EP0130028A2 - Verfahren und Apparat zur Bilderzeugung - Google Patents

Verfahren und Apparat zur Bilderzeugung Download PDF

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Publication number
EP0130028A2
EP0130028A2 EP84304105A EP84304105A EP0130028A2 EP 0130028 A2 EP0130028 A2 EP 0130028A2 EP 84304105 A EP84304105 A EP 84304105A EP 84304105 A EP84304105 A EP 84304105A EP 0130028 A2 EP0130028 A2 EP 0130028A2
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EP
European Patent Office
Prior art keywords
plate
discharge
electrode
layer
stylus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP84304105A
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English (en)
French (fr)
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EP0130028A3 (de
Inventor
Franklin Sadler Love Iii
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Milliken Research Corp
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Milliken Research Corp
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Publication date
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Publication of EP0130028A2 publication Critical patent/EP0130028A2/de
Publication of EP0130028A3 publication Critical patent/EP0130028A3/de
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme

Definitions

  • This invention relates to a method for imaging a substrate having a coating thereon which is transformable by means of a relatively low current electrical discharge.
  • this invention relates to a method whereby commonly available lithographic printing plates may be electronically imaged inexpensively, and subsequently used in conventional lithographic printing processes without requiring a conventional photocomposition or photo-typesetting step.
  • the lithographic printing plate is imaged by means of a photographic process during which a photographically-generated film positive or negative transparency carrying the desired image is first prepared and then projected onto or exposed in contact with the light sensitive surface of the plate.
  • the plate may be exposed directly by the original copy without the need for an intermediate film transparency (i.e., by reflection), but such systems still require the initial preparation of "camera-ready" copy.
  • an image carrier i.e., an imaged lithographic printing plate
  • Such systems may, for example, rely upon a laser beam which impinges upon a light sensitive plate surface, or rely upon an electrical spark or arc, or other source of energy, which removes one or more layers of material from the surface of a lithographic-type plate, often a plate having a special construction, or may use electrostatic charges to define the desired image.
  • Lithographic plate imaging systems of these types frequently have significant shortcomings, among the most significant being one or more of the following: the relative complexity and therefore high cost and low reliability of the apparatus necessary to implement these systems, and the high cost of the specially formulated and prepared lithographic plates which generally must be used in such systems or the generally low quality of the resulting printed image.
  • the process of this invention overcomes these disadvantages by providing an efficient, inexpensive system for generating, for example, an image of extremely high quality on a variety of relatively inexpensive diazonium resin lithographic plates of conventional design, without the need for specialized plate coatings, or the need for photocomposition, "camera-ready” art or copy preparation, or photoconversion steps, and preferably using image data which is electronically generated or stored.
  • Photopolymer or other plates may also be imaged using the techniques herein, although diazonium resin-type plates are generally preferred.
  • a relatively low current electrical discharge is used to produce a latent image capable of conventional image development on the plate surface by inducing a chemical change in the material found on the face of the plate which changes the relative solubility of the plate coating in the areas traced by the discharge, without displacing or removing significant quantities of the coating material as is usually done with spark-type systems, and without relying upon photo-induced processes commonly encountered in laser systems.
  • Roll 10 serves as a support for conventional lithographic plate 20.
  • Appropriate securing means 12, 14 may be employed to attach plate 20 securely to roll 10 during the imaging process described below.
  • Means 12, 14 may be any means capable of attaching and holding a lithographic plate of conventional design on a roll surface, such as, for example, means employing an array of tapered pins as is used by many offset lithographic press manufacturers to attach and secure lithographic plates having a row of holes for accommodating the pins along each end. It is preferred that the plate itself be at least moderately electrically conductive, so that the plate may be electrically grounded during the imaging process.
  • means 12; 14 may be designed to afford a grounding path from the plate 20, as, for example, by electrically grounding roll 10 and ensuring that means 12, 14 are in electrical contact with both the roll 10 and the conductive plate 20.
  • Other arrangements for electrically grounding the plate 20 may be used as well.
  • roll 10 may be rotated by means of motor 5 and belt drive 7.
  • Angular displacement sensor 16 may also be associated with roll 10. Such sensor may be used to indicate the precise rotational position of roll 10, and is particularly desirable if the pattern is to be placed on the plate automatically by electronic means, as is discussed below.
  • assembly 30 is comprised of: (1) electrically conductive stylus assembly 32, including an electrode or stylus 31 for establishing an electrical discharge within a discharge region between electrode or stylus 31 and the opposing surface of plate 20, (2) gas means 36 for supplying the discharge region with a gas, and (3) ionization promotion means 34 directed into the discharge region between the tip of stylus 31 and the opposing surface of plate 20.
  • a primary function of electrical imaging assembly 30 is to establish and interrupt, or modulate, in accordance with externally supplied pattern information, an electrical discharge within the region between the surface of plate 20 and the tip of stylus 31 capable of forming a latent image on the surface of plate 20 in accordance with the teachings herein.
  • Varying the intensity of the discharge is also contemplated. It is foreseen that the intensity may be varied within the ranges specified herein by varying the current supplied to a pre-existing discharge, or by rapidly initiating and terminating a discharge with the desired current level.
  • Stylus 31 may be constructed of any suitable electrically conductive material.
  • stylus 31 is comprised of a material which is not susceptible to excessive wear when used as an electrode during the imaging process, such as, for example, steel.
  • 'Tip radii of from about 0.0005 inch to about 0.001 inch have been used with success; it is foreseen other tip radii outside this range may be advantageous in certain applications.
  • Stylus 31 may be partially encased in a sheath of a protective, electrically insulating material, depicted at 33 in Fig. 3, to electrically isolate and facilitate handling and positioning of the stylus tip.
  • the tip of stylus 31 is preferably positioned radially perpendicular to the surface of plate 20, at a distance ranging from about 0.001 inch to about 0.010 inch, although it should be emphasized that greater or lesser distances are known to be operable.
  • the discharge gap the-immediate region between the tip of stylus 31 and the opposed surface of plate 20 shall be referred to as the discharge gap.
  • the stylus may be attached to a translating stage 38 capable of precisely controllable motion along the rotational axis of roll 10; data specifying the relative position of stage 38 is preferably made available to a pattern data processor to facilitate the relative position of stylus 31 over the surface of plate 20 and to assure proper synchronization of the flow of pattern data to the stylus to maintain accurate image re-creation on the plate surface.
  • Gas means 36 serves as a source for inserting sufficient quantities of an ionizable gas which is relatively inert with respect to the plate surface in the absence of an electric discharge into the discharge gap. In an elementary form, it need be nothing more than the open end of a section of hollow tubing, leading from a source of the desired gas, having an end which is positioned near and directed toward the discharge gap. Of course other, more elaborate means may be employed if desired or found advantageous. Shown in detail in Figures 2 and 3, stylus 31 may be mounted in a collar 33 in which a small gas passage may be provided adjacent and parallel to the axis of stylus 31 to provide localized placement of the desired gas in the vicinity of the stylus tip. Among others, commercially available relatively inert gases distributed for spark chamber applications have been found generally suitable and satisfactory. Such gases can have helium and neon as principal constituents. The presence of oxygen in the discharge gap appears to inhibit the imaging process of this invention.
  • Ionization or breakdown promotion means 34 may be any means which is found effective in promotiny electrical breakdown of the gas in the discharge gap.
  • means 34 may be a shielded corotron device, comprising a short section of tungsten wire positioned within a semi-cylindrical, electrically grounded shield. The wire is impressed with a relatively high negative voltage (on the order of kilovolts) at relatively low current (on the order of milliamps), for example, from high voltage source 80.
  • Such corona discharge devices are commonly employed in electrostatic copying machines as an ion source for charging the xerographic plate.
  • the electrical discharge phenomenon utilized in this invention is separate and distinct from the arc or spark discharge phenomena described in the literature.
  • Much of the literature addresses electrical discharge phenomena which occur at low or extremely low pressures, and wherein a relatively large anode is positioned at a substantial distance from a relatively large cathode.
  • the electrical discharge may occur at or near atmospheric pressure, and occurs between a needle-like stylus and a substantially flat plate, with a gap spacing of only perhaps 0.001 to 0.010 inch or so.
  • Typical time-averaged electrical current values may range from about 2x10 amperes to about 2x10 -3 amperes, although operation above this range, but below the spark discharge regime, may be preferred under some conditions.
  • the electrical discharge utilized in this invention is not sufficiently intense to displace or remove significant or substantial quantities of the plate coating. No physical change in the underlying plate surface is observed. The nature of the transformation mechanisms involved are not known. To what extent the same chemical reactions which occur in conventional imaging (e.g., photographic) processes occur during the imaging process of this invention is not known; it merely appears that the post-treatment behavior of the resulting latent image is generally similar to that of a conventionally imaged plate. It is believed that the electrical discharge forms a stream of ions which are directed into the plate coating. The interaction of these ions with the chemical compounds in the coating is believed to cause a chemical transformation in the coating which modifies the relative solubility of the coating.
  • insolubilizing effect is used herein to mean the chemical (or whatever other) effects which such discharge treatment has on these plates which permit such plates to be developed and used in a manner similar to conventional plates which have been exposed or imaged by conventional (e.g., photographic) methods.
  • Current limiting resistor 40 may be used to prevent the electrical current between the stylus 31 and the surface of plate 20 from becoming excessive. Excessive current can result in the transition of the discharge phenomenon between stylus 31 and plate 20 from the normal low current electrical discharge used in this invention to the arc discharge behavior described in the literature. Excessive current can also result in the undesirable rearrangement or removal of substantial portions of the coating on the surface of plate 20. It should be noted that the electrical discharge preferred for use in this invention is characterized by a negative differential resistance. This means that increases (decreases) in the time-averaged discharge current are accompanied by decreases (increases) in the voltage measured across the discharge gap.
  • gap voltages were found to increase from 159 volts at a discharge current of 3 mill lamps to 190 volts at a discharge current of 50 microamps.
  • the use of a current limiting resistor prevents the discharge current from approaching values which would characterize an arc-type discharge. Because increasing the time-averaged current within the discharge gap also tends to increase the width of the image lines, changing the value of such resistor allows for adjustment of the width of the lines appearing on the resulting imaged plate.
  • Block 60 schematically depicts a voltage source adapted to provide voltages within the range of about 200 to about 2000 volts, at current levels within a range of between about 2x10 -6 and about 2x10 -3 amperes.
  • Block 65 depicts a high speed switch capable of switching the voltage generated by the voltage source 60 at the frequencies necessary for the desired image resolution or print gauge.
  • the necessary switching frequency is of course a function of the speed at which the surface of plate 20 is traced over or scanned by stylus 31, the desired image resolution, as well as other factors, such as the delay between the application of the requisite voltage and the. initiation of the electrical discharge. It has been found that, for imaging small (e.g., 10 x 15 inch) lithographic plates at a roll circumferential speed of about 12 inches per second and a print gauge of about 100 lines per inch, switching frequencies within the range of about 1.0 to about 1.5 kilohertz are necessary.
  • FIG. 4 An example of one circuit which may be used in this application is shown schematically in Fig. 4.
  • the circuit operates as follows: Data input at nodes A, B in the form of a train of +5 volt pulses are shifted from a ground reference to a bias voltage reference across nodes C, D by voltage level shifter 100.
  • MOSFET Q2 then amplifies the output of level shifter 100, relative to the bias voltage. This results in a signal GD wherein the +5 volt data pulses are now on the order of +400 volts, referenced to the +250 volt bias voltage.
  • MOSFET Q2 acts as a voltage follower, decoupling the output of MOSFET driver Q1 from the discharge gap and load resistor R L .
  • Voltage JF represents the buffered, amplified, shifted data output of high speed switch 65. The output voltage of approximately 650 volts is divided between current limiting resistor R L and the gap formed between the stylus tip and the plate surface.
  • the circuit depicted in Fig. 4 may be any by which a logic signal of modest voltage (e.g., 5 volts) from the pattern generation means may be impressed upon a relatively high voltage d.c. bias (e.g. 250 volts).
  • a relatively high voltage d.c. bias e.g. 250 volts.
  • an optical coupler such as that available from Texas Instruments (of Dallas, Texas) as Model TIL 111 may be used.
  • Use of such a bias scheme permits the stage shown in Figure 4 to achieve switching of approximately 650 volts (to ground) with only about 400 volts across the output transistors.
  • the pattern data processor represented by block 55 represents the means by which the required switching instructions dictated by the pattern data from block 50 are sent to the high speed switch 65 so that the desired pattern data is synchronized with the appropriate relative location of the stylus on the face of plate 20, and in registry with the latent image previously generated on the face of plate 20, thereby resulting in the proper initiation and interruption of the electrical discharge as the stylus sweeps over the areas of the plate intended to carry the pattern.
  • Any suitable means for generating or retrieving such instructions may be employed. Pattern data of course may be generated manually, but in most situations electronic generation or retrieval of pattern data or switching instructions is preferred, for example, through the use of analog or digital data storage means such as magnetic or paper tape, a ROM, RAM, or EPROM, a bubble memory, etc.
  • Appropriate data from the angular displacement sensor 16 associated with roll 10 may be input to processor 55 to facilitate the necessary task of converting the pattern data to a series of switching instructions to switching means 65, and translating instructions to translating means 38 which will result in a train of correctly timed and sequenced electrical discharges between stylus 31 and the relatively moving face of plate 20.
  • the desired result is the ability to vary the effective area in which the latent image-forming chemical transformation takes place within the surface of plate 20 traced by the stylus, and thereby vary the effective resolution or effective print gauge of the imaging process.
  • one or more dots of almost any desired diameter within the range of the system may be generated, without the need for'having to limit dot size to one of a relatively few available choices, or having to build larger "dots" from the massing or aggregation of smaller dots of uniform size, as is done in many conventional laser systems.
  • Such capability is advantageous in producing latent images wherein extremely fine detail or half-tone graphics are desired.
  • an electrical discharge having a current value lower than some minimum value does net leave a visible image on the plate of Example III.
  • some minimum value e.g., perhaps 10 microamps or so
  • raising the current level from a low level such as, for example, 10 microamps, to a level at which a good quality visible image is obtained (e.g., perhaps 30-40 microamps) can reduce the desired time lag (i.e., the time between the application of the requisite electrical potential between the stylus and the plate and the establishment of the electrical discharge induced thereby) over the reductions observed when only a corotron or ultraviolet light source is used.
  • pattern data information generated or stored in data source 50 is fed to pattern data processor 55, which receives the instructions along with data on the rotational position of roll 10 from angular displacement sensor 16. Processor 55 then generates two sets of instructions. One set of instructions is sent to translating stage 38 to assure correct placement of the imaging stylus along the axis of roll 10. A second set of instructions is sent to high speed switch 65 to generate the train of voltage pulses necessary to establish the sequence of electrical discharges which serve to image the plate with the desired pattern information.
  • the current sent from switch 65 passes through R L , a load resistor which serves to limit the direct current delivered to stylus 31, which stylus may be precisely spaced from the surface of plate 20 by means of a micrometer assembly 37 or other means.
  • the voltage impressed upon stylus 31 is electrically positive with respect to the plate, although in some cases, a negative stylus polarity may be preferred.
  • Imaging assembly 30 is traversed across the face of plate 20 by translating stage 38.
  • gas means 36 introduces a controlled quantity of a relatively inert gas such as argon or a mixture of helium and neon into the discharge gap, i.e., the region between stylus 31 and the surface of plate 20.
  • Ionization promotion means 34 is also directed toward the region between stylus 31 and the surface of plate 20 for reasons discussed above.
  • Motor 5 is used to turn roll 10 at a constant rate via belt 7 thereby allowing stylus 31 to scan over the entire surface of plate 20, which is temporarily but securely attached to the perimeter of roll 10, and allowing the electrical discharge to sweep over all pattern areas on the plate.
  • the plate surface in those areas becomes resistant to (i.e., relatively insoluble in) the developing materials used in developing such plates.
  • These plates, imaged by the electrical discharge process of this invention, may thereafter be developed using conventional developing techniques.
  • the electrical discharge employed in this invention has been used to place a latent image on a variety of commercially available, lithographic-type printing plates under a variety of operating conditions, as may be determined from the following illustrative examples, which are not intended to be limiting in any way. Additive-type plates have been found to be particularly suitable for use in connection with this invention.
  • a corotron comprised of a section of tungsten wire 1.3 inches long and 0.004 inch in diameter, centered along the axis of a halved section of aluminum tubing approximately 1.5 inches in length.
  • the wire is energized with 2 milliamps at 7 kilovolts.
  • the corotron is positioned in close operable proximity (approximately one inch) to the stylus tip and plate surface.
  • Source of Pattern Data EPROM, with appropriate associated electronics of conventional design.
  • the plate was continuously rotated on the roll with a roll circumferential speed of approximately 12 inches/second. Ambient light in the vicinity of the apparatus was subdued to prevent fogging of the photosensitive plate. Applied voltage and time-averaged current values during the electrical discharge period were maintained at 650 volts and 80 microamps, respectively, with the polarity of the voltage on the stylus being positive with respect to the grounded plate roll. The stylus was slowly and automatically traversed along the axis of roll rotation at a rate of approximately 0.2 inch/minute, thereby causing the stylus to trace a closely spaced helical path on the plate surface.
  • the desired pattern was adapted from a standard lithographic diagnostic pattern, requiring both solid areas and minimum dot diameters of approximately 0.005 inch. The maximum switching frequency was about 2.5 kilohertz.
  • the plate was removed from the roll and developed conventionally, i.e., the plate was treated with process gum (R Process Gum, a product of 311 Corporation of St. Paul, Minnesota), and then with a lacquer developer (Reliable Red Lacquer Developer, distributed by Anchor/Lithkemco of Hicksville, New York) for image reinforcement.
  • process gum R Process Gum, a product of 311 Corporation of St. Paul, Minnesota
  • lacquer developer Reliable Red Lacquer Developer, distributed by Anchor/Lithkemco of Hicksville, New York
  • the resulting developed plate exhibited visually outstanding detail, with excellent solid areas, distinct lines having a width of approximately 8 mils, and no background.
  • the plate was then placed on a sheet fed offset lithographic duplicator of conventional design.
  • the ink chosen was Multilith SF Ink, Standard Black (SF-10-C), distributed by AM Hultigraphics of Mt. Prospect, Illinois.
  • the dampening solution was 3M Duplicator Fountain Concentrate, distributed by 3M Corporation of St. Paul, Minnesota, diluted as directed (1-15 parts by volume).
  • the paper chosen was a conventional white business paper having a basis weight of 20 pounds, distributed by International Paper Company.
  • the first sheets to be printed carried an exceptionally clear and detailed image corresponding to the areas of the plate contacted by the electrical discharge, with uniform, saturated solid areas, well-formed dots of the desired size, and no background.
  • the press was run, with customary adjustments, until 20,000 sheets were printed.
  • the last sheets to be printed were visually substantially indistinguishable from those printed at the beginning of the press run.
  • Example I The plate of Example I was rotated on the device of Example I, except that the stylus was replaced by a pair of styli each spaced approximately 3 mils from the plate surface and approximately 2 mils from each other. A single 2.2 megohm resistor was placed in series with each stylus. A voltage of approximately 1000 volts was impressed across the stylus/resistor pair which resulted in a strong visible glow between the stylus tips, but no visible discharge to the plate.
  • the plate was developed as in Example I (i.e., conventionally, as if having been exposed to actinic light). No image was observed on the plate, indicating that the light from the observed glow visible discharge was insufficient to cause imaging of the plate.
  • Example I The plate of Example I was imaged and developed in accordance with the teachings of Example I, except that the resistance values for the current limiting resistor R were varied over a range which permitted monitoring of current in the discharge region.
  • the associated image quality and line width achieved is given below.
  • Example I The procedures of Example I were followed, except that the plate used was an LKK "wipe-on” type plate, using LKK “Wipe-0" Sensitizer Base and LKK “Wipe-O” Sensitizer Powder, all distributed by Anchor/Lithkemco of Lynbrook, New York.
  • the plate was developed in accordance with the distributor's instructions, using the distributor's developing chemicals.
  • the image obtained on the plate was well defined, with excellent contrast and resolution.
  • the plate was used to print several hundred copies, each carrying an excellent printed image.
  • Example I The procedures of Example I were followed, except that the plate used was a Citiplate Custom 10, distributed by Citiplate, Inc. of Jackson, Tennessee. A negative polarity on the stylus was used. The plate was developed in accordance with the distributor's instructions, using the distributor's developing chemicals. The image obtained on the plate was well defined, with excellent contrast and resolution. The plate was used to print several hundred copies, each carrying an excellent printed image.
  • Example V The procedures of Example V were followed, except that positive polarity on the stylus was used, and process gum was used as part of the developing process. Results generally similar to those of Example V were achieved.
  • Example I The procedure of Example I was followed except that the plate used was a Kodak POLYMATIC S plate, a photopolymer plate distributed by Eastman Kodak Co., of Rochester, New York. The plate was developed in accordance with the distributor's instructions, using the distributor's specified chemicals. The image on the plate was well defined with good contrast.
  • the plate used was a Kodak POLYMATIC S plate, a photopolymer plate distributed by Eastman Kodak Co., of Rochester, New York.
  • the plate was developed in accordance with the distributor's instructions, using the distributor's specified chemicals.
  • the image on the plate was well defined with good contrast.
  • Example I The procedure of Example I was followed except that the plate used was an Agfa Gevaert COPYRAPID diffusion transfer plate, distriubted by Agfa Gevaert, Inc. of Teterboro, New Jersey.
  • the plate using conventional imaging techniques, is not exposed to light during the imaging or developing process.
  • the plate was imaged using the invention disclosed herein, and was developed in accordance with the distributor's instructions using the distributor's specified chemicals. The image on the plate was well defined, with excellent contrast and resolution.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture Or Reproduction Of Printing Formes (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)
  • Photoreceptors In Electrophotography (AREA)
EP84304105A 1983-06-17 1984-06-18 Verfahren und Apparat zur Bilderzeugung Withdrawn EP0130028A3 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US50552083A 1983-06-17 1983-06-17
US60358684A 1984-04-25 1984-04-25
US603586 1984-04-25
US505520 2000-02-17

Publications (2)

Publication Number Publication Date
EP0130028A2 true EP0130028A2 (de) 1985-01-02
EP0130028A3 EP0130028A3 (de) 1985-06-05

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EP84304105A Withdrawn EP0130028A3 (de) 1983-06-17 1984-06-18 Verfahren und Apparat zur Bilderzeugung

Country Status (7)

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EP (1) EP0130028A3 (de)
AU (1) AU2941384A (de)
CA (1) CA1228889A (de)
DK (1) DK295684A (de)
ES (2) ES8606135A1 (de)
FI (1) FI842446A (de)
NO (1) NO842421L (de)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0160920A2 (de) * 1984-05-08 1985-11-13 Hoechst Aktiengesellschaft Einstufiges elektrochemisches Bilderzeugungsverfahren für Reproduktionsschichten
EP0167352A2 (de) * 1984-06-28 1986-01-08 Milliken Research Corporation Bilderzeugungsverfahren, Vorrichtung und Produkt
US5005479A (en) * 1988-08-19 1991-04-09 Presstek, Inc. Method and apparatus for imaging printing plates by spark discharge
US5052292A (en) * 1989-09-21 1991-10-01 Presstek, Inc. Method and means for controlling overburn in spark-imaged lithography plates
US5062364A (en) * 1989-03-29 1991-11-05 Presstek, Inc. Plasma-jet imaging method
US5091052A (en) * 1990-10-01 1992-02-25 Presstek, Inc. Method for producing individualized labels
WO1992005957A1 (en) * 1990-09-28 1992-04-16 Presstek, Inc. Plasma-jet imaging apparatus and method
US5121688A (en) * 1988-08-19 1992-06-16 Presstek, Inc. Spark-discharge recording head with position sensor and control for imaging lithographic printing plates
US5161465A (en) * 1988-08-19 1992-11-10 Presstek, Inc. Method of extending the useful life and enhancing performance of lithographic printing plates
US5163368A (en) * 1988-08-19 1992-11-17 Presst, Inc. Printing apparatus with image error correction and ink regulation control
US5174205A (en) * 1991-01-09 1992-12-29 Kline John F Controller for spark discharge imaging
US5235914A (en) * 1988-08-19 1993-08-17 Presstek, Inc. Apparatus and method for imaging lithographic printing plates using spark discharges
US5237923A (en) * 1988-08-19 1993-08-24 Presstek, Inc. Apparatus and method for imaging lithographic printing plates using spark discharges
US5272979A (en) * 1989-03-29 1993-12-28 Presstek, Inc. Plasma-jet imaging apparatus and method
US5813345A (en) * 1996-09-09 1998-09-29 Presstek, Inc. Lithographic imaging system for interchangeable plate cylinders
US5868075A (en) * 1997-02-26 1999-02-09 Presstek, Inc. Method and apparatus for imaging a seamless print medium
US6947153B1 (en) 2000-11-20 2005-09-20 Presstek, Inc. Method and apparatus for optimized image processing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3106155A (en) * 1960-07-28 1963-10-08 Eastman Kodak Co Electrolytic recording with organic polymers
DE2511734A1 (de) * 1974-03-18 1975-09-25 Kansai Paint Co Ltd Verfahren zur herstellung einer flachdruckplatte oder -folie
FR2392828A1 (fr) * 1977-06-03 1978-12-29 Hell Rudolf Procede d'impression a plat
EP0101266A2 (de) * 1982-08-09 1984-02-22 Milliken Research Corporation Druckverfahren und Vorrichtung

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3106155A (en) * 1960-07-28 1963-10-08 Eastman Kodak Co Electrolytic recording with organic polymers
DE2511734A1 (de) * 1974-03-18 1975-09-25 Kansai Paint Co Ltd Verfahren zur herstellung einer flachdruckplatte oder -folie
FR2392828A1 (fr) * 1977-06-03 1978-12-29 Hell Rudolf Procede d'impression a plat
EP0101266A2 (de) * 1982-08-09 1984-02-22 Milliken Research Corporation Druckverfahren und Vorrichtung

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENTS ABSTRACTS OF JAPAN, vol.7, no.79 (M-204) (1224) March 31, 1983 *
PATENTS ABSTRACTS OF JAPAN, vol.7, no.85 (M-206) (1230) April 9, 1983 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0160920A2 (de) * 1984-05-08 1985-11-13 Hoechst Aktiengesellschaft Einstufiges elektrochemisches Bilderzeugungsverfahren für Reproduktionsschichten
EP0160920A3 (en) * 1984-05-08 1987-09-02 Hoechst Aktiengesellschaft One-step electrochemical image-forming process for reproduction sheets
EP0167352A2 (de) * 1984-06-28 1986-01-08 Milliken Research Corporation Bilderzeugungsverfahren, Vorrichtung und Produkt
EP0167352A3 (de) * 1984-06-28 1987-09-09 Milliken Research Corporation Bilderzeugungsverfahren, Vorrichtung und Produkt
US5121688A (en) * 1988-08-19 1992-06-16 Presstek, Inc. Spark-discharge recording head with position sensor and control for imaging lithographic printing plates
US5005479A (en) * 1988-08-19 1991-04-09 Presstek, Inc. Method and apparatus for imaging printing plates by spark discharge
US5235914A (en) * 1988-08-19 1993-08-17 Presstek, Inc. Apparatus and method for imaging lithographic printing plates using spark discharges
US5161465A (en) * 1988-08-19 1992-11-10 Presstek, Inc. Method of extending the useful life and enhancing performance of lithographic printing plates
US5163368A (en) * 1988-08-19 1992-11-17 Presst, Inc. Printing apparatus with image error correction and ink regulation control
US5237923A (en) * 1988-08-19 1993-08-24 Presstek, Inc. Apparatus and method for imaging lithographic printing plates using spark discharges
US5062364A (en) * 1989-03-29 1991-11-05 Presstek, Inc. Plasma-jet imaging method
US5272979A (en) * 1989-03-29 1993-12-28 Presstek, Inc. Plasma-jet imaging apparatus and method
US5052292A (en) * 1989-09-21 1991-10-01 Presstek, Inc. Method and means for controlling overburn in spark-imaged lithography plates
WO1992005957A1 (en) * 1990-09-28 1992-04-16 Presstek, Inc. Plasma-jet imaging apparatus and method
US5091052A (en) * 1990-10-01 1992-02-25 Presstek, Inc. Method for producing individualized labels
US5174205A (en) * 1991-01-09 1992-12-29 Kline John F Controller for spark discharge imaging
US5813345A (en) * 1996-09-09 1998-09-29 Presstek, Inc. Lithographic imaging system for interchangeable plate cylinders
US5868075A (en) * 1997-02-26 1999-02-09 Presstek, Inc. Method and apparatus for imaging a seamless print medium
US6947153B1 (en) 2000-11-20 2005-09-20 Presstek, Inc. Method and apparatus for optimized image processing

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AU2941384A (en) 1984-12-20
FI842446A (fi) 1984-12-18
ES533493A0 (es) 1986-04-16
FI842446A0 (fi) 1984-06-15
EP0130028A3 (de) 1985-06-05
ES8700606A1 (es) 1986-10-16
CA1228889A (en) 1987-11-03
ES8606135A1 (es) 1986-04-16
DK295684D0 (da) 1984-06-15
ES547022A0 (es) 1986-10-16
NO842421L (no) 1984-12-18
DK295684A (da) 1984-12-18

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