Keyswitch having backlight module with three lighting units and two light modifiers

A backlight keyswitch comprising:

• a keyswitch body having a cap with at least one symbol formed thereon;
• and
• a backlight module disposed under the cap, the backlight module comprising:
• a light-blocking sheet having a transparent region corresponding to the cap;
• a light guide plate disposed under the light-blocking sheet and having an accommodating hole corresponding to the cap;
• a backlight circuit board disposed under the light guide plate and having a backlight source, the backlight source being disposed in the accommodating hole and comprising a first lighting unit, a second lighting unit, and a third lighting unit, wherein the first lighting unit, the third lighting unit, and the second lighting unit are arranged sequentially along a longitudinal direction for emitting a first color light, a third color light, and a second color light respectively to be incident to the transparent region after light mixing;
• a first adhesive layer disposed in parallel to the light guide plate, the first adhesive layer extending along a first hole edge of the accommodating hole and corresponding to the first lighting unit;
• and
• a second adhesive layer disposed in parallel to the light guide plate, the second adhesive layer extending along a second hole edge of the accommodating hole and corresponding to the second lighting unit, and the second adhesive layer and the first adhesive layer together defining at least one first adhesive gap area in a transverse direction;
• wherein the second adhesive layer scatters the second color light to reduce the second color light reaching an outer side of the second adhesive layer in the longitudinal direction, and the at least one first adhesive gap area makes more second color light incident to a first outer side region adjacent to the first lighting unit;
• the first adhesive layer scatters the first color light to reduce the first color light reaching an outer side of the first adhesive layer in the longitudinal direction, and the at least one first adhesive gap area makes more first color light incident to a second outer side region adjacent to the second lighting unit.

A backlight module comprising:

• a light-blocking sheet having a transparent region;
• a light guide plate disposed under the light-blocking sheet and having an accommodating hole;
• a backlight circuit board disposed under the light guide plate and having a backlight source, the backlight source being disposed in the accommodating hole and comprising a first lighting unit, a second lighting unit, and a third lighting unit, wherein the first lighting unit, the third lighting unit, and the second lighting unit are arranged sequentially along a longitudinal direction for emitting a first color light, a third color light, and a second color light respectively to be incident to the transparent region after light mixing;
• a first ink layer formed on the light-blocking sheet and located outside the first lighting unit, a color of the first ink layer at least corresponding to a color of the second color light to achieve a mixed color with the first color light;
• and
• a second ink layer formed on the light-blocking sheet and located outside the second lighting unit, a color of the second ink layer at least corresponding to a color of the first color light to achieve the mixed color with the second color light.

A backlight module comprising:

• a light-blocking sheet having a transparent region;
• a light guide plate having an accommodating hole;
• a backlight circuit board disposed under the light guide plate and having a backlight source, the backlight source being disposed in the accommodating hole and comprising a first lighting unit, a second lighting unit, and a third lighting unit, wherein the first lighting unit, the third lighting unit, and the second lighting unit are arranged sequentially along a longitudinal direction for emitting a first color light, a third color light, and a second color light respectively to be incident to the transparent region after light mixing;
• a first adhesive layer disposed in parallel to the light guide plate, the first adhesive layer extending along a first hole edge of the accommodating hole and corresponding to the first lighting unit;
• and
• a second adhesive layer disposed in parallel to the light guide plate, the second adhesive layer extending along a second hole edge of the accommodating hole and corresponding to the second lighting unit, and the second adhesive layer and the first adhesive layer together defining at least one first adhesive gap area in a transverse direction;
• wherein the second adhesive layer scatters the second color light to reduce the second color light reaching an outer side of the second adhesive layer in the longitudinal direction, and the at least one first adhesive gap area makes more second color light incident to a first outer side region adjacent to the first lighting unit;
• the first adhesive layer scatters the first color light to reduce the first color light reaching an outer side of the first adhesive layer in the longitudinal direction, and the at least one first adhesive gap area makes more first color light incident to a second outer side region adjacent to the second lighting unit.