US20050133982A1 - Paper conveyance apparatus for an image forming apparatus and a method thereof - Google Patents
Paper conveyance apparatus for an image forming apparatus and a method thereof Download PDFInfo
- Publication number
- US20050133982A1 US20050133982A1 US10/893,974 US89397404A US2005133982A1 US 20050133982 A1 US20050133982 A1 US 20050133982A1 US 89397404 A US89397404 A US 89397404A US 2005133982 A1 US2005133982 A1 US 2005133982A1
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- United States
- Prior art keywords
- roller
- idle gear
- reversible
- reversible roller
- gear
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 15
- 230000002441 reversible effect Effects 0.000 claims abstract description 88
- 238000005299 abrasion Methods 0.000 claims abstract description 14
- 238000010586 diagram Methods 0.000 description 9
- 230000008901 benefit Effects 0.000 description 3
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- 229920000459 Nitrile rubber Polymers 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 229920002943 EPDM rubber Polymers 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J13/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, specially adapted for supporting or handling copy material in short lengths, e.g. sheets
- B41J13/02—Rollers
- B41J13/025—Special roller holding or lifting means, e.g. for temporarily raising one roller of a pair of nipping rollers for inserting printing material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H5/00—Feeding articles separated from piles; Feeding articles to machines
- B65H5/06—Feeding articles separated from piles; Feeding articles to machines by rollers or balls, e.g. between rollers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J11/00—Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form
- B41J11/02—Platens
- B41J11/14—Platen-shift mechanisms; Driving gear therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
- B41J29/38—Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2404/00—Parts for transporting or guiding the handled material
- B65H2404/10—Rollers
- B65H2404/14—Roller pairs
- B65H2404/143—Roller pairs driving roller and idler roller arrangement
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2404/00—Parts for transporting or guiding the handled material
- B65H2404/10—Rollers
- B65H2404/14—Roller pairs
- B65H2404/144—Roller pairs with relative movement of the rollers to / from each other
- B65H2404/1441—Roller pairs with relative movement of the rollers to / from each other involving controlled actuator
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H2601/00—Problem to be solved or advantage achieved
- B65H2601/10—Ensuring correct operation
- B65H2601/12—Compensating; Taking-up
- B65H2601/121—Wear
Definitions
- the present invention relates to an image forming apparatus. More particularly, the present invention relates to a paper feeder and method for an image forming apparatus, for reducing the malfunction caused by abrasion of a reversible roller that rotates forwards and backwards in contact with a conveyance roller so that paper sheets are picked up one by one.
- FIG. 1 is a diagram illustrating a conventional electrophotographic image forming apparatus 1 which feeds a paper P using a knock-up plate type of a feeding device 2 .
- a paper P is picked up by a pickup roller.
- a conveyance apparatus 10 having a plurality of rollers is provided to prevent the simultaneous feeding of two or more paper sheets.
- the conveyance apparatus 10 consists of a conveyance roller 11 and a reversible roller 12 .
- a torque limiter 13 is mounted on the same axis of the reversible roller 12 .
- a reversible motor (not shown) for reversely rotating the reversible roller 12 is provided independently from a driving device for rotating the conveyance roller 11 .
- the reversible roller 12 rotates in an opposite direction to the conveyance roller 11 .
- the reversible roller 12 separates the top paper sheet from the underlying paper sheets using a difference in the coefficient of friction between the reversible roller 12 and the conveyance roller 11 .
- the friction force between the conveyance roller 11 and the reversible roller 12 becomes greater than a predetermined torque of the coaxial torque limiter 13 , thereby making the reversible roller 12 rotate in the same direction of the rotation of the conveyance roller 11 .
- a reversible gear 14 is also mounted on the same axis of the reversible roller 12 to receive a driving force from the reversible motor.
- the reversible gear 14 rotates in a direction opposite to the direction of rotation of the torque limiter 13 , and operates independently from the rotation of the conveyance roller 11 .
- the conveyance roller 11 and the reversible roller 12 comprise a rubber having a predetermined solidity, friction coefficient and durability, such as a Natural Rubber (NR), an Acrylonitrile Butadiene Rubber (NBR), an Ethylene-Proplyene-Diene (EPDM), a urethane or a silicon.
- NR Natural Rubber
- NBR Acrylonitrile Butadiene Rubber
- EPDM Ethylene-Proplyene-Diene
- the reversible roller 12 rotates in the opposite direction to a paper feeding direction, the surface of the reversible roller 12 contacting the conveyance roller 11 is apt to be easily abraded. As the surface of the reversible roller 12 becomes abraded, a conveyance roller shaft S 1 and a reversible roller shaft S 2 are not maintained in parallel with each other but form an incline, as shown in FIG. 2 . This problem results from the fixed position of the reversible gear 14 . When the conveyance roller shaft S 1 and the reversible roller shaft S 2 are not in parallel with each other, the conveyance roller 11 and the reversible roller 12 do not contact sufficiently to separate two or more paper sheets fed together and smoothly feed the paper sheets sequentially. Accordingly, the abrasion of the reversible roller 12 may cause errors in the operation of the image forming apparatus.
- an aspect of the present invention is to solve at least the above problems and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a paper feeder and method for an image forming apparatus, having an improved structure to reduce the malfunction caused by abrasion of a reversible roller that rotates forwards and backwards in contact with a conveyance roller so that paper sheets are picked up sequentially.
- a paper feeder and method for an image forming apparatus comprise a conveyance roller, a reversible roller, a driving motor and an idle gear.
- the conveyance roller and the reversible roller being in contact with each other, rotate in the same direction as or the opposite direction to a direction of paper feed to convey paper sheets to an image forming section, separating paper sheets which are fed together.
- the reversible roller is transmitted with a driving force by the driving motor which is separate from the conveyance roller.
- a gear train including an idle gear is used. The center of rotation of the idle gear is movable so that a contacting force between the conveyance roller and the reversible roller can be kept over a predetermined level even when the reversible roller is abraded.
- the idle gear is preferable movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.
- the central shaft of the idle gear may move along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.
- the swing slot has an inner periphery with a curvature corresponding to the curved swing track of the idle gear.
- the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.
- the swing slot may include an elastic member for elastically supporting the central shaft of the idle gear.
- FIG. 1 is a diagram illustrating a conventional image forming apparatus
- FIG. 2 is a diagram illustrating a state in which a conveyance roller and a reversible roller of the conventional image forming apparatus are inclined due to abrasion of the reversible roller;
- FIG. 3 is a diagram illustrating a state in which rotation shafts of a conveyance roller and a reversible roller according to an embodiment of the present invention move in response to the abrasion of a reversible roller;
- FIG. 4 is a diagram illustrating a sectional view of an arrangement of gears, motors and shafts according to an embodiment of the present invention
- FIG. 5 is a diagram illustrating a gear train of a reversible roller according to a first embodiment of the present invention.
- FIG. 6 is a diagram illustrating a gear train of a reversible roller according to a second embodiment of the present invention.
- FIG. 3 is a diagram illustrating a paper feeder according to an embodiment of the present invention.
- the conveyance apparatus 100 includes a conveyance roller 110 , and a reversible roller 120 pressed against the conveyance roller 110 at a predetermined pressure.
- a conveyance gear 112 and a reversible gear 122 are provided to receive a driving force from respective driving sources (not shown).
- a load regulator having a torque limiter T coaxial to the reversible roller 120 is mounted on a reversible roller shaft 121 .
- the torque limiter T detects whether the friction force between the conveyance roller 110 and the reversible roller 120 is reduced by a paper sheet fed between the two rollers 110 and 120 to a level below a predetermined friction coefficient.
- the reversible roller 120 rotates in the same direction as the conveyance roller 110 to convey the paper.
- the reversible roller 120 rotates in an opposite direction to the conveyance roller 110 according to a detection signal from the torque limiter T in order to separate the fed paper sheets so that only the top paper sheet is conveyed to an image forming section.
- a paper picked up by a pickup roller is fed between the conveyance roller 110 and the reversible roller 120 , and conveyed to the image forming section. If the friction between the conveyance roller 110 and the reversible roller 120 is greater than a predetermined coefficient of friction, the reversible roller 120 rotates in the same direction of the rotation of the conveyance roller 110 . In contrast, if the friction is smaller than the predetermined coefficient of friction, the reversible roller 120 rotates in the opposite direction. The longer the reversible roller 120 is used, the more it becomes abraded due to friction with the conveyance roller 110 .
- the reversible roller shaft 121 moves parallel by a distance ‘d’ toward the conveyance roller shaft 110 as shown in FIGS. 3 and 4 . Therefore, in order to continuously transmit a driving force to the reversible roller 120 from a driving motor 130 ( FIG. 4 ), an idle gear 140 is required, which flexibly moves to be kept in mesh with the reversible gear 122 even when the position of the reversible roller shaft 121 is changed. As shown in FIG. 4 , the central shaft Ci of the idle gear 140 is designed to be movable.
- the central shaft Ci of the idle gear 140 moves along a swing track A as shown in FIG. 4 to maintain the idle gear 140 and the reversible gear 122 in mesh.
- the central shaft Ci of the idle gear 140 is slidably mounted on one sidewall W ( FIGS. 5 and 6 ) of the image forming apparatus.
- the central shaft Ci also moves along the swing track A to maintain the idle gear 140 and the reversible gear 120 in mesh.
- the swing track A may be a part of the circumference of a virtual circle having a radius corresponding to the distance between the central shaft Cm of the driving gear 131 and the central shaft Ci of the idle gear 140 .
- FIGS. 5 and 6 are diagrams illustrating the idle gear 140 with the central shaft Ci movable along the swing track A according to first and second embodiments of the present invention.
- the central shaft Ci of the idle gear 140 is slidably mounted on one sidewall W of the image forming apparatus.
- the sidewall W has a curved swing slot 141 having a curvature corresponding to the swing track A and a width corresponding to the diameter of the central shaft Ci. Accordingly, when the position of the reversible roller shaft 121 is changed due to the abrasion of the reversible roller 120 , the central shaft Ci slides along the swing slot 141 to maintain the idle gear 140 and the reversible gear 122 in mesh.
- the curved swing slot 141 has a width corresponding to the diameter of the central shaft Ci of the idle gear 140 . Also, the swing slot 141 has a curvature corresponding to the curved swing track A.
- the central shaft Ci of the idle gear 140 is slidably mounted on one sidewall W of the image forming apparatus.
- the sidewall W has a straight swing slot 142 formed in a direction of a tangent to the swing track A, and having a width corresponding to the diameter of the central shaft Ci.
- An elastic member 143 such as a compression spring is mounted within the swing slot 142 . The elastic member 143 exerts an elastic restoring force so that the idle gear 140 can be maintained in mesh with the reversible gear 122 .
- the reversible roller shaft 121 moves parallel toward the conveyance roller 110 by a distance corresponding the abraded thickness of the reversible roller 120 , thereby preventing a biased abrasion of the reversible roller 120 and any error of feeding plural paper sheets at once.
- the idle gear 140 for transmitting the driving force to the reversible roller 120 is swung to move upward as much as the shortened distance so that the reversible roller 120 can be constantly in contact with the conveyance roller 110 . Accordingly, by eliminating any causes of biased abrasion of the reversible roller 120 , reliability of the image forming apparatus is ensured.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sheets, Magazines, And Separation Thereof (AREA)
Abstract
A paper conveyance apparatus and method for an image forming apparatus are disclosed. The paper conveyance apparatus and method provide an improved structure in which when the distance between the conveyance roller shaft and the reversible roller shaft is shortened due to the abrasion of the reversible roller, the center of a gear train which transmits a driving force to the reversible roller is swung to move as much as the shortened distance so that the reversible roller can be continuously in contact with the conveyance roller. The paper conveyance apparatus and method comprise a conveyance roller for conveying a paper sheet to an image forming section, a reversible roller for contacting the conveyance roller, a driving motor having a driving gear for supplying a driving force to the reversible roller, and an idle gear for transmitting a driving force from the driving motor to the reversible roller. The center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.
Description
- This application claims the benefit under 35 U.S.C. § 119(a) of Korean Application No. 2003-93183, filed Dec. 18, 2003, in the Korean Intellectual Property Office, the entire contents of which is incorporated herein by reference.
- 1. Field of the Invention
- The present invention relates to an image forming apparatus. More particularly, the present invention relates to a paper feeder and method for an image forming apparatus, for reducing the malfunction caused by abrasion of a reversible roller that rotates forwards and backwards in contact with a conveyance roller so that paper sheets are picked up one by one.
- 2. Description of the Related Art
-
FIG. 1 is a diagram illustrating a conventional electrophotographicimage forming apparatus 1 which feeds a paper P using a knock-up plate type of afeeding device 2. As shown inFIG. 1 , a paper P is picked up by a pickup roller. Aconveyance apparatus 10 having a plurality of rollers is provided to prevent the simultaneous feeding of two or more paper sheets. - As shown in
FIG. 2 , theconveyance apparatus 10 consists of aconveyance roller 11 and areversible roller 12. Atorque limiter 13 is mounted on the same axis of thereversible roller 12. Also, a reversible motor (not shown) for reversely rotating thereversible roller 12 is provided independently from a driving device for rotating theconveyance roller 11. - The
reversible roller 12 rotates in an opposite direction to theconveyance roller 11. When two or more paper sheets are fed at once, thereversible roller 12 separates the top paper sheet from the underlying paper sheets using a difference in the coefficient of friction between thereversible roller 12 and theconveyance roller 11. When a single paper sheet is fed, the friction force between theconveyance roller 11 and thereversible roller 12 becomes greater than a predetermined torque of thecoaxial torque limiter 13, thereby making thereversible roller 12 rotate in the same direction of the rotation of theconveyance roller 11. Areversible gear 14 is also mounted on the same axis of thereversible roller 12 to receive a driving force from the reversible motor. Thereversible gear 14 rotates in a direction opposite to the direction of rotation of thetorque limiter 13, and operates independently from the rotation of theconveyance roller 11. - The
conveyance roller 11 and thereversible roller 12 comprise a rubber having a predetermined solidity, friction coefficient and durability, such as a Natural Rubber (NR), an Acrylonitrile Butadiene Rubber (NBR), an Ethylene-Proplyene-Diene (EPDM), a urethane or a silicon. - Since the
reversible roller 12 rotates in the opposite direction to a paper feeding direction, the surface of thereversible roller 12 contacting theconveyance roller 11 is apt to be easily abraded. As the surface of thereversible roller 12 becomes abraded, a conveyance roller shaft S1 and a reversible roller shaft S2 are not maintained in parallel with each other but form an incline, as shown inFIG. 2 . This problem results from the fixed position of thereversible gear 14. When the conveyance roller shaft S1 and the reversible roller shaft S2 are not in parallel with each other, theconveyance roller 11 and thereversible roller 12 do not contact sufficiently to separate two or more paper sheets fed together and smoothly feed the paper sheets sequentially. Accordingly, the abrasion of thereversible roller 12 may cause errors in the operation of the image forming apparatus. - An aspect of the present invention is to solve at least the above problems and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a paper feeder and method for an image forming apparatus, having an improved structure to reduce the malfunction caused by abrasion of a reversible roller that rotates forwards and backwards in contact with a conveyance roller so that paper sheets are picked up sequentially.
- In order to achieve the above-described aspects of the present invention, there is provided a paper feeder and method for an image forming apparatus. The paper feeder and method comprise a conveyance roller, a reversible roller, a driving motor and an idle gear. The conveyance roller and the reversible roller, being in contact with each other, rotate in the same direction as or the opposite direction to a direction of paper feed to convey paper sheets to an image forming section, separating paper sheets which are fed together. The reversible roller is transmitted with a driving force by the driving motor which is separate from the conveyance roller. In order to transmit the driving force, a gear train including an idle gear is used. The center of rotation of the idle gear is movable so that a contacting force between the conveyance roller and the reversible roller can be kept over a predetermined level even when the reversible roller is abraded.
- The idle gear is preferable movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.
- The central shaft of the idle gear may move along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.
- According to a first embodiment of the present invention, the swing slot has an inner periphery with a curvature corresponding to the curved swing track of the idle gear.
- According to a second embodiment of the present invention, the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear. The swing slot may include an elastic member for elastically supporting the central shaft of the idle gear.
- The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which:
-
FIG. 1 is a diagram illustrating a conventional image forming apparatus; -
FIG. 2 is a diagram illustrating a state in which a conveyance roller and a reversible roller of the conventional image forming apparatus are inclined due to abrasion of the reversible roller; -
FIG. 3 is a diagram illustrating a state in which rotation shafts of a conveyance roller and a reversible roller according to an embodiment of the present invention move in response to the abrasion of a reversible roller; -
FIG. 4 is a diagram illustrating a sectional view of an arrangement of gears, motors and shafts according to an embodiment of the present invention; -
FIG. 5 is a diagram illustrating a gear train of a reversible roller according to a first embodiment of the present invention; and -
FIG. 6 is a diagram illustrating a gear train of a reversible roller according to a second embodiment of the present invention. - Throughout the drawings, it should be noted that the same or similar elements are denoted by like reference numerals.
- Hereinafter, a few embodiments of a paper conveyance apparatus and method for an image forming apparatus according to embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
-
FIG. 3 is a diagram illustrating a paper feeder according to an embodiment of the present invention. - As shown in
FIG. 3 , theconveyance apparatus 100 includes aconveyance roller 110, and areversible roller 120 pressed against theconveyance roller 110 at a predetermined pressure. In order to rotate theconveyance roller 110 and thereversible roller 120, aconveyance gear 112 and areversible gear 122 are provided to receive a driving force from respective driving sources (not shown). - A load regulator having a torque limiter T coaxial to the
reversible roller 120 is mounted on areversible roller shaft 121. The torque limiter T detects whether the friction force between theconveyance roller 110 and thereversible roller 120 is reduced by a paper sheet fed between the tworollers reversible roller 120 rotates in the same direction as theconveyance roller 110 to convey the paper. When two or more paper sheets are fed at once, thereversible roller 120 rotates in an opposite direction to theconveyance roller 110 according to a detection signal from the torque limiter T in order to separate the fed paper sheets so that only the top paper sheet is conveyed to an image forming section. - More specifically, a paper picked up by a pickup roller is fed between the
conveyance roller 110 and thereversible roller 120, and conveyed to the image forming section. If the friction between theconveyance roller 110 and thereversible roller 120 is greater than a predetermined coefficient of friction, thereversible roller 120 rotates in the same direction of the rotation of theconveyance roller 110. In contrast, if the friction is smaller than the predetermined coefficient of friction, thereversible roller 120 rotates in the opposite direction. The longer thereversible roller 120 is used, the more it becomes abraded due to friction with theconveyance roller 110. With the increase of the abrasion of thereversible roller 120, thereversible roller shaft 121 moves parallel by a distance ‘d’ toward theconveyance roller shaft 110 as shown inFIGS. 3 and 4 . Therefore, in order to continuously transmit a driving force to thereversible roller 120 from a driving motor 130 (FIG. 4 ), anidle gear 140 is required, which flexibly moves to be kept in mesh with thereversible gear 122 even when the position of thereversible roller shaft 121 is changed. As shown inFIG. 4 , the central shaft Ci of theidle gear 140 is designed to be movable. - The central shaft Ci of the
idle gear 140 moves along a swing track A as shown inFIG. 4 to maintain theidle gear 140 and thereversible gear 122 in mesh. The central shaft Ci of theidle gear 140 is slidably mounted on one sidewall W (FIGS. 5 and 6 ) of the image forming apparatus. When thereversible roller shaft 121 moves parallel toward theconveyance roller shaft 111, the central shaft Ci also moves along the swing track A to maintain theidle gear 140 and thereversible gear 120 in mesh. The swing track A may be a part of the circumference of a virtual circle having a radius corresponding to the distance between the central shaft Cm of thedriving gear 131 and the central shaft Ci of theidle gear 140. -
FIGS. 5 and 6 are diagrams illustrating theidle gear 140 with the central shaft Ci movable along the swing track A according to first and second embodiments of the present invention. - In accordance with the first embodiment of the present invention, the central shaft Ci of the
idle gear 140 is slidably mounted on one sidewall W of the image forming apparatus. For this, the sidewall W has acurved swing slot 141 having a curvature corresponding to the swing track A and a width corresponding to the diameter of the central shaft Ci. Accordingly, when the position of thereversible roller shaft 121 is changed due to the abrasion of thereversible roller 120, the central shaft Ci slides along theswing slot 141 to maintain theidle gear 140 and thereversible gear 122 in mesh. - As shown in
FIG. 5 , thecurved swing slot 141 has a width corresponding to the diameter of the central shaft Ci of theidle gear 140. Also, theswing slot 141 has a curvature corresponding to the curved swing track A. - According to the second embodiment of the present invention, the central shaft Ci of the
idle gear 140 is slidably mounted on one sidewall W of the image forming apparatus. In this connection, the sidewall W has astraight swing slot 142 formed in a direction of a tangent to the swing track A, and having a width corresponding to the diameter of the central shaft Ci. Anelastic member 143 such as a compression spring is mounted within theswing slot 142. Theelastic member 143 exerts an elastic restoring force so that theidle gear 140 can be maintained in mesh with thereversible gear 122. - In the
paper conveyance apparatus 100 for an image forming apparatus according to the first and second embodiments of the present invention, when thereversible roller 120 is abraded, thereversible roller shaft 121 moves parallel toward theconveyance roller 110 by a distance corresponding the abraded thickness of thereversible roller 120, thereby preventing a biased abrasion of thereversible roller 120 and any error of feeding plural paper sheets at once. - When the distance between the
conveyance roller shaft 111 and thereversible roller shaft 121 is shortened due to the abrasion of thereversible roller 120, theidle gear 140 for transmitting the driving force to thereversible roller 120 is swung to move upward as much as the shortened distance so that thereversible roller 120 can be constantly in contact with theconveyance roller 110. Accordingly, by eliminating any causes of biased abrasion of thereversible roller 120, reliability of the image forming apparatus is ensured. - While the invention has been shown and described with reference to certain embodiments thereof, it should be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (12)
1. A paper conveyance apparatus for an image forming apparatus, comprising:
a conveyance roller for conveying a paper sheet to an image forming section;
a reversible roller for contacting the conveyance roller;
a driving motor having a driving gear for supplying a driving force to the reversible roller; and
an idle gear for transmitting a driving force from the driving motor to the reversible roller,
wherein the center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.
2. The paper conveyance apparatus according to claim 2 , wherein the idle gear is movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to a distance between the center of the driving gear and the center of the idle gear.
3. The paper conveyance apparatus according to claim 2 , wherein a central shaft of the idle gear is movable along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.
4. The paper conveyance apparatus according to claim 3 , wherein the swing slot has an inner periphery with a curvature corresponding to the swing track of the idle gear.
5. The paper conveyance apparatus according to claim 3 , wherein the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.
6. The paper conveyance apparatus according to claim 5 , wherein the swing slot comprises an elastic member for elastically supporting the central shaft of the idle gear.
7. A method of feeding paper in an image forming apparatus, comprising:
conveying a paper sheet to an image forming section via a conveyance roller;
contacting the conveyance roller via a reversible roller;
supplying a driving force to the reversible roller via a driving motor having a driving gear; and
transmitting a driving force from the driving motor to the reversible roller via an idle gear,
wherein the center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.
8. The method according to claim 7 , wherein the idle gear is movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to a distance between the center of the driving gear and the center of the idle gear.
9. The method according to claim 8 , further comprising:
providing a central shaft of the idle gear which is movable along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.
10. The method according to claim 9 , wherein the swing slot has an inner periphery with a curvature corresponding to the swing track of the idle gear.
11. The method according to claim 9 , wherein the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.
12. The method according to claim 11 , wherein the swing slot comprises an elastic member for elastically supporting the central shaft of the idle gear.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR2003-93183 | 2003-12-18 | ||
KR1020030093183A KR20050061771A (en) | 2003-12-18 | 2003-12-18 | Sheet feeding apparatus for image forming apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
US20050133982A1 true US20050133982A1 (en) | 2005-06-23 |
Family
ID=34675820
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/893,974 Abandoned US20050133982A1 (en) | 2003-12-18 | 2004-07-20 | Paper conveyance apparatus for an image forming apparatus and a method thereof |
Country Status (3)
Country | Link |
---|---|
US (1) | US20050133982A1 (en) |
JP (1) | JP3769002B2 (en) |
KR (1) | KR20050061771A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100156031A1 (en) * | 2008-12-19 | 2010-06-24 | Samsung Electronics Co., Ltd. | Feeding unit and image forming apparatus having the same |
US20150329301A1 (en) * | 2014-05-19 | 2015-11-19 | Kyocera Document Solutions Inc. | Image forming apparatus |
Citations (10)
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KR930003004Y1 (en) * | 1990-10-11 | 1993-05-27 | 주식회사 신도리코 | Sheet feeding apparatus |
JP3610149B2 (en) * | 1996-02-20 | 2005-01-12 | キヤノン株式会社 | Image forming apparatus |
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JPH1159941A (en) * | 1997-08-07 | 1999-03-02 | Ricoh Co Ltd | Frr feeding type sheet feeder |
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- 2003-12-18 KR KR1020030093183A patent/KR20050061771A/en active Search and Examination
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- 2004-07-20 US US10/893,974 patent/US20050133982A1/en not_active Abandoned
- 2004-11-18 JP JP2004334201A patent/JP3769002B2/en not_active Expired - Fee Related
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US5172899A (en) * | 1989-04-28 | 1992-12-22 | Seikosha Co., Ltd. | Paper feeder |
US5470052A (en) * | 1992-05-30 | 1995-11-28 | Asakawa; Yoshiyuki | Overlapped transfer-preventing mechanism |
US5697603A (en) * | 1995-09-06 | 1997-12-16 | Brother Kogyo Kabushiki Kaisha | Sheet-supply device |
US5947465A (en) * | 1995-12-20 | 1999-09-07 | Brother Kogyo Kabushiki Kaisha | Sheet-supply device having a drive force transmission mechanism |
US5902058A (en) * | 1996-06-07 | 1999-05-11 | Canon Kabushiki Kaisha | Sheet conveying apparatus and image forming apparatus |
US5876032A (en) * | 1996-08-26 | 1999-03-02 | Brother Kogyo Kabushiki Kaisha | Sheet feeder and printer |
US6997453B2 (en) * | 2000-08-21 | 2006-02-14 | Ricoh Company, Ltd. | Method of and apparatus for feeding sheets, image formation apparatus, and method of manufacturing gears |
US6467767B2 (en) * | 2000-12-18 | 2002-10-22 | Canon Kabushiki Kaisha | Sheet feeding apparatus and image forming apparatus equipped with it |
US6942210B2 (en) * | 2002-04-05 | 2005-09-13 | Canon Kabushiki Kaisha | Sheet feeding apparatus and image forming apparatus |
US7125013B2 (en) * | 2002-08-16 | 2006-10-24 | Canon Kabushiki Kaisha | Automatic feeding device and recording apparatus provided with such automatic feeding device |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100156031A1 (en) * | 2008-12-19 | 2010-06-24 | Samsung Electronics Co., Ltd. | Feeding unit and image forming apparatus having the same |
US20150329301A1 (en) * | 2014-05-19 | 2015-11-19 | Kyocera Document Solutions Inc. | Image forming apparatus |
US9617098B2 (en) * | 2014-05-19 | 2017-04-11 | Kyocera Document Solutions Inc. | Image forming apparatus |
Also Published As
Publication number | Publication date |
---|---|
JP3769002B2 (en) | 2006-04-19 |
JP2005179057A (en) | 2005-07-07 |
KR20050061771A (en) | 2005-06-23 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SAMSUNG ELECTRONICS CO., LTD., KOREA, REPUBLIC OF Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KIM, YOUNG-MIN;AHN, BYUNG-SUN;PARK, SANG-CHEOL;REEL/FRAME:015600/0114 Effective date: 20040719 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |