DK548288A - DEVICE FOR REPLACING DATA - Google Patents

DEVICE FOR REPLACING DATA

Info

Publication number
DK548288A
DK548288A DK548288A DK548288A DK548288A DK 548288 A DK548288 A DK 548288A DK 548288 A DK548288 A DK 548288A DK 548288 A DK548288 A DK 548288A DK 548288 A DK548288 A DK 548288A
Authority
DK
Denmark
Prior art keywords
focus
control circuit
order
control amplifier
set voltage
Prior art date
Application number
DK548288A
Other languages
Danish (da)
Other versions
DK548288D0 (en
Inventor
Arthur Kurz
Original Assignee
Thomson Brandt Gmbh
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 Thomson Brandt Gmbh filed Critical Thomson Brandt Gmbh
Publication of DK548288D0 publication Critical patent/DK548288D0/en
Publication of DK548288A publication Critical patent/DK548288A/en

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/30—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters
    • H03F1/303—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters using a switching device
    • H03F1/304—Modifications of amplifiers to reduce influence of variations of temperature or supply voltage or other physical parameters using a switching device and using digital means
    • 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
    • G11B7/0901—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 for track following only
    • 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
    • G11B7/0908—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 for focusing only
    • G11B7/0909—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 for focusing only by astigmatic methods

Abstract

Apparatus for the reproduction of data which can be read contactlessly from a recording medium by means of an optical scanning device. Such apparatuses are equipped with a focus control circuit, in order to focus the light beam scanning the data onto the recording medium, and with a track control circuit, in order to be able to guide the light beam on the data tracks. However, the control amplifier (FR) of the focus control circuit is affected by an off-set voltage, which varies with the temperature and ageing of the control amplifier. In order to compensate automatically for the off-set voltage of the control amplifier (FR) of the focus control circuit, an input of the control amplifier (FR) is fed an off-set compensation voltage, which is varied until the high-frequency components of the focus error signal (FE) assume a minimum, since in this case the off-set voltage is optimally compensated. CD players, video-disc players, draw-disc players, magneto-optical equipment. <IMAGE>
DK548288A 1987-09-30 1988-09-30 DEVICE FOR REPLACING DATA DK548288A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19873732997 DE3732997A1 (en) 1987-09-30 1987-09-30 DEVICE FOR PLAYING BACK DATA

Publications (2)

Publication Number Publication Date
DK548288D0 DK548288D0 (en) 1988-09-30
DK548288A true DK548288A (en) 1989-03-31

Family

ID=6337266

Family Applications (1)

Application Number Title Priority Date Filing Date
DK548288A DK548288A (en) 1987-09-30 1988-09-30 DEVICE FOR REPLACING DATA

Country Status (10)

Country Link
EP (1) EP0309719B1 (en)
JP (1) JP2956770B2 (en)
KR (1) KR960016359B1 (en)
AT (1) ATE78624T1 (en)
DE (2) DE3732997A1 (en)
DK (1) DK548288A (en)
ES (1) ES2034068T3 (en)
GR (1) GR3005801T3 (en)
HK (1) HK5696A (en)
HU (1) HUT63010A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03115918U (en) * 1990-02-28 1991-12-02
DE4102857A1 (en) * 1991-01-31 1992-08-06 Thomson Brandt Gmbh Beam focussing control method for CD player - varying offset compensation voltage fed to focussing control circuit until bit error rate of scanned data signal reaches minimum
DE102006020830B4 (en) * 2006-05-04 2014-02-13 Siemens Aktiengesellschaft Controller for a high-frequency amplifier

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS598144A (en) * 1982-07-05 1984-01-17 Trio Kenwood Corp Optical information reader
JPS61177646A (en) * 1985-02-04 1986-08-09 インタ−ナショナル　ビジネス　マシ−ンズ　コ−ポレ−ション Optical disc
CA1261467A (en) * 1985-11-28 1989-09-26 Akira Minami Focus servomechanism control system of optical disc system having offset setting means
DE3605561A1 (en) * 1986-02-21 1987-08-27 Thomson Brandt Gmbh METHOD FOR COMPENSATING THE OFFSET VOLTAGE OF A CONTROL AMPLIFIER AND CIRCUIT ARRANGEMENT FOR IMPLEMENTING THE METHOD

Also Published As

Publication number Publication date
JPH01109539A (en) 1989-04-26
HK5696A (en) 1996-01-19
KR960016359B1 (en) 1996-12-09
EP0309719A1 (en) 1989-04-05
ES2034068T3 (en) 1993-04-01
DK548288D0 (en) 1988-09-30
DE3873004D1 (en) 1992-08-27
HUT63010A (en) 1993-06-28
ATE78624T1 (en) 1992-08-15
JP2956770B2 (en) 1999-10-04
EP0309719B1 (en) 1992-07-22
DE3732997A1 (en) 1989-04-13
GR3005801T3 (en) 1993-06-07

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Legal Events

Date Code Title Description
AHS Application shelved for other reasons than non-payment