LIQUID CRYSTAL OPTICAL ELEMENT

摘要

PURPOSE:To surely prevent light leakage and to improve a shutter characteristic by setting the wavelength hand of transmitted light in a homogeneously oriented state of a liquid crystal material so as to have the spectral trasmission characteristic different from the emission wavelength band of a light source. CONSTITUTION:A liquid crystal 16 for 2-frequency driving is sealed in a liquid crystal cell subjected to a horizontal orientation treatment and the axis of polarization of one polarizing plate 17a or 17b is inclined 45 deg. with an orientation direction 31 of liquid crystal molecules and the axes 32, 33 of polarization of the upper and lower polarizing plates 17a, 17b are intersected at right angle. The liquid crystal cell is so formed as to have the spectral transmission characteristic different from the emission wavelength hand of the light source in the wavelength band of the transmitted light in the homogeneously oriented state of the liquid crystal. The double refractive anisotropy deltan of the liquid crystal and the thickness (d) of the liquid crystal layer are so set as to have the small transmittance with respect to the emission wavelength of the light source in the state in which the liquid crystal of the liquid crystal cell is homogeneously oriented. The light leakage in an insulating part B is thereby surely prevented.