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Self-Cleaning Dust Protection for Optical Components

IP.com Disclosure Number: IPCOM000101661D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Hasler, W: AUTHOR [+3]

Abstract

For accurate position detection of documents, such as passbooks, in printers, a sensor and an LED (light-emitting diode) may be used. By glass spheres 5, 6, installed in paper path 4 and protecting LED 3 and sensor 2 from dust, the beam path of LED 3 is very finely focussed and amplified. This permits determining the exact position of document 1. At the same time, glass spheres 5, 6 are self-cleaning, for paper dust is automatically removed each time document 1 and spheres 5, 6 come into contact.

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Self-Cleaning Dust Protection for Optical Components

       For accurate position detection of documents, such as
passbooks, in printers, a sensor and an LED (light-emitting diode)
may be used.  By glass spheres 5, 6, installed in paper path 4 and
protecting LED 3 and sensor 2 from dust, the beam path of LED 3 is
very finely focussed and amplified.  This permits determining the
exact position of document 1.  At the same time, glass spheres 5, 6
are self-cleaning, for paper dust is automatically removed each time
document 1 and spheres 5, 6 come into contact.

      As optical imaging elements, glass spheres 5, 6 are associated
with LED 3 and sensor 2, respectively.  Glass sphere 6 is illuminated
by LED 3 through an aperture tube 7. The sphere causes the light to
be focussed and amplified. The light beam traverses document path 4
in parallel, entering the second sphere 5 from where it is fed to
sensor 2 through an aperture tube 8.

      Highly accurate position control of a document is also ensured
at a small amount of LED light.  An additional advantage is obtained
by spheres 5, 6 being positioned in the document path, which produces
a self-cleaning effect. As document 1 passes the spheres, it
automatically cleans them.  Document damage is prevented by the
curved surface of the spheres.