BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet-feeding mechanism and an image processing device using the same. The image processing device is a scanning device, a printing device, or a multi-function printer for example.
2. Description of the Prior Art
In a conventional image processing device such as a scanning device, a printing device, or a multi-function printer, its sheet-feeding mechanism is designed to have single roller, and has the following disadvantages: single roller can not process a large number of sheets (such as over 100 sheets); additionally, the sheet may be skewed during a sheet-feeding process due to tolerance or wear of the roller, and thus affects the image processing result.
SUMMARY OF THE INVENTION
To solve the above problems, the present invention discloses a sheet-feeding mechanism utilized in an image processing device for feeding a sheet. The sheet-feeding mechanism comprises an upper housing and a lower housing disposed opposite the upper housing, an input tray, a main roller, a separating device, a first auxiliary roller and a first pressing unit. The upper housing and the lower housing form a passageway. The input tray is connected to the lower housing, for placing the sheet. The main roller is disposed in the lower housing, and utilized for feeding the sheet placed on the input tray in a feeding direction. The separating device is disposed on a downstream position of the main roller in the lower housing, for feeding the sheet one by one. The first auxiliary roller is disposed on a lateral side of the main roller in the lower housing, and utilized for feeding the sheet in the feeding direction. The first pressing unit is disposed in the upper housing and opposite the first auxiliary roller, and utilized for pressing the sheet in a downward direction from the upper housing to the lower housing. Furthermore, the first auxiliary roller and the first pressing unit jointly nip the sheet.
The present invention also discloses an image processing device comprising the sheet-feeding mechanism mentioned above and an image processing unit. The image processing unit is disposed in the passageway, and utilized for image processing the sheet fed by the sheet-feeding mechanism.
The sheet-feeding mechanism and the image processing device using the same disclosed by the present invention add auxiliary rollers and pressing units on lateral sides of the main roller for assisting the main roller to feed the sheet and increasing friction between the sheet, the main roller and the auxiliary rollers, and thus a large number of sheets (such as over 100 sheets) can be loaded in the sheet-feeding mechanism and the image processing device using the same disclosed by the present invention. In addition, adding auxiliary rollers and pressing units on lateral sides of the main roller can uniform the feeding force for the sheets, and thus a skewed sheet will not be skewed again or even the skewed sheet can be de-skewed during sheet-feeding process.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top-view diagram of a sheet-feeding mechanism in accordance with a first embodiment of the present invention.
FIG. 2 shows a side-view diagram of a sheet-feeding mechanism in accordance with the first embodiment of the present invention.
FIG. 3 shows a front-view diagram of a sheet-feeding mechanism in accordance with the first embodiment of the present invention.
FIG. 4 shows a front-view diagram of a sheet-feeding mechanism in accordance with the first embodiment of the present invention.
FIG. 5 shows a top-view diagram of a sheet-feeding mechanism in accordance with a second embodiment of the present invention.
FIG. 6 shows a top-view diagram of a sheet-feeding mechanism in accordance with a third embodiment of the present invention.
FIG. 7 shows a top-view diagram of a sheet-feeding mechanism in accordance with a fourth embodiment of the present invention.
FIG. 8 shows a side-view diagram of an image processing device in accordance with an embodiment of the present invention.
FIG. 9 shows a side-view diagram of an image processing device in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
Please refer to FIGS. 1-3 together. FIGS. 1-3 respectively show a top-view diagram, a side-view diagram, and a front-view diagram of a sheet-feeding mechanism 100 in accordance with a first embodiment of the present invention. As shown in FIG. 1, the sheet-feeding mechanism 100 of the present invention is utilized for feeding a sheet P and utilized in an image processing device. The sheet-feeding mechanism 100 comprises: an upper housing 110 and a lower housing 112 disposed opposite the upper housing 110, an input tray 114, a main roller 120, a separating device 130, a first auxiliary roller 140, a first pressing unit 142, a second auxiliary roller 150, and a second pressing unit 152. The upper housing 110 and the lower housing 112 form a passageway 170. The input tray 114 is connected to the lower housing 112, for placing the sheet P. The main roller 120 is disposed in the lower housing 112, and utilized for feeding the sheet P placed on the input tray in a feeding direction D from the input tray 114.
The separating device 130 is disposed on a downstream position of the main roller 120 in the lower housing 112 and arranged with the main roller 120 in a same axis y, for feeding the sheet P one by one. In other words, the main roller 120 is disposed in front of the separating device 130. The separating device 130 comprises a separating roller 132 and a separating pad 134. The first auxiliary roller 140 is disposed on a lateral side of a same lateral axis x of the main roller 120 in the lower housing 112, and utilized for feeding the sheet P in the feeding direction D. The first pressing unit 142 is disposed in the upper housing 110 and opposite the first auxiliary roller 140, and utilized for pressing the sheet P in a downward direction from the upper housing 110 to the lower housing 112. Furthermore, the first auxiliary roller 140 and the first pressing unit 142 jointly nip the sheet P, and the first pressing unit 142 comprises a roller 144 for contacting with the sheet P.
Furthermore, the first pressing unit 142 also can comprise a first weight block 146 (such as a metal block or a heavy object for making the first pressing unit 142 heavier), or the roller 144 can be made by metal to generate a normal force for pressing the sheet P in a direction toward the lower housing 112, to increase friction between the sheet P and the main roller 120, the first auxiliary roller 140, and the second auxiliary roller 150, and the sheet P can be fed easily when there is a few sheets to be fed. Or, the first pressing unit 142 also can comprise a first elastic element 148, as shown in FIG. 4, for pressing the sheet P to increase friction between the sheet P and the main roller 120, the first auxiliary roller 140, and the second auxiliary roller 150. The second auxiliary roller 150 is disposed on another lateral side of the same axis x of the main roller 120 in the lower housing 112, for feeding the sheet P in the feeding direction D. The second pressing unit 152 is disposed in the upper housing 110 and corresponding to the second auxiliary roller 150, for pressing the sheet P in a downward direction from the upper housing 110 to the lower housing 112, wherein the second auxiliary roller 150 and the second pressing unit 152 jointly nip the sheet P. The second pressing unit 152 comprises a roller 154 for contacting with the sheet P. Furthermore, the second pressing unit 152 also can comprise a second weight block 156 (such as a metal block or a heavy object for making the second pressing unit 152 heavier), or the roller 154 can be made by metal to generate a normal force for pressing the sheet P in a direction toward the lower housing 112, to increase friction between the sheet P and the main roller 120, the first auxiliary roller 140, and the second auxiliary roller 150, and the sheet P can be fed easily when there is a few sheets to be fed. Or, the second pressing unit 152 also can comprise a second elastic element 148 (as shown in FIG. 4) for pressing the sheet P to increase friction between the sheet P and the main roller 120, the first auxiliary roller 140, and the second auxiliary roller 150. In this embodiment, the friction between the sheet P and the main roller 120, the first auxiliary roller 140, and the second auxiliary roller 150 is driven by a driving motor 160.
Please refer to FIG. 5. FIG. 5 shows a top-view diagram of a sheet-feeding mechanism 100 in accordance with a second embodiment of the present invention. In the second embodiment, the first auxiliary roller 140 and the second auxiliary roller 150 are disposed on a lateral axis x1 and the main roller 120 is disposed on a different lateral axis x2, and the purpose of the present invention also can be attained. This design can de-skew a to-be-fed sheet. For example, when the sheet P is fed by the main roller 120, the first auxiliary roller 140 and the second auxiliary roller 150 do not rotate temporarily. When a front edge of the sheet P touches a nipping position between the first auxiliary roller 140 and the first pressing unit 142, and a nipping position between the second auxiliary roller 150 and the second pressing unit 152, a certain motor steps or time is calculated and the first auxiliary roller 140 and the second auxiliary roller 150 start to rotate, so as to solve the sheet skewing problem for the sheet P.
Furthermore, in a third embodiment of the present invention as shown in FIG. 6, the first auxiliary roller 140 and the second auxiliary roller 150 are integrated with the main roller 120 to form a long main roller 190.
Additionally, in a fourth embodiment of the present invention as shown in FIG. 7, the second auxiliary roller 150 can be omitted, and the purpose of the present invention also can be attained.
The present invention also discloses an image processing device 200 comprising the sheet-feeding mechanism 100 above and an image processing unit. Please refer to FIG. 8. The image processing device 200 can be a scanning device, and the image processing unit can be a scanning module 210. When a scanning operation is required to be performed for the sheet P, the sheet P is fed by the sheet-feeding mechanism and transmitted to an output tray 220 after being scanned by the scanning module 210. Please further refer to FIG. 9. The image processing device 200 can be a printing device, and the image processing unit can be a printing module 210′. When a printing operation is required to be performed for the sheet P, the sheet P is fed by the sheet-feeding mechanism and transmitted to a output tray 220 after being printed by the printing module 210′.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention.
Patent Application
20100276867
