Fujitsu Corporation

Akio Takayasu

Masato Kobayashi

Kazumaro Takaiwa

Hideaki Koyano

Toshihiro Suzuki

Yoshinori Tanaka

Tetsuya Kobayashi

Tetsuya Hamada

Hisashi Yamaguchi

Takashi Kanno

Noriyuki Ohashi

Maki Hiraizumi

Kazuhiro Kunimatsu

Masaru Ishiwa

Hiroya Egoshi

Takeshi Goto

Tatsuru Iwaoka

Yasushi Yoshino

Minoru Tateno

Yukiko Miyazaki

Makoto Goshima

A redundant changeover apparatus causing no frame synchronization loss even upon occurrence of changeover between working system and protection system. In case of an in-apparatus synchronization system, when two input signals which are mutually asynchronous in phase are changed over by a changeover switch, a changeover switch, a clock extractor, a PLL circuit, and a clock changing portion transmit signals with clocks before the changeover being gradually changed to clocks after the changeover. Alternatively, in case of an in-apparatus synchronize system, data are separated from clocks so that the data are once changed to data with reference clocks, and then for the data, clocks before the changeover are gradually changed to clocks after the changeover.

Redundant changeover apparatus

An apparatus having n-number of working cross-connects for cross-connecting an n-bit input signals arriving from a plurality of input paths on a per-bit basis; n-number of first logic circuits for calculating the exclusive-ORs of each said n-bit and applying outputs to a standby cross-connect for providing outputs; n-number of second logic circuits for calculating the exclusive-ORs of said output signals from each of said working cross-connects and from the single standby cross-connect; and third logic circuits for selecting output signals of said working cross-connects and outputs of the second logic circuits. The apparatus detects the occurrence of an abnormality in working cross-connects by monitoring the outputs of the second logic circuits, identifies the faulty cross-connect by successively turning off one of the n-inputs to the first and second logic circuits, and select outputs from the second logic circuits instead of from the faulty cross-connect by using the third logic circuits.

Cross-connect apparatus

An optical transmission device in which optical signal switching is performed to allow the device to be reduced in size and also which is capable of efficient recovery from fault, thereby improving system expansibility and communication quality. Overhead terminating section converts an optical signal to an electric signal and performs an overhead process including extraction of fault information and setting of status information. Optical switch section performs a process of switching the optical signal between active and standby lines, and switching control section provides a switching command to the optical switch section in accordance with the fault information.

Optical transmission device and optical transmission system

A projection display device comprising three projection lenses arranged in a row in a side by side relationship and having respective optical axes extending toward a screen, and three liquid crystal display panels forming images of red, green and blue color lights, the liquid crystal display panels and the projection lenses being arranged to form sets individually. A mirror is arranged between the display element and the projection lens of at least one of the sets. Accordingly, one of the display elements is arranged so as to face in a first direction and the adjacent display element so as to face in a second direction. It is thus possible to reduce the distance between the adjacent projection lenses even if the size of the liquid crystal display panels is enlarged.

Liquid crystal projection display device with mirror

Growing community of inventors

Kawasaki, Japan

Akio Takayasu