Fujitsu Corporation

Megumi Yasuda

Shinichi Watarai

Yoshikazu Yamamoto

Makoto Inoue

Yukio Nishio

Yoshinori Wada

Yoji Houki

Yukitoshi Takano

Mikio Koga

Mie Toyohara

Yoji Hoki

An image forming apparatus is provided with a fixing unit having at least one fixing heat roller and a plurality of heat sources with respect to the one fixing heat roller, and a control unit for setting a target temperature with respect to each of the plurality of heat sources and independently controlling each of the heat sources.

Image forming apparatus with controlled heat sources in fixing unit

An image forming apparatus includes a plurality of image bearing members bearing latent images, image forming units for forming the latent images on the image bearing members, developing units for developing the latent images on the image bearing members, a transport belt for transporting a transfer member on which images of different colors developed by the developing units are successively transferred as the transfer member is transported, and image pickup elements, arranged obliquely to a main scan direction of the image forming units and located on a downstream of a most downstream one of the image bearing members along a direction in which the transport belt transports the transfer member. The image pickup elements detect as image information transmitted or reflected light quantity distributions of regions which include marks transferred on the transport belt from the image bearing members. The image forming apparatus further includes a correction unit for detecting correction quantities from error quantities of marks transferred from the image bearing members other than a reference image bearing member with respect to a reference mark transferred from the reference image bearing member based on the image information detected by the image pickup elements, and correcting positions of the latent images formed on the image bearing members other than the reference image bearing member depending on the correction quantities.

Image forming apparatus

A printing apparatus used in a computer system selects either one of a plurality of paper feed cassettes and prints image data onto a cut sheet supplied from the selected cassette. Paper sensors are individually attached at predetermined positions which are located just after a plurality of paper feed cassettes at the same distance. The paper conveying times from the attaching positions of the paper sensors to a print start request position have been preset. When the cassette is switched during the printing operation, the predetermined paper feed timing time is changed. When switching from the cassette at a near position to the cassette at a remote position, the paper feed timing time is set to a short time and the paper feeding operation from the cassette on the switching side is instructed. When switching from the cassette at a remote position to the cassette at a near position, the predetermined paper feed timing time is set to a long time and the paper feeding operation from the cassette on the switching side is instructed.

Paper feeding method and printing apparatus which continuously feeds out

The image forming device of this invention is related to a device such as a duplicator, a printer, a facsimile or the like in which a printing operation is carried out by utilizing an electrophotographic recording system and an electrostatic recording system, wherein the device includes a plurality of consumable working parts including at least a developing unit, a drum unit, a fixing unit, and a transfer unit, and the device further includes a unit for integrating the working time of each of the working parts, a memory for storing the integrated working time of each working part, a lifetime setting unit in which a predetermined lifetime of each working part is set, and a generator for generating an exchange requirement signal for at least one of the working parts when the integrated working time of the working part reaches the lifetime of the part set in the lifetime setting unit, whereby an image forming device having a system in which these consumable working parts can be exchanged at correct intervals, regardless of the conditions of use, is provided.

Image forming apparatus having an exchangeable unit exchange timing

A method of controlling a fuser unit of an image-forming apparatus such as a laser printer, in a warming-up stage, so that excess mechanical and electrostatic stresses are not imposed on the process elements. The method includes the steps of: starting the energization of a heater of a heat roller substantially at the same time as the commencement of an initialization process of mechanical and electrostatic conditions of the apparatus while rotating the heat roller and a backup roller together; stopping the rotation of the rollers after the initialization process has been completed; monitoring a surface temperature of the heat roller for a first predetermined period after the completion of the initialization; and if the surface temperature has reached a set value within the first predetermined period, determining that the fuser unit is ready for operation, and conversely, if the set value has not reached within the first predetermined period, carrying out an additional warming-up process of rotating the heat roller and the back-up roller again until the set value is reached, unless a second predetermined period has expired subsequent to the expiration of the first predetermined period.

Growing community of inventors

Kawasaki, Japan

Megumi Yasuda