Abstract: An exemplary inductor of a circuit board includes a base portion of the circuit board, a plurality of through holes defined in two opposite sides of the base portion and a conductive wiring passing through the through holes and wrapping the base portion. The inductor arranged in the circuit board allows height of the printed circuit board to be minimized.

Abstract: An exemplary circuit board (21) includes an indention portion at a side of the circuit board, and a plug slot (251). The indention portion includes a bottom wall (211) and a side wall (212), and the side wall located between the bottom wall and an end of the circuit board at the side of the circuit board. The plug slot is attached at the bottom wall and is adjacent the side wall. Spacing between the side wall and the plug slot at the bottom wall is less than spacing between the side wall and the plug slot at the end of the circuit board.

Abstract: An exemplary circuit board (21) includes an indention portion at a side of the circuit board, and a plug slot (251). The indention portion includes a bottom wall (211) and a side wall (212), and the side wall located between the bottom wall and an end of the circuit board at the side of the circuit board. The plug slot is attached at the bottom wall and is adjacent the side wall. Spacing between the side wall and the plug slot at the bottom wall is less than spacing between the side wall and the plug slot at the end of the circuit board.

Abstract: An exemplary residual image improving system (100) for an LCD includes an LCD panel, a gate driver, data driver, a video and timing control unit (12), a DC power supply (13), an power input terminal (VCC), and a current limiting resistor (R). The power input terminal receives operating power from an external power supply, and provides the operating power to the gate driver, the video and timing control unit, and the DC power supply. The video and timing control is connected to the power input terminal, and provides image signals and a timing signal to the data driver and the gate driver respectively. The DC power supply is connected to the power input terminal, and provides electric potential to the gate driver and the data driver. The data driver provides gray scale voltages to the LCD panel. The current limiting resistor is connected between the power input terminal and ground.