JP4241528B2 - Paper feeding device and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet feeding device and an image forming apparatus that maintain the uprightness of a side guide plate and improve operability and impact resistance during loading.

  In an image forming apparatus such as a copying machine, some paper feeding devices such as a paper feeding tray on which paper on which an image formed on an image carrier is transferred / fixed are compatible with various paper sizes. Such a paper feeding device has a side guide plate for regulating the side edge of the paper, and can slide according to the width of the paper to be used.

  Some paper feeders can stack more than 2000 sheets at a time. In such a sheet feeding device, a stacking section for stacking sheets is deep, and a side guide plate that regulates a side edge of the sheet has a height corresponding to the number of sheets that can be stacked at one time.

  One side guide plate is arranged on each side edge of the paper. When one side guide plate is slid by a rack gear attached to the lower end of the side guide plate and a pinion gear meshing with the rack gear, The guide plate is also slid so that the sheet is positioned from both ends. The side guide plate is further provided with a guide rod, which guides the sliding direction of the side guide plate.

  The side guide plate having such a structure concentrates the force on the joint between the side guide plate and the rack gear when the user slides with the upper end of the side guide plate or when the loading unit is loaded into the paper feeder. Take it. When the force applied to the joining portion is increased, the side guide plate is inclined obliquely, and the paper cannot be accurately regulated. In addition, there is a problem that the load on the guide rod that guides the slide of the side guide plate increases due to the side guide plate falling.

As a method for solving such a problem, there is a method in which an L-shaped metal plate is attached and reinforced at the joint portion between the side guide plate and the rack gear. A desired strength can be obtained by attaching a plurality of the metal plates. Also, rack gears and pinion gears are provided on the upper and lower ends on the outside of the side guide plate, and the upper and lower ends of the side guide are moved in conjunction with a pinion shaft that connects the upper and lower pinion gears. Yes (see, for example, Patent Document 1). Accordingly, when the upper end of the side guide plate moves, the lower end also moves in conjunction with each other, so that the force applied to the joint portion between the side guide and the rack gear can be reduced.
JP 2001-19173 (paragraph 0015, FIG. 3)

  However, in the method of attaching an L-shaped metal plate, when the amount of sheets to be loaded increases, it is necessary to attach a plurality of metal plates in a stacked manner, but in order to ensure the uprightness of the side guide plate only by the rigidity of the metal Need to obtain a great strength, which leads to an increase in size and cost of the apparatus.

  In the case of Patent Document 1, the rack gear protrudes outside the side guide plate. As the types of paper sizes that can be supported by the paper feeding device increase, the sliding range of the side guide plate becomes wider, and accordingly, the rack gear provided outside the side guide plate also needs to be lengthened. Therefore, there is a problem that the paper feeding device cannot be reduced in size.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device and an image forming apparatus that maintain the uprightness of a side guide plate and have improved operability and impact resistance during loading.

In order to achieve the above object, a sheet feeding device according to claim 1 is provided with a stacking unit for stacking sheets and a side guide plate that slides in a width direction of the sheet and regulates one of the side end portions of the sheet. And a hinge plate attached to the side guide plate on one side and the other side plate on the side plate of the stacking portion, and the hinge plate is hinged by engaging two sheet metals in a foldable manner. A structure is formed, and when the side guide plate is inclined, the inclination can be eliminated by the torsional rigidity of the two sheet metals .

The sheet feeding device according to claim 2 is attached to the stacking section for stacking sheets, two side guide plates that slide in the width direction of the sheets and restrict side edges of the sheets, and the side guide plates. In the sheet feeding device having two rack gears for guiding the sliding operation of the side guide plate and a pinion gear provided between the rack gears, one of the two side guide plates is the side guide plate. A hinge plate attached to the side plate of the stacking portion, and the hinge plate foldably engages two sheet metals to form a hinge structure, and the side guide plate When tilted, the tilt can be eliminated by the torsional rigidity of the two sheet metals .

The sheet feeding device according to claim 3, wherein one of the two sheet metals is rotatably fixed to the side guide plate at an upper end and a lower end of the sheet metal, and the other of the two sheet metals is The upper end of the sheet metal is rotatably fixed to the side plate of the stacking unit.

According to a fourth aspect of the present invention, the hinge plate is made of metal.
The sheet feeder according to claim 5 is characterized in that a reinforcing material is attached to the sheet metal.
The sheet feeding device according to claim 6 is characterized in that irregularities are formed on the sheet metal.
8. The image forming apparatus according to claim 7, further comprising: a sheet feeding device that feeds a sheet; and an image forming unit that forms an image on the sheet fed from the sheet feeding device. The apparatus is characterized by being one of the paper feeding apparatuses described above.

The sheet feeding device according to the first aspect includes a stacking unit, a side guide plate, and a hinge plate. Sheets are stacked on the stacking unit. A side guide plate that regulates the side edge of the stacked paper is slidably attached to the stacking unit, and a hinge plate is provided between the side guide plate and the side plate of the stacking unit. One end of the hinge plate is attached to the side guide plate, and the other end is attached to the side plate. When the user grabs and slides the upper end of the side guide plate, the lower end of the side guide plate also slides following the torsional rigidity of the hinge plate. Therefore, it is possible to maintain the uprightness of the side guide plate.

The sheet feeder according to claim 2 has a stacking unit, two side guide plates, two hinge plates , a rack gear, and a pinion gear . Rack gears are attached to the lower ends of the two side guide plates, respectively. When one side guide plate is slid by sandwiching the pinion gear between the two rack gears, the other side guide plate slides in conjunction with it. . A hinge plate is attached to each of the two side guide plates. One end of the hinge plate is attached to the side guide plate, and the other end is attached to the side plate of the stacking unit. Due to the torsional rigidity of the hinge plate, the upper end portion and the lower end portion of the side guide plate slide in conjunction with each other. .

In the paper feeding device according to claim 4, since the hinge plate is made of metal, when the side guide plate slides, the uprightness of the side guide plate can be maintained. According to the fifth aspect of the present invention, a reinforcing member is attached to the sheet metal, and since the unevenness is formed on the sheet metal, the rigidity of the sheet feeding apparatus can be increased and the uprightness of the side guide plate can be maintained. it can.

According to a seventh aspect of the present invention, the image forming apparatus includes a paper feeding device that feeds paper and an image forming unit that forms an image on the paper fed from the paper feeding device. By using the paper feeding device according to any one of claims 1 to 6 , the paper feeding device can prevent the image forming position from being defective due to the side guide plate falling down.

  Next, a sheet feeding device and an image forming apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an example of an image forming apparatus of the present invention. The image forming apparatus 1 forms an image on a sheet 2, and an image reading apparatus 3 that reads an image to be formed on the sheet 2 from a document is provided above the image forming apparatus 1.

  The image reading device 3 further reflects the light from the first mirror unit 4 and the first mirror unit 4 in which a light source that irradiates light on the document and a mirror that reflects light reflected from the document are integrally formed. The first and second mirror units 4 and 5 are movable in the left-right direction in FIG. In addition, the image reading device 3 includes an image sensor 6 that photoelectrically converts light, such as a CCD, and images light from the second mirror unit 5 on the image sensor 6 on the front surface of the image sensor 6. A lens 7 is provided.

  A platen glass 8 is provided on the upper surface of the image reading device 3, and the user places a document on the platen glass 8 and gives an instruction to start an image forming process. As a result, the first and second mirror units 4 and 5 scan the original and are converted into electric signals by the image sensor 6 and then stored in a storage device (not shown).

  Below the inside of the image forming apparatus 1, a plurality of sheet feeding trays 9 for stacking and storing a plurality of sheets 2 are provided in three stages in the vertical direction in the figure. Is provided with a paper feeding means 10 for feeding the paper 2 on which an image is to be formed one by one from the paper feed tray 9. The paper feeding means 10 is composed of a feeding roller 11, a paper roller 12 and a paper feed roller 13.

  An image forming unit 14 for forming an image is disposed above the paper feed tray 9. The image forming unit 14 includes a cylindrical photosensitive drum 15, and the photosensitive drum 15 is driven to rotate clockwise in FIG. 1 by a drum driving mechanism (not shown).

  A charging device 16 is provided in the vicinity of the upper peripheral surface of the photosensitive drum 15. The charging device 16 performs corona discharge on the surface of the photosensitive drum 15 to uniformly charge the surface of the photosensitive drum 15.

  An exposure device 17 using a laser diode or the like as an exposure light source is disposed around the photosensitive drum 15 and downstream of the charging device 16 in the rotation direction of the photosensitive drum 15. The exposure device 17 performs image exposure on the surface of the photosensitive drum 15 based on the image signal, thereby attenuating and extinguishing the electric charge on the surface of the photosensitive drum 15 in the exposed portion, thereby generating an electrostatic latent image. It is supposed to form.

  A developing device 18 is provided downstream of the exposure device 17 in the rotation direction of the photosensitive drum 15. The developing device 18 develops the electrostatic latent image formed on the surface of the photosensitive drum 15 with toner charged to the same polarity as that of the photosensitive drum 15 by a reversal developing method.

  A transfer separation device 19 is disposed downstream of the developing device 18 in the rotation direction of the photosensitive drum 15. A conveyance path for conveying the sheet 2 is formed between the transfer separation device 19 and the photosensitive drum 15. The transfer separation device 19 transfers the toner image to the paper 2 by discharging corona discharge from the back surface of the paper 2 in a state where the paper 2 is pressed against the photosensitive drum 15, and discharges the charged paper 2. As a result, the sheet 2 is separated from the photosensitive drum 15.

  A fixing device 20 is provided on the downstream side of the conveyance path of the transfer separation device 19. The sheet 2 is conveyed to the fixing device 20 so that the toner on the surface is melted by heat and fixed on the sheet 2.

  A cleaning device 21 that removes and cleans toner remaining on the surface of the photosensitive drum 15 is provided around the photosensitive drum 15 and on the downstream side of the transfer separating device 19 in the rotation direction of the photosensitive drum 15.

  A discharge tray 22 for discharging the sheet 2 on which an image is formed is provided on the side of the image forming apparatus 1. Further, an input operation unit (not shown) for inputting an instruction from the user is provided on the upper surface of the image forming apparatus 1.

  The image forming apparatus 1 has a large-capacity paper feeding device 23 attached to the outside in addition to the paper feeding tray 9 incorporated in the apparatus. The paper feeding device 23 has the paper 2 loaded therein, and the top paper 2 among the stacked papers 2 is fed to the image forming apparatus 1 by the paper feeding means 10. The sheet feeding unit 10 of the sheet feeding device 23 is the same as the sheet feeding unit 10 provided in the sheet feeding tray 9 built in the image forming apparatus 1, and includes a feeding roller 11, a separating roller 12, a sheet feeding roller 13, It is composed of

  The feed roller 11 is a roller that takes out the top sheet from the sheets 2 stacked on the sheet feeding device 23, and swings up and down by a solenoid (not shown). When the paper 2 is fed from the paper feeding device 23, the feeding roller 11 is brought into contact with the paper 2 by a solenoid, and the uppermost sheet can be taken out.

  The paper feed roller 13 contacts the upper surface of the paper 2 taken out by the delivery roller 11 and rotates so as to send the paper 2 to the image forming unit 14. Further, the rolling roller 12 contacts the lower surface of the sheet 2 and is driven when the torque exceeds a predetermined torque, and rotates in the conveyance direction of the sheet 2. When the delivery roller 11 takes out a plurality of sheets 2, the roller 12 stops because it does not reach a predetermined torque or more, and stops so that the second and subsequent sheets 2 are not conveyed. Only the uppermost sheet 2 is sent to the image forming unit 14.

  FIG. 2 is a perspective view showing a stacking unit for stacking sheets in the sheet feeding device. The paper feeding device 23 has a stacking unit 24 for stacking the paper 2 therein. The stacking unit 24 slides in the direction indicated by the arrow Y <b> 1, and can be pulled out from or loaded into the paper feeding device 23. The stacking portion 24 has a bottom portion 25 and side plates 26 and 27 formed by bending a sheet metal or the like, and stacks the sheets 2 in a space surrounded by them.

  In the space where the paper 2 is stacked, there is a paper lifting plate 28 for bringing the paper 2 into contact with the feed roller 11. Further, the stacking unit 24 is provided with side guide plates 29 and 30 for regulating the width of the paper 2 and a rear end guide plate 31 for regulating the rear end of the paper 2. The side guide plates 29 and 30 are slidable in the width direction of the paper 2, and the rear end guide plate 31 is slidable in the paper feeding direction of the paper 2.

  Below the sheet lifting plate 28, a guide rod 32 that regulates the sliding direction of the side guide plates 29 and 30 and a lock shaft 33 that locks the side guide plates 29 and 30 are provided. A rack gear (not shown) is attached to the side guide plates 29 and 30 below the paper lifting plate 28, and a pinion gear (not shown) is sandwiched between the rack gears. Accordingly, when the user slides the side guide plate 29, the side guide plate 30 slides in a direction opposite to the sliding direction of the side guide plate 29 in conjunction with the slide.

  The lock shaft 33 is attached to the side guide plate 30 and constitutes a lock mechanism together with a lock member (not shown) provided inside the side guide plate 29. The lock member can be locked and released by a user by a lever 34 provided on the side guide plate 29. In addition, the lock mechanism may have a configuration in which the lock shaft 33 is attached to the bottom portion 25.

  Further, the side guide plates 29 and 30 incorporate a fan (not shown) for spreading the paper 2, and the air blown from the blow-out opening 35 hits the loaded paper 2 so that air is placed between the loaded paper 2. Enters and can prevent double feeding.

  Between the side guide plates 29 and 30 and the side plates 26 and 27, hinge plates 36 and 37 each having a hinge structure formed of two metal plates are attached. The hinge plates 36 and 37 are made shorter than the height of the side guide plates 29 and 30 by the diameter of the guide rod 32 or the lock shaft 33, and are made of a metal having high torsional rigidity. In FIG. 2, the hinge plate 36 is attached so as to be folded toward the rear end guide plate 31, and the hinge plate 37 is attached so as to be folded toward the opposite direction, that is, toward the feed roller 11. The attachment direction of the hinge plates 36 and 37 can be attached so that the hinge plates 36 and 37 are both folded in the same direction, and is not limited to the embodiment of FIG.

  FIG. 3 is a perspective view of the hinge plate. Here, the description will be made using the hinge plate 37, but the hinge plate 36 has the same structure. The hinge plate 37 is made of sheet metal 38, 39 formed by punching a metal plate having a thickness of about 1.6 mm to 2.0 mm by pressing or the like and bending the upper end portion and the lower end portion. The metal plates 38 and 39 become one hinge plate 37 by fixing the upper and lower bent portions with pins 40 or the like.

  The side plate 27 and the hinge plate 37 are fixed to a fixing member (not shown) provided on the side plate 27 and an upper end portion of the sheet metal 38 so as to be rotatable by a pin 41 or the like. The lower end of the sheet metal 38 is attached to the bottom 25 with a stepped screw 42. The side guide plate 30 and the hinge plate 37 are fixed so that the upper and lower ends of the sheet metal 39 and a fixing member (not shown) provided on the side guide plate 30 can be rotated by a pin 43. Between the pins 41 and 43 and the stepped screw 42 and a hole (not shown) that is inserted through the hinge plate 37, the hinge plate 37 is not opened and closed and there is no sense of play. A gap of a degree is provided.

  In the sheet feeding device 23 having the hinge plates 36 and 37 having such a structure, when the user tries to widen the interval between the side guide plates 29 and 30, the following is performed. The user pushes the lever 34 to unlock the side guide plates 29 and 30 and slides the side guide plate 29 toward the side plate 26. Here, when the user grabs and slides the upper part of the side guide plate 29, the upper part of the side guide plate 29 moves ahead of the lower part, and the side guide plate 29 is slightly inclined. . At this time, the hinge plate 36 is in a state in which the hinge is closed at the upper part from the lower part. In this state, the metal plates 38 and 39 are twisted. However, since the metal plates 38 and 39 are metal plates having high torsional rigidity, the lower hinge of the hinge plate 36 is closed in order to eliminate the twist. As a result, since the lower part of the side guide plate 29 slides in conjunction with each other, the uprightness of the side guide plate 29 is maintained.

  Further, in order to further increase the rigidity of the hinge plates 36 and 37, a reinforcing material having a shape such as an X type or a Z shape is attached to the metal plates 38 and 39, or unevenness such as an X type or a Z type is applied to the metal plates 38 and 39 by pressing. May be formed.

  Note that, in the paper feeding device 23 of this embodiment, the two side guide plates 29 and 30 regulate both side edges of the paper 2. However, the present invention can also be applied to a paper feeding device 23 in which one side edge of the sheet 2 is abutted against the side plate 26 or the side plate 27 of the stacking unit 24 and the other end is regulated by the side guide plate 29 or 30. Is possible.

  Furthermore, as another embodiment, there is a paper feeding device 23 in which a reinforcing plate without a hinge structure is attached only to the side guide plates 29 and 30. The reinforcing plate is attached between the side guide plates 29 and 30 and the side plates 26 and 27 so as to be perpendicular or substantially perpendicular to the plane of the side guide plates 29 and 30. Even in such a configuration, the verticality of the side guide plates 29 and 30 is maintained by the rigidity of the reinforcing plate.

1 is a configuration diagram illustrating an example of an image forming apparatus of the present invention. FIG. 6 is a perspective view illustrating a stacking unit that stacks sheets of the sheet feeding device. It is a perspective view of a hinge board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Paper 23 Paper feeder 24 Stacking part 26, 27 Side plate 29, 30 Side guide plate 36, 37 Hinge plate

Claims (7)

A loading section for loading paper;
A side guide plate that slides in the width direction of the paper and regulates one of the side edges of the paper;
One is attached to the side guide plate, the hinge plate and the other is attached to the side plate of the loading section,
Have
The hinge plate forms a hinge structure by engaging two sheet metals so as to be foldable, and the inclination can be eliminated by the torsional rigidity of the two sheet metals when the side guide plate is inclined. A paper feeder characterized by. A loading section for loading paper;
Two side guide plates that slide in the width direction of the paper and regulate the side edges of the paper;
Two rack gears attached to the side guide plate and guiding the sliding movement of the side guide plate;
A pinion gear provided between the rack gears;
In a paper feeder having
Wherein the two side guide plates attached one to the side guide plates, have a hinge plate attached to the other to the side plate of the loading section,
The hinge plate forms a hinge structure by foldably engaging two metal plates, and the inclination can be eliminated by the torsional rigidity of the two metal plates when the side guide plate is inclined. Characteristic paper feeder. One of the two metal plates is rotatably fixed to the side guide plate at the upper and lower ends of the metal plate,
3. The sheet feeding device according to claim 1, wherein the other of the two metal plates is rotatably fixed to a side plate of the stacking portion at an upper end of the metal plate. 4. . The paper feeding device according to claim 1, wherein the hinge plate is made of metal. The sheet feeding device according to any one of claims 1 to 4, wherein a reinforcing material is attached to the sheet metal. 5. The sheet feeding device according to claim 1, wherein unevenness is formed on the sheet metal. A paper feeder for feeding paper,
An image forming unit that forms an image on a sheet fed from the sheet feeding device;
In an image forming apparatus having
The image forming apparatus according to claim 1 , wherein the sheet feeding device is the sheet feeding device according to claim 1 .

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