PURPOSE: To change over transmittance width and absolute value according to applications and to lessen the eyes' fatigue by sticking synthetic resins into which a photochromic material is incorporated to at least either side of a film- like liquid crystal panel which is a lens part.
CONSTITUTION: A liquid crystal cell is constituted by holding a nematic liquid crystal added with a proper amt. of a dextrorotatory chiral material between a film-like upper substrate 1 subjected to rubbing and a film-like lower substrate 2 by means of a seal 3. Further, the absorption axis of a polarizing plate 4 and the rubbing direction of the film-like upper substrate 1 as well as the absorption axis of a polarizing plate 5 and the rubbing direction of the film-like lower substrate 2 are aligned. The polarizing plates 4, 5 having 41% parallel transmittance and 98% degree of polarization are used for the polarizing plates 4, 5. The liquid crystal element is stuck to diethylene glycol bis-ally carbonate resin plates 8, 9 via adhesive layers 6, 7 from both sides. The photochromic material colors gradually and the transmittance changes between 10% and 20% if there are many UV rays in a high-illuminace place, such as skiing ground.
KASAI YOSHIHIKO
EGAWA MASARU
