Patent attributes
The present invention is directed to an optical disc recorder laser power control apparatus utilizing two different current sources to solve the problem caused by the contradiction between control resolution and control range. The first current source and the second current source are connected in parallel to a single control output pin. The first current source and the second current source may work independently from each other. The laser driver controls emission power of one of the laser diodes with a driving current supplied from the single control output pin coupled to both the first current source and the second current source. Advantageously, the fine laser power control pitch from the first current source contributes to fine control resolution, while the coarse laser power control from the second current source provides a wide control range for various kinds of laser diodes.
