Light sensing method

Abstract

A light detecting method is provided. The light detecting method includes following steps. A light beam is sensed to generate a photocurrent. A predetermined current is subtracted from the photocurrent. The photocurrent is converted to a voltage.

What is claimed is: 
     
         1 . A light detecting method, comprising:
 sensing a light beam to generate a photocurrent;   subtracting a predetermined current from the photocurrent; and   converting the photocurrent to a voltage.   
     
     
         2 . The light detecting method as claimed in  claim 1 , wherein the light beam is sensed by a light sensor. 
     
     
         3 . The light detecting method as claimed in  claim 2 , further comprising a step of determining the amount of the predetermined current and the amount of the photocurrent according to a color enable signal and a register table. 
     
     
         4 . The light detecting method as claimed in  claim 3 , wherein the predetermined current is generated by a programmable current source, and the light beam is sensed by a photodiode array. 
     
     
         5 . The light detecting method as claimed in  claim 2 , wherein the amount of the predetermined current is set as a threshold current value such that the voltage is converted from the photocurrent when the amount of the photocurrent is greater than the threshold current value.