Optical Compensation Film for Liquid Crystal Display

KSU.189

Abstract: This invention is a new promising technique for manufacturing OCF, which are used for achievement of achromatic and high-contrast appearance and wide viewing angle characteristics of liquid crystal displays.  The invention uses a thin film of photosensitive polymers revealing effect of light-induced anisotropy.  The compensation film is produced by the polymer film exposed with polarized and/or not-polarized light in the range of an absorption band of the film.  The value of phase retardation is determined with the exposure time, and the direction of the anisotropy axis is determined with the polarization of the light beam and the angle between the beam and the plane of the polymer film.  The method proposed does not require the use of LC materials and mechanical treatment.  It also slows effective control of the phase retardation value and the direction the anisotropy axis to optimize the characteristics of OCF.

Applications: This patent is applicable to the manufacture of compensation films for all types of liquid crystal displays and shutters, including TN, STN, VA, OCB and ECB mode.

Advantages: The technique of this patent has several advantages over existing compensation film manufacturing techniques.  The process is simple, reproducible and yields defect-free films.  The process provides much more flexibility in the tailoring of film optical properties than existing techniques.  Films with different optic axis orientations can be easily realized with minor process variations.  Tilted biaxial as well as uniaxial structures can be fabricated by this technique.

Inventors: Kelly, Chien, Reznikov, Yaroshchuk