Patent Application
20110062653
This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-213833, filed on Sep. 15, 2009, the entire content of which is incorporated herein by reference.
Embodiments described herein relates generally to a media stocker for stacking and holding a recording medium to be fed into a paper feed opening of an image forming apparatus, the media stocker provided integrally with or separately from the image forming apparatus, a paper feeder using the media stocker, and a method for controlling the configuration of a recording medium stacked and held in the media stocker or the paper feeder.
A media stocker vertically elevates a feeder plate to allow a large number of recording media to abut against a pickup roller. In this construction, the media stocker may stock a number of recording media, for example, several hundred pieces.
As such, since the media stocker stocks a large number of recording media, a large force is applied to the feeder plate. For this reason, an elevating device for vertically elevating a feeder plate generally supports the feeder plate by holding both sides of the feeder plate, which are the upstream side and the downstream side in the direction of conveying a recording medium.
However, when a feeder plate is supported by holding both sides of the feeder plate, i.e., the upstream side and the downstream side in the direction of conveying a recording medium, a whole device becomes large-scaled and complicated in structure. Accordingly, in one embodiment, a media stocker has a feeder plate supported by holding one side of the feeder plate, i.e., a cantilever-supported feeder plate, as shown in
In
As the number of recording media M stacked and held on feeder plate A increases, the weight of recording media M increases. Thus, in the construction of the media stocker, a free end of feeder plate A is inclined downwardly, as shown in
However, in the related field to the media stocker, it is generally known that the desired configuration of the uppermost recording medium at the pickup position of a pickup roller is to remain level. If the uppermost of recording media M is inclined, the direction of picking up recording media M at pickup roller PU is also inclined, as shown in
According to an embodiment, a media stocker includes a feeder plate configured to maintain a plurality of recording media in a stacked state thereon, a vertically elevating device configured to cantilever-support the feeder plate, and a guide member disposed vertically to face a free end of the feeder plate and configured to guide the recording media stacked on the feeder plate. And the media stocker includes a roller attached to the free end side of the feeder plate and rotatable around a horizontal shaft, the outer circumferential surface of the roller being in contact with the guide member at a position higher than the position of the uppermost support point of the feeder plate by the elevating device.
Now, an exemplary embodiment will be hereinafter described in detail with reference to
Separating device 51 includes conveying roller 52 and separating roller 53 with feeding path SP of recording media M interposed therebetween. Conveying roller 52 is installed above feeding path SP and separating roller 53 is installed below feeding path SP. When pickup roller 41 begins to rotate for picking up to convey the uppermost of recording media M, conveying roller 52 rotates to apply conveying force to the picked one of recording media M. Separating roller 53 rotates together when conveying roller 52 begins to rotate. When the picked one of recording media M reaches a position just ahead of separating device 51, separating roller 53 pauses to rotate. However, at this point, as well as the uppermost of recording media M, other recording media of recording media M that are positioned below the uppermost are frictionally conveyed to separating device 51 by the pick-up and conveyance of pickup roller 41. In this respect, separating roller 53 pauses to rotate just before the picked one of recording media M reaches separating device 51, thereby other recording media positioned below the uppermost hit against separating roller 53 may be blocked. Then, only the uppermost of recording media M is separated from other recording media, and is conveyed to conveying roller 52 so as to be fed into a paper feed opening (not shown) of an image forming apparatus. In this case, a conveying force applied to the uppermost of recording media M by the rotation of conveying roller 52 is larger than a frictional force between the uppermost of recording media M and the blocked other recording media positioned just below the uppermost. Consequently, a plurality of recording media M picked up by pickup roller 41 are processed by separating device 51 so that only the uppermost of recording media M is separated to be fed.
In this respect, the pause of the rotation of separating roller 53 is performed by a one-way clutch (not shown). In addition, for example, whether the picked one of recording media M reaches a position just ahead of separating device 51 is determined by using a sensor 61 disposed between pickup roller 41 and separating device 51. In one embodiment, the sensor 61 may be a transmission type sensor, but not limited.
Moreover, separating device 51 is not limited the type as described above. For example, separating device 51 may be a reverse roller type.
Next, media stocker 101 is described. Media stocker 101 has feeder plate 103 attached to a sheet of base template 102 with feeder plate 103 being capable of elevating. Feeder plate 103 is cantilever-supported by base template 102 and is capable of elevating. Feeder plate 103 has a free end FE at a side opposite to the cantilever-supported side. Elevating device 104 elevates feeder plate 103. Thus, feeder plate 103 will be described after elevating device 104 is described.
In addition, elevating device 104 includes a pair of belt winding devices 109 disposed at both sides of base template 102. Each of belt winding devices 109 has endless belt 111 stretched between a pair of upper and lower pulleys 110. The lower pulley receives rotary force from a driving source (not shown) to rotate, which causes endless belt 111 to turn. In this respect, elevating device 104 has connecting section 112 provided on roller holding member 107 with connected to each of endless belts 111. Thereby, rotary force of endless belts 111 is transmitted to roller holding member 107 to elevate feeder plate 103.
As shown in
Bottom frame 114 of media stocker 101 also supports base template 102 to secure rigidity together with other frames of media stocker 101. Accordingly, bottom frame 114 and guide member 113 fixed at the upper end implement a strong and firm structure with rigidity.
Feeder plate 103 will now be described hereinafter. Feeder plate 103 includes roller 117 attached to free end FE. Roller 117 is rotatable around roller shaft 118, which is arranged horizontally, so as to be in contact with guide member 113. As shown in
The outer circumferential surface of roller 117 is disposed to be in contact with guide member 113. In this respect, the contact between roller 117 and guide member 113 may be a constant contact or temporary contact which occurs when a stack of recording media M are loaded on feeder plate 103. In other words, roller 117 may be slightly separated from guide member 113 when recording media M are not loaded on feeder plate 103, and may be in contact with guide member 113 when recording media M are loaded on feeder plate 103 to make feeder plate 103 inclined downwardly due to its weight. In this case, roller 117 may be in contact with guide member 113 when at least a predetermined maximum number of recording media M should be loaded on feeder plate 103.
From the foregoing, as shown in
Under such a construction, media stocker 101 stocks and stores a large number of recording media M so as to prepare for the pickup and conveyance of recording media M by pickup roller 41. Recording media M are placed on feeder plate 103 for stock. As such, a plurality of recording media M are stacked and stored by feeder plate 103, which may elevate recording media M.
Subsequently, as the number of the stacked recording media M increases, free end FE of feeder plate 103 may be inclined downwardly due to the weight of recording media M. At this point, a turning trajectory according to the downwardly inclining movement of free end FE is convex outwardly from a vertical plane including free end FE at its initial position. This is because the triangle formed by support point UP, support point LP and contact position CP has an obtuse angle formed by a side between support point LP and support point UP and a side between support point UP and contact position CP. Accordingly, roller 117 abuts against guide member 113 so that free end FE of feeder plate 103 can be prevented from being inclined downwardly.
In this respect, when free end FE of feeder plate 103 starts to be inclined downwardly due to the weight of the plurality of recording media M stacked and held on the feeder plate, guide member 113 supports the position where a turning trajectory according to the downwardly inclining movement of free end FE is convex outwardly from a vertical plane including free end FE at its initial position.
As described above, according to the exemplary embodiment, since the downwardly inclining movement of feeder plate 103 is prevented by guide member 113, although feeder plate 103 is cantilevered, the configuration of the uppermost of recording media M stacked on feeder plate 103 can be maintained level. As a result of maintaining level the configuration of the uppermost of recording media M, pickup roller 41 pick up and convey recording media M with maintaining level, so that separating device 51 may separate and feed without causing problems. Accordingly, a failure in conveying recording media M can be prevented.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel media stocker, paper feeder using the media stocker, and method for controlling the configuration of a recording medium described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the media stocker, the paper feeder using the media stocker, and the method for controlling the configuration of a recording medium described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-213833 | Sep 2009 | JP | national |
