CN1215471C - Light source correction system - Google Patents

Light source correction system Download PDF

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Publication number
CN1215471C
CN1215471C CN 02120293 CN02120293A CN1215471C CN 1215471 C CN1215471 C CN 1215471C CN 02120293 CN02120293 CN 02120293 CN 02120293 A CN02120293 A CN 02120293A CN 1215471 C CN1215471 C CN 1215471C
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signal
signals
standard
digital
light
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CN1459782A (en
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刘兴华
黄耀正
萧麟
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BenQ Corp
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BenQ Corp
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Abstract

The present invention provides a light source correction system with the advantages of high accuracy and low cost, which uses a standard laser diode for carrying out precorrection on a light detector. After a current correction signal produced by the light detector is processed, and after a corresponding power standard relationship is saved in an electrically erasable programmable ROM, the standard relationship which corresponds to the light detector can be used for correcting the power of light sources of other laser diodes to be measured.

Description

Light source correcting system
Technical field
The present invention is about a kind of corrective system of light source, and particularly a kind of have pinpoint accuracy and a cost-effective corrective system.
Background technology
Along with the increase of high power capacity memory storage media demand amount, important role is day by day played the part of in the use of discs.Because the imprinting of discs relies on the interior optical disk head of recorder high temperature is gone up and produced to laser focusing at dye coating (Dye), its position is got to by laser beam and is produced chemical change, this place's reflectivity is with regard to step-down, therefore a series of measuring point (Pits) that is produced with do not got to and reflectivity higher signal point (Lands) by laser beam, be combined into the digital information (0 and 1) of having represented.
Yet for each different CD player, beat the lasing light emitter on discs, but often because the energy degree of accuracy of different laser differs, and the concave shape that the measuring point of per unit is formed differs, and the mistake when causing reading data.This is all to have the error in less difference and optical read head (OPU) assembling to cause owing to the family curve at the laser diode on the different CD player changes.Therefore, general CD burning device before dispatching from the factory, all must be done the correction (Laser PowerCalibration) of laser power, to guarantee the accuracy of the laser energy that it is sent.
Traditionally, utilize combining of a power detector (Power Meter) and a detecting device (Sensor Probe),, do the correction before dispatching from the factory, surplus expense of this cover instrument is about ten ten thousand yuan the laser diodes source.Yet, spread all over maintenance center outside thousands of factory all over the world, if also all be equipped with this equipment and do laser-adjusting, it is built, and to install the expense that is equipped with very huge.
The present invention is promptly at this problem, and research and development one cover is with low cost, and the lasing light emitter corrective system of pinpoint accuracy.
Summary of the invention
The purpose of this invention is to provide a kind of tool pinpoint accuracy and corrective system with low cost.
Light source correcting system of the present invention comprises a computing machine, a photodetector (Photo Detector), a current/voltage converter, an electro-erasable programmable ROM (read-only memory) (EEPROM), an analog/digital converter, an interface convertor and a microprocessor.
Photodetector receives the light signal from laser diode, and exports after being converted into a current signal, and current/voltage converter receives the current signal from photodetector, is converted into a voltage signal and output.Then, the voltage signal of the simulation of being exported by current/voltage converter is converted to a digital signal by an analog/digital converter, and this digital signal is the power unit of an expression luminous energy usually.At last, by microprocessor via an interface convertor with this power signal transmissions to computing machine, interface convertor is in order to adjusting the communications protocol between computing machine and the analog/digital converter, and microprocessor is then in order to the transmission of control interface converter and analog/digital converter.
Be used in timing, utilize a laser diode that can send accurate power, the calibration standard of being used as corrective system, claim that herein it is the standard laser diode, utilize above-mentioned system, step ground increases the emissive power of standard laser diode, and photodetector is stored in all standard laser diodes pairing normalized current signal of light signal that sends and the standard relationship of sending the power signal of light signal in the electro-erasable programmable ROM (read-only memory).
When using this corrective system, after computing machine reads standard relationship stored in the electro-erasable programmable ROM (read-only memory) earlier, the testing laser diode is replaced the standard laser diode, by computer control testing laser diode with the first power emission light signal, this light signal produces first digital signal with respect to optical signal power after this corrective system is handled, the electric current that is read this first digital signal by computing machine compares in standard relationship, can compare in standard relationship the most approaching and greater than the current signal of first digital signal with the most approaching and less than the current signal two opposite groups current signal value of first digital signal, two groups of signal values thus, the relative power that these two groups of current signals are read in standard relationship and the current signal value of first digital signal, can calculate the power of the current signal that is relevant to first digital signal by the interpolation method, this power is the power of the actual light signal that sends of testing laser diode.
By computer control testing laser diode at every turn with the intensity of step change emissive power, make this intensity in possible power bracket, repeat above-mentioned steps and can arrive the acceptable degree of accuracy in power bracket the capability correction that laser diode to be measured is sent.
For above-mentioned purpose of the present invention, feature and advantage can be become apparent, hereinafter enumerate a preferred embodiment, be described in detail as follows.
Description of drawings
Fig. 1 is the synoptic diagram of light source correcting system of the present invention.
Fig. 2 for the present invention one at the method for proofreading and correct that laser diode developed.
Fig. 3 shows that one is applied to the means for correcting of the laser diode of CD player.
Embodiment
The invention provides a tackling pinpoint accuracy and light source correcting system with low cost, this system comprises computing machine 130, photodetector 101, current/voltage converter 102, an electro-erasable programmable ROM (read-only memory) 103, analog/digital converter 121, interface convertor 122 and microprocessor 123 etc., please refer to Fig. 1, it is the synoptic diagram of light source correcting system.The light source correcting system of present embodiment comprises first module 110, second module 120 and computing machine 130, wherein the function of first module 110 is in order to receive the laser beam from a laser diode 200, and the function of second module 120 is judged the size of its laser beam in order to the signal of digitizing from first module 110 in order to the user.
First module 110 of the present invention is arranged in the utensil, and also comprises a photodetector 101, current/voltage converter 102 and an electro-erasable programmable ROM (read-only memory) 103.120 of second modules of the present invention also comprise an analog/digital converter 121, an interface convertor 122 and a microprocessor 123.Wherein, interface convertor 122 for example is the RS232 interface convertor.
Laser beam from laser diode 200, received by photodetector 101,101 light signals with laser beam of photodiode are converted to a current signal and output, wherein, laser diode 200 of the present invention can be a standard laser diode (that is so-called golden sample (golden sample)) that can send accurate laser energy, or a laser diode to be corrected, and photodetector 101 can be a photodiode.Then, the current signal by current/voltage converter 102 receives from photodetector 101 is converted into a voltage signal.
Then, the voltage signal of the simulation of being exported by current/voltage converter 102 is converted to a digital signal through an analog/digital converter 121, and the employed unit of this digital signal is the representation unit of a luminous energy usually, as the unit of power: mW.At last, via an interface convertor 122 with this power signal transmissions to computing machine 130.Interface convertor 122 is in order to as the transmission interface between computing machine 130 and the analog/digital converter 122, and the microprocessor 123 in second module 120 is then in order to the transmission of control interface converter 122 with analog/digital converter 121.
When this light source correcting system running, at first need earlier characteristic records with photodetector 101 in ROM (read-only memory) 103, utilize a standard laser diode that can send accurate laser energy, this standard laser diode 200 is one can be between 0~50.0mW, then send the light signal that power increases progressively in regular turn by computing machine 130 these standard laser diodes of order, for example: 0,0.2mW, 0.4mW, 0.6mW,,,, 49.8mW, 50.0mW.Its relative current value is light signal and handles the current signal that the back is exported via photodetector 101 and current/voltage converter 102; And these light signals are the power signal of the numeral after current signal is handled through analog/digital converter 121 and interface convertor 122 in the real power of this corrective system.Therefore, the optical signal power that is sent by the standard laser diode, can produce the standard relationship of current signal and power signal corresponding to this corrective system light signal 101 received current signals, promptly be recorded in the electro-erasable programmable ROM (read-only memory) 103 by computing machine 130, then this light source correcting system can begin to proofread and correct other laser diodes to be corrected.
The selection of the step size that reaches mentioned herein, for example employed laser diode emitted power scope is 0~50mW, if the selection of this step is with less step, for example the step of 0.05mW can be accomplished point-device correction, but the standard relationship quantity of required storage is big, need to store with electro-erasable programmable ROM (read-only memory) capacious, cost up, if the big adjustment power of selecting of step, except that precision is affected, photodetector is when the low light signal of detection power, the characteristic of nonlinear of photodetector is obvious more, make trimming process can't reach ± requirement of 5% degree of accuracy under, so the capacity of considering not waste the electro-erasable programmable ROM (read-only memory) and ± requirement of 5% degree of accuracy, step power changes the best with 0.2mW~0.6mW.
The correction program of light source correcting system is as follows, if laser diode 200 is a laser diode to be corrected, then computing machine is earlier by reading standard relationship in the electro-erasable programmable ROM (read-only memory) 103, and after ordering this laser diode to be corrected to send the luminous energy that increases progressively in regular turn, photodetector 101 receives this luminous energy and produces an electric current, the voltage signal that this electric current is exported from current/voltage converter 102 reaches the current signal of the power that interface convertor 122 photodetector of exporting 101 received through the analog digital conversion, can in standard relationship, find and receive this current signal most and greater than this current signal and less than the standard relationship value of the two groups of electric currents and the power of the current value of this current signal, calculating by the interpolation method can calculate the corresponding performance number of current signal, repeats this step and this testing laser diode can be proofreaied and correct.
For example, if computing machine 130 orders laser diode output P to be corrected tThe energy of mW, the current signal that the result measures through this corrective system is i tMA, then the found out i in standard relationship 1, i 2Two groups of current values, wherein i 1<i t<i 2, and i 1, i 2In the numerical value of standard relationship, approach i most t, i 1, i 2At the corresponding power of standard relationship is P 1, P 2, can draw by the calculating of interpolation method
P t ′ = P 1 - P 2 i 1 - i 2 · i t + ( P 1 - P 1 - P 2 i 1 - i 2 · i 1 )
P wherein t' emitted power in fact when being laser diode also is the power after the correction, notes by computing machine 130.Afterwards, computing machine orders laser diode to be corrected to send 0.2mW in regular turn by the way, 0.4mW,,,, each laser diode is sent light source to be proofreaied and correct, computing machine orders step size that laser diode to be corrected sends power still being the best at 0.2mW~0.6mW in regular turn herein, can obtain the demand of degree of accuracy, the result that will proofread and correct is recorded in the CD player by computing machine 130 at last, when using CD player to do imprinting work afterwards, promptly carry out imprinting work to proofread and correct the back accurate power.
In sum, corrective system provided by the present invention, only need be equipped with one records the standard relationship of standard laser diode in this corrective system and gets final product, just be stored in the standard relationship of electro-erasable programmable ROM (read-only memory) 103, afterwards, when one laser diode to be corrected is applied to this corrective system, also will produce the non-standard relation of another current signal and power signal, at this moment, proofread and correct and note for laser diode to be corrected by the standard relationship in the electro-erasable programmable ROM (read-only memory) 103, use the accurate power after laser diode to be corrected can use correction afterwards, with the purpose of the correction that reaches laser diode to be corrected.Therefore, even use a photodetector 101 that the linearity is not good, all can use the present invention and make light source correcting system, to reach the effect of accurate correction.Below, will be with the formation method of flowchart text corrective system of the present invention, to disclose purpose of the present invention more significantly.
Please refer to Fig. 2, its for the present invention one at the method for proofreading and correct that laser diode developed, wherein, step 11 to step 13 be a standard laser diode combine with corrective system of the present invention carry out method, that is regulate the family curve of photodetector 101 and be recorded in electro-erasable programmable formula ROM (read-only memory) 103, step 21 to step 23 is the implementation method of a laser diode to be corrected and corrective system of the present invention.
At first, carry out step 11, with a standard laser diode applications in corrective system of the present invention; Then, carry out step 12, send the light signal that power increases progressively in regular turn by computing machine 103 command standard diodes, this optical signals photodetector 101 receives and produces current signal; Then, in step 13, the current signal that current/voltage converter 102 outputs receive corresponding to photodetector 101, interface convertor 122 then output corresponding to the digital signal of the power of light signal, the formed standard relationship of this current signal and power signal is recorded in it among electro-erasable programmable ROM (read-only memory) 103 by computing machine 103.
Proceed step 21, the standard laser diode is substituted by a laser diode to be corrected; And carry out step 22, read standard relationship and order laser diode to be corrected by computing machine 103, send the light signal of power increment in regular turn, at this moment, the relative current signal standard of comparison of light signal relation can find out the most approaching and greater than and less than the numerical value of two groups of current/power of this current signal, by the interior difference operation of computing machine 103, can calculate the actual power that sends of laser diode to be corrected; At last, then carry out step 23, the result proofreaied and correct in computing machine 103 records, is stored in the CD player of using this laser diode to be corrected, finishes bearing calibration of the present invention.
Corrective system of the present invention and bearing calibration can be applicable in the various examples that need to proofread and correct, for example the light source correcting system of a laser diode.As shown in Figure 3, it shows that one is applied to the means for correcting of the laser diode 200 of CD player 20, and a laser diode 200 places the inside of CD player 20, and CD player 20 comprises a CD tray 21, and CD tray 21 can parallel shift-in or shift out CD player 20.First module 110 places on the laser diode 200, to receive the light signal from laser diode 200.First module 110 and one second module 120 of means for correcting couple, and second module 120 and a computing machine 130 couple, and 130 in computing machine more couples with first module 110 and CD player 20, to finish the function of correction of the present invention.
The invention effect, corrective system provided by the present invention, not only can be under the situation that optical element lacks to some extent, for example: the photodetector that the linearity is not good, make laser disome to be corrected be proofreaied and correct the result accurately, more under the requirement of the degree of accuracy that does not lose correction, reduced the cost of proofreading and correct.
In sum; though the present invention with preferred embodiment openly as above; right its is not in order to limit the present invention; any those skilled in the art; under the situation that does not break away from the spirit and scope of the present invention; when can doing various changes and improvement, so protection scope of the present invention is as the criterion when looking the scope that accompanying Claim defines.

Claims (19)

1. system that a light source is proofreaied and correct, this light source can send out a plurality of light signals that comprise first light signal, and its system comprises at least:
One pick-up unit is used for receiving and measuring these a plurality of light signals, and sends a plurality of simulating signals that comprise first simulating signal;
One measuring apparatus is used for receiving these a plurality of simulating signals, and sends a plurality of digital signals that comprise first digital signal;
One storage device, be used to store a standard relationship, this standard relationship is that a standard light signal optical source is sent and sent this a plurality of standard analog signals after the power of a plurality of standard light signal correspondences and this pick-up unit receive this a plurality of standard light signals, is formed by sending this a plurality of standardized digital signal behind these these a plurality of standard analog signals of measuring apparatus reception; And
One judgment means, be used to read this standard relationship and receive this first digital signal, between one second digital signal and a three digital signal of this first digital signal in standard relationship, this second digital signal and this three digital signal in standard relationship respectively with respect to one second power and one the 3rd power;
Calculate and export the performance number of this first light signal by a predetermined account form.
2. the system as claimed in claim 1, wherein this light source and this standard light signal optical source are respectively a laser diode to be corrected and the standard laser diode that can send accurate light signal.
3. the system as claimed in claim 1, wherein this storage device is an electro-erasable programmable ROM (read-only memory).
4. the system as claimed in claim 1, wherein this pick-up unit also comprises:
One signal receiver is used to receive a plurality of signals that this light source is sent, and a plurality of standard light signals of being sent of this standard light signal optical source, and sends a plurality of current signals and a plurality of normalized current signal respectively; And
One signal converter is used for receiving these a plurality of current signals and this a plurality of normalized current signals, and sends a plurality of voltage signals and a plurality of normal voltage signal.
5. system as claimed in claim 4, wherein this signal receiver is a photodiode.
6. system as claimed in claim 4, wherein this signal converter is a current/voltage converter.
7. the system as claimed in claim 1, wherein this measuring apparatus also comprises:
One analog/digital converter is used for receiving these a plurality of simulating signals and this a plurality of standard analog signals, and sends these a plurality of digital signals and this a plurality of standardized digital signals;
One interface convertor is used for receiving these a plurality of digital signals and this a plurality of standardized digital signals, and exports this judgment means to, and this interface convertor is adjusted the communications protocol interface between this analog/digital converter and this judgment means; And
One microprocessor is used to control the transmission of this analog/digital converter and this interface convertor.
8. system as claimed in claim 7, wherein this interface convertor is the RS232 interface convertor.
9. the system as claimed in claim 1, this predetermined way is an interpolation method.
10. the system as claimed in claim 1, the watt level that this light source produces a sequence sends out a plurality of signals, and the interval of this watt level is greater than 0.2mW and less than 0.6mW.
11. the system as claimed in claim 1, the power of these a plurality of standard light signals are a sequence, and the interval of its watt level is greater than 0.2mW and less than 0.6mW.
12. the method that a light source is proofreaied and correct, wherein this light source, a pick-up unit, a measuring apparatus, a storage device and a judgment means couple, and this pick-up unit and this measuring apparatus couple, and this method comprises the following steps:
(a) this signal generation apparatus is a standard sources;
(b) this judgment means makes this standard sources send the signal that energy increases progressively in regular turn, this pick-up unit can detect relative a plurality of standard analog signals and deliver to this measuring apparatus, and this measuring apparatus is handled these a plurality of standard analog signals and exported a plurality of standardized digital signals to this judgment means;
(c) this judgment means writes down a plurality of standard relationship of these a plurality of standard analog signals and these a plurality of standardized digital signals in this storage device;
(d) replacing this light source is a light source to be measured;
(e) this judgment means reads these a plurality of standard relationship in this storage device;
(f) this judgment means makes this light source produce one first light signal, this first light signal is treated to first simulating signal through this pick-up unit, this first simulating signal is treated to one first digital signal through this measuring apparatus, and this first digital signal is sent to this judgment means;
(g) this judgment means utilizes this first digital signal to compare two groups of signals near one first digital signal by this standard relationship, these two groups of signals can be corresponding to two groups of performance numbers of this standard relationship, calculate first performance number with respect to first signal by the interpolation method;
(h) make the constantly watt level of change first signal of this signal generation apparatus by this judgment means, with repeating step (f)~(h);
13. method as claimed in claim 12, wherein this light source and this standard light signal optical source are respectively a laser diode to be corrected and the standard laser diode that can send accurate light signal.
14. method as claimed in claim 12, wherein this storage device is an electro-erasable programmable ROM (read-only memory).
15. method as claimed in claim 12, wherein this pick-up unit also comprises:
One signal receiver is used to receive a plurality of signals that this light source is sent, and a plurality of standard light signals of being sent of this standard light signal optical source, and sends a plurality of current signals and a plurality of normalized current signal respectively; And
One signal converter is used for receiving these a plurality of current signals and this a plurality of normalized current signals, and sends a plurality of voltage signals and a plurality of normal voltage signal.
16. method as claimed in claim 15, wherein this signal receiver is a photodiode.
17. method as claimed in claim 15, wherein this signal converter is a current/voltage converter.
18. method as claimed in claim 12, wherein this measuring apparatus also comprises:
One analog/digital converter is used for receiving these a plurality of simulating signals and this a plurality of standard analog signals, and sends these a plurality of digital signals and this a plurality of standardized digital signals;
One interface convertor is used for receiving these a plurality of digital signals and this a plurality of standardized digital signals, and exports this judgment means to, and this interface convertor is adjusted the communications protocol interface between this analog/digital converter and this judgment means; And
One microprocessor is used to control the transmission of this analog/digital converter and this interface convertor.
19. method as claimed in claim 18, wherein this interface convertor is the RS232 interface convertor.
CN 02120293 2002-05-22 2002-05-22 Light source correction system Expired - Fee Related CN1215471C (en)

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Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
CN 02120293 CN1215471C (en) 2002-05-22 2002-05-22 Light source correction system

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CN1459782A CN1459782A (en) 2003-12-03
CN1215471C true CN1215471C (en) 2005-08-17

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