A sheet feeder device that stores and sends out a transfer medium includes: a sheet feeder device main unit having an opening formed at an upper portion and including an upstream partial lid located on an upstream side and a downstream partial lid located on a downstream side, the upstream partial lid and the downstream partial lid covering at least part of the opening; a sheet feed tray provided in the sheet feeder device main unit, the transfer medium being loaded onto the sheet feed tray; an elevating unit configured to lift up and down the sheet feed tray; and a control unit configured to control the lifting up and down of the sheet feed tray, wherein the control unit senses opening and closing of the upstream partial lid and the downstream partial lid, and controls the lifting up and down being performed by the elevating unit.

The present invention relates to a paper feeding apparatus. The paper feeding apparatus includes: a main body configured such that a paper discharge outlet, a space, and a door are formed therein; a plurality of guide rails formed inside the main body in vertical directions; a plurality of guide rods formed inside the main body in vertical directions; a paper support plate formed in a plate shape so that paper is stacked and supported thereon, and configured such that a plurality of bushings, insertion grooves, and a multi-stage screw are formed in connection with the paper support plate; a power unit including a motor provided with a driving pulley, a driven pulley, and a chain configured to connect the driving pulley and the driven pulley; and a sensor configured to measure the weight of paper, and a controller configured to control the driving of the power unit.

The present invention relates to a paper feeding apparatus. The paper feeding apparatus includes: a main body configured such that a paper discharge outlet, a space, and a door are formed therein; a plurality of guide rails formed inside the main body in vertical directions; a plurality of guide rods formed inside the main body in vertical directions; a paper support plate formed in a plate shape so that paper is stacked and supported thereon, and configured such that a plurality of bushings, insertion grooves, and a multi-stage screw are formed in connection with the paper support plate; a power unit including a motor provided with a driving pulley, a driven pulley, and a chain configured to connect the driving pulley and the driven pulley; and a sensor configured to measure the weight of paper, and a controller configured to control the driving of the power unit.

A sheet feeding apparatus includes a sheet stacker, an air blower, a suction feeder, a lifting mechanism, an elevation detection sensor, an elevation detection sensor, a feed detection sensor, and processing circuitry. The air blower blows air to float an uppermost sheet of sheets stacked on the sheet stacker. The processing circuitry drives the lifting mechanism such that the sheet stacker is lifted by an elevation amount determined based on a sheet thickness of the sheets stacked on the sheet stacker, each time a sheet is detected when a number of sheets detected is smaller than a threshold number of sheets, and stops lifting of the sheet stacker until a sheet is not detected when the number of sheets reaches the threshold number of sheets, while repeatedly feeding the uppermost sheet and counting the number of sheets.

A sheet feeding apparatus includes a sheet stacker, an air blower, a suction feeder, a lifting mechanism, an elevation detection sensor, an elevation detection sensor, a feed detection sensor, and processing circuitry. The air blower blows air to float an uppermost sheet of sheets stacked on the sheet stacker. The processing circuitry drives the lifting mechanism such that the sheet stacker is lifted by an elevation amount determined based on a sheet thickness of the sheets stacked on the sheet stacker, each time a sheet is detected when a number of sheets detected is smaller than a threshold number of sheets, and stops lifting of the sheet stacker until a sheet is not detected when the number of sheets reaches the threshold number of sheets, while repeatedly feeding the uppermost sheet and counting the number of sheets.

A sheet feeder includes an apparatus main body, a sheet housing unit, and a sheet feeding unit. The sheet housing unit includes a housing space, a lift plate, an elevating mechanism, and a side fence. The elevating mechanism includes a pair of first wires, a pair of second wires, first pulleys, second pulleys, a reel, and a pair of first connecting members. The reel winds up the pair of first wires and the pair of second wires. The pair of first connecting members are connected to be relatively movable with respect to the lift plate in a vertical direction, causes a relative position to vary with respect to the lift plate in a vertical direction in accordance with a weight of the plurality of sheets loaded on the lift plate, and causes the lift plate to move upward when the weight is lighter than a predetermined value.

A sheet feeder includes an apparatus main body, a sheet housing unit, and a sheet feeding unit. The sheet housing unit includes a housing space, a lift plate, an elevating mechanism, and a side fence. The elevating mechanism includes a pair of first wires, a pair of second wires, first pulleys, second pulleys, a reel, and a pair of first connecting members. The reel winds up the pair of first wires and the pair of second wires. The pair of first connecting members are connected to be relatively movable with respect to the lift plate in a vertical direction, causes a relative position to vary with respect to the lift plate in a vertical direction in accordance with a weight of the plurality of sheets loaded on the lift plate, and causes the lift plate to move upward when the weight is lighter than a predetermined value.

An image forming apparatus includes a lift plate, an actuator, a photosensor, and a controller. Paper is placed on the lift plate. The lift plate is driven to increase a first inclination angle in response to a decrease in a residual amount of the paper placed on the lift plate. The first inclination angle indicates an angle of inclination of the lift plate with respect to a horizontal plane. A second inclination angle indicating an angle of inclination of the actuator with respect to the horizontal plane increases in response to an increase in the first inclination angle. The actuator increases or decreases a transmitted light quantity along with an increase in the second inclination angle. The photosensor detects the transmitted light quantity. The controller calculates the residual amount of the paper on the basis of the transmitted light quantity.

A sheet feeder device that stores and sends out a transfer medium includes: a sheet feeder device main unit having an opening formed at an upper portion and including an upstream partial lid located on an upstream side and a downstream partial lid located on a downstream side, the upstream partial lid and the downstream partial lid covering at least part of the opening; a sheet feed tray provided in the sheet feeder device main unit, the transfer medium being loaded onto the sheet feed tray; an elevating unit configured to lift up and down the sheet feed tray; and a control unit configured to control the lifting up and down of the sheet feed tray, wherein the control unit senses opening and closing of the upstream partial lid and the downstream partial lid, and controls the lifting up and down being performed by the elevating unit.

A sheet feeder device that stores and sends out a transfer medium includes: a sheet feeder device main unit having an opening formed at an upper portion and including an upstream partial lid located on an upstream side and a downstream partial lid located on a downstream side, the upstream partial lid and the downstream partial lid covering at least part of the opening; a sheet feed tray provided in the sheet feeder device main unit, the transfer medium being loaded onto the sheet feed tray; an elevating unit configured to lift up and down the sheet feed tray; and a control unit configured to control the lifting up and down of the sheet feed tray, wherein the control unit senses opening and closing of the upstream partial lid and the downstream partial lid, and controls the lifting up and down being performed by the elevating unit.