by Joe Hallett

Display technology is a bit like automobile technology. Most users are more interested in performance, cost and maintenance issues than in what's under the hood. This is particularly true when the various competing display technologies all have been refined to the extent necessary to produce predictable, satisfactory results, without unwanted surprises.

Some newer projector technologies show promise, and competition is still rages, resulting in quality displays at a fraction of the cost one would have paid just two or three years ago.

Plasma screens and LED walls are gaining a foothold in the church environment, but the vast majority of churches are using projectors based on small liquid crystal devices (LCD) and deformable micromirror devices (DMD).

First off, let's defining some of these terms and technologies, then we'll get some input on the state of the video display marketplace and where things may be headed.

LCD technology uses electrical voltage to align liquid crystals into various shapes and orientations. When light passes through the liquid crystals, it is bent into a range of shapes and colors that produce video images. LCD technology is usually found in small- to medium-sized projectors. LCoS (Liquid Crystal on Silicon), a new reflective application of liquid crystal technology, is discussed later.

DMD is a reflective imaging technology produced by Texas Instruments (TI) and is commercially named "Digital Light Processing (DLP). Each DMD chip contains over 750,000 deformable (moveable) micromirrors that produce images based on their orientation. The reflected light off the micromirrors is then filtered to add the appropriate colors. DLP is a technology that is found in smaller projectors using a single DMD chip, but the technology
adapts well to larger displays using three-chip DMD systems.

Plasma displays are like large, thin television screens that operate under the same basic principle as a fluorescent lamp or neon tube. A plasma display, however, can consist of over a million tiny red, green and blue fluorescent tubes set on a flat glass substrate. Colored light coming from each fluorescent element is controlled to form a video display. In churches, this technology is often used for displays in overflow seating areas, as announcement boards in lobbies and for small group meetings.

LED walls use a series of tiny, very bright light emitting devices (diodes) that look like tiny Christmas lights. These LED's are typically used in arrays of red green and blue (RGB). Using these three colors, they can create any color combination. Due to their brightness, and the ability to make very large displays, these displays are often used in broad daylight for sporting events, concerts and billboards. Churches with high ambient light environments may have excellent results using LED walls.

Until recently, differences in performance of the projector technologies were more apparent. The Projection Display Shootout at the International Communications Industries Association (ICIA)'s Infocomm show was the premier opportunity to judge image quality of various projectors in a side-by-side setting. In a significant move this year, the ICIA has dropped the shootout. Differences in image quality among competing projector products are no longer great enough to justify the Shootout's cost, and industry consolidation has greatly reduced the number of competing manufacturers.

Still, innovations and improvements continue. A number of firms are building the imaging device on top of its semiconductor chip, taking advantage of well-established semiconductor manufacturing methods to reduce the complexity of interconnections, and lowering manufacturing costs. One version, called Liquid Crystal on Silicon (LCoS), a reflective LCD-based design, has been has been successfully adopted by JVC in its Digital-Integrated Light Amplifier (D-ILA) products, including a very high-resolution displays for electronic cinema.

An RCA 50-inch tabletop High Definition (720p format) TV set is just reaching stores. The unit, which uses three SXGA-format LCoS devices, supplied by Three-Five Systems of Tempe, AZ, weighs less than 100 pounds and is only 18 inches deep. "The growth pattern has been normal for a new technology," according to Three-Five Systems VP Al Davis. "It takes time to develop manufacturing facilities, special test equipment and infrastructure. It's taken longer than some people expected, but today it's here!"

Three-Five Systems expects LCoS technology to be an attractive solution for higher-resolution video applications. "We're at 1920 by 1200 pixels," said Davis. "We're working with far-East manufacturers to develop light engines for front-projection [displays]."

Silicon Light Machines, San Jose, CA, has developed another deformable mirror system for projection display in which the image is formed a line at a time by tiny reflective ribbons. The resulting line images are placed one above another by a scanner in the projection optical system. Although no product plans have been announced, this technology continues to have promise. Sony has acquired exclusive rights to develop SLM technology for display applications.

Is there a "sleeper" technology that will revolutionize the display business? "I think those days are over," says iSuppli/Stanford Resources VP Dave Mentley. "You don't easily set up manufacturing [of a new technology]." iSuppli/Stanford Resources is a San Jose market intelligence services firm that follows the display industry.

"In LCD projectors, the big thing is shrinking size and adding features. But they really need good lamp technology," says Dick Blaha of Mitre Corporation, Bedford, MA, who presents an annual overview of display technologies at the Infocomm show. "Metal halide is inexpensive and OK if you don't care about performance. I would like to replace [lamps] with lasers."

Innovations in projector technology also include applying computer-networking technology to remote operation of projectors. Wireless technology is being used to reduce installation wiring. These features are becoming available in various combinations from most projector manufacturers and third-party equipment suppliers. The addition of specialized software to networked projectors can improve maintenance and reduce operating costs through remote control, on-off switching, maintenance and troubleshooting. According to In Focus Systems of Wilsonville, OR, its recently announced networking software can send maintenance e-mail from the projector, "…notifying service providers of information such as dwindling lamp or the need for filter changes."

A decade ago, outdoor signboards used small incandescent lamps to form messages and simple graphics. Then, like so many things, solid state technology took over. "It started with just red light-emitting diodes (LEDs)," says Troy Dodson, president of Lighthouse, a manufacturer of LED walls based in Cary, NC. "Now it's red, blue and green."

A new generation of bright flat displays using arrays of surface-mounted (SMD) LEDs has emerged over the past several years from Barco, Lighthouse, Saco and others. Specialized applications range from super-bright outdoor signage along the Las Vegas strip to rock concerts to promotional displays at major trade shows.

According to Dodson, surface mounting of the LEDs allows tighter grouping of the three primary colors, improving image quality for closer viewing, which is especially useful for indoor applications. The panels' high brightness helps in outdoor installations and in buildings - such as churches - where large windows can expose the interior to daylight conditions. But brightness can be turned down for more comfortable viewing, if necessary.

Where do we go from here when there doesn't seem to be another major new display technology waiting to be unleashed? Resolution will continue to increase, but the need for higher resolution is driven by a combination of factors including screen size and viewing distance. The availability of program material in the proper format is an issue. For wide acceptance, there must be underlying standards that control the image format and resolution.

Whatever happens in technology, the display business is big and growing. Much of the growth will be in flat panels, according to iSuppli/Stanford Resources, worldwide revenues for large screen displays will top $2.5 billion in 2001, and is projected to grow to more than $5.5 billion by 2007. According to senior analyst Sanju Khatri, "Use of plasma display panels indoors and LED video technologies outdoors for signage and billboards will be powering the growth of large screen display revenues for the foreseeable future."

Churches looking to add or upgrade large displays should benefit from current trends toward stabilizing technologies and lowering costs for the consumer market. But there still will be decisions to be made, according to JVC's Walton. "The gradual adoption of HDTV is something that churches must become more aware of. They will have to think about whether 16x9 scene formats will it be important, or even 5x4 SXGA. When blown up to a 20-foot screen, even a DVD will show up differences, making a dramatic difference in image quality on the screen."

Introducing a new display technology takes time. Early designs must be refined, manufacturing volume must be built up, and equipment makers must create new products based upon the newly available display components. Companies must be in the game for the long term. Whether CRTs or LEDs, DMDs or Plasma, large or small LCDs, all of these devices must be produced in large quantities to stabilize manufacturing yield, which greatly influences cost. So the introduction of new display technologies into high volume consumer products is good news for the buyer of traditional professional audio/visual equipment.