摘要:
An image forming apparatus having a developing device of the type using a two-component type developer and developing an electrostatic latent image by a bias electric field having an alternating electric field. A predetermined reference latent image is electrostatically formed on an image carrier by a reference latent image forming device and then developed by the developing device to become a reference toner image. An irregularity detecting circuit determines the degree of difference between the density of the edge and the density of the central portion of the reference toner image. A bias electric field control circuit controls the bias electric field in matching relation to the output of the irregularity detecting circuit, thereby preventing the image quality from being degraded by a change in the resistance of the carrier.
摘要:
Image forming equipment having an image carrier and a developer carrier located face-to-face and forming an AC-superposed DC electric field between them to develop a latent image electrostatically formed on the image carrier. Sensors responsive to image forming conditions are provided and protected from noise ascribable to an AC component included in the electric field in the event when the sensors operate.
摘要:
A developing system of the type using a two-component developer and capable of reproducing image densities and halftone images stably with no regard to changes in ambient conditions and aging. At least two toner image patterns each having a different toner density are formed on a photoconductive element. The amounts of toner deposited on the individual patterns are sensed by a photosensor, while the supply of toner to a developer and the dynamic range of a latent image are controlled in combination in response to the output of the photosensor.
摘要:
A developing device for image forming equipment capable of agitating and mixing a fresh toner and a developer sufficiently is disclosed. The device eliminates a change in image density among individual copies, irregularity in density corresponding to the spiral pitch of, for example, a toner transport screw, and irregularity in density in the front-and-rear direction (axial direction of a developing sleeve) ascribable to defective agitation. To replace or clean a desire part or parts built in a developing device, the device is divided into two such that the desired parts are freely accessible. This facilitates the cleaning and replacement of such parts.
摘要:
Color image forming equipment capable of immediately responding to a sharp change in environment and producing stable images over a long period of time. An information value relating to the amount of toner deposition on a photoconductive element which changes with a change in environment and effects the formation of an image with a reference value which defines a first and a second environment. Variable dynamic range control devices each being optimal for respective one of the first and second environments are selectively used on the basis of the result of the above comparison.
摘要:
An image forming method and an apparatus therefor applicable to a color copier. A signal value representative of a reflection and appearing when the output of a photosensor is minimum in response to a change in the amount of toner deposition on a photoconductive element is detected. This maintains the density of a predetermined reference pattern used to sense an image density constant despite the change in, for example, the reflection characteristic of the photoconductive element. A bias for development is so changed as to maintain the output of the photosensor constant, so that the effective bias remains constant relative to the charge potential on the photoconductive element.
摘要:
An image forming apparatus has a photoconductive element, a developing sleeve, a photosensor and a control device for controlling the dynamic range of an image. A background output VSG is produced from the photosensor when the photoconductive element is rotating and the developing sleeve is rotating and a background output VSG+ is produced from the photosensor when the photoconductive element is rotating and the developing sleeve is not rotating. The control device controls a developing bias, a charge potential, a quantity of exposing light or an amount of toner supply in response to the greater of the two values VSG or VSG+. Also, the gradient of the background output VSG is determined and is used to decide whether the image forming apparatus is in an unusual state or not.
摘要:
An image forming device includes a plurality of developing devices and a photosensitive drum. Each of the developing devices includes a developer carrying roller. One of the developing devices is moved to a developing position confronting the photosensitive drum which is formed with a latent image. A first developing bias including a d.c. component and an a.c. component is applied to the developer carrying roller and developer on the developer carrying roller is rendered in contact with the latent image on the photosensitive drum so that the latent image is developed. On the other hand, when the developer on the developer carrying roller comes in contact with and separates from the photosensitive drum due to the movement of the developing device, a second developing bias is applied to the developer carrying roller. The second developing bias generates an electric field where the developer on the developer carrying roller is more reluctant to move toward the photosensitive drum as compared with the first developing bias. The second developing bias may include only a d.c. component.
摘要:
An apparatus for forming an image includes a photosensitive body, an optical write unit which scans a light beam along a main scan path on a photosensitive body to create a latent image thereon, the light beam having power levels corresponding to multi-level image data, and a shading correction unit which corrects shading along the main scan path by making adjustment to the multi-level image data along the main scan path, and changes the adjustment on a condition-specific basis.
摘要:
A two-component developer including toner and magnetic carriers is provided. The two-component developer is characterized in that when a development device including a developer bearing member bearing the two-component developer is operated under a development condition of an image forming apparatus using a quasi-photoconductor in which a 10 μm thick layer of tetrafluoroethylene resin is provided to a conductive material, the number of times of light emission occurring in a magnetic brush formed on the developer bearing member due to partial conduction in the magnetic brush is 10 times or less per second at an observation cross section that is perpendicular relative to a rotation axis of the developer bearing member.