Appeal No. 1999-2529
Application 08/915,683
Furthermore, both of Tanemura (e.g., col. 3, lines 54-63; col. 6, lines 2-6; col. 11, line 66,
to col. 12, line 2; and Example 1) and Shuto (e.g., col. 7, lines 44-46; col. col. 11, lines 17-23;
and Example 1) teach the use of the same chemical sensitizers for the core as those disclosed in
Evans, including gold sensitizers alone or in combination with other sensitizers, and exemplify
sodium thiosulfate and chloroauric acid (tetrahydrate). Tanemura discloses that using at least one
thiosulfonate compound of formulae (II) through (IV) thereof results in emulsions which provide
a high contrast direct positive image having a low minimum image density (Dmin) and a high
maximum image density (Dmax) (e.g., col. 2, line 63, to col. 3, line 5) while Shuto discloses that
using at least one thiosulfonate compound of formulae (I) through (III) thereof results in
emulsions which provide a high contrast direct positive image in which the Dmin is reduced
without reducing the Dmax. While Shuto discloses that at least one compound of the formula (IV)
must also be used, such a compound would be included in the claimed emulsions of appealed
claim 1 because of the transitional term “comprising.” See In re Baxter, 656 F.2d 679, 686-87,
210 USPQ 795, 802-03 (CCPA 1981) (“As long as one of the monomers in the reaction is
propylene, any other monomer may be present, because the term ‘comprises’ permits the
inclusion of other steps, elements, or materials.”).
Thus, Tanemura and Shuto, separately and together would have taught one of ordinary
skill in this art that cores of core/shell tabular grains, including those of Evans, which are
preferably composed of silver bromide, can be chemically sensitized by using gold sensitizers
alone or in combination with other sensitizers as also disclosed by Evans, in the presence of
thiosulfonate compounds in order to obtain certain image density properties.
Based on this evidence, we find that one of ordinary skill in this art would have found in
the combined teachings of Evans, Tanemura and Shuto the reasonable suggestion to chemically
sensitize the core silver halide, particularly silver bromide, of core/shell tabular grains of Evans
with a gold sensitizer in combination with the presence of the thiosulfonate compounds of
Tanemura and Shuto, and also with other sensitizers, in order to obtain core/shell tabular grains
for use in the internal latent image direct positive photographic silver halide emulsions of Evans
in the reasonable expectation of obtaining the advantages high-contrast positive images with the
minimum and maximum image densities taught by Tanemura and Shuto. Accordingly, prima
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