Nec Corporation

Hitachi, Ltd.

Akihiro Miyamoto

Satoshi Arai

Hiromi Ueda

Kunio Takahashi

Ryuichi Ikematsu

Haruhiko Matsunaga

Yoshitaka Tsumoto

This multileaf collimator is provided with multiple leaves which limit the area irradiated by a radiation beam and which are arranged in the thickness direction. Each of the leaves is provided with a protruded portion which is formed protruding towards a first surface of the leaf, a depressed portion which is formed in the second surface of the leaf and into which the protruded portion formed on another leaf is inserted, a first curved surface which is formed between the first surface of the leaf and the lateral surface of the protruded portion, and a second curved surface which is formed between the second surface of the leaf and the lateral surface of the depressed portion.

Multileaf collimator and radiation treatment device

A radiation therapy apparatus includes: an annular gantry; an irradiation unit which is provided on the gantry and configured to radiate radiation; a support which supports the gantry; a rotation-driving mechanism which is provided between the gantry and the support and rotates the gantry around a horizontal central axis of the gantry. The rotation-driving mechanism includes: annular rails that are provided on the gantry; and sliding members which are provided on regions of the support that correspond to a lower half of the gantry, slidably guide the rails, and receive at least a load of the gantry in a vertical direction.

Radiation therapy apparatus

A reception device in the ATM communication apparatus has a format conversion buffer, an underflow detecting circuit, and an in-device empty cell insertion control circuit in each of the active and backup systems. The format conversion buffer effects a format conversion on a transmission path from a format in which an ATM cell is inserted in only the payload of an SDH frame to a format in which an ATM cell is inserted in both the overhead and payload of an SDH frame, thereby to absorb the difference between transmission path lengths of the active and backup systems. The underflow detecting circuit detects an underflow of the format conversion buffer and outputs a detected underflow signal. The in-device empty cell insertion control circuit outputs an in-device empty cell insertion instruction signal in response to a detected underflow signal from the underflow detecting circuit in one of the active and backup systems. An in-device empty cell insertion circuit inserts an in-device empty cell into an output signal from the format conversion buffer in response to an in-device empty cell insertion instruction signal. For switching between the active and backup systems, an in-device empty cell is inserted to prevent cells from being shifted out of phase between the active and backup systems.

Uninterrupted switching between active and backup systems in ATM communication apparatus

An ATM cell format converter comprises conversion memory having a plurality of addresses for temporarily storing an ATM cell so as to perform ATM cell-format conversion. The ATM cell is separated into a plurality of data blocks and written into the addresses of the conversion memory together with indicators including a first indicator for indicating the beginning one of the data blocks in the ATM cell and a plurality of second indicators for indicating the other data blocks which follow the beginning data block in the ATM cell. The stored data blocks are read out from the conversion memory to form a converted ATM cell having, as the beginning data block in the converted ATM cell, one of the data blocks read out together with the first indicator. Alternatively, the indicators may be stored in another memory having a plurality of addresses corresponding to the addresses of the conversion memory.

ATM cell format converter using cell start indicator for generating

In a test method and apparatus for testing a virtual path in an asynchronous transfer mode system, a sequence number is included in an operation administrating monitoring (OAM) cell to specify the OAM cell for testing a virtual path between transmission and reception sides. The sequence number is inserted into the OAM cell by the use of an idle cell and is received by a sequence number test circuit included in the reception side. The sequence number in the OAM is collated with a result of counting the OAM cell in the reception side to detect coincidence or non-coincidence between the sequence number and the result of counting. On detecting the non-coincidence, a loss of the OAM cell or wrong reception of the OAM cell is detected on the reception side. Otherwise normal operation is confirmed between the transmission and the reception sides.

Growing community of inventors

Tokyo, Japan

Akihiro Miyamoto