IP Library Granted Patent US 7,636,542
Granted Patent B2
US 7,636,542 · App. 11/170,948 · Granted Dec 22, 2009

Duplexing ADF using a paperpath shorter than the length of paper to be duplexed

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Quick Facts
Patent No.
US 7,636,542
App. No.
11/170,948
Granted
Dec 22, 2009
Kind
B2
Abstract

An improved apparatus for duplex scanning using a paper path shorter than the length of paper to be duplexed allows a smaller duplexing ADF footprint, without decreasing scan quality. The apparatus includes a friction drive system which allows rollers to rotate with an exit shaft when exit said shaft rotates in a first direction or with a passing media sheet when said exit shaft rotates in a second direction.

Claims (39)

1. A duplexing auto-document feeder comprising:

an input tray;

a feedpath including a simplex path and a duplex path, said simplex path and said duplex path defining a switchback loop;

an image sensor in an optical communication with said feedpath; and

an exit system comprising an exit shaft and a friction drive system having driven rollers wherein a media leading edge portion and a media wailing edge portion simultaneously pass through said exit system in opposite directions and said friction drive system comprising driven rollers mounted on said exit shaft wherein said friction drive system allows rotation of said driven rollers in a direction opposite to rotation of said exit shaft as said trailing edge and said leading edge pass through said exit system.

2. The duplexing auto-document feeder of claim 1 , wherein said driven rollers of said friction drive system comprise a first roller, a second roller and a third roller.

3. The duplexing auto-document feeder of claim 2 , wherein said first roller and said third roller are disposed against hubs located on said exit shaft.

4. The duplexing auto-document feeder of claim 3 , further comprising a first biasing member disposed between said first roller and said second roller.

5. The duplexing auto-document feeder of claim 4 , further comprising a second biasing member disposed between said second roller and said third roller.

6. The auto-document feeder of claim 2 , wherein said first roller, said second roller and said third roller rotate with said exit shaft when said exit shaft rotates in a first direction and no media is present.

7. The auto-document feeder of claim 2 , wherein said first roller, said second roller and said third roller rotate with media movement when said exit shaft rotates in a second direction.

8. A duplexing auto-document feeder, comprising:

a media feed system;

a feedpath including an input a switchback path for switching a media sheet from a first side to a second side and an exit system comprising an exit shaft and exit rollers mounted on said exit shaft; and

a friction drive on said exit shaft providing motion of a media sheet through said exit system and into said switchback path and allowing relative motion between said exit shaft and said exit rollers.

9. The duplexing auto-document feeder of claim 8 , wherein said friction drive allows said exit rollers rotation either with said exit shaft or with said media sheet passing through said exit system adjacent said exit rollers.

10. The duplexing auto-document feeder of claim 8 , wherein said exit shaft is a reversing shaft.

11. The duplexing auto-document feeder of claim 8 , said switchback path further comprising an entry and an exit at said exit system wherein a leading edge and a trailing edge of said media sheet simultaneously pass.

12. The duplexing auto-document feeder of claim 11 , further comprising an exit drive roller, wherein said exit drive roller rotates with said leading edge of said media sheet and an exit idler rotates with said trailing edge of said media sheet.

13. A duplexing auto-document feeder, comprising:

a media input system and a media exit;

a feedpath extending between said input system and said media exit;

said feedpath having a simplex path and a duplex path forming a switchback loop;

said switchback loop in feeding communication with an exit system;

said exit system comprising an exit shaft and at least one roller mounted to and driven by said exit shaft wherein said at least one roller rotates with said exit shaft or with an adjacent media depending on a direction of rotation of said exit shaft; and

wherein said exit system further comprises a friction drive system that allows relative motion between said exit shaft and said at least one roller.

14. The duplexing auto-document feeder of claim 13 , wherein said at least one roller further comprises a first roller, a second roller, and a third roller.

15. The duplexing auto-document feeder of claim 14 further comprising a first hub and a second hub connected to said exit shaft, said first hub and said second hub frictionally engaging said first roller and said third roller, respectively.

16. The duplexing auto-document feeder of claim 15 , wherein said first roller and said third roller rotate with said shaft or with said adjacent media.

17. The duplexing auto-document feeder of claim 14 , wherein said second roller rotates with said exit shaft when said exit shaft rotates in one direction.

18. The duplexing auto-document feeder of claim 17 , wherein said second roller rotates with a media passing said second roller when said exit shaft rotates in a second direction.

19. A duplexing auto-document feeder comprising:

an input tray;

a feedpath including a simplex path and a duplex path, said simplex path and said duplex path defining a switchback loop;

an image sensor in an optical communication with said feedpath; and

an exit system comprising an exit shaft and a friction drive system having driven rollers wherein a media leading edge portion and a media trailing edge portion simultaneously pass through said exit system in opposite directions and said friction drive system allows rotation of said driven rollers in a direction opposite to rotation of said exit shaft as said trailing edge and leading edge pass through said exit system;

wherein said driven rollers of said friction drive system comprise a first roller, a second roller and a third roller, said first roller and said third roller are disposed against hubs located on said exit shaft, a first biasing member disposed between said first roller and said second roller, a second biasing member disposed between said second roller and said third roller.

20. The duplexing auto-document feeder of claim 8 further comprising driven rollers wherein said driver rollers of said friction drive system comprise a first roller, a second roller and a third roller, said first roller and said third roller are disposed are disposed against hubs located on said exit shaft, a first biasing member disposed between said first roller and said second roller, a second biasing member disposed between said second roller and said third roller.

21. The duplexing auto-document feeder of claim 15 further comprising a first biasing member disposed between said first roller and said second roller, a second biasing member disposed between said second roller and said third roller.

Assignments (8)
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0192 →
SECURITY INTEREST Recorded Jan 5, 2026
From: LEXMARK INTERNATIONAL, INC.
To: BANK TRUST COMPANY, NATIONAL ASSOCIATION
Reel/Frame 074202/0293 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: CITIBANK, N.A.
Reel/Frame 073007/0118 →
SECURITY INTEREST Recorded Sep 23, 2025
From: LEXMARK INTERNATIONAL, INC.
To: JEFFERIES FINANCE LLC
Reel/Frame 073007/0346 →
RELEASE OF SECURITY INTEREST Recorded Jan 18, 2024
From: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 066345/0026 →
CORRECTIVE ASSIGNMENT TO CORRECT THE INCORRECT U.S. PATENT NUMBER PREVIOUSLY RECORDED AT REEL: 046989 FRAME: 0396. ASSIGNOR(S) HEREBY CONFIRMS THE PATENT SECURITY AGREEMENT. Recorded Oct 24, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 047760/0795 →
PATENT SECURITY AGREEMENT Recorded Aug 30, 2018
From: LEXMARK INTERNATIONAL, INC.
To: CHINA CITIC BANK CORPORATION LIMITED, GUANGZHOU BRANCH, AS COLLATERAL AGENT
Reel/Frame 046989/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2005
From: WASHNOCK, GREGORY P.; WEBB, GREGORY T.
To: LEXMARK INTERNATIONAL, INC.
Reel/Frame 016758/0745 →