Canon Kabushiki Kaisha

Naoki Iwami

Hidejiro Kadowaki

Takao Aoki

Koji Suzuki

Katsuichi Shimizu

Yoshikazu Yokomizo

Shunichi Masuda

Hatsuo Tajima

Yoshihiro Kawatsura

Kimio Nakahata

Shunichi Kubo

Eiichi Kondo

Tetsuji Tachika

Yasuhide Kurosaki

Akihiro Tomosada

An electrophotographic apparatus for forming color images has a photosensitive member, a charging device for applying a primary charge, an imaging device for selectively exposing the photosensitive member to image light of different color components and a device for uniformly exposing the photosensitive member to near infrared light substantially simultaneously with the image exposure. Different color images are sequentially formed, developed and transferred to a transfer material to form a resultant color image with good color balance.

Apparatus for color electrophotography

The image forming method is executed by projecting a light image on a rotatable recording member to consecutively form electrostatic latent images corresponding to the light image, developing the latent images, projecting a predetermined amount of light onto a non-imaged area present between two consecutive latent images on the recording member to form an electrostatic image, detecting potential of the electrostatic image, and controlling the development of the latent images next to the electrostatic image detected during the detection of the potential in response to the detection results. This method is performed in the image forming apparatus which includes a rotatable recording member, processing units for projecting a light image onto the recording member to consecutively form electrostatic latent images corresponding to the light image, a developer unit for developing the latent images, a voltage applying circuit for applying a voltage to the developer unit, a projecting unit for projecting a predetermined amount of light onto a non-imaged area present between two consecutive latent images on the recording member, a detector for detecting surface potential of the non-imaged area, and a controller for controlling the voltage applying circuit in response to detection output from the detector in the development of the latent image next to the non-imaged area in the developer unit.

Apparatus for forming an image on a recording member

Image forming process and apparatus therefor

This specification discloses an electrophotographic method and apparatus for forming an electrostatic latent image on a photosensitive medium having a conductive layer, a photoconductive layer and an insulating layer. The method comprises a primary charging step, an image light exposure step, a secondary charging step, a tone regulating step and a whole surface exposure step.

Electrophotographic method

Process and apparatus for electrophotography are disclosed in which a photosensitive medium basically composed of an electrically conductive layer, a photoconductive layer and an insulating layer is used. The process comprises the steps of applying onto the surface of the photosensitive medium a uniform corona discharge with a predetermined polarity, exposing it to an original light image, applying to it a secondary corona discharge with a component of the opposite polarity to that of the primary uniform corona discharge simultaneously with or immediately after the image-wise exposure, uniformly exposing it to near infrared light almost simultaneously with the secondary corona discharge and subjecting it to a whole surface exposure with white light so as to form an electrostatic latent image corresponding to the original light image. Apparatus for carrying out the electrophotographic process comprises the above mentioned type of photosensitive medium, means for exposing the photosensitive medium to a light image, means for forming an electrostatic latent image on it in accordance with the image-wise exposure by said exposure means, near infrared exposure means for exposing it to light of near infrared range and developing means.

Process and apparatus for electrophotography

In a color image formation apparatus which comprises a photosensitive medium, optical image exposure device for exposing the photosensitive medium to an optical image having light components of an image original, and electrostatic latent image formation device for forming electrostatic latent images on the photosensitive medium in accordance with the exposure to the optical image. The image formation apparatus includes a color separating device having a plurality of color separating filters disposed along the optical path of the optical image exposure device, a developing device having a plurality of developing units for supplying different color developers to develop the electrostatic latent images formed on the photosensitive medium by the electrostatic latent image formation device, a mode setting element for designating the combination of one of the color separating filters and one of the developing units, and a control device for reading the combination of a predetermined color separating filter and a predetermined color developing unit designated by the mode setting device and for causing the designated color separating filter and the designated color developing unit to cooperate with each other.

Color image formation apparatus

Growing community of inventors

Tokyo, Japan

Naoki Iwami