Method and means for changing pit depth on an optical recordable medium

摘要

Method and apparatus for improving the characteristics of the surface effects on a replicated optical disc the master for which is recorded on an optical recording apparatus which includes a writing light beam source and an optical modulator for modulating the intensity of the writing beam of light above and below a threshold level of a moving recording medium in response to a modulator drive signal for recording information on the medium, the light beam being capable of forming a track of surface effects or indicia in the moving master recording medium when the writing beam is above threshold and incapable of forming surface effects in the moving recording medium when the writing beam is below threshold. The method includes receiving a substantially rectangular waveform intended to control the optical modulator. A radius dependent duty cycle ramp function is introduced into the optical modulator drive signal for altering the depth or height of recorded pits or bumps on the recording medium to compensate for the depth or height versus radius phenomenon experienced in the molding process.