Rotary feeding member, sheet feeding apparatus and image forming apparatus

1. A rotary feeding member configured to feed a sheet by rotating in contact with the sheet, the rotary feeding member comprising:

a plurality of first regions each including a plurality of first protruding portions and a plurality of first recessed portions, the plurality of first protruding portions being provided, on a cross-section perpendicular to a rotation axis direction of the rotary feeding member, at a plurality of positions in a rotating direction of the rotary feeding member; and

a plurality of second regions each including a plurality of second protruding portions and a plurality of second recessed portions, the plurality of second protruding portions being provided, on the cross-section, at a plurality of positions in the rotating direction of the rotary feeding member,

wherein the plurality of first protruding portions and the plurality of second protruding portions constitute an outer circumferential surface of the rotary feeding member to be in contact with the sheet,

wherein the plurality of first recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of first protruding portions in the rotating direction, the plurality of first recessed portions being recessed to a first depth with respect to the outer circumferential surface,

wherein the plurality of second recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of second protruding portions in the rotating direction, the plurality of second recessed portions being recessed to a second depth smaller than the first depth with respect to the outer circumferential surface,

wherein on the cross-section, the plurality of first regions and the plurality of second regions are alternately arranged in the rotating direction, and

wherein a ratio of the second depth to the first depth is 0.4 or greater and 0.8 or less.

2. The rotary feeding member according to claim 1 ,

wherein on the cross-section perpendicular to the rotation axis direction, a ratio of a sum of lengths in the rotating direction of the plurality of first regions to that of the plurality of second regions is 2 or greater and 3 or less.

3. The rotary feeding member according to claim 1 ,

wherein both the plurality of first recessed portions and the plurality of second recessed portions are grooves extending in a direction intersecting the rotating direction.

4. The rotary feeding member according to claim 3 ,

wherein the grooves extend in parallel with the rotation axis direction from one end to the other end of the rotary feeding member in the rotation axis direction.

5. The rotary feeding member according to claim 1 ,

wherein the outer circumferential surface is a lattice shape when viewed from an outside of the rotary feeding member, the plurality of first protruding portions and the plurality of second protruding portions being portions of the lattice shape on the cross-section, and

wherein when viewed from the outside, the plurality of first recessed portions and the plurality of second recessed portions are recessed shapes that are separated from each other by the lattice shape of the outer circumferential surface.

6. The rotary feeding member according to claim 1 ,

wherein the plurality of first protruding portions and the plurality of second protruding portions are protrusions separated from each other when viewed from an outside of the rotary feeding member,

wherein when viewed from the outside, the plurality of first recessed portions at the first depth and the plurality of second recessed portions at the second depth are arranged to form a lattice shaped surface that separates the protrusions from each other.

7. The rotary feeding member according to claim 1 ,

wherein a ratio of the second depth to the first depth is 0.5 or greater and 0.7 or less.

8. The rotary feeding member according to claim 1 ,

wherein the rotary feeding member comprises a core formed of synthetic resin and an outer portion attached on an outer circumference of the core, and

wherein the plurality of first protruding portions, the plurality of second protruding portions, the plurality of first recessed portions and the plurality of second recessed portions are formed on the outer portion.

9. The rotary feeding member according to claim 1 ,

wherein a number of the first protruding portions within each of the plurality of first regions is greater than a number of the second protruding portions within each of the plurality of second regions.

10. A sheet feeding apparatus comprising:

a sheet supporting portion configured to support a sheet;

a rotary feeding member configured to feed the sheet in a sheet feeding direction by rotating in contact with the sheet supported on the sheet supporting portion;

a sheet detector configured to detect the sheet at a position downstream of the rotary feeding member in the sheet feeding direction; and

a controller configured to execute a notification operation of notifying of information about replacement of the rotary feeding member based on a detection result of the sheet detector,

wherein the rotary feeding member comprises:

a plurality of first regions each including a plurality of first protruding portions and a plurality of first recessed portions, the plurality of first protruding portions being provided, on a cross-section perpendicular to a rotation axis direction of the rotary feeding member, at a plurality of positions in a rotating direction of the rotary feeding member; and

a plurality of second regions each including a plurality of second protruding portions and a plurality of second recessed portions, the plurality of second protruding portions being provided, on the cross-section, at a plurality of positions in the rotating direction of the rotary feeding member,

wherein the plurality of first protruding portions and the plurality of second protruding portions constitute an outer circumferential surface of the rotary feeding member to be in contact with the sheet,

wherein the plurality of first recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of first protruding portions in the rotating direction, the plurality of first recessed portions being recessed to a first depth with respect to the outer circumferential surface,

wherein the plurality of second recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of second protruding portions in the rotating direction, the plurality of second recessed portions being recessed to a second depth smaller than the first depth with respect to the outer circumferential surface,

wherein on the cross-section, the plurality of first regions and the plurality of second regions are alternately arranged in the rotating direction, and

wherein a ratio of the second depth to the first depth is 0.4 or greater and 0.8 or less.

11. The sheet feeding apparatus according to claim 10 ,

wherein the controller executes the notification operation if an elapsed time, from start of rotation of the rotary feeding member to detection of the sheet by the sheet detector, exceeds a predetermined length of time.

12. The sheet feeding apparatus according to claim 10 , further comprising a communication unit through which the controller communicates with an external device, and

wherein in the notification operation, the controller transmits a signal through the communication unit to the external device that causes the external device to display information recommending replacement of the rotary feeding member.

13. The sheet feeding apparatus according to claim 10 , further comprising a display device configured to display information,

wherein in the notification operation, the controller controls the display device to display information recommending replacement of the rotary feeding member.

14. The sheet feeding apparatus according to claim 10 ,

wherein the rotary feeding member comprises a first roller arranged above the sheet supporting portion and configured to rotate in contact with an upper surface of the sheet supported on the sheet supporting portion so as to deliver the sheet out of the sheet supporting portion.

15. The sheet feeding apparatus according to claim 10 , further comprising a separation member configured to separate sheets,

wherein the rotary feeding member comprises a second roller configured to feed the sheet in contact with the separation member such that the sheet is separated from another sheet at a nip portion between the rotary feeding member and the separation member.

16. The sheet feeding apparatus according to claim 10 ,

wherein the rotary feeding member is a roller member, in which the outer circumferential surface is a cylindrical shape centering on a rotation axis of the roller member, and in which the plurality of first recessed portions and the plurality of second recessed portions are recessed from the outer circumferential surface inwardly toward the rotation axis.

17. The sheet feeding apparatus according to claim 10 ,

wherein a number of the first protruding portions within each of the plurality of first regions is greater than a number of the second protruding portions within each of the plurality of second regions.

18. An image forming apparatus comprising:

a rotary feeding member configured to feed a sheet by rotating in contact with the sheet; and

an image forming unit configured to form an image on a sheet fed by the rotary feeding member;

wherein the rotary feeding member comprises:

a plurality of first regions each including a plurality of first protruding portions and a plurality of first recessed portions, the plurality of first protruding portions being provided, on a cross-section perpendicular to a rotation axis direction of the rotary feeding member, at a plurality of positions in a rotating direction of the rotary feeding member; and

a plurality of second regions each including a plurality of second protruding portions and a plurality of second recessed portions, the plurality of second protruding portions being provided, on the cross-section, at a plurality of positions in the rotating direction of the rotary feeding member,

wherein the plurality of first protruding portions and the plurality of second protruding portions constitute an outer circumferential surface of the rotary feeding member to be in contact with the sheet,

wherein the plurality of first recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of first protruding portions in the rotating direction, the plurality of first recessed portions being recessed to a first depth with respect to the outer circumferential surface,

wherein the plurality of second recessed portions are each provided, on the cross-section, between any adjacent two of the plurality of second protruding portions in the rotating direction, the plurality of second recessed portions being recessed to a second depth smaller than the first depth with respect to the outer circumferential surface,

wherein on the cross-section, the plurality of first regions and the plurality of second regions are alternately arranged in the rotating direction, and

wherein a ratio of the second depth to the first depth is 0.4 or greater and 0.8 or less.