Canon Kabushiki Kaisha

Canon Information Systems, Inc.

Gregory F Beck

Richard D Ray

Royce Earle Slick

James Albert Fontana

Wei Zhou

Douglas L Palmer

Osman Ozay Oktay

Robert D Wadsworth

Don Francis Purpura

Tony K Ip

Walter D Kuver

Alistair Michael Egan

Elias Montenegro

Edward A Summit

Trent Lee England

Lisa Walker

A system for transmitting and receiving data formatted in IEEE 1394 standard between devices using a same IEEE 1394 broadcast channel includes a CPU interfaced to a bus, a first 1394 interface connected to the bus via a first physical and link layers, and a second 1394 interface connected to the bus via a second physical and link layer. The CPU is configured for 1) receiving data from the bus, prefixing a header to the received data, and retransmitting the received data with the prefixed header onto the bus; and 2) receiving data prefixed with a header, interpreting the header to identify which of the first or second interfaces should receive the data, and transmitting the data over the bus to the identified 1394 interface.

Channel protocol for IEEE 1394 data transmission

A digital video network interface for transferring isochronous video data over an asynchronous local area network, including an isochronous interface for transmitting digital video data isochronously, a memory comprising first and second buffers for storing the isochronous video data, a network interface for transmitting video data from either the first or second buffers over the asynchronous local area network, and a memory buffer manager for controlling the output of the video data over the asynchronous local area network and for controlling the input/output of video data into/from the first or second buffers, wherein, when either the first or second buffers is filled with video data, the memory buffer manager shifts the input of data into an empty buffer and begins outputting video data to the asynchronous local area network from a filled buffer, upon receiving access to the local area network. Complementary ones of such video network interfaces may be provided on a network so as to permit one-way video streaming (to one or more receiving sites) or two-way video conferencing with network interfaces operating in full-duplex mode.

Digital video network interface

In a two-line telephone controller which includes a line select switch which operates complementarily to a force busy relay that allows an unselected telephone line to be forced to a busy state, a method for using the force busy relay also to place an active line on hold. The method includes detecting an incoming call on an inactive line, switching the line select switch to the inactive line, receiving an instruction to place the active line on hold, and responding to the hold instruction by closing an off-hook relay so as to connect the force busy switch across the active telephone line, opening a first handset select switch for the active telephone line, and closing a second handset select switch so as to select the incoming call on the ringing line. Because the force busy switch is connected across the formerly-active telephone line, loop current is maintained, thereby placing and maintaining the formerly-active call on hold.

Two-line telephone controller with hold feature

A communications control board, has, provided on a single board, an arrangement for performing standard modem/facsimile/telephone control functions as well as circuitry for performing functions, such as audio play and audio-line input and output functions. In one embodiment, a soundboard may be provided with text-to-speech control functions in conjunction with the single-board controller.

Communication control board with audio functions

An arbitration device for shared RAM which arbitrates between first and second requests from first and second processors having respectively different first and second clocks and bus widths which may differ from that of shared RAM. A synchronizer synchronizes the first access request to the second clock so as to obtain clock-synchronized access requests, one of the clock-synchronized access requests is delayed by a fractional part of the second clock so as to yield time-offset access requests, and a hold-off circuit grants access to a first-to-arrive time-offset access request and holds off processing of a second-to arrive time-offset access request until processing of the first access request is complete. A shared RAM interface, responsive to access grant signals from the hold off circuit, gives access to the shared RAM in correspondence to the access grant signal. The shared RAM interface includes a strobe generator for generating upper and lower strobe signals for strobing upper and lower parts of the differently-widthed bus onto shared RAM.

Arbitration device for arbitrating access requests from first and second

A computer-controlled communication board which includes a data access arrangement which functions as an intermediary between multiple telephone lines, a data communication device such as a fax/modem/voice chipset, and a standard telephone handset. The data access arrangement has a line select switch which switchably connects one of the multiple telephone lines to the data communication device via a single transformer and associated 2/4 converter. Off-hook switches are provided for each telephone line so that the data communication device can cause the selected telephone line to go off-hook. Likewise, ring detectors are provided for each telephone line so that the data communication device can detect which of those lines is ringing. Telephone handset switches may be provided for each telephone line so that the telephone handset may be switchably connected to any one of the multiple telephone lines. The data access arrangement may be configured so that unused lines appear 'busy' to incoming calls, or it may be configured in a voice local mode in which the telephone handset may be used for play out and recording of audio information.

Two-line telephone controller

Growing community of inventors

Laguna Hills, CA, United States of America

Gregory F Beck