Sharp Kabushiki Kaisha Corporation

Takashi Nishimura

Toru Ueda

Kazuyuki Sumi

Yuji Ichikawa

Daisuke Nakano

Hirohisa Wakai

Masafumi Takahashi

Hiroshi Kusao

Satoshi Terada

Kazuhito Nagura

Fumihiro Fukae

Yutaka Ikeda

Kazuyuki Suga

Noritoshi Kakoh

In optical two-way communication using a single optical fiber, part of the light transmitted from an apparatus is received as stray light by the apparatus itself. This occasionally hampers accurate detection of disconnection from the partner apparatus and of the start of data communication by the partner apparatus after the establishment of connection. To overcome this, the timing with which an apparatus transmits a tone signal after the establishment of connection is compared with the timing with which the apparatus receives a tone signal from the partner apparatus, and the two apparatuses use different sets of data transmission properties (for example, different wavelengths) to accurately detect disconnection. Moreover, based on the properties of the received light and the characteristics of the receiving amplifier, repetition of the same code for longer than a predetermined period is detected to accurately detect disconnection. Furthermore, in response to a request for data communication after the establishment of connection, a tone signal having a different pattern from that used to establish connection is used to accurately detect the start of data communication.

Apparatus and method for data communication including establishing communication using tone signal

A digital optical communication device includes an optical reception circuit converting an optical signal received from any external source to an electric signal, a decoding circuit decoding the electric signal resultant from conversion by the optical reception circuit and judging whether or not the decoding is normally completed, a reception light intensity level judgement circuit judging an intensity level of received light based on the electric signal, a coding circuit coding transmission data, and an optical transmission circuit determining a light emission intensity based on result of the judgement by the reception light intensity level judgement circuit and on result of the judgement by the decoding circuit, and converting the transmission data coded by the coding circuit to an optical signal with the light emission intensity. The optical transmission circuit determines the light emission intensity based on the result of judgement by the reception light intensity level judgement circuit and on the result of judgement by the decoding circuit, so that the light emission intensity can appropriately be controlled and the power consumption can be reduced.

Digital optical communication device and method for transmitting and receiving data with light emission intensity controlled

A transmission method uses multiple kinds of control codes to be exchanged on a serial transmission path between a sender side and a receiver side, and each of the multiple kinds of control codes has bits smaller in number than a predetermined fixed length. The transmission method includes the steps of inspecting the received bit string in groups of bits of the number of the control code, and thereby determining whether one of the multiple kinds of control codes is present in the serial signal received on the serial transmission path or not, selecting the control code to be sent based on a result of the determination in the determining step, sending, onto the serial transmission path, a bit string containing at least the control code to be sent based on the result of the determination in the determining step, and receiving the data code by inspecting the received bit string in groups of bits of the fixed length in response to the detection of the control code indicating the start of transmission of the data from the opposite side in the determining step.

Transmission method and device

A method of half duplex transmission of a packetized digital data includes the steps of inputting a new packet to be transmitted to a first-in-first-out storage, determining whether the new packet contains time information related to synchronization with other electronic device, responsive to the determination that the new packet contains time information, updating a local timer of the electronic device with a prescribed value, continuously incrementing the local timer, responsive to a timing enabling transmission of the new packet by the transmitting/receiving unit of the electronic device, reading the new packet from the first-in-first-out storage, determining whether the new packet contains time information or not, changing the time information by using a value of the local timer to prevent mismatch in synchronization with other electronic device, and outputting to the bus through the transmitting/receiving unit.

Method and apparatus for transmitting packet for synchronization using half duplex transmission medium

An electronic apparatus comprising a detecting unit, a communications unit, and a power control circuit. The power control circuit supplies power to a communication circuit unit based upon a result of detection of the detecting unit.

Electronic apparatus having communication function using detachable communication cable, capable of reducing power consumption and stable operation

Between two nodes, data in the form of two different signals are transmitted bidirectionally, in accordance with IEEE1394 through one optical fiber cable. At the time of data transmission, data of two different signals is converted to data of one type of signal at one node, and transmitted to the optical fiber cable, and at the other node, the data received from the optical fiber cable is converted to the original data of two different signals, and transmitted to a subsequent processing circuit in accordance with IEEE1394. At this time, in a transmission sequence for requesting and granting priority of transmission over the optical fiber cable between both nodes, the priority of transmission is granted alternately to both nodes.

Signal transmission system for high speed serial bus

In a communication network in which a plurality of equipments each having a function implementing unit having a plurality of functions and a communication control unit having communication function communicating with each other, the communication control unit includes a recording medium and stores on the recording medium in advance a plurality of pieces of function information related to at least one function held by the corresponding function implementing unit, and inquires function information of each of other equipments at the time of communication. Therefore, management of various equipments and function information of various equipments in correspondence with each other becomes unnecessary, load in processing including communication is relieved and functions of respective equipments can be controlled efficiently.

Communication method, communication system and computer readable

When a scan line is interpolated, pixels on scan lines above and below the scan line which are referenced is interpolated in the horizontal direction. These pixels on the upper and lower scan lines are divided into blocks. Correlations between the upper and lower blocks with respect to a target pixel to be interpolated are calculated. Based on an evaluating function which is formed based on the correlations but is corrected with reference to the distance (or the direction) from the target pixel to each of the blocks, an optimal interpolating direction is selected. In addition, the difference in the pixel data between the interpolated pixel and each of the pixels around the interpolated pixel is checked in order to find interpolation errors. When an interpolating pixel data is determined to be erroneous, the pixel is interpolated using the pixels of data above and below the pixel.

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Tenri, Japan

Takashi Nishimura