Drive device for a light-emitting component
View Patent ↗A drive device for a light emitting component includes a reference source for generating a power stipulation signal that stipulates a desired power. A correction device compensates for a temperature-dictated measurement error of the photodetector by modifying, in a temperature-dependent manner, the power stipulation signal generated by the reference source. A regulating device is connected to the reference source and generates a regulating signal that regulates the light power of the light emitting component to minimize the deviation between the actual light power and the desired light power. This configuration avoids monitor tracking errors of a monitor diode used to measure the actual light power.
1. A drive device for a light-emitting component, comprising:
a reference source for generating a power stipulation signal stipulating a desired light power;
a photodetector for measuring an actual light power of the light-emitting component;
a regulating device connected to said photodetector and said reference source, said regulating device generating a regulating signal for regulating the actual light power of the light-emitting component such that a deviation between the desired light power and the actual light power becomes minimal; and
a correction device for compensating for a temperature-dictated measurement error of the photodetector by modifying, in a temperature-dependent manner, the power stipulation signal generated by said reference source.
2. The drive device according to claim 1 , wherein said correction device includes a memory storing a plurality of correction values for modifying the power stipulation signal in the temperature-dependent manner.
3. The drive device according to claim 2 , wherein:
said correction device includes a control device and a temperature sensor;
said control device and said temperature sensor are configured for obtaining a measured temperature value by measuring a temperature of the monitor diode or a temperature proportional to the temperature of the monitor diode; and
said control device is configured for reading a correction value associated with the measured temperature value from said memory.
4. The drive device according to claim 3 , wherein said control device is formed by a controller module.
5. The drive device according to claim 3 , wherein said control device is formed by a microprocessor.
6. The drive device according to claim 2 , wherein said memory stores the plurality of correction values and a plurality of temperature levels or temperature ranges associated with the plurality of correction values in table form.
7. The drive device according to claim 2 , wherein said memory stores the plurality of correction values and a plurality temperature levels or temperature ranges associated with the plurality of correction values as look-up table.
8. The drive device according to claim 2 , wherein said memory is freely programmable.
9. The drive device according to claim, 2 , wherein:
said correction device includes a control device and a temperature sensor;
said control device and said temperature sensor are configured for obtaining a measured temperature value by measuring a temperature of the monitor diode or a temperature proportional to the temperature of the monitor diode;
said control device is configured for reading a correction value associated with the measured temperature value from said memory; and
said correction device includes a digital-to-analog converter connected downstream of said control device.
10. The drive device according to claim 9 , wherein:
said digital-to-analog converter forms an analog modification signal from the correction value read from said memory by said control device or an auxiliary correction value derived from the correction value;
the power stipulation signal of said reference source ( 30 ) is modified using the modification signal.
11. The drive device according to claim 10 , wherein:
said correction device includes an analog adder configured for adding the modification signal of said digital-to-analog converter or an auxiliary modification signal formed from the modification signal to the power stipulation signal of said reference source.
12. The drive device according to claim 11 , wherein said adder is formed by an operational amplifier circuit.
13. The drive device according to claim 1 , in combination with the light-emitting component, wherein the light-emitting component is a laser.
14. The drive device according to claim 1 , in combination with the light-emitting component, wherein the light-emitting component has a monitor diode forming said photodetector.
15. A method for driving a light-emitting component, which comprises:
defining a stipulated desired light power by stipulating a desired light power;
obtaining a measured actual light power by measuring an actual light power of the light-emitting component with a photodetector;
regulating the light-emitting component such that a deviation between the desired light power and the measured actual light power becomes minimal;
compensating for a temperature-dictated measurement error of the photodetector by modifying the stipulated desired light power in a temperature-dependent manner.
16. The method according to claim 15 , which further comprises: reading a plurality of correction values from a memory for modifying the stipulated desired light power.
17. The method according to claim 16 , which further comprises: storing the plurality of correction values in table form in the memory.
18. The method according to claim 16 , which further comprises: storing the plurality of correction values as a look-up table in the memory.