A compact backlight system has a light-emitting panel (1) with a front wall (2), a rear wall (3) situated opposite thereto, and furthermore, between the front and the rear wall (2, 3), a translucent input edge surface (4) for coupling light into the light-emitting panel (1). A light source (6, 6', . . . ) is associated with the input edge surface (4). According to the invention, the rear wall (3) in a first portion (12) of the light-emitting panel (1) is provided with a multiplicity of steps (13, 13', . . . ), and a second portion (22) of the light-emitting panel (1) widens from the input edge surface (4) in a direction facing the first portion (12). Preferably, a surface (17) of the steps (13, 13', . . . ) facing the input edge surface (4) makes an angle .beta..sub.av.gtoreq.5.degree. (with respect to a normal on a bisecting plane (20) bisecting the light-emitting panel (1).