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( 74472 of 74472 ) |
United States Patent | 3,553,378 |
Alter , et al. | January 5, 1971 |
Information retrieval apparatus providing selective access by subscribers through telephone lines to a plurality of program sources is described. Common control equipment including a marker is employed for connecting each subscriber to a program matrix. All subscribers may access the same program nearly simultaneously. Crossbar switches are used for the marker in the common control equipment and for the program matrix.
Inventors: | Alter; Soloman (Hartsdale, NY), Goodfellow; John A. (Yonkers, NY), Kane; Robert F. (New York, NY) |
Assignee: |
Dialscan Systems, Inc.
(New York,
NY)
|
Appl. No.: | 04/726,733 |
Filed: | May 6, 1968 |
Current U.S. Class: | 379/76 ; 379/84 |
Current International Class: | G08B 5/22 (20060101); H04M 3/487 (20060101); H04M 3/493 (20060101); H04m 001/64 (); H04m 011/08 () |
Field of Search: | 179/6CO,6R,2R,DP 340/152 |
1337197 | April 1920 | Clausen |
2092493 | September 1937 | Allen et al. |
2993960 | July 1961 | Anderson |
3199226 | August 1965 | Joslow |
3347989 | October 1967 | Riddell |
3352973 | November 1967 | Bodenstein |
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