Illuminated keyboard and backlight module thereof

A backlight module, comprising:

• a light guide plate comprising a side, a first backlight region and a second backlight region, wherein each of the first backlight region and the second backlight region comprises a plurality of keycap backlight areas, each of the keycap backlight areas is configured with a through hole;
• a first light-emitting unit comprising a plurality of light-emitting elements, wherein the light-emitting elements of the first light-emitting unit are disposed corresponding to the through holes in the keycap backlight areas of the first backlight region, respectively, and the light-emitting elements of the first light-emitting unit are electrically connected to each other in parallel;
• a second light-emitting unit comprising a plurality of light-emitting elements, wherein the light-emitting elements of the second light-emitting unit are disposed corresponding to the through holes in the keycap backlight areas of the second backlight region, respectively, and the light-emitting elements of the second light-emitting unit are electrically connected to each other in parallel;
• a first resistor electrically connected to the first light-emitting unit in series;
• a second resistor electrically connected to the second light-emitting unit in series;
• a circuit board disposed under the light guide plate, wherein the first light-emitting unit, the second light-emitting unit, the first resistor and the second resistor are disposed on the circuit board;
• and
• a light shielding plate comprising a planar region and a plurality of convex regions, wherein the planar region is configured with a plurality of openings for outputting light, and the light-emitting elements are disposed corresponding to the convex regions, respectively;
• wherein, a first total area of the openings corresponding to the keycap backlight areas of the first backlight region is not equal to a second total area of the openings corresponding to the keycap backlight areas of the second backlight region,
• wherein each of the light-emitting elements comprises a plurality of light outputting surfaces perpendicular to an upper surface of the light guide plate,
• wherein the light outputting surfaces comprise a first light outputting surface, a normal direction of the first light outputting surface and the side of the light guide plate form an acute angle, and the acute angle is between 35° and 60°.

A backlight module, comprising:

• a light guide plate comprising a side, a first backlight region and a second backlight region, wherein each of the first backlight region and the second backlight region comprises a plurality of keycap backlight areas, each of the keycap backlight areas is configured with a through hole;
• a first light-emitting unit comprising a plurality of light-emitting elements, wherein the light-emitting elements of the first light-emitting unit are disposed corresponding to the through holes in the keycap backlight areas of the first backlight region, respectively, and the light-emitting elements of the first light-emitting unit are electrically connected to each other in parallel;
• a second light-emitting unit comprising a plurality of light-emitting elements, wherein the light-emitting elements of the second light-emitting unit are disposed corresponding to the through holes in the keycap backlight areas of the second backlight region, respectively, and the light-emitting elements of the second light-emitting unit are electrically connected to each other in parallel;
• a first resistor electrically connected to the first light-emitting unit in series;
• a second resistor electrically connected to the second light-emitting unit in series;
• a circuit board disposed under the light guide plate, wherein the first light-emitting unit, the second light-emitting unit, the first resistor and the second resistor are disposed on the circuit board;
• and
• a light shielding plate comprising a planar region and a plurality of convex regions, wherein the planar region is configured with a plurality of openings for outputting light, and the light-emitting elements are disposed corresponding to the convex regions, respectively;
• wherein, a first total area of the openings corresponding to the keycap backlight areas of the first backlight region is not equal to a second total area of the openings corresponding to the keycap backlight areas of the second backlight region,
• wherein a reflection portion is provided between a light-emitting element of the light-emitting elements and a convex region of the convex regions, and the reflection portion is disposed above the light-emitting element for reflecting light emitted from the light-emitting element.