Arrangement for illuminating the adjusting knob of an input unit by means of transmitted light

An arrangement of illuminating an adjusting knob of an input unit by means of transmitted light, the input unit having a rotary switch which is fastened on a dividing wall and a setting stem of which, carrying the adjusting knob, reaches through to an opposite side of the dividing wall, and at least one light source being provided, located on the rotary switch side, characterized in that a light guide is provided, in that on the light guide there is formed a light-exiting face corresponding to the region of the adjusting knob to be illuminated, in that the light guide is secured against rotation and fixed on the dividing wall on the adjusting knob side, the light guide reaches through the dividing wall to the light source, a light-guide channel with a light entering face assigned to the light source is formed on the light guide, the light guide being fastened on the dividing wall indirectly when the input unit is fastened, the fastening of the input unit takes place by means of a screwed connection, with a threaded lug being provided on the input unit, and in that a receptacle corresponding to the diameter of the threaded lug and a clearance serving for the leading through of the light-guide channel are formed in the dividing wall.