Patent ID: 8044897

Claim:
A light source control apparatus, for controlling N light-emitting devices directly connected in series, wherein N+1 nodes are sequentially defined at two terminals of each light-emitting device, and each of the light-emitting devices is a light emitting diode, wherein N is a natural number and N is larger than 1, the light source control apparatus comprising: a testing circuit, coupled to the N+1 nodes to transmit a testing current to light-emitting devices between Ith node and Jth node, wherein I and J are natural numbers, and N+1>=J>I>=1; and a compensation circuit, coupled to the N+1 nodes to measure a brightness of light-emitting devices between the Ith node and the Jth node, for deciding a value of a compensation current according to an intensity of brightness, and providing the compensation current to light-emitting devices between the Ith node and the Jth node, wherein the compensation circuit comprises: a brightness measuring circuit, for measuring a brightness of the light-emitting devices between the Ith node and the Jth node, so as to generate a brightness indication signal; a control circuit, for determining a value of the compensation current according to the brightness indication signal, and outputting a first compensation signal and a second compensation signal according to the value of the compensation current; and a compensation unit, coupled to the N+1 nodes to directly transmit the compensation current to the light-emitting devices between the Ith node and the Jth node according to the first compensation signal, and directly sink the compensation current flowing to the Jth node according to the second compensation signal.