  We study two-dimensional equilibrium configurations of nematic liquid crystal
(NLC) director in a cell confined between two parallel surfaces: a planar
surface and a spatially modulated one. The relief of the modulated surface is
described by a smooth periodic sine-like function. The director easy axis
orientation is homeotropic at one of the bounding surfaces and is planar at the
other one. Strong NLC anchoring with both surfaces is assumed. We consider the
case where disclination lines occur in the bulk of NLC strictly above local
extrema of the modulated surface. These disclination lines run along the crests
and troughs of the relief waves. In the approximation of planar director
deformations we obtain analytical expressions describing a director
distribution in the bulk of the cell. Equilibrium distances from disclination
lines to the modulated surface are calculated and their dependences on the cell
thickness and the period and depth of the surface relief are studied. It is
shown that the distances from disclination lines to the modulated surface
decrease as the depth of the relief increases.
