Topic: NTT DoCoMo
Category: Mobile Phones
Technorati: Linking Blogs

I'm glad to see the world getting more and more wireless. Honestly, wires have really started to bother me.

NTT DoCoMo, champion of all things wireless, now takes their "contactless" philosophy a step further (you may remember their contactless IC FeliCa phones, and our FeliCa BLOWOUT coverage over a year ago), announcing a pretty exciting development yesterday.

In cooperation with Panasonic Mobile Communications, they have developed a contactless recharging stand. I know basically nothing of how it works, besides that it uses "electromagnetic induction." I thought the o­nly way to combine "contactless" and "power" was with microwave radiation, and SimCity 2000 taught me microwaves can get quite nasty. Shows what I know.

Anyway, more details inside.

On July 6 2005, NTT DoCoMo announced in cooperation with Panasonic Mobile Communications that they have experimented with contactless recharging. A FOMA phone can be recharged by simply placing it o­n a level-surfaced recharging pad.

The system uses electromagnetic induction to send recharging electricity to the handset's battery. The system accomplishes contactless electricity delivery through a pad that has a coil for transmission, and a reception coil inside of the handset itself.

Although contactless electricity delivery has been used in electric shavers and toothbrushes, thesize and weight stood as obstacles between this technology and mobile phones. But now, a thin secondary coil is o­n the cover portion of the battery pack, allowing for the introduction of the technology to mobile phones with no drastic hardware changes.

"[The technology] can be supported by just changing some of electric wiring and the battery cover" (DoCoMo). In practical terms, it took 120 minutes to charge the battery of the P900i using this system. This is about 33% more versus 90 minutes of current charging methods.

The thin coil has a high electric transmission efficiency, where the conversion efficiency is about 60%, exceeding the current 30%. Since the connection is contactless, the system is waterproof and minimizes space usage, and perhaps most interestingly, can be used o­n any shape of handset. Plans for the future include linkage with chargers for notebook PCs, PDAs, and other such devices.

You could say that, but in its current state, it is still an experimental device; the cost is simply too high for the time being. "We have to make it possible at a price that can be mass-produced. We're still not done with the size yet, either. We have absolutely not idea when this will become commercialized" (DoCoMo PR).

This recharging stand is planned to be o­n display at "WIRELESS JAPAN 2005," scheduled to take place from July 13th to 15th at Tokyo's Big Sight.