Title:
OPTICAL STORAGE MEDIUM
Document Type and Number:
WIPO Patent Application WO/2000/065409
Kind Code:
A2
Abstract:
The invention refers to an optical storage medium from which information can be read out and/or into which information can be recorded with a light beam (6), said optical storage medium comprising one or more base members (1) bearing on the side of the base members (1) on which the light beam (6) is incident, one or more information storage layers (3) and at least one light-transmissive cover film (5) wherein said cover films (5) are bonded to each other, to the surface (2) of the base members (1) on which the light beam (6) is incident and/or to one or more information storage layers (3) by means of one or more light-transmissive pressure-sensitive adhesive layers (4), and wherein said cover films (5) are essentially optically isotropic at least at the wavelength or wavelength spectrum, respectively, of said light beam (6).
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Inventors:
SCHOEPPEL WOLFGANG (DE)
Application Number:
PCT/EP2000/003650
Publication Date:
November 02, 2000
Filing Date:
April 22, 2000
Export Citation:
Assignee:
3M INNOVATIVE PROPERTIES CO (US)
SCHOEPPEL WOLFGANG (DE)
SCHOEPPEL WOLFGANG (DE)
International Classes:
G03G5/00; G11B7/24; G11B7/254; G11B7/2542; G11B7/257; G11B7/26; G11B7/253; G11B7/2534; G11B7/258; G11B7/2585; (IPC1-7): G03G5/00
Foreign References:
| EP0287394A2 | 1988-10-19 | |||
| EP0384041A1 | 1990-08-29 | |||
| EP0855703A2 | 1998-07-29 | |||
| EP0526224A1 | 1993-02-03 | |||
| EP0345360A1 | 1989-12-13 | |||
| US4551733A | 1985-11-05 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 1998, no. O D, 30 January 1998 (1998-01-30) & JP 09 237440 A (NITTO DENKO CORP), 9 September 1997 (1997-09-09)
PATENT ABSTRACTS OF JAPAN vol. 009, no. 285 (P-404), 12 November 1985 (1985-11-12) & JP 60 125945 A (DAICEL KAGAKU KOGYO KK), 5 July 1985 (1985-07-05)
PATENT ABSTRACTS OF JAPAN vol. 99, no. 2, 26 February 1999 (1999-02-26) & JP 10 302316 A (RICOH CO LTD), 13 November 1998 (1998-11-13)
PATENT ABSTRACTS OF JAPAN vol. 013, no. 131 (P-850), 31 March 1989 (1989-03-31) & JP 63 300439 A (MATSUSHITA ELECTRIC IND CO LTD), 7 December 1988 (1988-12-07)
PATENT ABSTRACTS OF JAPAN vol. 006, no. 145 (P-132), 4 August 1982 (1982-08-04) & JP 57 066538 A (TOSHIBA CORP), 22 April 1982 (1982-04-22)
PATENT ABSTRACTS OF JAPAN vol. 012, no. 062 (P-670), 25 February 1988 (1988-02-25) & JP 62 204450 A (FUJITSU LTD), 9 September 1987 (1987-09-09)
PATENT ABSTRACTS OF JAPAN vol. 012, no. 288 (P-741), 8 August 1988 (1988-08-08) & JP 63 064645 A (CANON INC), 23 March 1988 (1988-03-23)
DATABASE WPI Section Ch, Week 198929 Derwent Publications Ltd., London, GB; Class A14, AN 1989-210062 XP002144535 & JP 01 146916 A (HITACHI LTD), 8 June 1989 (1989-06-08)
PATENT ABSTRACTS OF JAPAN vol. 009, no. 285 (P-404), 12 November 1985 (1985-11-12) & JP 60 125945 A (DAICEL KAGAKU KOGYO KK), 5 July 1985 (1985-07-05)
PATENT ABSTRACTS OF JAPAN vol. 99, no. 2, 26 February 1999 (1999-02-26) & JP 10 302316 A (RICOH CO LTD), 13 November 1998 (1998-11-13)
PATENT ABSTRACTS OF JAPAN vol. 013, no. 131 (P-850), 31 March 1989 (1989-03-31) & JP 63 300439 A (MATSUSHITA ELECTRIC IND CO LTD), 7 December 1988 (1988-12-07)
PATENT ABSTRACTS OF JAPAN vol. 006, no. 145 (P-132), 4 August 1982 (1982-08-04) & JP 57 066538 A (TOSHIBA CORP), 22 April 1982 (1982-04-22)
PATENT ABSTRACTS OF JAPAN vol. 012, no. 062 (P-670), 25 February 1988 (1988-02-25) & JP 62 204450 A (FUJITSU LTD), 9 September 1987 (1987-09-09)
PATENT ABSTRACTS OF JAPAN vol. 012, no. 288 (P-741), 8 August 1988 (1988-08-08) & JP 63 064645 A (CANON INC), 23 March 1988 (1988-03-23)
DATABASE WPI Section Ch, Week 198929 Derwent Publications Ltd., London, GB; Class A14, AN 1989-210062 XP002144535 & JP 01 146916 A (HITACHI LTD), 8 June 1989 (1989-06-08)
Attorney, Agent or Firm:
Wilhelm, Stefan M. (3M Deutschland GmbH Office of Intellectual
Property Counsel Carl-Schurz-Str. 1 Neuss, DE)
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Claims:
Patent Claims
| 1. | Optical storage medium from which information can be read out and/or into which information can be recorded with a light beam (6), said optical storage medium comprising one or more base members (1) bearing on the side of the base members (1) on which the light beam (6) is incident, one or more information storage layers (3) and at least one light transmissive cover film (5) wherein said cover films (5) are bonded to each other, to the surface (2) of the base members (1) on which the light beam (6) is incident and/or to one or more information storage layers (3) by means of one or more lighttransmissive pressuresensitive adhesive layers (4), and wherein said cover films (5) are essentially optically isotropic at least at 20 °C and at least at the wavelength or wavelength spectrum, respectively, of said light beam (6). |
| 2. | Optical storage medium according to claim 1 wherein said cover films (5) exhibit a vertical birefringence of less than 0.001 at 20 °C at least at the wavelength or wavelength spectrum, respectively, of said light beam (6). |
| 3. | Optical storage medium according to any of claims 1 and 2 wherein said cover films (5) exhibit an inplane retardation of less than + 30 nm at 20 °C at least at the wavelength or wavelength spectrum, respectively, of said light beam (6). |
| 4. | Optical storage medium according to claims 12, comprising one base member (1) the surface (2) of which bearing a structure of pits on which an information storage layer (3) is formed. |
| 5. | Optical storage medium according to claims 14 comprising one light transmissive cover film (5) bonded to the information storage layer (3) on the surface (2) of the base member (1) by means of a lighttransmissive pressuresensitive adhesive layer (4). |
| 6. | Optical storage medium according to one of claims 15 wherein the light transmissive cover film or films (5) is or are formed by casting of one or more polymers dissolved in a solvent with subsequent drying and/or curing. |
| 7. | Optical storage medium according to claim 6 wherein the polymers dissolve in a solvent are selected from a group of polymers consisting of polycarbonate, cellulose triacetate or polyolefinbased polymers. |
| 8. | Optical storage medium according to one of claims 15 wherein the light transmissive cover film or films (5) are formed by casting of a polymerizable precursor of a polymer with subsequent curing. |
| 9. | Optical storage medium according to claim 8 wherein the polymerizable precursor of the polymer comprises at least one acrylicfunctional monomer which, when polymerized, displays a glass transition temperature of at least 10 °C and is not friable. |
| 10. | Optical storage medium according to claims 8 or 9 wherein the polymerizable precursor of the polymer contains blended therein one or more further polymers. |
| 11. | Optical storage medium according to claims 810 wherein the polymerizable precursor of the polymer comprises a monomer component selected from the group comprising (methyl) methacrylate, (methyl) ethylacrylate, (methyl) propylacrylate, lower amounts of (methyl) (C4 C8 alkyl) acrylates, acrylonitrile, styrene alkyl acrylates, methacrylamides and alkyl substituted methacrylamides, one or more polymerization initiators and optionally one or more vinyl monomers having one or more unsaturated double bonds copolymerizable with the monomer (s) of the polymerizable precursor. |
| 12. | Optical storage medium according to any of claims 1 to 11 wherein the thickness of the lighttransmissive cover film or films (5) is from 10 lim to 200 pm. |
| 13. | Optical storage medium according to any of claims 112 wherein the thickness of the lighttransmissive pressuresensitive adhesive layer or layers (4) is from 10 pm to 100 m. |
| 14. | Optical storage medium according to any of claims 113 wherein the variation of the thickness of each lighttransmissive cover film (5) and/or the variation of the thickness of the optical recording medium introduced by each lighttransmissive cover film (5) as measured across an arbitrarily selected crosssection of the optical recording medium over its entire extension is not more that about 3 pLm. |
| 15. | Optical storage medium according to any of claims 114 wherein the variation of the thickness of each lighttransmissive pressuresensitive adhesive layer (4) and/or the variation of the thickness of the optical recording medium introduced by each lighttransmissive pressuresensitive adhesive layer (4) as measured across an arbitrarily selected crosssection of the optical recording medium over its entire extension is not more than about 3 J. m. |
| 16. | Optical storage medium according to any of claims 115 comprising one lighttransmissive cover film (5) and one lighttransmissive pressure sensitive adhesive layer (4) wherein the sum of the variation of the thickness of the lighttransmissive cover film (5) or the variation of the thickness of the optical medium introduced by the lighttransmissive cover film (5), respectively, and the variation of the thickness of the light transmissive pressuresensitive adhesive layer (4) or the variation of the thickness of the optical recording medium introduced by the pressure sensitive adhesive layer (4), respectively, is not more than 5 m, whereby such sum is measured across an arbitrarily selected crosssection of the optical recording medium over its entire extension. |
| 17. | Method of preparing an optical recording medium according to any of claims 116 comprising (1) providing at least one base member (1) having a surface (2) on which the light beam (6) is incident, said surface optionally comprising a structure of pits bearing an information storage layer (3), (2) providing a multilayer film (12) comprising in the order given a releasable protective film (7), a lighttransmissive cover film (5) the inner surface of which optionally comprising a structure of pits bearing an information storage layer (3), a lighttransmissive pressuresensitive adhesive layer (4) and a release liner (8), optionally further comprising between the lighttransmissive cover film (5) and the pressure sensitive adhesive film one or more further lighttransmissive cover films (5') bonded to each other by means of one or more further light transmissive pressuresensitive adhesive layers (4') (3) removing said release liner (8) and (4) laminating the multilayer film (12) to the surface (2) of the information storage layer (3) on the surface (2) of the base member (1). |
| 18. | Method according to claim 17 wherein at least one of the lighttransmissive cover films (5) and (5'), respectively, are prepared by casting a curable precursor of such lighttransmissive cover films (5) and (5'), respectively, onto a surface with subsequent curing, whereby said surface may be formed by a nonexposed surface of one of the layers of the multilayer film (12) or by a substrate on which the lighttransmissive cover film is formed with subsequent incorporation as a cured layer into the multilayer film (12). |
Description:
Inter al Appileatbn No INTERNATIONALSEARCH REPORT C.(Continuatlon) DOCUMENTS CONSIDERED TOBERELEVANT Category° Citationofdocument,withindication,whereappropnate,oftherelev
antpassagesRelevanttodaimNo. YEP0855703A(KITANOENGINEERINGCOLTD)1-18 29July1998(1998-07-29) column2,line5-column3,line36;claim 1 column5,line50-column6,line3 XEP0526224A(CANONKK)1-8,13, 3February1993(1993-02-03)17,18 Ypage4,line21-line24;claims1,22;12,14-16 figure1 XPATENTABSTRACTSOFJAPAN1 vol.009,no.285(P-404), 12November1985(1985-11-12) &JP60125945A(DAICELKAGAKUKOGYOKK), 5July1985(1985-07-05) abstract XPATENTABSTRACTSOFJAPAN1 vol.99,no.2, 26February1999(1999-02-26) &JP10302316A(RICOHCOLTD), 13November1998(1998-11-13) abstract YPATENTABSTRACTSOFJAPAN8-13 vol.013,no.131(P-850), 31March1989(1989-03-31) &JP63300439A(MATSUSHITAELECTRICIND COLTD),7December1988(1988-12-07) abstract XEP0345360A(FUJIMORIKOGYOCO)1,3 13December1989(1989-12-13) page4,line8-line13;example2 XUS4551733A(CORNETJEANETAL)1,2 5November1985(1985-11-05) column3,line14-line30;claims1,2,5 XPATENTABSTRACTSOFJAPAN1,2 vol.006,no.145(P-132), 4August1982(1982-08-04) &JP57066538A(TOSHIBACORP), 22April1982(1982-04-22) abstract XPATENTABSTRACTSOFJAPAN1,2 vol.012,no.062(P-670), 25February1988(1988-02-25) &JP62204450A(FUJITSULTD), 9September1987(1987-09-09) abstract 1 1 INTERNATIONALSEARCHREPORT m PCT/EP00/03650 C.(Continuation)DOCUMENTSCONSIDEREDTOBERELEVANT Category° Citation of document, with indication,whereappropnate,oftherelevantpassagesRelevanttoda
imNo. XPATENTABSTRACTSOFJAPAN1,3, vol.012,no.288(P-741),14-16 8August1988(1988-08-08) &JP63064645A(CANONINC), 23March1988(1988-03-23) abstract XDATABASEWPI1,3 SectionCh,Week198929 DerwentPublicationsLtd.,London,GB; ClassA14,AN1989-210062 XP002144535 &JP01146916A(HITACHILTD), 8June1989(1989-06-08) abstract 1 INTERNATIONALSEARCHREPORT lnti-sal Application No 7notion on patent fwnily members PCT/EP 00/03650 PatentdocumentPublication Patent family Publication citedinsearchreportdatemember(s)date EP0287394A19-10-1988JP2754204B 20-05-1998 JP63271741A 09-11-1988 DE3888006D07-04-1994 DE3888006T 21-07-1994 JP1078447A 23-03-1989 JP2531738B 04-09-1996 US5248990A 28-09-1993 JP 09237440 A 09-09-1997 NONE EP0384041A29-08-1990DE68916530D 04-08-1994 DE68916530T 24-11-1994 JP2266979A 31-10-1990 JP2899711B 02-06-1999 US5147490A 15-09-1992 EP0855703A29-07-1998JP10208319A 07-08-1998 US 5980677 A 09-11-1999US 5980677 A 09-11-1999 EP0526224A03-02-1993JP5198009A 06-08-1993 US 5312714 A 17-05-1994JP 60125945 A 05-07-1985 NONEus5312714 A 17-05-1994 JP60125945A05-07-1985NONE JP 10302316 A 13-11-1998 NONE JP63300439A07-12-1988JP2094780C 02-10-1996 JP 8003916 B 17-01-1996JP 8fl03916 B 17-O1-1996 EP0345360A13-12-1989JP1162250A 26-06-1989 JP2545253B 16-10-1996 DE3855235D 30-05-1996 DE3855235T 05-09-1996 WO8906036A 29-06-1989 US5051314A 24-09-1991 US4551733A05-11-1985FR2524186A 30-09-1983 CA1193364A 10-09-1985 DE3376904D 07-07-1988 EP0089874A 28-09-1983 JP2519025B 31-07-1996 JP58171735A 08-10-1983 JP57066538A22-04-1982JP1614334C 15-08-1991 JP 63018252 B 18-04-1988JP 63018252 B 18-04-1988 JP62204450A09-09-1987NONE JP63064645A23-03-1988JP2075406C 25-07-1996 JP7107753B 15-11-1995 JP 1146916 A 08-06-1989 NONE