Abstract:
Data recording method and apparatus for optical memory cards which are adapted to prevent a recording error due to step-out during a data recording operation, and minimize a decrease in the recording capacity of an optical memory card. While data are recorded, an output from a SYNC mark detecting circuit (2) and that from an internal synchronizing signal generating circuit (3) are compared with each other in a comparator circuit (4). When step-out occurs, a write signal generating circuit (5) is stopped and the data recording operation is interrupted, and a re-recording operation is started at a frame adjacent to the frame in which a recording error occurred, on the basis of the value in a write cycle counter, whereby a decrease in the recording capacity of the optical memory card is minimized.
Abstract:
The present invention relates to a drive device and method of reading from or writing to a record carrier (10), wherein data is input or output via an interface (32) using a first format according to a first file system. In the drive device (30), the first format is mapped to a second format according to a second file system used on the record carrier (10). Thereby, it is possible to use different storage technology with the same interface, for example, a hard-disc based Microdrive can be used with a Compact Flash interface. This is especially advantageous in connection with removable drive devices.
Abstract:
Recording medium can be handled more easily because a card insertion direction to a card processor need not be limited to one direction. A magnetic stripe (11) of a magnetic card (10) stores, in a direction of the arrow (C) and in a sequence mentioned, a preamble data (21), a forward direction decision data (25), STX (24), a recording/reproducing data (23), backward direction decision data (26) and a postamble data (22). The forward direction decision data (25) and the backward direction decision data (26) consist of data rows of logical values, 0 and 1, which are combined under a preset condition, with the reverse arrangement of the backward direction decision data (26) not agreeing with the forward arrangement of the forward direction decision data (25). Therefore, a reading direction of a magnetic data can be specified by detecting either the forward direction decision data (25) disposed in a forward direction and following the preamble data (21) or the backward direction decision data (26) disposed in a reverse direction and following the postamble data (22).
Abstract:
A method and a device for recording data in an optical memory card which facilitate discrimination between an unrecorded area and a recorded area in the optical memory card and which prevent double over writing. Recording pits are formed so that data to be recorded on the optical memory card is recorded in the same way as when recorded in the MFM-RZ modulation system. Data that was recorded in the NRZI-RZ modulation system is reproduced and then recorded in the MFM-RZ modulation system. This method forms the recording pits at least every 2 recording intervals or less in the recorded area in the optical memory card, making it possible to discriminate the recorded area of the optical memory card from the unrecorded area according to the presence or absence of the recording pits and thereby prevent double writing.
Abstract:
An optical disk recording medium comprising an optical disk recording medium body and a display unit provided on the front side of the optical disk recording medium body, characterized in that a signal recording/deleting unit permitting the recording, rewriting and deleting of data is provided in the program area of the optical disk recording medium body, and data corresponding to what are displayed on the display unit are recorded in the signal recording/deleting unit.
Abstract:
An audiovisual data recording/reproducing system comprises receiving means for receiving commands from a controller; means that reads command reception information, data I/O information, buffer control information, write control information, and read control information on the storage device of the type corresponding to a received command from memory in order to load the retrieved information into registers; and processing means for performing control according to the contents of the registers.
Abstract:
A method and device for controlling the tracking of an optical memory card by which synchronism can be established easily, a track holding mistake can be detected and corrected easily, high speed operation can be realized and the double-writing, etc. can be avoided. The guide tracks (2) for optical memory cards are composed of the rows of guide track segments (4, 4a, 4b, 4c and 4d). A synchronizing signal is extracted from the row pattern of the guide tracks detected by photodetectors (11 and 12) and a data recording track (1) is identified to establish synchronism and a track holding mistake is detected and corrected.
Abstract:
Data are reproduced by reciprocally driving an optical card (200) in a direction parallel with tracks (T). A guide portion (G) without data pit is formed on both sides of each of the tracks to prevent read errors from occuring during the acceleration and deceleration of reciprocal movement. Track identification data (I) and end-of-track data (E) are recorded adjacent to the guide portion, and user data (U) are recorded therebetween. The user data are divided into groups which are recorded on the optical card in a dispersed manner. On the optical card are provided a directory pointer region (212), a directory region (213) and a data region (214). When the directory is changed accompanying a change in the data region, a new directory is written on the directory region, and a directory pointer that always indicates the position of the latest directory is written onto the directory pointer region.
Abstract:
A concrete data format to achieve the following assignments, i.e., (1) to control the reading operation of a line sensor for a unit read column, (2) to maintain synchronism with data bits during the reading operation, (3) to discriminate neighboring unit read columns, (4) to cope with the generation of errors during the reading operation, and (5) to efficiently access the data. To achieve the above assignments, the data bits are arranged in the form of unit read columns, bars are provided to guide the line sensor, and a format is formed to instruct a central position of the unit read columns. Further, special bars are provided to correct the inclination of the line sensor. The data bits are arranged at predetermined periods, and synchronizing bits are provided to maintain synchronism with the period of data bits during the reading operation. There are further provided discrimination bits to discriminate the neighboring unit read columns during the reading operation. The discrimination bits may be so arranged that columns of even numbers and columns of odd numbers are discriminated from each other. Besides, the discrimination bits may be composed of three bits to increase the reliability. The format of this invention has particular error check bit(s) to cope with errors that may develop during the reading operation. Further, the data are recorded in a dispersed manner to cope with errors such as local smudges, and others. To efficiently acces the data, necessary data such as predetermined addresses are recorded together with general data. The invention further discloses a method of forming bits by modulating digital signals, and an optical system and a signal processing system of a reader for the optical data recording card. The optical data recorded in by the method of the invention is expected to find extensive applications as a recording medium for computer programs, video and music data, and a variety of data bases.