+

WO1998010271A1 - Dispositif d'inspection de la surface d'un disque optique double face - Google Patents

Dispositif d'inspection de la surface d'un disque optique double face Download PDF

Info

Publication number
WO1998010271A1
WO1998010271A1 PCT/IB1997/001231 IB9701231W WO9810271A1 WO 1998010271 A1 WO1998010271 A1 WO 1998010271A1 IB 9701231 W IB9701231 W IB 9701231W WO 9810271 A1 WO9810271 A1 WO 9810271A1
Authority
WO
WIPO (PCT)
Prior art keywords
compact disc
light
disc
detection means
values
Prior art date
Application number
PCT/IB1997/001231
Other languages
English (en)
Inventor
John M. Suhan
Original Assignee
Wea Manufacturing, 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 Wea Manufacturing, Inc. filed Critical Wea Manufacturing, Inc.
Priority to AU43167/97A priority Critical patent/AU735879B2/en
Priority to JP10512426A priority patent/JPH11515108A/ja
Priority to EP97941166A priority patent/EP0865607A4/fr
Publication of WO1998010271A1 publication Critical patent/WO1998010271A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/9506—Optical discs

Definitions

  • This invention relates to the manufacture of optical discs, such as compact discs for the optical recording of digital data.
  • optical discs such as compact discs for the optical recording of digital data.
  • quality control for defects of the surfaces of double sided optical discs during the manufacturing process are particularly important.
  • Compact discs are record carriers for digital or analog information, for example audio and/or video information, which have the form of a flat disc-shaped plastic surface on which a data modulated optical structure is provided in accordance with the information.
  • the data is formed as pits of varying length present in the surface and arranged in a spiral path.
  • the pits have nanometer dimensions and are formed by injection molding against a mold having corresponding raised regions.
  • the information stored on the compact disc is recovered in a reader, usually called a player, which rotates the compact disc and guides a laser device along the spiral track as the compact disc rotates.
  • the presence or absence of pits under the laser is detected as a change in the luminance returned from the surface directly below the laser. In this manner the length of the pits is detected and decoded as data.
  • Recently double surfaced compacts discs have been proposed that are formed from two relatively thin compact discs that are bonded together with their readable surfaces exposed.
  • stampers are prepared since each has only a reasonable number of uses before it is degraded in the molding process. These stampers are prepared by coating thin metallic layers upon a surface having the inverse pit pattern, i.e. raised areas where pits are desired in the next generation of copies. The process begins with a surface called the compact disc.
  • the critical dimensions of the recorded pits on the optical disc are of the order of magnitude of the wavelength of visible light. Accordingly, it is critical to quality control that the surfaces of the produced disc be inspected for absence of imperfections of even micron size that can be detected as deviations from flatness of the disc surface. This must be accomplished as part of a mass production line. Presently discs are scanned on one side and a robot arm turns the disc over so that the second side may be scanned. What is needed is an apparatus for simultaneously scanning both sides of the compact disc without having to invert the disc in the apparatus . There has been consideration of the detection of defects in or on disc surfaces by the use of light. In particular, U.S. patent 4,306,808 issued Dec. 22, 1981 for a "Disc flaw inspection system".
  • U.S. patent 4,741,042 issued Apr. 26, 1988 for an image processing system for detecting bruises on fruit.
  • the system employed a line scan camera to obtain a series of gray levels from the fruit as it rotated. The image was processed to determine size of bruise by assuming that the circular shape of a region of differing gray level should be interpreted as a bruise.
  • U.S. patent 4,403,230 issued Sep. 6, 1983 for "Inspection of castings”. A revolving camera is employed during the inspection for defects.
  • U.S. patent 4,335,960 issued Jun. 22, 1982 for "Apparatus for detecting the presence of surface irregularities in articles made of transparent material".
  • This apparatus detected spikes on the inside base of disc containers, which were passed rotatably over a slit having an opaque line in the slit.
  • Two light sources emit light that refracted at an oblique angle through the container base into a diode camera when there was an irregularity.
  • U.S. patent 5,204,911 issued Apr. 20, 1993 for an "Inspection method using unique templates and histogram analysis”. This system was used for detecting defects in products either stationary or on a production line. A line-scan camera was used to compare an image with values stored in a matrix corresponding to geometrical grid areas of the product.
  • U.S. patent 5,147,047 issued Sep. 15, 1992 for a "Pellet inspection system”.
  • This system used a multi-camera system on all sides of a hot radiant material transferred along a predetermined transfer line
  • the prior art has been concerned with the detection of the irregularity of surfaces and has used optical systems to determine the presence of such irregularities, none of the systems appear adapted to simultaneously view both surfaces in an assembly line production where the surfaces are separated by an opaque layer.
  • the present invention is a system for detecting imperfections of both planar surface of a double sided compact disc.
  • the system includes a self-centering chuck for retaining the compact disc and allowing it to rotate beneath an illumination source so that it illuminates the surface under test along a radius.
  • a radius is meant a narrow slit of the disc along a line from near its center to the edge of the disc or along a portion of a diameter. It is not necessary to include a central portion of the disc where no data is usually recorded.
  • the invention includes a pair of video cameras or other video monitoring devices for receiving light from the illumination source that reflects from the surfaces under study.
  • the camera is a detection means, which is oriented to receive illumination reflected only from an imperfectly flat portion of the surface being inspected.
  • a stepping motor or other means for rotating is used to turn the compact disc through a number of positions during at least one complete revolution while it is exposed to the light source.
  • the signal received in the video camera is then processed to compare the light level received with that from an assumed flat portion of the disc. If a significant discrepancy is found between the light reflected from different radii, the disc is rejected.
  • Figure 1 is a perspective view of the compact disc in an inspection station of the present invention.
  • Figure 1 shows a stage of an assembly line for the production of compact discs.
  • a compact disc 1_ is brought by a conveyer belt 3_ into an inspection chamber (not shown) where it is detected by a sensor 5_.
  • a self- centering chuck 1_ engages the compact disc through a hole in its center.
  • the surfaces of the disc are both illuminated by light sources 9, which illuminate at least a narrow radial strip j-_l of the surface of each side of the compact disc.
  • a line scan camera is preferred for this operation because it is capable of much higher spatial resolution than the traditional two-dimensional photosite video cameras .
  • a servo-motor I9 drives the shaft 2_1 and the chuck to cause rotation of the compact disc beneath the camera 15.
  • a reference line of video data is collected from the image of the disc beneath the line-scan cameras L5.
  • the illumination sources 9_ are preferably incandescent illumination that employs precise angles of incidence (depicted in the figure as lines emanating from the sources 9. These angles are chosen so that a surface of the compact disc without defects appears "dark” to the camera. Defects, such as the bump 2 ⁇ 3 in the view of the camera will appear “bright” to the camera.
  • the image of the camera is divided into pixels. Preferably 2048 useable pixels are employed across the array of the line scan camera.
  • the image is accepted as a reference image. If any pixels appear to be “bright” the disc is repositioned by rotation for a proper reference line until such a reference line is found. It is necessary to establish a template value and to compare this with the values of different radii, and not merely rely upon the simple association of brightness with imperfection and darkness with perfection.
  • the line scan camera employs 2048 usable pixels across its array.
  • the reference image is comprised of 2048 8-bit (0-255) intensity values which correspond to the actual intensity distribution of light across the linear array. If the scan of the disc is to reveal no defects, the test intensity values should remain near the reference value within some small tolerance value. If the scan of the disc is to reveal defects, the test intensity values will deviate from the reference intensity beyond some tolerance which is predetermined by experimentation and practical specification. It has been found acceptable if the tolerance value is approximately 0.8% and the deviation be calculated as a mean square value of less than 0.6%.
  • the compact disc is rotated through angles so that the different radial scans slightly overlap at their edges.
  • the stepping motor is then advanced until the entire surface has been scanned at least one time.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)

Abstract

La présente invention concerne un système permettant de détecter simultanément des imperfections sur les deux faces d'un disque compact double face (1). Ce système comprend un mandrin (7) à auto-centrage qui maintient le disque compact (1) en place et le fait tourner sous deux sources lumineuses (9) et devant deux caméras vidéo (15) ou autres dispositifs destinés à recevoir la lumière de la source lumineuse (9) réfléchie par la surface inspectée (17). Les caméras (15) sont orientées de manière à ne recevoir que la lumière réfléchie par une partie imparfaitement plate des surfaces inspectées (17). Un moteur pas-à-pas (19) est utilisé pour faire tourner le disque compact (1) d'une position à une autre au moins pendant un tour complet tandis que celui-ci est exposé aux sources lumineuses (9). On traite ensuite les signaux reçus par les caméras vidéo (15) au moyen d'un algorithme de référence afin de comparer le niveau de lumière reçu avec celui qui provient d'une partie présumée plate du disque.
PCT/IB1997/001231 1996-09-05 1997-09-05 Dispositif d'inspection de la surface d'un disque optique double face WO1998010271A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU43167/97A AU735879B2 (en) 1996-09-05 1997-09-05 Double sided optical disc surface inspector
JP10512426A JPH11515108A (ja) 1996-09-05 1997-09-05 両面光ディスク面検査装置
EP97941166A EP0865607A4 (fr) 1996-09-05 1997-09-05 Dispositif d'inspection de la surface d'un disque optique double face

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US70860896A 1996-09-05 1996-09-05
US08/708,608 1996-09-05

Publications (1)

Publication Number Publication Date
WO1998010271A1 true WO1998010271A1 (fr) 1998-03-12

Family

ID=24846479

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB1997/001231 WO1998010271A1 (fr) 1996-09-05 1997-09-05 Dispositif d'inspection de la surface d'un disque optique double face

Country Status (4)

Country Link
EP (1) EP0865607A4 (fr)
JP (1) JPH11515108A (fr)
AU (1) AU735879B2 (fr)
WO (1) WO1998010271A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1063640A3 (fr) * 1999-06-25 2001-05-09 Basler Aktiengesellschaft Procédé pour le contrôle optique d'une couche intermédiaire dans un objet plat comprenant au moins trois couches
DE102004058126A1 (de) * 2004-12-02 2006-06-08 Leica Microsystems Jena Gmbh Vorrichtung zur Inspektion der Vorder- und Rückseite eines scheibenförmigen Objekts
EP1850118A1 (fr) * 2006-04-24 2007-10-31 Siemens Aktiengesellschaft Méthode de détection des particules métalliques
DE19924583B4 (de) * 1998-05-28 2009-06-10 Advantest Corp. Verfahren und Einrichtung zur Oberflächenzustandsüberwachung
US7755749B2 (en) 2005-04-21 2010-07-13 Sumitomo Electric Industries, Ltd. Superconducting wire inspection apparatus and method

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5198189B2 (ja) * 2008-08-29 2013-05-15 富士フイルム株式会社 ハードディスク検査装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4665317A (en) * 1984-02-10 1987-05-12 Institute De Recherches De La Siderurgie Francaise (Irsid) Process and equipment for sensing surface defects on a moving strip
US4764969A (en) * 1986-01-28 1988-08-16 Kabushiki Kaisha Toshiba Apparatus for inspecting the surface of a material
US4954723A (en) * 1988-06-13 1990-09-04 Fuji Photo Film Co., Ltd. Disk surface inspection method and apparatus therefor

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2933736B2 (ja) * 1991-02-28 1999-08-16 キヤノン株式会社 表面状態検査装置
JPH0743311A (ja) * 1993-07-29 1995-02-14 Canon Inc 表面状態検査装置及び該装置を備える露光装置
US5581348A (en) * 1993-07-29 1996-12-03 Canon Kabushiki Kaisha Surface inspecting device using bisected multi-mode laser beam and system having the same
JPH07140089A (ja) * 1993-11-16 1995-06-02 Hitachi Electron Eng Co Ltd 磁気ディスクのスクラッチ傷検査装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4665317A (en) * 1984-02-10 1987-05-12 Institute De Recherches De La Siderurgie Francaise (Irsid) Process and equipment for sensing surface defects on a moving strip
US4764969A (en) * 1986-01-28 1988-08-16 Kabushiki Kaisha Toshiba Apparatus for inspecting the surface of a material
US4954723A (en) * 1988-06-13 1990-09-04 Fuji Photo Film Co., Ltd. Disk surface inspection method and apparatus therefor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0865607A4 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19924583B4 (de) * 1998-05-28 2009-06-10 Advantest Corp. Verfahren und Einrichtung zur Oberflächenzustandsüberwachung
EP1063640A3 (fr) * 1999-06-25 2001-05-09 Basler Aktiengesellschaft Procédé pour le contrôle optique d'une couche intermédiaire dans un objet plat comprenant au moins trois couches
DE102004058126A1 (de) * 2004-12-02 2006-06-08 Leica Microsystems Jena Gmbh Vorrichtung zur Inspektion der Vorder- und Rückseite eines scheibenförmigen Objekts
US7755749B2 (en) 2005-04-21 2010-07-13 Sumitomo Electric Industries, Ltd. Superconducting wire inspection apparatus and method
EP1850118A1 (fr) * 2006-04-24 2007-10-31 Siemens Aktiengesellschaft Méthode de détection des particules métalliques

Also Published As

Publication number Publication date
EP0865607A4 (fr) 1999-12-01
JPH11515108A (ja) 1999-12-21
AU735879B2 (en) 2001-07-19
AU4316797A (en) 1998-03-26
EP0865607A1 (fr) 1998-09-23

Similar Documents

Publication Publication Date Title
US4701612A (en) Inspection of container finish
JP3612444B2 (ja) 単一領域のアレイセンサと交互のストロボ光源を使用する容器の検査装置及びその方法
US4410278A (en) Method and apparatus for appearance inspection
US3930141A (en) Automatic tire classifying apparatus
CA1095619A (fr) Systeme pour detecter les defectuosites
US5200801A (en) Inspection of container finish
JP2001228093A (ja) 容器の密封面領域の検査
AU735879B2 (en) Double sided optical disc surface inspector
JP7382519B2 (ja) ガラスびんの検査方法及びガラスびんの製造方法並びにガラスびんの検査装置
EP0865605B1 (fr) Dispositif et procede d'inspection d'une surface d'un disque de verre
US4541716A (en) Detection of defects in a circular or spiral diffraction grating
JP4243431B2 (ja) 透明又は半透明な容器に担持されたレリーフを読み込むための方法及び装置
JPH11508039A (ja) 物体の表面検査
JPH11507138A (ja) 透明容器上のレリーフ読取り装置
JPS6055762B2 (ja) 円筒物体外観検査装置
US5917933A (en) Method and device for carrying out the quality control of an object
JPH0797087B2 (ja) 容器割目の検査
JPH09105618A (ja) 物体の平滑な面の欠陥検査方法及び装置並びに物体表面の粗さ測定方法及び装置
JPH10253547A (ja) 基板外観検査システム
WO2001055705A1 (fr) Installation et procede pour la detection de glacures
JPH10253543A (ja) 基板外観検査装置及び方法
JPH0470555A (ja) 球体表面検査装置
JP3349494B2 (ja) 円盤状体の検査方法及び検査装置
JPS61107144A (ja) 容器の検査方法
Beloborodov et al. High productive optoelectronic pellets surface inspection for nuclear reactors

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP SG

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

ENP Entry into the national phase

Ref country code: JP

Ref document number: 1998 512426

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1997941166

Country of ref document: EP

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWP Wipo information: published in national office

Ref document number: 1997941166

Country of ref document: EP

WWW Wipo information: withdrawn in national office

Ref document number: 1997941166

Country of ref document: EP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载