JP5409863B2 - Paper storage device and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a sheet storage device including a cursor for aligning sheets stacked on a sheet stacking plate, and an image forming apparatus including the sheet storage device.

  Image forming apparatuses such as copiers, printers, and facsimiles that form images on paper by electrophotography are provided with a paper feed cassette that is detachable from the main body. A paper stacking plate swingable about a fulcrum, a movable cursor for aligning the papers stacked on the paper stacking plate, and a cursor lever having a lock portion for locking the movement of the cursor Is provided.

  In such a paper feed cassette, the movement of the cursor is locked by the lock claw provided on the cursor lever engaging the lock claw formed on the bottom surface of the paper feed cassette. The cursor is unlocked by tilting and releasing the engagement between the lock claw of the cursor lever and the lock claw on the paper feed cassette side.

  By the way, although various proposals have been made so far for a mechanism for operating the cursor lever to unlock the cursor (see Patent Documents 1 to 3), the operation direction of the cursor lever is the same as the movement direction of the cursor. Many mechanisms are used because they are natural and easy to operate.

JP-A-11-189341 JP 2001-097561 A JP 2001-187642 A

  However, in the conventional paper feed cassette, since the fulcrum of the cursor lever is disposed immediately below the operation unit (power point), a space for the stroke required for the operation of the cursor lever is required when unlocking the cursor. There was a problem that it was difficult to realize space saving.

  In addition, in order to save space, there is a system that uses a method of unlocking the cursor by pulling up the cursor lever, but there is a problem that the operability is poor.

  SUMMARY An advantage of some aspects of the invention is that it provides a sheet storage device capable of realizing space saving while ensuring high operability and an image forming apparatus including the same. There is to do.

In order to achieve the above object, an invention according to claim 1 is an apparatus for storing paper fed to an image forming unit,
A paper loading plate that can swing around a fulcrum;
A movable cursor for aligning the sheets stacked on the sheet stacking board;
A cursor lever having a lock claw for locking the movement of the cursor;
In a paper storage device comprising:
The cursor lever is formed in an L shape in a side view with a horizontal portion and a vertical portion, a fulcrum is disposed on one side portion of the horizontal portion, and the other end of the horizontal portion where the horizontal portion and the vertical portion intersect with each other. Arrange the lock claw and the operation part in the vertical part,
Between the cursor and the cursor lever, a spring for biasing the cursor lever in the locking direction around the fulcrum is mounted,
The fulcrum of the cursor lever is disposed in the space between the cursor and the bottom of the paper storage device, and the distance from the fulcrum to the lock claw and the distance from the lock claw to the operation unit are set to be approximately equal,
By tilting the cursor lever against the urging force of the spring in the direction of movement of the cursor about the fulcrum, the lock claw of the cursor lever is released from the lock claw on the bottom surface of the paper storage device, and A paper storage device configured to release a lock.

  According to a second aspect of the present invention, there is provided an image forming apparatus including the paper storage device according to the first aspect and an image forming unit.

  According to the present invention, since the cursor is unlocked by tilting the cursor lever in the direction of movement of the cursor, the operability of the cursor lever when unlocking the cursor is improved. Then, the fulcrum of the cursor lever is arranged in the space between the cursor and the bottom of the paper storage device, and the distance from the fulcrum to the lock claw (action point) and the distance from the lock claw to the operation unit (force point) are reduced. Since they are set equal, the stroke required for the operation of the cursor lever when unlocking the cursor can be reduced, thereby realizing space saving.

1 is a side sectional view of an image forming apparatus (laser beam printer) according to the present invention. It is a perspective view of a paper feed cassette which is one form of a paper storage device according to the present invention. It is a perspective view of the cursor of the paper feed cassette which is one form of the paper storage device according to the present invention. It is a perspective view of the cursor of the paper feed cassette which is one form of the paper storage device according to the present invention. It is the sectional view on the AA line of FIG. It is a perspective view of the cursor lever of the paper feed cassette which is one form of the paper storage device according to the present invention. It is a fragmentary sectional view of a paper feed cassette showing a state at the time of cursor lock. It is a fragmentary sectional view of a paper feed cassette which shows the state where the lock of the cursor was canceled.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a side sectional view of a laser beam printer as an embodiment of an image forming apparatus according to the present invention. The illustrated laser beam printer 1 includes a box-shaped apparatus main body 1a, and an upper surface of the apparatus main body 1a. An inclined concave discharge tray 32 is provided at the center of the sheet. Further, an openable and closable manual feed tray 8 is provided at the upper part of the front surface of the apparatus main body 1a (the left side in FIG. 1 is the front), and a paper feed cassette 7 according to the present invention is provided at the lower part of the apparatus main body 1a. This paper feed cassette 7 can be pulled out to the front side.

  Thus, the laser beam printer 1 according to the present embodiment is based on image data transmitted from a terminal (not shown) while transporting the paper along the transport path L provided in the apparatus main body 1a. An image is formed on a sheet, and the conveyance path L includes a horizontal portion L1 extending substantially horizontally from the front to the rear (right to left in FIG. 1) in the apparatus main body 1a, and the horizontal portion L1. The vertical portion L2 that rises substantially vertically from the end portion is configured in a substantially L shape in side view.

  Further, the laser beam printer 1 includes a paper feeding unit 2 provided at a lower portion of the apparatus main body 1a, an image forming unit 3 provided at a substantially central portion in the apparatus main body 1a above the paper feeding unit 2, The fixing unit 4 disposed behind the image forming unit 3, the concave paper discharge unit 5 provided on the upper surface of the apparatus main body 1 a above the fixing unit 4, the horizontal unit L 1 of the transport path L, and the paper feed A switchback portion 6 provided between the cassette 7 and the cassette 7 is provided.

  The paper feed unit 2 stores paper and feeds the paper toward the image forming unit 3, and includes the paper feed cassette 7.

  Here, the paper feed cassette 7 has a rectangular box shape with an open upper surface, and has a function of feeding sheets (not shown) stacked and accommodated therein one by one, as shown in the figure. In the state where it is mounted in the apparatus main body 1a, it is located below the horizontal portion L1 of the transport path L.

  The paper cassette 7 is provided with a paper stacking plate 10 that swings up and down about a shaft 12 on the back side in the mounting direction of the paper cassette 7 and a spring 9 that pushes up the paper stacking plate 10. Details of the configuration will be described later.

  Further, the paper feeding unit 2 feeds the paper stacked on the paper stacking plate 10 in the paper feeding cassette 7 one by one, and picks up the picked up paper to the horizontal part L1 of the transport path L. In addition to the feed roller 14 and the retard roller 15, a plurality of paper feed rollers 16, 17, 18, a registration roller 19 that temporarily feeds the fed paper and supplies it to the image forming unit 3 at a predetermined timing, as well as the manual feed tray 8. A pickup roller 20 is provided for taking out the paper placed on the printer.

  The image forming unit 3 forms an image on a sheet supplied from the sheet feeding device 2, and is an image carrier that is rotatably disposed at a substantially central portion in the front-rear direction of the horizontal portion L 1 of the transport path L. A photosensitive drum 21, a primary charger 22 disposed around the photosensitive drum 21, a developing device 23, a transfer roller 24 and a cleaning device 25, a laser scanner unit (LSU) 26 disposed above them, a toner hopper 27, and the like. Yes.

  The fixing unit 4 is for fixing the toner image transferred onto the paper in the image forming unit 3 to the paper, and includes a heating roller 28 and a pressure roller 29 that rotate while being pressed against each other. Yes.

  Further, the paper discharge unit 5 is for discharging the paper on which the toner image has been fixed in the fixing unit 4 to the outside of the apparatus main body 1a, and is provided in the middle of the vertical portion L2 of the transport path L. A pair of conveying rollers 30 and a pair of paper discharge rollers 31 provided at the end of the vertical portion L2 and the paper discharge tray 32 for stacking sheets discharged to the outside of the apparatus main body 1a.

  The switchback unit 6 is used when images are formed on both sides of a sheet. The switchback unit 6 is provided in another conveyance path L ′ disposed below the horizontal portion L1 of the conveyance path L and its proper position. A plurality of conveyance roller pairs 36 are provided.

  Next, an image forming operation of the laser beam printer 1 having the above configuration will be described.

  For example, when a print start signal is transmitted to the laser beam printer 1 from a terminal such as a personal computer (personal computer), in the image forming unit 3, the photosensitive drum 21 is driven in the direction indicated by the arrow (clockwise) in FIG. ) And the surface thereof is uniformly charged to a predetermined potential by the primary charger 22. When a laser beam based on the image data transmitted from the terminal is output from the laser scanner unit 26 and irradiated onto the photosensitive drum 21, an electrostatic latent image is formed on the photosensitive drum 21. Then, the electrostatic latent image formed on the photosensitive drum 21 is developed by the developing device 23 using toner as a developer to be visualized as a toner image.

  At the same time, in the paper feeding unit 2, for example, the sheets stored in the paper feeding cassette 7 are picked up one by one from the uppermost one by the pickup roller 13, and the feed roller 14, the retard roller 15, and the paper feeding rollers 16, 17. , 18 are sent to the horizontal portion L1 of the transport path L, and after being temporarily put into a standby state by the registration roller pair 19, are supplied to the image forming portion 3 at a predetermined timing synchronized with the toner image on the photosensitive drum 21. The When an image is formed on the paper stacked on the manual feed tray 8, the paper is taken out one by one by the pickup roller 20 and sent out to the horizontal portion L 1 of the transport path L by the paper feeding rollers 16 and 18. .

  In the image forming unit 3, the sheet supplied to the transfer nip between the photosensitive drum 21 and the transfer roller 24 is conveyed while being pressed against the photosensitive drum 21 by the transfer roller 24, thereby its surface (transfer surface). ), The toner image on the photosensitive drum 21 is transferred. The sheet on which the toner image has been transferred is conveyed to the fixing unit 4, and is heated and pressed in the process of being sandwiched and conveyed by the heating roller 28 and the pressure roller 29 in the fixing unit 4. Get fixed. The toner remaining on the surface of the photosensitive drum 21 after transfer of the toner image onto the sheet (transfer residual toner) and electric charge are removed by the cleaning device 25.

  Thus, the sheet on which the toner image is fixed on the surface by the fixing unit 4 is conveyed upward through the vertical portion L2 of the conveying path L by the conveying roller pair 30, and the upper portion of the apparatus main body 1a by the discharge roller pair 31. The paper is discharged and stacked on a paper discharge tray 32 provided in the front.

  The above is a series of operations when an image is formed on one side of a sheet. When an image is formed on both sides of a sheet, a sheet having a toner image fixed on one side by a fixing unit 4 is transported to a pair of conveying rollers 30. Then, the sheet is fed to the vertical portion L2 of the conveyance path L, and then the sheet is switched back by reversing the conveyance roller pair 30 and fed to another conveyance path L ′. Then, the paper is transported forward (to the right in FIG. 1) along the transport path L ′ by a plurality of transport roller pairs 36 provided in the transport path L ′, and the paper is fed by the paper feed rollers 16, 17, 18. If the sheet is fed again to the horizontal portion L1 of the transport path L, the front and back of the sheet are reversed, and thereafter, the toner image on the photosensitive drum 21 is transferred to the surface of the sheet (the other side on which no image is formed) by the same operation as described above. Image is formed on both surfaces of the paper. The paper on which images are formed on both sides in this way is transported upward along the vertical portion L2 of the transport path L by the transport roller 30 in the same manner as described above, and is discharged to the paper discharge tray 32 by the pair of paper discharge rollers 31. .

  Next, details of the configuration of the paper feed cassette 7 according to the present invention will be described with reference to FIGS.

  2 is a perspective view of the paper feed cassette, FIGS. 3 and 4 are perspective views of the cursor of the paper feed cassette, FIG. 5 is a cross-sectional view taken along line AA in FIG. 4, FIG. 6 is a perspective view of the cursor lever, and FIG. Is a partial cross-sectional view of the paper feed cassette showing a state when the cursor is locked, and FIG. 8 is a partial cross-sectional view of the paper feed cassette showing a state where the cursor is unlocked.

  The sheet cassette 7 shown in FIG. 2 has a rectangular box shape with an open upper surface. Inside the sheet cassette 7, there is a sheet stacking plate 10 and a spring 9 (see FIG. 1) that pushes it up. A cursor 33 is provided at the center in the width direction so as to be movable in the front-rear direction (attachment / detachment direction of the paper feed cassette 7).

  The cursor 33 is for aligning sheets (not shown) stacked on the sheet stacking plate 10, and is integrally formed in an L shape in side view as shown in FIGS. A cursor lever 34, which is also integrally formed in an L shape in a side view, is incorporated in the inside so as to be tiltable.

  As shown in FIG. 6, the cursor lever 34 has a horizontal portion 34A and a vertical portion 34B, and slits 34C are formed at two positions in the width direction of the horizontal portion 34A. A cylindrical fulcrum 34a is integrally formed at the front end portion of the horizontal portion 34A, and the rear end portion (right angle portion) of the horizontal portion 34A has a width direction (in FIG. 5). Three rows of lock claws 34b extending in the direction perpendicular to the paper surface are formed in the front-rear direction (left-right direction in FIG. 5). These lock claws 34b constitute a lock portion of the cursor lever 34, which is formed in the center in the width direction of the bottom surface of the paper feed cassette 7 in the front-rear direction, as shown in FIGS. The plurality of lock claws 7a are selectively engaged to lock or unlock the movement of the cursor 33 in the front-rear direction.

  In addition, an operation portion 34c is disposed above the vertical portion 34B of the cursor lever 34. When the cursor lever 34 is incorporated in the cursor 33 as shown in FIG. It is arranged in a space S between 33 and the bottom surface of the paper feed cassette 7. In the cursor lever 34, the distance X from the fulcrum 34a to the lock part (lock claw 34b) and the distance Y from the lock part (lock claw 34b) to the operation part 34c are set to be substantially equal (X≈Y). The fulcrum 34a and the operation portion (power point) 34c are separated by a predetermined distance.

  By the way, as shown in FIG. 5, a boss-like spring receiver 34d protruding from a cursor lever 34 incorporated in the cursor 33 and a boss-like spring protruding from the cursor 33 above the spring receiver 34d. A spring 35 is compressed between the receptacles 33a, and the cursor 35 causes the lock claw 34b to engage with the lock claw 7a on the paper feed cassette 7 side with the spring 35 as a center (clockwise in FIG. 5). Direction).

  FIG. 7 shows a state where the lock claw 35b of the cursor lever 34 is engaged with the lock claw 7a on the paper feed cassette 7 side and the movement of the cursor 33 is locked. From this state, as shown in FIG. When the operation portion 34c of the cursor lever 34 is pushed in the same direction as the movement direction of the cursor 33 (arrow a direction), the cursor lever 34 tilts in the arrow b direction (counterclockwise) with the fulcrum 34a as a center. Thus, since the lock claw 34b is disengaged from the lock claw 7a on the paper feed cassette 7 side, the cursor 33 is unlocked, and the cursor 33 is freely moved and its position is adjusted. After the position of the cursor 33 is adjusted in this way, when the hand is released from the operation portion 34c of the cursor lever 34, the cursor lever 34 is moved in the reverse direction (clockwise in FIG. 8) about the fulcrum 34a by the biasing force of the spring 35. ) And the lock claw 34b is reengaged with the lock claw 7a on the paper feed cassette 7 side as shown in FIG. 7, so that the movement of the cursor 33 is locked.

  Thus, in the present embodiment, since the cursor 33 is unlocked by tilting the cursor lever 34 in the moving direction of the cursor 33, the operability of the cursor lever 34 when unlocking the cursor 33 is improved. Enhanced.

  Further, the fulcrum 34a of the cursor lever 34 is disposed in the space S between the cursor 33 and the bottom surface of the paper feed cassette 7, and the distance X from the fulcrum 34a to the lock portion (lock claw 34b) as the action point and the lock portion. Since the distance Y from the (lock claw 34b) to the operating portion (power point) 34c is set to be substantially equal (X≈Y), the stroke required for operating the cursor lever 34 when the cursor 33 is unlocked can be reduced. Space saving can be realized. When the cursor lever 34 is incorporated into the cursor 33, the outer side of the slit 34 </ b> C provided in the horizontal portion 34 </ b> A of the cursor lever 34 is bent toward the slit 34 </ b> C and the fulcrum 34 a is fitted into the hole of the cursor 33.

  In the above description, the present invention has been described with reference to a laser beam printer and a paper cassette that is detachably mounted on the laser beam printer. However, the present invention is not limited to a printer, but also a copying machine, a facsimile machine, and a complex machine thereof. Needless to say, the present invention can be similarly applied to other arbitrary image forming apparatuses and the like, and a paper storage device permanently installed therein.

1 Laser beam printer (image forming device)
DESCRIPTION OF SYMBOLS 1a Image forming apparatus main body 2 Paper feed part 3 Image formation part 4 Fixing part 5 Paper discharge part 6 Switchback part 7 Paper feed cassette (paper storage device)
7a Paper cassette lock claw 8 Manual feed tray 9 Spring 10 Paper stacking plate 12 Axis (fulcrum)
DESCRIPTION OF SYMBOLS 13 Pickup roller 14 Feed roller 15 Retard roller 16-18 Feed roller 19 Registration roller pair 20 Pickup roller 21 Photosensitive drum 22 Primary charger 23 Developing device 24 Transfer roller 25 Cleaning device 26 Laser scanner unit (LSU)
27 Toner hopper 28 Heating roller 29 Pressure roller 30 Conveying roller pair 31 Discharging roller pair 32 Discharging tray 33 Cursor 33a Cursor spring receiver 34 Cursor lever 34A Cursor lever horizontal portion 34B Cursor lever vertical portion 34C Cursor lever slit 34a Cursor lever fulcrum 34b Cursor lever lock claw (lock part)
34c Cursor lever operation (power point)
34d Cursor lever spring receiver 35 Spring 36 Conveying roller pair L, L 'Conveying path L1 Conveying path horizontal part L2 Conveying path vertical part S Space between cursor and paper feed cassette bottom X Lock part from cursor lever fulcrum Distance Y Distance from the cursor lever lock to the control unit

Claims (2)

An apparatus for storing paper fed to an image forming unit,
A paper loading plate that can swing around a fulcrum;
A movable cursor for aligning the sheets stacked on the sheet stacking board;
A cursor lever having a lock claw for locking the movement of the cursor;
In a paper storage device comprising:
The cursor lever is formed in an L shape in a side view with a horizontal portion and a vertical portion, a fulcrum is disposed on one side portion of the horizontal portion, and the other end of the horizontal portion where the horizontal portion and the vertical portion intersect with each other. Arrange the lock claw and the operation part in the vertical part,
Between the cursor and the cursor lever, a spring for biasing the cursor lever in the locking direction around the fulcrum is mounted,
The fulcrum of the cursor lever is disposed in the space between the cursor and the bottom of the paper storage device, and the distance from the fulcrum to the lock claw and the distance from the lock claw to the operation unit are set to be approximately equal,
By tilting the cursor lever against the urging force of the spring in the direction of movement of the cursor about the fulcrum, the lock claw of the cursor lever is released from the lock claw on the bottom surface of the paper storage device, and A paper storage device configured to release a lock. An image forming apparatus comprising the sheet storage device according to claim 1 and an image forming unit.

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