US20070280067A1 - Apparatus having switchable servo gains and offsets for optical disk drive and method thereof - Google Patents

Apparatus having switchable servo gains and offsets for optical disk drive and method thereof Download PDF

Info

Publication number
US20070280067A1
US20070280067A1 US11/837,898 US83789807A US2007280067A1 US 20070280067 A1 US20070280067 A1 US 20070280067A1 US 83789807 A US83789807 A US 83789807A US 2007280067 A1 US2007280067 A1 US 2007280067A1
Authority
US
United States
Prior art keywords
gain
pick
head
servo
optical disk
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/837,898
Inventor
Hsu-Feng Ho
Shun-Yung Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MediaTek Inc
Original Assignee
MediaTek Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MediaTek Inc filed Critical MediaTek Inc
Priority to US11/837,898 priority Critical patent/US20070280067A1/en
Publication of US20070280067A1 publication Critical patent/US20070280067A1/en
Priority to US12/468,565 priority patent/US8027230B2/en
Priority to US13/214,309 priority patent/US20110299373A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/094—Methods and circuits for servo offset compensation
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0941—Methods and circuits for servo gain or phase compensation during operation

Definitions

  • the present invention relates to an apparatus having switchable servo gains and offsets for an optical disk device and the method thereof, and more particularly, to a servo control system of an optical disk device that makes adjustments in the gains and offsets according to the working status of the pick-up head.
  • an electromechanical actuator drives a pick-up head so as to focus laser beams to be points on an optical disk. Then, any stored binary data is read and judged by the magnitude of the light rays received by a photo-detector; meanwhile, the received rays function as servo control signals for driving the pick-up head. In other words, the laser points are accurately focused on an adequate track, using such an optical signal to drive the pick-up head.
  • focus error (FE) signals is interfered with crosstalk that arises from the motion of the pick-up head along the radial direction of an optical disk.
  • a carrier wave is induced on the FE signal from the interference of a tracking error (TE) signal.
  • TE tracking error
  • the pick-up head moves from an inner portion to an outer portion along a spiral groove where data is recorded, thus the TE signal is almost inactive and the FE signal is free from the interference of the crosstalk effect on itself.
  • the reflectivity of a data area is different from that of a blank area.
  • the photodetector of the pick-up head detects various reflective signals while it is passing the aforesaid areas.
  • Data is saved in both the groove areas and the land areas of a DVD-RAM disk.
  • the reflective signals generated in the groove areas are different from those generated in the land areas where refractive indices are lower than the land areas′ in terms of their characteristics.
  • the servo control is unstable, as it hardly converges.
  • the objective of the present invention is to provide an apparatus having switchable servo gains and offsets for an optical disk drive and the method thereof, wherein the adjustments of the servo gains and offsets are depended on the working status of the pick-up head so as to stabilize the servo loop control system of the optical disk drive.
  • the present invention is to provide an apparatus having switchable servo gains and offsets for an optical disk drive and the method thereof, wherein adjustments in gains and offsets are achieved through the coupling of a servo signal and a switch with several changeable paths.
  • the servo signals are to be either designated to be deducted a first offset through the switch and then output a converted signal in proportion to a first gain unit, or designated to be deducted a second offset, and then output a converted signal in proportion to a second gain unit.
  • the switch is switched on/off in the light of the working status of the pick-up head, for example, seeking or tracking, at a data area or at a blank area, and at a groove area or at a land area, so as to choose different offsets and gains to have the conversion of the servo signals.
  • the input signal of the switch is a signal that results from the synthesis and amplification of a track error or a focusing error with a pre-amplifier.
  • the input signal is subjected to conversion conducted by the first gain unit or the second gain unit, and then it is coupled to a controller.
  • FIG. 1 is a schematic diagram of a servo control system for an optical disk drive in accordance with the present invention
  • FIG. 2 is a waveform diagram of a TE signal
  • FIG. 3 is a schematic diagram showing that a pick-up head writes or reads data on an optical disk
  • FIG. 4 is a waveform diagram of a TE signal in response to a DVD-RAM disk.
  • FIG. 1 is a schematic diagram of a servo control system of an optical disk drive in accordance with the present invention.
  • the seeking or tracking servo control system 10 of the optical disk device is equipped with a pick-up head 11 intended to read data recorded in an optical disk 40 .
  • the pick-up head 11 generates a TE signal or a FE signal that functions as an input signal to the servo control system 10 .
  • the input signal is sent to a pre-amplifier 12 to have signal synthesis and amplification.
  • the amplified control signal is allowed to couple to either a first gain circuit 17 or a second gain circuit 18 ; with the first gain circuit 17 , the amplified control signal has a slice level shift in response to a first offset 131 , and then it is converted at a constant proportion by a first gain unit 141 before it is output; similarly, with the second gain circuit 18 , the amplified control signal has a slice level shift in response to a second offset 132 , and then it is converted at another constant proportion by a second gain unit 142 before it is output.
  • the servo gain may be greater or less than one, or even a negative value.
  • the objective of the present invention is to normalize the input signals of a controller 15 by either the first gain unit 141 or the second gain unit 142 , so as to enhance the stability of the servo control system.
  • the control signal generated by the controller 15 makes a driver 16 output a driving signal, and the pick-up head 11 responds after it receives the driving signal.
  • the switch 19 is switched on/off in light of the working status of the pick-up head 11 . Its application to three statuses is as follows:
  • the seeking or focusing servo control system makes the switch 19 switch to the second gain circuit 18 so as to reduce the sensitivity of the servo loop to noise signals by diminishing its servo gain. Conversely, if the pick-up head 11 is changed to track tracks, the switch 19 is switched to the first gain circuit 17 , and the servo gain of the second gain circuit 18 is less than that of the first gain circuit 17 .
  • the first offset 131 of the first gain circuit 17 and the magnitude of the gain of the first gain unit 141 can be determined by a track error or a focusing error intended for actual off-line detection (the second offset 132 and the gain value of the second gain unit 142 are determined in the same way).
  • FIG. 2 it is a waveform diagram of a TE signal, wherein AP denotes the peak-to-peak (or crest-to-trough) interval of a TE signal, and M denotes a slice level, or a DC component.
  • servo control system designs always entail setting the peak-to-peak interval and the DC component.
  • the quotient is designated as the gain of the first gain unit 141 .
  • the difference between the DC component actually measured and a default DC component is designated as the magnitude of the first offset 131 .
  • the servo control system makes the switch 19 switch to the second gain circuit 18 so as to decrease its servo gain. Conversely, if the pick-up head 11 stays in a data area to read data from there, the switch 19 is switched to the first gain circuits 17 so as to increase its servo gain.
  • the corresponding magnitude of the gains and offsets can be obtained by the TE signal that is generated by the pick-up head staying either in the blank area or data area on-line.
  • the calculating method of the magnitude is the same as the aforesaid descriptions.
  • FIG. 3 is a schematic diagram showing how a pick-up head writes or reads data on an optical disk.
  • Optical disks with ordinary specifications, such as CD-R, DVD-R and DVD-RW always have data stored in their groove areas 41 .
  • DVD-RAM stores data in both the groove areas 41 and the land areas 42 ; for its corresponding TE signal, please refer to the trough 41 ′ and the peak 42 ′ in FIG. 4 .
  • the convergence direction A of the trough 41 ′ is opposite to the convergence direction B of the peak 42 ′.
  • the gain of the first gain circuit 17 and that of the second gain circuit 18 have opposite signs, where not only do their offsets have opposite signs, but also the magnitude of their offsets differ.
  • the switch 19 is switched to the first gain circuit 17 . If the pick-up head 11 is in a land area 42 , the switch 19 is switched to the second gain circuit 18 .
  • DSP Digital signal processing
  • the peak and the trough of the servo signals can be measured so as to figure out the corresponding offset and gain.
  • the peak-trough interval and the DC component determine the magnitude of the offset and the gain, as far as the real-time calculated TE signal (or FE signal) are concerned.

Landscapes

  • Optical Recording Or Reproduction (AREA)
  • Moving Of The Head For Recording And Reproducing By Optical Means (AREA)

Abstract

An apparatus having switchable servo gains and offsets for an optical disk drive adjusts its gains and offsets through the coupling of a servo signal and a switch with several changeable paths. The servo signals are either designated to undergo signal reduction with respect to a first offset through the switch and then be output after a first gain unit performed proportional conversion, or designated to undergo signal reduction with respect to a second offset and then be output after a second gain unit performed proportional conversion. The switch is switched on/off in the light of the working status of the pick-up head, for example, seeking or tracking, at a data area or at a blank area, and at a groove area or at a land area, so as to choose different offsets and gains to have the conversion of the servo signals.

Description

    CROSS REFERENCE TO RELATED APPLICATIONS
  • This application is a divisional application of U.S. application Ser. No. 10/710,416 field Jul. 8, 2004, and is based on and claims priority from Taiwanese Patent Application No. 092132463 filed Nov. 19, 2003.
    • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates to an apparatus having switchable servo gains and offsets for an optical disk device and the method thereof, and more particularly, to a servo control system of an optical disk device that makes adjustments in the gains and offsets according to the working status of the pick-up head.
  • 2. Description of the Related Art
  • The more progressive information technology is, the more versatile the kind of data storage is. In this regard, the optical disk drive has apparently become an important data storage tool available on the market. For an optical disk drive to operate, an electromechanical actuator drives a pick-up head so as to focus laser beams to be points on an optical disk. Then, any stored binary data is read and judged by the magnitude of the light rays received by a photo-detector; meanwhile, the received rays function as servo control signals for driving the pick-up head. In other words, the laser points are accurately focused on an adequate track, using such an optical signal to drive the pick-up head.
  • During the seeking process carried out by an optical disk drive, focus error (FE) signals is interfered with crosstalk that arises from the motion of the pick-up head along the radial direction of an optical disk. In other words, a carrier wave is induced on the FE signal from the interference of a tracking error (TE) signal. However, during the following or tracking process, the pick-up head moves from an inner portion to an outer portion along a spiral groove where data is recorded, thus the TE signal is almost inactive and the FE signal is free from the interference of the crosstalk effect on itself.
  • It is not feasible to adjust the gain of a conventional servo loop system for optical disk drives in the light of the working status of a pick-up head; thus, servo control is usually unstable, as it hardly converges. For instance, it is impossible to diminish the gain of the focusing loop system whenever seeking is underway; as a result, an inadequate response arises from that the interfering crosstalk signals are mistaken for normal FE signals. However, if the gain is set to a relatively small value, the response speed of the focusing loop control is compromised during the tracking process.
  • On the other hand, in regard to an ordinary optical disk, the reflectivity of a data area is different from that of a blank area. Hence, the photodetector of the pick-up head detects various reflective signals while it is passing the aforesaid areas. Data is saved in both the groove areas and the land areas of a DVD-RAM disk. Similarly, the reflective signals generated in the groove areas are different from those generated in the land areas where refractive indices are lower than the land areas′ in terms of their characteristics. However, it is not also feasible to adjust the gain and the offset of the conventional servo loop system according to the position of the pick-up head where a data area or a blank area exists or where a groove area or a land area exists. By the same token, the servo control is unstable, as it hardly converges.
    • SUMMARY OF THE INVENTION
  • The objective of the present invention is to provide an apparatus having switchable servo gains and offsets for an optical disk drive and the method thereof, wherein the adjustments of the servo gains and offsets are depended on the working status of the pick-up head so as to stabilize the servo loop control system of the optical disk drive.
  • In order to achieve the objective, the present invention is to provide an apparatus having switchable servo gains and offsets for an optical disk drive and the method thereof, wherein adjustments in gains and offsets are achieved through the coupling of a servo signal and a switch with several changeable paths. The servo signals are to be either designated to be deducted a first offset through the switch and then output a converted signal in proportion to a first gain unit, or designated to be deducted a second offset, and then output a converted signal in proportion to a second gain unit. The switch is switched on/off in the light of the working status of the pick-up head, for example, seeking or tracking, at a data area or at a blank area, and at a groove area or at a land area, so as to choose different offsets and gains to have the conversion of the servo signals.
  • The input signal of the switch is a signal that results from the synthesis and amplification of a track error or a focusing error with a pre-amplifier. The input signal is subjected to conversion conducted by the first gain unit or the second gain unit, and then it is coupled to a controller.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • The invention will be described according to the appended drawings in which:
  • FIG. 1 is a schematic diagram of a servo control system for an optical disk drive in accordance with the present invention;
  • FIG. 2 is a waveform diagram of a TE signal;
  • FIG. 3 is a schematic diagram showing that a pick-up head writes or reads data on an optical disk; and
  • FIG. 4 is a waveform diagram of a TE signal in response to a DVD-RAM disk.
    • PREFERRED EMBODIMENT OF THE PRESENT INVENTION
  • FIG. 1 is a schematic diagram of a servo control system of an optical disk drive in accordance with the present invention. The seeking or tracking servo control system 10 of the optical disk device is equipped with a pick-up head 11 intended to read data recorded in an optical disk 40. The pick-up head 11 generates a TE signal or a FE signal that functions as an input signal to the servo control system 10. The input signal is sent to a pre-amplifier 12 to have signal synthesis and amplification. With a switch 19, the amplified control signal is allowed to couple to either a first gain circuit 17 or a second gain circuit 18; with the first gain circuit 17, the amplified control signal has a slice level shift in response to a first offset 131, and then it is converted at a constant proportion by a first gain unit 141 before it is output; similarly, with the second gain circuit 18, the amplified control signal has a slice level shift in response to a second offset 132, and then it is converted at another constant proportion by a second gain unit 142 before it is output. The servo gain may be greater or less than one, or even a negative value.
  • The objective of the present invention is to normalize the input signals of a controller 15 by either the first gain unit 141 or the second gain unit 142, so as to enhance the stability of the servo control system. The control signal generated by the controller 15 makes a driver 16 output a driving signal, and the pick-up head 11 responds after it receives the driving signal.
  • According to the present invention, the switch 19 is switched on/off in light of the working status of the pick-up head 11. Its application to three statuses is as follows:
  • I. Seeking/Tracking
  • If the pick-up head 11 seeks tracks, the seeking or focusing servo control system makes the switch 19 switch to the second gain circuit 18 so as to reduce the sensitivity of the servo loop to noise signals by diminishing its servo gain. Conversely, if the pick-up head 11 is changed to track tracks, the switch 19 is switched to the first gain circuit 17, and the servo gain of the second gain circuit 18 is less than that of the first gain circuit 17.
  • The first offset 131 of the first gain circuit 17 and the magnitude of the gain of the first gain unit 141 can be determined by a track error or a focusing error intended for actual off-line detection (the second offset 132 and the gain value of the second gain unit 142 are determined in the same way). As shown in FIG. 2, it is a waveform diagram of a TE signal, wherein AP denotes the peak-to-peak (or crest-to-trough) interval of a TE signal, and M denotes a slice level, or a DC component. Also, servo control system designs always entail setting the peak-to-peak interval and the DC component. AP divided by a default peak-to-peak interval equals a quotient, and the quotient is designated as the gain of the first gain unit 141. Furthermore, the difference between the DC component actually measured and a default DC component is designated as the magnitude of the first offset 131.
  • II. Blank Area/Data Area
  • If the pick-up head 11 stays in a blank area, the servo control system makes the switch 19 switch to the second gain circuit 18 so as to decrease its servo gain. Conversely, if the pick-up head 11 stays in a data area to read data from there, the switch 19 is switched to the first gain circuits 17 so as to increase its servo gain.
  • Similarly, the corresponding magnitude of the gains and offsets can be obtained by the TE signal that is generated by the pick-up head staying either in the blank area or data area on-line. The calculating method of the magnitude is the same as the aforesaid descriptions.
  • III. Groove Area/Land Area
  • FIG. 3 is a schematic diagram showing how a pick-up head writes or reads data on an optical disk. Optical disks with ordinary specifications, such as CD-R, DVD-R and DVD-RW, always have data stored in their groove areas 41. However, DVD-RAM stores data in both the groove areas 41 and the land areas 42; for its corresponding TE signal, please refer to the trough 41′ and the peak 42′ in FIG. 4. The convergence direction A of the trough 41′ is opposite to the convergence direction B of the peak 42′. Hence, the gain of the first gain circuit 17 and that of the second gain circuit 18 have opposite signs, where not only do their offsets have opposite signs, but also the magnitude of their offsets differ.
  • If the pick-up head 11 is in a groove area 41, the switch 19 is switched to the first gain circuit 17. If the pick-up head 11 is in a land area 42, the switch 19 is switched to the second gain circuit 18.
  • Digital signal processing (DSP) technique may be applied to the present invention, that is, the real-time status of a pick-up head is detected on-line while programs are running, so that switching occurs automatically in response to the various statuses mentioned earlier. With a DSP or an analog circuit, the peak and the trough of the servo signals can be measured so as to figure out the corresponding offset and gain. In other words, if an optical drive is at a read or write state, the peak-trough interval and the DC component determine the magnitude of the offset and the gain, as far as the real-time calculated TE signal (or FE signal) are concerned.
  • Furthermore, it is feasible to calculate the offset and the gain in an off-line, such as a free track-locking status and a focusing servo control status, that is, directly calculate the gain and the offset of a TE signal or a FE signal, using an open loop.
  • The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by persons skilled in the art without departing from the scope of the following claims.

Claims (21)

1. A method for switching servo gains and offsets for an optical disk drive, the method comprising:
determining the location of a pick-up head on an optical disk having respective areas thereon with low and high reflective ratios;
outputting a signal obtained by multiplying a servo signal by a first gain if the pick-up head is at a location with a low reflective ratio on the optical disk; and
outputting a normalized signal obtained by multiplying the servo signal by a second gain smaller than the first gain if the pick-up head is at a location on the optical disk with a high reflective ratio.
2. The method for switching servo gains and offsets for an optical disk drive of claim 1, wherein the servo signal is a TE signal or a FE signal.
3. The method for switching servo gains and offsets for an optical disk drive of claim 1, wherein the outputted servo signal is from the conversion of the first gain when the pick-up head is in a blank area, and the outputted servo signal is from the conversion of the second gain when the pick-up head is in a data area.
4. The method for switching servo gains and offsets for an optical disk drive of claim 1, wherein the outputted servo signal is from the conversion of the first gain when the pick-up head is in a groove area, and the outputted servo signal is from the conversion of the second gain when the pick-up head is in a land area.
5. The method for switching servo gains and offsets for an optical disk drive of claim 1, further comprising the step of:
determining the values of a first offset, a second offset, a first gain unit and a second gain unit by means of on-line or off-line detecting the servo signal.
6. A method for switching servo gains and offsets for an optical disk drive, the method comprising:
determining the location of a pick-up head on an optical disk based upon a reflective ratio on the optical disk;
outputting a signal after converting a servo signal by a first gain if the pick-up head is in a tracking status; and
outputting a normalized signal with respect to a level of the converted servo signal by multiplying the servo signal by a second gain less than the first gain if the pick-up head is in a seeking status.
7. The method for switching servo gains and offsets for an optical disk drive of claim 6, further comprising the step of:
determining the values of offsets, the first gain and the second gain by means of on-line detecting the servo signal.
8. The method for switching servo gains and offsets for an optical disk drive of claim 6, further comprising the step of:
determining the values of offsets, the first gain and the second gain by means of off-line detecting the servo signal.
9. A method for switching servo gains and offsets for an optical disk drive, the method comprising:
determining a working status of a pick-up head based upon a reflective ratio on the optical disk; and
selectively processing a servo signal from the pick-up head in response to the determined working status of the pick-up head,
wherein the servo signal is amplified by a first gain when the pick-up head is in a tracking status and the servo signal is amplified by a second gain less than the first gain when the pick-up head is in a seeking status.
10. The method of claim 9, further comprising outputting a normalized control signal comprising the servo signal amplified by the second gain when the pick-up head is in a seeking status.
11. The method of claim 10, further comprising driving the pick-up head by using the normalized control signal.
12. The method of claim 9, further comprising outputting a control signal comprising the servo signal amplified by the first gain when the pick-up head is in a tracking status.
13. The method of claim 9, further comprising selectively adding an offset to the servo signal in response to the determined working status of the pick-up head.
14. An apparatus having switchable servo gains and offsets for an optical disk drive, comprising:
means for determining the location of a pick-up head on an optical disk having respective areas thereon with low and high reflective ratios;
means for outputting a signal obtained by multiplying a servo signal by a first gain if the pick-up head is at a location with a low reflective ratio on the optical disk; and
means for outputting a normalized signal obtained by multiplying the servo signal by a second gain smaller than the first gain if the pick-up head is at a location on the optical disk with a high reflective ratio.
15. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 14, wherein the servo signal is a TE signal or a FE signal.
16. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 14, wherein the outputted servo signal is from the conversion of the first gain when the pick-up head is in a blank area, and the outputted servo signal is from the conversion of the second gain when the pick-up head is in a data area.
17. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 14, wherein the outputted servo signal is from the conversion of the first gain when the pick-up head is in a groove area, and the outputted servo signal is from the conversion of the second gain when the pick-up head is in a land area.
18. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 14, further comprising means for determining the values of a first offset, a second offset, a first gain unit and a second gain unit by means of on-line or off-line detecting the servo signal.
19. An apparatus having switchable servo gains and offsets for an optical disk drive, comprising:
means for determining the location of a pick-up head on an optical disk based upon a reflective ratio on the optical disk;
means for outputting a signal after converting a servo signal by a first gain if the pick-up head is in a tracking status; and
means for outputting a normalized signal with respect to a level of the converted servo signal by multiplying the servo signal by a second gain less than the first gain if the pick-up head is in a seeking status.
20. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 19, further comprising means for determining the values of offsets, the first gain and the second gain by means of on-line detecting the servo signal.
21. The apparatus having switchable servo gains and offsets for an optical disk drive of claim 19, further comprising means for determining the values of offsets, the first gain and the second gain by means of off-line detecting the servo signal.
US11/837,898 2003-11-19 2007-08-13 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof Abandoned US20070280067A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US11/837,898 US20070280067A1 (en) 2003-11-19 2007-08-13 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US12/468,565 US8027230B2 (en) 2003-11-19 2009-05-19 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US13/214,309 US20110299373A1 (en) 2003-11-19 2011-08-22 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
TW092132463A TWI253636B (en) 2003-11-19 2003-11-19 Apparatus with switching servo gain and offset for optical disk device and method thereof
TW092132463 2003-11-19
US10/710,416 US7272085B2 (en) 2003-11-19 2004-07-08 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US11/837,898 US20070280067A1 (en) 2003-11-19 2007-08-13 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/710,416 Division US7272085B2 (en) 2003-11-19 2004-07-08 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/468,565 Division US8027230B2 (en) 2003-11-19 2009-05-19 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Publications (1)

Publication Number Publication Date
US20070280067A1 true US20070280067A1 (en) 2007-12-06

Family

ID=34568662

Family Applications (4)

Application Number Title Priority Date Filing Date
US10/710,416 Expired - Fee Related US7272085B2 (en) 2003-11-19 2004-07-08 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US11/837,898 Abandoned US20070280067A1 (en) 2003-11-19 2007-08-13 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US12/468,565 Expired - Fee Related US8027230B2 (en) 2003-11-19 2009-05-19 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US13/214,309 Abandoned US20110299373A1 (en) 2003-11-19 2011-08-22 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/710,416 Expired - Fee Related US7272085B2 (en) 2003-11-19 2004-07-08 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Family Applications After (2)

Application Number Title Priority Date Filing Date
US12/468,565 Expired - Fee Related US8027230B2 (en) 2003-11-19 2009-05-19 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US13/214,309 Abandoned US20110299373A1 (en) 2003-11-19 2011-08-22 Apparatus having switchable servo gains and offsets for optical disk drive and method thereof

Country Status (2)

Country Link
US (4) US7272085B2 (en)
TW (1) TWI253636B (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI253636B (en) * 2003-11-19 2006-04-21 Mediatek Inc Apparatus with switching servo gain and offset for optical disk device and method thereof
WO2006072914A2 (en) * 2005-01-10 2006-07-13 Koninklijke Philips Electronics, N.V. Optical disc focussing actuator control at optimal bandwidth
WO2007069655A2 (en) * 2005-12-15 2007-06-21 Matsushita Electric Ind Co Ltd Optical disc device, crosstalk correction method, and integrated circuit
JP2009539201A (en) * 2006-06-01 2009-11-12 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Optimizing focus crosstalk canceling
US20090196133A1 (en) * 2008-02-04 2009-08-06 Chia-Wei Liang Signal processing apparatus for optical disc and method thereof
US20130037319A1 (en) * 2011-08-08 2013-02-14 Brian A. Feiner Bi-directional cable guide
US8731028B2 (en) 2011-12-02 2014-05-20 Futurewei Technologies, Inc. Method and apparatus for modulation and coding scheme adaption in a MIMO system
US9281008B1 (en) 2012-10-10 2016-03-08 Seagate Technology Llc Multiple track pitches for SMR
US8922930B1 (en) 2012-10-11 2014-12-30 Seagate Technology Llc Limit disc nodes by band usage
US8879183B1 (en) 2012-10-11 2014-11-04 Seagate Technology Llc Segmenting of read-modify-write operations
US8896961B1 (en) 2012-10-11 2014-11-25 Seagate Technology Llc Reader positioning in shingled magnetic recording
US9286936B1 (en) 2013-02-21 2016-03-15 Seagate Technology Llc Zone based band mapping
NL2020618B1 (en) 2018-01-12 2019-07-18 Illumina Inc Real time controller switching

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4700334A (en) * 1984-05-23 1987-10-13 Sony Corporation Tracking control with two servoloops for use in optical disc players
US4890273A (en) * 1985-01-31 1989-12-26 Olympus Optical Co., Ltd. Optical information recording/reproducing system with variable gain servo error correction in response to detected track formats
US5268883A (en) * 1989-10-16 1993-12-07 Matsushita Electric Industrial Co., Ltd. Track access device and tracking control device
US5568461A (en) * 1994-04-20 1996-10-22 Matsushita Electric Industrial Co., Ltd. Optical information recording and reproducing apparatus
US6434096B1 (en) * 1999-02-26 2002-08-13 Matsushita Electric Industrial Co., Ltd. Optical information recording/reproducing device
US7164630B2 (en) * 2002-01-31 2007-01-16 Kabushiki Kaisha Toshiba Optical disk apparatus
US7307926B2 (en) * 2002-09-18 2007-12-11 Matsushita Electric Industrial Co., Ltd. Apparatus and method for tracking control

Family Cites Families (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3783561T2 (en) * 1986-10-24 1993-05-06 Pioneer Electronic Corp SERVO DEVICE FOR A SLED.
JPH0654542B2 (en) * 1987-08-28 1994-07-20 富士通株式会社 Optical storage
JPH02103790A (en) * 1988-10-11 1990-04-16 Pioneer Electron Corp Tracking servo device
JP2734562B2 (en) * 1988-10-13 1998-03-30 松下電器産業株式会社 Tracking servo method
US5251194A (en) * 1989-04-17 1993-10-05 Mitsubishi Denki Kabushiki Kaisha Techniques for controlling beam position and focus in optical disk drives
JP2820808B2 (en) * 1991-03-29 1998-11-05 コニカ株式会社 Focus control mechanism of optical disk device
JPH04368637A (en) * 1991-06-17 1992-12-21 Sony Corp Servo circuit
JP3074877B2 (en) * 1991-11-22 2000-08-07 ソニー株式会社 Optical disk player
US6522606B1 (en) * 1992-02-27 2003-02-18 Fujitsu Limited Optical pickup servo control apparatus with stored compensatory values
JPH07279270A (en) 1994-04-06 1995-10-24 Fujita Corp Sealing device for joint
KR0162607B1 (en) * 1995-12-20 1999-01-15 김광호 Voice coil motor moving control circuit
JPH1021566A (en) * 1996-07-05 1998-01-23 Sony Corp Tracking servo device
US5712636A (en) * 1996-07-09 1998-01-27 Quantum Corp. Pulse-width-modulated digital-to-analog converter with high gain and low gain modes
JPH1091971A (en) 1996-09-12 1998-04-10 Sony Corp Tracking controller and method for optical disk device
JPH10334574A (en) * 1997-05-27 1998-12-18 Victor Co Of Japan Ltd Optical disk discriminating device
DE69807406T2 (en) 1997-10-01 2003-04-24 Nippon Catalytic Chem Ind Process for the preparation of alkylamino (meth) acrylate and an apparatus therefor
JP3442984B2 (en) * 1997-12-26 2003-09-02 シャープ株式会社 Optical pickup position control device
FR2777561B1 (en) 1998-04-21 2000-06-02 Atochem Elf Sa PROCESS FOR THE CONTINUOUS MANUFACTURE OF DIALKYLAMINOALKYL (METH) ACRYLATES
JP4477178B2 (en) 1999-12-21 2010-06-09 ダイヤニトリックス株式会社 Method for producing alkylaminoalkyl ester of (meth) acrylic acid
JP2001172236A (en) 1999-12-21 2001-06-26 Mitsubishi Rayon Co Ltd Method for purifying dimethylaminoethyl acrylate
JP4519969B2 (en) 1999-12-21 2010-08-04 ダイヤニトリックス株式会社 Method for producing dimethylaminoethyl acrylate
JP2001297454A (en) * 2000-04-14 2001-10-26 Matsushita Electric Ind Co Ltd Optical disk device
US6906985B2 (en) * 2001-01-25 2005-06-14 Dphi Acquisitions, Inc. Calibration of tracking error signal gain in a tracking servo system
JP2002269938A (en) * 2001-02-28 2002-09-20 Internatl Business Mach Corp <Ibm> Disk driver, head position control method and hard disk drive
TW509913B (en) 2001-03-21 2002-11-11 Via Tech Inc Optical disk driver tracking method
US6952382B2 (en) * 2001-04-11 2005-10-04 Matsushita Electric Industrial Co., Ltd. Recording/reproduction apparatus, recording/reproduction method and information recording medium
DE10127939A1 (en) 2001-06-08 2002-05-29 Basf Ag Production of (meth)acrylate esters, e.g. dialkylaminoethyl (meth)acrylates, by catalytic transesterification involves four-stage distillation
DE10127938A1 (en) 2001-06-08 2002-07-25 Basf Ag Production of basic dialkylaminoethyl(meth)acrylates, useful for production of (co)polymers for paints, dispersion or adhesives comprises esterification of (meth)acrylic acid alkyl esters.
US6934227B2 (en) * 2001-09-06 2005-08-23 Matsushita Electric Industrial Co., Ltd. Optical disk device, semiconductor integrated circuit, pickup control method and vibration component detection method
TWI283403B (en) * 2002-02-19 2007-07-01 Via Tech Inc Focus control method and device
FR2839070A1 (en) 2002-04-30 2003-10-31 Atofina PROCESS FOR THE CONTINUOUS MANUFACTURE OF DIMETHYLAMINOETHYL ACRYLATE
TWI223796B (en) * 2002-05-23 2004-11-11 Via Optical Solution Inc Control method for switching actuating modes
JP2004145965A (en) * 2002-10-24 2004-05-20 Matsushita Electric Ind Co Ltd Optical recording/reproducing device
JP2004189650A (en) 2002-12-10 2004-07-08 Mitsubishi Rayon Co Ltd Method for producing (meth)acrylic ester
US7057843B2 (en) * 2003-05-28 2006-06-06 Stmicroelectronics, Inc. Disk drive control circuit and method
US7411086B2 (en) 2003-05-28 2008-08-12 Dia-Nitrix Co., Ltd. Process for the production of n-alkylaminoalkyl (meth)acrylates
TWI253636B (en) * 2003-11-19 2006-04-21 Mediatek Inc Apparatus with switching servo gain and offset for optical disk device and method thereof
GB0523340D0 (en) 2005-11-16 2005-12-28 Ciba Sc Holding Ag Manufacture of esters

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4700334A (en) * 1984-05-23 1987-10-13 Sony Corporation Tracking control with two servoloops for use in optical disc players
US4890273A (en) * 1985-01-31 1989-12-26 Olympus Optical Co., Ltd. Optical information recording/reproducing system with variable gain servo error correction in response to detected track formats
US5268883A (en) * 1989-10-16 1993-12-07 Matsushita Electric Industrial Co., Ltd. Track access device and tracking control device
US5568461A (en) * 1994-04-20 1996-10-22 Matsushita Electric Industrial Co., Ltd. Optical information recording and reproducing apparatus
US6434096B1 (en) * 1999-02-26 2002-08-13 Matsushita Electric Industrial Co., Ltd. Optical information recording/reproducing device
US7164630B2 (en) * 2002-01-31 2007-01-16 Kabushiki Kaisha Toshiba Optical disk apparatus
US7307926B2 (en) * 2002-09-18 2007-12-11 Matsushita Electric Industrial Co., Ltd. Apparatus and method for tracking control

Also Published As

Publication number Publication date
US20050105417A1 (en) 2005-05-19
US7272085B2 (en) 2007-09-18
US20110299373A1 (en) 2011-12-08
US20090262610A1 (en) 2009-10-22
TWI253636B (en) 2006-04-21
US8027230B2 (en) 2011-09-27
TW200518057A (en) 2005-06-01

Similar Documents

Publication Publication Date Title
US8027230B2 (en) Apparatus having switchable servo gains and offsets for optical disk drive and method thereof
US7164630B2 (en) Optical disk apparatus
US6738325B2 (en) Optical disk unit capable of reducing tracking offset
JP2935908B2 (en) Light spot position detector
US6687202B1 (en) Pickup control device for optical disk drive which adjusts loop gain or determines sample rate
US7518961B2 (en) Optical disk recording and reproducing apparatus for recording and reproducing data in and from optical disk
US8085629B2 (en) Optical focus error offset to reduce radial to vertical crosstalk
JPH0668498A (en) Information recording medium processor
JP2009015894A (en) Optical disc apparatus, controller of optical disc apparatus, and control method of optical disc apparatus
KR100260435B1 (en) Servo compansation and apparatus for optical disc having defect
JP2000090444A (en) Feed speed controller of information reading point for disk player
US20040071053A1 (en) Detecting device, detecting method, and optical disk device
JP2003248942A (en) Optical disk device
JP2001266371A (en) Information recording and reproducing device
US7362670B2 (en) Optical disc drive
JP3931774B2 (en) Defect detection device
KR100195019B1 (en) How to determine the type of optical disc in the optical disc player
WO2005101388A1 (en) Optical disc recording/reproduction device
JP2008047164A (en) Defect detecting circuit and controller
US20090296548A1 (en) Method for measuring and optimizing radial to vertical crosstalk
KR100624266B1 (en) Method for controlling track servo of holographic rom disk
JP2005092992A (en) Optical disk drive
JP2001084605A (en) Optical disk device
KR100432847B1 (en) An apparatus and method for detecting wobble signal
JPH11120577A (en) Optical disk device

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION