CCFLs Move From Backlights Into the Spotlight
2009/04/03 | By Ken LiuEarly this year, representatives from Taiwan's leading manufacturers of cold cathode fluorescent lamps (CCFLs) and CCFL backlight modules met to discuss establishing an industry standard for the lamps in general lighting.
CCFL lamps have long been the most widely used backlight source in liquid-crystal display (LCD) TVs, notebook displays and computer monitors. Now, Taiwanese manufacturers hope to make the lamps available for general lighting to cash in on the rising eco-friendly trend and put idled capacity back to work as LCD oversupply hammers down profits.
"A common specification interface, or standard, is needed to migrate CCFL lamps from backlight to lighting applications if the migration is to be viable," says J.F. Huang, deputy director of the Image Design Division of Display Technology Center under the government-backed Industrial Technology Research Institute.
Huang has won government support for his proposal to cultivate a CCFL-lighting industry cluster on the island after coming up with the project in October 2008. "I plan to organize 15 manufacturers to develop a CNS [Chinese National Standard] standard for the industry and an industry cluster over a period of three years," Huang says. In Taiwan, government procurement contracts are limited to CNS-certified suppliers.
"There are too many specification inconsistencies between backlight makers. For instance, lamp diameter in the application can be three millimeters, four millimeters, and even five millimeters. The electrical properties of the lamps also vary from manufacturer to manufacturer. If they insist on their own specifications, their lamps can not be used on each other's lighting fixtures, raising market fears that no competitive alternative is available for any of the specific specification," notes Huang.
Benefits Over LED Lamps
Huang believes that CCFL is more likely than LED to become the next-generation light source if a common interface standard can be hammered out. "Compared with LED, CCFL is already a mature light source. Besides, LEDs also need a common standard," he notes. The maturity of CCFLs, Huang says, is proven by the long lifespan of LCD backlights. "As the backlight of LCD TVs, most of the lamps now assure a minimum lifespan of 80,000 hours and 100,000 on and off operations," he says.
CCFL lamps, Huang adds, are also easier to replace than LED lamps. "CCFL lamps are as easy to replace as a fluorescent tube. But an LED light is made up of a cluster of emitters, which complicates replacement, especially when there are only one or two dead emitters," he notes.
However, Huang confesses CCFL is still behind T5 lamp in luminous efficacy competition, delivering an average of 60 lumens per watt versus around 100 lumens per watt. He stresses, though, that CCFL can be made with less materials, such as mercury, than T5 lamps. "Due to their small size, CCFL allows more illumination to be reflected from lighting fixture," he notes.
Huang also plans to help manufacturers to build up one to two brand names in the world CCFL-lighting market. "LCD makers have no branded products. So when the market sours, they are in a much more fragile position than contract buyers," Huang says. The anemic LCD market has idled about half of the capacity at Taiwan's CCFL manufacturers, according to industry insiders.
Compared with other major CCFL suppliers like Japan and South Korea, Taiwan, Huang believes, is much more likely to become the world's No.1 CCFL-lighting supplier. "Taiwan's first advantage is its position as the world's biggest LCD supplier. This has created the large demand needed for local CCFL makers to bring down production costs. Another advantage is that Taiwanese lamp makers can adjust more flexibly to the market compared to their Japanese and South Korean counterparts. South Korean and Japanese CCFL makers are completely controlled by their parent companies, whereas Taiwanese CCFL makers have a relatively high level of discretion," he analyzes.
Taiwan supplies over 40% of the world's LCD panels, leading Japan and South Korea. Not surprisingly, the three economies produce over 95% of the world's CCFLs combined, with mainland China making up much of the remainder.
Huang thinks that Europe is an ideal launch market for Taiwanese CCFL lighting products. "Europeans are more ready than other people to accept new eco-friendly products. And the low mercury content of CCFLs, compared to T5 lamp, is a good selling point," he says.
Setting the Bar High
GIO Optoelectronics Corp., Taiwan's No. 2 CCFL maker held by LCD maker Chi Mei Optoelectronics Corp., started making CCFL lighting fixtures in the second half of 2008. So far, it has built its 4mm-diameter lamps into T-bar (with grid cover), compact-spiral, under-cabinet, and tunnel lighting fixtures.
GIO has erected a tough barrier to keep low-quality rivals from catching up with it in near term. It has moved forward the efficacy of its 1.1-meter-long lamp to 80 lumens per watt and plans to further migrate to 90 lumens per watt by the end of this year. The tubes are used in the company's compact spiral lamps with an efficiency of 50 lumens per watt. "We are the world's first CCFL manufacturer to introduce spiral lamp rated higher than 10W," boasts an unnamed GIO executive. Also, he says the company launched the world's first two-meter-long CCFL lamp for making U-shape backlights.
According to the executive, the lamp's light output has grown in proportion to its length since the world's first CCFL was introduced in Japan in 1986. The company now cranks out lamps in length ranging from 250 to 1,500 millimeters, with 900mm lamps rated at 11W, 1,300mm lamps at 16W and 1,500mm lamps at 19W.
"When CCFLs achieve high enough wattages, lighting applications could create a new market for makers at a time when LCD oversupply worldwide has idled a lot of capacity at backlight manufacturers," the GIO executive says.
The GIO executive says that CCFLs have several advantages over traditional lamps, including longer lifespan, less energy use, lower mercury content, lower UV radiation, and dimmable light intensity. Longer lifespan-up to 80,000 in LCD TV backlight applications-is another bonus, he says. GIO has reduced the life of the lamps for compact spiral lamps to a guaranteed 20,000 hours. Its tunnel lights and T8 lamps for T-bar lighting fixtures both guarantee 30,000 hours.
Hot Prospects for Cold Lamps
The executive ascribes CCFL's longevity mostly to its unique activation mode, which he says is different from that of hot cathode fluorescent lamps (HCFL), the kind used most widely in fluorescent lamps today. "Cold cathode fluorescent lamps are 'cold' because of their cold-activation mode whereas hot cathode lamps are 'hot' because they have a hot-activation mode. The latter is activated by burning the filament to generate electrons whereas the former is activated by high voltage," he says.
Hot lamp filaments are coated with an electron powder called an "emitter," which discharges electrons that bump into argon and mercury gas molecules, generating ultraviolet rays when the electricity streaming through the two electrodes of the lamp starts burning the filament at high temperature. The coating is eaten away a little bit each time the lamp is started. The electrons in a cold cathode lamp are discharged when a kilowatt-level voltage "sputters" the lamp's nickel electrodes. "Cold lamps have no emitter coat to erode. So, it can last much longer than hot types," the GIO executive notes.
CCFL lamps do not give off UV-B rays, though they emit a low level of UV-A rays. The UV-B rays, the executive notes, can tan skin.
The company has started testing its CCFL lighting products on road signs along some arterials in Kaohsiung City.
GIO is developing several unique techniques, including production automation for compact spiral lamps, to move its CCFL lighting business forward. "GIO is currently the only CCFL maker in Taiwan to turn out compact spiral CCFL lamps on automated lines," the GIO executive says. The most challenging part of the production, he notes, is spiraling the straight tubes. "Glass is fragile so its especially hard to curve a thin glass tube," the executive notes.
Complicating the task, he adds, is the fact that the tubes are filled with phosphor powder, mercury and argon gases before spiraling the tubes. "Other manufacturers usually fill these components after finishing the spiraling because the tubes are much easier to break during the curving process if they are filled with gases. They can easily fill these components after spiraling the tubes, but these components especially phosphor powder can hardly spread evenly in the lamps. That usually shortens the life of the lamp," he adds. The company now cranks out around one to two million compact spiral lamps a month and has installed the lamps with a patent-pending dimmable technology. They come in cold-white and warm-white types.
The T8 CCFL lamp is another leading-edge product made by GIO. The company builds CCFL tube into T8 lamp, whose diameter is 25mm, to make the lamp available for fitting into T8 lighting fixtures, currently the mostly used lighting products in premises including offices and marts. "Other manufacturers may have such product, but ours is very unique because we've developed a very special approach to bury all the high-voltage circuits in the bigger tube. Users are kept from touching the dangerous high-voltage circuits by absolute seal. And we build two low-voltage electrodes on the two ends of the tube to conduct electricity into the tube. That's know-how," he says. He claims CCFL lamp saves 10% to 15% more electricity compared with T8 fluorescent lamp.
The company has reportedly improved the best color rendering performance of its CCFL lamps to over 80, around 20 short of the perfect 100 achieved by sunlight.
GIO forecasts that its lighting business will contribute NT$600 million (US$18 million) in revenue this year.
Seeking Relief From Flagging LCD Market
Hit hard in the money-losing LCD-TV market, Team Shine Electronics Co., Ltd., an assembler of LCD TVs and CRT TVs, is also aggressively developing lighting applications for CCFLs. The company has also called for the establishment of a standard in the CCFL lighting industry, says Julian Yieh, Team Shine's director for business development.
Yieh notes that CCFL lighting fixtures are still below the CNS standards for fluorescent lighting fixtures in terms of efficiency, so manufacturers need an industry standard to compete for government contracts. He says the CNS requires fluorescent lighting fixtures longer than 60 centimeters to put out 60 lumens per watt.
"The national requirement is not fair for CCFL lighting fixtures because CCFL lamps have advantages that traditional fluorescent lamps do not," Yieh stresses. "For instance, our tests prove that in a 1,080-square-foot room, 25 CCFL T-bar lighting fixtures can produce as much luminance as 30 T8 lighting fixtures. In addition, a CCFL T-bar at 60W gives same amount of luminance as a T8 fixture set at 80 to 90W," According to Yieh, CCFL's candela-distribution curve is rounder than T8's, allowing its illumination to cover more dead angles than a T8 bulb. Compared with T5 lamps, CCFL lamps generate around 10 centigrade less of heat in a 144-sq.-feet room for each lamp, the company's tests show.
"CCFLs also have a much longer life span than generic fluorescent lamps, and the new-generation lamps do not flicker," Yieh adds. His company's products are guaranteed for three years. "Our CCFL lamps begin decaying after 30,000 hours of operation and their useful lifespan can reach up to 50,000 hours," he reports. The company sources CCFL lamps from dedicated manufacturers and develops its own lighting fixtures.
Compared with LED T-bar lighting fixture sets, CCFL T-bar fixtures, Yieh reports, are much more competitive, with estimated pricing of NT$2,500-3,000 (US$75-90) vs. NT$40,000 (US$1,212) a set.
In the CCFL lighting market, Yieh boasts, his company has many advantages over other potential rivals. "We're knowledgeable about power-supply design thanks to our long operation in the household appliance industry and we have set up solid relationship with big domestic retailers," he says. The company was founded in 1983 to assemble monitors for game machines before working as a contract supplier of television sets. Brand-name household-appliance suppliers like Sampo and Kolin are among the company's major buyers.
But as an assembler of TV sets, the company has no option but to poach illumination talents from dedicated manufacturers, mostly Shih Kwang Light & Electric Co., Ltd., which was formerly known as Taiwan Fluorescent Lamp Co., Ltd.
Unlike its TV-assembly operation, the company will use the "Monix" brand on part of its lighting fixture output, while the remainder of the fixtures will be sold under the contract buyers' brands. The company says that its CCFL lighting fixtures are well suited for public-work projects and replacement projects.
Winning Trust
Louis Lu, an assistant vice president of Wellypower Optronics Corp., Taiwan's No.1 CCFL maker, welcomes a common standard for the lamps for lighting purpose. But he also insists that the standard must be stringent enough to prevent disqualified products from entering the Taiwan market. "Some European lighting heavyweights are paying attention to this type of lighting and have started sourcing from Asian manufacturers. So, only quality can win their trust," Lu says, adding that his company has begun shipping CCFL lamps to European lighting manufacturers.
The company has introduced compact spiral lamps, T-bar lighting fixtures, and under-cabinet lighting fixtures. "We diversified into the lighting industry around two or three years ago by introducing lamps for advertisement signs and light boxes," Lu says.
The company's CCFL lamps come in lengths ranging from 33mm to 150mm, with diameters of 1.8mm to 6.5mm. For its T-bar lighting fixtures, the major size specification is 60cm x 60cm, though the company is also developing a 60cm by 120cm version. The company's T-bar has a lifespan of 30,000 hours and its compact spiral lamp can last for 20,000 hours.
Wellypower Optronics' compact spiral lamps are categorized into cold-white, neutral-white and warm-white light types. The company has introduced 5W, 7W, 9W and 12W compact spiral lamps, with color rendering ranging from 80 to 95. They are rated to produce over 60 lumens per watt and are dimmable
Lu points out that applying CCFLs to general lighting provides the manufacturers a chance to grab share of the comparatively stable lighting market at a time when the backlight market is wildly fluctuating. The demand for CCFLs should also benefit from the energy conservation trend. "A CCFL compact spiral lamp lasts six times longer than a traditional compact fluorescent lamp and 20 times longer than an incandescent lamp. A CCFL lamp also produces five times more light than an incandescent bulb of the same wattage," stresses Lu.
Taiwan has several production advantages over Japan and South Korea in the CCFL lighting market, Lu says. "One of them is the sheer size of LCD production in Taiwan, which provides a solid basis for CCFL makers to finely adjust their production and achieve better quality at a lower price," he notes.