Optical Character Recognition - History

History

Early optical character recognition could be traced to activity around two issues: expanding telegraphy and creating reading devices for the blind. In 1914, Emanuel Goldberg developed a machine that read characters and converted them into standard telegraph code. Around the same time, Edmund Fournier d'Albe developed the Optophone, a handheld scanner that when moved across a printed page, produced tones that corresponded to specific letters or characters.

Goldberg continued to develop OCR technology for data entry. Later, he proposed photographing data records and then, using photocells, matching the photos against a template containing the desired identification pattern. In 1929 Gustav Tauschek had similar ideas, and obtained a patent on OCR in Germany. Paul W. Handel also obtained a US patent on such template-matching OCR technology in USA in 1933 (U.S. Patent 1,915,993). In 1935 Tauschek was also granted a US patent on his method (U.S. Patent 2,026,329).

In 1949, RCA engineers worked on the first primitive computer-type OCR to help blind people for the US Veterans Administration, but instead of converting the printed characters to machine language, their device converted it to machine language and then spoke the letters: an early text-to-speech technology. It proved far too expensive and was not pursued after testing.

In 1950, David H. Shepard, a cryptanalyst at the Armed Forces Security Agency in the United States, addressed the problem of converting printed messages into machine language for computer processing and built a machine to do this, called "Gismo.". He received a patent for his "Apparatus for Reading" in 1953 U.S. Patent 2,663,758. “Gismo” could read 23 letters of the English alphabet, comprehend Morse Code, read musical notations, read aloud from printed pages, and duplicate typewritten pages. Shepard went on to found Intelligent Machines Research Corporation (IMR), which soon developed the world's first commercial OCR systems.

In 1955, the first commercial system was installed at the Reader's Digest, which used OCR to input sales reports into a computer. It converted the typewritten reports into punched cards for input into the computer in the magazine’s subscription department, for help in processing the shipment of 15-20 million books a year. The second system was sold to the Standard Oil Company for reading credit card imprints for billing purposes. Other systems sold by IMR during the late 1950s included a bill stub reader to the Ohio Bell Telephone Company and a page scanner to the United States Air Force for reading and transmitting by teletype typewritten messages. IBM and others were later licensed on Shepard's OCR patents.

In about 1965, Reader's Digest and RCA collaborated to build an OCR document reader designed to digitize the serial numbers on Reader's Digest coupons returned from advertisements. The fonts used on the documents were printed by an RCA Drum printer using the OCR-A font. The reader was connected directly to an RCA 301 computer (one of the first solid state computers). This reader was followed by a specialised document reader installed at TWA where the reader processed Airline Ticket stock. The readers processed documents at a rate of 1,500 documents per minute, and checked each document, rejecting those it was not able to process correctly. The product became part of the RCA product line as a reader designed to process "Turn around Documents" such as those utility and insurance bills returned with payments.

The United States Postal Service has been using OCR machines to sort mail since 1965 based on technology devised primarily by the prolific inventor Jacob Rabinow. The first use of OCR in Europe was by the British General Post Office (GPO). In 1965 it began planning an entire banking system, the National Giro, using OCR technology, a process that revolutionized bill payment systems in the UK. Canada Post has been using OCR systems since 1971. OCR systems read the name and address of the addressee at the first mechanized sorting center, and print a routing bar code on the envelope based on the postal code. To avoid confusion with the human-readable address field which can be located anywhere on the letter, special ink (orange in visible light) is used that is clearly visible under ultraviolet light. Envelopes may then be processed with equipment based on simple bar code readers.