CN1178215C - Method for quickly regulating focusing error signal level of optical disc drive - Google Patents
Method for quickly regulating focusing error signal level of optical disc drive Download PDFInfo
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- CN1178215C CN1178215C CNB011294825A CN01129482A CN1178215C CN 1178215 C CN1178215 C CN 1178215C CN B011294825 A CNB011294825 A CN B011294825A CN 01129482 A CN01129482 A CN 01129482A CN 1178215 C CN1178215 C CN 1178215C
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Abstract
The present invention relates to a method for quickly regulating a focus servo error signal level of an optical drive, which comprises the steps: selecting a fiducial focus servo error signal level, and making a focus objective lens go bottom; moving the focus objective lens to the CD direction, and starting to detect whether the focus servo error signal level passes through a focus point; if the difference between the two signal levels goes beyond the error excepted, the gain adjusted by a prime amplifier is calculated; the direction of travel of the focus objective lens is changed, and then the detection process, the comparison process and the adjustment process are repeated; if the focus point has been passed through, and the difference between the two signal levels is in the error excepted, moving focus objective lens is stopped and then the adjustment process is ended.
Description
Technical field
The present invention is a kind of method of quickly regulating focusing error signal level of optical disc drive, particularly about a kind of by means of detection to focus point, focusing objective len (object lens) is only moved up and down near focus point, carry out the signal level adjustment effectively, to quicken the level adjustment of CD-ROM drive servo error signal.
Background technology
The optical read head of general CD-ROM drive is when reading, as shown in Figure 1, be to produce laser by laser diode 11a, via producing focus point 14a behind optical splitter (beam splitter) 12a and focusing objective len (object lens) 13a, control this focusing objective len 13a by focus actuator (focus actuator) 15a and do and move up and down, and then change the position of focus point 14a.Focus point 14a beats this optical splitter of the reflected light process 12a that produces behind disc 16a, it is directed on the photodetector 17a, and obtains some useful optical signallings from this photodetector 17a.In order to obtain the high correct signal of reliability, just need carry out focus control, to control the position of this focusing objective len 13a, make this disc 16a do rotation up and down during beat (verticalwobble), can keep the focus point 14a of laser beam by this focusing objective len 13a drops on the reflection horizon 161a of this disc 16a, in order to the access of data.
See also shown in Figure 2, normally carry out focus control with a closed loop control system 20a, the feedback signal of optical head is produced focusing error signal (focus error) via pre-amplifier (pre-amp) 21a, again via compensator (compensator) 22a decision compensation control voltage, promote this focusing objective len 13a by motor driver (motor driver) 23a at last, make laser beam focus on this disc 16a.Before this compensator of design 22a, must determine focusing error signal level earlier, it is the DC current gain that can have influence on this compensator 22a because of it, focusing error signal level is high more, the DC current gain of required compensator 22a is low more, and focusing error signal level is low more, and the DC current gain of required compensator 22a is high more, that is, be inverse relation between the DC current gain of focusing error signal level and this compensator 22a.
On the other hand, compensator 22a is not identical in the phase boundaries (phase margin) of resulting system bandwidth of different platform (bandwidth) and stability (stability) thereof, the factor of influence has the gain of dynamic perfromance, motor driver 23a of focus actuator 15a itself and focusing error signal level etc., and power, the reflectivity of disc 16a, opto-electronic conversion integrated circuit (the photo detect integrated circuit of focusing error signal level and this laser diode 11a; PDIC) relevant with gain of pre-amplifier 21a etc., that is, the laser diode 11a power of different platform may be different, and the gain of its opto-electronic conversion integrated circuit also is not quite similar, and different disc 16a also have different reflectivity, and the difference of reflectivity can have influence on focusing error signal.In addition, for identical input term signal, different pre-amplifier 21a have identical setting value, also have the output of different sizes, therefore, if will make the focusing error signal that inputs to this compensator 22a identical as far as possible, need to adjust the yield value of this pre-amplifier 21a usually.
Known common employing S curve (S-curve search) mode of searching is adjusted focusing error signal level, with foundation as this pre-amplifier of adjustment 21a, by this focus actuator 15a this focusing objective len 13a is sunk to the bottom earlier, promptly past d1 moves to the end away from the direction of disc, again with the past d2 direction of this focusing objective len 13a, promptly move toward disc 16a direction, if it is far away excessively that this focus point 14a surpasses the reflection horizon 161a of this disc 16a, then this focusing objective len 13a is moved toward d1, so repeatedly, to adjust focusing error signal level, its waveform as shown in Figure 3, for doing three S curves, searches and corresponding focus error signal focusing objective len 13a, wherein FE is a focus error signal, FOSO is the control output of focus actuator 15a, but because of needs this focusing objective len 13a is done moving by a relatively large margin, therefore needs the long time of cost.
As from the foregoing, the method for above-mentioned known quickly regulating focusing error signal level of optical disc drive on reality is used, obviously has inconvenience and exists with shortcoming, and need be improved.
Therefore, the improving of the above-mentioned shortcoming of inventor's thoughts is that the spy concentrates on studies and cooperates the utilization of scientific principle, proposes a kind of reasonable in design and effectively improve the above-mentioned the present invention who arrives that lacks finally.
Summary of the invention
In order to improve above-mentioned every shortcoming of known method, fundamental purpose of the present invention is to be carried out and do not needed ancillary cost that hardware is installed by software, just can carry out the adjustment of focus error signal level.
In order to reach above-mentioned purpose, the method that the present invention mainly provides a kind of quickly regulating focusing error signal level of optical disc drive comprises: the focusing error signal level of chosen in advance reference; Focusing objective len is moved to the end toward the direction away from disc, again this focusing objective len is moved toward the disc direction; Detect focusing error signal level, judge the position of the focus point of this focusing objective len by this; If the reflection horizon of this focus point by disc, whether focusing error signal level that relatively should reference differs in the error amount of a permission with this focusing error signal level; And if, then stop to move this focusing objective len, and finish this method; If focusing error signal level and this focusing error signal level of this reference differ outside the error amount of this permission, then calculate the gain that a pre-amplifier should be adjusted, and make this focusing objective len toward moving away from the direction of disc, return the step that detects focusing error signal level.
Reach technology, means and the effect that predetermined purpose is taked in order to make those of ordinary skill in the art can further understand the present invention, see also following about detailed description of the present invention and accompanying drawing, believe purpose of the present invention, feature and characteristics, when obtaining thus deeply and concrete understanding, yet accompanying drawing only provides reference and explanation usefulness, is not to be used for the present invention is limited.
Description of drawings
Fig. 1 is that known optical read head focuses on the action synoptic diagram;
Fig. 2 is a known closed loop control system circuit block diagram;
Fig. 3 is that known S curve search pattern is adjusted the focusing error signal level oscillogram;
Fig. 4 is an adjustment process flow diagram of the present invention;
Fig. 5 is an adjustment focusing error signal level oscillogram of the present invention.
Embodiment
See also shown in Figure 4ly, Fig. 4 is a workflow diagram of the present invention.The present invention is a kind of method of quickly regulating focusing error signal level of optical disc drive, comprises the following steps:
Step 11: the focusing error signal level of selected reference;
Step 12: open this laser diode, and with this focusing objective len toward moving to the end away from the direction of disc, promptly to focusing objective len itself can be away from farthest that of disc;
Step 13: this focusing objective len is moved toward the disc direction;
Step 14: detect focusing error signal level;
Step 15: judge whether the focus point of this focusing objective len passes through the reflection horizon of this disc?
If then enter step 16;
If not, then transfer to and continue mobile step 19, and get back to step 14;
Step 16: the focusing error signal level of itself and preset reference is made comparisons, with as the foundation of adjusting this pre-amplifier;
Step 17: within the error that allows? if then enter step 18;
If not, then calculate the gain that this pre-amplifier should be adjusted, and transfer to focusing objective len is moved step 20 toward the direction away from disc, and get back to step 14;
Step 18: stop to move this focusing objective len, and turn off laser diode, to finish the adjustment program.
Again, Fig. 5 is that the present invention carries out the oscillogram of focusing error signal level when adjusting, with itself and Fig. 3 more as can be known, the present invention takes time, and (Δ t=115.62ms, the focusing error signal level of benchmark=0.5V) are about known S curve search pattern (1/10th of Δ=897.40ms).
In view of the above, can be fast and efficiently focusing error signal is adjusted to a reference level, reduced the influence of focusing error signal level to system bandwidth and stable phase angle border.
The above; only be the detailed description and the accompanying drawing of the specific embodiment of one of the best of the present invention; be that feature of the present invention is not limited thereto; be not in order to restriction the present invention; scope of patent protection of the present invention should be as the criterion with following claims; all closing in the embodiment of the spirit variation similar of the present patent application scope of patent protection with it; all should be included in the category of the present invention; anyly be familiar with those of ordinary skill in the art, the variation that can expect easily or modify the scope of patent protection that all can be encompassed in following the application.
Claims (1)
1, a kind of method of quickly regulating focusing error signal level of optical disc drive comprises the following steps:
(a) focusing error signal level of chosen in advance one reference;
(b) focusing objective len is moved to the end toward a direction away from disc, again this focusing objective len is moved toward the disc direction;
(c) detect a focusing error signal level, judge the position of a focus point of this focusing objective len by this;
(d) if the reflection horizon of this focus point by disc, focusing error signal level that relatively should reference and this focusing error signal level whether differ in the error amount of a permission and
(e) if then stop to move this focusing objective len, and finish this method; If focusing error signal level and this focusing error signal level of this reference differ outside the error amount of this permission, then calculate the gain that a pre-amplifier should be adjusted, and make this focusing objective len toward moving away from the direction of disc, return step (c).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011294825A CN1178215C (en) | 2001-06-21 | 2001-06-21 | Method for quickly regulating focusing error signal level of optical disc drive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011294825A CN1178215C (en) | 2001-06-21 | 2001-06-21 | Method for quickly regulating focusing error signal level of optical disc drive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1393861A CN1393861A (en) | 2003-01-29 |
| CN1178215C true CN1178215C (en) | 2004-12-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB011294825A Expired - Fee Related CN1178215C (en) | 2001-06-21 | 2001-06-21 | Method for quickly regulating focusing error signal level of optical disc drive |
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| CN (1) | CN1178215C (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100373473C (en) * | 2003-04-18 | 2008-03-05 | 松下电器产业株式会社 | Optical disc controller |
| CN100362574C (en) * | 2003-10-13 | 2008-01-16 | 联发科技股份有限公司 | Optical medium determination method |
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2001
- 2001-06-21 CN CNB011294825A patent/CN1178215C/en not_active Expired - Fee Related
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| Publication number | Publication date |
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| CN1393861A (en) | 2003-01-29 |
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