Bright Future Ahead for Organic TVs

Bright Future Ahead for Organic TVs

Sony's new organic light-emitting diode (OLED) television debuts in Japan later this year promising greater energy efficiency and color quality despite some manufacturing challenges
 

	Image: Courtesy of Sony
	ORGANIC VISION:  Sony's new XEL-1 television may have only an 11-inch screen, but it uses organic light-emitting diode (OLED) technology that promises advanced levels of contrast and brightness, a broad spectrum of color reproduction and a rapid video response rate.

At a time when the screen size of television sets is growing so fast that it appears headed to eclipse that of movie theater screens, the latest breakthrough in display technology has come in the form of an ultraslim 11-inch (28-centimeter) screen that is a mere 0.12 inch (three millimeters) thick at its thinnest point.

The innovation in Sony's new XEL-1 television is its use of organic light-emitting diode (OLED) technology that promises advanced levels of contrast and brightness, a broad spectrum of color reproduction and a rapid video response rate. OLED technology is also touted for its environmental friendliness.

Sony plans to introduce the XEL-1 television in December exclusively to the Japanese market at a cost of 200,000 yen (around $1,700) per unit. The company has not announced plans to offer an OLED TV in North America, although it is considering marketing it outside of Japan, a Sony spokesman says. He adds that Sony is "actively working on larger OLED screen sizes."

Whereas a liquid-crystal display (LCD) removes light from a backplane to create its picture, an OLED emits light, which creates "a rather substantial amount of efficiency," says Stephen Forrest, a University of Michigan at Ann Arbor vice president for research and a professor of electrical engineering and computer science. Since OLED pixels only consume energy when they're in use, they can consume up to 40 percent less energy than LCDs. "LCD screens also have polarizers (applied to the LCD glass plate)," he says, "that make viewing very angle dependent. OLEDs don't have all of the viewing angle deficiencies."

Image: Courtesy of Sony
TRIM TV:  Seen here in profile, the XEL-1 is 3 mm at its thinnest point.

OLEDs also make it possible for manufacturers to incorporate some fun novelties into their products. For instance, OLED panels could be made to show images on both sides, and they can be clear when they are turned off.

"The displays that Sony is making are really quite beautiful," says Mark Thompson, chairman of the University of Southern California's chemistry department, who has studied the use of organic molecules to create an organic LED. "It's a shame they're only 11 inches."

There are several obstacles to making larger OLED displays. The most glaring: in an OLED TV, there is a transistor backplane that controls the brightness of each pixel. "You need millions and millions of these transistors—with very few failures—to make this work," Thompson says. In order for an OLED to be more energy efficient and produce a clearer picture than an LCD screen, there needs to be a way to deposit red, green and blue pixels where each transistor is positioned. This challenge grows exponentially as the screen size grows.

Sony has demonstrated a 27-inch OLED prototype display, but the screen actually consists of four individual displays arranged to produce a single image, Thompson says. This sets up an additional hurdle, because the colors are difficult to match from one display to the next.

To make OLED a practical technology that's used more broadly, Sony will also have to find ways to ensure that the color quality of the screen can last long enough to justify the price. Sony said the XEL-1 has a viewing life of 30,000 hours, which allows a user to watch eight hours of television each day for 10 years. "When you put light through organic material, it tends to degrade rapidly over time," Forrest says. "We have to have long-lifetime displays, otherwise people won't buy them."

Sony's research into the use of organic materials began in 1994 and a decade later led to the mass production of small-size, color OLED panels in mobile devices. The company last month began mass producing the organic panel used in the XEL-1, which Sony says is the first stage of its OLED TV business. Sony rival Samsung demonstrated a 40-inch OLED TV in 2005 but has not moved the technology into production. Fremont, Calif.–based iriver America uses OLED technology in the displays of its Clix digital audio players, and Nokia offers OLED displays in some of its cell phones.

"Sony's approach is to develop a reliable production line for making moderate-size displays," Thompson says. "What Sony is doing is very smart, because they're saying, 'Let's just start manufacturing.'"

If OLED technology takes off, LCD's days are numbered. "LCD is having a real problem with advances in video, because it can't keep up with the millisecond video response rates as well as CRT (cathode-ray tube) and plasma screens can," Thompson says.

OLED technology will have an impact well beyond video screens as the U.S. Department of Energy encourages replacing old incandescent bulbs with more efficient and environmentally friendly alternatives. Fluorescent bulbs have proved to be an efficient option, but they contain hazardous chemicals such as mercury that are not easy to dispose of when they run out of juice.

Forrest is researching the use of electroluminescent light sources such as OLEDs to replace incandescent and fluorescent lighting sources. It is a formidable challenge, given that more than 125 years of manufacturing experience has enabled companies to sell incandescent bulbs for less than a dollar. Fluorescent lighting is coming down in price and uses only a quarter the energy of incandescent bulbs, "but you can't just throw them away when you're done with them," he says. "They need to be recycled."

Black Is Better than White for Energy-Efficient Screens

Fact or Fiction?: Black Is Better than White for Energy-Efficient Screens

Black isn't the new green 

	Image: iStockphoto
	BLACK HOLE:  LCD monitors, which have no phosphors and represent the lion's share of every new monitor purchased in the developed world, use more energy than CRTs to display a black screen.

The green computing movement demands that all computer users shed the energy-wasting practices to which they've grown accustomed—so you decide that you're going to power down your PC at night, invest in an Energy Star–approved laptop, and only visit Web pages that eschew white space in favor of ostensibly more energy-efficient black backgrounds.

Before you tune out and turn off, you should know that black isn't necessarily the new green. Because computer monitors come in a variety of shapes and sizes, and not all monitors create black and white the same way, there's no proof that, on the whole, increased usage of black images would save more energy than the continued use of white ones. In fact in newer liquid-crystal display, or LCD, monitors white is actually slightly more energy efficient than black.

The notion that black screens save electricity certainly makes sense when you're talking about cathode-ray tube, or CRT, technology that works by moving an electron beam back and forth across the back of the screen. "The front screen is covered with red, blue and green phosphors," says Bill Schindler, vice president of electrical engineering for Panasonic Plasma Display Laboratory of America. To produce white, the electron beam is directed at the phosphors. However, "when the screen is black, you don't have to fire the beam," he adds.

CRT monitors, which until a few years ago were the predominant models among PC users, consume more power when a computer screen is white. To confirm this, Schindler measured the energy output of an 18-inch (45.7-centimeter) CRT monitor and found it used 102 watts when the screen was white but only 79 watts when the display was black.

Image: iStockphoto
WHITE NOT ALWAYS RIGHT:  CRT monitors, which until a few years ago were the predominant models among PC users, consume more power when a computer screen is white.

This is not the case, however, with LCD monitors, which have no phosphors and represent the lion's share of every new monitored purchased in the developed world, including those used by laptops. Instead, LCD displays rely on an array of thin-tube fluorescent bulbs that provide a constant source of light to create a white screen. To make it black, LCDs rely on a diffuser to block this light. As a result, LCDs use more energy than CRTs to display a black screen. Measuring a 17-inch (43-centimeter) LCD monitor, Schindler found that white required 22.6 watts, while black came in a tad higher at 23.2 watts. With a 20-inch (50.8-centimeter) LCD, black required 6 percent more energy than white.

One of the most visible manifestations of the belief that black screens save energy is Blackle, an online search engine whose Web site is cast almost entirely in black. Created by Heap Media, Blackle exists "to remind people of the need to take small steps every day to save energy," says Blackle founder Toby Heap, who launched the site in January. "I do not expect the energy savings from Blackle to change the world on their own, but the point of Blackle is that every little bit counts."

One of the key arguments in favor of black screens is a 2002 research study produced by Lawrence Berkeley National Laboratory entitled "Energy Use and Power Levels in New Monitors and Personal Computers." The report indicates that "a given monitor requires more power to display a white (or light) screen than a black (or dark) screen." Indeed, that study reports that black screens consistently require less energy than white screens, regardless of whether the monitor is a CRT or LCD.

"It depends on the resting state of the LCD as to whether they require energy to stop light or to allow light to pass through," Heap explains. "This is why screen tests show that some CCFL (cold cathode fluorescent lamp) LCD screens save energy and some use a bit more. All of the scientific test data we have come across shows a slight saving on black LCD screens, which suggests that the rest state on many LCD screens does not allow light through." Heap also points out that a large number of Blackle users come from India and South America, where CRTs are still commonly sold.

Even though Google isn't tied to Blackle other than powering its search engine, Google green energy czar Bill Weihl in August posted a blog disputing the notion of black as the new green. "We applaud the spirit of the idea, but our own analysis as well as that of others shows that making the Google homepage black will not reduce energy consumption," he wrote. "To the contrary, on flat-panel monitors (already estimated to be 75 percent of the market), displaying black may actually increase energy usage."

New advances in LCD technologies could eventually validate the belief that black is better. Newer types of LCD include a dynamic dimming capability that changes the strength of the backlight based on the image being displayed. Heap also points out that many of the new monitor technologies such as LCDs backlit with light-emitting diodes (LED), plasma screens and organic LED screens do not have a constant backlight "so we will see larger savings with Blackle as these new monitors replace the CCFL LCDs," he says.

In the meantime, the world is evenly split between CRT and LCD monitors, totaling roughly 405 million and 401 million respectively in 2007, according to iSuppli data. So if you're still toiling away in front of a hefty CRT monitor that takes up three-quarters of your desk, then black screens will save you some energy. For those who've graduated to thinner LCD models, black screens are actually sucking up more energy then their white counterparts.

Astronomers See Second Earth in the Making

Astronomers See Second Earth in the Making 

Astronomers have spotted evidence of a second Earth being built around a distant star 424 light-years away.

Using NASA's Spitzer Space Telescope, astronomers have spotted a huge belt of warm dust swirling around a young star called HD 113766 that is just slightly larger than our sun. The dust belt, which scientists suspect is clumping together to form planets, is located in the middle of the star system's terrestrial habitable zone where temperatures are moderate enough to sustain liquid water. Scientists estimate there is enough material in the belt to form a Mars-sized world or larger.

At approximately 10 million years old, the star is just the right age for forming rocky planets, the researchers say. Their finding will be detailed in an upcoming issue of Astrophysical Journal.

"The timing for this system to be building an Earth is very good," said study team member Carey Lisse of the Johns Hopkins University Applied Physics Laboratory in Baltimore, Md.

If the star system were too young, the planet-forming disk would be full of gas, and it would be making gas-giant planets like Jupiter instead. If it were too old, Spitzer would have spotted rocky planets that had long ago formed.

The star system also has the right mix of dusty materials in its disk to form an Earth-like planet, Lisse said.

Using Spitzer's infrared spectrometer instrument, the team determined that the material around HD 113766 is more processed than the snowball-like stuff that makes up infant solar systems and comets, which are considered cosmic "refrigerators" because they contain pristine ingredients from the solar system's formative period. But it is also not as processed as the stuff found in mature planets and asteroids.

"The material mix in this belt is most reminiscent of the stuff found in lava flows on Earth," Lisse said. "I thought of Mauna Kea [in Hawaii] material when I first saw the dust composition in this system - it contains raw rock and it's abundant in iron sulfides, which are similar to fool's gold."

Earlier this year, scientists announced they had found evidence for one, and possibly two, already formed Earth-like planets around Gliese 581, a dim red star located only 20.5 light-years away. The possible planets, called Gliese 581c and Gliese 581d, are located at about the right distance from their star to support liquid water and life as we know it, but many more observations are needed to confirm this.

To date, planet hunters have discovered more than 250 extrasolar planets, or "exoplanets." Most of the distant worlds, however, are giant gas planets several times the size of Jupiter.

While life is known to exist only on our planet, the range of exoplanet types found so far has astronomers increasingly confident that many worlds in our galaxy could be habitable. Finding Earth-like worlds in habitable zones is a first step toward the technically challenging task of discovering biology outside our solar system.

Related Images
 
This artist's conception shows a binary system, 
called HD 113766, where astronomers suspect 
a rocky Earth-like planet is forming around one of 
the stars. Credit: NASA/JPL-Caltech/JHUAPL

The Science of Knots Unraveled

The Science of Knots Unraveled 

Tangled telephone cords and electronic cables that come to resemble bird nests can frazzle even the most stoic person. Now researchers have unraveled the mystery behind how such knots form.

Two physicists used string-tumbling experiments and mathematical models to create a step-by-step recipe for knot formation and determined which factors cause the knottiest knots. Their research, published online this week by the Proceedings of the National Academy of Sciences, sheds light on an everyday phenomenon about which little was known beyond the madness it incites.

"It's a common annoyance in everyday life, that anything that's like a string inevitably seems to get itself into a knot,” said the study's senior author Douglas Smith of the University of California, San Diego.

He added, “Very little experimental work had been done to apply knot theory to the analysis and classification of real, physical knots."

All tied up

Smith and UCSD colleague Dorian Raymer ran a series of homespun experiments in which they dropped a string into a box and tumbled it for 10 seconds (one revolution per second). They repeated the string-dropping more than 3,000 times varying the length and stiffness of the string, box size and tumbling speed.

Digital photos and video of the tumbling strings revealed: Strings shorter than 1.5 feet (.46 meters) didn't form knots; the likelihood of knotting sharply increased as string length went from 1.5 feet to 5 feet (.46 meters to 1.5 meters); and beyond this length, knotting probability leveled off.

Observations could only go so far. “It is virtually impossible to distinguish different knots just by looking at them,” Raymer said.

Raymer developed a computer program to try and mimic their observations. From the model, they created a simplified "lifecycle" of a knot from tidy beginning to titanic tangle. Once dropped, the string formed concentric coils. Next, the string's free end weaved through the coils, with a 50 percent likelihood of crossing under or over the coil and following a path to the left or right.

Knot busters

The best knotting came from very flexible, long string contained in a large box. "A highly flexible string placed in a very large container will have a higher probability of becoming knotted than a stiff one that's confined in a smaller container," Smith told LiveScience.

The researchers suggest that cramped quarters limit the tumbling motion that facilitates the string weaving through the coils. That would explain why knots were less likely to form in smaller compared with larger boxes.

But in real life, most people don't tumble cords and wires on a daily basis. Smith explained that while this tumbling is not a requirement for knots to form, some motion is necessary.

"Surprisingly little disturbance or motion is even needed," Smith said. "It's quite easy for something to get knotted." Even the act of picking up the phone and placing it back down could be enough jostling to trigger knot formation.

While there is no magical knot buster, Smith advised what all sailors, cowboys, electricians, sewers and knitters know: to avoid tangles, keep a cord or string tied in a coil so it can't move. 

Related Images

Repeated experiments, in which physicists dropped a string into a box and tumbled it around, revealed how knots form. Credit: Dorian Raymer, UCSD

Repair or Replace?

Repair or Replace?

Filed under: Appliances, Energy efficiency, Recycling, reuse, reduction

As long as you've got electronics and appliances in your home, you're inevitably going to be faced with a choice: Something breaks. Now what?

According to a 2005 Consumer Reports survey, Americans are repairing 16 percent fewer products—including high-cost items like television sets and refrigerators—than in 1997. The number of appliance-repairs shops has declined roughly 37 percent in 15 years while the number of electronics-repair shops has plummeted by 64 percent. So-called "e-waste"--computer monitors, televisions and other electronic waste—is the fastest growing portion of the U.S. waste stream. In 2005, electronics accounted for 2.63 million tons of waste—only 12.5 percent of which was recycled.

If you're lucky enough to find a repair shop, it may seem that the best environmental option would be to hang on to old appliances and electronics for as long as possible. Along with the environmental impact of new-product production, there's another concern: Many electronics contain heavy metals (such as lead and mercury), flame retardants and other toxic chemicals that can wash into waterways and pollute groundwater if sent to a landfill. But older products can be a big drain of household energy. "You need to consider buying a new product—which must be manufactured—or fixing your existing product, which may not be up to the latest energy standards," says Greg Keoleian, Ph.D., co-director of the Center for Sustainable Systems at the University of Michigan.

From a price perspective, if the cost to repair a household appliance is more than half the price of a new product, advances in energy efficiency will generally make buying a newer model the cheaper choice. Based on these numbers and considering today's more environmentally friendly technologies, here's a guide to when you should repair or replace.

Washers

* Replace all top loaders.

When Keoleian and his colleagues compared the average lifecycle of a washing machine (14 years) with the amount of water and emissions that could be saved by a newer model, they determined that even replacing a 2005 machine could have water-saving benefits. The reason: Water- and energy-saving technology continues to evolve as companies push beyond standards. It's most important to replace top loaders with Energy Star-labeled new front loaders as soon as possible; although they're generally more expensive, these models circulate clothes in a shallower pool of water, using less water and heat, and saving money in the long run. (Getting rid of a pre-1994 washer, for example, can save a family $110 a year on utility bills.) For models, see our Washing Machine Product Report.

Clothes Dryer

* Repair if possible, but line dry clothing whenever you can.

As long as your dryer has a moisture sensor (nearly all models in operation today should), it functions at about the same efficiency as current models, according to the American Council for an Energy-Efficient Economy. A dryer's average life cycle is about 13 years, so if it's possible to fix it during this time, try that first. When it is time to buy a new dryer, look for one with the sensor in the drum, as opposed to in the exhaust vent; it will shut off a little sooner and save slightly more energy. However, since dryers consume large amounts of energy, line drying or hanging your clothes on a rack is a better option. For dryers and drying racks, see Virtuous Cycles.

Refrigerators

* Replace all models manufactured before 2001.

New refrigerators consume 75 percent less energy than those produced in the late 1970s, and are even more efficient than models just six years old, Keoleian's research has found. The newest federal standards went into effect in 2001—so if you need to make repairs on an older fridge, it's worth getting a new one instead. When replacing your refrigerator, opt for a top-freezer configuration rather than a side-by-side, and make sure it's Energy Star-certified. A new refrigerator should then last you about 14 years. And resist the urge to hold on to your old fridge or give it away, since inefficient old models can cost over $100 a year to run. Most communities have specific requirements for disposing of refrigerators and other large appliances; visit www.earth911.org for information in your area. For models, see our Refrigerator Product Report.

Dishwasher

* Replace non-Energy Star models.

Newer, more efficient dishwashers use less hot water, have energy-efficient motors and use sensors to determine the length of the wash cycle—making Energy Star models 25 percent more efficient than the minimum federal standards. This can mean a savings of $25 a year if you replace a pre-1994 machine. When shopping for a new dishwasher, choose one with a "light wash" or "energy saving" cycle—and expect to hang onto it for about 9 years, suggests the National Association of Home Builders. And remember that handwashing dishes is an inefficient alternative, generally wasting more water than dishwashers. For models, see our Dishwasher Product Report.

Air conditioners

* Replace window units older than 10 years and central-air systems older than 10, but consider alternative cooling methods.

Upgrading your window units to a more efficient model can cut energy bills by an average of $14 a year, estimates the Energy Star program. The most efficient room air conditioners have higher-efficiency compressors, fan motors and heat-transfer surfaces than previous models. Central ACs are rated according to their seasonal energy efficiency ratio (SEER)—for which most 1992 to 2005 models score about a 10; older ACs have ratings of only 6 or 7. New minimum standards set in 2006 require current central-air units to have a SEER of at least 13. Because of the coolants used, old room-AC units need to be disposed of in hazardous waste facilities; old central units are usually disposed of by the contractor hired to install the new unit, but always ask ahead of time to ensure proper disposal.

Before you buy, however, consider alternatives such as ceiling fans, evaporative coolers (if you live in a dry climate), whole-house fans and landscaping or decorating changes, all of which can keep your home comfortable for a fraction of the cost (see Keep Your Cool With Less AC). For models, see our Air Conditioner Product Report.

Water heaters

* Replace all electric heaters, and any gas heaters older than 10 years.

If you have an electric heating system, you can achieve a 50 percent energy savings used by switching to a high-efficiency gas model. Gas heating systems can last for about 25 years but will operate for years at very low efficiency before they finally fail [but do they operate at low efficiency because of something that can be repaired?] ; if yours is more than 10 years old, it probably operates at less than 50 percent efficiency and deserves to be replaced. Consider a "demand," or tankless, system, in which water is circulated through a large coil and heated only when needed. Although EnergyStar doesn't certify these models, the government estimates that they can save between 45 and 60 percent of water heating energy and up to $1,800 a year when compared to standard, minimum-efficiency heaters.

Computers

* Repair as long as you can.

"The manufacture of brand new computer models uses more than four times the energy and resources it would take to extend the life of an older machine for another few years, says Sheila Davis, executive director of the Silicon Valley Toxics Coalition—so it's best to always repair it yours if possible. Memory can be added to slow computers (1-gig will run about $100 and you can install it yourself). But it's important to consider the repair process, says Davis: Name brand computers often have proprietary parts and need to be shipped back to the manufacturer—or sometimes even overseas—to be fixed. "White box" computers, that is, generic models without name brand parts, can easily be upgraded at local computer stores, but warranties for them can be tricky. They come without software, and finding technical support may be difficult. White box models are available online or at large computer chains.

If you prefer a name-brand item, choose one with a strong takeback program that will guarantee your computer won't end up in a landfill. Dell takes back all branded products for free; others accept new models or charge a small fee. Visit www.computertakeback.com/docUploads/Using_takeback_programsv7a.pdf for a comparison of most popular brands. As far as desktops versus laptops, it's a toss-up: "Even though laptops are smaller, they often have just as many chemicals to dispose of," says Davis. If you still have a large cathode-ray tube (CRT) monitor, replace it with a flat-panel liquid crystal display: A 15-inch LCD screen uses about 18 watts of energy, as opposed to about 200 for CRT's. For models, see our Computers Product Report.

Smaller electronics

* Replace, but recycle.

It's probably not financially practical to repair electronics such as printers, televisions, and digital cameras, but it's best to keep them out of landfills. Before ditching them, always consult the instruction manual and consider contacting the manufacturer; sometimes they'll provide repairs for a small fee. When they do need to be disposed of, visit www.greenerchoices.org for recycling options that won't put toxic chemicals back into the environment. Cell phones, for example, are often reprogrammed and donated to women facing domestic violence (as a 911 lifeline), and chains such as Best Buy and Staples often sponsor collection drives for other broken electronics (see also www.eco-cell.org). Apple will take back iPods (as well as cellphones), offering a 10 percent discount towards your next purchase. 

Resources

To recycling appliances, check with your local sanitation department or visit www.Earth911.org.

Repair Clinic: www.repairclinic.com

Point and Click Appliance Repair: www.pcappliancerepair.com