Outdoor laptop with sunlight readable display
Getac has released a rugged outdoor laptop with a very advanced sunlight readable display – the B300.
What Getac calls “QuadraClearTM Technology” increases screen brightness and uses a proprietary anti-reflective technology to enable daylight view-ability six times better than previous solutions. If you need to use a laptop outdoors, or in a vehicle, this technology is fantastic.
Computer displays aren’t valuable if you can’t read them, and bright sunlight can easily make most screens nearly unusable. In order to avoid errors, diminished productivity, physical danger, and eye strain, highly visible displays are essential for users of rugged mobile devices, from law enforcement and military personnel to utility workers and in-vehicle deployments.
Increased brightness, reduced reflectivity
There are two conventional approaches to optimizing view-ability—increasing the level of screen brightness and decreasing reflectivity (typically with anti-reflective screen coatings). A key issue with increasing screen brightness is that a brighter fluorescent backlight consumes dramatically more power, cutting battery life in portable devices. Anti-reflective coatings tend to be expensive; they can add to the cost of a touchscreen by as much as a factor of three to four. Both methods are significantly limited in their ability to improve display appearance in bright sunlight on their own.
Getac’s solution combines proprietary technologies for both screen brightness and anti-reflectivity to overcome these limitations. QuadraClearTM technology enables display view-ability that is more than six times better than competing solutions, while still maintaining the battery life required in a mobile device like an outdoor laptop.
QuadraClear™ technology allows notebook displays to be visible even in the harshest direct sunlight. There are four main elements:
- High-Brightness: QuadraClear™ requires a display with a minimum 1200 NITs* brightness.
- Anti-Reflective Coatings: Anti-reflective coatings are the first defense to reduce the reflections from the sun’s powerful rays.
- Linear Polarizer: The linear polarizer blocks one axis of the sun’s rays that enter the monitor’s glass.
- Circular Polarizer: A quarter-wave retardation film creates a circular polarization that will cause the remaining axis of the sun’s rays to be blocked as it passes back through the linear polarizer.
* For more information on Nits, go to: http://en.wikipedia.org/wiki/Nit_(unit)
The reduction of reflected light enabled by circular polarization
The key means of increasing outdoor view-ability is to increase the contrast between the information being displayed and the sunlight being reflected by the screen. One simple “brute force” method is to increase the display brightness in an effort to compete with the sun.
Typical displays are generally in the range of 250 to 1,000 NITs.
Because of the power limitations mentioned above, it is difficult for manufacturers to go beyond these levels. To compensate for this power drain, default power schemes often automatically dim the display when it is on battery power, which is precisely when users need maximum display brightness.
For QuadraClear™, Getac created a display backlight based on light-emitting diode (LED) sources to replace the cold cathode fluorescent lamps (CCFLs) that are commonly used. The less diffused light from an LED enables a power-efficient, super-bright display operating at 1,200 NITs, without sacrificing battery life or resorting to undesirable power-management schemes.
LEDs Overcome Florescent Limitations
Energy Efficient: LED display backlights can save significantly on power and heat, relative to CCFLs.
- Mercury-Free: Unlike CCFLs, LEDs contain no mercury, enabling regulatory compliance.
- Durable: The solid-state construction of LEDs tends to be more durable than glass-enveloped CCFLs.
- Consistent: LEDs have a superior profile to CCFLs in terms of deteriorating in brightness over time.
Active Anti-Reflective Process is Superior to Coatings Alone
While the super-bright backlight technology is very valuable, Getac engineers know that it is only one part of the solution. Direct sunlight is typically in the range of approximately 10,000 to 100,000 Lux, significantly higher than displays.
Touchscreen displays typically have five layers, and each untreated touchscreen layer reflects approximately four percent of the sunlight. Those reflections can easily overwhelm the brightest backlights alone, making anti-reflective technology vitally important for an outdoor laptop.
Getac QuadraClear™ Sunlight Readable Technology uses an active anti-reflective process based on circular polarization to block reflected light, dramatically increasing view-ability, even under the harshest daylight conditions. The net effect of this technique in reducing the amount of light reflected back from a display is shown in Figure 1.
On the top of Figure 1, approximately four percent of the light incident on each surface is reflected back (depending on the layer’s composition), with an additive effect that results in as much as 20 percent of the ambient light being reflected back to the user. On the right, circular polarization blocks almost all reflection from the display layers behind the outermost layer. Combined with an antireflective coating on the outermost layer (saving considerable cost compared to putting coatings on all layers), this technology can potentially limit the total reflectivity to as little as 0.9%.
The reduction of reflected light enabled by circular polarization
The Mechanism of Circular Polarization
The process of blocking reflections using circular polarization consists of the following five steps:
Combination of Technologies Results in Superior View-ability
the view-ability of a display in bright sunlight is determined by the combination of display brightness and display reflectivity, which is often referred to as effective
contrast ratio (ECR):
ECR = 1 + (display brightness / reflected light)
In this relationship, display brightness is measured in NITs, and reflected light is expressed as the percentage of reflected ambient light (a higher ECR indicates better view-ability).
Analysis of the Getac B300 1200 NITs display reveals an ECR of 41.7*, compared to 6.6 and 6.9* by the two competitors in the study. To put those numbers into context, consider the following illustration:
Outdoor Laptop real-world examples:
Getac comments and photos courtesy of: www.ruggedpcreview.com
The first picture below shows the two machines outdoors on a bright morning. The B300 is set to use its light sensor to come up with what it considers proper backlight strength. The Gateway is set to its maximum brightness, and it’s actually a good display that is far more readable outdoors than most consumer notebook LCDs. However, you can already see one of the B300 display’s big advantages: no reflections. The B300 screen has a semi-matte surface and probably a degree of anti-glare treatment. As a result, there are no reflections whereas the Gateway screen almost looks like a mirror.
Below are the two machines in broad daylight and from an angle. The glossy Gateway display is now completely mirror-like and unusable. The B300 outdoor laptop display still shows no reflections at all, but it turns a little milky. That’s usually a combination of the diffusing effect from anti-glare treatment and the changing viewability of the LCD when viewed from an angle:
Outdoor Laptop test – directly into the sun
The toughest test sunlight-viewable displays must pass is when they directly face the sun. In the picture on the left, the B300’s light sensor cranked up the backlight to maximum normal level. The display remains marginally readable, but is on the verge of washing out. This is where using many other notebooks claiming outdoor view-ability becomes frustrating. With the B300, you simply push the high-bright button for a much brighter, clearer picture.
Customized for outdoor use in the real world
For modifications, mounts, system integration of rugged outdoor laptops, please contact ProCustom Group
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