Browse Prior Art Database

Tomographic Imaging of Toners

IP.com Disclosure Number: IPCOM000036246D
Original Publication Date: 1989-Sep-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Hendriks, F: AUTHOR

Abstract

Disclosed is a tomographic method of measuring the distribution of toner in an electrophotographic printer or copier.

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Tomographic Imaging of Toners

Disclosed is a tomographic method of measuring the distribution of toner in an electrophotographic printer or copier.

The precise knowledge of the motion of toner, liquid or solid in printing is of great practical use, because it affords better insight into development physics. Unfortunately, information must typically be gathered in places where the toner is least accessible.

Tomography is an imaging method based on the deconvolution or reconstruction of information gathered remotely by an array of transmitters and sensors 1. A typical reconstruction algorithm is given in 2. An advantage of tomography is that it is non-intrusive and that the sensors can be protected from degradation by the toner.

To focus the idea, assume that one wants to know the distribution of non- magnetic, non-conducting toner particles in a portion of an electrophotographic printer, such as the toner recovery area, the region "upstream" of the toner doctor blade, or even the development nip.

One surrounds the region of interest with a number of electrodes 1. A large number of capacitance measurements are carried out between the electrodes, and the distribution of toner is reconstructed on the basis of the difference in permittivity of the toner and air (a factor of about 2.5).

If the toner is magnetic, the technique relies on permeance. Then the information is based on the even larger difference of magnetic susceptibility between air and toner. However, the s...