JP2008083407A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer designed so that sheets of paper the number of which matches a specification can be stacked on a sheet stacking section. <P>SOLUTION: A printer for forming images on paper includes: a first paper ejection tray 4 on which sheets of paper ejected from the ejection port 13a of the main body 1 of the printer are placed; a second paper ejection tray 3 on which sheets of paper ejected from the main body 1 are placed; a switching guide 14 that switches a paper ejection path for selecting the first paper ejection tray 4 or second paper ejection tray 3 for use as the place where sheets of paper are ejected; and strike parts 30a and 30b that are disposed on parts of the switching guide 14 and struck against the wall face 17 of the main body 1 provided with the ejection port 13a. By operating the switching guide 14, the image forming apparatus intermittently strikes the strike parts 30a and 30b against the wall face 17. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

  In general, in an image forming apparatus, a toner image is formed on a sheet based on scanned document data or data transmitted from a personal computer (PC) by a user, and the sheet on which the image is formed is discharged from the apparatus main body. And stacked on a paper discharge tray (see, for example, Patent Document 1).

  In the image forming apparatus configured as described above, the sheet stacking surface of the sheet discharge tray is disposed below the discharge port provided in the apparatus main body in order to discharge the sheet to the sheet discharge tray. The number of sheets stacked corresponding to the height from the sheet stacking surface to the discharge port is the number of sheets that can be stacked on a discharge tray determined in advance by specifications.

FIG. 11 is a side configuration diagram of the vicinity of a paper discharge tray 1000 of a conventional printer. As shown in FIG. 11, a discharge port 1002 for discharging a sheet is formed on the wall surface 1004 above the sheet placement surface 1001 of the discharge tray 1000, and a pair of discharge rollers 1003 is formed in the vicinity of the discharge port. Is provided. The number of stacked sheets corresponding to the height 1005 shown in FIG. 11 is the number of stacked sheets defined in the specification.
JP 2004-061755 A

  However, the trailing edge 1006a of the paper 1006 discharged onto the tray from the discharge port 1002 may lean against the wall surface 1004 between the discharge port 1002 and the paper stacking surface 1001, and may not fall on the paper stacking surface 1001. In this manner, a plurality of sheets are discharged onto the sheet stacking surface 1001 so that the trailing end of the sheet does not fall on the sheet stacking surface 1001, and the trailing end 1006 a ′ of the uppermost sheet 1006 ′ is an outlet 1002 as shown in FIG. In this case, the sheet 1006 ″ to be discharged next may be pushed out of the sheet discharge tray 1000 and dropped. As described above, there is a problem that the sheet may fall from the discharge tray 1000 until the number of sheets determined by the specification is reached.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of preventing a sheet from dropping from a sheet discharge tray before reaching the number of sheets according to a specification in consideration of the problem of a conventional sheet discharge tray. To do.

In order to achieve the above object, the first present invention provides:
An image forming apparatus for forming an image on a sheet,
A sheet placement section for placing the sheet discharged from the discharge port of the apparatus main body of the image forming apparatus;
A contact portion that hits the wall surface of the apparatus main body provided with the discharge port;
An image forming apparatus comprising: a control unit that performs control to intermittently apply the contact portion.

The second aspect of the present invention is
The sheet placing portion is a first sheet placing portion,
A second sheet placement section for placing a sheet discharged from the apparatus main body,
A switching guide for switching a paper discharge path in order to select one of the first sheet placement portion and the second sheet placement portion as a discharge destination of the sheet,
The contact portion is provided in a part of the switching guide,
The control unit is
In the image forming apparatus according to the first aspect of the present invention, the contact portion is brought into contact with the wall surface by operating the switching guide.

The third aspect of the present invention
The control unit is
The image forming apparatus according to the first aspect of the present invention, wherein each time the sheet is discharged, the contact portion is brought into contact with the wall surface.

  According to the present invention, it is possible to provide an image forming apparatus capable of preventing a sheet from dropping from the sheet placement unit until the number of sheets according to the specification is reached.

  Embodiments of the present invention will be described below with reference to the drawings. A printer will be described as an example of the image forming apparatus of the present invention.

(Embodiment)
The printer according to the embodiment of the present invention will be described below.

  FIG. 1 is an external view of a printer according to an embodiment of the present invention.

  As shown in FIG. 1, the printer according to the present embodiment includes a paper feed tray 2 arranged at the bottom of the apparatus main body 1 for storing paper to be printed, and a first paper on which printed paper is discharged and stacked. 2 paper discharge tray 3 and first paper discharge tray 4 are provided. A manual feed tray 5 that can be opened and closed is provided on the surface 18 of the apparatus main body 1. The second paper discharge tray 3 is an FD tray provided on the upper surface of the apparatus main body 1, and the first paper discharge tray 4 is an FU tray provided on the back surface 17 of the apparatus main body 1.

  FIG. 2 is a side configuration diagram of the printer according to the present embodiment.

  As shown in FIG. 2, the printer according to the present embodiment includes the paper feed tray 2 disposed at the bottom of the apparatus main body 1 and an image transfer unit 6 that forms a toner image on the paper supplied from the paper feed tray 2. A fixing unit 7 for fixing the formed toner image onto the paper, a discharge unit 8 including rollers 81 and 82 for discharging the paper on which the image is formed, and a paper discharged from the discharge unit 8 are stacked. The second paper discharge tray 3 is provided on the upper surface of the apparatus main body 1 to be operated. In addition, three rollers are used to convey the sheet on which the image is fixed on one side by the image transfer unit 6 and the fixing unit 7 to the discharge unit 8 side and then to the image transfer unit 6 side again in order to form images on both sides. A sheet reversing unit 9 composed of 91, 92, 93, etc. is installed.

  Further, the paper feed tray 2 is provided with a lift plate 21 for lifting the paper to supply the paper to the image transfer unit 6, and the lifted paper is conveyed above the paper feed tray 2. A pickup roller 22, a feed roller 23 for preventing double feeding of sheets, and a retard roller 24 are provided.

  Next, the image transfer unit 6 will be described.

  The image transfer unit 6 irradiates light on the surface of the photoconductive drum 61 other than a portion where an image is formed by charging the photoconductive drum 61, a charging unit 62 for charging the surface of the photoconductive drum 61, and charging charges. An exposure unit that removes and forms an electrostatic latent image (see arrow 63 in FIG. 2), and a developing device 64 that attaches toner to the electrostatic latent image formed on the surface of the photosensitive drum 61 to form a visible image; have. Further, the image transfer unit 6 presses the conveyed paper against the photosensitive drum 61, applies a charge opposite to the toner and transfers the toner to the paper by electrostatic force, and the surface of the photosensitive drum 61. It has a slow current remover (not shown) for removing the charge, and a cleaning unit 66 for removing toner remaining on the photosensitive drum 61 without being transferred.

  Next, the fixing unit 7 will be described. The fixing unit 7 includes a fixing roller 71 having a heater and a pressure roller 72 in pressure contact with the fixing roller 71.

  Next, a conveyance path for conveying a sheet will be described.

  The paper is conveyed from the paper feed tray 2 to the paper reversing unit 9 through the image transfer unit 6 and the fixing unit 7. This conveyance path 10 is illustrated by a solid line arrow. A branch point P is provided on the downstream side of the sheet reversing unit 9 with reference to the sheet conveyance direction of the conveyance path 10. At this branch point P, the transport path 10 is connected to a second paper discharge path 11 through which the paper is transported to the second paper discharge tray 3 via the discharge unit 8, and a discharge roller disposed in the vicinity of the branch point P. 12 and the roller 121 are branched to a first paper discharge path 13 that is discharged to the first paper discharge tray 4. In addition, a switching guide 14 is provided at the branch point P for switching the conveyance path of the paper to either the second paper discharge path 11 or the first paper discharge path 13. The second paper discharge path 11 and the first paper discharge path 13 are also indicated by solid arrows.

  FIG. 3 is a view of the state in which the first paper discharge tray 4 is attached as viewed from the outside of the apparatus main body 1. As shown in FIG. A paper discharge port 13 a from the first paper discharge path 13 is formed above the placement surface 41. In FIG. 3, only a part of the back surface 17 of the apparatus main body 1 is shown.

  Further, as shown in FIG. 2, when an image is formed on both sides of a sheet, a reverse conveyance path 20 is provided for conveying again the sheet having an image formed on one side from the branch point P to the image transfer unit 6. ing. The reverse conveyance path 20 is shown in FIG. 2 by a dotted arrow.

  FIG. 4 is a side configuration diagram of the vicinity of the branch point P and the first paper discharge tray 4. FIG. 4 shows a state in which the switching guide 14 is switched so that the sheet conveyed by the rollers 91 and 92 passes through the first sheet discharge path 13 and is discharged to the first sheet discharge tray 4. When the switching guide 14 in this state rotates in the direction of arrow A, the conveyance of the sheet to the first sheet discharge path 13 is hindered, and the sheet is conveyed to the second sheet discharge path 11.

  FIG. 5 is an enlarged view of the vicinity of the switching guide 14 in the state of FIG. As shown in FIG. 5, the switching guide 14 has a substantially triangular conveyance guide portion 140 when viewed from the side, and the conveyance guide portion 140 has a longitudinal direction in the width direction (perpendicular to the paper surface) of the conveyed paper. And is configured to be rotatable around a shaft 141 provided in the vicinity of one vertex of the triangle.

  The switching guide 14 has a protrusion 145 formed in the longitudinal direction at one end in the paper width direction. FIG. 6 is a perspective view of an end portion of the switching guide 14. As shown in FIG. 6, a protruding portion 147 is formed at one end of the conveyance guide portion 140 in the paper width direction and above the shaft 141 so as to protrude in the paper width direction. The protrusion 145 described above is formed at the end 147a of the protrusion 147 in the sheet width direction. Further, at the end 147a of the protruding portion 147 in the sheet width direction, hitting portions 30a and 30b are formed at two upper and lower portions so as to protrude toward the back surface 17 side (sheet conveying direction) of the apparatus main body 1. The contact portions 30 a and 30 b are formed so as to be positioned above and below the protrusion 145.

  As shown in FIG. 5, a solenoid 26 having a coil portion 261 and an iron core 262 is provided, and the tip of the iron core 262 and the projection 145 are connected by a connecting member 146. A roller 121 is rotatably attached to the shaft 141 (see FIG. 2).

  Next, a state where the paper discharge path is switched by the switching guide 14 will be described.

  In the state shown in FIG. 5, the paper discharged from the fixing unit 7 passes through the first paper discharge path 13 and is discharged to the first paper discharge tray 4. Note that a surface 140 b located below the shaft 141 of the substantially triangular conveyance guide part 140 as viewed from the side surface forms a part of the first paper discharge path 13.

  FIG. 7 is a diagram illustrating a state where the iron core is moved in the direction of arrow B from the state of FIG. 5 and the discharge path is switched to the second discharge path 11 by the switching guide 14. As shown in FIG. 7, when the iron core 262 of the solenoid 26 is drawn into the coil portion 261, the switching guide 14 rotates in the arrow A direction from the state of FIG. 5. Then, the switching guide 14 prevents the sheet from being conveyed to the first sheet discharge path 13, and the sheet is conveyed toward the second sheet discharge path 11. In this state, a surface 140 a facing the shaft 141 of the substantially triangular conveyance guide 140 viewed from the side surface forms a part of the second paper discharge path 11.

  FIG. 8 is a perspective view of the vicinity of the portion P viewed from the inside of the apparatus main body 1. As shown in FIG. 8, the inner surface of the back surface 17 is formed with a protruding portion 17 a that protrudes toward the inside of the apparatus main body 1 and that has the paper width direction as a longitudinal direction. The protruding portion 17a has a tapered portion 17b on the upper side.

  When the switching guide 14 is switched so that the paper passes through the first paper discharge path 13 and is discharged to the first paper discharge tray 4, the upper contact portion 30a is placed on the back surface as shown in the Q part of FIG. It hits the taper part 17b of the 17 protrusion part 17a. On the other hand, when the switching guide 14 is switched so that the paper passes through the second paper discharge path 11 and is discharged to the second paper discharge tray 3, the lower contact portion 30b as shown in the R portion of FIG. Hits the protrusion 17a of the back surface 17.

  That is, when the solenoid 26 is reciprocated once so as to switch the switching guide 14, the back surface 17 is vibrated twice by the contact portions 30a and 30b.

  In addition, a control unit (not shown) for controlling the solenoid 26 is provided to operate the switching guide 14 when the user selects a paper discharge destination, duplex printing, paper discharge, or the like.

  An example of the sheet placement portion and the first sheet placement portion of the present invention corresponds to the first paper discharge tray 4 of the present embodiment, and an example of the second sheet placement portion of the present invention is the present embodiment. This corresponds to the second paper discharge tray 3 of the form. An example of the wall surface of the present invention corresponds to the back surface 17 of the present embodiment.

  Next, the operation of the printer of the present embodiment having the above configuration will be described.

  First, the operation during single-sided printing will be described.

  When a user sends a printer print command from a PC (personal computer), paper is fed from the paper feed tray 2 or the manual feed tray 5, and a toner image is transferred onto the paper by the image transfer unit 6. Then, the transferred toner image is fixed on the paper by the fixing unit 7.

  When the first paper discharge tray 4 is selected as the discharge destination of the sheet on which the toner image is fixed, the switching guide 14 is pushed by the iron core 262, and as shown in FIG. 2 The path to the paper discharge path 11 is blocked.

  In this state, after the paper is discharged through the first paper discharge path 13, the solenoid 26 is controlled so that the iron core 262 is drawn into the coil portion 261 (see arrow B). Under the control of the solenoid 26, as shown in FIG. 6, the contact portion 30b contacts the ridge portion 17a, and the back surface 17 is vibrated.

  Next, the solenoid 26 is controlled so as to push out the iron core 262 from the coil portion 261, and the switching guide 14 is again placed in a state of closing the second paper discharge path 11 (see FIG. 5). At this time, the contact portion 30a located at the upper portion of the switching guide 14 hits the tapered portion 17b of the ridge portion 17a, and vibration is applied to the back surface 17.

  Subsequently, after the sheet having the toner image fixed thereon is discharged, the iron core 262 is reciprocated once in the same manner as described above, and vibration is applied to the back surface 17.

  Thus, each time a sheet is discharged to the first paper discharge tray 4, the back surface 17 is vibrated by the contact portions 30a and 30b hitting the protrusion 17a once.

  Accordingly, as shown in FIG. 9, the rear end 27a of the discharged paper 27 leans against the back surface 17, and even when the paper 27 does not fall on the paper placement surface 41, the back surface 17 is vibrated. Thus, it can be dropped onto the paper placing surface 41. Therefore, it is possible to prevent the sheet from dropping from the first paper discharge tray 4 until the number of sheets according to the specification is reached.

  Next, the operation during duplex printing will be described.

  An image is formed on one side of the sheet by the image transfer unit 6 and the fixing unit 7 based on the transmission data from the user.

  Next, the sheet on which an image is formed on one side is conveyed to the second sheet discharge path 11, temporarily stopped, and conveyed in the reverse direction. The sheet conveyed in the reverse direction passes between the rollers 92 and 93 and is conveyed to the reverse conveyance path 20.

  Next, an image is formed in the image transfer unit 6 on the other side of the sheet.

  Here, at the time of duplex printing, since the paper is once transported to the second paper discharge path 11 to be reversed, the switching guide 14 is switched to transport the paper to the second paper discharge path 11. Therefore, when the user has selected to discharge the paper to the first paper discharge tray 4, the switching guide 14 is operated to switch the paper discharge path to the first paper discharge path 13.

  Then, the paper is discharged from the apparatus main body 1 via the first paper discharge path 13 and placed on the first paper discharge tray 4.

  Thus, during duplex printing, it is necessary to operate the switching guide 14 in order to switch the paper discharge path, and the operation of the switching guide 14 applies vibration to the back surface 17 by the contact portions 30a and 30b. Therefore, even when the paper discharged first to the first paper discharge tray 4 leans against the back surface 17 (see FIG. 9), the back surface 17 is vibrated when the paper discharge path is switched during the next double-sided printing. The given paper discharged first falls on the paper stacking surface 41.

  That is, in the case of double-sided printing, it is not necessary to bother to vibrate the back surface 17 every time the paper is discharged, and the back surface is vibrated in the course of the transport path switching operation. .

  As described above, also in the case of duplex printing, it is possible to prevent the sheet from dropping from the first discharge tray 4 until the number of sheets according to the specification is reached.

  In this embodiment, in the case of single-sided printing, control is performed so as to apply vibration to the back surface 17 every time one sheet is discharged to the first paper discharge tray 4. Control may be performed to give vibration.

  Further, in the present embodiment, the two paper discharge paths, the first paper discharge path 13 and the second paper discharge path 11, are provided, but a configuration including only the first paper discharge path 13 may be used.

  FIG. 10 is a side configuration diagram showing a configuration including only the first paper discharge path 13. In this case, since it is not necessary to provide the switching guide 14 in order to switch the paper discharge path, a contact member 28 for applying vibration to the back surface 17 is provided. The contact member 28 is rotatably attached to the shaft 141 described above, and includes a protrusion 282 in the paper width direction above the position where the shaft 141 is attached. The protrusion 282 is connected to the tip of the iron core 262 via the connecting member 283. The upper and lower ends of the contact member 28 are provided with contact portions 30a and 30b protruding toward the back surface 17 in the same manner as described above.

  5 and 7, the contact member 28 is rotated by the control of the solenoid 26, and the contact portions 30 a and 30 b come into contact with the protruding portion 17 a of the back surface 17, so that vibration is applied to the back surface 17. .

  Further, in this embodiment, vibration is applied only to the back surface 17 on which the first paper discharge tray 4 is provided, but on the lower surface 3a of the paper discharge port 11a to the second paper discharge tray 3. Alternatively, vibration may be applied (see FIG. 2). Giving vibration to the surface 3a can be realized, for example, by providing a contact member 28 and a solenoid 26 as shown in FIG. 10 inside the surface 3a. In this case, an example of the wall surface of the present invention corresponds to the surface 3a.

  In the present embodiment, the contact portions 30a and 30b are applied to the protrusion 17a on the back surface 17, but the contact portions 30a and 30b may be applied to the back surface 17 without providing the protrusion 17a.

  Further, in the present embodiment, the contact portions are provided with the contact portions 30a and 30b at the upper and lower positions with the protrusion 282 interposed therebetween, but may be provided only in one of them.

  An example of the sheet of the present invention corresponds to the sheet of the present embodiment, but may be an OHP sheet.

  The image forming apparatus according to the present invention has an effect capable of preventing the sheet from dropping from the sheet placement section until the number of sheets conforms to the specification, and is an image forming apparatus such as a printer, a facsimile machine, and a copying machine. Useful as.

1 is an external view of a printer according to an embodiment of the present invention. 1 is a side configuration diagram of a printer according to an embodiment of the present invention. 1 is an external view of a first paper discharge tray attached to a printer main body according to an embodiment of the present invention. FIG. 3 is a side configuration diagram of a first paper discharge tray attached to the main body of the printer according to the embodiment of the present invention. FIG. 3 is a side configuration diagram in the vicinity of a printer switching guide according to an embodiment of the present invention. The enlarged view of the edge part of the switching guide in embodiment concerning this invention FIG. 3 is a side configuration diagram in the vicinity of a printer switching guide according to an embodiment of the present invention. FIG. 4 is a perspective view of the vicinity of the switching guide as viewed from the inside of the printer according to the embodiment of the present invention. The figure which shows the state which the rear end of the paper discharged | emitted by the 1st paper discharge tray of the printer in embodiment concerning this invention leans against the back side surface FIG. 6 is a side view of the vicinity of the discharge outlet in a modification of the printer according to the embodiment of the present invention. Side view of the vicinity of the discharge tray of a conventional printer

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper feed tray 3 2nd discharge tray 4 1st discharge tray 5 Manual feed tray 6 Image transfer unit 7 Fixing unit 8 Discharge unit 9 Paper reversing unit 10 Conveyance path 11 2nd discharge path 12 Discharge roller 13 1st DESCRIPTION OF SYMBOLS 1 Paper discharge path 14 Switching guide 17 Back side surface 17a Projection part 17b Tapered part 18 Front side surface 20 Reverse conveyance path 26 Solenoid 28 Contact member 30a, 30b Contact part 41 Paper mounting surface 140 Conveyance guide part 141 Axis 145 Protrusion 146 Connecting member 147 Protruding part 261 Coil part 262 Iron core 282 Protrusion 283 Connecting member

Claims (3)

An image forming apparatus for forming an image on a sheet,
A sheet placement section for placing the sheet discharged from the discharge port of the apparatus main body of the image forming apparatus;
A contact portion that hits the wall surface of the apparatus main body provided with the discharge port;
An image forming apparatus comprising: a control unit that performs control to intermittently apply the contact portion. The sheet placing portion is a first sheet placing portion,
A second sheet placement section for placing a sheet discharged from the apparatus main body,
A switching guide for switching a paper discharge path in order to select one of the first sheet placement portion and the second sheet placement portion as a discharge destination of the sheet,
The contact portion is provided in a part of the switching guide,
The control unit is
The image forming apparatus according to claim 1, wherein the contact portion is brought into contact with the wall surface by operating the switching guide. The control unit is
The image forming apparatus according to claim 1, wherein each time the sheet is discharged, the contact portion is brought into contact with the wall surface.

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