Canon Kabushiki Kaisha

Kazuhiro Kosuga

Yuji Yamanaka

Taro Ikeda

Fumihiko Hirata

A sheet feeding rollerwhich feeds a sheet S stacked on a sheet supporting platecapable of being lifted and lowered is swingably supported at a swing end of a sheet feeding roller supporting armwhich is arranged swingably in an up-and-down direction and a roller biasing member applies a force to the sheet feeding roller supporting arm in a direction that the sheet feeding roller is pressed to sheets S stacked on a sheet stack tray. A swing fulcrumis arranged in a range between a tangential line of the sheet feeding roller at the upstreammost pressing position against the sheet feeding direction and a tangential line of the sheet feeding roller at the downstreammost pressing position out of pressing positions where the sheet feeding roller is pressed to the sheets as being varied in accordance with a sheet stacking state of the sheets.

Sheet feeding apparatus and image forming apparatus

A sheet feeding rollerwhich feeds a sheet stacked on a sheet supporting platecapable of being lifted and lowered is supported by a support portion as being linearly movable in an up-and-down direction, and a roller biasing member applies a force to the support portion in a direction in which the sheet feeding roller is pressed to s sheet stacked on the sheet supporting plate. A biasing directionof the sheet feeding roller due to the roller biasing member is set within a range between a normal line of the sheet feeding roller at the upstreammost pressing position against the sheet feeding direction and a normal line of the sheet feeding roller at the downstreammost pressing position out of the pressing positions where the sheet feeding roller is pressed to the sheet as being varied in accordance with a sheet stacking state of the sheets.

An image forming apparatus includes a sheet storage unit, a sheet feeding unit, a conveyance path for conveying a sheet to the image forming unit, a plurality of sheet detection sensors disposed along the conveyance path, a determination unit for determining whether predetermined time elapses from a detection of a front end of the sheet until a detection of a rear end of the sheet and a discharge unit. When the determination unit determines that the predetermined time has elapsed based on the detection by the sheet detection sensor disposed in the furthest upstream position among the plurality of sheet detection sensors, the sheet is discharged from the discharge unit, and when the determination unit determines that the predetermined time has elapsed based on the detection by the sheet detection sensors other than that disposed in the furthest upstream position, the sheet is stopped.

Image forming apparatus

Even if a sheet surface detection mechanism outputs a signal indicating that an uppermost sheet among blown-up sheets is within a conveyance range, if a trailing edge sheet surface sensor outputs a signal indicating that the uppermost sheet among the blown-up sheets is lower than the conveyance range when the conveyed uppermost sheet passes by the trailing edge sheet surface sensor, a lifting and lowering portion is controlled to lift the tray so that the uppermost sheet is positioned within the conveyance range.

The present invention provides a sheet conveying apparatus and an image forming apparatus having the same, in which a jammed sheet can be easily viewed and easily removed. A sheet conveying apparatus of the present invention comprises a fixation guide portion fixed on an apparatus body; a first guide portion disposed to face the fixation guide portion; a second guide portion disposed to face the fixation guide portion, wherein the first guide portion and the second guide portion are arranged in a line along a sheet conveying direction and each of the first guide portion and the second guide portion is independently movable; a sheet conveying path formed by the fixation guide, the first guide portion and the second guide portion, and a movement mechanism that moves the second guide portion away from the fixation guide portion, when the first guide portion is moved to open the sheet conveying path.

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Abiko, Japan

Kazuhiro Kosuga