IMAGE READING APPARATUS AND IMAGE FORMING APPARATUS

• US 20140368894A1
• Filed: 05/23/2014
• Published: 12/18/2014
• Est. Priority Date: 06/13/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamamoto, Yuichi, Sakuma, Tomofumi
• Granted Patent: US 9,100,521 B2
• Time in Patent Office: Days
• US Class Current: 358/498
• CPC Class Codes: G03G 15/605 Holders for originals or exposure platens for photographic purposes in general G03B
• CPC Class Codes: H04N 1/00554 Latches or hinges therefor
• CPC Class Codes: H04N 1/0057 Conveying sheets before or after scanning arrangements for conveying sheets as part of the scanning operation H04N1/04 and subgroups
• CPC Class Codes: H04N 1/121 Feeding arrangements transporting sheets to or from the scanning position H04N1/0057; control or error compensation of sub-scanning velocity H04N1/0473

Abstract

An image reading apparatus includes: an opening/closing portion configured to be rotatable around a hinge shaft; a biasing portion configured to apply a force to the opening/closing portion such that moment of the hinge shaft rotation higher than moment of the hinge shaft rotation according to self-weight of the opening/closing member is generated in a state in which the opening/closing portion is placed in a range up to a predetermined rotation angle from a closed position with respect to the apparatus main body, and moment of the hinge shaft rotation that is balanced with the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion is generated in a state in which the opening/closing portion is opened more than the predetermined rotation angle; and a holding portion configured to maintain the opening/closing portion at the closed position.

Claims

1. An image reading apparatus comprising:

an apparatus main body;

an opening/closing portion configured to be rotatable with respect to the main body, around a hinge shaft;

a biasing portion configured to apply a force to the opening/closing portion in an opening direction to generate a moment of the hinge shaft rotation higher than the moment of the hinge shaft rotation according to self-weight of the opening/closing portion, in a state in which the opening/closing portion is in a range up to a predetermined rotation angle from a closed position with respect to the apparatus main body, and to generate a moment of the hinge shaft rotation that is substantially balanced with the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion, in a state in which the opening/closing portion is opened more than the predetermined rotation angle; and

a holding portion configured to maintain the opening/closing portion at the closed position.

2. The image reading apparatus according to claim 1,

wherein the biasing portion includes a first elastic member that applies a force to the opening/closing portion in the opening direction and a second elastic member that applies a force to the opening/closing portion in the opening direction,

wherein, in a range up to the predetermined rotation angle from the closed state of the opening/closing portion with respect to the apparatus main body, both the first elastic member and the second elastic member apply forces to the opening/closing portion in the opening direction, and

wherein, in a state in which the opening/closing portion is opened more than the predetermined rotation angle with respect to the apparatus main body, the second elastic member does not act, but the first elastic member applies a force to the opening/closing portion in the opening direction.

3. The image reading apparatus according to claim 2, wherein the biasing portion includes an adjustment portion configured to adjust the predetermined rotation angle by changing the position of the second elastic member in an expanding/contracting direction.

4. The image reading apparatus according to claim 1,

wherein the biasing portion includes an elastic member configured to apply a force to the opening/closing portion in the opening direction, a housing configured to house the elastic member, and a cam member configured to include first and second cam faces brought into contact with the housing,

wherein, in a state in which the opening/closing portion is placed in a range up to the predetermined rotation angle from the closed position with respect to the apparatus main body, the housing abuts the first cam face of the cam member such that the elastic member generates a moment higher than the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion, and

wherein, in a state in which the opening/closing portion is opened more than the predetermined rotation angle with respect to the apparatus main body, the housing abuts the second cam face of the cam member such that the elastic member generates a moment substantially balanced with the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion.

5. The image reading apparatus according to claim 1, wherein the holding portion is configured by a magnet that is disposed on one of the apparatus main body and the opening/closing portion and a magnetic body disposed on the other and maintains the opening/closing portion at the closed position with respect to the apparatus main body using a magnetic coupling force.

6. The image reading apparatus according to claim 1, wherein the holding portion is configured by a hook member that is disposed on one of the apparatus main body and the opening/closing portion and a hook supporting portion disposed on the other and maintains the opening/closing portion at the closed position with respect to the apparatus main body by causing the hook member and the hook supporting portion to be engaged with each other.

7. The image reading apparatus according to claim 1, further comprising a handle portion used for opening the opening/closing portion, wherein the handle portion is disposed on the side of one of the apparatus main body and the opening/closing portion and is attached to be able to release the closure performed by the holding portion.

8. The image reading apparatus according to claim 1, wherein the apparatus main body includes an original placement portion on which an original is placed and an image reading unit that reads the original placed on the original placement portion, and the opening/closing portion is an original feeding device that sends an original to the original placement portion.

9. The image reading apparatus according to claim 1, further comprising:

a first attachment member configured to be fixed to the apparatus main body; and

a second attachment member configured to be fixed to the opening/closing portion,

wherein the hinge shaft is connected to the first attachment member so as to allow the second attachment member to be rotatable with respect to the first attachment member, and

wherein the biasing portion is disposed between the first attachment member and the second attachment member.

10. An image forming apparatus comprising:

an image reading portion configured to read an original; and

an image forming portion configured to form an image on a sheet,

wherein the image reading unit includes;

an apparatus main body including an original placement portion on which the original is placed and an image reading unit that reads the original placed on the original placement portion;

an opening/closing portion to be rotatable around a hinge shaft so as to be opened or closed the original placement portion;

a biasing portion configured apply a force to the opening/closing portion in an opening direction such that moment of the hinge shaft rotation higher than moment of the hinge shaft rotation according to self-weight of the opening/closing portion is generated so as to open the opening/closing portion in a state in which the opening/closing portion is placed in a range up to a predetermined rotation angle from a closed position with respect to the apparatus main body, and moment of the hinge shaft rotation that is balanced with the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion is generated so as to stop the opening/closing portion in a state in which the opening/closing portion is opened more than the predetermined rotation angle; and

a holding portion configured to maintain the opening/closing portion at the closed position with respect to the upper face of the apparatus main body.

11. An image reading apparatus comprising:

an apparatus main body;

an opening/closing portion configured to be rotatable with respect to the main body around a hinge shaft;

a biasing portion configured to apply a force to the opening/closing portion in an opening direction such that the opening/closing portion is rotated in the opening direction in a state in which the opening/closing portion is placed in a range up to a predetermined rotation angle from a closed position with respect to the apparatus main body, and the opening/closing portion is stopped in a state in which the opening/closing portion is opened more than the predetermined rotation angle; and

a holding portion configured to maintain the opening/closing portion at the closed position.

12. The image reading apparatus according to claim 11,

wherein the biasing portion includes a first elastic member that applies a force to the opening/closing portion in the opening direction and a second elastic member that applies a force to the opening/closing portion in the opening direction,

wherein, in a range up to the predetermined rotation angle from the closed state of the opening/closing portion with respect to the apparatus main body, both the first elastic member and the second elastic member apply forces to the opening/closing portion in the opening direction, and

wherein, in a state in which the opening/closing portion is opened more than the predetermined rotation angle with respect to the apparatus main body, the second elastic member does not act, but the first elastic member applies a force to the opening/closing portion in the opening direction.

13. The image reading apparatus according to claim 11, wherein the biasing portion includes an adjustment portion configured to adjust the predetermined rotation angle by changing the position of the second elastic member in an expanding/contracting direction.

14. The image reading apparatus according to claim 11,

wherein the biasing portion includes an elastic member configured to apply a force to the opening/closing portion in the opening direction, a housing configured to house the elastic member, and a cam member configured to include first and second cam faces brought into contact with the housing,

wherein, in a state in which the opening/closing portion is placed in a range up to the predetermined rotation angle from the closed position with respect to the apparatus main body, the housing abuts the first cam face of the cam member such that the elastic member generates a moment higher than the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion, and

wherein, in a state in which the opening/closing portion is opened more than the predetermined rotation angle with respect to the apparatus main body, the housing abuts the second cam face of the cam member such that the elastic member generates a moment substantially balanced with the moment of the hinge shaft rotation according to the self-weight of the opening/closing portion.

15. The image reading apparatus according to claim 11, wherein the holding portion is configured by a magnet that is disposed on one of the apparatus main body and the opening/closing portion and a magnetic body disposed on the other and maintains the opening/closing portion at the closed position with respect to the apparatus main body using a magnetic coupling force.

16. The image reading apparatus according to claim 11, wherein the holding portion is configured by a hook member that is disposed on one of the apparatus main body and the opening/closing portion and a hook supporting portion disposed on the other and maintains the opening/closing portion at the closed position with respect to the apparatus main body by causing the hook member and the hook supporting portion to be engaged with each other.

17. The image reading apparatus according to claim 11, further comprising a handle portion used for opening the opening/closing portion,

wherein the handle portion is disposed on the side of one of the apparatus main body and the opening/closing portion and is attached to be able to release the closure performed by the holding portion.

18. The image reading apparatus according to claim 11, wherein the apparatus main body includes an original placement portion on which an original is placed and an image reading unit that reads the original placed on the original placement portion, and the opening/closing portion is an original feeding device that sends an original to the original placement portion.

19. The image reading apparatus according to claim 11, further comprising:

a first attachment member configured to be fixed to the apparatus main body; and

a second attachment member configured to be fixed to the opening/closing portion,

wherein the hinge shaft is connected to the first attachment member so as to allow the second attachment member to be rotatable with respect to the first attachment member, and

wherein the biasing portion is disposed between the first attachment member and the second attachment member.