JP2006199403A - Paper feeding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding device realizing miniaturization of the device and cost reduction while enabling paper-feeding of a plurality of paper sizes. <P>SOLUTION: The paper feeding device 18 has a paper feed hopper 20 detachably attached to the paper feeding device 18 and stacking and storing paper sheets; a pickup roller 24 for picking up the uppermost paper sheet stored in the paper feed hopper 20; and a stepping motor 68. The paper feed hopper 20 has a first hopper 70; and a second hopper 72 arranged in the paper stacking direction of the first hopper 70 and horizontally movably provided on the first hopper 70 to the paper feeding direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet supply apparatus, for example, a sheet supply apparatus used in an image forming apparatus.

  In general, an apparatus having a sheet supply device for supplying a sheet to an image forming unit of an image forming apparatus is known. Usually, the paper is stored in a hopper or the like, and the paper stored in the hopper is supplied to the conveyance path. In this type of paper feeding apparatus, it is known to feed a plurality of paper sizes with a single hopper (for example, Patent Documents 1 to 3).

JP-A-4-246031 JP-A-5-8870 Japanese Patent Laid-Open No. 11-11701

  For example, Patent Document 1 discloses that copy papers of different sizes can be stored in one cassette case, and copy papers of different sizes can be selectively taken out and fed. Further, for example, in Patent Document 2, a large cassette is divided into two to form an integral two-stage cassette, so that the function of the two-stage cassette can be provided without increasing the size of the apparatus, and a large-size cassette can be mounted. It is disclosed to do so. Further, for example, Patent Document 3 discloses that two sheet trays are arranged one after the other along the sheet feeding direction, so that the entire sheet feeding device can be lowered.

  However, the invention disclosed in Patent Document 1 has a problem that the pick roller must be moved when changing the paper. When the pick roller is moved, it becomes difficult to apply appropriate pressure to the paper, and the paper conveyance path needs to be changed. Moreover, in the invention disclosed in Patent Document 2, there is a problem that the cost increases because a plurality of pick rollers are used. In addition, in the invention disclosed in Patent Document 3, there is a problem that sheets of the same size cannot be fed because sheets of the same size are stored in two in one sheet cassette.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a paper feeding device that solves the above-mentioned conventional problems and realizes a reduction in the size and cost of the device while enabling paper feeding of a plurality of paper sizes.

  The present invention is characterized in that at least a sheet feeding device main body, a pickup roller fixed to the sheet feeding device main body, a movably provided relative to the sheet feeding device main body, and a sheet is stacked and accommodated. When two hoppers and one hopper whose uppermost sheet is in contact with the pickup roller are moved, the other hoppers are moved so that the uppermost sheet loaded on the other hopper contacts the pickup roller. It is in a paper feeding device having cooperation means for linking the hoppers so as to be moved.

  Preferably, it further has drive means for moving at least one hopper.

  Preferably, the one hopper moves horizontally with respect to the sheet feeding apparatus body, and the other hopper swings with respect to the sheet feeding apparatus body.

  Preferably, the one hopper has a support member that slidably supports the other one hopper.

  Preferably, the one hopper is detachably attached to the other one hopper.

  Preferably, there is a detection means for detecting the presence or absence of the one hopper provided to be removable from the other one hopper.

  According to the present invention, by having at least two hoppers and linkage means for linking these hoppers, paper feeding that enables paper feeding of a plurality of paper sizes and realizes downsizing and cost reduction of the apparatus. An apparatus can be realized.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an image forming apparatus 10 according to an embodiment of the present invention. The image forming apparatus 10 includes an image forming apparatus main body 12, an image forming unit 14 is mounted in the image forming apparatus main body 12, and a discharge unit 16 is provided on the upper portion of the image forming apparatus main body 12. A paper feeding device 18 is provided below the image forming apparatus main body 12. The sheet feeding device 18 includes a sheet feeding hopper 20 that accommodates a sheet bundle, and a pickup roller 24 that picks up the sheet at the top of the sheet bundle accommodated in the sheet feeding hopper 20.

  The discharge unit 16 includes an inclined unit 30 that is rotatable with respect to the image forming apparatus main body 12. The inclined portion 30 has a low discharge port portion and is inclined so as to gradually increase in the front direction (right direction in FIG. 1), with the discharge port portion as a lower end and a higher tip as an upper end. . The inclined portion 30 is supported by the image forming apparatus main body 12 so as to be rotatable around the lower end. As shown by a two-dot chain line in FIG. 1, when the inclined portion 30 is rotated upward and opened, an opening portion 32 is formed, and a process cartridge 34 (to be described later) can be attached and detached through the opening portion 32. .

  The image forming means 14 is of, for example, an electrophotographic system, and includes an image carrier 36 made of a photosensitive member, a charging device 38 made of, for example, a charging roll for uniformly charging the image carrier 36, and charged by the charging device 38. An optical writing device 40 for writing a latent image on the image carrier 36 by light, a developing device 42 for visualizing the latent image of the image carrier 36 formed by the optical writing device 40 with a developer, and the developing device. For example, a transfer device 44 composed of, for example, a transfer roll for transferring the developer image by the paper 42 to the paper, a cleaning device 46 composed of, for example, a blade for cleaning the developer remaining on the image carrier 36, and the paper transferred by the transfer device 44 For example, a fixing device 48 composed of a pressure roll and a heating roll. The optical writing device 40 is composed of, for example, an optical scanning laser exposure device, and is arranged in the vicinity of the front surface (right side surface in FIG. 1) of the image forming apparatus main body 12 in parallel with the paper feeding hopper 20 of the paper feeding device 18. To expose. The developing device 42 includes a developing roll 50 that faces the image carrier 36.

  The process cartridge 34 is obtained by integrating an image carrier 36, a charging device 38, a developing device 42, and a cleaning device 46. The process cartridge 34 is disposed immediately below the inclined portion 30 of the discharge portion 16 and is attached / detached through the opening portion 32 formed when the inclined portion 30 is opened as described above.

  In the image forming apparatus main body 12, for example, a resist roll 52 is arranged on the upstream side of the transfer device 44. The sheet conveyed from the sheet feeding hopper 20 of the sheet feeding device 18 to the conveying path 54 is temporarily stopped by the registration roll 52 and sent to the image forming unit 14 at a predetermined timing to form an image. It is discharged to the discharge unit 16.

  However, in the case of duplex printing, it is returned to the reverse path. That is, the front of the discharge roll 56 is divided into two forks, and a switching claw 58 is provided at the divided portion, and a reversing path 60 is formed to return from the divided portion to the registration roll 52. The reversing path 60 is provided with transport rolls 62a to 62c. In the case of double-sided printing, the switching claw 58 is switched to the side that opens the reversing path 60, and the discharge roll 56 is in front of the rear end of the sheet. Thus, the discharge roll 56 is reversed, the paper is guided to the reverse path 60, and is discharged to the discharge portion 16 through the resist roll 52, the transfer device 44 and the image carrier 36, and the fixing device 48.

  Next, the sheet feeding device 18 will be described with reference to FIGS.

  The sheet feeding device 18 has an opening 64 in which the front side (right side surface in FIG. 1) of the image forming apparatus 10 is opened. The paper feed hopper 20 is detachably accommodated in the opening 64.

  The pickup roller 24 is fixed to a rotating shaft 66 that is rotatably supported by the frame of the paper feeding device 18, and is disposed in the vicinity of the front part in the paper feeding direction at the top of the paper feeding hopper 20. The pickup roller 24 is rotated by a driving means (not shown) so as to pick the uppermost sheet in a sheet bundle placed on a sheet feeding hopper 20 described later. Further, a stepping motor 68 serving as a driving unit, which will be described later, is provided on the frame of the paper feeding device 18 and moves the second hopper 72 of the hopper 20.

  The sheet feeding hopper 20 has, for example, two hoppers (a first hopper 70 and a second hopper 72).

  As shown in FIG. 2, the first hopper 70 has a box shape with an upper surface opened, and a first bottom plate 74 is provided on the bottom surface of the first hopper 70. The first bottom plate 74 is swingably supported by the first hopper 70, and a sheet bundle 76 is placed on the upper surface of the first bottom plate 74. Further, a compression spring 78 as a first urging means is provided in the vicinity of the front end in the sheet feeding direction between the first hopper 70 and the first bottom plate 74. The compression spring 78 urges the first bottom plate 74 toward the pickup roller 24.

  The first bottom plate 74 of the first hopper 70 is provided with a set of side guides 80 that come into contact with both side edges (from the sheet feeding direction) of the sheet bundle 74. An end guide 82 is slidably provided at the rear end position of the sheet bundle 76 on the bottom surface of the first hopper 70. The side guides 80 and the end guides 82 hold the sheet bundle 76 placed on the upper surface of the first bottom plate 74.

  FIG. 2 shows a state in which the sheet bundle 76 placed on the first bottom plate 74 is brought into contact with the pickup roller 24 by a compression spring 78 and the uppermost sheet of the sheet bundle 76 is picked by the pickup roller 24. Show. That is, the first hopper 70 in the paper feed hopper 20 is being used.

  As shown in FIG. 2, the second hopper 72 has a box shape with an upper surface opened, and is provided in a part of the first hopper 70 described above. That is, the second hopper 72 is provided on the upper side of the first hopper 70 in the paper stacking direction, and the upper surface of the first hopper 70 and the upper surface of the second hopper 72 are arranged to have the same height. Yes. Further, when the first hopper 70 is used, the rear end surface of the second hopper 72 in the paper feeding direction is arranged to protrude from the rear end surface of the first hopper 70 in the paper feeding direction.

  As shown in FIGS. 2 and 3, a second bottom plate 84 is provided on the bottom surface of the second hopper 72. The second bottom plate 84 is swingably supported by the second hopper 72, and a sheet bundle 86 is placed on the upper surface of the second bottom plate 84.

  The second bottom plate 84 of the second hopper 72 is provided with a set of side guides 88 that come into contact with both side edges (from the paper feeding direction) of the sheet bundle 86. An end guide 90 is slidably provided at the rear end position of the sheet bundle 86 on the bottom surface of the second hopper 72. These side guides 88 and end guides 90 hold a sheet bundle 86 placed on the upper surface of the second bottom plate 84.

  The side guide 80 of the first bottom plate 74 and the side guide 88 of the second bottom plate 84 described above are provided slidably with respect to the first bottom plate 74 and the second bottom plate 84. Further, the side guide 80 and the side guide 88 are provided so as to be fitted into the notch 92 so as to swing together with the first bottom plate 74 and the second bottom plate 84 (FIGS. 5A and 5B). Show).

  As shown in FIG. 4, the guide rail 94 as a support member is formed in a rod shape having a predetermined width, and is provided on the inner wall surfaces on both sides when viewed from the feeding direction of the first hopper 70. For example, the guide rail 94 is horizontally disposed from the front end to the rear end of the first hopper 70 at a position where the first hopper 70 is divided into two in the sheet stacking direction (vertical direction of the first hopper). . The second hopper is placed on the upper surface of the guide rail 94. That is, the second hopper 72 is provided to be slidable in the paper feeding direction with respect to the first hopper 70.

  The stepping motor 66 is disposed so as to contact the upper surface of the second hopper 72. A pinion gear 96 is fixed to the drive shaft (output shaft) of the stepping motor 66. The pinion gear 96 meshes with a rack 98 provided on the upper surface of the second hopper 72. Accordingly, when the stepping motor 96 rotates forward and backward, the second hopper 72 moves back and forth with respect to the paper feeding direction.

  In the second hopper 68 described above, for example, a paper having a size smaller than that of the paper bundle 84 of the first hopper 70 is placed. That is, the paper size loaded and accommodated in the first hopper differs from the paper 84 loaded and accommodated in the second hopper. As a result, a plurality of paper sizes can be fed by a single sheet feeding hopper without using a plurality of sheet feeding apparatuses, and thus the apparatus can be reduced in size and cost.

  Here, the cooperative operation between the hoppers when the first hopper 70 and the second hopper 72 are switched will be described with reference to FIGS.

  The first hopper 70 and the second hopper 72 have a first bottom plate 74, a compression spring 78, a second bottom plate 84, an inclined member 100, and a bottom plate pushing-down means 104 as linkage means.

  As shown in FIGS. 3 and 4, the inclined member 100 is formed in a longitudinal triangular shape having a predetermined inclination, and is provided on the inner wall surfaces on both sides (paper feeding direction) of the first hopper 70. The inclined member 100 is disposed in the vicinity of the front of the first hopper (paper feeding direction) at a position above the guide rail 94 described above.

  As shown in FIG. 4, the second bottom plate 84 of the second hopper 72 is provided with a protrusion 102 so as to come into contact with the inclined surface of the inclined member 100 described above. That is, when the second hopper 72 moves forward (paper feeding direction), the protrusion 102 of the second bottom plate 74 moves while sliding on the inclined surface of the inclined portion 100.

  As shown in FIGS. 2 and 3, the bottom plate pressing means 104 is provided on both sides (from the paper feeding direction) of the first bottom plate 74 of the first hopper 70. The bottom plate pressing means 104 is formed with an inclined surface having a predetermined inclination.

  FIG. 2 shows a state in which the uppermost sheet of the sheet bundle 76 accommodated in the first hopper 70 is in contact with the pickup roller 24.

  When the second hopper 72 is moved forward (paper feeding direction), the vicinity of the tip of the lower portion of the second hopper 72 comes into contact with the inclined surface of the push-down member 104 of the first hopper 70.

  The second hopper 72 pushes down the push-down member 104 against the biasing force of the compression spring 78 that biases the first bottom plate 74. As a result, the second bottom plate 84 of the second hopper 72 rotates downward (left rotation in FIG. 2).

  On the other hand, the second bottom plate 84 of the second hopper 72 is urged toward the pickup roller 24 by sliding while the inclined member 100 and the protruding portion 102 of the second bottom plate 84 are in contact with each other. Thus, the sheet bundle 86 placed on the second bottom plate 84 comes into contact with the pickup roller 24.

  Contrary to the above, when the second hopper 70 in which the uppermost sheet is in contact with the pickup roller 24 is moved rearward (paper feeding direction), the uppermost sheet loaded on the first hopper 72 is moved. The sheet comes into contact with the pickup roller 24.

  At this time, the contact between the pickup roller 24 and the sheet bundle 86 placed on the second hopper 72 is released by the weight of the sheet bundle 86 as the second hopper 72 moves rearward (paper feeding direction). Is done.

  Thus, since the first hopper 70 and the second hopper 72 use the same pickup roller 24, it is possible to realize cost reduction without providing a new pick roller. Further, it is not necessary to provide a new paper conveyance path.

  Note that when the second hopper 72 is moved by the stepping motor 68, the switching between the first hopper 70 and the second hopper 72 is automatically performed.

  Next, a large capacity hopper by the first hopper will be described with reference to FIGS.

  As shown in FIG. 6, a large number of sheet bundles 76 are stacked and accommodated in the first hopper 70. The second hopper 72 is removed from the first hopper 70. As described above, the second hopper 72 is detachably provided to the first hopper 70.

  Further, the first hopper 70 is provided with a detection sensor 106 as detection means. The detection sensor 106 detects the presence or absence of the second hopper 72. When the detection sensor 106 detects that the second hopper 72 is not present, the result is displayed on an operation panel (not shown). Thereby, the user can recognize that the first hopper 70 is used as a large capacity hopper.

  Further, as shown in FIG. 7, the side guide 80 is extendable (sliding) so that a large capacity of paper can be stacked and accommodated. As described above, when the first hopper 70 is used as a large capacity hopper, the side guide 80 can be extended in the vertical direction. Similarly to the side guide 80, the end guide 82 is also extendable (sliding). Note that the side guide 80 and the end guide 82 may be replaced with ones having a higher height in accordance with the height of the sheets to be stacked and accommodated.

  As described above, the first hopper can be used as a large-capacity hopper by removing the second hopper 72. As a result, a new large-capacity hopper is not required even during mass printing on the same paper size, and cost reduction can be realized.

  The operation of the above embodiment will be described.

  The paper feeding hopper 20 is removed from the frame of the paper feeding device 18, and the second hopper 72 is removed from the first hopper 70. In this manner, by removing the second hopper 72, it is possible to easily set the paper on the first hopper 70.

  A sheet bundle 76 is stacked and accommodated in the first hopper 70, a second hopper 72 is mounted on the first hopper 70, and a sheet bundle 86 having a size different from that of the first hopper 70 is attached to the second hopper 72. To house.

  A sheet feeding hopper 20 is mounted on the frame of the sheet feeding device 18 and a predetermined operation is performed on an operation panel (not shown). For example, as shown in FIG. 2, from a sheet bundle 76 accommodated in the first hopper 70. Paper is fed.

  For example, when changing the paper size, when a predetermined operation is performed on an operation panel (not shown), the stepping motor 68 is driven. As a result, as shown in FIG. 3, the second hopper 72 automatically moves forward in the paper feeding direction, the first hopper 70 rotates downward, and the sheet bundle accommodated in the second hopper 72. Paper is fed from 86.

  As described above, when the user selects a desired sheet using the operation panel (not shown), a drive command is transmitted to the above-described stepping motor 66. In addition, the stepping motor 66 is driven by this drive command, and the first hopper 70 and the second hopper 72 are switched. As a result, the paper is automatically switched, so that the user can use a plurality of paper sizes without being aware of it.

  For example, when processing a large amount of sheets of the same size, the sheet feeding hopper 20 is removed from the frame of the sheet feeding device 18, and the second hopper 72 is removed from the first hopper 70.

  The side guide 80 and the end guide 82 of the first hopper 70 are extended. A large amount of sheets are stacked and stored in the first hopper 70, and the sheet feeding hopper 20 is mounted on the frame of the sheet feeding device 18.

  Thereafter, a desired operation (paper replacement, paper switching, etc.) is performed in the same procedure as described above.

  Next, a second example of the paper feed hopper 20 is shown in FIG.

  As shown in FIG. 8, the rear end of the second hopper 72 may be accommodated in the first hopper 70. As a result, the first hopper 70 can accommodate a larger size sheet.

1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating the sheet feeding device according to the embodiment of the present invention and illustrating the use of the first hopper. It is sectional drawing which shows the paper feeder concerning embodiment of this invention, and represents the time of 2nd hopper use. 2A and 2B show a state in which the second hopper moves relative to the first hopper in the paper feeding hopper of the paper feeding device according to the embodiment of the present invention, in which (a) is a longitudinal sectional view and (b) is an upper surface of (a). FIG. The side guide used for the paper feed hopper of the paper feeder which concerns on embodiment of this invention is shown, (c) is a longitudinal cross-sectional view, (d) is a top view of (c). It is sectional drawing which shows the paper feed hopper of the paper feeder which concerns on embodiment of this invention, and shows the time of large capacity hopper use by the 1st hopper. The side guide used for the paper feed hopper of the paper feeder which concerns on embodiment of this invention is shown, (e) is a longitudinal cross-sectional view, (f) is a top view of (e). It is sectional drawing which shows the 2nd example of the paper feed hopper in the paper feeder which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 20 Paper feed hopper 24 Pick roller 68 Stepping motor 70 1st hopper 72 2nd hopper 74 1st bottom board 78 Compression spring 84 2nd bottom board 86 Sheet bundle 94 Guide rail 96 Pinion Gear 98 Rack 100 Inclining member 102 Protruding portion 104 Bottom plate pressing member 106 Detection sensor

Claims (6)

A paper feeder main body, and a pickup roller fixed to the paper feeder main body;
At least two hoppers that are movably provided with respect to the paper feeder main body and on which sheets are stacked and accommodated;
When one hopper whose uppermost sheet is in contact with the pickup roller is moved, the hopper is moved so that the uppermost sheet loaded on the other hopper is in contact with the pickup roller. A linkage means to link them,
A sheet feeding device comprising:   The sheet feeding device according to claim 1, further comprising driving means for moving at least one hopper.   3. The sheet feeding device according to claim 1, wherein the one hopper moves horizontally with respect to the sheet feeding device body, and the other one hopper swings with respect to the sheet feeding device body.   4. The sheet feeding device according to claim 1, wherein the one hopper includes a support member that slidably supports the other one hopper.   5. The sheet feeding device according to claim 1, wherein the one hopper is detachably attached to the other one hopper.   6. The sheet feeding device according to claim 5, further comprising detection means for detecting presence / absence of the one hopper that is detachably attached to the other one hopper.

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