Reference voltage generation means for controlling a display
AssigneeGeneral Electric Company
InventorGary L. Engle
Life of this patent
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Abstract
A position reference voltage for controlling the electron beam of a display in an ultrasonic scanning system includes circuitry for receiving a position voltage from a scanner in the system, and a voltage from a variable voltage source. When the variable voltage exceeds the position voltage the variable voltage is locked whereby a new position voltage for the display is derived from the sum of the locked voltages and the scanner position voltage. The variable voltage source includes a digital counter and a digital to analog converter. A comparator compares the sum of the variable voltage and the scanner position voltage, with a reference potential and a flip-flop responds to the comparator to disable the counter when the summed voltages exceed the reference potential.
Claims9
In a system in which a display is responsive to signals from a scanner including position voltages from said scanner relative to a reference scanner position and reference voltage, means for establishing a new reference position signal for said display when said scanner is at a desired new reference position comprising
- voltage means for generating a variable voltage,
- comparator means for receiving and comparing said variable voltage and said position voltage from said scanner, and,
- means responsive to said comparator means for holding said voltage means at a fixed voltage level when said comparator means indicates that said variable voltage exceeds said position voltage.
In an ultrasonic scanner system and the like in which the position of a scanner on a display is defined by X and Y coordinates expressed in voltage levels relative to a reference voltage level at a reference scanner position, apparatus responsive to position voltages from the scanner for establishing a new reference point for controlling the display comprising
- first means for providing a voltage in response to voltages from said scanner when said scanner is moved to a desired reference point,
- counter means,
- digital to analog converter means interconnected with said counter means for generating a variable voltage in response to count from said counter means,
- comparator means for receiving and comparing said variable voltage from said digital to analog converter and said voltage from said first means, and
- means connected with said comparator means for stopping a count in said counter means when said variable voltage exceeds said voltage from said first means whereby a voltage from said comparator means establishes a new position voltage for controlling said display.
Dependencies are inferred from the claim text.