Patent ID: 7436869
Filing Date: 2008-10-14
Classification: H01S

Abstract:
1. A laser circuit substrate comprising: a main power transmission wiring pattern; a ground wiring pattern; a first wiring pattern and second wiring pattern which are connected in parallel with each other from said main power transmission wiring pattern; a first circuit which is connected between said first wiring pattern and ground wiring pattern and has a semiconductor laser element and a driving circuit for driving said semiconductor laser element; and a second circuit which is connected between said second wiring pattern and ground wiring pattern and has a compensation element and driving device of the compensation element, wherein said first circuit is a light-emitting circuit for making the semiconductor laser element to emit light, and said second circuit is a compensation circuit which has an electric characteristic equal to an electric characteristic of said light-emitting circuit and the compensation circuit being complementarily drive, said first wiring pattern is divided at a first point into a third wiring pattern and fourth wiring pattern from a first circuit side, and a first capacitor is connected to the first point, said second wiring pattern is divided at a second point into a fifth wiring pattern and sixth wiring pattern from a second circuit side, and a second capacitor is connected to the second point, and a sum of impedances of said first circuit and third wiring pattern viewed from the first point is set to be substantially equal to a sum of impedances of said second circuit and fifth wiring pattern viewed from the second point.