IBM Makes LCD Breakthrough
Fine-tunes development process; should lead to lower costs.
In what’s hailed as a breakthrough development, IBM (IBM, info) researchers say they have found a way to put a new face on your computer. By developing a new process for manufacturing computer displays, IBM claims it can save manufacturers money while improving screen quality and viewing angles.
The research infuses some predictability into the mysterious science behind flat liquid crystal display (LCD) screens, which are used in laptops and, with increasing frequency, desktop computers. The current LCD development method is based on a process discovered 95 years ago that proved when a polymer layer, or substrate, is rubbed, the liquid crystals align to the direction of the rubbing. Without rubbing, the liquid crystal molecules would orient themselves in many different directions and could not be controlled.
When properly aligned, the molecules inside an LCD, in response to electronic signals sent by the computer, turn pixels on and off by twisting and rotating.
However, scientists have never fully understood why the rubbing worked. And the process was somewhat laborious because it required a step in which the panels are taken out of the “clean room” — where the computer screens are built — and rubbed with a dusty cloth to activate the liquid crystal alignment.
“They still don’t understand why the rubbing works,” says Praveen Chaudhari, lead scientist on the IBM project. “They’ve tried and there have been many ideas, but it’s hard to prove they are right. This is something that had to be changed because you have everything running in a clean room, and then you are rubbing with a cloth, which picks up all kinds of debris.”
The rubbing process also invites more streaks on the computer screen, which is an obvious problem.
“It creates a whole set of problems known to the industry,” says Chaudhari. “A few years ago, when I asked IBM what science could do for them, they jumped and said `Fix this problem!'”
So Chaudhari came up with a new non-contact method that uses beams of ions — electrically charged atoms — to align the liquid crystal molecules inside the flat-panel displays.
“It occurred to me: ‘Why not try to put directionality on the surface by shooting atoms at the surface?” explains Chaudhari. “Much like billiard balls, atoms will respond when they are hit. We tried it, and it works.”
In a nutshell, the process means the developers can stay in the clean room, and they can avoid streaks because, as Chaudhari says, they are just “tickling the atoms at the surface” rather than rubbing them.
The real upshot is that those steps will save manufacturers money, and increase yield in the $20 billion LCD business.
Jay Patel, a senior analyst with the Yankee Group, sees many advantages to the new process, including the fact that it adds more predictability to the LCD development systems.
“This is certainly more scientific, and therein lies a greater potential to improve the process overall down the road,” says Patel.
But perhaps more important is what the development could mean for the future of computer monitors. Up until now, it has largely been cost that has kept people from buying the more convenient and compact LCD screens.
“LCD is a growing industry,” says Patel. “But the main deterrent up until now is the cost. In my mind, there’s no reason to have these big and clunky monitors on all of our desks. At some point you are going to see these flat LCD screens on everybody’s desk and wall. This takes us one step closer to that.”
IBM is considering licensing the patented process to other manufacturers in the flat-panel display industry. The company expects to have converted the pilot manufacturing line it used to develop this new technique into a production line by the end of the year.