Review

Electronic products have never looked so good, the result in large measure to the continuing heady pace of advancement in display and indicator technologies. In fact, no month goes by without the introduction of new displays that promise to bring sharper, brighter, clearer images and text and data presentations to electronic products of just about every size. Numerous improvements are also being registered for touch-screen technology, resulting in the screens finding their way onto increasing numbers of products large and small. And further livening up the display market is the emergence of new technologies that hold great promise of not only outperforming or costing less than existing displays, but also opening up entirely new application areas, such as ultra-thin televisions and "electronic" newspapers and other flexible products. New generations of indicators, mostly led by smaller, brighter, cheaper LEDs, are also finding their way into the marketplace with considerable frequency. Below are highlighted several of the more interesting displays and indicators covered in EEPN since the first of the year.

Tapping a new technology called Feed Forward Driving (FFD), Optrex America (optrex.com) has developed a line of TFT LCDs that is said to display fast-changing images and text with increased clarity. FFD technology, in the form of an ASIC that also houses frame memory and a lookup table, serves to greatly accelerate the frame-to-frame process and to eliminate the problem of slow intra-grayscale response times associated with TFT LCDs.

By adding a white subpixel to the three needed to generate a color LCD's primary colors, Samsung Semiconductor (samsung-semi.com) says it can increase the luminance of LCD fluorescent backlights by a whopping 30% to 70%. The new technology reportedly has been demonstrated in LCDs ranging from 2" to 17" in size. Sharp Microelectronics (sharpusa.com), in turn, employs its proprietary advanced super view (ASV) technology to produce the LQ370T3LZ11, a 37" TFT LCD that boasts of a 3.15-million-dot resolution and a signal response time of 15 ms. Other proprietary technology was employed to eliminate the ghosting and/or after images that appear on the LCD when displaying high-speed motion.

A VGA (640 x 480) resolution, 6.4" color TFT display was developed by Apollo Display Technologies (apollodisplays.com) that touts 300-nit brightness plus an integrated touch-screen that is said to eliminate the pixel haze created by standard touch-screens used on high-pixel-density displays. The touch-screen's four-wire, Clear-Clear Touch technology is said to eliminate interference with light transmitted through the LCD's pixels. The display includes two field-replaceable CCFL backlights.

In the miniature-size LCD arena, Lumex (lumex.com) has a 20.3 x 10.2 x 2.80 mm, 4-digit SIP display whose characters stand only 0.174" high. Model LCD-S401M14TF incorporates three decimal points with displayed numbers ranging from 0.001 to 9999. Also, it includes units of measure for pressure indication and operates from a 5.0 Vac supply.

Several interesting indicators have recently entered the marketplace. One is Stanley Electric's (stanley-electric.com) 1105CK, a SMT LED offering a super-wide, 180° viewing angle and uniform light distribution, both useful features in backlighting assignments. Forward voltage is 2.1V typical and 2.8V maximum at 10 mA.

In a 6-pin configuration, Sharp Microelectronics's RGB, super-luminosity, tough-and-flush (TAF) LEDs are designed to be connected in series for use as backlights to drive colors independently with the same current. The result is better control of both heat output and color. Other novel lighting-related applications include: JKL Components's (jkllamps.com) miniature, 2.4 mm diameter x 440 mm long BF2440 CCFLs for backlighting large, 36" to 60" LCDs; Durel's (durel.com) DFLX thin, pliable EL lamps for illuminaating keypads; and Visual Communications's (vcclite.com) LMS Series lens-and-litepipe units designed to provide environmental sealing for display panels when the LED is attached to a circuit board

—Joe DelGatto

Outlook

Brighter Days Lie Ahead
While organic light emitting diodes (OLEDs) are still in their infancy, the displays have already found their way into commercial products, with the number of design-ins expected to skyrocket over the next several years. Product is already available from two companies spearheading much of the work in OLED material science and manufacturing—namely, the industrial giants DuPont and Kodak—and they, together with a large number of other companies, both large and small, are expected to launch many new OLED products over the next 12 months. Even so, the LCD, an OLED rival, is becoming an ever-stronger competitor in the display market, with new LCDs expected to feature even higher performance, lower power dissipation, and much larger sizes than existing units. Other technologies expected to be sources of important new display and indicator products in 2004 include: plasma and AMLCD displays, touch-screens, display-related ICs, and LEDs.

—JDG