Optical disk initialization method and apparatus
View Patent ↗A method and apparatus for initializing an optical recording medium comprising a phase change material using a series of flashes of light. A series of low-power, high duty cycle flashes of light are produced to initialize the media to a crystalline form, onto which data may be recorded. In accordance with another aspect of this invention, a spiral flash bulb with centrally located connectors comprises the flash illumination source for initializing the optical recording media.
1. A method of initializing an optical recording medium comprising:
exposing said medium to a first flash of light from a light source, said flash of light having a duration greater than one micro-second and less than about one millisecond; and
repeating said exposure one or more additional times at a rate of at least about one flash per second.
2. The method of claim 1 comprising exposing said media to two or more 100 to 200 micro-second flashes.
3. The method of claim 2 , further comprising generating said flashes at a repetition rate of approximately 10 to 50 flashes per second.
4. The method of claim 1 , comprising exposing said media to five approximately 150 micro-second flashes.
5. The method of claim 1 , wherein the process is stopped before initialization is complete to prime the surface for writing crystalized marks on amorphous medium.
6. The method of claim 1 further comprising the step of rotating said media during said exposing.
7. An apparatus for initializing an optical recording media comprising:
one or more flashbulbs;
a support configured to hold said media in approximate alignment with said one or more flashbulbs; and
a control circuit configured to flash said one or more flashbulbs, at a rate of at least about one flash per second, wherein said flash has a duration greater than one micro-second and less than about one millisecond and said media is exposed to two or more flashes.
8. The apparatus of claim 7 , wherein said support is rotatable.
9. The apparatus of claim 7 , wherein said one or more flashbulbs is in a spiral configuration having ends located proximate to the center of the spiral.
10. The apparatus of claim 7 , further comprising a transparent or semi-transparent plate between said one or more flashbulbs and said media.
11. The apparatus of claim 10 , wherein said plate is diffusing.
12. The apparatus of claim 10 , wherein said plate comprises a variable neutral density filter formed by exposure of a photosensitive material to said flash.
13. The apparatus of claim 7 , wherein an outside diameter of one or more flashbulbs is larger than an outside diameter of said media in order to assure proper illumination uniformity at outside parts of said media.
14. The apparatus of claim 7 , wherein said control circuit is further configured to expose said media to two or more 100 to 200 micro-second flashes.
15. The apparatus according to claim 7 , wherein said control signal is further configured to generate said flashes at a repetition rate of approximately 10 to 50 flashes per second.
16. The apparatus of claim 7 , wherein said control circuit is further configured to expose said media to five approximately 150 micro-second flashes produced at a repetition rate of approximately 30 flashes per second.
17. The apparatus of claim 7 , wherein said control circuit is further configured to stop initialization before initialization is complete to prime a surface of said media for writing crystalized marks on amorphous medium.
18. A method of initializing an optical recording media comprising exposing a layer of material on said media to a series of two or more low energy, high duty-cycle flashes of light.
19. The method of claim 18 , wherein each of said flashes has sufficient intensity and duration to only partially crystallize said layer of material.
20. The method of claim 19 , wherein said duty cycle is high enough to substantially completely crystallize said layer of material within approximately five seconds.
21. The method of claim 19 , wherein said duration is greater than one micro-second and less than about one millisecond.
22. The method of claim 19 , wherein said duty cycle is more than about 10 flashes per second.
23. The method according to claim 1 , comprising exposing said media to flashes produced at a repetition rate of approximately 30 flashes per second.
24. The apparatus of claim 10 , wherein said plate is wavelength-selective.
25. The apparatus of claim 10 , wherein said plate comprises a variable neutral density filter.