Light guide plate structure and light-guide-plate manufacturing method thereof

A light-guide-plate manufacturing method comprising:

• disposing a light guide plate having a light exit surface and a bottom surface in a keyboard and under keyswitches;
• forming a micro structure on the bottom surface;
• forming a first medium layer and a second medium layer on the light exit surface and the micro structure respectively by a surface coating process or a co-extrusion process, a refractive index of the first medium layer and a refractive index of the second medium layer being less than a refractive index of the light guide plate but greater than a refractive index of air, and a constant interval being formed between the first medium layer and the micro structure no matter the keyswitches are pressed or not;
• and
• forming a reflection layer on the second medium layer.

A backlight keyboard comprising:

• a substrate;
• a plurality of keyswitches disposed on the substrate;
• and
• a light guide plate structure disposed under the substrate corresponding to the keyswitches, the light guide plate structure comprising:
• a light guide plate having a light exit surface and a bottom surface opposite to the light exit surface;
• a first medium layer formed on the light exit surface;
• a micro structure formed on the bottom surface for redirecting light inside the light guide plate to emit from the light exit surface, and a constant interval being formed between the first medium layer and the micro structure no matter the keyswitches are pressed or not;
• a second medium layer formed on the micro structure, a refractive index of the first medium layer and a refractive index of the second medium layer being less than a refractive index of the light guide plate but greater than a refractive index of air;
• and
• a reflection layer formed on the second medium layer for reflecting light inside the light guide plate to emit from the light exit surface.