Abstract: In an image forming apparatus, a paper sheet cassette stores a bunch of paper sheets to be fed. A media sensor unit measures a thickness and a surface roughness of one paper sheet fed and transported from the paper sheet cassette. A residual sheet amount sensor detects a residual amount of the paper sheets in the paper sheet cassette. A residual sheet number estimating unit estimates the number of residual paper sheets in the paper sheet cassette on the basis of (a) a thickness of a bunch of the paper sheet in the paper sheet cassette, the thickness of the bunch corresponding to the residual amount detected by the residual sheet amount sensor and (b) the thickness of the one sheet and the surface roughness of the one sheet measured by the media sensor unit.

Abstract: In an image forming apparatus, a paper sheet cassette stores a bunch of paper sheets to be fed. A media sensor unit measures a thickness and a surface roughness of one paper sheet fed and transported from the paper sheet cassette. A residual sheet amount sensor detects a residual amount of the paper sheets in the paper sheet cassette. A residual sheet number estimating unit estimates the number of residual paper sheets in the paper sheet cassette on the basis of (a) a thickness of a bunch of the paper sheet in the paper sheet cassette, the thickness of the bunch corresponding to the residual amount detected by the residual sheet amount sensor and (b) the thickness of the one sheet and the surface roughness of the one sheet measured by the media sensor unit.

Abstract: An image forming apparatus includes a paper type detection unit, a paper type determination unit, a paper search unit, and a paper change unit. The paper type detection unit detects a type of a paper conveyed from a paper feeding cassette by a sensor. The paper type determination unit determines whether there is a change in the type of the paper during the printing. The paper search unit searches whether there is an appropriate paper feeding cassette for accommodating papers having paper types equal to types of papers before paper types are changed when there is a change in the type of the paper during the printing as a result of the determination. The paper change unit processes the paper with the changed type and resumes conveyance of papers from the existing appropriate paper feeding cassette when there is the appropriate paper feeding cassette as a result of the search.

Abstract: An image forming apparatus includes a paper type detection unit, a paper type determination unit, a paper search unit, and a paper change unit. The paper type detection unit detects a type of a paper conveyed from a paper feeding cassette by a sensor. The paper type determination unit determines whether there is a change in the type of the paper during the printing. The paper search unit searches whether there is an appropriate paper feeding cassette for accommodating papers having paper types equal to types of papers before paper types are changed when there is a change in the type of the paper during the printing as a result of the determination. The paper change unit processes the paper with the changed type and resumes conveyance of papers from the existing appropriate paper feeding cassette when there is the appropriate paper feeding cassette as a result of the search.

Abstract: An image forming apparatus includes a plurality of optical scanning devices, a job receiver, a job executor, an image discriminator, a temperature condition judger and a temperature adjuster. When a formation-target image is a single-color image and an image to be formed next is a multi-color image, the temperature adjuster drives a motor of one optical scanning device at a second rotating speed slower than a rotating speed during an image forming operation and drives motors of unused optical scanning devices at a third rotating speed faster than the second rotating speed if a temperature condition is satisfied upon the completion of an image forming operation of the single-color image.

Abstract: An image forming apparatus includes a plurality of optical scanning devices, a mode receiver, a temperature condition judger and a temperature adjuster. In the case of forming an image using one optical scanning device, the temperature adjuster drives motors of unused optical scanning devices at a first rotation speed if a predetermined temperature condition is satisfied and drives the motors of the unused optical scanning devices at a second rotation speed slower than the first rotation speed if image formation is finished during the drive at the first rotation speed.

Abstract: An image forming apparatus includes an apparatus main body, a plurality of optical scanning devices, first temperature detectors for detecting the temperatures of the optical scanning devices, a second temperature detector for detecting the temperature of the apparatus main body, a first condition judger, a second condition judger and a temperature adjuster. The temperature adjuster performs a total motor drive process for driving the motors of all the optical scanning devices if a predetermined first condition is satisfied and a predetermined second condition is satisfied. On the other hand, the temperature adjuster drives the motor of the one optical scanning device and does not drive the motors of all the optical scanning devices excluding the one optical scanning device if the first condition is satisfied, but the second condition is not satisfied.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.