The flat-panel display is a highly visible element of the best digital signage application. During the specification and selection process, it becomes clear that many options exist. This article addresses the selection of flat panel displays for use in interior and outdoor, weather-resistant housings.
End-users tend to not get overly excited over flat-panel selection unless the deployment is large or very high profile to the digital team. Smaller system integrators that are expected to provide trustworthy, fact-based objectivity tend toward recommending the familiar and are advised to assess a wider range of options and models given advancements in flat-panel features. Larger system providers and operators such as Stratacache that provide to Walmart, McDonald’s and other retail, food services and banking end-users, operate lab and testing facilities to ensure the most suitable flat panel display is selected for the end-user application.
The lines appear to have been blurring between consumer and commercial-grade displays with descriptors such as «consumer» or «light duty commercial,» which calls upon a deeper assessment of the available flat-panel options. It is what is «under the hood» that matters most in the cost-benefit decision.
The term «good enough,» defines the relationship between cost and benefit. Cost reflects production, service and mark-up while benefits reflect functionality and expected life.
Tip: The term «meets specification» better suits flat-panel display selection than «good enough.»
While the display device is the most visible element of digital signage, the cost of the flat panel has declined to be a minimal proportion of the total system cost over its life, with content far outweighing any other element.
Too often, the selection decision is made in the same way a vehicle is chosen with a bias toward a brand name (Chevrolet, Ford, Honda, BMW, etc.) and size (sedan, truck, SUV), where appearance and cost greatly influence the purchase decision. Several firms dominate the supply of commercial-grade digital signage flat-panel displays with each offering a range of sizes and operating features, as well as prices that correspond accordingly.
Differentiating aspects are as follows: size, shape, bezel width, thickness, ease of mounting, inputs, integrated processing, display control, brightness, contrast ratio, resolution, image appearance, refresh rate, usable viewing angle, warranty terms, energy conservation capabilities, and reliability of supply.
There are three general models of flat panel-displays: LCD, LED and organic light-emitting diode (OLED).
LCD displays are generally less expensive, wider in depth and weigh more than LED displays. LCD displays have been the most widely used type of display for signage until recently, but manufacturers have started to discontinue LCD CCFL displays in favor of the performance and economies of LED panels that are back-lit, edge-lit and direct-lit. LED types use either a matrix of LEDs behind the screen or an array of side-mounted LEDs to replace the cold cathode fluorescent light lamps. Although the concept is generally the same as back-lighting back-lighting, LED displays offer a sharper, clearer image and offer brighter colors and better contrast over LCD. LEDs also offer lower operating costs by using up to 50 percent less power consumption than CCFLs. Additionally, LEDs offer a slimmer profile, with some commercial displays being less than a few millimeters in depth versus up to 5 inches with CCFL displays.
OLED technology is emerging as an advanced flat-panel display option. These flexible, bright, ultra-thin, highly energy efficient displays are similar to a regular LED, except that they are made up of organic semiconductor material sandwiched between two electrodes that produce light when a current is made to flow through its volume.
Tip: LCDs offer a preferred long-life, high-performance, cost-effective solution, while the benefits of OLED may be best suited to deliver the «wow factor» of very high profile or architectural media.
As with vehicles, external appearance does matter. Bezel width and depth, and even the appearance of the manufacturer’s name contribute to the aesthetic appeal.
Tip: A narrow bezel and minimal depth will allow the display to be seen as more modern over a longer period.
In deciding on a consumer TV or commercial quality flat panel display for the digital signage application, the decision is easily made. Whereas consumer (in-home) TVs are produced for a two- to four-year life operating three to four hours per day (depending on the brand), commercial-grade flat panels are engineered for 60,000+ duty hours, (18 hours of operation for 365 days equals 6,570 hours of operation per year). Warranties reflecting this ruggedness are typically for one year on the in-home TV versus three to four years on the digital-signage display. In-home TVs are not designed to operate in portrait mode and they usually lack the inputs and display controls that maximize the return on the digital-signage investment.
Display providers such as LG Electronics use commercial-grade components that are designed to prolong the life of the display where heat, dust and humidity are elements of the display environment. Conformal coating is a thin protective chemical coating or polymer film that is topically applied to circuit boards to protect electronic circuits from harsh environments. When applied, this breathing coating «conforms» to the circuit assembly, filtering water vapor and solid debris.
Commercial-grade components and LED lighting can be effectively cooled using convection, typically negating the need for supplemental fan cooling. Fanless flat panel operations reduce noise and energy requirements while pulling less contaminated air into the workings of the display device.
The International Electrotechnical Commission has developed IP, or Ingress Protection ratings, to define the degree of protection a specific enclosure provides. This rating measures external influences that come in contact with an enclosure from any direction. Some LG display models have passed the rigorous dust ingress test to receive their exclusive IP5X certifications for dust-proofing, providing complete protection against contact and are made to resist dust buildup to assure the best lifetime performance and less heat generation.
Tip: Consumer quality TVs are simple not suitable in dirty, hot or humid environments and are a false economy over using commercial-grade flat panel displays.
A single replacement of a consumer quality panel can increase its cost over the commercial grade panel, and operational economies may be sacrificed since commercial-use features are typically not included in home-use TVs.
The display and the content the display presents are joined at the hip. The visual appeal and feel that makes a vehicle attractive is similar to the flat-panel selection. The warmth, hue and presentation of content can differ from product to product.
As with vehicles, what is «under the hood» matters most. Beyond product life, the selection decision must be based on functions, performance and the expected total cost of ownership over the expected life of the device.
«Effective management capabilities are a vital consideration when choosing a digital signage display, and integral for reducing staff time and resources spent monitoring and maintaining displays,» said Dan Smith, director of digital signage for LG Electronics USA Inc. «Displays using Simple Network Management Protocol standards allow systems integrators to remotely communicate with screens using standard network communication protocols for more efficient management and troubleshooting. Additionally, the ability to monitor the front of the display with a panel-facing pixel sensor and to continuously communicate with the screen, even when the backlight is powered down, are important for screen management. Robust connectivity options, such as Wi-Fi, hardwiring, and failover options for failed image inputs, also ensure that content is always running seamlessly».
Connectivity between the flat-panel display and media player should be considered in the selection criteria. The media player can be embedded in the display, but most digital signage uses an exterior media player to take advantage of the functionality of the content management software. Connections for proximity cabling such as DVI, HDMI or DP will be required in the display. Also, the distance between the media player and display will require connectivity such as transmitter/receiver, wired or wireless, allowing the signal to go from the source media player to the display.
Connectivity of the flat panel to the signage network manager and performance reporting are of increasing consideration in flat-panel selection, as is the fail-over function that enables content display from internal memory without a playlist interruption even when all external inputs are not working.
Functions such as automatic adjustment to ambient light conditions, screen wash to remove phantom image or «burn in,» and display control for image adjustment, user «lock out» and other features add the value that flat-panel displays deliver while minimizing costs and service disruption.
Beyond service life, the quality of image presentation is the key consideration in display selection. Brightness, resolution, refresh rate and color accuracy, including the «true black» of the «at rest» display, are worthy of attention during selection.
While most flat-panel displays claim almost a 180-degree viewing angle, image quality off the perpendicular viewing axis and at wide angles can quickly erode. The real issue for display selection is the degree to which the content is easily viewable from a wider horizontal angle or vertical angles without brightness or color degradation.
Off-axis viewing of displays located in walkways or used in information exhibits, customer services or drive-thru situations requires that the content be clearly visible without distortion or haze from a wide viewing angle. The content must attract the eye and be adequate to influence a decision from as wide a viewing angle as possible in order to maximize the value of the display investment. The use of anti-reflection coating or anti-glare glass can improve the ease of viewing and image quality in off axis viewing situations in particular.
Tip: All flat-panel display models are not created equal.
Connectivity, features and adjustment control add to the benefits the display can deliver over it service life. Unlike the plug-and-play of home TV, which requires minimal setup, digital signage is a demanding application of media presentation requiring long hours of reliable use. They must often be set for optimal performance in the environment in which they will operate with internal adjustments automatically applied for optimal performance. Assure that optimal performance is part of your total cost-of- ownership-assessment.
Flat panels can be purchased from the original equipment manufacturer, of which LG Electronics and Samsung are examples, or from firms such as NEC that source key components from the OEM. Distributors such as ADI Global, Synnex, Ingram Micro, Tech Data and many others work closely with flat-panel providers in the supply chain. (A Google search of “flat panel distributor” gets 1.2 million options). Resellers of flat panels and providers of digital signage systems work through OEMs and distributors to best meet end user needs.
The end user will benefit from sourcing their flat panel displays from a provider that has a long track record and deep experience in this element of digital signage. The supplier should be healthy from a corporate standpoint to assure that they are still around to honor warranty and model upgrade should these be required.
Tip: As distributors are influenced to recommend a particular flat-panel model based on the requirement, sales professionals are also influenced by inventory levels, special promotions and commission structures.
The end user or integrator is urged to know the requirement and use scenario as clearly and deeply as possible, and to be open to options that may appear to cost more initially, but that will have better performance and a lower total cost of ownership over the four to eight years of expected operation of the flat panel.
In conclusion, the best selection of a flat-panel digital signage display ultimately comes down to this question: What will best show the content that we want to display at the lowest cost over the time of its use? Answering this question requires the end user and its supplier to assess the purchase against a range of options, the most important of which may be «under the hood.» The selection decision is a time to set aside biases and make a decision based on facts.