WO1999046771A1 - Disque optique et bague pour disque optique - Google Patents

Disque optique et bague pour disque optique Download PDF

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Publication number
WO1999046771A1
WO1999046771A1 PCT/JP1999/000883 JP9900883W WO9946771A1 WO 1999046771 A1 WO1999046771 A1 WO 1999046771A1 JP 9900883 W JP9900883 W JP 9900883W WO 9946771 A1 WO9946771 A1 WO 9946771A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical disk
optical
ring
optical disc
disk
Prior art date
Application number
PCT/JP1999/000883
Other languages
English (en)
Japanese (ja)
Inventor
Hideki Izumi
Original Assignee
Hideki Izumi
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 Hideki Izumi filed Critical Hideki Izumi
Publication of WO1999046771A1 publication Critical patent/WO1999046771A1/fr

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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
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material

Definitions

  • the present invention relates to an optical disc, and more particularly, to an optical disc on which information signals are recorded or reproduced by irradiation with a laser beam.
  • optical disks on which information signals are recorded or reproduced by irradiating a single laser beam include magneto-optical disks, write-once optical disks, digital audio disks (so-called compact disks (CD)), and optical video disks. Recording media have been put to practical use.
  • Each of these optical discs includes a transparent substrate formed of a resin such as acrylic or polycarbonate or glass, and a reflective film formed on a main surface of the substrate.
  • an array of concave pits is formed on a substrate to serve as an information recording unit.
  • the depth of the pit is about 14 wavelengths of the irradiated laser light.
  • a reflective film is formed on the information recording section.
  • a laser beam is applied to a reflective film covering a pit in accordance with an information signal, and reproduction is performed by detecting a change in reflectance caused by a thousand squares of light caused thereby.
  • Audio CDs have excellent physical properties, and the operation of the CD player is simple, so the current LP record player has almost disappeared.
  • CD players are superior in terms of frequency characteristics, distortion characteristics, S / N ratio, dynamic range, wow-and-flat, etc.
  • low-level noise commonly called digital noise, which is not included in LP record players, is present in the sound played by CD players. This digital noise affects the harmony and tone that are considered most important in music. Musicians sensitive to sound quality — Dio enthusiasts have long noticed the difference. In recent years, CD player manufacturers have also been working to solve the above problems. In other words, various R & D activities are being conducted to minimize digital noise generated in electronic circuits.
  • the laser beam is directed perpendicular to the disc surface. Then, the intensity of the reflected light, which is reflected by the surface on which the pits (elongated holes) are formed and returns, is detected by an optical pickup. The signal detected by the optical pickup is converted into a digital electric signal to reproduce music information.
  • the pit when the pit is irradiated with the laser beam, a part of the pit is scattered at the edge of the pit.
  • the scattered laser light travels toward the inner edge and the outer edge of the disk while being repeatedly reflected on the upper and lower surfaces of the disk.
  • the scattered laser light reaching the inner or outer edge of the disk will be reflected back there.
  • the scattered laser light generated for each pit is repeatedly reflected in the disk and accumulated, so that it is amplified to an intensity that cannot be ignored. It returns to the direction of the optical pickup and corresponds to the presence or absence of a pit. It overlaps with the reflected light and enters the optical pickup. As a result, the signal detected by the optical pickup does not accurately correspond to the arrangement of the pits.
  • Japanese Utility Model Laid-Open No. 5—5 483 proposes that the outer or inner edge of an optical disc be coated with green color that absorbs the hue of a laser beam and that diffusely reflected light be absorbed.
  • Japanese Patent Application Laid-Open No. 7-93832 discloses a method of making the outer edge, inner edge, clamping area, or corrugation portion of a disk opaque in order to further diffuse and weaken diffusely reflected light. ing.
  • Japanese Patent Application Laid-Open No. Hei 9-128881 proposes that a V-shaped groove is provided concentrically in a clamping area and diffusely reflected light is collected and attenuated in this part.
  • a CD player rotating an optical disc with stable rotation for playback leads to an improvement in playback sound quality or playback image quality.
  • the sound to be recorded is sampled at 44.1 kHz, and the dynamics are expressed in 256 levels.
  • Music information is recorded in a recording area on the disc surface as a pit array formed with a width of 1 m or less and a track pitch of about 2.
  • a laser beam narrowed to a diameter of about 1 to 2 im by an optical pickup is used for reproducing music information.
  • Japanese Patent Application Laid-Open No. Hei 9-259,496 discloses a configuration in which an optical disc is sandwiched between a transparent clamp table and a turntable which is the same as or larger than an optical disc and rotated. ing. Further, Japanese Patent Application Laid-Open No. Hei 9-3163167 discloses a CD player provided with means for adsorbing an optical disk to a turntable. As described above, several methods for reducing digital noise other than noise generated in the electronic circuit of a CD player have been proposed. However, with regard to the irregular reflection of light rays inside the optical disk, an absorber for laser light has also been developed and marketed, but the effect of expecting more reflection than absorption has not been obtained.
  • a general object of the present invention is to provide an improved useful optical disk which solves the above-mentioned problems.
  • a more specific object of the present invention is to provide an optical disc capable of preventing surface runout during rotation of the optical disc.
  • Another object of the present invention is to provide an optical disc capable of reducing the digital noise caused by the optical disc itself by diffusing and attenuating the reflected light generated by the irregular reflection of light rays inside the optical disc. .
  • an optical disk from which recorded information is read by reflected light of an irradiated light beam, wherein the optical disk has upper and lower surfaces and near the outer edge of the optical disk.
  • An optical disk is provided which has a plurality of through holes extending between upper and lower surfaces and inclined with respect to the rotation direction of the optical disk.
  • an optical disk from which recorded information is read by reflected light of an irradiated light beam, wherein the optical disk extends between the upper and lower surfaces of the disk and the upper and lower surfaces provided on the outer edge of the disk.
  • an optical disc comprising a plurality of grooves which are inclined with respect to the rotation direction of the optical disc.
  • an optical disk from which recorded information is read by reflected light of an irradiated light beam, wherein the optical disk is provided on an outer edge of the disk and an outer edge of the disk with respect to a rotation direction of the optical disk.
  • An optical disk comprising a plurality of inclined fin-shaped protrusions is provided.
  • the inclination angle of the fin-shaped protrusion with respect to the rotation direction of each optical disk is in the range of 45 degrees to 80 degrees.
  • a ring for an optical disc mountable on an optical disc from which recorded information is picked up by reflected light of an irradiated light beam wherein the ring is mountable on an outer edge of the optical disc.
  • An optical disc ring comprising a main body and a plurality of fin-shaped protrusions provided on a radially outer peripheral surface of the ring main body and inclined with respect to the rotation direction of the optical disc is provided.
  • the optical disk is mounted with the optical disk ring mounted.
  • air flow is generated by the fin-shaped protrusions of the optical disk ring.
  • a reaction force acts on the optical disk by this air flow. Therefore, if the direction in which the reaction force acts is the direction of the turntable, the optical disc is pressed against the table, and the runout during rotation is suppressed.
  • the inclination angle of the fin-shaped protrusion with respect to the rotation direction of each optical disk is in the range of 45 degrees to 80 degrees.
  • the ring main body may have an extending portion extending toward the radial direction side of the optical disc and abutting on the lower surface of the optical disc when the ring main body is mounted on the optical disc.
  • FIG. 1A is a cross-sectional view of a part of a compact disc (CD) according to a first embodiment of the present invention, where CD is set in a CD player.
  • CD compact disc
  • FIG. 1B is an enlarged cross-sectional view along a circumferential direction of a part of the CD shown in FIG. 1A.
  • FIG. 2 is a side view of a part of a CD according to a second embodiment of the present invention as viewed from the outer peripheral side.
  • FIG. 3A is a perspective view of a part of a CD according to a third embodiment of the present invention as viewed from above.
  • FIG. 3B is a perspective view of the CD— portion shown in FIG. 3A as viewed from below.
  • FIG. 4 is a perspective view showing a state in which the optical disk ring according to the present invention is mounted on a CD.
  • BEST MODE FOR CARRYING OUT THE INVENTION Through research and development on the effective recording and preservation of images on CDs (Compact Discs), measures to reduce digital noise generated inside conventional electronic circuits alone can be used as measures to reduce digital noise that occurs during playback signals on optical discs. Turned out to be insufficient. Therefore, the present inventor paid attention to the reduction of digital noise caused by the optical disk itself, and found that digital noise can be reduced by improving the irregular reflection, diffusion characteristics, and rotational stability inside the optical disk. .
  • FIG. 1A is a cross-sectional view of a part of a compact disc (CD) 10 according to a first embodiment of the present invention, where CD 10 is set in a CD player.
  • CD 10 compact disc
  • the recording surface of the CD 10 is mounted downward, and the laser beam 22 is projected from the optical pickup 20 provided on the lower surface 11 B side of the CD 10 .
  • the upper surface 11 A of the CD 10 is supported by the turntable 24, and the protrusion (not shown) of the clamper connected from the bottom to the module (not shown) is inserted into the center hole of the CD 10. Inserted.
  • the CD 10 is pushed upward by the clamper and clamped between the clamper and the turntable 24. Then, the CD 10 is rotated by driving the turntable 24.
  • FIG. 1B is an enlarged cross-sectional view of a part of CD 10 along the circumferential direction.
  • through holes 12 inclined 45 degrees in the circumferential direction are formed at equal intervals in the circumferential direction.
  • Each of the through holes 12 extends between the upper surface 11A and the lower surface 11B of the optical disk 10.
  • the light generated by the irregular reflection of the laser beam inside the optical disk is diffused in the outer and inner peripheral directions while being repeatedly reflected on the upper and lower surfaces of the optical disk.
  • the reflected light traveling in the inner circumferential direction is reflected on the inner end face of the optical disk.
  • the inner edge surface of the optical disk is a convex curved surface with respect to the reflected light, and is diffused and attenuated by reflection.
  • the outer edge of the optical disk is usually formed by a plane perpendicular to the upper and lower surfaces of the optical disk. Therefore, the reflected light traveling in the outer peripheral direction in the optical disk is reflected in the inner peripheral direction of the optical disk at the outer end face of the optical disk. The reflected light is repeatedly reflected on the upper and lower surfaces of the disk, is emitted from the optical disk while traveling in the inner circumferential direction, and may enter the optical pickup. This causes generation of digital noise, which affects reproduction sound quality or image quality.
  • reflected light traveling radially outward due to irregular reflection in the CD 10 enters the through-hole 12 and is attenuated by diffusion. Therefore, in the CD 10 of the present embodiment, in addition to the reduction of digital noise due to the prevention of surface runout due to rotation, the reduction of digital noise due to diffuse attenuation of reflected light due to irregular reflection in the disk can be achieved.
  • FIG. 2 is a side view of a part of the CD 30 according to the second embodiment of the present invention as viewed from the outer peripheral side.
  • the outer peripheral surface of CD 30 is formed in a saw blade shape.
  • the blade surface 14 is provided at an angle of 45 degrees in the circumferential direction. That is, a plurality of grooves 34 are formed on the outer edge face 32 of the CD 30 at equal intervals in the circumferential direction. Each of the plurality of grooves 34 extends between the upper surface 31A and the lower surface 31B of the optical disk 30, and extends in the rotational direction of the disk. It is inclined at 45 degrees to this.
  • FIG. 3A is a perspective view of a part of the CD 40 according to the third embodiment of the present invention viewed from above
  • FIG. 3B is a view of a part of the CD 40 shown in FIG. 3A viewed from below.
  • FIG. 3A is a perspective view of a part of the CD 40 according to the third embodiment of the present invention viewed from above
  • FIG. 3B is a view of a part of the CD 40 shown in FIG. 3A viewed from below.
  • a large number of fin-shaped protrusions 42 are provided on the outer peripheral surface 41 of the CD 40.
  • the convex portion 42 generates an airflow by the rotation of the CD 40, whereby the CD 40 is pressed in the direction of a turntable (not shown). Therefore, the rotational vibration of the CD 40 can be suppressed. Further, the reflected light inside the CD 40 is emitted to the outside of the CD 40 or diffused and attenuated by the convex portion 42.
  • the inclination angle of the convex portion 42 of the fin is preferably 45 degrees or more, and may be about 80 degrees.
  • the inventor removed the upper cover of the CD player, rotated the conventional CD and the above-mentioned CD 40 under the same conditions, and visually checked the runout. Due to the high-speed rotation, a considerable air flow was generated around the conventional CD, and the conventional CD clearly had runout.
  • the CD 40 according to the present example also generated a considerably strong airflow around it, but had a small rotational runout that could not be visually confirmed.
  • FIG. 4 is a perspective view showing a state in which the optical disk ring 60 according to the present invention is mounted on the CD 50.
  • the ring 60 is an annular member made of plastic, and has a large number of fins 62 provided on an outer peripheral portion thereof. Fin 62 is at a certain angle
  • the formed small plate-like projection is formed integrally with the main body 61 of the ring 60.
  • the fins 62 may be adhesively fixed to the ring body 61.
  • the fin 62 generates an airflow when the CD 50 rotates, and presses the CD 50 in the direction of the turntable (upward in the figure).
  • the ring 60 is fitted from the lower surface 52 side of the CD 50 such that the lower surface 52 of the CD 50 is in close contact with the projecting portion 64 at the lower inside of the ring.
  • the upper surface 54 which is the mounting surface of the CD 50 is pressed and clamped by a turntable (not shown). For this reason, the rotation touch of the CD 50 is suppressed, and diffuse reflection inside can be reduced.

Landscapes

  • Optical Head (AREA)
  • Holding Or Fastening Of Disk On Rotational Shaft (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

La présente invention concerne un disque optique (10) dont la zone proche du bord périphérique externe est pourvu d'une pluralité de trous traversants (12) joignant entre elles la face supérieure et la face inférieure (11A, 11B). Ces trous sont inclinés par rapport au sens de rotation du disque optique. Il en résulte une force ayant tendance à appliquer le disque sur la platine (24) concourant à empêcher les vibrations superficielles pendant la rotation du disque optique. Selon d'autres réalisations, ces trous traversants (12) peuvent être remplacés par des sillons inclinés (34) ou des protubérances en forme d'ailettes au niveau de la surface du bord périphérique externe du disque optique.
PCT/JP1999/000883 1998-03-12 1999-02-25 Disque optique et bague pour disque optique WO1999046771A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP8291098 1998-03-12
JP10/82910 1998-03-12
JP10/193792 1998-06-23
JP10193792A JPH11328727A (ja) 1998-03-12 1998-06-23 光ディスク及び光ディスク用リング

Publications (1)

Publication Number Publication Date
WO1999046771A1 true WO1999046771A1 (fr) 1999-09-16

Family

ID=26423938

Family Applications (2)

Application Number Title Priority Date Filing Date
PCT/JP1999/000882 WO1999046770A1 (fr) 1998-03-12 1999-02-25 Disque optique
PCT/JP1999/000883 WO1999046771A1 (fr) 1998-03-12 1999-02-25 Disque optique et bague pour disque optique

Family Applications Before (1)

Application Number Title Priority Date Filing Date
PCT/JP1999/000882 WO1999046770A1 (fr) 1998-03-12 1999-02-25 Disque optique

Country Status (2)

Country Link
JP (1) JPH11328727A (fr)
WO (2) WO1999046770A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11247288B2 (en) 2017-12-19 2022-02-15 Daihen Corporation Welding position detection device, welding position detection method, and welding robot system

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1193701A1 (fr) 2000-09-29 2002-04-03 Ricoh Company, Ltd. Support d'enregistrement optique et procédé de fabrication du support d'enregistrement optique
US20020136155A1 (en) * 2001-03-06 2002-09-26 Chieh-Ho Chen CD safe to hold
US6865745B2 (en) * 2001-08-10 2005-03-08 Wea Manufacturing, Inc. Methods and apparatus for reducing the shrinkage of an optical disc's clamp area and the resulting optical disc

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5712009U (fr) * 1980-06-24 1982-01-21
JPH0652060U (ja) * 1992-12-08 1994-07-15 九州日立マクセル株式会社 ディスク用ガードリング
JPH06309701A (ja) * 1993-04-28 1994-11-04 Ricoh Co Ltd ディスク状記録媒体

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0547035A (ja) * 1991-08-15 1993-02-26 Japan Synthetic Rubber Co Ltd 光デイスク基板
JPH05138679A (ja) * 1991-11-20 1993-06-08 Matsushita Electric Ind Co Ltd 光デイスク用樹脂成形基材および金型

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5712009U (fr) * 1980-06-24 1982-01-21
JPH0652060U (ja) * 1992-12-08 1994-07-15 九州日立マクセル株式会社 ディスク用ガードリング
JPH06309701A (ja) * 1993-04-28 1994-11-04 Ricoh Co Ltd ディスク状記録媒体

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11247288B2 (en) 2017-12-19 2022-02-15 Daihen Corporation Welding position detection device, welding position detection method, and welding robot system

Also Published As

Publication number Publication date
JPH11328727A (ja) 1999-11-30
WO1999046770A1 (fr) 1999-09-16

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