Flat panel display

Today Flat panel displays are widely used. They cover a growing number of technologies that enable video displays that are lighter and much thinner compared to the traditional television and video displays which mostly use cathode ray tubes. They are usually less than 4 inches (100 mm) thick. And are divided into two general categories, viz. Volatile or Static.

Volatile

Volatile displays require constant power output to refresh the image on screen many times a second. The image appears steady because the images are refreshed more often than the human eye can perceive.

Examples of Volatile Displays:

• DLP (Digital Light Processing)
• Plasma displays
• Liquid crystal displays (LCDs)
• Organic light-emitting diode displays (OLEDs)
• Light-emitting diode display (LED)
• Electroluminescent displays (ELDs)
• Surface-conduction electron-emitter displays (SEDs)
• Field emission displays (FEDs)
• Nano-emissive display (NEDs)

Only the first five of these displays are commercially available today, though OLED displays are beginning deployment only in small sizes (mainly in cellular telephones).

Static

Static flat panel displays rely on materials whose color states are bistable. This means that the image they hold requires no energy to maintain, but instead requires energy to change. This results in a much more energy efficient display, but with a tendency towards slow refresh rates which are undesirable in an interactive display.

Examples of Static displays are:

• electrophoretic displays (e.g. E Ink's electrophoretic imaging film)
• bichromal ball displays (e.g. Xerox's Gyricon)
• Interferometric Modulator displays (e.g. Qualcomm's iMod, a MEMS display.)
• Cholesteric displays (e.g. MagInk, Kent Displays)
• Bistable nematic liquid crystal displays (e.g. ZBD).

Bistable flat panel displays are beginning deployment in limited applications (Cholesteric displays, manufactured by Magink, in outdoor advertising; electrophoretic displays in e-book products from Sony and iRex; and bistable liquid crystal displays from ZBD in store shelf labels).

Flat panel displays balance their smaller footprint and trendy modern look with high production costs and in many cases inferior images compared with traditional CRTs. In many applications, specifically modern portable devices such as laptops, cellular phones, and digital cameras, whatever disadvantages are overcome by the portability requirements.

Digital Signage: Issues

Though Digital Signage (through LED ticker signs and LED video walls) has been in vogue for decades in the past it has however, not yet become a major public medium. The following are the likely reasons:

** Uncertain ROI: The cost of deploying digital signage currently stands prohibitive. Not only are large outdoor screens expensive (the LED signs in front of the Las Vegas Wynn Resort cost $15 million, for example) but much more common & cheaper form of digital signs based on LCD and plasma screens still represents a significant chunk of investment when a large network is planned.

For example, the cost of installing one screen in a single restaurant in a large fast-food chain runs to millions of dollars. Any such investment has to be justified by a clear ROI plan before receiving approval;

** Unproven advertising effectiveness: Like the Internet in the early 1990s, the digital signage medium has not yet been widely accepted as a cost-effective advertising medium compared to the traditional means (TV, radio, flyers, etc.);

** Lack of proven technology –The technology used today has largely been originated from consumer-grade personal computer and DVD technology, which has not been designed to stand up to 24x7x365 pattern. Today, the demand by professional digital signage is 24x7x365 usage. Often under stress these systems can break, resulting in damage to brand image and liability disputes between advertisers and network operators.

The above issues are being addressed in the following ways:

** ROI: Studies have shown digital signage to be effective in aiding customer recall and retention of displayed information in large-scale merchandising applications, especially taking into account the downward trend in LCD panel and playback device prices. Today a small-scale retail or restaurant digital signage installation can be implemented for just $4-6,000, whose ROI may be realized immediately.

** Outdoor advertising picking up momentum – advertising dollars have been consistently shifting from traditional media such as TV and radio into outdoor advertising, creating a double-digit-growth new advertising segment which includes digital signage. However, ad agencies are still slow to explore the potential of out-of-home TV.

** Development of dedicated platform solutions – new technology has been developed that features reliability magnitudes greater than consumer-grade technology. Like professional TV broadcasting systems, the new technology enables worldwide content distribution and playback to stand up to the test of time.