Advantage is taken of the fact that in optical navigation devices it is
possible to measure the intensity of light impacting the pixel array of
photo-diodes. Based upon such an intensity determination, a feedback
signal is used to reduce the intensity of the light to a point where it
is equal to or less than a predetermined value. In one embodiment, the
discharge rate of a capacitive power supply is used to determine the
intensity of the light source impacting the pixels. When the discharge
rate is faster than a given amount the inference is that the light
intensity is too great and power is reduced to the light source to reduce
the intensity.