Sheet loader, image forming apparatus incorporating the sheet loader, and image reader incorporating the sheet loader

Patent metadata

Field	Value
Publication number	US-10183818-B2
Application number	US-201514629694-A
Country	US
Kind code	B2
Filing date	Feb 24, 2015
Priority date	Feb 25, 2014
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A sheet loader includes a sheet loading part and a sheet length detector. The sheet loading part has a loading face on which a sheet is loaded. The sheet length detector is provided to the sheet loading part to detect a length of the sheet by obtaining information whether the loading face either contacts or approaches a surface of the sheet disposed facing the loading face at a given position on the loading face in a sheet conveying direction of the sheet loading part. The sheet length detector includes multiple projections retreatably extending outward beyond the loading face of the sheet loading part, and a projection retreating detector detecting whether the multiple projections are retreated under the loading face. At least one of the multiple projections is disposed closer to an upstream end of the sheet loading part than the other.

First claim

What is claimed is:

1. A sheet loader comprising:
a sheet loading part having a loading face on which a sheet is loaded; and
a sheet length detector provided to the sheet loading part to detect a length of the sheet by obtaining information whether the loading face either contacts or approaches a surface of the sheet disposed facing the loading face at a given position on the loading face in a sheet conveying direction of the sheet loading part,
the sheet length detector comprising
a common rotatable shaft;
multiple projections, mounted on the common rotatable shaft, each of which retreatably extends above the loading face of the sheet loading part; and
a single projection retreating detector extending from the common rotatable shaft and having only a single light blocking part, the single projection retreating detector being configured to detect whether each of the multiple projections are retreated beneath the loading face,
wherein at least one of the multiple projections is disposed at an upstream end of the sheet loading part in the sheet conveying direction.

2. The sheet loader according to claim 1 ,
wherein the at least one of the multiple projections is disposed outside from the other of the multiple projections in a direction perpendicular to the sheet conveying direction on the sheet loading part.

3. The sheet loader according to claim 2 , further comprising an extendable loading part to extend from the upstream end of the sheet loading part in the sheet conveying direction and to switch a state of the sheet loading part between an extended state in which the extendable loading part holds a trailing end of the sheet extending outside the loading face toward an upstream side of the sheet loading part in the sheet conveying direction and a non-extended state in which the extendable loading part does not hold the trailing end of the sheet extending outside the loading face,
wherein, when the extendable loading part is in the non-extended state, the at least one of the multiple projections is located at a position capable of detecting the sheet extending from the loading face of the sheet loading part toward the upstream side in the sheet conveying direction.

4. The sheet loader according to claim 3 , wherein the extendable loading part has an inclined surface that is slanted to the loading face at a part where any one of the multiple projections extends from the loading face of the sheet loading part.

5. The sheet loader according to claim 3 , further comprising an inclined surface that is slanted to the loading face at an upstream end of the extendable loading part in the sheet conveying direction.

6. The sheet loader according to claim 3 , further comprising an inclined surface that is slanted to the loading face at the upstream end of the extendable loading part in the sheet conveying direction when the extendable loading part is at least in a non-extended state.

7. The sheet loader according to claim 3 , further comprising:
a sheet width detector to detect a width of the sheet loaded on the loading face of the sheet loading part in a width direction perpendicular to the sheet conveying direction; and
a sheet size discriminator to discriminate whether the sheet loaded on the loading face of the sheet loading part has a size of given multiple types of sheets based on detection results obtained by the sheet length detector and detection results of the sheet width detector.

8. The sheet loader according to claim 2 , further comprising an inclined surface that is slanted to the loading face at a part where any one of the multiple projections extends from the loading face of the sheet loading part.

9. The sheet loader according to claim 2 , further comprising an inclined surface that is slanted to the loading face at the upstream end of the sheet loading part in the sheet conveying direction when an extendable loading part is at least in a non-extended state.

10. The sheet loader according to claim 2 , further comprising:
a sheet width detector to detect a width of the sheet loaded on the loading face of the sheet loading part in a width direction perpendicular to the sheet conveying direction; and
a sheet size discriminator to discriminate whether the sheet loaded on the loading face of the sheet loading part has a size of given multiple types of sheets based on detection results obtained by the sheet length detector and detection results of the sheet width detector.

11. The sheet loader according to claim 2 , wherein the sheet length detector includes a reflective optical sensor.

12. The sheet loader according to claim 1 , further comprising an extendable loading part to extend from the upstream end of the sheet loading part in the sheet conveying direction and to switch a state of the sheet loading part between an extended state in which the extendable loading part holds a trailing end of the sheet extending outside the loading face toward an upstream side of the sheet loading part in the sheet conveying direction and a non-extended state in which the extendable loading part does not hold the trailing end of the sheet extending outside the loading face,
wherein, when the extendable loading part is in the non-extended state, the at least one of the multiple projections is located at a position capable of detecting the sheet extending from the loading face of the sheet loading part toward the upstream side in the sheet conveying direction.

13. The sheet loader according to claim 1 , further comprising an inclined surface that is slanted to the loading face at a part where any one of the multiple projections extends from the loading face of the sheet loading part.

14. The sheet loader according to claim 1 , further comprising an inclined surface that is slanted to the loading face at the upstream end of the sheet loading part in the sheet conveying direction.

15. The sheet loader according to claim 1 , further comprising an inclined surface that is slanted to the loading face at the upstream end of the sheet loading part in the sheet conveying direction when an extendable loading part is at least in a non-extended state.

16. The sheet loader according to claim 1 , further comprising:
a sheet width detector to detect a width of the sheet loaded on the loading face of the sheet loading part in a width direction perpendicular to the sheet conveying direction; and
a sheet size discriminator to discriminate whether the sheet loaded on the loading face of the sheet loading part has a size of given multiple types of sheets based on detection results obtained by the sheet length detector and detection results of the sheet width detector.

17. The sheet loader according to claim 1 , wherein the sheet length detector includes a reflective optical sensor.

18. An image forming apparatus comprising:
the sheet loader according to claim 1 ; and
an image forming part to form and transfer an image onto the sheet fed from the sheet loader.

19. An image reader comprising:
the sheet loader according to claim 1 ; and
an image reading member to receive and read an image formed on the sheet loaded on the sheet loader.

20. The sheet loader according to claim 1 , wherein the multiple projections include at least three slant parts that form an apex of the respective projection.

Assignees

• Shinkawa Shohei
• Yamamoto Kazuya
• Ricoh Co Ltd

Inventors

• Shinkawa Shohei
• Yamamoto Kazuya

Classifications

• B65H2511/51

  Presence · CPC title

• B65H2511/515

  Absence · CPC title

• B65H1/04 Primary

  adapted to support articles substantially horizontally, e.g. for separation from top of pile · CPC title

• B65H2220/03

  indicating an entity which is measured, estimated, evaluated, calculated or determined but which does not constitute an entity which is adjusted or changed by the control process per se · CPC title

• B65H2405/324

  between operative position and non operative position · CPC title