Pre-heat addressed vapor rejection for fountain solution image formation
11691435 · 2023-07-04
Assignee
Inventors
- Janos Veres (San Jose, CA, US)
- David K. Biegelsen (Portola Valley, CA)
- Gregory B. Anderson (Emerald Hills, CA)
- Joerg Martini (San Francisco, CA)
- Joanne L. Lee (Palo Alto, CA, US)
Cpc classification
B41J2/0057
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A method and system for enabling a patterned liquid, can involve creating a heat image on an imaging blanket by selectively heating the imaging blanket with a digitally controlled energy source, and subjecting the heat image to a selective deposition of a fountain solution material to enable vapor condensation on unheated areas and vapor rejection from heated areas to generate a fountain material image.
Claims
1. A method for enabling a patterned liquid, comprising: creating a heat image on an imaging blanket by selectively laser heating the imaging blanket with a digitally controlled energy source; subjecting the heat image to a selective deposition of a fountain solution material from a vapor phase to enable vapor condensation on unheated areas and vapor rejection from heated areas to generate a fountain material image; wherein the digitally controlled energy source comprises a light source that heats a surface region of the imaging blanket; and wherein the light source comprises at least one of: a vertical cavity surface emitting (VCSEL) array, a light emitting diode (LED) array, a laser light source that emits a pixilated light beam as a pixelated line laser beam, or a modulated laser line source.
2. The method of claim 1 further comprising developing the fountain material image on the imaging blanket with an ink.
3. The method of claim 1 further comprising: extracting vapor by a vacuum to facilitate prevention of re-condensation; transferring an ink to an image receiving media substrate.
4. The method of claim 1 further comprising: developing the fountain material image on the imaging blanket with an ink; and transferring the ink to an image receiving media substrate.
5. The method of claim 1 wherein; the imaging blanket comprises an optically absorbing blanket.
6. The method of claim 1 wherein the imaging blanket comprises a rotatable blanket.
7. A system for enabling a patterned liquid, comprising: an imaging blanket; and a digitally controlled energy source, wherein a heat image is created on the imaging blanket by selectively laser heating the imaging blanket with the digitally controlled energy source, and wherein the heat image is subject to a selective deposition of a fountain solution material from a vapor phase to enable vapor condensation on unheated areas and vapor rejection from heated areas to generate a fountain material image; wherein the digitally controlled energy source comprises a light source comprising at least one of: a vertical cavity surface emitting (VCSEL) array, a light emitting diode (LED) array, and a laser light source that emits a pixilated light beam as a pixelated line laser beam.
8. The system of claim 7 wherein the fountain material image is developed on the imaging blanket with an ink.
9. The system of claim 7 wherein: vapor is extracted by a vacuum to facilitate prevention of re-condensation; an ink is transferred to an image receiving media substrate.
10. The system of claim 7 wherein: the fountain material image is developed on the imaging blanket with an ink; and the ink is transferred to an image receiving media substrate.
11. The system of claim 7 wherein the light source heats a surface region of the imaging blanket, and the imaging blanket comprises an optically absorbing blanket.
12. The system of claim 7 wherein the imaging blanket comprises a rotatable blanket.
13. A system for enabling a patterned liquid, comprising: at least one processor and a memory, the memory storing instructions to cause the at least one processor to perform: creating a heat image on an imaging blanket by selectively laser heating the imaging blanket with a digitally controlled energy source; and subjecting the heat image to a selective deposition of a fountain solution material from a vapor phase to enable vapor condensation on unheated areas and vapor rejection from heated areas to generate a fountain material image; wherein the digitally controlled energy source comprises a light source comprising at least one of: a vertical cavity surface emitting (VCSEL) array, a light emitting diode (LED) array, and a modulated laser line source.
14. The system of claim 13 wherein the instructions are further configured to cause the at least one processor to perform: developing the fountain material image on the imaging blanket with an ink.
15. The system of claim 13 wherein the instructions are further configured to cause the at least one processor to perform: extracting vapor by a vacuum to facilitate prevention of re-condensation; transferring an ink to an image receiving media substrate.
16. The system of claim 13 wherein the light source heats a surface region of the imaging blanket.
17. The system of claim 13 wherein the imaging blanket comprises a rotatable blanket.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the embodiments.
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DETAILED DESCRIPTION
(8) The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate one or more embodiments and are not intended to limit the scope thereof. Exemplary embodiments are intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the composition, apparatus and systems as described herein.
(9) A more complete understanding of the processes, systems and apparatuses disclosed herein can be obtained by reference to the accompanying drawings. These figures are merely schematic representations based on convenience and the ease of demonstrating the existing art and/or the present development, and are, therefore, not intended to indicate relative size and dimensions of the assemblies or components thereof. In the drawing, like reference numerals may be used throughout to designate similar or identical elements.
(10) Subject matter will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific example embodiments. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein; example embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, or systems. Accordingly, embodiments may, for example, take the form of hardware, software, firmware, or any combination thereof (other than software per se). The following detailed description is, therefore, not intended to be interpreted in a limiting sense.
(11) Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, phrases such as “in one embodiment” or “in an example embodiment” and variations thereof as utilized herein do not necessarily refer to the same embodiment and the phrase “in another embodiment” or “in another example embodiment” and variations thereof as utilized herein may or may not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter include combinations of example embodiments in whole or in part.
(12) In general, terminology may be understood, at least in part, from usage in context. For example, terms such as “and,” “or,” or “and/or” as used herein may include a variety of meanings that may depend, at least in part, upon the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures, or characteristics in a plural sense. Similarly, terms such as “a,” “an,” or “the”, again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.
(13) Although specific terms are used in the following description for the sake of clarity, these terms are intended to refer only to the particular structure of the embodiments selected for illustration in the drawings, and are not intended to define or limit the scope of the disclosure. In the drawings and the following description below, it is to be understood that like numeric designations refer to components of like function.
(14) The term ‘fountain solution’ as utilized herein generally refers to a material, which can adhere to a substrate and may split in an inking nip to reject ink from adhering to the substrate. In some situations the fountain solution can adhere to a substrate and bind ink, which does not otherwise adhere to the substrate. Below we will speak of the former use, however it should be read as applying in either modality. The fluid (i.e., liquid, solution, etc) referred to herein can be a water or aqueous-based fountain solution which can be applied in an airborne state such as by vapor or by direct contact with a wetted imaging member through a series of rollers for uniformly wetting a member with the fluid. The solution or fluid can be non-aqueous composed of, for example, silicone fluids (e.g., such as D3, D4, D5, OS10, OS20, OS30 and the like), Isopar fluids, and polyfluorinated ether or fluorinated silicone fluid.
(15) Note that the term ‘fountain solution’ as utilized herein is not limited to the aforementioned splitting feature. That is, a ‘fountain solution’ can include, for example, a thin fountain solution that does not split, but which can adhere to the ink and may be removed from the substrate in its entirety. Thus, a fountain solution may include situations involving a non-splitting, complete removal of the fountain solution by ink. Furthermore, the fountain solution may only partially or may not at all adhere to the ink, thereby still rejecting the transfer of ink to the substrate. In this case, removal of the fountain solution after the inking nip may be required.
(16) The modifier “about” used in connection with a quantity may be inclusive of the stated value and can have a meaning dictated by the context (for example, it may include at least the degree of error associated with the measurement of the particular quantity). When used with a specific value, it should also be considered as disclosing that value. For example, the term “about 2” also discloses the value “2” and the range “from about 2 to about 4” also discloses the range “from 2 to 4.”
(17) Although embodiments are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. For example, “a plurality of stations” may include two or more stations. The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather can be used to distinguish one element from another. The terms “a” and “an” herein may not denote a limitation of quantity, but rather can denote the presence of at least one of the referenced item.
(18) The term “printing device”, “printing system”, or “digital printing system” as used herein can refer to a digital copier or printer, scanner, image printing machine, digital production press, document processing system, image reproduction machine, bookmaking machine, facsimile machine, multi-function machine, or the like and can include several marking engines, feed mechanism, scanning assembly as well as other print media processing units, such as paper feeders, finishers, and the like. The digital printing system can handle sheets, webs, marking materials, and the like. A digital printing system can place marks on any surface, and the like and is any machine that can read marks on input sheets; or any combination of such machines.
(19) The term “printing device”, “printing system”, or “digital printing system” and variations thereof as used herein may refer to devices and systems based on ink printing or which can provide imaged liquid layers for applications other than ink printing, such as, for example, three-dimensional (3D) layer-by-layer construction using ultraviolet (UV) curable liquids.
(20) The acronym ‘DALI’ refers to the term ‘Digital Architecture for Lithographic Inks’. DALI has in some instances also been referred to as ‘Digital Advanced Lithographic Imaging’. Thus, the terms ‘Digital Advanced Lithographic Imaging’ and ‘Digital Architecture for Lithographic Inks’ can be utilized interchangeably to refer to the same type of DALI printing system, DALI printing device or DALI printing method.
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(23) The digital printing system 101 may be implemented as a DALI printer/DALI printing system. In the embodiment shown in
(24) DALI printing systems can involve the use of DALI print process high power lasers and the ability to modulate them in a pixel-by-pixel fashion to produce latent fountain solution images that can be used to ink the printing blanket. As shown in
(25) In the DALI printing process, a continuous thin layer (tens of nanometers) of fountain solution, which can be deposited on the surface of the printing blanket, may reject the transfer of ink to the blanket. A high-power laser can be used to heat the surface region of the optically absorbing blanket and thereby evaporate the fountain solution in an image-wise pattern. The laser must, however, heat the blanket sufficiently to supply the latent heat of evaporation as well as the sensible heat to raise the fluid to its evaporation temperature (e.g., ˜175 C). The evaporated areas can be then inked, and the ink can be transferred to a receiving medium.
(26) A number of steps or operations are shown in
(27) In Step 2, a fountain solution vapor deposition can be implemented. For example, the Step 2 operation can involve deposition of a fountain solution (e.g., D4, fluorosilicone oil) from a vapor phase onto an optically absorbing blanket 12 (e.g., 50 . . . 100 nm D4 condensed onto blanket).
(28) In Step 3, vapor extraction may be implemented. For example, D4 vapor can be extracted by vacuum to prevent re-condensation. In Step 4, an inking operation may be implemented. That is, high viscosity ink can be transferred to the blanket, but rejected by D4 on the blanket followed by the rendering of a positive ink image on the blanket. In Step 5, an operation can be implemented involving ink transfer to a substrate (paper, etc.). In Step 6, an operation involve cleaning (and oiling) of the blanket can be implemented.
(29) Although DALI printing systems can enable the digital printing of high viscosity inks with a high resolution, the DALI printing process can be relatively expensive to implement and run due to the cost of high-power lasers and their modulation devices. Solutions are thus needed to reduce costs significantly for DALI printing systems. The embodiment shown in
(30) An example of a digitally controlled energy source, which can be used with the embodiment shown in
(31) The embodiments disclosed herein involve a method (e.g., method 400 shown in
(32) The amount of energy needed to prevent fluid accumulation may be much less than the amount of energy that may be needed to evaporate the fountain solution, because the temperature of the underlying blanket may not need to reach the evaporation temperature of the fountain solution, but may only need to attain a temperature above the condensation point of the fountain solution for the given pressure, typically around 1 atm. Furthermore, recondensation of digitally evaporated fountain solution will pose much less of an issue. The pre-heating process can be accomplished on current DALI printers by moving the imager upstream of a vapor deposition system or a vapor deposition process.
(33) Another embodiment of the pre-heat method of forming an image can involve allowing for or permitting the functions of the image formation surface/roll and the inking surface/roll to be separated by the addition of an intermediate roll/surface to the system. This separation can allow the surfaces to be separately optimized to perform a single function. The image formation roll/surface can be optimized for energy absorption while the blanket roll/surface can be optimized for ink pick up and release.
(34) A wide latitude of marking (printing) materials may be used with the digital printing system 101, including marking materials with pigment loading greater than 10% by weight. Note that disclosure uses the term ‘ink’ to refer to a broad range of printing or marking materials to include those, which are commonly understood to be inks, pigments, and other materials, which may be applied by a printing system to produce an output image on a image receiving media substrate.
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(36) In accordance with the disclosed embodiments, a method of fountain solution image generation can be implemented either on the DALI blanket directly or on an intermediate roller or other surface and subsequent transfer to a DALI blanket. Specifically, the disclosed approach entails heating a surface (e.g., on a roller with an optically absorbing surface) with relatively low power, image-wise laser illumination or other heating means, to control vapor deposition. Above a certain surface temperature physisorbed vapor evaporates rapidly leaving an uncoated surface whereas at a slightly lower surface temperature vapor resides long enough to nucleate a liquid film.
(37) Importantly, the surface temperature at which vapor rejection takes place is far lower than that needed to evaporate a liquid film. Also, the temperature difference between that required to reject vapor deposition and allow for vapor deposition, is relatively small. The liquid image thus generated can be either used directly or subsequently transferred (split) in a nip formed between the intermediate roller surface and the DALI blanket. DALI inking and transfer to an image receiver medium can be then performed as in the current DALI process. The use of an intermediate roller can allow for separate optimization of the properties of the vapor rejecting surface and the DALI blanket.
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(39) Thus, at low surface temperatures, molecules may “stick” and a surface liquid or solid can develop. At slightly higher temperatures molecules can leave the surface before nucleation can occur and the surface can be left basically denuded of molecules. Therefore, by image-wise heating a cool surface image-wise region of liquid coverage and no coverage can be created. This can be referred to as “Preheat Addressed Vapor Rejection” or “PHAVoR”.
(40) Depending on the surface free energies of the solid substrate and the liquid, the temperature range between sticking and rejection can be as small as, for example, ˜5-10 C and the transition range can lie more than 100 C below the surface temperature required to rapidly evaporate a surface liquid. Ideally the arrival rate of molecules may be just higher than necessary to entirely cover the surface in its low temperature condition with the desired thickness of condensed liquid or solid in the dwell time under the incident flux.
(41) An embodiment can involve the use of vapor deposition. That is, an optically absorbing, low surface energy material can be image-wise heated by a pixelated light beam (e.g., a raster scanned, intensity modulated laser, a pixelated line laser beam, a VCSEL or LED array, etc.) projected onto a surface. Alternatively, a thermal print head may be used to create the surface thermal excursions.
(42) It may be desirable to have the process direction length between heating and complete development be as short as possible so that the surface does not cool below the vapor rejection range due to conduction into the bulk while still in the presence of fountain solution vapor. It may also be desirable to place the vapor deposition system as close as feasible (1) to the transfer nip (e.g., such as transfer nip 112 shown in
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(44) The image 350 depicted in
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(46) Following implementation of the operation depicted at block 402, a step, operation, or instructions can be implemented as depicted at block 404 to subject the heat image to a selective deposition of a fountain solution material on unheated areas to generate a fountain material image. The step or operation shown at block 404 thus involves subjecting the heat image to a selective deposition of a fountain solution material to enable vapor condensation on unheated areas and vapor rejection from heated areas to generate a fountain material image.
(47) The steps, operations or instructions of method 400 shown in
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(49) The heat image may be created on the imaging blanket by laser patterning with the digitally controlled energy source. Note that in some embodiments, this laser patterning may involve digital patterning of the fountain digital patterning of the fountain solution with NIR laser light, with the blanket 113 shown in
(50) In some instances, vapor (e.g., a D4 vapor) can be extracted by vacuum to prevent re-condensation. A high viscosity ink, for example, can be then transferred to the blanket 113, but rejected by D4 on the blanket, followed by a positive ink image on the blanket. The ink can be then transferred to the media substrate (e.g., as shown at block 408). Additional operations may involve cleaning (and oiling) of the blanket 113 as discussed previously.
(51) The techniques described herein can be applied to various types of digital printing systems such as DALI printing systems. In the above description, specific details of various embodiments are provided. However, some embodiments may be practiced with less than all of these specific details. In other instances, certain methods, procedures, components, structures, and/or functions are described in no more detail than to enable the various embodiments of the invention, for the sake of brevity and clarity.
(52) Although the operations of the method(s) herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions, steps, operations or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner. In a preferred embodiment, the step or operation shown at block 402 in
(53) It should also be noted that at least some of the operations for the methods described herein may be implemented using software instructions stored on a computer useable storage medium for execution by a computer. As an example, an embodiment of a computer program product includes a computer useable storage medium to store a computer readable program.
(54) The computer-useable or computer-readable storage medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device). Examples of non-transitory computer-useable and computer-readable storage media include a semiconductor or solid-state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk, and an optical disk. Current examples of optical disks include a compact disk with read only memory (CD-ROM), a compact disk with read/write (CD-R/W), a digital video disk (DVD), Flash memory, and so on.
(55) Alternatively, embodiments of the invention may be implemented entirely in hardware or in an implementation containing both hardware and software elements. In embodiments that do utilize software, the software may include but is not limited to firmware, resident software, microcode, etc.
(56) In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.
(57) Based on the foregoing, it can be appreciated that a number of preferred and alternative embodiments are discussed herein. For example, in one embodiment, a method for enabling a patterned liquid, can involve creating a heat image on an imaging blanket by selectively heating the imaging blanket with a digitally controlled energy source, and subjecting the heat image to a selective deposition of a fountain solution material on unheated areas to generate a fountain material image.
(58) An embodiment of the method can further involve developing the fountain material image on the imaging blanket with an ink.
(59) An embodiment of the method can further involve transferring an ink to an image receiving media substrate.
(60) An embodiment of the method can further involve: developing the fountain material image on the imaging blanket with an ink, and transferring the ink to an image receiving media substrate.
(61) In an embodiment of the method, the imaging blanket can comprise an optically absorbing blanket.
(62) An embodiment of the method can further involve creating the heat image on the imaging blanket by selectively heating the imaging blanket with the digitally controlled energy source through laser patterning.
(63) In an embodiment of the method, the digitally controlled energy source can comprise one or more of: a laser source, a thermal print head, a flashlight, a light projection, an electron beam, and an array of heated pins.
(64) In another embodiment, a system for enabling a patterned liquid can include: an imaging blanket, and a digitally controlled energy source, wherein a heat image is created on the imaging blanket by selectively heating the imaging blanket with the digitally controlled energy source, and wherein the heat image is subject to a selective deposition of a fountain solution material on unheated areas to generate a fountain material image.
(65) In an embodiment of the system, the fountain material image can be developed on the imaging blanket with an ink.
(66) In an embodiment of the system, an ink can be transferred to an image receiving media substrate.
(67) In an embodiment of the system, the fountain material image can be developed on the imaging blanket with an ink, and the ink can be transferred to an image receiving media substrate.
(68) In an embodiment of the system, imaging blanket can comprise an optically absorbing blanket.
(69) In an embodiment of the system, the heat image can be created on the imaging blanket by laser patterning with the digitally controlled energy source.
(70) In an embodiment of the system, the digitally controlled energy source can comprise one or more of: a laser source, a thermal print head, a flashlight, a light projection, an electron beam, and an array of heated pins.
(71) In yet another embodiment, a system for enabling a patterned liquid, can include at least one processor and a memory, the memory storing instructions to cause the at least one processor to perform: creating a heat image on an imaging blanket by selectively heating the imaging blanket with a digitally controlled energy source; and subjecting the heat image to a selective deposition of a fountain solution material on unheated areas to generate a fountain material image.
(72) The aforementioned instructions can be further configured to cause the at least one processor to perform: developing the fountain material image on the imaging blanket with an ink. Furthermore, such instructions can be configured to cause the at least one processor to perform: transferring an ink to an image receiving media substrate. In addition, such instructions can be configured to cause the at least one processor to perform: creating the heat image on the imaging blanket by selectively heating the imaging blanket with the digitally controlled energy source through laser patterning.
(73) It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. It will also be appreciated that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.