Kabushiki Kaisha Toshiba

Takashi Shimazaki

Mitsuaki Kohyama

Kunihiko Miura

Koji Imamiya

Toshihiro Kasai

Hideo Mukai

Goro Oda

Haruhiko Ishida

Toshiro Honda

Kenichi Tsuneeda

Seiichiro Fushimi

Niro Nagata

Minoru Tezuka

A device for developing a latent image on an image bearing member includes a developing roller, rotatably mounted facing the image bearing member, for transferring a developing agent to the image bearing member, and a supply roller, rotatably mounted adjacent to the developing roller, for supplying the developing agent to the developing roller at a supplying portion. The developing agent is stored in the storing member and is provided to the supply roller upstream of the supplying portion with respect to a rotating direction of the supply roller. A disordering member, mounted downstream of the supplying portion with respect to the rotating direction of the supply roller, disorders the developing agent on the surface of the supply roller to prevent the developing agent from causing hardening of the supply roller.

Developing device having disordering member in contact with supply roller

In an image forming apparatus has a photosensitive drum, the drum is charged by a main charger. A light beam bearing image information is applied to the drum by an exposure system to form a latent image on the surface of the drum. The latent image is developed by a developing unit, using a toner to form a toner image on the drum surface. The toner image is transfered to the surface of a paper sheet by a transfer charger. The developing unit serves to remove, simultaneously with the development of the latent image, the toner remaining on the drum surface after the transfer by the transfer charger. Before the removing of the remaining toner, the drum is in sliding contact with a brush member. The remaining toner is temporarily attracted to the brush member by the bias voltage applied to the brush member, with the result that the remaining toner becomes easy to separate from the drum. In the apparatus, the drum and at least the brush member are integrated as one process unit. The process unit is removably insertable into a predetermined operative position in the body of the apparatus. Accordingly, when the drum is removed from the operative position, the toner attracted to the brush member is prevented from scattering in the body by removing the brush member with the drum.

Image forming apparatus having distribution brush and image carrier

An image forming apparatus according to the present invention comprises a photosensitive drum which is characterized by a charge generating layer and a charge transport layer. The drum is charged by means of a main charger. At this time, electric charge is produced and held in the charge generating layer. A light-beam bearing image information is applied to the charge generating layer of the drum through the charge transmission layer, by an exposure system. Thereupon, an electrostatic latent image corresponding to the image information is formed on the surface of the drum. The latent image is developed by means of a developing unit using a toner. Thus, a toner image is formed on the drum surface, from which it is transferred to the surface of a paper sheet by a transfer charger. The developing unit also serves to remove, simultaneously with the development of the electrostatic latent image, those toner particles remaining on the drum surface after the transfer by the transfer charger. The image forming apparatus is particularly characterized in that the light beam, applied by the exposure system, is also guided through the charge transport layer of the photosensitive drum to those regions of the charge generating layer shaded by the residual toner particles, thereby preventing white spots from being formed on a solid black image.

Image forming apparatus using an image carrier with multiple layers

A microfilm reader printer has a reader unit which projects a microfilm image onto a screen and a printer unit which reproduces copies of the microfilm image. The printer unit includes an optical device for forming the electrostatic image on a photoreceptor by exposing the microfilm image onto the photoreceptor and a developing device for visualizing the electrostatic latent image formed on the photoreceptor. The developing device has a developing unit for achieving reversal development. The photoreceptor receives a uniformly recharging process by a recharging unit and an overall exposure by an exposure unit. Then, the developed image is removed and the latent image is reversely developed again by the developing unit. A positive copy may be reproduced from both positive and negative types of a microfilm by selectively operating the recharging unit, exposure unit and developing unit.

Apparatus for reproducing a copy image according to either a positive

A thermal ink-jet type image forming apparatus includes a thermal head and a movable ink film reciprocating on the head. The ink film comprises a pair of ink impermeable portions and an ink permeable portion positioned between the ink impermeable portions pair in the moving direction thereof. A separation layer is provided to each surface of the ink impermeable portions pair of the film at the thermal head side. When the recording operation is completed, one of the separation layers of the ink film is held in contact with the thermal head to prevent the ink film from being held in contact with the thermal head directly. This construction prevents the ink film from adhering to the thermal head by a dried ink after the recording operation is completed.

Thermal ink-jet type image forming apparatus

An image forming apparatus comprises an image carrier, a main charger for charging the image carrier, an exposure unit for exposing the image carrier to form a latent image thereon, developing unit for developing the latent image to form a developed image on the image carrier with a developing agent, the developing unit is provided so that there is a gap between it and the image carrier, and a transferring charger for transferring the developed image onto a sheet-like material. A bias voltage is applied across the developing unit and image carrier to cause the developing agent to transfer from the developing unit to the latent image via the gap, and to cause the residual developing agent remaining on the image carrier after the developed image transferring by the transferring charger to transfer to the developing unit via the gap.

Image forming apparatus including means for removing residual toner

In a thermal head used in a printer, a rod-shaped mounting member carries heating elements thereon. The mounting member is formed of a metal material, and the heating elements are arranged over the peripheral surface of the mounting member with an insulating material interposed. Excess heat accumulated in the heating elements is quickly transmitted to the mounting member and diffused.

Thermal printing head

A non-impact printing apparatus in which an ink carrier film is formed to have a plurality of holes or recesses, the holes are filled with ink, and then the film filled at the holes with the ink is selectively heated by a thermal printing head according to image information to generate bubbles within the ink in the heated holes and thus to eject the ink onto a printing paper under influence of the pressure of the generated bubbles. The effective diameter of each of hole provided on the ink carrier film is less than the thickness thereof thus improving the image quality.

Non-impact printing apparatus

In a thermal head according to the present invention, a rod-like member having a circular cross-section is mounted on a support member. An array of heating elements is provided on the rod-like member. Drive signal side electrodes and driving power source side electrodes are connected to each heating element. The drive signal side electrodes are connected to a driver integrated circuit (IC). The driving power source side electrodes are connected in common at ends thereof to provide a common electrode. The common electrode extends along the outer circumferential surface of the rod-like member, is exposed on the side of the driver IC along the surface of the rod-like member opposing the support member, and is connected to a driving power source pattern on the side of the driver IC. A thermistor for detecting a temperature is provided in the vicinity of the rod-like member.

An electrophotographic device is provided with a photosensitive drum having a plurality of photosensitive layers which are different from one another in spectral sensitivity. First and second uniform exposure devices are adjacent to each other about the photosensitive drum. Each of the first and second uniform exposure devices includes a plurality of single color light sources. The light sources of the first exposure device have a different color than the light sources of the second exposure device. The colors correspond to the spectral sensitivity of each of the photosensitive layers, and are used as the uniform exposure light source for the photosensitive drum.

Electrophotographic device

A developing apparatus is constructed so that a first rugged surface portion is formed on that portion of the surface of an elastic blade which faces and is pressed against a developing roller, thereby reducing the conveying force to carry the developing agent in contact with the first rugged surface portion under the pressure of the elastic blade. In this way, the layer of the developing agent flowing to the contact point between the developing roller and the elastic blade is gradually thinned to form a uniformly thin layer of developing agent on the surface of the developing roller.

Developing apparatus

A developing apparatus is provided with a developing roll for carrying a toner thereon and an elastic blade pressed against the surface of the developing roll to apply the toner thereto. The toner is thus applied to the surface of the developing roll by the elastic blade to form a thin layer of the toner on the surface of the developing roll. The thin layer is opposed to a photosensitive drum at a predetermined space to deposit the toner on an electrostatic latent image in the photosensitive drum. The elastic blade is pivotally supported by a pivotal shaft about a central portion of the elastic blade.

A developing apparatus is provided with a developing roller for carrying a toner thereon in a housing. An elastic blade is pressed against the surface of the developing roller in one direction to apply the toner, so that the toner is applied to the surface of the developing roller by the elastic blade to form a toner layer on the surface of the developing roller. The toner layer is opposed to a photosensitive drum at a predetermined space to deposit the toner on a latent image on the photosensitive drum. The elastic blade comprises a fixed plate and a contact plate which are fixed to each other at one end thereof. The other end of the fixed plate is fixed to the housing. A central portion of the contact plate is pressed against the surface of the developing roller.

A developing apparatus is provided with a developing roll for carrying a toner thereon and an elastic blade pressed against the surface of the developing roll to apply the toner thereto. The toner is thus applied to the surface of the developing roll by the elastic blade to form a thin layer of the toner on the surface of the developing roll. The thin layer is opposed to a photosensitive drum at a predetermined space to deposit the toner on an electrostatic latent image in the photosensitive drum. A regulation member is attached to the housing so as to positioned between the housing and the elastic blade. The regulation member has an outlet port of a first width at a central portion thereof. The elastic blade is pressed against the developing roll with a second width greater than the first width.

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Yokohama, Japan

Takashi Shimazaki