DOCUMENT FEEDER
A document feeder includes a housing, a sheet pick-up arm and a stopper. The housing includes a sheet feeding path for placing paper sheets thereon. The sheet pick-up arm is movable between a first position and a second position. The sheet pick-up arm has a protrusion structure. The stopper is disposed under the sheet feeding path and includes a pivotal portion and a sheet stop portion. The sheet stop portion has a hooking part corresponding to the protrusion structure. When the sheet pick-up arm is moved to the first position, the protrusion structure is located in the swing track of the hooking part to restrain the swing range of the sheet stop portion. When the sheet pick-up arm is moved to the second position, the protrusion structure is deviated from the swing track of the hooking part to permit free swing of the sheet stop portion.
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The present invention relates to a document feeder, and more particularly to a document feeder having a stopper.
BACKGROUND OF THE INVENTIONConventionally, for scanning several paper sheets, the paper sheets should be manually placed on the scanning platform of the image scanners one by one. This means of manually feeding the paper sheets is time-consuming and laboring. Nowadays, the image scanner usually has a document feeder for successively and continuously feeding many paper sheets. As known, a conventional document feeder has a sheet pick-up module arranged in the sheet feeding path for automatically feeding the paper sheets one by one at a time.
For assuring that a stack of paper sheets are precisely positioned within the sheet feeding path, the document feeder further has a stopper under the sheet pick-up module. When the stack of paper sheets enters the sheet feeding path, the stopper is sustained against the front edges of the stack such that the paper sheets are positioned under the sheet pick-up module. Once the paper sheets are stopped by the stopper, the user may feel that the paper sheets are placed in position. When the sheet pick-up module performs the sheet pick-up operation, the stopper is shifted such that the paper sheets are smoothly transported through the sheet feeding path.
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However, the stopper 12 of the conventional document feeder still has some drawbacks. For example, when the sheet pick-up module 11 is in the standby position, the sheet stop portion 122 of the stopper 12 is only sustained against the lower portions of the paper sheets, but the upper portion of the paper sheets may suppress the tilt portion 121 of the stopper 12. As a result, the sheet stop portion 122 is rotated under the sheet feeding path before the sheet pick-up operation is done, so that the function of the stopping the paper sheets is lost.
In views of the above-described disadvantages resulted from the prior art, the applicant keeps on carving unflaggingly to develop an improved document feeder according to the present invention through wholehearted experience and research.
SUMMARY OF THE INVENTIONIt is an object of the present invention to provide a document feeder for properly stopping or allowing the paper sheets to be transported through the sheet feeding path with the cooperation of the sheet pick-up arm and the stopper.
In accordance with an aspect of the present invention, there is provided a document feeder. The document feeder includes a housing, a sheet pick-up arm and a stopper. The housing includes a sheet feeding path for placing paper sheets thereon. The sheet pick-up arm is pivotally mounted above the sheet feeding path and movable between a first position and a second position. The sheet pick-up arm has a protrusion structure. The stopper is disposed under the sheet feeding path and includes a pivotal portion and a sheet stop portion. The sheet stop portion has a hooking part corresponding to the protrusion structure. When the sheet pick-up arm is moved to the first position, the protrusion structure is located in the swing track of the hooking part to restrain the swing range of the sheet stop portion. When the sheet pick-up arm is moved to the second position, the protrusion structure is deviated from the swing track of the hooking part to permit free swing of the sheet stop portion.
In an embodiment, the sheet pick-up arm comprises a sheet pick-up roller and a sheet separation roller.
In an embodiment, the document feeder further comprises a driving shaft for driving the sheet pick-up arm, wherein the sheet separation roller is sheathed around the driving shaft.
In an embodiment, the stopper further comprises a loading portion. The loading portion and the sheet stop portion are arranged on opposite sides of the pivotal portion. With the pivotal portion serving as a fulcrum, the torque applied on the loading portion is greater than the torque applied on the sheet stop portion.
In an embodiment, the document feeder further comprises a torsion spring having an end sustained against the sheet stop portion.
The above objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
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The stopper 22 includes a pivotal portion 221, a loading portion 222 and a sheet stop portion 223. The pivotal portion 221 is accommodated within a recess 202 (as is also shown in
In addition, the sheet stop portion 223 has a hooking part 223A extending from a first lateral side thereof. Corresponding to the hooking part 223A, the sheet pick-up arm 211 has a protrusion structure 211C extending from a second lateral side thereof. When the sheet pick-up arm 211 is lifted to the standby position as shown in
In this embodiment of the document feeder 2, the hooking part 223A is extended from the first lateral side of the sheet stop portion 223, and the protrusion structure 21 IC is extended from the second lateral side of the sheet pick-up arm 211. When the hooking part 223A is located in the swing track 223A′ of the hooking part 223A, the sheet stop portion 223 will maintains at its upright position to stop the paper sheets. Whereas, the hooking part 223A is deviated from the swing track 223A′ of the hooking part 223A, a free swing of the sheet stop portion 23 is permitted such that the paper sheets S is transported through the sheet feeding path 201.
As previously described, in the conventional document feeder, the upper portions of the paper sheets may suppress the tilt portion of the stopper when the sheet pick-up module is in the standby position. That is, the function of the stopping the paper sheets is readily lost by using the conventional document feeder. By the present document feeder 2, with the cooperation of the hooking part 223A of the sheet stop portion 23 and the protrusion structure 211C of the sheet pick-up arm 211, the function of stopping the paper sheets is selectively enabled or disabled when the sheet pick-up arm 211 is lifted to the standby position or lower to the sheet feeding position. As a consequence, the upper portions of the paper sheets are still stopped when the paper sheets S are placed on the sheet feeding path.
Hereinafter, a process of performing the sheet pick-up operation by the sheet pick-up module 21 and the stopper 22 of the document feeder 2 will be illustrated with reference to
First of all, as shown in
Next, as shown in
Next, as shown in
In
In
After the sheet feeding operation is finished, the sheet pick-up arm 211 is lifted to the standby position. Meanwhile, the protrusion structure 21 IC is located in the swing track 223A′ of the hooking part 223A, thereby restraining the swing range of the sheet stop portion 223.
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As previously described, the sheet stop portion 223 will be kept at the upright position due to the torque applied on the loading portion 222. Alternatively, the document feeder 2 further includes a torsion spring 224 having an end sustained against the sheet stop portion 223. Once the paper sheets S suppresses the sheet stop portion 223 to permit rotation of the sheet stop portion 223, a torsion force is resulted from the torsion spring 224. After the paper sheets S is transported across the sheet stop portion 223 and the sheet stop portion 223 is no longer suppressed by the sheet stop portion 223, the torsion force of the torsion spring 224 will facilitate the reverse rotation of the sheet stop portion 223 to the upright position.
While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Claims
1. A document feeder comprising:
- a housing including a sheet feeding path for placing paper sheets thereon;
- a sheet pick-up arm pivotally mounted above said sheet feeding path and movable between a first position and a second position, wherein said sheet pick-up arm has a protrusion structure; and
- a stopper disposed under said sheet feeding path and comprising a pivotal portion and a sheet stop portion, said sheet stop portion having a hooking part corresponding to said protrusion structure,
- wherein said protrusion structure is located in the swing track of said hooking part to restrain the swing range of said sheet stop portion when said sheet pick-up arm is moved to said first position, and said protrusion structure is deviated from the swing track of said hooking part to permit free swing of said sheet stop portion when said sheet pick-up arm is moved to said second position.
2. The document feeder according to claim 1 where said sheet pick-up arm comprises a sheet pick-up roller and a sheet separation roller.
3. The document feeder according to claim 1 further comprising a driving shaft for driving said sheet pick-up arm, wherein said sheet separation roller is sheathed around the driving shaft.
4. The document feeder according to claim 1 wherein said stopper further comprises a loading portion, said loading portion and said sheet stop portion being arranged on opposite sides of said pivotal portion, wherein the torque applied on said loading portion is greater than the torque applied on said sheet stop portion with said pivotal portion serving as a fulcrum.
5. The document feeder according to claim 1 further comprising a torsion spring having an end sustained against said sheet stop portion.
Type: Application
Filed: Sep 6, 2006
Publication Date: Mar 6, 2008
Applicant: PRIMAX ELECTRONICS LTD. (Taipei)
Inventor: Hsin-Wen Lee (Taipei)
Application Number: 11/470,448
International Classification: B65H 3/06 (20060101);