Patent ID: 8813676

Claim:
A user interface for a controller, comprising: a panel having multiple indicia representing a user-selectable parameter; a knob configured to protrude from the panel and movable about a central axis relative to the multiple indicia; and a light projector comprising: an illuminating device below the panel; a light conduit located along the central axis and optically coupled to the illumination device to carry light from the light source along the central axis; a reflector located within the knob and optically coupled to the light conduit to reflect the carried light; and a lens located on the knob and optically coupled to the reflector to project the reflected carried light as converging beam of light downwardly onto the panel to form a discrete spot of light on the panel; wherein the discrete spot of light is in physical proximity with the multiple indicia such that movement of the knob relative to the multiple indicia causes a corresponding movement of the discrete spot of light, and the spot of light indicates which of the multiple indicia is selected by the knob.