Kabushiki Kaisha Toshiba

Masayuki Takami

Mitsuru Sugawara

Yoshiki Namba

Mototaka Kitajima

Takashi Yano

Yoshio Inagaki

Fumihiko Shimizu

Taro Shibagaki

Sadao Tanikoshi

Kazuhiko Ide

Katsumi Kusama

Kyosuke Dobashi

Takehiko Atsumi

Akitoshi Yoshinaga

Mitsuru Otani

Masahiro Kataoka

An optical transmission system comprises master unit and remote unit, the master unit includes optical transmitter transmits the optical signal to the optical fiber at a fixed averaged output level, the remote unit includes optical receiver receives optical signal via optical fiber, and optical receiver includes light receiving element converts optical signal into electric signal, variable gain amplifier amplifies the electric signal at a gain corresponding to a value of a given adjustment voltage, gain controller supplied power for, a defined control period, controls the adjustment voltage to stabilize an averaged level of the electric signal to a defined value, and feed-forward-controls a gain of variable gain amplifier, a shut off unit shuts off supply of power to the gain control circuit when the control period ends, and a keeping unit keeps a value of an adjustment voltage applied to the variable gain amplifier.

Optical transmission system, optical receiver, and its gain adjustment method

Electronic devices to which power is supplied from a power supplying unit commonly connected with other electronic devices, each of the electronic devices comprising a switch unit having an input terminal, an output terminal and a control terminal to which a control signal to close between the input terminal and the output terminal, a number input unit to which unique identification information is input, and a timing unit connected to the power supplying device together with the input terminal and inputting the control signal to the control terminal after a lapse of a delay time set in response to the identification information from a start timing of power supplying by the power supplying device.

Electronic device, power source control method, ROF system and its power supplying method and remote unit

Optical signals inputted to input ports are split in half by 1&#xd7;2 optical splitters respectively and the resulting signals are inputted to the input terminals of an optical matrix switch. The optical matrix switch switches between the routes of the individual optical signals and outputs the signal at any of the output ports. This enables the optical signal from the same input port to be outputted at two different output ports, which makes it possible to effect 'bridge' at the time of protection switching.

Optical switching apparatus and optical transmission apparatus

A sharp phase variation of a clock is suppressed when master/slave status of a first and second communication device is changed over. The first and second communication devices respectively include clock selection circuits and clock production circuits for producing a synchronous clock from the selected clock, respectively, and supply the selected clock as the synchronous clock to the other communication device which is a mating-side device. One of the first and the second communication devices is a reference selection side and becomes a slave side, and the other device is a mating synchronous clock selection side and becomes a master side. Respective data signals from the communication devices are bit multiplexed in a multiplexing device on the basis of the synchronous clock. The first communication device includes a delay circuit for delaying the mating-side synchronous clock by a phase difference between a clock transmitted from the selection circuit through the clock production circuit and a clock transmitted in the mating-side device from the selection circuit through the selection circuit and the clock production circuit. In this manner, both clocks inputted into the selection circuits are made synchronous by the delay processing, so that a sharp phase variation at the master/slave changeover is suppressed and the multiplexed output from the multiplexing device remains virtually undisturbed during a master/slave change over event.

Master-slave multiplex communication system and PLL circuit applied to

In a digital signal time-division multiplex apparatus according to the present invention, digital signals transmitted through a plurality of channels are converted into low-order section frame signals in response to sync signals by low-order section frame processing boards provided for their respective channels. The low-order section frame processing boards are arranged in parallel on a mother board at regular intervals. The low-order section frame signals processed by the low-order section frame processing boards are supplied to a high-order section frame processing board and sequentially selected within one frame, thereby generating time-division multiplex signals. The sync signals are generated by a sync signal generating board and transmitted to a sync signal transmitting line formed on the mother board. The sync signal transmitting line is formed so as to transmit the sync signals in a direction in which the low-order section frame processing boards are arranged. The sync signals are supplied to the low-order section frame processing boards through the sync signal transmitting line in a bus line system. The low-order section frame signals generated from the low-order section frame processing boards are transmitted to a plurality of low-order section frame signal transmitting lines formed in the direction in which the sync signals are transmitted, and supplied to the high-order section frame processing board through the low-order section frame signal transmission lines.

Digital signal time-division multiplex apparatus

An optical communication apparatus which comprises a printed circuit board, plural circuit elements fixed to the printed circuit board, the circuit elements having terminals extended to the printed circuit board, a photosensitive glass base fixed to the printed circuit board, various optical components accurately fixed to the glass base, the optical elements respectively having plural leads, and corresponding conductive members for electrically connecting the terminals of the circuit elements and the corresponding leads of the optical components, the conductive members each having a rigidity smaller than the rigidity of the corresponding leads of the optical components.

Growing community of inventors

Fuchu, Japan

Masayuki Takami