CN100535999C

CN100535999C - Apparatus and method for controlling gain of servo signal of optical disc drive

Info

Publication number: CN100535999C
Application number: CNB2007101096618A
Authority: CN
Inventors: 廖嘉伟; 陈志清; 郑裕; 俞铭九; 蓝国荣; 林俊佑; 周书弘
Original assignee: MediaTek Inc
Current assignee: MediaTek Inc
Priority date: 2006-06-05
Filing date: 2007-06-05
Publication date: 2009-09-02
Anticipated expiration: 2027-06-05
Also published as: TW200805321A; CN101086852A; TWI346947B

Abstract

The invention provides a device for controlling the gain of a servo signal of an optical drive. When the CD-ROM drive meets the change of the operation state, the device adjusts and controls the gain values of a plurality of servo signals of the servo system of the CD-ROM drive according to a closed loop mode or a state reset mode. The apparatus includes at least one automatic gain control loop for compensating a gain value of the servo signal with a selectable bandwidth for a specific period of time after the change of the operation state in the closed loop mode to accelerate convergence of the servo signal. The apparatus further includes at least one automatic gain control loop for resetting an initial value of a gain value of the servo signal with a pre-stored convergence value of a loop ratio of an automatic gain control loop corresponding to a current operation state or a default value immediately after the operation state is changed in the state resetting mode to accelerate convergence of the servo signal.

Description

The device and method of the servo signal gains of control CD-ROM drive

Technical field

The invention relates to CD-ROM drive, particularly relevant for the servo-drive system (servo system) of CD-ROM drive.

Background technology

The servo-drive system control CD reading head of CD-ROM drive and the action of CD motor are to read the CD of different-format under different situations.Servo-drive system is some particular aspects by the indivedual Control Servo System of a plurality of servosignals.For instance, the rail of seeking of tracking error (tracking error) signal controlling servo-drive system moves (seeking), and the focusing of focusing error (focusing error) signal controlling servo-drive system action.Servosignal is according to the reflected signal strength of main beam (main beam) and auxilliary light beam (sub beam) and synthesize, main beam and assist light beam and be all CD reading head and be projected to laser on the discs.In order under the different operating situation, all to obtain suitable servosignal, need be when synthesizing servosignal with suitable yield value to amplify servosignal to the strength grade that is suitable for handling.

Figure 10 is the synoptic diagram that is projeced into the focus of main beam of optical disc surface and two auxilliary light beams.Data of optical disk is with the track of the pattern of pit (pits) or non-pit record at optical disc surface.When the focus of laser beam was projected on the track, the reflectivity of laser can have or not pit to change according to place, focus place, thereby data is reflected on the intensity of reflected signal.The focus 7102 of main beam is projeced into track N and moves reading the data on it along track N, and the

focus

7104 and 7106 of auxilliary light beam is projeced into track N other base station (land) N and N-1 respectively.Then the reflected signal strength of main beam and auxilliary light beam is detected by the optical sensor of CD reading head.Then, synthetic a plurality of servosignals according to reflected signal, and just can read to carry out optical disc data according to the servosignal Control Servo System.

Yet when the reflected signal strength that reads the position of optical disc surface changed, the signal intensity of light sensors also changed thereupon, thereby influenced the degree of stability of servosignal.For instance, the reflected signal strength of the white space of no datat record is just inequality with the reflected signal strength of the data area that the data record is arranged.When optical disc surface read the position when white space switches to the data area, the intensity of servosignal will change because of the variation of reflected signal strength.Therefore, need to adjust the gain amplifier value of servosignal,, and make the intensity of servosignal when different reflection condition, all remain on same level with the difference of automatic compensatory reflex signal intensity.

In addition, change if be projected to the main beam intensity of CD, the gain amplifier value of servosignal also need be made corresponding modification.Figure 11 is the contrast synoptic diagram of the intensity and the main beam intensity of CD reflection signal.When main beam intensity increased, the reflected signal strength that optical sensor receives but weakened gradually, and this is to increase the relation that causes raceway surface to melt because of main beam intensity.When raceway surface melts, just form the lower pit of reflected signal strength (pit), and record is formed on the CD.Yet the reflected signal strength of auxilliary light beam still remains on same level.This moment is owing to the part servosignal is to reach the reflected signal strength of assisting light beam according to main beam simultaneously to synthesize, therefore need balance variation difference between the two, so that the reflected signal strength of main beam and auxilliary light beam reaches the level of balance after amplifying, and keep the stable of servosignal.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of device of gain of the servosignal of controlling CD-ROM drive, to solve the problem that prior art exists.When this CD-ROM drive ran into operational state change, this device was reseted the yield value of a plurality of servosignals that mode adjustment is controlled the servo-drive system of this CD-ROM drive according to a closed loop pattern or a state.This device comprises at least one automative interest increasing controlling circuit, be used under this closed loop pattern, in the specific period after this operational state change with the yield value of the described servosignal of a selectable bandwidth compensation, to quicken the convergence of described servosignal.This device also comprises at least one automative interest increasing controlling circuit, being used to this state resets under the pattern, after this operational state change immediately with corresponding to the convergency value of the loop ratio of the automative interest increasing controlling circuit that stores in advance of present mode of operation or the initial value that a default value is reseted the yield value of described servosignal, to quicken the convergence of described servosignal.

The present invention also provides a kind of device of gain of the servosignal of controlling CD-ROM drive.This device comprises one first automatic gain controller and one second automatic gain controller.When this CD-ROM drive runs into operational state change, this first automatic gain controller is adjusted a loop ratio value of a main beam (main-beam) to control the yield value of a plurality of servosignals, the reflected signal strength of this main beam of the CD that CD-ROM drive is projected to when this operational state change changes, and described servosignal is controlled a servo-drive system of this CD-ROM drive.When this CD-ROM drive runs into operational state change, this second automatic gain controller is adjusted the yield value of an auxilliary light beam (sub-beam) with this main beam of balance and the reflected signal strength that is somebody's turn to do auxilliary light beam according to a major-minor light beam ratio value, wherein this major-minor light beam ratio value is this major-minor light beam of reflection and the ratio that should assist the reflected signal strength of light beam.

The present invention also provides a kind of method of gain of the servosignal of controlling CD-ROM drive.Wherein the servo-drive system of this CD-ROM drive is controlled by a plurality of servosignal.At first, when this CD-ROM drive runs into operational state change, reset the yield value that mode adjustment is controlled described servosignal according to a closed loop pattern or a state.Then, under this closed loop pattern, in the specific period after this operational state change with the yield value of the described servosignal of a selectable bandwidth compensation of at least one automative interest increasing controlling circuit, to quicken the convergence of described servosignal.Then, reset under the pattern in this state, after this operational state change immediately with corresponding to the convergency value of the loop ratio of the automative interest increasing controlling circuit that stores in advance of present mode of operation or the initial value that a default value is reseted the yield value of the servosignal described in this at least one automative interest increasing controlling circuit, to quicken the convergence of described servosignal.

Description of drawings

Fig. 1 is the block diagram according to digital servo signal generator of the present invention;

Fig. 2 A is the block diagram according to first automatic gain controller of the present invention;

Fig. 2 B is the block diagram according to second automatic gain controller of the present invention;

The synoptic diagram of convergence process during the rate variable of Fig. 3 show circuit;

Fig. 4 is the block diagram of gain control circuit of first automatic gain controller of Fig. 2 A;

Fig. 5 is the block diagram of gain control circuit of second automatic gain controller of Fig. 2 B;

Fig. 6 shows the generation and the amplification process of tracking error signal;

The generation of Fig. 7 display beams and signal and amplification process;

Fig. 8 state of being shown in reset first and second automatic gain controller under the pattern to the storage of loop ratio value and major-minor light beam ratio value with reset action;

Fig. 9 is shown in the closed loop pattern and state is reseted the convergence process in the automatic gain controller loop under the pattern;

Figure 10 is the synoptic diagram that is projeced into the focus of main beam of optical disc surface and two auxilliary light beams; And

Figure 11 is the contrast synoptic diagram of the intensity and the main beam intensity of CD reflection signal.

Drawing reference numeral:

(Fig. 1)

402～main beam summation module

404～main beam is recommended module

406～main beam focusing error module

412～auxilliary light beam summation module

414～auxilliary light beam is recommended module

416～auxilliary light beam focusing error module

422～light beam and signal generator module

424～tracking error signal generation module

426～focus error signal generation module

432～the first automatic gain controllers

434～the second automatic gain controllers

(Fig. 2 A/2B)

510～loop proportional control module

520,570～data storage module

530,580～gain control circuit

560～major-minor light beam ratio control module

(Fig. 3)

702～tracking error signal gain buffer

704～focus error signal gain buffer

706～light beam and signal gain buffer

710～control module

(Fig. 4)

802～auxilliary light beam sum signal gain buffer

804～auxilliary light beam push-pull signal gain buffer

806～auxilliary light beam focus error signal gain buffer

810～control module

(Fig. 5)

404～main beam is recommended module

414～auxilliary light beam is recommended module

434～the second automatic gain controllers

424～tracking error signal generation module

432～the first automatic gain controllers

904～amplification module

906～filtering module

(Fig. 6)

402～main beam summation module

412～auxilliary light beam summation module

434～the second automatic gain controllers

422～light beam and signal generator module

432～the first automatic gain controllers

1004～amplification module

1006～filtering module

Embodiment

For above-mentioned and other purposes of the present invention, feature and advantage can be become apparent, several preferred embodiments cited below particularly, and cooperate Figure of description, be described in detail below:

Fig. 1 is the block diagram of digital servo signal generator 400.Digital servo signal generator 400 is an embodiment of the digital servo signal generator 280 of Fig. 1.The digital light sensor signal A of main beam ", B ", C ", D " at first be sent to main beam summation module 402, main beam is recommended (push-pull) module 404, main beam focusing error module 406.Main beam summation module 402 is with signal A ", B ", C ", D " obtained mutually a main beam sum signal MS.Main beam is recommended the main beam push-pull signal MP that 404 of modules produce expression [(A "+D ")-(B "+C ")].406 basis signal A of main beam focusing error module ", B ", C ", D " derive a main beam focus error signal MF.

Similarly, the digital light sensor signal E of auxilliary light beam ", F ", G ", H " at first be sent to auxilliary light beam summation module 412, auxilliary light beam is recommended module 414, auxilliary light beam focusing error module 416.Auxilliary light beam summation module 412 is with signal E ", F ", G ", H " obtained an auxilliary light beam sum signal SS mutually.Auxilliary light beam is recommended the auxilliary light beam push-pull signal SP that 414 of modules produce expression [(E "+H ")-(F "+G ")].Auxilliary 416 basis signal E of light beam focusing error module ", F ", G ", H " derive an auxilliary light beam focus error signal SF.

Tracking error (tracking error) signal generator module 424 is then derived tracking error signal TE according to main beam push-pull signal MP and auxilliary light beam push-pull signal SP.Focusing error (focusing error) signal generator module 426 is then derived focus error signal FE according to main beam focus error signal MF and auxilliary light beam focus error signal SF.Light beam and signal generator module 422 then produces expression signal A according to main beam sum signal MS and auxilliary light beam sum signal SS ", B ", C ", D " the present main beam and the signal C_MS of sum, and expression signal E ", F ", G ", H " the at present auxilliary light beam and the signal C_SS of sum.Auxilliary light beam sum signal ABAD may be present main beam and signal C_MS or auxilliary at present light beam and signal C_SS.Though only occur three servosignal TE, FE and SBAD among Fig. 1, digital servo signal generator 400 can comprise the module that produces other servosignals such as CE or RFRP signal.

Though produced servosignal TE, FE, and SBAD, must suitably amplify servosignal, with the intensity of under different operating conditions, keeping servosignal to identical level.As previously mentioned, run into operational state change and when the reflected radio signal intensity was changed, the voltage of servosignal need be through adjusting to keep its stability when CD-ROM drive.For instance, the zone of reading that operational state change may betide CD changes to the clear area from the data field, or CD-ROM drive changes to write activity by reading action.

Therefore, when operational state change took place, device 430 must be adjusted the gain of servosignal automatically.Device 430 comprises first gain controller 432, and it produces gain signal G according to target voltage T_MS and present main beam and signal C_MS ₁₁, G ₁₂, G ₁₃Light beam and signal generator module 422, tracking error signal generation module 424, focus error signal generation module 426 are then according to gain signal G ₁₁, G ₁₂, G ₁₃Amplify light beam and signal (main/sub-beam addition, SBAD), tracking error signal TE, focus error signal FE, under the different operating situation, to keep described servosignal in the same electrical voltage levels.

Device 430 also comprises second gain controller 434, and it produces gain signal G according to main beam and signal C_SS and at present auxilliary light beam and signal C_SS at present ₂₁, G ₂₂, G ₂₃Auxilliary light beam summation module 412, auxilliary light beam are recommended module 414, auxilliary light beam focusing error module 416 then according to gain signal G ₂₁, G ₂₂, G ₂₃Amplify auxilliary light beam sum signal SS, auxilliary light beam push-pull signal SP, auxilliary light beam focus error signal SF, reach the reflected signal strength of auxilliary light beam in the same electrical voltage levels with balance main beam under the different operating situation.

Fig. 2 A is the block diagram according to first automatic gain controller 500 of the present invention.First automatic gain controller 500 comprises loop proportional control module 510, gain control circuit 530, reaches data storage module 520.First automatic gain controller 500 is adjusted the yield value G of the loop ratio value (loop ratio) of main beam with control servosignal SBAD, TE, FE when mode of operation changes ₁₁, G ₁₂, G ₁₃Loop proportional control module 510 is according to main beam and signal C_MS and target voltage T_MS determine this loop ratio value at present.Because the loop ratio value is represented present voltage and the ratio of target voltage of the reflected signal strength of main beam, thereby can be according to the yield value of loop ratio value decision servosignal TE, FE, SBAD, and compensate servosignal to the target voltage level.Gain control circuit 530 is then according to loop ratio value signal deciding gain signal G ₁₁, G ₁₂, G ₁₃

Gain G when servosignal ₁₁, G ₁₂, G ₁₃After determining, servosignal FE, TE, SBAD just can amplify accordingly according to gain.Yet, gain signal G ₁₁, G ₁₂, G ₁₃Speed of convergence very slow, need very long a period of time just can make servosignal reach suitable target voltage level.The synoptic diagram of convergence process during the rate variable of Fig. 3 show circuit.Curve 610 is shown in the normal convergence process of loop ratio.In time t ₁The time, mode of operation is sent out and is received change, and the loop ratio value is slowly in time point t ₅Just reach desired value V ₁, thereby postponed the amplification process of servosignal.

In order to quicken the convergence of servosignal, when CD-ROM drive is found the mode of operation change, just make two automatic gain controllers enter closed loop pattern or state reset two kinds of patterns of pattern one of them.If first automatic gain controller 500 adopts the closed loop pattern, be convenient to compensate with high bandwidth between one section given period after mode of operation changes the gain of servosignal.Shown in the curve 606 of Fig. 3, under the pattern of closed loop, because be with high bandwidth compensating gain value, the loop ratio value is ahead of time in time point t ₃Reach desired value V ₁, thereby quickened the amplification process of servosignal.After the special time warp, automatic gain controller returns back to lower bandwidth.

Automatic gain controller still has another state to reset pattern.When servosignal was restrained, the data storage module 520 of first automatic gain controller 500 stored the convergency value of the loop ratio under the different conditions in advance.When first automatic gain controller 500 taked state to reset pattern with the amplification servosignal, whenever running into operational state change, the initial value that loop proportional control module 510 is reseted the loop ratio immediately was the convergency value that last time stored under the corresponding state.Curve 602 is under state is reseted pattern, and first automatic gain controller 500 is reset to the convergency value V that last time stored with the initial value of loop ratio ₃The time convergence process.Owing to the convergency value V that last time stored ₃Near desired value V ₁, thereby the loop ratio value is ahead of time in time point t ₂Convergence, and quickened convergence process.Curve 604 is under state is reseted pattern, and first automatic gain controller 500 is reset to the convergency value V that last time stored with the initial value of loop ratio ₂The time convergence process.Owing to the convergency value V that last time stored ₂From desired value V ₁One segment distance is arranged, thereby the loop ratio value is in time point t ₄Just convergence.Reset under the pattern in state, after the initial value of loop ratio was reset to the convergency value or default value that last time stores, automatic gain controller was set as the closed loop dynamically to adjust the loop ratio value.

Fig. 2 B is the block diagram according to second automatic gain controller 550 of the present invention.Second automatic gain controller 550 comprises major-minor light beam ratio control module 560, gain control circuit 580, reaches data storage module 570.Second automatic gain controller 550 is adjusted the yield value G of the relevant auxilliary light beam sum signal SS of auxilliary light beam, auxilliary light beam push-pull signal SP, auxilliary light beam focus error signal SF when mode of operation changes ₂₁, G ₂₂, G ₂₃Major-minor light beam ratio control module 560 is according to main beam and signal C_MS and at present auxilliary light beam and signal C_SS determine major-minor light beam ratio value MS_ratio at present.Because the ratio of the reflected signal strength of major-minor light beam ratio value representation main beam and the reflected signal strength of auxilliary light beam, thereby can be according to the reflected signal strength of major-minor light beam ratio value balance main beam and the reflected signal strength of auxilliary light beam, and guarantee that servosignal TE, FE, SBAD's is stable.Gain control circuit 580 is then according to major-minor light beam ratio value decision gain signal G ₂₁, G ₂₂, G ₂₃The thin portion structure of gain control circuit 580 illustrates with Fig. 5.Same, second automatic gain controller 550 also can adopt closed loop pattern or state to reset one of them amplification process to control auxilliary light beam sum signal SS, auxilliary light beam push-pull signal SP, to assist light beam focus error signal SF of two kinds of patterns of pattern, so that the convergence of signal for faster.

Fig. 4 is the block diagram of gain control circuit 700 of first automatic gain controller of Fig. 2 A.The yield value of tracking error signal gain buffer 702, focus error signal gain buffer 704, light beam and signal gain buffer 706 temporary respectively servosignal TE, FE, SBAD.Three multipliers 712,714,716 multiply each other yield value and the loop ratio value of servosignal TE, FE, SBAD respectively.Control module 710 produces switching signal SW_TE, SW_FE, SW_SBAD according to a write signal and a blank signal.Write signal represents that CD-ROM drive is in write state or reading state, and blank signal represents that whether just reading CD puts blank section or data segments.Therefore, whether control module 710 can have the variation of mode of operation and switch the yield value of servosignal according to the decision of write signal and blank signal.Switching signal SW_TE, SW_FE, SW_SBAD switch the yield value G of servosignal TE, FE, SBAD ₁₁, G ₁₂, G ₁₃Value after multiplying each other for the script yield value or with the loop ratio value.

Fig. 5 is the block diagram of gain control circuit 800 of second automatic gain controller of Fig. 2 B.Auxilliary light beam sum signal gain buffer 802, auxilliary light beam push-pull signal gain buffer 804, the auxilliary light beam sum signal SS that the temporary respectively auxilliary light beam of auxilliary light beam focus error signal gain buffer 806 is relevant, the yield value of auxilliary light beam push-pull signal SP, auxilliary light beam focus error signal SF.Yield value and major-minor light beam ratio value MS_ratio that three multipliers 812,814,816 will be assisted light beam coherent signal SS, SP, SF respectively multiply each other.Control module 810 produces switching signal SW_SS, SW_SP, SW_SF according to a write signal and a blank signal.Same, write signal represents that CD-ROM drive is in write state or reading state, and blank signal represents that whether just reading CD puts blank section or data segments.Therefore, whether control module 810 can have the variation of mode of operation and switch the yield value of assisting the light beam coherent signal according to write signal and blank signal decision.Switching signal SW_TE, SW_FE, SW_SBAD switch the yield value G of auxilliary light beam coherent signal SS, SP, SF ₂₁, G ₂₂, G ₂₃Value after multiplying each other for the script yield value or with major-minor light beam ratio value.

Fig. 6 shows generation and the amplification process of tracking error signal TE.Main beam is recommended module 404 according to main beam signal A ", B ", C ", D " produce main beam push-pull signal MP.Auxilliary light beam is recommended module 414 according to auxilliary beam signal E ", F ", G ", H " produce auxilliary light beam push-pull signal SP.Second automatic gain controller 434 produces the gain G of auxilliary light beam push-pull signal SP ₂₂With the intensity of balance main beam push-pull signal MP and auxilliary light beam push-pull signal SP, and auxilliary light beam is recommended module 414 according to gain G ₂₂Amplify auxilliary light beam push-pull signal SP.Subtraction device 902 subtracts each other main beam push-pull signal MP and auxilliary light beam push-pull signal SP to produce tracking error signal.First automatic gain controller 432 produces the gain G of tracking error signal ₁₂So that the intensity of tracking error signal is kept unanimity under the different operating situation, and amplification module 904 is according to gain G ₁₂Amplify tracking error signal.At last, filtering module 906 filters tracking error signal and produces the tracking error signal TE of output, seeks the rail action for CD-ROM drive control.

The generation of Fig. 7 display beams and signal SBAD and amplification process.Main beam summation module 402 is according to main beam signal A ", B ", C ", D " produce main beam sum signal MS.Auxilliary light beam summation module 412 is according to auxilliary beam signal E ", F ", G ", H " produce auxilliary light beam sum signal SS.Second automatic gain controller 434 produces the gain G of auxilliary light beam sum signal SS ₂₁With the intensity of balance main beam sum signal MS and auxilliary light beam sum signal SS, and auxilliary light beam summation module 412 is according to gain G ₂₁Amplify auxilliary light beam sum signal SS.Multiplexer 1002 is depending on the circumstances or the needs of the situation selected one of them from main beam sum signal MS and auxilliary light beam sum signal SS.First automatic gain controller 432 produces the gain G of selecteed main beam sum signal MS or auxilliary light beam sum signal SS ₁₁So that its intensity is kept unanimity under the different operating situation, and amplification module 904 is according to gain G ₁₁Amplify selecteed main beam sum signal MS or auxilliary light beam sum signal SS.At last, filter through filtering module 906, and produce the light beam and the signal SBAD of output, use for CD player.

Fig. 8 state of being shown in reset first and second automatic gain controller under the pattern to the storage of loop ratio value and major-minor light beam ratio value with reset action.As described before, write signal and blank signal can be in order to the opportunitys of decision operational state change generation.For instance, the zone of reading of CD becomes blank section in time T 1 from data segments, and becomes data segments in time T 2 from blank section.CD-ROM drive becomes write activity in time T 3 from reading action again, and becomes from write activity in time T 4 and to read action.The all corresponding operational state change of each time T 1～T5, and all carry out the storage of loop ratio value and reset action in described operational state change.

For instance, because the zone of reading of CD becomes blank section in time T 1 from data segments, the loop proportional control module 510 of reseting first automatic gain controller 500 under the pattern in state stores the convergency value of the loop ratio under the present data mode immediately to data storage module 520.Meanwhile, loop proportional control module 510 also is reset to the initial value of loop ratio the convergency value of the loop ratio under the corresponding space state that is stored in advance before in the data storage module 520.In addition, because CD-ROM drive becomes write activity in time T 3 from reading action again, reset in state that the major-minor light beam ratio control module 550 of second automatic gain controller 560 stores the convergency value of the major-minor light beam ratio under the present data mode immediately to data storage module 570 under the pattern.Meanwhile, major-minor light beam ratio control module 560 also is reset to the initial value of major-minor light beam ratio the convergency value of the major-minor light beam ratio under the corresponding write activity that is stored in advance before in the data storage module 570.

Fig. 9 is shown in the closed loop pattern and state is reseted the convergence process in the automatic gain controller loop under the pattern.Identical operations state variation among time point T1～T5 correspondence and Fig. 8.Loop ratio value 1 is shown in the convergence process of the loop ratio value under the pattern of closed loop, and loop ratio value 2 is shown in the convergence process that bonding state is reseted the loop ratio value under pattern and the closed loop pattern.The loop bandwidth of automatic gain controller is variable.Because loop ratio value 1 can improve loop bandwidth when operational state change, so the convergence process of loop ratio value 1 is quickened many.In addition, because the initial value of loop ratio 2 is set as default value or storage values in advance immediately when operational state change, loop ratio value 2 can be restrained rapidly, to quicken the convergence process of servosignal.

The invention provides the device of the gain of the servosignal of controlling CD-ROM drive.The generation of servosignal and its gain adjustment are to implement in digital field, thereby can quicken the adjustment of the gain of servosignal.This device comprises first automatic gain controller, in order to adjust the loop ratio value that can determine signal gain, so that servosignal is kept identical electric pressure under the different operating state.This device comprises second automatic gain controller, in order to adjust the major-minor light beam ratio value that can determine signal gain, with compensation main beam reflected signal strength and the auxilliary difference of beam reflection signal intensity under the different operating state.In addition, this device is reseted pattern to quicken the convergence of servosignal when gain is adjusted in conjunction with the closed loop pattern of employing and a state.

Though the present invention discloses as above with preferred embodiment; right its is not in order to limiting the present invention, any those who familiarize themselves with the technology, without departing from the spirit and scope of the present invention; when can doing a little change and retouching, so protection scope of the present invention is as the criterion when looking the claim person of defining.

Claims

1. A device for controlling the gain of a servo signal of an optical drive, whenever the optical drive encounters a change in operating state, the device adjusts a plurality of servo signals controlling the servo system of the optical drive according to a closed loop mode or a state reset mode The gain value is characterized in that the device comprises:

At least one automatic gain control loop is used to compensate the gain value of the servo signal with a selectable bandwidth within a certain period of time after the change of the operating state in the closed loop mode, so as to accelerate the Convergence of the servo signal described above; and

At least one automatic gain control loop, used to use a pre-stored convergence value of the loop ratio of an automatic gain control loop corresponding to the current operating state immediately after the change of the operating state in the state reset mode Or reset the initial value of the gain value of the servo signal to a default value, so as to speed up the convergence of the servo signal.

2. The device for controlling the gain of a servo signal of an optical drive according to claim 1, wherein the change in the operating state refers to the transition of the optical drive between one of a plurality of operating states, The operating state includes a writing state, a blank state, and a data state, and in the writing state, the optical drive writes data into an optical disc, and in the data state, the optical drive A data section of the optical disc is read, and in the blank state, the optical drive reads a blank section of the optical disc.

3. The device for controlling the gain of the servo signal of an optical drive as claimed in claim 2, wherein, in the state reset mode, the device stores the loop ratio of the at least one automatic gain control loop The convergence value, and then reset the initial value of the loop ratio of the at least one automatic gain control loop when the operating state changes to the convergence value of the previously stored loop ratio corresponding to the current operating state, so as to adjust the The gain value of the servo signal.

4. The device for controlling the gain of the servo signal of the optical drive as claimed in claim 1, wherein the servo signal includes a tracking error signal for controlling the tracking operation of the optical drive, and a tracking error signal for controlling the tracking operation of the optical drive. A focus error signal for the focusing action of the sensor, and a beam sum signal representing the reflected signal strength of a main beam or a secondary beam.

5. The device for controlling the gain of the servo signal of an optical drive as claimed in claim 2, wherein said device determines whether an operation state change occurs according to a write signal and a blank signal, and said write signal indicates Whether the optical drive is switching between a writing action and a reading action, and the blank signal indicates whether the position where the optical drive reads the optical disc is switching between a data segment and a blank segment.

6. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 1, wherein said servo signal is a digital signal, and said device is to digitally adjust the gain value of said servo signal .

7. A device for controlling the gain of a servo signal of an optical drive, characterized in that the device comprises:

A first automatic gain controller, whenever the optical drive encounters a change in operating state, adjusts a loop ratio value of a main beam to control the gain values of a plurality of servo signals, and the optical drive projects when the operating state changes the intensity of the reflected signal of the main beam to an optical disc varies, and the servo signal controls a servo system of the optical drive; and

a second automatic gain controller for adjusting the gain value of an auxiliary beam according to a ratio of main and auxiliary beams to balance reflections of the main beam and the auxiliary beam whenever the optical drive encounters a change in operating state Signal strength, wherein the ratio of main and auxiliary beams reflects the ratio of reflected signal intensities between the main beam and the auxiliary beam.

8. The device for controlling the gain of the servo signal of the optical drive as claimed in claim 7, wherein the servo signal includes a tracking error signal for controlling the tracking operation of the optical drive, and a tracking error signal for controlling the tracking operation of the optical drive. A focus error signal for the focusing action of the sensor, and a beam sum signal representing the reflected signal strength of a main beam or a secondary beam.

9. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 8, wherein said first automatic gain controller comprises:

A loop proportional control module, which calculates the loop proportional value according to the reflected signal intensity of the main beam and a target voltage; and

A first gain control circuit, coupled to the loop proportional control module, determines the gain value of the servo signal according to the loop proportional value.

10. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 8, wherein said second automatic gain controller comprises:

A main and auxiliary beam ratio control module, which calculates the main and auxiliary beam ratio value according to the reflected signal intensity of the main beam and the reflected signal intensity of the auxiliary beam; and

A second gain control circuit, coupled to the main and auxiliary beam ratio control module, determines the gain value of a plurality of auxiliary beam related signals used to synthesize the servo signal according to the main and auxiliary beam ratio value.

11. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 9, wherein said first gain control circuit comprises:

a first multiplier, which multiplies the loop proportional value by a first tracking error signal gain value to obtain a second tracking error signal gain value;

a second multiplier, which multiplies the loop ratio value by a first focus error signal gain value to obtain a second focus error signal gain value;

a third multiplier for multiplying said loop ratio value by a first beam and signal gain value to obtain a second beam and signal gain value; and

A first control module, select one of the gain value of the tracking error signal from the gain value of the first tracking error signal and the gain value of the second tracking error signal as the gain value of the tracking error signal, and the gain value of the tracking error signal is determined by the One of the first focus error signal gain value and the second focus error signal gain value is selected as the gain value of the focus error signal, and the first beam and signal gain value and the second focus error signal gain value One of the two beam and signal gain values is selected as the gain value of the beam and signal.

12. The device for controlling the gain of a servo signal of an optical drive according to claim 10, wherein said second gain control circuit comprises:

A fourth multiplier, which multiplies the main and auxiliary beam ratio value by a first auxiliary beam addition signal gain value to obtain a second auxiliary beam addition signal gain value;

A fifth multiplier, which multiplies the main and auxiliary beam ratio value by a first auxiliary beam push-pull signal gain value to obtain a second auxiliary beam push-pull signal gain value;

A sixth multiplier, which multiplies the main and auxiliary beam ratio value by a first auxiliary beam focus error signal gain value to obtain a second auxiliary beam focus error signal gain value; and

A second control module, selecting one of the gain values of the first auxiliary beam addition signal and the second auxiliary beam addition signal gain value as the gain value of the auxiliary beam addition signal, by One of the gain value of the push-pull signal of the first auxiliary beam and the gain value of the push-pull signal of the second auxiliary beam is selected as the gain value of a push-pull signal of the auxiliary beam, and is focused by the first auxiliary beam One of the gain value of the error signal and the gain value of the focus error signal of the second auxiliary beam is selected as a gain value of the focus error signal of the auxiliary beam;

The auxiliary beam addition signal, auxiliary beam push-pull signal, and auxiliary beam focus error signal are generated by the reflection signal of the auxiliary beam and are used to synthesize the light beam and signal, and the tracking error signal, and the focus error signal.

13. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 7, wherein said change in operating state refers to a transition of said optical drive between one of a plurality of operating states, The operating state includes a writing state, a blank state, and a data state, and in the writing state, the optical drive writes data into an optical disc, and in the data state, the optical drive A data section of the optical disc is read, and in the blank state, the optical drive reads a blank section of the optical disc.

14. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 7, wherein said servo signal is a digital signal, and said device is to digitally adjust the gain value of said servo signal .

15. The device for controlling the gain of a servo signal of an optical drive as claimed in claim 8, wherein said first gain controller controls a tracking error signal generation module, a focus error signal generation module, and a light beam The sum signal generation module is used to amplify the gain of the signal, the tracking error signal generation module generates the tracking error signal according to a main beam push-pull signal and an auxiliary beam push-pull signal, and the focus error signal generates The module generates the focus error signal according to a main beam focus error signal and an auxiliary beam focus error signal, and the beam and signal generation module generates the said beam and signal according to a main beam addition signal and an auxiliary beam addition signal Beams and signals, wherein the main beam push-pull signal, the main beam focus error signal, and the main beam sum signal are derived from the reflected signal intensity of the main beam, and the auxiliary beam The push-pull signal, the focus error signal of the auxiliary beam, and the addition signal of the auxiliary beam are derived from the reflected signal intensity of the auxiliary beam.

16. The device for controlling the gain of the servo signal of an optical drive as claimed in claim 15, wherein said second gain controller controls an auxiliary beam addition module, an auxiliary beam focus error module, and an auxiliary beam The push-pull module is used to amplify the gain of the signal, wherein the auxiliary beam addition module generates the auxiliary beam addition signal, the auxiliary beam focus error module generates the auxiliary beam focus error signal, and the The auxiliary beam push-pull module generates the auxiliary beam push-pull signal.

17. A method for controlling the gain of a servo signal of an optical drive, characterized in that the servo system of the optical drive is controlled by a plurality of servo signals, the method comprising the following steps:

Adjusting and controlling the gain value of the servo signal according to a closed-loop mode or a state reset mode whenever the optical drive encounters an operation state change;

In said closed-loop mode, the gain value of said servo signal is compensated with a selectable bandwidth of at least one automatic gain control loop within a certain period of time after said operating state changes, so as to accelerate said convergence of servo signals; and

In the state reset mode, after the change of the operating state, the automatic gain control loop is reset with a pre-stored convergence value or a default value of the loop ratio of the automatic gain control loop corresponding to the current operating state. An initial value of the gain value of the servo signal in at least one automatic gain control loop to accelerate the convergence of the servo signal.

18. The method for controlling the gain of a servo signal of an optical drive according to claim 17, wherein the change in the operating state refers to a transition of the optical drive between one of a plurality of operating states, The operating state includes a writing state, a blank state, and a data state, and in the writing state, the optical drive writes data into an optical disc, and in the data state, the optical drive A data section of the optical disc is read, and in the blank state, the optical drive reads a blank section of the optical disc.

19. The method for controlling the gain of the servo signal of an optical drive as claimed in claim 18, wherein the reset of the initial value of the gain value of the servo signal in the state reset mode further comprises the following steps :

pre-stored convergence values corresponding to loop ratios of the at least one automatic gain control loop under different operating states; and

When the operating state changes, resetting the initial value of the loop ratio of the at least one automatic gain control loop corresponds to the convergence value of the previously stored loop ratio corresponding to the current operating state, so as to adjust the servo signal gain value.

20. The method for controlling the gain of a servo signal of an optical drive as claimed in claim 18, wherein said method further comprises determining whether an operation state change occurs according to a write signal and a blank signal, wherein said write The input signal indicates whether the optical drive is switching between the writing action and the reading action, and the blank signal indicates whether the optical drive reads the part of the optical disc between the data segment and the blank segment transform.

21. The method for controlling the gain of a servo signal of an optical drive as claimed in claim 17, wherein said servo signal comprises a tracking error signal for controlling a tracking action of said optical drive, a tracking error signal for controlling said optical drive A focus error signal for the focusing action of the sensor, and a beam sum signal representing the reflected signal strength of a main beam or a secondary beam.

22. The method for controlling the gain of a servo signal of an optical disc drive as claimed in claim 17, wherein the servo signal is a digital signal, and the gain value of the servo signal is adjusted digitally.