A coordinate digitizer wherein a field generating device is positioned in proximity to the surface at a location to be digitized. Further means are provided for triggering the production of a magnetic field by the field generating device, the magnetic field transducing a propagating vibrational mode into the transmission media. Pick-up means are coupled to the transmission media and respond to the propagating vibrational mode for providing a signal to a utilizational device which will respond to the means triggering production of the field as well as to the pick-up means in order to provide a position signal corresponding to the time of propagation of the vibrational mode from its time of generation to its time of pick-up. The vibrational mode is effected by means of a strain wave magnetostrictively induced by the magnetic field into the transmission media. The transmission media constitutes a sheet of magnetostrictive material positioned beneath the support surface. The magnetic field generating device is positioned along the coordinate edges of the surface, and the pick-up is a point location in the form of an individual stylus in the shape of a writing implement or a cursor. The field may be energized by means of a series of pulses or by individual pulses as desired.
A position coordinate determination device wherein data generation lines are displaced from the edges of a data surface, and a sensing device is movably located on the surface. Erroneous detection of data resulting from reflection of signals at the edge of the sheet is inhibited by summing the times required for waves to pass between the sensor and both data generation lines. When this sum exceeds a predetermined level, an erroneous detection is indicated and the processing of the data may be inhibited.
A position coordinate determination device employing duodatum digitizations for each coordinate of a pair of respective coordinates and a ratiometric proportionality calculation for calculating a corrected coordinate digitization value in each measured coordinate.
A co-ordinate plate for a co-ordinate reader, which utilizes delays of oscillation waves in a magnetostrictive material. The co-ordinate plate is composed of a thin plate of magnetrostrictive material having a co-ordinate plane and similar propagation characteristics of magnetostrictive oscillation waves in directions of at least two co-ordinate axes of the co-ordinate plane, two exciting coils for producing magnetostrictive oscillation in the thin plate of magnetostrictive material in one and the other of co-ordinate directions of the co-ordinate plane, and flux keepers for shielding magnetic fluxes emanating from the exciting coils.
A system for determining X and Y coordinate positions on a surface wherein a first transducer generates plane waves having electromagnetic fields associated therewith, which plane waves travel along the direction of the X-coordinate and a second transducer generates plane waves having electromagnetic fields associated therewith, which plane waves travel along the direction of the Y-coordinate. A receiver transducer at the position to be determined detects the presence of the electromagnetic fields associated with the plane waves as they travel past the receiver transducer and the distances traveled by the plane waves are appropriately calculated either by determining the times of travel using pulse wave signals or by determining phase relationships using continuous wave signals.
A novel digitizer operable on an optical digitization basis comprises a transparent flat plate as a light active surface located on a graphic data recording medium, and a cursor functioning as an optical recognition device movable on the transparent flat plate. A predetermined coordinate correlative pattern is described on or in the transparent flat plate with a fluorescent paint. The cursor comprises a positioning arm provided on the outer periphery thereof to visually trace a data location on the recording medium in accordance with a movement of the cursor to effect positioning of the cursor with respect to the data location, an optical system including a light source, an optical filter assembly, and a light focusing lens etc., and a CCD sensor unit to sense light emitted from a partial pattern which falls within a predetermined limited visual range of the pattern. By irradiation of the pattern, fluorescent light is emitted therefrom. The optical digitizer is operative to determine position coordinates of a graphic data on the recording medium in accordance with an projected image of fluorescent light sensed by the sensor unit. Thus, such an implementation makes it possible to realize a small-sized, high accuracy digitizer completely free from influence of electromagnetic wave noise.
