Imaging system with rigidizer

• US 4,999,677 A
• Filed: 02/06/1989
• Issued: 03/12/1991
• Est. Priority Date: 02/06/1989
• Status: Expired due to Term

• Current Assignee: Indigo NV (HP Inc.)
• Original Assignee: Spectrum Sciences BV
• Inventors: Landa, Benzion, Fenster, Paul
• Primary Examiner(s): Pendegrass, Joan H.
• Application Number:
  US07/306,062
• Time in Patent Office: 764 Days
• Field of Search: 355/256, 355/271, 355/273, 355/274, 355/219
• US Class Current: 399/308
• CPC Class Codes: G03G 15/1605 using at least one intermediate support G03G15/1625 takes precedence
• CPC Class Codes: G03G 15/1675 with means for controlling the bias applied in the transfer nip
• CPC Class Codes: G03G 15/169 with means for preconditioning the toner image before the transfer G03G15/095 and G03G15/11 take precedence

Abstract

Apparatus for enhancement of image transfer including an image bearing surface and a second surface arranged for relative movement along a pathway whereby portions of the image bearing surface and the second surface sequentially come into propinquity and subsequently move out of propinquity, potential impression means associated with at least one portion of at least one of the image bearing surface and the second surface for impressing a potential on the at least one portion, and means for energizing the potential impression means only when such portions are located at predetermined locations along the pathway, thereby to provide image rigidization.

Claims

1. Apparatus for enhancing liquid toner image transfer comprising:

an image bearing surface movable in a first direction;

means for forming a liquid toner image on said image bearing surface;

a second surface arranged for movement relative to said image bearing surface whereby portions of the image bearing surface and the second surface sequentially come into propinquity and subsequently move out of propinquity;

potential impression means associated with at least one portion of at least one of the image bearing surface and the second surface for impressing a potential on said at least one portion; and

means for energizing said potential impression means only when such portions are located at predetermined locations along the pathway, thereby to provide image rigidization,

wherein said second surface is the surface of a roller and moves opposite to the movement of said image bearing surface thereby providing metering of excess liquid on said image bearing surface.

2. Apparatus according to claim 1 wherein:

said potential impression means comprises a plurality of electrical conductors associated with at least one of the image bearing surface and the second surface.

3. Apparatus according to claim 2 and also comprising means for energization of the electrical conductors to provide a desired electrical field at a desired location for producing image rigidization thereat.

4. Apparatus according to claim 2 comprising:

an intermediate transfer member for receiving said toner image from said image bearing surface after rigidization thereof, for transfer of said image to a substrate.

5. Apparatus according to claim 2 wherein said liquid toner image comprises image regions and background regions, said apparatus comprising:

means for removing pigmented toner particles from the background regions defined on the image bearing surface; and

squeegee means for removing excess liquid from said liquid toner image after rigidization thereof, prior to transfer of said image to a substrate.

6. Apparatus according to claim 2 and wherein:

said toner image comprises charged toner particles; and

said potential impression means comprises means for impressing upon a first region on said second surface a first potential of a polarity opposite to the polarity of said toner particles to provide background cleaning and for impressing upon a second region of said second surface a second potential of the same polarity as the polarity of said toner particles providing rigidization of said liquid toner image on said bearing surface.

7. Apparatus according to claim 1 and comprising:

an intermediate transfer member fo receiving the liquid toner image form said image bearing surface after rigidization thereof, for transfer of the thus rigidized image to a substrate.

8. Apparatus according to claim 1 wherein said liquid toner image comprises image regions and background regions, said apparatus comprising:

means for removing pigmented toner particles from the background regions defined on the image bearing surface; and

squeegee means for removing excess liquid from said toner image after rigidization thereof, prior to transfer of said image.

9. Apparatus according to claim 8 also comprising:

an intermediate transfer member for receiving said toner image from said image bearing surface after rigidization thereof, for transfer of said image to said substrate.

10. Apparatus according to claim 1 and wherein said second surface comprises a rotatable surface.

11. Apparatus for image transfer comprising:

a moving image bearing surface;

a static image compacting surface arranged for operative engagement with the image bearing surface and closely spaced therefrom to form an entrance region, and exit region and an interior region therebetween, and having formed therein at least one electrical conductor; and

means for energizing the at least one electrical conductor only in said interior region whereby a relatively high voltage difference may be developed between the image compacting surface and the image bearing surface.

12. Apparatus according to claim 11 and comprising:

an intermediate transfer member for receiving said liquid toner image from said image bearing surface after rigidization thereof, for transfer of said image to a substrate.

13. Apparatus according to claim 11 wherein said liquid toner image comprises image regions and background regions, said apparatus comprising:

means for removing pigmented toner particles from the background regions defined on the image bearing surface;

squeegee means for removing excess liquid from said liquid toner image after rigidization thereof, prior to transfer of said image to a substrate.

14. Apparatus according to claim 13 also comprising:

an intermediate transfer member for receiving said liquid toner image from said image bearing surface after rigidization thereof, for transfer of said image to a substrate.

15. Apparatus according to claim 11 and wherein energization of the at least one electrical conductor provides a desired electrical field at a desired location for producing image rigidization.

16. Apparatus for liquid toner image transfer comprising:

an image bearing surface;

means for forming a liquid toner image comprising charged toner particles on said image bearing surface;

a roller surface movable relative to said image bearing surface; and

potential impression means comprising means for impressing upon a first region on said roller surface a first potential to provide background cleaning and for impressing upon a second region of said roller surface a second potential of the same polarity as the polarity of said toner particles providing rigidization of said liquid toner image on said image bearing surface.

17. Apparatus according to claim 16 and wherein said image bearing surface moves opposite to the movement of said roller surface thereby providing metering of excess liquid on said image bearing surface.

18. Apparatus according to claim 16 wherein said first potential is of a polarity opposite to the polarity of said toner particles.