FR2251021B1 - - Google Patents

Info

Publication number
FR2251021B1
FR2251021B1 FR7439468A FR7439468A FR2251021B1 FR 2251021 B1 FR2251021 B1 FR 2251021B1 FR 7439468 A FR7439468 A FR 7439468A FR 7439468 A FR7439468 A FR 7439468A FR 2251021 B1 FR2251021 B1 FR 2251021B1
Authority
FR
France
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.)
Expired
Application number
FR7439468A
Other languages
French (fr)
Other versions
FR2251021A1 (en
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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
Priority claimed from JP12539573A external-priority patent/JPS5078340A/ja
Priority claimed from JP3796674A external-priority patent/JPS50132939A/ja
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of FR2251021A1 publication Critical patent/FR2251021A1/en
Application granted granted Critical
Publication of FR2251021B1 publication Critical patent/FR2251021B1/fr
Granted legal-status Critical Current

Links

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
    • G11B7/0908—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
    • G11B7/0917—Focus-error methods other than those covered by G11B7/0909 - G11B7/0916
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/40—Optical focusing aids
    • 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
FR7439468A 1973-11-09 1974-12-03 Automatic focussing system for laser beam on to moving object - has out of focus detector of beam of surface producing signal in feedback to correct Granted FR2251021A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP12539573A JPS5078340A (en) 1973-11-09 1973-11-09
JP3796674A JPS50132939A (en) 1974-04-05 1974-04-05

Publications (2)

Publication Number Publication Date
FR2251021A1 FR2251021A1 (en) 1975-06-06
FR2251021B1 true FR2251021B1 (en) 1979-06-08

Family

ID=26377151

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7439468A Granted FR2251021A1 (en) 1973-11-09 1974-12-03 Automatic focussing system for laser beam on to moving object - has out of focus detector of beam of surface producing signal in feedback to correct

Country Status (3)

Country Link
DE (1) DE2453364C3 (en)
FR (1) FR2251021A1 (en)
NL (1) NL7414695A (en)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5280007A (en) * 1975-12-26 1977-07-05 Sony Corp Video disc
NL178915C (en) * 1976-01-16 1986-06-02 Philips Nv AUTOMATIC OPTIC FOCUSING SYSTEM.
JPS52120805A (en) * 1976-04-02 1977-10-11 Sony Corp Servo apparatus
GB1603596A (en) * 1977-06-06 1981-11-25 Mca Disco Vision Optical transducer and focusing system
JPS54133305A (en) * 1978-04-07 1979-10-17 Hitachi Ltd Information recorder
JPS6053943B2 (en) * 1978-11-30 1985-11-28 キヤノン株式会社 Camera focus detection device
JPS6030015B2 (en) * 1979-05-09 1985-07-13 株式会社日立製作所 Light beam position control device
NL7904724A (en) * 1979-06-18 1980-12-22 Philips Nv OPTICAL SCANNER WITH FOCUSING SYSTEM.
JPS5793307A (en) * 1980-12-02 1982-06-10 Olympus Optical Co Ltd Automatic focusing system
DE3913229A1 (en) * 1988-09-19 1990-03-22 Pioneer Electronic Corp Optical disc playback system - has screening plate with needle aperture to control input to detector element
US5172366A (en) * 1988-09-19 1992-12-15 Pioneer Electronic Corporation Optical information reproducing apparatus with selective photodetector output
DE3934744A1 (en) * 1989-10-18 1991-04-25 Krupp Gmbh Non-contact thickness determn. - by moving focusing lens for laser beam
US20120133958A1 (en) 2010-11-30 2012-05-31 Widman Michael F Laser confocal sensor metrology system
WO2013119775A1 (en) 2012-02-10 2013-08-15 Johnson & Johnson Vision Care, Inc. Method and apparatus for determining a thickness profile of an ophthalmic lens using a single point thickness and refractive index measurements

Also Published As

Publication number Publication date
DE2453364B2 (en) 1978-06-22
DE2453364A1 (en) 1975-05-28
DE2453364C3 (en) 1979-02-22
FR2251021A1 (en) 1975-06-06
NL7414695A (en) 1975-05-13

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Legal Events

Date Code Title Description
ST Notification of lapse