Sheet Feeding Device Having Skew Calibration
A sheet feeding device having skew calibration which is disposed at a feeding end of a business machine. The sheet feeding device includes a driving module, a feeding module and a differential speed module. The sheet feeding device utilizes the differential speed module to provide the driving power transmitted from the driving module to two feeding rollers of the feeding module respectively, and utilizes the friction difference between these different feeding rollers to change the rotating speed or the rotating direction of the feeding rollers, so as to achieve the objective of actively calibrating the skewed sheet.
This application claims the benefit of Taiwan Patent Application No. 103213698, filed on Aug. 1, 2014, in the Taiwan Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present disclosure relates to a sheet feeding device, more particularly, to a sheet feeding device capable of utilizing differential speed device to solve the problem of skewed sheet during feeding.
2. Description of the Related Art
In order to meet the requirement for mass sheet operation, a common scanner, printer or multi-function printer on market usually has an automatic document feeder. The user can put a stack of sheets in the automatic document feeder, which will feed the sheets into the machine sequentially for performing scan, print, etc. If the user does not adjust the sheets to a correct position, or the sheet is skewed during feeding process, the printed or scanned image is skew. Therefore, the automatic document feeder usually has a special calibration scheme to correct the skewed sheet to decrease the skew degree of printed or scanned image before the sheet is fed into the work area of scan or print.
In traditional solution, a common approach is to utilize at least two motors incorporating with a clutch or a solenoid valve to perform active de-skew operation, so a speed difference between different feeding rollers can be controlled to calibrate the skewed sheet. However, it needs an extra time for the motor to drive the feeding roller from stop to rolling, and it also adds extra time to change driving direction, so the required time for operation of scan or print is increased. Moreover, frequently changing driving direction and rotation speed of the motor is easy to damage the actuator and the controller, so the lift time of the feeding device is reduced.
In addition, using many motors for calibration easily has problems of control error caused by signal delay, increased cost caused by many associated assemblies, hard to miniaturization due to large volume occupied by the motors.
SUMMARY OF THE INVENTIONAn exemplary embodiment of the present disclosure provides a sheet feeding device having skew calibration which utilizes a differential speed mechanism to drive the rotating speeds of two feeding rollers, respectively, so as to vary the rotating speed or rotating direction by the friction difference between different feeding rollers. Therefore, the active calibration can be achieved.
An exemplary embodiment of the present disclosure provides a sheet feeding device having skew calibration which utilizes engagement between gears of the differential speed mechanism to transmit driving power efficiently, so as to decrease the possibility of the system invalidation caused by signal delay or electric invalidation which is occurred easily while a motor controller is used.
According to one exemplary embodiment of the present disclosure, a sheet feeding device having skew calibration is disposed at a feeding end of a business machine. The sheet feeding device includes a driving module, a feeding module and a differential speed module. The driving module includes a power source and a driving transmission unit, and the driving transmission unit is linked to the power source. The feeding module includes a first feeding roller and a second feeding roller, and is disposed at the feeding end to feed a plurality of sheets into the business machine. The differential speed module includes a differential speed mechanism, a first output shaft and a second output shaft. The differential speed mechanism can be linked to the driving transmission unit to drive the first output shaft and the second output shaft. The first output shaft and the second output shaft are disposed at two sides of the differential speed mechanism respectively. The first output shaft and the first feeding roller are linked with each other, and the second output shaft and the second feeding roller are linked with each other. Preferably, the differential speed module utilizes a friction difference generated by the first feeding roller and the second feeding roller during the sheet feeding, to enable the first feeding roller and the second feeding roller to rotate at the same direction or different directions, so as to actively calibrate the plurality of sheets skewed.
Preferably, the driving transmission unit includes a gear set or a timing belt assembly.
Preferably, the differential speed mechanism includes a planetary gear set, a bevel gear set or a combination thereof.
Preferably, the first feeding roller and the second feeding roller are arranged coaxially.
Preferably, the differential speed module further includes a torque adjusting unit to adjust a torque required for driving the operation of the differential speed mechanism.
Preferably, the feeding module further includes a stopper to constrain a skew range of a plurality of sheets.
Preferably, the rotating speeds of the first feeding roller and the second feeding roller can be the same or different.
Preferably, the surfaces of the first feeding roller and the second feeding roller further include guiding surfaces to facilitate feeding of the plurality of sheets.
Preferably, the guiding surface includes small-scale bumpy structures.
Preferably, the guiding surface can be a rough surface.
Objectives of the present disclosure are to provide a sheet feeding device having skew calibration which has the following advantages:
1. Active skew calibration: the differential speed mechanism is utilized to drive two individual feeding rollers to rotate at the same direction or different directions, so as to actively correct the skewed sheet based on a friction difference between two feeding rollers.
Therefore, the sheets can be fed into the business machine smoothly.
2. low invalidation possibility: compared with the traditional device using an electric controller to control and drive motor, the differential speed mechanism has sufficient mechanism accuracy to maintain rotation efficiency for a long period of time, and the invalidation possibility that stall, slip or delay occurred between mechanism devices is lower than electric invalidation.
The detailed structure, operating principle and effects of the present disclosure will now be described in more details hereinafter with reference to the accompanying drawings that show various embodiments of the present disclosure as follows.
Reference will now be made in detail to the exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Therefore, it is to be understood that the foregoing is illustrative of exemplary embodiments and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed exemplary embodiments, as well as other exemplary embodiments, are intended to be included within the scope of the appended claims. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the inventive concept to those skilled in the art. The relative proportions and ratios of elements in the drawings may be exaggerated or diminished in size for the sake of clarity and convenience in the drawings, and such arbitrary proportions are only illustrative and not limiting in any way. The same reference numbers are used in the drawings and the description to refer to the same or like parts.
It will be understood that, although the terms ‘first’, ‘second’, ‘third’, etc., may be used herein to describe various elements, these elements should not be limited by these terms. The terms are used only for the purpose of distinguishing one component from another component. Thus, a first element discussed below could be termed a second element without departing from the teachings of embodiments. As used herein, the term “or” includes any and all combinations of one or more of the associated listed items.
Please refer to both of
The feeding module 20 includes a first feeding roller 21 and a second feeding roller 22, and is disposed at a feeding end to feed a plurality of sheets 8 into the business machine. In implementation, the first feeding roller 21 and the second feeding roller 22 are arranged coaxially to perform a smooth feeding operation. Moreover, the feeding module 20 can further be added a stopper 25 on a sheet depositing structure to constrain the skew range of a plurality of sheets 8. The stopper 25 can be a guarding plate or an adjustable clamping device.
For further illustration, the surfaces of the first feeding roller 21 and second feeding roller 22 can be performed a surface roughness process or be added small-scale bumpy structures, so the guiding surfaces 28 with different roughness are utilized to increase the surface friction for facilitating to feed the sheet 8.
The differential speed module 30 includes a differential speed mechanism 31, a first output shaft 32 and a second output shaft 33. The differential speed mechanism 31 can be linked to the driving transmission unit 12 to drive the first output shaft 32 and the second output shaft 33. The first output shaft 32 and the second output shaft 33 are disposed at two sides of the differential speed mechanism 31 respectively. The first output shaft 32 and the first feeding roller 21 are linked with each other, and the second output shaft 33 and the second feeding roller 22 are linked with each other.
The differential speed module 30 utilizes the friction difference generated by the first feeding roller 21 and the second feeding roller 22 during the sheet feeding, to enable the first feeding roller 21 and the second feeding roller 22 to rotate at the same direction or different directions, so as to actively calibrate the skew sheet 8 caused by improper placement. In implementation, the differential speed mechanism 31 can include a planetary gear set, bevel gear set or the combination thereof. The differential speed module 30 can further include a torque adjusting unit 35 to adjust the torque which is required to drive operation of the differential speed mechanism 31.
For example, during the sheet feeding process, the feeding module 20 directly receives the driving power transmitted from the driving module 10, to drive the first feeding roller 21 and the second feeding roller 22 to rotate at the same direction and the same speed.
When the sheet 8 is skewed due to improper placement, a side of the sheet 8 is contacted with the second feeding roller 22 first, and a frictional resistance is generated on the second feeding roller 22 to make the rotating speed of the second feeding roller 22 decrease, in the meantime, the differential speed module 30 transmits the driving power to the side having smaller friction to increase the rotating speed of the first feeding roller 21, so that the sheet 8 can be corrected the skew angle gradually, and fed into the business machine smoothly.
The sheet feeding device of the present disclosure utilizes the differential speed module to provide the driving power transmitted from the driving module to two feeding rollers of the feeding module, respectively, and utilizes the friction difference between these different feeding rollers to change the rotating speed or rotating direction of the feeding rollers, so as to achieve the objective of actively calibrate the skew sheet.
The above-mentioned descriptions represent merely the exemplary embodiment of the present disclosure, without any intention to limit the scope of the present disclosure thereto. Various equivalent changes, alternations or modifications based on the claims of present disclosure are all consequently viewed as being embraced by the scope of the present disclosure.
Claims
1. A sheet feeding device having skew calibration, disposed in a feeding end of a business machine, the sheet feeding device comprising:
- a driving module, comprising a power source and a driving transmission unit, the driving transmission unit linked to the power source;
- a feeding module, comprising a first feeding roller and a second feeding roller, and disposed at the feeding end to feed a plurality of sheets into the business machine; and
- a differential speed module, comprising a differential speed mechanism, a first output shaft and a second output shaft, and the differential speed mechanism linked to the driving transmission unit to drive the first output shaft and the second output shaft, and the first output shaft and the second output shaft disposed at two sides of the differential speed mechanism respectively, and the first output shaft and the first feeding roller linked with each other, and the second output shaft and the second feeding roller linked with each other;
- wherein the differential speed module utilizes the friction difference generated by the first feeding roller and the second feeding roller during the sheet feeding, to enable one of the first feeding roller and the second feeding roller having a smaller friction to increase a rotating speed, so as to actively calibrate the plurality of sheets skewed.
2. The sheet feeding device having skew calibration according to claim 1, wherein the driving transmission unit comprises a gear set or a timing belt assembly.
3. The sheet feeding device having skew calibration according to claim 1, wherein the differential speed mechanism comprises a planetary gear set, a bevel gear set or a combination thereof.
4. The sheet feeding device having skew calibration according to claim 1, wherein the first feeding roller and the second feeding roller are arranged coaxially.
5. The sheet feeding device having skew calibration according to claim 1, wherein the differential speed module further comprises a torque adjusting unit to adjust a torque required to drive the operation of the differential speed mechanism.
6. The sheet feeding device having skew calibration according to claim 1, wherein the feeding module further comprises a stopper to constrain a skew range of the plurality of sheets.
7. The sheet feeding device having skew calibration according to claim 1, wherein the rotating speeds of the first feeding roller and the second feeding roller are the same or different.
8. The sheet feeding device having skew calibration according to claim 1, wherein each of the first feeding roller and the second feeding roller further has a guiding surface on surface thereof, to facilitate the feeding of the plurality of sheets.
9. The sheet feeding device having skew calibration according to claim 8, wherein the guiding surface comprises small-scale bumpy structures.
10. The sheet feeding device having skew calibration according to claim 8, wherein the guiding surface is a rough surface.
Type: Application
Filed: Oct 22, 2014
Publication Date: Feb 4, 2016
Inventor: Sung-Po Cheng (Hsinchu)
Application Number: 14/521,023
