Static information storage and retrieval – Radiant energy – Color centers
Patent
1988-12-08
1991-07-16
Psitos, Aristotelis M.
Static information storage and retrieval
Radiant energy
Color centers
365126, 369100, 369110, 430945, G11C 1304, G11C 700
Patent
active
050329731
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to an optical recording material, in particular to an optical recording material utilizing a photochromistic compound or a photochemical hole burning reaction (hereinafter referred to as PHB reaction).
PRIOR ART
FIG. 1 is a sectional view showing the conventional optical recording material and apparatus. Referring now to FIG. 1, reference numeral (1a) designates a source of a laser beam for use in recording, reference numerals (1b), (1c) designates a laser beam, reference numeral (3) designates an objective lens, reference numeral (2) designates a disc, reference numeral (2a) designates an optical recording material such as tellurium compounds, and reference numeral (2b) designates an optical recording material-supporting substrate formed of glass and the like. Reference numeral (4) designates a pit (small hole) recorded in the optical recording material as an information.
In operation, the informations are recorded by collecting the laser beam (1b) on a surface of the optical recording material (2a) by means of the objective lens (3) while rotating the disc (2) and modulating the laser beam by means of the information to be written. Thus, the information is written in the optical recording material (2a) in the form of the pit (the small hole) formed by the thermal processing.
In the method, in which the information is written by means of the thermal processing by the use of the laser beam in the above described manner, only one bit enters one pit.
Since the conventional optical recording material has the above described construction, the quantity of informations written per unit area of the recording material is determined by the number of pits which can be formed per unit area of the recording material. As a rule, in the existing writing by the use of a laser beam a diameter of a laser spot is about one micron and also a diameter of the pit is about one micron at most. Accordingly, the number of pits, which can be written per one square centimeter (1 cm.sup.2), that is, the memory capacity, amounts to 10.sup.8 bits/cm.sup.2 at most.
DESCRIPTION OF THE INVENTION
It is an object of the present invention to stabilize the preservation of the recorded informations. In addition, in the preferred embodiments of the present invention, it is an object of the present invention to provide an optical recording material capable of increasing a limiting value of the memory capacity per unit area to 10.sup.8 bits/cm.sup.2 or more by eliminating the above described problems incidental to the prior art and giving the multiplicity capable of writing the information in one spot of the optical recording material even at an order of wavelength of a light but not one bit in one spot.
An optical recording material according to the present invention comprises a recording member in which a compound having an inherent wavelength range of an optical absorption spectrum and a property of changing characteristics of the optical absorption spectrum before and after the absorption of light by absorbing a light within the optical absorption spectral wavelength range is linked with at least one macromolecular chain.
In addition, concretely speaking, the above described recording member has at least two kinds of different optical absorption spectral wavelength ranges, a recording medium being formed of a mixture comprising these recording members, whereby the multiple recording at an order of wavelength becomes possible within at least two optical absorption spectral wavelength ranges.
According to the present invention, the information is recorded by the use of a compound changing characteristics of the optical absorption spectrum before and after the absorption of light as the optical recording material, so that the characteristics of the optical absorption spectrum can be changed by applying a light within the optical absorption wavelength range of the molecule to the optical recording material and the existence of this change can be recorded in the form of signal of binary c
REFERENCES:
patent: 3568167 (1971-03-01), Carson
patent: 3654626 (1972-04-01), Geller et al.
patent: 3720921 (1973-03-01), Schools et al.
patent: 4101976 (1978-07-01), Castro et al.
patent: 4103346 (1978-07-01), Haarer et al.
patent: 4158890 (1979-06-01), Burland
patent: 4459682 (1984-07-01), Mossberg
patent: 4649518 (1987-03-01), Sadijan
patent: 4816367 (1989-03-01), Sakojiri
patent: 4819210 (1989-04-01), Miura et al.
patent: 4879009 (1989-11-01), Clark
patent: 4904561 (1990-02-01), Yamamoto
patent: 4910116 (1990-03-01), Nakai
IEEE Transactions on Electron Devices, vol. ED-18, No. 9, Sep. 71, pp. 724-732, "A True-Dimensional Display", by Lewis et al.
Modern Optics, Mar. 1967, pp. 743-752, "Properties of Photochromic Memories", by Herman.
IBM Journal of Research and Development, vol. 26, No. 2, Mar. 1982, pp. 198-208, "Multiple Photochemical Hole Burning in Organic Glasses and Polymers by Guitierrez et al.".
IBM Tech. Discl. Bull., vol. 21, No. 8, Jan. 79, p. 3333, "Magnetic and Electric Field Addressing of PHB Memories", by Castro et al.
"Topical Meeting on Optical Data Storage", Apr. 18-20, 1984, pp. WC-A2-1-4, SC-A3-1-4 & Thc-B1-1-4.
Garcia Alfonso
Mitsubishi Denki & Kabushiki Kaisha
Psitos Aristotelis M.
LandOfFree
Optical recording material containing photochromic compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Optical recording material containing photochromic compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical recording material containing photochromic compounds will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-136564