Backlighting module for a display apparatus

#1. Field of the Invention

#The invention relates to a display apparatus, more particularly to a backlighting module for a display apparatus.

#2. Description of the Related Art

#Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

#FIG. 1 is a schematic exploded view of a conventional backlighting module;

#FIG. 2 is an enlarged fragmentary schematic sectional view of a light guide of the conventional backlighting module;

#Referring to FIG. 4, the first preferred embodiment of a backlighting module 3 according to the present invention is to be employed in a display apparatus (not shown), such as a liquid crystal display, and is shown to include a reflector 30, a linear light source 33, a light guide 2, a light diffuser 32, and a prism assembly 31.

#The linear light source 33 is surrounded by a curved reflecting surface 301 of the reflector 30 so that light propagates from the light source 33 along a first direction. The light guide 2 includes a plate body 20 disposed adjacent to the light source 33 in the first direction. The plate body 20 has first and second surfaces 201, 202 opposite to each other in a second direction that is transverse to the first direction. Referring further to FIG. 5, which is an enlarged view (not drawn to scale) of the light guide 2, the first and second surfaces 201, 202 of the plate body 20 are respectively formed with a plurality of elongated grooves 21, 22. The grooves 21 in the first surface 201 are transverse to the grooves 22 in the second surface 202. In addition, the grooves 21 in the first surface 201 are transverse to the first direction. The light guide 2 further includes a dielectric layer 23 formed on the first surface 201, and a reflective layer 24 formed on one side of the dielectric layer 23 opposite to the first surface 201. The dielectric layer 23 is formed by spin coating in a conventional manner, and has a thickness ranging from 10 to 40 micrometers. In addition, the dielectric layer 23 has a refractive index smaller than the refractive index (n=1.49) of the plate body 20 for enhancing emission of light through the second surface 202 and luminance distribution. Preferably, the dielectric layer 23 is formed from magnesium fluoride, which has a refractive index of 1.36, or silicon dioxide, which has a refractive index of 1.45). The reflective layer 24 is formed by sputtering in a conventional manner. Preferably, the reflective layer 24 is formed from a material that has good reflectivity and that has a light color, and has a thickness of about 100 Å (1 Å=10−10 m). The reflective layer 24 may be formed from a silvery white metal material, such as aluminum or silver. Alternatively, the reflective layer 24 may be formed from a white non-metal material, such as magnesium oxide or titanium oxide.

#Referring again to FIG. 4, the light guide 2 has a light incident end proximate to the light source 33 in the first direction. Light from the light source 33 enters into the light guide 2 via the light incident end, is guided by the light guide 2 toward the second surface 202 of the plate body 20, and exits the light guide 2 via the second surface 202.