We suppose that the phenomena of the light induced deformation in a thin liquid crystal (LC) layer depends strongly on tight. induced discharge on the boundary between substrate and the LC layer. It seems meaningful to find out,what decides about the charge gathering and trapping near this boundary. The creation of the electric potential traps in this area has been explained. The shape of the electric field distribution inside liquid crystalline layer has been found to recognize way of mentioned traps formation. The exact, soliton like solution of the Ericksen-Leslie equation (EL equation) in on isotropic elasticity approximation has been demonstrated for this aim. The measurement of the refractive indices profile across the liquid crystal layer has been fitted to the solution of EL equation allowing one to determine electric field distribution inside the LC layer. The structure and origin of the charge trapping mentioned above has been shown in detail. Obtained results allow one to get conditions for a tight induced discharge of the LC layer-substrate region.