Anordnung zum Identifizieren von Informationszeilen auf Dokumenten

1,109,349. Line identification. INTERNATIONAL BUSINESS MACHINES CORPORATION. 25 July. 1966 [9 Aug., 1965], No. 3309/66. Heading G4R. Line identification apparatus detects coded line representations fixed with respect to a document which bears lines to be identified. Fig. 4 shows a document which bears lines of characters (not shown) to be scanned and read by a cathode ray tube (and photomultiplier),. Sets of coded indicia in a line identification track are provided to allow lines to be identified for subsequent marking when they contain unreadable characters, and to facilitate indexing of the document after one group of lines has been scanned to bring the next group into position. Each set of coded indicia is a set of horizontal bars 19 present or absent to represent 1 and 0 respectively. Thicker so-called bracket bars 17 separate successive sets of the coded indicia. Other bars are provided as shown. The document is advanced until a photodetector 33 has detected both bars 30 and 29 after which it is stopped. The beam of the cathode ray tube is then at 35. The beam is moved rightwards until it encounters bar 27 when it backs off and moves downwards to read coded indicia 26 (bars present and absent) identifying the document. When a predetermined distance below a bracket bar 28, the beam moves rightwards in a line searching raster to find a line of characters. On detecting a line, the raster is normalized and centred on it (no details) as it moves rightwards. When it reaches the right-hand end of the line it returns leftwards to read the characters (no details). If all the characters are read successfully, the beam moves downwards and rasters along the next line. However, if a character could not be read the beam crosses horizontally into the line identification track then moves upwards. During the upward movement until the first bracket bar is detected, a first counter (354, Fig 2e, not shown) counts clock pulses to give a fine component of the line position, this fine component then being transferred to latches (363- 368, Fig. 2e, not shown). The coded indicia detected until the next bracket bar is reached give a coarse component of the line position and are gated into latches (377-382, Fig. 2e, not shown) under control of the decoded (410) output of the first counter (354) now being fed with clock pulses for this purpose. The fine and coarse components are passed to a central processor store. The beam returns downwards along the same path (despite Fig. 4)