Browse Prior Art Database

Static Punched Document Reader

IP.com Disclosure Number: IPCOM000074028D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 3 page(s) / 94K

Publishing Venue

IBM

Related People

Berkman, JW: AUTHOR [+3]

Abstract

This reader reads a perforated document card 10 when the document is stationary by driving air through the perforations of card 10 to a piston and switch matrix 12.

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Static Punched Document Reader

This reader reads a perforated document card 10 when the document is stationary by driving air through the perforations of card 10 to a piston and switch matrix 12.

A plenum chamber 14 is moved downwardly by rotatable cam 16 so as to cause an elastomeric gasket 18 to seal with document 10. A secondary motion by means of eccentric 20 drives down diaphragm 22 to compress air in plenum
14. The perforations in card 10 may, for example, be in thirty-two columns, with eighteen possible perforations in each column (six to each of three tiers); and the card bed 24 has 576 openings 26 in positions corresponding to the possible 576 perforations in card 10. Each of openings 26 is connected with a switch 28 so that when air flows from plenum 14 through a perforation in card 10 and through the corresponding opening 26 to the switch 28 connected thereto, electrical contact is made through the switch.

The 576 switches 28 may be connected in the matrix 30, each with a diode 32; and switches 28 in columns 1, 2, 3, etc., are connected with column decode logic 34 by means of leads a, b, c, etc.

The uppermost six switches 28 in the thirty-two columns for the first tier of perforations are in the matrix portion 30X, and the matrix portions 30Y and 30Z for the middle and lower tiers are identical to the portion 30X. The switches 28 in the matrix portion 30X are respectively connected with AND circuits 36, 38, 40, 42, 44, and 46 in block X which produce 1, 2, 4, 8, A, and B bits, respectively; and the switches 28 in the second and third matrix portions 30Y and 30Z are likewise connected by means of corresponding AND circuits in blocks Y and Z, which are identical with block X, with the output of AND circuits 36 to 46. The AND circuits in blocks X, Y, and Z are initialized from tier counter logic 48 so that the perforations in the first tier are read first, and subsequently the second and third tier perforations are read.

A start signal on lead 50 is generated from air ports 52, 54, 56, and 58 in card reader 59. ports 52, 54, and 56 are so positioned that, when card 10 is in proper reading position in contact with registration blocks 60 and 62, these ports are closed and the port 58 is outside of card 10. Springs 64 hold card 10...