Canon Kabushiki Kaisha

Yuichiro Toyohara

Tsuyoshi Kunishi

Kenichiro Kitajima

Haruhiko Omata

Tatsuomi Murayama

Yukio Watanabe

Fumitake Hirobe

Akihiro Noguchi

Motohide Shiozawa

Ken-ichiro Kitajima

Nobuatsu Sasanuma

Takeshi Menjo

Tetsuya Atsumi

Akinori Tanaka

Kouichi Hashimoto

Kazushige Nishiyama

Jiro Ishiduka

Mitsuka Abe

An image formation system includes an image forming apparatus for forming different color toner images on a recording material having a toner reception layer, a first heater for heating and pressing the toner image on the recording material, and a heater for heating and pressing the toner image on the recording material having been heated and pressed by the first heater. The first heater is operable so as to provide a granularity R of the toner image satisfying 0.5&#x2266;R&#x2266;4.0 and a glossiness G of the toner image satisfying 5&#x2266;G&#x2266;40, the second heater being operable so as to provide a granularity R of the toner image that is not more than 4.0 and a glossiness G of the toner image that is not less than 60.

Image formation system, image formation method, and image quality improvement method twice heating and pressing a toner image on a recording material

An image forming apparatus is provided that forms an image using developers of different tone and the same hue. When forming images for measurement for density control, the apparatus performs density control by forming a greater number of density levels of an image for measurement developed using a light developer than the number of density levels of an image for measurement developed using a dark developer. Thus, even if the amount of applied light developer may fluctuate, the fluctuation can be compensated to prevent the occurrence of pseudo-contours that lower image quality.

Image forming apparatus including density control and control method thereof

An image forming apparatus includes a developing apparatus for developing an electrostatic image with a developer comprising at least a toner and a first external additive, the developing apparatus including a plurality of developing devices, containing toners different in color or lightness from each other, in which at least two developing devices contain a dark color toner and a light color toner which have an identical hue and different lightnesses and the developing device containing the light color toner is subjected to a developing operation prior to another developing device; a first transfer apparatus for sequentially transferring toner images, which have been developed by the plurality of developing devices, onto an intermediary transfer member; and a second transfer apparatus for transferring the toner images from the intermediary transfer member all together onto a transfer medium The first external additive includes particles having an aspect ratio of not less than 1.0 and not more than 1.5 and a number-average particle size of not less than 0.06 &#x3bc;m and not more than 0.3 &#x3bc;m, and has a coverage thereof with respect to the light color toner larger than that with respect to the dark color toner in a transferred state on the intermediary transfer member.

Image forming apparatus using color toner and transparent toner

Image forming apparatus with a developer comprising at least a toner and a first external additive

A toner image forming device for forming, on the basis of input image signals, a toner image on a recording material with a first toner and a second toner having the same hue as the first toner and a density different from that of the first toner. A fixing device for heating and fixing the toner image on the recording material. A selecting device for selecting either one of a first mode and a second mode, wherein a glossiness level of a toner image outputted in response to the input image signals having the same density level is higher in the second mode than in the first mode. A changing device for changing, in response to selection of said selecting means, a fixing condition of said fixing means and a use ratio of the second toner at the input image signal corresponding to a predetermined density level.

Image forming apparatus capable of accomplishing uniformity in glossiness

In an image forming apparatus, an image forming condition is changed depending on whether or not a recording material on which a toner image is formed is ordinary high gloss paper or thermoplastic resin coated paper. More specifically, in the case where a high gloss mode is selected during image formation, judgement whether or not the high gloss paper is the ordinary high gloss paper or the thermoplastic resin coated paper is made. In the former case, a screen line number is set to 150 lpi, and in the latter case, the screen line number is set to 200 lpi. As a result, image failure due to collapse of a toner layer (during fixation) on the ordinary high gloss paper is prevented and high-quality toner image is formed on the thermoplastic resin coated paper.

Image forming apparatus

An image forming apparatus includes an image bearing member; an electrostatic image forming device for forming an electrostatic image on the image bearing member on the basis of an input signal; a developing device for developing the electrostatic image with toners having the same hue and having different densities; a toner image formation device for forming a toner image on a recording material; and a fixing device for fixing the toner image on the recording material, wherein a total of amounts per unit area of the toners which have the same hue and different densities and which constitute the toner image, is different when the toner image is formed on the basis of an input signal on a recording material which is a paper sheet and when the toner image is formed on the basis of the same input signal on a recording material which is an OHP sheet.

Image forming apparatus using two or more toners for ordinary paper or OHP sheet

An image forming apparatus includes an image bearing member for carrying an electrostatic image; a developing device for developing the electrostatic image with a plurality of toners having the same hue and having different densities; a toner image formation device for forming on a recording material a toner image constituted by the toner having the same hue and different densities; and a fixing device for fixing the toner image on the recording material, wherein a total of amounts per unit area of the toners which have the same hue and different densities and which constitute a part of the toner image, is substantially the same as a total of amounts per unit area of the toners which have the same hue and different densities and which constitute another part of the toner image having a different density.

An image forming apparatus includes an image bearing member for carrying an electrostatic image; a developing device for developing the electrostatic image with toners having the same hue and having different densities; a toner image formation device for forming a toner image on a recording material; and a fixing device for fixing the toner image on the recording material, wherein a ratio of amounts of toners having the same hue and different densities, which constitute the toner image is changed on the basis of a glossiness of the recording material.

Image forming apparatus capable of changing usage ratio among multiple toners

The image forming apparatus is equipped with a first photosensitive member, a plurality of first developing devices, a second photosensitive member, and a second developing device. In the image forming apparatus, toner images on the first photosensitive member and the second photosensitive member are transferred onto a transfer medium while one is superimposed on the other, whereby it is possible to form a high quality image using deep-color and light-color toners of the same hue and to prevent a deterioration in gradation property.

Image forming apparatus with interchangeable developing devices

An image forming apparatus includes a plurality of image forming devices for forming respective monochromatic images in accordance with input image signals. The apparatus is operable in a first mode for forming a multi-color image by the plurality of image forming devices at a first image formation speed and in a second mode for forming a multi-color image by the plurality of image forming devices at a second image formation speed. The apparatus also includes an execution device for executing, for respective image formation speeds, calibrating operations for correcting image density levels of output images formed by the image forming devices in response to image density levels of the input image signals.

Image forming apparatus having a plurality of image forming speeds

In case of a full-color image forming apparatus, Modulation Transfer Function (MTF) unevenness at an identical location in the longitudinal axis tends to be intensified. The image forming apparatus of the present invention includes a plurality of light emitting heads having rod lens arrays which focus imaging rays on photosensitive members and have different modulation transfer functions, thereby being capable of providing a high quality image at a low cost while preventing optical density unevenness from being produced in the image.

Image forming apparatus and manufacturing method thereof

An image forming apparatus includes an image bearing member; a charger for electrically charging the image bearing member; an electrostatic image forming device for forming an electrostatic image by selectively discharging a surface of the charged image bearing member; a developer for developing the electrostatic image formed on the image bearing member into a toner image; a transfer device for transferring the toner image from the image bearing member onto a transfer material; wherein the charger is capable of collecting residual toner from the image bearing member after an image transfer operation; an electric field forming device forms an electric field between the charger and the image bearing member to transfer the toner in the charger to the image bearing member; and a controller controls a length of time during which the electric field forming device forms the electric field, wherein the controller controls the length of time substantially in accordance with wear of a surface of the image bearing member.

Growing community of inventors

Fujisawa, Japan

Yuichiro Toyohara