Patent ID: 8593927

Claim:
A method of reading optical information, the method comprising: performing a first reference beam irradiation operation for irradiating a reference beam at one of first multiplexing angles to a first recording region, wherein optical information is recorded in the first recording region by the reference beam that is angularly multiplexed at the first multiplexing angles, and recorded in the second recording region by the reference beam that is angularly multiplexed to a second multiplexing angles which are between the first multiplexing angles, respectively, and wherein the second recording region is located adjacent to the first recording region or partially overlapped with the first recording region; and performing a first optical detection operation for detecting a first reproducing beam generated from the first recording region, wherein the first optical detection operation further performs detecting a second reproducing beam overlapping the first reproducing beam generated by irradiating the reference beam at the one of the first multiplexing angles to the second recording region, wherein the first optical detection operation further comprises a first optical determination operation for determining the first reproducing beam from the first and second reproducing beams overlapping each other, wherein the first optical determination operation comprises comparing light intensities of the first and second reproducing beams with each other, and determining the reproducing beam with a higher intensity between the first and second reproducing beams as the first reproducing beam, wherein the first optical detection operation further performs detecting a second reproducing beam overlapping the first reproducing beam generated by irradiating the reference beam at the one of the first multiplexing angles to the second recording region.