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Patent Searching and Data


Title:
SWITCH DEVICE AND ELECTRONIC MACHINE
Document Type and Number:
WIPO Patent Application WO/2018/179481
Kind Code:
A1
Abstract:
In this invention, each electrode Ex and a corresponding region of a top plate (12) facing the electrodes Ex constitute switches SWx that have a capacitance that changes from the corresponding region in the top plate (12) being pushed down toward the corresponding electrode Ex. A press-down detection circuit (21) calculates changes in capacitance which indicate the change in capacitance from a reference value for each switch SWx. The press-down detection circuit (21) calculates a maximum value and a total sum, from the change in capacitance of each switch SWx. When the change in capacitance of at least one switch SWx exceeds a threshold value TH_EDGE, and, when the ratio of the maximum value over the total sum is equal to or greater than a threshold value COMP_LEVELx and this state continues over SW_DET_COUNT times, the press-down detection circuit (21) determines that the switch having the maximum change in capacitance is in the pressed-down state.

Inventors:
YAMAMOTO MASAMI
TOKORO YUKINOBU
KAWAGOE SHOHEI
KAWASAKI KOJIRO
OKUDA TADAYOSHI
SHIOTA YOSUKE
Application Number:
PCT/JP2017/030652
Publication Date:
October 04, 2018
Filing Date:
August 28, 2017
Export Citation:
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Assignee:
PANASONIC IP MAN CO LTD (JP)
International Classes:
H01H36/00; G06F3/02; G06F3/041; G06F3/044; H01H13/00; H01H13/81
Foreign References:
JP2004112074A2004-04-08
JP2015133206A2015-07-23
JP2009238701A2009-10-15
JP2009258946A2009-11-05
JP2007122891A2007-05-17
JP2004245606A2004-09-02
US20140253503A12014-09-11
Other References:
See also references of EP 3605577A4
Attorney, Agent or Firm:
KAMATA Kenji et al. (JP)
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