The aim of this study was to compare the concentrations of airborne pollutants (i.e., PMs, TVOC, and ozone) released from a laser printer with a new and/or a refilled toner cartridge. Also we compared the concentrations before and after attaching a HEPA filter at the outlet of exhausted air for each printer. PMs, TVOC, and ozone were released from all three different branded printers with both toner cartridges in accordance with their both a brand new and a used condition. For PMs, there were generally significant differences of concentrations between a brand new and used toner (p<0.05). Ozone level differences were found between a new and a refilled toner, but were not significant (p>0.05). For TVOC, there were significant differences of concentrations among brands, and toluene (3.46mg/m³) only was identified. The overall 70% of reduction for PMs’concentrations occurred after attaching a HEPA filter(p<0.05), and these results were pronounced for TSP. These results showed that similar levels of airborne pollutants were released from a laser printer with a new and a refilled toner cartridge. Also, these results indicate that the usage of a HEPA filter may be an effective method for reducing the released pollutants from a laser printer.

Toner Display is based on an electrical movement of charged particles. Two types of black and white toners charged in the different electric polarity are enclosed in the air space between two electrodes. The particle movement is controlled by the external electric field applied between two transparent electrodes. The black toner is collected to the electrode by an electrostatic force across the insulating layer to display a black image. The white toners can be put back to the counter electrode by applying a reverse electric field, and white solid image is displayed. We have studied on the movement of three color particles independently to display color image in Color Toner Display. Two positively charged color particles with different amount of charge to mass ratio and negatively charged white particles were enclosed in the toner display cell. Yellow, cyan and white images were displayed by an application of voltage.