Abstract: A sheet feeding device includes a sheet carrying unit and an attraction separation and conveyance device. The sheet carrying unit is configured to carry thereon a sheet stack. The attraction separation and conveyance device is configured to electrostatically attract the uppermost sheet of the sheet stack and separate and convey the uppermost sheet from the sheet stack, and is placed between the upstream end and the central position in a sheet conveying direction of the sheet stack located at a sheet carrying position and having a minimum sheet size compatible with the sheet feeding device.

Abstract: A sheet feeder includes: an attracting and separating device disposed above a leading end portion in a sheet-feeding direction of a sheet stack, attracting and holding an uppermost sheet of the sheet stack with electrostatic force and separating the uppermost sheet from the sheet stack, a sheet loading device carrying the sheet stack, and including a first bottom plate carrying a rear-side portion of the sheet stack and a second bottom plate separated from the first bottom plate and carrying the leading end portion of the sheet stack below the attracting and separating device; and a lifting device lifting and lowering the sheet loading device, and including a first lifting device lifting and lowering the first bottom plate and a second lifting device lifting and lowering the second bottom plate to move the leading end portion of the sheet stack toward and away from the attracting and separating device.

Abstract: A sheet feeding device includes a sheet carrying unit, an attraction separation device electrostatically attracting and separating an uppermost sheet from a sheet stack and including multiple rollers, an endless dielectric belt stretched over the multiple rollers, and an elastic member provided inside a loop of the belt to cause the endless dielectric belt to contact the uppermost sheet, a sheet conveying device, and a lifting and lowering device. The lifting and lowering device lifts the sheet stack to a lift position at which the uppermost sheet contacts with the attraction separation device, and the attraction separation device stands by for a predetermined time to attract the uppermost sheet and starts to convey the uppermost sheet after the predetermined time elapses in a state in which the sheet stack remains at the lift position.

Abstract: A sheet feeder includes: an attracting and separating device disposed above a leading end portion in a sheet-feeding direction of a sheet stack, attracting and holding an uppermost sheet of the sheet stack with electrostatic force and separating the uppermost sheet from the sheet stack, a sheet loading device carrying the sheet stack, and including a first bottom plate carrying a rear-side portion of the sheet stack and a second bottom plate separated from the first bottom plate and carrying the leading end portion of the sheet stack below the attracting and separating device; and a lifting device lifting and lowering the sheet loading device, and including a first lifting device lifting and lowering the first bottom plate and a second lifting device lifting and lowering the second bottom plate to move the leading end portion of the sheet stack toward and away from the attracting and separating device.

Abstract: A sheet conveying device includes an attractive separation unit and a contacting and separating device. The attractive separation unit includes an attraction belt arranged to face the upper surface of a sheet stack, two rollers that stretch the attraction belt taut, with the upstream-side roller in the sheet conveying direction supported to be movable in substantially upward and downward directions within a predetermined range with respect to the upper surface of the sheet stack, and a charging device which charges a surface of the attraction belt. The contacting and separating device swings the attractive separation unit to make the attraction belt come into contact with and separate from the sheet stack, with a fulcrum of the swing of the attractive separation unit set to a position upstream in the sheet conveying direction of the upstream-side roller in the sheet conveying direction.

Abstract: An Inkjet printer includes a movable conveyance belt, a first charging device, and a second charging device. Upon the conveyance belt, a recording medium is placed and conveyed at a given conveyance speed in a longitudinal, conveyance direction of the belt. The first charging device is disposed in contact with the belt while supplied with a first alternating current voltage to create a first electrified portion in the conveyance belt where positive and negative electric charges are arranged alternately with each other in the conveyance direction for electrostatically attracting the recording medium to the belt. The second charging device is disposed adjacent the belt to contact the recording medium conveyed on the belt while supplied with a second alternating current voltage to create a second electrified portion in the recording medium for cancelling an electric field originating from the first electrified portion of the belt.

Abstract: A sheet feeding device that is incorporatable in an image forming apparatus includes an endless belt disposed facing an upper surface of a sheet stack to convey sheets of the sheet stack forward in a first moving direction of a surface thereof, an attraction unit to attract an uppermost sheet of the sheet stack to the endless belt, a contact and separation unit to contact and separate the endless belt relative to the sheet stack, and a controller to cause the endless belt to contact or substantially contact the upper surface of the sheet stack to attract the uppermost sheet to the endless belt, perform a pre-separation operation in which the endless belt moves in a reverse direction that is opposite the sheet conveyance direction, and then perform a separating operation in which the endless belt separates from the sheet stack.

Abstract: A sheet conveying device includes an attraction belt, multiple rollers, a charging device, and a contacting and separating device. The attraction belt is arranged to face the upper surface of a stacked sheet stack. The multiple rollers stretch the attraction belt with tension. The charging device charges a surface of the attraction belt. The contacting and separating device causes the attraction belt to come into contact with and separate from the sheet stack, with different tensions set for the attraction belt at a contact position in contact with the uppermost sheet of the sheet stack and the attraction belt at a separation position separate from the sheet stack.

Abstract: A sheet feeding device that can be incorporated in an image forming apparatus includes a sheet feeder including a belt unit including an attraction belt facing a sheet stack and first and second tension rollers to keep the attraction belt taut, and a side holder to rotatably support the belt unit about the first tension roller that serves as a pivot of the sheet feeder being disposed upstream from the second tension roller in the sheet conveyance direction, a contact and separation drive unit to swing the sheet feeder to make the attraction belt contact with and separate from the sheet stack, and a swing range adjuster to adjust a range of swing of the belt unit with respect to the side holder between contact and separation of the attraction belt with respect to the sheet stack, according to a predetermined condition.

Abstract: A sheet feeder includes a loading member, an attraction separation unit, and a control device. The loading member carries sheet materials. The attraction separation unit includes an endless dielectric belt, holding rollers, and an adjustment device. The endless belt attracts and holds the uppermost one of the sheet materials. The holding rollers holding the endless belt include upstream and downstream holding rollers. The upstream holding roller is rotated around a shaft of the downstream holding roller as the rotation axis in accordance with rotation of the downstream holding roller. The adjustment device provided to the upstream holding roller adjusts the movement range of the upstream holding roller in the height direction. The control device controls, in accordance with the type of sheet materials, an operation of lifting and lowering the loading member, to thereby allow the adjustment device to adjust the movement range of the upstream holding roller.

Abstract: A sheet feeding device that can be incorporated in an image forming apparatus includes a sheet feeder including a belt unit including an attraction belt facing a sheet stack and first and second tension rollers to keep the attraction belt taut, and a side holder to rotatably support the belt unit about the first tension roller that serves as a pivot of the sheet feeder being disposed upstream from the second tension roller in the sheet conveyance direction, a contact and separation drive unit to swing the sheet feeder to make the attraction belt contact with and separate from the sheet stack, and a swing range adjuster to adjust a range of swing of the belt unit with respect to the side holder between contact and separation of the attraction belt with respect to the sheet stack, according to a predetermined condition.

Abstract: A sheet feeder includes an attraction separation unit including an attraction belt facing the upper surface of a stacked sheet bundle to attract an uppermost sheet thereof, and rotatably supported by a support member at a position upstream of the attraction belt in a sheet feeding direction; and a swing device for swinging the attraction separation unit around the support member as a fulcrum to move the attraction belt between an attraction position and a feed position more distant from the sheet bundle than the attraction position is. The swing device includes a first drive transmitting portion attached to a downstream end portion of the attraction separation unit and a second drive transmitting portion attached to the body of the sheet feeder and connected with the first drive transmitting portion. The first drive transmitting portion and the rack connect to swing the attraction separation unit.

Abstract: A sheet feeder includes: an attraction separation unit including an attraction belt stretched between rollers and facing the upper surface of a sheet bundle to attract an uppermost sheet thereof, rotatably supported by a support member at a position upstream of the attraction belt in a sheet feeding direction, and supporting the rollers to be released from the support upon contact of the rollers with the uppermost sheet via the attraction belt; and a swing device for swinging the attraction separation unit around the support member as a pivot to move the attraction belt between an attraction position and a feed position more distant from the sheet bundle than the attraction position, and swinging, after the uppermost sheet has been attracted to the attraction belt at the attraction position, the attraction belt to the feed position to be rotated to feed the uppermost sheet.

Abstract: A sheet feeding device includes a sheet carrying unit, an attraction separation device electrostatically attracting and separating an uppermost sheet from a sheet stack and including multiple rollers, an endless dielectric belt stretched over the multiple rollers, and an elastic member provided inside a loop of the belt to cause the endless dielectric belt to contact the uppermost sheet, a sheet conveying device, and a lifting and lowering device. The lifting and lowering device lifts the sheet stack to a lift position at which the uppermost sheet contacts with the attraction separation device, and the attraction separation device stands by for a predetermined time to attract the uppermost sheet and starts to convey the uppermost sheet after the predetermined time elapses in a state in which the sheet stack remains at the lift position.

Abstract: A sheet feeder attracts an uppermost sheet of a sheet stack of a plurality of stacked sheets, and feeds the sheet in a sheet feeding direction. The sheet feeder includes an endless belt, a charging device, and a control device. The endless belt is made of a dielectric material, passes over upstream and downstream rollers, and is disposed above the sheet stack to face the sheet stack. The charging device applies an alternating voltage to an outer circumferential surface of the endless belt to form thereon alternating charge patterns. The control device separately controls the respective rotation states of the upstream and downstream rollers to make a sheet contact surface of the endless belt go slack in sheet attraction and make the sheet contact surface of the endless belt taut with tension into a substantially flat surface in sheet conveyance.

Abstract: A sheet feeding device includes a sheet carrying unit, an attraction separation device electrostatically attracting and separating an uppermost sheet from a sheet stack and including multiple rollers, an endless dielectric belt stretched over the multiple rollers, and an elastic member provided inside a loop of the belt to cause the endless dielectric belt to contact the uppermost sheet, a sheet conveying device, and a lifting and lowering device. The lifting and lowering device lifts the sheet stack to a lift position at which the uppermost sheet contacts with the attraction separation device, and the attraction separation device stands by for a predetermined time to attract the uppermost sheet and starts to convey the uppermost sheet after the predetermined time elapses in a state in which the sheet stack remains at the lift position.

Abstract: A sheet feeding device that is incorporatable in an image forming apparatus includes an endless belt disposed facing an upper surface of a sheet stack to convey sheets of the sheet stack forward in a first moving direction of a surface thereof, an attraction unit to attract an uppermost sheet of the sheet stack to the endless belt, a contact and separation unit to contact and separate the endless belt relative to the sheet stack, and a controller to cause the endless belt to contact or substantially contact the upper surface of the sheet stack to attract the uppermost sheet to the endless belt, perform a pre-separation operation in which the endless belt moves in a reverse direction that is opposite the sheet conveyance direction, and then perform a separating operation in which the endless belt separates from the sheet stack.

Abstract: A sheet feeding device that can be incorporated in an image forming apparatus includes a sheet feeder including a belt unit including an attraction belt facing a sheet stack and first and second tension rollers to keep the attraction belt taut, and a side holder to rotatably support the belt unit about the first tension roller that serves as a pivot of the sheet feeder being disposed upstream from the second tension roller in the sheet conveyance direction, a contact and separation drive unit to swing the sheet feeder to make the attraction belt contact with and separate from the sheet stack, and a swing range adjuster to adjust a range of swing of the belt unit with respect to the side holder between contact and separation of the attraction belt with respect to the sheet stack, according to a predetermined condition.

Abstract: A sheet conveying device includes an attractive separation unit and a contacting and separating device. The attractive separation unit includes an attraction belt arranged to face the upper surface of a sheet stack, two rollers that stretch the attraction belt taut, with the upstream-side roller in the sheet conveying direction supported to be movable in substantially upward and downward directions within a predetermined range with respect to the upper surface of the sheet stack, and a charging device which charges a surface of the attraction belt. The contacting and separating device swings the attractive separation unit to make the attraction belt come into contact with and separate from the sheet stack, with a fulcrum of the swing of the attractive separation unit set to a position upstream in the sheet conveying direction of the upstream-side roller in the sheet conveying direction.

Abstract: A sheet conveying device includes an attraction belt, multiple rollers, a charging device, and a contacting and separating device. The attraction belt is arranged to face the upper surface of a stacked sheet stack. The multiple rollers stretch the attraction belt with tension. The charging device charges a surface of the attraction belt. The contacting and separating device causes the attraction belt to come into contact with and separate from the sheet stack, with different tensions set for the attraction belt at a contact position in contact with the uppermost sheet of the sheet stack and the attraction belt at a separation position separate from the sheet stack.