Digital Signage – Understanding Screens

Flat screen technology has only been around a few years but already it has not only replaced its forerunner the CRT TV in our homes but also these thinner TV systems has paved the way for a revolution in out of home advertising.

But the demands on digital signage differ to those placed on home entertainment screens and while technologies like HD (High Definition) make quite a difference when you’re watching the latest Hollywood blockbuster, it will have little impact on an advertising campaign run on a HD digital signage screen.

However, there is a difference in the differing technologies used in modern flat screen TVs with advantages and disadvantages to them both. Generally when it comes to modern flat screen TVs they come in two varieties – the LCD (Liquid Crystal display) or plasma.

There was a time when there were quite sharp differences in the two technologies. Plasmas used to be brighter and have a better quality image, while LCD TVs used less power and were less susceptible to screen burn.

However, technology has advanced quite sharply and now the differences in the two technologies are negligible and more consideration should be given to protecting the screens to ensure the quality of image doesn’t diminish due to other factors.

Unlike home entertainment use, screens used in digital signage are often left exposed to direct sunlight or kept continually on. Heat build up and the direct glare of the sun can damage both LCD and plasma screens.

Some digital signage enclosures use clever technologies to ensure the screens of modern plasmas and LCD’s are protected. Air curtains are often used in some LCD enclosures, these blow a curtain of cool air across the screen preventing sun glare from causing hotspots. Anti-glare glass is also used extensively in LCD and plasma enclosures to ensure the screen is as readable as possible under direct glare.

When running a digital signage campaign, protecting the screen is crucial as the only outlay other than running costs is caused by replacing the screens. However, both running costs and protection may have become decidingly easier thanks to the development of LCD screens with LED backlights.

These use an array of light emitting diodes (LED) to generate the backlight of the TV. This not only uses a lot less power than conventional LCD technology but also they do not get as hot ensuring the screen costs less to run and will last longer.

About the Author

Richard N Williams is a technical author and a specialist in the digital signage industry helping to develop outdoor digital signage and protection for plasmas. Please visit us for more information about LCD Enclosures or other digital signage solutions.

The Truth About Pure Black And Other Features Of Your LED Screen

In the past we discussed some basic information about LED technology. So just to summarize in case you missed anything, here’s a brief recap:

* LED = a semi-conductor that emits light
* Pixel = the basic luminous dot, which can contain one or more LEDs
* Pitch = the distance between pixels, expressed in millimetres
* Pure white = the perfect balance of red, green, and blue
* Minimum Viewing Distance (MVD) = the closest you can get before image appears pixelated. The type of screen, as well as the type of content displayed, plays a role here.
* LED screen = smaller modules (from 4*4cm to over 1*1m) assembled together
* Colors available = up to 280 trillion (65,000 * 65,000 * 65,000).
* Gamma correction = the exponential correction needed to adapt colors to the logarithmic vision of the human eyes

Now let’s take a deeper look into further features that define the quality of an LED screen. We mentioned several times the importance of having a pure white (the perfect balance of red, green, and blue) in order to have the highest image quality. Now lets see the importance of having pure black.

How do you obtain a pure black on an LED screen? Well, you do it by turning off all the LEDs. Pretty easy, huh? Actually, no. The biggest problem in obtaining pure black with an LED display is the fact that you do not use LEDs to get the black. In fact, if all the LEDs are switched off, you can’t rely on your advanced electronic control system.

So how do you do that? You ask the mechanical engineer – incredible, but true. Obtaining pure black is a question of mechanical structure of the LED screen. Indeed, pure black entirely depends on how dark the surface can get when the screen is turned off.

Trust me, it’s not easy. The main complication is that such a wide surface will always have a reflection factor, meaning that, if you are not careful, you might end up with a huge black mirror when you turn off the screen. That’s why the frontal design of the LED walls is so important, because it must be dark without being flat and reflective as a mirror.

Why, exactly, is pure black so important? Because it defines the contrast levels of the LED screen. The contrast level is the difference between the light emitted by the display and the environmental light reflected by the screen’s surface. Minor is the light reflected, higher is the contrast and, therefore, the color depth and the naturalness of the images.

To increase the contrast level, professional LED screen manufacturers provide particular anti-reflex flyers that split the light and don’t reflect it, increasing the visibility of the screen even in direct sunlight. The contrast level of a LED display is a fundamental factor to take into consideration, especially during huge events broadcast via television.

What should you be aware of when broadcasting an live event on your LED screen? First of all, the LED wall refresh rate. The refresh rate indicates the number of times that the image refreshes every second. For example, a PC monitor has a refresh rate of 72Hz and, therefore, refreshes all the pixels of the screen, from top to bottom, 72 times every second. To provide a comparison, most TV monitors have a refresh rate of 50Hz and only few products of the last generation have a 100Hz refresh rate.

Professional LED screens have a minimum refresh rate of 240Hz, which is almost triple of that of most advanced TV monitors. The refresh rate is fundamental, because it determines the image’s quality: if it is too low, the LED screen would display a flickering image when recorded by a professional camera. Some manufacturers offer a refresh rate as high as 2000Hz to meet the demands of the broadcast industry, especially important for events with rapid camera movements and HD format.

Secondly, be aware of brightness levels. Depending on the location, you might have different needs for brightness. Outdoor events will obviously require an incredibly high brightness to contrast the sunlight. However, if the event is indoors, you must have a lower brightness in order to avoid solarization. To provide you with a practical example, an average frontal brightness is 2,000 to 3,000 NITs for indoor use and up to 5,000 to 6,000 NITs for outdoor use LED screen.

About the Author

Get the FREE ebook specifically for LED Screens Buyers by Fabio Aversa. He is a recognized LED Displays specialist and marketing manager for Euro Display, a leading LED Screens manufacturer and supplier company.

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Light Bars LED the Lights for the Future

In an incandescent light bulb 90% of the energy it uses ends up as heat. Only 10% is converted into light. This makes the incandescent bulb a low efficiency light source. The more efficient fluorescent was a bit more efficient but until the compact fluorescent arrived its use was limited. The latest light source to have developed is the light emitting diode or the LED. They are mounted in sets of two or more in light bars LED for many uses.

Due to the fact that they do not use vacuum chambers like incandescent bulbs and fluorescent bulbs they are called solid-state light sources. The early LEDs were able to emit only red light and the intensity was very low. These were used as indicator lights. First they were used in expensive equipment such as laboratory equipments and x-ray machines. Later they were used in TV sets and other cheaper items and came into widespread use. Further research was able to discover light emitting diodes of different colors and finally the ones with high intensity light were made. These high intensity light ones are used in light bars LED

These new light emitting diodes are used in a variety of applications such as street traffic signal lights and ambulances in addition to being used as indicator lights in appliances. One use of the more developed high intensity light emitting diodes is in torchlights. Unlike the tungsten filament bulbs these bulbs are able to emit high intensity light and also they last a long time. There are some brands of torchlight that guarantee the bulb for more than 50,000 hrs. When these are used in light bars LED they could be used to illuminate large areas. These light bars are replacing neon lights that were decorating the streets some time back. The neon light uses a lot of energy to burn and this is the main reason for them to be replaces with LEDs.

Though the light bars LED are presently used in small scale for table lamps and emergency lamps the full-blown use of these solid state light sources have not yet arrived. However they are used in Kitchen illumination and such other applications in addition to their usage in trucks fire engines and ambulances as signal lights. Due to the present trends of energy saving the future holds a lot for the light bars LED, as they are ideal energy efficient lighting systems. There will be brighter and larger LEDs being developed to fulfill the need of the hour.

When the light bars LED come to illuminate offices, hotels and restaurants there will be a boom of LED lights as they are going to save a lot of money and the Compact fluorescent bulb which is the favorite over the incandescent bulb at the moment will be required to back up leaving the opportunity for the new discovery to take its place as it is more economical and more efficient.

Extreme Electrical Dynamics is a one-stop shop for LED light bars and many other items like Flashlights, Emergency Lights, Deck Lights, etc. Please visit the site for more details of various items available – http://www.extremetacticaldynamics.com/

About the Author

I am a Microsoft Certified Professional. I conduct Training and Certification Guidance for Microsoft .Net Certification Courses through my training institute-Sierra Infotech. I also own and manage a SEO Company and article Directory.

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