JP2011131961A - Paper feeding device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper feeding device structured to attain driving connection and cost reduction without causing a large load and a fault when inserting a paper feeding tray, and an image forming apparatus. <P>SOLUTION: A pinion gear is rotated to move a rack member 112, and a pressing arm 108 is rotated by a pressing spring 111. A bottom plate 101 is rotated around pivots 101a, 101b and lifted to press paper 3 on the bottom plate 101 to a pickup roller 2. When the rack member 112 is moved, a rack fixing member 114 is rotated to fall into a groove 112a of the rack member 112, and the rotation of the pinion gear 107 becomes free. The rack member 112 is moved in a reverse direction by the pressing spring 111 and stops in contact with the rack fixing member 114 mounted to an apparatus body of the image forming apparatus. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a paper feeding device that separates and conveys recording paper from a stack of stacked sheets, and an image forming apparatus including the paper feeding device.

  2. Description of the Related Art Conventionally, in a paper feeding device used in an image forming apparatus such as a copying machine, when papers stacked on a bottom plate in a paper feeding cassette or a paper feeding tray are fed one by one, the paper is fed prior to paper feeding. Must be brought into pressure contact with the paper feed roller (or pick up roller) provided above the paper (that is, the bottom plate is raised).

  In this bottom plate raising method, as disclosed in Patent Document 1, the paper is moved in parallel with the separation unit by raising and lowering the bottom plate, and the distance between the separation unit and the paper is made constant, thereby There are some that enable stable paper feeding regardless of the number of sheets. However, this method has a problem that a dedicated motor is required because the bottom plate is fixed, and a load is applied to the motor shaft.

  Patent Document 2 discloses a mechanism for raising and lowering the bottom plate by a toothless gear one turn. The gear stop member catches a pawl, but there is a problem in durability because the bottom plate is fastened by a claw.

  In other words, the method of raising the bottom plate by the motor is superior to the spring pressurization method, which has the disadvantage that the mounting force or output of the cassette or tray becomes heavy and the operability is reduced, but the configuration becomes complicated. There are disadvantages such as increased costs. Therefore, there is a method using a one-turn gear for removing the dedicated motor for raising the bottom plate for cost reduction, but another mechanism for supporting the bottom plate that is originally supported by driving is required.

  In some conventional technologies, the bottom plate is supported by raising the bottom plate with the rack and pinion and fixing the pinion, but the rack is fixed on the tray side, and the bottom plate can be raised, but it is separate from the lowering. This mechanism is necessary. Further, since the bottom plate does not descend immediately after the tray is pulled out, there is a concern about damage to the paper due to friction between the paper feed roller and the paper. Further, if 250 sheets of paper are stacked on the paper feed tray on the fixing member, a force of about 25 N is applied, and there is a concern about the durability problem depending on the fixing method.

  In addition, as a conventional technology, there is an electrical component such as a solenoid or worm gear, or a method of detecting and fixing that the rack has reached a fixed position by driving, but there are disadvantages such as increased cost and complicated configuration Occurs.

  The present invention provides a sheet feeding device including a bottom plate raising mechanism capable of reliably fixing and lowering the bottom plate and fixing the bottom plate without using a drive mechanism, and an image forming apparatus using the same. Objective.

  In the paper feeding device according to the first aspect of the present invention, a paper feed tray for stacking paper is provided with a bottom plate for setting paper, and is provided at a position below the bottom plate to move up and down to rotate. Push-up member, pressure arm connected to the push-up member, pressure spring connected to the pressure arm, rack connected to the pressure spring, a pinion gear for moving the rack, and the pinion gear In the paper feeding device having a bottom plate raising mechanism having a toothless gear connected to the toothless gear, a drive gear for transmitting driving to the toothless gear, and a solenoid for suppressing the toothless gear, the position of the rack after the bottom plate is raised A fixing member capable of fixing the paper tray is provided on a mounted device side on which the paper feed tray is mounted.

  According to a second aspect of the present invention, in the paper feeding device of the first aspect, the fixing member disposed on the mounted device side includes an inclined portion that guides the rack, a portion that stops the rack, and a force exerted by the rack. And a portion to which a spring for returning to a fixed position from a state moved by the rack is attached, and linearly moves perpendicular to the moving direction of the rack by the force exerted by the rack. To do.

  According to a third aspect of the present invention, in the paper feeding device of the first aspect, the fixing member disposed on the mounted device side includes an inclined portion that guides the rack, a portion that stops the rack, and a force exerted by the rack. And a portion to which a spring for returning to a fixed position from a state moved by the rack is attached, and is rotatable by a force exerted by the rack.

  An image forming apparatus according to a fourth aspect includes the paper feeding device according to any one of the first to third aspects.

  According to a fifth aspect of the present invention, there is provided a bottom plate for setting paper in a paper feed tray for stacking paper, a push-up member that is provided at a lower position of the bottom plate to be moved up and down, and rotates. A pressure arm connected to the pressure arm; a pressure spring connected to the pressure arm; a rack connected to the pressure spring; a pinion gear that moves the rack; and a toothless gear connected to the pinion gear; A sheet feeding device having a bottom plate raising mechanism having a drive gear for transmitting driving to the toothless gear, and a solenoid for suppressing the toothless gear, and a fixing member capable of fixing the position of the rack after the bottom plate is raised. It is provided in the image forming apparatus main body.

  According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the fixing member includes an inclined portion that guides the rack, a portion that stops the rack, a portion that supports a force exerted by the rack, and the rack. And a portion for attaching a spring for returning to a fixed position from the moved state, and linearly moves perpendicular to the moving direction of the rack by the force exerted by the rack.

  According to a seventh aspect of the present invention, in the image forming apparatus of the fifth aspect, the fixing member disposed on the mounted device side includes an inclined portion that guides the rack, a portion that stops the rack, and a force exerted by the rack. And a portion to which a spring for returning to a fixed position from a state moved by the rack is attached, and is rotatable by a force exerted by the rack.

  According to the present invention, it is possible to provide an image forming apparatus and an image forming apparatus that are provided with a bottom plate raising mechanism that is low in cost and does not deteriorate the operability of a cassette or tray by a simple mechanism.

1 is a diagram illustrating an outline of a sheet feeding device and an image forming apparatus according to an embodiment of the present invention. Explanatory drawing about separation conveyance of paper feeder Top view of the paper tray The perspective view (A) and the side view (B) of the bottom plate raising mechanism Operation explanation Operation explanation Explanatory drawing of drive transmission from the device body Feeding operation explanatory diagram Plan view showing the operation of the bottom plate raising mechanism

  In the present invention, a member for stopping the rack member is attached to the main body side, so that the rack member is stopped after the bottom plate is raised, thereby fixing the bottom plate, and the bottom plate is automatically lowered by removing the paper feed tray. Such an operation can be made with a simple configuration without using a driving force.

  For example, by attaching an inclined part, a rack fixing part, a part that supports the force received by the rack member, and a spring member to a rack fixing member that moves linearly in a direction different from the rack member, the rack member can be smoothly moved when the rack member is moving. When the fixing member is pushed down and the rack member comes to a fixed position, the rack fixing member is surely moved to the portion where the rack member is fixed by the spring, and the rack member is fixed. By attaching the spring member to the part that supports the force received by the rack member, the rack fixing member can be securely damaged by bringing the part that supports the force received by the rack member into contact with the wall after the rack member is fixed. Fix the rack member.

  FIG. 1 is a diagram showing an outline of a sheet feeding device and an image forming apparatus according to an embodiment of the present invention. The paper feed tray 100 can be taken in and out from the front (surface A) of the apparatus main body 1 (attached apparatus) of an image forming apparatus such as a copying machine (front loading paper feed tray system). A sheet feeding roller device 2 (a pickup roller 4, a feed roller 5, and a separation roller 6 described later) is provided in the apparatus main body 1, and the sheet 3 accommodated in the sheet feeding tray is fed in the direction of arrow B in the figure. The

Separation and conveyance of the sheet feeding device will be described with reference to FIG. In the figure, reference numeral 4 is an upper part of the paper feed tray 100 fixed to the feeding side, and at the time of feeding, a pick-up roller that presses and feeds the uppermost paper, and 5, 6 are feed rollers for preventing double feeding of the paper And a separate roller.

  The paper feed tray will be described with reference to FIG. The paper feed tray 100 includes a box-shaped tray main body 105 that is open at the top, a bottom plate 101 provided on the bottom surface of the tray main body, a pair of side fences 102 and 103, and an end fence 104.

  The bottom plate 101 is provided so as to be pivotable up and down with the support shafts 101a and 101b as fulcrums, and the sheets 3 are stacked on the bottom plate 101. The support shaft 101b is positioned on the back side of the paper feed tray 100, and the bottom plate 101 is rotated so that the front side (the front side in the paper feeding direction of the paper 3 fed from the bottom plate 101) moves up and down. The leading end side of the sheet 3 stacked on the bottom plate 101 is pressed against the pickup roller 4 (see FIGS. 2 and 3).

  The side fences 102 and 103 are provided so as to be slidable along the horizontal width direction (direction orthogonal to the paper feeding direction) of the paper 3 stacked on the bottom plate 101. The slid side fences 102 and 103 are brought into contact with the side surface of the sheet 3, and the stacking position of the sheet 3 is positioned. The side fences 102 and 103 are connected by a rack gear 106 and a pinion gear 107, and slide by the same size in a direction in which the side fences 102 and 103 come in contact with each other.

  The end fence 104 is provided so as to be slidable along the vertical width direction (paper feeding direction) of the sheets 3 stacked on the bottom plate 101. The slid end fence 104 is brought into contact with the rear end of the sheet 3, and the stacking position of the sheet 3 is positioned. The end fence 104 is connected by a latch (not shown) of about 1 mm, and the end fence 104 moves by one latch.

  With reference to FIG. 4A, the bottom plate raising mechanism attached to the paper feed tray will be described. Further, a pressure arm 108 that pushes up the bottom plate 101 from below and a pressure shaft 109 that fixes the push-up member are provided at the bottom of the tray body 105. A pressure arm 108 is further fixed on the extension line of the pressure shaft. One end of a pressure spring 111 is attached to the pressure arm 108, and a rack member 112 attached to the paper feed tray 100 is attached to the other end. When the rack member 112 moves horizontally by a pinion gear 113 attached to the paper feed tray 100 and reaches a predetermined position, the pinion gear is fixed by a rack fixing member 114 attached to the apparatus main body 1.

The operation of the bottom plate raising mechanism will be described with reference to FIG. The drive transmission from the apparatus main body 1 will be described separately.
The pinion gear 107 rotates, the rack member 112 moves (moves in the X direction), the pressurizing arm 108 is rotated by the pressurizing spring 111, the bottom plate 101 rotates about the support shafts 101a and 101b, and rises. The sheet 3 on the bottom plate 101 is pressed against the roller 2.

  Further, the rack member 112 moves in the direction of the arrow X, rotates the rack fixing member 114, the rack solid member 114 falls into the groove 112a of the rack member 112, and the rotation of the pinion gear 107 is free (the connection with the chipped gear member is canceled). The rack member 112 moves in the direction opposite to the arrow X (by the pressure spring 111) and comes into contact with the rack solid member 114 and stops.

  With reference to FIG. 5, drive transmission in the apparatus main body 1, that is, drive transmission to the pinion gear 107 mounted with a paper feed tray will be described. A chip gear 116 is rotatably attached to the apparatus body 1. A spring 115 is attached to the chipped gear 116 and the other is attached to the apparatus main body 1. The chipped gear 116 is rotated by a spring 115 with a predetermined force in the direction of the arrow. The flapper solenoid 117 is screwed to the apparatus main body 1, the flapper part 119 is hooked on the stopper part of the chipped gear 116, and the chipped gear 116 stops rotating by the flapper part 119.

  The drive transmission operation will be described with reference to FIG. The flapper solenoid 117 is energized, the flapper part 119 is attracted to the main body (rotates downward), and the flapper part 119 is removed from the stopper of the chipped gear 116. Then, the toothless gear 116 is rotated by the spring 115 and is engaged with the drive gear 118. At the same time, the pinion gear 113 is also bitten. When the chip gear 116 is rotated by the drive gear 118, the pinion gear 113 is rotated, and the energization to the flapper solenoid 117 is turned off after a predetermined time has elapsed, the stopper member of the chip gear 116 is caught by the flapper portion 119, and the chip gear. 116 stops (after one rotation). The drive gear 118 is rotated counterclockwise by a motor (not shown). Further, there is no problem even if the drive gear 118 is always driven.

A flow of sheet feeding operation will be described.
(1) A user sets a paper feed tray 100 with recording paper and inserts the paper feed tray 100 into the apparatus main body 1.
(2) When the paper feed tray 100 is installed, a tray detection switch or sensor (not shown) is turned on, and the apparatus body 1 recognizes that the paper feed tray 100 is installed.
(3) The paper feed preparation operation is started.
(4) The motor (not shown) is rotated to rotate the drive gear 118, and the flapper solenoid 117 is energized for 1 second.
(5) When the flapper solenoid 117 is turned on, the rack member 112 is moved while the chip gear 116 is rotated once as in the above operation, and the bottom plate 101 is raised and contacts the pickup roller 4. The rack member 112 is fixed by a rack fixing member 114 attached to the apparatus main body 1.
(6) This completes the paper feed preparation operation.
(7) In the paper feeding operation, the paper feeding roller device 2 is driven by a paper feeding command to separate and transport the recording paper.
(8) Replace or supply the recording paper.
(9) Pull out the paper feed tray 100.
(10) The rack fixing member 114 attached to the apparatus main body 1 is detached from the rack member 112 and pulled by the pressure spring 111, and the bottom plate is lowered (initial position).
(11) The user replaces or replenishes the recording paper and performs the operation (1) described above.

  In such an operation, when the bottom plate 101 is raised and the rack member 112 is fixed to the rack fixing member 114, a force of about 25 N is applied to the rack fixing member 114 depending on the amount of recording paper loaded, but about 250 sheets. It will take. In addition, the bottom plate cannot be fixed unless the rack fixing member 114 is securely inserted into the groove of the rack member 112. In this embodiment, the rack member 112 can be reliably fixed, and the durable rack fixing member 114 can be realized.

  The rack fixing member 120 shown in FIG. 6 will be described. FIG. 7 shows a view of FIG. 4 as viewed from above. As shown in FIG. 7A, the rack fixing member 120 has an inclined portion 123, a rack fixing portion 124, and a portion 125 that supports the force that the rack fixing member 120 exerts on the rack member 112. The rack fixing member 120 moves the rack. It moves linearly perpendicular to the direction. The rack fixing member 120 protrudes toward the paper feed tray 100 from a hole formed in the wall 121 disposed in the back of the paper feed tray 100, and a supporting portion 125 is in contact with the wall in the initial state.

  When the rack member 112 moves in the direction of the arrow, the rack fixing member 120 is moved downward by the inclined portion 123 as shown in FIG. 6B, and when the rack member 112 is grooved, the rack member 112 is returned to the initial position by the spring 122. Fixed. By providing the inclined portion 123 in this manner, the rack fixing member 120 is reliably pushed down, and the rack member 112 can be reliably fixed when the groove of the rack member 112 comes.

  The rack fixing member 130 shown in FIG. 8 will be described. FIG. 9 is a top view of FIG. As shown in FIG. 9, the rack fixing member 130 has a portion 135 that supports the force exerted on the rack member 112, and the rack fixing member 130 rotates about a shaft 137. The rack fixing member 130 is a portion supported by a wall 121 disposed in the back of the paper feed tray 100 and is in contact with the rack fixing member 130 in the initial state.

  When the rack member 112 moves in the direction of the arrow, the rack member 112 is rotated by pushing the inclined portion 133 as shown in FIG. 9B. When the rack member 112 has a groove, the rack member 112 is attached to the wall 121 and the rack fixing member 130. The rack member 112 is fixed to the initial position by the torsion spring 132 attached to the projection 136. By providing the inclined portion 133 in this manner, the rack member 112 can reliably rotate the rack fixing member 130, and the rack member 112 can be reliably fixed when the groove of the rack member 112 comes. In order to support the force received from the rack member 112, the rack member 112 can be fixed without being damaged.

1: Image forming apparatus main body 2: Paper feed roller device 3: Paper 4: Pickup roller 5: Feed roller 6: Separating roller 100: Paper feed tray 101: Bottom plate 101a, 101b: Bottom plate support shafts 102, 103: Side fence 104: End fence 105: Tray body 106: Rack gear 107: Pinion gear 108: Pressure arm 109: Pressure shaft 111: Pressure spring 112: Rack member 112a: Rack member groove 113: Pinion gear 114: Rack fixing member 116 : Chipped gear 115: spring 117: flapper solenoid 118: drive gear 119: flapper part 120: rack fixing member 121: wall 123: inclined part 124: rack fixing part 125: part supporting force 130: rack fixing member 132: spring 133: Inclined part 135: The supporting portion 136: protrusion 137: Axis

JP 09-263335 A Japanese Patent Application Laid-Open No. 06-056283

Claims (7)

A bottom plate for setting paper in a paper feed tray for stacking paper, a push-up member that is provided at a lower position of the bottom plate for rotating the bottom plate, and a pressure arm connected to the push-up member; A pressure spring connected to the pressure arm, a rack connected to the pressure spring, a pinion gear for moving the rack, a toothless gear connected to the pinion gear, and driving to the toothless gear In a paper feeding device having a bottom plate raising mechanism having a drive gear and a solenoid for suppressing the missing gear,
A sheet feeding device, wherein a fixing member capable of fixing the position of the rack after the bottom plate is raised is provided on a mounted device side on which the sheet feeding tray is mounted. The paper feeding device according to claim 1.
The fixing member arranged on the mounted device side is
An inclined portion for guiding the rack;
A portion for stopping the rack;

A portion supporting the force exerted by the rack;
A portion for attaching a spring for returning to a fixed position from the state moved by the rack;
A sheet feeding device that linearly moves perpendicularly to a moving direction of the rack by a force exerted by the rack. The paper feeding device according to claim 1.
The fixing member arranged on the mounted device side is
An inclined portion for guiding the rack;
A portion for stopping the rack;
A portion supporting the force exerted by the rack;
A portion for attaching a spring for returning to a fixed position from the state moved by the rack;
A sheet feeding device that is rotatable by a force exerted by the rack.   An image forming apparatus comprising the paper feeding device according to claim 1. A bottom plate for setting paper in a paper feed tray for stacking paper, a push-up member that is provided at a lower position of the bottom plate for rotating the bottom plate, and a pressure arm connected to the push-up member; A pressure spring connected to the pressure arm, a rack connected to the pressure spring, a pinion gear for moving the rack, a toothless gear connected to the pinion gear, and driving to the toothless gear A sheet feeder provided with a bottom plate raising mechanism having a drive gear and a solenoid for suppressing the toothless gear;
The image forming apparatus main body is provided with a fixing member that can fix the position of the rack after the bottom plate is raised.
An image forming apparatus. The image forming apparatus according to claim 5.
The fixing member is
An inclined portion for guiding the rack;
A portion for stopping the rack;
A portion supporting the force exerted by the rack;
A portion for attaching a spring for returning to a fixed position from the state moved by the rack;
An image forming apparatus, wherein the rack is linearly moved perpendicularly to a moving direction of the rack by a force exerted by the rack. The image forming apparatus according to claim 5.
The fixing member arranged on the mounted device side is
An inclined portion for guiding the rack;
A portion for stopping the rack;
A portion supporting the force exerted by the rack;
A portion for attaching a spring for returning to a fixed position from the state moved by the rack;
An image forming apparatus, wherein the image forming apparatus is rotatable by a force exerted by the rack.