The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2007
Filed:
Dec. 10, 2001
Takeshi Asahi, Tokyo, JP;
Jun Kitahara, Tokyo, JP;
Toru Owada, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention provides a digital copying method for preventing complete copying by the use of digital copying. A data generating portion includes a storage device which generates a plurality of digital copies having mutually different amounts of effective information from original digital data, and stores the set of digital content having the digital copies encrypted different numbers of times in a memory. A digital output portion decrypts the set of digital content retrieved from the memory a prescribed number of times, making usable and outputting one of the digital copies in the set of digital content. An analog output portion extracts the digital copy that has been encrypted zero times from the set of digital content, converts that copy to analog data, and outputs that data.