JP3871022B2 - Separating paper feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an FRR type separation sheet feeding device.
[0002]
[Prior art]
A conventional example of the FRR type paper feeder will be described with reference to FIG. The sheet S loaded in the sheet feeding unit is guided by the front guide plate 101 and rises while the front surface (front end side) in the transport direction is aligned, and is brought into contact with the sheet S only during the sheet transport by the calling roller 103 that rotates. The first sheet S1 moves in the transport direction. Note that the calling roller 103 moves to the retracted position and is not in contact with the paper S except during paper conveyance.
[0003]
When the first sheet S1 is transported, the second sheet S2 below it may also be sent together due to friction between the sheets, and the sheets S1 and S2 are transported in the transport direction. A torque limiter 107 that transmits only a desired friction torque to a conveyance roller 105 made of an elastic material that rotates in the conveyance direction by the roller drive shaft 104 and a return roller drive shaft 106 that rotates in the return direction at a position opposite to the roller. Then, the elastic material return roller 108 that rotates is fed to a region where the elastic roller returns to contact with each other with a desired pressing force.
[0004]
When the first sheet S1 and the second sheet S2 overlap each other and enter the nip portion between the transport roller 105 and the return roller 108, the first sheet S1 is fed in the transport direction by the transport force of the transport roller 105. However, the second sheet S2 is pushed back by the conveying force of the return roller 108 rotating in the return direction, and is in a state of waiting on the upstream side between the rollers 105 and 108.
[0005]
Further, as shown in FIGS. 4 and 5, the applicant of the present application, as shown in FIG. 4 and FIG. 5, uses an FRR-type separation feed using a transport roller 110 and a return roller 111 made of a highly rigid material having a number of protrusions 109 in the circumferential direction. Paper devices are proposed in Japanese Patent Laid-Open Nos. 2000-362368 and 2000-390746. In FIG. 4, there is no sheet between the conveyance roller 110 and the return roller 111, and the gear 112 formed on one end side of the conveyance roller 110 and the gear 113 formed on one end side of the return roller 111 are engaged with each other. In this state, the return roller 111 is rotated in the paper conveyance direction by the conveyance roller 110. FIG. 5 shows a state in which one sheet S is inserted between the conveyance roller 110 and the return roller 111, and the protrusion 109 of the conveyance roller 110 and the protrusion 109 of the return roller 111 pierce the sheet S. In this state, the return roller 111 is rotated in the paper conveyance direction by the conveyance roller 110.
[0006]
Here, a material having high rigidity means a material having a longitudinal elastic modulus (Young's modulus) of 1 GPa or more. For example, steel (100 to 210 GPa), titanium (116 GPa), aluminum (70.3 GPa), glass (71 GPa), glass Polycarbonate containing fibers (10.8 to 3.1 GPa), alumina (3800 GPa), alumina ceramics (3000 GPa), and the like.
[0007]
[Problems to be solved by the invention]
In the FRR system in which the protruding portion 109 having high rigidity is pierced into the sheet S to acquire the conveying force and the separating force of the sheet S as in the separation sheet feeding device shown in FIGS. The thickness is related to the thickness of the paper S to be used. In particular, in the extreme case, when the projection height is greater than the paper thickness, the paper S is perforated and the paper surface is destroyed (hole damage), and the image formation quality is subsequently deteriorated. And so on.
[0008]
Further, when a plurality of sheets S to be separated exist between the transport roller 110 and the return roller 111, the protrusion 109 is skewed into the plurality of sheets S when the protrusion height> the sheet thickness. Therefore, the original sheet separation function does not work.
[0009]
In this case, this is dealt with by adopting a structure in which the protrusion height of the protrusion 109 of both rollers 110 and 111 is set to be equal to or less than the sheet thickness. However, since the sheet S is not interposed, the transport roller 110 and the return roller 111 are arranged. Are in contact with each other, the apexes of the protrusions 109 come into contact with the tooth bottoms of the corresponding rollers 111 and 110 and wear and deform, and a desired protrusion height cannot be ensured. In some cases, the piercing performance of the paper may deteriorate and the separation / feeding performance may deteriorate.
[0010]
In addition, since the transport roller 110 and the return roller 111 are rotated with a constant pressure set, the paper due to the load at the front end of the paper S when the paper S enters the nip portion between the transport roller 110 and the return roller 111. S buckling is likely to occur.
[0011]
SUMMARY OF THE INVENTION An object of the present invention is to provide a separation sheet feeding device that can prevent the tip of a protrusion from being worn and can perform stable separation sheet feeding.
[0012]
Another object of the present invention is to provide a separation sheet feeding device that can prevent the sheet from buckling due to the load at the leading end of the sheet when the sheet enters the nip portion of the conveyance roller and the return roller.
[0013]
[Means for Solving the Problems]
According to a first aspect of the present invention, in the FRR-type separation paper feeding device that separates and feeds paper with a transport roller and a return roller, the transport roller and the return roller have a plurality of protrusions in the circumferential direction. When the paper reaches the nip portion between the transport roller and the return roller, the transport roller and the return roller are released, and the paper is The transfer roller and the return roller can be contacted and separated so that the transfer roller and the return roller come into contact with each other after reaching the transfer roller and the return roller. The contact / separation signal between the transport roller and the return roller is set to be the same as a start signal of the calling roller or a start signal of the calling roller, and the transport roller The return roller is moved toward and away from the roller and the calling roller is driven. Drive and is carried out by a common drive source.
[0014]
Here, the conveyance roller and the return roller are in a released state, the conveyance roller and the return roller are separated from each other, and the protrusion of the conveyance roller and the protrusion of the return roller are the return roller or the conveyance roller on the other side. It means that it is in a state of not touching. The contact between the conveyance roller and the return roller means that the conveyance roller and the return roller nip the sheet.
[0015]
Therefore, when the sheet reaches the nip portion between the conveyance roller and the return roller, the conveyance roller and the return roller are in a released state, and the protrusion of the conveyance roller rotates in contact with the return roller. Since the protrusions of the rollers are prevented from rotating in contact with the transport roller, wear of the protrusions is prevented, the performance of the protrusions sticking to the paper is maintained, and the protrusions are inserted into the paper. The separation and feeding performance of the paper to be performed is maintained well.
[0016]
Further, since the conveyed paper is sent between the transport roller and the return roller which are in the released state, the buckling of the paper when the paper is fed between the transport roller and the return roller is prevented.
[0020]
Here, the calling roller is a member that feeds the stacked sheets toward the nip portion between the transport roller and the return roller.
[0021]
Therefore, the timing of contact between the conveying roller and the return roller and the contact / separation drive are used for the start roller and the drive source of the calling roller, so that the cost of the apparatus is reduced.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIG. The sheet called by the calling roller 3 advances to the nip portion between the conveyance roller 5 and the return roller 8. The conveyance roller 5 and the return roller 8 are rigid bodies having a large number of protrusions 9 as described with reference to FIGS. 4 and 5 in the circumferential direction.
[0023]
Immediately before the sheet reaches the nip portion between the conveying roller 5 and the return roller 8, the leading edge of the sheet can be detected by the sensor 20 that is a sheet detecting unit. By this detection signal, the solenoid 17 is attracted, and the lever 18 rotates around the support shaft 18a, whereby the return roller driven shaft 6 is pushed downward, and a gap is formed between the transport roller 5 and the return roller 8. . This gap is a value through which the paper can pass and is set to about 0.1 to 1 mm. When the sheet reaches the nip portion between the conveyance roller 5 and the return roller 8, the suction of the solenoid 17 is released, and the conveyance roller 5 and the return roller 8 come into contact with each other to pick up the sheet. Since the timing at which the solenoid 17 is released is set so as to be delayed for a predetermined time after being sucked, the sheet is conveyed when the leading edge of the sheet passes through the nip portion between the conveyance roller 5 and the return roller 8. 5 and the return roller 8 can be used.
[0024]
The transport roller 5 is fixed to a transport roller drive shaft 4 that is driven by a motor (not shown). The return roller 8 is attached to the return roller driven shaft 6 via a torque limiter 7, and is connected to a gear 6-1 fixed to the return roller driven shaft 6 and a motor (not shown) and is driven to rotate. A gear 6-3 fixed to the roller drive shaft 6-4 is engaged.
[0025]
The calling roller 3 is provided so as to be movable to a position close to and away from the uppermost sheet among the sheets stacked in the sheet feeding unit (not shown), and in response to a start signal for starting the calling operation. The solenoid 15a is sucked, and the calling roller 3 moves to a position where it contacts the paper. Further, a driving belt 3 for transmitting a driving force from the conveying roller 5 to the calling roller 3 between a pulley 3-1 attached to the calling roller 3 and a pulley (not shown) attached to the conveying roller 5. -2 is wound.
[0026]
After the sheet is fed into the nip portion between the conveyance roller 5 and the return roller 8, the sheet is picked up by the conveyance roller 5 and the return roller 8, and the protrusion 9 of the conveyance roller 5 and the protrusion 9 of the return roller 8 Pierces the paper. Then, the driving force is transmitted from the motor to each of the transport roller 5 and the return roller 8, so that when the received sheet is one sheet, the return roller 8 is rotated by the transport roller 5 and the sheet is transported. Is done. When there are two or more prepared sheets, the conveying roller 5 rotates in the sheet conveying direction and the return roller 8 rotates in the sheet returning direction, and only one sheet on the conveying roller 5 side is conveyed. The other sheets are returned to the paper feed unit side.
[0027]
Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same part as the part demonstrated in FIG. 1 is shown with the same code | symbol, and description is also abbreviate | omitted.
[0028]
The calling roller 3 is provided so as to be movable to a position close to and away from the uppermost sheet among the sheets stacked in the sheet feeding unit, and the solenoid 15 is attracted by a start signal for starting the calling operation. As a result, the calling roller 3 moves to a position where it contacts the paper.
[0029]
The solenoid 15 is connected to the lever 18 through a wire 22 stretched around the pulleys 21a, 21b, and 21c, and rotates the lever 18 around the support shaft 18a. The roller driven shaft 6 is moved up and down, and the return roller 8 is brought into contact with and separated from the conveying roller 5.
[0030]
That is, in this embodiment, the movement of the calling roller 3 to the contact / separation position with respect to the sheet and the drive for bringing the return roller 8 into and out of contact with the conveying roller 5 are performed by one start signal and one solenoid 15 is moved. It is done as a drive source.
[0031]
【The invention's effect】
According to the first aspect of the present invention, when the paper reaches the nip portion between the conveyance roller and the return roller, the conveyance roller and the return roller are in a released state, and the protrusion of the conveyance roller comes into contact with the return roller. And the protrusion of the return roller is prevented from rotating in contact with the conveyance roller, so that the wear of each protrusion can be prevented and the piercing performance of the protrusion on the paper can be maintained. It is possible to maintain good paper separation and feeding performance performed by piercing the protrusions into the paper. Further, since the sheet to be conveyed is sent between the conveyance roller and the return roller in the released state, it is possible to prevent the sheet from buckling when the sheet is fed between the conveyance roller and the return roller.
[0033]
Furthermore, according to the first aspect of the present invention, the contact roller separation roller timing and the contact / separation drive are performed using the calling roller start signal and the drive source. Therefore, a dedicated device for contacting and separating is not necessary, and the cost of the device can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a separation sheet feeding device according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a separation sheet feeding device according to a second embodiment of the present invention.
FIG. 3 is a side view showing a conventional separation sheet feeding device.
FIG. 4 is a cross-sectional view showing the content of the invention of the prior application in which protrusions are formed on the conveying roller and the return roller.
FIG. 5 is a cross-sectional view showing the contents of the invention of the prior application in which protrusions are formed on the conveying roller and the return roller.
[Explanation of symbols]
3 Calling roller 5 Conveying roller 8 Returning roller 15 Drive source 20 Paper detection means

Claims (1)

In an FRR type separation feeding device that separates and feeds paper with a conveyance roller and a return roller,
The transport roller and the return roller are rollers of a highly rigid material having a number of protrusions in the circumferential direction,
When the paper reaches the nip portion between the transport roller and the return roller, the transport roller and the return roller are released, and the paper is released from the transport roller and the return roller. The transport roller and the return roller are detachably provided so that the transport roller and the return roller come into contact with each other after reaching the roller .
A contact / separation signal between the transport roller and the return roller is set to be the same as a start signal of the calling roller or a start signal of the calling roller, and the return roller to the transport roller is set. A sheet feeding device characterized in that the contact / separation driving of the roller and the driving of the calling roller are performed by a common driving source .

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