Canon Kabushiki Kaisha

Hironobu Nihei

Yoshitaka Hibi

Naoki Inoue

Takayuki Mizuta

Ryuhei Shoji

Shotoku Matsui

An image forming apparatus includes a registration roller, a revering roller, and a detecting unit to detect a recording material. A control unit, in a case in which (i) the recording material has a length such that the recording material is conveyed by the registration roller in a state in which a trailing end of the recording material has not passed the reversing roller and (ii) the recording material is conveyed by the registration roller and the reversing roller, decelerates a conveyance speed of the recording material upstream of the detecting unit in a conveyance direction, or controls to stop the conveyance of the recording material.

Image forming apparatus with deceleration of conveyance speed of recording material upstream of detecting unit or stopping of conveyance of recording material

A recording material feeding device includes a stacking portion, a driving source, a holding member, a torque limiter for limiting transmission of a driving torque from the driving source to the stacking portion in a case that the driving source rotates in a state in which the holding member holds the position of the stacking portion; a storing portion for storing information on a holding state of the holding member; and a controller for controlling the driving source to rotate at a rotational speed slower when the information is information indicating that the holding member holds the position of the stacking portion than when the information is information indicating that the holding member does not hold the position of the stacking portion.

Recording material feeding device with control of motor speed

The motor that drives a reverse unit, and a CPU configured to switch an image formation mode between a full color mode for forming an image using image forming stations and a black and white mode for forming an image using the image forming station are provided. If the image is formed on a first recording material supplied by a sheet feeding roller pair and subsequently an image is formed on a second recording material supplied by a sheet refeeding unit, the motor continuously drives the reverse unit. If the image formation mode for the first recording material is different from the image formation mode for the second recording material, the CPU switches the image formation mode to the full color mode, and forms the images on the first recording material and the second recording material.

Image forming apparatus

Recording material feeding device

The image forming apparatus includes a sheet discharge sensor that detects a recording material, a fixing device that nips the recording material to fix an unfixed toner image onto the recording material, a fixing motor that drives the fixing device, and an engine control unit that controls the fixing motor. The fixing device includes a fixing roller, a pressure unit that forms a first nip portion with the fixing roller to press the fixing roller, and a heating unit that forms a second nip portion with the fixing roller to heat the fixing roller. The first nip portion nips the recording material to fix the toner image onto the recording material. When determining that the recording material is wound around the fixing device using the sheet discharge sensor, the engine control unit continues to drive the fixing motor.

Image forming apparatus controlling timing of switching between image formation modes

An image forming apparatus includes first and second photosensitive members; first and second light sources; a rotatable polygonal mirror; a first signal output portion; and a second signal output portion. The first light source emits the light at timing on the basis of the first signal, and the second light source emits the light at timing on the basis of the second signal so that latent images are formed on the first and second photosensitive members, respectively, and then are developed with developers to form developer images on the first and second photosensitive members, respectively, and then an image is formed by superposing the developer images. Before output of a second signal from the second signal output portion is started, the first light source emits the light on the basis of a first signal to start formation of the latent image on the first photosensitive member.

Image forming apparatus with multiple light sources timing control

This invention has as its object to improve an image formation throughput. An image forming apparatus of this invention times a time required until an image formation is ready to start after a reference signal is output, and executes the image formation when the image formation is ready to start (for example, initial processes are complete). Furthermore, when the next reference signal is output during the image formation, the image forming apparatus executes an image formation of the next color after a waiting process based on the timed time.

An image forming apparatus performs control so that a wrinkle is formed at a predetermined position of an intermediate transfer belt and, when forming a toner image having such a large size that the toner image overlaps the wrinkle formed in the intermediate transfer belt, the leading edge and the trailing edge of the toner image overlap the wrinkle.

Image forming apparatus for image transfer onto a transfer member

An image forming apparatus stops the intermediate transfer belt so that a wrinkle is formed at a predetermined position of an intermediate transfer belt and, by detecting a reference mark during a preparation operation for forming an image when starting image formation, the toner image is not transferred onto the wrinkle formed in the intermediate transfer belt when formation of a toner image is started immediately after the preparation operation has been completed.

The length of recording paper being conveyed to an image forming section is detected. If it is found that the length is shorter as a result of the detection, the recording paper is conveyed to a reversing section to be refed to the image forming section to continue conveyance of the recording paper as in the normal image formation, but without performing the image formation. As a result, the sequence of the recording paper ejected to the paper output section is the same as that of normal printing. Thus a user can easily decide the paper on which the image formation is not carried out normally.

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Yokohama, Japan

Hironobu Nihei