Hon Hai Precision Industry Co., Ltd.

Sutech Trading Limited

Wen-Feng Cheng

Tung-Ming Hsu

Ming-Fu Hsu

Chien-Min Chen

A direct type backlight module () includes a substrate (), a diffusion sheet () disposed above the substrate, a plurality of spacers () and a plurality of light sources (). The spacers are disposed between the substrate and the diffusion sheet. Each spacer includes a bottom surface () contacting with the substrate. A groove () is defined in the bottom surface, and a light incident surface () is defined on inner surface of the groove. A pair of wings is disposed on two sides of the bottom surface for supporting the diffusion sheet. Each wing includes an outer side surface and an inner side surface, and a transflective film is formed on the inner side surfaces of the wing. The light sources are respectively disposed in the grooves.

Direct type backlight module

A light guide () for illuminating keys of a keyboard or keypad of a portable electronic device, includes an array of apertures () and a groove () at one end of the light guide. The apertures are configured to illuminate the keys via a light source (). 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.

Keypad light guide

A back light system () includes a light guide plate () and light sources (). The light guide plate includes an optical output surface (), a bottom surface () opposite to the output surface, and optical input surfaces () between the output and bottom surfaces. The light sources are positioned adjacent the input surfaces respectively. A thickness of a middle of the light guide plate is less than a thickness of a periphery of the light guide plate. In operation, light beams from two opposite of the light sources provide ample optical energy to a middle area of the output surface. In addition, a total optical energy at peripheral areas of the output surface is the same as or similar to a total optical energy at the middle area of the output surface. Thus, the back light system provides very high and highly uniform brightness for an associated LCD.

Light guide plate and back light system using same

A light guide for illuminating keys of a keyboard or keypad of a portable electronic device includes an array of apertures, at least one groove and at least a protrusion. The apertures are defined in the light guide and are configured to illuminate the keys via at least a light source. The groove is disposed in one end of the light guide for receiving light from the light source. The light guide can provide a desired uniform illumination by means of fewer light sources, and can improve optical uniformity by eliminating the bright areas occurring adjacent to the light sources.

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Tu-Cheng, Taiwan

Wen-Feng Cheng