A driver circuit includes a first voltage conversion unit, a second voltage conversion unit, a third voltage conversion unit, a light driver and a control circuit. The first voltage conversion unit may convert a first voltage to a second voltage. The second voltage conversion unit may convert the second voltage to a third voltage in a non-electrically isolated manner. The third voltage conversion unit may convert the second voltage to a fourth voltage in a non-electrically isolated manner. The light driver may receive the third voltage and a control signal to generate a control current according to the control signal. The control circuit may receive the fourth voltage and an image signal to generate the control signal according to the image signal.