Browse Prior Art Database

Compact Expandable Viewer

IP.com Disclosure Number: IPCOM000074703D
Original Publication Date: 1971-May-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Cox, RE: AUTHOR

Abstract

A microfiche viewer with a compact optics system is collapsible to minimum size when not in use, but expandable to project an image within a range of selectable magnifications. Light from source 1 passes through transparency 2 on glass plate 3 and along an optical path 4a,b,c via objective lens 5, lower mirror 6 and upper mirror 7 to viewing screen 8 in front housing 9. Mirrors 6,7 are rockably supported on pins 10,11, respectively, disposed on the center line of path 4. Pivot pin 12 connects 6 to cam track 13 in rear housing 14. Pivot pin 15 connects 7 to cam track 16 in fixed housing 17. Rotating knob 18 clockwise causes pinion 19 through oppositely arranged racks 20,21 to move 9 and 14 toward each other for reducing the image on screen 8 or compacting the viewer when not in use.

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Compact Expandable Viewer

A microfiche viewer with a compact optics system is collapsible to minimum size when not in use, but expandable to project an image within a range of selectable magnifications. Light from source 1 passes through transparency 2 on glass plate 3 and along an optical path 4a,b,c via objective lens 5, lower mirror 6 and upper mirror 7 to viewing screen 8 in front housing 9. Mirrors 6,7 are rockably supported on pins 10,11, respectively, disposed on the center line of path 4. Pivot pin 12 connects 6 to cam track 13 in rear housing 14. Pivot pin 15 connects 7 to cam track 16 in fixed housing 17. Rotating knob 18 clockwise causes pinion 19 through oppositely arranged racks 20,21 to move 9 and 14 toward each other for reducing the image on screen 8 or compacting the viewer when not in use. Rotating 18 counterclockwise spreads 9 and 14 as desired to increase image magnification on 8 as 11 moves at right angles to 8.

Since pins 10,11 always lie on the center line of optical path 4 and pivoting of mirrors 6,7 is coordinated by 13,16, the angular relationship between mirrors, screen and the lens is maintained despite variations in total length of the optical path corresponding to the selected degree of magnification.

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