Undertaking
Patent
1978-12-14
1980-03-25
Cardillo, Jr., Raymond F.
Undertaking
1791003V, 274 42R, 3461351, H04N 576, G11B 724
Patent
active
041953134
ABSTRACT:
A flat major surface of a disc-shaped substrate (e.g., of glass) is coated with a light-reflective layer (e.g., of aluminum) which is coated with a dielectric material (e.g., silicon dioxide) highly transparent for light of a frequency supplied by a recording laser and of a thickness equal to an integer multiple of the half-wavelength of the laser light output in the dielectric material. The dielectric material is coated with a layer of material moderately absorptive for light of the frequency supplied by the recording laser (e.g., an organic dye such as fluorescein). The coating parameters are chosen to establish an anti-reflection condition for the coated record blank at the recording light frequency. The light output of the laser, which is intensity modulated in accordance with a signal to be recorded, is focused upon the coated surface of the disc as the disc is rotated. With the peak intensity of the focused light sufficient to cause ablation of the absorptive layer, an information track is formed as a succession of spaced pits in which the reflective layer is effectively exposed through the layer of dielectric material. For playback, light of a constant intensity is focused on the information track as the disc is rotated. The focused light is of insufficient intensity to effect ablation of the remaining absorptive layer, but is of a frequency at which the undisturbed regions of the coated disc exhibit an anti-reflection condition. A photodetector, positioned to receive light reflected from the information track as the pits pass through the path of the focused light, develops a signal representative of the recorded information.
REFERENCES:
patent: 3665483 (1972-05-01), Becker et al.
patent: 4023185 (1977-05-01), Bloom et al.
patent: 4069487 (1978-01-01), Kasai et al.
patent: 4097895 (1978-06-01), Spong
patent: 4101907 (1978-07-01), Bell et al.
Greenblott, "High Density Recording by Vaporization of Film Areas," IBM Tech. Disc. Bulletin, vol. 14, No. 8, 1/72, p. 2358.
Bartolini Robert A.
Bell Alan E.
Cardillo, Jr. Raymond F.
RCA Corporation
Roehling J. E.
Tripoli J. S.
Whitacre E. M.
LandOfFree
Antireflective information record having an optically passive tr does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antireflective information record having an optically passive tr, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antireflective information record having an optically passive tr will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1404278