Method and control system for controlling output power of laser diode

Abstract

The present invention relates to a control method and a control system of output power controlling for a laser diode. The method includes utilizing a first test control signal for driving the laser diode to generate a first laser beam, detecting the power of the first laser beam for generating a first detecting signal, utilizing a second test control signal for driving the laser diode to generate a second laser beam, detecting power of the second laser beam for generating a second detecting signal, determining a relationship between output power of the laser diode and a driving signal according to the first and second test control signals and the first and second detecting signals, and controlling output power of the laser diode according to the relationship. The control system includes at least a driving circuit, a sensor, and an estimator to perform the above steps. The power wandering effect resulting from the change of temperature can be processed in the present invention and the time for steadying the output power of a laser diode are greatly reduced by making the original power of the laser diode approach to the object power.

Description

technical field [0001] The invention relates to a technology for controlling output power, in particular to a control system and method for dynamically adjusting the relationship between laser power and its control value to obtain the optimum output power of a laser diode, specifically a control system and method for controlling laser power A control system and method for diode output power. Background technique [0002] With the advancement of computer technology and the popularization of the Internet, optical drives have become increasingly important in our daily lives. For example, users can access a large amount of information and store all downloaded information by connecting a personal computer to the Internet. into the disc. Because the optical disc has the advantages of high capacity, small size and low cost, the products related to the optical disc have become more diverse and important. Disc), data can also be written to rewritable discs, in addition, another pro...

AI Technical Summary

Problems solved by technology

like figure 2 The traditional closed loop shown uses an integrator 30 to overcome this problem, which usually takes a lot of time, so the existing power control loop 10 cannot effectively compensate the drive signal S d Due to the error caused by power drift due to temperature changes, the performance of the optical drive will also deteriorate accordingly.

[0007] in addition, figure 2 The power control loop 10 shown is an analog circuit, which uses a capacitor to maintain the size of the control value (such as the control voltage). However, the optical drive sometimes pauses for a short period of time during the process of burning data, and then continues to burn the remaining data. When recording into an optical disc, when it is paused, the leakage current (leakage current) will cause the charge stored in the capacitor to lose, so the control value when the recording process is suspended will be different from the control value when the recording process is reactivated, so the power control Another disadvantage of the loop 10 is that it takes time to adjust the problem that the output power of the laser diode 50 is different from the target power caused by the above-mentioned capacitance leakage effect

[0008] In addition, there is another element that must be considered in the manufacturing process, because an optical read-write head usually has several channels (channel) (such as read channel and write channel) and a laser diode, that is, the traditional closed-loop power The control loop 10 cannot control all channels at the same time, so the effects caused by temperature changes must be ignored or compensated by a fixed value only in some channels

Images