Fujitsu Corporation

Hisako Koyanagi

Hiroyuki Rokugawa

Jun Tanaka

Tomohiro Ishihara

Michio Kusayanagi

A data transmission apparatus is provided for transmitting data received from a user terminal device through a plurality of networks to a destination, the user terminal device executing communication using an Internet protocol. The data transmission apparatus includes a routing table storing information relating a destination address of the data and addresses of the plurality of networks; an information table storing static and dynamic information about the plurality of networks; and a selection unit selecting one or the plurality of networks, through which the data transmission apparatus transmits the data to the destination, based on the static and dynamic information. The data transmission apparatus enables data transmission through the appropriate network by selecting the appropriate network based on the static and dynamic information about the plurality of networks.

Data transmission apparatus selecting efficient network or service class

A light emitting device driving circuit capable of, at all times, securing a constant optical output by a simple configuration even in a case of driving a light emitting device having characteristics changing according to temperature fluctuations, provided with a driving transistor for feeding a bias current and a pulse current to a light emitting device having a grounded-cathode, an adjusting resistor for adjusting the pulse current and bias current fed to the light emitting device, and a resistive dividing circuit comprising series-connected dividing resistors for individually setting the pulse current and bias current, the series-connected dividing resistors being constituted by a temperature dependent resistive unit.

Light emitting device driving circuit

A light-emitting element driving circuit includes a drive transistor having a first terminal receiving a power supply voltage, a second terminal coupled to an anode of a light-emitting element, and a control terminal receiving an input signal, the drive transistor supplying a pulse current and a first bias current to the light-emitting element. A constant-current source is coupled to the anode of the light-emitting element and supplies a second bias current to the light-emitting element. A compensation circuit controls the second bias current so that a variation in the first bias current due to a temperature variation can be compensated for thereby the sum of the first and second bias currents is kept constant.

Growing community of inventors

Kawasaki, Japan

Hisako Koyanagi