Abstract: A positively chargeable single-component developer for visualizing electrostatic latent images comprises a binding resin having an acid value of 1.5 to 10 (KOH mg/g), a colorant, and an additive such as polyfluoroethylene fine powder having an electron attractive group. The additive is added in an amount of 0.05 part by weight to 2 parts by weight with respect to 100 parts by weight of the positively chargeable single-component developer. The acid value of the binding resin may be adjusted by mixing two or more resins having different acid values. The developer prevents a surface of a photosensitive member from decrease in electric potential which would be otherwise caused by electrons released when toner particles and the photosensitive member are frictionally charged. Accordingly, the developer makes it possible to provide good image quality with less fog and with a dense density.

Abstract: The present invention provides a photographic material with a pH at 25.degree. C. of at most 7, containing on a support at least one layer, comprising a prefogged direct-positive silver halide emulsion spectrally sensitized with one or more electron-accepting sensitizing dyes in a total amount of at least 0.15 mmole/mole silver halide, the silver halide crystals of said prefogged direct-positive silver halide emulsion containing silver chloride for at least 60 mole %, silver bromide in a range from 0.5 mole % to 39.98 mole % and silver iodide in a range from 0.02 mole % to 2 mole %, characterized in that said silver halide cristals contain silver iodide for at least 0.20 mmole/mole AgX in the outer 10% by weight of said cristals and said layer contains a gelatin species containing Ca.sup.2+ in an amount ranging from 0.2% to 1% by weight.

Abstract: A film is disclosed for duplicating a silver image in a radiographic film. A single monodispersed fogged direct-positive emulsion layer is employed. To extend exposure latitude the emulsion layer contains micro-crystalline particles of a dye that competes with the fogged direct positive grains of the emulsion layer for absorption of exposing radiation and can be decolorized during photographic processing.

Abstract: A direct positive silver halide photographic material and a method for forming a high contrast image using the same are disclosed, in which a pre-fogged direct positive silver halide emulsion layer contains a salt of a nitrogen-containing compound having at least one pyridine nucleus and at least one pyridinium nucleus. The photographic material, after imagewise exposure, is developed with an alkaline developer containing a developing agent, preferably a reductance compound. The photographic material provides high contrast characteristics having a gamma exceeding 10.

Abstract: An azomethine dye is disclosed, represented by the general formula (I), (II) or (III): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently represents a hydrogen atom or nonmetallic atom group; X represents --OH or --NR.sup.5 R.sup.6 ; R.sup.5 and R.sup.6 each independently represents a hydrogen atom, alkyl group, aryl group or heterocyclic group; R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.12 and R.sup.13 each independently represents a hydrogen atom or nonmetallic atom group; and R.sup.1 and R.sup.2, and/or R.sup.2 and R.sup.5, and/or R.sup.5 and R.sup.6, and/or R.sup.6 and R.sup.3, and/or R.sup.3 and R.sup.4, and/or R.sup.7 and R.sup.8, and/or R.sup.9 and R.sup.10, and/or R.sup.11 and R.sup.12, and/or R.sup.12 and R.sup.13 may be connected to each other to form a cyclic structure.

Abstract: A silver halide photographic material having at least one hydrophilic colloid layer, wherein at least one hydrophilic colloid layer is a silver halide photographic emulsion layer, and at least one hydrophilic colloid layer contains a compound represented by the general formula (I): ##STR1## wherein A.sub.1 and A.sub.2 both represent hydrogen atoms, or one of them represents a hydrogen atom and the other represents a sulfonyl group or ##STR2## (wherein R.sub.0 represents an alkyl group, an alkenyl group, an aryl group, an alkoxy group or an aryloxy group, and l.sub.1 represents 1 or 2); G represents ##STR3## (wherein m.sub.1 represents 1 or 2), --SO.sub.2 --, --SO--, ##STR4## (wherein R.sub.

Abstract: A direct positive image forming method comprising development processing an imagewise exposed direct positive photographic light-sensitive material which comprises a support having thereon at least one layer containing internal latent image type silver halide grains not having been previously fogged after fogging treatment or while fogging treatment, wherein the fogging treatment is conducted in the presence of a compound represented by the following general formula (I): ##STR1## wherein A.sub.1 and A.sub.2 both represent a hydrogen atom or one of A.sub.1 and A.sub.2 represents a hydrogen atom and the other represents a sulfonyl group or an acyl group; G.sub.1 represents a carbonyl group, a sulfonyl group, a sulfoxy group, ##STR2## or an iminomethylene group; L.sub.1 represents a divalent linkage group; X.sub.1 represents --O-- or ##STR3## wherein R.sub.4 represents a hydrogen atom, an alkyl group or an aryl group); Y.sub.1 represents ##STR4## R.sub.1 and R.sub.

Abstract: Direct positive photographic films are disclosed having novel density enhancers of the formula ##STR1## wherein A is oxygen or sulfur, and B is selected from the group consisting of hydrogen, alkyl haloalkyl, hydroxyalkyl, alkylamino and alkoxy. Photographic materials coated with emulsions having these density enhancers display good optical density while maintaining high speed capability.

Abstract: The present invention relates to a process for forming a direct positive color image, wherein bleaching time is reduced and color reproduction is not deteriorated. According to the present invention, there is provided a process for forming a direct positive color image comprising exposing a photosensitive material comprising, on a support, at least one photographic emulsion layer containing previously unfogged internal latent image-type silver halide grains and a color image-forming coupler, color-developing the same in the presence of a nucleating agent and/or fogging light, and then processing it with a processing solution having a bleaching effect, characterized in that a bleaching accelerator is incorporated into the processing bath having the bleaching effect or a pre-processing bath, or said bleaching accelerator is incorporated into the photosensitive material.

Abstract: A direct positive silver halide photographic material comprising a support having thereon at least one silver halide emulsion layer comprising a prefogged direct-positive silver halide emulsion, preferably one having a chloride content of at least 70 mol%, said emulsion layer or a hydrophilic colloid layer adjacent to said emulsion layer containing at least one compound represented by the following general formula (I) and, optionally, a specified organic desensitizer, ##STR1## wherein Z.sub.

Abstract: There is provided a high speed and high contrast direct positive silver halide photographic emulsion which is free of discoloration by containing therein a dimethine dye having an indolenine ring which contains a cyano group as a substituent.

Abstract: Photographic film units and processes are disclosed which provide a negative image, wherein exposed silver is developed to high covering power silver and unexposed silver halide is reduced to low covering power silver.

Abstract: A high contrast, chemically fogged direct positive type silver halide photosensitive material is described containing at least one ammine complex salt selected from those including cobalt, nickel, ruthenium or chromium, by which the contrast in the lower optical density region is improved while retaining superior Dmax and sensitivity.

Abstract: Direct-positive photographic material having at least one layer which contains a silver halide emulsion surface-fogged by chemical means or by exposure and a tri-nuclear cyanine dye, which has the formula ##EQU1## in which A.sub.1 is .dbd.CH-- or .dbd.CH--CH.dbd.CH--, Z.sub.1 is a monocyclic or polycyclic heterocyclic radical which is linked by a double bond to the adjacent methine group, Z.sup..sym. is a positively charged radical which is mesomeric to Z.sub.1 and is linked by a single bond to the adjacent methine group, Z.sub.2 --is a nitrogen-heterocyclic radical which has its single positive charge on the nitrogen atom and Z.sub.3 .dbd. is a radical which has no charge on the nitrogen atom and is mesomeric to Z.sub.2, at least one of the radicals Z.sub.

Abstract: The definition of a photographic emulsion of the positive acting type that would normally produce a positive image is improved by normally exposing the emulsion to actinic radiation and developing the photographic emulsion, bleaching it, exposing the emulsion again to actinic radiation and redeveloping it to reverse the image that would normally result on the film.

Abstract: Silver halide emulsions are disclosed containing silver halide grains capable of forming an internal latent image. Incorporated in the emulsions is a diphenylmethane nucleating agent, thereby permitting a direct-positive image to be formed on imagewise exposure and photographic processing.

Abstract: Direct-positive photographic material which has at least one layer which contains a silver halide emulsion surface-fogged by chemical means or by exposure and, as a sensitizer, a trinuclear tetramethinecyanine dye in which all or some of the methine hydrogen atoms have been replaced by fluorine, chlorine, bromine or iodine atoms. The novel trinuclear tetramethinecyanine dyes impart an excellent blue-sensitivity to the photographic materials. Furthermore, high maximum densities and very low minimum densities are achieved.

Abstract: Direct positive silver halide emulsions are provided which contain fogged silver halide grains the said grains being heterodisperse and containing silver iodide in an amount of more than 10 mole % and at most 20 mole % relative to the total amount of silver halide. The emulsions have increased sensitivity and reduced gradation which is suitable for continuous tone reproduction.

Abstract: Direct-positive silver halide photographic sensitive materials of high sensitivity and capable of forming a high-contrast image are obtained by incorporating anion-type cyanine dyes having a polarographic oxidation halfwave potential not less positive than +0.4 V in externally fogged direct-positive silver halide emulsions containing not less than 70 mole-% of bromide. Additional incorporation of a development accelerator such as 2-mercaptoimidazoline improves developability.

Abstract: A process is disclosed of forming in a silver halide photographic element a visible image corresponding to a pattern of ultrasonic exposure. This process is characterized by providing in the photographic element internally fogged silver halide grains and contacting the element with a transport liquid in the presence of a solute capable of rendering the internally fogged silver halide grains developable in a surface developer. The element is then imagewise ultrasonically exposed and developed with a surface developer to produce a visible image defined by the pattern of ultrasonic exposure.