Patent ID: 11886136
Assignee: BROTHER KOGYO KABUSHIKI KAISHA
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. An image forming apparatus comprising:
a plurality of rollers;
an endless belt stretched between the plurality of rollers and configured to convey a sheet in a conveyance direction, an upper surface of the endless belt serving as a conveyance surface;
a photosensitive drum provided above the endless belt in a gravitational direction;
a transfer roller configured to form an image on the sheet at a transfer nip between the photosensitive drum and the endless belt; and
a drum frame supporting the photosensitive drum, the drum frame including a first guide located between the transfer nip and a downstream end of the conveyance surface in the conveyance direction, the first guide facing the conveyance surface from above the conveyance surface in the gravitational direction, the first guide being configured to contact the sheet that is conveyed on the conveyance surface,
the first guide is a plate-like member including:
a first horizontal surface extending in a width direction perpendicular to the conveyance direction; and
a pair of first inclined surfaces extending from both ends of the first horizontal surface in the width direction, each of the pair of first inclined surfaces having one end adjacent to the first horizontal surface and an other end away from the one end in the width direction, each of the pair of first inclined surfaces being inclined to be closer to the endless belt from the one end toward the other end, the pair of first inclined surfaces being configured to contact both ends of the sheet in the width direction,

wherein the image forming apparatus is configured to form an image on a sheet having a first width in the width direction and on a sheet having a second width greater than the first width;
wherein a distance between the other end of each of the pair of first inclined surfaces in the width direction is larger than the first width;
wherein a size of the first horizontal surface in the width direction is smaller than the first width;
wherein the image forming apparatus further comprises:
a fixing device configured to thermally fix an image formed on the sheet, the fixing device including a heat roller and a pressure roller in contact with the heat roller to form a fixing nip for nipping the sheet, the fixing device including a second guide located between the first guide and the fixing nip in the conveyance direction in a conveyance path of the sheet;

wherein the second guide includes:
a second horizontal surface extending in the width direction; and
a pair of second inclined surfaces extending from both ends of the second horizontal surface in the width direction, each of the pair of second inclined surfaces having an inner end adjacent to the second horizontal surface and an outer end away from the inner end in the width direction, each of the pair of second inclined surfaces being inclined downward from the inner end toward the outer end, the pair of second inclined surfaces being configured to contact both ends of the sheet in the width direction,

wherein a distance between the outer end of each of the pair of second inclined surfaces in the width direction is larger than the second width;
wherein a size of the second horizontal surface in the width direction is smaller than the second width; and
wherein the size of the second horizontal surface in the width direction is larger than the distance between the other end of each of the pair of first inclined surfaces in the width direction.