Abstract: The disclosure provides an electrophotographic photoreceptor and an electrophotographic imaging apparatus including the photoreceptor, wherein the electrophotographic photoreceptor comprises: a conductive substrate; a charge generating layer formed on the conductive substrate; a charge transport layer formed on the charge generating layer; and an overcoat layer formed on the charge transport layer, wherein the ratio (R2/R1) of the surface resistance value (R2) of the overcoat layer to the surface resistance value (R1) of the charge transport layer is from about 0.01 to about 1.5.

Abstract: An electrophotographic photoreceptor including a photosensitive layer which includes a titanyl phthalocyanine crystal having a major absorption peak at a wavelength of 780 nm±10 nm and a minor absorption peak having an intensity of ¾ or less of the major absorption peak at 690 nm±10 nm in the visible-infrared absorption spectrum and a distyryl compound having a predetermined structure. An electrophotographic image forming apparatus employing the electrophotographic photoreceptor is also provided. The electrophotographic photoreceptor and the electrophotographic image forming apparatus have good photosensitivity and charging properties and good stability over repeated charging obtained by using an optimum combination of a new crystal type of a highly photosensitive titanyl phthalocyanine and a distyryl compound which is a charge transporting material that is compatible with the titanyl phthalocyanine.

Abstract: An electrophotographic photoreceptor and an electrophotographic imaging apparatus include an asymmetric naphthalenetetracarboxylic acid diimide derivative. The asymmetric naphthalenetetracarboxylic acid diimide derivative has increased solubility in organic solvents and improved compatibility with binder resins, thus providing excellent electron transporting ability. The electrophotographic photoreceptor containing the asymmetric naphthalenetetracarboxylic acid diimide compound according to the present invention can maintain a constant surface potential after being repeatedly used for an extended time. The electrophotographic photoreceptor according to the present invention can provide a high image quality for an extended time.

Abstract: A two-layered electrophotographic photoreceptor is formed. The two-layered electrophotographic photoreceptor includes an electrically conductive substrate and a charge generating layer and a charge transporting layer form on the electrically conductive substrate, wherein the charge generating layer is a naphthalenetetracarboxylic acid diimide derivative represented by: The two-layered electrophotographic photoreceptor has high photosensitivity and low residual potential.

Abstract: An electrophotographic photoreceptor is provided containing a specific asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group. An electrophotographic imaging apparatus, an electrophotographic cartridge, and an electrophotographic drum employing the electrophotographic photoreceptor are also provided. The naphthalenetetracarboxylic acid diimide derivative has high solubility in an organic solvent, compatibility with a binder resin, and electron transporting ability. The electrophotographic photoreceptor manufactured using the naphthalenetetracarboxylic acid diimide derivatives has an excellent electrostatic property.

Abstract: An electrophotographic photoreceptor including: an electrically conductive substrate; a charge generating layer disposed on the electrically conductive substrate and includes a charge generating material dispersed or dissolved in a binder resin and an asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group dispersed or dissolved in the binder resin. The photoreceptor also has a charge transporting layer that is disposed on the charge generating layer and includes a charge transporting material that is dispersed or dissolved in the binder resin. An electrophotographic image forming apparatus including the electrophotographic photoreceptor. The two-layered type electrophotographic photoreceptor has good interlayer adhesive force and good electrical properties such as good photosensitivity and low residual potential after exposure.

Abstract: An electrophotographic photoreceptor containing a naphthalenetetracarboxylic acid diimide derivative of Formula (1), which has a branched alkyl group substituted with an aryl group at the ?-position with regard to nitrogen atoms of imide groups: wherein R1 and R2 are independently selected from the group consisting of a hydrogen atom, a halogen atom, a C1-C20 substituted or unsubstituted alkyl group, and a C1-C20 substituted or unsubstituted alkoxy group; R3 is selected from the group consisting of a C1-C20 substituted or unsubstituted alkyl group, a C1-C20 substituted or unsubstituted alkoxy group, a C7-C30 substituted or unsubstituted aralkyl group, and a group having the formula —(CH2)n—Y—R4; Ar is a C6-C30 substituted or unsubstituted aryl group; Y is an oxygen or sulfur atom; R4 is a hydrogen atom or a C1-C20 substituted or unsubstituted alkyl group; and n is an integer between 1 and 12.

Abstract: An electrophotographic photoreceptor includes a photosensitive layer including a charge generating material, a charge transporting material and a binder resin in a single layer, formed on an electrically conductive substrate. The single photosensitive layer includes an upper photosensitive layer portion and a lower photosensitive layer portion. The upper photosensitive layer portion has a higher concentration of the electron transporting material than that of the lower photosensitive layer portion. A method of preparing the electrophotographic photoreceptor, and an electrophotographic imaging apparatus employing the electrophotographic photoreceptor are provided. The single-layered type electrophotographic photoreceptor according to the present invention shows high sensitivity and excellent repetition stability of electrical properties, while still having advantages of a conventional single-layered photoreceptor, thereby being able to have highly practical applications.

Abstract: A composition for an overcoat layer suitable for use in an organophotoreceptor for liquid toner, an organophotoreceptor manufactured by employing the composition and an electrophotographic imaging apparatus containing the organophotoreceptor. Since the organophotoreceptor can maintain higher charge potential and low residual or discharge potential, the lifetime of the organophotoreceptor can be extended. Also, since the organophotoreceptor has good solvent resistance and abrasion resistance, it can be advantageously used for liquid toner.

Abstract: A photoconductor which can be effectively used in an electrophotographic image forming apparatus using a light source emitting short-wavelength light, and an electrophotographic image forming apparatus using the photoconductor. The photoconductor of the electrophotographic image forming apparatus using a short-wavelength light source includes a supporter and a photoconductive layer, which is formed on the supporter, wherein the photoconductive layer may include a naphthalenetetracarboxylic acid diimide derivative represented by the following Formula (I), in which, R1, R2, and R3 are each independently selected from the group consisting of a hydrogen atom, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, and a substituted or unsubstituted C7 to C30 aralkyl group.

Abstract: New compounds having an electron transferring capability, and an electrophotographic photoreceptor including the new compounds are disclosed. The compound according to the present invention is represented by the following Formula 2: where R1, R2 and R3 are independently selected from the group consisting of a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 aralkyl group, and a halogen; m is 0 or an integer of 1 to 4; and n is 0 or an integer of 1 to 5. These compounds can be used an electron transferring material of an undercoating layer or a photoconductive layer of an electrophotographic photoreceptor. The electron transferring material of the invention produces an electrophotographic photoreceptor having improved electrical characteristics.

Abstract: An organic photoreceptor and an electrophotographic image forming apparatus provided including the organic photoreceptor, wherein the organic photoreceptor has the shortage of a conventional single-layered type photoreceptor and has higher photosensitivity and good repetition stability. The photoreceptor has a photosensitive layer on an electrically conductive substrate where the photosensitive layer has an electron transporting material that increases in concentration toward the interface between the substrate and the photosensitive layer.

Abstract: An organic photoreceptor and an electrophotographic image forming apparatus employing the organic photoreceptor are provided, where the organic photoreceptor has high photosensitivity with respect to light radiation at short wavelengths and low exposure potential. Specifically, an organic photoreceptor for short wavelengths having a photosensitive layer including a naphthalene tetracarboxylic acid diimide derivative is formed on an electrically conductive substrate.

Abstract: A phenylazomethylene-cyclohexadienone derivative and an electrophotographic photoreceptor include a compound that is represented by the following formula: wherein R1 and R2 are independently selected from the group consisting of a substituted or unsubstituted alkyl group having 1 to 20 carbon atom(s), a substituted or unsubstituted alkoxy group having 1 to 20 carbon atom(s), a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, and a halogen; A is selected from the group consisting of nitro group, cyano group and sulfone group; l is a natural number of 0 to 4; m is a natural number of 0 to 4; and n is a natural number of 1 to 5, and the electrophotographic photoreceptor according to the present invention comprises the phenylazomethylene-cyclohexadienone derivative. An electrophotographic photoreceptor having an improved electrical characteristic and a desirable image quality is provided.

Abstract: Naphthalenetetracarboxylic acid diimide derivatives and an electrophotographic photoconductive material containing the naphthalenetetracarboxylic acid diimide derivatives. The naphthalenetetracarboxylic acid diimide derivatives have a structure represented by the following formula: in which, R1 and R2 are each independently selected from the group consisting of a substituted or non-substituted C1-C20 alkyl group; a substituted or non-substituted C1-C20 alkoxy group; a substituted or non-substituted C6-C30 aryl group; and a substituted or non-substituted C7-C30 aralkyl group; and halogen. The electrophotographic photoconductive material includes the naphthalenetetracarboxylic acid diimide derivatives as an electron transferring material.

Abstract: An electrophotographic photoreceptor including a photosensitive layer which includes a titanyl phthalocyanine crystal having a major absorption peak at a wavelength of 780 nm±10 nm and a minor absorption peak having an intensity of ¾ or less of the major absorption peak at 690 nm±10 nm in the visible-infrared absorption spectrum and a distyryl compound having a predetermined structure. An electrophotographic image forming apparatus employing the electrophotographic photoreceptor is also provided. The electrophotographic photoreceptor and the electrophotographic image forming apparatus have good photosensitivity and charging properties and good stability over repeated charging obtained by using an optimum combination of a new crystal type of a highly photosensitive titanyl phthalocyanine and a distyryl compound which is a charge transporting material that is compatible with the titanyl phthalocyanine.

Abstract: An electrophotographic photoreceptor includes a conductive substrate, a photoconductive layer formed on the conductive substrate containing a charge generating material and a charge transferring material, and a protective layer formed on the photoconductive layer for protecting the photoconductive layer. The protective layer contains an alcohol-soluble polyamide resin and an alcohol-soluble chelate compound. According to the present invention, the electrophotographic photoreceptor has the protective layer with chelate compound has improved adhesive properties to the photoconductive layer and improved the electrostatic characteristic and productivity.

Abstract: A titanyl phthalocyanine crystal has a major absorption peak at a wavelength of 780 nm±10 nm in the visible-infrared absorption spectrum and a minor absorption peak has an intensity of ¾ or less of the major absorption peak at 700 nm±10 nm. A method of manufacturing the crystal, an electrophotographic photoreceptor including the crystal as a charge generating material, and an electrophotographic image forming apparatus are also provided. The electrophotographic photoreceptor using the titanyl phthalocyanine crystal as the charge generating material has good sensitivity and a good residual current property and in addition, good stability.

Abstract: An electrophotographic photoreceptor including: an electrically conductive substrate; a charge generating layer disposed on the electrically conductive substrate and includes a charge generating material dispersed or dissolved in a binder resin and an asymmetric naphthalenetetracarboxylic acid diimide derivative having a nitro group dispersed or dissolved in the binder resin. The photoreceptor also has a charge transporting layer that is disposed on the charge generating layer and includes a charge transporting material that is dispersed or dissolved in the binder resin. An electrophotographic image forming apparatus including the electrophotographic photoreceptor. The two-layered type electrophotographic photoreceptor has good interlayer adhesive force and good electrical properties such as good photosensitivity and low residual potential after exposure.

Abstract: A composition for an overcoat layer suitable for use in an organophotoreceptor for liquid toner, an organophotoreceptor manufactured by employing the composition and an electrophotographic imaging apparatus containing the organophotoreceptor. Since the organophotoreceptor can maintain higher charge potential and low residual or discharge potential, the lifetime of the organophotoreceptor can be extended. Also, since the organophotoreceptor has good solvent resistance and abrasion resistance, it can be advantageously used for liquid toner.