Patent ID: 6680888
Filing Date: 2004-01-20
Classification: G11B

Abstract:
An information recording and reading apparatus for recording information by changing a state of a recording area on an information recording medium with a light irradiated by an optical head, comprising:a recording pulse generating circuit for generating a recording pulse; a laser driver for driving the optical head in response to the recording pulse; a detection circuit for detecting a reflective light state of the recording area; and a controller for controlling an irradiation power of the light in response to the reflective light state to record information on the information recording medium by the laser driver, wherein the controller controls an irradiation light in accordance with a first detected reflective light amount without recording on the recording area and a second detected reflective light amount with information recorded thereon so as to chance the irradiation power of the irradiation light in accordance with an already recorded state of the recording area while detecting a mark during the recording of information in the recording area; wherein the controller changes the irradiation light when overwriting on a part of the information recording medium where the mark is present on the information recording medium; and wherein the controller decreases the irradiation power of the light when overwriting on a part of the information recording medium where the mark is present on the information recording medium.