Ricoh Company, Ltd.

Yusuke Ishizaki

Hiroyuki Iwasaki

Takahisa Koike

Hideyuki Takayama

Minoru Takahashi

Motoharu Takahashi

Masahiro Ashikawa

Kohhei Yamaguchi

Masashi Kasamai

Takaaki Kaneko

Takehiro Chiba

An abnormality detecting device includes: a light emitter including a light-emitting element disposed at one side of a conveyed medium, and configured to emit a laser beam having a width in a thickness direction of the medium by the light-emitting element; a light receiver disposed at the other side of the medium to be opposed to the light emitter across the medium, including a plurality of light-receiving elements arranged in the thickness direction of the medium, and configured to receive, by the plurality of light-receiving elements, the laser beam emitted by the light emitter; and a detecting unit configured to detect a lift of the medium in a case where a number of light-receiving elements indicating received light amounts not exceeding a first threshold and being arranged successively in the thickness direction among the plurality of light-receiving elements exceeds a second threshold.

Abnormality detecting device, abnormality detecting method, computer program product, and image forming device

A mark detecting device includes: a belt on which a plurality of marks are provided along a moving direction of the belt; a light-emitting element configured to irradiate at least one of the marks with light; a light-receiving element configured to receive a reflected light reflected from at least one of the belt and the mark of the light irradiated from the light-emitting element and output a signal; and a light amount adjuster configured to compare a first value obtained from the signal output by the light-receiving element and a second value obtained from a signal output by the light-receiving element after the first value is obtained, and to perform light amount adjustment of the light-emitting element when a difference between the first value and the second value is a first threshold or more.

Mark detecting device, belt control device, image forming apparatus, mark detecting method, and computer-readable recording medium

There is provided a driving apparatus comprising: a driving unit configured to rotate a driving shaft; a speed setting unit for setting a rotational speed of the driving shaft; a driving shaft joint connected with the driving shaft to rotate with the driving shaft for transmitting driving-force to a driven apparatus, the driving shaft joint being fitted into a driven shaft joint connected with the driven apparatus that is made detachable; a rotational position detection unit configured to detect a predetermined rotational position of the driving shaft joint; and a driving control unit configured to control the driving unit; wherein upon the driven apparatus being detached, the driving control unit controls the driving unit to stop the rotating driving shaft based on a detection result of the rotational position detection unit after the speed setting unit sets the rotational speed of the driving shaft to be a first rotational speed.

Driving apparatus, image forming apparatus, method of driving control and program

A belt conveyance apparatus including a driving roller to rotate and drive a belt, a first detector to detect surface speed of the belt, and a second detector to detect rotation speed of the driving roller. There is a first calculator to calculate a first deviation from target speed based on the surface speed and the target speed, and a memory to store a correction value corresponding to the first deviation. A second calculator calculates a second deviation from the target speed corrected by the first deviation based on the target speed, the first deviation and the rotation speed of the driving roller. A controller controls the rotation speed of the driving roller based on the second deviation. There is also a switch to switch the first deviation to the correction value stored in the memory when controller judges that the first detector is abnormal.

Belt conveyance apparatus including a belt and a driving roller in an image forming apparatus or system

A belt transport apparatus includes a first computation unit that computes a first deviation between a surface speed of a belt and a target speed of the belt, a position controller that computes a speed correction value based on the first deviation, a speed deviation ratio computation unit that computes a ratio of the belt surface speed and a rotational speed of a driving roller, a second computation unit that selectively computes according to predetermined conditions one of a second deviation between the rotational speed and a sum of an increment of the speed correction value and the target speed and a third deviation between the rotational speed and a sum of a value corrected according to the ratio stored in a storage unit and the target speed, and a control unit that controls the rotational speed based on the one of the second and third deviations.

Belt transport apparatus, image forming apparatus, and image forming system

A medium conveying apparatus includes a conveying status detecting unit configured to determine a conveyance status of a medium based on a driving torque of a driving unit, wherein the conveying unit is configured to convey the medium at a reference speed, the reference speed being faster than the upstream conveying unit at least when the medium is conveyed from the upstream conveying unit, and the reference speed being slower than the downstream conveying unit at least when the medium is conveyed to the downstream conveying unit, and wherein the conveyance status of the medium is detected by the comparison of a prescribed reference torque to the driving torque of the driving unit at least when the medium is conveyed between the upstream conveying unit and the conveying unit or when the medium is conveyed between the conveying unit and the downstream conveying unit.

Medium conveying apparatus, image forming apparatus, medium conveying system, and medium conveying method

A recording medium conveyor includes a first conveyance part conveying a recording medium; a second conveyance part conveying the conveyed recording medium toward a transfer position; a detection part detecting the position of the recording medium conveyed by the second conveyance part; a position error detection part detecting a position error between the transfer position and a position at which there is to be the recording medium when an image reaches the transfer position; a position error storage part storing the detected position errors; a steady-state position error calculation part calculating a steady-state position error from the stored position errors; a first control part controlling the conveyance speed of the first conveyance part to reduce the steady-state position error; and a second control part controlling the conveyance speed of the second conveyance part to reduce the detected position error, with the steady-state position error being reduced.

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Kanagawa, Japan

Yusuke Ishizaki