Reflective type liquid crystal display device and wearable device provided with same

Abstract

A reflective liquid crystal display device has a first substrate having a first electrode that reflects light; a second substrate having a second electrode that transmits light; a liquid crystal layer provided between the first electrode and the second electrode, including a nematic liquid crystal material having negative dielectric anisotropy Δε and a chiral agent, having nearly vertical alignment when no voltage is applied, and having twist alignment or hybrid alignment when white voltage is applied; and a polarizing layer provided on the observer side of the second substrate and at least one retarder layer disposed between the polarizing layer and the second substrate, wherein the reflective liquid crystal display device has a drive circuit that applies black voltage or white voltage across the liquid crystal layer at a frame rate of 1 fps or less, and when applying white voltage across the liquid crystal layer over a plurality of frames, the drive circuit applies the white display voltage whose polarity is inverted for each frame with respect to the potential of the second electrode, and assuming that a natural pitch of the nematic liquid crystal material including the chiral agent is p, that a thickness of the liquid crystal layer is d, and that a birefringence of the nematic liquid crystal material is Δn, 60°<β60°·d/p|<180° and 237 nm≤Δnd≤≤331 nm are established.