Abstract: Embodiments of the present invention involve printing members that utilize a particle-fusion imaging mechanism but avoid susceptibility to handling damage. In particular, printing plates in accordance with the invention may utilize two phases, and these may originate, during manufacture, as two particle systems. Both systems are initially dispersed in a single coating applied as a layer, or in multiple coatings applied as adjacent layers, on a substrate. The second particle system exhibits a glass-transition or thermal coalescing temperature well above room temperature and also above the temperature at which the coating is dried. The coalescing temperature of the first particle system is below the drying temperature. As a result, when the coating is dried, the first particle system coalesces and forms a binder that entrains the second particle system, which has not coalesced.

Abstract: A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye that is defined by Structure (I) shown in the disclosure, which dyes comprise one or more ethylenically unsaturated polymerizable groups in an organic group that is attached to the methine chain. These infrared radiation absorbing dyes exhibit a reduced tendency to crystallize in the imageable layers in the presence of tetraaryl borate counter anions and therefore provide improved shelf life.

Abstract: Disclosed are a photosensitive composition containing an aqueous dispersion and having excellent storage stability, and a photosensitive lithographic printing plate material using the photosensitive composition and being capable of being developed using water, which is advantageous not only in that the photosensitive lithographic printing plate material exhibits high sensitivity and high image quality as well as excellent storage stability, but also in that even when the printing plate material is repeatedly subjected to developing treatment using water, the generation of sludge derived from the photosensitive composition in the developer repeatedly used is suppressed, achieving excellent developing properties.

Abstract: A positive-working lithographic printing plate precursor has an outermost imageable layer that is present at a dry coverage weight of at least 0.7 g/m2 and up to and including 1.6 g/m2 and comprises a primary polymeric binder comprising recurring units of a hydroxyaryl acetal or a hydroxyaryl ester, or recurring units of both a hydroxyaryl acetal and a hydroxyaryl ester. The outermost imageable layer also contains an alkali-soluble secondary vinyl polymer that is not a primary polymeric binder and a non-polymeric polyhydric phenol. These precursors comprise an infrared radiation absorber to make them sensitive and imageable using infrared radiation. After imaging, the precursors can be processed (developed) using an relatively low pH developer such as a silicate- or metasilicate-free developer.

Abstract: A polymerizable composition contains: (A) a polymer compound having (a1) a repeating unit having a structure represented by the following formula (a1-1) in a side chain thereof; and (B) a polymerization initiator, and in the formula (a1-1), R11 and R12 each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a sulfo group, an alkylsulfonyl group, a arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group or a carbamoyl group, R13, R14 and R15 each independently represents a hydrogen atom, an alkyl group or an aryl group, L1 represents a divalent connecting group, Y1 represents a single bond or a divalent connecting group selected from the group consisting of —CO—, —O—, —HN—, a divalent aliphatic group, a divalent aromatic group and a combination of these groups, and * indicates a site connecting to a main chain of the polymer compound.

Abstract: Negative-Working Lithographic Printing Plate Precursors can be provided with desired contrast coloration after imaging using a coloring fluid that includes a water-insoluble colorant that is soluble in a water-insoluble fatty alcohol. The coloring fluid provides an optical density change in the exposed regions of at least OD2 that is greater than the original optical density of those regions, OD1. The coloring fluid can be applied immediately after imaging and before processing, or it can be applied as part of the developer or processing solution, or it can be applied after processing. The coloring fluid can also be applied to imaged precursors that are designed for either off-press or on-press development.

Abstract: An actinic ray-sensitive or radiation-sensitive resin composition comprising (A) a guanidine compound having a logP value of 1.2 or more, and (B) a compound capable of generating an acid upon irradiation with an actinic ray or radiation.

Abstract: An infrared sensitive, positive-working, image forming composition and element are disclosed. The image forming composition comprises a 1,1-di[(alkylphenoxy)ethoxy]cyclohexane, an infrared absorbing dye having a maximum absorption peak in the range of from about 700 nm to about 1100 nm, and a novolac polymer. The composition is applied and dried on a planar, hydrophilic substrate to form an image forming element, in particular, a planographic printing plate. Upon imagewise exposure to a near-infrared radiation source, the infrared dye absorbs light in the exposed areas and converts it to heat, which causes a disruption in the matrix of the image forming composition. Upon development with an aqueous alkaline developer, the exposed areas are removed while the nonexposed areas remain, thus forming a positive image.

Abstract: A positive-working lithographic printing plate precursor for infrared laser is provided that includes, layered sequentially above a support, a lower layer and an upper layer, the lower layer and/or the upper layer including an infrared absorbing agent, either the lower layer comprising an alkali-soluble group-containing graft copolymer or the upper layer comprising a sulfonamide group-, active imide group-, and/or amide group-containing graft copolymer, and the graft copolymer being a polyurethane resin having as a graft chain an ethylenically unsaturated monomer-derived constitutional unit. There is also provided a process for making a lithographic printing plate, the process including in sequence an exposure step of imagewise exposing by means of an infrared laser the positive-working lithographic printing plate precursor for infrared laser and a development step of developing using an aqueous alkali solution with a pH of 8.5 to 10.8.

Abstract: A process for making a lithographic printing plate, comprising: an exposure step of imagewise exposing a lithographic printing plate precursor that comprises, above a hydrophilic support, a photosensitive layer comprising (A) a compound that generates a radical upon the application of light or heat, (B) a polymer having an aromatic carboxy group in a side chain, (C) a polymerizable compound, and (D) an infrared absorber; and a development processing step using one type of processing liquid, wherein the processing liquid has a pH of 8.5 to 10.8.

Abstract: A lithographic printing plate precursor includes a cyanine dye, characterized in that the cyanine dye includes two different chromophoric groups, a chromophoric group that has its main absorption in the infrared region and another chromophoric group that has its main absorption in the visible light region.

Abstract: A method of conditioning the surface of a work piece, particularly of a strip or sheet, more particularly of a lithostrip or lithosheet, including an aluminum alloy is provided. The method for conditioning the surface of a work piece and a work piece including an aluminum alloy enabling an increasing manufacturing speed in electro-chemically graining and maintaining at the same time a high quality of the grained surface, includes a conditioning method which comprises at least the two steps, degreasing the surface of the work piece with a degreasing medium and subsequently cleaning the surface of the work piece by pickling.

Abstract: Electrochemically grained and anodized aluminum supports are treated with a post-treatment coating solution containing a polymer derived at least in part from vinyl phosphonic acid and phosphoric acid. This post-treated support is useful as substrates in the preparation of lithographic printing plate precursors. The post-treatment substrate treatment enables wide latitude in manufacturing and compatibility with silicate-free developers to achieve negligible background staining and oxide attack.

Abstract: A method for making a lithographic printing plate precursor is disclosed comprising the steps of a. providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, a photopolymerizable coating comprising a photopolymerizable composition, and an overcoat layer comprising a water soluble low molecular weight acid, wherein said overcoat layer has a surface pH-value ranging between 1 to 6; b. image-wise exposing the precursor; c. optionally heating the exposed precursor; d. processing the obtained precursor by applying a gum solution and optionally brushing the precursor, and/or by mounting the precursor on a plate cylinder of a lithographic printing press and rotating the plate cylinder while feeding dampening liquid and/or ink to the coating.

Abstract: Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free-radical polymerization, (ii) at least one sensitizer, and (iii) at least one coinitiator capable of forming free radicals together with the sensitizer, said coinitiator being other than metallocenes, characterized in that the at least one sensitizer comprises a compound of formula (I) wherein at least one of the groups R9 to R12 is a bulky group which has a van der Waals volume of at least 55 ?3.

Abstract: A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye that is defined by Structure (I) shown in the disclosure, which dyes comprise one or more ethylenically unsaturated polymerizable groups in an organic group that is attached to the methine chain. These infrared radiation absorbing dyes exhibit a reduced tendency to crystallize in the imageable layers in the presence of tetraaryl borate counter anions and therefore provide improved shelf life.

Abstract: The invention provides a near infrared absorption polymer comprising at least two different pendent infra-red chromophoric moieties covalently bonded to the backbone of an alkali-soluble resin, at least one of which is an indole cyanine dye and the other of which is a benz[e]-indole cyanine dye. When used in the coating of a heat sensitive positive working lithographic printing plate precursor the stabilization time needed after manufacture is significantly reduced, avoiding further conditioning processes before use. The precursors are preferably imagewise exposed with a near-infrared laser emitting at between 780 nm and 850 nm.

Abstract: A lithographic printing plate precursor includes a support and one or more layers, one of the one or more layers is a photosensitive layer containing an initiator compound, a polymerizable compound and a binder polymer, and a layer being in contact with the support of the one or more layers contains a copolymer containing a repeating unit having a zwitterionic structure and a repeating unit having a structure capable of interacting with a surface of the support.

Abstract: The present invention relates to a printing element comprising at least one polymer layer on a substrate which has photoimageable constituents and a chemically functionalized polymer to make the polymer layer either more hydrophobic or hydrophilic. In one embodiment of the present invention, the printing element comprises two adjacent polymer layers on a substrate in which the photoimaged layer comprises a polymer chemically modified with hydrophobic fluoroalkyl side groups to provide differential wetting with hydrophilic inks.

Abstract: A method for applying a light-blocking material onto an imagewise exposed lithographic printing plate is disclosed. The exposed plate comprises on a substrate a photosensitive layer having hardened areas and non-hardened areas (for negative plate) or solubilized areas and non-solubilized areas (for positive plate). The non-hardened or solubilized areas of said photosensitive layer are removable with ink and/or fountain solution on a lithographic press. The light-blocking material is applied to the plate preferably from a solution or dispersion containing such material. The application of the light-blocking material prevents at least a portion of the room light in a certain wavelength (such as ultraviolet) range from reaching the photosensitive layer, thus allowing improved room light stability of the exposed plate.

Abstract: A method for printing a desired periodic or quasi-periodic pattern of dot features into a photosensitive layer disposed on a substrate including the steps of designing a mask pattern having a periodic or quasi-periodic array of unit cells each having a ring feature, forming a mask with said mask pattern, arranging the mask substantially parallel to the photosensitive layer, arranging the distance of the photosensitive layer from the mask and illuminating the mask according to one of the methods of achromatic Talbot lithography and displacement Talbot lithography, whereby the illumination transmitted by the mask exposes the photosensitive layer to an integrated intensity distribution that prints the desired pattern.

Abstract: A process for making a lithographic printing plate is provided that includes a step of producing a negative-working lithographic printing plate precursor comprising a photopolymerizable photosensitive layer above a support; a step of imagewise exposing the negative-working lithographic printing plate precursor; and a step of developing the exposed negative-working lithographic printing plate precursor by means of a developer comprising at least (Component A) a compound represented by Formula (I), (Component B) a compound represented by Formula (II), and (Component C) water.

Abstract: Provided is lithographic printing plates and processes for preparing the lithographic printing plates having excellent printing durability, staining resistance and staining resistance over time. A lithographic printing plate precursor comprising: a substrate; a photosensitive layer provided on the substrate; and an extra layer optionally provided between the substrate and the photosensitive layer; wherein the photosensitive layer or the extra layer adjacent to the substrate contains (A) a copolymer; and wherein the copolymer (A) comprises: (a1) a repeating unit having a structure represented by formula (a1-1) below in a side chain, and (a2) a repeating unit having at least one of the structures represented by formulae (a2-1) to (a2-6) below in a side chain. L1 represents a single bond, a divalent aromatic group containing 6 to 14 carbon atoms, —C(?O)—O—, or —C(—0)?NR2— (wherein R2 represents a hydrogen atom, alkyl or aryl).

Abstract: A lithographic printing plate precursor includes, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area with at least one of printing ink and dampening water on a printing machine after exposure and contains (A) an infrared absorbing dye, (B) a polymerization initiator, (C) a polymerizable compound and (D) a binder polymer having an alkylene oxide group; and a protective layer containing (E) a hydrophilic polymer containing at least a repeating unit represented by the formula (1) as defined herein and a repeating unit represented by the formula (2) as defined herein.

Abstract: Negative-working lithographic printing plate precursor a negative-working imagable layer and an outermost water-soluble overcoat layer that is disposed directly on the negative-working imagable layer. The outermost water-soluble overcoat layer comprises: (1) one or more film-forming water-soluble polymeric binders, and (2) organic wax particles dispersed therein. The organic wax particles have an average largest dimension of at least 0.05 ?m and up to and including 0.7 ?m, as determined from a scanning electron micrographic of the dried outermost water-soluble overcoat layer. Useful organic wax particles include fluorinated or non-fluorinated hydrocarbon wax particles.

Abstract: A positive-working lithographic printing plate precursor which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer, a heat and/or light-sensitive coating comprising an infrared absorbing agent and a binder including a monomeric unit including a salicyclic acid group and a monomeric unit including a sulfonamide group.

Abstract: A positive-working lithographic printing plate precursor is disclosed which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer a heat and/or light-sensitive coating including an infrared absorbing agent, a compound including a blocked isocyanate group and an alkali soluble resin comprising a monomeric unit including a Lewis base moiety.

Abstract: A method of manufacturing an engraved plate used in intaglio printing, said plate being engraved by a tool, for example a laser beam, characterized in that the engraving tool uses data from a depth-map, based on a three-dimensional raster image of the document to be printed.

Abstract: A lithographic printing plate precursor comprising an image-recording layer, said image-recording layer being photopolymerizable upon exposure to light having a wavelength of from 300 to 500 nm and containing a mixture of sensitizers.

Abstract: The present invention relates to a printing element having at least one polymer layer which has photoimageable constituents and a chemically functionalized polymer to make the polymer layer either more hydrophobic or hydrophilic. In one embodiment, the printing element comprises two adjacent polymer layers on a substrate in which the photoimaged layer comprises a polymer chemically modified with hydrophobic fluoroalkyl side groups to provide differential wetting with hydrophilic inks.

Abstract: A method of developing a photocurable printing blank to produce a relief pattern comprising a plurality of relief dots. The photocurable printing blank comprises a backing layer having at least one photocurable layer disposed thereon, a barrier layer disposed on the at least one photocurable layer, and a laser ablatable mask layer disposed on top of the barrier layer.

Abstract: A positive-working multi-layer lithographic printing plate precursor has an inner imageable layer disposed over a substrate. This inner imageable layer comprises one or more first polymeric binders that are present in a total amount of at least 50 weight % and up to and including 97 weight %, based on total inner imageable layer dry weight. The precursor also has an ink-receptive outer imageable layer disposed over the inner imageable layer and this ink-receptive outer imageable layer comprises one or more second polymeric binders that are different than the first polymeric binder. Each of the one or more first polymeric binders has a weight average molecular weight of at least 200,000 and can also have a polydispersity of at least 4.

Abstract: A process for the manufacture of organically developable, photopolymerizable flexographic elements on flexible metallic supports by coating a flexible metallic support with a tack-free adhesive coating composition which is insoluble and non-swelling in printing inks and organic developers, attaching an elastomeric, photopolymerizable layer to a protective film, and laminating the photopolymerizable layer to the metallic support coated with said adhesive coating composition. A photopolymerizable flexographic element comprising a photopolymerizable layer which is attached to a metallic support by means of a tack-free adhesive film that is non-swelling and insoluble in printing inks and organic developers.

Abstract: Lithographic printing plates are prepared from lithographic printing plate precursors that have an imageable layer comprising hydrophobic thermosetting particles that comprise a curable composition having certain properties. Upon exposure to imaging radiation such as infrared radiation, the hydrophobic thermosetting particles are cured and fused to each other and to the substrate. Such particles can be readily removed in the non-exposed regions of the imageable layer by dry rubbing or other simple processes without the use of alkaline developers or gumming solutions.

Abstract: Infrared radiation-sensitive, positive-working lithographic printing plate precursors have improved scratch resistance in their outermost imageable layer because that layer comprises a unique combination of first and second alkali solution-soluble or -dispersible resins. The first alkali solution-soluble or -dispersible resin is an acid-functionalized novolak or acid-functionalized resole resin. The second alkali solution-soluble or -dispersible resin is a polyurethane or polyurethane urea comprising a polysiloxane unit segment in the polyurethane or polyurethane urea backbone or a side chain.

Abstract: A silicate-free alkaline aqueous developer composition has a pH of at least 12 and comprises a metal cation M2+ selected from barium, calcium, strontium, and zinc cations, and a chelating agent that has a complex formation constant (log K) for the metal cation of at least 3.5 and less than or equal to 4.5, and a log K for aluminum ion that is 7 or less. This developer composition can be used to process positive-working lithographic printing plate precursors to provide lithographic printing plates.

Abstract: Lithographic printing plate precursors can have an imageable layer that includes a polymeric binder having an acid number of at least 30 mg KOH/g of polymer to and including 150 mg KOH/g of polymer, at least 3 weight % of recurring units derived from one or more N-alkoxymethyl (alkyl)acrylamides or alkoxymethyl (alkyl)acrylates, at least 2 weight % of recurring units having pendant 1H-tetrazole groups, and at least 10 weight % of recurring units having pendant cyano groups. The use of such polymeric binders provides good bakeability and chemical solvent resistance, especially for positive-working precursors.

Abstract: A combined laminating and exposing apparatus for exposing a photosensitive printing blank to actinic radiation in a printing plate manufacturing system and a method of using the same are disclosed. The photosensitive printing blank comprises a backing layer, at least one photocurable layer disposed on the backing layer, and a laser ablatable mask layer disposed on the at least one photocurable layer, wherein the laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. The exposing apparatus comprises: (a) a laminating apparatus for laminating an oxygen barrier layer to a top of the laser ablated mask layer; (b) a conveyor; (c) a first exposing device for imagewise exposing the at least one photocurable layer to actinic radiation, and (d) a second exposing device for exposing the at least one photocurable layer to actinic radiation through the backing layer.

Abstract: A silicate-free alkaline aqueous developer composition has a pH of at least 12 and comprises a hydroxide alkali agent, a metal cation M2+ selected from barium, calcium, strontium, and zinc cations, a chelating agent for the metal cation, and an alkali metal salt that is different than the other components. These developer compositions can be used to process imaged positive-working lithographic printing plate precursors to prepare lithographic printing plates.

Abstract: A lithographic printing plate precursor includes a support, an undercoat layer and an image-recording layer in this order, in which by exposing imagewise the image-recording layer with laser and then supplying at least any of printing ink and dampening water on a cylinder of a printing machine, an unexposed area of the image-recording layer can be removed, and the image-recording layer contains (A) a polymerization initiator, (B) a polymerizable compound and (C) a binder polymer, and the undercoat layer contains the copolymer (D1) as defined herein and the copolymer (D2) as defined herein and a weight of the copolymer (D1) is from 5 to 95% based on a total weight of the copolymers (D1) and (D2).

Abstract: Lithographic printing plates can be obtained by contacting infrared radiation-imaged negative-working lithographic printing plate precursors with a processing solution having a pH less than 9 and comprising a UV photoinitiator. After this processing, the lithographic printing plate is floodwise exposed with UV radiation. Providing a UV-photoinitiator in the processing solution followed by UV exposure can increase imaging sensitivity and printing plate run-length, and reduce print background.

Abstract: A method is described for producing an imaged lithographic printing plate, wherein the developer comprises a hydrophilic polymer comprising (m1) structural units derived from at least one compound comprising both a polyalkylene oxide chain and a free radical polymerizable group, and (m2) structural units derived from at least one compound copolymerizable with the free radical polymerizable group of (i) and comprising at least one functional group with pKs<5.

Abstract: A lithographic printing plate precursor is provided that exhibits less blooming without using a specific polymerization initiator, infrared radiation absorbing agent and the like. The lithographic printing plate precursor comprises a substrate having thereon an image forming layer comprising a radiation-sensitive composition which comprises a radical polymerizable component, an infrared radiation absorbing agent and a radical polymerization initiator, wherein the radiation-sensitive composition comprises a fluorinated copolymer substantially having no hydrophilic moiety.

Abstract: A lithographic printing plate precursor, comprising a support having thereon an image-recording layer containing (A) an infrared absorbing agent, (B) a radical polymerization initiator, (C) a radical polymerizable compound, (D) a polymer compound containing a polyoxyalkylene structure and (E) an ultraviolet absorbing agent and being capable of forming an image by supplying at least one of printing ink and dampening water on a printing machine after imagewise exposure to remove an unexposed area of the image-recording layer.

Abstract: A positive-working lithographic printing plate precursor has an outermost imageable layer that is present at a dry coverage weight of at least 0.7 g/m2 and up to and including 1.6 g/m2 and comprises a primary polymeric binder comprising recurring units of a hydroxyaryl acetal or a hydroxyaryl ester, or recurring units of both a hydroxyaryl acetal and a hydroxyaryl ester. The outermost imageable layer also contains an alkali-soluble secondary vinyl polymer that is not a primary polymeric binder and a non-polymeric polyhydric phenol. These precursors comprise an infrared radiation absorber to make them sensitive and imageable using infrared radiation. After imaging, the precursors can be processed (developed) using an relatively low pH developer such as a silicate- or metasilicate-free developer.

Abstract: A relief (or flexographic) printing precursor has first and second radiation-sensitive layers, or a plurality of radiation-sensitive layers. The first radiation-sensitive layer is sensitive to a first imaging radiation having a first ?max. The second radiation-sensitive layer is disposed on the first radiation-sensitive layer and is sensitive to a second imaging radiation having a second ?max that differs from the first ?max by at least 25 nm. An infrared radiation ablatable layer can be present and is opaque or insensitive to the first and second imaging radiations and contains an infrared radiation absorbing compound. These relief printing precursors can be used to prepare flexographic printing plates, cylinders, or sleeves where the ablatable layer is used to form an integral mask on the element. Use of the invention provides a relief image without any loss in the strength of the small dots and can be carried out using multiple irradiation steps using the same apparatus.

Abstract: A collector mirror exchanging apparatus is capable of safely and easily exchanging a collector mirror for collecting extreme ultra violet light emitted from plasma generated within a chamber of an extreme ultra violet light source apparatus. The collector mirror exchanging apparatus includes: a supporting base for supporting a collector mirror or a collector mirror structure; and a guiding rail disposed on the supporting base and regulating a moving direction of the collector mirror or the collector mirror structure; wherein at least the collector mirror is taken out of the chamber by moving the collector mirror or the collector mirror structure along the guiding rail on the supporting base.

Abstract: The invention provides a photosensitive element and a method for preparing a printing form from the element. The photosensitive element includes a layer of a photosensitive composition containing a binder, a monomer, and a Norrish type II photoinitiator, wherein the photosensitive layer has a transmittance to actinic radiation of less than 20% and contains reinforcing particles of graphene and/or carbon nanotubes.

Abstract: A method of making a relief image printing element from a photosensitive printing blank is provided. A photosensitive printing blank with a laser ablatable layer disposed on at least one photocurable layer is ablated with a laser to create an in situ mask. The printing blank is then exposed to at least one source of actinic radiation through the in situ mask to selectively cross link and cure portions of the photocurable layer. Diffusion of air into the at least one photocurable layer is limited during the exposing step and preferably at least one of the type, power and incident angle of illumination of the at least one source of actinic radiation is altered during the exposure step. The resulting relief image comprises a plurality of dots and a dot shape of the plurality of dots is produced that is highly resistant to print fluting for printing on corrugated board.

Abstract: To provide a method of preparing a lithographic printing plate comprising exposing imagewise a lithographic printing plate precursor including a support, a photosensitive layer containing a binder polymer and a radical polymerizable compound having viscosity of 9,000 mPa·s or less at 25° C. and a protective layer in this order and developing the exposed lithographic printing plate precursor with a developer without passing through a heat treatment, as a method of preparing a lithographic printing plate capable of forming an image area which is cured at high sensitivity and has good printing durability and halftone dot reproducibility and capable of easily reproducing a halftone dot image because of excellent stability of halftone dot reproduction to exhibit a small restriction on setting of the time described above, even without conducting a preheat treatment.