Patent · US Expired

Compound type of keyboard detector

US5668544A · kind A · utility

9Cited by
1References
1Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1996
Grant dateSep 16, 1997
Priority date
Expiry dateFeb 26, 2016

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03M11/20
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A compound type keyboard detector is disclosed. It comprises a time-sequencing generator, a keyboard scanner, a column input port and a row input port, a column lock and a row lock, a keyboard-synchronization detector, a keyboard detector and a keyboard decoder. With the unique design of the keyboard detector in conjunction with the various circuits that are associated therewith, a given number of pins can be used for a relatively greater number of input keys, or a smaller number of pins can be used for relatively complicated input keyw. This type of keyboard detector is good for small IC products, and can reduce the manufacturing cost thereof.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.