Charge/Mass Particle Spectrometer
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
In electrophotographic copiers and printers, charged black marking particles (toner) are attracted to and adhere to an electrostatic image on the photoconductor. We have found a device for measurement of charge-to-mass ratio of individual particles. A schematic diagram is shown in Fig. 1. The developer mix is used to blow the toner off the carrier beads. The toner particles enter an area of air flow directed toward the entrance aperture of the main chamber. Using a combination of filters and honeycomb structures, the air flow in the main chamber is laminar with a known transverse velocity profile. This is necessary for the tractable handling of the data. Toner particles that enter the main chamber are subjected to an electric field, causing the particles to move transversely toward or away from the metal electrodes.