The digital printing process comprises the printing of liquid toner on both substrate sides. Thereto developed portions of a first and a second liquid toner are transferred to the first side and fused by exposure to infrared radiation and by subsequent contact fusing. The substrate is conditioned for a further transfer step by maintaining a substantially uniform water content therein during and after the fusing step, in which further transfer step at least one further developed portion of liquid toner is transferred to a side of the substrate. This occurs particularly by limiting heat development in the liquid toner, such as by using a black toner liquid with an absorbance at 800 nm of at most than 0.8. Fig. 2
G03G 15/10 - Apparatus for electrographic processes using a charge pattern for developing using a liquid developer
G03G 15/20 - Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
G03G 9/12 - Developers with toner particles in liquid developer mixtures
G03G 15/23 - Apparatus for electrographic processes using a charge pattern involving the combination of more than one step according to groups specially adapted for copying both sides of an original or for copying on both sides of a recording or image-receiving material
2.
A METHOD OF DIGITALLY PRINTING AND A DIGITAL PRINTING APPARATUS
In the method of digitally printing an image onto a substrate, a liquid toner dispersion comprising toner particles in a substantially non-polar carrier liquid is applied to the substrate as a plurality of droplets and in accordance with a pattern, said pattern being based on the image to be printed. The liquid toner dispersion is thereafter splitted into a first and a second layer, which first layer is rich in toner particles and located adjacent to the first surface, which second layer is rich in carrier liquid. At least part of the second layer is removed by means of a liquid removal device; and the compacted toner particles is fused to obtain the image.
The digital printing system comprises a development member in rotational contact with a further member for imagewise transferring liquid toner from the development member optionally via said further member to a substrate. The system is such that toner residue remains on the development member after the transfer. Treatment means are present for patternwise treatment of said toner residue on said development member, especially by addition of a dispersing agent, so as to facilitate removal of the toner residue by means of removal means. Control means are present for controlling the patternwise treatment. The system is used for robust and continuous printing and is suitable for recycling of the toner residue into liquid toner.
The printing method comprises the steps of (1) Transferring after charging a charged liquid developer dispersion from a surface of the first member optionally via the at least one further member to a substrate, wherein excess liquid developer dispersion remains present on the first member after said transfer; (2) Treating the excess liquid developer dispersion so as to facilitate its removal from the first member (3) removing, at least substantially, the treated excess liquid developer dispersion from the surface of the first member by means of a removal device, and (4) upon interrupting or terminating the printing, removing material adhered to the removal device.
A digital printing apparatus using liquid toner comprising carrier liquid, a dispersing agent and imaging particles, the apparatus comprising: an imaging member adapted to sustain a pattern of electric charge forming a latent image on its surface; a development member arranged to receive a quantity of liquid toner; and to develop said latent image by transferring a portion of said quantity of liquid toner onto said imaging member in accordance with said pattern; a melting unit arranged downstream of the imaging member and configured to melt imaging particles of a transferred part of the portion of liquid toner, said part being transferred from the imaging member, wherein there is provided a dispersing capacity modification unit downstream of the imaging member, said dispersing capacity modification unit being configured for reducing the dispersing capacity of the dispersing agent in the transferred part of the portion of liquid toner.
A digital printing apparatus using liquid toner comprising carrier liquid and imaging particles, the apparatus comprising: an imaging member adapted to sustain a pattern of electric charge forming a latent image on its surface; a development member arranged to receive a quantity of liquid toner; and to develop said latent image by transferring a portion of said quantity of liquid toner onto said imaging member in accordance with said pattern; wherein the apparatus further comprises: a transfer member downstream of the imaging member, said transfer member being arranged for transferring a portion of the liquid toner from the imaging member to a substrate, and being provided with an outer layer adapted to receive said portion of liquid toner and to absorb carrier liquid thereof; and a removal means for removing absorbed carrier liquid from said outer layer.
G03G 15/11 - Removing excess liquid developer e.g. by heat
G03G 15/16 - Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern
The digital printing apparatus uses a liquid toner comprising toner particles in a carrier liquid for printing an image on a substrate. It comprises an imaging member (140) adapted to sustain a pattern of electric charge forming a latent image on its surface; a development member (130) arranged to receive a quantity of the liquid toner dispersion and to develop said latent image; means for transfer (150, 160) of the liquid toner dispersion from the imaging member (140) to the substrate (199) at a transfer location, and a fusing unit (670). The apparatus further comprises a liquid removal unit (650) arranged for removal of carrier liquid from the substrate (199), and upstream of said fusing unit (670).
G03G 15/11 - Removing excess liquid developer e.g. by heat
G03G 15/16 - Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern
The ink composition comprises pigment particles and a stimulus responsive dispersing agent for dispersing said pigment particles in a protic polar solvent, for instance for inkjet printing, which stimulus responsive dispersing agent comprises an anchoring part for anchoring to said pigment particles, a stimulus responsive part as shown in formula (XXa) or (XXb) and a hydrophilic part for solvent stabilization of the pigment, wherein the stimulus responsive part upon exposure to a stimulus initiates decomposition of the stimulus responsive dispersing agent. The paper with the printed ink can be deinked in an industrial deinking process.
The liquid toner dispersion has a relative low shear viscosity between 1.25 and 225 and a relative conductivity between 0.3 and 30. The liquid toner dispersion comprises toner particles in a non-polar carrier liquid, as well as dispersing agent. This liquid toner dispersion is used in a digital printing process comprising the step of adding dispersing agent during recycling of excess liquid toner dispersion remaining on a development member after patterned transfer of liquid toner dispersion to the imaging member.
The invention relates to a method for illuminating printing plates (5) in which the light from a light source (2) is imaged on a two-dimensional light modulator (4) having a plurality of rows of light-modulated cells (8), and said light is modulated thereby, whereupon the light modulator (4) is imaged on light-sensitive material (5) via an imaging beam path (11), wherein the light-sensitive material (5) is moved relative to the light modulator (4) substantially perpendicularly to the direction of the rows of light-modulated cells (8) at a relative speed and wherein the data pattern to be imaged on the light-sensitive material (5) is displayed beginning in the first row of the light modulator (4) in each row consecutively during a respective exposure time (T, T') and then moved to the subsequent row of the light modulator (4). In order to improve said method, the invention proposes that the image (10) of the data pattern be held substantially stationary relative to the light-sensitive material (5) during the exposure time (T, T').
B41J 2/465 - Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using masks, e.g. light-switching masks
B41J 2/47 - Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of radiation to a printing material or impression-transfer material using the combination of scanning and modulation of light
H04N 1/195 - Scanning arrangements using multi-element arrays the array comprising a two-dimensional array
patents