environmental
factors such as shock, vibration and frigid temperatures.
LED backlighting technology enables all these benefits while
maintaining reasonable thermal levels of the LCD.
VarTech’s new LED backlight technology
will soon be implemented and can achieve complete sunlight
readability luminance levels ranging from approximately 800
to 1300 nits at low power consumption levels. With VarTech’s
new LED high bright technology, a 15” 1000 nit LCD will
consume approximately 24W of power compared to our equivalent
15” actively enhanced CCFL solution which consumes 65W.
Additionally, VarTech’s LED backlighting systems do
not require heaters as needed by CCFL solutions for use within
extreme low temperature ranges. This is beneficial in many
outdoor applications that operate in frigid temperatures and
immediate LCD response time operation is critical. The LCD
can immediately be turned to full brightness without any lag
time which can typically be caused by the use of integrated
heaters.
VarTech’s LED backlight enhancement
offers a number of key benefits over traditional CCFL enhanced
solutions:
Improved ruggedness
Increased reliability
Increased product life, 100,000
hours…that’s 200% longer than tradition CCFL
Reduced EMI emissions
Not effected by external ambient
interferences such as fluorescent inverters from overhead
lights or audio devices
More realistic transitions depicting
day-to-night changes
Increased shock and vibration
protection
Improved dimming, flicker free
down to 0.5 nits
LEDs do not need heaters and
can be turned on to full brightness immediately
Display is less fragile than
a glass tube filled with pressurized gasses
As LED backlight begins its end-of-life
transition a single lamp may fail at varying times unlike
the loss of the entire backlight function with a CCFL high
bright
RoHS compliance
VarTech can also combine its LED technology
with its VBOND
process.
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