Abstract: A backlight module (1) includes a light source (92), a light guide plate (80), and a frame (60). The frame contains the light source and the light guide plate. The frame includes a base plate (65) defining a transflective region (651) and a plurality of holes (652) defined in the transflective region. A portion of light beams from the light source is reflected by the transflective region out one main face of the backlight module, and a remainder of the light beams passes through the transflective region to emit from another main face of the backlight module. The backlight module and frame provide a double-sided emitting structure for a double-sided LCD. This avoids the need for an expensive transflector.

Abstract: A light guide (20) for illuminating keys of a keyboard or keypad of a portable electronic device, includes an array of apertures (22) and a groove (21) at one end of the light guide. The apertures are configured to illuminate the keys via a light source (10). The light source is disposed adjacent to the groove. A peripheral wall around each aperture is configured partially as a reflecting surface, and partially as a transmitting surface. The reflecting angle of the reflecting surface is larger than a critical total internal reflection angle so as to transfer the light farther. The light guide has a desired uniform light by means of a light source. This provides the portable electronic device consuming little power.

Abstract: A liquid crystal display device (20) includes two liquid crystal display panels (25, 26) and a backlight module sandwiched between the two liquid crystal display panels. The backlight module includes a first light guide plate (23), a second light guide plate (24), a light source (21) disposed adjacent to the first and second light guide plates, and a double-sided reflecting plate (22) sandwiched between the first and second light guide plates. The liquid crystal display device includes the double-sided reflecting plate, which is sandwiched between the first and second light guide plates, and can reflect light beams from the light source toward the first and second light guide plates. The first and second light guide plates, which are pressuredly pressed together by molds with the reflecting plate to form the backlight module, are two independent optical members, and do not affect each other. Therefore, the liquid crystal display device has good display quality.