The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 28, 1981
Filed:
Mar. 02, 1979
Takuji Mukaemachi, Yokohama, JP;
Tetsuo Takeshita, Yokohama, JP;
Keiichi Shimizu, Higashikurume, JP;
Ryoichi Himeno, Iruma, JP;
Nippon Telegraph and Telephone Public Corp., Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A multi-stage switching network comprises a plurality of unitary switch matrices each including a number of cross-point circuits each of which in turn includes a memory circuit operatively connected to the associated cross-point switches in a speech path. The plurality of the unitary switch matrices are arranged in a matrix array in which each stage of the multi-stage switching network is constituted by the unitary switch matrices arrayed in at least one column thereof and interconnected through links. The memory circuit for performing ON/OFF control of the associated cross-point switches in each of the switch matrices incorporates therein at least three logical control signal input terminals to which at least an information signal for designating the switch matrix to be selected and information signals for designating a row and a column in the selected switch matrix are applied, the latter information signals being produced in common to all the switch matrices, whereby a given cross-point determined by these information signals in the selected matrix is selected and correspondingly controlled. The ON/OFF control of the cross-point switch is effected sequentially by a stage selecting information signal from stage to stage.