Education | AV Distribution Tutorial Choosing the right display Other video display options CRT Older cathode ray tube (CRT) displays are still around; usually they’re older analog TVs or VGA monitors. They’re bulky, offer low resolutions, and look very dated but can be a low-cost option in areas where appearance is secondary. Projected A front or rear LCD/DLP projector is a compact device that projects an image on a screen. These devices are handy for trade shows, meetings, or anywhere it would be impractical to bring along a full-sized monitor. OLED Organic light-emitting diode (OLED) displays are the displays of the future. They’re lightweight, thin, and energy-saving but not yet available at a price that makes them practical for general use. Video-wall specific displays These can be LED video cubes or rear-projection cubes that are designed to be stacked on one another for a virtually seamless video wall display. Factors to consider when choosing a display Picture quality Plasma displays reproduce color more accurately with deeper blacks and display moving images with remarkable clarity. They provide excellent performance with their high-contrast levels and color saturation, and have the edge when it comes to viewing angles. In fact, plasma screens have as much as a 160° viewing angle, whereas LCDs display at 130 – 140° angles. However, they also carry the risk of image burn-in (the permanent disfiguring of a screen image caused by the continuous display of a high-contrast object). The most popular video display options LCD Liquid-crystal displays (LCDs) are today’s most popular choice for flat-panel video displays. These low-power, flat-panel displays consist of a liquid containing crystals sandwiched between filtering layers of glass or plastic. When electric current is passed through the material, the molecules of the liquid crystal twist so that they either reflect or transmit light from an external source, usually a cold cathode fluorescent lamp (CCFL). LED LED displays are actually LCD TVs that use LEDs as their light source, instead of traditional CCFLs. In fact, these displays are often referred to as LED LCDs. LED displays tend to be brighter and perform better than LCDs, but they also tend to be higher-end models, which may have more to do with their superior performance than their technology. Plasma Plasma flat-panel displays use small cells that contain electrically charged ionized gases, which fluoresce when electrically charged. Although plasma displays are waning in popularity and are available only in larger sizes — generally 42 inches and up — their deep blacks and high contrast ratios make them a good choice when implementing large displays that are intended to be eye-catching. Professional grade vs. consumer grade When selecting a video display, you may find that “professional grade” or “commercial grade” models cost significantly more than televisions you can buy at the local “mega mart.” The primary difference is that professional-grade displays are built to stay on 24/7 for weeks and months at a time without breaking down. They may also offer features such as video-wall processors, scheduling options, and lockable control panels not normally found in consumer-grade televisions. 14 LCD displays, on the other hand, don’t have quite the color accuracy of plasmas, but they’re brighter and have a sharpness advantage with a higher number of pixels per square inch. These additional pixels make LCD technology better at displaying static images from computers or VGA sources in full-color detail. Applications with large amounts of data and written material display particularly well on LCDs. What’s more, there’s no risk of image burn-in. Durability With LCD screens, there are essentially no parts to wear out. They last as long as their backlights do, with displays lasting, on average, 50,000 – 75,000 hours. That’s why LCD screens are especially good for applications such as digital signage or displays that require around-the-clock use. Plasma screens, however, use a combination of electric currents and noble gases (argon, neon, and xenon) to produce a glow, which in turn yields brilliant color. The half-life of these gases, however, is only around 25,000 hours. The glow they produce grows dimmer over time. They’re also prone to burn-in or ghosting of images, although this is less of a problem with newer models. Power consumption Early plasmas had a very high power consumption; some as high as 5W per square inch. These values are now down in the 0.3 – 1.0-watt range, depending on screen size. LCDs typically run in the 0.1 – 0.3-watt per square inch range, and LEDs are even lower. Manufacturers are now required to provide power consumption information, but keep in mind that there are two values for consumption, default and calibrated, so be sure you’re comparing like values. Making the choice In general, plasma produces a clearer picture with a wider viewing angle and a better response time for fast motion playback, making it a good choice whenever you need a large screen to show a very visually active display, for instance, in applications displaying sports footage or active advertisements. LCDs are better at displaying detailed, static information. Because LCDs are brighter, they’re ideal for venues with lots of ambient light. They’re also the best choice for 24/7 applications because of their lower power consumption. For these reasons, LCDs are preferred for professional AV display installations. Tech Support 030 - 241 77 99 | Sales 030 - 241 77 77 | On-Site Services 030 - 241 77 44
Display Methods Display Configurations Using a video display to your advantage. Orientation Most video displays are rectangular, so you have the option of mounting them horizontally (landscape) or vertically (portrait). Although the horizontal configuration is far more common — probably because people are used to seeing TVs like this — a vertical video screen can make a striking display. Also in some situations, such as when mounting a display on an architectural column, a vertical display is more practical. Horizontal (Landscape) Vertical (Portrait) Common display configurations Individual video screens The most common digital signage application is individual video screens displaying information. Often multiple screens in various locations are networked through a digital signage system, so they all show the same information and can be updated at the same time. Touchscreens The same technology you see at ATMs and information kiosks can supplement your digital signage setup when you want to give the viewer the ability to get information on demand. You can use standalone touchscreens or touch bezel overlays that affix to existing plasma or LCD screens and make them interactive. Touchscreens actively engage people and interact with them, making them an ideal medium for advertising and distributing information. Video walls A video wall of four, six, nine, or even more video screens working together to make a single display saves money as compared to a single very large screen. These large, tiled video displays are frequently used in public areas such as stadiums, airports, and shopping malls. Screens designed for use in video walls have narrow bezels to minimize gaps between active display areas. They usually have connections to daisychain power and video signals between screens to simplify cabling. Although large video walls require special controllers, small video walls can be set up just using multimonitor video cards. KVM-switched tiling Some KVM switches enable you to tile images from as many as four video cameras and/or computer screens on a single display while providing control over individual windows. This application is often used in security or controlroom situations. Great places to deploy digital signage Endcap digital signage Retail stores are ideal locations for eye-catching digital signage. Displays in endcaps can advertise specials and highlight new products. An interactive touchscreen can help customers locate products, offer serving suggestions, show demos, and help with sizing. Transit Riders on public transit — whether trains, buses, or taxis — can be informed of schedules, fares, and service changes. They appreciate having a news scroll and weather information to keep them up on things. This is also a perfect venue for advertising aimed at the busy commuter. Store windows A rear LCD/DLP projector can project messages and images on an acrylic projection screen in a store window, providing an animated alternative to a static window display. Or project messages as 3D images with a laser hologram projector. Restaurants and cafeterias Digital signage is ideal for displaying menus and the day’s special, complete with pictures so guests know what to expect. The addition of a touchscreen ordering system speeds service and cuts down on labor costs. Museums Museums often take advantage of digital signage to provide history and background about their exhibits. Touchscreen signage enhances visitors’ experiences by enabling them to interact with the exhibit. Gas pumps Interactive touchscreens provide prompts that enable customers to use their payment card and advertise specials on car washes or oil changes while customers fill their tanks. Wearable digital signage Forget boring name tags — your sales team can wear tiny LCD screens that show advertisements for your company or product on the sales floor or at trade shows. For more information and our online store, visit www.blackbox.nl 15
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