Patent ID: 11903243
Assignee: LG CHEM, LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. An optical film comprising a holographic optical element in which a refractive index changing pattern is recorded,
wherein the refractive index changing pattern includes a refractive index changing unit region in which a refractive index varies along the plane direction, and the refractive index changing unit region comprises at least one high-refraction unit region and at least one low-refraction unit region,
wherein the plane direction is a direction parallel to the plane of the optical film having the maximum area,
wherein the holographic optical element comprises a photosensitive material,
wherein the refractive index continuously changes in a sinusoidal waveform in the refractive index changing unit region, and
wherein the refractive index changing unit region comprises a plurality of high-refraction unit regions and a plurality of low-refraction unit regions, the local maximum refractive index of the high-refraction unit regions decreases in the direction away from the center of the refractive index changing unit region along the plane direction, or the local minimum refractive index of the low-refraction unit regions increases in the direction away from the center of the refractive index changing unit region along the plane direction.