INFORMATION READER FOR OPTICAL RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an information reader for optical recording media which can accurately read recording information out of a recording medium having a hologram pattern recorded. SOLUTION: When a light beam of specific wavelength converged by an optical means 14 irradiates optical recording media 10 which have diffraction gratings formed as a pattern of interference fringes of a hologen and arrayed in two dimension, its reflected or transmitted light is received by a means 20 to read the hologram pattern 12 of the diffraction gratings. The information reader for optical recording media which has the means 20 is provided with a means 17 which limits the range wherein the recording medium 10 is irradiated with the high beam from the optical means 14 between the optical means 14 and recording medium 20.