Konica Corporation

Konishiroku Photo Industry Co., Ltd.

Jun-ichi Hamada

Yukio Okamoto

Mitsuo Motohashi

Masakazu Fukuchi

Hiroshi Tokunaga

Masahiko Itaya

Kunihisa Yoshino

Yoshiko Shindo

Takahiro Tuchiya

An image forming apparatus which detects deterioration of developer contained in a developing unit, and if it is the case, the toner is discharged out of the developing unit through a surface of an image carrying member. The apparatus is provided with a sensor to measure toner concentration in developer contained in the developing unit, a drive controller to control a supply amount of toner into the developing unit based on the toner concentration, a calculating unit to obtain average toner supply during a predetermined period, a detecting unit to detect the deterioration of the developer by comparing the average toner supply with a reference data stored in a memory.

Image forming apparatus having a developer deterioration detecting device

The invention provides an apparatus for forming a toner image on plural types of recording materials. A transfer device includes a transfer belt to bring a recording material into contact with an imaging surface of photoreceptor so that the toner image is transferred to the recording material, and a charging device for charging the recording material carried on said transfer belt before the toner image is transferred to the recording material. The type of the recording material is detected and the charging device is controlled in accordance with the type of the recording material.

Image forming apparatus

The present invention relates to a color copying apparatus which prevents toner scattering from a tip portion of a cleaner to an image area of an image carrying drum. An exposing device forms a stripe latent image in a stripe area at an upstream of the image area of an image carrying drum in a rotating direction of the image carrying drum, and a developing device stops development within the stripe area. The result is a generation of a sharp potential gap in the stripe area. The cleaner starts cleaning by touching to the stripe area, and accumulated toner on the tip of the cleaner is attracted by the sharp potential gap and is held within the stripe area. This prevents the toner from being scattered to the image area of the image carrying drum.

Residual toner cleaning apparatus for color image forming device

An image forming apparatus wherein a toner image is formed in a non-image area on an image retainer and a toner is attached to a cleaning blade for cleaning residual toner by cleaning the toner image by the cleaning blade. The toner image is shaped in a slender line, a stripe, or the like. The toner image is formed every image forming process.

Image forming apparatus with improved image retainer cleaning means

An electrophotographic image forming apparatus for forming an image on a recording sheet comprises a photosensitive drum for holding a toner image thereon, in developer for forming the toner image on the photosensitive drum, an image transfer device for electrostatically transferring the toner image from the photosensitive drum to the recording sheet, and a sheet separator for separating the recording sheet from the photosensitive drum as the recording sheet advances. The sheet is controlled to generate a discharge voltage which includes separator at least alternating currents at various duty factors.

Paper separating charger capable of discharging currents of various duty

A method of forming an electric signal wherein the signal level corresponding to the selected color in the original indicates the maximum or minimum value. The original is exposed to the light and the reflected light is introduced into a photoelectric converting means through two different paths, each of which has a filter corresponding to a different selected color. These two signals are multiplied by a predetermined ratio, and are combined to obtain the final image signal.

Growing community of inventors

Hachioji, Japan

Jun-ichi Hamada