The Eyes Have It
Sales of LCD monitors are expected to increase by the year 2006 to 113 million and an 82% share of the desktop monitor market.
The marketing research firm DisplaySearch predicts that LCD monitors will overtake CRT monitors on a revenue basis in 2002, on a unit basis in 2004, and outsell them more than 5 to 1 in 2006. Conversely, according to their 950-page 2002 LCD Monitor Strategy Report, CRT monitors are expected to decline to 22 million units and a 16% market share.
Greater panel inventories and declining monitor sales in the second quarter of 2002 produced lower panel prices and lower LCD monitor street prices through aggressive channel promotions. This enabled the LCD monitor market to rebound in the third quarter. By size, 17-inch LCD monitor shipments continued to gain ground, and 19-inch LCD monitors were the fastest growing market segment for the third consecutive quarter. Larger panels were expected to continue to gain share at the expense of 15-inch models as the price gap between them continues to narrow.
In addition to reasonable prices, these lightweight, space-saving designs display the sharpest images. Because they address pixels directly (each pixel corresponds to a physical display component), images appear crisper than when viewed on traditional monitors, and many people feel the clearer images cause less eyestrain. LCDs also produce less heat than CRTs, so this can create significant energy savings where air conditioning is required.
Keep Your Eye on the Future
Now there's a new technology on the horizon. OLED (Organic Light Emitting Display) panels use organic materials to produce light. When thin layers of this material are sandwiched between appropriate anode and cathode layers, a small voltage (typically 2 - 10 volts) applied across the material will cause it to emit light in a process called electroluminescence. This combination of anode materials, cathode materials and light emitting organic materials forms the OLED.
The US Defense Advanced Research Project Agency (DARPA) is trying to speed development of FOLEDs (Flexible Organic Light Emitting Displays). In fact, a contract has been awarded to Universal Display Corporation (www.universaldisplay.com) to create flexible substrates that range from transparent plastic to opaque metal foils. One of several prototypes based on FOLED technology that is due to ship in two to three years is a flexible, retractable pen-based display. FOLEDs sit on pliable surfaces such as thin plastic strips or metal foils, and can be laminated onto a wall, instrument panel, or piece of clothing, or bent or rolled, allowing retractable designs, like a window shade - as with the pen-based display.
UDC is also developing a Transparent Organic Light Emitting Device (TOLED) that could be used as a display on windshields and cockpit windows. The combination of flexibility and transparency raises new possibilities for displays. OLED offers higher brightness, lower power consumption and a larger viewing area than other flat-panel display technologies, and at a lower cost. But at this point, mainstream uses of all types of OLED are still years away.
Several other companies are working on such next-generation displays, including Kodak (the originator of the underlying technology), Cambridge Display Technology, Dow Chemical, and DuPont. As a result of a recent agreement, Eastman Kodak and eMagin (www.emagin.com) are also working together to create cost-effective OLED micro displays. Sony, Hitachi, Philips, Toshiba, IBM, Sanyo, Pioneer, and numerous startups have invested in OLED technology as well.
How do OLEDs differ from LCDs?
The most important difference between LCDs and OLEDs is that the OLEDs are emissive displays, which means that they generate their own light. LCDs are passive displays, and simply transmit or block an external light source to form an image. The light source for LCDs is typically either ambient light reflected by a metallic layer behind the display, or by a backlight system. Emissive displays don't need ambient light to be viewable, and don't require a backlight. This eliminates the cost, space, weight and power consumption of a backlighting system, and offers an image with much higher contrast. In addition, emissive OLED displays offer a much wider viewing angle of 160 degrees. Although large OLED panel prototypes have been shown at engineering shows, only a few products have shipped so far, and only in devices using much smaller displays, such as cell phones and car audio receivers.
Eastman Kodak Company has led OLED research since its scientists discovered the technology in 1987. Since then, Kodak researchers have made a number of major breakthroughs which led to patents on basic OLED materials, device structure, doping techniques to drastically improve efficiency and control color, thin-film deposition methods, patterning methods, as well as designs and fabrication methods for both passive and active-matrix OLED panels. OLED display technology has evolved to provide a high-brightness, full-color, dime-thin screen that can display images with far more clarity than the conventional liquid crystal displays used in many electronic devices.
Several companies are close to producing OLED panels. One UDC prototype is an Internet cell phone/PDA with the company's flexible OLED (FOLED) screen, made from clear plastic films. Another prototype is a razor-thin Samsung cell phone that has a 2.2-inch display created with phosphorescent OLED (PHOLED) technology. OLED technology can be used to great benefit for both direct view and microdisplay applications. In both cases, OLEDs offer higher efficiency and lower weight than competing liquid crystal displays, since they don't require backlights or reflective light sources. These are very important attributes for head-mounted and portable products.
Scientists at the Xerox Research Center of Canada are developing semiconducting organic polymers that show promise for enabling the printing of electronic patterns on plastic substrates. Such materials could be alternatives to silicon transistors and lead to surprising applications, like a television screen rendered on a poster. Imagine monitors made of single sheets of flexible plastic!
The main advantages of this new technology are:
Next month the 2nd Annual Flexible Microelectronics & Displays Workshop Conference will be hosted by the US Display Consortium (www.usdc.org) in partnership with SEMI (Semiconductor Equipment and Materials International, the trade association serving 2400 member companies of the global semiconductor equipment, materials and flat panel display industries, the Army Research Laboratory (ARL), and DuPont Displays. The office of the Secretary of the Army has set in place a 5-year strategic initiative to stimulate the creation of flexible display capability for both military and commercial applications. To support this objective, the conference will review technology trends, major technology and manufacturing issues, product applications, and market evolution for these components. Cambridge Display Technology (CDT), the initial developer of light emitting polymers (LEP), is now leading industry efforts in their research and commercial development. Based on DuPont's core expertise in polymer science, DuPont Displays' efforts will bring together enabling technology to create a new class of displays for the information industry.
The convergence of communications, information management and entertainment into single product platforms will push performance demands on displays beyond the level of current technologies, making the dreams of today the reality of tomorrow. And the products will definitely be easy on the eyes.
Beverly Rosenbaum, a HAL-PC member, is a 1999 and 2000 Houston Press Club “Excellence in Journalism” award winner. She can be reached at firstname.lastname@example.org.