Nippon Telegraph and Telephone Public Corporation

Fujitsu Corporation

Nec Corporation

Mitsubishi Denki Kabushiki Kaisha

Nippon Telegraph and Telephone Corporation

Lion Corporation

Nec Corporation and Nippon Telegraph and Telephone Corporation

Hideo Kuroda

Naoki Mukawa

Kiichi Matsuda

Mitsuo Nishiwaki

Shuzo Tsugane

Hideo Hashimoto

Makoto Hiraoka

Tokumichi Murakami

Hiroaki Kikuchi

Yuji Shimada

Kazumoto Iinuma

Yukihiko Iijima

Ayumu Nonaka

Koji Nekoda

Fumio Kanaya

Hiroshi Fukuda

Toshihiro Honma

Yasunori Sakamoto

A system and method of transmitting client data encoded according to an 8B/10B encoding between a client side and an optical communication network side, including inserting padding signals in an amount corresponding to a rate difference between a clock on the client side and a clock in the optical transmission device and controlling a clock to be used as a reference in transmitting the client data to synchronize with a clock having been used as a reference in transmitting the client data on the basis of a ratio of padding signals having been inserted in the client data.

Optical transmission device, optical transmission system, and bandwidth control method

A water-decomposable non-woven fabric comprises a water-dispersible fiber layer, each fiber of which is bound with one another using a water-soluble binder comprising an unsaturated carboxylic acid/unsaturated carboxylic acid ester copolymer in which 1 to 60 mole % of the repeating units derived from the unsaturated carboxylic acid is in the form of a salt and which is soluble in tap water but is insoluble in an aqueous solution containing not less than 0.5% by weight of a neutral inorganic salt comprising a monovalent ion; the water-dispersible fiber layer being composed of a mixture of 40 to 90% by weight of fibers having a crimp number of 19/inch or less, 10 to 60% by weight of fibers having a crimp number of 20/inch to 25/inch, and not more than 10% by weight of fibers having a crimp number of 26/inch or more; and a content of the binder in the non-woven fabric being 1 to 30% by weight relative to the total weight of the non-woven fabric. The non-woven fabric has a good feeling (high softness and good touch) and sufficient mechanical strength, and can be easily broken and dispersed by throwing into a large amount of water.

Water-decomposable non-woven fabric

A basic cell type full search vector quantization coder has a plurality of basic cells and a minimum distortion output vector detector. In each basic cell a common K-dimensional input vector is divided by b into b sub-blocks and n output vectors are read one by one out of a set of N output vectors. The output vectors are also divided by b. Comparison is made K/b times between the components of the input and the output vectors to detect one of n output vectors positioned at the shortest distance from the input vector. The detctor compares the outputs supplied by the basic cells and detects one of the output vectors producing the minimum distortion, whose index signal being an output of the coder.

Basic cell type full search vector quantization coder

An inter-frame encoding/decoding equipment for television signals consists of inter-frame encoding equipment encoding a difference between television signals and the output of a frame memory and inter-frame decoding equipment which receives an encoded signal sent from the inter-frame encoding device via a transmission line, which decodes by adding the output of the frame memory to the encoded signal. The inter-frame encoding equipment is provided with a first operation circuit which operates the remainders obtained by dividing, by a predetermined value, the number of bits of logic '1' in the bit groups into which the output or the input of the frame memory is divided by a predetermined unit. The inter-frame decoding equipment is provided with a second operation circuit which operates the remainders obtained by dividing, by a predetermined value, the number of bits of logic '1' in the bit groups into which the output or the input of the frame memory is divided by a predetermined unit. The inter-frame decoding equipment is further provided with a comparator circuit which compares and checks the values operated by the first and the second operation circuits to detect a transmission error.

System for detecting a transmission error

A video signal frame memory is refreshed without requiring either a separate transmission line or the transmission of bursts of data. This is done by dividing the frame signals into blocks of data, which are further divided into lines and sub-blocks. During each frame, refreshing signals are sent on a sub-block basis, thereby distributing the refreshing control signals and preventing many signals from being sent in bursts.

Method and arrangement for refreshing a frame memory in an interframe

A predictive coding/decoding system for block-formed picture signals includes predictive coding and decoding units in transmitter and receiver sides, respectively: each of the predictive coding and decoding units is provided with a control pulse generator responsive to a horizontal synchronization pulse in the picture signal to produce a sampling signal and a select signal, and a pair of selectors together responsive to the select signal to select a sum of a prediction signal and a prediction error signal or a fixed value as an input of a prediction circuit, the pair of selectors selecting the fixed value for a partial picture block including a fraction of pixels due to the block formation.

Predictine coding/decoding system for block-formed picture signals

Inter-frame encoding/decoding equipment for television signals includes inter-frame encoding equipment generating an encoded signal by encoding a difference between television signals and the output of a frame memory and inter-frame decoding equipment which receives the encoded signal sent from the inter-frame encoding device via a transmission line. The decoding equipment decodes by adding its output of the frame memory to the encoded signal. The inter-frame encoding equipment is provided with a first operation circuit which calculates remainders obtained by dividing a predetermined value, into bit groups of the output or the input of the frame memory. The inter-frame decoding equipment is provided with a second operation circuit which calculates remainders obtained by dividing, the predetermined value, into the bit groups of the output or the input of its frame memory. The inter-frame decoding equipment is further provided with a comparator circuit which compares and checks the remainders calculated by the first and the second operation circuits to detect a transmission error.

Intraframe coding and decoding equipment are used in a communication network for digital video signals. Video signal sources which have various frequency deviations are transmitted by the communication network. Each of the intraframe coding and decoding equipment items has a locked sampling coding algorithm which is suitable for an input video signal with high frequency precision and a nonlocked sampling coding algorithm which is suitable for an input video signal with low frequency precision. It is determined whether or not the frequency precision (i.e., the frequency deviation of the sync signal) falls within a predetermined range. One of the coding algorithms is selected in accordance with a detection result. The coding algorithm can be selected in accordance with a decoding algorithm of a receiving-side equipment. Switching of the coding algorithms is performed simultaneously with switching of the clock signals of the locked and unlocked sampling clocks.

Intraframe coding and decoding equipment for video signals of different

A digital data code conversion circuit for a variable-word-length data code includes a data code conversion portion and a preparation circuit. In the preparation circuit, a variable-word-length data code having a word length greater than a number n is divided into a plurality of variable-word-length data codes having a word length less than or equal to the number n. The divided variable-word-length data codes are converted into fixed-word-length data codes having a word length n in the data code conversion portion.

Digital data code conversion circuit for variable-word-length data code

An interframe coding method performs predictive coding by dividing an input video signal into blocks each of which has a predetermined size, wherein a second memory for storing background data is arranged in addition to a first memory for storing coded picture data, and a block having a minimum prediction error among blocks read out from the first and second memories is detected as an optimal predictive block for every block of the input video signal, whereby predictive coding is performed by using the optimal predictive block. According to this method, after a moving element in the picture is displaced, the background area is monitored by using as predictive value data stored in the second memory. A prediction error becomes small, and coding efficiency is improved. In particular, motion compensated interframe coding is performed in addition to detection of the background area, thereby further improving the coding efficiency. The background image stored in the second memory is properly updated in accordance with the input video signal.

Interframe coding method and apparatus therefor

An input video signal is fed to a substracter wherein a difference is taken between the input and the output from a frame memory to provide a difference signal, the magnitude of which is controlled by a magnitude adjuster. The controlled output is then fed to a threshold circuit, from which a significant difference signal is derived which has a magnitude above a given level. The significant difference signal is quantized by an encoder into a code having a reduced number of bits as compared with the inputted significant difference signal. The quantized code is written into a buffer memory, and is read out therefrom at a uniform bit rate to a transmission line. A sum of a signal indicative of the representative level of the quantized code from the encoder and the output of the frame memory is formed in an adder, and the sum signal is written into the frame memory and read out subsequently or after one frame. The occupancy of the buffer memory is detected to provide a control over the magnitude adjuster in accordance with the detected value so as to prevent an overflow from the buffer memory. A signal to refresh the frame memory located on the receiving side is transmitted by writing the output of the adder into the buffer memory after switching from the output of the encoder to the output of the adder.

Growing community of inventors

Kanagawa, Japan

Hideo Kuroda