Patent GB-1263775-A (GB)
Title: Improvements in or relating to document handling apparatus
IPC: G06V10/10
Filed: 1969-05-06
Abstract: 1,263,775. Character recognition. SCANDATA CORP. 6 May, 1969 [5 June, 1968], No. 23102/69. Heading G4R. In document handling apparatus, transport of a document from an input bin 34 to an output bin 36 is controlled in accordance with information generated by document-location-sensing means and a character recognition system, including incrementing of the document at a reading station. Roller 44, resting on top of a stack of documents in input bin 34, and rollers 46, 48, 50, 52 are driven to pass the top document on to a belt 60, roller 48 rotating in the reverse direction to prevent more than one document passing at a time, aided by stop 94. Detection of the document by a photo-cell PS1 disconnects the drive to rollers 44, 46, 48 to prevent a second document following immediately. The belt 60 is drawn around a platen 62 by a step-motor 90, the document being held on the belt by a partial vacuum and passed to a reading window 42 where each required line of characters is optically scanned in turn to feed the recognition system, the document then being delivered into one of 3 output bin sections 66, 68, 70 according to information on the document e.g. print quality, under control of the recognition computer. The recognition computer controls a "cycle select" bi-stable to put the apparatus into a feed cycle, used for advancing the document to the reading window 42 and, after reading, passing it to the output bin 36, or a line increment cycle, used for advancing the document line-by-line past the reading window 42. In a feed cycle, the computer presets a step counter to all ones, and first and second pulse generators drive the step motor 90 and decrement the step counter respectively. The clutch in the drive to rollers 44, 46, 48 is energized to feed a document until photo-cell PS1 detects the document, as stated. Detection of the document by a photo-cell PS2 inhibits the pulse supply to the step motor 90 and informs the computer which puts the apparatus into a line increment cycle in which the computer loads the step counter with the number of steps of motor 90 required to move to the line of print to be scanned, and the first pulse generator drives the step motor 90 and decrements the step counter. When the count reaches zero, the supply of pulses is inhibited and the computer is informed. The line is scanned, then the procedure is repeated to move the next required line of the document into position. Information on the document may inform the computer which lines are not required to be read. After all the required lines have been scanned, the computer switches the apparatus to the feed cycle to feed the next document from the input bin 34 and the current document to the output bin 36. During a feed cycle, a fault detector signals a paper-handling fault to the computer and stops the input feed, if the step counter reaches a predetermined count before the photo-cell PS1 detects the document. This is also used to stop the apparatus after the last document has been passed to the output bin 36, subject to detection of this by a photo-cell PS3. Pulse feed to the step counter is inhibited during a feed cycle by the AND of outputs from photo-cells PS2 and PS3, so that if output of a document (photo-cell PS3) is not completed by the time the next document reaches photo-cell PS2, the step counter continues to step down and when it reaches zero, the fault detector signals a paper-handling fault to the computer.