Patent Application
20070273684
The “state” can include any data relating to the first storage element. For example, state data may comprise the number of times that the first data storage element has been accessed. Such a function can be useful for restricting the number of times the data in the first data storage element 1a is read. State might also contain a reference to the most recently read portion of one or more text, audio, or video files represented on the first storage element 1a. The state may reference a the execution of an application or game stored on the first storage element. In like manner, the state can be used to refer to one or more hyperlinked documents as might be opened and traversed in a web browser.
A benefit of using different storage materials for the first storage element 1a and the second storage element 1b is that specific properties of the different storage materials can be advantageous for different types of data. For example, some data storage materials have a high data storage capacity. Other data storage materials may accept additional data or may permit the erasure of existing data. By using two different data storage materials, the portable data storage device can exhibit data storage and retrieval properties that are more difficult to achieve in portable data storage devices which use only one data storage material.
For example, a DVD-like portable data storage device 1 may have a first storage element 1a which comprises a read-only first storage material containing video data. In this example, the first storage material has a high data-density and is therefore capable of storing a large quantity of data. The second storage element comprises a second storage material which may hold significantly less data. In this example, the second storage material permits writing additional data into storage, but does not permit any erasing of data from the second storage element 1b. Such a portable data storage device can be used as part of a system to prevent the portable data storage device 1 from being read more than a certain number of times.
A benefit of placing both storage elements on the same portable data storage device is that the state data can be kept with the stored data at all times. In this way, an application can be kept with its configuration, a virtual machine can be kept with its state, and a series of documents can be kept with a number of annotations or revisions.
Where a number of users are reading from the first storage element 1a from time to time, a corresponding plurality of state information references may be stored on magnetic element 1b, subject to suitable addressing controls by control device 5 (e.g. each user may identify himself or herself by a personal code).
In some embodiments, it may be advantageous to enable reading from (or writing to) the second storage element at a distance different from that for which the first storage element may be accessed. In one example, a radio frequency request can determine if any media (portable data storage devices) within a 6 foot radius have not been read.
While changes and variations to the embodiments may be made by those skilled in the art of data storage and retrieval, the scope of the invention is to be determined by the appended claims.
