Graph-reading digital converter

Claim 2

Apparatus for digitizing graphically represented data or the like comprising: a frame mounted for translational movement on wheel means in a selected direction along a surface graph to provide a measure of one coordinate of the graph; a stylus attached to a pivot on the frame for rotational movement about an axis generally orthogonal to the direction of translational movement, which pivot is movable with said frame, the stylus being intended to follow a line or curve of the surface graph in operation; and separate digitizing transducers respectively coupled to the wheel means and to the stylus for providing discrete electrical digital signals indiCative of the travel of the frame in said selected direction and the degree of rotation of said stylus about said axis respectively.

Claim 3

Apparatus in accordance with claim 1 further including means mounted on said frame for accurately driving the transducer connected thereto through frictional engagement with said surface graph.

Claim 4

Apparatus in accordance with claim 2 wherein said frame mounted means comprises a pair of rotatable wheels having a frictional surface to support said frame for translational movement by rolling without slippage over said graph surface.

Claim 5

Apparatus in accordance with claim 1 wherein said frame may be positioned on said surface graph for movement of the entire apparatus in any direction parallel to said surface graph.

Claim 6

Apparatus in accordance with claim 1 further including a mechanism coupled to said transducers for recording said electrical signals at selected points during the traversal of said graph.

Claim 7

Apparatus as claimed in claim 1 comprising: a frame; an axle rotatably mounted under said frame, said axle containing two rigidly mounted wheels having a frictional surface which can roll without slippage over a flat surface on which graphic data is presented; a stylus pivotably mounted to the frame for angular movement about an axis orthogonal to the direction of travel of the frame over the surface; first means coupled to the axle for measuring and recording digitally the angular rotation of the axle as an indication of distance which the frame has moved as a result of the rolling of said wheels over a flat surface; second means for measuring and recording digitally the angle of the stylus relative to the said frame; and electrical means for controlling a recording sequence associated with said first and second means, whereby the apparatus as a whole moves over the flat surface on which the graphical data is presented.

Claim 8

Apparatus in accordance with claim 6 further including: light transmitting means connected to the stylus for enhancing the curve following capability thereof, which light transmitting means comprises: first and second groups of light transmitting fibers with their upper ends exposed to light, and third, fourth and fifth groups of light transmitting fibers with their upper ends serving as light indicators, said five groups being transversely cut and exposed at their lower end where they form a selected cross-sectional pattern, such pattern resembling a cross with the first and second groups being generally aligned parallel to the movement of said frame, with the third and fifth groups forming a line that is generally perpendicular to the movement of said frame, and with the fourth group being centrally located relative to the other four groups, said five groups tending to indicate relative levels of intensity of reflected light at three points on a line transverse to the direction of movement of said frame so as to facilitate the selective positioning of the stylus relative to said area of interest.

Claim 9

Apparatus in accordance with claim 7 wherein the exposure to light of the fibers in said first and second groups is transferable from one group to the other in order to avoid loss of contact with the line being followed.

Claim 10

Apparatus in accordance with claim 6 further including: a sighting member adjustably affixed to said frame for sighting along a reference mark on said graph to determine the direction of translational movement of said apparatus relative to said mark.

Claim 11

Apparatus in accordance with claim 6 wherein: the first means comprises a first shaft angle encoder coupled to the axle for obtaining binary electrical counts which measure the rotation of the wheels with respect to the frame; and the second means comprises a second shaft angle encoder for obtaining binary electrical counts which measure the angular position of the stylus relative to the frame.

Claim 12

Apparatus in accordance with claim 10 further comprising: a third shaft Angle encoder coupled to rotate with a selected one of the first and second shaft angle encoders for providing incremental pulses in a form representing a coded interpolation count between two different position signals of the associated one of said first and second encoders.

Claim 13

Apparatus as claimed in claim 6 including: a first switching-type shaft position encoder which converts the rolling displacement of said frame into digital electrical signals; a second such encoder which converts the angular position of said stylus relative to said frame into additional digital signals; means for scanning, amplifying and tape recording the signals from said encoders; a sheath to enclose lengths of glass fibers extending from the vicinity of a small area on a flat surface on which said frame rolls to a raised location which may be near the top of said stylus or of structure mounted hereby; a first and second group of glass fibers with their upper ends controllably exposed to light, and a third, fourth, and fifth group of glass fibers with their upper ends serving as light indicators, said five groups being transversely cut and exposed by said sheath at their lower end where they form a certain cross-sectional pattern, this pattern resembling a cross with the first and second said groups being generally aligned parallel to the movement of said frame, with the third and fifth said groups forming a line that is generally perpendicular to the movement of said frame, and with the fourth said group being located at the center of a circle formed by the other four said groups, said five groups, when positioned over an area containing a line or a dark spot on paper, tending to indicate relative levels of intensity of reflected light at three points on a line transverse to the direction of movement of said frame so that they facilitate the automatic positioning of said stylus relative to the center or edge of a given line.

Claim 14

Apparatus for digitally recording the numerical values of an arc sine function of one of the coordinates and a multi-term function of the other coordinate in a one-linear-coordinate-plus-one-polar-coordinate reference system of a horizontally-movable position of a stylus, comprising: a frame; an axle rotatably mounted under said frame, said axle containing two rigidly mounted knurled-rim wheels which can roll without slippage over a flat surface on which graphic data is mounted; a stylus on an arm which is pivotable about a vertical axis on said frame; two brush-contacting, pattern-conducting encoding discs driven by relative motions between said frame and one each of said axle and said stylus; a flip-flop shift register for producing a scanning sequence; a diode matrix of AND gates to effect scanning; OR gates to combine signals so that each flip-flop of said each shift register enables transmission of only a fraction of the total number of bits on said discs; switching means operable to set the first flip-flop of said shift register and reset the others at the beginning of each encoding disc scanning and recording operation; a pulse amplifier triggered by a step from the first flip-flop of said shift register; a motorized clutch-operated paper tape punch in which a clutch coil is operated by said pulse amplifier; cam switches within said punch to provide clocking pulses to said shift register and to reinforce cut-off signals from said amplifying gates; code magnets operable by signals from said amplifying gates so that one hole is punched in paper tape each time one of the brushes in contact with said encoder discs is in contact with a metallic surface during a clutch-operated punching cycle; a means for additional marking of tape; and an array of light-conducting fibers mounted for movement with the stylus and comprising a first set for directing light to an area of interest and a second set for transmitting light reflected from the area of interest to a remote indicatoR for use in selectively positioning the stylus relative to said area of interest.

Claim 15

Apparatus for digitally recording the numerical values of an arc sine function of one of the coordinates and a multi-term function of the other coordinate in a one-linear-coordinate-plus-one-polar-coordinate reference system of a horizontally-movable position of a stylus, comprising: a frame; an axle rotatably mounted under said frame, said axle containing two rigidly mounted knurled-rim wheels which can roll without slippage over a flat surface on which graphic data is mounted; a stylus on an arm which is pivotable about a vertical axis on said frame; two brush-contacting, pattern-conducting encoding discs driven by relative motions between said frame and one each of said axle and said stylus; a flip-flop shift register for producing a scanning sequence; a diode matrix of AND gates to effect scanning; OR gates to combine signals so that each flip-flop of said each shift register enables transmission of only a fraction of the total number of bits on said discs; switching means operable to set the first flip-flop of said shift register and reset the others at the beginning of each encoding disc scanning and recording operation; a pulse amplifier triggered by a step from the first flip-flop of said shift register; a motorized clutch-operated paper tape punch in which a clutch coil is operated by said pulse amplifier; cam switches within said punch to provide clocking pulses to said shift register and to reinforce cut-off signals from said amplifying gates; code magnets operable by signals from said amplifying gates so that one hole is punched in paper tape each time one of the brushes in contact with said encoder discs is in contact with a metallic surface during a clutch-operated punching cycle; a means for additional marking of tape; and an array of light-conducting fibers mounted for movement with the stylus and comprising a first set for directing light to an area of interest and a second set for transmitting light reflected from the area of interest to a remote indicatoR for use in selectively positioning the stylus relative to said area of interest.