| 摘要 |
PROBLEM TO BE SOLVED: To double the information recording density of an information recording medium such as an optical ROM. SOLUTION: By the information recording method of irradiating a recorded medium with light of wavelength λ and recording and reproducing information by making use of variation in the intensity of its transmitted or reflected light, slits or gratings of width a<λ are formed in pits as recording units of information in different orthogonal directions by the pits to constitute the information recording medium 6. A lighting optical system 1 of the information reproducing device 100 irradiates the slits, etc., formed in pits with parallel or vertical linear polarized light or two kinds of slit, etc., with linear polarized light at 45 deg. and a detection optical system detects which direction the slits are formed in. In addition to the conventional presence/absence state (binary) of pits, two kinds of pitch information can be detected to double the information recording density. |
