Patent ID: 7308010

Claim:
A laser drive device comrrising: an integrated circuit having formed therein a generator device that generates a pulse width modulation signal based on image data, and a supply current control device, said integrated circuit having plural ports; and a plurality of resistors having different values each externally attached to one of said ports, wherein said supply current control device supplies a driving current to a laser beam-emitting device via said ports and said resistors, wherein said supply current control device includes a plurality of switching devices each attached to one of said ports, and a signal output device that outputs signals to any of said switching devices, to selectively switch said switching devices, wherein said integrated circuit has at least one second predetermined port, said second predetermined port having externally attached thereto at least one second resistor, through which an offset current is caused to flow, wherein said supply current control device comprises at least one second switching device that turns on and off at least one offset current to be supplied to the laser beam-emitting device via said second predetermined port and said second resistor, and wherein said signal output device of said supply current control device outputs a control signal for turning on and off the offset current to said second switching device.