| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for acquiring differentiation efficiency for highly accurately determining the differentiation efficiency for controlling light emission power of a light source. <P>SOLUTION: A boundary is estimated at which light emission characteristics indicating relation between the driving current and the light emission power of the light source is shifted from nonlinear to linear (step 401 to 435) and the differentiation efficiency is determined based on the light emission characteristics at this boundary and the light emission characteristics in at least one arbitrary position existing nearer the high light emission power side than the boundary. As a result, the differentiation efficiency is determined on the basis of the light emission characteristics in at least two different points within the region where the relation between the driving current and the light emission power is nearly linear. The accuracy of the differentiation efficiency can thus be improved. <P>COPYRIGHT: (C)2004,JPO |
