Minolta Company, Ltd.

Minolta Camera Kabushiki Kaisha

Tamotsu Sakuraba

Akihiro Kawasaki

Shinichi Takemoto

Koji Uno

Tateki Oka

Tetsumaru Fujita

Hirofumi Hasegawa

Hiroshi Goto

Hitoshi Saito

Hirokatsu Shimada

Kazuyoshi Hara

Yasuo Tanaka

Hiroyuki Maeda

Masami Eda

Masataka Yagi

Hiroshi Toda

Hirofumi Hasagawa

The inventive developing apparatus 10 includes: a developing roller 15 rotating in a predetermined direction; a regulating blade 16 for regulating layer thickness of developer G1 on the developer roller; 15; and a supplying roller 17 disposed at the upper stream than the regulating blade 16 while the developing apparatus 10 rotates in the predetermined direction. Further, the developing apparatus 10 rotates the developing roller 15 in the reverse direction for the predetermined direction during a predetermined period. Thereby, agglomerates stopping at the space between the developing roller 15 and the regulating blade 16 escape therefrom and developer leak and defective supply of developer and the like are cleared away. While the developing roller 15 is rotated in the reverse direction, the agglomerates escaped from the space come to contact with the supplying roller 17 and are crashed by press of the developing roller 15 and the supplying roller 17. As a result, agglomerates escaped from the space between the regulating blade 16 and the developing roller 15 is prevented from stopping therebetween again and accumulating in developer.

Developing apparatus having a contact roller, an image forming apparatus

Cleaning effectiveness is improved, and inadequate charging of the photosensitive member due to soiling of the charging brush as well as image noise such as background fog are suppressed by a developing device capable of recovering residual toner regardless of the toner charge polarity. In an image forming apparatus provided with a developing device including a developing sleeve for developing an electrostatic latent image on photosensitive member via toner and recovering residual toner from the surface of photosensitive member, a power unit is provided for forming a direct current electric field between photosensitive member and developing sleeve during developing, and forming alternating current electric fields between photosensitive member and developing sleeve 16 during cleaning of residual toners.

Image forming apparatus with developing recovery device

Developer material remaining on an image bearing member after transfer are collected by a developer. A cleaning member is arranged between a charger and an exposure in contact with the image bearing member, for collecting the residual developer material. A bias controller controls biases to be applied to a cleaner, a charger, and a developer. During an image forming process, the biases are so determined that the residual toner on the image bearing member is collected by the cleaner. While the image forming process is not performed, the biases are so determined that the collected toner is removed from the cleaner to the image bearing member and then collected by the developer.

Image forming apparatus

A voltage that has a difference in potential in the polarity direction opposite to the charge of the developer relative to the voltage applied to the sleeve by power supply 34 is applied to the control member by power supply 36. By this use of power supply 36, when the amount of remaining developer has fallen to a prescribed level, the conveyance of the developer to the photosensitive member by the sleeve is prevented, preventing image formation. Therefore, the image formation operation does not continue where the amount of remaining developer is small, which in turn eliminates the scattering of developer and maintains the cleanliness of the interior of the apparatus.

Developing device having means for preventing toner scattering

In a charging device used in a cleanerless image forming apparatus and including a charging brush in contact with an image bearing member, a scraping member is provided which is in contact with the charging brush with a predetermined amount of indentation overlap on an upstream side of a contact portion between the charging brush and the image bearing member with respect to a rotational direction of the charging brush. With such an arrangement, the developer, which is scraped from the charging brush by the scraping member and then adheres onto the image bearing member, is recharged by the charging brush so as to be collected by a developing-cleaning device.

Charging device

An image forming apparatus which is provided with a developing device having a rotatable developing member opposite to a rotatable photoreceptor at a developing region for transporting a developer to bring the developer into contact with the photoreceptor at the developing region, and a paper particle removing member provided at a downstream side from the developing region with respect to a rotational direction of the developing member for removing paper particles from the developer held on the developing member.

Developing device in an image forming apparatus for removing particulate

A developing device for use in an image forming apparatus like a copying machine or printer that develops an electrostatic latent image formed on an electrostatic latent image carrier to obtain a visible image. In the developing device, a toner charge erasing member contacts with the surface of a developing agent carrier and is connected to a power supply which applies developing bias voltage, so that a toner charge erasing bias voltage is applied to the toner charge erasing member from the power supply. A connection circuit provided between the toner charge erasing member and the power supply to maintain a constant electric potential difference between the developing bias voltage and the toner charge erasing bias voltage.

Developing device having biasing circuit for charge erasing member

An image forming apparatus having a developing device which develops an electrostatic latent image formed on an electrostatic latent image carrier to obtain a visible image. The developing device includes a charge erasing member that erases the electrical charge of residual toner on a developing agent carrier by a charge erasing bias voltage applied thereto. When exposure or not developing is not performed in the image forming apparatus, the charge erasing bias voltage is applied to the charge erasing member. While, during exposure or developing, the charge erasing bias voltage is not applied to the charge erasing member for preventing leaks or discharge phenomenon between the charge erasing member and the developing agent carrier.

Image forming apparatus with residual toner removal

An one-component developing device includes an electrically conductive member which is located in a region extending from a position downstream, with respect to a moving direction of a surface of a toner carrying member, to a developing region, and is in contact with the surface of the toner carrying member. A surface of the electrically conductive member contacting the developing sleeve is formed of material, of which charge polarity is shifted to the same polarity side as a regular charge polarity of the toner in view of charge series, and which contains highly conductive material dispersed therein.

One-component developing device with system for removing surplus toner

An image forming apparatus accommodates a developing bias power unit for applying a bias voltage to a developing sleeve confronting a photosensitive member. The developing bias power unit includes a DC power source, an electricity storage element interposed between the DC power source and the developing sleeve, and a controller for on-off controlling the DC power source. When an output of the DC power source is activated, the electricity storage element is electrically charged by an output voltage of the DC power source, and a first voltage is applied to the developing sleeve. In contrast, when the output of the DC power source is deactivated, a second voltage of reverse polarity is applied to the developing sleeve by electric charge held in the electricity storage element.

Growing community of inventors

Toyokawa, Japan

Tamotsu Sakuraba