Abstract: The method and system serve to notify the user of an event through a control device. Active notification takes place even when the computer sound and screen are disabled, for example, when in a power saving mode or screen saving mode. Notification may include visual notification, audio notification, vibratory notification, or tactile notification. Tactile notification can also serve to provide a private notification system which will not alert or disturb other people in the vicinity of the user. Such tactile notification can be provided by means of a texture change in the surface of the control device. One way in which this could be done is by raising a plurality of pegs through the surface of a control device to change its texture.

Abstract: An encoder having a movable element with a first polarized filter coupled to the movable element. A second polarized filter is either stationary, or moves differently from the first polarized filter. A photo-emitter and photodetector are arranged on opposite sides of the two polarized filters. Thus, when the polarized filters are aligned in phase, a maximum amount of light will penetrate to the photodetector. However, as they become out of phase due to movement of one of the filters, the amount of light will decrease, as a function of the amount of movement.