Circuit and method for controlling light-emitting components

Abstract

Circuit arrangement or circuit, in particular driver circuit, and a method for controlling at least one light-emitting component, such as an electro-optical transducer, a light-emitting diode (LED), an electroluminescent diode, a laser, or a semiconductor laser, by switching a switching element between a first switching position and a second switching position, and the voltage supply is effected by a supply element, such as a voltage source or a current source supported by a decoupling capacitor on the output side, so that current drain and output resistance are as low as possible, so that the highest possible frequency or switching speed as well as the highest possible output voltage for the light-emitting component can be achieved, the light-emitting component is controlled by varying its operating voltage, in particular by switching between the switching positions, and the first and second switching positions are of low impedance for the operating frequency.

What is claimed is: 
     
         1 . A circuit for controlling at least one light-emitting component, comprising:
 a) at least one supply element provided for supplying the circuit with voltage;   b) at least one switching element provided, and being switchable at least between a first switching position and a second switching position; and   c) the light-emitting component:
 i) can be supplied with a first operating voltage in the first switching position of the switching element; 
 ii) can be supplied with a second operating voltage in the second switching position of the switching element; and 
 iii) can be controlled by switching between the first operating voltage and the second operating voltage. 
   
     
     
         2 . The circuit according to  claim 1 , wherein:
 a) the light-emitting component is configured as at least one electro-optical transducer, in particular as at least one light-emitting diode (=L[ight]E[mitting]D[iode]) or electroluminescent diode or as at least one laser, such as at least one semiconductor laser.   
     
     
         3 . The circuit according to  claim 1 , wherein:
 a) the supply element is configured as:
 i) at least one voltage source; or 
 ii) at least one current source supported by a decoupling capacitor on the output side. 
   
     
     
         4 . The circuit according to  claim 1 , wherein:
 a) the supply element includes at least two supply elements each configured as a voltage source, and:
 i) in the first switching position almost the entire voltage provided by the first voltage source drops as first operating voltage at the light-emitting component; and 
 ii) in the second switching position almost the entire voltage provided by the second voltage source drops as second operating voltage at the light-emitting component. 
   
     
     
         5 . The circuit according to  claim 1 , wherein:
 a) the supply element includes at least two supply elements which are connected to one another in parallel, each configured as a current source supported by a decoupling capacitor on the output side, in particular by at least one decoupling capacitor, which are connected to at least one supply voltage, in particular to at least one Thévenin voltage.   
     
     
         6 . The circuit according to  claim 1 , wherein:
 a) at least one diode polarized in the forward direction, in particular towards the switching element, for example at least one pn diode or at least one Schottky diode, is connected between at least one of the supply elements and the switching element.   
     
     
         7 . The circuit according to  claim 1 , wherein:
 a) a transistor is connected between at least one of the supply elements and the switching element;   b) the drain connection of said transistor being connected to the first supply element or to the second supply element;   c) the gate connection of said transistor being connected to at least one supporting supply element, in particular to at least one supporting voltage source; and   d) the source connection of said transistor being connected to the input connection of the light-emitting component.   
     
     
         8 . The circuit according to  claim 1 , wherein:
 a) the switching element is configured as at least two transistors;   b) the respective drain connection of said transistors being connected to the first supply element or to the second supply element;   c) the gate connection of said transistors being connected to at least one control device, in particular to at least one signal source or its gate connection, in particular via at least one resistance element, to at least one supporting supply element, in particular to at least one supporting voltage source; and   d) the respective source connections of said transistor being connected to one another and to the input connection of the light-emitting component.   
     
     
         9 . The circuit according to  claim 7 , wherein:
 a) the transistor or the transistors is or are configured as at least one or two M[etal]O[xide]S[emiconductor]F[ield]E[ffect]T[ransistor](s) or as at least one or two MOS transistor(s), in particular as at least one or two n-channel F[ield]E[ffect]T[ransistor](s).   
     
     
         10 . The circuit according to  claim 6 , wherein:
 a) at least one regulating and/or processing element, in particular at least one comparator and/or by at least one amplifier, is provided:   b) the, in particular first, input connection whereof is connected to the second supply element, in particular to the second current source supported by a decoupling capacitor on the output side;   c) the optional second input connection whereof is connected to at least one optional reference voltage source or reference voltage source; and   d) the output connection whereof is connected to the supporting supply element.   
     
     
         11 . A method for controlling at least one light-emitting component, comprising:
 a) switching at least one switching element at least between a first switching position and a second switching position, and the voltage supply is effected by use of at least one supply element; and   b) the light-emitting component is controlled by varying its operating voltage.   
     
     
         12 . The method according to  claim 11 , wherein:
 a) the operating voltage of the light-emitting component is varied by switching between the switching positions, of which at least the first switching position and the second switching position are of low impedance for the operating frequency.   
     
     
         13 . The method according to  claim 11 , wherein:
 a) the supply elements are each configured as a voltage source; and   b) the light-emitting component is supplied:
 i) in the first switching position with the entire or almost the entire voltage provided by the first voltage source; and 
 ii) in the second switching position with the entire or almost the entire voltage provided by the second voltage source. 
   
     
     
         14 . The method according to  claim 11 , wherein:
 a) the supply elements are configured as current sources connected to one another in parallel, each supported by a decoupling capacitor on the output side in particular by at least one decoupling capacitor, which are connected to at least one supply voltage, in particular to at least one voltage source, for example to at least one battery.   
     
     
         15 . Use of the circuit according to  claim 1  in:
 a) at least one, in particular mobile, telecommunication system, for example in at least one communication device, such as in at least one mobile telephone; 
 b) in at least one, in particular mobile, data communication system or in at least one, in particular mobile, data processing device, for example in at least one handheld, in at least one notebook or in at least one P[ersonal]D[igital]A[ssistant]; 
 c) in at least one, in particular mobile, data recording and/or reproducing device, for example in at least one camcorder, in at least one digital camera or in at least one H[igh]D[efinition]T[ele]V[ision]; or 
 d) in at least one transportation means, for example in at least one driver assistance system or in at least one navigation system of an automobile.