Abstract: An image forming apparatus includes an image bearing member for carrying an electrostatic image; developing means for developing the electrostatic image with toners having the same hue and having different densities; toner image formation means for forming a toner image on a recording material; and fixing means for fixing the toner image on the recording material, wherein 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.

Abstract: An image forming apparatus includes an image bearing member; electrostatic image forming means for forming an electrostatic image on the image bearing member on the basis of an input signal; developing means for developing the electrostatic image with toners having the same hue and having different densities; toner image formation means for forming a toner image on a recording material; and fixing means 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 between when the toner image is formed on the basis of an input signal on the recording material which is a paper sheet and when the toner image is formed on the basis of the same input signal on the recording material which is an OHP sheet.

Abstract: An image forming apparatus includes an image bearing member for carrying an electrostatic image; developing means for developing the electrostatic image with a plurality of toners having the same hue and having different densities; toner image formation means for forming on a recording material a toner image constituted by the toner having the same hue and different densities; and fixing means 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 membe

Abstract: An image forming apparatus includes an image bearing member for bearing a latent image and a charger for charging the image bearing member. The charged image bearing member is exposed to form the latent image and a developing unit develops the latent image. One of an exposure amount reduction mode for executing image formation by reducing an exposure amount and a normal mode for executing image formation with a normal exposure amount is selected. A correction amount of a look-up table for gradational correction is changed when the exposure amount reduction mode is selected.

Abstract: An image forming apparatus for outputting an image through an electrophotographic process in accordance with a digital image signal includes an electrophotographic photosensitive member; an optical system for applying light information to the photosensitive member; a developing device for forming a toner image on the photosensitive member; an input path for a plurality of digital image signals containing a bi-level digital image signal and a multi-level digital image signal; a controller for changing developing condition of the developing device when the image is outputted in accordance with the bi-level digital image signal, and changing an image forming condition which is different from the developing condition when an image is outputted in accordance with a multi-level digital image signal.

Abstract: There is herein disclosed an image forming apparatus comprising an image bearing member for bearing an electrostatic image, a developing device for developing the electrostatic image on the image bearing member, a temperature and humidity sensor for detecting temperature and humidity, a deciding device for deciding an image forming condition based on the detection output of the temperature and humidity detection sensor, and a correcting device for correcting the decision of the image forming condition by the deciding means in a low humid environment and at continuous image formation.

Abstract: An image forming apparatus includes an image bearing member; charger for electrically charged said image bearing member; electrostatic image forming means for forming an electrostatic image by selectively discharging a surface of said image bearing member charged by said charger; developing means for developing the electrostatic image on said image bearing member into a toner image with toner; transfer means for transferring the toner image from said image bearing member onto a transfer material; wherein said charger is capable of collecting residual toner remaining on said image bearing member after image transfer operation by said transfer means; electric field forming means for forming an electric field between said charger and said image bearing member to transfer the toner in said charger to said image bearing member; and control means for controlling a length of time for which said electric field forming means forms the electric field.

Abstract: An image forming apparatus has an image forming device for forming a toner image on a recording material and a fixing device for fixing the toner image on the recording. An image forming speed at which the toner image is formed by the image forming device is adapted to be selected to be a first speed or a second speed greater than the first speed. A control device is provided so that, when the second speed is selected, a maximum toner amount per unit area of the toner image becomes smaller than that when the first speed is selected.

Abstract: An image forming apparatus includes an LED array for performing exposure according to an input image signal, a photoconductive drum on which an electrostatic latent image is formed by exposure with the LED array, a developing device for making the electrostatic image visible, a transfer charger for transferring the visible image onto a transfer material, and a fixing device for fixing the image on the transfer material. When the operating speed in an image forming process equals the image forming speed, and the image forming speed can be switched among a plurality of levels, the image forming condition is changed in accordance with the image forming speed.

Abstract: The invention provides an image forming apparatus which, in case of switching to an exposure amount reduction mode for executing the image formation with an exposure amount reduced from that in the normal image formation in order to prevent ghost image generation resulting from the exposure memory effect of the photosensitive member, corrects a look-up table for gradational correction for the intermediate density or is provided with a look-up table for the exposure amount reduction mode.

Abstract: An image forming apparatus includes an image bearing member; image forming means for forming an image on the image bearing member in accordance with an image signal; wherein the apparatus is operable in a first mode in which the image is formed by the image forming means on the image bearing member which is rotated at a first peripheral speed and in a second mode in which the image is formed by the image forming means on the image bearing member which is rotated at a second peripheral speed different from the first peripheral speed; wherein a calibration for correcting a density level of the image formed on the image bearing member relative to a density level of the image signal, is executed for each of the modes.

Abstract: An image forming apparatus includes an LED array for performing exposure according to an input image signal, a photoconductive drum on which an electrostatic latent image is formed by exposure with the LED array, a developing device for making the electrostatic image visible, a transfer charger for transferring the visible image onto a transfer material, and a fixing device for fixing the image on the transfer material. When the operating speed in an image forming process equals the image forming speed, and the image forming speed can be switched among a plurality of levels, the image forming condition is changed in accordance with the image forming speed.

Abstract: There is herein disclosed an image forming apparatus comprising an image bearing member for bearing an electrostatic image, a developing device for developing the electrostatic image on the image bearing member, a temperature and humidity sensor for detecting temperature and humidity, a deciding device for deciding an image forming condition based on the detection output of the temperature and humidity detection sensor, and a correcting device for correcting the decision of the image forming condition by the deciding means in a low humid environment and at continuous image formation.

Abstract: 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.

Abstract: When an image is adjusted to compensate for individual differences among image forming units, there are cases where a phenomenon occurs in which a contour that is originally non-existent appears in a low-density portion, namely an area other than that where the output density characteristic is linear. In such instances image quality deteriorates markedly when importance is placed upon tonality. To solve this problem, a printer is caused to print an image diagnostic pattern, the image diagnostic pattern that has been printed is read by a reader and the linear portion of the output density characteristic of a design center value and the linear portion of the read output density characteristic are approximated by straight lines. Both of the output density characteristics are compared and image adjustment coefficients A, B are compared. The coefficients A, B thus obtained are set in a primary converter and gamma tables in a gamma converter are changed over in conformity with the values of the coefficients A, B.