公开(公告)号：US3675240A

公开(公告)日：1972-07-04

申请号：US3675240D

申请日：1969-12-23

Applicant: BELL TELEPHONE LABOR INC

Inventor： ANDERSON ROBERT V ,  HAGELBARGER DAVID W

IPC: H03K17/972

CPC classification number: H03K17/972

Abstract: A magnetic keyboard and associated encoding circuitry are described. A permanent magnet on each of the keys of the keyboard alters the switching characteristics of a ferrite core associated with that key when the key is depressed. Logic circuitry is provided which determines when the addresses of depressed keys are to be entered in an output shift register and which addresses are to be transmitted. A unique lockout feature prevents both the transmission of address information from the output shift register if more than one key is depressed and the inadvertent retransmission of the address of a core already transmitted.

Abstract translation: 描述了磁性键盘和相关联的编码电路。 当键被按下时，键盘的每个键上的永磁体改变与该键相关联的铁氧体磁心的切换特性。 提供了逻辑电路，其确定何时将输入按键的地址输入到输出移位寄存器以及哪些地址将被发送。 独特的锁定功能可以防止输出移位寄存器的地址信息传输，如果按下多个键，并且已经发送了一个内核地址的意外重发。