Patent attributes
A keycap provides glyphs that are selectively visible. An exemplary keycap comprises a housing that has an at least partially transparent top side. A glyph made of a polarizing material is placed on the top side of the keycap. The glyph has a first plane of polarization. A liquid crystal panel is disposed inside the housing underneath the glyph. The liquid crystal panel is larger than the glyph above it. A polarizing filter having a second plane of polarization is arranged between the liquid crystal panel and a reflective carrier plate. Light enters the keycap through the transparent top side and is reflected at the bottom of the keycap by the reflective carrier plate. The reflected light is polarized by the polarization filter. The polarized light passes through the liquid crystal panel, which selectively rotates the polarization plane of light passing through it if the liquid crystal panel is active.
