JPS5749908A - Method and device for detecting focus - Google Patents

Method and device for detecting focus

Info

Publication number
JPS5749908A
JPS5749908A JP55125252A JP12525280A JPS5749908A JP S5749908 A JPS5749908 A JP S5749908A JP 55125252 A JP55125252 A JP 55125252A JP 12525280 A JP12525280 A JP 12525280A JP S5749908 A JPS5749908 A JP S5749908A
Authority
JP
Japan
Prior art keywords
reflecting surface
photodetector
constitution
reflected light
angle
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.)
Granted
Application number
JP55125252A
Other languages
Japanese (ja)
Other versions
JPS647407B2 (en
Inventor
Hisatsune Tsuda
Asao Hayashi
Kenichi Oikami
Masatoshi Ida
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.)
Olympus Corp
Original Assignee
Olympus Corp
Olympus Optical Co 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
Application filed by Olympus Corp, Olympus Optical Co Ltd filed Critical Olympus Corp
Priority to JP55125252A priority Critical patent/JPS5749908A/en
Publication of JPS5749908A publication Critical patent/JPS5749908A/en
Publication of JPS647407B2 publication Critical patent/JPS647407B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/30—Systems for automatic generation of focusing signals using parallactic triangle with a base line
    • G02B7/32—Systems for automatic generation of focusing signals using parallactic triangle with a base line using active means, e.g. light emitter
    • 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

Abstract

PURPOSE:To facilitate optical adjustment and to simplify constitution by making reflected light incident to an optical member having a reflecting surface at an angle less than a critical angle, and by detecting and comparing the quantity of reflected light from the reflecting surface with a prescribed threshold level. CONSTITUTION:Reflected light from the reflecting surface 27a of a detection prism 27 is photodetected by a photodetector 28. As a disk 26 in an in-focus state is distplaced in a direction (a), the angle of the incidence of light to the reflecting surface 27a approximates a critical angle, so the quantity of the light incident to the photodetector 28 increases. As it is displaced in a direction (b), the quantity of the incident light decreases. The output of the photodetector 28 is supplied to one input terminal of a differential amplifier 34, and a reference voltage Vr from a reference voltage source 35 to the other input terminal. This voltage Vr is set nearly equal to the output voltage of a low-pass filter 33 in the in-focus state. Consequently, focusing-error signals showing the direction and extent of displacement of the disk 26 from an in-focus position are obtained from the output terminal of the differential amplifier 34. Thus, optical adjustment is facilitated and constitution is simplified.
JP55125252A 1980-09-11 1980-09-11 Method and device for detecting focus Granted JPS5749908A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55125252A JPS5749908A (en) 1980-09-11 1980-09-11 Method and device for detecting focus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55125252A JPS5749908A (en) 1980-09-11 1980-09-11 Method and device for detecting focus

Publications (2)

Publication Number Publication Date
JPS5749908A true JPS5749908A (en) 1982-03-24
JPS647407B2 JPS647407B2 (en) 1989-02-08

Family

ID=14905509

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55125252A Granted JPS5749908A (en) 1980-09-11 1980-09-11 Method and device for detecting focus

Country Status (1)

Country Link
JP (1) JPS5749908A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6390860B2 (en) 1997-04-18 2002-05-21 Yazaki Corporation Connector with a terminal deflection preventing mechanism
US9281596B2 (en) 2013-08-26 2016-03-08 Dai-Ichi Seiko Co., Ltd. Connector terminal and method of fabricating the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6390860B2 (en) 1997-04-18 2002-05-21 Yazaki Corporation Connector with a terminal deflection preventing mechanism
US9281596B2 (en) 2013-08-26 2016-03-08 Dai-Ichi Seiko Co., Ltd. Connector terminal and method of fabricating the same

Also Published As

Publication number Publication date
JPS647407B2 (en) 1989-02-08

Similar Documents

Publication Publication Date Title
JPS567246A (en) Method and unit for focus detection
JPS5753832A (en) Method and device for recording of optical information
AU538975B2 (en) Focus detector
JPS5752005A (en) Focus detecting method
JPS5749908A (en) Method and device for detecting focus
JPS6111637A (en) Liquid body sensor
JPS5746334A (en) Optical information reproducer
JPS57105831A (en) Detector for optical position
JPS5471652A (en) Automatic dimmer for microscope light source
JPS5737751A (en) Optical reader
JPS5753834A (en) Optical information reader
JPS54116904A (en) Optical information reader
JPS5766535A (en) Focus detector
JPS56111136A (en) Protective device for reader of optical disc player
JPS54134427A (en) Focusing device
JPS6413239A (en) Optical pickup
JPS57183639A (en) Focus detector
SU1472760A1 (en) Device for non-contact measurements of part dimensions
JPS5710107A (en) Control system for scanning signal
JPS5683847A (en) Focus detecting device in optical information reproducing device
JPS5760306A (en) Method and device for detecting focal point
JPS5912575Y2 (en) photodetector
JPS57123797A (en) Motional feedback type speaker
JPS5555228A (en) Optical element
JPS57161709A (en) Focusing point detector