Patent GB-1265067-A (GB)
IPC: G06F3/01
Filed: 1969-05-21
Abstract: 1,265,067. Stereoscopic displays; seismic exploration. TEXAS INSTRUMENTS Inc. 21 May, 1969 [24 June, 1968], No. 25857/69. Headings H4D and H4T. A three-dimensional stereoscopic display apparatus stores in a memory array the threedimensional co-ordinates of plural points defining an object and its relationship to surrounding points, and a pair of displays show two dimensional images derived from point coordinate data selected from the memory; the images being spatially related so that when viewed simultaneously and stereoscopically a three-dimensional image is produced; oriented by selection of the stored points to be displayed from the memory by a control module, which also enables rotation of the image about a coordinate axis, and reduction or enlargement of its scale. In geophysical exploration of subsurface strata structures, an explosive charge 10 (Fig. 1) is detonated in a borehole 12 by exploder 14 triggered from signal generator 16, and initiates seismic waves, e.g. 18, 20, reflected from a subsurface structure 22 to detectors, e.g. 24, 25. Similar reflections are detected at, e.g., 26 to 29 from structure 22 and the underlying structures and the wave data from, e.g., 24 to 29 is amplified, attenuated and modulated at 36 for magnetic storage at 42, which also stores the individual attenuator settings and the firing time; the stored information representing the subsurface structure. The seismic data from 42 is transferred to input file 44 (Fig. 2), and read in by input/output channel 46 for information transmissions to input/output program unit 48 forming part of a digital computer core memory 50, which may be read out over 46 to output file 52. Each information bit is identified by its point of origin, assigned three-dimensional co-ordinates X 1 , X 2 , X 3  and stored in memory array 54, which thus acquires all the seismic information derived from Fig. 1 identified as to origin by threedimensional co-ordinates. Image generator 56 generates image codes from selected stored points for L and R image output buffers 58, 60 of array capacity sufficient for the number of points to be displayed, having rows and columns accommodating in each row the two display co-ordinates of a point while column C accommodates a code relating a point to its surrounding points. The stored programs are transmitted to C.R.T. controls 62, 64 over input/output channel 66 to generate analogue voltages energizing the guns of C.R.T.'s 68, 72 to display on screens 70, 74, respective two-dimensional images of the selected points, which are stereoscopically viewed over an optical system 76 to generate a three-dimensional image. A three-dimensional spatial mark is derived from co-ordinates stored in mark array 98, programmed for a desired orientation and fed into image generator 56 and output buffers 58, 60; the mark being movable by updating memory array 54 from on-line typewriter 100 over input/output channel 66 to the model modification module 102, so as to redefine the three-dimensional location of the spatial mark. On-line typewriter 102 also assigns an identification member to a displayed seismic interface by interconnection of the modification module 102 to label array 104, whose information is programmed into the output buffers 58, 60 through image generator 56 together with the other display information. A label is located on the model by moving the spatial mark to the appropriate portion thereof, after which the label is filed into the memory. A control console connected to core memory 50 over input/output channel 66 has pushbutton arrays 108 to traverse the spatial mark nearer or farther, left or right, up or down relative to the observer by operating a mark shift module 110 to continuously and incrementally update the stored mark array information in 98 to produce movement in the required sense. Other push-button arrays 112, 114, 116 instruct a linear transform module 118 connected to memory array 54, respectively, to move the model farther or closer left or right, or up or down, relatively to the observer or to increase or decrease the scale representation. A new model may be introduced into the memory aray 54 by operation of the on-line typewriter 100 over modification module 102 connected to the input/output program unit 48, to supply new information. The image generator defines a different twodimensional image for each of buffers 58, 60, which develop distinct displays at projection locations corresponding to the interocular distance of the observer (Fig. 3, not shown), and the viewing angle of the displayed model is controlled by the image generator programme (Fig. 4, not shown).