Matsushita Electric Industrial Co., Ltd.

Takahisa Sakai

Yuji Mizuguchi

Noboru Katta

Toshihiko Kurosaki

Hirotsugu Kawada

Toshihisa Ikeda

Nobuhiko Yasui

Yutaka Takahira

Kenichi Moriguchi

Toshitomo Umei

Toshio Oga

Akihiro Yamamoto

Osamu Shibata

Susumu Ibaraki

Toshiaki Mori

Takashi Akita

Toshikazu Hattori

Hirotsugu Kawata

A data transmission system in which normal transmission can be performed irrespectively of the inserting orientation of a connector is provided. A transmitting device transmits to a receiving device a differential transmission signal including polarity decision data for deciding the polarity of the connector. Based on the polarity decision data included in the differential transmission signal transmitted from the transmitting device, the receiving device decides whether the polarity of the connector has been reversed or not. When it is decided that the polarity has not been reversed, the receiving device reads data from the differential transmission signal. When it is decided that the polarity has been reversed, the polarity of the differential transmission signal is reversed for data reading.

Data transmission system

A digital data transmission apparatus includes a transmitting end () that includes: a binary/quadrary conversion unit () for converting a data stream; a coding unit () for mapping converted data to be coded; a digital filter (); a D/A conversion unit (); a low-pass filter () for attenuating noises which are caused by folding distortion; a differential driver (); low-pass filters () and () for eliminating noises from differentially outputted signals; and a common mode choke coil () for eliminating common mode noises and outputting a resultant signal to a twisted pair cable (), and a receiving end () that includes: a low-pass filter () for eliminating noises from the twisted pair cable; a receiver (); an A/D conversion unit (); a digital filter (); an evaluation unit () for evaluating a signal level of a received signal; a decoding unit () for decoding the signal level into received data; and a synchronization unit () for generating a clock.

Digital data transmitter

A digital data transmission apparatus includes a transmitting end () that includes: a binary/quadrary conversion unit () for converting a data stream; a coding unit () for mapping the converted data to be coded; a digital filter (); a D/A conversion unit (); a low-pass filter () for eliminating a high-band signal; a differential driver () for inputting an analog signal that has passed through the low-pass filter into a twisted pair cable (), and a receiving end () that includes: a low-pass filter () for eliminating noises from both wires of the twisted pair cable; a receiver () for receiving the signals that have passed through the low-pass filter; an A/D conversion unit (); a digital filter (); an evaluation unit () for evaluating a signal level of a received signal; a decoding unit () for decoding the signal level into receipt data; and a synchronization unit () for generating a clock.

Digital data transmitter, transmission line encoding method, and decoding method

A ring-shaped network quickly performs initialization even when a plurality of data transmission apparatuses are connected thereto. Each data transmission apparatus outputs received data to a device connected thereto while performing establishment of clock synchronization based on the received data, and when synchronization is established, it resends the received data. Further, when synchronization of the connected device is established, it sends data supplied from the connected device. Further, a master data transmission apparatus outputs data at turn-on of power or immediately after reset, and a next-stage slave data transmission apparatus receives the data to establish synchronization, and resends the received data when synchronization is established. Thus, synchronization of all the data transmission apparatuses is established while making a round of this data, and then synchronization of devices connected to the respective data transmission apparatuses is established.

Ring network and data transmitter

An evaluation level setting method and a data reception apparatus in which the method is implemented accurately evaluate signal levels in multi-valued transmission for transmitting data while assigning one or more bits of data as one data symbol to a signal level. A data transmission apparatus outputs an initialization pattern signal at turn-on of power or after reset, and the data reception apparatus establishes clock synchronization on the basis of the received initialization pattern signal and starts data reception after setting of evaluation levels to be used for threshold evaluation of signal levels.

Judgment level setting method and data receiver

A first initialization pattern signal is a signal in which a maximum signal level and a minimum signal level appear alternately, and a second initialization pattern signal is a signal in which all signal levels appear in a predetermined arrangement. In a ring-shaped network including plural stages of data transmission apparatuses (), a transmission unit () of each data transmission apparatus outputs the first initialization pattern signal successively to a next-stage data transmission apparatus at turn-on of power or immediately after reset, and a reception unit () establishes clock synchronization on the basis of the first initialization pattern signal received. When synchronization is established in all of the data transmission apparatuses, the transmission unit () outputs the second initialization pattern signal successively to the next-stage data transmission apparatus, and the reception unit () sets evaluation levels for the respective signal levels on the basis of the received second initialization pattern signal, and transmission/reception of data is started when evaluation levels are set in all of the data transmission apparatuses.

Initializing method and data transmitter

A receiver includes a noise reduction circuit for eliminating noise from a differential signal transmitted through a differential transmission line, and a data recovery circuit for recovering data from a differential signal outputted from the noise reduction circuit. The noise reduction circuit includes common-mode chokes for reflecting common-mode noise superimposed on an input differential signal, and a common-mode noise reduction circuit for directing the common-mode noise reflected by the common-mode chokes to a low potential point of the common-mode noise reduction circuit.

Receiver

A control device determines whether an image generated by merging several concurrently picked-up images has consistent image quality on a display device. If determined No, image quality parameters set in each image pickup device are so controlled as to make the image quality of the merged image consistent. Therefore, the merged image can assuredly have consistent image quality. Further, a signal processing device detects, based on positions of nodes and attributes of cameras, a connection indicating which node is connected to which camera and with what attribute. The signal processing device in advance stores every detectable connection and a plurality of image processing programs corresponding to each connection, and selects and carries out one of the image processing programs corresponding to the detected connection.

Image pickup system and vehicle-mounted-type sensor system

A data transmission system including first and second source devices for transmitting video data (isochronous data) outputted from first and second data output units, and a sink device for receiving the video data transmitted from the source devices and outputting the data to a video composition device, in which the video data supplied from the data output units to the source device are synchronized in frame units and transmitted from the source devices to one sink device. In the data transmission system, synchronous information (reference signal information) in the video composition device is transmitted from the sink device to the source devices, and timing reference signals in the data output units are generated by the source devices based on the synchronous information.

System, method and apparatus for data transmission

An S/P converterconverts input data from serial to parallel for every two bits in different timings, thereby outputting two types of parallel data. Based on the input data, a timing detectordetects a timing which corresponds to boundaries between bits of a data portion before biphase encoding. Based on the detection result of the timing detector, a selectorselects either one of the two types of parallel data output from the S/P converter

Communication device

In a network of a topology of a loop and a bus, occurrence of a failure is detected and a location of the failure is specified. Occurrence of the failure is detected by detecting that a specific signal pattern to be received at regular time intervals within a fixed time period is not received. A node which has detected occurrence of the failure transmits or receives a specifying signal among the nodes, and decide whether or not the failure has occurred adjacently to itself. A packet indicating a decided location of the failure is transmitted or received among nodes, and thereby respective nodes specify the location of the failure. When the failure has occurred at the master node, a node having a smallest node ID after waiting time according to the node ID operates as the alternative master node.

Network system, network terminal, and method for specifying location of failure in network system

A communications system and a communications device are provided that can reduce the difference in data reaching time with a simple structure and can play audio without making listeners feeling strange. A communications device is coupled to a network and a device such as a CD player or the like. The communications device includes a network interface unit , a network controller communicating with the device and others, and a CPU controlling these components. Furthermore, the network interface unit , a transmission signal processing unit and a reception signal processing unit converts the data format appropriate for the network controller and the network , respectively. A transmission scheme determination unit determines the transmission scheme used among nodes. First and second switches and each have a contact A and a contact B, connecting either one of these contacts based on a control signal from the transmission scheme determination unit

System and device for communications

A master station,produces a token packet for isochronous data in which a slave station,and slave stations,and,serving as a sending station and receiving stations are designated using IDs for isochronous data &ldquo;&num;,&rdquo; and &ldquo;&num;,&rdquo; in accordance with contents described in a table,held in its inner part so as to manage a transmission bandwidth using a token packet sending/analysis executing device,and sends out the produced token packet to a transition path,on the downstream side. The slave station,sends out an isochronous data packet,using the token packet for isochronous data,According to the token packet for isochronous data,the slave stations,and,are designated as receiving stations using the ID for isochronous data &ldquo;&num;,&rdquo;, so that the slave stations,and,perform the above-mentioned operations, to receive the isochronous data packet,The sending station can thus transmit the same isochronous data to a plurality of receiving stations belonging to a broadcast group, so that it is possible to establish multicast communication (communication to a plurality of nodes).

Communication network

A network system comprises a main loop in which one master node which issues a token packet for data communication, and at least one slave node are connected in a loop; a first sub loop in which the master node, one sub-master node, and at least one slave node are connected in a loop; and at least one second sub loop in which the master node, at least two sub-master nodes including the sub-master node of the first sub loop, and at least one slave node are connected in a loop. In this network system, each node has an analysis execution unit which performs analysis of the token packet, control of data transmission and data reception, and a switch for changing the connection. When each node receives and analyzes the token packet, it controls the switch so as to output, transmit, or discard the token packet and a data packet. Therefore, addition of nodes and loops is facilitated while maintaining the transmission efficiency, without increasing the packet transmission time.

Network system

A master station including at least a token packet (Iso) management table in which the overall band of the bus is partitioned into certain bands, rewrites the token packet (Iso) management table according to the bandwidth required in Isochronous data transmission between stations to at least control transmission of token packets (Iso) and dynamically control the bandwidth.

Growing community of inventors

Amagasaki, Japan

Takahisa Sakai