Patent ID: 8714850

Claim:
A backlight module used in a lighting keyboard, the backlight module comprising: a light guiding plate for guiding light; and a masking disposed above the light guiding plate, the masking comprising: a support layer comprising an upper surface and a lower surface opposite to the upper surface, the lower surface facing toward the light guiding plate; a reflective layer disposed on the upper surface, the reflective layer reflecting the light toward the light guiding plate, the reflective layer comprising a second opening; and a light absorbing layer disposed above the reflective layer, the light absorbing layer comprising a first opening, the second opening at least overlapping the first opening, so that the light passes through the masking from the lower surface to the upper surface by passing through an overlapped portion where the first opening and the second opening are overlapped; wherein a reflectivity of the reflective layer is higher than a reflectivity of the light absorbing layer, so that the reflective layer makes the light not entering the second opening substantially reflected back to the light guiding plate without being absorbed by the light absorbing layer.