Takeshi Tomimori, an engineer at Mitsubishi Electric Corp. , in Tokyo, had an idea. What if you could alert a cellphone user of incoming messages by displaying an icon on the screen? He worked out the details for what Mitsubishi’s lawyers called, in their 1999 filing, a “Mobile Communication Apparatus Notifying User of Reproduction Waiting Information Effectively. ” Three years and three months later, the U.S. Patent and Trademark Office awarded Tomimori and his employer Patent No. 6,456,841. Let’s call it Icon, for short.