发明名称 |
INHIBITOR FOR INTERFERENCE OF CAPACITIVE KEYBOARD |
摘要 |
The signals from the readout lines are taken to a subtractor which calculates the difference between the readout and a reference line in the keyboard. The difference output signal is used, together with the parasitic signals which have entered the keyboard from external electromagnetic sources removed. The keyboard remains sensitive to operation by a low capacitance touch. The keyboard consists of keypads surrounded by an earthed screen backed by pairs of emitting electrodes excited in sequence by an alternating signal and receiving electrodes (B) coupled capacitatively by the presence of a finger near the emitter electrodes. The reference electrode (21) may be one or the combination of several of the other readout electrodes such as the adjacent pair in a keypad matrix. Each readout line is integrated and compared with two reference levels. The comparator outputs are OR-gated and used to inhibit keyboard operation whilst interference persists. |
申请公布号 |
JPS57176448(A) |
申请公布日期 |
1982.10.29 |
申请号 |
JP19820055233 |
申请日期 |
1982.04.02 |
申请人 |
COMMISSARIAT A L'ENERGIE ATOMIQUE |
发明人 |
MARUSERU OODOIN;JIYANNMARUKU FUEDERI;ROBEERU PUJIYOWA |
分类号 |
G06F3/044;H01H36/00;H03K17/96 |
主分类号 |
G06F3/044 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|