JP2006117387A - Medium feeding device and recording device and liquid injection device equipped with the medium feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medium feeding device preventing collision noise caused by collision of rear ends of media with a feeding path at the time of media feeding, and a recording device and a liquid injection device equipped with the medium feeding device. <P>SOLUTION: In an ink-jet type multifunction apparatus 100 in the first embodiment of this invention, the medium feeding device includes an intermediate (feeding) roller 45 feeding media, a retard roller unit 43 arranged so as to abut on the intermediate roller 45 and separating overlapped and fed media, and a front paper return unit 44 having a paper return claw part 71a for returning separated media in the lower layer. A paper return back face part 71b is formed so as to constitute part of the feeding path of the media. The paper return back face part 71b of the front paper return unit 44 thereby functions as a guide for fed media. As a result, this can prevent the fed media from being rapidly moved to and collided with the feeding path after the fed media passed through a tip of the paper return claw part 71a, and can prevent generation of collision noise. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a feeding roller that feeds a medium, a retard roller that is disposed so as to be in contact with the feeding roller, and that separates the fed medium, and a claw that returns the separated lower medium. The present invention relates to a medium feeding device including a return mechanism provided therein, a recording device including the medium feeding device, and a liquid ejecting apparatus.

  Conventionally, a feeding mechanism of an ink jet printer, which is one of recording apparatuses, uses a separation mechanism composed of a separation roller and a hook-like member called a return claw as one of means for separating and returning a double-fed medium. It had been. For example, in the feeding device disclosed in Patent Document 1, a separation mechanism including a separation roller that rotates while being pressed against a feed roller is used. In this mechanism, a medium detection sensor is attached to the rear of the medium feeding path of the feed roller, and the medium detection sensor and a solenoid are connected. Further, a link mechanism is connected to the solenoid, and a return claw that moves in response to a command is installed behind the feed roller through a link mechanism combined with the solenoid.

  In this apparatus, first, the double fed medium is separated by a separation roller and a feed roller. The medium detection sensor at the tip of the separation roller detects the separated medium, and the medium detection sensor transmits the information to the solenoid. Then, a command is issued to move the return claw from the solenoid to the combined link mechanism. As a result, the return claw moves to return the double fed paper. This device makes it possible to reliably separate the media and feed them one by one.

Japanese Patent Laid-Open No. 5-147831

  In the return mechanism used in the above-described conventional feeding device, when a strong paper is separated and fed, the rear end of the separated paper collides with the paper path to generate a sound. Usually, the paper separated by the separation mechanism is divided into a paper to be fed and a paper to be pushed back, and the paper to be pushed back is pushed back by a claw of a return claw. Further, the fed paper is fed while being in contact with the tip of the return claw. At this time, there is no particular guide until the trailing edge of the fed paper leaves the leading end of the return claw and then comes into contact with the paper path. The trailing edge of the paper suddenly moves and collides with the path. This is not a major problem when feeding weak paper, but for strong paper, sound is generated because it strikes the paper path vigorously to bend.

  The present invention has been made in view of the various problems as described above, and an object of the present invention is to prevent a collision sound generated when the rear end of the medium collides with the feeding path when feeding the medium. The present invention provides a possible medium feeding device, and a recording apparatus and a liquid ejecting apparatus including the medium feeding device.

  In order to achieve the above object, in the medium feeding device of the present invention, a feeding roller that feeds the medium, a retard roller that is disposed so as to be in contact with the feeding roller and separates the multi-feed medium, and a separation roller And a return mechanism having a claw for returning the lower layer of the medium, and after the return mechanism has returned the medium, the back surface of the claw has a part of the medium feed path. It is characterized by being formed. As a result, the back surface of the return claw of the return mechanism functions as a guide for the feeding medium, so that the medium to be fed is prevented from abruptly moving and colliding with the feeding path after passing through the tip of the returning claw. Thus, it is possible to prevent the occurrence of a collision sound.

  Further, the angle formed by the surface including the back surface immediately after returning the medium and the contact surface of the feeding roller at the intersection line between the surface and the outer peripheral surface of the feeding roller is an acute angle. And As a result, even when a strong medium is fed, the back surface functions as a medium guide, so that the medium is vigorously prevented from colliding with the feeding path and is generated when the medium collides. It is possible to prevent the collision sound.

  Further, the back surface is formed so as to continue to contact the back surface until a rear end of the medium to be fed comes into contact with another part of the feed path. As a result, the fed medium does not move away from the back surface until it abuts the feeding path, so that a collision with the feeding path due to a sudden movement of the medium can be prevented, and further, a collision sound of the medium can be prevented. It is possible to do.

  In order to achieve the above object, the medium feeding device of the present invention is a medium feeding device for supplying a medium, which is a storage device for recording on a medium characterized by having each of the above-described separation mechanisms. It is characterized by having a medium feeding device. The liquid ejecting apparatus of the present invention is a liquid ejecting apparatus that ejects a liquid onto a medium to be ejected, and is characterized by including the medium feeding device. Accordingly, it is possible to provide a medium feeding device, a storage device, and a liquid ejecting device that exhibit the above-described effects.

  Hereinafter, as an embodiment of a medium feeding apparatus according to the present invention, a medium feeding apparatus used in an ink jet printer that is one of recording apparatuses will be described with reference to FIGS. The embodiments described below do not limit the invention according to the claims, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent.

  FIG. 1 is a perspective view showing the entire external configuration of an inkjet type multifunction peripheral that is one of recording apparatuses according to an embodiment of the present invention, FIG. 2 is a perspective view showing the internal structure, and FIG. It is the schematic side view. The ink jet type multifunction peripheral 100 has a printer function capable of recording on, for example, a JIS standard L size, A6 size to A4 size cut sheet or postcard, a JIS standard size A4 size original, Equipped with a scanner function that can read originals up to US standard letter size, and a copy function that can copy to JIS standard L size, 2L size, B5 size, A4 size, six cuts, postcard size paper ing.

  As shown in FIG. 1, the inkjet multifunction peripheral 100 is entirely covered with a substantially rectangular parallelepiped housing 101, a printer 110 is disposed in the lower stage, and a scanner 120 is disposed in the upper stage. ing. A paper feeding unit 130 is disposed on the back side, and a paper feeding / discharging unit 140 is disposed on the front side. Since the user can select one or both of the paper feeding unit 130 on the rear side and the paper feeding / discharging unit 140 on the front side as the setting direction of the paper before recording, the degree of freedom of the installation position of the inkjet multifunction peripheral 100 Can be increased. Furthermore, since the paper after recording is always discharged from the paper supply / discharge section 140 on the front side, the user can easily take out the paper.

  A rectangular flat plate-shaped scanner cover 102 shown in FIG. 1 is disposed on the upper surface of the housing 101. The scanner cover 102 has a handle 103 formed at the front, and is attached so as to be rotatable in the direction of the arrow a in the figure around a rear rotation shaft. When using the scanner 120, the user can open and close the scanner cover 102 by inserting a finger into the handle 103, so that the user can easily put in and out the document.

  On both sides of the front surface of the housing 101, cartridge housing portions 104 into which the plurality of ink cartridges 10 shown in FIG. Each ink cartridge 10 stores ink of each color for recording. Each cartridge storage section 104 is covered with a transparent or translucent cartridge cover 105 shown in FIG. The cartridge cover 105 is attached so as to be rotatable in the direction of the arrow b shown in the figure around a rotation shaft at the lower part thereof. Even if the user does not lift the entire heavy scanner 120 and open the inside of the printer 110 as in the prior art, the ink cartridge can be released by simply pressing the cartridge cover 105 to release the locking portion and opening the cartridge storage portion 104. Since 10 replacement operations and the like can be performed, work efficiency can be improved.

  As shown in FIG. 1, an operation unit 106 for instructing each operation of the printer 110, the scanner 120, and the copy is disposed in front of the scanner cover 102 on the upper surface of the housing 101. The operation unit 106 includes a power system for turning on / off the power, an operation system for operating the cueing of paper, operating an ink flushing, a processing system for performing image processing, etc. A liquid crystal panel 107 and the like for displaying are provided. The user can operate buttons and the like while looking at the liquid crystal panel 107 for confirmation.

  In the housing 101, as shown in FIGS. 2 and 3, a paper feed / discharge unit 140, a paper feed unit 130, a recording unit 150, and the like are disposed. As shown in FIG. 1, a rear paper feed port 131 that is opened upward in a rectangular shape is formed in the paper feed unit 130, and a frame 132 is disposed along both the edge and the rear edge of the rear paper feed port 131. Has been. As shown in FIGS. 1 to 3, the frame 132 automatically includes a paper support 133 that supports one or more sheets to be fed and a sheet supported by the paper support 133 one by one. A rear sheet feeding mechanism (hereinafter referred to as a rear ASF) 134 for feeding the sheet is disposed.

  FIG. 4 is a side view showing details of the paper support 133 and the rear ASF 134, which will be described with reference to FIGS. The paper support 133 includes a first support 21 and a second support 22 that support the back side of the paper, a fixed edge guide 23 that guides both side edges of the paper, a movable edge guide 24, and the like. The rear ASF 134 is a hopper 31 that lifts the paper supported by the paper support 133, a paper feed roller 32 that picks up the paper lifted by the hopper 31, and a paper that is multi-fed by the paper feed roller 32. A retard roller 33 that separates only one sheet, a rear sheet return unit 34 that returns the remaining sheets separated by the retard roller 33 to the hopper 31, and the like are provided.

  The first support 21 is formed in a flat plate shape and is disposed inside the rear wall of the frame 132 so as to be retractable and retractable. The second support 22 is formed in a flat plate shape so that the first support 21 can be stored and pulled out. It is arranged. Since the first support 21 and the second support 22 are formed to be extendable in the paper feeding direction, they can be stored compactly when not in use, and various sizes of paper can be stored when in use. Can support reliably.

  The fixed edge guide 23 is formed integrally with the hopper 31 in a shape along the right side wall when viewed from the front side of the frame 132, and the movable edge guide 24 is formed along the left side wall when viewed from the front side of the frame 132. And is attached to the hopper 31 so as to be movable between the left side wall and the right side wall of the frame 132 substantially parallel to the rear wall of the frame 132. Since the fixed edge guide 23 and the movable edge guide 24 can reliably guide both side edges of the paper even if the paper sizes are different, the feeding can be performed with high accuracy.

  The hopper 31 is formed in a flat plate shape on which paper can be placed, and is disposed substantially parallel to the rear wall of the frame 132. The lower end is positioned near the paper feed roller 32, and the upper end is the rear wall of the frame 132. It arrange | positions so that it may be located close to the top part. The hopper 31 is provided with the other end of a compression spring (not shown) having one end attached to the rear wall of the frame 132 on the back surface on the lower end side, and the lower end side pivots about the upper end side by expansion and contraction of the compression spring. It is arranged like this.

  The paper feed roller 32 is formed in a D-shape with a part of the cross-section cut away, and is disposed near the lower end of the hopper 31. The paper feed roller 32 rotates intermittently and frictionally feeds the paper lifted by the hopper 31. It is supposed to send. The retard roller 33 is disposed so as to be in contact with the paper feed roller 32, and when the paper is fed by the paper feed roller 32, only the uppermost paper is frictionally separated from the lower paper. Yes. The rear paper return unit 34 is formed in the shape of a claw and is disposed in the vicinity of the paper feed roller 32. The lower paper separated by the retard roller 33 is placed on the claw and returned to the hopper 31. .

  As shown in FIGS. 2 and 3, the paper supply / discharge unit 140 is formed with a front paper supply / discharge port 141 that opens in a rectangular shape toward the front, and paper is supplied below the front paper supply / discharge port 141. A tray 142 is disposed, and a paper discharge tray 143 is disposed above the paper feed tray 142. As shown in FIG. 3, a front sheet feeding mechanism 144 that automatically feeds the sheets stored in the sheet feeding tray 142 one by one, and a sheet discharging tray are provided at the side of the front sheet feeding / discharging port 141. A front sheet discharge mechanism 145 for automatically discharging sheets is provided at 143.

  In the present invention, a medium feeding device having the front paper feed / discharge port 141, the paper feed tray 142, the paper discharge tray 143, the front paper feed mechanism 144, and the front paper discharge mechanism 145 is referred to as a front ASF 340.

  As shown in FIGS. 2 and 3, the paper feed tray 142 is formed in a flat plate shape, and the paper to be fed before recording is stacked and stored on the upper surface. As shown in FIGS. 2 and 3, the paper discharge tray 143 includes a first tray 143a, a second tray 143b, and a third tray 143c. The first tray 143a is formed in a flat plate shape, and the rear part is rotatably disposed on the main body frame 108 of the paper feed / discharge unit 140, and the second tray 143b is formed in a flat plate shape and the first tray 143a. The third tray 143c is formed in a flat plate shape so as to be retractable and retractable on the second tray 143b.

  The paper discharge tray 143 is configured such that the paper to be discharged after recording is stacked and placed on the upper surface with the second tray 143b and the third tray 143c pulled out. Since the second tray 143b and the third tray 143c are formed to be extendable in the paper discharge direction, they can be stored compactly when not in use, and various sizes of paper can be discharged when in use. The stacked sheets can be surely stacked and placed. The paper supply / discharge unit 140 is also configured to be able to manually feed and supply a tray containing thick paper, an optical disk, or the like that cannot be bent during paper supply / discharge. .

  FIG. 5 is a side view showing details of the front sheet feeding mechanism 144, which will be described with reference to FIGS. The front paper feed mechanism 144 includes a pickup roller unit 41 that takes out the paper stored in the paper feed tray 142, and a bank portion 42 that changes the direction of the paper taken out by the pickup roller unit 41. Further, a retard roller unit 43 that separates the sheets fed by the pickup roller unit 41 into only one sheet, and a characteristic portion of the present invention that returns the remaining sheets separated by the retard roller unit 43 to the sheet feed tray 142. Including a front paper return unit (return mechanism) 44, an intermediate roller (feed roller) 45 that reverses the fed paper into a U-shape, an assist roller 46, and the like.

  The pickup roller unit 41 is disposed above the rear portion of the paper feed tray 142 and is pivotable up and down with respect to the paper feed tray 142. The pickup roller unit 41 descends and frictionally feeds the paper stored in the paper feed tray 142. It is supposed to send. The bank portion 42 is disposed to be inclined rearward at the rear portion of the paper feed tray 142, and changes the direction of the leading edge of the paper fed by the pickup roller unit 41 upward. .

  The retard roller unit 43 is disposed so as to come into contact with the intermediate roller 45, and when the sheets are fed by the pickup roller unit 41, only the uppermost sheet is frictionally separated from the lower layer sheet. Yes. The front paper return unit 44 including the characteristic part of the present invention is formed in a claw shape and is disposed in the vicinity of the retard roller unit 43, and the lower layer paper separated by the retard roller unit 43 is hung on the claw. To return to the paper feed tray 142. The assist roller 46 is disposed so as to be in constant contact with the intermediate roller 45. The uppermost sheet separated by the retard roller unit 43 is sandwiched between the intermediate roller 45 and reversed into a U-shape so that the platen Feed to 155.

  As shown in FIG. 3, the front discharge mechanism 145 includes a first discharge roller 51 and a first jagged roller 52, a second discharge roller 53 and a second jagged roller 54, and the like. The first paper discharge roller 51 is disposed on the downstream side of the platen 155, and sandwiches and discharges the paper passing through the platen 155 together with the first knurled roller 52. Further, the second paper discharge roller 53 The paper is disposed downstream of the first paper discharge roller 51, and the paper is nipped together with the second jagged roller 54 to be discharged onto the paper discharge tray 143.

  As shown in FIG. 3, the recording unit 150 includes a paper feed roller 151 that feeds paper in the sub-scanning direction in synchronization with the recording operation, a driven roller 152 thereof, and a carriage 153 that moves in the main scanning direction in synchronization with the recording operation. A recording head 154 that discharges ink in synchronization with the recording operation, a platen 155 that holds the paper during recording flat, and the like are provided.

  As shown in FIG. 3, the paper feed roller 151 is arranged on the upstream side of the platen 155 in the conveyance, and the paper fed by the paper feed roller 32 or the paper fed reversely by the intermediate roller 45 is shown in FIG. The paper feed mechanism 156 shown in FIG. 4 is sandwiched with the driven roller 152 and sent out to the platen 155. The carriage 153 is inserted through the carriage guide shaft 157 shown in FIG. 3 above the platen 155 and connected to the carriage belt 158 shown in FIG. 2. When the carriage belt 158 is operated by the carriage motor 159 shown in FIG. Along with the movement of the carriage belt 158, the carriage belt 158 is guided by the carriage guide shaft 157 to reciprocate.

  As shown in FIG. 3, the recording head 154 is mounted on the carriage 153 at a predetermined distance from the platen 155. For example, the recording head for black ink that discharges black ink, yellow, cyan, light cyan, And a plurality of color ink recording heads for ejecting magenta and light magenta inks, respectively. The recording head 154 is provided with a pressure generating chamber and a nozzle opening connected to the pressure generating chamber. The size of the recording head 154 is controlled from the nozzle opening toward the sheet by storing ink in the pressure generating chamber and pressurizing it with a predetermined pressure. Ink droplets are discharged. Next, the front ASF 340 including the characteristic mechanism of the present invention will be described with reference to the drawings.

  FIG. 6 is an explanatory diagram showing the feeding path R of the front ASF 340 and each mechanism on the feeding path R. In the feeding path R of the front ASF 340, as shown in FIG. 6, from the upstream side of paper feeding, the paper feeding tray 142, the pickup roller unit 41, the bank 42, the retard roller unit 43, and the retard roller unit 43 are provided. An intermediate roller (feed roller) 45 that contacts and separates from the retard roller 61, an assist roller 46, a paper feed roller 151 and its driven roller 152, a first paper discharge roller 51, a first jagged roller 52, 2 paper discharge roller 53, second jagged roller 54, and paper discharge tray 143, and the above are arranged in order. Further, a sheet placed on the sheet feed tray 142 is denoted by P, and a sheet fed to the feeding path R is denoted by P1.

  When the sheet P1 is fed to the feeding path R of the front ASF 340, how each mechanism on the feeding path R moves will be described with reference to FIG. First, the paper P placed on the paper feed tray 142 is conveyed to the bank 42 by the pickup roller unit 41. Then, the bank portion 42 changes the direction of the leading edge of the paper P <b> 1 to the direction of the intermediate roller 45. Further, when the paper P is double-fed, the retard separation is performed by the retard roller unit 43 that contacts and separates from the intermediate roller 45, and the double-fed paper is shown in FIG. The paper is returned to the paper feed tray 142 by the front paper return unit (return mechanism) 44 shown. The sheet P1 to be fed separated by the separation mechanism is fed in the direction of the platen 155 shown in FIG. 3 by the intermediate roller 45 and the assist roller 46, and the paper feed roller 151 and its driven roller in front of the platen 155. 152 receives the fed paper. Further, the paper feed roller 151 and its driven roller 152 feed the paper P1 onto the platen 155, and the first paper discharge roller 51, the first jagged roller 52, the second paper discharge roller 53, and the second jagged roller located thereabove. 54. Then, the first paper discharge roller 51, the first jagged roller 52, the second paper discharge roller 53, and the second jagged roller 54 discharge the paper P1 to the paper discharge tray 143 ahead. The above is the feeding route R. Next, an outline of the front paper return unit 44 including the characteristic part of the present invention will be described with reference to the drawings.

  7 is a perspective view of the retard roller unit 43 and the front paper return unit 44 as viewed from the front side. FIG. 8 is a perspective view of the retard roller unit 43 and the front paper return unit 44 extracted from the mechanical parts. is there.

  As shown in FIGS. 6 and 7, the retard roller unit 43 is in contact with the intermediate roller 45, and the retard roller 61 separates the double fed paper so as to feed only the uppermost sheet P 1. And a roller holder 62 that rotatably supports the retard roller 61 so as to abut against and separate from the intermediate roller 45. The retard roller 61 is formed in a cylindrical shape, and the circumferential surface is covered with, for example, rubber or the like in order to increase the friction coefficient. The roller holder 62 pivotally supports the retard roller 61 at one end and is rotatably supported by the frame 47 at the other end. The roller holder 62 can pivot at one end around the other end. It is swingably held.

  As shown in FIGS. 7 and 8, the front paper return unit 44 including the characterizing portion of the present invention is juxtaposed to the frame 47 together with the retard roller unit 43. The front paper return unit 44 includes a retard roller 61. A paper return 71 for pushing back the lower layer paper P separated by the above, a paper return shaft 72 for turning the paper return 71 and swinging the retard roller 61, a cam floor 73 for transmitting a driving force to the paper return shaft 72, and Has no cam clutch. The paper return 71 is integrally formed with the paper return shaft 72 so as to protrude from the paper return shaft 72 on both sides of the retard roller 61. The cam floor 73 is formed in an L shape and is formed integrally with the paper return shaft 72 so as to protrude from one end of the paper return shaft 72.

  Further, the paper return shaft 72 has a function of turning the paper return 71 and swinging the retard roller 61. Therefore, a cam 75 for turning the roller holder 62 is integrally formed on the paper return shaft 72, and a cam receiver 76 that contacts and separates from the cam 75 is integrally formed on the roller holder 62. . By forming the paper return shaft 72, the paper return 71, and the cam 75 by adjusting the phases, the paper return 71 is rotated without interfering with the roller holder 62 when the paper return shaft 72 is rotated. The retard roller 61 can be swung.

  Note that the shape of the paper return 71, which is a characteristic part of the present invention, will be described later with reference to the drawings because of the effects of the present invention, and is omitted here. Next, the separation operation of the paper P by the retard roller unit 43 and the front paper return unit 44 including the characteristic part of the present invention will be described with reference to the drawings.

  FIGS. 9-11 is explanatory drawing which showed the separation operation | movement of the retard roller unit 43 and the front paper return unit 44 containing the characteristic part of this invention. 9 is a state diagram when the paper P1 fed by the pickup roller unit 41 starts to be fed, and FIG. 10 is a state diagram when the paper P is double fed by the pickup roller unit 41. FIG. 11 is a state diagram when the paper P fed by the front paper return unit 44 including the characteristic part of the present invention is separated and pushed back. Here, let P2 be the paper that is double fed and pushed back.

  As shown in FIG. 9, the sheet P <b> 1 to be fed is the top sheet of the sheet P in the sheet feed tray 142. The sheet P1 receives a driving force when the pickup roller unit 41 comes into contact with the sheet P1, and is fed to the bank 42. Here, the bank portion 42 has an inclined surface that changes the direction of the sheet P1 in the direction of the intermediate roller 45 by the propulsive force transmitted from the pickup roller unit 41 to the sheet. The paper P1 changes the direction of the leading edge.

  However, when the contact force of the pickup roller unit 41 and the friction coefficient of the paper P are high, the paper P2 may be double fed together with the fed paper P1 as shown in FIG. Accordingly, a retard roller unit 43 is provided in order to prevent the double feeding of the paper P2 to the platen 155 (see FIG. 3). The retard roller unit 43 separates the fed paper P1 and the double fed paper P2 by bringing the intermediate roller 45 and the retard roller 61 into contact with and separating from each other. The retard roller unit 43 brings the retard roller 61 into contact with the intermediate roller 45, and when the paper P2 is double-fed, separates the paper P1 to be fed from the paper P2 that has been double-fed and feeds the paper to be fed. Feed only P1.

  Next, the separation mechanism of the retard roller unit 43 will be described. The retard roller 61 has an outer peripheral surface covered with rubber or the like having a high friction coefficient and does not have a power source. Therefore, when only the paper P1 is fed, the retard roller 61 is dependent on the power of the intermediate roller 45 via the paper P1. To be rotated. In addition, since a torque limiter (not shown) is provided, a rotational resistance always acts on the retard roller 61 in the direction opposite to the rotational direction. That is, when the intermediate roller 45 and the retard roller 61 are in contact with each other and both rollers are rotating, the retard roller 61 is rotated by the intermediate roller 45 while receiving a rotational resistance. When the sheets P1 and P2 are fed in this state, the sheet P1 to be fed is generated in the tangential direction of the contact point (NIP point) between the intermediate roller 45 and the retard roller 61 as the intermediate roller 45 rotates. A frictional resistance acts between the feeding force and the double fed paper P2. Further, the double fed paper P2 receives a frictional resistance acting between the fed paper P1 and a force caused by a rotational resistance from the retard roller 61. Since the resistance between the sheets P1 and P2 is smaller than the feeding force of the intermediate roller 45 and the rotational resistance of the retard roller 61, the fed sheet P1 slides on the double fed sheet P2. Be fed. In addition, the double fed paper P2 is stopped by the retard roller 61, separated, and stays just below the NIP point.

  Next, as shown in FIG. 11, the double fed paper P2 separated by the retard roller unit 43 and staying at the NIP point is fed by the paper return 71 of the front paper return unit 44 including the characteristic part of the present invention. It is pushed back to the paper feed tray 142. Further, the fed paper P1 is fed through the front end of the paper return 71. At this time, the retard roller unit 43 separates the retard roller 61 from the intermediate roller 45 and retracts to the frame 47 so that the front roller unit 44 is replaced by the power from the paper return shaft 72. Conversely, when the retard roller unit 43 brings the intermediate roller 45 and the retard roller 61 into contact with each other, the paper return 71 moves backward into the frame 47. As described above, the retard roller unit 43 and the front paper return unit 44 separate the double-feed paper P2, and can perform two operations of separation and paper return by alternately developing the paper P2. is there.

  In such a configuration, an operation in the case of recording on a sheet by the inkjet multifunction peripheral 100 will be described. The user stores a plurality of sheets of paper before recording in the paper feed tray 142 and activates the inkjet multifunction peripheral 100. The sheets stacked and stored in the sheet feed tray 142 are frictionally fed to the intermediate roller (feed roller) 45 by the pickup roller unit 41, and only the uppermost sheet is driven by the sheet return shaft 72. The lower layer paper separated and fed by the (separation mechanism) is returned to the paper feed tray 142 by the paper return 71 driven by the paper return shaft 72. The paper is skewed and cueed, and is nipped by the paper feed roller 151 driven by the paper feed mechanism 156 and its driven roller 152 and fed to the platen 155.

  The sheet is recorded by a recording head 154 mounted on a carriage 153 scanned by a carriage motor 159 and a carriage belt 158. At this time, the control unit of the inkjet multifunction peripheral 100 supplies each color ink to the recording head 154 from a total of seven color ink cartridges, for example, yellow, magenta, light magenta, cyan, light cyan, and black. High-precision ink dot control, halftone processing, and the like are executed by controlling the driving of the carriage 153 and the paper feed roller 151. The paper on which recording has been completed is sandwiched between the first paper discharge roller 51 and the first jagged roller 52, the second paper discharge roller 53 and the second jagged roller 54 driven by the paper feed mechanism 156, and the paper supply / discharge unit 140. And is stacked and placed on a paper discharge tray 143. Next, the paper return 71 which is this characteristic part will be described with reference to the drawings.

  FIG. 12 is a first diagram for explaining the shape of the paper return 71 which is a characteristic part of the present invention. FIG. 13 is an explanatory diagram of a conventionally used front paper return unit 441 (comparative example). FIG. 14 is a second view for explaining the paper return 71 which is a characteristic part of the present invention, and is a state in which the rear end of the paper P1 is fed while contacting the back portion of the paper return 71. Indicates.

  The paper return 71 shown in FIG. 12 has a paper return claw portion (return claw) 71a for pushing back the double-feed paper P2, and a paper return back portion (back surface of the claw) 71b which is a characteristic part of the present invention. It is characterized by. The paper return back surface portion 71b is integrated with a feed path guide portion R1 formed of a curved surface facing the intermediate roller 45 of the frame 47 shown in FIG. 7, and the paper fed by the intermediate roller 45 passes therethrough. A feeding path R is formed.

  On the other hand, the front paper return unit 441 shown in FIG. 13 is a comparative example with the above-described front paper return unit 44, and the paper return back surface portion 711b of the comparative example is located with respect to the feeding path R as shown in the figure. It has a shape that is largely cut out, and does not form a feeding path R for the fed paper P1. Further, the paper return claw portion 711a is formed so as to be substantially perpendicular to the double fed paper P2. The front paper return unit 441 shown in FIG. 13 is the same as the front paper return unit 44 according to this embodiment except for the shape of the paper return 71.

  As described above, the paper return back surface portion 711b does not form the feeding path R of the paper P1 to be fed, and even if the rear end of the paper P1 touches the paper return back surface portion 711b, Since the return back surface portion 711b has a shape that is largely cut off with respect to the feeding path R, even if the paper P1 is touched, it does not have sufficient resistance. Therefore, the paper return back surface portion 711b does not serve as a guide, and the rear end of the fed paper P1 passes through the front end of the paper return claw portion 711a and does not stay on the paper return back surface portion 711b. It moves suddenly and collides with the feeding route guide R11. At this time, when a strong paper is fed, the paper P1 has a large U-shape at the intermediate roller 45 as shown in FIG. A strong repulsive force can be generated. Since the paper return back surface portion 711b does not serve as a guide for suppressing the repulsive force, the rear end of the paper P1 collides with the feeding path guide portion R11 so as to bend, and a sound is generated.

  Further, since the paper return claw portion 711a that pushes back the double-fed paper P2 also has a shape that is substantially perpendicular to the double-fed paper P2, the leading edge of the paper P2 is bent. Furthermore, since the overlap amount t1 of the paper return claw portion 711a is large, the paper return claw portion 71a scratches the back surface of the fed paper P1 and creates a scratch.

  On the other hand, in the front paper return unit 44 according to the present embodiment shown in FIGS. 12 and 14, the paper return back surface portion 71b of the paper return 71 shown in FIG. 14 forms a supply path for the paper P1 to be supplied. Further, the rear end of the paper P1 to be fed is in contact with the paper return back surface portion 71b until it abuts the feeding path guide portion R1. Further, the paper return back surface portion 71b is an angle formed by the tangent line of the intermediate roller 45 drawn from above the intersection 71c between the outer peripheral surface of the intermediate roller 45 and the surface including the paper return back surface portion 71b, and the paper return back surface portion 71b. It is formed so that θ1 has an acute angle.

  Accordingly, as shown in FIG. 14, when the paper return 71 protrudes from the frame 47 shown in FIG. 7 and feeds the paper P1, the paper return back surface portion 71b causes the paper P1 to be fed to be a feed path guide portion. The paper return back surface portion 71b itself becomes the feeding path R so that it does not suddenly move to R1 and collide, and further, the paper is returned until the trailing edge of the fed paper P1 comes into contact with the feeding path guide R1. It serves as a guide that continues to contact the back surface portion 71b. As a result, the paper P1 is prevented from suddenly colliding with the feeding route guide R1.

  Further, the angle θ1 formed between the paper return back surface portion 71b and the tangent line of the intermediate roller 45 drawn from the intersection 71c between the outer peripheral surface of the intermediate roller 45 and the surface including the paper return back surface portion 71b. Is formed so as to have an acute angle, even if the paper P1 to be fed is a strong paper, the rear end of the paper is in contact with the paper return back surface portion 71b and is fed to the feeding path guide portion R1. It is possible to contact. For this reason, the fed paper P1 does not collide with the feeding path guide R1 vigorously so as to bend, and it is possible to prevent the sound generated by this collision. In addition, it is known from experience that if the angle θ1 is 40 degrees or less, it is possible to prevent the generation of sound due to a strong paper. The smaller the angle θ1, the more the sound can be suppressed. It is also known to be effective. However, since the paper return 71 needs to be retracted into the frame 47 shown in FIG. 7, it is formed to be 24 degrees in this embodiment.

  The angle θ1 formed between the paper return back surface portion 71b and the tangent to the intermediate roller 45 drawn from the intersection 71c between the outer peripheral surface of the intermediate roller 45 and the surface including the paper return back surface portion 71b is an acute angle. The reason why it is formed so as to have the following angle will be described. This is because, when a strong paper is being fed, the paper P1 has a large U-shape at the intermediate roller 45 as described above. A strong repulsive force can be generated. This is one of the causes that the rear end of the paper P1 suddenly moves and collides with the path. Here, if the value of the angle θ1 formed by the paper return back surface portion 71b and the tangent line of the intermediate roller 45 drawn from the contact 71c is large, even if the rear end of the paper P1 touches the paper return back surface portion 71b, it is sufficient. This is because the trailing edge of the sheet P1 collides with the feeding guide portion R1 without serving as a resistance and serving as a guide. Therefore, the angle θ1 is formed to be an acute angle that can give a large resistance to the rear end of the paper P1.

  The paper return 71 is disposed so as not to contact the intermediate roller 45 even if it protrudes when returning the paper. When the separated paper P2 is pushed back, the leading end of the paper return claw 71a protrudes slightly overlapping the NIP point on the outer peripheral surface of the intermediate roller 45. At this time, if the overlap amount t is too large, the paper return claw 71a will scratch the back surface of the fed paper P1 and create a scratch. Therefore, the overlap amount t is suitably adjusted so that the back surface of the fed paper P1 is not damaged. In the present embodiment, the overlap amount t is set to 0 mm to 1.75 mm. Thus, the paper return claw 71a can be fed without causing any damage to the back surface of the paper P1 to be fed.

  Further, the paper return claw portion 71a is not flat in the tip shape of the claw but is recessed as shown in FIGS. This shape can reduce the force applied to the leading end of the double-fed paper P2 when the double-fed paper P2 is returned, thereby reducing the leading edge folding phenomenon of the double-fed paper P2. It has become possible.

  Further, since no silent material or the like is used for preventing the occurrence of collision noise, it leads to cost reduction.

  As described above, according to the inkjet type multifunction peripheral 100 of one embodiment of the present invention, the medium (feed) roller 45 that feeds the medium, the medium that is disposed so as to be in contact with the intermediate roller 45, and is double fed. The medium feeding device includes a retard roller unit 43 that separates the paper and a front paper return unit 44 that includes a paper return claw 71a that returns the separated lower layer medium. After the medium is returned, the paper return back surface portion 71b is formed so as to form a part of the medium feeding path. As a result, the paper return back surface portion 71b of the front paper return unit 43 functions as a guide for the feeding medium, so that the medium to be fed moves rapidly to the feeding path after passing through the front end of the paper return claw portion 71a. Thus, it is possible to prevent a collision and to prevent a collision sound.

  Further, the angle θ1 formed by the surface including the paper return back surface portion 71b immediately after the medium is returned and the contact surface of the intermediate roller 45 at the intersection line between the surface and the outer peripheral surface of the intermediate roller 45 is an acute angle. Features. Thereby, even when a medium with a strong strength is fed, the paper return back surface portion 71b functions as a medium guide, so that the medium can be prevented from colliding with the feeding path guide portion R1 vigorously so as to bend, It is possible to prevent a collision sound generated when the medium collides.

  Further, the paper return back surface portion 71b is formed so as to continue to contact the paper return back surface portion 71b until the rear end of the medium to be fed comes into contact with another portion of the feed path guide portion R1. And As a result, the fed medium does not leave the paper return back surface portion 71b until it abuts the feeding route guide R1, and can prevent a collision with the feeding route guide R1 due to a sudden movement of the medium. Further, it is possible to prevent the collision sound of the medium.

  Any recording apparatus provided with a medium feeding device can be applied to, for example, a facsimile machine, a copying machine, and the like. In addition to a recording apparatus, the meaning of a liquid ejecting apparatus that ejects a liquid corresponding to its use from a liquid ejecting head onto an ejected medium instead of ink and attaches the liquid to the ejected medium is, for example, a liquid crystal display or the like Color material jet head used for manufacturing color filters, electrode material (conductive paste) jet head used for electrode formation for organic EL display and surface emitting display (FED), bio-organic jet head used for biochip manufacturing, precision pipette The present invention can also be applied to an apparatus equipped with a sample ejection head or the like.

1 is a perspective view illustrating an overall appearance configuration of an ink jet type multifunction peripheral that is one of recording apparatuses according to an embodiment of the present invention. FIG. 2 is a perspective view showing an internal structure of the multifunction machine of FIG. 1. FIG. 3 is a schematic side view of the internal structure of the multifunction machine of FIG. 2. FIG. 2 is a side view showing details of a paper support and a rear ASF of the multifunction machine of FIG. 1. FIG. 2 is a side view showing details of a front ASF of the multifunction machine of FIG. 1. It is explanatory drawing of the cross section which extracted the feeding path | route of front ASF, and each mechanism on the feeding path | route. It is the perspective view which looked at the mechanism of a retard roller unit and a front paper return unit from the front side. It is the perspective view which extracted the retard roller unit and the mechanism part of a front paper return unit. FIG. 6 is a state diagram when a sheet fed by a pickup roller unit starts to be fed. FIG. 6 is a state diagram when double feeding of paper fed by a pickup roller unit occurs. FIG. 6 is a state diagram when a sheet is pushed back by a front sheet return unit including a characteristic part of the present invention. It is the 1st figure for demonstrating the shape of the paper return which is the characteristic part of this invention. It is explanatory drawing of the front paper return unit (comparative example) used conventionally. It is a 2nd figure for demonstrating the paper return which is a characteristic part of this invention.

Explanation of symbols

21 First support, 22 Second support, 23 Fixed edge guide, 24 Movable edge guide, 31 Hopper, 32 Feed roller, 43 Retard roller unit, 44 Front paper return unit, 45 Intermediate roller (feed roller), 61 retard Roller, 62 Roller holder, 63 Retard roller tension spring, 71, 81 Paper return, 71a Paper return claw part, 71b Paper return back part, 72, 82 Paper return shaft, 73 Cam floor, 74 Cam clutch, 75 Cam, 76 Cam floor, 100 Inkjet MFP, 101 Housing, 110 Printer, 120 Scanner, 130 Paper Feed Unit, 131 Rear Paper Feed Port, 132 Frame, 133 Paper Support, 134 Rear ASF, 140 Paper Feed / Discharge Portion, 141 Front Paper Feed / Discharge Port, 142 paper feed tray, 143 paper discharge tray, 1 4 Front paper feeding mechanism, 150 a recording unit, 340 a front ASF

Claims (5)

A feeding roller for feeding the medium;
A retard roller disposed so as to be in contact with the feeding roller and separating the multi-feed medium;
A return mechanism with a claw for returning the separated lower layer medium, and a medium feeding device comprising:
A medium feeding device, wherein the back surface of the claw is formed so as to form a part of a medium feeding path after the returning mechanism returns the medium. An angle formed by a surface including the back surface immediately after returning the medium and a contact surface of the feeding roller at an intersection line between the surface and the outer peripheral surface of the feeding roller is an acute angle. The medium feeding device according to claim 1. The back surface is formed so as to continue to contact the back surface until a rear end of the medium to be fed comes into contact with another part of the feed path. Medium feeding device. A recording device for recording on a medium,
A recording apparatus comprising the medium feeding device according to claim 1. A liquid ejecting apparatus that ejects liquid onto an ejection target medium,
A liquid ejecting apparatus comprising the medium feeding device according to claim 1.

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