US Patent 11923156 Backlight module and lighting keyboard

A back light module is applied to a lighting keyboard with a plurality of keyswitches and includes a lighting unit, a light guide plate, a light penetrating membrane, a light calibration layer and an adhering component. The light guide plate has an opening used to accommodate the lighting unit. The light penetrating membrane is disposed on the light guide plate. The light calibration layer is disposed on the light penetrating membrane and has a second contour. The adhering component is disposed between the light guide plate and the light penetrating membrane, and has a first contour greater than the second contour. The adhering component includes a front region, a rear region and a hollow region. The front region is covered by the light calibration layer. The rear region is partly covered or not covered by the light calibration layer. The hollow region corresponds to and is larger than the opening.