Patent ID: 6307676
Filing Date: 2001-10-23
Classification: G02B

Abstract:
An optical polarizer comprising:a dichroic polarizer, anda reflective polarizer positioned in the same optical path as the dichroic polarizer, the reflective olarizer comprisinga plurality of first optical layers comprising a first copolyester, the copolyester being semicrystalline and birefringent, anda plurality of second optical layers comprising a second copolyester having an in-plane birefringence of about 0.04 or less, at 632.8 nm, after the optical polarizer has been formed, the second copolyester comprising carboxylate subunits and glycol subunits, wherein 0.01 to 2.5 mol % of the combined carboxylate and glycol subunits are derived from compounds with three or more carboxylate or ester functional groups, compounds with three of more hydroxy functional groups, or a combination thereof.