Hitachi, Ltd.

Mariko Kasai

Tsutomu Hara

Hitoshi Yokota

Takashi Suga

Hideo Sawada

Tatsuhiko Matsuoka

Nobuhiro Kato

Hiromu Ishihara

Giichirou Yokokura

In a circuit board having a multilayer structure comprising a ground pattern and a power-supply pattern both, for example, by forming a plurality of slits along each side of the ground pattern or the power-supply pattern, a long thin conduction path connecting a corner and a side center of the ground pattern is formed and resistive elements are placed in the middles of the conduction path to short, circuit the corner and a side center of the ground pattern. Therefore, portions corresponding to an antinode and a node or antinode and an antinode of a standing wave are short-circuited. The standing wave is generated when electric power is supplied to ICs and LSIs mounted on the circuit board. Thus, noise sources caused by the standing wave cancel each other. As a result, the occurrence of an antiresonance phenomenon and an increase in impedance of the power supplying system caused by the standing wave can be suppressed.

Reducing impedance of power supplying system in a circuit board by connecting two points in one of a power supply pattern and a ground pattern by a resistive member

The objective of the present invention is to provide an information processing device that is operable by a battery and which suppresses the generation of standing waves and has little radiation noise. In the information processing device of the present invention having means for connecting to a battery pack that stores a battery for supplying power to the information processing device, there is one or more capacitive element (for example, a capacitor) in the proximity of the terminals of the positive and negative poles of the battery when the battery pack is connected to the information processing device, and it is possible for at least the terminal of the positive pole of the battery or the terminal of the negative pole of the battery to be connected electrically to the ground of the information processing device by way of this capacitive element.

Battery pack and an information processing device in which the battery pack is detachable/attachable

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Ebina, Japan

Mariko Kasai