Electrostatic recording method with delayed control voltage

Claim 1

An electrostatic recording method for forming an electric charge image on a dielectric layer by (1) contacting a one surface control electrostatic recording head having rows of many recording needle electrodes and control electrodes adjacent to said recording needle electrodes, with the dielectric layer formed on a recording medium having a conductive substrate, and (2) applying a recording voltage to the recording needle electrodes and applying a control voltage having smaller rise time constant than the recording voltage to the control electrodes in the same period; the improvement wherein: the control voltage is applied to the control electrodes at a time, T d , later than the application of the recording voltage to the recording needle electrodes, T d being of a size so that the total voltage induced in the conductive substrate by the control voltage and the recording voltage has reached a potential equal to a large fraction of the maximum potential, and T d being significantly less than the time necessary for crosstalk voltage attenuation; whereby variations in environmental humidity and temperature do not effect recording density.