Coulter Systems Corporation

Ferdinand Martinez

Manfred R Kuehnle

Stanley F Ignasiak

Carol M Barry

I V Runyan

An electrostatic transfer medium comprising a sheet formed of a transparent polyester plastic substrate having a thin transparent coating of a compatible polyester resinous composition having a softening range less than the softening range of the substrate material. A high resolution transparency is formed by electrophotographically forming a toned latent electrostatic image of a document upon an electrophotographic member, bringing the transfer medium into engagement with the image under localized pressure and heat to form a laminate and separating the cooled laminate whereby the image is transferred fully to the coating, the transfer being effected with minimal loss of optical density or resolution and practically no residue remaining on the electrophotographic member. The laminate may be cooled prior to separation.

Image transfer material

An opaque reflective print copy is produced by transferring via heat and pressure, an electrophotographically formed toner image to a presoftened transparent thermoplastic thin layer carried bonded to an opaque substrate. The print is formed of at least one generally planar toner image layer embedded in the plastic layer near the outer surface thereof whereby light illuminating the print enters the thin layer and is reflected from the interface between said layer and said substrate, passing through the toner particles as well as being reflected from the toner particles themselves, whereby to provide an image having greater depth intensity and contrast than can be obtained using silver halide photographic film, all without distortion of the image, loss in density or loss in resolution. The substrate may have smooth or roughened surface, and may be selected from plain or coated paper, metal, stone, stretchable and/or inflatable media as well as irregularly shaped objects. Successive toner images may be applied superimposed one on the other in layers and in registry by softening the thermoplastic layer after transfer thereto of one toner image and applying the next toner image thereto. The intermediate heating embeds the toner image and readies the receptor to receive the next toner image.

Electrophotographic method for producing an opaque print

A method of electrophotographic color reproduction by forming sequentially superimposed toner images of each color successively on the photoconductive surface of an electrophotographic recording member. The photoconductive surface is charged uniformly by a corona generator to a predetermined charge level. The charged surface is exposed to a first color radiation pattern from a source thereof to form a latent electrostatic charge image on said surface. The resulting latent charge image is toned with one color toner to produce a first toner image. The resulting toner image is dried. Thereafter, a charge is applied uniformly to the same photoconductive surface including those portions thereof carrying the dried first toner image in a manner so that the generated charged ions effectively tunnel through the dry adjacent toner particles defining first toner image to reach the photoconductive surface. The resulting charge potential is uniformly distributed over the entire photoconductor surface, including the toned and untoned areas thereof. Thereafter, the entire charged surface is exposed to a second radiation color pattern from a source thereof, the radiation penetrating the first toner image to produce a second latent electrostatic charge image on said overall surface. Toning is effected with a second color toner to define a second toned color toner image superimposed in proper registry. The second toner image is dried and the aforementioned steps are repeated until the desired number of color toner images superimposed one upon the other are completed to form a desired composite color toner image. The complete image is transferred to an image receptor in a single transfer step to achieve the desired print reproduction.

Multicolor electrophotographic imaging process

A method of preparing a lithographic printing plate, and the resulting printing plate, by applying an acidified oxidizing agent such as aqueous potassium permanganate solution to the toned electrostatic latent image on the photoconductive layer of an electrophotographic member to define water-receptive non-printing areas. The thus treated surface may be washed or further treated with conventional ferrocyanide ion containing fountain solutions or gum arabic, but only if desired.

Lithographic printing plate and process for making same

A flexible offset printing plate is formed from a directly imaged electrophotographic member comprising an inorganic coating of a photoconductive material on a polyester substrate. The photoconductive material is an oriented crystalline deposit about 3000 Angstroms thick which has been directly sputtered with radiofrequency energy in a process using a Langmuir sheath to produce a light sensitive, readily imaged abrasion-resistant, transparent coating. It is deposited on a sheet of dimensionally stable, transparent polyester film having a thickness of about 0.005 inch with an intervening sandwiched layer of ohmic material such as indium-tin oxide about 300 Angstroms thick. The transparency of the ohmic layer and the photoconductive coating on a transparent substrate result in a transparent plate. The electrophotographic member is imaged by charging, exposure and toning with a suitable toner. The non-imaged parts of the surface are rendered hydrophilic (having a strong affinity for water and repellant to greasy ink) by suitable chemical and/or mechanical treatment while the imaged and toned parts are rendered hydrophobic (water-repellant and having a strong affinity for greasy ink). This may simply comprise choosing a type of toner which is inherently hydrophobic. The plate is mounted in an offset press and printing effected as though it were a conventional offset plate using the usual grease- or oil-based inks.

Growing community of inventors

Belmont, MA, United States of America

Ferdinand Martinez