Abstract:
PROBLEM TO BE SOLVED: To provide a positively-charged single-layer type electrophotographic photoreceptor that has excellent abrasion resistance and electric characteristics, and an image forming apparatus that includes the positively-charged single-layer type electrophotographic photoreceptor as an image carrier.SOLUTION: A positively-charged single-layer type electrophotographic photoreceptor has a single-layer structured photosensitive layer formed on a conductive substrate, the photosensitive layer including a charge generating material, a charge transport material, a filler, and a binder resin, and is used as an image carrier in an image forming apparatus that includes a charging unit employing a contact charging method. The photosensitive layer contains the filler including one or more types of fine particles having the volume average particle diameter within a predetermined range and selected from the group consisting of silica fine particles and resin fine particles.
Abstract:
PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor capable of suppressing transfer memory while suppressing the occurrence of black dots, and an image forming apparatus that suppresses the occurrence of transfer memory and is capable of forming suitable images.SOLUTION: An electrophotographic photoreceptor is formed by providing a photosensitive layer directly on a conductive substrate comprising oxidation-treated aluminum or an aluminum alloy. On the surface of the conductive substrate, a resistive layer is formed, which has field intensity in a range of 1.67×10to 3.33×10V/cm and volume resistivity (x) in a range of 2.38×10to 3.01×10Ωcm that are measured by a predetermined measuring method (X).
Abstract:
PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor including a single-layered photosensitive layer capable of suppressing the occurrence of black spots and image defects due to a memory effect even when the photosensitive layer has a small thickness, and to provide an image forming apparatus including the electrophotographic photoreceptor as an image carrier.SOLUTION: In an electrophotographic photoreceptor, a specific polycarbonate resin is used in the amount of at least 30 mass% or more as a binder resin used in a single-layered photosensitive layer; and a phthalocyanine pigment is used as a charge generating material in the photosensitive layer, and a charge transport material is included in the photosensitive layer in the amount within a specific range.
Abstract:
PROBLEM TO BE SOLVED: To provide a positively-charged single-layered electrophotographic photoreceptor capable of suppressing the occurrence of a transfer memory even when applied to a high-speed process, and an image forming apparatus using the same.SOLUTION: A positively-charged single-layered electrophotographic photoreceptor includes a photosensitive layer containing at least a charge generating material, an electron transport material, a hole transport material, and a binder resin in a single layer on a conductive base material. The charge generating material contains a phthalocyanine pigment; the content of the electron transport material to the binder resin is 45 to 100 mass%; and when the photoreceptor is charged at +800 V, then charged at -800 V, and exposed at both voltages under conditions of an exposure wavelength of 780 nm, and exposure energy to make a bright potential at 150 V after the lapse of 300 ms after the exposure, a difference between the absolute values of both bright potentials is 150 V or less.
Abstract:
PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that includes a thin photosensitive layer having high sensitivity and excellent light resistance, and an image forming apparatus that includes the electrophotographic photoreceptor as an image carrier.SOLUTION: An electrophotographic photoreceptor includes, on a supporting substrate, a photosensitive layer in a thickness of 25 μm or less formed at least of a charge generating material, a charge transport material, and a binder resin. The charge generating material is a phthalocyanine pigment; and the charge transport material does not have the maximum absorption peak between 450 nm to 550 nm, and contains at least one type of specific compound as an electron transport material for the charge transport material.
Abstract:
PROBLEM TO BE SOLVED: To provide a single-layered electrophotographic photoreceptor capable of suppressing the occurrence of an exposure memory and black dots to provide good images even when used in a high-speed process, and an image forming apparatus using the same.SOLUTION: An electrophotographic photoreceptor includes a photosensitive layer containing at least a charge generating material, an electron transport material, a hole transport material, and a binder resin in a single layer on a conductive base material. The photosensitive layer has a thickness of 10 to 40 μm; the charge generating material contains an oxotitanyl phthalocyanine pigment; the hole transport material is contained in the amount of 50 to 120 parts by mass, and the electron transport material is contained in the amount of 55 to 80 parts by mass, relative to 100 parts by mass of the binder resin; and the binder resin includes a polycarbonate resin containing 15 to 60 mass% of specific repeating unit.
Abstract:
PROBLEM TO BE SOLVED: To provide a single-layered electrophotographic photoreceptor capable of suppressing the occurrence of an exposure memory to provide good images even when used in a high-speed process, and an image forming apparatus using the same.SOLUTION: A single-layered electrophotographic photoreceptor includes a photosensitive layer containing at least a charge generating material, an electron transport material, a hole transport material, and a binder resin in a single layer on a conductive base material. The charge generating material contains a phthalocyanine pigment, and an N-type pigment containing at least a perylene pigment and an azo pigment; and the total amount of the N-type pigment is 0.03 parts by mass or more and 10 parts by mass or less relative to 1 part by mass of the phthalocyanine pigment.
Abstract:
PROBLEM TO BE SOLVED: To provide a positively-charged electrophotographic photoreceptor having higher sensitivity than a conventional positively-charged single-layer electrophotographic photoreceptor, and to provide an image forming apparatus including the positively-charged electrophotographic photoreceptor as an image carrier.SOLUTION: On a conductive substrate, a charge transport layer containing a hole transport material, an electron transport material, and a binder resin, and a charge generating/transport layer containing a charge generating material, a hole transport material, an electron transport material, and a binder resin are laminated in order. The amount of electron transport material contained in the charge transport layer falls within a predetermined range.
Abstract:
PROBLEM TO BE SOLVED: To provide a positively-charged photoreceptor more highly sensitive than a conventional single-layered electrophotographic photoreceptor; and to provide an image forming apparatus including the positively-charged photoreceptor as an image carrier.SOLUTION: A positively-charged electrophotographic photoreceptor is formed by laminating (I) a charge transport layer comprising at least a hole transport material and a binder resin, and (II) a charge generating and transport layer containing at least a charge generating material, an electron transport material, a hole transport material, and a binder resin in a single layer, at least in this order on a conductive substrate. The binder resins in the charge transport layer and the charge generating and transport layer are different from each other, and either one of the binder resins contains a polyvinyl acetal resin.
Abstract:
PROBLEM TO BE SOLVED: To provide a positively-charged electrophotographic photoreceptor more highly sensitive than a conventional positively-charged single-layered electrophotographic photoreceptor; and to provide an image forming apparatus including the positively-charged electrophotographic photoreceptor as an image carrier.SOLUTION: A charge transport layer containing a hole transport material and a binder resin, and a charge generating and transport layer containing a charge generating material, a hole transport material, an electron transport material, and a binder resin, are sequentially laminated on a conductive substrate, so as to form a laminated photosensitive layer; and the charge transport layer includes a polyarylate resin as the binder resin.