GB1205540A - Improvements relating to the beam processing of a workpiece - Google Patents

Abstract

1,205,540. Programmed control of beam machining. INTERNATIONAL BUSINESS MACHINES CORP. July 11, 1969 [July 23, 1968], No.34978/69. Heading G3N. A programme for controlling an electron, ion or laser beam processor is generated by causing the beam 5 to scan a pattern 53 having marks 54 corresponding to points at which a workpiece is to be processed (welded or drilled ), producing a signal in response to the beam impinging on a mark, and storing a representation of the position of the beam when said signal is produced. The processor has X and Y deflector coils or plates 6, 7 energized via amplifiers 29, 30 and digital/analogue converters 27, 28 by counters 25, 26 in which the magnitude of the deflection is represented in binary form. During processing, instructions are fed to the counters from a magnetic tape or other programme source 9, which also instructs devices 32, 33 controlling the strength and duration of beam pulses, or device 31 which produces a train of pulses. For creating the programme the circuit shown in thick lines is used. The beam is caused to scan a pattern 53 with a raster type movement by supplying continuous pulses from a generator 50 to the X counter 25, which when full sends one pulse to the Y counter 26 and recycles. Impingement of the beam on a printed or metallic mark 54 is detected by a photo-cell, photo-multiplier or scintillator 55 sensitive to reflected light or secondary electrons and a signal is passed through an AND gate 57 to a "clock" 60 and to an inverter 58 which closes another AND gate 52 to interrupt the scanning of the beam. The clock 60 switches the programme 9 to the receive mode and opens gates 66, 67, 68 which pass the counts in the X and Y counters and external information 69 on beam pulse strength and duration to the programme store. It also closes AND gate 57 to interrupt the signal from detector 55 so that gate 52 is again opened and scanning resumed.