Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Two or more radiation-sensitive layers containing other than...
Reexamination Certificate
2001-09-10
2003-09-02
Letscher, Geraldine (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Two or more radiation-sensitive layers containing other than...
C430S496000, C430S502000, C430S503000, C430S504000, C430S506000, C430S507000
Reexamination Certificate
active
06613501
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to silver halide color photographic materials exhibiting enhanced sensitivity sufficient for recording images and superior graininess, and a color image forming process by use thereof.
BACKGROUND OF THE INVENTION
Silver halide photographic light-sensitive materials and a system making use thereof recently progressed, enabling any one to simply obtain high quality color images.
On the other hand are also under way rapid advances of so-called digital still cameras employing CCD as an imaging element. In order to obtain image quality close to silver salt photographic images, cameras installed with a CCD element having a few million pixels have been introduced into the consumer market for amateur use. Digital still cameras can directly obtain digitized image data, without necessitating any step for developing an exposed photographic film, such as in a conventional color photographic system, whereby images can be instantaneously confirmed on a liquid crystal monitor at the time of picture-taking or obtained digital information can be utilized in various manners. Although improvements in performance of CCD employed as an imaging element for digital cameras has progressed markedly, it is limited in providing enhanced sensitivity, while increasing the number of pixels within a limited size. Further, it is in principle difficult to provide broad latitude within a limitation of a low-priced and simple camera system. Accordingly, if silver halide photographic materials achieve further enhanced sensitivity and broad latitude and can be loaded into low-priced and easily handling goods, such as a lens-fitted film package, a fascinating system for users can be provided.
The speed of silver halide photographic materials are enhanced over time and among commercially available color negative film, film having an ISO speed of 400 is mainly employed. As is well known, enlarging silver halide grains is effective to enhance the speed of a silver halide photographic material. However, the use of silver halide grains having a relatively large size often deteriorates graininess, vitiating image quality. Increasing the number of silver halide grains per unit area of photographic material is effective to improve such a disadvantage. In commercially available color negative films, the silver coverage proportionally increases with an increase in speed. However, in cases when high sensitive silver halide grains are integrated, in a relative high silver coverage, into a photographic material, influences due to natural radiation cannot be neglected, resulting in deterioration in performance, such as increased fogging or deteriorated graininess caused during product storage. To overcome such problems, U.S. Pat. No. 5,091,293 discloses a technique for reducing silver coverage of a photographic material, while exhibiting a relatively high speed. However, the technique disclosed therein was insufficient for compensating for lowered sensitivity or deteriorated graininess accompanied with the reduction in silver coverage.
Regarding requirements for resource-saving and cost reduction, however, there is still desired a silver halide photographic material having a relatively low silver coverage, without vitiating sensitivity or graininess, while exhibiting superior radiation resistance.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a silver halide photographic material for camera use, exhibiting enhanced sensitivity, improved graininess and superior radiation resistance, irrespective of its relatively low silver coverage.
The object of the invention can be accomplished by the following constitution:
1. A silver halide photographic light-sensitive material comprising on a support a blue-sensitive silver halide light-sensitive unit comprising at least a blue-sensitive silver halide emulsion layer containing a yellow dye forming coupler, a green-sensitive silver halide light-sensitive unit comprising at least a green-sensitive silver halide emulsion layer containing a magenta dye forming coupler, and a red-sensitive silver halide-light sensitive unit comprising at least a red-sensitive silver halide emulsion layer containing a cyan dye forming coupler, wherein a coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of the blue-sensitive unit (denoted as CUB) is not less than 80%, a coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of the green-sensitive unit (denoted CUG) is 30 to 75% and a coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of the red-sensitive unit (denoted as CUR) is not less than 80%.
Furthermore, preferred embodiments of the invention are as follows:
2. a silver halide photographic light-sensitive material comprising a support having thereon a blue-sensitive silver halide light-sensitive unit comprising at least a blue-sensitive silver halide emulsion layer containing a yellow coupler, a green-sensitive silver halide light-sensitive unit comprising at least a green-sensitive silver halide emulsion layer containing a magenta coupler, and a red-sensitive silver halide-light sensitive unit comprising at least a red-sensitive silver halide emulsion layer containing a cyan coupler, wherein a coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of each of the light-sensitive units meets the following requirements:
(1) blue-sensitive unit≧80%
(2) green-sensitive unit of 30 to 75%
(3) red-sensitive unit≧80%;
3. the silver halide photographic material as described in 2, wherein the coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of each of the light-sensitive units is the following order:
blue-sensitive unit>red-sensitive unit>green-sensitive unit;
4. the silver halide photographic material as described in 2, wherein the coefficient of utilization of an oxidation product of a color developing agent in a maximum density area of each of the light-sensitive units is the following order:
red-sensitive unit>blue-sensitive unit>green-sensitive unit;
5. a silver halide photographic light-sensitive material comprising a support having thereon a blue-sensitive silver halide light-sensitive unit comprising at least a blue-sensitive silver halide emulsion layer containing a yellow coupler, a green-sensitive silver halide light-sensitive unit comprising at least a green-sensitive silver halide emulsion layer containing a magenta coupler, and a red-sensitive silver halide-light sensitive unit comprising at least a red-sensitive silver halide emulsion layer containing a cyan coupler, wherein a coefficient of development of silver halide in a maximum density area of the blue-sensitive silver halide light-sensitive unit is 70 to 90% when subjected to blue light exposure and said coefficient being 50 to 70% when subjected to neutral white neutral light exposure;
6. a silver halide photographic light-sensitive material comprising a support having thereon a blue-sensitive silver halide light-sensitive unit comprising at least a blue-sensitive silver halide emulsion layer containing a yellow coupler, a green-sensitive silver halide light-sensitive unit comprising at least a green-sensitive silver halide emulsion layer containing a magenta coupler, and a red-sensitive silver halide-light sensitive unit comprising at least a red-sensitive silver halide emulsion layer containing a cyan coupler, wherein a coefficient of development of silver halide in a maximum density area of the red-sensitive silver halide light-sensitive unit is 70 to 90% when subjected to red light exposure, and said coefficient being 40 to 60% when subjected to neutral white light exposure
7. a silver halide photographic light-sensitive material comprising a support having thereon a blue-sensitive silver halide light-sensitive unit comprising at least a blue-sensitive silver halide emulsion
Fukazawa Fumie
Ito Tsukasa
Konica Corporation
Letscher Geraldine
Muserlian, Lucas and Mercanti LLP
LandOfFree
Silver halide photographic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Silver halide photographic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Silver halide photographic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3006641