Diffraction type liquid crystal lens and multi focus diffraction type liquid crystal lenses

摘要

To provide a diffraction liquid crystal lens and a multifocal diffraction liquid crystal lens always having a thin liquid crystal layer and i.e., having a focal distance adjustable at a high speed and having high transmittance of incident light irrespective of the focal distance or a lens aperture. SOLUTION: The diffraction liquid crystal lens comprises transparent substrates 2 which are located opposite to each other via spacers 6 and have transparent electrodes 3 and alignment layers 4 laminated ON their inner surfaces and liquid crystal molecules 5 sealed in the gap between the transparent substrates 2. It is characterized by making at least one alignment layer 4 have a plurality of orbicular zone region groups A1 each group of which consisting of two concentric orbicular zone regions A11, A12 subjected to alignment treatment so as to make alignment directions of the liquid crystal molecules 5 different from each other and by making the orbicular zone region groups A1 aligned like concentric circles and by making widths b between the adjacent orbicular zone region groups A1 gradually get more reduced as going more exterior from the center of the alignment layer 4.