Multimedia stockpilers need not worry about laptops, digital video recorders or portable music players hitting a storage capacity ceiling any time soon.

Hitachi Ltd. says its researchers have successfully shrunken a key component in hard drives to a nanoscale, which will pave the way for quadrupling today's storage limits to four terabytes for desktop computers and one terabyte on laptops in 2011.

A terabyte can hold the text of roughly one million books, 250 hours of high-definition video, or a quarter million songs.

"It means the industry is making good progress to advance the capacity of disk drives and move to smaller form factors," said John Rydning, an analyst at market research firm IDC.

The feat, which Hitachi plans to present Monday at the Perpendicular Magnetic Recording Conference in Tokyo, revisits a technology known as giant magnetoresistance, or GMR, that was the basis of the work of two European scientists who won the Nobel Prize in Physics last week.

A hard drive has a metal disk that spins as an arm with an electromagnetic head at its tip hovers over it. The head reads bits of data by registering the magnetic bearing of the particles on the disk.

Capacities of hard drives have grown as researchers have crammed more bits of data closer together while also making the heads sensitive enough to read the data. The industry looks to new technologies every time physical limitations kick in, and GMR — which allows for extremely thin layers of alternating metals to detect weak changes in magnetism — was one of the breakthroughs that led to the fastest growth rate in the early 2000s, allowing hard drives to double in capacity every year.

But GMR-based heads maxed out, and the industry replaced the technology in recent years with an entirely different kind of head. Yet researchers are predicting that technology will soon run into capacity problems, and now GMR is making a comeback as the next-generation successor.

"We changed the direction of the current and adjusted the materials to get good properties," said John Best, chief technologist for Hitachi's data-storage unit.

By doing so, Hitachi said it has created the world's smallest disk drive heads, ones that are in the 30-nanometer to 50-nanometer range, or about 2,000 times smaller than the width of an average human hair.

Other hard drive companies are working on similar technology as well, Rydning said. He predicted the entire disk drive industry will begin migrating to this new type of GMR-based technology in 2009.