Seismic trace center-line generator

Claim 3

The system of claim 1 wherein said generator includes: a. a shift register having a plurality of stages, one for each of said seismic channels, b. a clock coupled to said shift registEr for shifting said register sequentially the entire length of said register for each sweep of said electron beam, c. a plurality of first gates, one for each of said seismic channels, having one input coupled to the selector switch representative of the seismic channel and having a second input coupled to the shift register stage representative of the respective seismic channel, whereby said gates provide enabling signals upon said shift register being shifted to those stages representative of the seismic channels selected by said selector switches, and d. a monostable multivibrator having an input coupled to the output of each of said first gates, said multivibrator providing a center-line pulse upon the presence of an enabling signal on any one of said first gates.

Claim 4

The system of claim 2 further including: a second gate having said multiplexed modulation signals applied to a first input and said center-line pulses applied to a second input, the output of said second gate being applied to said cathode-ray tube to intensity modulate said electron beam with both said multiplexed modulation signals and said center-line pulses as it sweeps across the face of said cathode-ray tube.

Claim 5

The system of claim 2 including: a switch coupled to each of said plurality of first gates which, when closed, enables said second inputs of said first gates to be coupled to the shift register stages representative of the reverse order of said seismic channels, whereby said first gates provide enabling signals upon said shift register being shifted to those stages representative of the reverse order of the seismic channels selected by said selector switches.

Claim 6

In a seismic data processing system for photographically reproducing seismic data from a plurality of seismic channels including a converter for providing a plurality of pulse width modulation signals representing the data contained on each seismic channel, a multiplexer for successively applying one modulation signal for each of said plurality of seismic channels to a cathode-ray tube to successively intensity modulate the electron beam one time during each sweep of the electron beam across the face of said cathode-ray tube for each of said seismic channels, and a drum plotter for photographically reproducing in a side-by-side relationship each sweep of said electron beam whereby a plurality of seismic traces are recorded simultaneously in parallel, the combination therewith of: a. a plurality of selector switches, one for each of said seismic channels, b. a shift register having a plurality of stages, one for each of said seismic channels, c. a clock coupled to said shift register for shifting said register sequentially the entire length of said register for each sweep of said electron beam, d. a plurality of first gates, one for each of said seismic channels, having one input coupled to the selector switch representative of the seismic channel and a second input coupled to the shift register stage representative of the respective seismic channel, whereby said first gates provide enabling signals upon said shift register being shifted to those stages representative of the seismic channels selected by said selector switches, e. a monostable multivibrator having an input coupled to the output of each of said first gates, said multivibrator providing a center-line pulse upon the presence of an enabling signal on any one of said first gates, and f. a second gate having one input coupled to the output of said multiplexer and a second input coupled to the output of said multivibrator, thereby coupling both modulation signals and center-line pulses to said cathode-ray tube for intensity modulation of the electron beam.

Claim 7

In a seismic data processing system for photographically reproducing seismic data from a plurality of seismic channels including a converter for providing a plurality of pulse width modulation signals representing the data contained on each seismic channel, a multiplexer for successively applying one modulation signal for each of said plurality of seismic channels to a cathode-ray tube to successively intensity modulate the electron beam one time during each sweep of the electron beam across the face of said cathode-ray tube for each of said seismic channels, and a drum plotter for photographically reproducing in a side-by-side relationship each sweep of said electron beam whereby a plurality of seismic traces are recorded simultaneously in parallel, the combination therewith of: a. a plurality of selector switches, one for each of said seismic channels, b. a shift register having a plurality of stages, one for each of said seismic channels, c. a clock coupled to said shift register for shifting said register sequentially the entire length of said register for each sweep of said electron beam, d. a plurality of first gates, one for each of said seismic channels, having one input coupled to the selector switch representative of the seismic channel and a second input coupled to the shift register stage representative of the respective seismic channel, whereby said first gates provide enabling signals upon said shift register being shifted to those stages representative of the seismic channels selected by said selector switches, e. a monostable multivibrator having an input coupled to the output of each of said first gates, said multivibrator providing a center-line pulse upon the presence of an enabling signal on any one of said first gates, and f. a second gate having one input coupled to the output of said multiplexer and a second input coupled to the output of said multivibrator, thereby coupling both modulation signals and center-line pulses to said cathode-ray tube for intensity modulation of the electron beam.