Apparatus for printing black and plural highlight color images in a single pass
AssigneeXerox Corporation
InventorHoward M. Stark
Life of this patent
Estimating the term…
Abstract
The method and apparatus for rendering latent electrostatic images visible using multiple colors of dry toner or developer and more particularly to printing toner images in black and at least two highlighting colors in a single pass of the imaging surface through the processing areas of the printing apparatus. Two of the toners are attracted to only one charge level on a charge retentive surface to thereby providing black and one highlight color while two toners are attracted to another charge level to form the second highlight color.
Claims20
Apparatus for forming latent electrostatic images on a charge retentive surface and rendering them visible with black and at least two highlight color toners in a single pass of the imaging surface through the processing areas of a printing system, said apparatus comprising:
- means for uniformly charging said charge retentive surface;
- an exposure system for discharging said charge retentive surface to at least four voltage levels corresponding to image and background areas;
- and
- means including a plurality of developer structures each including a developer housing containing a different color toner for rendering at least three image areas visible, each of two of said three image areas being rendered visible by the application of only one of said different color toners to said two image areas on said charge retentive surface and one of said image areas being rendered visible by the application of two of said different color toners to one image area on said charge retentive surface.
Method of forming latent electrostatic images on a charge retentive surface and rendering them visible with black and at least two highlight color toners in a single pass of the imaging surface through the processing areas of a printing system, said method comprising:
- uniformly charging said charge retentive surface;
- exposing said uniformly charged charge retentive surface to thereby discharge it to at least four voltage levels corresponding to image and background areas;
- and
- providing means including a plurality of developer structures each including a developer housing containing a different color toner for rendering at least three image areas visible, each of two of said three image areas being rendered visible by the application of only one of said different color toners to said two image areas on said charge retentive surface and one of said image areas being rendered visible by the application of two of said different color toners to one image area on said charge retentive surface.
Apparatus for forming latent electrostatic images on a charge retentive surface and rendering them visible with black and at least two highlight color toners in a single pass of the imaging surface through the processing areas of a printing system, said apparatus comprising:
- means for uniformly charging said charge retentive surface;
- an exposure system for discharging said charge retentive surface to at least four voltage levels corresponding to image and background areas;
- and
- means including a plurality of developer structures each including a developer housing containing a different color toner for rendering at least three image areas visible;
- means for simultaneously transferring said the images in said three image areas to a copy substrate.
Dependencies are inferred from the claim text.