Abstract: A cryptographic key 1 constituted to be freely attachable and detachable to/from a personal computer 2 encrypting and decrypting data by use of a cipher key includes: a pseudo random number generator 14 for generating a pseudo random number of a chaotic time series based on a data size of the data, a chaotic function and an initial value of the chaotic function; and a USB controller 12 for receiving the data size of the data from the personal computer 2 and transmitting the pseudo random number of the chaotic time series as the cipher key to the personal computer 2, the pseudo random number being generated in the pseudo random number generator 14, when the cryptographic key 1 is attached to the personal computer 2.

Abstract: An optical module includes: a plurality of leads arranged in at least two lines, at least portions of the plurality of the leads being mounted on a circuit board; an optical semiconductor for emitting or receiving an optical signal; and a circuit portion connected to the optical semiconductor, for transmitting a pair of differential signals to or receiving a pair of differential signals from the circuit board through a pair of differential signal leads among the plurality of the leads. The pair of the differential signal leads are provided adjacent and in parallel to each other in one of the at least two lines.

Abstract: An optical distributor includes an optical-signal input port, a light receiving device, a light emitting device, a light splitter, and optical signal output ports. The light receiving device converts an optical light signal input to the optical-signal input port into an electric signal. The light emitting device converts the electric signal into an optical signal. The optical splitter 14 splits the converted optical signal into two optical signals. The optical-signal output ports output the split optical signals. The light receiving device includes a light receiving element, a pre-amplifier, and a limiting amplifier. The light emitting device includes a light-source drive element and a light emitting element.

Abstract: A circuit board device suppress with a small number of terminal elements unwanted irradiation originating between a power supply layer and a ground layer, even when a configuration of the power supply layer and the ground layer on the circuit board is complex, and a design support device thereof. The circuit board device has a power supply layer and a ground layer disposed in opposition to one another. A dielectric is disposed between the power supply layer and the ground layer. A power supply surface is divided into two power supply surfaces and by a slit having a generally T-shaped configuration to form power supply surface edges. The power supply surface edges retain across a predetermined length L a characteristic impedance present between the power supply layer and the ground layer. A terminal load is connected to a terminal portion of the power supply surface edges.

Abstract: An optical signal communication apparatus includes a light transceiving section, a digital signal control section and a flexible wiring board. The light transceiving section performs at least one of transmission and reception of optical signals. The digital signal control section is disposed in a casing body and processes digital electronic signals from the light transceiving section. The flexible wiring board connects the light transceiving section with the digital signal control section. An insulating member is provided at the casing body, and the flexible wiring board is disposed on the insulating member.

Abstract: An optical signal transmission device including an optical signal receiving section, an optical signal transmitting section, a support member, and a digital signal control section. The optical signal receiving section receives an optical signal by a light-receiving element mounted on a board, converts the optical signal to a digital electric signal and outputs the digital electric signal. The digital signal control section processes the digital electric signal. The optical signal transmitting section converts a digital electric signal to an optical signal by a light-emitting element and outputs the optical signal. The optical signal receiving section and the optical signal transmitting section are provided on different surfaces of a support member.

Abstract: A printed wiring board is provided which can be applied even to circuit boards operating at high speed, and which can suppress electromagnetic wave radiation, and which can suppress a deterioration in density of mounting. At the printed wiring board, a first signal wire layer, a first ground layer having a first power source wire, a second ground layer having a second power source wire, and a second signal wire layer, are laminated. The first ground layer and the second ground layer are interlayer connected by many via holes. Return current, of signal current flowing through a signal wire, flows in the first ground layer, and a path of the return current is cut midway therealong at a position of the first power source wire. However, the return current is detoured by the via hole to the second ground layer, and flows thereat.

Abstract: The first and second light-emitting regions are provided on the light source. When the first optical fiber having the first core diameter is connected, the light emitted from the first light-emitting region enters the first core. When the second optical fiber having a greater core diameter than the first core diameter is connected, the lights emitted from the first and second light-emitting regions enter the second core. It is thus possible to connect the optical transmission device with multiple optical fibers having different core diameters. It is thus possible to provide the optical transmission device and the communication device, which are low in cost and high in convenience.

Abstract: An encryption key device can be freely attached to and detached from an information processor encrypting or decrypting data and includes a memory, a pseudorandom number generator, and a controller. The memory stores an application program to operate the encryption key device and a group ID specifying permission for use of the encryption key device. The pseudorandom number generator generates a pseudorandom number according to an encryption function using the group ID stored in the memory as an initial value of the encryption function. The controller causes the pseudorandom number generator to generate the pseudorandom number according to data size received from the information processor operating according to the application program and sends the generated pseudorandom number and the group ID read from the memory to the information processor.

Abstract: An optical signal transmitting device includes: a semiconductor laser diode that is disposed so that its periphery is covered by a laser package and which emits laser light in accordance with information to be transmitted; and a light limiting member that covers at least part of the periphery of the semiconductor laser diode and limits the light amount and divergence angle of the laser light emitted from the semiconductor laser diode. An opening is formed in a side wall of the light limiting member, and the laser light whose light amount and divergence angle have been limited by the light limiting member is guided to optical fiber connected to an optical signal device.

Abstract: A protection key for hardware includes a first storage area configured to store a key data used for permission to use software installed in a information processor, a second storage area configured to store a data table including a plurality of random numbers, a receiver configured to receive a cryptography key from the information processor, a coder/decoder configured to encrypt the key data based on the cryptography key by picking one random number from the data table, and a transmitter configured to transmit the encrypted key data to the information processor.

Abstract: In an optical signal transmission system which can perform high-speed optical transmission not lower than 1 Gbps, VCSEL has light-emission points. A core diameter of an optical fiber GI-POF is set to not lower than 200 ?m, and the light-emission points of VCSEL are arranged inside an outer periphery at an end face of GI-POF. A polymerization composition material constituting the core of GI-POF is made of a compound containing deuterated poly methacrylic ester. A wavelength of the light beam of VCSEL is set to the range of 770 nm to 810 nm.

Abstract: A protection key provided with an information processor includes a memory unit including a first storage area to store first data used for permission to use of software installed in the information processor and a second storage area to store second data, the second data being the same as the data stored in another protection key for permission to use other software installed in the information processor, and a controller configured to determine whether the second data is valid, wherein the controller transmits the second data to the information processor when the second data is valid and transmits the first data to the information processor when the second data is invalid.

Abstract: A chaos-generating loop includes a one dimensional mapping circuit (13) with non-linear input-output characteristics for generating chaos, a linear or non-linear AD converter (15) for converting an analog output of the one dimensional mapping circuit (13) to digital form, a sample-and-hold circuit (17) for holding and outputting the digitally converted value from the AD converter (15), in response to an external clock (C), and a linear or non-linear DA converter (19) for converting an output of the sample-and-hold circuit (17) to analog form and outputting this analog signal to the one dimensional mapping circuit (13), and a decoder for outputting a chaos stream in response to the output of the sample-and-hold circuit (17).

Abstract: An optical distributor includes an optical-signal input port, a light receiving device, a light emitting device, a light splitter, and optical signal output ports. The light receiving device converts an optical light signal input to the optical-signal input port into an electric signal. The light emitting device converts the electric signal into an optical signal. The optical splitter 14 splits the converted optical signal into two optical signals. The optical-signal output ports output the split optical signals. The light receiving device includes a light receiving element, a pre-amplifier, and a limiting amplifier. The light emitting device includes a light-source drive element and a light emitting element.

Abstract: In an optical transmission apparatus in which a plurality of nodes are optically connected to one another via an optical transmission path, a light signal which is coded so that a mixture ratio of 1 and 0 constituting data is made close to 50% is transmitted through the optical transmission path. When a light signal is not emitted from all of the nodes, a dummy signal which is an AC-like signal is emitted to the optical transmission path. Therefore, an optoelectric conversion section can be always set to an active state, and the signal recognizability can be prevented from being lowered.

Abstract: A signal transmission system has a master node and plural slave nodes performing data transmission with the master node. The master node has a serial-to-parallel converter for converting a serial data signal from each slave node into a parallel data signal. Each slave node has a transmission aligner for performing word alignment processing upon a parallel data signals, and a parallel-to-serial converter for converting the parallel data signal subjected to the word alignment processing by the transmission aligner into a serial data signal, and outputting the serial data signal to the master node.

Abstract: A design aid apparatus includes an input section, an antenna propensity determination section, an output section, and a memory storing design data for a plurality of structures comprising an electronic device to be designed. Conductivity of a structure is determined based on conductivity information of the structure read out from the memory. The antenna propensity determination section determines a contact relation, which expresses a state of electrical contact between a conductive structure having conductivity and another conductive structure, based on information relating to shapes and arrangements of structures stored in the memory. A length of a route between a reference conductive structure and the conductive structure is determined. The antenna propensity of the electronic device is evaluated based on the route length.

Abstract: A cryptographic key 1 constituted to be freely attachable and detachable to/from a personal computer 2 encrypting and decrypting data by use of a cipher key includes: a pseudo random number generator 14 for generating a pseudo random number of a chaotic time series based on a data size of the data, a chaotic function and an initial value of the chaotic function; and a USB controller 12 for receiving the data size of the data from the personal computer 2 and transmitting the pseudo random number of the chaotic time series as the cipher key to the personal computer 2, the pseudo random number being generated in the pseudo random number generator 14, when the cryptographic key 1 is attached to the personal computer 2.

Abstract: A printed wiring board is provided which can be applied even to circuit boards operating at high speed, and which can suppress electromagnetic wave radiation, and which can suppress a deterioration in density of mounting. At the printed wiring board, a first signal wire layer, a first ground layer having a first power source wire, a second ground layer having a second power source wire, and a second signal wire layer, are laminated. The first ground layer and the second ground layer are interlayer-connected by many via holes. Return current, of signal current flowing through a signal wire, flows in the first ground layer, and a path of the return current is cut midway therealong at a position of the first power source wire. However, the return current is detoured by the via hole to the second ground layer, and flows thereat.