We Engineer Light
High Bright Displays Offer a Low Power High Bright Solution
VarTech has engineered a new low power,
high bright, sunlight readable technology which increases
ruggedness and product life without increasing heat.
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 -40°C, but as
well be adequately readable when exposed to extreme optical
conditions such as direct and/or indirect sunlight, glare
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 6.6 nits (contrast ratio of 300:1).
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.
Another approach is the use of passive enhancement
technology such as transflective films. A transflective LCD
is by definition a compromise. Throughout outdoors environments,
some of the ambient light is reflected by the screen. As the
ambient light gets brighter, the screen is supposed to look
better and in reality it will only look its best in direct
sunlight and of course this isn't at all feasible in real
world life. Indoors, however, only a fraction of the backlight
is transmitted through the LCD, so the screen tends to look
dim and low-contrast, with muted colors. Although transflective
films are designed to reflect ambient light back out of the
LCD display to augment its performance in direct sunlight,
transflective panels have insufficient transmissive luminance
(typically ~200 nits) to be considered usable in diffuse lighting
conditions where direct sunlight is not available (e.g., cloudy
or rainy days).
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 800 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 has coupled this technology with
the usage of harsh duty, very wide operational temperature
LCD cells, typically with a -50C to +100C clearing range.
Additionally, each panel is engineered with VarTech’s proprietary
Enhanced Light Transmission Technology (ELTT) and Optical
Bonding (VBOND), a UV protected solid, transparent bond. This
procedure permanently bonds the front protective glass overlay
or touch screen directly to the frontal face of the display.
VarTech’s unique optical bond eliminates reflection from the
two internal layers and utilizes an adhesive that matches
the index of refraction of the flat panel and the overlay.
As well, the outer surface of the protective window is chemically
treated with anti-reflecting coatings which matches the front
surface of the glass with the index of refraction of air.
This combination reduces the total reflection of the display
and front cover glass to less than 2% of the ambient light.
A reduction of reflection of this level, all but eliminates
reflective loss in most ambient lighting conditions. With
reductions of this level, displays with 250 to 450 nits of
brightness (cd/m2), traditionally not viewable in direct sunlight,
will now be readable in very high ambient brightness or indirect
lighting conditions. This method also removes all air gaps,
therefore reducing the number of internal reflecting surfaces
which can lead to significant degradation of the LCD’s optical
performance. For more information regarding our VBOND process,
please click here.
Currently VarTech’s new LED backlight technology
has beeen successfully implemented into our new All-Weather
series products and can achieve complete sunlight
readability luminance levels ranging from approximately 800
to 1500 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
High color gamut achievable with
high power LED
Increased product life, 100,000
hours…that’s 200% longer than tradition CCFL
Lower EMI (Electromagnetic Interference)
Not effected by external ambient
interferences such as fluorescent inverters from overhead
lights or audio devices
More realistic transitions depicting
Wide thermal range without heaters
Increased shock and vibration
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
here to view Vartech's All-Weather All-Terrain
series of products.