JP3564282B2 - Paper feeder - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a sheet feeding device for an image forming apparatus such as a plain paper copying machine, a facsimile, a printer, and the like.
[0002]
[Prior art]
2. Description of the Related Art In a paper feeder for an image forming apparatus such as a plain paper copier, a paper feeder is generally used to feed paper stored in a paper stacking section, as described in, for example, JP-A-56-7847. The pickup roller is disposed on the side, and a paper separating mechanism configured by a feed roller and a separation roller that is driven to rotate in a direction opposite to the sheet feeding direction via a torque limiter is disposed downstream of the pickup roller. Thus, a means is used in which the sheet called by the pickup roller is separated by a separating mechanism to feed the sheets one by one to the downstream. However, when paper containing a large amount of paper dust is being handled, the performance of the rubber that forms the surface of these rollers is degraded over time due to the adhesion of paper dust or the like, and a paper conveyance failure (jam) occurs.
[0003]
The adhesion of the paper dust to the surface of the rubber roller may be caused by physically sticking the paper dust to the surface of the rubber, or by causing the rubber surface to be charged by the friction and sucking the paper dust.
[0004]
The mechanism of the jam is shown below. As described in Japanese Utility Model Application Laid-open No. Sho 100-100347, the polished surface formed on each rubber roller at the time of manufacture is worn by the leading edge of the paper, and the unevenness of the roller surface is reduced. This tendency is particularly likely to occur in separation rollers. If the fineness of the paper powder adheres to the surface of the roller due to less unevenness, the rubber surface of the separation roller and the paper are not gripped and slippage occurs. Normally, when the feed roller transports one sheet of paper, the separation roller must follow the paper and rotate in the transport direction, but if slip occurs, the separation roller moves in the opposite direction to the transport direction due to the action of the torque limiter. And a transport load occurs, causing a jam. Further, the paper dust also adheres to the feed roller and the pickup roller. When the conveying force of these rollers is reduced by the paper powder and becomes lower than the conveying load of the separation rollers, a jam occurs.
[0005]
Therefore, in order to surely prevent the adhering matter on the surface of the rubber roller such as paper dust generated by friction by the rubber roller (that is, rubber roller) at the time of paper feeding from entering the image forming apparatus main body, Japanese Patent Application Laid-Open No. H3-128831 is disclosed. In the following description, "a paper cassette which is detachably loaded into a paper feeding section of the image forming apparatus main body, a take-out means for taking out the paper in the paper feed cassette, and a sheet taken out by the take-out means, one sheet at a time. Paper feed means comprising a transport roller for separating and feeding paper and a separation roller on the main body side of the forming apparatus; and removing at least one of the transport roller and the separation roller of the paper feed means in contact with these rollers. And a paper feeder having a cleaning blade member that performs cleaning. A paper cassette which is detachably mounted in a paper feeding unit, a take-out means for taking out the paper in the paper feed cassette, and the paper taken out by the take-out means are separated and fed one by one to the image forming apparatus main body side. And a cleaning roller member that rolls on at least one of the transport roller and the separation roller of the paper transport unit and removes adhered matter on these rollers. Paper feeder characterized by the following). However, merely providing the cleaning blade member or the cleaning roller member as proposed in these publications does not provide sufficient paper powder removal performance, especially for the separation roller. For example, three transporting behaviors of the separation roller that occur during normal paper transporting (that is, a forward rotation behavior that follows the rotation of the feed roller when only one sheet is picked up by the pickup roller, that is, follows the transporting of the sheet) When multiple sheets are picked up by the pick-up roller and the double-feeding is performed, the excessive rotation of the sheet is returned to the sheet stacking section, and the sheet is stopped at the nip between the feed roller and the separation roller. When the paper is transported for a long time, especially when the separation roller is almost stationary, a large amount of paper dust adheres to a part of the separation roller. The means described in the above document cannot be completely removed, and a jam occurs.
[0006]
On the other hand, in Japanese Patent Application Laid-Open No. Hei 4-3743, in order to improve the performance of cleaning the roller surface, a paper feeder for feeding out paper stored in a paper tray and a paper disposed downstream of the roller are provided. In a sheet feeding device configured with a separating mechanism, a cleaning member is disposed for a feeding unit of the sheet separating mechanism, and the cleaning member is configured to clean a surface of the feeding unit. A cleaning device for a paper feeder, comprising a superabsorbent member and configured to impart wettability to the cleaning member by the moisture in the air so that the cleaning performance can be improved. Proposed. Japanese Patent Application Laid-Open No. Hei 4-3745 describes a paper feeder comprising a roller unit for feeding out a sheet from the top of a sheet stored in a sheet tray, and a sheet separating mechanism disposed downstream of the roller unit. A paper feeder for an image forming apparatus, wherein a polishing member is disposed with respect to a feed unit of the sheet separating mechanism, and the surface of the feed unit is polished by the polishing member. It has been proposed to remove the paper dust and dust attached to the surface by polishing the surface of the rubber constituting the rubber at any time, and to remove the deteriorated portion of the surface to prevent a decrease in the coefficient of friction. . Japanese Patent Application Laid-Open No. Hei 9-77290 discloses that "the uppermost sheet accommodated in the sheet stacking means is provided so as to be capable of coming into contact with and separating from the uppermost sheet. First feeding means for feeding a sheet from an upper sheet, second feeding means for feeding a sheet fed from the first feeding means, and contact / separation of the first feeding means with respect to an uppermost sheet The sheet feeding device having a second feeding unit cleaning device configured to be able to contact and separate from the second feeding unit by moving in conjunction with the operation. It has been proposed to reduce abrasion and damage while maintaining the cleaning ability of the feed roller by reducing the frequency of contact of the cleaning device with the feed roller. Japanese Patent Application Laid-Open No. Hei 9-110201 discloses that “a paper feed roller for feeding paper is detachably provided in the axial direction with respect to a roller shaft, and a conductive resin film is brought into contact with the surface of the paper feed roller. And a conductive resin film that removes static electricity on the surface of the paper feed roller and removes foreign matter on the surface of the paper feed roller. The paper feeder is characterized by forming a plurality of cuts in the direction perpendicular to the axis of the paper roller, and the paper feed roller is replaced by the conductive resin film for static elimination and cleaning. It has been proposed to solve the inconvenience that the original frictional force of the paper feed roller cannot be maintained due to the poor contact state with the roller and the occurrence of poor static elimination and poor cleaning. . However, the paper dust removing means disclosed in these documents does not consider the removal of the paper dust of the separation roller, so that the jam prevention action is not sufficient.
[0007]
Further, if the paper dust removing means described in the above-mentioned document is used, the overall size of the sheet feeding device in the vertical direction or the horizontal direction is increased, which is not suitable for actual use.
[0008]
[Problems to be solved by the invention]
According to the present invention, the paper dust removing means for the feed roller and the pickup roller is compactly arranged to prevent the paper feeder from being enlarged, and to remove paper dust due to damage at the time of removing each roller during maintenance. It is an object to prevent a function from being lowered.
[0009]
[Means for Solving the Problems]
According to the present invention, there is provided a feed roller supported by a feed roller drive shaft and rotationally driven in a paper feed direction, and a feed roller which is in contact with the feed roller and is opposite to the paper feed direction via a torque limiter. A roller group including a separation roller that is driven to rotate, and a pickup roller that calls the transfer material from the transfer material loaded on the transfer material loading unit and feeds the transfer material to a contact portion between the feed roller and the separation roller. And a sheet feeding device having cleaning means for the roller group, provided with a swing arm configured to be swingable about the feed roller drive shaft as a center axis, wherein the swing arm is A hollow idler gear shaft that pivotally supports an idler gear that transmits a driving force of a feed roller drive shaft to the pickup roller; A shaft for a pickup roller rotatably supporting the pickup roller, wherein the cleaning unit is disposed in a space between the feed roller and the pickup roller, and the surface of one of these rollers is provided. Or a cleaning member that contacts both surfaces with a predetermined pressure, the cleaning member includes a holder, and an elastic member that is supported by the holder and contacts a predetermined roller surface. A sheet feeding device characterized in that one end of a holder is configured to be inserted into a hollow portion of the idler gear shaft, and the other end is configured to be engaged with the feed roller drive shaft. Is done.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view of main parts of a manual sheet feeder as one embodiment of the present invention. FIG. 2 is a schematic view of a main part when the manual sheet feeder shown in FIG. 1 is viewed in the direction of arrow A. FIG. 3 is a timing chart of one control example of the sheet feeding device shown in FIGS. FIG. 4 is a perspective view of the manual sheet feeder according to the present embodiment in a state where the transfer material detecting unit is in a normal operation position. FIG. 5 is a view similar to FIG. 4 in a state where the transfer material detecting unit has been moved to the maintenance position.
[0014]
As can be seen from FIG. 1, the transfer material, for example, the paper 1 stacked on the manual feed tray is picked up by the pickup roller 2 and separated one by one by the feed roller 3 and the separation roller 4 to the downstream, that is, the image. The sheet is conveyed into the forming apparatus (the mechanism for separating and conveying the sheet by the feed roller 3 and the separation roller 4 is a well-known conventional technique, and is omitted here).
[0015]
As shown in FIG. 2, the feed roller 3 is pivotally supported by a feed roller drive shaft 5, and can be rotated and stopped by a feed clutch (not shown). A gear 31 is disposed at an end of the feed roller 3, and a driving force is transmitted from the gear 31 to the gear 21 of the pickup roller 2 via the idler gear 6. The idler gear 6 and the pickup roller 2 are provided with a shaft portion 71 (a shaft portion for an idler gear) and a shaft portion 72 (a shaft for a pickup roller) of the pickup arm 7 serving as a swing arm configured to be swingable around the feed roller drive shaft 5. Section). The shaft portion 71 forms the shaft of the idler gear 6 and is hollow as can be seen from FIG. In the embodiment shown in FIGS. 1 and 2, a first cleaning member for the pickup roller 2 and the feed roller 3 that constitutes a cleaning unit for a roller group including the pickup roller 2, the feed roller 3, and the separation roller 4. Is formed of a holder 8 and a neutralizing brush 9 supported by the holder 8, and is disposed in a space between the pickup roller 2 and the feed roller 3 and abuts on their surfaces by the neutralizing brush 9. ing. At this time, one end 81 of the holder 8 is formed so as to be fittable into the hollow portion of the shaft 71. A central portion 82 of the holder 8 has a space for attaching the charge removing brush 9. The charge removing brush 9 is attached to the feed roller 3 side of the holder central portion 82 and is in contact with the feed roller 3, and the brush portion 91 is attached to the pickup roller 2 and is in contact with the pickup roller 2. It is formed from the brush portion 92 that is being made. The other end 83 of the holder 8 is configured to be able to snap-fit to the feed roller drive shaft 5 on the side opposite to the pickup arm 7 across the feed roller 3. In the present embodiment, space saving is achieved by arranging the main part of the first cleaning member in the space between the pickup roller 2 and the feed roller 3. Further, if the holder 8 is made of a conductive resin, the electric charges charged in the pickup roller 2 and the feed roller 3 can be released to the feed roller drive shaft 5 which is in contact with the ground at a position (not shown). Also, the effect of preventing the adhesion of paper powder due to static electricity can be exhibited. Since the static elimination brush 9 has a brush-like structure, it does not bend when removing and attaching the abutted rollers or when removing and attaching the first cleaning member itself. This is advantageous for preventing the cleaning performance from being reduced after such maintenance.
[0016]
As a second cleaning member for the separation roller 4, a neutralizing brush 11 directly attached to a grounded guide plate 10 at a position (not shown) is brought into contact with the separation roller 4. The charge removing brush 11 has the same effect as the charge removing brush 9.
[0017]
An example of an advantageous control method of the above-described paper feeding apparatus will be described with reference to a timing chart shown in FIG. In the control of the normal sheet feeding operation, the feed clutch is turned off at the time when the conveyed sheet is fed to a certain extent by the feed roller 3 in order to prevent the occurrence of a jam. In this state, the transfer material detecting means 12 detects the presence or absence of a sheet on the manual feed tray. For example, in the examples of FIGS. 4 and 5, the transfer material detection unit 12 includes a filler 121, a roller 122 at the filler tip, a shutter unit 123, and a photo interrupter 124. When the presence of paper is detected, the feed clutch is turned on again, and the next paper transport operation is performed. In the normal control, when the absence of the sheet is detected, the main motor (not shown) for driving the roller group is stopped while the feed clutch remains OFF. However, in the paper feeder according to the present invention, when the transfer material detecting means 12 detects that there is no paper, the feed clutch is turned on again for a predetermined time before the main motor stops, and the feed roller 3 and the separation roller 4 The roller group is driven to rotate in a state where there is no paper at the contact portion of the roller. Thereby, the attached matter such as paper powder attached to the separation roller 4 can be transferred to the feed roller 3, and the attached matter of the separation roller 4 is directly removed by the charge removing brush 11 in contact with the separation roller 4. At the same time, the brush portion 91 of the neutralizing brush 9 that is in contact with the feed roller 3 is also removed. Therefore, even if a large amount of paper dust is deposited on a part of the separation roller 4, it can be effectively removed.
[0018]
In the control example described above, an example is described in which the presence or absence of a sheet is detected after the feed clutch is temporarily turned off based on the control of the actual sheet feeding operation. However, the feed clutch does not necessarily have to be once turned off. Absent. What is important is that the roller group is controlled to rotate for a predetermined time in a state where there is no sheet at the contact portion between the feed roller 3 and the separation roller 4.
[0019]
FIG. 5 is a diagram showing a state when the holder 8 is replaced or cleaned. When removing the holder 8, the holder 8 is first rotated in the direction of arrow B with the transfer material detecting means 12 retracted to the maintenance position in advance, and is further pulled out in the direction of arrow C, that is, in the longitudinal direction.
[0020]
In the above-described embodiment, the discharging brush is brought into contact with all the rollers, but it is also effective to make the brush contact only with the separation roller 4. Also, since the static elimination brush is soft, there is no need to bend like a mylar even if each roller is extracted.
[0021]
【The invention's effect】
In the sheet feeding device according to the first aspect, the cleaning unit is disposed in a space between the feed roller and the pickup roller, and abuts on one or both surfaces of these rollers at a predetermined pressure. Since the sheet feeder has the member, it is possible to configure a sheet feeder that is substantially the same size as the sheet feeder without the paper dust removing unit and is resistant to paper dust.
[0023]
In the paper feeder according to the second and third aspects, since the cleaning member is a conductive member that is electrically grounded, the electric charge charged on the surface of the roller can be released. It is possible to prevent adhesion.
[0024]
In the sheet feeding device according to the fourth aspect , a portion of the cleaning member that contacts the roller surface is configured by a discharging brush. Since the brush has a soft tip, it does not bend when removing the roller and has excellent durability.Therefore, the cleaning member is not damaged by the attachment / detachment of the roller during maintenance and the attachment / detachment of the cleaning member. It is also possible to prevent the occurrence of poor static elimination and poor cleaning of the roller surface due to the occurrence.
[Brief description of the drawings]
FIG. 1 is a schematic view of a main part related to the present invention of a manual sheet feeder as one embodiment of the present invention.
FIG. 2 is a schematic arrow view of a main part related to the present invention when the manual sheet feeder shown in FIG. 1 is viewed in the direction of arrow A;
FIG. 3 is a timing chart of one control example of the sheet feeding device shown in FIGS. 1 and 2;
FIG. 4 is a perspective view of the sheet feeding device shown in FIG. 1 in a state where a transfer material detecting unit is in a normal operation position.
FIG. 5 is a perspective view of the sheet feeding device shown in FIG. 1 in a state where a transfer material detecting unit has been moved to a maintenance position.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Paper 2 Pickup roller 3 Feed roller 4 Separation roller 5 Feed roller drive shaft 6 Idler gear 7 Pickup arm 8 Holder 9 Static elimination brush 10 Guide plate 11 Static elimination brush 12 Transfer material detecting means 21 Gear part 31 Gear part 71 Shaft part 72 Shaft part 81 Holder end portion 82 Holder center portion 83 Holder end portion 91 Static electricity removal brush brush portion 92 Static electricity removal brush brush portion

Claims (4)

A feed roller supported by the feed roller drive shaft and driven to rotate in the sheet feeding direction, and a separation roller in contact with the feed roller and driven to rotate in the direction opposite to the sheet feeding direction via a torque limiter; A roller group including a pickup roller for calling the transfer material from the transfer material loaded on the transfer material loading unit and feeding the transfer material to a contact portion between the feed roller and the separation roller; and A sheet feeder having cleaning means for
A swing arm configured to swing around the feed roller drive shaft is provided, and the swing arm pivotally supports an idler gear that transmits a driving force of the feed roller drive shaft to the pickup roller. -Shaped idler gear shaft portion, and a pickup roller shaft portion rotatably supporting the pickup roller,
The cleaning unit has a cleaning member disposed in a space between the feed roller and the pickup roller and abutting at a predetermined pressure on one or both surfaces of these rollers,
The cleaning member has a holder, and an elastic member supported by the holder and in contact with a predetermined roller surface, so that one end of the holder can be inserted into a hollow portion of the shaft for the idler gear. A sheet feeding device, wherein the sheet feeding device is configured so that the other end can be engaged with the feed roller drive shaft. The sheet feeding device according to claim 1 , wherein the cleaning member is a conductive member that is electrically grounded. The holder of the cleaning member is made of a resin material having conductivity, the elastic member is a conductive elastic body, and the feed roller drive shaft is made of a conductive material and grounded. The paper feeding device according to claim 1 , wherein 4. The sheet feeding device according to claim 2 , wherein at least a portion of the cleaning member that comes into contact with the roller surface is configured by a static elimination brush. 5.

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