Small Low-Ozone-Emission Solid-State Charger

Abstract

The authors developed a small low-ozone-emission solid-state charger for laser printers and copy machines. The solid-state charger consists of a solid-state ion generator and an ozone decomposition space. The A3-sized solid-state ion generator is 360 mm in length, 0.6 mm in thickness and 10 mm in width. Its volume is less than 4 % of the volume of a conventional wire-charger. An AC voltage of 2.4 kVp-p (5 kHz) is applied to the solid-state ion generator, and an ion current that is sufficient for a printing speed of 20 PPM is generated. In order to attain the required service life of several hundred hours, a thin film layer of SiO₂ is used to protect the ion generator electrode. In addition, a heater is used behind the ceramic substrate to remove moisture and prevent the generation of nitric acid. The ozone decomposition space is also heated to decompose the generated ozone. Consequently, ozone emission is less than 20 % of that in a conventional wire-charger.