Claims
- 1. An optical disc, comprising:
- a pair of transparent substrates, one of said substrates having a surface opposing a surface of the other substrate, each of said pair of substrates including at least one layer enabling recording of information;
- an adhesive bonding and laminating said pair of substrates together, said adhesive contacting the opposing surfaces of said substrates over a major portion of a surface area of each of said pair of substrates;
- wherein said optical disc has an instantaneous axial acceleration<2 G.
- 2. An optical disc according to claim 1, wherein said optical disc includes an opening of circular cross-section at a center thereof and said adhesive contacts said opposing surfaces from a portion adjacent said opening radially outwardly to at least a portion adjacent a perimeter of said optical disc.
- 3. An optical disc according to claim 1, wherein said optical disc has a skew angle<5 mrad after being heated to a temperature above room temperature.
- 4. An optical disc according to claim 1, wherein said optical disc has a shear mass<20 .mu.m measured at room temperature after being heated to a temperature above room temperature.
- 5. An optical disc according to claim 1, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at 80.degree. C. for one hour.
- 6. An optical disc according to claim 1, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at 80.degree. C. for up to one hour.
- 7. An optical disc according to claim 1, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at a temperature of from 50 to 60.degree. C. for 1,000 hours.
- 8. An optical disc according to claim 1, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at a temperature of from 50 to 60.degree. C. for up to 1,000 hours.
- 9. An optical disc according to any one of claims 2 to 8, wherein said layer enabling recording of information is formed of a material solely responsive to light, and records domains without going through phase changes or shape changes in response to light or magnetic fields.
- 10. An optical disc according to any one of claims 2 to 8, wherein each of said pair of substrates has a thickness no greater than 1.2 mm.
- 11. An optical disc according to claim 1, wherein each of said substrates has an optical distortion less than 50 nm.
- 12. An optical disc according to claim 2, wherein said optical disc has a shear mass<20 .mu.m measured at room temperature after being heated at 80.degree. C. for one hour.
- 13. An optical disc according to claim 1, wherein said optical disc has a shear mass<20 .mu.m measured at room temperature after being heated at 80.degree. C. for up to one hour.
- 14. An optical disc according to claim 1, wherein said optical disc has a shear mass<20 .mu.m measured at room temperature after being left for 1,000 hours as heated at a temperature of from 50 to 60.degree. C.
- 15. An optical disc according to claim 1, wherein said optical disc has a shear mass<20 .mu.m measured at room temperature after being heated at a temperature of from 50 to 60.degree. C. for up to 1,000 hours.
- 16. An optical disc according to any one of claims 12 to 15, wherein each of said substrates has a thickness no greater than 1.2 mm.
- 17. An optical disc according to any one of claims 12 to 15, wherein each of said substrates has an optical distortion less than 50 nm.
- 18. An optical disc, comprising:
- a pair of transparent substrates, one of said substrates having a surface opposing a surface of the other substrate, each of said pair of substrates including at least one layer enabling recording of information;
- an adhesive bonding and laminating said pair of substrates together, wherein said layer enabling recording of information extends substantially in a direction of a plane of an opposing surface of said at least one of said pair of substrates, and said adhesive contacts the opposing surfaces at least in a region of the extent of said layer enabling recording of information;
- wherein said optical disc has an instantaneous axial acceleration<2 G.
- 19. An optical disc according to claim 18, wherein said optical disc has a skew angle<5 mrad after being heated to a temperature above room temperature.
- 20. An optical disc according to claim 18, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at 80.degree. C. for one hour.
- 21. An optical disc according to claim 18, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at 80.degree. C. for up to one hour.
- 22. An optical disc according to claim 18, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at a temperature of from 50 to 60.degree. C. for 1,000 hours.
- 23. An optical disc according to claim 18, wherein said optical disc has a skew angle<5 mrad measured at room temperature after being heated at a temperature of from 50 to 60.degree. C. for up to 1,000 hours.
- 24. An optical disc comprising:
- a pair of transparent substrates bonded and laminated with each other by means of an adhesive having a Shore hardness after cure of at least A30, each of said substrates having at least one layer enabling recording of information,
- wherein said optical disc has an instantaneous axial acceleration<2 G.
- 25. An optical disc according to claim 24, wherein each of said pair of substrates has a thickness not greater than 1.2 mm.
- 26. An optical disc according to claim 24, wherein said adhesive is a chemical reaction adhesive.
- 27. An optical disc according to any one of claims 2, 21, and 18 wherein said adhesive is a chemical reaction adhesive.
- 28. An optical disc according to any one of claims 2, 21, and 18 wherein said adhesive has a Shore hardness after cure of at least A30.
- 29. An optical disc according to any one of claims 2, 18, and 47, wherein said adhesive has a Shore hardness after cure no greater than A80.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3-056460 |
Mar 1991 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 08/671,841, filed Jun. 28, 1996, now U.S. Pat. No. 5,686,227 which is a continuation of application Ser. No. 08/375,730, filed Jan. 20, 1995, now U.S. Pat. No. 5,543,271 which is a continuation application of application Ser. No. 08/053,483, filed Apr. 29, 1993 (now U.S. Pat. No. 5,401,610) which is a divisional application of application Ser. No. 07/855,511, filed Mar. 20, 1992 (now U.S. Pat. No. 5,244,775).
US Referenced Citations (15)
Foreign Referenced Citations (3)
Number |
Date |
Country |
61-050231 |
Mar 1986 |
JPX |
61-142545 |
Jun 1986 |
JPX |
61-151853 |
Jul 1986 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
855511 |
Mar 1992 |
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Continuations (3)
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Number |
Date |
Country |
Parent |
671841 |
Jun 1996 |
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Parent |
375730 |
Jan 1995 |
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Parent |
053483 |
Apr 1993 |
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