Radiation imagery chemistry: process – composition – or product th – Color imaging process – Laser or radiation exposure other than visible light
Reexamination Certificate
2003-03-21
2004-06-08
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Color imaging process
Laser or radiation exposure other than visible light
C430S486000, C430S933000
Reexamination Certificate
active
06746832
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a method of producing an image on silver halide color light-sensitive materials. In particular, the present invention relates to an image-forming method that is adaptable to output an image based on digital image data for area modulation, and it provides an image that is improved in quality; that is free from scratches and unevenness in density; that has high sharpness, and that is reduced in the yellowing (yellow stain) at the white background. Further, the present invention relates to an image-forming method that is excellent in aptitudes for high intensity exposure and to rapid processing. Particularly, the present invention relates to an image-forming method that is adaptable to a direct digital color proof, using a silver halide color light-sensitive material, in which a color image is formed based on area-modulated image data (dot image data).
BACKGROUND OF THE INVENTION
The recent progress of image digitization has enabled one to use a printing process, such as CTP (Computer To Plate), in which a lith-plate need not to be formed. Along with this, the major trend of the purpose of producing proofs has changed from inspection of lith-plates for confirmation of print finish, and improvements in proof quality and high speed processing are therefore expected.
As proofs that can cope with digitization, there are low-quality proofs that almost cannot reproduce dots, though inexpensive, such as those obtained with systems represented by an ink jet system; high-quality proofs that enable the reproduction of dots and hue close to those of printed products, though expensive and reduced in productivity, such as those obtained with systems represented by a laser thermal system; and medium quality proofs, which have an intermediate cost performance between the two, and which use silver halide color light-sensitive materials.
Conventionally, the main purpose of producing a color proof is to inspect a lith-plate prior to preparing a printing plate. For this, in a proof using a silver halide light-sensitive material, a reversal light-sensitive material is generally used to obtain a positive image directly from a lith-plate (positive image). A proof using a silver halide light-sensitive material in an analogue system (contact exposure, from a lith-plate), before digital systems were put to practical use, had a certain level of qualities with respect to dot reproducibility and color reproducibility. Therefore, in practicing digital systems, a system using a conventional reversal-series light-sensitive material as the light-sensitive material and the treatment therefor, has been established (see, for example, JP-A-2000-147723 (“JP-A” means unexamined published Japanese patent application)).
The digitization of data for a plate enabled reversing by calculation, and it was not necessarily required to prepare a light-sensitive material having a reversal function. This is why studies have been started to design a proof system using a negative-type light-sensitive material (see, for example, JP-A-2002-122969).
In a color proof system, it takes time to carry out exposure, because a light-sensitive material with a size (for example, A3 size) larger than a usual photographic print (using density modulation) is exposed, and also the reproducibility of dots and high quality are required because the image is expressed by dots. In particular, reproducibility of characters coexisting in the image, and of fine characters, is strongly demanded.
To improve productivity, high-speed exposure using a multi-channel system comprising multiple exposure light sources having the same wavelengths, adjustment for high speed development processing, and the like, are carried out. However, along with improved productivity, image unevenness in a print image is easily caused.
To improve the productivity of the system, it is preferred that a silver halide emulsion with a high silver chloride content, which is suitable for rapid development processing, be used. However, such a high silver chloride content emulsion is known to have the disadvantage of being large in its high intensity reciprocity law failure. Since sensitivity reduction and gradation softening at high intensities deteriorate the suitability of printing paper to laser scanning exposure and high-intensity light-emitting diode array scanning exposure which are expected as a recording method for digital image information exhibiting a high image quality. Therefore, development of means for preventing the high intensity reciprocity law failure of silver halide emulsions having high silver chloride contents has become important. Furthermore, reducing the processing time in order to perform rapid processing generally results in an increase in passing speed of a photosensitive material through a processing apparatus, but in turn results in a shortened immersion time of the photosensitive material in the processing solution. This causes various problems that the image in the print tends to have streaks and unevenness where the density has increased, and that the white background becomes colored in yellow, and so on. Accordingly, it has been necessary to deal with these problems as well.
Under the circumstances, the inventors of the present invention have made extensive studies. As a result, they have found that the streaks and unevenness formed during the aforementioned development processing are reduced by providing regions where the content(s) of silver bromide and/or silver iodide is higher than that in the other regions at a portion or a plurality of portions between the center and the surface of grains. However, it has been found that this is not necessarily satisfactory when handling image data that is area-modulated, and that, if an emulsion containing such grains is used, the aforementioned phenomenon; yellow stain at the white background is caused significantly, and the reproducibility of characters is more deteriorated.
JP-A-58-95736, JP-A-63-89840, U.S. Pat. No. 4,820,624, U.S. Pat. No. 5,284,743 disclose that high sensitivity can be achieved by incorporating, in an emulsion with a high silver chloride content, a phase with a high silver bromide content in various forms in a localized manner. In these publications, however, no explicit mention has been made on the means for reducing yellowing of the white background:when emulsions containing a silver bromide- and/or silver iodide-containing phase are used.
In JP-A-2001-281823, on the other hand, a method for removing a residual color due to a sensitizing dye is described. However, there is nothing described as to the problem concerning the handling of area-modulated image data, and as to the problem concerning scratches and unevenness of the image.
SUMMARY OF THE INVENTION
The present invention is a color image forming method, which comprises:
subjecting a silver halide color photosensitive material to exposure; and thereafter processing the silver halide color photosensitive material with a processing solution, wherein the silver halide color photosensitive material comprises, on a support, at least one silver halide emulsion layer containing a yellow dye-forming coupler, at least one silver halide emulsion layer containing a magenta dye-forming coupler, at least one silver halide emulsion layer containing a cyan dye-forming coupler, a color mixing prevention layer, and a protective layer, wherein a silver halide emulsion in at least one of the silver halide emulsion layers comprises at least one kind of silver halide grains selected from the group consisting of silver chlorobromide grains, silver chloroiodide grains, and silver chloroiodobromide grains, each having a silver chloride content of 95mol % or more, and each having a region where a content of silver bromide and/or silver iodide is higher than other regions of the silver halide grains,
wherein the exposure is performed based on digital image data that has been modulated into data for area modulation and converted into exposure-device-dependent digital data for exposure, and
wherein the p
Nakai Yasufumi
Okazaki Kentaro
Yokokawa Takuya
Fuji Photo Film Co. , Ltd.
Le Hoa Van
Sughrue & Mion, PLLC
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