Vodafone has announced a new handset from Sharp that includes a face-recognition security system.

The 904SH handset will go on sale in Japan on April. Its VGA screen with 480 pixels by 640 pixels has four times the resolution of screens found on most high-end handsets currently on sale. A prototype of the phone was shown at the 3GSM World Congress in Europe earlier this month.

The security system uses a small camera positioned under the main display and replaces the pin-code or fingerprint authentication sometimes found in other phones.

It is based on technology from Oki Electric and is capable of authenticating within 1 second whether the face of the person trying to use the phone matches that of the pre-registered owner. Should recognition fail, for example, in a dark room, a back up system involving a question and answer can be used.

Other features of the 904SH include support for network-based software upgrades. This allows users to download new and updated firmware across the network when required. At present upgrades typically need a visit to a service centre or shop.

The phone will also include a Java-based chat applet that can set up an impromptu chat between up to 8 people nearby using Bluetooth. Compatible clients will be installed in future handsets, Vodafone said.

"In a meeting you can enjoy chatting with your colleague without making any noise," said Hiroshi Ohta, executive vice president and head of production and service development at Vodafone's Japan unit, at a Tokyo news conference.

The handset also has a new motion control sensor that measures both the phone's posture in three dimensions and acceleration, which is an improvement on sensors found in earlier Vodafone handsets, the company said. The sensor is mainly used for games but the new handset will include software that can identify star constellations in the sky when the phone is pointed at them.

The 904SH has a 3.2-megapixel camera with 2X optical zoom and supports the Felica nearfield wireless communications system. This latter support means it is possible to use the handset as a touch-and-go transport pass on railways in the Tokyo area and for payment in convenience stores and other shops that accept the Edy e-money system.

Vodafone's Ota wouldn't comment on if the handset would be released overseas but said discussions would take place with other group companies.