NL9100628A - PROXIMITY PRINTING UNIT. - Google Patents

Description

Extract

The invention relates to both a method and an apparatus for printing an image onto a removable thicker dielectric layer than is commonly used in other systems. The method and device can have one or more image coloring stations on a conductive substrate. When two or more stations with separate image-generating and image-coloring members are used, complicated image registration structures are avoided. The dielectric layer used is at least 0.2 mil thick and is removed from the system after imaging, developed, fixed and laminated or covered with a layer of the same family of resins used for the dielectric layer or layers. The imaged and covered layer can be attached to a substrate, such as a tile primer or a wallpaper primer, either before or after the completion of the method of the invention. The cover additionally strengthens the dielectric layer considerably. The final colored (or monochrome) image is removed from the printing device after the cover has been laminated thereon.

Contactless printing unit.

The invention relates to a new printing system and in particular to a system using the ion projection technique.

Several systems are known that are used in electrographic printing. In general, these systems use a charge pattern corresponding to a desired image. This charge is deposited on a photoconductive or dielectric surface of a drum or belt. This surface carrying the latent electrostatic image is moved through a toner station where an opposite charge coloring material adheres to the charged areas of the dielectric surface to form a visible image. The drum or belt is advanced and the colored image is either transferred to a receiving medium or melted directly onto the charged surface. After the melting operation in the transfer system, the dielectric can be treated in various ways to clean its surface from residual charge or toner or both. This cleaning can be performed by any known electrostatic cleaning method.

In electrographic imaging and printing processes, both photo-conductive insulators and dielectrics are used, yet they are very different from one another. Photoconductive insulators will only hold an electrical charge in the dark making them useful in limited applications such as copiers and the like. Dielectrics, on the other hand, can retain an electric charge in the presence of visible light, making them much more useful for use in commercial manufacturing processes such as the invention.

Many electrostatic printing systems are also known, such as those described in U.S. Pat. Nos. 3,023,731, 3,701,996, 4,155,093, 4,267,556, 4,494,129, 4,518,468, 4,675,703, and 4,821,066. All of these systems describe non-contact printing systems using electrostatic images that can be visualized in one or more color-giving stations. In these systems, ions are thrown from an ion generating member onto the surface of a dielectric layer by means of a printhead as described by Fotland in U.S. Pat. Nos. 4,155,093 and 4,276,556. Generally, the printhead consists of a construction of two electrodes separated by a solid dielectric element, a solid dielectric element and a third electrode for extracting ions. The first electrode is a driving electrode and the second is a driving electrode: they are both in contact with the separating dielectric layer. There is an air space at the junction of the control electrode and the solid dielectric element. A high-frequency high-voltage discharge is initiated between the two electrodes, creating a cloud of negative and positive ions in the air space adjacent to the control electrode. The ions are drawn through a hole in the third electrode by an electrostatic field formed between the second electrode and the third. In U.S. Patent 4,267,556, the imaging ion generator takes the form of a multiplexed array of finger electrodes and selection bars separated by a solid dielectric element. The ions are generated at openings in the finger electrodes at intersections of the matrix and are pulled out to form an image on a receiving element. Grayscale control is achieved by pulse width modulation of the second (finger) electrode, as described in U.S. Patent 4,941,313. While known ion projection heads are useful in many applications, they are not suitable for use in systems having a relatively thick and therefore low-capacity dielectric image layer. In general, systems using an ion projection printing technique use powder toners. In electrography, liquid development systems are best suited for accurately displaying grayscale images and high resolution development. The components of toner systems can contaminate the electrodes in known ion-projection heads and render them practically ineffective. When liquid toners - are used, contamination of the ion projection cartridge is a greater problem than when using traditional dry powder toners. This is because the toner particles in liquid toners are considerably smaller than in dry powder toners (namely, 1 micron versus 25 microns), and also because there is a liquid component that evaporates. Thus, there is a high probability that the remaining toner and / or solvents will migrate to the ion projection cartridge causing a loss of ion emission efficiency or a total loss of emission. The inclusion of an air knife prior to the ion projection head can decrease the exposure of the head to contamination. The air knife will prevent exposure of the ion projection head to the toner particles and the solvents in liquid toners by flushing the space around the ion projection head with solvent-free air or another gas. In addition, the known projection heads are not particularly desirable for printing in different shades of gray. Better and new ion projection heads are needed to achieve better results in systems using fluid development systems and those that strive for acceptable gray scale density. Known ion projection heads are not only not particularly desirable for prints of different gray levels, but have significant limitations on the number of gray levels that can be obtained. For example, most manage to achieve only four shades of gray.

In addition to the shortcomings in known printheads, the known ion projection printing systems have not been specifically developed to accommodate high-speed multi-color printing systems. Therefore, although ion generating systems use an essentially good technique, there are a number of important improvements that must be found before these systems can be used to produce high-quality, high-speed, multicolour end products.

It is therefore an object of the invention to provide an ion generating contactless printing system in which the above stated drawbacks are absent.

Another object of the invention is to provide a printing system which can deliver high-speed color printing without transitions and magazine quality.

. Yet another object of the invention is to provide an efficient printing system that can achieve high speeds with an improved image recorder.

Yet another object of the invention is to provide an electrographic printing system in which considerably thicker, relatively low-capacity dielectric layers can be used, and can provide accurate images of different grayscale images.

Another object of the invention is yet to provide a contactless printing system that can be used in the manufacture of relatively thick finished products.

Yet another object of the invention is to provide an electrographic printing system which is particularly suitable for high speed color systems using liquid toners.

Yet another object of the invention is to provide a new electrographic printing system suitable for both direct imaging and transfer imaging.

Yet another object of the invention is to provide a contactless printing system capable of delivering magazine-quality prints in continuous color and high speed.

Yet another object of the invention is to provide a new system and device for manufacturing products carrying colored images that have better quality, density and resolution.

Yet another object of the invention is to provide; of a contactless printing system that can produce images with up to thirty-two levels on the gray scale.

The above-mentioned objects and other objects are achieved according to the invention by providing a printing system that can use organic dielectric layers up to about 10 mils thick. In this system, these relatively thick dielectric layers are electrostatically imaged using a new printhead. After the new printhead deposits the latent image on the surface of the dielectric, a new liquid toner containing practically the same resin as in the dielectric is used to form a visible image. While the process of the invention can be used for single-color printing, it is particularly suitable for use in a multi-color system. The new system can also significantly improve the display of grayscale. For example, it can yield up to thirty-two levels on the gray scale. In a multi-color system, the imaged dielectric image layer continues steadily through a series of developing stations each containing the appropriately colored toner. Each toner responds to selective latent images corresponding to the multi-color image in the desired final color balance. The recording of the obtained color images can be obtained by any known recording means, such as that disclosed in U.S. Patent No. 4,821,066. The accuracy of the registration can be controlled by means of the appropriate recording mechanism. In addition, it is important to the invention that the correct toner particle be used, i.e. a toner particle that will respond to fixing by pressure, a solvent, spray, heat or other suitable means without any significant deformation of the toner particle. An important aspect of the invention is the use of a toner or coloring material containing the same synthetic resin as the resin used in the dielectric layer. » By "same" is meant the identical resin or a resin from the same family, such as polyvinyl chloride and vinyl copolymers; chloride with small amounts of vinyl acetate, and so on.

Extreme care must be taken to ensure that no defects occur in the dielectric layer. Defects, such as game gaps, in the dielectric layer can cause a total failure of the system? due to charge leakage, charge weakening * or other electrical imperfections associated with the integrity of the latent image. Some dielectrics useful in the system described herein include organic resins, such as acrylic resins like polymethyl methacrylate, vinyl-based polymeric materials, and other suitable organic resins including polyimides, which are listed below in this description. Also, the dielectric used should not be affected by high temperature or high humidity. In addition, the dielectric must have significant breakdown strength, a high rate of charge acceptance, and a relatively low charge leakage coefficient. These are influenced by the relative humidity (due to the absorption of moisture by some materials) and by the temperature because some dielectric materials lose their dielectric properties at high temperature. As stated previously, the material must be practically free from all pinholes and must have the proper built-in adhesion properties to bond with toners, other layers or primers in all lamination steps after printing. Dielectrics for use in the invention should be those that provide all of the above-mentioned qualities, such as the above-mentioned organic synthetic resins. Other known thick inorganic dielectric materials, such as alumina, gas enamels, and the like, should be carefully avoided because of their tendency to tear under stress, causing cracks and surface defects. Also, because of their relative affinity to water, they could still cause an electrical leakage path and supply the ions that cause dielectric absorption.

If they prove to be suitable, some inorganic materials can be combined with the organic dielectrics according to the invention. The resistivity of the dielectric layer according to the invention should be at least 1012 ohm centimeters. As stated previously, it is also important that the dielectric has a high load acceptance and significant breakdown strength. -¾

The charge image is created on the dielectric layer mentioned above by means of a new printhead specifically modified to work with the thicker electrical layers of the invention. Generally, in ionographic systems, the head used creates high frequency discharges and relatively high voltages initiated between two electrodes. The discharge creates a cloud of negative and positive ions in the air space adjacent to the finger electrode. The negative ions are accelerated by a positive field resulting in a charge deposition on the surface of the dielectric layer to form the latent image. As explained previously, existing print heads are not useful in the invention because the number of ions deposited per FR cycle is too large. A new printhead is needed to get the necessary charge and image properties into the system of the invention. Generally, this new printhead differs from typical prior art printheads (such as that described in U.S. Patent 4,160,257) in the following ways: (1) the new printhead has a greater distance between the finger electrode and the screen electrode, (2) adding an additional shield electrode beyond the first, (3) changing the diameter of the hole in the finger electrode, and (4) any combination of the aforementioned ways.

The air knives may be provided with additional openings near the ion projection head for introducing an inert gas, preferably piece dust, in the vicinity of the ion projection head to prevent exothermic chemical reactions that may take place during ionization, thereby significantly increasing the operating temperature of the ion projection head is lowered.

A liquid toner is highly preferred in the system described here over dry toner because of the grayscale, higher density, density control and resolution capabilities that can be obtained. The following considerations are important when choosing the liquid toner of the invention: (1) color stability when exposed to ultraviolet light, (2) color stability when bonded in a plasticizer system and exposed to a high temperature, (3) color gamut that can be reached with the toners, (4) suitability for obtaining the desired maximum optical density, namely (1.7), and (5) suitability for obtaining the desired optical density over the range of voltages or charges at the invention is applied (q / m ratio). .....-

In the system described here, the toned image can be fixed by conventional means such as heat, a solvent, a pressure spray or other suitable fixative. Typical fixatives are described in U.S. Patents 4,267,556, 4,518,468, and 4,494,129. Since the dielectric layer is removed from the conductive substrate at the end of the process, there is no need to remove any residual charge or any contamination.

The dielectric can be deposited on a conductive endless belt, a conductive drum or other conductive substrates using any suitable means that provides its surface practically free from defects. The terms "conductive substrate" or "drum" ... used in this specification and claims include in conductive drums, tapes, endless tapes or combinations thereof. In some cases, a belt and drum can be used in the same system.

In some or a first embodiment of the invention, a liquid dielectric composition is deposited on the top surface of an endless conductive tape. This dielectric layer is then passed through a curing and removal means of the liquid or solvent thereby forming a continuous dielectric layer on the belt. An interrupted layer must be able to capture and retain a latent electrostatic image after curing. The dielectric layer is preferably about 0.2 to about 1.5 mils thick but may still be about 10 mils thick if appropriate. An endless belt is in some cases preferable to a drum because of the space occupied, the uniformity of the procedure and the tolerances, better control of the dielectric layer when deposited with liquid, easy separation of the product and providing a system that a? has better energy efficiency.

Another method of obtaining a dielectric layer on the conductive substrate surface is by using a pre-formed dielectric film. This film is usually conveyed from the reel or other delivery device to the endless belt. The film is unwound on the conductive tape and an adhesive is applied to effect at least temporary firm contact with the tape. Otherwise, a thin permanent dielectric can be made part of the endless conductive tape and charged to a known potential by some ordinary device. The preformed dielectric film can be oppositely charged and then applied to the charged dielectric side of the endless conductive tape thereby generating an electrostatic field and thereby again a force that attracts the preformed dielectric film to the endless conductive tape. The contact must be firm enough to transport and process the dielectric layer through each station, but the layer must eventually be removable in the separation station. Once the dielectric layer is formed on the conductive tape, it is discharged by conventional means to provide an electrically clean uncontaminated surface that can accept a sharp image-wise ion charge. After the novel printhead of the invention has been used to deposit the latent image on the dielectric layer, the endless belt and the imaged dielectric layer pass through a developing station where the dielectric is colored using a new liquid toner. This liquid toner contains a resin of the same family as that used in the dielectric, namely of the vinyl family, the acrylic family or the polyester family. Once the image is colored, it is passed through a heat evaporation station and / or a fixing station, such as a heated plate or melt rollers. As stated earlier, if desired, use can be made of pressure fixing, spray fixing or other suitable fixing means.

Once the image is fixed on the dielectric, the dielectric layer can be laminated and then removed or further attached to a thicker base structure. In a preferred embodiment, a clear cover fabric, such as a polyvinyl chloride film, is laminated to the imaged dielectric layer to yield an end product. Otherwise, the dielectric layer can be used as the sole imaging component of an end product. This clear cover laminate also provides stability to the imaged dielectric layer and prevents it from shrinking or deforming upon cooling. When laminating the clear cover to the dielectric, an adhesive is preferably used which facilitates the bonding of these two layers.

The final imaged product consists of a dielectric layer, preferably a clear or blank dielectric with a thickness of about 0.2 to 1.5 mil and with a clear cover laminate of from 3 to 20 mil, and a substrate with a thickness of about 60 to 100 mils. In a particular embodiment of this invention, a top layer or cover layer of polyvinyl chloride or other visually clear material is superimposed over the imaged surface of a blank dielectric. The clear cover may be thinner than 3 mils for products that do not require abrasion resistance, such as a decorated ceiling tile, and may be applied as a composition using conventional spraying agents, roller application agents and drying agents. In a multi-colored system, this laminate or cover is applied after the last color has been fixed on the dielectric layer. However, if it is desired to give the developed image the illusion of depth, this thin clear film or cover is applied to each monochrome colored image after it is fixed. These thin clear films are approximately 2.5 mils thick, but may have any suitable thickness depending on the desired result. When the illusion of an image depth is desired, the first dielectric layer is preferably white and the following dielectric layers are colorless. However, all dielectric layers can be colorless if this enhances the desired results. There are a number of versions of the process described here, in particular those involving post-system or post-system treatments. For example, in a post-treatment procedure, all substrates such as those used in wallpaper bases, tile base structures or any other decorative matter may be combined with the image-bearing dielectric layer.

In a second embodiment of the invention, a printing system is provided using a thick, low capacity (up to 10 mil) dielectric layer on a conductive drum; instead of a tire as in the first embodiment. Two or more new ion projection heads, coupled with respective color application systems, have been placed around the conductive drum, the drum being driven by this thick dielectric layer or by any other device. Moving the drum by a "powerful" means includes that the dielectric layer drives the drum or an energy source, such as electricity or the like, moves the drum. There is no usual registration. needed from station to station because each color producing station will only develop the latent image presented to it by the preceding ion projection head. The recording is performed electrically by this invention without the need for complex or complicated recording devices. The new ion projection head or ion projection cartridge being used, consists of a cartridge mounting device provided with "air knives", one on either side of the cartridge. These air knives are essentially openings parallel to the axis of the drum through which compressed air is flowed. The openings are designed to produce a pressure gradient that is approximately tangential to the drum surface and to the cartridge, and so that they produce turbulence. In this way, residual toner solutions or solvents (such as ISOPAR) are evaporated from the drum surface and the remaining toner particles are wiped away from the drum surface. The air knives may contain further openings near the ion projection head for introducing an inert gas, preferably nitrogen, in the vicinity of the ion projection head to prevent exothermic chemical reactions that may take place during ionization, thereby reducing the operating temperature of the significantly reduce ion projection head. Also, there are means in the ion-projection cartridge that allow to control the degree of charge. This is important for better printing of different shades of gray on a dielectric layer. A feature of the system described herein is its ability to provide up to thirty-two grayscale levels in each color unit station.

The method and device according to the invention have been developed in particular for use in a multi-color printing system. The thicker dielectric layer of from about 0.2 mil to about 10.0 mil is applied to the surface of a conductive drum. This layer can be obtained by any suitable means, such as a film coming from a dispensing roll or reel. As stated previously, for best results, it is preferable to use a dielectric layer with a thickness of from about 0.5 to 3.0 mils. It is important that the dielectric film or layer be practically free from surface defects when positioned on the conductive substrate and that the dielectric layer must have the strength and proper built-in adhesive properties to bond with the toner particles used. Preferred dielectric materials for use in the invention are organic synthetic resins such as polyvinyl chloride, polymethyl methacrylate, nonporous vinyl films consisting of polyvinyl chloride copolymers of vinyl chloride with minor proportions of other materials such as vinyl acetate, vinylidene chloride and other vinyl esters such as vinyl propionate, vinyl butyrate, as well as alkyl-substituted vinyl esters. Although preference is given to dielectrics based on polyvinyl chloride, the invention has wide application to other polymeric materials consisting of: polyethylenes, polyacrylates, for example polymethyl methacrylate, copolymers of methyl methacrylate, such as methyl n-butyl methacrylate, polybutyl methacrylate, polybutyl acrylate, polyurethane, polyamides, polyesters, polystyrene and polycarbonates. Typically, films made from poly (vinyl chloride), polyurethane, polyesters? polyacrylates and blends of the same copolymers made therefrom are used. Known thick inorganic dielectric materials such as aluminum oxide, glass, enamels and the like should be avoided when used alone because of the tendency of these materials to crack and their relative affinity to water. However, if appropriate, some non-organic materials may be combined with the preferred organic synthetic resin dielectrics of the invention. After the dielectric film or layer of an organic synthetic resin has been image-charged by means of the first new printhead according to the invention, the film is moved to a first color application station and then to a series of printhead color application stations. Each of the color application or development stations will color the latent image presented thereon by means of the print head of that station. Each color generating station or color generating unit will provide a different color toner so that only each selectively latent image will attract toner resulting in an electrically recorded colored final image. For example, after the dielectric material film is applied to a surface of a conductive drum and after its surface is discharged, the film can proceed to a first station where an initial latent image is deposited on the dielectric layer and colored by a black toner. After being colored and fixed by some suitable means, the dielectric is moved to a second station where a second latent image is applied and colored with a cyan blue toner. After the colored image is fixed, the dielectric layer is moved to a third station where a third latent image is applied and colored with a magenta toner. After fixation, the dielectric is moved to a fourth station where a fourth latent image is applied and developed or colored by means of a yellow toner, etc. After the last image-producing and coloring station, the color-recorded image is sprayed with a cover to fix the combined image in place. The cover can be used as a final coat or as an adhesive (heat activated) to combine with other covers. In a preferred embodiment, a clear fabric, such as polyvinyl chloride, is used to cover the imaged dielectric layer. Another suitable cover can be used. Typical lamination cover materials can be used, such as non-porous vinyl films consisting of poly (vinyl chloride), copolymers of vinyl chloride with minor amounts of other materials, such as vinyl acetate, vinylidene chloride, and other vinyl esters, such as vinyl propionate, vinyl butyrate, as well as alkyl-substituted vinyl esters. Although animal dielectrics based on poly (vinyl chloride) are preferred, the invention has wide application to other polymeric materials which; consist of polyethylenes, polyacrylates (e.g., polymethyl methacrylate), copolymers of methyl methacrylate, such as methyl / n-butyl methacrylate, polybutyl methacrylate, polybutyl acrylate, polyurethane polyamides, polyesters, polystyrene and polycarbonates. Also copolymers of any of the foregoing substances or mixtures thereof * can be used when this cover is applied to the dielectric layer, an adhesive which facilitates the adhesion of the two layers can be used. The final imaged dielectric layer is then removed from the drum and prepared for a subsequent processing. The thickness of the cover, namely 3.0 to 20.0 mils, is important to the structure of the invention. At least 3.0 mil is needed to strengthen the dielectric layer, less than 3.0 mil from the cover does not impart desired structural strength to the thin dielectric layer. When a floor covering finished product is desired, up to 20.0 mil covering provides the required abrasion resistance: more than 20.0 mil would be equally effective but would be exaggerated since 20.0 mil is more than sufficient to provide necessary protection to the decorative imaged dielectric layer, as well as the necessary abrasion resistance for even a floor tile.

In the second embodiment, each toner developing station member is provided with a specific colored liquid toner, preferably with a synthetic resin of the same chemical family as the synthetic resin used in the dielectric layer. After contacting the liquid toner with the latent image, the solvent or liquid component of the liquid toner is removed by some suitable means, such as an evaporation chamber or a heated plate. After the liquid component is removed from the imaged surface, then the layer is passed through a suitable fixative. Any suitable fixative can be used such as pressure fixation, heat fixation, spray fixation or any other appropriate fixative. Fixation combinations can be used if desired. Various suitable liquid toners can be used. Typical liquid toners useful in the invention are manufactured by Hilord Chemical Corp., Hauppauge, NY and by Research Labs of Australia. The final covered and imaged dielectric layer can be? combined with a thicker substrate or can be used by itself as the final product. If desired, another station can be used in the system where a substrate is applied prior to the separation station.

The dielectric layer used is a clear, colored or blank dielectric which may be from about 0.2 to 10.0 mils thick, but preferably from about 0.5 to about 0.3 mils thick. A covered laminate is used that is from 3 to 20 mils thick, and the substrate to be adhered later is preferably about 60 to 100 mils thick. In one embodiment of the invention, a top layer of polyvinyl chloride or other visually clear material is covered over the imaged surface with the clear or clear dielectric. In this multi-color system, this laminate or cover is applied after the last color has been fixed on the dielectric layer. However, if it is desired to impart an illusion of depth to the developed image, this thin clear film or thin clear laminate is applied to each monochrome colored image after it is fixed. These thin clear films are about 2.5 mils thick, but may have any suitable thickness depending on the desired result. If an illusion of image depth is desired, the first dielectric layer can be white or colored, but the others are colorless. Also, all dielectric layers can be colorless if this enhances the desired results. There are a number of versions of the process described here, particularly in those following a subsequent treatment or post-system treatment. For example, as stated above, a variety of substrates such as those used in wallpaper basecoats, backing structures, or any other decorative item can be combined with the imaged dielectric layer.

Examples and preferred embodiments

The following examples are examples of the specific contactless printing process of the invention. Examples 1-4 illustrate typical procedures using the endless belt of the first embodiment of the invention, while Examples 5-8 illustrate a second embodiment using a drum as the conductive substrate.

Example 1

A dielectric vinyl coating made from a composition consisting of 20% solids from VAGH resin, manufactured by Union Carbide, in a methyl isobityl ketone solvent (MIBK) was applied to a 3 mil thick stainless steel band using a smoothing knife. The coating was dried in an oven at 130 ° F with the resulting 0.5 mil. The coated stainless steel band was passed along an AC discharge corona to neutralize the surface of the dielectric coating. An ionographic printhead S3000, manufactured by Delphax Systems, Mississauga, Canada, in combination with an environment of nitrogen was used to apply a charge to the dielectric coating. The nitrogen formed an inerting and cooling curtain between the lower printhead screen and the dielectric coating.

Pulse width modulation of the head, provided by a separate electronics package, ranged between 0.8 and 2.2 microseconds in sixteen consecutive increments. The charge was applied to the dielectric coating in the form of a checkerboard pattern with different charge levels. The dielectric was then stained with a cyan blue liquid toner (CPA-04) supplied by the Reseacrh Labs of Australia, Adelaide, Australia. The toner was at 4% concentration in ISOPAR 6. The developing system used was a three-roll type used by the Savin Corp.y Stamford, Conn, in the 7450 photocopier and adapted for this process. After evaporating the ISOPAR using a combination of heated air and a heated plate on the back of the stainless steel strip, the surface temperature measured 100 ° F. The toner was fixed on the surface of the dielectric coating using a solution of 16.7% solids of VAGH resin in a solvent mixture of MI BK and methyl ethyl ketone (MEK). The fixation process was spray fixation followed by drying with heated air. While the dielectric coating was still attached to the stainless steel band, it was passed through a pair of laminating rollers where a 3 mil thick clear rigid polyvinyl chloride film manufactured by Klockner Pentaplast, Gordonsville, Va. was applied to the fixed colored surface of the dielectric. The temperature when laminating at 250 ° F. The entire construction was then cooled to room temperature and separated from the stainless steel strip.

The resulting film showed clear blocks of cyan blue color packed between the dielectric coating and the 4 mil rigid polyvinyl chloride film with different optical densities and showed sixteen gray levels.

This electrographically imaged construction can be further processed by laminating the dielectric side of the laminate to a 10 mil thick white vinyl coated sheet using a conventional flat printing press at 250 ° F. The laminated structure was cooled to room temperature before being taken off the press.

The resulting structure is in the form of a poster typical of use in the graphic arts industry.

Example 2

The electrographically imaged structure separate from the stainless steel strip of Example 1 can be further incorporated into a floor tile construction. In this case, the dielectric coating will be bonded to a 60 mil thick tile basecoat consisting of limestone and vinyl: binders, plasticizers, and stabilizers. The decorated laminate taken from the stainless steel strip is then combined with the 60 mil tile base coat in a heated press. Press conditions were 320 ° F, 30 seconds and 80 psi. After cooling to ambient temperature, the resulting laminate structure was completely bonded to the tile primer with the electrographic image completely intact.

Example 3

A 1.5 mil thick dielectric film of rigid white polyvinyl chloride manufactured by Orchard Corp., St. Louis, Mo. was bonded to the stainless steel band using the same dielectric coating as applied in Example 1. In this. In this case, before the VAGH coating was completely dried and the 1.5 mil thick white film was applied to the tape at a surface temperature of 250 ° F. The film contained a 0.2 mil thick coating of the same VAGH resin previously applied to the film using conventional rotogravure printing agents. After cooling, the film was corona discharged and exposed electrographically image-wise, as in Example 1. The same process with the ionographic head configuration employed in Example 1 was used in this example to form an image and color the 1.5 mil thick white dielectric film. After evaporation of the ISOPAR, the colored image was fixed in a fixing nip with a steel-over-rubber roller at a surface temperature of 200 ° F. The fixing roller was at 125 ° F to prevent the toner from separating from the dielectric surface as it passed through the nip.

The resulting construction was taken off the tape at room temperature and then laminated to the same base coat as in Example 2 to form a floor tile construction.

Example 4

A 10 mil thick clear rigid polyvinyl chloride dielectric film made by Klockner Pentaplast, Gordonsville, Va. Was bonded to a stainless steel band as described in Example 1. The film was imaged and colored using the same configuration and the same process as described in Example 1. After evaporation of the ISOPAR, the gray-scale configuration was covered with a clear spray layer of a 16.7% VAGH resin in a mixture of MIBK and MEK solvents. After evaporation of the solvent using a conventional drying means, the imaged and colored construction of the tape was removed after cooling to room temperature.

In a next step, the fixed side of the imaged 10 mil thick dielectric film was laminated to the surface of a 100 mil thick conical primer consisting of limestone and vinyl: binders, stabilizers and plasticizers. Laminating conditions were the same as described in Example 2. The resulting construction was well adhered to the cone base coat * and proved suitable for installation as a floor tile construction. areas in heavy traffic, such as shopping promenades and the like.

Example 5

A 1.5 mil thick stiff and clear poly (vinyl chloride) dielectric film, manufactured by Orchard Corp., St. Louis, Mo., was placed in intimate contact around a 4 inch diameter grounded aluminum drum. A S3000 monographic printhead, manufactured by Delphax Systems, Mississauga, Canada, in combination with a nitrogen environment was used to apply charge to the dielectric. The head was spaced about 10 mils above the surface of the dielectric film. The nitrogen formed an inerting curtain between the lower screen of the printhead and the dielectric. Pu 1 s width modulator ia., Of the head supplied by a separate electronics package ranged between 0.8 and 3.4 microsecond in 0.1 microsecond increments. The charge was applied to the dielectric film in the form of a checkerboard pattern with different charge levels. The dielectric was then stained with a cyan blue toner (CPA-04) supplied by the Research Labs of Australia, Adelaide, Australia. The toner was in a concentration of 4% in ISOPAR. The developing system used was a three-roll type used for the Savin Corp., Stamford, CT., In the 7450 photocopier, and suitable for this process. After the evaporation of the ISOPAR, the toner was fixed on the dielectric film using a 3.0 mil thick clear laminable vinyl film manufactured by the Flexcon Company, Spencer, MA.

The resulting film showed clear blocks of cyan blue color with different optical densities and showed sixteen shades of gray.

This laminate construction can be further processed to create a floor tile construction by subsequent lamination of the clear dielectric layer of the imaged and protected laminate construction using a conventional planographic press on a 60 mil thick tile base consisting of limestone and vinyl binders, plasticizers and stabilizers.

Example 6

A 2.7 mil thick stiff white poly (vinyl chloride) dielectric film, manufactured by Orchard Corp., St. Louis, Mo., was placed in intimate contact around a 4 inch diameter grounded aluminum drum. The same ionographic head configuration and the same process used in Example 5 were used in this example to image and color the thicker charged dielectric film. After evaporation of the ISOPAR, the gray scale checkerboard image was fixed using a clear acrylic plastic spray layer commonly found in graphic arts shops.

This laminate construction can be further processed by spray-coating a conventional pressure-sensitive adhesive on the back of the white film and laminating it... A rigid plate to form an ad poster.

Example 7

A 1 mil thick clear acrylic film, made by Mitsubishi Rayon Company, Ltd., Tokyo, Japan, was imaged and colored using the same configuration and process described in Example 1. After evaporation of the I SOP AR, it was grayscale checkerboard image fixed using a 3 mil thick white vinyl lamination film. The back of the white layer can then be conventionally coated with a pressure sensitive acrylic adhesive and laminated to a 3/4 inch thick inorganic mineral fiber sheet to form a decorated ceiling tile.

Example 8

A 10 mil thick clear rigid poly (vinyl chloride) dielectric film manufactured by Klockner Pentaplast, Gordonsville, VA was imaged and discolored using; the same configuration and process as described in Example 5. After evaporation of the ISOPAR, the gray scale configuration was covered using a clear spray adhesive of 16.7% solids of VAGH resin, manufactured by Union Carbide, in a solvent mixture of methyl isobutyl ketone and methyl ethyl ketone, and vinyl stabilizers. After drying the cover, it was laminated to a 100 mil thick layer of the same tile base coat as described in Example 5.

While the decorated product of Example 5 can be used as a floor tile for domestic use, the end use of this example may be a commercial floor tile application where a firmer and thicker layer is desirable for exceptional wear resistance.

Brief description of the drawing

Figure 1 is a schematic side view of the printing system of the invention as described above as the first embodiment.

Figure 2 is a schematic side view of another version of the first embodiment of the printing system according to the invention.

Figure 3 is a schematic side view of another version of the first embodiment of the printing system according to the invention.

Figures 4a, 4b and 4c are a side view of the final product obtained by the multi-color process according to the invention, as described in Figure 1, Figure 2 and in combination with a substrate.

Figure 5 is a side view of the printing system according to the first embodiment of the invention using a number of copying stations.

Figure 6 is a schematic side view of the new printing system according to the second embodiment of the invention.

Description of the drawing and preferred embodiments

For the sake of clarity in the drawings, a number of stations are shown out of proportion to the entire system. It is also possible that parts of less significance are not? are shown.

In Figure 1, a pressure system has been proposed that includes a stainless steel or otherwise conductive track or belt that is driven by a suitable motor. The belt 1 is carried over a series of primary rollers 2 and other suitable support and guide structures. The tape 1 is passed through a series of electrographic stations generally similar to those used in conventional electrography or xerography, i.e. charging, developing and fixing stations. However, in the process described here, a considerably thicker dielectric material is used and it can be applied to the belt 1 in a layer starting from a solution, a powder or a liquid composition. Although the dielectric material will be described as being coated in a solution, if appropriate, the dielectric may be added as a powder or as a cured dielectric. This coating is effected in the yield at ion 3. After application of the solution in the station 3, the belt 1 with the liquid dielectric composition thereon is passed through an evaporation chamber 4 where the liquid or the solvent of the dielectric composition is removed, a white or colorless dielectric layer 5 remaining on the belt 1. To ensure that the layer 5 has a surface free from defects, at least one additional thin clear or white or different colored dielectric film 10 can be applied in the dielectric unwinding station 6. The dielectric 5 used in the station 3 is intended to be is deposited, and the dielectric film 10 fed into the station 6 now provides a final dielectric layer having a thickness of up to about 10.0 mils. Present on the tape 1 is now a two-layered dielectric material consisting of the dielectric layer 5 deposited in the station 3 and the dielectric film 10 deposited in the film station 6. The dielectric film 10 may have a built-in adhesive material that can be activated by a heater in the film station 6. As will be described below in Figure 2 and Figure 3, stations 3 and 6 may be used together or separately from one another herein. system are applied. Once the surface defect-free dielectric layers 5 and 10 are deposited on the belt 1, the combined dielectric layer is surface-discharged by means of a corona discharge 7 to provide an electrically clean dielectric that transfers the charge from the can accept and hold latent image. When reference is made in this Figure 1 to the "dielectric layer", it is meant to consist of layers 5 and 10. Once the dielectric layer has been discharged by any suitable means, it is operatively passed through the display station 8 containing a device for generating charged particles in an image configuration. These ions in an imagewise configuration are withdrawn from the printhead in station 8 to form the latent electrostatic image on the combined dielectric layers 5 and 10. The novel printhead used in the invention is used in a nitrogen atmosphere or other inert atmosphere where exothermic chemical reactions are prevented to thereby significantly reduce the printhead operating temperature. This extends the life of the print head and improves performance. An air knife is also used with the ion projection head which will prevent the ion projection head from being exposed to toner particles and / or solvents in liquid toners by flushing the space around the ion projection head with solvent-free air or other gases. The dielectric layer containing the latent image is then passed through a liquid toner in the developing station 9 where the latent image is exposed on the layer. It is preferred that the new liquid toner used in the invention described herein contains a synthetic resin of the same family as the synthetic resin used in the dielectric layers 5 and 10. By using the same family of synthetic resins in both the toner and the dielectric there is greater adhesion of the toner particle to the dielectric layer. The colored image is then passed under a heated plate 11 to evaporate the ISOPAR and / or another solvent from the liquid toner. ISOPAR is a registered trademark of EXXON. The dielectric layer is then passed through fixative nip rolls 12 which are heated or pressurized where the colored image is set or fixed on the dielectric. The adhesive resin used in the toner assists in adhering the colored particles together except for the purpose already mentioned. The dielectric layer with the image fixed or set at the rollers 12 is then moved to the station 14 where an adhesive coating is placed on the image-bearing surface of the dielectric layer. This adhesive allows the clear cover 15 to bond with the imaged dielectric layer. In the station or under the cap 18, the liquid of the adhesive is removed prior to a coating of the clear cover 15 on the dielectric layer. A clear cover 15 of polyvinyl chloride or other suitable material is supplied from the coil 13. This cover 15, in addition to maintaining the integrity of the image, prevents the dielectric layer from shrinking after drying. Suitable cover materials include non-porous vinyl materials consisting of polyvinyl chloride, vinyl chloride copolymers with minor amounts of other materials, such as vinyl acetate, vinylidene chloride, and other esters, such as vinyl propionate, vinyl butyrate, as well as alkyl-substituted vinyl esters. Although the polyvinyl chloride-based cover is preferred, the invention has wide application to other polymeric materials including polyethylenes, polyacrylates (e.g., polymethyl methacrylate), copolymers of methyl methacrylate, such as methyl / n-butyl methacrylate, polybutyl methacrylate, polybutyl acrylate, polyurethane. rooster, polyamides, polyesters, polystyrene and polycarbonates. Polymers of any of the foregoing materials or mixtures of the foregoing materials may also be used. Typically, cover materials, where appropriate, are films made of polyvinyl chloride, polyurethanes, polyesters, polyacrylates, copolymers made therefrom, and mixtures thereof. Some dielectric films may / if appropriate be clear or white or any other desired color. The resulting layer is moved to the rollers 17 which fix the clear cover layer 15 in position on the dielectric layer. In a color system, the above-described process is repeated with successive color stations until the desired colored image is obtained prior to covering. The resulting covered dielectric layer can be used as a final product or combined after the separation station 19 with other substrates in subsequent steps. For example, a thicker substrate, such as a tile, wallpaper, cloth, or the like, can be adhered to the bottom surface (the surface that does not carry an image *) of the dielectric layer. After passing through the rollers 17: where the cover 15 is bonded to the dielectric layer, the resulting combined layer is passed between cooling rolls (or other cooling means) 16 and then to a cooling and separation roll 19 where the final product is separated from band 1. The final product 20 is separated from the belt 1 by heating or any other suitable means to release it from the belt 1. This generally occurs at 38 ° C or less when using. the dielectric materials according to the invention. For materials having a composition that they are subsequently heat activated types of adhesives as well as dielectrics, loosening of the tape 1 can be improved by using thin release coatings, such as Teflon * FEP which are a permanent part of the top surface of the conductive tape 1. (* Teflon is believed to be a registered trademark of DuPont.) These materials include nonporous vinyl materials including polyvinyl chloride, vinyl chloride copolymers with minor amounts of other materials, such as vinyl acetate, vinylidene chloride, and other vinyl esters, such as vinyl propionate vinyl butyrate, as well as alkyl-substituted vinyl esters. Although the polyvinyl chloride-based dielectrics are preferred, the invention has wide application to other polymeric materials consisting of: polyethylenes, polyacrylates (polymethyl methacrylate), copolymers of methyl methacrylate, such as methyl / n-butyl methacrylate, polybutyl methacrylate, polybuthylacrylate, polyurethane, polyamides, . polyesters, polystyrene and polycarbonates. Copolymers of any of the aforementioned materials or mixtures of these materials may also be used. The materials can be used for the dielectric 5 or the dielectric film 10 and they can be the same or different from each other. As stated previously, the colored image can be fixed in the station 12 by pressure, heat, spraying or other suitable fixing method. In any of these fixing processes, especially in a multi-color system, the toner particle must be fixed without being significantly deformed or without the diameter of the toner particle being deformed. This is important in order to maintain optimal color quality and ditto resolution of the final color image.

The final product 20 collected at the station 19 consists of a dielectric layer 5, a second dielectric layer 10 and a cover layer 15. The combined thickness of layers 5 and 10 is from 0.2 to about 10.0 mil and the thickness of the cover layer 15 is from about 3.0 to about 20 mils.

The thickness of the cover, namely 3 to 20 mil, is important for the structure according to the invention. At least 3.0 mil is required to strengthen the dielectric layer: less than 3.0 mil of covering does not provide desired structural strength to the existing dielectric layer. When a finished floor covering product is required, up to 20.0 mil covering provides the necessary wear resistance; above 20.0 mil would be just as effective but would be too much because 20.0 mil is more than enough to provide the necessary protection to the decorative image dielectric layer and the necessary abrasion resistance for even floor tiles.

In Figure 2, a dielectric solution or a dielectric liquid composition is coated in station 29 on an endless conductive tape 1. The liquid composition is controlled in such a manner that upon evaporation of the solvent or liquid therefrom, a dielectric layer 23 of a thickness of from about 0.2 to about 10.0 mils remains on the belt 1 and the surface of the dielectric layer free from defects. The solvent or liquid is removed by passing the dielectric solution or composition through an evaporation chamber 21. Once the dielectric coating of 0.2 to about 10.0 is obtained, the surface is electrically discharged using a discharge corona 22 or other suitable means. After being discharged, the dielectric layer 23 is charged in the image configuration in the station 30 by the same means as described with respect to Figure 1. As the dielectric layer 23 proceeds, carrying the latent image, it passes through a development station 24 where the latent image is colored and visualized. The liquid is removed from the toner and the colored image is fixed by any suitable means, such as fixing by pressure, heat or spraying in the fixing device 25. After passing through the developing station 24 provided with the heated plate 24a, the colored and imaged dielectric 23 is passed between fixing rollers 25. In the station 26, an adhesive is applied to the image-bearing surface of the dielectric layer 23 and this adhesive is dried in the dryer 27. The adhesive is now tacky and ready for adhesion to a clean cover 31. This cover is applied from a stock 31 such as of polyvinyl chloride. The applied adhesive also aids in fixing the toner on the surface of the dielectric and applying the clear cover 31 encapsulates the toner 1 between the dielectric layer 23 and the cover 31. Not only does the cover 31 combine with the dielectric layer 23 but it also prevents shrinkage of the dielectric layer 23. The combined layer is passed between heating rolls 34 and from there to cooling rolls 32 and 33 and then taken as the final product at the separation roller 33 (which is also a cooling roll). ........

The endless belt 1 is then moved without interruption to an appropriate cleaning station 35 to remove all debris and is now ready to accept another layer of dielectric material in the coating station 29.

In Figure 3, the same series of steps as described in Figure 2 are followed, except that instead of a dielectric solution deposited on the endless belt 1 at 29 in Figure 2, in Figure 3 a coil 36 of a dielectric film material is the dielectric layer 37 on the surface of the tape 1. This film 37 can also have a thickness of 0.2 to 10.0 mil and preferably 0.2 to 1.5 mil. The film 37 is adhered to the tape 1 by some suitable means and the film is electrically discharged into the station 38. The film 37 may optionally be provided with an adhesive. The dielectric film 37 is then image-charged in the station 39 (by the same method as in Figure 1 and Figure 2), colored or developed in the developing station 40, and in the fixing rollers or station 41, the toner material is fixed. After the toner material is fixed in place, the image-bearing film 37 is moved to the station 42 where an adhesive is applied over the imaged surface of the film 37; This adhesive allows the clear cover to be bonded to the image-bearing dielectric layer 37. After some of the liquid has been removed from the adhesive to make the adhesive * in the station 43 tacky, the imaged, layer 37 with the adhesive surface moved to the station 37. A cover film 45 is supplied from a cover coil 46 and is then passed between the heating rollers 47. The covered film is then passed between heating rollers 47 where the cover 45 is pressed firmly and secured to the image-bearing dielectric layer 37. The film is then moved to the cooling roller 48 and the separation roller 49 where the final product 50 is taken from the belt 1. The endless belt 1 is then cleaned by a cleaning blade or other member 51 and is ready to accept a subsequent film coating of dielectric material and to go through another "imaging cycle" i.e. applying, developing, fixing and loosening it.

Figure 4a shows in a side view a cross section of the end product 20 described in figure 1. The final product of the systems of Figures 2 and 3 will be the same as the product of Figure 4 except that they will not have two dielectric layers 5 and 10. In Figure 2, the final product will have only layer 23, and in Figure 3, the final product will have only layer 37. This product 20 is the result of the system described here when the system of Figure 1 is used in applying more colors. When more than one color toner 52 is applied to the dielectric layer 10, each toner particle 52 has built-in adhesion properties of a synthetic resin which allow to adhere to the dielectric layer 10 and to each other. The clear polyvinyl chloride cover 15 of from about 3 to 20 mils helps encapsulate the toner and provides the structural stability of image and dielectric. In addition, the cover 15 minimizes shrinkage of the dielectric layers 5 and 10. A primer or substrate can be laminated to the top surface of the dielectric 5 to form a composite final product, such as a tile or wallpaper. Each decorative image can therefore be delivered electrographically to any substrate used for tiles, wallpaper, ceiling products or floor products.

In figure 4b is a side view of a cross section of a. final product of Figures 2 and 3 shown. In both Figure 2 and Figure 3, only a single dielectric layer is used, namely the layer 23 in Figure 2 and the layer 37 in Figure 3. However, the two end products will look the same and so Figure 4b shows a dielectric layer 23 with a clear covering layer 31. Between the layer 23 and the layer 31 are the fixed toner particles 52.

Figure 4c shows a cross-sectional side view of a final product of Figure 1 with a substrate 70 (such as a tile or wallpaper) attached to the surface of the non-image dielectric layer 5. An adhesive can be placed between layers 15, 10, 5 and 70 if desired to improve adhesion. When using an adhesive, it should be clear and not interfere with the visual or chemical properties of any of the layers. The substrate 70 is bonded to the non-image-bearing surface of the dielectric by placing an adhesive between layers 5 and 70 and pressing them together. Any suitable means can be used to join the substrate 70 to the surface of the dielectric layer facing away from the surface with the covering layer 15 above it. An additional substrate station may be, for example, in the systems of Figures 1, 2 or 3 placed in any eligible place.

In all of the described figures, means can be used to return the dielectric layer to the same printhead for at least a second image formation at a point after fixing the first image. This embodiment will be used in place of the multiple station system shown in Figure 5. Therefore, any of the systems shown in Figures 1, 2 and 3 may have any known means for re-passing the dielectric through the same stations. layer (after fixing a first image), i.e. through an imaging station or printhead, a developing station, a station for removing, developer or toner liquid, a toner fixing station and a laminating ring or cover station.

Figure 5 shows an imaging or printing system similar to that described in Figure 2, except that Figure 5 shows a number of image-generating and coloring or developing stations. In Figure 5, a liquid dielectric is layered; on the endless belt 1 in the coating station 52 and the liquid is evaporated in a drying chamber 53. Here, a dielectric layer 54 with a thickness of up to about 10.0 mil remains on the belt 1. This layer 54 is then de-surface-charged at the corona discharge 55 and is charged image-wise at the printhead 56. The latent image formed at 56 is then fed to a first developing station 57 where a liquid toner of a first color is applied. The liquid from this toner is removed in the dryer 58 and the resulting colored image is fixed in the fixing nips or rollers 59. The imaged dielectric layer 54 is then passed through printheads 71, 72 and 73 creating latent images in different colors, and developing stations 60, 61 and 62 where differently colored toners are applied, each of which is fixed at fixing rollers 59. Each toner in stations 57, 60, 61 and 62 will selectively respond to selective latent images created by printheads 56, 71 , 72 and 73 on the dielectric layer 54. The finally imaged dielectric layer is then moved to the station 63 where an adhesive is applied to the image-bearing surface and to a station 64 where all of the liquid is removed from the adhesive. part making it tacky and ready to be combined with a clear cover 65. Cover 65 wo is pressed onto the adhesive layer 54 and heated at the rollers 66. A cooling roll 67 removes all heat from the obtained layered structure and this obtained structure is fed to cooling / separation rolls 68 where; the product 69 from the belt 1 is taken off. Belt 1 is then cleaned and prepared for the next run or cycle.

Figure 6 shows a second embodiment of the invention in which a conductive aluminum drum 74 is provided with any suitable drive means to rotate the drum if desired. A source of a dielectric film 75 is placed in a current relationship with the drum 74 and is supplied thereon. by means of a film dispenser or source 75. A dielectric film 76 having a preferred thickness of about 0.5 to about 3.0 mils is passed around the surface around a film driven roller 77; face of the drum 74. The dielectric film used is a white dielectric composed of poly (vinyl chloride); however, any of the above dielectric materials may be used if they are suitable or better. As the dielectric film 76 approaches a station unit A, its surface is discharged by means of a discharge corona 78 to provide an electrically cleaner dielectric layer 76 that can accept and retain the latent electrostatic charge. A corona discharge 78 may be used in the system if desired prior to any of stations A-D. For the sake of clarity, the corona discharge 78 is shown in the drawing only prior to station A. Once the dielectric layer 76 is discharged, it is operatively moved to the station A where an ion printhead 79 deposits a first charge thereon in an image configuration. Still in station A, this latent image is contacted with a black toner material from a toner reservoir 80, which toner is designated BPA-06, manufactured by Research Labs of Australia, Adelaide, Australia. After the black liquid toner is attracted to the first latent image, a liquid removing or evaporating means 81 removes the liquid component from the black liquid toner and the toner is fixed on the first latent image or first image in the image fixing member 82. The station A consists of the components 79, 80, 81 and 82. Conventional fixation methods such as pressure fixation, spraying, heat, combinations thereof or any other suitable fixer may be used in fixer 82. Once the first image is fixed, the dielectric film 76 is moved to the station. unit D where a second printhead 83 deposits a second latent electrostatic image on the dielectric layer 76. This second latent electrostatic image on the dielectric layer 76 is then moved to a second toner reservoir 84 containing a cyan blue liquid toner. The second toner has been prepared with a toner designated CPA-04 manufactured by Research Labs of Australia, Adelaide, Australia. After the cyan blue liquid toner is on. has come into contact with the latent image and the toner particles contained therein are attracted to the second latent image, the liquid component of the cyan blue liquid toner is removed in the liquid remover 85 and the residual toner is fixed on the first colored and developed image by means of the fixer 86. Station B consists of the elements or components 83, 84, 85 and 86 and all subsequent stations will be composed of such components. In the station unit C, the dielectric layer 76 carrying the first and second images is image-wise charged by a third ion prosaic head 87 to obtain a third latent electrostatic image. This third image is moved to a third liquid developer or toner reservoir 88, filled with a magenta color toner. This toner is designated MPA-02 manufactured by Research Labs of Australia, Adelaide, Australia. After the magenta toner is attracted to the third latent image, the liquid portion of the toner is removed in the evaporator or liquid remover 89 and the residual magenta toner is fixed in place in the fixer 90. The imaged dielectric layer 76 is then moved to the station unit D where a fourth latent electrostatic image is deposited thereon by means of an ion projection cartridge or head 91. As in the previous stations, the imagewise information is electrically communicated to each printhead which then reacts with the corresponding imagewise deposition of ions on the dielectric layer 76. This fourth latent image is moved to a fourth liquid toner reservoir 92 where a yellow toner, designated YPA-03, manufactured by Research Labs of Australia, Adelaide, Australia, is deposited in the fourth image-wise configuration at the dielectric layer. The liquid developer is then dried in the liquid remover 93 and the fourth image is fixed in the fixer 94. The resulting colored image is then covered in the laminating station 95 with an apparently clear material such as polyvinyl chloride. This cover 96 can be sprayed onto the image-bearing dielectric layer 76 or use a film cover layer 96 or any other suitable cover means. Cover 96 has a thickness of about 3 to 20 mils but may be thicker if desired. An adhesive can be used to provide better adhesion of the cover 96 (if it is a film) to the image-bearing dielectric layer 76. The cover 96 can be applied as a lacquer layer, as a film or in any other suitable manner. The obtained two-layer film (layers 76 and 96) is then moved as the product layer 97, dried in; the drying station 98 and removed from the system in the separation station 99.

Any number of station units greater than two can be used in the method and apparatus of the second embodiment of the invention. An important feature is the provision of a color image system where registration is simple and effective. This can be done in the system described here with two or more images. An additional step that follows the air drying in the drying station 98 can be used in the system described here, i.e. where a thick substrate is attached to the underside (not image-bearing) of the obtained layer 97. This substrate can be a primer are used, for example, in tiles, wallpaper, ceiling products or flooring products or the like. This step is not shown in the drawing because these and many other process steps can be used to combine the product layer 97 with a variety of other materials or objects. For ease of handling, the dielectric film used in the invention is preferably about 0.5 to about 3.0 mils thick, but any thickness up to about 10.0 mils or more can be used.

The preferred embodiment and the optimum preferred embodiments of the invention have been described and shown in the accompanying drawing to illustrate the underlying principles of the invention, but it should be understood that numerous modifications and derivations can be obtained without departing from the spirit and the scope of the invention.

Claims (53)

1. Contactless printer, characterized by a combination of a dielectric layer dispenser, an endless conductive tape, at least one printhead, at least one developer station, at least one toner fixing station, at least one laminating station. and a separation station which, in combination, have a printing system, wherein the dielectric layer delivery means has means for providing a dielectric layer on the endless belt at a point in the system preceding the printhead, the laminating station has means for depositing a cover on an electrographically imaged surface of the dielectric layer to form a laminated dielectric layer, and the separating station has means following the laminating station to separate the laminated dielectric layer from the conductive tape without end. Printer according to claim 1, characterized in that the system is a monochromatic system. Printer according to claim 1, characterized in that the system is a multi-color system. The printer according to claim 1, characterized in that the dielectric layer delivery means has means for supplying the dielectric layer at least 0.2 mil thick. The printer according to claim 1, characterized in that the dielectric layer delivery means has means for supplying the dielectric layer from about 0.2 mil to about 10.0 mil. A printer according to claim 1, characterized in that the dielectric layer delivery means has means for depositing a dielectric layer on the endless conductive belt in a liquid composition, the printer having means for subsequently removing the liquid portion therefrom to form a dielectric layer capable of recording and retaining a latent electrostatic image. Printer according to claim 1, characterized in that the system is provided with means for laminating fixed images following each image fixation. A printer according to claim 1, characterized in that the system is provided with means for providing at least one additional imaging cycle following the separation of the dielectric layer from the endless belt. A printer according to claim 1, characterized by means in the system following the laminating station for attaching a primer or substrate to an unimaged surface of the laminated dielectric layer. A printer according to claim 1, characterized by a film delivery means for supplying the dielectric layer to the surface of the endless belt at a point of the system ahead of the printhead. 11. Contactless printer, characterized by a conductive, endless belt, a dielectric layer on the endless belt, at least one printhead for imagewise loading the dielectric layer, at least one image developer station, at least one developer liquid removal station, at least one toner fixing station, at least one laminating station and a separating station to provide a printing system in combination, a means for depositing a first dielectric layer on the endless conductive tape, the dielectric layer having a substantially continuous surface that can receive an electrostatic latent image and holding, the endless tape has means for moving the tape through each of the stations, further means for returning the dielectric layer to a print head for at least a second imagewise charge, and a continuous advancement means beyond a final separation station, e and means in the separation station for removing at least substantially the entire first dielectric layer from the endless conductive tape, a means for moving the endless conductive tape beyond the separation station to an element capable of depositing at least a second dielectric layer on the endless conductive tape, and means for moving the second dielectric layer to the printhead and continuously through the subsequent stations. A printer according to claim 11, characterized by a number of toner developer stations. A printer according to claim 11, characterized by a number of printheads positioned prior to the developer stations. A printer according to claim 11, characterized by means for applying an adhesive to the dielectric layer before a laminating station and after applying an image to the dielectric layer. A printer according to claim 11, characterized by a means for providing a substrate for the dielectric layer, which means is positioned in the system following the separation state. A printer according to claim 11, characterized in that the system comprises at least one of the following: a first station for delivering a dielectric layer, a dielectric discharge station, an imaging station in the form of a printhead an image developing station, a liquid evaporation station, an image fixing station, an adhesive applying station, a substrate delivering station, a laminating station, and a separating station, the printer being provided with means for repeating endless conductive tape displacements the stations are passed more than once. A printer according to claim 11, characterized in that all dielectric layers have a thickness of at least 0.2 mil. A printer according to claim 11, characterized in that all dielectric layers have a thickness of from about 0.2 mil to about 10.0 mil. A printer according to claim 11, characterized in that all dielectric layers are deposited on the endless conductive tape in a liquid composition, and provided with means for subsequently removing the liquid portion therefrom to form a dielectric layer . can capture and hold latent electrostatic image. 20. An electrographic method comprising, in at least a certain order, the following steps: applying a dielectric layer to the surface of an endless conductive tape, electro-discharging at least a certain surface of the dielectric layer, applying an imagewise charge on the pre-discharged surface of the dielectric layer, then passing the dielectric layer through a developing station and a developer liquid removal station thereby making the imagewise charge into a visible image, fixing the visible image, d on the surface of the dielectric layer dielectric layer, covering the visible image with a lamination layer, ..... fixing the lamination layer on the surface of the dielectric layer to form a laminated image-bearing dielectric layer, removing the laminated image-bearing dielectric layer from the conductive endless tape, cleaning d The conductive tape and continuously repeating these steps to obtain a desired product. A method according to claim 20, characterized in that the dielectric layer is supplied to the surface of the endless conductive tape by applying a liquid to the surface containing the dielectric and evaporating the liquid portion to thereby form a dielectric layer with appropriate electrographic properties. A method according to claim 21, characterized in that the dielectric layer is supplied to the surface of the endless belt by a member delivering a dielectric film. A method according to claim 20, characterized in that the dielectric layer is sequentially imaged, developed and fixed in a number of passes prior to laminating. A method according to claim 20, characterized in that the dielectric layer is sequentially imaged, developed and fixed in a plurality of passes, and lamination is applied to each developed image in each pass. A method according to claim 20, characterized in that in a substrate station a thicker substrate is applied to a surface of the dielectric layer on the other side of the laminated surface, the substrate station being present for removing the laminated and a provided dielectric layer of the endless tape. A method according to claim 20, characterized in that a layer with a thickness of 0.2 mil to 10.0 mil of a dielectric material is supplied to the surface of the endless conductive tape. A method according to claim 20, characterized in that the dielectric layer is continuously fed to the endless conductive tape after cleaning. 28. Contactless printer, characterized in combination by a conductive drum, a drum rotating actuator, a dielectric layer dispenser, at least two image coloring stations, a cover station and a dielectric layer separator station forming a printing system by this combination, wherein the dielectric delivery means has means which apply a dielectric layer to the conductive drum at a point in the system preceding a first image coloring station, wherein at least one additional image coloring station is positioned following the first image coloring station, wherein each of the image coloring stations is provided in at least one ion projection printhead in a fixed order and at least one toner applying unit is provided with means for coloring; of a latent image deposited on the dielectric layer by an ion projection printhead positioned immediately in front of the toner applying unit, and the cover station is positioned in the system following the first image coloring station but prior to the dielectric layer separation station. The printer according to claim 28, characterized in that the image coloring stations are provided with toner reservoirs of different colors. 30. A printer according to claim 28, characterized in that the image coloring stations successively charge the dielectric layer imagewise and imagewise as the layer passes therethrough. A printer according to claim 28, characterized in that each image coloring station is provided with at least one ion projection printhead, at least one reservoir for a liquid toner and at least one liquid removal means, which liquid removal means is suitable for removing liquid from a developed image. A printer according to claim 28, characterized in that each image coloring station is provided with at least one ion-printhead printhead, at least one reservoir of a liquid toner, at least one liquid removal device and at least one toner fixer. 33. A printer according to claim 28, characterized in that the system includes at least one toner fixer in each of the image coloring stations at a point following the ion projection print head and the toner applying unit. The printer according to claim 28, characterized in that a cover-drying structure is positioned in the system at a point prior to the dielectric layer separation station. The printer according to claim 28, characterized in that the dielectric-delivering member continuously supplies a layer of dielectric material to the surface of the conductive drum at a rate substantially equal to the rate at which the dielectric layer is deposited in the dielectric layer separating station is becoming; deleted. The printer according to claim 28, characterized in that at least four image coloring stations are positioned successively around the conductive drum, each of the stations having a supply of colored liquid toner different from the others. 37. Contactless printer, characterized by the combination of a conductive drum, a drum rotating driver, a dielectric layer dispenser, at least two image coloring stations, a dielectric cover station and a dielectric layer separating station a printing system, wherein the dielectric layer delivery member is adapted to apply a dielectric layer to the conductive drum at a point in the system which is a discharge member prior to all image coloring stations. that in ..... the system is positioned immediately after the dielectric layer delivery member and is arranged to electrically discharge a surface of the dielectric layer, a first image coloring station disposed after the discharge member and at least one additional image coloring station positioned after the first image coloring station, each of the image coloring stations comprising at least one ion printhead print head and at least one toner applying unit, said toner applying unit including means for coloring or developing a latent image deposited on the dielectric layer by an ion-prism head positioned therefor, wherein the dielectric capping station is positioned in the system following the image coloring stations but prior to the dielectric layer separation station. A printer according to claim 37, characterized in that the image coloring stations are provided with toner reservoirs of different colors. A printer according to claim 37, characterized in that the image coloring stations successively charge the dielectric layer imagewise and imagewise as it passes through. A printer according to claim 37, characterized in that each image coloring station is provided with at least one ion projection printhead, at least one reservoir of a liquid toner and at least one liquid removal means, the liquid removal means being suitable for removing liquid from a development image . A printer according to claim 37, characterized in that each image coloring station is provided with at least one ion projection printhead, at least one reservoir of a liquid toner, at least one liquid removal device and at least one toner fixer. The printer according to claim 37, characterized in that the system includes at least one toner fixer in each of the image coloring stations at a point following the ion projection printhead and the toner applying unit. A printer according to claim 37, characterized in that a cover drying structure is positioned in the system at a point prior to the dielectric layer separation station. The printer according to claim 37, characterized in that the dielectric dispenser continuously supplies a layer of dielectric material to the surface of the conductive drum at the rate substantially equal to the rate of removal of the dielectric layer in the dielectric layer. separation station for the dielectric layer. The printer according to claim 37, characterized in that at least four image coloring stations are positioned successively around and above the conductive drum, each of the stations having a supply of colored liquid toner different from that of the others. 46. An electrophotographic method, characterized by applying a layer of a dielectric layer or material to the surface of a conductive drum, electrically discharging at least one surface of the dielectric layer, then moving the dielectric stations through a series of image coloring stations material, providing a first imagewise latent electrostatic charge on the pre-discharged surface of the dielectric layer in a first station, passing the latent electrostatic charge to a first toner-producing member where the charge is visualized, fixing the visible image on the surface of dielectric layer, then moving the dielectric layer to at least a second station where a second latent electrostatic image is deposited on the dielectric layer and then colored in a second toner producing member where the second latent elect rostatic image until a second visible image is made, fixing the second visible image, continuing the process until the desired final colored image is obtained, covering the desired final colored image with a cover and removing or separating of an obtained, imaged and covered dielectric layer of the drum. A method according to claim 46, characterized in that a different color is applied in the respective image coloring stations. The method of claim 46, characterized in that another latent electrostatic image is applied in each of the image coloring stations. 49. A method according to claim 46, characterized in that each of the image coloring stations is provided with a means for depositing a different latent image on the dielectric material and is provided with a means for coloring the different latent images with a color toner that is different from that of the other image coloring stations. A method according to claim 46, characterized in that the colored image is fixed prior to proceeding to a next image coloring station. A method according to claim 46, characterized in that the dielectric layer is displaced by at least four image coloring stations prior to removing the imaged and covered dielectric layer from the drum. A method according to claim 46, characterized in that the practically clear cover is dried prior to removing the imaged and covered dielectric layer from the drum. A method according to claim 46, characterized in that each image formed and colored in each of the image coloring stations is superimposed on or combined with the previous images formed to thereby provide a colored image.