Patent ID: 8660158

Claim:
A semiconductor laser drive circuit controlling a semiconductor laser diode connected to an output terminal by providing a drive electric current to the semiconductor laser diode, comprising: a constant electric current source configured to provide an electric current to the output terminal, the constant electric current source being connected at one end to a first electric power terminal and connected at the other end to the output terminal; a current sinking circuit connected at one end to the output terminal and connected at the other end to a second electric power terminal; a current sourcing circuit configured to provide a predetermined electric current to one of the output terminal and the current sinking circuit, the current sourcing circuit being connected at one end to the first electric power terminal and connected at the other end to the output terminal; and a terminating resistor having a resistance component equal to a resistance component of the semiconductor laser diode, the terminating resistor being connected at one end to the one end of the circuit sinking circuit and connected at the other end to the other end of the current sourcing circuit.