JPH11157685A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a trouble such as the occurrence of a jam by rotatively driving at least one of a feed roller and a separation roller at the timing when no transfer paper exists between the feed roller having a cleaning means and the separation roller, and cleaning the surfaces of the rollers. SOLUTION: A cleaning member is constituted of a holder 8 and a discharge brush 9 supported by the holder 8, it is arranged in the space between a pickup roller 2 and a feed roller 3, and it is kept in contact with their surfaces by the de-electrifying brush 9. When a transfer paper detecting means 12 detects no paper, a feed clutch is turned on for the prescribed time before a main motor is stopped, and the rollers 3, 4 are rotatively driven with no paper kept at the contact section between the feed roller 3 and the separation roller 4. The deposit such as paper powder stuck to the separation roller 4 is transferred to the feed roller 3 and is removed by the discharge brush 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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]

2. Description of the Related Art In a paper feeder for an image forming apparatus such as a plain paper copier, generally, for example, Japanese Patent Application Laid-Open No.
As described in Japanese Patent Publication No. 47, a pickup roller is arranged on the sheet sending side to send out the sheet housed in the sheet stacking section, and supplied downstream of the pickup roller via a feed roller and a torque limiter. Means for separating a sheet called by a pickup roller by a separating mechanism and feeding the sheet one by one to a downstream stream by disposing a sheet separating mechanism constituted by a separation roller rotated and driven in a direction opposite to the sheet direction. Is used. However, when paper containing a large amount of paper dust is being handled, the performance of the rubber forming the surface of these rollers is degraded over time due to the adhesion of paper dust and the like, and a paper conveyance failure (jam) occurs.

[0003] The adhesion of paper dust to the surface of the rubber roller occurs when paper dust is physically pierced into the rubber surface, and when the rubber surface is charged by friction and sucks paper dust. is there.

The mechanism of the jam is described 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 surface of the roller has less irregularities and fine paper powder adheres to the surface, slippage occurs because the rubber surface of the separation roller and the paper are not gripped. 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 a 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 is generated, causing a jam. Further, the paper powder also adheres to the feed roller and the pickup roller. If the conveying force of these rollers is reduced by paper dust and becomes lower than the conveying load of the separation rollers, a jam occurs.

Therefore, in order to surely prevent adhering matter on the surface of the rubber roller such as paper dust generated by friction by a 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. HEI 9-163572 is disclosed. In Japanese Patent Application Laid-Open No. 3-128831, "a paper feed cassette removably mounted in a paper feed unit of an image forming apparatus main body, a take-out means for taking out the paper in the paper feed cassette, and A paper feed means comprising a transport roller and a separation roller for separating and feeding the image to the image forming apparatus main body one sheet at a time; and a paper feeding means provided in contact with at least one of the transport roller and the separation roller of the paper feed means. A sheet feeding device comprising a cleaning blade member for removing a kimono ";
No. 832, "a sheet cassette which is removably mounted in a sheet feeding section of an 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 feeding means comprising a transport roller for separating and feeding the image forming apparatus main body and a separation roller;
There has been proposed a sheet feeder comprising a cleaning roller member which rolls on at least one of the transport roller and the separation roller of the paper feeding means and removes adhered matter on these rollers. However, by merely providing the cleaning blade member or the cleaning roller member as proposed in these, it is not possible to obtain sufficient paper dust removing 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 transport of the sheet) In the case where a plurality of sheets are picked up by a pick-up roller and the double feed is performed, a reverse rotation behavior in which extra sheets are sent back to the sheet stacking section,
And when the paper is transported for a long period of time, especially when the separation roller is almost stationary, the paper may be partially formed on the separation roller in the nip portion between the feed roller and the separation roller. The powder adheres in a large amount, but the paper powder adhered in such a large amount cannot be completely removed by the means described in the above-mentioned document, and a jam occurs.

On the other hand, in Japanese Patent Application Laid-Open No. 4-3743, a feed roller means for feeding out a sheet stored in a sheet tray,
In a paper feeder comprising a sheet separating mechanism disposed downstream of the roller means, a cleaning member is arranged for the feeding means of the sheet separating mechanism, and the surface of the feeding means is cleaned by the cleaning member. And
A sheet feeder, wherein the cleaning member includes a highly water-absorbing member and is configured to impart wettability to the cleaning member by moisture in the air, so that cleaning performance can be improved. Cleaning device "has been proposed. Japanese Patent Application Laid-Open No. Hei 4-3745 discloses a paper feeder comprising a roller unit for feeding a sheet from the top of a sheet housed 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 dirt 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 the sheet fed from the upper sheet, second feeding means for feeding the sheet fed from the first feeding means, and contact and separation of the first feeding means with respect to the uppermost sheet The sheet feeding device having a second feeding device cleaning device configured to be able to contact and separate from the second feeding device by moving in conjunction with the operation, the feed roller (i.e., 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. In JP-A-9-110201,
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 electrically grounded. In a paper feeder for removing static electricity on the surface of the paper feed roller with a film and removing foreign matter on the surface of the paper feed roller, a direction perpendicular to the axis of the paper feed roller is on the pressing contact side of the conductive resin film. The paper feed device characterized by forming a plurality of cuts in the conductive resin film '', when the paper feed roller is replaced, the conductive resin film for static elimination and cleaning is deformed and the contact state with the paper feed roller is deteriorated. It has been proposed to solve the inconvenience that the original frictional force of the paper feed roller cannot be maintained due to poor static elimination or poor cleaning. However, the paper dust removing means disclosed in these documents does not consider the removal of the paper dust from the separation roller, so that the jam preventing action is not sufficient.

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]

DISCLOSURE OF THE INVENTION The present invention relates to an actual use which can prevent inconveniences such as the occurrence of jams by more effectively cleaning the surfaces of a pickup roller, a feed roller, and a separation roller. It is an object of the present invention to provide a paper feeder suitable for a computer. In this case, the first problem is to make it possible to sufficiently remove the paper dust particularly from the separation roller, and the paper dust removal means for the feed roller and the pickup roller is compactly arranged, so that the paper dust removal means is reduced. The second problem is to prevent the paper feeder from becoming larger due to the provision of the paper feeder, and to prevent the paper dust removal function from being reduced due to damage at the time of removal of each roller during maintenance. Make it an issue.

[0009]

According to the first object of the present invention, there is provided a feed roller which is supported by a feed roller drive shaft and is driven to rotate in a sheet feeding direction. A separation roller that is driven to rotate in a direction opposite to the paper feeding direction via a limiter, and a transfer material that is called from the transfer material loaded on the transfer material loading unit and is brought into contact with the contact roller between the feed roller and the separation roller. In a paper feeding device having a roller group including a pickup roller for feeding the transfer material and a cleaning unit for the roller group, the cleaning unit contacts at least a surface of a separation roller of the roller group. The cleaning member and the transfer material detecting means provided to detect the presence or absence of the transfer material loaded on the transfer material Control means for rotating at least one of the feed roller and the separation roller for a predetermined time at a timing when there is no transfer material in the contact portion between the feed roller and the separation roller after detecting the absence of the transfer material during operation. And a paper feeder characterized by having the following.

[0010] The second problem is that a feed roller supported by a feed roller drive shaft and driven to rotate in a paper feed direction is in contact with the feed roller and is opposed to the feed direction via a torque limiter. A separation roller that is driven to rotate in the direction, 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. In a paper feeder having a group of rollers and a cleaning unit for the group of rollers, the cleaning unit is disposed in a space between the feed roller and the pickup roller, and one of these rollers is provided. And a cleaning member that abuts at a predetermined pressure on one or both surfaces. That. At this time, a swing arm configured to swing around the feed roller drive shaft is provided, and the swing arm transmits the driving force of the feed roller drive shaft to the pickup roller. A hollow shaft for an idler gear that pivotally supports an idler gear, and a shaft for a pickup roller that rotatably supports the pickup roller, wherein the cleaning member is a holder, and the cleaning member is supported by the holder and has a predetermined shape. An elastic member that comes into contact with the roller surface, one end of the holder is configured to be inserted into the hollow portion of the idler gear shaft, and the other end of the holder is swung with the feed roller therebetween. Conveniently it is arranged to be able to engage said feed roller drive shaft on the side opposite the arm.

The cleaning member is an electrically grounded conductive member, the holder is made of a resin material having conductivity, and the elastic member is a conductive elastic body. This is advantageous in that the electric charge generated by friction on the surface of each roller is released to prevent paper dust from adhering to the roller surface due to static electricity.

[0012] The third problem is solved by that a portion of the cleaning member that comes into contact with the surface of the roller is formed of a static elimination brush. This is because, by using such a brush-like member, the contact portion of the cleaning member with the roller surface does not bend when the roller is extracted and attached.

[0013]

Embodiments of the present invention will be described below 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 shows the manual sheet feeder shown in FIG.
It is the schematic of the principal part when it sees in a direction. FIG.
4 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 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.

As can be seen from FIG. 1, the transfer material, for example, paper 1 stacked on the manual feed tray is picked up by a pick-up roller 2 and separated one by one by a feed roller 3 and a separation roller 4 to the downstream. That is, the sheet is conveyed into the image 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).

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 a pickup arm 7 serving as a swing arm configured to swing around the feed roller drive shaft 5. Section). The shaft portion 71 forms the shaft of the idler gear 6, and is hollow as shown in 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. Holder 8
There is a space for attaching the neutralization brush 9 in the central portion 82 of the first embodiment. 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 on the pickup roller 2 and the feed roller 3 are also reduced.
Since it can escape to the feed roller drive shaft 5 which is in contact with the ground at a position (not shown), 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 roller or when removing and attaching the first cleaning member itself. This is advantageous for preventing the cleaning performance from being reduced after such maintenance.

As a second cleaning member for the separation roller 4, a neutralization 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.

An example of an advantageous control method of the above-described sheet feeding device is as follows.
This will be described with reference to the 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 detecting unit 12 includes a filler 121, a roller 122 at a 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 normal control, when the absence of paper is detected, the feed clutch remains off and
A main motor (not shown) for driving the roller group is stopped. However, in the paper feeding device according to the present invention, when the transfer material detecting means 12 detects that there is no paper, the feed clutch is again turned on for a predetermined time before the main motor stops.
N, and the roller group is rotationally driven in a state where there is no sheet at the contact portion between the feed roller 3 and the separation roller 4. Thereby, the adhered matter such as paper powder adhered to the separation roller 4 can be transferred to the feed roller 3, and the adhered matter of the separation roller 4 is directly removed by the static elimination 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.

In the above-described control example, an example has been 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 paper feeding operation. However, the feed clutch is not necessarily turned off once. That is not to say. What is important is that the rollers are controlled so as to rotate for a predetermined time in a state where there is no paper at the contact portion between the feed roller 3 and the separation roller 4.

FIG. 5 is a view 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.

In the above embodiment, all the rollers are brought into contact with the neutralizing brush. However, it is also effective to have only the contact with the separation roller 4. In addition, since the static elimination brush is soft, there is no fear that it will bend like a mylar even if each roller is extracted.

[0021]

According to the paper feeder of the present invention, the cleaning means for cleaning the roller group of the paper feeder includes: a cleaning member contacting at least the surface of the separation roller of the roller group; After the transfer material detecting means provided to detect the presence or absence of the transfer material loaded on the loading means detects the absence of the transfer material during the paper feeding operation, the transfer material is contacted between the feed roller and the separation roller. Control means for rotating at least one of the feed roller and the separation roller at a predetermined timing for a predetermined period of time, so that the paper dust deposited on the separation roller can be directly removed and a part of the paper powder is transferred to the feed roller. It is possible to remove the paper dust from the separation roller more effectively, so that the occurrence of jam is sufficiently prevented. Ukoto can.

In the paper feeder according to the second and third aspects, the cleaning means is disposed in a space between the feed roller and the pickup roller and is provided on one or both surfaces of these rollers. Since the cleaning device has the cleaning member that comes into contact with the predetermined pressure, it is possible to configure a paper feeding device having substantially the same size as the paper feeding device without the paper dust removing unit and having a high resistance to paper dust.

In the paper feeder according to the fourth and fifth aspects, since the cleaning member is a conductive member that is electrically grounded, the electric charge charged on the roller surface can be released. It is possible to prevent adhesion of powder and the like.

In the paper feeder according to the present invention, a portion of the cleaning member that contacts the roller surface is formed of a neutralizing brush. Since the brush has a soft tip, it does not bend when removing the rollers and has excellent durability.Therefore, the cleaning member is not damaged by the attachment and detachment of the rollers during maintenance and the attachment and detachment of the cleaning member. It is also possible to prevent the occurrence of defective static elimination and poor cleaning of the roller surface due to this.

[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 End part of holder 82 Center part of holder 83 End part of holder 91 Brush part of static elimination brush 92 Brush part of static elimination brush

Claims (6)

[Claims] 1. A feed roller supported by a feed roller drive shaft and driven to rotate in a sheet feeding direction, and a feed roller which is in contact with the feed roller and is driven to rotate in a direction opposite to the sheet feeding direction via a torque limiter. A separation roller, and a pickup group that includes 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 a cleaning unit for the roller group, wherein the cleaning unit includes a cleaning member that contacts at least a surface of a separation roller in the roller group, and a transfer material stacked on the transfer material stacking unit. After the transfer material detecting means provided to detect the presence or absence of the transfer material Sheet feeding apparatus characterized by having a person the the contact portion at no transfer material timing feed roller and control means for rotating a predetermined time at least one of the separation roller between the separation roller and. 2. A feed roller supported by a feed roller drive shaft and driven to rotate in the sheet feeding direction, and abutting on the feed roller and driven to rotate in a direction opposite to the sheet feeding direction via a torque limiter. A separation roller, and a pickup group that includes 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 feeder having cleaning means for the roller group, wherein the cleaning means is disposed in a space between the feed roller and the pickup roller, and the surface of one or both of these rollers is provided. A sheet feeding device having a cleaning member that comes into contact with a surface at a predetermined pressure. 3. A swing arm configured to swing about the feed roller drive shaft as a center axis is provided, and the swing arm applies a driving force of the feed roller drive shaft to the pickup roller. A hollow idler gear shaft for pivotally supporting the idler gear to be transmitted; and a pickup roller shaft for rotatably supporting the pickup roller. The cleaning member is supported by the holder and the holder. And an elastic member that abuts on a predetermined roller surface. One end of the holder is configured to be inserted into a hollow portion of the idler gear shaft, and the other end is the feed roller drive shaft. The sheet feeding device according to claim 2, wherein the sheet feeding device is configured to be able to engage with the sheet feeding device. 4. The cleaning member according to claim 1, wherein said cleaning member is an electrically grounded conductive member.
The sheet feeding device according to any one of the above. 5. The feed roller driving shaft is made of a conductive material and grounded, wherein the holder is made of a resin material having conductivity, the elastic member is a conductive elastic body. The sheet feeding device according to claim 3, wherein 6. The sheet feeding device according to claim 4, wherein at least a portion of the cleaning member that contacts the roller surface is formed of a charge removing brush.