公开(公告)号：US09240295B2

公开(公告)日：2016-01-19

申请号：US13233214

申请日：2011-09-15

Applicant: Hong Chean Choo ,  Kien Beng Tan ,  Gee Heng Loh

Inventor： Hong Chean Choo ,  Kien Beng Tan ,  Gee Heng Loh

IPC: H03K17/94 ,  H03M11/00 ,  H03K17/62 ,  H01H13/70

CPC classification number: H01H13/70 ,  H01H2239/004 ,  H01H2239/01

Abstract: Disclosed is keypad circuitry operable to detect a pressed key while reducing electromagnetic interference (EMI). The keypad circuitry is operable to reduce EMI in two ways: a) reducing the voltage swing occurring at the row circuitry and column circuitry of the keypad, and b) reducing the number of signal transitions by restricting the signal transitions to occurring at the column and row corresponding to a pressed key. By limiting signal transitions to occurring only at the row and column corresponding to a pressed key, fewer signal transitions occur, and thus, less EMI is produced. Additionally, reduced voltage swings at the row circuitry and column circuitry results in reduced EMI.

Abstract translation: 公开了可操作以在减少电磁干扰（EMI）的同时检测按下的键的键盘电路。 键盘电路可操作以两种方式降低EMI：a）降低在键盘的行电路和列电路处发生的电压摆幅，以及b）通过限制信号转变发生在列而减少信号转换的数量，以及 行对应于按下的键。 通过将信号转换限制在对应于按下的键的行和列上才发生，产生较少的信号转换，从而产生更少的EMI。 另外，行电路和列电路的减小的电压摆幅导致EMI降低。

公开(公告)号：US20130069805A1

公开(公告)日：2013-03-21

申请号：US13233214

申请日：2011-09-15

Applicant: Hong Chean Choo ,  Kien Beng Tan ,  Gee Heng Loh

Inventor： Hong Chean Choo ,  Kien Beng Tan ,  Gee Heng Loh

IPC: H03K17/94

CPC classification number: H01H13/70 ,  H01H2239/004 ,  H01H2239/01

Abstract: Disclosed is keypad circuitry operable to detect a pressed key while reducing electromagnetic interference (EMI). The keypad circuitry is operable to reduce EMI in two ways: a) reducing the voltage swing occurring at the row circuitry and column circuitry of the keypad, and b) reducing the number of signal transitions by restricting the signal transitions to occurring at the column and row corresponding to a pressed key. By limiting signal transitions to occurring only at the row and column corresponding to a pressed key, fewer signal transitions occur, and thus, less EMI is produced. Additionally, reduced voltage swings at the row circuitry and column circuitry results in reduced EMI.

Abstract translation: 公开了可操作以在减少电磁干扰（EMI）的同时检测按下的键的键盘电路。 键盘电路可操作以两种方式降低EMI：a）降低在键盘的行电路和列电路处发生的电压摆幅，以及b）通过限制信号转变发生在列而减少信号转换的数量，以及 行对应于按下的键。 通过将信号转换限制在对应于按下的键的行和列上才发生，产生较少的信号转换，从而产生更少的EMI。 另外，行电路和列电路的减小的电压摆幅导致EMI降低。