Abstract: In the present invention, a pigment is irradiated with a microwave so as to improve a surface thereof. Further, letting A be an area of a portion having hydrophilic groups on a surface of the pigment and B be an area of the other portion thereon, which are respectively found by measuring infrared spectrometers of the pigment, a ratio (A/B) is not less than 4. Water base ink according to the present invention is obtained by dispersing such a pigment in an aqueous medium.

Abstract: An ink-jet recording head (10) includes a plate (32,36) having a recess and a nozzle (38) fluidly communicated with the recess, a diaphragm (28) for covering the recess to form a cavity (34) with the plate for receiving an ink material (46), and an actuator (18) for vibrating to force the diaphragm to eject the ink material through the nozzle. Also, the diaphragm is pre-tensioned so that the diaphragm continues to deform elastically in response to vibrations of said actuator. Preferably, the diaphragm is pre-tensioned to have an elongation percentage of 0.15 to 3%.

Abstract: In a process for image formation, an electrostatic latent image is formed on a photosensitive member having an amorphous carbon layer as an outermost surface layer. The electrostatic latent image is developed with toner to form a toner image. The toner image is transferred to transfer paper of which pH-value according to JIS-P-8133 is in a range from 7.0 to 8.5.

Abstract: An image forming apparatus having a rotatable photosensitive member a charging device for charging a surface of the photosensitive member prior to forming an electrophotographic latent image and a power source for applying a charge voltage which includes at least AC component to the charging device. The charging device includes a rotatable brush member which is formed by implanting piles formed by brush fibers on a base member and provided in contact with the photosensitive member. The photosensitive member and charging device and power source are provided to satisfy the following condition:V.sub.D =K.vertline.f.sub.AC -f.sub.p .vertline.(0<K.ltoreq.3),wherein V.sub.D is a moving speed of the surface of said photosensitive member, K is a constant, f.sub.AC is frequency of the AC component and fp is a pile frequency which is represented by V.sub.B /d (V.sub.B is the moving speed of the base material and d is a pile pitch).

Abstract: A contact charging device which charges the surface of an electrostatic latent image carrying member rotating at a high speed by contacting a charging member to the surface of the image carrying member. The charging member has a conductive substrate, a conductive elastic layer superimposed over the conductive substrate and having a JIS-A hardness of 30.degree. or greater, and a conductive resin layer superimposed over the conductive elastic layer and having a 10% elongation load of not more than 700 gf on a 1 cm wide section.

Abstract: A charging device including a charging member which is in contact with or minutely spaced from a surface of a photosensitive member, device for applying a constant voltage to the charging member, and a controller for controlling the voltage applied to the charging member when a current flowing from the charging member to the surface of the photosensitive member exceeds a predetermined value.

Abstract: A contact charging device having a charging member including a rotatable support member and a plurality of flexible films. One end of each the films is attached to the support member, and a free end of each the films is in contact with surface of the charge-receiving member for charging the surface of a charge-receiving member.

Abstract: A charging device and method in which a charging member, for example, of a brush, plate, film or roller type, for charging a charge-receiving member is disposed at a predetermined distance from the charge-receiving member. The distance is adjusted at not greater than a discharge start distance when the discharge is started and is adjusted at greater than the discharge start distance and less than a discharge stop distance after the discharge is started. The discharge start distance is the distance at the start of discharge when two electrodes are in close proximity as a voltage is applied, and the discharge stop distance is the distance directly before a stable discharge stops when two electrodes are separated while in state of discharge.

Abstract: The present invention provides a photosensitive member composed of a photosensitive layer and a surface protective layer on an electrically substrate in this order, in which the surface protective layer comprises an amorphous carbon layer which has a specified ratio of absorptivity coefficients of infrared absorption peaks in infrared absorption spectrum.

Abstract: The present invention relates to an image forming apparatus having a rotatably disposed photosensitive member, a charger disposed in opposed relation to the surface of the photosensitive member for charging the surface of the photosensitive member, and a protection shutter disposed adjacent to the charger, the shutter having a protecting member which statically adheres to the surface of the photosensitive member to shield the surface of the photosensitive member from the charger.

Abstract: The present invention relates to a method for image formation in which an electrostatic latent image is formed on an image supporting member having a carbon-based high-hardness surface coating layer. The electrostatic latent image is developed with a toner which includes resin particles composed of at least a binder resin and a colorant, specific fine particles fixed on the surface of the resin particles and post-treatment fine particles mixed with the resin particles on the surface of which the fine particles are fixed. The fine particles prevent the post-treatment fine particles from being embedded in the resin particles. The developed toner image is then transferred onto a transfer member to form the image.

Abstract: An image forming apparatus provided with a contact charging device, in which an electrically conductive member contacts a surface of an electrostatic latent image carrier for charging the surface, wherein at least impurity atom selected from the group consisting of elements of Group IA, II, VI and VII of the periodic table is adhered to the electrically conductive member, and a total content of the impurity atom is in a range from 0.05 wt % to 0.45 wt% with respect to all atoms including the impurity atom and atoms forming the electrically conductive member.

Abstract: This invention provides an image forming apparatus comprising:a photosensitive member having an amorphous carbon layer on a surface thereof; anda developing device accommodating a toner for developing an electrostatic latent image formed on the surface of the photosensitive member, the toner including magnetic particles each of which has at least either of octahedron shape and irregular shape.

Abstract: A contact member for controlling an electrostatic state of a surface of a chargeable member includes electrically conductive base members, and flame retardant material included in the base members.

Abstract: An image forming apparatus includes electrostatic latent image carrier having a moving surface to be charged and contact charging device for selectively applying a first charging voltage and a second charging voltage to the surface to be charged, the second charging voltage having the same polarity as the first charging voltage and having an absolute value smaller than that of the first charging voltage, the first charging voltage being applied to an electrostatic latent image forming region of the surface to be charged, the first charging voltage being changed to the second charging voltage when a region confronting the contact charging device moves from the electrostatic latent image forming region to a non-image portion in accordance with movement of the surface to be charged.

Abstract: This invention relate to a production method of a photosensitive member having an organic photosensitive layer and a surface protective layer in this order on an electrically conductive substrate comprising;a first step of forming the organic photosensitive layer on the electrically conductive substrate,a second step of eliminating an outermost surface portion of the organic photosensitive layer, anda third step of forming the surface protective layer under vacuum conditions on the organic photosensitive layer.

Abstract: A photoreceptor for contact charging to be used in an electrophotographic process, which includes an electrically conductive base and a photosensitive layer formed on the base so as to be charged by contact charging, and is characterized in that even when pin holes or photosensitive layer lacking portions in the form of pin holes are present on he photosensitive layer, short-circuiting is safely and positively prevented over a long period. The electrically conductive base further includes a base main body of aluminum alloy having Brinell hardness higher than 40 H.sub.B, and an alumite treatment applied over the surface of the aluminum alloy base main body.

Abstract: The present invention relates to a photosensitive member comprising:an electrically conductive substrate,an organic photosensitive layer formed on or over the electrically conductive substrate, the organic photosensitive layer comprising an antioxidant and/or a charge transporting material, anda surface protective layer formed on the organic photosensitive member,characterized by that the antioxidant and/or the charge transporting material is (are) contained in a more increased quantity with being closer to the interface between the surface protective layer and the organic photosensitive layer.

Abstract: An image forming apparatus having a detachable imaging cartridge which includes a photosensitive member charged by a charge brush having brush fibers. At least one of the photosensitive member and the charging brush is detachable from the imaging cartridge, and the detachable one is attached to the imaging cartridge through a guide member so that the brush fibers of the charge brush are indented toward a downstream side relative to a predetermined position of the charge brush with respect to the rotational direction of the photosensitive member.

Abstract: A contact charger for charging an image bearing member includes a support member, a flexible film supported by the support member and having a free end adapted to contact the surface of the image bearing member, and a power device for applying a charging voltage to the flexible film wherein the flexible film has an electrically conductive substrate layer and an electrically insulated overcoat layer superposed onto the substrate layer.