US Patent 11257638 Key structure

A key structure includes a bottom plate, a keycap, a lifting mechanism, a thin-film switch layer and a backlight module. The bottom plate has a through hole. The lifting mechanism is pivotally connected to the bottom plate and the keycap. The thin-film switch layer has a reflective structure corresponding to the through hole. The backlight module includes a light source and a reflective layer. The light source is configured to emit light towards the reflective structure. The reflective layer is disposed surrounding the light source to reflect a reflected light from the reflective structure to the thin-film switch layer.