A key device includes a bottom plate, a light guiding membrane switch, and a keycap. The light guiding membrane switch is disposed on the bottom plate and includes a lower membrane layer, an upper membrane layer, a light guiding spacing layer, a reflective layer, and an adhering layer. The upper membrane layer is disposed above the lower membrane layer and farer from the bottom plate than the lower membrane layer. The light guiding spacing layer is disposed between the lower membrane layer and the upper membrane layer and includes opposite upper and lower surfaces. The reflective layer is securely fastened on the upper surface. The adhering layer is adhered between the reflective layer and the upper membrane layer, and a position and a shape of the adhering layer correspond to a position and a shape of the reflective layer.

A touch-sensitive light guide film has an emitting layer, a light guiding layer, a flexible transparent layer and a light source. The emitting layer has a first circuit. The light guiding layer located on one side of the emitting layer has a second circuit and a receiving space. The receiving space is concavely or thoroughly disposed on the light guiding layer. The flexible transparent layer disposed between the emitting layer and the light guiding layer, has a through hole and a receiving hole. The through hole is relative in position to the first circuit and the second circuit, and in the through hole, the first circuit and the second circuit may contact when the flexible transparent layer is compressed. The light source is disposed on the emitting layer and penetrating the receiving hole and protruding into the receiving space.

A touch-sensitive light guide film has an emitting layer, a light guiding layer, a flexible transparent layer and a light source. The emitting layer has a first circuit. The light guiding layer located on one side of the emitting layer has a second circuit and a receiving space. The receiving space is concavely or thoroughly disposed on the light guiding layer. The flexible transparent layer disposed between the emitting layer and the light guiding layer, has a through hole and a receiving hole. The through hole is relative in position to the first circuit and the second circuit, and in the through hole, the first circuit and the second circuit may contact when the flexible transparent layer is compressed. The light source is disposed on the emitting layer and penetrating the receiving hole and protruding into the receiving space.

A key device includes a bottom plate, a light guiding membrane switch, and a keycap. The light guiding membrane switch is disposed on the bottom plate and includes a lower membrane layer, an upper membrane layer, a light guiding spacing layer, a reflective layer, and an adhering layer. The upper membrane layer is disposed above the lower membrane layer and farther from the bottom plate than the lower membrane layer. The light guiding spacing layer is disposed between the lower membrane layer and the upper membrane layer and includes opposite upper and lower surfaces. The reflective layer is securely fastened on the upper surface. The adhering layer is adhered between the reflective layer and the upper membrane layer, and a position and a shape of the adhering layer correspond to a position and a shape of the reflective layer.

A multicolor illumination keyboard includes a light-emitting element, a color filter and plural keys. The plural keys are located above the light-emitting element. The color filter is arranged between the plural keys and the light-emitting element. After a source light emitted by the light-emitting element passes through the color filter, plural color lights are generated. The plural color lights are outputted from the plural keys. Consequently, the plural keys are illuminated in a multicolor manner.

A multicolor illumination keyboard includes a light-emitting element, a color filter and plural keys. The plural keys are located above the light-emitting element. The color filter is arranged between the plural keys and the light-emitting element. After a source light emitted by the light-emitting element passes through the color filter, plural color lights are generated. The plural color lights are outputted from the plural keys. Consequently, the plural keys are illuminated in a multicolor manner.