Image forming apparatus

Patent metadata

Field	Value
Publication number	US-2019302660-A1
Application number	US-201916357470-A
Country	US
Kind code	A1
Filing date	Mar 19, 2019
Priority date	Mar 27, 2018
Publication date	Oct 3, 2019
Grant date	—

Abstract

A toner image is formed on a first sheet surface and then heated. A conveyance unit includes a first rotary member configured to contact the first sheet surface and a second rotary member configured to contact a second sheet surface opposite to the first sheet surface. A conveyance guide is provided with an opening through which air is blown to the first sheet surface. The conveyance guide includes a first surface part and a second surface part. The first surface part is disposed on a location in a width direction overlapping with a location in the width direction of the first rotary member. In at least a part of a range between the opening and the first rotary member in the sheet conveyance direction, the first surface part is protruded with respect to the second surface part in a height direction.

First claim

What is claimed is:

1 . An image forming apparatus comprising:
a toner image forming portion configured to form a toner image on a sheet; a heating unit configured to heat the toner image that is formed on the sheet by the toner image forming portion; a conveyance unit configured to convey the sheet with the toner image that is formed on a first sheet surface of the sheet by the toner image forming portion and is heated by the heating unit, the conveyance unit comprising a first rotary member configured to contact the first sheet surface of the sheet and a second rotary member configured to contact a second sheet surface of the sheet opposite to the first sheet surface; a conveyance guide configured to face the first sheet surface of the sheet and guide the sheet toward the conveyance unit, the conveyance guide being provided with an opening located between the heating unit and the conveyance unit in a sheet conveyance direction; and an air blower configured to blow air to the first sheet surface of the sheet through the opening, wherein the conveyance guide comprises a first surface part and a second surface part, the first surface part being disposed on a location in a width direction overlapping with a location in the width direction of the first rotary member, the width direction being perpendicular to the sheet conveyance direction, the second surface part being disposed adjacent to the first surface part in the width direction, and wherein in at least a part of a range between the opening and the first rotary member in the sheet conveyance direction, the first surface part is protruded with respect to the second surface part in a height direction, the height direction being a direction along a line drawn from an axis of the first rotary member toward an axis of the second rotary member in a cross section perpendicular to the width direction.

2 . The image forming apparatus according to claim 1 , wherein the first rotary member is one of a plurality of first rotary members disposed at a plurality of positions in the width direction, and
wherein the first surface part is one of a plurality of first surface parts disposed at a plurality of positions in the width direction respectively corresponding to the plurality of first rotary members.

3 . The image forming apparatus according to claim 2 , wherein the opening is one of a plurality of openings disposed at a plurality of positions in the width direction respectively corresponding to the plurality of first rotary members,
wherein each of the plurality of first rotary members comprises an outer circumferential surface configured to come in contact with the sheet, a middle position of the outer circumferential surface in the width direction being located within a range in the width direction where a corresponding one among the plurality of first surface parts is provided, and within a range in the width direction where a corresponding one among the plurality of openings is provided.

4 . The image forming apparatus according to claim 3 , wherein the second surface part is one of a plurality of second surface parts disposed alternately with the plurality of first surface parts at a plurality of positions in the width direction,
wherein a plurality of sets each including one of the plurality of first rotary members, one of the plurality of first surface parts, and one of the plurality of openings are disposed alternately with the plurality of second surface parts in the width direction.

5 . The image forming apparatus according to claim 1 , wherein an amount of projection of the first surface part in the height direction with respect to the second surface part reaches a maximum at a downstream end portion of the first surface part in the sheet conveyance direction.

6 . The image forming apparatus according to claim 1 , wherein the first surface part is inclined with respect to the second surface part such that the first surface part protrudes further in the height direction compared to the second surface part as the first surface part extends further downstream in the sheet conveyance direction.

7 . The image forming apparatus according to claim 1 , wherein the conveyance guide comprises a first rib disposed on an edge portion of the opening in the width direction and extending in the sheet conveyance direction, and
wherein the first surface part protrudes with respect to the second surface part in the height direction at a position downstream of the first rib in the sheet conveyance direction.

8 . The image forming apparatus according to claim 1 , wherein the conveyance guide comprises a second rib extending along the sheet conveyance direction over a range in the sheet conveyance direction where the first surface part is provided, and
wherein the second rib is disposed on the second surface part and separated from the first surface part in the width direction.

9 . The image forming apparatus according to claim 8 , wherein the second rib protrudes higher than or to a same height as the first surface part in the height direction.

10 . The image forming apparatus according to claim 8 , wherein a width of the first surface part in the width direction is larger than a width of the second rib in the width direction.

11 . The image forming apparatus according to claim 1 , further comprising an upstream conveyance unit configured to nip and convey the sheet,
wherein the first surface part is disposed such that a gap is formed between the first surface part and the sheet in the height direction in a state where the sheet is tightly stretched between the conveyance unit and the upstream conveyance unit.

12 . The image forming apparatus according to claim 1 , wherein the first surface part comprises a first portion and a second portion, the second portion being disposed downstream of the first portion in the sheet conveyance direction, and
wherein, in a cross section perpendicular to the width direction, the first portion extends in a direction inclined with respect to the second surface part while the second portion extends in the sheet conveyance direction, the first portion protruding further in the height direction compared to the second surface part as the first portion extends further downstream in the sheet conveyance direction.

13 . The image forming apparatus according to claim 12 , wherein the first portion is inclined with respect to a plane perpendicular to the width direction and is configured to guide air supplied from the opening toward either side in the width direction along with the air flowing downstream in the sheet conveyance direction.

Assignees

• Canon Kk

Inventors

• Nakajima Keita
• Abe Kenji
• Inoue Tomonari
• Osada Takehito
• Katahira Ko

Classifications

• G03G15/2017

  Structural details of the fixing unit in general, e.g. cooling means, heat shielding means (G03G15/2053 takes precedence) · CPC title

• G03G21/185

  the process cartridge being mounted parallel to the axis of the photosensitive member · CPC title

• G03G15/2028 Primary

  with means for handling the copy material in the fixing nip, e.g. introduction guides, stripping means · CPC title

• G03G21/1803

  Arrangements or disposition of the complete process cartridge or parts thereof · CPC title