1. Field of the Invention
This invention relates to a duplex automatic document feeder and a duplex document scanning method using the same, and more particularly to a duplex automatic document feeder applicable to a copy machine, and a duplex document scanning method using the same.
2. Description of the Related Art
Referring to
When the feeder 1 is operated in a simplex document-feeding mode, the document is fed from the document-setting tray 11, and is moved through the first transfer path 101 and the scanning module 12 for scanning of the document. Subsequently, the document is moved onto the ejecting tray 13 through the second transfer path 102 with the switching gate 14 being disposed in a first position shown by the solid lines in
When the feeder 1 is operated in a duplex document-feeding mode, the document is moved from the first transfer path 101 onto the second transfer path 102 for scanning of a first side surface thereof. At the same time, the switching gate 14 is pivoted to a second position shown by the phantom lines in
The feeder 1 has the following disadvantages:
To solve the paper jam problem, in US Patent Application Publication No. 2002/0054382 and U.S. Pat. No. 6,307,614, the roller unit 16 is replaced with two roller units each defining a nip.
Referring to
The lower roller 25 is movable relative to the middle roller 23 between upper and lower positions shown respectively by the solid and phantom lines in
However, the structure of the feeder 2 is complex due to the presence of the elevating mechanism. This increases the manufacturing costs of the feeder 2.
The object of this invention is to provide a duplex automatic document feeder and a duplex document scanning method using the same that can overcome the abovementioned disadvantages associated with the prior art.
According to an aspect of this invention, there is provided a duplex automatic document feeder adapted for use in an image-formation device. The image-formation device has a scanning module for scanning a document. The duplex automatic document feeder comprises:
a feeding tray adapted for feeding the document;
a first path adapted to extend from the feeding tray to the scanning module so as to invert the document when the document is moved along the first path;
a feeding/separating roller adapted for moving the document from the feeding tray onto the first path;
an ejecting tray;
a first reversing roller unit disposed in proximity to the ejecting tray and adapted for allowing the document to move in a direction onto the ejecting tray and in an opposite direction to reverse the document;
a second path adapted to extend from the scanning module to the first reversing roller unit and adapted for guiding movement of the document just after a first scanning operation is performed on the document;
a third path in spatial communication with the first and second paths and adapted for guiding movement of the reversed document from the first reversing roller unit onto an intermediate portion of the first path;
a second reversing roller unit disposed in proximity to the first reversing roller unit and adapted for reversing the document;
a fourth path in spatial communication with the second path and the second reversing roller unit and adapted for guiding movement of the document just after a second scanning operation is performed on the document;
an ejecting path adapted for guiding movement of the document from the second reversing roller unit onto an intermediate portion of the second path; and
a first guide unit adapted to be controlled to guide movement of the document along a selected one of the second and fourth paths.
According to another aspect of this invention, a duplex document scanning method comprises the steps of:
(a) moving a document along a first path to pass through a scanning module so as to perform a scanning operation on a first side surface of the document;
(b) moving the document along a second path into a first reversing roller unit;
(c) driving the first reversing roller unit to reverse and move the document from the first reversing roller unit onto the first path via a third path to thereby pass again through the scanning module so as to perform a scanning operation on a second side surface of the document opposite to the first side surface;
(d) moving the document along a fourth path into a second reversing roller unit; and
(e) driving the second reversing roller unit to reverse and move the document from the second reversing roller unit into the first reversing roller unit via a portion of the fourth path, an ejecting path, and a portion of the second path onto an ejecting tray.
These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this invention, with reference to the accompanying drawings, in which:
a is a fragmentary schematic side view of the first preferred embodiment of a duplex automatic document feeder according to this invention in a state of use with a copy machine;
b is a schematic side view of the first preferred embodiment, illustrating a first-side scanning path;
c is a schematic side view of the first preferred embodiment, illustrating a second-side scanning path;
d is a schematic side view of the first preferred embodiment, illustrating a document-inverting path;
e is a schematic side view illustrating a modification to an ejecting path of the first preferred embodiment;
a is a schematic side view of the second preferred embodiment of a duplex automatic document feeder, illustrating a first-side scanning path;
b is a schematic side view of the second preferred embodiment, illustrating a second-side scanning path;
c is a schematic side view of the second preferred embodiment, illustrating a document-inverting path;
d is a schematic side view illustrating a modification to first and second reversing roller units of the second preferred embodiment;
e is a fragmentary schematic side view of the second preferred embodiment, illustrating a junction between second and third paths;
a is a schematic side view of the third preferred embodiment of a duplex automatic document feeder, illustrating a first-side scanning path;
b is a schematic side view of the third preferred embodiment, illustrating a second-side scanning path;
c is a schematic side view of the third preferred embodiment, illustrating a document-inverting path;
d is a schematic view of a first guide unit of the third preferred embodiment; and
e is a schematic side view illustrating modification to first and second reversing roller units of the third preferred embodiment.
Before the present invention is described in greater detail in connection with the preferred embodiments, it should be noted that similar elements and structures are designated by like reference numerals throughout the entire disclosure.
The duplex automatic document feeder of this invention is applicable to a copy machine, a fax machine, a scanner, or other image forming devices. In each of the following embodiments, this invention is described in an exemplary application to a copy machine.
Referring to
The scanning module 32 is disposed under the feeding tray 311. The first path 301 extends from the feeding tray 311 to the scanning module 32. Two transfer roller units 51, 52 are disposed along the first path 301 and in proximity to the scanning module 32 and the feeding tray 311, respectively. The first sensor 41 is disposed along the first path 301 between the transfer roller unit 51 and the scanning module 32. A stack of documents (not shown) to be scanned can be placed on the feeding tray 311 such that the uppermost document (referred to as “the document” hereinafter) is in frictional contact with the feeding/separating roller 312. The feeding/separating roller 312 is driven by a motor (not shown) to move the document onto the first path 301. Through operation of the transfer roller units 51, 52, the document is moved from the first path 301 onto the second path 302 via the scanning module 32. When the document is moved along the first path 301, it is inverted. When the document is passed through the scanning module 32, it is scanned.
The second path 302 has a front end 3021 in spatial communication with a downstream or lower end of the first path 301, and a rear end 3022 in spatial communication with the first reversing roller unit 331. The first reversing roller unit 331 is disposed in proximity to and between the ejecting tray 30 and the rear end 3022 of the second path 302. The first reversing roller unit 331 includes a middle roller 333 and an upper roller 334 flanking the rear end 3022 of the second path 302. The upper roller 334 is disposed above and in frictional contact with the middle roller 333 to define a nip therebetween. The middle roller 333 can be driven by a motor (not shown) of the control module to rotate clockwise to thereby move the document onto the ejecting tray 30, or counterclockwise to reverse the document. The third sensor 43 is disposed in proximity to the rear end 3022 of the second path 302 and the first reversing roller unit 331 so as to output a signal for activation of the first reversing roller unit 331 to rotate just before the document is moved into the first reversing roller unit 331.
The third path 303 is disposed between the feeding tray 311 and the second path 302, and has a front end in spatial communication with an intermediate portion of the first path 301, and a rear end in spatial communication with a portion of the second path 302 adjacent to the rear end 3022. As such, the first path 301 has an upper path portion 301′ disposed above the front end of the third path 303, and a lower path portion 301″ disposed below the front end of the third, path 303.
The second guide unit 45 is disposed at a junction between the second and third paths 302, 303, and is configured as an elongated Mylar plate having a fixed end and a movable end that is disposed at a close position shown in
The fourth path 304 has a front end in spatial communication with a portion of the second path 302 adjacent to the front end 3021 of the second path 302, and a rear end in spatial communication with the second reversing roller unit 332. The second reversing roller unit 332 includes the middle roller 333 and a lower roller 335 flanking the rear end of the fourth path 304. The lower roller 335 is disposed under and in frictional contact with the middle roller 333 to define a nip therebetween. The second sensor 42 is disposed in proximity to the fourth path 304 and the second reversing roller unit 332 so as to output a signal for activation of the second reversing roller unit 332 to rotate just before the document is moved into the second reversing roller unit 332.
The first guide unit 34 includes a switching gate 341 disposed pivotally at a junction between the second and fourth paths 302, 304. The switching gate 341 is pivotable between a first position shown in
The ejecting path 305 is provided at a mounting member 401 disposed fixedly in the housing unit, and has upper and lower ends in spatial communication with the second and fourth paths 302, 304, respectively.
The third guide unit 46 is disposed at a junction between the ejecting path 305 and the second path 302 so as to prevent movement of the document from the second path 302 onto the ejecting path 305 while allowing for movement of the document from the ejecting path 305 onto the second path 302. The fourth guide unit 47 is disposed at a junction between the ejecting path 305 and the fourth path 304 so as to prevent movement of the document from the ejecting path 305 onto the fourth path 304 while allowing for movement of the document from the fourth path 304 onto the ejecting path 305.
With particular reference to
With particular reference to
With particular reference to
A duplex document spanning method using the duplex automatic document feeder 3 includes the following steps:
Due to the presence of the fourth path 304, occurrence of paper jams can be prevented, and the distance traveled by the document is reduced significantly, thereby improving the operating efficiency of the feeder 3 as compared to that of U.S. Pat. No. 5,784,680. Furthermore, the structure for changing the position of the switching gate 341 is simpler than that for moving the lower roller (see
Alternatively, with reference to
a, 5b, 5c, 5d, and 5e show the second preferred embodiment of a duplex automatic document feeder 3′ according to this invention, which is similar in construction to the first preferred embodiment. In this embodiment, the second path 302′ is in spatial communication with the ejecting path 305 at a position under that whereat the second path 302′ is in spatial communication with the third path 303. In addition, the third guide unit 46 (see
A duplex document scanning method using this embodiment is the same as that using the first preferred embodiment.
d shows modified first and second reversing roller units 331′, 332′. The modified first reversing unit 331′ includes two rollers 3310 flanking the rear end 3022′ of the second path 302′ and defining a nip therebetween so as to allow for movement of the document therebetween. The modified second reversing roller unit 332′ includes two rollers 332Q flanking the rear end of the fourth path 304 and defining a nip therebetween so as to allow for movement of the document therebetween.
With particular reference to
a, 6b, and 6c, show the third preferred embodiment of a duplex automatic document feeder 3″′ according to this invention, which is similar in construction to the previous preferred embodiments. The main difference between this embodiment and the previous preferred embodiments resides in that the ejecting path 305 is in spatial communication with the junction between the second path 302″′ and the fourth path 304″′.
With particular reference to
With reference to
In view of the above, in the duplex automatic document feeder, since the upper and lower rollers 334, 335 are not movable relative to the middle roller 333, it is not necessary to provide an elevating mechanism for moving the upper and lower rollers 334, 335, thereby resulting in a simple structure. Furthermore, leading and trailing ends of the document cannot be clamped between the first or second reversing roller unit 331, 332. Thus, occurrence of a paper jam can be avoided.
With this invention thus explained, it is apparent that numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated by the appended claims.
Number | Date | Country | Kind |
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096129815 | Aug 2007 | TW | national |
This is a Divisional patent application of Ser. No. 12/003,800 filed 2 Jan. 2008, which was filed as a Continuation-in-Part (CIP) of U.S. patent application Ser. No. 11/699,374, filed on Jan. 30, 2007. This application also claims priority of Taiwanese Application No. 096129815, filed on Aug. 13, 2007. The entire disclosure of the prior application, Ser. No. 12/003,800, from which an oath or declaration is supplied, is considered a part of the disclosure of the accompanying Divisional application and is hereby incorporated by reference.
Number | Date | Country | |
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Parent | 12003800 | Jan 2008 | US |
Child | 12699435 | US |
Number | Date | Country | |
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Parent | 11699374 | Jan 2007 | US |
Child | 12003800 | US |