A backlight apparatus includes a plurality of support members that maintain a diffuser plate in a fixed and level position with respect to the lamps and the housing that contains the lamps, to produce uniform illumination. The support members extend from the diffuser plate disposed at an open face of the housing, to the opposed back part of the housing, and include male-female interlocking parts to provide support. The support members include a set of cooperating portions, an upper and lower portion. The upper and lower portions may combine to provide a cavity in the support member. A cold cathode fluorescent lamp may extend through the cavity and the upper and lower portions may be secured to the diffuser plate and housing, respectively, by extending through openings formed in the diffuser plate or housing.