Patents Assigned to Talos Systems, Inc.
  • Patent number: 4423286
    Abstract: A digitizing system includes a first plurality of spaced parallel grid conductors and a second plurality of spaced parallel grid conductors orthogonal to the first plurality of spaced parallel grid conductors. The location of a movable coil arranged on a pen or cursor is determined for each plurality of grid conductors coarsely by sampling the voltage induced in one of the grid conductors from a signal applied to the coil to determine whether the coil is above or below this grid conductor. Through careful selection, a very few grid conductors can be sampled to quickly locate the two grid conductors immediately adjacent to the center of the driven coil. The ratio of the voltages present on these two grid conductors is matched against a list of known ratios representing various positions between the two grid conductors.
    Type: Grant
    Filed: July 21, 1982
    Date of Patent: December 27, 1983
    Assignee: Talos Systems, Inc.
    Inventor: Gary A. Bergeron
  • Patent number: 4260852
    Abstract: A digitizing system includes a plurality of spaced parallel grid conductors embedded beneath a support surface. A movable pen coil powered by an amplifier induces AC signals in the grid conductors. The grid conductors are scanned at a first rate from a reference point to detect the approximate location of the pen coil. The grid conductors are then "up scanned" at a second rate toward the pen coil. As the scan counter is incremented, a pen position counter is simultaneously incremented at a third rate which is substantially greater than the second rate to effect interpolation between grid conductors. The up scanning is halted when a rectified and integrated waveform resulting from the up scanning operation undergoes a phase change. A first digital number contained in the pen position counter then is stored. The polarity of the signal driving the pen coil then is reversed. The grid conductors are then "down scanned" at the second rate toward the pen coil.
    Type: Grant
    Filed: May 24, 1979
    Date of Patent: April 7, 1981
    Assignee: Talos Systems, Inc.
    Inventor: George A. Fencl
  • Patent number: 4227044
    Abstract: A pen status indicating system for a digitizer pen utilized in conjunction with a digitizer having a grid of spaced conductors positioned beneath a writing surface. The digitizer includes an electronic system which scans the spaced conductors and senses signals produced in the spaced conductors by a transmitting coil located near the writing tip of a pen used to write on the writing surface. The pen status indicating system senses whether the writing tip of the pen is pressed against the writing surface. The pen status indicating system includes a split inductor having a movable core coupled in direct communication with a pen cartridge having the writing tip connected thereto.
    Type: Grant
    Filed: January 22, 1979
    Date of Patent: October 7, 1980
    Assignee: Talos Systems, Inc.
    Inventor: George A. Fencl
  • Patent number: 4210775
    Abstract: A method and apparatus are provided for converting a position of a pen to a digital number representing the pen position with respect to a grid of conductors. A coil disposed above the tip of the pen is driven by a continuous AC input voltage of fixed frequency and amplitude, thereby inducing corresponding signals in each of the conductors of the grid. Scanning circuitry sequentially scans the grid conductors, first in the X direction and then in the Y direction, thereby sequentially coupling the induced signals to the input of a differential amplifier. A position counter is reset at the beginning of scanning in each direction and is incremented at a rate proportional to and greater than the scanning rate. The outputs of the differential amplifier are inputted to a phase sensitive detector producing a characteristic output which changes polarity as grid conductors on opposite sides of the pen tip location are sequentially scanned.
    Type: Grant
    Filed: July 3, 1978
    Date of Patent: July 1, 1980
    Assignee: Talos Systems, Inc.
    Inventors: James L. Rodgers, Billy C. Fowler
  • Patent number: 4185165
    Abstract: A low noise system and method are provided for sequentially sensing induced signals in a plurality of digitizer grid conductors. The digitizer includes a coil disposed above the tip of a pen. The coil induces the signals in the grid conductors. The system includes scanning circuitry which sequentially scans the grid conductors, which are oriented in an X direction and a Y direction, causing the induced signal to be sequentially coupled to the input of a differential amplifier. The X and Y grid conductors each have first ends connected to corresponding inputs of first and second multiplexers. The X and Y grid conductors each also have corresponding second ends connected to first and second corresponding common conductors. The outputs of the first and second multiplexers are coupled, respectively, to first and second inputs of the differential amplifier. The first and second common conductors are coupled, respectively, to the outputs of the second and first multiplexers.
    Type: Grant
    Filed: July 3, 1978
    Date of Patent: January 22, 1980
    Assignee: Talos Systems, Inc.
    Inventor: George A. Fencl
  • Patent number: 4022971
    Abstract: A system is disclosed for converting the location and movement of a manually controlled instrument into corresponding electrical signals. The manually controlled instrument responds to the phase and frequency of an electrical field that varies to represent position information on an orthogonal writing grid. A single, phase-locked loop is utilized to produce both a first signal corresponding to the instrument location along an x-axis and a second signal corresponding to the instrument location along a y-axis. The first and second signals both represent the differential between pairs of related absolute signals. The differential signals are independent of normal signal variations and other error sources. The field is generated by first selecting sets of conductors that are positioned orthogonally with respect to each other. Signals are then applied to the respective sets of conductors to thus generate an electric field at the location of the intersection of the orthogonal sets.
    Type: Grant
    Filed: April 28, 1976
    Date of Patent: May 10, 1977
    Assignee: Talos Systems, Inc.
    Inventor: James L. Rodgers
  • Patent number: 3983322
    Abstract: A system is disclosed for converting the location and movement of a manually controlled instrument into corresponding electrical signals. The manually controlled instrument responds to the phase and frequency of an electrical field that varies to represent position information on an orthogonal writing grid. A single, phase-locked loop is utilized to produce both a first signal corresponding to the instrument location along an x-axis and as second signal corresponding to the instrument location along a y-axis. The first and second signals both represent the differential between pairs of related absolute signals. The differential signals are independent of normal signal variations and other error sources.
    Type: Grant
    Filed: July 31, 1975
    Date of Patent: September 28, 1976
    Assignee: Talos Systems, Inc.
    Inventor: James L. Rodgers