Patent ID: 9007883
Filing Date: 2015-04-14
Classification: G11B,Y10T

Abstract:
1. An optical recording and reading method for recording information in a recording and reading layer in an optical recording medium, the optical recording medium comprising the recording and reading layer and a servo layer, the recording and reading layer being previously stacked or formed afterward and having no concavo-convex pattern for tracking control, the servo layer having a concavo-convex pattern or a groove for tracking control formed therein, wherein a recording and reading beam having a second wavelength shorter than a first wavelength is applied to the recording and reading layer to record or read information while a tracking beam having the first wavelength is applied to the servo layer to perform tracking control, and wherein a reflectance of the servo layer at a time when light of the recording and reading beam having the second wavelength is applied through the recording and reading layer to the servo layer is lower than a reflectance of the servo layer at a time when light of the tracking beam having the first wavelength is applied through the recording and reading layer to the servo layer.