US20070108696A1 - Sheet feeder capable of reducing multi feed - Google Patents
Sheet feeder capable of reducing multi feed Download PDFInfo
- Publication number
- US20070108696A1 US20070108696A1 US11/600,233 US60023306A US2007108696A1 US 20070108696 A1 US20070108696 A1 US 20070108696A1 US 60023306 A US60023306 A US 60023306A US 2007108696 A1 US2007108696 A1 US 2007108696A1
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- US
- United States
- Prior art keywords
- sheet
- feed roller
- sheet feeder
- protruding guide
- guide member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H3/00—Separating articles from piles
- B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
- B65H3/52—Friction retainers acting on under or rear side of article being separated
- B65H3/5207—Non-driven retainers, e.g. movable retainers being moved by the motion of the article
- B65H3/5215—Non-driven retainers, e.g. movable retainers being moved by the motion of the article the retainers positioned under articles separated from the top of the pile
- B65H3/5223—Retainers of the pad-type, e.g. friction pads
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H3/00—Separating articles from piles
- B65H3/02—Separating articles from piles using friction forces between articles and separator
- B65H3/06—Rollers or like rotary separators
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H3/00—Separating articles from piles
- B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
- B65H3/54—Pressing or holding devices
Definitions
- Example embodiments generally relate to a sheet feeder that may include a feed roller, a sole plate, and/or a separation pad member, and for example to a sheet feeder capable of reducing a multi feed.
- a background image forming apparatus such as a printer, a copying machine, and/or a facsimile may use a sheet feeder for feeding sheet in a predetermined or desired direction one by one.
- a friction pad separation type sheet feeder is well known because of its low cost. Most conventional sheet feeders are capable of feeding a wide variation of sheets and are low cost.
- friction pad separation type sheet feeders There are at least two types of friction pad separation type sheet feeders in general.
- One has a feed roller and a friction pad to form a nip press region with a predetermined or given nip pressure and also has a sole plate to constantly push sheets against the feed roller.
- the other has a sole plate that moves between an evacuation position and a pressing feed roller position for the feeding of every sheet, and when operating is stopped, the sole plate is in the evacuation position.
- FIG. 1 illustrates a configuration of a background sheet feeder.
- FIG. 2 also illustrates a configuration of the background sheet feeder when a multi feed occurs in the sheet feeder in FIG. 1 .
- the background sheet feeder may include a feed roller 101 , a separation pad member 102 , a spindle 103 , a friction pad 104 , and a sole plate 105 .
- the feed roller 101 may feed a sheet P by rotating clockwise.
- the separation pad member 102 may move the spindle 103 as a fulcrum to form a nip press region N between the friction pad 104 and the feed roller 101 by pushing member that is not shown.
- the sole plate 105 pushes a stacked sheet P against the feed roller 101 by moving up and down by a driving member that is not shown.
- the sole plate 105 may be moved to a pressing position shown as a chain double-dashed line from an evacuation position shown as a solid line in FIG. 1 , so that a stacked sheet P is pressed against an undersurface of the feed roller 101 . Holding this position, rotating the feed roller 101 feeds a top sheet into the nip press region N between the friction pad 104 and the feed roller 101 . When only one sheet P is fed, the sheet P passes through the nip press region N downstream correctly. But, when a multi feed occurs, the friction pad 104 stops under sheet P, only a top sheet P is fed downstream with a rotation force of the feed roller 101 .
- the sole plate 105 moves between an evacuation position and a pressing feed roller position for the feeding at every sheet for feeding, and when operating is stopped, the sole plate 105 is located at the evacuation position.
- an operator may easily set the sheets P on the sole plate 105 .
- the separation pad member 102 may move down, because a first thick sheet P 1 has a stiffness or a weight to generate a down force.
- a tip part A of the separation pad member 102 is pushed down by the first thick sheet P 1 and the second thick sheet P 2 , so that the nip press region N may be open.
- a necessary nip pressure may not be generated at the nip press region N, so that a multi feed may occur, in which the second thick sheet P 2 is fed with the first thick sheet P 1 .
- Example embodiments are directed to a sheet feeder that may more effectively reduce multi feed.
- a sheet feeder may include a feed roller to feed a plurality of sheets, a sole plate to press stacked sheets against the feed roller moving between an evacuation position and a pressing feed roller position, a separation pad member provided downstream from the sole plate in a feeding sheet direction switching between in contact and out of contact with the feed roller to separate each of the plurality of sheets one by one, and a protruding guide member provided near the separation pad member in a feeding sheet path to guide each of the plurality of sheets by contacting an under side of each sheet and controlling a downward movement of each sheet.
- FIG. 1 illustrates a configuration of a background sheet feeder
- FIG. 2 also illustrates a configuration of the background sheet feeder when a multi feed occurs in the sheet feeder in FIG. 1 ;
- FIG. 3 illustrates a configuration of an electrophotographic apparatus according to example embodiments
- FIG. 4A is an example perspective diagram of a sheet feeder in a manual bypass tray of the electrophotographic apparatus of FIG. 3 ;
- FIG. 4B is an example perspective diagram of a guide plate of the sheet feeder of FIG. 4A ;
- FIG. 5 is an example perspective diagram of a part of the sheet feeder of FIG. 4A ;
- FIG. 6 is an example perspective diagram of a pressing plate of the sheet feeder of FIG. 4A ;
- FIG. 7 is an example perspective diagram of a back of the pressing plate of the sheet feeder of FIG. 4A ;
- FIG. 8 is an example cross-sectional diagram of a part of the sheet feeder of FIG. 4A ;
- FIG. 9 is an example cross-sectional diagram of a part of the sheet feeder of FIG. 4A ;
- FIG. 10 is an example cross-sectional diagram illustrating part of the sheet feeder of FIG. 4A ;
- FIG. 11 is another example cross-sectional diagram of part of the sheet feeder of FIG. 4A ;
- FIG. 12 is another example cross-sectional diagram of part of the sheet feeder of FIG. 4A ;
- FIG. 13 is another example cross-sectional diagram of part of the sheet feeder of FIG. 4A ;
- FIG. 14 is another example cross-sectional diagram of part of the sheet feeder of FIG. 4A ;
- FIG. 15 is another example cross-sectional diagram of part of the sheet feeder of FIG. 4A .
- FIG. 3 illustrates an electrophotographic apparatus according to example embodiments.
- a main body 1 may include an image forming section 2 in the center and a feed section 3 under the image forming section 2 .
- the feed section 3 may include sheet cassettes 4 a , 4 b , 4 c , and 4 d .
- the sheet cassettes 4 a , 4 b , 4 c , and 4 d may be provided like a drawer and may slide in the cross direction in FIG. 3 .
- a scanner 5 may be provided on the topside of the image forming section 2 , which scans an original image and converts the original image to an electric signal.
- a catch tray 7 may be provided on the left side (downstream) of the image forming section 2 , on which an ejected sheet P is stacked.
- a manual bypass tray 8 may be provided on the right side (upstream) of the image forming section 2 capable of opening and closing as a cover of the main body 1 , which feeds a sheet P by a manual bypass.
- An image forming unit 10 for each color such as for example, a yellow (Y), a magenta (M), a cyan (C), and a black (K) is provided above a middle transfer belt 9 that is an endless belt.
- a charging unit 12 , a developing unit 13 , a cleaner 14 , and/or an exposing unit 15 a that may be a part of a light beam device 15 may be provided around a photo conductor drum 11 for each color to form an electrophotographic process.
- the charging unit 12 may charge the surface of the photo conductor drum 11 .
- the exposing unit 15 a may expose the surface of the photo conductor drum 11 with laser light to form an electrostatic latent image on the surface of the photo conductor drum 11 .
- the developing unit 13 may develop the electrostatic latent image into a visible toner image. After transferring on the surface of the photo conductor drum 11 , waste toner may be removed by the cleaner 14 .
- a toner of each color on the photo conductor drum 11 may be transferred onto the middle transfer belt 9 to form a full color image.
- the full color image on the middle transfer belt 9 may be transferred onto the sheet P with a transferring device 16 .
- the sheet P may be conveyed from the sheet cassettes 4 a , 4 b , 4 c , and 4 d or the manual bypass tray 8 .
- the full color image on the sheet P may be fixed on the sheet P in a fixing unit 17 .
- a sheet ejecting roller 18 may eject the sheet P onto the catch tray 7 .
- a conveyance path 20 may connect each of the sheet cassettes 4 a , 4 b , 4 c , and 4 d , the manual bypass tray 8 , and a resist roller 19 , so that the sheet P is conveyed to the resist roller 19 through the conveyance path 20 .
- the resist roller may hold the sheet P, and send the sheet P so that the paper sheet P may have a predetermined or desired position against the toner image on the middle transfer belt 9 .
- a sheet feeder in example embodiments may be applied to both the sheet cassettes 4 a , 4 b , 4 c , and 4 d , and the manual bypass tray 8 .
- the manual bypass tray 8 Below is an example of the manual bypass tray 8 .
- FIG. 4A is an example perspective diagram of a sheet feeder in a manual bypass tray of the electrophotographic apparatus of FIG. 3 .
- FIG. 4B is an example perspective diagram of a guide plate of the sheet feeder of FIG. 4A .
- FIG. 5 is an example perspective diagram of a part of the sheet feeder of FIG. 4A .
- FIG. 6 is an example perspective diagram of a pressing plate of the sheet feeder of FIG. 4A .
- FIG. 7 is an example perspective diagram of a back of the pressing plate of the sheet feeder of FIG. 4A .
- a sheet feeder 30 may be a friction pad separation type sheet feeder for a manual bypass tray.
- the sheet feeder 30 may include a feed roller 31 , a sole plate 32 , a friction pad 33 a (shown in FIG. 5 ), and/or a separation pad member 33 .
- the feed roller 31 may feed a sheet P from a stacked sheets P on the manual bypass tray 8 .
- the sole plate 32 may be located near the feed roller 32 and may push the stacked sheets P against the feed roller 32 , and may move between an evacuation position and a pressing feed roller position.
- the friction pad 33 a may be located downstream from the sole plate 32 , may be separate the fed sheet P one by one using friction force.
- the friction pad 33 a may be provided on the separation pad member 33 that may be a plate like member.
- the friction pad 33 a may be made of a material with a relatively high friction coefficient, for example, a rubber, a rubber cork, a foaming urethane, a thermoplastic elastomer, etc.
- the separation pad member 33 may move a spindle 33 b as a fulcrum.
- the spindle 33 b may be located downstream of the separation pad member 33 .
- a plastic structure 34 may be provided as a lower part of the sheet feeder 30 .
- the plastic structure 34 may include a guide plate 34 a and a side guide plate 34 b formed, for example, by integral moulding.
- the guide plate 34 a and the side guide plate 34 b may guide the fed sheet P.
- the feed roller 31 and the separation pad member 33 may be positioned in the center of the sheet width direction that intersects perpendicularly with the feed direction of the sheet, and the feed roller 31 may be provided on a feed roller shaft 35 that has a longitudinal direction the same as the sheet width direction. Both ends of the feed roller shaft 35 may be provided on the side guide plate 34 b through a roller bearing 36 that may rotate freely.
- the feed roller 31 has a form that a part of a cylinder is cut by a plane parallel to a center line.
- the feed roller 31 may have a feed roller 31 a that forms a cylinder, and a cutout part 31 b .
- a guide roller 37 which may have a disk shape and may have a smaller diameter than the feed roller 31 a , may be provided on each end of the feed roller 31 .
- the guide roller 37 is omitted on one side in FIG. 5 .
- a cam 38 may be provided on each end of the feed roller shaft 35 .
- a missing tooth gear 39 for transmitting driving force to the feed roller shaft 35 may be provided on one end of the feed roller shaft 35 .
- the missing tooth gear 39 may have a form lacking a portion of a circle, and when the missing tooth gear 39 and an input gear (not shown) mesh with each other, the feed roller shaft 35 and the feed roller 31 may be rotated. When the input gear rotates to reach a cutout part of the missing tooth gear 39 , a driving force from the input gear to the missing tooth gear 39 is cut off, and rotation of the feed roller shaft 35 and the feed roller 31 may be stopped.
- a feed roller position control member 40 may be fixed to the other end side of the feed roller shaft 35 .
- a first projection 41 may be formed on the feed roller position control member 40 .
- a flapper 44 of a solenoid 43 catches the first projection 41 , rotation of the feed roller shaft 35 and the feed roller 31 may be controlled.
- a second projection 45 may be formed on the feed roller position control member 40 .
- a tension spring 46 may be provided on the second projection 45 , which pulls the feed roller shaft 35 and the feed roller 31 in a rotating direction of feeding a sheet P.
- Rotation of the feed roller shaft 35 and the feed roller 31 may be intermittently performed as follows.
- the solenoid 43 turns off and the flapper 44 is caught by the first projection 41 . Therefore, rotation of the feed roller shaft 35 and the feed roller 31 are stopped. After that, the solenoid 43 may turn on at a certain or desired timing, the catch between the flapper 44 and the first projection 41 is not present. Then, the feed roller shaft 35 and the feed roller 31 may rotate in the feed direction by pulling force of the tension spring 46 , and the rotation causes a mesh between the missing tooth gear 39 and the input gear.
- the missing tooth gear 39 rotates by almost 360 degrees until a non-mesh-position, and the feed roller 31 also rotates by almost 360 degrees.
- the solenoid 43 turns off and the flapper 44 is caught by the first projection 41 . Therefore, the rotation of the feed roller shaft 35 and the feed roller 31 are stopped.
- the guide plate 34 a may be opened at a feed roller 31 position, and the separation pad member 33 may be located at the opening position.
- the separation pad member 33 may move a spindle 33 b as a fulcrum.
- the friction pad 33 a may be attached by, for example, a double-stick tape on the separation pad member 33 , which faces the feed roller 31 .
- a compression spring 47 may be provided under the separation pad member 33 , and the friction pad 33 a may press the surface of the feed roller 31 by a pressing force of the compression spring 47 .
- the sole plate 32 may be formed with resin.
- An arc projection 32 a may be provided on each side of the sole plate 32 to face the cam 38 , which may be located outside of a sheet P stack area.
- a guide roller 48 may be provided at the arc projection 32 a , which contacts a surface of the cam 38 .
- the guide roller 48 may be formed with resin, for example, polyacetal.
- a U-type slot may be provided on the arc projection 32 a for attaching the guide roller 48 , an entrance of which may be slightly narrower than a guide roller shaft. Therefore, the guide roller 48 may not easily escape. When attaching the guide roller 48 , the slot may be extended by the elasticity of the resin.
- a concave area 32 b may be formed on the sole plate 32 center in the width direction, which may face the feed roller 31 .
- a friction pad 49 may be attached on the concave area 32 b.
- a guide pin 50 may be provided near a side plate 34 b on the plastic structure 34 .
- two pins 50 may serve as a guide.
- a guide hole 51 (shown in FIG. 6 ) may be is formed in each side of the sole plate 32 so that the guide pin 51 may pass through the guide hole 51 .
- the guide hole 51 is located outside of a sheet P stack area so that it may not prevent feeding sheet P.
- a conic compression spring 52 may be provided between the sole plate 32 and the plastic structure 34 , which presses the sole plate 32 against the feed roller 31 .
- the conic compression spring 52 may be formed around the guide pin 50 , and a pressing direction by the conic compression spring 52 may be the same as an axis of the guide hole 51 .
- the feed roller shaft 35 and the feed roller 31 may be driven to rotate intermittently by an on-and-off of the solenoid 43 and a transfer from the input gear to the missing tooth gear 39 .
- the cam 38 may also rotate at the time of this intermittent rotation. When the cam 38 rotates, it contacts the arc projection 32 a and the guide roller 48 , or it releases that contact. Then the sole plate 32 moves toward a separating direction from the feed roller 31 , which may be pressed with the conic compression spring 52 against the feed roller 31 .
- the cam 38 separates from the arc projection 32 a and the guide roller 48 , and the sole plate 32 is located in the pressing feed roller position pressing the stacked sheet P against the feed roller 31 a .
- the cam 38 contacts with the arc projection 32 a and the guide roller 48 , the sole plate 32 moves to the evacuation position and pressing the stacked sheet P against the feed roller 31 a is released.
- a pressing direction of the sole plate 52 by the conic compression spring 52 may be the same as an axis of the guide hole 51 , and the cam 38 may contact the arc projection 32 a and the guide roller 48 near the guide hole 51 . Therefore, a bending stress of the sole plate 32 may be reduced during its movement between the evacuation position and the pressing feed roller position. Even if the sole plate 32 is made of resin, a deformation which may cause a feed performance decrease may not occur, and durability of the sole plate 32 may increase.
- a charge of a static electricity by friction with the sheet P may be smaller, so that it may be unnecessary to connect to ground to reduce or eliminate static electricity.
- FIG. 8 is an example cross-sectional diagram of a part of the sheet feeder 30 of FIG. 4A .
- the sheet feeder 30 may be a friction pad separation type sheet feeder for a manual bypass tray.
- the sheet feeder 30 may include the manual bypass tray 8 , the feed roller 31 , the sole plate 32 , the friction pad 33 a , and/or the separation pad member 33 .
- the friction pad 33 a may be provided on the separation pad member 33 that may be a board-like or plate-like member.
- the compression spring 47 may be provided under the separation pad member 33 .
- the conic compression spring 52 may be provided between the sole plate 32 and the plastic structure 34 .
- the friction pad 33 a may be made of a material with a relatively high friction coefficient, for example, a rubber, a rubber cork, a foaming urethane, a thermoplastic elastomer, etc.
- the separation pad member 33 may move the spindle 33 b as a fulcrum.
- the spindle 33 b may be located downstream of the separation pad member 33 .
- a protruding guide portion 55 may protrude from the guide plate 34 a near both sides of the separation pad member 33 , which guides an under side of the sheet P.
- a tip part 55 a of the protruding guide portion 55 may be formed higher than a sheet approaching guide part 33 c of the separation pad member 33 when the feed roller 31 and the friction pad 33 a contacts.
- FIG. 9 is an example cross-sectional diagram of a part of the sheet feeder 30 of FIG. 4A .
- the sole plate 32 with stacked paper P may move from the evacuation position shown as a solid line to the pressing feed roller position shown as a chain double-dashed line. Then, the sheet P is pressed against an undersurface of the feed roller 31 . Holding this position and driving the feed roller 31 to rotate may cause feeding of top sheet P into the nip N between the feed roller 31 and the friction pad 33 a .
- the sheet P passes through the nip press region N downstream correctly by a rotation of the feed roller 31 . But, when a multi feed occurs, the friction pad 33 a stops an under sheet P, only a top sheet P is fed downstream with a rotation force of the feed roller 31 . Thus, a proper feed with a separation is performed.
- the sole plate 32 that moves between the evacuation position and the pressing feed roller position for feeding every sheet, and when operating is stopped, the sole plate 32 is located at the evacuation position.
- an operator may easily set the sheets P on the sole plate 32 .
- FIG. 10 is an example cross-sectional diagram illustrating a multi feed in a part of the sheet feeder 30 of FIG. 4A .
- the separation pad member 102 may move down, because a first thick sheet P 1 may have sufficient stiffness or weight to generate a down force.
- the down force caused by the thick sheet P 1 may be reduced because the tip part 55 a of the protruding guide portion 55 , which protrudes higher than the sheet approaching guide part 33 c , pushes the under side of the sheet P 2 up and reduces or eliminates a part of the down force.
- the sheet approaching guide part 33 c may not depressed by the sheet P and the nip press region N between the feed roller 31 and the separation pad member 33 may not open.
- a chance of a multi feed is reduced because a proper nip pressure is constantly applied.
- various types of sheets may be used easily without changing a characteristic value, for example, a nip pressure.
- the sole plate 32 falls to the evacuation position, the sole plate 32 sides of the sheets P 1 and P 2 hang down. Even if the sole plate 32 falls, the tip part 55 a of the protruding guide portion 55 supports the sheets P 1 and P 2 , so that the nip press region N between the feed roller 31 and the separation pad member 33 may not open. As a result, the proper nip pressure may be constantly applied, and a feed with a good separation is performed.
- the protruding guide portion 55 may act as a nip press holding member at the nip press region N by contacting the sheet P that is fed into the nip N.
- the protruding guide portion 55 may also act as a member that prevents the sheet P from hanging down from a feeding path. Therefore, a feed with a good separation is performed constantly.
- conveyance guide members may be provided, for example, a guide plate 56 and a conveyance roller 57 that guide the sheet P steeply as shown in FIG. 10 .
- conveyance guide members may be provided, for example, a guide plate 56 and a conveyance roller 57 that guide the sheet P steeply as shown in FIG. 10 .
- flexibility in the design of feeding or conveyance path may increase.
- a conveyance load rise due to the thick sheet at the separation pad member 33 may be reduced especially with many stacked thick sheets.
- the protruding guide portion 55 is provided upstream of the sheet approaching guide part 33 c . Further, as shown in FIG. 9 , a gap K between G (the tip part 55 a ) and F (an undersurface of the feed roller 31 ) is provided. Therefore, feeding block formed sheets P into the nip N may be reduced or prevented.
- the protruding guide portion 55 is formed of a lower friction material, for example, using resin coating, a rise of the conveyance load by frictional resistance with a sheet may be reduced, and a slip ratio rise at the time of feeding may also be reduced.
- the protruding guide portion 55 is formed of a wear-proof material, for example, a metal or a plastic containing glass fiber, a wear of the protruding guide portion 55 by contacting with the sheet may be reduced. Therefore, an effect of pressing the sheet may be maintained for a longer period, and an effect of reducing multi feed may also continue for a longer period.
- a wear-proof material for example, a metal or a plastic containing glass fiber
- An angle of gradient of the tip part 55 a of the protruding guide portion 55 may be almost the same as the sheet feeding angle to the nip press region N. This may reduce a rise of a feed load, and feeding sheet into the nip press region N may be performed smoothly.
- FIG. 11 is another example cross-sectional diagram of part of the sheet feeder 30 of FIG. 4A .
- a length of a projection of the protruding guide portion 55 may be adjustable according to a type of sheet.
- a rack 55 b may be provided on an under part of the protruding guide portion 55 so that the rack 55 b meshes with a pinion gear 58 .
- the pinion gear 58 may be rotated using a control lever 59 , so that the protruding guide portion 55 moves up and down via the rack 55 b.
- a height adjustable protruding guide portion 55 may reduce or eliminate the folding problem of the thin sheet.
- a wave of the sheet may occur or an OHP sheet may be scratched.
- the thin sheet may generate a smaller down force at the sheet approaching guide part 33 c of the separation pad member 33 .
- lowering the height of the projection of the protruding guide portion 55 may reduce an occurrence of wave and/or scratch.
- FIG. 12 is another example cross-sectional diagram of part of the sheet feeder 30 of FIG. 4A .
- a roller 60 for guiding sheet may be provided at the tip part 55 a of the protruding guide portion 55 .
- a thick sheet may generate a larger down force, so that a conveyance load may become larger at the protruding guide portion 55 .
- the roller 60 may reduce the conveyance load and hold a proper conveyance force, so that various types of sheets may be used. In general, it may be necessary to increase a feed pressure for holding a proper conveyance force. In example embodiments shown in FIG. 12 , it may be unnecessary to change a characteristic value, and various types of sheets may be used.
- FIG. 13 is another example cross-sectional diagram of part of the sheet feeder 30 of FIG. 4A .
- a relay conveyance roller 61 may be provided downstream from the feed roller 31 .
- the relay conveyance roller 61 may be located close to the friction pad 33 a of the separation pad member 33 , and may be arranged as one pair on both sides of the separation pad member 33 . Thus, it is possible to reduce or prevent non-sending at the time of feeding in a last sheet of OHP that tends to have a short conveyance distance due to a high slip tendency by using the relay conveyance roller 61 close to the nip press region N as much as possible.
- FIG. 14 is another example cross-sectional diagram of part of the sheet feeder 30 of FIG. 4A .
- a separation pad member 33 may be almost horizontally oriented.
- a bent or inclined part 33 d may be formed on a friction pad 33 a at the end of the separation pad member 33 , so that an inside corner M, which faces a sheet path, is formed at the bent or inclined part 33 d.
- the inside corner M may act to prevent multi feed because the inside corner M may resist a sheet passing.
- FIG. 15 is another example cross-sectional diagram part of the sheet feeder 30 of FIG. 4A .
- An inside corner M on a friction pad 33 a may be located at the nip press region N.
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Abstract
A sheet feeder reducing multi feed, which may include a feed roller to feed a plurality of sheets, a sole plate to press stacked sheets against the feed roller moving between an evacuation position and a pressing feed roller position, a separation pad member provided downstream from the sole plate in a feeding sheet direction switching between in contact and out of contact with the feed roller to separate the plurality of sheets one by one, and a protruding guide member provided near the separation pad member in a feeding sheet path to guide the sheets by contacting an under side of each sheet each to control the sheet's downward movement.
Description
- 1. Field
- Example embodiments generally relate to a sheet feeder that may include a feed roller, a sole plate, and/or a separation pad member, and for example to a sheet feeder capable of reducing a multi feed.
- 2. Discussion of the Background
- A background image forming apparatus such as a printer, a copying machine, and/or a facsimile may use a sheet feeder for feeding sheet in a predetermined or desired direction one by one. A friction pad separation type sheet feeder is well known because of its low cost. Most conventional sheet feeders are capable of feeding a wide variation of sheets and are low cost.
- There are at least two types of friction pad separation type sheet feeders in general. One has a feed roller and a friction pad to form a nip press region with a predetermined or given nip pressure and also has a sole plate to constantly push sheets against the feed roller. The other has a sole plate that moves between an evacuation position and a pressing feed roller position for the feeding of every sheet, and when operating is stopped, the sole plate is in the evacuation position.
-
FIG. 1 illustrates a configuration of a background sheet feeder.FIG. 2 also illustrates a configuration of the background sheet feeder when a multi feed occurs in the sheet feeder inFIG. 1 . As shown inFIG. 1 , the background sheet feeder may include afeed roller 101, aseparation pad member 102, aspindle 103, afriction pad 104, and asole plate 105. Thefeed roller 101 may feed a sheet P by rotating clockwise. Theseparation pad member 102 may move thespindle 103 as a fulcrum to form a nip press region N between thefriction pad 104 and thefeed roller 101 by pushing member that is not shown. Thesole plate 105 pushes a stacked sheet P against thefeed roller 101 by moving up and down by a driving member that is not shown. - At the time of feeding, the
sole plate 105 may be moved to a pressing position shown as a chain double-dashed line from an evacuation position shown as a solid line inFIG. 1 , so that a stacked sheet P is pressed against an undersurface of thefeed roller 101. Holding this position, rotating thefeed roller 101 feeds a top sheet into the nip press region N between thefriction pad 104 and thefeed roller 101. When only one sheet P is fed, the sheet P passes through the nip press region N downstream correctly. But, when a multi feed occurs, thefriction pad 104 stops under sheet P, only a top sheet P is fed downstream with a rotation force of thefeed roller 101. - The
sole plate 105 moves between an evacuation position and a pressing feed roller position for the feeding at every sheet for feeding, and when operating is stopped, thesole plate 105 is located at the evacuation position. When thesole plate 105 is located at the evacuation position, an operator may easily set the sheets P on thesole plate 105. - As shown in
FIG. 2 , when the sheet P, which may include a thick sheet on top of it, is multi fed, theseparation pad member 102 may move down, because a first thick sheet P1 has a stiffness or a weight to generate a down force. - If, a first thick sheet P1 and a second thick sheet P2 are multi fed, a tip part A of the
separation pad member 102 is pushed down by the first thick sheet P1 and the second thick sheet P2, so that the nip press region N may be open. - Therefore, a necessary nip pressure may not be generated at the nip press region N, so that a multi feed may occur, in which the second thick sheet P2 is fed with the first thick sheet P1.
- Example embodiments are directed to a sheet feeder that may more effectively reduce multi feed. In example embodiments, a sheet feeder may include a feed roller to feed a plurality of sheets, a sole plate to press stacked sheets against the feed roller moving between an evacuation position and a pressing feed roller position, a separation pad member provided downstream from the sole plate in a feeding sheet direction switching between in contact and out of contact with the feed roller to separate each of the plurality of sheets one by one, and a protruding guide member provided near the separation pad member in a feeding sheet path to guide each of the plurality of sheets by contacting an under side of each sheet and controlling a downward movement of each sheet.
- A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
-
FIG. 1 illustrates a configuration of a background sheet feeder; -
FIG. 2 also illustrates a configuration of the background sheet feeder when a multi feed occurs in the sheet feeder inFIG. 1 ; -
FIG. 3 illustrates a configuration of an electrophotographic apparatus according to example embodiments; -
FIG. 4A is an example perspective diagram of a sheet feeder in a manual bypass tray of the electrophotographic apparatus ofFIG. 3 ; -
FIG. 4B is an example perspective diagram of a guide plate of the sheet feeder ofFIG. 4A ; -
FIG. 5 is an example perspective diagram of a part of the sheet feeder ofFIG. 4A ; -
FIG. 6 is an example perspective diagram of a pressing plate of the sheet feeder ofFIG. 4A ; -
FIG. 7 is an example perspective diagram of a back of the pressing plate of the sheet feeder ofFIG. 4A ; -
FIG. 8 is an example cross-sectional diagram of a part of the sheet feeder ofFIG. 4A ; -
FIG. 9 is an example cross-sectional diagram of a part of the sheet feeder ofFIG. 4A ; -
FIG. 10 is an example cross-sectional diagram illustrating part of the sheet feeder ofFIG. 4A ; -
FIG. 11 is another example cross-sectional diagram of part of the sheet feeder ofFIG. 4A ; -
FIG. 12 is another example cross-sectional diagram of part of the sheet feeder ofFIG. 4A ; -
FIG. 13 is another example cross-sectional diagram of part of the sheet feeder ofFIG. 4A ; -
FIG. 14 is another example cross-sectional diagram of part of the sheet feeder ofFIG. 4A ; and -
FIG. 15 is another example cross-sectional diagram of part of the sheet feeder ofFIG. 4A . - In describing example embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner. Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, particularly to
FIG. 3 , an electrophotographic apparatus 1 according to example embodiments is explained. -
FIG. 3 illustrates an electrophotographic apparatus according to example embodiments. A main body 1 may include animage forming section 2 in the center and a feed section 3 under theimage forming section 2. The feed section 3 may includesheet cassettes sheet cassettes FIG. 3 . - A
scanner 5 may be provided on the topside of theimage forming section 2, which scans an original image and converts the original image to an electric signal. Acatch tray 7 may be provided on the left side (downstream) of theimage forming section 2, on which an ejected sheet P is stacked. Amanual bypass tray 8 may be provided on the right side (upstream) of theimage forming section 2 capable of opening and closing as a cover of the main body 1, which feeds a sheet P by a manual bypass. - An
image forming unit 10 for each color, such as for example, a yellow (Y), a magenta (M), a cyan (C), and a black (K) is provided above amiddle transfer belt 9 that is an endless belt. In theimage forming unit 10, a chargingunit 12, a developingunit 13, a cleaner 14, and/or an exposingunit 15 a that may be a part of alight beam device 15 may be provided around aphoto conductor drum 11 for each color to form an electrophotographic process. - The charging
unit 12 may charge the surface of thephoto conductor drum 11. The exposingunit 15 a may expose the surface of thephoto conductor drum 11 with laser light to form an electrostatic latent image on the surface of thephoto conductor drum 11. The developingunit 13 may develop the electrostatic latent image into a visible toner image. After transferring on the surface of thephoto conductor drum 11, waste toner may be removed by the cleaner 14. - A toner of each color on the
photo conductor drum 11 may be transferred onto themiddle transfer belt 9 to form a full color image. The full color image on themiddle transfer belt 9 may be transferred onto the sheet P with a transferringdevice 16. The sheet P may be conveyed from thesheet cassettes manual bypass tray 8. The full color image on the sheet P may be fixed on the sheet P in a fixingunit 17. Asheet ejecting roller 18 may eject the sheet P onto thecatch tray 7. - A
conveyance path 20 may connect each of thesheet cassettes manual bypass tray 8, and a resistroller 19, so that the sheet P is conveyed to the resistroller 19 through theconveyance path 20. The resist roller may hold the sheet P, and send the sheet P so that the paper sheet P may have a predetermined or desired position against the toner image on themiddle transfer belt 9. - A sheet feeder in example embodiments, may be applied to both the
sheet cassettes manual bypass tray 8. Below is an example of themanual bypass tray 8. -
FIG. 4A is an example perspective diagram of a sheet feeder in a manual bypass tray of the electrophotographic apparatus ofFIG. 3 .FIG. 4B is an example perspective diagram of a guide plate of the sheet feeder ofFIG. 4A .FIG. 5 is an example perspective diagram of a part of the sheet feeder ofFIG. 4A .FIG. 6 is an example perspective diagram of a pressing plate of the sheet feeder ofFIG. 4A .FIG. 7 is an example perspective diagram of a back of the pressing plate of the sheet feeder ofFIG. 4A . - A
sheet feeder 30 may be a friction pad separation type sheet feeder for a manual bypass tray. Thesheet feeder 30 may include afeed roller 31, asole plate 32, afriction pad 33 a (shown inFIG. 5 ), and/or aseparation pad member 33. Thefeed roller 31 may feed a sheet P from a stacked sheets P on themanual bypass tray 8. Thesole plate 32 may be located near thefeed roller 32 and may push the stacked sheets P against thefeed roller 32, and may move between an evacuation position and a pressing feed roller position. Thefriction pad 33 a may be located downstream from thesole plate 32, may be separate the fed sheet P one by one using friction force. Thefriction pad 33 a may be provided on theseparation pad member 33 that may be a plate like member. - The
friction pad 33 a may be made of a material with a relatively high friction coefficient, for example, a rubber, a rubber cork, a foaming urethane, a thermoplastic elastomer, etc. Theseparation pad member 33 may move aspindle 33 b as a fulcrum. Thespindle 33 b may be located downstream of theseparation pad member 33. - A
plastic structure 34 may be provided as a lower part of thesheet feeder 30. Theplastic structure 34 may include aguide plate 34 a and aside guide plate 34 b formed, for example, by integral moulding. Theguide plate 34 a and theside guide plate 34 b may guide the fed sheet P. - The
feed roller 31 and theseparation pad member 33 may be positioned in the center of the sheet width direction that intersects perpendicularly with the feed direction of the sheet, and thefeed roller 31 may be provided on afeed roller shaft 35 that has a longitudinal direction the same as the sheet width direction. Both ends of thefeed roller shaft 35 may be provided on theside guide plate 34 b through aroller bearing 36 that may rotate freely. - As shown in
FIG. 5 , thefeed roller 31 has a form that a part of a cylinder is cut by a plane parallel to a center line. Thefeed roller 31 may have afeed roller 31 a that forms a cylinder, and acutout part 31 b. Aguide roller 37, which may have a disk shape and may have a smaller diameter than thefeed roller 31 a, may be provided on each end of thefeed roller 31. Theguide roller 37 is omitted on one side inFIG. 5 . - A
cam 38 may be provided on each end of thefeed roller shaft 35. A missingtooth gear 39 for transmitting driving force to thefeed roller shaft 35 may be provided on one end of thefeed roller shaft 35. The missingtooth gear 39 may have a form lacking a portion of a circle, and when the missingtooth gear 39 and an input gear (not shown) mesh with each other, thefeed roller shaft 35 and thefeed roller 31 may be rotated. When the input gear rotates to reach a cutout part of the missingtooth gear 39, a driving force from the input gear to the missingtooth gear 39 is cut off, and rotation of thefeed roller shaft 35 and thefeed roller 31 may be stopped. - A feed roller
position control member 40 may be fixed to the other end side of thefeed roller shaft 35. Afirst projection 41 may be formed on the feed rollerposition control member 40. When aflapper 44 of asolenoid 43 catches thefirst projection 41, rotation of thefeed roller shaft 35 and thefeed roller 31 may be controlled. Further, asecond projection 45 may be formed on the feed rollerposition control member 40. Atension spring 46 may be provided on thesecond projection 45, which pulls thefeed roller shaft 35 and thefeed roller 31 in a rotating direction of feeding a sheet P. - Rotation of the
feed roller shaft 35 and thefeed roller 31 may be intermittently performed as follows. - When the missing
tooth gear 39 and the input gear do not mesh with each other, thesolenoid 43 turns off and theflapper 44 is caught by thefirst projection 41. Therefore, rotation of thefeed roller shaft 35 and thefeed roller 31 are stopped. After that, thesolenoid 43 may turn on at a certain or desired timing, the catch between theflapper 44 and thefirst projection 41 is not present. Then, thefeed roller shaft 35 and thefeed roller 31 may rotate in the feed direction by pulling force of thetension spring 46, and the rotation causes a mesh between the missingtooth gear 39 and the input gear. - After the mesh between the missing
tooth gear 39 and the input gear, the missingtooth gear 39 rotates by almost 360 degrees until a non-mesh-position, and thefeed roller 31 also rotates by almost 360 degrees. When the missingtooth gear 39 and the input gear do not mesh with each other, thesolenoid 43 turns off and theflapper 44 is caught by thefirst projection 41. Therefore, the rotation of thefeed roller shaft 35 and thefeed roller 31 are stopped. - The
guide plate 34 a may be opened at afeed roller 31 position, and theseparation pad member 33 may be located at the opening position. Theseparation pad member 33 may move aspindle 33 b as a fulcrum. Thefriction pad 33 a may be attached by, for example, a double-stick tape on theseparation pad member 33, which faces thefeed roller 31. Acompression spring 47 may be provided under theseparation pad member 33, and thefriction pad 33 a may press the surface of thefeed roller 31 by a pressing force of thecompression spring 47. - The
sole plate 32 may be formed with resin. Anarc projection 32 a may be provided on each side of thesole plate 32 to face thecam 38, which may be located outside of a sheet P stack area. Aguide roller 48 may be provided at thearc projection 32 a, which contacts a surface of thecam 38. Theguide roller 48 may be formed with resin, for example, polyacetal. A U-type slot may be provided on thearc projection 32 a for attaching theguide roller 48, an entrance of which may be slightly narrower than a guide roller shaft. Therefore, theguide roller 48 may not easily escape. When attaching theguide roller 48, the slot may be extended by the elasticity of the resin. - A
concave area 32 b may be formed on thesole plate 32 center in the width direction, which may face thefeed roller 31. Afriction pad 49 may be attached on theconcave area 32 b. - A
guide pin 50 may be provided near aside plate 34 b on theplastic structure 34. When thesole plate 32 moves between an evacuation position and a pressing feed roller position, twopins 50 may serve as a guide. A guide hole 51 (shown inFIG. 6 ) may be is formed in each side of thesole plate 32 so that theguide pin 51 may pass through theguide hole 51. Theguide hole 51 is located outside of a sheet P stack area so that it may not prevent feeding sheet P. - A
conic compression spring 52 may be provided between thesole plate 32 and theplastic structure 34, which presses thesole plate 32 against thefeed roller 31. Theconic compression spring 52 may be formed around theguide pin 50, and a pressing direction by theconic compression spring 52 may be the same as an axis of theguide hole 51. - The
feed roller shaft 35 and thefeed roller 31 may be driven to rotate intermittently by an on-and-off of thesolenoid 43 and a transfer from the input gear to the missingtooth gear 39. Thecam 38 may also rotate at the time of this intermittent rotation. When thecam 38 rotates, it contacts thearc projection 32 a and theguide roller 48, or it releases that contact. Then thesole plate 32 moves toward a separating direction from thefeed roller 31, which may be pressed with theconic compression spring 52 against thefeed roller 31. - When the
feed roller 31 a faces thesole plate 32, thecam 38 separates from thearc projection 32 a and theguide roller 48, and thesole plate 32 is located in the pressing feed roller position pressing the stacked sheet P against thefeed roller 31 a. When thecam 38 contacts with thearc projection 32 a and theguide roller 48, thesole plate 32 moves to the evacuation position and pressing the stacked sheet P against thefeed roller 31 a is released. - A pressing direction of the
sole plate 52 by theconic compression spring 52 may be the same as an axis of theguide hole 51, and thecam 38 may contact thearc projection 32 a and theguide roller 48 near theguide hole 51. Therefore, a bending stress of thesole plate 32 may be reduced during its movement between the evacuation position and the pressing feed roller position. Even if thesole plate 32 is made of resin, a deformation which may cause a feed performance decrease may not occur, and durability of thesole plate 32 may increase. - Further, if the
sole plate 32 is made of resin, a charge of a static electricity by friction with the sheet P may be smaller, so that it may be unnecessary to connect to ground to reduce or eliminate static electricity. -
FIG. 8 is an example cross-sectional diagram of a part of thesheet feeder 30 ofFIG. 4A . Thesheet feeder 30 may be a friction pad separation type sheet feeder for a manual bypass tray. Thesheet feeder 30 may include themanual bypass tray 8, thefeed roller 31, thesole plate 32, thefriction pad 33 a, and/or theseparation pad member 33. Thefriction pad 33 a may be provided on theseparation pad member 33 that may be a board-like or plate-like member. Thecompression spring 47 may be provided under theseparation pad member 33. Theconic compression spring 52 may be provided between thesole plate 32 and theplastic structure 34. - The
friction pad 33 a may be made of a material with a relatively high friction coefficient, for example, a rubber, a rubber cork, a foaming urethane, a thermoplastic elastomer, etc. Theseparation pad member 33 may move thespindle 33 b as a fulcrum. Thespindle 33 b may be located downstream of theseparation pad member 33. - As shown in
FIG. 4B , a protrudingguide portion 55 may protrude from theguide plate 34 a near both sides of theseparation pad member 33, which guides an under side of the sheet P. Atip part 55 a of the protrudingguide portion 55 may be formed higher than a sheet approachingguide part 33 c of theseparation pad member 33 when thefeed roller 31 and thefriction pad 33 a contacts. -
FIG. 9 is an example cross-sectional diagram of a part of thesheet feeder 30 ofFIG. 4A . At the time of feeding, thesole plate 32 with stacked paper P may move from the evacuation position shown as a solid line to the pressing feed roller position shown as a chain double-dashed line. Then, the sheet P is pressed against an undersurface of thefeed roller 31. Holding this position and driving thefeed roller 31 to rotate may cause feeding of top sheet P into the nip N between thefeed roller 31 and thefriction pad 33 a. When only one sheet P is fed, the sheet P passes through the nip press region N downstream correctly by a rotation of thefeed roller 31. But, when a multi feed occurs, thefriction pad 33 a stops an under sheet P, only a top sheet P is fed downstream with a rotation force of thefeed roller 31. Thus, a proper feed with a separation is performed. - The
sole plate 32 that moves between the evacuation position and the pressing feed roller position for feeding every sheet, and when operating is stopped, thesole plate 32 is located at the evacuation position. When thesole plate 32 is located at the evacuation position, an operator may easily set the sheets P on thesole plate 32. -
FIG. 10 is an example cross-sectional diagram illustrating a multi feed in a part of thesheet feeder 30 ofFIG. 4A . As shown inFIGS. 1 and 2 , when the sheet P, which includes a thick sheet on top, is multi fed, theseparation pad member 102 may move down, because a first thick sheet P1 may have sufficient stiffness or weight to generate a down force. As shown inFIG. 10 , the down force caused by the thick sheet P1 may be reduced because thetip part 55 a of the protrudingguide portion 55, which protrudes higher than the sheet approachingguide part 33 c, pushes the under side of the sheet P2 up and reduces or eliminates a part of the down force. - Therefore, the sheet approaching
guide part 33 c may not depressed by the sheet P and the nip press region N between thefeed roller 31 and theseparation pad member 33 may not open. As a result, a chance of a multi feed is reduced because a proper nip pressure is constantly applied. Because the down force from the thick sheet is reduced or eliminated, various types of sheets may be used easily without changing a characteristic value, for example, a nip pressure. - When the top sheet P1 is fed from the
sole plate 32, thesole plate 32 falls to the evacuation position, thesole plate 32 sides of the sheets P1 and P2 hang down. Even if thesole plate 32 falls, thetip part 55 a of the protrudingguide portion 55 supports the sheets P1 and P2, so that the nip press region N between thefeed roller 31 and theseparation pad member 33 may not open. As a result, the proper nip pressure may be constantly applied, and a feed with a good separation is performed. - The protruding
guide portion 55 may act as a nip press holding member at the nip press region N by contacting the sheet P that is fed into the nip N. The protrudingguide portion 55 may also act as a member that prevents the sheet P from hanging down from a feeding path. Therefore, a feed with a good separation is performed constantly. - Because a depression of the protruding
guide portion 55 is suppressed, conveyance guide members may be provided, for example, aguide plate 56 and aconveyance roller 57 that guide the sheet P steeply as shown inFIG. 10 . As a result flexibility in the design of feeding or conveyance path may increase. A conveyance load rise due to the thick sheet at theseparation pad member 33 may be reduced especially with many stacked thick sheets. - In example embodiments, the protruding
guide portion 55 is provided upstream of the sheet approachingguide part 33 c. Further, as shown inFIG. 9 , a gap K between G (thetip part 55 a) and F (an undersurface of the feed roller 31) is provided. Therefore, feeding block formed sheets P into the nip N may be reduced or prevented. - If the protruding
guide portion 55 is formed of a lower friction material, for example, using resin coating, a rise of the conveyance load by frictional resistance with a sheet may be reduced, and a slip ratio rise at the time of feeding may also be reduced. - If the protruding
guide portion 55 is formed of a wear-proof material, for example, a metal or a plastic containing glass fiber, a wear of the protrudingguide portion 55 by contacting with the sheet may be reduced. Therefore, an effect of pressing the sheet may be maintained for a longer period, and an effect of reducing multi feed may also continue for a longer period. - An angle of gradient of the
tip part 55 a of the protrudingguide portion 55 may be almost the same as the sheet feeding angle to the nip press region N. This may reduce a rise of a feed load, and feeding sheet into the nip press region N may be performed smoothly. -
FIG. 11 is another example cross-sectional diagram of part of thesheet feeder 30 ofFIG. 4A . A length of a projection of the protrudingguide portion 55 may be adjustable according to a type of sheet. - As shown in
FIG. 11 , arack 55 b may be provided on an under part of the protrudingguide portion 55 so that therack 55 b meshes with apinion gear 58. Thepinion gear 58 may be rotated using acontrol lever 59, so that the protrudingguide portion 55 moves up and down via therack 55 b. - When the protruding
guide portion 55 protrudes into a sheet conveyance path, an edge part of a thin sheet P may fold due to a large feeding angle to thefriction pad 33 a. But a height adjustable protrudingguide portion 55 may reduce or eliminate the folding problem of the thin sheet. - When a thin sheet is twisted, a wave of the sheet may occur or an OHP sheet may be scratched. Thus, the thin sheet may generate a smaller down force at the sheet approaching
guide part 33 c of theseparation pad member 33. In example embodiments, lowering the height of the projection of the protrudingguide portion 55 may reduce an occurrence of wave and/or scratch. -
FIG. 12 is another example cross-sectional diagram of part of thesheet feeder 30 ofFIG. 4A . Aroller 60 for guiding sheet may be provided at thetip part 55 a of the protrudingguide portion 55. - A thick sheet may generate a larger down force, so that a conveyance load may become larger at the protruding
guide portion 55. Theroller 60 may reduce the conveyance load and hold a proper conveyance force, so that various types of sheets may be used. In general, it may be necessary to increase a feed pressure for holding a proper conveyance force. In example embodiments shown inFIG. 12 , it may be unnecessary to change a characteristic value, and various types of sheets may be used. -
FIG. 13 is another example cross-sectional diagram of part of thesheet feeder 30 ofFIG. 4A . Arelay conveyance roller 61 may be provided downstream from thefeed roller 31. - The
relay conveyance roller 61 may be located close to thefriction pad 33 a of theseparation pad member 33, and may be arranged as one pair on both sides of theseparation pad member 33. Thus, it is possible to reduce or prevent non-sending at the time of feeding in a last sheet of OHP that tends to have a short conveyance distance due to a high slip tendency by using therelay conveyance roller 61 close to the nip press region N as much as possible. -
FIG. 14 is another example cross-sectional diagram of part of thesheet feeder 30 ofFIG. 4A . Aseparation pad member 33 may be almost horizontally oriented. A bent orinclined part 33 d may be formed on afriction pad 33 a at the end of theseparation pad member 33, so that an inside corner M, which faces a sheet path, is formed at the bent orinclined part 33 d. - When the
separation pad member 33 is almost horizontally oriented, a thick sheet may easily pass through the nip press region N. The inside corner M may act to prevent multi feed because the inside corner M may resist a sheet passing. -
FIG. 15 is another example cross-sectional diagram part of thesheet feeder 30 ofFIG. 4A . An inside corner M on afriction pad 33 a may be located at the nip press region N. - When the inside corner M is separated from the nip press region N, an edge of sheet P may swing away from the nip press region N, so that the multi feed prevents function of the inside where M may be reduced. When the inside corner M is located at the nip press region N, a movement of the edge of the sheet P is reduced, so that the multi feed preventing function the inside corner M is improved.
- Any construction of example embodiments may be suitably adopted according to an apparatus's construction.
- Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure of this patent specification may be practiced otherwise than as specifically described herein.
- This patent specification is based on Japanese patent applications, No. JPAP2005-331412 filed on Nov. 16, 2005 in the Japan Patent Office, the entire contents of which are incorporated by reference herein.
Claims (15)
1. A sheet feeder, comprising:
a feed roller to feed a plurality of sheets;
a sole plate to press stacked sheets against the feed roller, which is movable between an evacuation position and a pressing feed roller position;
a separation pad member provided downstream from the sole plate in a feeding sheet direction capable of switching between in contact and out of contact with the feed roller to separate each of the plurality sheets one by one in a nip press region with the feed roller; and
a protruding guide member provided near the separation pad member in a feeding sheet path to guide each of the plurality sheets by contacting an under side of each of the plurality of sheets and controlling a downward movement of each of the plurality of sheets.
2. The sheet feeder of claim 1 , wherein the protruding guide member is a nip press holding member in the nip press region.
3. The sheet feeder of claim 1 , wherein the protruding guide member prevents each of the plurality of sheets from deviating from the feeding sheet path.
4. The sheet feeder of claim 1 , wherein the protruding guide member is provided upstream from the nip press region in the feeding sheet path.
5. The sheet feeder of claim 1 , wherein the protruding guide member protrudes in the feeding sheet path through the nip press region.
6. The sheet feeder of claim 1 , wherein the protruding guide member protrudes higher than a sheet approaching edge part of the separation pad member in the feeding sheet path when the feed roller is in contact with the separation pad member.
7. The sheet feeder of claim 1 , wherein the protruding guide member is provided as a pair of protruding guide members on both sides of the separation pad member in the feeding sheet path.
8. The sheet feeder of claim 1 , wherein the protruding guide member is provided to form a gap between a tip of the protruding guide member and an undersurface of the feed roller.
9. The sheet feeder of claim 1 , wherein the protruding guide member is formed with a lower friction material.
10. The sheet feeder of claim 1 , wherein the protruding guide member is formed with an abrasion resistant material.
11. The sheet feeder of claim 1 , wherein a height of the protruding guide member is adjustable.
12. The sheet feeder of claim 1 , wherein the protruding guide member includes a roller to guide each of the plurality of sheets.
13. The sheet feeder of claim 1 , wherein an angle of gradient of a tip of the protruding guide member is almost the same as a sheet feeding angle into the nip press region.
14. The sheet feeder of claim 1 , wherein a downstream part of the separation pad member rotates under the feed roller and the separation pad member includes a friction pad on the nip press region side of the separation pad member.
15. The sheet feeder of claim 1 , further comprising:
a guide member to upwardly guide each of the plurality of sheets passing through the nip press region.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005331412A JP2007137559A (en) | 2005-11-16 | 2005-11-16 | Paper feeding device |
JP2005-331412 | 2005-11-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070108696A1 true US20070108696A1 (en) | 2007-05-17 |
Family
ID=38039959
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/600,233 Abandoned US20070108696A1 (en) | 2005-11-16 | 2006-11-16 | Sheet feeder capable of reducing multi feed |
Country Status (2)
Country | Link |
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US (1) | US20070108696A1 (en) |
JP (1) | JP2007137559A (en) |
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US20080099976A1 (en) * | 2004-08-24 | 2008-05-01 | Seiko Epson Corporation | Paper Feeding Method and Paper Feeder |
US20080122890A1 (en) * | 2006-11-27 | 2008-05-29 | Mamoru Yorimoto | Image forming method and apparatus capable for preventing cockling |
US20080315497A1 (en) * | 2007-06-20 | 2008-12-25 | Seiko Epson Corporation | Feeding apparatus and recording apparatus |
CN101920857A (en) * | 2009-06-11 | 2010-12-22 | 株式会社理光 | Sheet transport mechanism and image forming apparatus incorporating same |
US20110156340A1 (en) * | 2009-12-28 | 2011-06-30 | Brother Kogyo Kabushiki Kaisha | Sheet feed device |
US20120080836A1 (en) * | 2010-10-05 | 2012-04-05 | Ricoh Company, Limited | Sheet feeder and image forming apparatus including the same |
US20130303343A1 (en) * | 2012-05-11 | 2013-11-14 | Gary Tritton | Method and apparatus for land and aquatic exercise |
US20130328261A1 (en) * | 2012-06-06 | 2013-12-12 | Avision Inc. | Automatic feeding apparatus with sheet-input assisting mechanism |
CN103538942A (en) * | 2012-07-13 | 2014-01-29 | 虹光精密工业(苏州)有限公司 | Automatic paper feedback device with paper feeding auxiliary device |
US20140203495A1 (en) * | 2013-01-18 | 2014-07-24 | Pfu Limited | Medium supply device |
US20140292972A1 (en) * | 2013-03-29 | 2014-10-02 | Brother Kogyo Kabushiki Kaisha | Recording apparatus |
US9242815B2 (en) | 2013-01-18 | 2016-01-26 | Pfu Limited | Medium supply device |
US9915907B2 (en) * | 2016-07-29 | 2018-03-13 | Pfu Limited | Document conveying apparatus, control method, and computer-readable, non-transitory medium |
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JP4997170B2 (en) * | 2007-11-08 | 2012-08-08 | 株式会社リコー | Paper feeding device and image forming apparatus |
JP6247553B2 (en) * | 2014-01-31 | 2017-12-13 | 株式会社沖データ | Medium supply apparatus and image forming apparatus |
JP7413689B2 (en) * | 2019-09-13 | 2024-01-16 | 富士フイルムビジネスイノベーション株式会社 | Conveyance device and image forming device |
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US20140292972A1 (en) * | 2013-03-29 | 2014-10-02 | Brother Kogyo Kabushiki Kaisha | Recording apparatus |
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