Oki Data Corporation

Toyokazu Shiraishi

Masahiro Fukuda

Tatsuya Murakami

Kazuhiko Nagaoka

Koji Ida

Kiyoshi Matsuda

Naoki Sunaga

Nobutoshi Chigira

Shuuichi Fujikura

An image formation apparatus that includes: first to third image formation units provided in this order in a traveling direction of a transfer target medium; a detector configured to detect first to third correction patterns formed on the transfer target medium by the first to third image formation units, respectively; and a control unit programed to control image misregistration correction based on a result of detection by the detector. The control unit causes the first and third image formation units to form the first and third correction patterns on the transfer target medium, respectively. When an amount of image misregistration between the first correction pattern and the third correction pattern is less than a predetermined value, the control unit neither causes the second image formation unit to form the second correction pattern, nor executes the image misregistration correction.

Image formation apparatus that executes misregistration correction

A medium carrying device includes: first and second carrying part that carry a medium to a second position via a first position; a slack detection unit positioned between the first and second carrying part and detecting slack in the medium; a medium carrying detection part that detects a carrying state of the medium; an input part that receives a recovery instruction when an abnormality is detected in the carrying state of the medium by the medium carrying detection part; a controller that stops the carrying of the medium by the first and second carrying parts when the abnormality is detected in the carrying state of the medium by the medium carrying detection part and that resumes the carrying of the medium by the first and second carrying parts according to a detection result by the slack detection part when the input part receives the recovery instruction.

Medium carrying device, image forming device, and medium carrying method

An image forming device includes a carrying part, an image forming part, a fuser, a fusion temperature controller, a winding part, a storage part and a controller. The controller stops a carrying of recording medium by the carrying part and heating by the fusion temperature controller, after the carrying part carries the recording medium by a predetermined length while the fusion temperature controller heats the fuser, when printing is started in a state where the recording medium is not wound on the winding part, and resumes the carrying of the recording medium by the carrying part and the heating by the fusion temperature controller upon detection that the time measured by the measurement part has reached the stop time for the recording medium stored in the storage part.

Image forming device

An image forming apparatus includes a consumable supply remaining amount detection unit for detecting a remaining amount of a consumable supply; a printable length detection unit for determining a printable length of a medium printable with the remaining amount; a printable length determining processing unit for determining whether the printable length is smaller than a requested print length of the medium requested with print data; and a printing processing unit for performing a partial printing operation when the printable length determining processing unit determines that the printable length is smaller than the requested print length.

Image forming apparatus with printing processing unit

A fixing apparatus including a belt, a pressuring portion placed facing the belt, and a temperature levelling portion made of heat conducting material placed to be extended in the direction of the width of the belt and to be put on said belt; so as to keep the temperature distribution on the belt uniform in its width direction, without wasting heat, while keeping print quality stable.

Fixing apparatus with a temperature levelling member for an image forming apparatus

In an image forming apparatus which has a medium thickness detecting unit for detecting a thickness of print medium and forms an image by an electrophotographic process, the apparatus has a unit for detecting the thickness of print medium that is used after a predetermined operation and a unit for detecting the thicknesses of print media on a paper feed tray at a period of a predetermined number of print pages. A target temperature of a fixing device is set on the basis of the thickness of print medium that is used after the predetermined operation and the thicknesses of print media detected at the period of the predetermined number of print pages. A waiting time is reduced and print quality can be maintained by this apparatus.

Fixing temperature control method and image forming apparatus with detection of thickness of a print medium

A medium thickness detecting apparatus detects the thickness of a recording medium. A displacement section is disposed in a transport path through which a recording medium passes. When the recording medium passes the displacement section, the displacement section displaces in a direction substantially normal to the surface of a recording medium. An amplifying section amplifies a displacement of the displacement section by a predetermined factor. A thickness determining section outputs a signal representative of an amplified value of the displacement. The displacement section may be one of two rollers between which the recording medium passes, and displaces upward when the recording medium passes between the two rollers. Alternatively, the displacement section my be positioned to sit on a stage provided in the transport path such that the displacement section is pushed away from the stage when the recording medium passes between the displacement section and the surface.

Medium thickness detecting apparatus

An image-recording apparatus has a plurality of image-forming sections. Each image forming section has a transfer point where a corresponding toner image is transferred from a photoconductive drum onto a print medium when the print medium passes through the transfer point. Each of the image-forming sections includes a surface that opposes the print medium and an electrically conductive film to which a high concentration of carbon black is contained and which is provided on the surface. The surface is downstream of the photoconductive drum with respect to a direction of travel of the print medium. The surface and print medium are spaced apart by a distance in the range of 1 to 3 mm and the electrically conductive member has a sheet resistance value of 15 k&OHgr;/&square; to 10 M&OHgr;/&square;.

Image recording apparatus having electrically conductive members for preventing charge migration

An electrophotographic has a transfer belt, a plurality of image-bearing bodies, and a plurality of transferring devices. The transfer belt is driven to run with a print medium placed thereon. The plurality of image-bearing bodies are disposed in a direction in which the transfer belt runs. Each of the plurality of transferring devices opposes a corresponding one of the plurality of image bearing bodies to form a transfer section. Each of the transferring devices selectively receives a first voltage (i.e., transfer voltage Va) and a second voltage (i.e., non-transfer voltage Vb) same as or lower than the first voltage. The first voltage is received when an image of a corresponding color is being transferred from a corresponding one of the image bearing bodies to the print medium. The second voltage is received when the image of the corresponding color is not being transferred from the corresponding one of the image bearing bodies to the print medium.

Electrophotographic printer

An electrophotographic printer includes a rotating photoconductive drum, a developing unit, a transfer roller, and a neutralizer. The neutralizer neutralizes a second area of the surface of the photoconductive drum different from a second area in which the toner is applied. A sensor may be provided along the transport path to detect a leading end and a trailing end of the print medium passing along the transport path. In accordance with the sensor output, the neutralizer neutralizes the second area (i.e., top margin and bottom margin) on the photoconductive drum adjacent the leading end and the trailing end of the print medium. A neutralization data generator may be added. The neutralization data generator searches the bit map data for dots which should be printed, and produces neutralization data on the basis of the dots. Then, the neutralizer illuminates only the second area (i.e., areas in which toner is absent) in accordance with the neutralization data. The neutralization data generator inverts bit map data produced by a controller to produce the neutralization data and the neutralizer includes light emitting elements energized in accordance with the neutralization data to illuminated the area in which toner is absent. The neutralization data generator produces the neutralization data such that there is a buffer area surrounding the first area having a predetermined width. The buffer area is not neutralized.

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Tokyo, Japan

Toyokazu Shiraishi