US Patent 7884558 Driver apparatus and method

A driver apparatus is provided for controlling a light source array comprising at least first and second light sources, the light source array used for illuminating a scan region on a target object, wherein light reflected from said target object is captured by a detector. The driver apparatus comprises a single integrated circuit comprising processing means for processing image data received from the detector, a switching array comprising at least first and second switches for switching the respective first and second light sources, and a current source for controlling the flow of current through the light sources. In this way the LED switching circuitry that controls an LED array is 15 placed on the same integrated circuit (i.e. monolithic circuit) as the analogue processing circuitry that processes the image data, with the current source controlling the flow of current through the LEDs in the LED array.