Paper sheet transporting device and image forming apparatus using the same

1. A paper sheet transporting device comprising:

a transport belt including an endless belt that is wound around and rotates on support rolls and in which plural air holes are formed, the transport belt sucking a paper sheet onto an outer peripheral surface of that belt and transporting the paper sheet through a constant section;

a suction duct that is disposed in a state where it exists at least in an inside space surrounded by an inner peripheral surface of the transport belt, the suction duct being equipped with a suction surface portion in which plural suction openings that face and open to the inner peripheral surface of the transport belt passing a paper sheet suction section are formed at intervals in an rotating axial direction of the transport belt and an air duct portion that is connected to an inner surface side of the suction surface portion and allows air taken in from the suction openings to pass through; and

an air suction device that is connected via a connecting duct to the air duct portion of the suction duct and sucks air,

wherein in the air duct portion of the suction duct, a suction confluence opening that collects the air that is sucked and allows the air to pass through is disposed in a position included in a region where the suction openings whose suction force is relatively the highest of the plural suction openings exist and which position is away from the inner surface side of the suction surface portion, with the air duct portion being formed in a shape where the opening cross-sectional area of the air duct portion becomes relatively narrower away from the suction confluence opening in the rotating axial direction of the transport belt,

wherein the suction duct is a box-shaped structure disposed in a state where it exists at least in the inside space of the transport belt, and

wherein one surface of the boxlike structure is formed as the suction surface portion, with the suction confluence opening and the air duct portion being formed, and at least one part of the connecting duct being formed, by disposing a plate-shaped member to partition the interior space of the boxlike structure,

wherein the plate-shaped member comprises two plate-shaped members,

wherein the two plate-shaped members are disposed in a state where one end portion of each in the rotating axial direction of the transport belt are an interval apart from each other in a state where the one end portions are distanced from one inner surface of the boxlike structure that faces the inner surface side of the suction surface portion, with the space of the clearance between the end portions being formed as the suction confluence opening, and

wherein the two plate-shaped members are disposed in a state where they are slanted so as to become closer to the suction surface portion away from the positions of the one end portions in the rotating axial direction of the transport belt, with the space between the two plate-shaped members and the suction surface portion being formed as the air duct portion and with the space between the one plate-shaped member and the one inner surface of the boxlike structure being formed as the at least one part of the connecting duct.

2. The paper sheet transporting device according to claim 1 ,

wherein the two plate-shaped members are side-plated plate-shaped members having, on side portions thereof on both sides in the rotating axial direction of the transport belt, side plates that reach and contact the one inner surface, and

wherein the side-plated plate-shaped members are disposed in a state where clearances respectively exist between the two side plates and inner surfaces of the interior space of the boxlike structure on an upstream side and a downstream side in a paper sheet transporting direction resulting from the transport belt, with the spaces of the clearances being formed as parts of the air duct portion.

3. The paper sheet transporting device according to claim 2 ,

wherein the paper sheet transporting device has a structure where a clearance existing between the one end portion of the plate-shaped member other than the plate-shaped member of the plate-shaped members that configures the at least one part of the connecting duct and the one inner surface in the interior space is closed off.

4. The paper sheet transporting device according to claim 1 ,

wherein the paper sheet transporting device has a structure where a clearance existing between the one end portion of the plate-shaped member other than the plate-shaped member of the plate-shaped members that configures the at least one part of the connecting duct and the one inner surface in the interior space is closed off.

5. An image forming apparatus, comprising:

an image forming section that forms an image on a paper sheet, wherein the image forming apparatus is equipped with the paper sheet transporting device of claim 1 as at least one part of a device that transports the paper sheet.

6. A paper sheet transporting device comprising:

a transport belt including an endless belt that is wound around and rotates on support rolls and in which plural air holes are formed, the transport belt sucking a paper sheet onto an outer peripheral surface of that belt and transporting the paper sheet through a constant section;

a suction duct that is disposed in a state where it exists at least in an inside space surrounded by an inner peripheral surface of the transport belt, the suction duct being equipped with a suction surface portion in which plural suction openings that face and open to the inner peripheral surface of the transport belt passing a paper sheet suction section are formed at intervals in an rotating axial direction of the transport belt and an air duct portion that is connected to an inner surface side of the suction surface portion and allows air taken in from the suction openings to pass through; and

an air suction device that is connected via a connecting duct to the air duct portion of the suction duct and sucks air,

wherein in the air duct portion of the suction duct, a suction confluence opening that collects the air that is sucked and allows the air to pass through is disposed in a position included in a region where the suction openings whose suction force is relatively the highest of the plural suction openings exist and which position is away from the inner surface side of the suction surface portion, with the air duct portion being formed in a shape where the opening cross-sectional area of the air duct portion becomes relatively narrower away from the suction confluence opening in the rotating axial direction of the transport belt,

wherein the connecting duct is disposed in a state where the connecting duct passes through the inside space of the transport belt and projects from a side portion of that inside space,

wherein the suction duct is a box-shaped structure disposed in a state where it exists at least in the inside space of the transport belt,

wherein one surface of the boxlike structure is formed as the suction surface portion, with the suction confluence opening and the air duct portion being formed, and at least one part of the connecting duct being formed, by disposing a plate-shaped member to partition the interior space of the boxlike structure,

wherein the plate-shaped member comprises two plate-shaped members,

wherein the two plate-shaped members are disposed in a state where one end portion of each in the rotating axial direction of the transport belt are an interval apart from each other in a state where the one end portions are distanced from one inner surface of the boxlike structure that faces the inner surface side of the suction surface portion, with the space of the clearance between the end portions being formed as the suction confluence opening, and

wherein the two plate-shaped members are disposed in a state where they are slanted so as to become closer to the suction surface portion away from the positions of the one end portions in the rotating axial direction of the transport belt, with the space between the two plate-shaped members and the suction surface portion being formed as the air duct portion and with the space between the one plate-shaped member and the one inner surface of the boxlike structure being formed as the at least one part of the connecting duct.

7. The paper sheet transporting device according to claim 6 ,

wherein the two plate-shaped members are side-plated plate-shaped members having, on side portions thereof on both sides in the rotating axial direction of the transport belt, side plates that reach and contact the one inner surface, and

wherein the side-plated plate-shaped members are disposed in a state where clearances respectively exist between the two side plates and inner surfaces of the interior space of the boxlike structure on an upstream side and a downstream side in a paper sheet transporting direction resulting from the transport belt, with the spaces of the clearances being formed as parts of the air duct portion.

8. The paper sheet transporting device according to claim 7 ,

wherein the paper sheet transporting device has a structure where a clearance existing between the one end portion of the plate-shaped member other than the plate-shaped member of the plate-shaped members that configures the at least one part of the connecting duct and the one inner surface in the interior space is closed off.

9. The paper sheet transporting device according to claim 6 ,

wherein the paper sheet transporting device has a structure where a clearance existing between the one end portion of the plate-shaped member other than the plate-shaped member of the plate-shaped members that configures the at least one part of the connecting duct and the one inner surface in the interior space is closed off.