ApplicationNo. 05/808998 filed on 06/22/1977
US Classes:340/815.62, Electromagnetic actuator for indicator matrix345/111With a permanent magnet placed on movable display elements
ExaminersPrimary: Pitts, Harold I.
Attorney, Agent or Firm
International ClassG09F 9/37 (20060101)
AbstractA selected message is displayed by an electromagnetic information display system having a matrix of display openings formed through a display board for receiving therein a plurality of solenoid coils. Magnetic display elements are disposed within each of the solenoid coils. The magnetic display elements have permanently magnetized poles located at opposite ends thereof and further have contrastingly colored surfaces associated with the magnetic poles. The solenoid coils are electrically interconnected for selectively inducing a magnetic field within any of the coils for aligning the display elements. A plurality of drivers are connected on an individual basis to one lead of all coils positioned within a column to output a ground or reference voltage as determined by the input of the driver. A set of digital strobes applies an output voltage one-half that of the reference voltage to the opposite lead of the solenoid coils positioned within a row for determining the direction of the magnetic field within the coils. A ferromagnetic back plate latches the display elements into the alignment determined by the direction of the magnetic field.