发明名称 |
Key interface circuit with reduced number of input terminals |
摘要 |
A static key interface circuit has an input terminal coupled to N key switches, where N is an integer greater than one. The N key switches are biased at different potentials, which are supplied to the input terminal when the key switches are closed. A multilevel detector in the key interface circuit detects the potential of the input terminal and generates corresponding result data. A dynamic key interface circuit has an input terminal coupled to P rows of N key switches each and scans the P rows in turn, using a similar multilevel detector. The multilevel detector increases the number of key switches connectable to a single input terminal by a factor of N.
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申请公布号 |
US6075390(A) |
申请公布日期 |
2000.06.13 |
申请号 |
US19980069941 |
申请日期 |
1998.04.30 |
申请人 |
OKI ELECTRIC INDUSTRY CO., LTD. |
发明人 |
SHIN, YASUHIRO;FUJII, TERUYUKI |
分类号 |
G06F3/023;H03M11/20;H03M11/24;(IPC1-7):H03K5/22 |
主分类号 |
G06F3/023 |
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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