JP2007106598A - Sheet feeder, image recorder and image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet feeder capable of eliminating jamming of a sheet when attaching and detaching a sheet storage means by easily attaching and detaching the sheet storage means with a simple constitution even when arranging a feeding means in a constant fixing position to the sheet storage means. <P>SOLUTION: A movable member 5 is arranged so as to be movable between an abutting position abutting on a loading sheet S by further projecting from the feeding means 2 and a retreat position separating from the loading sheet by retreating from the feeding means. A control means controls so as to separate the sheet from the feeding means by positioning the movable member in the abutting position when attaching and detaching the sheet storage means 1 and to bring the sheet into pressure contact with the feeding means by positioning the movable member in the retreat position when performing feeding operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet feeding apparatus to which a sheet storage unit on which sheets are stacked is detachably mounted, and an image recording apparatus and an image reading apparatus using the sheet feeding apparatus.

  In an image recording apparatus or image reading apparatus such as a printer, a copying machine, or a scanner, a sheet feeding apparatus for separating and supplying sheets such as a recording medium such as recording paper or a document having an image into the apparatus one by one Is used. In this sheet feeding apparatus, a cassette is used which constitutes a detachable sheet storage means composed of a casing on which sheets are stacked. FIG. 9 is a longitudinal sectional view showing a state in which the conventional sheet feeding apparatus is capable of feeding operation. FIG. 9A shows a configuration in which the feeding roller is arranged below the stacked sheets, and FIG. 2 shows a configuration in which a feed roller is arranged on the upper side of a stacked sheet. 9A and 9B, the sheets S stored in the cassettes 101 and 201 constituting the box-shaped sheet storage means are pressed against the feeding rollers 102 and 202 constituting the feeding means. When the feeding roller is rotated by a driving unit (not shown), the sheet S is fed in the X and Y directions indicated by arrows by friction with the surfaces of the feeding rollers 102 and 202.

  In each sheet feeding apparatus shown in FIGS. 9A and 9B, the cassettes 101 and 201 are guided along the guide members 103 and 203, and intersect with the feeding direction (direction perpendicular to the paper surface). It can be pulled out or inserted into. Further, pressure plates 104 and 204 constituting pressure contact means for pressing the sheet to the feeding roller are provided. In either case of the feeding roller 102 disposed below the sheet and the feeding roller 202 disposed above the sheet, the feeding operation tends to become unstable due to friction caused by the weight of the feeding roller or the sheet alone. . Therefore, generally, at least one of the feeding roller and the pressure plate is urged by the spring members 106 and 206 so as to press the sheet against the feeding roller.

  When the user replenishes the sheet, the box-shaped cassettes 101 and 201 are pulled out from the sheet feeding apparatus to replenish the sheet, and the replenished cassette is mounted again. Regarding the cassette mounting / removal direction, there are those that are attached / detached in the direction of arrow AB parallel to the sheet feeding direction, and those that are attached / detached in the direction intersecting the sheet feeding direction (direction perpendicular to the paper surface). ing.

On the other hand, at the time of feeding operation, the sheet is pressed against the feeding roller in order to give a conveying force. However, if the sheet is pressed against the feeding roller when the cassette is attached or detached, a large force is required for the pulling operation, and it becomes difficult to pull the cassette. At the same time, there is a high possibility that the sheet will jam when the cassette is pulled out. Conversely, when the cassette is mounted, if the feeding roller and the sheet are in a position where they interfere with each other, there is a high possibility that the sheet will jam. As a means for solving such inconvenience, generally, when the cassette is pulled out, at least one of the feeding roller and the pressure plate is retracted to separate the feeding roller from the sheet. Japanese Patent Application Laid-Open No. 2004-228561 discloses a paper feeding device having a mechanism for retracting a feeding roller from a sheet.
Japanese Patent No. 3302670

  However, in the method of retracting the feeding roller that receives rotational driving from the sheet, it is required to ensure the positioning accuracy of the rotation center. In addition, it is required to ensure rigidity to counter the reaction force of the sheet feeding force and the pressing force of the pressure plate. Therefore, a complicated mechanism as described in Patent Document 1 is required to actually realize it. On the other hand, the method of retracting the pressure plate with the feeding roller as a fixed type can be implemented with a relatively simple mechanism as compared with the method of moving the feeding roller. However, in this method, as shown in FIG. 9A, when the feeding roller 102 is disposed below the stacked sheets, the sheet S falls down due to its own weight even if the pressure plate 104 is retracted upward. It becomes a state. For this reason, there is a high possibility that the sheet jams when the cassette 101 is attached and detached, and it is difficult to eliminate the above disadvantages.

  The present invention has been made in view of such technical problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding apparatus and an image recording apparatus capable of easily attaching and detaching the sheet storing means with a simple configuration even when the feeding means is arranged at a fixed position with respect to the sheet storing means. And providing an image reading apparatus.

  In order to achieve the above object, the present invention provides a removable sheet storage means for storing a sheet, a feeding means for feeding a sheet from the sheet storage means, and the sheet storage means stacked on the sheet storage means. In a sheet feeding apparatus having a pressure contacting means for pressing a sheet against the feeding means, the sheet is brought into contact with the sheet stored in the sheet storing means when the sheet storing means is mounted on the apparatus. A guide member that guides the sheet so as not to contact the feeding unit, and the sheet storage unit feeds the sheet so that the sheet contacts the feeding unit when the feeding unit feeds the sheet. And a moving means for moving the guide member after being mounted on the apparatus.

  According to the present invention, even when the feeding unit is arranged at a fixed position with respect to the sheet storage unit, the sheet feeding device and the image recording apparatus can be easily attached and detached with a simple configuration. And an image reading apparatus.

  Embodiments of the present invention will be specifically described below with reference to the drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a longitudinal sectional view of an embodiment of a sheet feeding apparatus according to the present invention. FIG. 1A shows a state in which a movable member (sheet guide member) 5 is in contact with a sheet S stacked on a cassette 1. (B) shows a state where the feeding roller 2 is in contact with the sheets stacked on the cassette. In FIG. 1, reference numeral 1 denotes a cassette constituting sheet storage means for stacking sheets S in a sheet form. Reference numeral 2 denotes a cassette for separating and feeding the sheets stacked on the cassette 1 one by one. It is a feed roller which constitutes a feed means arranged on the lower side. The cassette 1 is arranged in a direction intersecting the sheet feeding direction (usually a direction perpendicular to the sheet feeding device) by guide members (guide means) 3 arranged before and after (front and rear in the sheet feeding direction). It is guided to be detachable.

  On the opposite side of the cassette 1 from the feeding roller 2 (upper side of the sheet S), there is provided a pressure plate 4 constituting pressure contact means for pressing the sheets S stacked on the cassette 1 against the feeding roller. The pressure plate 4 is urged toward the feeding roller 2 by a spring 6 which is a downward urging means. The pressure plate 4 can be switched between two states, a pressure contact state in which the sheet is pressed against the feeding roller 2 by a spring biasing force and a pressure release state in which the pressure contact of the sheet is released. A movable member 5 that is movable in the vertical direction is provided in the vicinity of the feeding roller 2. This movable member is composed of a pair of plate-like or rib-like members extending in a direction crossing the feeding direction at positions near the feeding roller 2 in the front and rear direction.

  The movable member 5 protrudes above the feeding roller 2 to contact the lower surface of the sheet S stacked on the cassette 1 and retreats below the feeding roller. It is possible to move between a retracted position (downward position) that is separated from the lower surface of the sheet S. The movement of the movable member is performed by a driving means such as a solenoid controlled by a control means (not shown). An opening (not shown) for allowing the feeding roller 2 and the movable member 5 to contact the lower surface of the stacked sheets S is formed on the bottom surface of the cassette 1. The movable member 5 supports the sheet S against the spring biasing force of the pressure plate 4 in place of the feeding roller 2 at the contact position. When the movable member is in the retracted position, the sheet S is in pressure contact with the feeding roller 2 by the spring biasing force of the pressure plate 4 and is in a feedable state.

  That is, the pressure plate 4 and the movable member 5 in the sheet feeding apparatus according to the present embodiment are in the state shown in FIG. 1A and the state shown in FIG. It is configured to be able to control switching between such states. FIG. 1A shows a state in which the cassette 1 can be easily attached and detached by separating the feeding roller from the sheet. FIG. 1B shows a state in which the feeding operation is enabled by bringing the feeding roller into pressure contact with the sheet. An arrow P in FIG. 1B indicates the feeding direction of the sheet S when the feeding roller 2 is rotated in the arrow direction (counterclockwise direction in the drawing).

  The sheet feeding apparatus according to the present embodiment is widely applicable as long as it supplies a recording medium such as recording paper or a sheet-like member such as a document to the image recording unit or the image reading unit. . For example, the present invention can be applied to a sheet feeding apparatus such as a printer, a copier, a facsimile machine, a scanner, or a combination of these, or a composite device or system. That is, the sheet feeding apparatus according to the present embodiment can be used in an image recording apparatus that records an image on a sheet by a recording unit based on image information, whereby an image recording apparatus that exhibits similar effects can be configured. . In addition, the sheet feeding device according to the present embodiment can be used in an image reading device that reads an image formed on a sheet by a reading unit, whereby an image reading device that exhibits the same effect can be configured.

  2 is a cross-sectional view of the sheet feeding apparatus in FIG. 1 taken along line 2-2 in FIG. In FIG. 2, (a) and (b) show a state in the middle when the sheet storage means is mounted. (C) shows a state in which the insertion of the sheet storage means is completed but the movable member is in the protruding position and is in contact with the sheet. Further, (d) shows a state in which the sheet is pressed against the feeding roller by retracting the movable member after the insertion of the sheet storage means is inserted. Next, with reference to FIGS. 2A and 2B, an operation of mounting and pulling out the cassette 1 that is a sheet storage unit in the sheet feeding apparatus according to the present embodiment will be described. As shown in FIG. 2, the pair of plate-like members constituting the movable member 5 has a height decreasing toward the edge in a direction in which the cassette 1 is attached / detached (a direction intersecting the sheet feeding direction). An inclined portion (tapered shape) 5a is provided.

  In FIG. 2, when the cassette 1 is mounted, the movable member 5 is in a position protruding upward from the feeding roller 2 as shown in FIG. In this state, the cassette is inserted in the direction of the arrow parallel to the rotation shaft 2a of the feeding roller 2. When the cassette is inserted along the taper shape 5a, the top surface of the movable member 5 contacts the bottom surface of the stacked sheet S through an opening (not shown) formed in the bottom surface of the cassette 1, as shown in FIG. Touch. This (b) shows a state in the middle of inserting the cassette 1, and the sheet is lifted by the top surface including the tapered shape 5 a of the movable member 5 and held in a state of being separated from the feeding roller 2. Therefore, the cassette can be inserted without causing the stacked sheets to interfere with the feeding roller.

  In FIG. 2, (c) shows a state where the cassette insertion is completed, and when the cassette insertion is completed, the movable member 5 protrudes from the feeding roller 2 and the sheet is separated from the feeding roller. . When the sheet is fed, the movable member 5 is moved in the direction of the arrow (downward) and retracted below the feeding roller 2 as shown in FIG. In this state (d), the sheet S in the cassette is pressed against the feeding roller 2 by the action of the pressure plate 4 (FIG. 1) biased by the spring, and the feeding operation is possible.

  When the cassette 1 is pulled out from the sheet feeding apparatus, the movable member 5 is moved upward by the control operation of the control means, and is brought into the state of (c) protruding from the feeding roller 2 again. In this state, since the sheet S is separated from the feeding roller 2, the cassette can be pulled out easily and quickly without jamming the sheet. That is, it can be easily removed by the process from (b) to (a) as opposed to the insertion.

  3 to 5 show an embodiment in which the movable member 5 is moved by a moving means having a cam and a solenoid.

  3 to 5, reference numeral 7 denotes a cam member. The cam member 7 has a cam surface 7 a that contacts the movable member 5 and pushes the movable member 5 upward. 8 is a solenoid that moves the cam member 7, and when energized, moves the cam member 7 to the left in FIG. 5 and pushes the movable member 5 upward. A return spring 9 pulls the cam member 7 back to the home position when the solenoid 8 is off. A control circuit 10 controls the solenoid.

  When the cassette 1 is loaded, as shown in FIG. 5A, the solenoid 8 is excited by the signal from the control circuit 10 to move the cam member 7 to the left against the urging force of the return spring 9. . The movable member 5 is moved upward by the cam surface 7 a of the cam member 7, and is positioned at a guide position for guiding the sheet bundle in the cassette 1 to be loaded so as not to contact the outer periphery of the feeding roller 2. At the guide position, the upper surface of the movable member 5 is higher than the outer periphery of the feed roller 2.

  When the cassette 1 is inserted into the apparatus while being guided by the guide member 3 as shown in FIG. 5 (b), the movable member 5 and the feed roller 2 are placed inside the cassette through the opening 1a formed at the bottom of the cassette 1. Break into.

  The sheet bundle in the cassette 1 is guided to the inclined portion 5a of the movable member 5 without coming into contact with the feeding roller 2, and is placed on the movable member 5 as shown in FIGS. 3 and 5C. As shown in FIG. 6, since the cassette 1 is surrounded on all sides by the wall 1b, the edge of the sheet is supported by the wall 1b and the bundled state is maintained.

  When the cassette 1 is moved to the loading position in the apparatus, the control circuit 10 turns off the solenoid 8. The cam member 7 is returned to the home position by the return spring 9, and the movable member 5 moves downward as shown in FIGS. 4, 5 (d), and 7, and the sheet bundle can come into contact with the feeding roller 2. .

FIG. 8 shows an embodiment in which the present invention is applied to an image recording apparatus or an image reading apparatus.
In FIG. 8, reference numeral 10 denotes an image recording apparatus or image reading apparatus.
Reference numeral 11 denotes the feeding device described with reference to FIGS. An image recording unit 12 records an image on a sheet fed by the feeding device 11. A discharge roller 14 discharges the sheet on which the image is formed by the image recording unit to the outside of the image recording apparatus 10.

  In the case of an image reading apparatus, an image reading unit 13 is arranged instead of the image recording unit 12. The image reading unit reads an image of the sheet fed by the feeding device 11.

  According to the above-described embodiment, the movable unit is movable between the contact position that contacts the sheet S by projecting from the feeding unit 2 and the retreat position that is separated from the sheet by retreating from the feeding unit. A member 5 is provided. The control unit positions the movable member 5 at the contact position when the sheet storage unit 1 is attached or detached, and separates the sheet from the feeding unit. The control unit controls the sheet to be brought into pressure contact with the feeding unit by positioning the movable member at the retracted position when performing the feeding operation. For this reason, even in the sheet feeding apparatus configured to detach the sheet storage unit 1 without retracting the feeding unit 2, the sheet storage unit can be easily pulled out and easily inserted with a simple configuration. With this configuration, there is provided a sheet feeding apparatus that can eliminate jamming of the sheet when the sheet storage unit is attached and detached.

FIG. 2 is a longitudinal sectional view of an embodiment of a sheet feeding apparatus according to the present invention, in which (a) shows a state where a movable member protrudes from a feeding roller and lifts a sheet. FIG. 6B is a diagram illustrating a sheet feeding apparatus in a state where the sheet can be fed when the movable member retracts and the sheet is pressed against the feeding roller. FIG. 2 is a cross-sectional view of the sheet feeding device in FIG. 1. (A) And (b) shows the state in the middle when attaching a sheet storage apparatus. (C) shows a state where the mounting of the sheet storage device is completed but the movable member is in contact with the sheet. FIG. 6D is a diagram illustrating a state where the movable member is retracted and the sheet and the feeding roller are pressed against each other after the sheet storage unit is loaded. The figure which shows the effect | action of the cam member which moves a movable member. The figure which shows the effect | action of a cam member. The figure which shows the effect | action of a cam member. The perspective view which shows the positional relationship of a feeding roller and cassette before loading a cassette. The perspective view which shows the positional relationship of a feeding roller and the cassette of the state which loaded the cassette. 1 is a diagram showing an embodiment in which the present invention is applied to an image recording apparatus or an image reading apparatus. FIG. 6 is a longitudinal sectional view illustrating a conventional sheet feeding apparatus, where (a) shows a configuration in which a feeding roller is arranged on the lower side of the sheet, and (b) shows a configuration in which the feeding roller is arranged on the upper side of the sheet The configuration is shown.

Explanation of symbols

1 Sheet storage means (cassette)
2 Feeding means (feeding roller)
3 Guide member 4 Pressure contact means (pressure plate)
5 Movable member 5a Inclined part (tapered shape)
6 Biasing means (spring)
S sheet

Claims (10)

A removable sheet storage means for storing the sheet;
A feeding means for feeding a sheet from the sheet storage means;
A sheet feeding apparatus having a pressure contact means for pressing the sheets stacked on the sheet storage means against the feeding means;
A guide member for guiding the sheet storage means so as not to come into contact with the feeding means when contacting the sheet stored in the sheet storage means when the sheet storage means is mounted on the apparatus;
Moving means for moving the guide member after the sheet storage means is mounted on the sheet feeding apparatus so that the sheet comes into contact with the feeding means when the feeding means feeds the sheet; ,
A sheet feeding apparatus comprising:   The sheet feeding apparatus according to claim 1, further comprising a guide unit configured to guide the sheet storing unit so as to move in a direction intersecting a sheet feeding direction when the sheet storing unit is mounted on the apparatus.   The sheet feeding apparatus according to claim 1, wherein the feeding unit includes a feeding roller that feeds a sheet by rotating in contact with the stacked sheets.   The sheet feeding apparatus according to claim 3, further comprising: a guide unit that guides the sheet storing unit in a direction parallel to a rotation axis of the feeding roller when the sheet storing unit is mounted on the apparatus.   The sheet feeding apparatus according to claim 1, wherein a relative positional relationship between the feeding unit and the sheet storing unit is unchanged in a state where the sheet storing unit is mounted.   The feeding means is disposed below the sheet storage means, and the guide member is arranged so that the sheet stored in the sheet storage means moves above the feeding means when the sheet storage means is mounted. The sheet feeding device according to claim 1, wherein the sheet feeding device is guided.   The sheet feeding device according to claim 1, wherein the guide member guides the sheet until the mounting of the sheet storage unit to the device is completed.   The sheet feeding apparatus according to claim 1, wherein the moving unit moves the guide member so that the sheet comes into contact with the feeding unit after the sheet storage unit is completely attached to the apparatus. A removable sheet storage means for storing the sheet;
A feeding means for feeding a sheet from the sheet storage means;
Pressure contact means for pressing the sheets stacked in the sheet storage means against the feeding means;
In an image recording apparatus having image recording means for recording an image on a sheet fed by the feeding means,
A guide member for guiding the sheet storage means so as not to come into contact with the feeding means when contacting the sheet stored in the sheet storage means when the sheet storage means is mounted on the apparatus;
Moving means for moving the guide member after the sheet storage means is mounted on the apparatus so that the sheet comes into contact with the feeding means when the feeding means feeds the sheet;
An image recording apparatus comprising: A removable sheet storage means for storing the sheet;
A feeding means for feeding a sheet from the sheet storage means;
Pressure contact means for pressing the sheets stacked in the sheet storage means against the feeding means;
In an image reading apparatus having image reading means for reading an image of a sheet fed by the feeding means,
A guide member for guiding the sheet storage means so as not to come into contact with the feeding means when contacting the sheet stored in the sheet storage means when the sheet storage means is mounted on the apparatus;
Moving means for moving the guide member after the sheet storage means is mounted on the apparatus so that the sheet comes into contact with the feeding means when the feeding means feeds the sheet;
An image reading apparatus comprising:

Images