RANDOM VIBRATION WAVE RETARDATION PLATE AND OPTICAL FILM AND/OR OPTICAL PICKUP DEVICE HAS THEM

摘要

The present invention relates to a broadband phase retardation plate for converting a polarization state of incident light and emitting the converted light. The broadband phase retardation plate comprises at least three retardation plates with the same phase retardation value, wherein the retardation plates convert the polarization state of the incident light in at least one wavelength band using a combination of adjusted angles of optical axes (?) of the respective retardation plates. According to the present invention, there is provided a broadband phase retardation plate, and an optical element and/or an optical pickup device having the phase retardation plate, which can minimize a deviation in quality of products and reduce a percent defective by correcting an error in the angle of optical axis, and can be easily manufactured and produced.