Fujitsu Corporation

Satoshi Itami

Kenichi Utsumi

Masaru Nakahara

Hiroshi Suzuki

Kazuo Nakashima

Masahiro Nakada

Koichi Tezuka

Tohru Fujimaki

Kazunori Naito

Kyoko Miyabe

Kazushi Uno

Toshikatsu Narumi

Satoshi Komura

Makoto Yoshioka

Takashi Tsubokura

Koichi Ogawa

Kyouko Miyabe

An optical information recording/reproducing apparatus records information on and/or reproduces information from an optical recording medium based on a reflected light beam from the optical recording medium. The apparatus includes a light splitting part having a plurality of light splitting stages which split the reflected light beam from the optical recording medium into a plurality of light beams, and a photodetector unit including a plurality of photodetectors which receive the plurality of light beams from the light splitting part. The photodetector unit includes a plurality of photodetectors which receive light beams used to detect a focal error, at least one photodetector which receives a light beam used to detect a tracking error, and a plurality of photodetectors which receive light beams used to detect magneto-optic information recorded on the optical recording medium.

Optical information recording/reproducing apparatus

A vendor ID is written to a system area of a write-once optical disk. When the write-once optical disk is loaded onto a write-once disk drive, a control CPU reads the vendor ID. The vendor ID is written into the header of software received through an interface unit. When the software is input to an SD circuit, the control CPU reads the vendor ID. The control CPU compares the vendor ID in the system area of the write-once optical disk with the vendor ID of the header of the software and checks whether or not the two IDs are identical. If the two IDs correspond to each other, the control CPU writes the software to the write-once optical disk.

Software processing apparatus writing software to a medium only if identification information in the software corresponds to identification information in the medium

An optical disk includes a user accessible area having a plurality of blocks and flag data recorded on the optical disk. The flag data indicates whether or not each of the blocks is in an erased state in which there is no recorded data. A flag area stores the flag data, and area data indicating that the optical disk has the flag area is recorded on the optical disk.

Optical disk and optical disk apparatus

In a method for preventing unauthorized use of a recording medium having a user accessible area and a user inaccessible area, first information is read from the user inaccessible area of the recording medium. The first information is compared with second information concerning a true recording medium (lawfully produced copy). It is then concluded that the recording medium is the true recording medium when the first information corresponds to the second information.

Unauthorized use preventing method for optical disks, optical disk

A CD-ROM stores encrypted software. When a user desires to decrypt and install this software, an approval preparatory key is generated by an installer. This approval preparatory key is generated based on time data. When the user informs a center of this approval preparatory key, the center calculates a difference between this approval preparatory key and a decrypting key and vends this calculated result to a user in the form of an approval key. When the user inputs this approval key to an installer, the installer generates a decrypting key by adding the approval preparatory key to the approval key. The installer decrypts the software by this decrypting key and installs the encrypted software into a personal computer system.

System for decrypting encrypted software

A removable storage medium relates to a removable storage medium embodying an external storage medium for computer equipment. The removable storage medium can be inserted in an external storage apparatus connected to a computer equipment unit, and stores predetermined programs. The removable storage medium includes a correspondence table for specifying a correspondence relation between a physical drive configuration of the computer equipment unit connected to the external storage apparatus and a logical drive configuration of the stored programs. A recording device is provided for recording information on the correspondence table.

Removable storage medium and computer system using the same

An optical information recording/reproducing apparatus records information on and/or reproduces information from an optical recording medium and detects a focal error based on a reflected light beam from the optical recording medium. The apparatus includes a composite prism which deflects a part of the reflected light beam to at least two positions excluding a central part of the reflected light beam, and a photodetector device having a plurality of photodetectors which respectively detect the deflected parts of the reflected light beam and output detection outputs. The focal error is detected based on the detection outputs of the photodetector device.

Optical information recording/reproducing apparatus having a composite

Optical disk having an erased-state indicator and optical disk apparatus

A method of preventing a fraudulent use of an optical disk having a read-write region and a read-only region, comprising the steps of: writing data for designating the boundary between the read-write region and the read-only region into a predetermined block of the optical disk; reading the data out of the predetermined block prior to the execution of the software recorded on an optical disk as an object of fraudulent use check; reading data out of a block which is assumed to be in the read-only region by reference to the data read out of the predetermined block, and writing the data read out of the block in the assumed read-only region into the same block; reading data out of a block which is assumed to be in the read-write region by reference to the data read out of the predetermined block, and writing the data read out of the block in the assumed read-write region into the same block; and judging that the optical disk as an object of fraudulent use check is not a fraudulent copy when the data writing operation is impossible in the block in the assumed read-only region but possible in the block in the assumed read-write region.

Optical disk and method of preventing fraudulent use of optical disk

Unauthorized use prevention method for optical disks, optical disk

A character string retrieval system retrieves a character string corresponding to a retrieval key input thereto from a text file including a plurality of characters. The system includes an index indicating position data identifying a position of each of characters in the text file and indicating next character data identifying either a character or a character string formed of a plurality of characters arranged next to each of the characters in the text file, a selecting unit for selecting a first character from characters forming the character string corresponding to the retrieval key, a determining unit for determining, with reference to said index, whether or not a character or a character string next to the first character, selected by said selecting unit, in the retrieval key is equal to a character or a character string identified by the character data corresponding to the first character; and output unit for outputting a retrieval result when said determining unit determines that a character or a character string next to the first character in the retrieval key is equal to a character or a character string identified by the character data corresponding to the first character, the retrieval result being obtained based on the position data corresponding to the first character in said index.

Growing community of inventors

Kawasaki, Japan

Satoshi Itami