Browse Prior Art Database

Sensing Apparatus

IP.com Disclosure Number: IPCOM000096016D
Original Publication Date: 1964-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Rohland, WS: AUTHOR

Abstract

Document 1 having punched holes 2 representing data bits is fed by rollers 3 across a light-reflective backing surface 4. Data on document 1 is sensed serial-by-bit, serial-by-column by apparatus indicated generally at 6. A plurality of light rods or bundles of optical fibers 9 transmits light from single light source 7 to each of four bit positions. The output ends of rods 9 fixed in block 8 are spaced just above the surface of document 1 so that each bit position is equally illuminated.

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Sensing Apparatus

Document 1 having punched holes 2 representing data bits is fed by rollers 3 across a light-reflective backing surface 4. Data on document 1 is sensed serial- by-bit, serial-by-column by apparatus indicated generally at 6. A plurality of light rods or bundles of optical fibers 9 transmits light from single light source 7 to each of four bit positions. The output ends of rods 9 fixed in block 8 are spaced just above the surface of document 1 so that each bit position is equally illuminated.

Light reflected from the surface of document 1 is transmitted through a plurality of rods 10 to the periphery of rotatable cylinder 14. Cylinder 14 fixed to shaft 18 is driven at constant velocity by motor 20. A photocell mounted inside cylinder 14 and rotatable with it is positioned to detect any light entering aperture
16. As 14 rotates, aperture 16 scans the output ends of rods 10. The output end of constantly illuminated rod 12, provided for generation of timing signals, is also scanned.

Signals generated by the photocell are inductively removed from the rotating assembly via a pot-core transformer indicated generally at 21. Transformer 21 has a primary housing 22a fixed to shaft 18 and a stationary secondary housing 22b. Toroidal primary winding 36 is placed in series with the photocell through leads 34 and toroidal secondary winding 38 is connected across output leads 26.

Signals generated by the photocell are of three levels. Low level signals are generated by light reflected from the surface of document 1 the surface being of low reflectivity. Medium level signals are generated by light reflected from backing surface 4 and indicate the presence of a data bit. High level signals are gener...