# US 5,581,290 A · Heating and cooling roller for electrostratic printing

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- Number: US 5,581,290 A
- Document ID: US5581290A
- Status: Granted
- Kind: A
- Application number: 08/397,747
- Filed: 1995-03-02
- Granted: 1996-12-03
- Earliest claimed: 1993-12-13
- Inventors: Manfred R. Kuehnle
- Web page: https://patentgrep.com/patent/US5581290A

## CPC

- G03G 15/751: {relating to drum (G03G15/757 takes precedence)}
- B41J 2/415: by passing charged particles through a hole or a slit
- C09D 11/02: Printing inks (C09D11/30 takes precedence)
- G03G 15/0194: {primary transfer to the final recording medium (G03G15/0184 takes precedence)}
- G03G 15/321: {by charge transfer onto the recording material in accordance with the image}
- G03G 2215/0103: Plural electrographic recording members
- G03G 2215/0631: melted, or otherwise made liquid
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)

## Abstract

A printing ink comprises a clear, transparent, polymeric carrier material and uniform, colloidal size charged color particles evenly dispersed therein. The carrier and the particles are adhesively bonded to one another so as to form a matrix which can collectively respond to an externally imposed electrostatic field to promote co-movement of a "bite" of ink to an imaging medium without change of the bulk particle/carrier ratio. During the printing process, the ink is melted and exposed to electrostatically charged latent image areas on a heated image cylinder, resulting in the transfer of the ink thereto in proportion to the electrostatic field strength. The ink exhibits a relatively sharp liquid-to-solid transition, thereby enabling rapid ink solidification and complete transfer from the imaging medium to the relatively cool printing substrate. Also disclosed is a printing method and apparatus that facilitate continuous, variable and on-demand color printing in conjunction with the ink. Use of essentially monodispersed, color-coated, colloidal size, spherical particles in the ink results in excellent color purity and chromaticity range.

## Claims

### Claim 1

An image member responsive to an external field emission imaging head and for receiving removable printing ink, said image member comprising:
a. a generally cylindrical body having cooling means for cooling said printing ink associated therewith and a shaft extending therefrom;
b. a thermally and electrically insulating elastic member encasing the body;
c. heating means for heating said printing ink associated with the insulating member;
d. a continuous electrically conductive sleeve tightly surrounding the insulating member; and
e. a dielectric surface layer surrounding said sleeve.

### Claim 2 (depends on 1)

The image member of claim 1 wherein the dielectric surface exhibits high surface resistivity.

### Claim 3 (depends on 1)

The image member of claim 1 wherein the dielectric surface layer is thin and flexible.

### Claim 4 (depends on 1)

The image member of claim 1 wherein the dielectric surface layer is smooth and has surface-energy characteristics to readily release ionic charges when the printing ink is removed.