Control method applied to edge detection apparatus and control apparatus thereof

A control apparatus used in an edge detection device, wherein the edge detection device comprises a light emitting device, and receives an output light generated by the light emitting device driven by a driving signal in order to generate a sensed signal, the control apparatus comprising:

• an adjusting module, for adjusting the driving signal;
• a sensed signal intensity detecting module, for determining a first intensity difference value corresponding to a difference between high and low intensities of the sensed signal;
• and determining a second intensity difference value corresponding to a difference between high and low intensities of the sensed signal in response to adjusting of the driving signal by the adjusting module;
• and
• an error calculating module, coupled to the sensed signal intensity detecting module, for comparing the first intensity difference value and the second intensity difference value to generate a comparison result;
• wherein the adjusting module further adjusts the driving signal in accordance with the comparison result.