Liq. crystal screen display method - using differing frequencies to address each row and column of screen

摘要

The display screen is composed of liquid crystals with electrodes placed in rows and columns to allow a point on the screen to be activated by suitable addressing of row and column to give either a bright screen with a dark point or dark screen with a dark point either by activating a single point or activating all points except one. The method of addressing uses periodic voltages at differing frequencies applied to different rows and columns. A location on the screen is only activated effectively if the sinusoidal or rectangular voltages applied to row and column electrodes have the same frequency. Other points fluctuate at the beat frequency between the two imposed frequencies, thus the frequencies used must be chosen so that their beat frequency exceeds 20 Hz, to prevent disturbance to the viewer.