Southampton-based touch sensor chip firm Quantum Research Group is taking legal action against Apple over the capacitive sensing technology used in iPod Click Wheels.

“We are suing Apple over charge-transfer technology in iPods,” Quantum’s CEO Hal Philipp told EW. “Some are based on Cypress’ PSoC chip and used in a way we believe infringes our patent.”

The legal action against Apple was initiated in December 2005 but all concerned have been keeping quiet about it until now.

Apple recently revealed that it filed an answer “denying all material allegations and asserting numerous affirmative defences”. It also filed “counterclaims for non-infringement and invalidity”, in July.

“There are settlement discussions going on but I believe it will go to trial later this year,” said Quantum’s Philipp. “I am hoping iPhone does not contain Quantum-patented charge-transfer technology.”

Philipp said he respects Apple products and expects Quantum to gain from the buzz around its iPhone.

“I think Cypress’ PSoC is a fine chip and we are fans of Apple products,” he said. “Within hours of the iPhone announcement our phone began to ring. iPhone itself is going to drive specification in terms of capacitive touchscreens. It is a good bit of news for Quantum.”

iPhone does not have a conventional numerical key pad. It has a touchscreen which emulates a key pad when numerical input is required.

“Our chips have been designed into mobile phone touchscreens,” said Philipp, “but I can’t tell you which ones yet.”

While pleased about the increasing acceptance of capacitive touchscreens, Philipp is concerned about some poorly executed designs.

Naming a design that has nothing to do with Apple or Cypress, a Quantum spokesman said: “One of the important points we want to make, is that all touch technologies are not the same.”

Philipp also made it clear that some iPods use a capacitive touch sensor from Synaptics, which does not infringe Quantum’s patents.