发明名称 |
PROGRAM CONTROLLED CAPACITIVE KEYBOARD SENSING SYSTEM |
摘要 |
<p>PROGRAM CONTROLLED CAPACITIVE KEYBOARD SENSING SYSTEM An improved sensing apparatus for detecting impedance changes in a variable impedance matrix keyboard is described. A microprocessor is utilized to control the basic key intersections scanning and for accurately calibrating and adjusting the sensing threshold of the sense amplifier prior to testing each key intersection so that the effects of stray impedance and varying voltage levels may be compensated for.</p> |
申请公布号 |
CA1147868(A) |
申请公布日期 |
1983.06.07 |
申请号 |
CA19800352829 |
申请日期 |
1980.05.27 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
DAHL, JEROME P.;EPLEY, PHILLIP R.;FOX, JON E. |
分类号 |
G06F3/02;G06F3/023;H03K17/96;H03K17/98;H03M11/20;(IPC1-7):G06F3/023 |
主分类号 |
G06F3/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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