Sheet conveyance apparatus and image forming apparatus having multiple driven rollers supported by guides in a curved conveyance path
A sheet conveyance apparatus includes a first nip portion to convey a sheet in a sheet conveyance direction, a second nip portion to convey the sheet, and a guide unit to form a curved conveyance path that curves with respect to the sheet conveyance direction. The guide unit includes a first guide, a second guide to form at least a part of a curved conveyance path with the first guide, a first driven roller rotatably supported by the first guide, and a second driven roller rotatably supported by the second guide. When viewed in a width direction orthogonal to the sheet conveyance direction, a part of the first guide is formed so as not to intersect with a straight line passing through a first contact point and a second contact point.
1 . A sheet conveyance apparatus comprising:
a first conveyance unit configured to form a first nip portion, the first conveyance unit being configured to convey a sheet in a sheet conveyance direction by the first nip portion;
a second conveyance unit arranged downstream of the first conveyance unit in the sheet conveyance direction and configured to form a second nip portion, the second conveyance unit being configured to convey the sheet by the second nip portion; and
a guide unit configured to form a curved conveyance path that curves with respect to the sheet conveyance direction, the guide unit being configured to guide the sheet conveyed by the first conveyance unit to the second conveyance unit,
wherein the guide unit includes:
a first guide;
a second guide configured to form at least a part of the curved conveyance path with the first guide, the first guide forming an outer side of the curved conveyance path, the second guide forming an inner side of the curved conveyance path;
a first driven roller rotatably supported by the first guide, and rotatably driven with respect to the sheet by coming into contact with the sheet, at a first contact point, conveyed through the curved conveyance path by the second conveyance unit; and
a second driven roller rotatably supported by the second guide and arranged downstream of the first driven roller in the sheet conveyance direction, the second driven roller being rotatably driven with respect to the sheet by coming into contact with the sheet, at a second contact point, conveyed through the curved conveyance path by the second conveyance unit,
wherein, when viewed in a width direction orthogonal to the sheet conveyance direction, a part of the first guide is formed so as not to intersect with a straight line passing through the first contact point and the second contact point, and is positioned upstream of the first contact point in the sheet conveyance direction, and
wherein a horizontal component of the sheet conveyance direction in which the first nip portion of the first conveyance unit conveys the sheet is opposite to a horizontal component of a direction in which the second nip portion of the second conveyance unit conveys the sheet.
2 . The sheet conveyance apparatus according to claim 1 , wherein the first guide includes:
a first guide surface extending to approach the second guide toward a downstream side in the sheet conveyance direction, the first guide surface being formed so as not to intersect with the straight line; and
a second guide surface formed continuously from a vertex that is a downstream end of the first guide surface in the sheet conveyance direction, the second guide surface bending at the vertex from the first guide surface, and extending along the second guide, and
wherein, when viewed in the width direction, the first driven roller is arranged so as to overlap the vertex.
3 . The sheet conveyance apparatus according to claim 2 , wherein, when viewed in the width direction, an outer circumferential surface of the first driven roller is arranged so as to be more projected into the curved conveyance path than the vertex.
4 . The sheet conveyance apparatus according to claim 2 , wherein, when viewed in the width direction, the first guide surface is arranged so as to intersect with a nip line of the first nip portion.
5 . The sheet conveyance apparatus according to claim 2 , wherein, when viewed in the width direction, the first contact point is closer with respect to a straight line passing through the second contact point and a downstream end portion, in the sheet conveyance direction, of the first nip portion than an upstream end, in the sheet conveyance direction, of the first guide surface.
6 . The sheet conveyance apparatus according to claim 2 , wherein the first guide surface and the second guide surface are constituted by distal end portions of a plurality of ribs disposed on the first guide.
7 . The sheet conveyance apparatus according to claim 1 , wherein each of the first driven roller and the second driven roller is configured so as not to nip the sheet conveyed through the curved conveyance path.
8 . The sheet conveyance apparatus according to claim 1 , wherein a rotation shaft of the first driven roller and a rotation shaft of the second driven roller are parallel to the width direction.
9 . The sheet conveyance apparatus according to claim 1 , wherein a rotation shaft of the first driven roller and a rotation shaft of the second driven roller are inclined with respect to the width direction.
10 . The sheet conveyance apparatus according to claim 1 , further comprising:
a casing accommodating the first conveyance unit, the second conveyance unit, and the guide unit, and including an opening; and
a door supported by the casing and configured to open and close the opening,
wherein, when the door is opened, a gap between the first guide and the second guide is exposed an outside of the sheet conveyance apparatus via the opening, and
wherein the first guide and the second guide are configured so as not to allow a user to access the first conveyance unit via the gap.
11 . The sheet conveyance apparatus according to claim 1 , further comprising:
a casing accommodating the first conveyance unit, the second conveyance unit, and the guide unit, and including an opening; and
a door supported by the casing and configured to open and close the opening,
wherein, when the door is opened, a gap between the first guide and the second driven roller is exposed an outside of the sheet conveyance apparatus via the opening, and
wherein the first guide and the second driven roller are configured so as not to allow a user to access the first conveyance unit via the gap.
12 . The sheet conveyance apparatus according to claim 1 , wherein the first conveyance unit includes a heating rotary member and a pressing rotary member configured to fix a toner image transferred onto the sheet on the sheet, and
wherein the first driven roller is arranged on the same side as the pressing rotary member with respect to the curved conveyance path.
13 . The sheet conveyance apparatus according to claim 12 , wherein the heating rotary member is a film.
14 . The sheet conveyance apparatus according to claim 12 , wherein the width direction is a direction parallel to a rotation shaft of the pressing rotary member.
15 . The sheet conveyance apparatus according to claim 1 , wherein the second conveyance unit includes a sheet discharge roller pair that discharges the sheet outside of the sheet conveyance apparatus.
16 . An image forming apparatus comprising:
an image forming unit configured to form an image on a sheet; and
the sheet conveyance apparatus according to claim 1 .
17 . A sheet conveyance apparatus comprising:
a first conveyance unit configured to form a first nip portion, the first conveyance unit being configured to convey a sheet in a sheet conveyance direction by the first nip portion;
a second conveyance unit arranged downstream of the first conveyance unit in the sheet conveyance direction, the second conveyance unit being configured to convey the sheet; and
a guide unit configured to form a curved conveyance path that curves with respect to the sheet conveyance direction, the guide unit being configured to guide the sheet conveyed by the first conveyance unit to the second conveyance unit,
wherein the guide unit includes:
a first guide;
a second guide configured to form at least a part of the curved conveyance path with the first guide, the first guide forming an outer side of the curved conveyance path, the second guide forming an inner side of the curved conveyance path;
a first driven roller rotatably supported by the first guide, and rotatably driven with respect to the sheet by coming into contact with the sheet, at a first contact point, conveyed through the curved conveyance path by the second conveyance unit; and
a second driven roller rotatably supported by the second guide and arranged downstream of the first driven roller in the sheet conveyance direction, the second driven roller being rotatably driven with respect to the sheet by coming into contact with the sheet, at a second contact point, conveyed through the curved conveyance path by the second conveyance unit,
wherein, when viewed in a width direction orthogonal to the sheet conveyance direction, a part of the first guide is formed so as not to intersect with a straight line passing through the first contact point and the second contact point, and is positioned upstream of the first contact point in the sheet conveyance direction, and
wherein the first guide is disposed below the sheet conveyed by the first conveyance unit to the second conveyance unit.
18 . The sheet conveyance apparatus according to claim 17 , wherein the first guide includes:
a first guide surface extending to approach the second guide toward a downstream side in the sheet conveyance direction, the first guide surface being formed so as not to intersect with the straight line; and
a second guide surface formed continuously from a vertex that is a downstream end of the first guide surface in the sheet conveyance direction, the second guide surface bending at the vertex from the first guide surface, and extending along the second guide, and
wherein, when viewed in the width direction, the first driven roller is arranged so as to overlap the vertex.
19 . The sheet conveyance apparatus according to claim 18 , wherein, when viewed in the width direction, an outer circumferential surface of the first driven roller is arranged so as to be more projected into the curved conveyance path than the vertex.
20 . The sheet conveyance apparatus according to claim 18 , wherein, when viewed in the width direction, the first guide surface is arranged so as to intersect with a nip line of the first nip portion.