Patent 7894804 was granted and assigned to Fujitsu on February, 2011 by the United States Patent and Trademark Office.
A communication device comprises a first memory which stores telephone books, each including identification information and a name of a communication party, a second memory which stores communication histories, each including a communication time and identification information and a name of a communication party, a changing device which changes a telephone book stored in the first memory, and a control device which, when the telephone book is changed, changes a communication history stored in the second memory in accordance with a content of change.