Abstract: A printed wiring board design method including the steps of designing placement and wiring for circuit components based on circuit information on a mounting surface of the board; excluding a placement region and a wiring region for the circuit components from the mounting surface to thereby calculate a placement and wiring enable region for an EMC component in which the EMC component can be placed and wiring can be laid down; and calculating the placement and wiring range for the EMC component based on an EMC design rule from the calculated placement and wiring enable region for the EMC component. Thus, a printed wiring board design method is provided in which placement of and wiring for a new bypass capacitor or the like can be implemented and a region satisfying restraint items from the design rule can be clearly displayed as a new input enable region on a CAD screen.

Abstract: A CAD apparatus designing patterns of a printed board. The apparatus includes a signal wiring pattern detecting unit for detecting a signal wiring pattern, and a guard ground detecting unit for tracing the signal wiring pattern along the longitudinal direction thereof, in order to detect whether or not a guard ground exists within a distance from the signal wiring pattern to a predetermined first discriminant value, identify a non-guard ground section within the distance to the first discriminant value, and to detect whether or not a guard ground exists within another distance from the signal wiring pattern to a second discriminant value, which is larger than the first discriminant value. The apparatus also includes a return path judging unit for judging an error of guard ground when no guard ground exists within the distance to the second discriminant value, thereby quickly checking a return path without mistake.

Abstract: A radiation noise suppression circuit for a differential transmission line includes a differential transmission line which has plus line signal wiring to which a plus line signal of a differential signal is applied, and minus line signal wiring to which a minus line signal of the differential signal is applied, and connects a differential driver and a differential receiver. Plus line signal GND wiring and minus line signal GND wiring which are connected between the differential driver and the differential receiver are wired along the differential transmission line. A distance between the plus line signal wiring and the plus line signal GND wiring is substantially equal to a distance between the minus line signal wiring and the minus line signal GND wiring.

Abstract: A radiation noise suppression circuit for a differential transmission line includes a differential transmission line which has plus line signal wiring of a differential signal and minus line signal wiring of the differential signal, and connects a differential driver and a differential receiver; signal GND wiring. A first impedance element and a second impedance element have substantially the same impedance value, and are connected in series between the plus line signal wiring and the minus line signal wiring at a location nearer to the differential receiver than a coil unit. A third impedance element is connected to a junction point. The first impedance element and the second impedance element are connected.

Abstract: An element placement check system for checking element placement on a printed wiring board having wiring by which a power supply terminal of an integrated circuit and a power supply decoupling element for the power supply terminal are connected on a mounting surface on which the integrated circuit is mounted, wherein the wiring is connected to a power supply plane for providing a direct current power supply to the power supply terminal through a power supply via hole, including: element distance detecting means detecting a first wire length between the power supply decoupling element and the power supply terminal; power supply via hole distance detecting means detecting a second wire length between the power supply via hole and the power supply terminal; and determination means determining a positional relationship of the power supply decoupling element and the power supply via hole to the power supply terminal based on the first and second wire lengths, thereby providing a check system and a printed wiring b

Abstract: To provide a common mode radiation inhibit circuit for a differential transmission line which can inhibit quadratic common mode radiation by ensuring a continuity of grand level at a point of change of a signal grand, including a differential transmission line which is constituted of a pair of signal wiring, and transmits differential signals, signal grounds which are arranged along the differential transmission line, and each have a change point on its way, a transformer, and a reference ground, wherein a primary side of the transformer is connected between an electric midpoint of the pair of signal wiring, and the signal ground at one side of the front and back of the change point of the signal grounds, wherein the secondary side of the transformer is connected between the electric midpoint of the pair of signal wiring and the signal ground at another side of the front and back of the change point, and wherein the reference ground is connected to a point which becomes a neutral sheet of the primary side of

Abstract: A checking unit includes a power net extracting means for extracting a power net with power attribution, which is segmented by a power-decoupling element, with reference to circuit design data of the printed wiring board; a parts number extracting means for extracting a parts number of an integrated circuit which is connected to the extracted power net; a parts headcount calculating means for calculating a headcount of the extracted parts; a judging means for comparing the extracted parts headcount with a predetermined reference value; and a representing means for representing a name of the power net and the parts number of the integrated circuit as an unprocessed location of power decoupling when the headcount is larger than the reference value, whereby inspecting quickly whether or not a power supply in use, which is shared by each of the integrated circuits, is decoupled at higher frequencies by the power-decoupling element.

Abstract: A CAD apparatus for designing patterns of a printed board, includes: a signal wiring pattern detecting unit 22 for detecting a signal wiring pattern with reference to wiring information of the printed board; a guard ground detecting unit 23 for tracing the signal wiring pattern along the longitudinal direction thereof, to detect whether or not a guard ground exists within a distance from the signal wiring pattern to a predetermined first discriminant value GL, and for identifying a non-guard ground section in which no guard ground exists within the distance to the first discriminant value GL, and for detecting whether or not a guard ground exists within another distance from the signal wiring pattern to a second discriminant value GU, which is larger than the first discriminant value GL, in the non-guard ground section; and a return path judging unit 25 for judging an error of guard ground when no guard ground exists within the distance to the second discriminant value GU in the non-guard ground section, ther

Abstract: An element placement check system for checking element placement on a printed wiring board having wiring by which a power supply terminal of an integrated circuit and a power supply decoupling element for the power supply terminal are connected on a mounting surface on which the integrated circuit is mounted, wherein the wiring is connected to a power supply plane for providing a direct current power supply to the power supply terminal through a power supply via hole, including: element distance detecting means detecting a first wire length between the power supply decoupling element and the power supply terminal; power supply via hole distance detecting means detecting a second wire length between the power supply via hole and the power supply terminal; and determination means determining a positional relationship of the power supply decoupling element and the power supply via hole to the power supply terminal based on the first and second wire lengths, thereby providing a check system and a printed wiring b

Abstract: A printed wiring board design method including the steps of designing placement and wiring for circuit components based on circuit information on a mounting surface of the board; excluding a placement region and a wiring region for the circuit components from the mounting surface to thereby calculate a placement and wiring enable region for an EMC component in which the EMC component can be placed and wiring can be laid down; and calculating the placement and wiring range for the EMC component based on an EMC design rule from the calculated placement and wiring enable region for the EMC component, thereby providing a printed wiring board design method in which a placement of and wiring for a new bypass capacitor or the like can be implemented and a region satisfying restraint items from the design rule can be clearly displayed as a new input enable region on a CAD screen.

Abstract: A radiation noise suppression circuit for a differential transmission line includes a differential transmission line which has plus line signal wiring to which a plus line signal of a differential signal is applied, and minus line signal wiring to which a minus line signal of the differential signal is applied, and connects a differential driver and a differential receiver, plus line signal GND wiring and minus line signal GND wiring which are connected between the differential driver and the differential receiver, and are wired along the differential transmission line, and a coil unit in which each of the plus line signal wiring, minus line signal wiring, plus line signal GND wiring, and minus line signal GND wiring is wound in the same winding direction, wherein a distance between the plus line signal wiring and the plus line signal GND wiring is substantially equal to a distance between the minus line signal wiring and the minus line signal GND wiring.

Abstract: A radiation noise suppression circuit for a differential transmission line includes a differential transmission line which has plus line signal wiring of a differential signal and minus line signal wiring of the differential signal, and connects a differential driver and a differential receiver; signal GND wiring one end of which is connected to the differential driver, and is wired outside along the differential transmission line; a coil unit in which each of the plus line signal wiring, the minus line signal wiring, and said signal GND wiring is wound in the same winding direction; a first impedance element and a second impedance element which have substantially the same impedance value, and which are connected in series between the plus line signal wiring and the minus line signal wiring at a location nearer to the differential receiver than the coil unit; and, a third impedance element one end of which is connected to a junction point, where the first impedance element and the second impedance element are

Abstract: To provide a common mode radiation inhibit circuit for a differential transmission line which can inhibit quadratic common mode radiation by ensuring a continuity of grand level at a point of change of a signal grand, including a differential transmission line which is constituted of a pair of signal wiring, and transmits differential signals, signal grounds which are arranged along the differential transmission line, and each have a change point on its way, a transformer, and a reference ground, wherein a primary side of the transformer is connected between an electric midpoint of the pair of signal wiring, and the signal ground at one side of the front and back of the change point of the signal grounds, wherein the secondary side of the transformer is connected between the electric midpoint of the pair of signal wiring and the signal ground at another side of the front and back of the change point, and wherein the reference ground is connected to a point which becomes a neutral sheet of the primary side of

Abstract: A management information display unit that is able to form management information for managing the power supply state of fuel cells and displays the management information while allowing the management information to be identified as to which electronic device of the electronic devices pertains to the management information on basis of identification information inputted from a plurality of electronic devices that are able to output the formed management information in correlation with the identification information of the fuel cell, and information transmitting part for transmitting the identification information and the management information while allowing the information to be inputted to the management information display unit are provided.

Abstract: In a high-frequency impedance type magnetic head having high impedance and capable of efficiently detecting a change in impedance, an electrically conductive metal film is sandwiched between two soft magnetic films, and the two soft magnetic films form a portion of a magnetic path. The thickness of one soft magnetic film is smaller than the thickness of the other soft magnetic film. The electrically conductive metal thin film has a pair of electrodes at respective ends thereof, to which are connected an oscillator for applying a high frequency carrier signal to the electrodes and a high frequency amplifier having a demodulator circuit. Further, an electrically conductive metal film winding is provided, and a DC current is applied to the electrically conductive metal film winding at the time of reproduction, while on the other hand, a signal current is applied to the electrically conductive metal film winding at the time of recording.

Abstract: In a high-frequency impedance type magnetic head having high impedance and capable of efficiently detecting a change in impedance, an electrically conductive metal film is sandwiched between two soft magnetic films, and the two soft magnetic films form a portion of a magnetic path. The thickness of one soft magnetic film is smaller than the thickness of the other soft magnetic film. The electrically conductive metal thin film has a pair of electrodes at respective ends thereof, to which are connected an oscillator for applying a high frequency carrier signal to the electrodes and a high frequency amplifier having a demodulator circuit. Further, an electrically conductive metal film winding is provided, and a DC current is applied to the electrically conductive metal film winding at the time of reproduction, while on the other hand, a signal current is applied to the electrically conductive metal film winding at the time of recording.

Abstract: In a high-frequency impedance type magnetic head having high impedance and capable of efficiently detecting a change in impedance, an electrically conductive metal film is sandwiched between two soft magnetic films, and the two soft magnetic films form a portion of a magnetic path. The thickness of one soft magnetic film is smaller than the thickness of the other soft magnetic film. The electrically conductive metal thin film has a pair of electrodes at respective ends thereof, to which are connected an oscillator for applying a high frequency carrier signal to the electrodes and a high frequency amplifier having a demodulator circuit. Further, an electrically conductive metal film winding is provided, and a DC current is applied to the electrically conductive metal film winding at the time of reproduction, while on the other hand, a signal current is applied to the electrically conductive metal film winding at the time of recording.

Abstract: An optical pickup includes an object lens; a lens holder for holding the object lens; a visco-elastic suspender for suspending the lens holder so as to be movable in a focusing direction and a tracking direction; a driving section for driving the lens holder in the focusing direction and the tracking direction, the driving section including a magnet, a yoke and a driving coil provided on the lens holder. The magnet and the yoke form a magnetic circuit. A heat-insulating area is located between the object lens and the driving coil, and the heat-insulating area includes a heat-insulating material which has a thermal conductivity lower than that of the lens holder.