BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an object feeder, and particularly relates to an object feeder with a tray part having a function for automatically adjusting the angle of paper feeding.
2. Description of the Prior Art
Paper feeders are widely used in various kinds of office machines such as copy machines, printers or fax machines. Their function is to transmit the papers one by one to a processing device such as a print module to ensure continuing procession.
Please refer to FIG. 1. FIG. 1 is a schematic diagram illustrating a prior art paper feeder 100. The paper feeder 100 includes a paper object separating ramp 110 and a tray part 120. Normally, the paper feeder 100 is designed so that the pickup roller 130 only catches one paper at a time. Normal force N occurs while the pickup roller 130 contacts the papers, and the possibility of also catching the next paper is increased, i.e. multi-feeding can occur if N is large enough to provide a frictional force to the next paper. On the other hand, misfeeding may occur if the normal force N is too small. Prior art paper feeders always utilize normal force ACM (auto-compensated-mechanism) to prevent such problems from occurring.
Please refer to FIG. 2. FIG. 2 is a schematic diagram illustrating the relation between N/P (the ratio between normal force N and paper picking force P) and paper stacking height h. In the prior art, N/P is proportional to d-h (where d indicates the distance between a hub 132 of an ACM structure and the tray part 120). Thus, if d is fixed and h increases, N/P will decrease. As shown in FIG. 2, N/P is inversely proportional to h. N/P is 0.55 and 0.9 respectively if h is 15 mm and 0 mm (the height of only one paper). That is, the normal force from the ACM structure when h=0 mm is 1.6 times the normal force from the ACM when h=15 mm if the paper picking force P is the same. In other words, normal force N is inversely proportional to paper height h, but a larger normal force N provides a larger frictional force to the next paper and the possibility for multi-feeding is increased. The paper separating ramp should provide suitable resistance to prevent such multi-feeding from occurring.
Please refer to FIG. 1 again. As can be seen, the force from the paper separating ramp 110 to the front edges of papers (the frictional force) prevents the next paper from also being fed. The frictional force depends on the ramp angle θ, paper weight and the frictional coefficient μ between the front edges of papers and the ramp. The larger the ramp angle θ, the smaller the resistant force to the paper. On the other hand, the smaller the ramp angle θ, the larger the resistant force to the paper. Also, the larger the friction coefficient μ, the larger the resistant force to the paper. According to the prior art, the threshold value of μ for feeding papers smoothly is μ=tan (ψ−π/2). Thus, the paper can be fed smoothly if the angle between the paper separating ramp and the paper reaches the threshold angle ψ. For papers with larger weight, the probability for multi-feeding is increased if the angle is too large, and mis-feeding or a paper jam may happen if the angle is too small. Thus, the paper feeder design becomes more complex.
The paper separating method applied to self-compensation mechanism can be classified into three groups as detailed below:
(1) As shown in FIG. 1, the paper separating ramp is designed to have flexibility and the paper separating face can compensate the paper entering angle corresponding to the paper weight. The paper with a larger weight will press the ramp (to the left) to generate a larger paper entering angle to decrease the resistant force. In practice, if a user places papers by utilizing too large a force, the ramp may be pressed, affecting the initial entering angle due to the force from the user even when light-weighted papers are utilized, thus the compensating function may be useless.
(2) U.S. Pat. No. 6,880,821 discloses an apparatus for compensating resistant force for papers of different weight by controlling the location of the paper separating ramp 110. Therefore, for papers with larger weight, the paper separating ramp 110 is located far from a paper pickup device, and for papers with smaller weight, the paper separating ramp 110 is located near the paper pickup device. Such a kind of apparatus is too complicated, however, and the user must determine the weight of papers and control the location of the paper separating ramp 110 manually if the compensation mechanism is desired to be applied.
(3) U.S. Pat. No. 5,895,040 discloses an apparatus with a paper separating ramp 110 having a buckling device with a comparatively large frictional coefficient value such that a paper can be separated from another paper due to buckling force during pick-up. Also, the buckling device has flexibility such that the paper head of papers of large weight push the buckling device flexibly. Afterwards, the paper separating operation is performed by the ramp with a comparatively low frictional coefficient, thereby the mis-feed or jam due to insufficient twist force provided by the self-compensation structure can be avoided.
One of the objectives of the present invention is to solve the problem where the ratio between the normal force N and picking-up force P will be too high if the stacking height of papers is low such that multi-feeding occurs. Another objective of the present invention is to provide a paper separating structure to prevent a next paper from being fed due to frictional force between the papers.
SUMMARY OF THE INVENTION The present invention provides an object feeding system for providing a buffering space between the pickup roller and the hollow part while the pickup roller picks up papers to decrease a necessary normal force when the stacking height of papers is low (that is, the ratio between the normal force N and the paper catching force P). Also, the paper entering angle between the paper and ramp can be compensated according to the normal force to solve the above-mentioned problem by achieving the effect of buckling paper separating.
The present invention provides an object-feeding system. The feeding system includes an object feeder and a pickup roller. The object feeder includes an object separating ramp and a tray part. The object separating ramp is placed along an object feeding direction. The tray part is for loading at least an object to be fed, and the tray part includes a main body and a protruding portion sticking out from the main body and connected to the object separating ramp, wherein the protruding portion constitutes a hollow with this main body situated in the hollow. The pickup roller is for feeding the object by rolling, wherein the hollow and the pickup roller are located at separate two sides of the object and the pickup roller is located above the hollow.
The present invention also provides an object-feeding system comprising an object feeder and a pickup roller. The object feeder comprises: an object separating ramp, placed along an object feeding direction; a tray part, for loading at least an object to be fed and an elastic supporting device, located above a hollow. The tray part includes a main body; and a protruding portion, sticking out from the main body and connected to the object separating ramp, wherein the protruding portion and the main body form a hollow part. The pickup roller is used for feeding the object by rolling, wherein the hollow part and the pickup roller are respectively located at two sides of the object and the pickup roller is located above the hollow part.
The present invention also provides an object-feeding system comprising an object feeder and a pickup roller. The object feeder comprises an object separating ramp placed along an object feeding direction and a tray part. The tray part includes a first tray connected to the object separating ramp; and a second tray located on the first tray, for loading at least one object to be fed, wherein the second tray is made of elastic material. The pickup roller is used for feeding the object by rolling.
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 is a schematic diagram illustrating a prior art paper feeder.
FIG. 2 is the ratio between the normal force and paper picking force corresponding to paper height.
FIG. 3 is a schematic diagram illustrating an object feeding system according to a preferred embodiment of the present invention, comprising an object feeder according to a first embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating the paper picking operation of the object feeding system shown in FIG. 3.
FIG. 5 is a schematic diagram illustrating the operation of the object isolating device.
FIG. 6 is a schematic diagram illustrating an object feeder according to a second embodiment of the present invention.
FIG. 7 is a schematic diagram illustrating an object feeder according to a third embodiment of the present invention.
FIG. 8 is a schematic diagram illustrating an object feeder according to a fourth embodiment of the present invention.
FIG. 9 is a schematic diagram illustrating an object feeder according to a fifth embodiment of the present invention.
FIG. 10 is a schematic diagram illustrating an object feeder according to a sixth embodiment of the present invention.
FIG. 11 is a schematic diagram illustrating an object feeder according to a seventh embodiment of the present invention.
FIG. 12 is a schematic diagram illustrating an object feeder according to an eighth embodiment of the present invention.
FIG. 13 is a schematic diagram illustrating an object feeder according to a ninth embodiment of the present invention.
FIG. 14 is a schematic diagram illustrating an object feeder according to a tenth embodiment of the present invention.
DETAILED DESCRIPTION Please refer to FIG. 3. FIG. 3 is a schematic diagram illustrating an object feeding system according to a preferred embodiment of the present invention. As shown in FIG. 3, the object feeding system 200 comprises an object feeder 300, a pickup roller 210 and an object to be fed 330 (ex: a paper). The object feeder 300 according to the first embodiment shown in FIG. 3 comprises an object separating ramp 310, a tray part 320 and an object isolating device 360, wherein the object separating ramp 310 is placed along an object feeding direction for the object to be fed 330; and the tray part 320 is used for loading at least an object to be fed 330. As shown in FIG. 3, the tray part 320 includes a main body 322 and a protruding portion 324. The protruding portion 324 sticks out from the main body 322 and connects to the object separating ramp 310, and the protruding portion 324 and the main body 322 form a hollow part 350. In the present embodiment, the hollow part 350 is located on the protruding part 324, where a first surface 325 facing the object to be fed 330 of the main body 322 is higher than a second surface 323 facing the object to be fed of the protruding part 324. Furthermore, the pickup roller 210 has a normal force self-compensation structure for feeding the object to be fed 330 by rolling. Also, the hollow part 350 and the pickup roller 210 are respectively located at two sides of the object to be fed 330, and the pickup roller 210 is located above the hollow part 350.
It should be noted that since the first surface 325 is higher than the second surface 323 while the object to be fed 330 is located in the object feeder 300, the front edge part of the object to be fed 330 tilts down in the direction from the main body 322 to the protruding part 324. Thus the object feeder 300 is separated from a first object surface 332 located above the first face 325 and a second object surface 334 located above the second face 323.
As shown in FIG. 3, the pickup roller 210 presses down to touch the second object surface 334 while the pickup roller 210 starts to operate. The distance D between the hub 212 and tray part 320 of the pickup roller 210 is smaller than the distance d in the prior art. Thus, the ratio N/P between normal force N and paper picking force P will decrease such that the problem of a too large normal force N due to a high N/P value from low stacking height of papers is removed.
Please refer to FIG. 4. FIG. 4 is a schematic diagram illustrating the paper picking operation of the object feeding system shown in FIG. 3. The angle between the object separating ramp 310 and the second object surface 334 is θ having a relatively small value such that the object separating ramp 310 provides more resistance to an object head 335, and the pickup roller 210 should provide extra normal force to press the object to be fed 330 down. At the same time, the second object surface 334 suffers the pressure from the pickup roller 210 to generate deformation, and the second object surface 334 generates shift. As shown in FIG. 4, an angle ψ is formed between the object separating ramp 310 and the shifted second object surface 334. The object to be fed 330 can be smoothly picked up from the pickup roller 210 if the pickup roller 210 keeps pressing down to continuously increase the angle between the object separating ramp 310 and the shifted second object surface 334 to reach μ=tan(ψ−π/2). In this case, the curving operation of the object to be fed 330 is similar to the buckling effect shown in the prior art (3) and the function of paper separating can thereby be reached.
FIG. 5 is a schematic diagram illustrating the operation of the object isolating device 360 shown in FIG. 3. The object isolating device 360 is revolvably connected to the protruding part 324, and is located at a first location 362 vertical to the tray part 320 to isolate the object to be fed 330 and the object separating ramp 310 while the object feeder 300 is pulled out from a machine body (not illustrated). Additionally, a protruding lump 370 pushes a bottom 366 of the object isolating device 360 out if the object feeder 300 is pushed into the main body of the machine, and a top 368 of the object isolating device 360 revolves to a second location 364 in an anti-clockwise direction to allow the object 330 to be fed. Therefore the object to be fed 330 will not contact the object separating ramp 310, such that the limitation is decreased and the shape-changing ability of the paper is increased. In turn, the demand for motor torque during paper picking process is decreased and the damage due to the curing of the object header 335 is also decreased.
Please refer to FIG. 6. FIG. 6 is a schematic diagram illustrating an object feeding system 601 according to a second embodiment of the present invention. As shown in FIG. 6, the object feeding system 601 comprises an object feeder 600 and a pickup roller 210. The object feeder 600 comprises an object separating ramp 610, a tray part 620 and an object isolating device 660, wherein the object separating ramp 610 is placed along an object feeding direction, and the tray part 620 is used for loading at least an object to be fed (not illustrated). As shown in FIG. 6, the tray part 620 includes a main body 622, a protruding portion 624 and an elastic supporting device 626. The protruding portion 624 sticks out from the main body 622 and connects to the object separating ramp 610, and the protruding portion 624 and the main body 622 form a hollow part 650. In the present embodiment, the hollow part 650 is located on the protruding part 624, where a surface facing the object to be fed of the main body 622 is higher than a surface facing the object to be fed of the protruding part 624. In the present embodiment, the elastic supporting device 626 is located on the surface facing the object to be fed of the protruding part 624 and the protruding part 624 comprises a supporting board 627 and an elastic device 629, for example, a string, with two ends respectively connected to the supporting board 627 and the protruding part 624 to provide an elastic force to the supporting board 627. Furthermore, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 650 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 650. The operation of the object feeding system 601 is similar to that of the object feeding system 200. That is, the pickup roller will press down the object to be fed and the supporting board 627 jointly to curve the object to be fed, and a detailed description therefore omitted for brevity.
Please refer to FIG. 7. FIG. 7 is a schematic diagram illustrating an object feeding system 701 according to a third embodiment of the present invention. As shown in FIG. 7, the object feeding system 701 comprises an object feeder 700 and a pickup roller 210. The object feeder 700 comprises an object separating ramp 710, a tray part 720 and an object isolating device 760, wherein the object separating ramp 710 is placed along an object feeding direction, and the tray part 720 is used for loading at least an object to be fed (not illustrated). The tray part 720 comprises: a first tray 722, connected to the object separating ramp 710; and a second tray 724, located on the first tray 722, for loading at least one object to be fed, wherein the second tray is made of elastic material such as a spongy material. In this embodiment, the object feeding system 701 also uses the same paper separating operation as the object feeding system 200, that is, the pickup roller will press down the object to be fed and the second tray 724 jointly to curve the object to be fed.
Please refer to FIG. 8. FIG. 8 is a schematic diagram illustrating an object feeding system 801 according to a fourth embodiment of the present invention. As shown in FIG. 8, the object feeding system 801 comprises an object feeder 800 and a pickup roller 210. The object feeder 800 comprises an object separating ramp 810, a tray part 820 and an object isolating device 860, wherein the object separating ramp 810 is placed along an object feeding direction, and the tray part 820 is used for loading at least an object to be fed (not illustrated). The tray part 820 comprises: a main body 822, a protruding portion 824, and an elastic supporting device 825. The protruding portion 824 sticks out from the main body 822 and connects to the object separating ramp 810. The protruding portion 824 and the main body 825 form the hollow part 850. In this embodiment, the hollow part 850 is located on the protruding part 824, and the elastic supporting device 825 is made of elastic material such as a spongy material. Additionally, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 850 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 850. The operation of the object feeding system 801 is similar to that of the object feeding system 701, the main difference being that the object feeder 800 does not provide a full layer of elastic material on the tray part 820. Since the pickup roller 210 only touches the front region of the object to be fed 330, as shown in FIG. 3, the elastic material just needs to be provided below the pickup roller 210 to perform the paper separating function.
Please refer to FIG. 9. FIG. 9 is a schematic diagram illustrating an object feeding system 901 according to a fifth embodiment of the present invention. As shown in FIG. 9, the object feeding system 901 comprises an object feeder 900 and a pickup roller 210. The object feeder 900 comprises an object separating ramp 910, a tray part 920 and an object isolating device 960, wherein the object separating ramp 910 is placed along an object feeding direction, and the tray part 920 is used for loading at least an object to be fed 930. The tray part 920 comprises: a main body 922 and a protruding portion 924. The protruding portion 924 sticks out from the main body 922 and connects to the object separating ramp 910. The protruding portion 924 and the main body 922 form a hollow part 950. In the present embodiment, the hollow part 950 is located on the main body 922, where a first surface 925 facing the object to be fed 930 of the main body 922 is higher than a second surface 923 facing the object to be fed 930 of the protruding part 924. Additionally, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed 930 by rolling. Also, the hollow part 950 and the pickup roller 210 are respectively located at two sides of the object to be fed 930, and the pickup roller 210 is located above the hollow part 950.
The operation of the object feeding system 901 is similar to the object feeding system 200. It should be noted that there is no apparent difference between the distance D (the distance between the hub 212 of the pickup roller 210 and the tray part 920) and the distance d of the prior art. Thus, according to FIG. 2, the ratio N/P between the normal force N and paper picking force P cannot be improved, but there is still compensation for the paper entering angle while picking up papers.
Please refer to FIG. 10. FIG. 10 is a schematic diagram illustrating an object feeding system 1001 according to a sixth embodiment of the present invention. As shown in FIG. 10, the object feeding system 1001 comprises an object feeder 1000 and a pickup roller 210. The object feeder 1000 comprises an object separating ramp 1010, a tray part 1020 and an object isolating device 1060, wherein the object separating ramp 1010 is placed along an object feeding direction, and the tray part 1020 is used for loading at least an object to be fed (not illustrated). As shown in FIG. 10, the tray part 1020 includes a main body 1022, and a protruding portion 1024. The protruding portion 1024 sticks out from the main body 1022 and connects to the object separating ramp 1010, and a hollow part 1050 is formed on the main body 1022. The elastic supporting device 1026 is located on the surface of the hollow part 1050 facing the object to be fed, and the elastic supporting device 1026 comprises a supporting board 1027 and an elastic device 1029. The elastic device 1029, for example a string, has two ends respectively connected to the supporting board 1027 and the protruding part 1024 to provide an elastic force to the supporting board 1027. Furthermore, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 1050 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 1050. The paper separating operation of the object feeding system 1001 is similar to that of the object feeding system 901, that is, the pickup roller will press down the object to be fed and the supporting board 1027 jointly to curve the object to be fed, thus it is omitted for brevity.
Please refer to FIG. 11. FIG. 11 is a schematic diagram illustrating an object feeding system 1101 according to a seventh embodiment of the present invention. As shown in FIG. 11, the object feeding system 1101 comprises an object feeder 1100 and a pickup roller 210. The object feeder 1100 comprises an object separating ramp 1110, a tray part 1120 and an object isolating device 1160, wherein the object separating ramp 1110 is placed along an object feeding direction, and the tray part 1120 is used for loading at least an object to be fed (not illustrated). In this embodiment, the tray part 1120 includes a main body 1122, a protruding portion 1124, and an elastic supporting device 1125. The protruding portion 1124 sticks out from the main body 1122 and connects to the object separating ramp 1110, and a hollow part 1150 is formed on the main body 1122. The elastic supporting device 1125 is located on the surface of the hollow part 1150 facing the object to be fed, and the elastic supporting device 1125 is made of elastic material such as a spongy material. Furthermore, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 1150 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 1150. The paper separating operation of the object feeding system 1101 is similar to that of the object feeding system 910, and thus is omitted for brevity.
Please refer to FIG. 12. FIG. 12 is a schematic diagram illustrating an object feeding system 1201 according to an eighth embodiment of the present invention. As shown in FIG. 12, the object feeding system 1201 comprises an object feeder 1200 and a pickup roller 210. The object feeder 1200 comprises an object separating ramp 1210, a tray part 1220 and an object isolating device 1260, wherein the object separating ramp 1210 is placed along an object feeding direction, and the tray part 1220 is used for loading at least an object to be fed (not illustrated). The tray part 1220 includes a main body 1222, and a protruding portion 1224. The protruding portion 1224 sticks out from the main body 1222 and connects to the object separating ramp 1210. In this embodiment, the main body 1222 and the protruding portion 1224 form the hollow part 1250. Additionally, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 1250 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 1250. The operation of the object feeding system 1201 is similar to that of the object feeding system 910, and thus is omitted for brevity.
Please refer to FIG. 13. FIG. 13 is a schematic diagram illustrating an object feeding system 1301 according to a ninth embodiment of the present invention. As shown in FIG. 13, the object feeding system 1301 comprises an object feeder 1300 and a pickup roller 210. The object feeder 1300 comprises an object separating ramp 1310, a tray part 1320 and an object isolating device 1360, wherein the object separating ramp 1310 is placed along an object feeding direction, and the tray part 1320 is used for loading at least an object to be fed (not illustrated). The tray part 1320 includes a main body 1322, a protruding portion 1324. The protruding portion 1324 sticks out from the main body 1322 and connects to the object separating ramp 1310, and the main body 1222 and the protruding part 1224 form a hollow part 1350. The elastic supporting device 1326 is located on the surface of the hollow part 1350 facing the object to be fed, and the elastic supporting device 1326 comprises a supporting board 1327 and an elastic device 1329. The elastic device 1329, for example, a string, has two ends respectively connected to the supporting board 1327 and the protruding part 1324 to provide an elastic force to the supporting board 1327.
Furthermore, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 1350 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 1350. The paper separating operation of the object feeding system 1301 is similar to that of the object feeding system 901, that is, the pickup roller will press down the object to be fed and the supporting board 1327 jointly to curve the object to be fed, thus it is omitted for brevity. In this embodiment, flexible material such as a film can be located above the hollow part 1350 for connecting the main body 1322 and the protruding part 1324 to substitute for the supporting board 1327 and the elastic device 1329.
Please refer to FIG. 14. FIG. 14 is a schematic diagram illustrating an object feeding system 1401 according to a tenth embodiment of the present invention. As shown in FIG. 14, the object feeding system 1401 comprises an object feeder 1400 and a pickup roller 210. The object feeder 1400 comprises an object separating ramp 1410, and a tray part 1420, wherein the object separating ramp 1410 is placed along an object feeding direction, and the tray part 1420 is used for loading at least an object to be fed (not illustrated). The tray part 1420 includes a main body 1422, a protruding portion 1424 and an elastic supporting device 1425. The protruding portion 1420 sticks out from the main body 1422 and connects to the object separating ramp 1410. In this embodiment, the hollow part 1450 is located between the main body 1222 and the protruding portion 1224 and the elastic supporting device 1425 is made of elastic material such as a spongy material. Additionally, the pickup roller 210 has a normal force self-compensation structure to feed the object to be fed by rolling. Also, the hollow part 1450 and the pickup roller 210 are respectively located at two sides of the object to be fed, and the pickup roller 210 is located above the hollow part 1450. The paper separating operation of the object feeding system 1401 is similar to that of the object feeding system 910, and thus is omitted for brevity.
It should be noted that the object isolating device is not necessary and the object feeding system can still operate without the object separating device. Additionally, the first embodiment is only a preferred embodiment of the present invention and is not a limitation of the scope of the disclosed system. The object feeding system with a pickup roller having a buffer region below for performing paper separating function also falls in the scope of the present invention.
The present invention provides an object feeding system for providing a buffering space between the pickup roller and a hollow part while the pickup roller picking up papers to decrease a necessary normal force when the stacking height of papers is low (that is, the ratio between the normal force N and the paper catching force P). Also, the paper entering angle between the paper and ramp can be compensated according to the normal force to solve the above-mentioned problems by achieving the effect of buckling paper separating.
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. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
