| 摘要 |
PURPOSE:To measure the specific charge of toner particles with high accuracy by measuring the moving speed of the charged toner particles in an electric field in a single direction as a Doppler frequency. CONSTITUTION:A measurement position P is set at an almost center part between parallel electrode plates 1a and 1b and the direction of the electric field is set in a toner particle falling direction. A laser beam 6 from a laser light source 5 is split by a beam splitter 7 into two beams 6a and 6b which are nearly equal in intensity and those two laser beams are passed through the 1st lens 8 to cross each other at the measurement position P. Scattered light 9 from the measurement position P is guided to a detector (photoelectric converter) 12 through a slit, a pinhole 10, and a condenser lens 11. Then photoelectric conversion is performed and the vertical moving speed of the toner particle is measured as the Doppler frequency. This measurement is repeated while the electric field is varied and the specific charge of the toner particle is found from those measured values. |
