CN104980604A - Automatic paper feeder - Google Patents

Abstract

The invention relates to an automatic paper feeding device, which comprises an upper cover, a paper feeding channel and a paper detection module. The paper detection module comprises a metal element, a coil, a detection circuit and a control unit. The metal element is arranged on the first side of the paper feeding channel, and the coil, the detection circuit and the control unit are all arranged on the second side of the paper feeding channel. When the paper passes through the paper detection element, the metal element is pushed by the paper, so that the magnetic force generated by the coil is changed, and the detection circuit can detect the change of the magnetic force. When the control unit judges that the variation of the magnetic force is larger than a preset magnetic force value, the multi-paper feeding is judged to occur.

Description

Automatic paper feeder

technical field

The invention relates to an automatic paper feeding device, in particular to an automatic paper feeding device applied to a scanning device.

Background technique

With the development of science and technology, the preservation of documents has evolved from traditional paper document filing to electronic document storage. The tool generally used for document electronic work is a scanning device, which is used to scan the contents of paper documents. Converted into electronic files in a way that allows users to disseminate, organize or save.

Early scanning devices can only scan images on one side of a document. When users want to scan images on both sides of a document, they must manually turn over the document so that the scanning device can scan images on the other side of the document. In view of the fact that manual flipping is too troublesome, an automatic paper feeding device has been developed on the market. When used with a flatbed scanner, double-sided scanning can be completed without manual flipping. However, the automatic paper feeding device is not only used in conjunction with the scanning module, it can also be applied to the printing module to form a printing device.

Next, the structure of the existing automatic paper feeding device will be described, taking the structure of the scanning device formed by the existing automatic paper feeding device in conjunction with a flatbed scanner as an example. Please refer to FIG. 1 , which is a schematic side view of the structure of an existing automatic document feeding device and a flatbed scanner. The existing automatic paper feeding device 1 includes a paper taking module 10, an upper cover 11, a friction pad 12, a paper feeding channel 13, a paper input box 14, a paper output box 15, a plurality of paper feeding roller groups 16 and A paper output roller group 17. The input tray 14 is used for placing a plurality of papers S, and the output tray 15 is located below the input tray 14 for placing a plurality of scanned sheets S. The paper picking module 10 is located under the upper cover 11, and is used to feed a plurality of papers S from the paper tray 14 into the paper feeding channel 13. The paper picking module 10 includes a paper picking roller 101 and a paper separation roller 102. The paper picking roller 101 is used to contact with a plurality of sheets S to feed a plurality of sheets S, and the separation roller 102 is used to separate a plurality of sheets S, so that only one sheet S of the plurality of sheets S enters the paper feeding channel 13 during each feeding process . The friction pad 12 is located below the separation roller 102 and is used to provide a friction force to the paper S in contact with the friction pad 12 among the plurality of paper S, so as to assist the separation roller 102 to feed only one paper S into the paper feeding path 13 .

A plurality of paper feeding roller sets 16 are located on the paper feeding channel 13 for feeding the paper S to move in the paper feeding channel 13, and a paper output roller set 17 is arranged near the paper output box 15 for feeding the paper S to Output tray 15. The flatbed scanner 2 is arranged below the automatic paper feeding device 1, the flatbed scanner 2 includes a scanning module 20, and the paper feeding channel 13 passes above the scanning module 20, so that the paper S is scanned when passing through the scanning module 20. The paper s.

Next, the operation of the conventional automatic paper feeding device 1 will be described. When the existing automatic paper feeding device 1 starts to operate, its paper picking module 10 swings down with the axis of the paper separation roller 102 and is close to the upper cover 11, so that the paper picking roller 101 of the paper picking module 10 can be aligned with the paper tray The plurality of sheets S on 14 are brought into contact, and the plurality of sheets S are fed. When a plurality of paper S is fed by the paper pickup roller 101 , the uppermost paper S among the plurality of paper S is in contact with the separation roller 102 , and the lowermost paper S among the plurality of paper S is in contact with the friction pad 12 , The plurality of papers S are separated due to the friction force provided by the friction pad 12 , and the uppermost paper S is fed into the paper feeding channel 13 .

Next, the paper S is fed by a plurality of paper feeding roller sets 16 and moves in the paper feeding passage 13. When the paper S passes above the scanning module 20, the scanning module 20 scans the paper S to obtain the paper Scanned image files of S. Finally, the scanned paper S is fed to the paper output tray 15 by the paper discharge roller set 17, and the topmost paper S is scanned, and the scanning of the rest of the paper S is the same as the above process, so it will not be repeated. After all the papers S have been scanned, the papers S are taken out from the output tray 15 .

However, after the existing automatic document feeding device 1 has been used for a long time, the function of the paper pickup roller 101, the paper separation roller 102 and the friction pad 12 has deteriorated due to long-term wear and tear, so that when a stack of paper is ready to be scanned, it is easy to In the case of double feeding or multi feeding, two or more sheets of paper are fed into a sheet-fed scanner at a time. When double feeding occurs, the second paper to be fed is partially overlapped with the first paper or the second paper is completely overlapped with the first paper, causing the second paper to be scanned incompletely or cannot be scanned. Scan to wait for the situation, so as to cause the user's trouble. Therefore, there is a need for an automatic paper feeding device that can detect the occurrence of multiple paper feeding.

Contents of the invention

The object of the present invention is to provide an automatic paper feeding device capable of detecting the occurrence of multiple paper feeding.

In a preferred embodiment, the present invention provides an automatic paper feeding device for sequentially feeding a plurality of papers to a scanning area of a scanning module, the automatic paper feeding device includes a main body, an upper cover, a feeding Paper box, a paper output box, a paper feeding channel and a paper detection module. The upper cover covers part of the main body, and the paper tray is connected to the main body for placing the plurality of papers thereon. The output tray is arranged on the main body for placing the plurality of papers passing through the scanning area, and the paper feeding channel is arranged between the input tray and the output tray and is located under the upper cover for for the plurality of sheets to pass through. The paper detection module is arranged on the paper feeding channel to detect whether multiple paper feeding occurs. The paper detection module includes a metal element, a coil, a detection circuit and a control unit. The metal element is arranged on a first side of the paper feeding passage, and the coil is arranged on a second side of the paper feeding passage for outputting a magnetic force according to an electromagnetic effect. The detection circuit is arranged on the second side of the paper feeding channel and connected to the coil, and is used to supply power to the coil to cause the coil to generate the electromagnetic effect, or to detect a first detection circuit according to whether the metal element is pushed by the paper. A magnetism value or a second magnetism value. The control unit is disposed on the second side of the paper feeding channel and connected to the detection circuit, and is used to determine whether multiple paper feeding occurs according to a variation between the first magnetic force value and the second magnetic force value; wherein When the variation is greater than a preset magnetic force value, it is determined that multi-feeding occurs.

The automatic paper feeding device of the present invention can judge whether multiple paper feeding occurs according to the magnetic force change generated when the paper passes through the paper detection module, and when multiple paper feeding occurs, eject multiple papers to the paper tray to avoid scanning leakage page situation. In addition, since the paper detection module of the present invention only includes a metal element, a coil, a detection circuit and a control unit, its structure is simple and its operation is simple, so adding a paper detection module to the automatic paper feeding device does not require too high a cost. In line with cost considerations. Therefore, the automatic paper feeding device of the present invention does not scan missing pages due to multi-feeding.

Description of drawings

FIG. 1 is a schematic side view of the structure of an existing automatic paper feeding device and a flatbed scanner.

Fig. 2 is a schematic side view of the structure of the automatic paper feeding device in the first preferred embodiment of the present invention in a ready state.

FIG. 3 is a structural schematic diagram of the paper detection module of the automatic paper feeding device in the first preferred embodiment of the present invention.

FIG. 4 is a schematic structural view of the upper cover and metal components of the automatic paper feeding device in the first preferred embodiment of the present invention.

Fig. 5 is a schematic side view of the structure of the automatic paper feeding device of the present invention in the paper feeding state in the first preferred embodiment.

Fig. 6 is a schematic side view of the structure of the automatic paper feeding device in the second preferred embodiment of the present invention in the paper feeding state.

FIG. 7 is a schematic structural view of the upper cover and the metal components of the automatic paper feeding device in the second preferred embodiment of the present invention.

Wherein, the reference signs are explained as follows:

1, 30, 50 automatic paper feeding device

2 flatbed scanners

3.5 Paper-fed scanning device

10, 38, 58 paper pickup module

11, 33, 53 cover

12 friction pad

13, 36, 56 paper feed channel

14, 34, 54 trays

15, 35, 55 output tray

16, 39, 59 Feed roller set

17, 40, 60 Paper output roller group

31, 51 scanning module

32, 52 body

37, 57 paper detection module

101, 382 paper pickup roller

102, 383 paper separation roller

301, 501 scanning area

331, 531 paper guide sheet

332, 533 Inner surface of upper cover

370, 570 circuit board

371, 571 Metal components

372 Coils

373 detection circuit

374 control unit

381, 581 Pick up arm

384, 584 Friction elements

532 elastic element

3711 First end of metal element

3712 Second end of metal element

G gap

S paper

Detailed ways

In view of the problems of the prior art, the present invention provides an automatic paper feeding device capable of detecting the occurrence of multiple paper feeding, so as to solve the disadvantages of the prior art. Firstly, the automatic paper feeding device of the present invention will be described. Please refer to FIG. 2 , which is a schematic side view of the structure of the automatic paper feeding device of the present invention in a first preferred embodiment in a ready state. Figure 2 shows a paper-feed scanning device 3, and the paper-feed scanning device 3 includes an automatic paper feed device 30 and a scanning module 31, the function of the scanning module 31 scans a plurality of papers S sequentially to generate corresponding A scanned image file of paper S. The automatic paper feeding device 30 is disposed on the scanning module 31 , and its function is to sequentially feed a plurality of papers S to a scanning area 301 of the scanning module 30 . The automatic paper feeding device 30 includes a main body 32, an upper cover 33, a paper input box 34, a paper output box 35, a paper feeding channel 36, a paper detection module 37, a paper picking module 38, and a paper feeding roller group 39 and a paper output roller group 40. The upper cover 33 covers part of the main body 32 , and the paper tray 34 is connected to the main body 32 , and its function is to place a plurality of papers S thereon. The output tray 35 is disposed on the main body 32 and below the input tray 34 , and its function is to place a plurality of papers S passing through the scanning area 301 , that is, a plurality of scanned papers S. The paper feeding channel 36 is disposed between the paper input tray 34 and the output tray 35 and under the upper cover 33 for a plurality of paper S to pass through.

In Fig. 2, the paper taking module 38 is arranged between the paper tray 34 and the paper feeding channel 36, and its function is to sequentially feed a plurality of papers S located on the paper tray 34 into the paper feeding channel 36, and the paper picking module 38 includes A paper fetching arm 381 , a paper fetching roller 382 , a paper separating roller 383 and a friction element 384 . The paper-feeding arm 381 is disposed above the first side of the paper-feeding passage 36 , and can swing relative to the paper-feeding passage 36 to be close to the paper-feeding passage 36 or away from the paper-feeding passage 36 . The pick-up roller 382 is arranged on the pick-up arm 381 and is close to the paper tray 34. Its function is to contact and contact with a plurality of paper S in response to the swing of the pick-up arm 381, and to feed a plurality of paper S into the paper feed in sequence. Channel 36. The paper separation roller 383 is disposed on the paper pickup arm 381 and parallel to the paper pickup roller 382 , and its function is to separate the fed papers S so that only one paper S among the multiple papers S can enter the paper feeding path 36 . The friction element 384 is disposed on the second side of the paper feeding path 36 , and its function is to provide a friction force for the plurality of papers S to help separate the plurality of papers S. In short, the paper separating roller 383 and the friction element 384 can ensure that only one piece of paper S enters the paper feeding path 36 during each paper feeding operation of the paper fetching module 38 (that is, normal paper feeding). The paper feeding roller set 39 is disposed on the paper feeding channel 36 , and its function is to sequentially feed a plurality of papers S into the scanning area 301 . The paper output roller set 40 is disposed on the paper feeding path 36 and close to the output tray 35 , and its function is to sequentially feed a plurality of sheets S passing through the scanning area 301 to the output tray 35 . In this preferred embodiment, the friction element 384 is a friction pad, but not limited thereto. In another preferred embodiment, the friction element can also be a friction roller.

Please refer to FIG. 2 and FIG. 3 at the same time. FIG. 3 is a structural diagram of the paper detection module of the automatic paper feeding device in the first preferred embodiment of the present invention. The paper detection module 37 is disposed on the paper feeding path 36 and its function is to detect whether multiple paper feeding occurs. The paper detection module 37 includes a metal element 371 , a coil 372 , a detection circuit 373 and a control unit 374 . The metal element 371 is arranged on the upper cover 33 in a swingable form and is located on the first side of the paper feeding passage 36, and the coil 372 is arranged on the second side of the paper feeding passage 36. When the coil 372 is conductive, it can generate an electromagnetic effect And output a magnetic force F. The detection circuit 373 is disposed on the second side of the paper feeding channel 36 and connected to the coil 372. It has two functions: firstly, it supplies power to the coil 372 to cause the coil 372 to generate an electromagnetic effect. Second, a first magnetic force value or a second magnetic force value is detected according to whether the metal element 371 is pushed by a single paper S or a plurality of paper S, wherein the first magnetic force value is defined as the metal element 371 is not pushed by the paper S , the magnetic force value detected by the detection circuit 373, and the second magnetic force value is defined as the magnetic force value detected by the detection circuit 373 when the metal element 371 is pushed by a single paper S or a plurality of paper S, that is, the second The magnetic force value varies with the number of sheets S pushing the metal member 371 .

The control unit 374 is disposed on the second side of the paper feeding channel 36 and connected to the detection circuit 373, and its function is to determine whether a Multi-feed. The setting of the preset magnetic value will be described in detail later. In this preferred embodiment, the metal element 371 is a thin metal sheet and can be made of copper or aluminum, and the coil 372 , the detection circuit 373 and the control unit 374 can be integrated in a circuit board 370 .

In short, the paper detection module 37 determines whether multiple paper feeding occurs by detecting the change of the magnetic force value. For example, when the metal element 371 is not pushed by the paper S (that is, no paper S passes through the paper detection module 37 ), the detection circuit 373 detects the first magnetic force value, and the first magnetic force value is A for example. When the metal element 371 is pushed by a piece of paper S, the detection circuit 373 detects a second magnetic force value, for example, the second magnetic force value is A+B. When the metal element 371 is pushed by two sheets of paper S, the detection circuit 373 detects a different second magnetic force value, and the second magnetic force value at this time is, for example, A+2B. Therefore, it can be seen that when the variation between the first magnetic force value and the second magnetic force value is equal to B, the control unit 374 can judge normal paper feeding, and when the variation between the first magnetic force value and the second magnetic force value is greater than B (for example, 2B or above), the control unit 374 judges that multiple feeding occurs. In this preferred embodiment, the preset magnetic force value in the setting control unit 374 is B, which corresponds to the magnetic force change value caused by a piece of paper S.

Next, the installation position of the metal member 371 will be described. Please refer to FIG. 2 and FIG. 4 at the same time. FIG. 4 is a structural schematic diagram of the upper cover and metal components of the automatic paper feeding device in the first preferred embodiment of the present invention. 4 shows the upper cover 33 of the automatic paper feeding device 30, and the upper cover 33 includes a plurality of paper guides 331, which are arranged on an inner surface 332 of the upper cover 33 and the plurality of paper guides 331 are perpendicular to the upper cover 33 When the upper cover 33 covers part of the main body 32 , a plurality of paper guides 331 are located above the paper feeding passage 36 . The metal element 371 is arranged between the two paper guide sheets 331, a first end 3711 of the metal element 371 is fixed on the two paper guide sheets 331, and a second end 3712 of the metal element 371 is located on the first side of the paper feeding path 36 , so that the paper S can push the metal element 371 through the paper detection module 37 in the paper feeding passage 36 . When the second end 3712 of the metal element 371 is pushed by the paper S, the second end 3712 of the metal element 371 swings relative to the first end 3711 of the metal element 371, so that the detection circuit 373 detects the second magnetic force value.

Please refer to FIG. 2 and FIG. 5 at the same time. FIG. 5 is a schematic side view of the structure of the automatic paper feeding device in the paper feeding state in the first preferred embodiment of the present invention. Before the user intends to use the paper-fed scanning device 3 to scan a plurality of papers S, the detection circuit 373 must detect the first magnetic force value corresponding to no paper S passing through the paper detection module 37 and the first magnetic force value corresponding to a paper S passing through the paper detection module 37. The second magnetic force value of the module 37 enables the control unit to obtain the change amount between the first magnetic force value and the second magnetic force value, and set the change amount as the preset magnetic force value. After the preset magnetic force value is set, the paper fetching arm 381 of the automatic paper feeding device 30 is in a state away from the paper feeding channel 36, so that the user can place a plurality of papers S on the paper tray 34. At this time, the automatic paper feeding device 30 is in a ready state, as shown in FIG. 2 .

When the automatic paper feeder 3 starts to run, its paper pick-up arm 381 swings down on the axis of the paper separation roller 383 and is close to the upper cover 33, so that the paper pick-up roller 382 can be aligned with a plurality of papers S on the paper tray 34. contact, the automatic paper feeding device 30 is in the paper feeding state at this time, as shown in FIG. 5 . On the other hand, the paper detection module 37 is running. Since no paper S passes through the paper detection module 37, the detection circuit 373 continuously detects a magnetic force value equal to the first magnetic force value (for example, A). Next, the pickup roller 382 sequentially feeds a plurality of sheets S. During the feeding process of the plurality of papers S by the paper picking roller 382, the uppermost paper S among the plurality of papers S is in contact with the separation roller 383, and the lowermost paper S among the plurality of papers S is in contact with the friction element 384, The plurality of papers S are separated due to the friction force provided by the friction pad 12, wherein the friction force between the separation roller 383 and the paper S is greater than the friction force between the paper S and the friction element 384, and the friction force between the paper S and the friction element 384 is greater than that between a plurality of sheets S. Through the design of the above-mentioned different friction forces, among the plurality of papers S, only the uppermost paper S is fed into the paper feeding channel 36 .

Next, the paper S moving in the paper feeding path 36 passes through the paper detection module 37. At this time, the paper S pushes the second end 3712 of the metal element 371 on the first side of the paper feeding path 36, so that the second end 3712 of the metal element 371 The two ends 3712 swing relative to the first end 3711 of the metal element 371. With the swing of the metal element 371, the electromagnetic effect generated by the coil 372 changes, so that the magnetic force value detected by the detection circuit 373 is changed from the first magnetic force value to the corresponding The second magnetic force value (for example, A+B) when a piece of paper S passes through the paper detection module 37 . At this time, the control unit 374 compares the change amount (that is, B) between the first magnetic force value and the second magnetic force value with the preset magnetic force value, and since the change amount and the preset magnetic force value are both B, the control unit 374 judges Feed the paper normally to continue the paper feeding job.

After the paper S passes through the paper detection module 37 , the metal element 371 is no longer pushed by the paper S and swings to the position before being pushed, and the magnetic force value detected by the detection circuit 373 is changed to the first magnetic force value again. On the other hand, the paper feeding roller set 39 feeds the paper S through the scanning area 301 of the scanning module 31 , and at this time, the scanning module 31 scans the paper S to obtain a scanned image file of the paper S. Finally, the scanned paper S is fed to the paper output tray 35 by the paper discharge roller set 40 , and the scanning of the uppermost paper S among the multiple paper S is completed. The above is the scanning situation without multiple paper feeding.

Next, the operation of the automatic paper feeding device 3 in which multiple paper feeding occurs will be described. The automatic paper feeding device 3 is changed from the ready state in FIG. 2 to the paper feeding state in FIG. 5 , and feeds multiple papers S into the paper feeding channel 36 . Two papers S are fed as an example for illustration. When two sheets of paper S pass through the paper detection module 37, the two sheets of paper S push the second end 3712 of the metal element 371 on the first side of the paper feeding path 36, so that the second end 3712 of the metal element 371 is relatively opposite to the metal element 371. The first end 3711 of the first end 3711 swings and the swing amplitude is greater than the swing amplitude of the metal element 371 pushed by the aforementioned piece of paper S. With the swing of the metal element 371, the electromagnetic effect generated by the coil 372 changes, so that the magnetic force value detected by the detection circuit 373 Change from the first magnetic force value to the second magnetic force value (for example, A+2B) corresponding to two sheets S passing through the paper detection module 37 .

At this time, the control unit 374 compares the variation between the first magnetic force value and the second magnetic force value (that is, 2B) with the preset magnetic force value. Since the variation is greater than the preset magnetic force value, the control unit 374 judges that multiple paper feed. Therefore, the control unit 374 outputs a control signal to make the pick-up roller 382 , the separation roller 383 and the feed roller set 39 reverse to eject the two sheets S into the paper tray 34 . Afterwards, the paper pickup roller 382 and the paper separation roller 383 stop rotating and feed the paper S into the paper feeding path 36 again, that is, the paper feeding operation is performed again. The above is the scanning situation where multi-feed occurs. The scanning of the rest of the paper S is the same as the above process, so it will not be described again. After all the papers S are scanned, the papers S are taken out from the output tray 35 .

It should be noted that the user must first detect the first magnetic force value corresponding to no paper S passing through the paper detection module 37 and the second magnetic force value corresponding to a paper S passing through the paper detection module 37 before each paper feeding operation. Only when the magnetic force value is set, the preset magnetic force value can be obtained. The reason is that the type and thickness of the paper in each paper feeding operation may be different, so the corresponding preset magnetic force value must be set for different paper to ensure the correctness of the judgment of the control unit 374 .

In addition, the present invention further provides a second preferred embodiment different from the aforementioned first preferred embodiment. Please refer to FIG. 6 , which is a schematic side view of the structure of the automatic paper feeding device in the paper feeding state in the second preferred embodiment of the present invention. Figure 6 shows a paper-feed scanning device 5, and the paper-feed scanning device 5 includes an automatic paper feeding device 50 and a scanning module 51, the scanning module 51 has a scanning area 501, and the automatic paper feeding device 50 includes a body 52 , an upper cover 53 , a paper input tray 54 , a paper output tray 55 , a paper feed path 56 , a paper detection module 57 , a paper pickup module 58 , a paper feed roller set 59 and a paper output roller set 60 . The paper pickup module 58 includes a paper pickup arm 581, a paper pickup roller 582, a paper separation roller 583 and a friction element 584, and the paper detection module 57 includes a metal element 571, a coil (not shown in the figure), a The detection circuit (not shown in the figure) and a control unit (not shown in the figure), and the coil, the detection circuit and the control unit can be integrated in a circuit board 570 . The structure and operation of the automatic paper feeding device 50 of this preferred embodiment are the same as those of the aforementioned first preferred embodiment, and will not be repeated here. The difference between this preferred embodiment and the first preferred embodiment lies in the arrangement of the metal element 571 , which is described in detail as follows.

Please refer to FIG. 6 and FIG. 7 at the same time. FIG. 7 is a schematic structural diagram of the upper cover and metal components of the automatic paper feeding device in the second preferred embodiment of the present invention. The upper cover 53 of this preferred embodiment includes a plurality of paper guides 531 and an elastic member 532. The plurality of paper guides 531 are arranged on an inner surface 533 of the upper cover 53 and the plurality of paper guides 531 are perpendicular to the upper cover. 53 of the inner surface 533, when the upper cover 53 covers part of the body 52, a plurality of paper guides 531 are located above the paper feeding passage 56. The elastic element 532 is arranged on the inner surface 533 of the upper cover 53 and is located in a gap G between the two paper guide pieces 531. The metal element 571 is fixed on the elastic element 532 so that the metal element 571 is located at the first position of the paper feeding path 53. on the side. In this preferred embodiment, the metal element 571 is a metal plate, and the elastic element 532 is a spring. But not limited thereto, in another preferred embodiment, the metal element can also be a metal block.

The operation of the paper S passing through the paper detection module 57 will be briefly described. When the automatic paper feeding device 50 performs the same paper picking work as in the first preferred embodiment and feeds a piece of paper S into the paper feeding passage, and when the paper S passes through the paper detection module 57, the paper S pushes the paper S located in the paper feeding passage 56 The metal element 571 on the first side moves toward the upper cover 53 with the pushing force of the paper S, and the elastic element 532 is pushed against by the metal element 571 to assume a compressed state. In response to the movement of the metal element 571, the electromagnetic effect generated by the coil 572 changes, so that the magnetic force value detected by the detection circuit 5 is changed from the first magnetic force value to the second magnetic force value corresponding to a piece of paper S passing through the paper detection module (for example, A+B). At this time, the control unit compares the change amount (that is, B) between the first magnetic force value and the second magnetic force value with the preset magnetic force value. paper to continue paper feeding. After the paper S passes through the paper detection module 57, the metal element 571 is no longer pushed by the paper S, so that the elastic element 532 returns to its original shape from the compressed state and provides an elastic force to the metal element 571, so that the metal element 571 moves to the position before being pushed, And the magnetic force value detected by the detection circuit is changed to the first magnetic force value again.

Next, when the automatic paper feeding device 50 performs the same paper picking work as in the first preferred embodiment and feeds two sheets of paper S into the paper feeding path, and when the two sheets of paper S pass through the paper detection module 57, the two sheets of paper S S pushes the metal element 571 on the first side of the paper feeding channel 56 , and the metal element 571 moves toward the upper cover 53 in response to the pushing force of the paper S, and the elastic element 532 is pressed against by the metal element 571 to assume a compressed state. Along with the movement of the metal element 571, the electromagnetic effect produced by the coil changes, so that the magnetic force value detected by the detection circuit is changed from the first magnetic force value to the second magnetic force value corresponding to two sheets of paper S passing through the paper detection module 57 (for example A+2B). Since the variation of the magnetic force value is larger than the preset magnetic force value, the control unit judges that multi-feeding occurs. Therefore, the control unit outputs a control signal to make the paper pickup roller 582 , the paper separation roller 583 and the paper feeding roller set 59 reverse to eject the two sheets of paper S into the paper tray 54 . As for the subsequent operation situation, it is the same as that of the first preferred embodiment, and no further description is given.

It should be noted that the automatic paper feeding device of the present invention is not only applicable to scanning devices, its paper detection module can also be applied to scanning devices, multi-functional business machines and paper shredding devices, and its operation conditions are the same reason, so I won’t repeat it.

According to the above two preferred embodiments, the automatic paper feeding device of the present invention can judge whether multiple paper feeding occurs according to the magnetic force change generated when the paper passes through the paper detection module, and eject multiple papers when multiple paper feeding occurs to the paper tray to avoid missing pages during scanning. In addition, since the paper detection module of the present invention only includes metal elements, coils, detection circuits, and a control unit, its structure is simple and its operation is simple, so adding a paper detection module to the automatic paper feeding device does not require too high a cost. 2 dollars. to meet cost considerations. Therefore, the automatic paper feeding device of the present invention does not scan missing pages due to multi-feeding.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Therefore, all other equivalent changes or modifications that do not deviate from the spirit disclosed in the present invention should be included in this case. within the scope of the patent application.

Claims (10)

1. an automatic paper feeder, in order to be sequentially fed to the one scan region of multiple paper to one scan module, this automatic paper feeder comprises:

One body;

One upper cover, is covered in this body of part;

One feeding box, is connected to this body, in order to place described multiple paper thereon;

One paper output box, is arranged on this body, in order to be placed through described multiple paper of this scanning area;

One paper-feeding channel, to be arranged between this feeding box and this paper output box and to be positioned at the below of this upper cover, passing through with for described multiple paper; And

One note detection module, is arranged on this paper-feeding channel, and in order to detect whether multiple paper feed occurs, this note detection module comprises:

One hardware, is arranged at one first side of this paper-feeding channel;

One coil, is arranged at one second side of this paper-feeding channel, in order to export a magnetic force according to a galvanomagnetic effect;

One testing circuit, be arranged at this second side of this paper-feeding channel and be connected to this coil, give this coil in order to power supply and make this coil produce this galvanomagnetic effect, or whether promoted by this paper according to this hardware and one first magnetic force value or one second magnetic force value detected; And

One control unit, is arranged at this second side of this paper-feeding channel and is connected to this testing circuit, in order to judge whether to occur multiple paper feed according to the variable quantity between this first magnetic force value and this second magnetic force value; Wherein when this variable quantity is greater than a default magnetic force value, judge multiple paper feed occurs.

2. automatic paper feeder as claimed in claim 1, wherein this upper cover comprises multiple paper guiding sheet, the inner surface being arranged at this upper cover is positioned at the top of this paper-feeding channel, this hardware is arranged between this two paper guiding sheet, one first end of this hardware is fixed on this two paper guiding sheet, and this second end of this hardware is positioned on this first side of this paper-feeding channel; Wherein when this paper being arranged in this paper-feeding channel is by this note detection module, this second end of this hardware is promoted by this paper and swings relative to this first end of this hardware, makes this testing circuit this second magnetic force value be detected.

3. automatic paper feeder as claimed in claim 1, wherein this upper cover comprises:

Multiple paper guiding sheet, the inner surface being arranged at this upper cover is positioned at the top of this paper-feeding channel; And

One flexible member, in the gap on this inner surface being arranged at this upper cover and between this two paper guiding sheet, and this hardware is fixed on this flexible member, makes this hardware be positioned on this first side of this paper-feeding channel; Wherein when this paper being arranged in this paper-feeding channel is by this note detection module, this hardware is promoted by this paper and moves relative to this paper-feeding channel, makes this testing circuit this second magnetic force value be detected.

4. automatic paper feeder as claimed in claim 1, wherein when this hardware is not promoted by this paper, this testing circuit detects this first magnetic force value; When this hardware is promoted by this paper, this testing circuit detects this second magnetic force value, and this variable quantity between this first magnetic force value and this second magnetic force value equals this default magnetic force value, makes this control unit judge normal paper feed; When this hardware is promoted by described multiple paper, this testing circuit detects this second magnetic force value, and this variable quantity between this first magnetic force value and this second magnetic force value is greater than this default magnetic force value, makes this control unit judge multiple paper feed occurs.

5. automatic paper feeder as claimed in claim 4, wherein this control unit sets this first magnetic force value and this variable quantity corresponded between this second magnetic force value that this hardware promoted by a paper equals this default magnetic force value.

6. automatic paper feeder as claimed in claim 1, wherein this automatic paper feeder also comprises:

One paper taking module, is arranged between this feeding box and this paper-feeding channel, enters this paper-feeding channel in order to be sequentially fed to the described multiple paper be positioned on this feeding box;

Paper feed roller set, is arranged on this paper-feeding channel, enters this scanning area in order to be sequentially fed to described multiple paper; And

One paper delivery roller set, to be arranged on this paper-feeding channel and close to this paper output box, in order to be sequentially fed through described multiple paper of this scanning area to this paper output box; Wherein when this control unit judges multiple paper feed occurs, this paper taking module and the reversion of this paper feed roller set, make to be retracted into this feeding box by the plurality of paper of this note detection module.

7. automatic paper feeder as claimed in claim 6, wherein this paper taking module comprises:

One gets paper arm, is arranged at the top of this first side of this paper-feeding channel, in order to swing relative to this paper-feeding channel;

One pickup roller, is arranged at this and gets on paper arm, contact in order to get the swing of paper arm along with this with described multiple paper, and is sequentially fed to described multiple paper and enters this paper-feeding channel; One comber, be arranged at this to get on paper arm and with this pickup roller side by side, in order to be separated described multiple paper, to enable in described multiple paper an only paper enter this paper-feeding channel; And

One friction element, is arranged on this second side of this paper-feeding channel, and in order to provide a frictional force to give described multiple paper, and auxiliary separating is from described multiple paper.

8. automatic paper feeder as claimed in claim 7, wherein this friction element is a friction roller or a friction pad.

9. automatic paper feeder as claimed in claim 1, wherein this hardware is a sheet metal, a metallic plate or a metal derby.

10. automatic paper feeder as claimed in claim 1, wherein this coil, this testing circuit and this control unit can be integrated in a circuit board.