SAN JOSE, Calif. Philips Flat Display Systems will work with WhoVision Systems Inc. to develop flat fingerprint sensors on glass for portable-computing and consumer-electronics products.
The companies plan to combine Philips' LCD manufacturing expertise and its intellectual property for capacitive fingerprint-sensing technology, both from the Flat Display Systems unit of Philips Components Division, with WhoVision's elastic light-emitting polymer technology for the touch surface of fingerprint sensors.
The companies expect to show product prototypes of fingerprint-sensor modules by the first quarter of 1999, and to ramp production by the second quarter of next year, said Alex Dickinson, chief executive officer of WhoVision (Lake Forest, Calif.).
Long term, the companies plan to integrate fingerprint-sensor technology into liquid-crystal displays for handhelds, PDAs, notebook computers and cell phones, Dickinson said.
Philips and WhoVision are taking a different approach to fingerprint sensors than other IC companies that have developed chips for the biometric market. The pair will develop a fingerprint sensor on glass, and use WhoVision's patented TactileSense light-emitting polymer to provide the opto-isolation layer between the electronics on the glass surface and the surface of the finger.
The sensor is expected to be manufactured by Philips in a process similar to that employed in the manufacture of active-matrix screens on glass.
WhoVision's light-emitting plastic coating, TactileSense, lights up when it comes in contact with the finger and an electrical field so that the fingerprint is optically imaged. The light-emitting plastic replaces the optics used in optical scanners, which currently dominate the live-scan fingerprint market.
The chip would perform the fingerprint recognition similar to the way in which capacitive-array sensors work, determining the contours of the fingerprint by calculating the various electrical signals of its ridges and valleys.
Dickinson said he believes the combination of glass and WhoVision's light-emitting coating provide a lower-cost solution to both optical scanners and solid-state fingerprint-sensor devices.
WhoVision officials say a fingerprint sensor built on glass would in general be cheaper than a solid-state device because the cost of a per-unit-square area of silicon is 10 to 20 times more than the cost of a unit-square area of glass.
Dickinson also believes a glass-based sensor would be more effective at reading fingerprint images because it could be larger than a solid-state-based device, so it would be able to read a larger area of a fingerprint.
But other industry players question how effective the technology will be. Bill McLean, vice president and chief marketing officer of Harris' AuthenTec Group (Palm Bay, Fla.), which has developed a fingerprint-sensor technology called FingerLoc, said he wondered "what quality of transistor Philips will be able to build on glass?"
McLean also challenged the idea that a larger, glass-based device would be more effective at reading fingerprints than solid-state-based sensors.
FingerLoc technology offers more accuracy at reading fingerprints on a larger segment of the population under a variety of conditions, McLean said. The FingerLoc's electronic-field antenna array device detects the ridges and valleys in the live layer of skin 8 to 10 millimeters below the skin surface. On the other hand, optical scanners and capacitive-array-based fingerprint sensors read only the outer, dead-skin layers of the finger. If the finger skin is dry, calloused or worn smooth by mechanical or chemical means, or if the finger surface is contaminated with dirt, oil or other substances, the sensor's effectiveness is diminished, he said.
Authentec executives recently visited a major PC manufacturer on the West Coast and did extensive testing with silicon-fingerprint sensors, McLean said. While the capacitive-array sensors had better results than the optical scanners, McLean said they still only worked with 90 to 91 percent of the population.
Authentec's FingerLoc technology was at the high end of effectiveness, McLean said.
Meanwhile, other fingerprint-sensor companies are already ramping into production. Lucent Technologies spin-off Veridicom (Santa Clara, Calif.) and STMicroelectronics have developed fingerprint sensors that use capacitive-sensor-array technology, building silicon ICs containing an array of sensor plates.
Thomson CSF uses a thermal array swipe sensor in its FingerChip, which requires a user to swipe his or her print across the sensor. The sensor measures a temperature differences between the ridges and valleys in the print. The FingerChip has already started to ship.
WhoVision's TactileSense material is currently being used by several PC peripheral manufacturers. Monitor maker Mag Technology USA (Irvine, Calif.) is integrating the WhoVision material into a fingerprint-identification device that will attach to a PC in order to provide security for PC users. Some keyboard manufacturers also are reportedly building the TactileSense material into keyboard products they plan to show at Comdex in November.