A sheet supply device and a sheet supply method include a guide roller disposed at an opposite side of a standby side roll with respect to a tangential line to an outer peripheral surface of the standby side roll at a pressing position in a state in which a pressing roller is pressed against a pressing position, and configured to guide a sheet from the pressing roller in a direction away from the standby side roll. Furthermore, the second guide roller is fixed to a moving unit so as to be configured to approach and move away from the standby side roll together with the pressing roller.

A controller includes a shaft control unit that controls driving of a shaft drive source such that a standby side roll is rotated, and a unit control unit that presses a pressing roller against an outer peripheral surface of the standby side roll via a sheet of a supply side roll by performing torque control on a unit drive source in a state in which the pressing roller is positioned in an area from a control switching position to the outer peripheral surface of the standby side roll together with performing position control on the unit drive source in a state in which the pressing roller is positioned in an area farther away from the standby side roll than the control switching position away from the outer peripheral surface of the standby side roll by a preset distance while the standby side roll is rotated by the shaft control unit.

A controller includes: an adhesion member position determination unit that determines a position of an adhesion member in a rotation direction of a roll on the basis of the result of detection from an adhesion member detector in a state in which the roll has been rotated by a shaft control unit; and an outer diameter determination unit that determines an outer diameter of the roll in a portion where the adhesion member is positioned, the determination being performed on the basis of the result of detection from an outer diameter detector in a state in which driving of shaft drive sources are controlled by the shaft control unit such that the adhesion member is positioned within a detection range of the outer diameter detector on the basis of the position of the adhesion member determined by the adhesion member position determination unit.

A conveyance device is capable of preventing a remaining portion of a cut sheet from being caught in a conveyance path. A sheet supply device includes an urging mechanism capable of switching between a supply state of applying force in a direction away from a pressing position to an upstream part, in a conveyance direction, of a cut position of a sheet of a supply side roll, the cut position being cut by a cutter, and a stopped state of stopping application of the force, and a controller configured to switch the urging mechanism from the stopped state to the supply state in accordance with a timing when the sheet is cut by the cutter.

An unwinder (1) of rolls (B1, B2) including a bearing structure (3) and two pairs of arms (11A, 11B; 13A, 13B) supported movable on the bearing structure (3). The unwinder further includes a splicing machine (31). The bearing structure (3) includes a base (5) and an upright (7) extending from the base, on which a cross member (33) is supported. The cross member (33) includes an intermediate portion (33A) rigidly bound to the upright (7) and a pair of lateral supports (33B, 33C) adapted to assume at least one operating position and one non-operating position, with respect to the inter-mediate portion (33A) of the cross member (33).

Provided is a sheet supply device capable of reliably joining sheets by accurately transmitting force for joining the sheets. A joining mechanism includes a pressing roller that presses a sheet of a supply side roll against the outer peripheral surface of a standby side roll; and a moving unit that supports the pressing roller such that the pressing roller is configured to approach and move away from the standby side roll supported by a support shaft disposed at a splice position in the radial direction of the standby side roll. The moving unit supports the pressing roller such that the center of the pressing roller is movable on a straight line passing through the center of a rotation shaft and the center of the support shaft disposed at the splice position.

A controller includes a shaft control unit that controls driving of a shaft drive source such that a standby side roll is rotated, and a unit control unit that presses a pressing roller against an outer peripheral surface of the standby side roll via a sheet of a supply side roll by performing torque control on a unit drive source in a state in which the pressing roller is positioned in an area from a control switching position to the outer peripheral surface of the standby side roll together with performing position control on the unit drive source in a state in which the pressing roller is positioned in an area farther away from the standby side roll than the control switching position away from the outer peripheral surface of the standby side roll by a preset distance while the standby side roll is rotated by the shaft control unit.

An unwinder (1) of rolls (B1, B2) including a bearing structure (3) and two pairs of arms (11A, 11B; 13A, 13B) supported movable on the bearing structure (3). The unwinder further includes a splicing machine (31). The bearing structure (3) includes a base (5) and an upright (7) extending from the base, on which a cross member (33) is supported. The cross member (33) includes an intermediate portion (33A) rigidly bound to the upright (7) and a pair of lateral supports (33B, 33C) adapted to assume at least one operating position and one non-operating position, with respect to the inter-mediate portion (33A) of the cross member (33).

Provided are a sheet supply device and a sheet supply method capable of keeping the precision of a sheet separating operation constant regardless of differences in diameter dimensions of rolls. A second guide roller is disposed at an opposite side of a standby side roll with respect to a tangential line to the outer peripheral surface of the standby side roll at a pressing position in a state in which the pressing roller is pressed against the pressing position, and guides a sheet such that the sheet is guided from the pressing roller in a direction away from the standby side roll. Furthermore, the second guide roller is fixed to a moving unit so as to be configured to approach and move away from the standby side roll together with the pressing roller.

Provided is a conveyance device capable of preventing a remaining portion of a cut sheet from being caught in a conveyance path. A sheet supply device includes an urging mechanism capable of switching between a supply state of applying force in a direction away from a pressing position to an upstream part, in a conveyance direction, of a cut position of a sheet of a supply side roll, the cut position being cut by a cutter, and a stopped state of stopping the supply of the force, and a controller that switches the urging mechanism from the stopped state to the supply state in accordance with a timing when the sheet is cut by the cutter.