The $5 ‘no moving parts’ fluid zoom lens – twice

Is Philips offering something somebody else prepared earlier?

This week at CeBIT Philips will formally unveil a cheap, no moving parts lens system that could make it feasible for a camera to come as standard with virtually anything electronic. But last month at 3GSM a similar system from French company Varioptic broke surface; the two appear to be unrelated, and as Varioptic has previously claimed to hold "two fundamental patents" covering the technology, one might speculate that a legal clash could be on the cards.

Philips's patent application, WO 03/069380, is for "a variable focus lens comprising a first fluid and a second, non-miscible, fluid in contact over a meniscus. A first electrode separated from the fluid bodies by a fluid contact layer, and a second electrode in contact with the first fluid to cause an electrowetting effect whereby the shape of the meniscus is altered."

Varioptic, in WO 99/18456, describes "a lens with variable focus comprising a chamber filled with a first liquid, a drop of a second liquid (11) being provided on a first surface zone of the chamber wall, wherein the chamber wall is made of an insulating material, the first liquid is conductive, the second liquid insulating, the first and second liquid are immiscible, with different optical indices and substantially of the same density. Means are provided for positioning said drop in inoperative position on said zone, comprising electrical means for applying a voltage stress between the conductive liquid and an electrode (16) arranged on said wall second surface, and centering means for maintaining the centering and controlling the shape of the drop edge while a voltage is being applied by electrowetting."

Cut to the chase, for those of you still with us - the systems both use an electric current to change the shape of a fluid lens, producing something with at least some similarity to the operation of the human eye. In addition to WO/99/18456, Varioptic's Bruno Berge also has WO 00/48763, which describes "A method for centering a drop of liquid on a given point on a surface."

Philips' application references both Berge's patent applications, describing such a lens as "complex to manufacture and, particularly in the cylindrical configuration, requires a relatively high voltage in order to alter the lens characteristics of the droplet," and adds that the technique proposed in 58763 means that "manufacture of such a lens remains relatively complex."

Philips is therefore clearly aware of Berge's applications, and must be taking the view that they're less impregnable than Varioptic claims. It may also be significant that Varioptic has begun signing up handset manufacturers, meaning that Philips had to break cover before the horse had entirely bolted.

A Varioptic spokesman declined to comment on the matter to The Register, but reiterated the company's confidence in the strength of its IP assets. Talks, quite possibly involving m'learned friends, would seem the logical next step. ®

Related links

Philips sets out its stall
Varioptic struts its prior art

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