Princeton University

Panasonic Technologies, Inc.

Matsushita Information Technology Laboratory

Richard J Lipton

Jonathan S Sandberg

Daniel P Lopresti

Henry F Korth

A certificate, calculated on the text of a document to be reproduced, is included in the document in a form which is machine-readable. Upon optical character recognition scanning, or other digitizing reproduction, the certificate is also scanned and stored for comparison. A new certificate is calculated on the contents of the reproduced document and compared to the scanned certificate. If the two certificates are different, it is known that at least one error exists in the reproduced document. More than one certificate can be provided for a document in order to facilitate error location on the document and error correction therein.

Certifiable optical character recognition

Independent heterogeneous computers are interconnected for oblivious, high speed, long distance communications. A printed circuit board with onboard RAM repeats all write commands through a data transmission media to a remote system. Each read and write cycle of the communicating computer is completed locally (using only local RAM). Apart from repeating write commands to a remote system, the invention is oblivious to the remote system. Data is transmitted from one machine to another without expensive communication protocols or transmission line latency induced wait states. A remote computer accesses network data only after it has been transmitted and stored in local memory. Multiple data transfers can be pipelined, that is, multiple datum may simultaneously reside in a high latency network/long transmission line. Although the time required to transmit any single datum remains proportional to the signal propagation delay, the time required to transmit multiple data is significantly reduced. Geographic separation, high speed transmission lines, low speed transmission lines, alternative means for data transmission, fault tolerance, one-way communications, multi-way communications, and high security can be supported by a single computer network of heterogeneous machines.

Growing community of inventors

Cranbury, NJ, United States of America

Richard J Lipton