Hitachi, Ltd.

Ricoh Printing Systems, Ltd.

Hitachi Prinitng Solutions, Inc.

Satoshi Narita

Nobuaki Fukasawa

Masahiko Saito

Junichi Shoji

Yuuichi Takano

Akira Shimizu

Akira Sasaki

Tomofumi Yoshida

Kazuhiro Wakamatsu

Shintaro Yamada

Shunichi Oohara

Yoshitaro Ishii

Masashi Yamamoto

Akira Shimada

Kazuo Kikuchi

Atsushi Onose

Yoshio Ohuchi

Michio Sumiyoshi

Koichi Sato

Tetsunori Kaneko

Tatsunari Sato

Kiminori Takada

An image forming apparatus is able to form steady test-pattern toner images for calibration of reflection density detection characteristics with ample toner. The operation consists of forming a test-pattern toner image for calibration of the reflection density detection characteristics, which is formed of a plurality of toner images of different colors aside from a reference test-pattern toner image for controlling image forming conditions, detecting the detection characteristics of a reflection density sensor from the result of detection of the quantity of toner attached to the test-pattern toner image for calibration of the reflection density detection characteristics, and calibrating the output characteristics of the reflection density sensor.

Image forming apparatus and method of detecting the detection characteristics of a reflection density sensor

An image forming apparatus includes a photosensitive belt carried by a driver device, for forming a toner image thereon; an internal transcription belt for transcribing the toner image; and a transcription portion for transcribing the toner image, which is transcribed on the internal transcription belt, onto a recording medium. A transcription side roller is suspended with the internal transcription belt thereon, and disposed on a side of a photosensitive belt side roller. Detectors detect a first cycle of the internal transcription belt, and a second cycle, which starts measurement delaying by &#xbd; cycle of the photosensitive belt side roller from the first cycle measurement start. A controller conducts speed compensation of the photosensitive belt by referring to the first cycle and the second cycle, wherein the internal transcription belt is in contact with the photosensitive belt, so that it is carried following thereafter.

Image forming apparatus for conducting speed compensation by internal transcription belt cycle measurement

The rotating speed of a photosensitive body is reduced for preventing deterioration thereof due to ozone in an electrophotographic device which comprises the photosensitive body, a charger which uniformly charges the surface of the photosensitive body, and a motor control unit which performs drive control for a motor which drives the photosensitive body. The motor control unit provides a plurality of speed levels including a first speed level for rotating the photosensitive body during printing and another speed level for rotating the photosensitive body at a reduced speed lower than the speed used during printing. The speed is changed-over between the plurality of speed levels depending on the operating condition. Thereby, deterioration of the photosensitive body due to ozone generated from the charger is prevented, and additional deterioration of the photosensitive body due to rotation thereof other than during a printing operation is also prevented.

Electrophotographic device

An image forming apparatus is capable of preventing with certainty the loading of a developing device an incorrect loading portion from being operated. The image forming apparatus includes a latent image holding body forming an electrostatic latent image, a developing device developing the electrostatic latent image to form a visible toner image, the developing device being detachably loaded in the image forming apparatus, a transfer device transferring the developed image onto a printing medium and a fixing device for fixing the transferred image. The image forming device can prevent an incorrect developing device loading in the image forming apparatus from being placed in a development enabled condition and can detect an active state of prevention.

Image forming apparatus

An image forming apparatus including an image forming device on which toner images are formed; a transfer device for transferring the toner images onto a record medium; a voltage-application unit for applying a transfer voltage to the transfer device; a current-detection unit for detecting current flowing between the image forming device and the transfer device; a storage unit for storing a first current value detected at a non-operation position of the transfer device, and a second current value detected at an operation position of the transfer device; and a transfer device state-determination unit for determining the presence of the transfer device and the occurrence of an anomaly in a contact operation of the transfer device with the image forming device and a shunt operation in which the transfer device is moved away from the image forming device.

Image formation apparatus with determination of state of transfer device

A double-surface printing apparatus, which is small-sized and has a simple construction to make it impossible to take out a sheet, of which one surface has been subjected to printing, from outside. The apparatus includes a paper discharge tray, to which sheets having been subjected to printing are discharged; a sheet reversing mechanism including a reversal/temporary storage unit for guiding a sheet in a direction different from a discharge direction toward the paper discharge tray, once exposing the sheet outside of the apparatus, and rotating conveying rollers in an opposite direction to thereby reverse the sheet; and a protective cover, which covers the sheet conveyed to the reversal/temporary storage unit so that a sheet, of which one-surface has been subjected to printing, cannot be taken out from outside.

Double-surface printing apparatus

Growing community of inventors

Hitachiota, Japan

Satoshi Narita