Radiation imagery chemistry: process – composition – or product th – Radiation sensitive product – Silver compound sensitizer containing
Reexamination Certificate
2002-12-23
2004-05-11
Le, Hoa Van (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Radiation sensitive product
Silver compound sensitizer containing
C430S502000, C430S567000, C345S418000
Reexamination Certificate
active
06733961
ABSTRACT:
FIELD OF THE INVENTION
This invention is directed to radiation sensitive high chloride silver halide emulsions useful in photography, including electronic printing methods wherein information is recorded in a pixel-by-pixel mode in a radiation silver halide emulsion layer, comprising iridium complex dopants located at specific sites in the emulsion grains and spectrally and chemically sensitized at relatively high pH.
DEFINITION OF TERMS
The term “high chloride” in referring to silver halide grains and emulsions indicates that chloride is present in a concentration of greater than 50 mole percent, based on total silver. In referring to grains and emulsions containing two or more halides, the halides are named in order of ascending concentrations.
The term “cubic grain” is employed to indicate a grain is that bounded by six {100} crystal faces. Typically the corners and edges of the grains show some rounding due to ripening, but no identifiable crystal faces other than the six {100} crystal faces. The six {100} crystal faces form three pairs of parallel {100} crystal faces that are equidistantly spaced.
The term “cubical grain” is employed to indicate grains that are at least in part bounded by {100} crystal faces satisfying the relative orientation and spacing of cubic grains. That is, three pairs of parallel {100} crystal faces are equidistantly spaced. Cubical grains include both cubic grains and grains that have one or more additional identifiable crystal faces. For example, tetradecahedral grains having six {100} and eight {111} crystal faces are a common form of cubical grains.
The term “central portion” in referring to cubical silver halide grains refers to that portion of the grain structure that is first precipitated accounting for up to 98 percent of total precipitated silver required to form the {100} crystal faces of the grains.
The term “dopant” is employed to indicate any material within the rock salt face centered cubic crystal lattice structure of a silver halide grain other than silver ion or halide ion.
The term “dopant band” is employed to indicate the portion of the grain formed during the time that dopant was introduced to the grain during precipitation process.
The term “normalized” molar addition rate hereinafter assigned the symbol R
n
is a measure of the intensity of rate of addition of silver salt solution to the reaction vessel in case of a double-jet precipitation process. R
n
is defined by the formula:
R
n
=Q
f
C
f
/M
where Q
f
is the volumetric rate (liters/min) of addition of silver salt solution into the reaction vessel, C
f
is the molar concentration (moles/liter) of the said solution, and M is total moles of silver halide host grains in the reaction vessel at the precise moment of above addition.
All references to the periodic table of elements periods and groups in discussing elements are based on the Periodic Table of Elements as adopted by the American Chemical Society and published in the
Chemical and Engineering News
, Feb. 4, 1985, p. 26. The term “Group VIII” is used to generically describe elements in groups 8, 9 and 10.
The term “log E” is the logarithm of exposure in lux-seconds.
Photographic speed is reported in relative log units and therefore referred to as relative log speed. 1.0 relative log speed unit is equal to 0.01 log E.
The term “contrast” or “&ggr;” is employed to indicate the slope of a line drawn from stated density points on the characteristic curve.
The term “reciprocity law failure” refers to the variation in response of an emulsion to a fixed light exposure due to variation in the specific exposure time.
Research Disclosure
is published by Kenneth Mason Publications, Ltd., Dudley House, 12 North St., Emsworth, Hampshire P010 7DQ, England.
BACKGROUND OF THE INVENTION
In its most commonly practiced form silver halide photography employs a film in a camera to produce, following photographic processing, a negative image on a transparent film support. A positive image for viewing is produced by exposing a photographic print element containing one or more silver halide emulsion layers coated on a reflective white support through the negative image in the camera film, followed by photographic processing. In a relatively recent variation negative image information is retrieved by scanning and stored in digital form. The digital image information is later used to expose imagewise the emulsion layer or layers of the photographic print element.
Whereas high bromide silver halide emulsions are the overwhelming commercial choice for camera films, high chloride cubic grain emulsions are the overwhelming commercial choice for photographic print elements. It is desired in high chloride emulsions for color paper applications to obtain high photographic speed at the desired curve shape.
Many known imaging systems require that a hard copy be provided from an image which is in digital form. A typical example of such a system is electronic printing of photographic images which involves control of individual pixel exposure. Such a system provides greater flexibility and the opportunity for improved print quality in comparison to optical methods of photographic printing. In a typical electronic printing method, an original image is first scanned to create a digital representation of the original scene. The data obtained is usually electronically enhanced to achieve desired effects such as increased image sharpness, reduced graininess and color correction. The exposure data is then provided to an electronic printer which reconstructs the data into a photographic print by means of small discrete elements (pixels) that together constitute an image. In a conventional electronic printing method, the recording element is scanned by one or more high energy beams to provide a short duration exposure in a pixel-by-pixel mode using a suitable source such as a cathode ray tube (CRT), light emitting diode (LED) or laser. Such methods are described in the patent literature, including, for example, Hioki U.S. Pat. No. 5,126,235; European Patent Application 479 167 A1 and European Patent Application 502 508 A1. Also, many of the basic principles of electronic printing are provided in Hunt,
The Reproduction of Color
, Fourth Edition, pages 306-307, (1987).
Reciprocity characteristics, usually referred to as reciprocity failure, are measured in terms of departures from the law of photographic reciprocity. The exposure (E) of a photographic element is the product of the intensity (I) of exposure multiplied by its duration (time):
E=I
×time
According to the photographic law of reciprocity, a photographic element should produce the same image with the same exposure, even though exposure intensity and time are varied . For example, an exposure for 1/100
th
of a second at a selected intensity should produce exactly the same result as an exposure of 10
−5
second at an intensity that is increased by a factor of 10
−3
. When photographic performance is noted to diverge from the reciprocity law, this is known as reciprocity failure.
A very typical observation in examining high chloride emulsions for photographic print applications is that the upper scale of photographic curve (also referred to as shoulder) falls off as the intensity of exposure increases and its time decreases. It has become increasing clear that with the continuing development of a variety of high intensity digital printing devices that photographic print materials with performance invariant to exposure time is increasingly important. When exposure times are reduced below one second to very short intervals (e.g., 10
−5
second or less), higher exposure intensities must be employed to compensate for the reduced exposure times. High intensity reciprocity failure (hereinafter also referred to as HIRF) occurs when photographic performance is noted to depart from the reciprocity law when such shorter exposure times are employed. Print materials which traditionally su
Bell Eric L.
Budz Jerzy A.
Hendricks, III Jess B.
Mydlarz Jerzy Z.
Anderson Andrew J.
Eastman Kodak Company
Le Hoa Van
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