초록 ▼

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 a

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.

대표청구항 ▼

An improved method of generating charged particles for electrostatic imaging which comprises: applying an alternating potential between a first electrode substantially in contact with one side of a solid dielectric member and a second electrode substantially in contact with an opposite side of the s

An improved method of generating charged particles for electrostatic imaging which comprises: applying an alternating potential between a first electrode substantially in contact with one side of a solid dielectric member and a second electrode substantially in contact with an opposite side of the solid dielectric member, said second electrode having an edge surface disposed opposite said first electrode to define a discharge region at the junction of the edge surface and the solid dielectric member, to induce charged particle producing electrical discharges in said air region between said solid dielectric member and the edge surface of said electrode; applying a charged particle extraction potential between said second electrode and a further electrode member to extract charged particles produced by the electrical discharges in said air region; and applying the external charged particles to a further member to form an electrostatic image, wherein the improvement comprises supplying a controlled gas to the discharge site to displace at least some of the air during charged particle generation, said controlled gas being selected from the group consisting of nitrogen, elemental noble gasses, mixtures of elemental noble gasses, and mixtures of nitrogen with one or more elemental noble gasses.