Minolta Camera Kabushiki Kaisha

Yoshihiro Ozaki

Kuniki Seino

Yasukuni Omata

Shoji Kondo

Shuichiro Kaneko

Masayuki Kuniyoshi

Kenjiro Ishii

Takao Saijo

Takanobu Ishido

The invention disclosed concerns a method and an apparatus for transferring a toner powder image from a toner image bearing member to a transfer paper by pressure. In transferring the toner image, a pressure roller is placed in contact with the surface of the toner image bearing member under a pressure of at least 20 kg/cm.sup.2 and sliding is produced between the toner image bearing member and the transfer paper. Two different methods can be used to produce the sliding. The first method is to rotate the pressure roller at a speed different from the rotating speed of the toner image bearing member and the second method is to rotate the pressure roller so disposed to intersect its rotating axis with the rotating axis of the toner image member at an angle of about 0.5.degree. to 2.degree..

Method of transferring toner powder image by pressure and apparatus

A residual charge erasing step in the electrophotographic process in which a transparent conductor backed photoconductor layer positioned in virtual contact with a conductor backed dielectric layer is exposed to a light image while a first voltage is applied between the conductors to produce on the dielectric layer an electrostatic latent image, the erasing step which is applied after the transfer of the latent image includes positioning the photoconductor and dielectric layers in virtual contact, illuminating the full surface of the photoconductor layer and applying between the conductors a second voltage of a polarity opposite to the first voltage and whose value is

Electrophotographic copying method with residual charge erasing step

An electrophotographic copying method in which there are employed a photosensitive member including a photoconductor layer backed by a conductive electrode and a dielectric layer backed by a conductive electrode comprises the steps of positioning the members with the layers in face-to-face virtual contact and while so positioned applying a voltage of a first polarity between the electrodes under dark conditions to cause gaseous discharges in the gaps between the layers and the charging of the dielectric layer and short circuiting the electrodes while illuminating the photoconductive layer until the electric field therein is zero, and then applying a voltage of reverse polarity between the electrodes while exposing the photoconducted layer to a light image to produce an electrostatic latent image thereof on the dielectric layer which is then separated from the photoconductor layer and the latent image developed and transferred to copy paper. Follower transfer of the developed image the dielectric layer is cleaned of residual toner and residual charges are removed by repositioning the dielectric layer in virtual contact with the photoconductor layer and alternately applying voltages of opposite polarities between the electrodes while illuminating the photoconductor layer. Equations setting forth the values of the applied voltages are given.

Electrophotographic image forming method

A method of producing an electrostatic latent image of an original includes the successive steps of positioning of face-to-face virtual contact a photoconductor layer superimposed on a conductive backing electrode and a dielectric layer superimposed on another conductive backing electrode, applying a direct current voltage of a first polarity between the electrodes of a value to produce gas discharges between the layers to charge the dielectric layer while the photoconductor layer is unexposed to any light, short circuiting the electrodes while exposing the full surface of the photoconductor layer to light until the electric field across the photoconductor layer is substantially zero and applying a voltage between the electrodes at a polarity opposite to the first polarity while exposing the photoconductor layer to the light image of an original. The dielectric layer may be a coating on a conductive copy paper or may be a driven endless conductive belt along which are located an image developing device, an image transfer device and a device for erasing residual toner and charges from the belt dielectric layer.

Method for forming an electrostatic latent image

A process for manufacturing a dielectric member from aluminum or aluminum alloy which includes the steps of subjecting the aluminum or aluminum alloy to anodic oxidation in a nonaqueous electrolytic solution containing an organic solvent and dehydrated boric acid to form an oxide layer thereon, and buffing the oxide layer with a composition containing insulative abrasive grains and insulative binding material.

Process for manufacturing dielectric member

In an electrophotographic copying apparatus of a type in which an electrostatic latent image of an original to be copied is formed, through suitable illumination means, on a dielectric surface of a transfer material or copy paper held under pressure between a photoreceptor plate and an electrically conductive pressure pad on a pressing plate during impression of a potential across the photoreceptor plate and the pressure pad, there are incorporated an improved pressing device for pressing the copy paper against the photoreceptor plate, and a fixing device having uniform heat radiation and operated through a special fixing temperature control circuit.

Growing community of inventors

Isehara, Japan

Yoshihiro Ozaki