Patent Application
20100140866
1. Field of the Invention
The present invention relates to a multiple documents feeding detection mechanism, more particularly, to a mechanism and a method of multiple documents feeding detection capable of detecting multiple documents by means of adjusting the action of a retarding roller.
2. The Related Art
Nowadays, image processing products, such as printers, scanners, fax machines, copy machines, are more and more popular on the current market for the purpose of automatically and sequentially processing a stack of documents. A multiple documents feeding detection mechanism is mounted on the image processing products mentioned above to detect the multiple documents feeding, and make sure the stack of documents is sequentially processed.
A conventional multiple documents feeding detection mechanism is disclosed in U.S. Pat. No. 6,212,130 which discloses an ultrasound detection mechanism. The ultrasound detection mechanism comprises an ultrasound beam generator located on the upper side, and an ultrasound receiver located on the lower side of a transport path of the image processor products respectively.
The ultrasound beam generator generates a beam of ultrasound energy radiating through the transport path. The ultrasound energy beam is received by the ultrasound receiver. While the ultrasound energy radiates through the air gap along the transport path, it will cause a weak attenuation. While the ultrasound energy radiates through a signal document introduced into the transport path, it will cause a general attenuation. While the ultrasound energy radiates through the multiple documents introduced into the transport path, it will cause a strong attenuation.
Therefore, the ultrasound detection mechanism determines the kind of the multiple documents introduced into the transport path by monitoring the magnitude of attenuation of the ultrasound energy.
However, the conventional ultrasound detection mechanism has some defects. Firstly, it often makes an incorrect judgment when the ultrasound energy radiates through a thick document introduced into the transport path, such as an IC card and a credit card. So it often causes an abnormal strong attenuation of the ultrasound.
Secondly, the precision of the ultrasound receiver is likely to be interfered by the ultrasound beam generator or the dusts on the cover of the ultrasound receiver. Thirdly, it is inconvenient to mount the ultrasound beam generator on the upper side of the transport path and the ultrasound receiver on the lower side of the transport path. Fourthly, the cost and the design for the ultrasound beam generator and the ultrasound receiver become more expensive and complex.
The object of the present invention is to provide a multiple documents feeding detection mechanism having an advancing roller with a first surface, a driving means, a retarding roller with a second surface, a clutch and a detecting means. The driving means provides a driving torque to the advancing roller. The clutch provides a resisting torque to the retarding roller.
The retarding roller connects to the advancing roller for transporting one piece of the document. The friction coefficient of the first surface is greater than the friction coefficient of the second surface, to make the friction coefficient of the second surface be greater than the friction coefficient of the document. Thus, the driving torque will be greater than the resisting torque.
The retarding roller is urged into rotation while there is a single document fed into a nip between the advancing roller and the retarding roller. In stead, the retarding roller is remained in standstill while multiple documents are fed into the nip. The detecting means detects whether multiple documents feeding occurred by detecting an action of the retarding roller.
A further object of the present invention is to provide a multiple documents feeding detection method comprising the following steps.
Therefore, the multiple documents feeding mechanism determines multiple documents feeding by detecting action of the retarding roller to be urged into rotation or remained standstill by comparing the friction coefficient of the advancing roller and the friction coefficient of the retarding roller, as well as the driving torque and the resisting torque.
Hence, the merit of the multiple documents feeding mechanism is that the thickness or amount of the document fed into the multiple documents feeding mechanism can be much more than ever. By means of monitoring the movement of the retarding roller to determine the multiple documents feeding can avoid the influence of dust, conveniently used to integrate with transportation means of an imaging product, and that the cost thereof is cheaper than the cost of the ultrasound detection mechanism.
The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which:
The object of the present invention is to provide a multiple documents feeding detection mechanism 100 applied to various imaging processing products, such as printers, scanners, fax machines, copy machines for detecting the multiple documents feeding. Please refer to
The scanner 9 defines a transporting path 90. The scanner 9 includes a document tray 91 arranged at a front of the transporting path 90, a document discharging tray 92 arranged at a rear of the transporting path 90, a document picking up means 93, a document feeding means 94, a document transporting means 95, a scanning means 96 and a document discharging means 97. The above elements are sequentially arranged along the transporting path 90.
A stack of documents is placed on the document tray 91. The document picking up means 93 picks up one piece of document from the stack of documents. The document feeding means 94 feeds the picked up document into the transporting path 90. The document transporting means 95 transports the fed document through the scanning means 96 to the document discharging means 97.
The scanning means 96, such as a CCD sensor module, scans the transported document. The document discharging means 97 discharges the transported document from the transporting path 90. Lastly, the document is transported out from the transporting path 90 and onto the document discharging tray 92.
Please refer to
The transporting roller means 1 comprises an advancing roller 11, a retarding roller 13, a clutch 15, and a motor 17. The advancing roller 11 is against the retarding roller 13 for transporting one piece of document therebetween. The clutch 15 applies a resisting torque to the retarding roller 13. The motor 17 applies a driving torque to the advancing roller 11 for driving the advancing roller 11 to supply an urging torque to the retarding roller 13. The urging torque abuts against the resisting torque applied to the retarding roller 13 by the clutch 15.
Please refer to
At the nip, the advancing roller 11 exerts a forward tangential force Fa on the retarding roller 13 and the resisting torque T applied to the retarding roller 13. The forward tangential force Fa is shown as Fa=Ua−r*N, wherein Ua−r is the friction coefficient of the advancing roller 11-to-retarding roller 13, N is the normal force for urging the advancing roller 11 and the retarding roller 13 together.
While there is no document fed into the nip, then the urging torque supplied from the advancing roller 11 is shown as Fa*Rb. If the retarding roller 13 is frictionally urged into rotation with the advancing roller 11 by the urging torque Fa*Rb, then the urging torque Fa*Rb must overcome the resisting torque T applied to the retarding roller 13. That is, Fa*Rb>T, wherein Rb is a radius of the retarding roller 13.
Please refer to
If a single document 3 is fed into the nip, the advancing roller 11 exerts a forward tangential force Fb on an upper surface of the document 3, meanwhile, the retarding roller 13 exerts a reverse tangential force Fc on a lower surface of the document 3. The forward tangential force Fb is shown as Fb=Ua−p*N, wherein Ua−p is the friction coefficient of the advancing roller 11-to-the document 3. The reverse tangential force Fc is shown as Fc=Ub−p*N, wherein Ub−p is the friction coefficient of the retarding roller 13-to-the document 3.
While the forward tangential force Fb overcomes the reverse tangential force Fc, the document 3 and the retarding roller 13 will be together urged into rotation with the advancing roller 11. That is, Fb>Fc, or Ua−p*N>Ub−p*N. The friction coefficient Ua−p of the advancing roller 11-to-the document 3 is greater than the friction coefficient Ub−p of the retarding roller 13-to-the document 3.
Thus, the urging torque supplied from the advancing roller 11 and transmitted through the document 3 is shown as Fc*Rb. While the retarding roller 13 frictionally connects to the document 3 and is urged into rotation with the advancing roller 11 by the urging torque Fc*Rb, the urging torque Fc*Rb must overcome the resisting torque T applied to the retarding roller 13. That is, Fc*Rb>T.
Please refer to
If multiple documents 3, 3′ are fed into the nip, the upper document 3 exerts a forward tangential force Fe on the lower document 3′, and the retarding roller 13 exerts a reverse tangential force Fd on the lower document 3′. The forward tangential force is shown as Fe=Up*N, wherein Up is the friction coefficient of the upper document 3-to-the lower document 3′. The reverse tangential force Fd is shown as Fd=Ub−p*N, wherein Ub−p is the friction coefficient of the retarding roller 13-to-the lower document 3′.
While the forward tangential force Fe can not overcome the reverse tangential force Fd, the lower document 3′ is remained at the nip. That is, Fd>Fe, or Ub−p*N>Up*N. The friction coefficient Ub−p of retarding roller 13-to-the lower document 3′ is greater than the friction coefficient Up of the upper document 3-to-the lower document 3′.
In order to remain the lower document 3′ at the nip and the retarding roller 13 in standstill by the resisting torque applied to the retarding roller 13, the urging torque supplied from the upper document 3 must be less than the resisting torque applied to the retarding roller 13. That is, Fe*Rb<T.
Therefore, if there is no document fed into the nip, then the retarding roller 13 frictionally connects to the advancing roller 11 and is urged into rotation with the advancing roller 11. If one piece of document 3 is fed into the nip, then the retarding roller 13 frictionally connects to the document 3 and is urged into rotation with the advancing roller 11. If multiple documents 3, 3′ are fed into the nip, then the retarding roller 13 is remained in standstill and the lower document 3′ is remained at the nip.
Please refer to
More specifically, the obstructing portion is the body of the disk 20 and the penetrating portion has a plurality of through holes 25 formed at the rim of the disk 20. The shaft 21 coaxially interconnects the retarding roller 13 and the disk 20. Two opposite sides of the disk 20 are located between the light source 22 and the sensor 23 respectively. The light source 22 and the sensor 23 are aligned with each other and aligned together with the through holes 25. The MPU 24 connects to the sensor 23.
Consequently, the disk 20 of the detecting means 2 is urged into rotation with the retarding roller 13 of the transporting means 1. If only one single document 3 is fed into the nip, then the disk 20 will be urged into rotation with the retarding roller 13. If multiple documents 3, 3′ are fed into the nip, then the disk 20 will be remained in standstill.
Please refer to
Please refer to
More specifically, while the sensor 23 receives an input signal detected as all light, the sensor 23 sends out a high potential (5 Voltage) signal. While the sensor 23 receives an input signal detected as all dark, the sensor 23 sends out a low potential (0 Voltage) signal. The MPU 24 determines that the multiple documents 3, 3′ are fed into the nip according to the received low potential signal or the received high potential signal from the sensor 23.
Please refer to
While the disk 20 is urged into rotation by the retarding roller 13, the light source 22 radiates a beam to the disk 20, which is reflected by the high reflecting portions 27 and then absorbed by the low reflecting portion 26 repeatedly. Thus, the sensor 23 receives an input signal detected as staggered light and dark, and then sends out a continuous pulse signal to the MPU 24.
While the disk 20 is remained in standstill with the retarding roller 13, the light source 22 radiates a beam to the disk 20 which is reflected by the high reflecting portions 27 or absorbed by the low reflecting portions 26. As described above, the MPU 24 determines whether the multiple documents 3, 3′ are fed into the nip according to the received signal from the sensor 23. Furthermore, the beam radiated from the light source 22 can be visible, such as while light, or invisible, such as infrared rays.
In order to urge the retarding roller 13 into rotation with the advancing roller 11 while a single document 3 fed into the nip, and remain the retarding roller 13 in standstill while multiple documents 3, 3′ is fed into the nip, it is assumed that Ua−p>Ub−p>Up. Moreover, in order to remain the lower document 3′ at the nip while multiple documents 3, 3′ is fed into the nip, it is assumed that Fd*Rb>T>Fe*Rb.
The multiple documents feeding mechanism 100 determines multiple documents feeding by monitoring the action of the transporting roller means 1. The retarding roller 13 is urged into rotation with the advancing roller 11 while a single document fed into the nip. In stead, the retarding roller 12 is remained in standstill while multiple documents 3, 3′ fed into the nip, by comparing the friction coefficient of the surface of the advancing roller 11 land the friction coefficient of the surface of the retarding roller, as well as the driving torque supplied by the motor 17 and the resisting torque supplied by the clutch 17.
The detecting means 2 detects multiple documents feeding via monitoring the action of the transporting roller means 1. The disk 20 is driven into rotation with the retarding roller 13. The disk 20 has a first light tuning portion, such as the obstructing portion and the low reflecting portion 26 described above, and a second light tuning portion, such as the penetrating portion and the high reflecting portion 27 described above.
The light source 22 radiates a beam to the disk 20, which is received by the sensor 23. The sensor 23 sends a first signal, such as continuous pulse signal described above, according to the received variable intensity of the beam alternately tuned by the first tuning portion and the second tuning portion. In this embodiment, the input signal is detected as staggered light and dark, due to movement of the disk.
The sensor 23 sends a second signal, such as the low potential signal or the high potential signal, according to the received constant intensity of the beam which is tuned by one of the first tuning portion and the second tuning portion. In this embodiment, the input signal detected as all dark and all light described above, due to standstill of the disk.
The MCU 24 determines the multiple documents 3, 3′ are fed into the nip according to the received first signal from the sensor 23. The MCU 24 determines that there is only one single document fed into the nip according to the received second signal from the sensor 23. Therefore, the multiple documents feeding detection mechanism 100 has the following advantages.
Firstly, the thickness of the document fed into the multiple documents feeding mechanism 100 is much more than ever. Secondly, the multiple documents feeding mechanism 100 can determine whether the multiple documents feeding being caused by monitoring the movement of the retarding roller 13.
It is capable of avoiding the influence by the dust. Thirdly, the multiple documents feeding detection mechanism 100 is integrated with the transportation means for being conveniently used. Fourthly, the cost of the detecting means 2 of the multiple documents feeding detection mechanism 100 is cheaper than the cost of the ultrasound beam generator and receiver.
Furthermore, the present invention is not limited to the embodiments described above; various additions, alterations and the like may be made within the scope of the present invention by a person skilled in the art. For example, respective embodiments may be appropriately combined.
