公开(公告)号：US20220182086A1

公开(公告)日：2022-06-09

申请号：US17514100

申请日：2021-10-29

Applicant: Hitachi, Ltd.

Inventor： Goro HAMAMOTO ,  Yutaka UEMATSU ,  Masahiro SHIRAISHI ,  Tatsuyuki OOTANI

IPC: H04B1/04

Abstract: A signal transmission device has a multi-point wiring structure in which termination resistors are mounted on both ends of a cable, and a plurality of PCBs connected to the cable transmit a signal through the cable. The PCB of a host node includes: a connector connected to the cable; a transformer unit that is connected to the connector via a first PCB transmission line and insulates the connector; an RS 485 transceiver that is connected to the transformer unit via a second PCB transmission line and transmits the signal to the PCB of another node or receives the signal from the PCB of another node; and AC termination that is provided in at least one of the first PCB transmission line and the second PCB transmission line and suppresses resonance and antiresonance in a reflection frequency characteristic of noise.

公开(公告)号：US20240164045A1

公开(公告)日：2024-05-16

申请号：US18281816

申请日：2022-03-07

Applicant: HITACHI, LTD.

Inventor： Koumei YOSHIDA ,  Goro HAMAMOTO

IPC: H05K7/20

CPC classification number: H05K7/20127 ,  H05K7/20445

Abstract: Provided is an electronic device that can prevent an increase in a temperature of an internal electronic component, and prevent a heat influence on adjacent electronic devices or the like. The electronic device includes: a circuit board on which a heat-generating element configured to generate heat is mounted; a housing in which the circuit board is housed; a heat dissipation portion connected to the housing and configured to dissipate heat; a heat transfer member disposed between the heat-generating element and the heat dissipation portion, and configured to transfer heat generated by the heat-generating element to the heat dissipation portion; and a housing cover provided on a side of the heat dissipation portion opposite to a side of the heat transfer member, in which a convection area that is a space where air convects is provided between the heat dissipation portion and the housing cover.

公开(公告)号：US20240080979A1

公开(公告)日：2024-03-07

申请号：US18223679

申请日：2023-07-19

Applicant: Hitachi, Ltd.

Inventor： Goro HAMAMOTO ,  Keisuke YAMAMOTO ,  Yutaka UEMATSU ,  Shinsuke ONOE ,  Yohei OSHIMA

IPC: H05K1/11 ,  H05K1/02

CPC classification number: H05K1/115 ,  H05K1/0215 ,  H05K2201/10159

Abstract: There is provided a printed wiring board including an outermost conductive layer that includes a plurality of conductive pads, a first conductive layer that includes a first inner-layer wiring and is stacked on the conductive layer, a second conductive layer that includes a second inner-layer wiring and is stacked on the conductive layer and the first conductive layer, a first signal via that connects one of the conductive pads and the first inner-layer wiring with each other, a second signal via connecting another one of the conductive pads and the second inner-layer wiring with each other, and a stitching via that is connected to a ground. The first inner-layer wiring and the second inner-layer wiring form a common wiring route in which the first inner-layer wiring and the second inner-layer wiring are stacked and disposed in a connection area in which the conductive pads are arranged.

公开(公告)号：US20220182057A1

公开(公告)日：2022-06-09

申请号：US17510501

申请日：2021-10-26

Applicant: Hitachi, Ltd.

Inventor： Goro HAMAMOTO ,  Tatsuyuki OOTANI ,  Yutaka UEMATSU ,  Jouji MATSUSHITA

IPC: H03K19/0175 ,  H03K19/00 ,  H03K19/09 ,  H03K19/17784 ,  G06F13/40

Abstract: Main wiring including a plurality of differential transmission lines for transmitting differential signals is formed on a motherboard. Termination resistors, provided at both ends of each of the plurality of differential transmission lines, connect the plurality of differential transmission lines to each other. A plurality of daughter boards are connected in parallel to each other via the main wiring. A line characteristic impedance of each differential transmission line is higher than a termination resistance value, which is a resistance value of the termination resistor.