Patent ID: 8632239

Claim:
A backlight system of a flat panel display device, wherein: the backlight system comprises a back frame and a circuit board; the back frame comprises primary assembling pieces and secondary assembling pieces; the primary assembling pieces are of a number of at least two, the at least two primary assembling pieces being joined to each other to form a connection therebetween; the secondary assembling pieces are arranged inside the back frame and joined to the back frame; and a rack is mounted to at least one of the assembling pieces to receive the circuit board mounted thereto in such a way that the circuit board is releasably mounted to the back frame, wherein the rack comprises a first bridge and a second bridge that are mounted, in parallel to each other, to the assembling pieces, each of the bridges having a side that is adjacent to the other bridge and is provided with two retention pawls projecting toward a front surface or a back surface of the back frame, each of the retention pawls comprising an extension arm extending from a side of the bridge and a hook formed by bending an end of the extension arm, the four extension arms collectively delimiting an installation trough having a trough wall structure, the circuit board being received in the installation trough, the four hooks forming a support structure on the bottom of the installation trough; and the trough wall structure comprises four trough walls that are provided at the same side with notches for engaging the circuit board, the circuit board having a side forming, at positions corresponding to the notches, projections for engaging the notches; and a spring plate is arranged on a trough wall opposite to the notches, the spring plate applying a force in a direction opposite to the notches to a corresponding edge of the circuit board so at to releasably retain the circuit board in the installation trough.