Patent ID: 7769064

Claim:
A laser diode control method used for a laser diode control device comprising: a laser diode; a drive device for supplying a current to the laser diode to drive the same; a pickup having the laser diode, an objective lens, objective lens moving means for changing a focus position of the objective lens, and a case for accommodating the elements; pickup moving means for moving the pickup to a predetermined radiating position; a temperature sensor for detecting temperature around the laser diode; a semiconductor memory and/or a hard disc device, and a controller, wherein, if temperature detected by the temperature sensor is equal to or below a predetermined value and if a pickup radiating position is located within a recording region on a recording medium, the controller controls the objective lens moving means to set a focus position of a laser beam being radiated to the recording medium to a position outside a recording layer of the recording medium; the controller controls the pickup moving means to move the pickup outside the recording region of the recording medium; and the controller controls the drive device to supply a current exceeding a threshold value to the laser diode, thereby outputting a laser beam, wherein, if the pickup is moved to a position outside the recording region of the recording medium, the controller controls the objective lens moving means to set a focus position of a laser beam being radiated to the recording medium to a position on an extension line of a recording layer of the recording medium, and the controller controls the drive device to supply a current exceeding a threshold value to the laser diode, thereby outputting a laser beam, wherein, if temperature detected by the temperature sensor is equal to or below a predetermined value, the laser diode control device does not record audio and/or video onto the recording medium, but records audio and/or video onto the semiconductor memory and/or the hard disc device.