Power control circuit for optical information recording device

Abstract

A power control circuit for an optical information recording device is disclosed. A power sampling signal from a photodiode is transmitted to a peal envelope acquiring circuit and a bottom envelope acquiring circuit and then sampled and held, which is fed-back to a laser diode driving circuit. The laser diode driving circuit alters a driving signal emitted to the laser diode according to the fed-back signal to adjust the power of the optical signal emitted from the laser diode. Therefore, cost is reduced and the power control circuit is particularly suitable for high-speed recordable optical disk drive.

1. A method for controlling a bias power of an optical disk device, comprising:
 generating a bottom envelope signal from a power sampling signal sensed by a photodiode of the optical disk device;   sampling the bottom envelope signal; and   controlling a bias power of the optical disk device responsive to the sampled bottom envelope signal,   wherein a frequency of the bottom envelope signal is lower than that of the power sampling signal.   
     
     
       2. The method according to  claim 1  wherein the step of generating the bottom envelope signal comprises:
 obtaining a negative half-wave of the power sampling signal; 
 selecting a candidate signal from the negative half-wave of the power sampling signal and the bottom envelope signal; and 
 obtaining a bottom value of the candidate signal as a next bottom envelope signal. 
 
     
     
       3. The method according to  claim 2  wherein a high frequency signal of the next bottom envelope signal is filtered out before performing the sampling step. 
     
     
       4. A method for controlling a write power of an optical disk device, comprising:
 generating a peak envelope signal from a power sampling signal sensed by a photodriode of the optical disk device;   sampling the peak envelope signal; and   controlling a write power of the optical disk device responsive to the sampled peak envelope signal,   wherein a frequency of the peak envelope signal is lower than that of the power sampling signal.   
     
     
       5. The method according to  claim 4  wherein the step of generating the peak envelope signal comprises:
 obtaining a postive half-wave of the power sampling signal; 
 selecting a candidate signal from the positive half-wave of the power sampling signal and the peak envelope signal; and 
 obtaining a peak value of the candidate signal as a next peak envelope signal. 
 
     
     
       6. The method according to  claim 5  wherein a high frequency signal of the next peak envelope signal is filtered out before performing the sampling step. 
     
     
       7. A bias power control circuit of an optical disk drive comprising:
 a bottom envelope acquiring circuit for outputting a bottom envelope signal responsive to a power sampling signal sensed by a photodiode of the optical disk device; and   a bias-period sample-and-hold circuit for sampling and outputting the bottom envelope signal wherein the bias power is controlled according to the sampled bottom envelope signal, and   wherein a frequency of the bottom envelope signal is lower than that of the power sampling signal.   
     
     
       8. The bias power control circuit of  claim 7  wherein the bottom envelope acquiring circuit further comprises:
 a selector for outputting a candidate signal selected from the bottom envelope signal and a negative half-wave of the power sampling signal; and 
 a bottom detector for obtaining a bottom value of the candidate signal as a next bottom envelope signal. 
 
     
     
       9. The basis power control circuit of  claim 8  further comprising an amplifier for filtering out a high frequency signal of the next bottom envelope signal before being sampled. 
     
     
       10. The bias power control circuit of  claim 8  wherein a diode driving circuit of the optical disk drive adjusts the bias power according to the sampled bottom envelope signal. 
     
     
       11. A write power control circuit for an optical disk drive comprising:
 a peak envelope acquiring circuit for outputting a peak envelope signal in responsive to a power sampling signal by a photodiode of the optical disk device; and   a write-period sample-and-hold circuit for sampling and outputting the peak envelope signal wherein the write power is controlled according to the sampled peak envelope signal, and wherein a frequency of the peak envelope signal is lower than that of the power sampling signal.   
     
     
       12. The write power control circuit of  claim 11  wherein the peak envelope acquiring circuit further comprises:
 a selector for outputting a candidate signal selected from the peak envelope signal and a positive half-wave of the power sampling signal; and 
 a peak detector for obtaining a peak value of the candidate signal as a next peak envelope signal. 
 
     
     
       13. The write power control circuit of  claim 12  further comprising an amplifier for filtered out a high frequency signal of the next peak envelope signal before being sampled. 
     
     
       14. The write power control circuit of  claim 11  wherein a diode driving circuit of the optical disk drive adjusts the write power according to the sampled peak envelope signal. 
     
     
       15. A method for controlling a power of an optical disk device for writing data to an optical disk, the method comprising:
 generating a power sampling signal according to the power of the optical disk device for writing data to the optical disk; and   controlling the power of the optical disk device based on an envelope of the power sampling signal, wherein the frequency of the envelope of the power sampling signal is lower than the frequency of the power sampling signal.   
     
     
       16. The method according to claim 15, wherein the step of generating comprises:
 generating the power sampling signal according to the power of the optical disk device for writing data to the optical disk sensed by a photodiode of the optical disk device.   
     
     
       17. The method according to claim 15, wherein the power of the optical disk device comprises a write power of the optical disk device and the envelope of the power sampling signal comprises a peak envelope of the power sampling signal, the step of controlling comprising:
 controlling the write power of the optical disk device based on the peak envelope of the power sampling signal.   
     
     
       18. The method according to claim 17, wherein the step of controlling further comprises:
 obtaining a positive half-wave of the power sampling signal;   selecting a output signal from the positive half-wave of the power sampling signal and a peak envelope signal corresponding to the peak envelope of the power sampling signal; and   obtaining a peak level of the output signal as a next peak envelope signal.   
     
     
       19. The method according to claim 15, wherein the power of the optical disk device comprises a bias power of the optical disk device and the envelope of the power sampling signal comprises a bottom envelope of the power sampling signal, the step of controlling comprising:
 controlling the bias power of the optical disk device based on the bottom envelope of the power sampling signal.   
     
     
       20. The method according to claim 19, wherein the step of controlling further comprises:
 obtaining a negative half-wave of the power sampling signal;   selecting a output signal from the negative half-wave of the power sampling signal and a bottom envelope signal corresponding to the bottom envelope of the power sampling signal; and   obtaining a bottom level of the output signal as a next bottom envelope signal.   
     
     
       21. A method for controlling a write power of an optical disk device, the method comprising:
 generating a power sampling signal by sensing the power generated by the optical disk device; and   controlling the write power of the optical disk device based on an average level of the power sampling signal within a plurality of write periods, wherein the frequency of the average level of the power sampling signal is lower than the frequency of the power sampling signal.   
     
     
       22. A method for controlling a bias power of an optical disk device, the method comprising:
 generating a power sampling signal by sensing the power generated by the optical disk device; and   controlling the bias power of the optical disk device based on an average level of the power sampling signal within a plurality of bias periods, wherein the frequency of the average level of the power sampling signal is lower than the frequency of the power sampling signal.   
     
     
       23. A power control circuit for controlling a power of an optical disk device for writing data to an optical disk, the power control circuit comprising:
 an element for generating a power sampling signal according to the power of the optical disk device for writing data to the optical disk; and   a controlling circuit for controlling the power of the optical disk device based on an envelope of the power sampling signal, wherein the frequency of the envelope of the power sampling signal is lower than the frequency of the power sampling signal.   
     
     
       24. The power control circuit according to claim 23, wherein the element comprises a photodiode. 
     
     
       25. The power control circuit according to claim 23, wherein the power of the optical disk device comprises a write power of the optical disk device and the envelope of the power sampling signal comprises a peak envelope of the power sampling signal, the controlling circuit controlling the write power of the optical disk device based on the peak envelope of the power sampling signal. 
     
     
       26. The power control circuit according to claim 25, wherein the controlling circuit comprises:
 a positive half-wave rectifier for obtaining a positive half-wave of the power sampling signal;   a multiplexer for selecting a output signal from the positive half-wave of the power sampling signal and a peak envelope signal corresponding to the peak envelope of the power sampling signal; and   a peak detector for obtaining a peak level of the output signal as a next peak envelope signal.   
     
     
       27. The power control circuit according to claim 23, wherein the power of the optical disk device comprises a bias power of the optical disk device and the envelope of the power sampling signal comprises a bottom envelope of the power sampling signal, the controlling circuit is controlling the bias power of the optical disk device based on the bottom envelope of the power sampling signal. 
     
     
       28. The power control circuit according to claim 27, wherein the controlling circuit comprises:
 a negative half-wave rectifier for obtaining a negative half-wave of the power sampling signal;   a multiplexer for selecting a output signal from the negative half-wave of the power sampling signal and a bottom envelope signal corresponding to the bottom envelope of the power sampling signal; and   a bottom detector for obtaining a bottom level of the output signal as a next bottom envelope signal.   
     
     
       29. A power control circuit for controlling a write power of an optical disk device, the power control circuit comprising:
 an element for sensing the power generated by the optical disk device to generate a power sampling signal; and   a controlling circuit for controlling the write power of the optical disk device based on an average level of the power sampling signal within a plurality of write periods, wherein the frequency of the average level of the power sampling signal is lower than the frequency of the power sampling signal.   
     
     
       30. A power control circuit for controlling a bias power of an optical disk device, the power control circuit comprising:
 an element for sensing the power generated by the optical disk device to generate a power sampling signal; and   a controlling circuit for controlling the bias power of the optical disk device based on an average level of the power sampling signal within a plurality of bias periods, wherein the frequency of the average level of the power sampling signal is lower than the frequency of the power sampling signal.