Patent ID: 7983575

Claim:
A photoreceptor charge transport layer thickness determining apparatus, comprising: a photoreceptor having the photoreceptor charge transport layer; a scorotron charge device including coronode wires and a scorotron grid positioned between the coronode wires and the photoreceptor charge transport layer, the scorotron charge device being configured to charge the photoreceptor charge transport layer using corona discharge to generate ions directed to a surface of the photoreceptor charge transport layer; a first current measuring device that measures a current supplied to the coronode wires and outputs a first current value; a second current measuring device that measures a current supplied from the scorotron grid and outputs a second current value; a processor that receives the first and second current values and determines a current (I dynamic ) delivered to the photoreceptor charge transport layer by subtracting the second current value from the first current value, and determines a thickness of the photoreceptor charge transport layer based on the current value (I dyunamic ); and a voltage measuring device that measures voltage of the scorotron grid and outputs a voltage value to the processor, wherein the processor determines the thickness of the photoreceptor charge transport layer using: I dyunamic =Cv ( V int −V initial )(1 −e −S/Cv ) C=ε 0 k/d× 10 6 , where d=the thickness of the photoreceptor charge transport layer that is to be determined, k=the dielectric constant of the photoreceptor charge transport layer (a known constant), ε 0 =permittivity of free space (8.85e—12), C=capacitance per unit area of the photoreceptor layer in μf/meter 2 (to be determined), v=velocity of the surface of the photoreceptor charge transport layer in meters/second (a known constant), V int =intercept voltage of the scorotron charge device (the measured voltage value), V initial =voltage of the entering surface of the photoreceptor charge transport layer prior to charging (assumed to be 0 volts), and S=slope of the scorotron charge device (a known constant).