LCD devices are commonly used as display devices for compact electronic apparatuses. This is because LCD devices not only provide good quality images, but also are very thin and consume little power. The liquid crystal in a liquid crystal display device is not capable of emitting light by itself. The liquid crystal has to be lit by a light source so as to clearly and sharply display text and images. Thus, a backlight module for an LCD is generally needed.
Referring to FIG. 6, a conventional backlight module 6 includes a light guide plate (LGP) 60, a plurality of light emitting diodes (LEDs) 62, a conductive line group 63, and an LED controller 64. The LGP 60 has a side surface 601 for receiving incident light beams, and a top surface 602 for emitting the light beams. The top surface 602 adjoins the side surface 601. The LEDs 62 are disposed adjacent to the side surface 601 of the LGP 60. The LED controller 64 is connected to each of the LEDs 62 via the connective line group 63, for controlling work states of the LEDs 62.
In operation, light beams emitted by the LEDs 62 enter the LGP 60 via the side surface 601, and are converted by the LGP 60 to form a surface light source at the top surface 602. However, each of the LEDs 62 has a certain limited angle of divergence of light beams emitted therefrom. Therefore, areas of the LGP 60 beyond the angles of divergence of the LEDs 62, such as area A, may be relatively dark areas. That is, the surface light source of the backlight module 6 may be non-uniform, and the performance of an associated LCD device may be visibly impaired. Furthermore, the LEDs 62 are connected to the LED controller 64 via the conductive line group 63, conductive lines of the conductive line group 63 are easily to be broken. This decreases a reliability of the backlight module 6.
What is needed, therefore, is a backlight module that can overcome the above-described deficiencies. What is also need is an LCD device employing such a backlight module.