| 摘要 |
A method and a device involving an electric iris diaphragm/shutter are disclosed for controlling particle transfer of electrically charged medication powder particles from a source to a defined target area, of a substrate. Spatial distribution of particles onto the target area is achieved by an electro-dynamic field technique (320) applied to the distribution and deposition of particles in a dose forming process. An electric iris diaphragm/shutter (130) is located between a particle generator (110) and the substrate (140) such that all particles must pass the iris diaphragm for being transferred to the substrate. By adjusting amplitude and frequency of a superimposed AC potential (136) charged particles will oscillate in the created AC field such that only small light particles will emerge from the iris diaphragm/shutter for further transfer in the dose forming process. |
