Browse Prior Art Database

Original Publication Date: 1978-Feb-28
Included in the Prior Art Database: 2004-Mar-31

Publishing Venue

Xerox Disclosure Journal


A toner holder and dispenser 10 for use in electrostatic reproduction machines wherein, for example, latent images are developed on a photoreceptor 28 by developing means 26. Dispenser 10 includes a housing 12 which contains a collaps-ible bag 14 for holding toner 16. As the toner 16 is dispensed through outlet 24, the bag 14 collapses under the force of gravity or an externally applied air pressure (not shown) . A light source 18 and photocell 20 arrangement mounted in the walls of housing 12 is coupled to a low toner level detection circuit 22. Thus, when the bag 14 collapses a predetermined distance, light from source 18 strikes photocell 20 which is detected by circuit 22 thereby signalling that more toner is needed. Since the toner 16 is isolated by bag 14 from the source 18 and photocell 20, the possibility of toner 16 sticking to either device and blocking the light therebetween when the majority of toner is otherwise depleted is eliminated.