Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
2002-12-30
2004-06-15
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S502000, C430S503000, C430S546000
Reexamination Certificate
active
06750001
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a silver halide color photographic material, which is exposed based on digital information and processed to prepare a color print, and an image forming method by the use thereof, and in particular to a silver halide color photographic material exhibiting enhanced character reproduction and capable of stably reproducing prints having reduced scanning unevenness in scene images even when exposed in various digital exposure apparatuses having different exposure light sources and exposure systems, and also capable of obtaining prints exhibiting little variation in density even when the time after completion of exposure and before the start of processing is varied; and an image forming method by use thereof.
BACKGROUND OF THE INVENTION
In recent years, opportunities of treating images as digital data have rapidly increased along with enhancement of operation capacity and progress in network technology. Image information obtained by digital cameras or image information which has been digitized from photographic film or prints using a scanner can be readily edited or added with characters or illustrations on a computer. Examples of hard copy material used for prepare a hard copy based on such digitized image information include a sublimation type thermal print, melt type thermal print, ink-jet print, electrostatic transfer type print, thermo-autochrome print and silver halide color photographic material. Of these, silver halide color photographic material (hereinafter, also referred to as photographic material) has greatly superior characteristics such as high sensitivity, superior tone, superior image lasting quality and lower cost, compared to other print material and therefore, is broadly employed for preparation of high quality hard copy prints.
Digitized image information can be readily edited on a computer, leading to increased opportunities of treating images comprised of a mixture of images based on photography data of people, landscapes, still-life and the like (hereinafter, also denoted as scenic images) and character images (specifically, thin small black text). Accordingly, reproduction of natural scenic images and character reproduction without blurring are simultaneously required in image output based on digital data.
Various types of digital exposure apparatuses performing exposure based on digitized image information are now commercially available and many kinds of models of digital exposure apparatuses have also been developed along with progresses in exposure light sources and exposure control apparatuses. Of these digital exposure apparatuses, apparatuses using a light source having a narrow wavelength distribution, such as laser or LED are becoming the main trend. However, the kind of lasers or LED installed in various types of digital exposure apparatuses is not unified and the exposure wavelength is often different for every exposure apparatus. Furthermore, even in cases where using the same light source, there are often differences in overlapping ratio of exposure beams, exposure time interval between adjacent picture elements (hereinafter, also denoted as pixels) and exposure time or intensity per pixel. Consequently, different exposure apparatuses often result in variation in reproduced print quality and consequently improvement thereof is strongly desired.
Of digital exposure systems, a scanning exposure system using an exposing light beam is known as one of the more popular exposure systems. In this system, there is known a system using the combination of plural light sources having the same color (hereinafter, such a system is also an array exposure system). In the case of the array exposure system, however, the operation of canceling exposure streaks often takes a bit of doing, compared to an exposure system using a single light source and improvement thereof is also desired. An array block in which plural pixels are simultaneously exposed is a popular embodiment, leading to cases in which adjacent pixels are simultaneously exposed in the array block and cases in which adjacent pixels are exposed at different timing with undergoing transport of the photographic material or movement of the exposure head therebetween. Specifically in cases where time intervals between the adjacent pixels are different, photographic material having stable characteristic with little variation in density has been desired to make an operation to cancel exposure streaks easier.
Furthermore, it is contemplated that an extremely short exposure time per pixel, such as 10
−10
to 10
−3
sec. per pixel results in a change in latent image forming efficiency or stability of formed latent images. Consequently, there occurs a phenomenon in which a change in interval between exposure and processing often causes variation in reproduced density (so-called latent-image shift) and improvement thereof has been sought.
Such problems may be overcome by optimization of photographic material for every exposure apparatus or every environment, however, this is not a realistic response in view of the numerous kinds of digital exposure apparatuses available on the market and the number of which will inevitably increase in the future. Accordingly, there have been photographic materials and image forming methods by which beautiful prints can be obtained, in which characters with sharp edges are reproduced without blurring nor streaking defects due to scanning exposure.
There have been proposed methods for enhancing image quality to overcome the foregoing problems. For example, JP-A No. 3-158847 (hereinafter, the term, JP-A is referred to as Japanese Patent Application Publication) discloses a method for controlling the average value of point gammas over a given density range and variation thereof. JP-A No. 8-36247 discloses a method in which the relationship of an instantaneous contrast value and an exposure amount is defined. JP-A No. 9-171237 discloses a method for enhancing the maximum gamma and fill-in Dmax within an exposure range to a given level or higher. JP-A No. 2000-321730 discloses controlling a density loss as a function of index color record lower in respective color forming layers over an exposure region of 1000 nano-sec. to 0.5 sec. to improve image quality over the broad exposure region. However, any of these methods aims mainly to enhance image quality and is silent with respect to stability in cases when the time after exposure and before the start of processing is varied.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a silver halide color photographic material, which is exposed based on digital information and processed to prepare a color print, and an image forming method by the use thereof, and in particular to a silver halide color photographic material exhibiting enhanced character reproduction and capable of stably reproducing prints having reduced scanning unevenness in scene images even when exposed in various digital exposure apparatuses having different exposure light sources and exposure systems, and also capable of obtaining prints exhibiting little variation in density even when the time after exposure and before the start of processing is varied; and an image forming method by use thereof.
The foregoing object of the invention can be accomplished by the following constitution:
A silver halide color photographic material comprising a support having thereon at least a yellow image forming layer, at least a magenta image forming layer and at least a cyan image forming layer, each of which contains light sensitive silver halide, wherein when the photographic material having been exposed to light for 10
−10
to 10
−3
sec. per pixel and processed, an effective tone range (hereinafter, also denoted simply as VE) of a color image. obtained in each of the color image forming layers is 0.65 to
DETAILED DESCRIPTION OF THE INVENTION
One aspect of the invention is characterized in that when subjected to exposure to light so that the exposure time is 10
−10
to 1
Ikeda Tsuyoshi
Miyazawa Kazuhiro
Nishimura Motoi
Sato Hirokazu
Konica Corporation
Letscher Geraldine
Muserlian Lucas and Mercanti
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