JP2014043335A - Paper feeder and image forming apparatus - Google Patents

Abstract

A paper supply device capable of reducing the amount of paper dust adhering to a paper is provided.
A sheet supply device that includes a separation roller and a separation pad arranged to face the separation roller and separates and supplies stacked sheets P one by one. A holder member 100 that holds the pad 35 and is supported so as to be able to come into contact with and separate from the separation roller 34 is provided. A through hole 112 is formed in the holder member 100 between the downstream edge of the holder member 100 and the downstream edge of the separation pad 35 in the paper P supply direction.
[Selection] Figure 2

Description

  The present invention relates to a sheet supply device for separating and supplying stacked sheets one by one and an image forming apparatus including the sheet supply device.

  2. Description of the Related Art Conventionally, there has been known a paper supply device that separates sheets stacked one by one by a separation roller and a separation pad attached to a holder member and supplies the separated sheets to an image forming unit (for example, Patent Documents). 1).

JP 2010-222107 A

  By the way, since paper dust is generated when the conveyed paper and the separation pad are in sliding contact with each other, the generated paper dust may accumulate on the holder member on the downstream side in the supply direction of the separation pad. When paper dust accumulates in the holder member, the accumulated paper dust easily adheres to the paper, and thus the amount of paper dust on the supplied paper may increase. In this case, for example, in an image forming apparatus including a paper supply device, there is a risk that the image quality may deteriorate due to an increase in the amount of paper dust on the paper.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a paper supply device and an image forming apparatus that can reduce the amount of paper dust adhering to the paper.

The present invention for achieving the above-described object is a paper supply device that includes a separation roller and a separation pad disposed to face the separation roller, and separates and feeds stacked sheets one by one. is there.
This paper supply apparatus includes a holder member that holds a separation pad and is supported so as to be able to come into contact with and separate from the separation roller.
An opening is formed in the holder member between the downstream edge of the holder member and the downstream edge of the separation pad in the paper supply direction.

  According to such a configuration, the paper dust generated by the sliding contact between the supplied paper and the separation pad can be collected at the opening formed on the downstream side in the supply direction of the separation pad, and thus adheres to the paper. The amount of paper dust can be reduced.

  In the paper supply device described above, the opening may be formed so as to overlap with at least a part of the separation roller in the paper width direction.

  Paper dust generated by the sliding contact between the paper and the separation pad is likely to be generated at the portion where the paper is pressed against the separation pad by the separation roller, so by forming the opening so as to overlap the width direction of the separation roller and the paper The generated paper dust can be collected effectively.

  In the paper supply device described above, the opening may be formed so as to overlap the entire separation roller in the width direction.

  According to this, paper dust generated at the portion where the paper is pressed against the separation pad by the separation roller can be collected more effectively and more reliably over the entire width direction of the separation roller.

  In the paper supply device described above, the holder member is provided so as to extend downstream from the separation pad in the supply direction and toward the downstream in the supply direction, and includes a guide portion that guides the paper to be conveyed. Can do.

  According to this, it is possible to satisfactorily supply paper.

  In the paper supply apparatus described above, the opening may be formed between the downstream side edge of the separation pad and the portion where the paper tip of the guide portion contacts.

  According to this, since it is possible to suppress the leading edge of the supplied paper from being caught by the edge of the opening, it is possible to suppress the occurrence of paper jam.

  In the paper supply apparatus described above, the holder member may have a recess in which the separation pad is disposed, and the opening may be formed downstream of the recess in the supply direction.

  According to this, the configuration of the holder member can be simplified as compared with the configuration in which the recess and the opening are formed separately. Further, the holder member can be reduced in size in the supply direction as compared with the configuration in which the recess and the opening are formed separately.

  In the paper supply apparatus described above, the holder member may be configured such that a weight is provided on the side opposite to the side where the separation pad is disposed.

  According to this, since it can suppress that the holder member supported so that contact / separation with respect to the separation roller vibrates, generation | occurrence | production of a noise etc. can be suppressed.

  In the paper supply device described above, the holder member is provided on the side opposite to the side where the separation pad is disposed so as to extend from the downstream side in the supply direction to the upstream side of the opening, and engages with the weight. It can be set as the structure which has these.

  According to this, falling of a weight can be suppressed compared with the structure which affixes a weight to a holder member with a double-sided tape etc., for example.

  In addition, the present invention for achieving the above-described object can be configured as an image forming apparatus including the above-described paper supply device.

  According to this, by reducing the amount of paper dust adhering to the paper in the paper supply device, it is possible to suppress deterioration in image quality due to the influence of paper dust.

  According to the present invention, the amount of paper dust adhering to the paper can be reduced.

1 is a diagram illustrating a schematic configuration of a laser printer as an example of an image forming apparatus according to an embodiment of the present invention. 2 is an enlarged cross-sectional view of a paper supply device. It is a perspective view of the holder member holding a separation pad. It is a longitudinal cross-sectional view near the hook part of the holder member holding a separation pad. It is a top view of the holder member holding a separation pad. It is the perspective view of the holder member seen from the opposite side to the side by which the separation pad is arrange | positioned. It is a top view of the holder member which concerns on a modification.

Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
In the following description, the direction will be described with reference to a user who uses the laser printer 1 as an example of the image forming apparatus. That is, the left side in FIG. 1 is “front”, the right side is “rear”, the front side is “right”, and the back side is “left”. Also, the vertical direction in FIG.

<Schematic configuration of laser printer>
As shown in FIG. 1, the laser printer 1 mainly includes a paper supply device 3 for supplying paper P and an image forming unit 4 for forming an image on the supplied paper P in a main body housing 2. I have.

  The paper supply device 3 is provided in the lower part of the main body housing 2 and includes a paper feed tray 31 that accommodates the paper P, a paper pressing plate 32, a paper feed roller 33, a separation roller 34, a separation pad 35, It mainly includes a conveyance roller 36. The paper P in the paper feed tray 31 is brought close to the paper feed roller 33 by the paper pressing plate 32 and sent out toward the separation roller 34 by the paper feed roller 33. The fed paper P is separated one by one by the separation roller 34 and the separation pad 35, and is supplied to the image forming unit 4 by the conveyance roller 36 and the registration roller 37.

  The image forming unit 4 mainly includes an exposure device 40, a process cartridge 50, and a fixing device 60.

  The exposure apparatus 40 is provided at the upper part in the main body housing 2 and mainly includes a laser light emitting unit (not shown), a polygon mirror 41 that is rotationally driven, lenses 42 and 43, and a reflecting mirror 44. Laser light (see the chain line) based on image data emitted from the laser light emitting unit is reflected or passed through the polygon mirror 41, the lens 42, the reflecting mirror 44, and the lens 43 in this order, and is scanned at high speed on the surface of the photosensitive drum 51. The

  The process cartridge 50 is disposed below the exposure apparatus 40 and can be exchanged by attaching to and detaching from the main body housing 2 through an opening formed when the front cover (reference numeral omitted) provided on the main body housing 2 is opened. It is configured. The process cartridge 50 mainly includes a photosensitive drum 51, a charger 52, a transfer roller 53, a developing roller 54, a supply roller 55, and a toner storage unit 56 that stores toner.

  The fixing device 60 is provided behind the process cartridge 50, and includes a heating roller 61 and a pressure roller 62 that is disposed to face the heating roller 61 and presses the heating roller 61.

  In the image forming unit 4, the surface of the photosensitive drum 51 is uniformly charged by the charger 52 and then exposed by high-speed scanning of laser light from the exposure device 40, so that the surface of the photosensitive drum 51 is statically exposed. An electrostatic latent image is formed. Further, the toner in the toner container 56 is supplied to the developing roller 54 via the supply roller 55 and is carried on the developing roller 54.

  Then, the toner carried on the developing roller 54 is supplied to the electrostatic latent image on the photosensitive drum 51, whereby the electrostatic latent image is visualized, and the toner image is formed on the photosensitive drum 51. It is formed. Thereafter, the paper P supplied from the paper supply device 3 is conveyed between the photosensitive drum 51 and the transfer roller 53, so that the toner image on the photosensitive drum 51 is transferred onto the paper P.

  The sheet P on which the toner image has been transferred is conveyed between the heating roller 61 and the pressure roller 62 so that the toner image is thermally fixed. The sheet P on which the toner image has been thermally fixed is transported on the transport path 23 by the transport roller 63 and is discharged from the transport path 23 onto the paper discharge tray 22 by the discharge roller 24.

<Detailed configuration of paper supply device>
Next, a detailed configuration of the paper supply device 3 according to the characteristic part of the present invention will be described.
In the following description, the supply direction of the paper P from the paper feed tray 31 toward the image forming unit 4 is simply referred to as “supply direction”. The upstream in the supply direction is simply referred to as “upstream”, and the downstream in the supply direction is simply referred to as “downstream”. Furthermore, the left-right direction, which is the width direction of the sheets P stacked in the sheet feed tray 31, may be simply referred to as “width direction”.

  As described above, the sheet feeding device 3 is a device for separating the sheets P stacked in the sheet feeding tray 31 one by one and feeding them to the image forming unit 4, and as shown in FIG. 34, the separation pad 35, and the like, and a resin holder member 100 that holds the separation pad 35 is provided.

  The separation roller 34 is disposed obliquely above and in front of the paper feed roller 33, and the rotation shaft 34 </ b> A is supported to be rotatable with respect to the main body housing 2. The separation roller 34 is configured to be driven to rotate when a driving force is inputted from a motor (not shown) provided in the main body housing 2 when the paper P is supplied. The separation roller 34 has a width W1 (see FIG. 5) of the roller portion 34R smaller than the width of the separation pad 35.

  The separation pad 35 is a thin plate-like member formed of a material having a large friction coefficient such as rubber or cork, and is disposed in a state of being in contact with the separation roller 34 diagonally in front of the separation roller 34.

  As shown in FIGS. 3 and 4, the holder member 100 includes a holding portion 110 that holds the separation pad 35 and a pair of covered members that extend obliquely upward on the downstream side from both sides in the width direction of the downstream end portion of the holding portion 110. It mainly includes a support portion 120 and a guide portion 130 provided between the pair of supported portions 120.

  A substantially cylindrical shaft 121 that protrudes outward in the width direction is provided at the downstream end of each supported portion 120. The holder member 100 is pivotally supported by the paper feed tray 31 so that the upstream end thereof can swing substantially vertically with respect to the paper feed tray 31. In other words, the holder member 100 is supported so as to be able to swing between the direction in which the holding unit 110 approaches and separates from the separation roller 34. The holder member 100 is biased so that the separation pad 35 is pressed against the separation roller 34 by a biasing member (not shown) such as a coil spring or a torsion spring.

  The guide unit 130 is a part that guides the paper P that is conveyed toward the image forming unit 4, and is downstream of the separation pad 35, specifically, obliquely downstream from the downstream end of the holding unit 110. It is provided so as to extend upward. The sheet P carried out from between the separation roller 34 and the separation pad 35 is directed toward the image forming unit 4 while the front end of the sheet P contacts the guide unit 130 and the lower surface of the sheet P is guided by the guide unit 130. Will be supplied.

  As described above, the holding unit 110 is a part that holds the separation pad 35, and as illustrated in FIG. 4, on the side facing the paper P (see the two-dot chain line) conveyed toward the image forming unit 4, It has the 1st recessed part 111 as an example of the recessed part of this invention formed so that the shape dented toward the substantially downward direction may be made. In this first recess 111, the separation pad 35 is disposed in a fixed state by being attached or the like.

  A through-hole 112 that penetrates in a substantially vertical direction is formed as an example of an opening at the downstream end of the bottom of the first recess 111. More specifically, as shown by hatching in FIG. 5, the through-hole 112 has a downstream edge portion 101 indicated by a thick solid line of the holder member 100 and a downstream side of the separation pad 35 in the paper P supply direction. It is formed so as to be positioned between the side edge portion 35A. The through hole 112 has a slit shape elongated in the width direction. More specifically, the through hole 112 overlaps the separation roller 34, more specifically, the entire roller portion 34R of the separation roller 34 in the width direction. The dimension W2 is larger than the dimension W1 in the width direction. Further, as shown in FIG. 4, the through-hole 112 is a portion where the downstream edge 35 </ b> A of the separation pad 35 and the leading end of the paper P of the guide portion 130 contact each other in the paper P supply direction (hereinafter referred to as “tip contact”). Part 131)).

  As shown in FIG. 4 and a perspective view of the holder member 100 viewed from below, the holding portion 110 is opposite to the side where the separation pad 35 is disposed, more specifically, the first recess 111. On the opposite side, a second recess 115 is formed so as to have a shape that is recessed substantially upward in FIG. The second recess 115 is provided with a plate-like weight 140 made of stainless steel or the like, one on each side in the width direction.

  The upstream portion of the weight 140 is lightly press-fitted between the left and right side walls 116 that form the second recess 115 and the substantially square pillar-shaped protrusion 117 that protrudes from the vicinity of the bottom center of the second recess 115. The downstream portion is held by the holder member 100 by engaging with a hook portion 150 provided on the opposite side of the holding portion 110 from the side where the separation pad 35 is disposed.

  A total of two hook portions 150 are provided corresponding to the two weights 140 provided on the holder member 100. The hook portion 150 extends from the downstream end of the holding portion 110, which is the downstream side of the through hole 112, toward the upstream side so as to straddle the through hole 112. An inclined surface 151 that is inclined toward the bottom of the second recess 115 is formed at the lower end of the hook portion 150. The weight 140 is hooked by pressing the inclined surface 151 by pressing the downstream portion toward the bottom of the second recess 115 after the upstream portion is lightly press-fitted between the side wall 116 and the protruding portion 117. The portion 150 is attached to the second recess 115 while being bent toward the downstream side. When the weight 140 is attached to the second recess 115, the hook portion 150 that has been bent returns to its original shape, and the tip engages with the weight 140.

  As shown in FIG. 4, in the present embodiment, the through hole 112 is formed using a through hole 113 provided at the downstream end of the bottom of the first recess 111. The separation pad 35 and each weight 140 are arranged so that the downstream end protrudes downstream from the upstream edge of the through hole 113, so that the upper and lower portions of the through hole 112 are supplied. The dimension in the direction is smaller than the dimension in the supply direction near the center in the vertical direction of the through hole 112, that is, the dimension L in the supply direction of the through hole 113.

  In such a configuration, the hook portion 150, more specifically, a portion of the hook portion 150 extending so as to straddle the through hole 112 is formed with a dimension that is the same as or smaller than the dimension L in the supply direction of the through hole 113. . In other words, the portion of the hook portion 150 extending so as to straddle the through hole 112 extends from the direction in which the one-dot chain line in FIG. 4 on the first recess 111 side extends through the through hole 113 of the holder member 100 to which the separation pad 35 is not attached. When viewed, the entire portion is formed between two dash-dot lines shown in FIG. With such a configuration of the holder member 100, for example, when the resin holder member 100 is molded by injecting a resin material into a mold such as injection molding, the mold is pulled out in the direction in which the one-dot chain line in FIG. 4 extends. Thus, both the through hole 113 and the hook portion 150 can be molded simultaneously.

  In the paper supply device 3 configured as described above, an operation of supplying the paper P from the paper feed tray 31 toward the image forming unit 4 is executed, so that the paper P, particularly the paper P, is separated by the separation roller 34. Paper dust is generated by the sliding contact between the paper P and the separation pad 35 between the portion pressed against the separation pad 35 and the separation pad 35.

  The paper dust generated at this time moves to the downstream side of the separation pad 35 as the paper P is conveyed. In this embodiment, the downstream edge portion 101 of the holder member 100 and the downstream edge portion 35A of the separation pad 35 are used. Since the through hole 112 is formed between the two, the paper powder passes through the through hole 112 and falls downward. In other words, in the paper supply device 3, paper dust generated by the sliding contact between the supplied paper P and the separation pad 35 is collected by the through hole 112 formed on the downstream side of the separation pad 35.

  As a result, paper dust is unlikely to collect on the holder member 100, for example, on the guide portion 130, on the downstream side of the separation pad 35, so that it is supplied in comparison with a configuration in which paper dust collects on the downstream side of the separation pad. The amount of paper dust adhering to the paper P can be reduced. As a result, it is possible to suppress a decrease in image quality due to the influence of paper dust in the laser printer 1.

  In particular, in the present embodiment, as shown in FIG. 5, since the through hole 112 is formed so as to overlap the entire roller portion 34 </ b> R of the separation roller 34 in the width direction, the sheet P is separated by the separation roller 34. It is possible to effectively and more reliably collect the paper dust generated at the portion pressed against the entire width direction of the separation roller 34.

  In the present embodiment, since the holder member 100 includes the guide portion 130 that guides the paper P, the paper P can be satisfactorily supplied also on the holder member 100.

  Further, as shown in FIG. 4, since the through hole 112 is formed between the downstream edge 35 </ b> A of the separation pad 35 and the tip contact portion 131 of the guide portion 130, the tip of the supplied paper P Can be prevented from being caught on the edge of the through-hole 112. Thereby, occurrence of paper jam (so-called jam) can be suppressed.

  Further, since the through hole 112 is formed on the downstream side of the first recess 111 in which the separation pad 35 is disposed, compared with a configuration in which the recess in which the through hole and the separation pad are disposed is formed separately. The configuration of the holder member 100 can be simplified. Moreover, the holder member 100 can be reduced in size in the supply direction as compared with a configuration in which the through hole and the recess are formed separately.

  Further, since the holder member 100 is provided with the weight 140 on the side opposite to the side where the separation pad 35 is disposed, the holder member 100 supported so as to be able to come in contact with and separate from the separation roller 34 vibrates. This can be suppressed. Thereby, generation | occurrence | production of noises, such as rattling noise accompanying operation | movement of the paper supply apparatus 3, can be suppressed.

  Furthermore, since the holder member 100 has a hook portion 150 that engages with the weight 140 on the side opposite to the side on which the separation pad 35 is disposed, for example, a structure in which the weight is simply attached to the holder member with a double-sided tape or the like. In comparison, falling off of the weight 140 can be suppressed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention as follows.

  In the above embodiment, as shown in FIG. 5, the through hole 112 is formed so as to overlap the entire roller portion 34R of the separation roller 34 in the width direction, but the present invention is not limited to this. . For example, as shown by hatching in FIG. 7, the through-hole 112 has a width of the roller portion 34 </ b> R so as to overlap a part of the roller portion 34 </ b> R in the width direction, such as a central portion of the roller portion 34 </ b> R of the separation roller 34. You may form with the dimension W3 of the width direction smaller than the dimension W1 of a direction. Moreover, although illustration is abbreviate | omitted, the through-hole may be formed in the dimension of the width direction same as the roller part of a separation roller. Also by these, the through hole overlaps with the generation location of the paper dust in the width direction, so that the generated paper dust can be effectively collected.

  In the embodiment, the through hole 112 is formed in the bottom of the first recess 111, that is, in the recess. However, the present invention is not limited to this, and is formed outside the recess, for example, in the guide portion 130 of the embodiment. It may be. Even in this case, in order to prevent the leading edge of the paper from coming into contact with the edge of the through hole, the through hole is formed between the downstream edge of the separation pad and the portion of the guide where the paper leading edge comes into contact. It is desirable to be formed between.

  In the embodiment, only one through hole 112 is formed in the holder member 100, but the present invention is not limited to this, and a plurality of through holes 112 may be formed. In this case, the through holes may be formed so as to be aligned in the width direction, may be formed so as to be aligned in the supply direction, or may be configured by combining these. Moreover, although the through-hole 112 was illustrated as an opening in the said embodiment, this invention is not limited to this, For example, an opening with a bottom, ie, a recessed part, may be sufficient as an opening.

  In the above embodiment, the downstream edge 35A of the separation pad 35 is formed in a planar shape parallel to the width direction of the paper, but the present invention is not limited to this. For example, the downstream side edge of the separation pad may be formed in a substantially comb-like shape having a plurality of convex portions arranged in the width direction of the paper and concave portions formed between adjacent convex portions. Further, the opening formed between the downstream edge of the holder member and the downstream edge of the separation pad may be formed in a shape that matches the shape of the downstream edge of the separation pad in plan view.

  In the said embodiment, although the holder member 100 had the guide part 130, this invention is not limited to this, The structure which does not have a guide part may be sufficient.

  In the said embodiment, although the holder member 100 had the hook part 150, this invention is not limited to this, The structure which does not have a hook part may be sufficient. In this case, the weight can be fixed to the holder member by, for example, a double-sided tape. Moreover, in the said embodiment, although the weight 140 was provided in the holder member 100, this invention is not limited to this, The structure by which the weight is not provided may be sufficient.

  In the above embodiment, the holder member 100 can be brought into contact with and separated from the separation roller 34 by the shaft portion 121 being supported by the paper feed tray 31 so as to be swingable. However, the present invention is limited to this. It is not something. For example, the holder member may be movable toward and away from the separation roller by being supported by a paper feed tray or the like so as to be movable in parallel.

  The paper supply device 3 according to the embodiment includes a paper feed roller 33 for feeding the paper P in the paper feed tray 31 and a separation roller 34 for separating the paper P one by one from the separation pad 35. Although provided separately, the present invention is not limited to this. For example, the paper supply device does not include the paper supply roller 33 of the above-described embodiment, and the separation roller exhibits both the function of feeding the paper and the function of separating the paper one by one from the separation pad. May be provided.

  In the above embodiment, the laser printer 1 is exemplified as the image forming apparatus. However, the present invention is not limited to this, and may be, for example, a copying machine or a multifunction machine including a document reading device such as a flat bed scanner. Further, the laser printer 1 of the above embodiment is a monochrome image forming apparatus, but the present invention is not limited to this, and may be a color image forming apparatus. The laser printer 1 of the above embodiment is an electrophotographic image forming apparatus. However, the present invention is not limited to this, and is, for example, an ink jet image forming apparatus or a thermal image forming apparatus. May be.

  In the above embodiment, the paper supply device 3 of the present invention is applied to the laser printer 1 as an image forming apparatus. However, the present invention is not limited to this. That is, the paper supply device of the present invention can be widely applied to devices that execute some processing on the paper supplied separately one by one.

DESCRIPTION OF SYMBOLS 1 Laser printer 3 Paper supply apparatus 34 Separation roller 35 Separation pad 35A Downstream side edge part 100 Holder member 101 Downstream side edge part 111 1st recessed part 112 Opening 130 Guide part 131 Tip contact part 140 Weight 150 Hook part P Paper

Claims (9)

A paper supply device that includes a separation roller and a separation pad disposed to face the separation roller, and separates and supplies the stacked paper one by one,
A holder member that holds the separation pad and is supported so as to be able to contact and separate from the separation roller;
The paper supply apparatus according to claim 1, wherein an opening is formed in the holder member between a downstream edge of the holder member and a downstream edge of the separation pad in the paper supply direction.   The paper supply device according to claim 1, wherein the opening is formed so as to overlap at least a part of the separation roller in a width direction of the paper.   The paper supply device according to claim 2, wherein the opening is formed so as to overlap the entire separation roller in the width direction.   2. The holder member according to claim 1, further comprising a guide portion that is provided so as to extend downstream in the supply direction from the separation pad toward the downstream side in the supply direction, and guides a sheet to be conveyed. The paper supply device according to claim 3.   The paper supply device according to claim 4, wherein the opening is formed between a downstream edge portion of the separation pad and a portion of the guide portion with which a paper front end abuts. The holder member has a recess in which the separation pad is disposed,
The paper supply device according to claim 1, wherein the opening is formed on the downstream side in the supply direction of the concave portion.   The paper supply device according to any one of claims 1 to 6, wherein the holder member is provided with a weight on a side opposite to a side on which the separation pad is arranged.   The holder member is provided on the opposite side to the side where the separation pad is disposed so as to extend from the downstream side in the supply direction of the opening toward the upstream side, and has a hook portion that engages with the weight. The paper supply device according to claim 7.   An image forming apparatus comprising the paper supply device according to claim 1.

Images