The present invention relates to a single-layer type electrophotographic photoreceptor for positive charging, comprising: a conductive support; and a photosensitive layer disposed on the conductive support and comprising a binder resin, a charge generation material, a hole transport material and a specific electron transport material within the same layer, wherein the photosensitive layer contains a specific aromatic compound.

The electrophotographic apparatus includes: an electrophotographic photosensitive member; a charging unit; an image-exposing unit; a charge transfer amount-sensing unit for sensing the amount of charge transferred to the electrophotographic photosensitive member; and an exposed portion potential-controlling unit for controlling the potential of each of the exposed portions of the electrophotographic photosensitive member based on a sensing result, which is obtained by charging the electrophotographic photosensitive member with the charging unit, performing image exposure with the image-exposing unit in at least one light amount weaker than a light amount in which the normalized radius of curvature R of the electrophotographic photosensitive member represented by the following equation (E1), the normalized radius of curvature being obtained by a method of measuring an EV curve, shows a minimum, and in at least two light amounts stronger than the light amount in which the normalized radius of curvature shows the minimum.

[00001]$\begin{array}{cc}R=\frac{{\left[1+{\left(\frac{\mathrm{dy}}{\mathrm{dx}}\right)}^2\right]}^{3/2}}{.Math.\frac{d^2}{{\mathrm{dx}}^2}.Math.}& \left(E1\right)\end{array}$

A spray gun, which contains: a coating liquid nozzle configured to discharge a coating liquid from an outlet; and a flow channel forming member configured to surround an outer perimeter surface of the coating liquid nozzle to form an air flow channel, through which atomizing air passes, between the outer perimeter surface of the coating liquid nozzle and the flow channel forming member, wherein the spray gun is configured to atomize the coating liquid with the atomizing air to spray the atomized coating liquid to a coating target, wherein a gap T of the narrowest part of the air flow channel is 0.48 mm or smaller, and wherein a ratio T/L of the gap T to a distance L from the narrowest part to an apical surface at which the outlet of the coating liquid nozzle is open is 0.60 or greater.

A spray gun, which contains: a coating liquid nozzle configured to discharge a coating liquid from an outlet; and a flow channel forming member configured to surround an outer perimeter surface of the coating liquid nozzle to form an air flow channel, through which atomizing air passes, between the outer perimeter surface of the coating liquid nozzle and the flow channel forming member, wherein the spray gun is configured to atomize the coating liquid with the atomizing air to spray the atomized coating liquid to a coating target, wherein a gap T of the narrowest part of the air flow channel is 0.48 mm or smaller, and wherein a ratio T/L of the gap T to a distance L from the narrowest part to an apical surface at which the outlet of the coating liquid nozzle is open is 0.60 or greater.

An image forming apparatus includes: an electrophotographic photoreceptor that includes an electroconductive substrate, an undercoat layer which is provided on the electroconductive substrate and has electrostatic capacitance per unit area of from 2.5×10.sup.−11 F/cm.sup.2 to 2.5×10.sup.−10 F/cm.sup.2, and a photosensitive layer provided on the undercoat layer; a charging unit; an electrostatic latent image forming unit; a developing unit; an intermediate transfer member; a primary transfer unit that primarily transfers the toner image formed on the surface of the electrophotographic photoreceptor, onto the surface of an intermediate transfer member, while providing a primary transfer current value of from 80 μA to 160 μA; and a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member, onto a surface of a recording medium.

An image forming apparatus includes: an electrophotographic photoreceptor that includes an electroconductive substrate, an undercoat layer which is provided on the electroconductive substrate and has electrostatic capacitance per unit area of from 2.5×10.sup.−11 F/cm.sup.2 to 2.5×10.sup.−10 F/cm.sup.2, and a photosensitive layer provided on the undercoat layer; a charging unit; an electrostatic latent image forming unit; a developing unit; an intermediate transfer member; a primary transfer unit that primarily transfers the toner image formed on the surface of the electrophotographic photoreceptor, onto the surface of an intermediate transfer member, while providing a primary transfer current value of from 80 μA to 160 μA; and a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member, onto a surface of a recording medium.

In a positively chargeable single-layer electrophotographic photosensitive member, a photosensitive layer contains at least a hole transport material, and particles of a first resin. A compound represented by general formula (1) is contained as the hole transport material. In the general formula (1), R.sub.1 represents an alkyl group having a carbon number of at least 2 and no greater than 4. R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 each represent, independently of one another, a hydrogen atom or an alkyl group having a carbon number of at least 1 and no greater than 4. Ar.sub.1 and Ar.sub.2 each represent, independently of each other, a hydrogen atom or an optionally substituted aryl group having a carbon number of at least 6 and no greater than 20. At least one of Ar.sub.1 and Ar.sub.2 represents an optionally substituted aryl group having a carbon number of at least 6 and no greater than 20. ##STR00001##

An electrophotographic photoreceptor includes a conductive substrate and a single-layer photosensitive layer on the conductive substrate. The photosensitive layer includes a binder resin, at least one selected from a hydroxygallium phthalocyanine pigment and a chlorogallium phthalocyanine pigment, a hole transporting material, and an electron transporting material and has a Martens hardness Hm of 170 N/mm.sup.2 or more and 200 N/mm.sup.2 or less.

Techniques, systems, and devices are disclosed for implementing a photoconductive device performing bulk conduction. In one exemplary aspect, a photoconductive device is disclosed. The device includes a light source configured to emit light; a crystalline material positioned to receive the light from the light source, wherein the crystalline material is doped with a dopant that forms a mid-gap state within a bandgap of the crystalline material to control a recombination time of the crystalline material; a first electrode coupled to the crystalline material to provide a first electrical contact for the crystalline material, and a second electrode coupled to the crystalline material to provide a second electrical contact for the crystalline material, wherein the first and the second electrodes are configured to establish an electric field across the crystalline material, and the crystalline material is configured to exhibit a substantially linear transconductance in response to receiving the light.

Techniques, systems, and devices are disclosed for implementing a photoconductive device performing bulk conduction. In one exemplary aspect, a photoconductive device is disclosed. The device includes a light source configured to emit light; a crystalline material positioned to receive the light from the light source, wherein the crystalline material is doped with a dopant that forms a mid-gap state within a bandgap of the crystalline material to control a recombination time of the crystalline material; a first electrode coupled to the crystalline material to provide a first electrical contact for the crystalline material, and a second electrode coupled to the crystalline material to provide a second electrical contact for the crystalline material, wherein the first and the second electrodes are configured to establish an electric field across the crystalline material, and the crystalline material is configured to exhibit a substantially linear transconductance in response to receiving the light.