A key switch mechanism comprising: a key button ; a plunger attached to the key button and displaceable between a neutral position and an activation position; an elastomeric dome which, when the plunger is in the neutral position, is non-deformed and which, when the plunger is in the activation position, is elastically deformed by the plunger ; a conductive spring having a stationary end portion and a moveable end portion , the stationary end portion electrically coupled to a circuit , and the moveable end portion coupled to the elastomeric dome in a manner to be moved when the plunger is displaced towards the activation position, in connection with the corresponding deformation of the elastomeric dome ; and an electrical contact electrically coupled to the circuit , wherein, when the plunger is in the neutral position, the electrical contact is arranged at a distance from the moveable end portion , and, when the plunger is in the activation position, the moveable end portion is moved to contact the electrical contact ; characterized in that the key switch mechanism further comprises: a light emitter arranged under the elastomeric dome ; wherein the elastomeric dome , the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole , the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome . a key button ; a plunger attached to the key button and displaceable between a neutral position and an activation position; an elastomeric dome which, when the plunger is in the neutral position, is non-deformed and which, when the plunger is in the activation position, is elastically deformed by the plunger ; a conductive spring having a stationary end portion and a moveable end portion , the stationary end portion electrically coupled to a circuit , and the moveable end portion coupled to the elastomeric dome in a manner to be moved when the plunger is displaced towards the activation position, in connection with the corresponding deformation of the elastomeric dome ; and an electrical contact electrically coupled to the circuit , wherein, when the plunger is in the neutral position, the electrical contact is arranged at a distance from the moveable end portion , and, when the plunger is in the activation position, the moveable end portion is moved to contact the electrical contact ; characterized in that the key switch mechanism further comprises: a light emitter arranged under the elastomeric dome ; wherein the elastomeric dome , the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole , the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome . a light emitter arranged under the elastomeric dome ; wherein the elastomeric dome , the plunger and the key button are each at least partially light permeable; and wherein the moveable end portion comprises a through hole , the through hole at least partially fitting over and around the elastomeric dome to couple the moveable end portion to the elastomeric dome . <EOS>