By ASHLEE VANCE


MOUNTAIN VIEW, California - For years, the computer industry has dabbled with the touch-screen technology that lets people poke icons on a display to accomplish tasks like picking a seat at an airport check-in kiosk. Apple elevated such technology from a novelty to a must-have feature on mobile devices with its iPhone. Users can flip through pictures with a flick of a finger, or make a document larger by placing two fingers against the screen and spreading them apart.

Now both personal computer manufacturers and software makers hope to do more with touch on larger devices by letting people use all 10 fingers.

“You don’t even operate your TV with two fingers,” said Amichai Ben- David, the chief executive officer of N-trig, which produces touch-screen technology for PC makers. “In order for this to feel really natural, you need more than two fingers for sure.”

The industry hopes the feature spurs sales. Hewlett-Packard, Dell, Intel and Microsoft expect that when companies and consumers increase their spending, touch technology will help persuade them to upgrade. Computers with the special screens will probably cost consumers about $100 more than standard machines.

Hewlett-Packard sells a PC with an early version of the technology. The $1,150 TouchSmart PC has been popular, the company says, particularly in kitchens as a family computer.

But Mr.Ben-David said only about two million of about 300 million PCs sold last year were touch computers.

Hewlett-Packard has already been promoting touch technology for large businesses. It sells a custom touch interface for both desktops and laptops. Customers can turn these machines into kiosks for, say, selling merchandise at a sporting event.

The PC industry wants to make touch functions more sophisticated, allowing on-screen objects to be twisted and turned with several fingers.

The next version of Windows from Microsoft, Windows 7, will usher in a new era of touch technology when it appears on PCs later this year, according to Mr.Ben-David. Backed by Microsoft, Israel-based N-trig uses software and sensors to create a computer screen that can interact with pens and fingers. N-trig’s technology works by pumping an electrical signal through the screen. When a finger hits the screen, the electricity is discharged. Software interprets that to move graphics on the screen.

Microsoft and N-trig have created a type of software interface that lets other companies add touch functions to their programs. Such touch software can handle lots of fingers hitting a screen at once rather than just relying on one or two digits, as most of today’s touch screens do.

SpaceClaim, which makes software for designing objects in 3-D, has taken a business-oriented approach to touch. Its software creates 3-D models that can be turned and altered via twohanded touches.

Frank DeSimone, the company’s head of development, urges other software makers to try something new rather than just replicating the functions of a mouse. “A lot of people say they will support touch, but they do a disservice to everyone by not doing anything interesting,” he said.