SHEET SUPPLY DEVICE AND IMAGE FORMING APPARATUS

• US 20150084263A1
• Filed: 09/19/2014
• Published: 03/26/2015
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: OKI Electric Industry Company Limited
• Original Assignee: Oki Data Corporation (OKI Electric Industry Company Limited)
• Inventors: KANZAWA, Naoki
• Granted Patent: US 9,114,944 B2
• Time in Patent Office: Days
• US Class Current: 271/3.2
• CPC Class Codes: B65H 1/04 adapted to support articles substantially horizontally, e.g. for separation from top of pile
• CPC Class Codes: B65H 1/14 comprising positively-acting mechanical devices B65H1/025 takes precedence
• CPC Class Codes: B65H 2801/09 Single-function copy machines
• CPC Class Codes: B65H 3/0676 with two or more separator rollers in the feeding direction
• CPC Class Codes: B65H 3/0684 on moving support, e.g. pivoting, for bringing the roller or like rotary separator into contact with the pile
• CPC Class Codes: B65H 3/5223 Retainers of the pad-type, e.g. friction pads
• CPC Class Codes: B65H 5/068 between one or more rollers or balls and stationary pressing, supporting or guiding elements
• CPC Class Codes: G03G 15/6511 Feeding devices for picking up or separation of copy sheets
• CPC Class Codes: G03G 15/6529 Transporting G03G15/6555 takes precedence

Abstract

A sheet supply device includes a medium loading part that includes a medium loading surface on which medium is loaded; and a medium supply part that is arranged facing the medium lading surface, and sandwiches the medium with the medium loading part applying a pressure to the medium, and sends the medium loaded in the medium loading part in a predetermined carrying direction. The medium loading part includes a first friction member arranged in a position facing the medium supply part so that the first friction member contacts the medium supply part when there is no medium on the medium loading part, and a second friction member arranged on an upstream side of the first friction member in the carrying direction, and a friction coefficient (μd) between the second friction member and the medium is larger than a friction coefficient (μc) between the first friction member and the medium.

Claims

1. A sheet supply device, comprising:

a medium loading part that includes a medium loading surface on which medium is loaded; and

a medium supply part that is arranged facing the medium lading surface, and sandwiches the medium with the medium loading part applying a pressure to the medium, and sends the medium loaded in the medium loading part in a predetermined carrying direction, wherein

the medium loading part includes

a first friction member that is arranged in a position facing the medium supply part so that the first friction member contacts the medium supply part when there is no medium on the medium loading part, and

a second friction member that is arranged on an upstream side of the first friction member in the carrying direction and

a friction coefficient (μ

d) between the second friction member and the medium is larger than a friction coefficient (μ

c) between the first friction member and the medium.

2. The sheet supply device according to claim 1, wherein

assuming that friction force generated between the medium and the first friction member is first friction force (Fd) and friction force generated between the medium and the second friction member is second friction force (Fc), the second friction force (Fc) is larger than the first friction force (Fd).

3. The sheet supply device according to claim 2, wherein

the loaded medium is configured of plural sheets, and

a formula below is satisfied:

Fa>

Fc+Fd>

Fb

where Fa, Fb, Fc and Fd mean friction forces that are generated at the moment that the medium supply part supplies one of the sheets,

Fa is generated between the medium supply part and the medium,

Fb is generated between the sheets.

4. The sheet supply device according to claim 1, further comprising:

a medium carrying part that is arranged on a downstream side of the medium supply part in the carrying direction; and

a third friction member that is arranged between the medium carrying part and the first friction member in the carrying direction.

5. The sheet supply device according to claim 2, wherein

the loaded medium is configured of plural sheets, and

inter-sheet friction force (Fb), which is generated between the loaded plural sheets of the medium while one of the sheets is carried, is smaller than the second friction force (Fc).

6. The sheet supply device according to claim 1, wherein

the second friction member is arranged with a predetermined distance (a) from the first friction member in the carrying direction.

7. The sheet supply device according to claim 6, wherein

the second friction member protrudes from the medium loading surface with a predetermined height (b) so that a ridge part is formed on the medium loading surface.

8. The sheet supply device according to claim 7, wherein

a ratio of the height (b)/the distance (a) ranges within 0.04 to 0.15.

9. The sheet supply device according to claim 1, wherein

the medium is an envelope formed by a pair of the sheets that are accumulated on the medium loading surface, and

both edges of the sheets in the medium carrying direction are connected, and

the envelop is arranged such that one of the edges is at the downstream side and the other of the edges is at the upstream side,

10. An image forming apparatus, comprising:

the sheet supply device according to claim 1.