Imaging system with compactor and squeegee

• US 4,974,027 A
• Filed: 02/06/1989
• Issued: 11/27/1990
• 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:
  US07/306,079
• Time in Patent Office: 659 Days
• Field of Search: 355/256, 355/271, 355/273, 355/274, 355/219
• US Class Current: 399/249
• 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 image transfer including an image bearing surface arranged to support a liquid toner image thereon, including image regions and background regions ,rigidizing means for rigidizing the toner image at the image regions, and squeegee means separate from the rigidizing means for removing excess liquid from the toner image after rigidization thereof, prior to transfer of the image to a substrate.

Claims

1. Apparatus for image transfer comprising:

an image bearing surface arranged to support a liquid toner image thereon, comprising image regions and background regions;

rigidizing means for rigidizing said toner image at said image regions; and

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

2. Apparatus according to claim 1 wherein said liquid toner image comprises charged toner particles and wherein said apparatus also comprises:

means for removing pigmented toner particles from the background regions comprising a background cleaning roller; and

wherein

said rigidizing means comprises a rigidizing roller maintained at a potential having a sign opposite to the sign of said charge on said charged toner particles.

3. Apparatus according to claim 1 wherein said rigidizing means comprises:

a second surface arranged for movement relative to said image bearing surface along a pathway whereby portions of the image bearing surface and of 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 said at least one portion is located at a predetermined location along the pathway, thereby to provide image rigidization.

4. Apparatus according to claim 3 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.

5. Apparatus according to claim 4 and wherein energization of the electrical conductors provides a desired electrical field at a desired location for producing image rigidization.

6. Apparatus according to claim 3 and wherein said potential impression means comprises means for impressing a first potential of a first polarity onto a first portion of said second surface and for simultaneously impressing a second potential of a second polarity onto a second portion of said second surface.

7. Apparatus according to claim 6 and wherein a liquid toner image formed of pigmented particles having a charge of said second polarity is provided on the image bearing surface, and wherein said first potential on said first portion provides background cleaning and said second potential on said second portion provides rigidization of said toner image on said image bearing surface.

8. Apparatus according to claim 7 and wherein said second surface is the surface of a roller and said second surface moves in a direction opposite to the movement of said image bearing surface thereby providing metering of excess liquid on said image bearing surface.

9. Apparatus according to claim 6 and comprising:

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

10. Apparatus according to claim 3 and wherein said second surface is the surface of a roller and said second surface moves in a direction opposite to the movement of said image bearing surface thereby providing metering of excess liquid on said image bearing surface.

11. Apparatus according to claim 10 and comprising:

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

12. Apparatus according to claim 1 wherein said rigidizing means comprises:

an image compacting surface arranged for operative engagement with the image bearing surface, the image compacting surface having formed thereon at least one electrical conductor; and

means for energizing the at least one electrical conductor at an interior location with respect to the engagement of the image compacting surface and the image bearing surface whereby a relatively high voltage difference may be developed between the image compacting surface and the image bearing surface.

13. Apparatus according to claim 12 and wherein said image compacting surface comprises a static surface relative to which the image bearing surface moves.

14. Apparatus according to claim 13 wherein said statics surface is spaced from said image bearing surface, and to form an entrance region, an exit region and an interior region therebetween, and wherein said energizing means is associated only with said interior region.

15. Apparatus according to claim 12 and comprising:

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

16. Apparatus according to claim 1 and wherein said rigidizing means comprises a rotatable surface.

17. Apparatus according to claim 1 and comprising:

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