This work presents a unitary mode to describe orientational structures of extreme free energy for unidimensional distortions of a chiral nematic layer with weak tilted anchoring at limiting surfaces, using structure parameters. The case of an applied electric field was also considered. A generalised expression for surface energy involving both polar and azimuthal deformations was introduced. A classification of possible structures having monotonous or non-monotonous variations of the tilt angle is presented The solving of the equation system that links the structure parameters in each case is given.