219results about "Optical erasing systems" patented technology

Methods and apparatus are provided for making an optically readable media unreadable. The method includes steps of (a) providing the media with an optically activated mechanism that degrades the reflectivity of a surface wherein information is encoded; (b) exposing the media to optical radiation for reading out the information; and, during the step of exposing, (c) initiating the operation of the optically activated mechanism. In this embodiment the step of initiating includes steps of (d) generating singlet oxygen in a layer disposed on the media; and (e) reacting the singlet oxygen with a metal-containing layer for oxidizing the surface of the metal-containing layer, thereby degrading the reflectivity of the surface. In a further aspect the optically activated mechanism causes a defocusing of a readout beam, thereby degrading reflection of the readout beam from a surface wherein information is encoded. In another embodiment the method deforms a surface of the layer resulting in readout beam aberration or in an inability to correctly stay on track. In another embodiment a portion of the surface is removed to the atmosphere, such as by evaporation of sublimation. In this embodiment a layer of the media is comprised of a volatile component and at least one other component. Removing at least some of volatile component by evaporation or sublimation causes an increase in at least one of photoabsorption or scattering or surface roughness with the remaining component, thereby rendering at least a portion of encoded information of the media unreadable, or affecting the tracking operation.

In a recording material, physical characteristic information of the recording medium, and more specifically, material information representing the material of the disc, is recorded. Accordingly, a recording apparatus and a reading apparatus easily and accurately determine the physical characteristics of the disc, thereby making it possible to provide suitable setting for performing an operation.

A recording medium destruction apparatus capable of confirming that a recording medium no longer required is destroyed to enter an unreadable state is provided. In a recording medium destruction apparatus 91 that drives a pin 1 for destroying a recording medium 15 so that information recorded on the recording medium 15 is irreproducible, there is provided monitoring means 50 for monitoring situations where the recording medium 15 is destroyed. There are provided code number assignment means for assigning a code number to the recording medium 15 to be destroyed, and recording means for recording, when the recording medium 15 has been destroyed, the code number assigned to the destroyed recording medium and the date on which the recording medium has been destroyed.

If the storage medium 29 runs out of space when storing clip-target information as clip data, data having higher deletion-target priority than others is deleted from among a plurality of stored data to have empty spaces on the storage medium 29, and then the new clip-target information is stored. The deletion-target priority is determined based on attribution of a plurality of stored data. In this manner, new clip-target information is stored without user's operation, after automatically deleting data having higher deletion-target priority than others (the deletion-target priority is determined based on attribution of clip data). Therefore it is avoided that important clip data is automatically deleted without a user being notified.

Data is recorded on packet basis to a track of an optical recording medium and the data is pseudo-erased by erasing contents information of the track having the data. Information indicating the end position of the packet containing the data is recorded on the optical recording medium and a new data is recorded to the track where the data has been pseudo-erased in accordance with the information indicating the end position of the packet.

Data is recorded on packet basis to a track of an optical recording medium and the data is pseudo-erased by erasing contents information of the track having the data. Information indicating the end position of the packet containing the data is recorded on the optical recording medium and a new data is recorded to the track where the data has been pseudo-erased in accordance with the information indicating the end position of the packet.