85results about "Holographic discs" patented technology

The present invention provides systems and methods for logically organizing data for storage and recovery on a data storage medium using a multi-level format. The present invention also provides systems and methods for protecting data stored on data storage medium so that the data may be recovered without errors.

An optical medium piracy system employing a state-change material in association with a digital data indicia, wherein when state-change material is activated to change state, the optical medium moves from an unreadable to a readable condition, or from a less readable to more readable condition.

A method for encoding in a holographic disk storage medium is provided. The method includes recording multiple micro-holograms such that the micro-holograms are aligned across a respective plurality of tracks and across a respective plurality of layers at a pre-determined location of an original holographic disk. The method also includes detecting a characteristic waveform signal of a reflected beam from the original holographic disk. The method further includes detecting a second waveform signal from a second holographic disk. The method also includes comparing the second waveform signal with the characteristic waveform signal. The method further includes determining authenticity of the second holographic disk based upon comparison.

A low-density parity-check (LDPC) decoder includes a plurality of bit node processing elements, and a plurality of check node processing elements. The LDPC decoder also includes a plurality of message passing memory blocks. A first routing matrix couples the plurality of bit node processing elements to the plurality of message passing memory blocks. A second routing matrix couples the plurality of check node processing elements to the plurality of message passing memory blocks. The first routing matrix and the second routing matrix enable each bit node to exchange LDPC decoding messages with an appropriate check node via a corresponding one of the message passing memory blocks.

A method for irradiating a medium with a wave which is designed to focus on a particular portion in the medium, the method includes: irradiating the medium with an electromagnetic wave which is scattered in the medium, and is not designed to focus on the particular portion in the medium; detecting a first signal caused by irradiating the medium with the electromagnetic waver; irradiating the medium with a reconstructed wave which is designed to focus on the particular portion in the medium; detecting a second signal caused by irradiating the medium with the reconstructed wave; and monitoring, based on the first and second signals, that the particular portion is irradiated by the reconstructed wave.

A portable data storage cartridge comprising a housing, a first information storage medium removeably disposed within the housing, a holographic data storage medium disposed within the housing, wherein the housing is formed to include an aperture, and wherein the holographic data storage medium is disposed adjacent the aperture.

A method for irradiating a medium with a wave which is designed to focus on a particular portion in the medium, the method includes: irradiating the medium with an electromagnetic wave which is scattered in the medium, and is not designed to focus on the particular portion in the medium; detecting a first signal caused by irradiating the medium with the electromagnetic waver; irradiating the medium with a reconstructed wave which is designed to focus on the particular portion in the medium; detecting a second signal caused by irradiating the medium with the reconstructed wave; and monitoring, based on the first and second signals, that the particular portion is irradiated by the reconstructed wave.

A recording and reproducing device includes: a reference light irradiating section; a spatial light modulating section for generating information light; an information light irradiating section for irradiating the same region as a region irradiated with the reference light, with the information light; a light detecting section for receiving reproduction light; a known data storage section; a defect examining section for examining a defective position of the spatial light modulating section or the light detecting section by irradiating the information light and the reference light to write the known page data to the holographic recording medium, and then irradiating the medium with the reference light to read the known page data written on the holographic recording medium from the reproduction light received by the light detecting section; and a reproducing control section for restoring and reproducing the original data of the defective position using information of the defective position detected by the defect examining section.

To provide an optical recording method including: applying information and reference beams onto an optical recording medium to record information therein, the optical recording medium having a recording layer for recording the information by holography, wherein at least the information beam is passed through a spatial light modulator and is formed as a two-dimensional pattern composed of a data area and a plurality of synchronization marks for detecting information concerning the positions of data recorded in the data area, and wherein the synchronization marks are arranged in a random pattern so that in a Fourier-transformed image of the two-dimensional pattern, light intensities derived from the synchronization marks are lower than light intensities in a Fourier-transformed image of a two-dimensional pattern composed of a data area and a plurality of synchronization marks arranged in a grid pattern, the light intensities being derived from the synchronization marks arranged in a grid pattern.

A system is disclosed wherein a content is distributed without using a network. The distributed content is acquired and reproduced by a content acquisition apparatus.

Systems and methods for constructing low-density parity check codes for holographic storage are provided. The methods include selecting parameters of a low-density parity check code, determining the number of bit processing elements and the amount of memory in an accompanying decoder, and constructing a mother matrix representation of a quasi-cyclic parity check matrix. The low-density parity check codes are optimized for performance, memory considerations, and throughput.

An apparatus and method for processing optical information using a low density parity check code are suggested. An optical information recording method includes the steps of encoding data to record into a low density parity check code; representing the data, which is encoded into the low density parity check code, to a spatial light modulator in the unit of a data page; and modulating a recording beam into the data page representing the spatial light modulator to be recorded in the form of hologram in a recording medium. By blocking inexact probability information from being concentrated in the LDPC code block, by achieving exact probability information through effective allocation of a mark, and by improving average accuracy of the pixel, which corresponds to the LDPC code, failure rate of decoding can be minimized so that decoding performance can be improved.

A recording and reproducing apparatus has a recording control section for multiplex-recording data in one of recording unit regions of a holographic recording medium; a reproducing control section for selectively reproducing the data multiplex-recorded in the recording unit region; a measuring section for causing specific data to be recorded in a recording unit region A to measure a maximum multiplex-recordable number N of the region A; a multiplicity setting section for setting (i) a multiplex-recording number M (M<N) of data to be recorded in the region A and (ii) a multiplex-recording number (N−M) of a buffer region of the region A, by using the maximum multiplex-recordable number N; and a storage section for storing the number N and the number M. When data B is to be recorded in the region A beyond multiplex-recording number M, the recording control section multiplex-records page data B in the buffer region of the region A within the range of the maximum multiplex-recordable number N.

A two-dimensional coding method includes: using a two-dimensional image containing plural reference pixels each having a different brightness and data pixels representing data in accordance with brightness; and coding a binary sequence of plural bits to be recorded as a hologram by matching the brightness level of the data pixel based on the brightnesses of the plural reference pixels.

A reproducing device including a light source that emits light for reproducing recorded information to a hologram recording medium subjected to recording of information by interference fringes of signal light and reference light, a light irradiating unit that generates the reference light for obtaining a reproduced image according to the recorded information and DC light having uniform intensity and phase, and irradiates the hologram recording medium with both the reference light and the DC light and with only the DC light, a light receiving unit that performs light-reception for the DC light and the reproduced image, and performs light-reception for the DC light, and a difference calculating unit that calculates a difference between an image signal obtained based on a light-reception result of the reproduced image and the DC light, and an image signal obtained based on a light-reception result of the DC light.

An encoding apparatus that converts m-bit data words into n-bit code words, where m and n are both integers and satisfy an expression 2n≧2m×2, includes a first conversion table in which 2m m-bit data words are associated with 2m n-bit code words selected from 2n n-bit code words, a second conversion table in which the 2m m-bit data words are associated with 2m n-bit code words that have been selected from the 2n n-bit code words and that do not overlap with the 2m n-bit code words in the first conversion table, and an encoder configured to select and output an n-bit code word with which an m-bit data word that has been input is associated in the first conversion table or an n-bit code word with which the m-bit data word that has been input is associated in the second conversion table, the selected and output n-bit code word having a smaller number of symbols “1”.

There is provided an optical information detecting method. The method includes: detecting an image of a source data page coded with balanced codewords by the use of 1:N (where N is greater than 1) excessive detection pixels; determining a distribution pattern of valid detection pixels and invalid detection pixels to be corrected in the detected image by the use of a light intensity distribution of the detected image; and dividing the detected image into balanced codeword detecting areas corresponding to the balanced codewords and sampling data of the balanced codeword detecting areas by the use of the determined distribution pattern and an optical distribution characteristic of the balanced codewords. Accordingly, it is possible to efficiently detect optical information by the use of a 1:N over-sampling method. Specifically, the distribution pattern of valid detection pixels and invalid detection pixels in the detected image of a data page can be properly used to sample a balanced code.

Holographic recording drives encode data for recording into a holographic medium. The steps comprise run length limited encoding three bytes of data into 5×5 matrix information, the data subject to a 4-byte error correction code; and providing the 5×5 matrix information to a spatial light modulator (SLM), as a portion of a two-dimensional pixel matrix of the spatial light modulator, for recording into a holographic image on the holographic medium.

This invention is a holographic recording medium including a track in which position information to specify a recording position and a reproducing position of page data is formed. The position information of the track is formed of position detection patterns. The position detection patterns each including a first detection mark row including center pits arranged at predetermined intervals; and a second detection mark row including side marks arranged at the same intervals as the intervals of the center pits, the side marks having lengths substantially corresponding to integral multiples of the intervals of the center pits. The second detection mark row is arranged adjacent to the first detection mark row such that both ends of the side marks are arranged so as to correspond to the center pits in a track width direction, and page data is recorded and reproduced on the basis of positions of the center pits or positions of the ends of the side marks.

Provided is an information encoding method and a holographic memory device which increase the amount of information per page of a holographic memory and reduce the bit error rate to ensure a larger multiplexing number. The holographic memory information encoding method expresses information of signal page data in a holographic memory as a multi-stage data using different resolution by block coding, and superimposes each data on a single page of signal page data. The multi-stage data using different resolution is realized by light amplitude data and phase data. The amplitude data is divided by area through block coding. When n odd-numbered ON bits exist in a divided area of the phase data, a phase of 2πs / n (where n and s are natural numbers) is imparted as s-th phase information to one value of binary data, and the same phase is imparted to the other value of binary data.

Hologram recording and reconstruction apparatuses and method thereof are provided. The hologram recording apparatus comprises a laser source, a spatial light modulator, and a Fourier lens. The laser source provides a coherent light beam. The spatial light modulator receives m-bits data to only determine a (p×q) block comprising ON-pixels less than OFF-pixels, and receives the coherent light beam to modulate with the (p×q) block to generate the signal beam. The Fourier lens focuses the signal beam on the hologram recording medium, so that when the focused signal beam and a focused reference beam is modulated together, the hologram data is generated to be recorded on the hologram recording medium.

Hologram recording and reconstruction apparatuses and method thereof are provided. The hologram recording apparatus comprises a laser source, a spatial light modulator, and a Fourier lens. The laser source provides a coherent light beam. The spatial light modulator receives m-bits data to only determine a (pxq) block comprising ON-pixels less than OFF-pixels, and receives the coherent light beam to modulate with the (pxq) block to generate the signal beam. The Fourier lens focuses the signal beam on the hologram recording medium, so that when the focused signal beam and a focused reference beam is modulated together, the hologram data is generated to be recorded on the hologram recording medium.

A recording and reproducing device includes: a reference light irradiating section; a spatial light modulating section for generating information light; an information light irradiating section for irradiating the same region as a region irradiated with the reference light, with the information light; a light detecting section for receiving reproduction light; a known data storage section; a defect examining section for examining a defective position of the spatial light modulating section or the light detecting section by irradiating the information light and the reference light to write the known page data to the holographic recording medium, and then irradiating the medium with the reference light to read the known page data written on the holographic recording medium from the reproduction light received by the light detecting section; and a reproducing control section for restoring and reproducing the original data of the defective position using information of the defective position detected by the defect examining section.

There is provided an optical information detecting method. The method includes: detecting an image of a source data page coded with balanced codewords by the use of 1:N (where N is greater than 1) excessive detection pixels; determining a distribution pattern of valid detection pixels and invalid detection pixels to be corrected in the detected image by the use of a light intensity distribution of the detected image; and dividing the detected image into balanced codeword detecting areas corresponding to the balanced codewords and sampling data of the balanced codeword detecting areas by the use of the determined distribution pattern and an optical distribution characteristic of the balanced codewords. Accordingly, it is possible to efficiently detect optical information by the use of a 1:N over-sampling method. Specifically, the distribution pattern of valid detection pixels and invalid detection pixels in the detected image of a data page can be properly used to sample a balanced code.

An optical information recording / reproducing apparatus using holography comprises a signal generation unit that modulates input data, adds at least one control bit to each group of N bits, performs an NRZI-modulation on the modulated data, determines the at least one control bit such that a digital sum value of the NRZI-modulated data is 0, performs NRZI modulation on the data whose at least one control bit was determined, and rearranges the data to generate 2-dimensional data; a pickup that records the 2-dimensional data in a hologram disc and reproduces the 2-dimensional data from the hologram disc; and a signal processing unit that corrects the 2-dimensional data reproduced by the pickup, performs NRZI-modulation on the 2-dimensional data that has undergone a binarization operation, removes the at least one control bit added during the recording, and demodulates the data according to a modulation rule used during the recording.

A portable data storage cartridge comprising a housing, a first information storage medium removeably disposed within the housing, a holographic data storage medium disposed within the housing, wherein the housing is formed to include an aperture, and wherein the holographic data storage medium is disposed adjacent the aperture.

An encoding device for converting m-bit data words into n-bit (both n and m are integers and 2n≧2m×2) code words includes a first encoding table in which 2m code words selected from the 2n n-bit code words correspond to 2m m-bit data words, a second encoding table in which 2m code words, which do not overlap with the code words in the first encoding table, of the 2n n-bit code words correspond to 2m m-bit data words, and an encoding unit which selects and outputs a code word, in which an absolute value of a code string DSV is smaller, from code words corresponding to the input m-bit data words in the first encoding table and code words corresponding to the input m-bit data words in the second encoding table.