GB1276951A - Data scanner - Google Patents

Abstract

1276951 Statistical apparatus DATATYPE CORP 4 May 1970 [27 May 1969] 21236/70 Heading G4M A document is driven longitudinally in the direction of arrow 136, Fig. 23, relative to a sensing head 350 until a line of indicia associated with a line of printed characters is detected, and the line of indicia is then sensed by transverse movement of head 350. Sensing head, Fig. 19.-Light sources 414 and optical systems 416, 418 having axes inclined at 45 degrees to document 124 have associated photodetectors 424, 430 for sensing the indicia and line designating marks respectively. The head is driven across the document by a motor 360 and chain 376, Fig. 23, and is returned by a spring. Detector circuit. Fig. 8.-The output of detector 424 triggers a monostable circuit 93 when the start bar of each indicia group is sensed, and astable multivibrator 94 produces a train of pulses to enable gate 95 and at the same time to provide a train of short sampling pulses from monostable circuit 94<SP>1</SP>. The output of gate 95 is integrated at 96 and fed to a trigger 97 which responds at a given level. After shaping at 97<SP>1</SP> the output is sampled at gate 98. Document feeding.-The document is placed on a bed 126, Fig. 23, and is aligned against a stop 128 and a side edge 130. The presence of the document is detected by a photodetector which energizes a solenoid 140 to retract the stop 128 and a solenoid 152 to actuate a clamp 132 to engage the document. The clamp 132 is mounted on a carriage 134 which is driven by a pin 314 on a chain 312 engaging a hook 316. The clamp is released when the carriage 134 reaches the left-hand position. As the carriage 134 moves, pins 178 on a programme bar obscure a photodetector 184 at preselected positions, and simultaneous detection of a line designating mark by detector 430, Fig. 19, causes interruption of the drive to carriage 134, and initiation of a scanning traverse by head 350. On detection of a carriage return or line feed code or on actuation of a limit switch by head 350, drive to carriage 134 is resumed either after or during return of head 350 to the starting position.