CN1153971A - Output control apparatus of semiconductor laser device - Google Patents
Output control apparatus of semiconductor laser device Download PDFInfo
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- CN1153971A CN1153971A CN 96119231 CN96119231A CN1153971A CN 1153971 A CN1153971 A CN 1153971A CN 96119231 CN96119231 CN 96119231 CN 96119231 A CN96119231 A CN 96119231A CN 1153971 A CN1153971 A CN 1153971A
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Abstract
A recording and reproducing apparatus includes a semiconductor laser device for irradiating a light beam, a driving circuit for driving the semiconductor laser device, and an oscillation device for generating a predetermined high-frequency signal. The high-frequency signal generated by this oscillation device is superposed onto a driving signal of the driving circuit in order to drive the semiconductor laser device.
Description
The present invention relates to the laser instrument opertaing device, when with laser irradiation such as mini disk (mini-disc (MD)) or magneto-optic (MO) dish on magnetic recording media during recorded information, opertaing device control laser instrument emission laser.
In known magneto-optic disk unit, during the record, owing to carry out magnetic recording on the signal recording surface of magneto-optic disk, therefore, the output of laser is higher.Such as with the semiconductor laser emitted laser of laser diode, irradiation is on such as the MO dish time, and MO coils recorded information.At playback duration, owing to only need to detect the return laser light that reflects from the information recording surface of magneto-optic disk.Therefore, the output of laser is lower.
But, have following defective.When the laser that returns when the signal recording surface from magneto-optic disk enters as the Laser emission end face (end-surface) of the semiconductor laser of lasing light emitter, because the output of playback duration laser is lower.Disturb the laser that returns by this semiconductor laser emitted laser, produce resonance, make laser modulated.For this reason, the high frequency superposition module of nominal comprises high frequency oscillator, and high frequency superposition module will be superimposed to from the high-frequency signal of high frequency superposition module on the drive current of semiconductor laser, with the influence of the Laser emission end face of eliminating the return laser light noise spectra of semiconductor lasers.
By comparison, when record, owing on the signal recording surface of magneto-optic disk, write down magneto-optic, this semiconductor laser is made the continuous light wave of emission, thereby laser output is higher by magnetic field modulation.And, because do not disturb the laser that returns from magneto-optic disk usually, do not cause resonance by the semiconductor laser emitted laser, therefore, do not carry out the high frequency superposition.And, for example in United States Patent (USP) 5495456, disclose, think that it also is good carrying out the high frequency superposition in recording process, and make the signal frequency of superposition be starkly lower than the used frequency of playback time.
But in the magneto-optic disk unit of structure as mentioned above, the output of every series-produced semiconductor laser is all inequality.Therefore, owing to be subjected to the quality influence of semiconductor laser, thereby the output of the laser in record rather unstable.In this case, laser can disturb the laser that is returned by magneto-optic disk, resonance occurs, forms the laser output that changes.
The result, when carrying out signal record with the magnetic field modulation method, assigned position place on the signal recording surface of magneto-optic disk forms spot (mark (magnetic domain by luminous point (spot) the L track T in accordance with regulations of semiconductor laser emitted light beams on the signal recording surface of magneto-optic disk, promptly, the magnetic recording part that the magnetic of representing with oblique line heats)), as shown in Figure 4.But, since the variation of laser output, the edge dislocation of this spot.
That is to say that when the laser that is sent by semiconductor laser is exported just often, shown in the first half of Fig. 5, laser output is almost constant.Thereby in this case, the track T of magneto-optic disk signal recording surface is heated equably by laser irradiation, and carries out thermo magnetic recording by the magnetic field of magnetic head.Shown in the bottom of Fig. 5.
By comparison, when the laser output of semiconductor laser is more weak, because the laser that is returned by magneto-optic disk is disturbed in laser output.Resonance occurs, laser output has the high output that is caused by resonance, shown in the top of Fig. 6.For this reason, such problem has appearred, for example be heated to the above part of predetermined temperature and will become big with respect to the track T of the signal recording surface of magneto-optic disk, output in this section will uprise, part by head records, that is, spot will be along the length displacement of track T, and instability occurs writing.When this displacement surpassed threshold value, write error will appear.
Therefore, in the manufacturing of magneto-optic disk unit, select the lasing light emitter of the semiconductor laser of normal laser output, to enable to eliminate laser output to the interference of the laser that returns by magneto-optic disk and the resonance of appearance as magneto-optic disk unit with semiconductor laser.Thereby, above-mentioned write error can not appear.
For this reason, following problem occurred, for example the qualification rate of the semiconductor laser of using in the magneto-optic disk unit descends, and the cost of semiconductor laser increases.
Consider the problems referred to above, the objective of the invention is, the output control equipment of the semiconductor laser in a kind of magneto-optic disk unit is provided, when record on it or from the magneto-optic disk playback time, changes, also can carry out normal recordings during the record even be used as the performance of the semiconductor laser of lasing light emitter.
For achieving the above object,, provide a kind of output control equipment of semiconductor laser, be used for the signal recording surface of information signal recording at magneto-optic disk according to the present invention, and/or from the information recording surface playback information signal of magneto-optic disk.This equipment is included in when record high-frequency signal is superimposed to the device that the drive signal of semiconductor laser gets on, and wherein, presses the pre-sizing of the recording track of magneto-optic disk.Carry out accurately signal record.
According to said structure,,, thereby eliminated the influence that the light beam that returned by magneto-optic disk causes at the end face of semiconductor laser because high-frequency signal is superimposed on the drive signal of semiconductor laser in when record.The result, even the laser by semiconductor laser output is lower during writing down, when the laser beam of returning when the signal recording surface by magneto-optic disk enters the end face of semiconductor laser, do not disturb the above-mentioned light beam that returns, resonance can not take place yet from this semiconductor laser emitted laser.
Thereby, to export owing to can obtain constant laser, signal can accurately be recorded on the desired trajectory on the signal recording surface of magneto-optic disk.
In one case, be when being superimposed to the identical signal of high-frequency signal on the drive signal of semiconductor laser promptly with playback duration at above-mentioned high-frequency signal, owing to used the high frequency superposition circuit that is used to reset, adopted identical high frequency superposition circuit at record with playback duration, thereby do not need on/off high frequency superposition circuit, so structure is simplified.
In one case, be when playback duration is superimposed to the high-frequency signal that the output amplitude on the drive signal of semiconductor laser is reduced promptly at above-mentioned high-frequency signal, use the high frequency superposition circuit of playback usefulness, because above-mentioned output amplitude reduces, thereby to superposition the drive signal of high-frequency signal control, make it be no more than ratings.To enable to press the desired trajectory laser that usefulness is exported on the signal recording surface of magneto-optic disk output record signal more accurately.
By the detailed description of doing below in conjunction with accompanying drawing, above-mentioned purpose of the present invention and other purpose, scheme and new feature will become clearer.
Fig. 1 is the block scheme according to first embodiment of laser output control equipment of the present invention;
Fig. 2 is the drive current I of semiconductor laser in the equipment shown in Figure 1 and the graph of relation of laser output P;
Fig. 3 is the block scheme according to second embodiment of laser output control equipment of the present invention;
Fig. 4 is luminous point and the magnetooptic recording view that forms on the track of magneto-optic disk in the conventional magneto-optic disk unit;
Fig. 5 is the synoptic diagram that is illustrated in laser output magnetooptic recording state just often when writing down in the magneto-optic disk shown in Figure 4 unit;
Fig. 6 is illustrated in when writing down in the magneto-optic disk shown in Figure 4 unit, and laser output is low slightly and the synoptic diagram of unsure state occurs writing.
Below describe the preferred embodiments of the present invention in detail referring to accompanying drawing 1 to 3.
Because the following embodiment that will illustrate is a concrete preference of the present invention, thereby various technical desirable conditions are arranged among these embodiment.But these embodiment are not the restriction to scope of the present invention.
Fig. 1 is first embodiment according to the laser output control equipment of magneto-optic disk of the present invention unit.
Among Fig. 1, laser output control equipment 10 comprises OR circuit 11, is used for being input to a logging mode signal write or from the replay mode signal Read that the control circuit of magneto-optic disk unit (not shown) comes its each input end; Switch 12, it is according to the output signal of OR circuit 11 and closure (closed); High frequency superposition module (superposition module) 14, it and switch 12 and power supply 13 series connection; With semiconductor laser 17, be used for and be applied thereto from the high-frequency signal of high frequency superposition module 14 with from the drive signal (drive current) of power choke coil 16.
OR circuit 11 is designed to, when input logging mode signal Write or playback duration input during the record during from the replay mode signal Read of the control circuit of magneto-optic disk unit, output signal.
Under the situation of Fig. 1, semiconductor laser 17 is made of laser diode.When the drive current I that adds by power choke coil 16 from driving circuit 15, semiconductor laser 17 work, output laser.
When switch 12 closures (closed), high frequency superposition module 14 is worked according to the driving voltage that is provided by power supply 13, and the high-frequency signal of output preset frequency, as 100MHZ to 1GHZ, and 600MHZ preferably.As a result, owing to eliminated the influence of the end face of return laser light noise spectra of semiconductor lasers 17, thereby the resonance that laser output and the interference between the return laser light from semiconductor laser 17 cause can not take place, thereby, Laser Modulation eliminated.
In this case, the hot time of the end face of semiconductor laser 17 is constant in the microsecond order of magnitude.When high-frequency signal was superimposed to this semiconductor laser 17, if superposition 100MHZ or the high-frequency signal more than it, the heat that produces on the end face of semiconductor laser 17 did not increase, and therefore, does not destroy the serviceable life of laser instrument.The inventor has confirmed the above fact.
Constitute the laser output control equipment 10 of present embodiment according to said structure.Below referring to Fig. 2 its running is described.
Among Fig. 2, the laser of semiconductor laser 17 output P is a linear function, and it is risen by threshold value Ith, with the driving circuit I response from driving circuit 15.
Playback duration has only replay mode signal Read input OR circuit 11, and switch 12 cuts out (closed).As a result, high frequency superposition module 14 is switched to " on ", and high-frequency signal is sent from high frequency superposition module 14, delivers to semiconductor laser 17 by capacitor C.
As shown in Figure 2, the drive current I1 lower at playback duration flows through semiconductor laser 17, and high-frequency signal is superimposed on the driving circuit I1.Therefore, because the high frequency superposition is arranged,, can not produce the export resonance of the laser of the semiconductor laser 17 that causes because of interference even introduce the laser that returns from CD yet.
Comparatively speaking, during the record, have only logging mode signal Write input OR circuit 11, switch 12 cuts out (closed).As a result, high frequency superposition module 14 is switched to " on ", delivers to semiconductor laser 17 from the high-frequency signal of this high frequency superposition module 14 by capacitor C.
As shown in Figure 2, during the record, bigger drive current I2 flows through semiconductor laser 17, and high-frequency signal is superimposed on this drive current I2.Therefore, even introduce the laser that returns by CD since superposition high frequency, can not cause export resonance because of interference by semiconductor laser 17 output laser.Therefore produce almost constant laser output with pulsating current.
For the signal source of above-mentioned generation high-frequency signal, used the high frequency superposition circuit that is used to reset.Therefore, thus needn't reset high frequency superposition circuit can make designs simplification.
In this case, the amplitude of drive current I2 and high-frequency signal is chosen to preferably that the laser peak that makes pulsating current output becomes ratings (rated value) or below the ratings.
Fig. 3 illustrates second embodiment according to the laser output control equipment of magneto-optic disk of the present invention unit.
Referring to Fig. 3, laser output control equipment 20 comprises two switches 21 and 22, it is respectively according to logging mode signal Write with from the replay mode signal Read open and close of the control circuit of magneto-optic disk unit (not shown), two power supplys 23 and 24, and they are connected with switch 21 and 22; High frequency superposition circuit (high-frequency model) 14, it is connected with 24 with power supply 23 with 22 by switch 21 respectively; Semiconductor laser 17 has applied on it from the high-frequency signal of high frequency superposition module 14 and the drive signal from driving circuit 15 (driving circuit) by power choke coil 16.
Switch 21 and 22 will switch to " on " and " off " from the voltage that power supply 23 and 24 is used to drive high frequency superposition module 14 respectively.Each switch 21 and 22 is according to logging mode signal Write and replay mode signal Read closure (closed).
Here, the voltage Vw of used power supply 23 during the record suitably is provided with, so that the laser peak of carrying from semiconductor laser 17 by the high frequency superposition becomes the ratings that is no more than laser output.
And high frequency superposition module 14 operates according to the voltage Vw that is provided by power supply 23 or 24 respectively or Vr, when switch 21 and 22 separately closed (closed), and the high-frequency signal of output preset frequency, for example 100MHZ is to 1GHZ, preferably 600MHZ.
In this case, driving voltage according to Vw with Vr and different.As a result, during writing down, select driving voltage Vw, the high frequency waves that an output of high frequency superposition module output spoke degree is reduced.
According to the laser output control equipment 20 of said structure, at playback duration, replay mode signal Read is imported into switch 22, makes switch 22 closures (closed).As a result, make the driving voltage Vr of power supply 24 be added to high frequency superposition module 14, high-frequency signal is delivered to semiconductor laser 17 from high frequency superposition module 14 by capacitor C.
Thereby as shown in Figure 2, at playback duration, less drive current I1 flows through semiconductor laser 17.High-frequency signal is superimposed on the drive current I1.Therefore, because the superposition high-frequency signal,, also can not produce resonance because of disturbing from the laser output of semiconductor laser 17 even entered return laser light from CD.Thereby, the constant light pulse of semiconductor laser 17 emissions.
By comparison, during the record, logging mode signal Write is imported into switch 21, makes switch 21 closures (closed).As a result, the driving voltage Vw that provides from power supply 23 is added to high frequency superposition module 14, and high-frequency signal is sent to semiconductor laser 17 from high frequency superposition module 14 by capacitor C.
In this case, owing to high frequency superposition module 14 operates according to the driving voltage Vw that is lower than playback duration.Thereby, lower from the amplitude of the high-frequency signal of high frequency superposition module 14 output than the amplitude of the high-frequency signal of output during resetting.Thereby the laser output amplitude of semiconductor laser 17 also reduces.Therefore, as shown in Figure 2, during the record, bigger drive current I2 flows through semiconductor laser 17, and high-frequency signal is superimposed on the drive current I2.Therefore, because the high frequency superposition, even the laser that returns from CD enters, the laser of being exported by semiconductor laser 17 can not produce resonance because of interference yet.Therefore, can produce almost constant laser output with pulsating current.
About illustrating above this point,, during writing down,, therefore, in record,, also can obtain constant laser output even the output of the laser of semiconductor laser is less because high-frequency signal is superimposed on the drive signal of semiconductor laser according to the present invention.Thereby signal accurately is recorded on the desired trajectory of signal recording surface of magneto-optic disk.
Therefore, even from device to a device, to the magneto-optic disc recording or from the magneto-optic disk playback duration be not constant as the output of the semiconductor laser of light source, according to the present invention, during writing down, also can carry out record normally.
Claims (13)
1, a kind of recording unit of Magnetooptic recording medium comprises:
Semiconductor laser is used the beam irradiation Magnetooptic recording medium;
Driving circuit is used for providing drive signal to described semiconductor laser; With
Oscillation device is used to produce 100MHZ or the above high-frequency signal of 100MHZ, and it is superimposed on the drive signal of described driving circuit output;
Wherein, send such signal to described semiconductor laser, this signal is that the high-frequency signal of described oscillatory circuit is superimposed to signal on the drive signal of described driving circuit.
2, according to the recording unit of claim 1, wherein, the high-frequency signal that is produced by described oscillatory circuit has the frequency for 100MHZ to 1GHZ.
3, according to the recording unit of claim 1, wherein, the high-frequency signal that is produced by described oscillatory circuit has the frequency of 600MHZ.
4, a kind of record of Magnetooptic recording medium and reproducing device comprise:
Semiconductor laser is used the beam irradiation Magnetooptic recording medium;
Driving circuit is used for providing drive signal to described semiconductor laser;
The signal oscillating device is used to produce high-frequency signal, and this signal will be superimposed on the drive signal of described driving circuit output;
Wherein, send such signal to described semiconductor laser at record and playback duration, this signal is that the high-frequency signal of oscillation device output is superimposed to signal on the drive signal of driving circuit output, and during writing down, with record data is that the vertical magnetic field that modulate on the basis is added to described Magnetooptic recording medium and with laser beam irradiation data is recorded on the described Magnetooptic recording medium, and at playback duration, with laser beam irradiation on described Magnetooptic recording medium, and according to the data of laser playback record on described Magnetooptic recording medium of returning by described Magnetooptic recording medium.
5, according to the record and the reproducing device of claim 4, wherein, the high-frequency signal that described oscillatory circuit produces has the frequency of 100MHZ to 1GHZ.
6, according to the record and the reproducing device of claim 4, wherein, the high-frequency signal that described oscillatory circuit produces has the frequency of 600MHZ.
7, according to the record and the reproducing device of claim 4, wherein, for the laser output that makes the described semiconductor laser during the record is greater than laser output at playback duration, described driving circuit drives also control semiconductor laser.
8, according to the record and the reproducing device of claim 4, wherein, for the output amplitude that makes the high-frequency signal that produces by described oscillation device during writing down less than the amplitude of playback duration, described driving circuit drives also control semiconductor laser.
9, a kind of record of Magnetooptic recording medium and reproducing device comprise:
Semiconductor laser, it uses the beam irradiation Magnetooptic recording medium;
Driving circuit is used for providing drive signal to described semiconductor laser;
The signal oscillating device is used to produce high-frequency signal, and this signal will be superimposed on the drive signal of driving circuit output;
The 1st power circuit is used for providing the 1st driving voltage to described oscillation device during the Magnetooptic recording medium record; With
The 2nd power circuit is used for providing the 2nd driving voltage from the Magnetooptic recording medium playback duration to described oscillation device;
Wherein, at record and playback duration, send such signal to described semiconductor laser, this signal is that the high-frequency signal of described oscillation device is superimposed to signal on the drive signal of driving circuit, and during writing down, with record data is that the vertical magnetic field that modulate on the basis is added on the Magnetooptic recording medium, irradiation laser beam recording data on described Magnetooptic recording medium, at playback duration, to described Magnetooptic recording medium, the data that write down on described Magnetooptic recording medium are read according to the laser that is returned by described Magnetooptic recording medium laser beam irradiation.
10,, wherein, set driving voltage from described the 1st power circuit and be lower than driving voltage from described the 2nd power circuit according to the record and the reproducing device of claim 9.
11, according to the record and the reproducing device of claim 9, wherein, the high-frequency signal that described oscillatory circuit produces has the frequency of 100MHZ to 1GHZ.
12, according to the record and the reproducing device of claim 9, wherein, the high-frequency signal that described oscillatory circuit produces has the frequency of 600MHZ.
13, according to the record and the reproducing device of claim 9, wherein, for making the laser output of the laser output of described semiconductor laser during writing down greater than playback duration, described driving circuit drives and controls described semiconductor laser.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 96119231 CN1153971A (en) | 1995-10-16 | 1996-10-16 | Output control apparatus of semiconductor laser device |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP293724/95 | 1995-10-16 | ||
| CN 96119231 CN1153971A (en) | 1995-10-16 | 1996-10-16 | Output control apparatus of semiconductor laser device |
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| Publication Number | Publication Date |
|---|---|
| CN1153971A true CN1153971A (en) | 1997-07-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 96119231 Pending CN1153971A (en) | 1995-10-16 | 1996-10-16 | Output control apparatus of semiconductor laser device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100440652C (en) * | 1997-08-05 | 2008-12-03 | 索尼株式会社 | Semiconductor laser driving method and optical disc apparatus |
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1996
- 1996-10-16 CN CN 96119231 patent/CN1153971A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100440652C (en) * | 1997-08-05 | 2008-12-03 | 索尼株式会社 | Semiconductor laser driving method and optical disc apparatus |
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