Abstract: An optical transmission device includes: an attenuator that attenuates an optical signal before being input into an optical element by a predetermined attenuation amount determined so that a level of an adjustment optical signal input into the optical element falls within a predetermined dynamic range of the optical element; and a controller that adjusts the predetermined attenuation amount so that a level of the optical signal input into the optical element falls within the predetermined dynamic range.

Abstract: An information recording medium (100) is a recording medium to/from which data can be written/read from a data processing apparatus. The recording medium includes a host interface (110) for communicating with the data processing apparatus, a data storage section (130) having a plurality of recording regions (#1, . . . ,#N) for storing data, and a region information storage section (124) for storing information on each recording region. The region information storage section (124) stores information about address attribute of each recording region of the data storage section (130). The information about the address attribute includes information indicating unit (byte or sector) of address specified on access to the recording region.

Abstract: A predetermined number of erasable blocks positioned at a start of a volume area in a semiconductor memory card are provided so as to include volume management information. A user area following the volume management information includes a plurality of clusters. A data length NOM of an area from a master boot record & partition table sector to a partition boot sector is determined so that the plurality of clusters in the user area are not arranged so as to straddle erasable block boundaries. Since cluster boundaries and erasable block boundaries in the user area are aligned, there is no need to perform wasteful processing in which two erasable blocks are erased to rewrite one cluster.

Abstract: An information recording medium such as a semiconductor memory card includes a first semiconductor memory having a first recording area accessed by a relatively small access unit and storing file system management information, a second semiconductor memory having a second recording area accessed by a relatively large access unit and storing file data (file entity data), and a controller for controlling the first and second semiconductor memories. The information recording medium selects either one of recording areas of the first and second semiconductor memories depending on the data type, and writes data into the selected recording area.

Abstract: A predetermined number of erasable blocks positioned at a start of a volume area in a semiconductor memory card are provided so as to include volume management information. A user area following the volume management information includes a plurality of clusters. A data length NOM of an area from a master boot record & partition table sector to a partition boot sector is determined so that the plurality of clusters in the user area are not arranged so as to straddle erasable block boundaries. Since cluster boundaries and erasable block boundaries in the user area are aligned, there is no need to perform wasteful processing in which two erasable blocks are erased to rewrite one cluster.

Abstract: While reproducing content stored in a recording medium, a user terminal as a data processing device downloads a related content as different content related to the reproduction target content from a content distribution server via a communication network. Immediately after the reproduction of the reproduction target content is completed, a notification prompting reproduction or purchase of the related content is provided. This permits immediate reproduction of the related content when the user purchases it, which reduces the user's waiting time, thus improving purchase motivation for the related content.

Abstract: A recording medium for recording digital data includes a content storage area for storing a plurality of content groups; a selector storage area for selecting one of the plurality of content groups; and a retrieved-information storage area for storing information to be retrieved. A data reproducing device switches selectors, whereby the data of all of the content groups can be reproduced in such a manner that the specification of the recording medium is conformed.

Abstract: A host information memory is provided in a semiconductor memory card and a data write start address and a data size supplied by an access unit are stored. A free physical area generation section determines whether or not to perform erasing of an invalid block of a nonvolatile memory when writing of data based on the data write start address and data size, and determines the number of blocks to be erased. When erasing, writing of data and erasing of invalid blocks are simultaneously performed with respect to different memory chips. Erase process of data, herewith, can be optimized and high speed access from the access unit to a semiconductor memory card can be realized.

Abstract: A region management method for an information recording medium capable of maintaining data interchangeability among devices and preventing malfunction when one information recording medium shared among devices different in type or number of file systems that can be interpreted by devices is provided. A recording region of the information recording medium is divided into a plurality of regions, and region information such as position and size of each region is held in the information recording medium. Different file systems are constructed in individual data recording regions. In response to a command from an information processing apparatus, accessible regions by the information processing apparatus are changed over by, for example, referring to validity flag information that indicates a presently valid region.

Abstract: A method for switching a transmission route in an optical network. A regenerator station extracts a main signal, and detects the input level of the main signal. When the input level falls below a threshold, the regenerator station determines that a failure occurs, and stops output of a main signal from the regenerator station, and transmits a control signal indicating occurrence of the failure to a receiver station, which separates the control signal from a main signal transmitted thereto, detects the input level of the main signal at the receiver station, analyzes the separated control signal, and determines whether or not a failure occurs. When the input level of the main signal at the receiver station falls below a threshold, or when the separated control signal indicates occurrence of a failure, the receiver station detects the occurrence of the failure, and switches the transmission route.

Abstract: When a file system control part 155A writes file data into a main memory 142, a file can be easily written continuously and the number of file copy can be decreased at updating a directory entry by writing the file data and a directory entry into different allocation units. In this manner, when using a nonvolatile memory in which physical block size as an erase unit is larger than cluster size, the write performance can be enhanced.

Abstract: A semiconductor recording medium holds an open flag showing presence or absence of consistency between content data stored in a data storage section and file system management information, in a system region not directly accessible from a host device. Upon receipt of a write request or erase request to the data storage section from the host device, the semiconductor recording medium automatically updates the open flag to “ON” (value showing possibility of inconsistency). When actual consistency is verified, the host device requests the recording medium to set the open flag to “OFF” (value showing presence of consistency). When mounting, the host device refers to the open flag with a special command to judge necessity for error check process.

Abstract: In a storage medium which has a number of areas, access to any area is controlled in accordance with whether or not access to another area is possible, and thereby, destruction of data due to malfunctioning or a wrong operation is prevented. A link control part which controls access to the second area based on the information on access to the first area is provided, and access to the second area is controlled on the basis of whether or not access to the first area is possible. Control becomes possible, such that access to the second area becomes impossible in the state where access to the first area is impossible, while access to the second area becomes possible in the case where access to the first area is possible.

Abstract: The server apparatus (120) includes a CPU (121), a RAM (122), a cipher processing unit (123) for carrying out encryption and decryption, a communication processing unit (124) for carrying out communication with an information processing terminal (100), a data storage unit (125) for storing information that does not require confidentiality, a distribution information storage unit (126) for storing information such as a program to be distributed, and a specific information distribution history holding unit (140) for holding a specific information distribution history (600) for managing a record of a program specific information of a program previously distributed to the information processing terminal (100).

Abstract: A semiconductor memory card 1 includes a user data area 21 and a management information area 22, in a data storing unit 2. According to a writing test command from a memory access device 6, a memory controller 3 writes data into a user data storing area and measures the writing rate, and transmits the measurement result to the memory access device 6 via a host interface unit 4. Thereby, the memory access device 6 can recognize the writing rate.

Abstract: An apparatus and method which can achieve high-speed data processing and long memory life and is effective to elimination of defragmentation of data, for example, is provided. A recording medium includes a logical-physical conversion table for storing correspondence of a logical address to a physical address of a block in a recording region. The recording medium has a function of replacing correspondence of a logical address to a physical address in the logical-physical conversion table, for a set of logical addresses. A data processing apparatus issues a replace command to the recording medium so that data can be rearranged on a consecutive region in the logical address space, thereby eliminating defragmentaion on the logical address space.

Abstract: An information recording medium includes a data storage section having a plurality of recording regions for storing data, and a region information storing section operable to store information about each recording region in the data storage section. The region information storing section stores information about a recording region (for example, a recording region has been accessed finally) which is set first as an accessible region when the information recording medium is initialized at the next time among a plurality of recording regions in the data storage section. A data processing apparatus refers to the information about the recording region and changes over a recording region to the recording region specified by the information about the recording region just after initialization of the recording medium.

Abstract: Areas in an information medium 507 having a plurality of information storing areas 506 which are managed by different file systems are switched by means of a display control part 502 and a medium control part 503, and information for clearly notifying the utilized information storing area 506 from the information medium 507 is displayed on a display part 501. In addition, a switched areas notifying part 508 is provided in order to notify to a user that the area has switched using a mode of display, sound, light or the like.

Abstract: An optical-level control apparatus includes a plurality of variable optical attenuators each used for attenuating an input optical signal included in a wavelength division multiplexing signal as a component having a specific wavelength by applying a variable attenuation quantity, a plurality of control units each used for executing automatic control for automatically controlling the attenuation quantity in order to adjust the optical level of an optical signal output by a corresponding one of the variable optical attenuators to a target level in an ordinary normal state of the input optical signal, and a detection unit for detecting a loss of light failure of an optical signal input to each of the variable optical attenuators and detecting disappearance of the loss of light failure.

Abstract: An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.