| 摘要 |
Method and apparatus for charged particle generation, particularly for use in electrographic imaging, in which charged particles are generated in a discharge region and extracted to form an electrostatic image, wherein a controlled gas is introduced into the discharge region for improved operation and service life. The controlled gas may consist of nitrogen, an elemental noble gas (or mixture of such gasses, or a mixture of nitrogen with one or more noble gasses. In the preferred charged particle generator designs, a high voltage alternating potential (drive voltage) is applied between driver and control electrodes separated by a solid dielectric member to induce glow discharges within apertures in the control electrodes. The charged particle generator may include only the driver and control electrodes, or may further include screen electrodes to regulate the extraction of charged particles. Injection controlled gas into the various discharge sites dramatically reduces the threshold voltages for charged particle generation as well as the corrosion and fouling of electrodes and dielectrics, providing a more durable device and improved electrographic print quality. Nitrogen and nitrogen-argon mixtures are preferred, particularly nitrogen-argon mixtures of about 2:1 volume ratio. The controlled gas may be injected at relatively low concentrations with advantageous results, as well as at higher concentrations. |
