PHASE DIFFERENCE PLATE

PURPOSE:To obtain the novel phase difference plate having an excellent visual field angle characteristic by using an inorg. layer-like compd. layer varying in intra-surface refractive index and the refractive index in a thickness direction. CONSTITUTION:The inorg. layer-like compd. layer to be used has a laminar structure in which unit crystal layers stack up on each other. Since the bond between the unit crystal layers is relatively weak, ions and molecules can be inserted by various physical and chemical methods between the unit crystal layers without breaking the structure of unit crystal layers. The compd. has the nature that the intra-surface refractive index and the refractive index in the thickness direction vary from each other. Such inorg. layer-like compd. includes, for example, clay ore, chalcogenides, etc., and the interlayer modified substances formed by inserting the ions and molecules between these unit crystal layers. The production of the phase difference plate is easy. The phase difference plate is usable for improving the display characteristics of various kinds of liquid crystal devices when the phase difference plate is used alone as the phase plate having no intra-surface double refractiveness or varying in the intra-surface refractive index and the refractive index in the thickness direction or used in combination with other films, etc.