Patent ID: 7255061
Filing Date: 2007-08-14
Classification: G05G,H01H

Abstract:
1. Control, comprising a knob ( 12 ; 12 a ) intended to be mounted in a wall element ( 16 ) in such a way that it can rotate, with an external end ( 30 ) facing towards the user and with a central cavity for housing a light-transmitting medium in order to be able to display different symbols, depending upon the rotational position of the knob, by optical projection towards the external end, in addition to which the control ( 10 ; 10 a ) comprises a disc element ( 32 ) upon which symbols are arranged that are to be displayed at the external end ( 30 ) of the knob ( 12 ; 12 a ), which disc element is located at the end of the knob ( 12 ; 12 a ) facing away from the external end ( 30 ) and concentric with this, and a light source ( 34 ) that is located on the side of the disc element ( 32 ) facing away from the knob ( 12 ; 12 a ) in order to illuminate the symbol on the disc element that is to be displayed at the external end of the knob at the time, characterized in that the disc element ( 32 ) upon which the symbols are arranged is stationary, in that the light-transmitting medium that is in the cavity comprises a prism ( 20 ), comprising an axial part ( 22 ) that is central in the knob ( 12 ; 12 a ) with a symbol display surface ( 28 ) at the external end of the knob, and a part ( 24 ) that is arranged at an angle to the central part ( 22 ) for receiving incident light from the illuminated symbol on the disc element ( 32 ) that is to be projected on the display surface ( 28 ) at the time and refracting this incident light towards the display surface, and in that the light source ( 34 ) is arranged to illuminate the symbol on the stationary disc element ( 32 ) that is to be displayed on the display surface ( 28 ) at the time, independent of the rotational position of the knob ( 12 ; 12 a ).