JP3129922U - Paper feeder - Google Patents

Abstract

The present invention provides a paper feeding device that can eliminate paper feeding jams or at least reduce the frequency of occurrence thereof.
SOLUTION: A plurality of upper sheets are taken out from a plurality of sheets stacked on a paper feed tray 2 by a scraper roller 4, and a scraper roller is provided by a pick-up roller 5 and a separating plate 6 provided downstream of the scraper roller 4. In the sheet feeding device 1 that separates the uppermost sheet of the plurality of sheets taken out from the sheet and conveys it downstream, the rotation ratio of the scraper roller 4 to the pickup roller 5 is set to 80% or less. As a result, the looseness of the paper that tends to occur between the pickup roller 5 and the scraper roller 4 is eliminated, and paper folding and paper jam due to this are prevented.
[Selection] Figure 1

Description

  The present invention can be used in various image forming apparatuses such as a printing apparatus and a copying apparatus, and relates to a paper feeding apparatus for supplying printing paper, which is a sheet-like image forming medium. The present invention relates to a sheet feeding device having a structure for reducing the occurrence of occurrence as much as possible.

2. Description of the Related Art Conventionally, as a paper feeding device used in a paper feeding unit or the like of an image forming apparatus, an apparatus having a structure as disclosed in Patent Document 1 below is known.
These sheet feeding devices generally include a scraper roller that rotates in contact with the upper surface of a sheet stacked on a freely elevating sheet feeding table, and a scraper plate (usually a rubber plate or the like) provided on the downstream side of the scraper roller. And a pickup roller that is rotatably disposed at an upper position substantially in contact with the sheeting plate and picks up and conveys paper between the sheeting plate. ing. Here, the scraper roller and the pickup roller are interlocked by a common motor and are driven at a constant speed. By this primary paper feeding means, a plurality of sheets are taken out from the paper stacked on the paper feed tray by the scraper roller and conveyed, and only one uppermost sheet is picked up and conveyed further downstream by the pickup roller and the separating plate. .

Further, a secondary paper feed unit including a pair of secondary paper feed rollers is provided on the downstream side of the primary paper feed unit, and the sheet fed from the primary paper feed unit is further formed on the downstream side. It can be conveyed to a means or the like.
JP 10-139191 A

  According to the conventional paper feeding device as described above, depending on the type of paper, since the frictional force of the separating plate is large, the paper can not be conveyed by the pickup roller, and the conveyance speed given to the paper by the pickup roller is expected. This value is lower than the above value and becomes lower than the conveying speed of the scraper roller, which may cause the sheet to bend between the pickup roller and the scraper roller.

  If the paper is stiff, such as thick paper, the force to restore the paper shape works strongly, so the paper can be fed normally without any slack. Since the force to restore the original is weak, the slack remains as it is, and this slack passes through the pickup roller, which causes paper breakage and causes paper jam.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device that can eliminate paper jam due to paper folding or at least reduce the frequency of occurrence.

The paper feeding device according to claim 1 is:
A plurality of sheets are taken out from a plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pick-up roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
The scraper roller has a rotation ratio with respect to the pickup roller of 80% or less.

The sheet feeding device according to claim 2 is:
A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
It is characterized by having a rotation speed variable means that can arbitrarily set a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%.

The paper feeding device according to claim 3 is the paper feeding device according to claim 2,
The rotation speed varying means is a belt-type transmission that interlocks the pickup roller driven by a motor and the scraper roller.

The paper feeding device according to claim 4 is the paper feeding device according to claim 2,
The rotation speed variable means is provided separately from a pickup drive motor for driving the pickup roller, so that the rotation speed of the scraper roller can be controlled to set a rotation ratio of the scraper roller with respect to the pickup roller. It is a scraper drive motor to drive.

The paper feeding device according to claim 5 is:
A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
A plurality of speed ratios are provided corresponding to the type of paper to be conveyed, and the rotation speed variable means is operated by selection to set the rotation ratio of the scraper roller to the pickup roller to a rotation ratio suitable for the type of paper. A paper type selection button,
It is characterized by having.

The paper feeding device according to claim 6 is:
A plurality of sheets are taken out from a plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pick-up roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
A rotation ratio setting button for operating the rotation speed variable means to arbitrarily set a rotation ratio of the scraper roller to the pickup roller;
It is characterized by having.

The sheet feeding device according to claim 7 is:
A plurality of sheets are taken out from a plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pick-up roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
By detecting the leading edge of the paper that is provided downstream of the pickup roller and is conveyed downstream by the pickup roller and the separation plate, the conveyance timing of the sheet conveyed downstream by the pickup roller and the separation plate is determined. A sensor to detect;
Control means for operating the rotation speed variable means based on the transport timing output by the sensor and setting a rotation ratio of the scraper roller to the pickup roller;
It is characterized by having.

  According to the paper feeding device of the first aspect, since the feeding speed of the pickup roller is always higher than the feeding speed of the scraper roller, there is no bending of the paper between the two, paper breakage or jamming Can be prevented.

  According to the paper feeding device of the second aspect, the rotation speed variable means can set the feed speed of the scraper roller to an optimum speed ratio according to the conditions such as the paper thickness with respect to the feed speed of the pickup roller. This makes it possible to carry out a good sheet without occurrence of the above.

  According to the paper feeding device of the third aspect, since the pickup roller driven by the motor and the scraper roller are linked via the belt-type transmission, the scraper roller is controlled by controlling the belt-type transmission. Can be set to an optimum speed ratio according to conditions such as the paper thickness with respect to the feed speed of the pick-up roller, and good paper conveyance without jamming or the like is possible.

  According to the paper feeder of the present invention, since the scraper roller and the pickup roller are driven by separate motors, the scraper roller feed speed is controlled by controlling the drive speed of the scraper roller motor. It is possible to set an optimum speed ratio according to the conditions such as the paper thickness with respect to the speed, and it is possible to perform good paper conveyance without occurrence of jam or the like.

  According to the paper feeding device of the fifth aspect, the feeding speed of the scraper roller can be set to the optimum speed ratio corresponding to the paper type with respect to the feeding speed of the pickup roller by the selection operation of the paper selection button.

  According to the sheet feeding device of the sixth aspect, the scraper roller feed speed can be set to the optimum speed ratio corresponding to the selected rotation ratio with respect to the pick-up roller feed speed by selecting the rotation ratio setting button.

  According to the sheet feeding device of the seventh aspect, the control unit operates the rotation speed variable unit based on the sheet conveyance timing output from the sensor, so that the rotation ratio of the scraper roller to the pickup roller becomes an optimum speed ratio. Can be set as follows.

  Hereinafter, an embodiment of the present invention which the applicant of the utility model registration thinks best at the time of filing in order to implement the present invention will be described with reference to FIGS.

1. First embodiment (first example, FIGS. 1 and 2)
1 and 2 show a first embodiment of the present invention, FIG. 1 is a perspective view showing an overall configuration of a paper feeding device, and FIG. 2 is a perspective view showing a drive shaft system in the paper feeding device.

The overall configuration of the sheet feeding device 1 will be described with reference to FIG.
First, the sheet feeding device 1 has a sheet feeding table 2 on which a plurality of sheets are stacked in a stacked state. A transport frame 3 is fixedly disposed adjacent to and along a paper feed edge that is downstream of the paper feed table 2. A scraper roller 4 is rotatably disposed above the sheet feed end of the sheet feed tray 2, and a pickup roller 5 and a scooping plate 6 are disposed adjacent to the downstream side of the scraper roller 4. The pickup roller 5 is rotatably disposed above the conveyance start end position of the conveyance frame 3. The separating plate 6 is disposed below the pickup roller 5 on the conveyance frame 3 and is a member made of a high friction material such as a rubber plate that sandwiches the uppermost sheet with the pickup roller 5 and sends it to the downstream side. is there. A pair of secondary paper feed rollers 7 are provided downstream of the transport frame 3 so as to be in rolling contact with each other through openings formed in the transport frame 3 so as to face each other vertically.

  At the time of paper conveyance, the scraper roller 4 rotates to take out a plurality of upper sheets and send them to the pickup roller 5 side. The pickup roller 5 and the separating plate 6 move the uppermost sheet to the lower layer side. The paper is separated from the paper and sent to the secondary paper feed roller 7 and then sent to the image forming section.

A drive shaft system in the paper feeding apparatus will be described with reference to FIGS.
The pickup roller 5 is connected via a drive shaft 9 that is connected to the output end of the drive motor 8 at one end. In addition to the pickup roller 5, a plurality of paper receiving rollers 10 are connected to the outer periphery of the drive shaft 9, and the paper receiving roller 10 cooperates with the pickup roller 5 while holding down the warped paper, to the downstream side. It is designed to be transported.

  The drive shaft 9 is connected to the drive shaft 14 of the scraper roller 4 through a gear mechanism provided in the gear box 11. In FIG. 2, an input gear 12 is connected to the drive shaft 9 in the gear box 11, and this input gear 12 meshes with an output gear 15 connected to the outer periphery of the drive shaft 14 via an intermediate gear 13. Yes.

  The gear ratio between the input gear 12 and the output gear 15 is set to approximately 27:34. With this gear ratio, the rotation speed of the scraper roller 4 is always limited to approximately 80% of the rotation speed of the pickup roller 5. As a result, by feeding the paper fed from the scraper roller 4 to the downstream side at a higher speed by the pickup roller 5, an appropriate tensile load corresponding to the speed difference is always applied to the paper. Causes of jamming such as paper deflection and paper breakage due to deflection are prevented.

  The speed ratio value of approximately 80% is a speed ratio that can be sent between the scraper roller 4 and the pickup roller 5 without applying excessive tension to the paper and without causing deflection of the paper due to idling. It is a numerical value that is empirically determined in advance by measurement or the like.

  In FIG. 2, the gear box 11 is fixed to a frame (not shown) of the apparatus, and both ends of the drive shaft 9 are of course rotatably supported by a frame (not shown) of the apparatus via a bearing or the like. is there.

2. Second Embodiment (Second Example, FIG. 3)
FIG. 3 shows a drive shaft system according to a second embodiment of the present invention in which the gear ratio is variable. In the following description of the present embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and only different portions or newly added portions are described using new reference numerals.

  In FIG. 3, one end of the drive shaft 9 of the pickup roller 5 is connected to the drive motor 8 via a pinion 20 and a gear 21 so as to be rotatable at a predetermined reduction ratio. A drive shaft 14 connected to the scraper roller 4 is rotatably connected to the drive shaft 9 via a continuously variable transmission 22.

  The transmission 22 shown in FIG. 3 is a belt-type CVT (continuously variable transmission), a transmission box 23 in which the drive shafts 9 and 14 are rotatably supported, and a transmission box 23 in the transmission box 23. 9, a drive pulley 24 connected to the drive shaft 14, a driven pulley 25 connected to the drive shaft 14, and a V-belt 26 wound endlessly between the pulleys 24 and 25.

  Among these, the driven pulley 25 is a fixed type, and the drive pulley 24 is formed with a V-shaped pulley groove, and one of the V-shaped can be moved in the axial direction with respect to the other. By an operation mechanism and variable control means such as a servo control system linked thereto, it is possible to approach and separate steplessly.

  As shown in FIG. 3, when the V-shaped grooves of the drive pulley 24 are separated from each other as much as possible, the diameter of the V-belt 26 is smaller than the diameter of the driven pulley 25 and the V-belt 26 is in contact with the driven pulley 25 as close as possible. The diameter is the same as the diameter of the driven pulley 25, and the variation range thereof can be set to 60 to 100% steplessly with respect to the diameter of the driven pulley 25.

  As a result, the feed speed of the scraper roller 4 can be varied in the range of 60% or constant speed compared to the feed speed of the pickup roller 5, thereby conveying the paper at the constant speed or the optimum speed ratio according to the paper thickness. Is possible.

3. Third Embodiment (Third Example, FIG. 4)
FIG. 4 shows a drive shaft system according to a third embodiment of the present invention in which the gear ratio is variable.
In FIG. 4, the scraper roller 4 and the pickup roller 5 are driven by two drive motors 30 and 31 that are independent of each other.

  That is, the drive shaft 14 of the scraper roller 4 is rotatably connected to one end of the input shaft 34 via the gear mechanism 33 in the gear box 32, and the drive motor 30 is connected to the other end of the input shaft 34. And a gear 36 for rotation. The gear ratio of the gear mechanism 33 is constant.

  On the other hand, the drive shaft 9 of the pickup roller 5 is rotatably connected to the drive motor 31 via a pinion 35 and a gear 36.

  Of these, the drive motor 31 for the pickup roller 5 has a constant rotational speed for the secondary paper feed roller 7 described above, while the drive motor 30 for the scraper roller 4 is centered on 80% of the rotational speed of the drive motor 31. And a variable control means (not shown) for controlling the drive motor 30 current in a range where the lower limit is 60% and the upper limit is 100%.

4). 4th Embodiment (4th example, FIG. 5)
FIG. 5 shows a side view of the fourth embodiment of the present invention. In FIG. 5, the drive shafts 14 and 9 of the scraper roller 4 and the pickup roller 5 are interlocked with the drive motor 8 through the continuously variable transmission mechanism of the second embodiment, or individually as in the third embodiment. It is assumed that the drive motors 30 and 31 are linked to each other.

  A sensor 40 for detecting the passage of the leading edge of the paper is disposed on the lower surface side of the transport frame 3 immediately before the secondary paper feed roller 7 in the paper transport direction. The detection signal of the sensor 40 is input to the sequential control means 41.

  The control means 41 has a function of controlling the basic sheet feeding operation by the sheet feeding device, and based on the detection value of the sensor 40, sets the rotation ratio of the scraper roller to the pickup roller to 80. In order to perform the control to be equal to or less than%, the second rotation speed changing means (the transmission 22 in the second embodiment, the drive motor 30 of the scraper roller 4 in the third embodiment) is driven to In the case of the embodiment, an operation command signal is given to the variable operation mechanism of the transmission 22, and in the case of the third embodiment, an operation command signal is given to the current control means of the drive motor 30.

  Based on the detection signal when the sensor 40 detects the leading edge of the paper sent from the pickup roller 5, the control means 41 starts the conveyance from a predetermined position until the leading edge is detected by the sensor 40. Is recognized as the paper detection timing. The paper detection timing and the optimum speed ratio of the scraper roller 4 with respect to the pickup roller 5 are obtained in advance by experiment and stored in the control means 41, and the speed ratio data corresponding to the actual paper detection timing detected as described above. Is read out, thereby controlling the rotation speed variable means. As a result, the slack of the paper between the pickup roller 5 and the scraper roller 4 is eliminated, and paper jamming due to paper folding is prevented.

5). Fifth embodiment (fifth example)
Although not shown, in each of the examples described above, the means for setting the rotation ratio of the scraper roller 4 to the pickup roller 5 to a rotation ratio suitable for the type of paper by operating the rotation speed variable means is conveyed. A plurality of paper type selection buttons provided corresponding to the paper types may be used, or a rotation ratio setting button for directly and arbitrarily setting the rotation ratio of the scraper roller 4 with respect to the pickup roller 5 may be used. These buttons can be provided on a control panel for operating the paper feeding device.

1 is a perspective view of a sheet feeding device according to a first embodiment of the present invention. It is a perspective view which shows the drive shaft system in the paper feeder. It is a top view of the drive shaft system in 2nd Embodiment of this invention. It is a top view of the drive shaft system by 3rd Embodiment of this invention. FIG. 10 is a side view of the vicinity of a sheet feeding device according to a fourth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Paper feed stand 3 Conveying frame 4 Scraper roller 5 Pickup roller 6 Scattering board 7 Secondary paper feed roller 8, 30, 31 Drive motor
9, 14 Drive shaft 12 Input gear 15 Output gear 22 Continuously variable transmission (pulley continuously variable transmission)
24, 25 Pulley 26 V belt 40 Sensor 41 Control means

Claims (7)

A plurality of sheets are taken out from a plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pick-up roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A paper feeding device having the scraper roller having a rotation ratio with respect to the pickup roller of 80% or less. A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A sheet feeding device, comprising: a rotation speed variable unit capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%. The sheet feeding device according to claim 2, wherein the rotation speed varying means is a belt-type transmission that interlocks the pickup roller driven by a motor and the scraper roller. The rotation speed variable means is provided separately from a pickup drive motor for driving the pickup roller, so that the rotation speed of the scraper roller can be controlled to set a rotation ratio of the scraper roller with respect to the pickup roller. The sheet feeding device according to claim 2, wherein the sheet feeding device is a scraper driving motor to be driven. A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
A plurality of speed ratios are provided corresponding to the type of paper to be conveyed, and the rotation speed variable means is operated by selection to set the rotation ratio of the scraper roller to the pickup roller to a rotation ratio suitable for the type of paper. A paper type selection button,
A sheet feeding device comprising: A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
A rotation ratio setting button for operating the rotation speed variable means to arbitrarily set a rotation ratio of the scraper roller to the pickup roller;
A sheet feeding device comprising: A plurality of sheets are taken out of the plurality of sheets stacked on the paper feed tray by a scraper roller, and the top of the plurality of sheets taken out by the scraper roller by a pickup roller and a separating plate provided downstream of the scraper roller. In the paper feeder that separates the upper paper from the other and conveys it downstream,
A rotation speed variable means capable of arbitrarily setting a rotation ratio of the scraper roller to the pickup roller within a predetermined range including 80%;
By detecting the leading edge of the paper that is provided downstream of the pickup roller and is conveyed downstream by the pickup roller and the separation plate, the conveyance timing of the sheet conveyed downstream by the pickup roller and the separation plate is determined. A sensor to detect;
Control means for operating the rotation speed variable means based on the transport timing output by the sensor and setting a rotation ratio of the scraper roller to the pickup roller;
A sheet feeding device comprising:

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