Patent ID: 7965277

Claim:
An optical navigation system comprising: a light source configured to emit light in response to a driving signal; an image sensor positioned to receive some of said light reflected from a target surface to capture frames of image data of said target surface; a current source connected to said light source to control said driving signal being applied to said light source; and an optical feedback system optically coupled to said light source to receive some of said light emitted from said light source, said optical feedback system being electrically connected to said current source to provide a control signal to said current source to control said driving signal being applied to said light source to control the power of said light emitted from said light source, wherein said optical feedback system comprises: a photodetector configured to produce electrical current in response to said light received at said photodetector; a current-to-voltage converter operably connected to said photodetector, said current-to-voltage converter being configured to convert said electrical current into an output voltage signal; an error amplifier operably connected to said current-to-voltage converter to compare said output voltage signal to a reference voltage signal to produce an error signal, said error signal being used as said control signal for said current source; and a reference circuit operably connected to at least said error amplifier to provide said reference voltage signal, said reference circuit being configured to produce a second reference voltage signal that is supplied to said current-to-voltage converter.