Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Satoshi Miyajima

Tadayuki Ueda

Takanobu Shiki

Eiji Nishikawa

Remi Ishikawa

Yoshihito Sasamoto

Hiroshi Oyama

Toru Kasamatsu

Teruhiko Fujikura

Yukinobu Iguchi

Yohei Yamada

Hiroyuki Yoshikawa

Akinori Kimata

Yuta Tachibana

Kouei Cho

Kosuke Sasaki

Masayuki Fukunaga

Kazumichi Yoshida

Takayuki Ueda

A rotation detector includes a motor, a current detector and a hardware processor. The motor includes coils of two or more phases and a rotor. The current detector detects currents flowing in coils of at least two phases among the coils of two or more phases. The hardware processor estimates an initial position of the rotor based on current values of the currents detected by the current detector to start the motor, controls an energization pattern on the phases to rotate and start the motor based on the estimated initial position, and determines whether the rotor stops or is rotating before completing the estimation of the initial position.

Rotation detector and image forming apparatus

An image forming apparatus that has a transfer device that includes an intermediate transfer belt that is tensioned by a plurality of support rollers, a secondary transfer roller that faces one of the support rollers via the intermediate transfer belt, a cam that adjust a pressing force that presses the intermediate transfer belt by the secondary transfer roller, a motor that drives the cam, and a conveyor that conveys a recording medium to a transfer nip formed between the intermediate transfer belt and the secondary transfer roller is provided with a controller that controls an operation of the motor. The controller executes first control of operating the motor with a constant torque and stopping the motor when a rotation angular speed of the motor is less than or equal to a first threshold and second control of operating the motor at a predetermined timing to adjust a transfer nip amount.

Image forming apparatus, transfer method, and storage medium storing transfer control program

A sheet conveying apparatus includes: a plurality of driving parts each connected to one end of corresponding one of a respective plurality of rotating shafts; a first torque adjuster connected to another end of each of the plurality of rotating shafts, the first torque adjuster applying first torque to the plurality of driving parts; a second torque adjuster that applies, to the driving parts, second torque for adjusting the first torque to be applied to the driving parts by the first torque adjuster; and a hardware processor that controls the second torque to be applied to the driving parts in the second torque adjuster in accordance with a number of revolutions of the driving part.

Sheet conveying apparatus

A drive apparatus according to the present invention includes a stepping motor that transmits power to a rotating shaft of a conveyance roller, a brushless motor that transmits power to the rotating shaft of the conveyance roller, a first controller that controls an operation of the stepping motor so that the stepping motor rotates at a constant speed, and a second controller that controls an operation of the brushless motor. The second controller switches control of the brushless motor between, in accordance with a conveyance state of the sheet, assist control in which power of the brushless motor assists a rotation of the stepping motor, brake control in which power of the brushless motor prevents the rotation of the stepping motor, and neutral control in which power of the brushless motor does not affect the rotation of the stepping motor.

Drive apparatus and image forming apparatus

A drive apparatus according to the present invention includes a first motor that transmits power to a rotating shaft of a conveyance roller for conveying a sheet, a second motor that transmits power to the rotating shaft of the conveyance roller, a storage that stores information indicating the driving force of the second motor during a period in which the conveyance roller conveys the sheet; and a controller that drives the second motor with the driving force indicated by the information during a period when the conveyance roller conveys the sheet, wherein the controller changes the information stored in the storage according to a load applied to the conveyance roller during the period when the conveyance roller conveys the sheet, and drives the second motor with a driving force indicated by the information after the change during a period when the conveyance roller conveys a next sheet.

An image forming apparatus includes the following. An upstream second conveying roller and a downstream second conveying roller form a loop on the long sheet. A deviation amount detector detects a deviation amount of the long sheet. A loop amount detector detects a loop amount in two positions in a width direction. A speed controller controls a rotating speed of the upstream second conveying roller and the downstream second conveying roller based on a deviation amount and a difference of loop amounts in two positions. Each of the upstream second conveying roller and the downstream second conveying roller includes a near roller and a far roller. The speed controller controls the rotating speed of the near roller and the far roller based on the deviation amount and the difference of the loop amounts in the two positions.

Image forming apparatus

A sheet conveying apparatus includes: a plurality of conveyors provided along a sheet conveying direction; a plurality of main driving parts that is respectively provided to the plurality of conveyors and independently drives the conveyors; an auxiliary driving part that drives the plurality of conveyors; and a transmitter that transmits driving force between the plurality of conveyors and transmits driving force of the auxiliary driving part to the plurality of conveyors.

Sheet conveying apparatus and image forming apparatus

An image forming apparatus detects that the temperature of a fixing member reaches a lower limit value at which the temperature once reduced by the start of a heating and fixing process to a paper turns to rise, after an image forming operation starts, and determines the type of the paper based on at least one of an elapsed time from a predetermined reference time point after the image forming operation starts to a time point at which it is detected that the temperature reaches the lower limit value, and a temperature difference between the temperature of the fixing member at the reference time point and the lower limit value.

In an image forming apparatus according to the present invention, when an image forming operation is started from a standby state, electric power is supplied to a heater by switching to a first fixing control to turn on and off the heater to heat a heating roller with a fixed duty ratio based on the detected temperature of the heating roller, and thereafter, when detecting a state that the falling detected temperature reaches a lower limit value at which the detected temperature turns to rising, electric power is supplied to the heater by switching to a second fixing control which changes a duty ratio in accordance with a temperature difference between the detected temperature and a target control temperature.

An image forming apparatus forms decision registration mark for deciding whether or not a color registration correction for correcting color shifts in the color image carries out on an intermediate transfer belt. The decision registration mark is formed by registering four color registration marks. Color registration sensors detect a detection width of the decision registration mark along a sub scanning direction. A control portion receives the detection width of the decision registration mark and decides whether or not the color registration correction carries out based on whether or not the detection width of the decision mark detected by the detection portion exceeds the period of reference time. When the detection width of the decision mark detected by the detection portion exceeds the period of reference time, the control portion carries out the color registration correction.

An image forming apparatus which allows a user to freely select a desired image quality is provided. The control unitsets a of registration set value Afor determining a color registration error suppression level and a dropout set value Afor determining a dropout occurrence suppression level. Also, the control unitsets a differential circumferential speed which is the difference between the circumferential speed of photoreceptor drumsY toK and the circumferential speed of an intermediate transfer belton the basis of the color registration set value Aand the dropout set value A. Then, the control unitcontrols the belt drive motorand the drum drive motoron the basis of the differential circumferential speed which is set.

An image forming apparatus includes an adjustment unit that adjusts an image transfer position of the sheet of paper along a main scanning direction that is orthogonal to a transporting direction of the sheet of paper, a fixing unit that fixes on the sheet of paper an toner image using fixing rollers and performs a fluctuation of the fixing roller to the main scanning direction, a detection unit that detects whether or not the fixing rollers of the fixing unit nip the sheet of paper, and a controller. The controller controls the fixing unit to perform the fluctuation of the fixing rollers when determining that the fixing rollers of the fixing unit do not nip the sheet of paper based on a detection result of the detection unit.

Image forming apparatus which controls fluctuation of fixing rollers based on a detected interval between transferred sheets of recording media

Provided are an image forming apparatus, a fixing device, and an image forming system using the same, including: an image forming section for transferring a toner image onto a recording sheet; a first and second fixing rollers for thermally fixing the toner image on the recording sheet; a first and second temperature sensors each provided at a plurality of positions in a longitudinal direction of the fixing roller; and a rocking section for reciprocally shifting at least one of the fixing rollers in the longitudinal direction of the fixing roller, wherein the temperature gradient of each of the fixing rollers is detected, a central position of reciprocal shift of one fixing roller which can be shifted is set such that the temperature gradient of the other fixing roller is cancelled, and then the one fixing roller is reciprocally shifted by the rocking section.

Image forming apparatus, fixing device, and image forming system using the same

To enhance the fixing quality of a fixing device to continuously fix sheets of a plurality of sizes, a carbon nanotube sheet, in which a plurality of carbon nanotubes are arranged such that the longitudinal directions thereof are oriented in the same direction, is provided on the surface of a heating rollerso that the carbon nanotube sheet ranges from the position a predetermined distance inside and the position a predetermined distance outside of the position through which each of the both edges of a sheet Pwith smaller width dimension than a sheet Pof the largest width dimension to be fixed passes.

Growing community of inventors

Hino, Japan

Satoshi Miyajima