Patent ID: 8649247
Filing Date: 2014-02-11
Classification: G11B

Abstract:
1. An optical power control method in which a power detection portion that detects optical power of light emitted from a light source is used to control the optical power, the method comprising: a first step of acquiring a temperature drift characteristic of the power detection portion by measuring an output value of the power detection portion; a second step of, based on the temperature drift characteristic acquired, checking whether or not a sensitivity of the power detection portion at a reference temperature falls within a predetermined range; a third step of, if the sensitivity falls within the predetermined range, determining to perform, without changing a gain of the power detection portion, a temperature correction relating to the power detection portion based on the temperature drift characteristic used for the checking of said sensitivity; a fourth step of, if the sensitivity falls outside the predetermined range, changing the gain of the power detection portion and repeatedly performing the first step and the second step until the sensitivity falls within the predetermined range; and a fifth step of performing the control of the optical power while performing the temperature correction based on the temperature drift characteristic determined to be used for the temperature correction and on a measured ambient temperature of the power detection portion.