Title:
PAPER FEEDING DEVICE AND MULTI-FUNCTION PRINTER USING THE SAME
Kind Code:
A1


Abstract:
A paper feeding device and a multi-function printer using the same are provided. At least one paper is fed from a paper entrance toward a paper exit by the paper feeding device, and the paper feeding device includes a first feeding path, a second feeding path, a pickup roller component and a suction element. The first feeding path intersects with a first end of the second feeding path so as to form a first intersection. The pickup roller component is disposed on the first feeding path to feed the paper located at the paper entrance into the first feeding path. The suction element is disposed above the first intersection and provides a suction. When the paper passes through the pickup roller component and is located between the pickup roller component and the suction element, the suction element guides the paper closest to the suction element onto the first feeding path.



Inventors:
Lin, Wen-ten (New Taipei City, TW)
Application Number:
14/215083
Publication Date:
06/04/2015
Filing Date:
03/17/2014
Assignee:
Cal-Comp Electronics & Communications Company Limited (New Taipei City, TW)
Primary Class:
Other Classes:
271/5
International Classes:
B65H5/26; B65H3/10; B65H5/06; B65H7/02
View Patent Images:
Related US Applications:
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20070114717Paper sheet handling apparatusMay, 2007Taniyama
20110290137IMAGE FORMING APPARATUSDecember, 2011Hatakeyama et al.
20050242494Apparatus for conveying sheets through a printing machineNovember, 2005Gunschera et al.
20070170639Media pulse-pick methodJuly, 2007Istre et al.
20070001374Paper feeding device and an electronic apparatus having the sameJanuary, 2007Lee
20050218583Apparatus for picking up an auxiliary stack when conveying sheets in a printing machineOctober, 2005Bantlin et al.
20110198799SEPARATOR FOR SEPARATING ENVELOPES FROM A STACKAugust, 2011Feijen et al.
20170068201SHEET CONVEYING APPARATUS, IMAGE READING APPARATUS, AND IMAGE FORMING APPARATUSMarch, 2017Fukushima
20020113365Sorting systemAugust, 2002Britton et al.
20040251614Sheet processing system and method for controlling such systemDecember, 2004Peeters



Primary Examiner:
MORRISON, THOMAS A
Attorney, Agent or Firm:
JCIPRNET (Taipei, TW)
Claims:
What is claimed is:

1. A paper feeding device, adapted to feed at least one paper, wherein the feeding paper device provides the at least one paper to be fed from a paper entrance toward a paper exit, the paper feeding device comprising: a first feeding path; a second feeding path, wherein the first feeding path intersects with a first end of the second feeding path, so as to form a first intersection; a pickup roller component, disposed on the first feeding path to feed the at least one paper located at the paper entrance into the first feeding path; and a suction element, disposed above the first intersection and providing a suction, wherein when the at least one paper passes through the pickup roller component and is located between the pickup roller component and the suction element, the suction element guides a paper closest to the suction element onto the first feeding path, in the meantime, another paper below the paper closest to the suction element enters the second feeding path.

2. The paper feeding device according to claim 1, further comprising: a first paper sensor, located on the second feeding path, and detecting whether the at least one paper passes through the second feeding path.

3. The paper feeding device according to claim 1, further comprising: a second paper sensor, located on the first feeding path, and detecting whether the at least one paper passes through the first feeding path.

4. The paper feeding device according to claim 1, wherein the pickup roller component comprises: a pickup roller, disposed at the paper entrance; and a separation roller component, located between the suction element and the pickup roller.

5. The paper feeding device according to claim 1, further comprising: a paper-out roller component, disposed at the paper exit and located on the first feeding path, wherein the paper-out roller component rotates toward a first direction, so as to feed the at least one paper located at the first feeding path out of the paper exit.

6. The paper feeding device according to claim 1, wherein a second end of the second feeding path relative to the first end intersects with the first feeding path so as to form a second intersection.

7. The paper feeding device according to claim 6, further comprising: a third feeding path, connected between the paper exit and the second feeding path.

8. The paper feeding device according to claim 7, wherein the paper-out roller component rotates toward a second direction, so as to enter the at least one paper into the second feeding path via the third feeding path, so that the at least one paper passes through the second intersection and re-enters into the first feeding path.

9. The paper feeding device according to claim 1, wherein an air outlet of the suction element faces a high-temperature element, and is configured to guide a heat dissipation airflow onto the high-temperature element.

10. A multi-function printer, comprising: a body, having a paper entrance and a paper exit; a paper feeding device, providing at least one paper to be fed from the paper entrance toward the paper exit, the paper feeding device comprising: a first feeding path; a second feeding path, wherein the first feeding path intersects with a first end of the second feeding path, so as to form a first intersection; a pickup roller component, disposed on the first feeding path to feed the at least one paper located at the paper entrance into the first feeding path; and a suction element, disposed above the first intersection and providing a suction, wherein when the at least one paper passes through the pickup roller component and is located between the pickup roller component and the suction element, the suction element guides a paper closest to the suction element onto the first feeding path, in the meantime, another paper below the paper closest to the suction element enters the second feeding path; and an image processing unit, disposed inside the body and located on the first feeding path, so as to perform an image process on the paper passing through the first feeding path.

11. The multi-function printer according to claim 10, wherein the paper feeding device further comprises: a first paper sensor, located on the second feeding path, and detecting whether the at least one paper passes through the second feeding path.

12. The multi-function printer according to claim 10, wherein the paper feeding device further comprises: a second paper sensor, located on the first feeding path, and detecting whether the at least one paper passes through the first feeding path.

13. The multi-function printer according to claim 10, wherein the pickup roller component comprises: a pickup roller, disposed at the paper entrance; and a separation roller component, located between the suction element and the pickup roller.

14. The multi-function printer according to claim 10, wherein the paper feeding device further comprises: a paper-out roller component, disposed at the paper exit and located on the first feeding path, wherein the paper-out roller component rotates toward a first direction, so as to feed the at least one paper located at the first feeding path out of the paper exit.

15. The multi-function printer according to claim 10, wherein a second end of the second feeding path relative to the first end intersects with the first feeding path so as to form a second intersection.

16. The multi-function printer according to claim 15, wherein the paper feeding device further comprises: a third feeding path, connected between the paper exit and the second feeding path.

17. The multi-function printer according to claim 16, wherein the paper-out roller component rotates toward a second direction, so as to enter the at least one paper into the second feeding path via the third feeding path, so that the at least one paper passes through the second intersection and re-enters into the first feeding path.

18. The multi-function printer according to claim 10, wherein an air outlet of the suction element faces a high-temperature element, and is configured to guide a heat dissipation airflow onto the high-temperature element.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 102143805, filed on Nov. 29, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

1. Technical Field

The present disclosure relates to a paper feeding device and a multi-function printer, and more particularly, to a paper feeding device capable of detecting successive multiple feed paper and a multi-function printer using the paper feeding device.

2. Description of Related Art

In the modern office, multi-function peripheral machine is one of the indispensable tools. The multi-function peripheral machine includes a copy machine, a printing machine, a scanning machine and printers having other functions, in which the printing machine and the scanning machine are the most commonly used. According to the demands of end-users, a paper feeding device capable of successive feeding has currently been developed in the market. The user just needs to place an entire document on the feeding tray of the paper feeding device which is capable of successive scanning (printing), the paper feeding device automatically drives these papers to enter the multi-function peripheral machine one by one, so as to perform further scanning (printing) and to omit the need of replacing the paper frequently from the user.

To be specific, when the successive scanning (printing) is performed on the papers, a paper transferring mechanism with automatic paper-separating function feeds the stack of paper into the multi-function printer one by one. However, when the common multi-function printer picks up the papers and performs successive scanning (printing), a phenomenon of plural papers being simultaneously fed into the multi-function printer is occurred due to a mechanical structure of the printer and differences of paper properties. The phenomenon of multiple papers being fed as described above may cause a page fault of a scanned output profile or even cause a phenomenon of paper jam, thereby damaging the original document. Therefore, a fine detecting mechanism for multiple feed paper is able to precisely detect one or more papers simultaneously being fed into the multi-function printer, in order for the multi-function printer to terminate feeding the papers thereinto and alter the user.

In the conventional multi-function printers, an ultrasonic detection technique or an optical detection technique is generally employed to determine whether the phenomenon of multiple papers being fed is occurred. Specifically, either the ultrasonic detection technique or the optical detection technique, the transmission rates of ultrasound and light passing through the paper are utilized to further detect whether the phenomenon of multiple papers being fed is occurred. However, due to differences of paper properties, the conventional detecting mechanism for multiple feed paper also requires an additional technique to distinguish the thickness of paper in advance, otherwise a misjudgment is likely to occur. Additionally, ultrasonic transmitters and sensors are high-cost components, and thus how to design a precise and low-cost detecting mechanism for multiple feed paper has become one of the concerns for researchers of the related field.

SUMMARY

The disclosure is directed to a paper feeding device capable of precisely detecting whether one or more papers simultaneously being fed into a multi-function printer, with low element cost.

The disclosure is directed to a multi-function printer capable of preventing paper jam or scanning (printing) error due to multiple feed paper, and has lower fabricating costs.

The disclosure provides a paper feeding device, which is adapted to feed at least one paper. The paper feeding device provides at least one paper to be fed from a paper entrance toward a paper exit, and the paper feeding device includes a first feeding path, a second feeding path, a pickup roller component and a suction element. The first feeding path intersects with a first end of the second feeding path so as to form a first intersection. The pickup roller component is disposed on the first feeding path to feed the at least one paper located at the paper entrance into the first feeding path. The suction element is disposed above the first intersection and provides suction. When the at least one paper passes through the pickup roller component and is located between the pickup roller component and the suction element, the suction element guides the paper closest to the suction element onto the first feeding path.

In one exemplary embodiment of the disclosure, the paper feeding device further includes a first paper sensor. The first paper sensor is located on the second feeding path, and detects whether the at least one paper passes through the second feeding path.

In one exemplary embodiment of the disclosure, the paper feeding device further includes a second paper sensor. The second paper sensor is located on the first feeding path, and detects whether the at least one paper passes through the first feeding path.

In one exemplary embodiment of the disclosure, the pickup roller component includes a pickup roller and a separation roller component. The pickup roller is disposed at the paper entrance. The separation roller component is located between the suction element and the pickup roller.

In one exemplary embodiment of the disclosure, the paper feeding device further includes a paper-out roller component. The paper-out roller component is disposed at the paper exit and located on the first feeding path. The paper-out roller component rotates toward a first direction, so as to feed the at least one paper located at the first feeding path out of the paper exit.

In one exemplary embodiment of the disclosure, a second end of the second feeding path relative to the first end intersects with the first feeding path so as to form a second intersection.

In one exemplary embodiment of the disclosure, the paper feeding device further includes a third feeding path. The third feeding path is connected between the paper exit and the second feeding path.

In one exemplary embodiment of the disclosure, the paper-out roller component rotates toward a second direction, so as to enter the at least one paper into the second feeding path via the third feeding path, so that the paper passes through the second intersection and re-enters into the first feeding path.

In one exemplary embodiment of the disclosure, an air outlet of the suction element faces a high-temperature element, and is configured to guide a heat dissipation airflow onto the high-temperature element.

The disclosure provides a multi-function printer which includes a body, a paper feeding device and an image processing unit. The body has a paper entrance and a paper exit. The paper feeding device provides at least one paper to be fed from the paper entrance toward the paper exit, and the paper feeding device includes a first feeding path, a second feeding path, a pickup roller component and a suction element. The first feeding path intersects with a first end of the second feeding path so as to form a first intersection. The pickup roller component is disposed on the first feeding path to feed the at least one paper located at the paper entrance into the first feeding path. The suction element is disposed above the first intersection and provides suction. When the at least one paper passes through the pickup roller component and is located between the pickup roller component and the suction element, the suction element guides the paper closest to the suction element onto the first feeding path. The image processing unit is disposed inside the body and located on the first feeding path, so as to perform an image process on the paper passing through the first feeding path.

In light of the above, in the embodiments of the disclosure, the paper is guided to the first feeding path through the upward suction from the suction element of the paper feeding device, in the meantime, another paper being simultaneously fed-in with such paper enters the second feeding path due to the suction has been shielded and no suction supply thereon. As such, when the first sensor disposed on the second feeding path detects the existence of paper, this indicates the paper feeding device feeds one or more paper at the same time, and thus the phenomenon of multiple papers being fed is precisely detected. Furthermore, in the paper feeding device performing double-sided scanning (printing) process, the second feeding path and the third feeding path for feeding back paper may be connected with each other, in order for a part of the second feeding path to serve as a part of the feed-back path. Accordingly, the first paper sensor may be concurrently served as a sensor for detecting whether the paper is fed back correctly, and thus the fabricating cost of the multi-function printer can be reduced effectively.

In order to make the aforementioned and other features and advantages of the disclosure more comprehensible, embodiments accompanying figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the disclosure. Here, the drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.

FIG. 1 is a partial cross-sectional schematic diagram illustrating a multi-function printer according to one exemplary embodiment of the disclosure.

FIG. 2A is a schematic diagram illustrating the multi-function printer depicted in FIG. 1 when feeding paper.

FIG. 2B is a schematic diagram illustrating a scenario of the multi-function printer depicted in FIG. 1 when feeding multiple papers.

FIG. 3 is a partial cross-sectional schematic diagram illustrating a multi-function printer according to another embodiment of the disclosure.

FIG. 4 is a schematic diagram illustrating the multi-function printer depicted in FIG. 3 when feeding paper.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a partial cross-sectional schematic diagram illustrating a multi-function printer according to one exemplary embodiment of the disclosure. Referring to FIG. 1, the multi-function printer 10 includes a body 100 and a paper feeding device 200. The body 100 has a paper entrance 110 and a paper exit 120, in which the paper is adapted to enter into the body 100 from the paper entrance 110 and to move out of the body 100 from the paper exit 120. The paper feeding device 200 includes a first feeding path D1, a second paper feeding path D2, a pickup roller component 220, a suction element 230, a first paper sensor 240 and a second paper sensor 270. The first feeding path D1 and the second feeding path D2 are disposed inside a housing 210, in which a first end of the second feeding path D2 intersects with the first feeding path D1 so as to form a first intersection N1. It should be noted that, in the embodiment, a second end of the second feeding path D2 intersects with the first feeding path D1 so as to form a second intersection N2, although the disclosure is not limited thereto. In other embodiments, the second end of the second feeding path D2 may also connect to other components of the multi-function printer 10.

The pickup roller component 220 is located on the first feeding path D1 and disposed at the paper entrance 110, and is configured to bring the paper located at the paper entrance 110 into the body 100. The suction element 230 is disposed above the first intersection N1, and may be a vacuum suction, for instance. The suction element 230 provides suction onto the paper brought by the pickup roller component 220 so as to guide the paper closest to the suction element 230 and the suction supplied thereon to the first feeding path D1. On the other hand, the first paper sensor 240 such as a touch sensor is located on the second feeding path D2, and is configured to detect whether another paper without the suction enters into the second feeding path D2.

To be specific, in the embodiment, the pickup roller component 220 includes a pickup roller 221 and a separation roller component 222. The pickup roller 221 is disposed at the paper entrance 110, and is configured to drive the paper located at the paper entrance 110 to move toward the first intersection N1. The separation roller component 222 is disposed on the first feeding path D1, and is located between the suction element 230 and the pickup roller 221. Furthermore, the paper feeding device 200 of the embodiment further includes a paper-out roller component 250. The paper-out roller component 250 is disposed at the paper exit 120 and located on the first feeding path D1, and is configured to feed the paper located at the first feeding path D1 out from the paper exit.

Moreover, it should be noted that, the multi-function printer 10 further has a first power source and a second power source. The first and second power sources such as motors are disposed inside the body 100, and are configured to provide power so as to drive these roller components to bring paper. Furthermore, in the embodiment, the first feeding path D1 has at least one bending portion C1 as shown in FIG. 1, where a feeding roller 260 is located at the bending portion C1, and is configured to bring the paper toward the paper exit 120. In the embodiment, the second paper sensor 270 is located on the first feeding path D1 and disposed between the feeding roller 260 and an image processing unit 300. The second paper sensor 270 is configured to detect whether the paper passes through the first feeding path D1. Further, the second paper sensor 270 may allow the multi-function printer 10 to accurately obtain a distance for the paper to arrive at the image processing unit 300 through sensing the paper, so as to ensure a correct starting time for the image processing of the multi-function printer 10.

However, FIG. 1 is an exemplary embodiment, which cannot be used to limit the disclosure. For example, the first feeding path D1 may also be a feeding path having a plurality of bending portions.

For a detailed description of the embodiment, FIG. 2A is a schematic diagram illustrating the multi-function printer depicted in FIG. 1 when feeding paper. Referring to FIG. 1 and FIG. 2A together, the first power source drives the pickup roller component 220 to bring the paper located at the paper entrance 110 into the multi-function printer 10. The paper from the paper entrance 110 sequentially passes through the pickup roller 221 and the separation roller component 222 on the first feeding path D1. When the paper passes through the pickup roller component 220 and is located between the pickup roller component 220 and the suction element 230, the suction element 230 provides suction onto the paper and guides the paper closest to the suction element 230 and entering the first intersection N1 into the first feeding path D1. Subsequently, the paper entered the first feeding path D1 is then transmitted by the feeding roller 260 and receives the image processing from the image processing unit 300. Afterwards, the second power source drives the paper-out roller component 250 to rotate toward a first direction, so as to feed the paper located at the first feeding path D1 out of the multi-function printer 10. In other words, the paper is finally fed out of the body 100 via the paper-out roller component 250 located at the paper exit 120. It should be noted that, the image processing unit 300 of the embodiment refers to the related devices that are capable of performing image-processing functions (scanning, printing or both) on the paper located at the first feeding path D1, but are not limited to the above functions.

However, it should be noted that, when the pickup roller 221 picks up more than one papers and the separation roller component 222 fails to separate these papers one by one, the more than one papers are guided by the separation roller component 222 to the first intersection N1. When the more than one papers pass through the suction element 230 below, the suction element 230 provides suction onto the top sheet of the papers and guides the paper located at the top of the papers and the suction supplied thereon into the first feeding path D1. On the other hand, since the suction from the suction element 230 has been shielded by the top sheet of the papers, other papers located at the bottom and being brought simultaneously by the separation roller component 222 are not affected by the suction of the suction element 230. By this way, these papers without supplying the suction thereon may pass through the first intersection N1 and are guided into the second feeding path D2, while the first paper sensor 240 located on the second feeding path S2 may also be able to detect the existence of paper.

Accordingly, the multi-function printer 10 may execute corresponding operations according to a sensing result of the first paper sensor 240. In the embodiment, when the first paper sensor 240 detects that another paper without supplying the suction thereon enters into the second feeding path D2, the multi-function printer 10 controls the first power source to terminate driving the pickup roller component 220, so as to stop successively bringing the paper into the multi-function printer 10. In addition, the multi-function printer 10 may also determine whether to activate a warning, such as one of an indicating text, a sound, and a lamplight or a combination thereof, according to the sensing result of the first paper sensor 240, such that the user may be informed that the phenomenon of multiple papers being fed is occurred in the multi-function printer 10.

In order for the user to manually remove the paper located at the second feeding path D2, the housing 210 of the embodiment may be a detachable structure, for instance. As shown in FIG. 1, an upper portion of the housing 210 and a lower portion of the housing 210 are connected to each other at an engaging plane S, in which the engaging plane S passes through a horizontal section of the second feeding path D2, for instance. Based on this, when the user lifts up or dismount the upper portion of the housing 210, the paper located at the second feeding path D2 is then able to be removed out. For example, FIG. 2B is a schematic diagram illustrating a scenario of the multi-function printer depicted in FIG. 1 when feeding multiple papers. When the first paper sensor 240 detects another paper without the suction enters into the second feeding path D2, the multi-function printer 10 controls the first power source to terminate driving the pickup roller component 220, so as to stop successively bringing the paper into the multi-function printer 10, such that the user is capable of manually removing the paper located at the second feeding path D2 successfully when the paper feeding device 200 is under the deactivation condition. Then, the user may lift up the upper portion of the housing 210 or dismount the upper portion of the housing 210 from the multi-function printer 10. By this way, the second feeding path D2 is exposed out of the multi-function printer 10, so that the user may remove the paper entering the second feeding path D2.

Besides, the suction element 230 of the embodiment may be a vacuum suction, for instance, and an air outlet thereof may be disposed to face a high-temperature element, which is configured to guide a heat dissipation airflow onto the high-temperature element. The high-temperature element may a motor, a motor driver, a processor or other elements prone to be overheated inside the multi-function printer 10, where the airflow derived from the air outlet of the vacuum suction allows these high-temperature elements to dissipate heat, so as to prevent the phenomenon that the element is damaged due to being overheated. It should be noted that, although the afire-described suction element 230 is a vacuum suction in the embodiment, the disclosure is not limited thereto, that is, a component configured to provide suction and guide a single sheet of paper to the first feeding path D1 in various devices among the existing techniques, may be applicable to the disclosure.

However, implementations of the disclosure are not limited to the afore-described embodiments, and the afore-described embodiments can be suitably modified according to an actual requirement. For example, in another embodiment of the disclosure, the afore-described components may be combined into a multi-function printer capable to perform double-sided feeding successively, so as to detect whether the phenomenon of multiple papers being fed is occurred during the double-sided scanning (printing) process.

FIG. 3 is a partial cross-sectional schematic diagram illustrating a multi-function printer according to another embodiment of the disclosure. Referring to FIG. 3, the multi-function printer 30 includes a body 500 and a paper feeding device 400. The body has a paper entrance 310 and a paper exit 320. The paper feeding device 400 includes a first feeding path D1, a second feeding path D2, a pickup roller component 420, a suction element 430 and a first paper sensor 440. The first feeding path D1 and a second feeding path D2 are disposed inside a housing 410, in which a first end of the second feeding path D2 intersects with the first feeding path D1 so as to form a first intersection N1.

The pickup roller component 420 is located on the first feeding path D1 and disposed at the paper entrance 310. The suction element 430 is disposed above the intersection N1. The suction element 430 provides suction onto the paper brought by the pickup roller component 420. On the other hand, the first paper sensor 440 is located on the second feeding path D2, and detects whether a paper enters into the second feeding path D2.

In the embodiment, the pickup roller component 420 includes a pickup roller 421 and a separation roller component 422. The pickup roller 421 is disposed at the paper entrance 310, and is configured to drive the paper located at the paper entrance 310 to move toward the first intersection N1. The separation roller component 422 is disposed on the first feeding path D1, and is located between the suction element 430 and the pickup roller 421. Furthermore, the paper feeding device 400 of the embodiment further includes a paper-out roller component 450 and a feeding roller 460, where the paper-out roller component 450 is disposed at the paper exit 320 and located on the first feeding path D1. Similarly, in the embodiment, an upper portion of the housing 410 and a lower portion of the housing 410 are connected to each other at an engaging plane S, in which the engaging plane S passes through a horizontal section of the second feeding path D2, for instance.

It should be noted that, for achieving the double-sided scanning (printing) function, the difference from the embodiment depicted in FIG. 1 is the housing of the embodiment has a third feeding path D3, and the paper feeding device 400 has a second paper sensor 470. The second paper sensor 470 is located on the first feeding path D1 and disposed between a second intersection N2 and a fourth intersection N4, and is configured to detect whether the paper passes through the first feeding path D1.

Since the housing 410 of the embodiment has the third feeding path D3, the multi-function printer 10 is able to pull back the paper from the third feeding path D3 and to perform the image processing on the back page of the paper. Specifically, similar to the embodiments described above, the first feeding path D1 and the second end of the second feeding path D2 are intersected at the second intersection N2. In addition, the second feeding path D2 and the first end of the third feeding path D3 are intersected at the third intersection N3, in which the third intersection N3 is located between the first intersection N1 and the second intersection N2. The first feeding path D1 and the second end of the third feeding path D3 are intersected at the fourth intersection N4, where the fourth intersection N4 is adjacent to the paper-out roller component 420. By this way, the second feeding path D2 and the third feeding path D3 for feeding back paper may be connected with each other, in order for a part of the second feeding path D2 (namely, the part between the second intersection N2 and the third intersection N3) to serve as a part of the feed-back path.

For a detailed description of the embodiment, FIG. 4 is a schematic diagram illustrating the multi-function printer depicted in FIG. 3 when feeding paper. Referring to FIG. 3 and FIG. 4 together, during the stage of processing the front page of the paper, the first power source drives the pickup roller component 420 to bring the paper located at the paper entrance 310 into the multi-function printer 30. The first sheet of paper from the paper entrance 310 sequentially passes through the pickup roller 421 and the separation roller component 422 located on the first feeding path D1. When the first sheet of paper passes through the pickup roller component 420 and is located between the pickup roller component 420 an the suction element 430, the suction element 430 provides suction onto the first sheet of paper and guides the first sheet of paper entering the first intersection N1 into the first feeding path D1. When the second paper sensor 470 detects the existence of the first sheet of paper, this indicates the first sheet of paper has completed feeding. As such, the multi-function printer 30 controls the first power source to terminate driving the pickup roller component 420 according to a sensing result of the second paper sensor 470, so as to prevent bringing the next sheet of paper into the multi-function printer 30 before the first sheet of paper completes the double-sided processing.

However, during the stage of processing the front page of the paper, when the pickup roller 421 simultaneously picks up more than one papers and the separation roller component 422 also fails to separate and feed these papers one by one, the more than one papers are guided by the pickup roller component 420 to the first intersection N1. The suction element 430 provides suction onto the top sheet of the papers and guides the paper located at the top of the papers and the suction supplied thereon into the first feeding path D1. Furthermore, other papers located at the bottom and being brought simultaneously by the separation roller component 422 are not affected by the suction of the suction element 430, thereby causing these papers without supplying suction thereon to be guided into the second feeding path D2. During the stage of processing the front page of the paper, when the first paper sensor 440 located on the second feeding path D2 detects the existence of paper, it indicates that the phenomenon of multiple papers being fed is occurred in the multi-function printer 30.

If the phenomenon of multiple papers being fed is not occurred in the multi-function printer 30 during the stage of processing the front page of the paper, the second power source drives the paper-out roller component 450 rotates toward the first direction M1, so as to bring the paper located at the first feeding path D1 toward the paper exit 320. As such, the paper is then transmitted by the feeding roller 460 and the paper-out roller component 450, and receives the image processing from the image processing unit 600. During the double-sided process, when the paper is transmitted to the paper exit 320, a tail end of the paper halts before the paper-out roller component 450.

Here, the multi-function printer 30 enters the stage of processing the back page of the paper, the second power source drives the paper-out roller component 450 to rotate toward a second direction M2, such that the paper is pulled back to the third feeding path D3 and is entered into the second feeding path D2 from the third intersection N3, and the paper passes through the second intersection N2 and re-enters into the first feeding path D1. Based on this, the image processing on the back page of the paper may be performed by having the paper to pass through the image processing unit 600 again.

It should be noted that, during the stage of processing the back page of the paper, when the first paper sensor 440 detects the paper passing through the second intersection N2 and re-entering the first feeding path D1, the multi-function printer 30 continues to control the second power source driving the paper-out roller component 450 to rotate toward the second direction M2, so as to successively send the paper back beside the feeding roller 460 on the first feeding path D1. In the embodiment, once the second paper sensor 470 beside the feeding roller 460 detects the existence of paper, the multi-function printer 30 controls the second power source to terminate driving the paper-out roller component 450, so that the paper-out roller component 450 is under the powerless condition. Specifically, once the second paper sensor 470 beside the feeding roller 460 detects the existence of paper, it indicates the feeding roller 460 has already been in contact with the paper located at the first feeding path D1. At this time, the multi-function printer 30 terminates driving the paper-out roller component 450, so that the paper on the first feeding path D1 may continue to move toward a direction of the image processing unit 600 through the drive of the feeding roller 460, so as to perform the image processing on the back page of the paper.

Subsequently, the paper due to the drive of the feeding roller 460 continuously passes through the second intersection N2 and moves toward the direction of the image processing unit 600. At this time, once the first paper sensor 440 detects no existence of paper, it indicates the tail end of the paper has already passed through the first paper sensor 440, and the multi-function printer 30 controls the second power source driving the paper-out roller component 450 to rotate toward the first direction M1, so as to feed the paper located at the first feeding path D1 out of the multi-function printer 30. That is to say, the first paper sensor 440 may be served as the sensor for detecting the phenomenon of multiple papers being fed during the stage of processing the front page of the paper, and may be served as the sensor for detecting whether the paper has been fed back correctly during the stage of processing the back page of the paper, thereby cutting down on the cost of additional sensor setup.

In light of the foregoing, in the embodiments of the disclosure, the paper is guided to the first feeding path through the upward suction from the suction element of the paper feeding device, in the meantime, another paper being simultaneously fed-in with such paper enters the second feeding path due to the suction has been shielded and no suction supply thereon. Accordingly, through the sensing result of the first paper sensor disposed on the second feeding path, whether the phenomenon of multiple papers being fed is occurred in the multi-function printer can be detected precisely. Furthermore, in the paper feeding device performing double-sided process, based on the design of feeding paths in the embodiments, the first paper sensor can concurrently be served as the sensor for detecting whether the paper has been fed back correctly, and thus the fabricating cost of the multi-function printer can be reduced effectively. Moreover, the air outlet of the suction element may aim at the high-temperature elements inside the multi-function printer, so that the airflow of the air outlet is served as the heat dissipation airflow, in order to allow these high-temperature elements to dissipate heat.

Although the disclosure has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure will be defined by the attached claims not by the above detailed descriptions.