JP4305906B2 - Image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus that adsorbs and conveys recording paper after image formation to a conveyance belt, and more particularly, to discharge of recording paper in a paper discharge unit of an image forming apparatus that adsorbs and conveys recording paper by charge charging of the conveyance belt. .

In an image forming apparatus such as an ink jet recording apparatus, when a paper feed roller, a transport roller, and a paper discharge roller are used for transporting recording paper (recording medium), when the recording paper is transported, Friction occurs between them, static electricity is generated, and electric charges accumulate on the transport path and recording paper. Further, even when an adsorption belt using electrostatic force or vacuum adsorption is used for transporting the recording paper, the recording paper is likely to accumulate electric charges and needs to be removed for reliable transport of the recording paper.
2. Description of the Related Art Conventionally, various means for removing static electricity as described below are known as means for removing charges accumulated on a recording medium and a conveyance path in an image forming apparatus that records on recording paper such as paper and OHP sheets. Yes.

  In Patent Document 1, a pinch roll that is in pressure contact with a conveyance roll disposed on the upstream side of an ink discharge portion of a recording head and a holder that holds the pinch roll are made of a conductive material and are installed via a frame. An ink jet recording apparatus is disclosed that efficiently removes static electricity on a recording paper that is charged during conveyance before printing by a recording head.

  In Patent Document 2, a neutralizing brush as a neutralizing unit is disposed in a non-printing area on both sides of a platen with a predetermined gap so as not to contact the nozzle cover and nozzle plate of each color recording head. An ink jet recording apparatus is disclosed in which static electricity accumulated in a nozzle cover due to rubbing or the like is removed, and malfunction or damage of an actuator element or the like due to static electricity is prevented.

Patent Document 3 discloses a paper feed roller that separates and transports recording sheets one by one from a plurality of stacked recording sheets, and a recording position of a recording head in which the recording sheets transported by the paper feed rollers are mounted on a recording head cartridge. An ink jet recording apparatus having a line feed roller that feeds into the sheet, and is provided between the feed roller and the line feed roller with a neutralizing unit that neutralizes the recording sheet so that the electrostatic charge amount is a predetermined value or less. An ink jet recording apparatus that does not stain the recording back surface of a recording sheet even when performing none recording is disclosed.
Japanese Patent Laid-Open No. 10-81008 Japanese Patent Laid-Open No. 10-16240 JP 2003-54069 A

  In a transport device that transports paper by attracting it to the transport belt by electrostatic force, after separating the paper from the transport belt, the paper is stacked on the paper discharge tray due to static electricity remaining on the side that the transport belt is in contact with In this case, there is a problem in that a discharge failure occurs due to sticking between sheets due to static electricity.

  In addition, even when a slow current member for removing residual static electricity is provided, if the paper is in contact with the slow current member, paper powder or ink during double-sided transport adheres to the slow current member and becomes dirty. There is a problem that the slow current efficiency is deteriorated and durability is lowered.

The present invention has been made in order to solve the above-mentioned problems. The invention of claim 1 is directed to a conveyance belt that adsorbs and conveys a recording medium by electric charges, a charging roller that applies electric charges to the conveyance belt, and In an image forming apparatus comprising a driving roller and a driven roller for passing a conveying belt, and a paper discharge tray on which the recording medium after image formation is stacked, the recording medium is disposed between the conveying belt and the paper discharge tray. characterized in that a discharging member which connects the side surface of the conveyor belt side an inverted L-shaped and the conveyor belt contact surface the sheet discharge tray.

The invention of claim 2 is the image forming apparatus according to claim 1, wherein the dividing conductive member is disposed at a predetermined distance away from the conveying surface, the recording medium can divided conductive by the dividing conductive member and a non-contact It is characterized by being.

The invention of claim 3 is the image forming apparatus according to claim 1 or 2, wherein the dividing conductive member is characterized by comprising a dividing conductive fabric.

The image forming apparatus according to claim 1, by dividing conductive immediately after separation of the sheet from the conveyor belt, it is possible to prevent the sticking of the sheet to the sheet being conveyed pathways and already discharge stack of sheets It becomes.

The image forming apparatus according to claim 2, by not contacting the paper with the removal collecting member, can be prevented paper powder adheres to the dividing collecting member. Although the image surface when the two-side printing comes to removing conductive member, it is possible to prevent the rubbing stain adhesion and the image plane of the ink removal collecting member.

The image forming apparatus according to claim 3, it is possible not to contact with the sheet removal collecting member dividing electrostatic conveyor belt surface of the recording medium with a simple and cheap construction.

The present invention includes a conveyor belt for conveying by suction the recording medium by electrostatic loading, a charging roller for imparting electric charge to the conveying belt, a driving roller and a driven roller passes over the conveyor belt, the object after the image formation an image forming apparatus having a paper discharge tray for stacking the recording medium, between the discharge tray and the conveyor belt, the conveyor belt contact surface of the recording medium, and, of the conveyor belt side of the sheet discharge tray characterized by the Moketako an inverted L-shaped divided conductive member dividing conductive wall surfaces, by such structure, without causing discharge failure caused by sticking due to static electricity of the sheet between, also, residual static electricity soiled adhered paper dust or ink removal collecting member for removing dividing collecting efficiency is deteriorated to one in which the durability is so does not decrease.

The image forming apparatus of the present invention will be described below based on the embodiments shown in FIGS.
FIG. 1 is a schematic sectional view showing an image forming apparatus according to an embodiment of the present invention.
The image forming apparatus shown in FIG. 1 includes a conveying belt 1 that adsorbs and conveys paper by electric charge, a driving roller 2 that drives the conveying belt 1, a driven roller 3 that cooperates with the driving roller 2 and passes the conveying belt 1, and conveying. A charging roller 4 for applying charge to the belt 1, a recording head 5, a discharge roller 7 for discharging a sheet after image formation, a spur roller 8 facing the discharge roller 7, and a sheet discharged from the discharge roller 7 ejection guide 9 guiding for, divided conductive sheet 10 which divided the charge remaining on the paper, and a paper discharge tray 11 for stacking the paper after the paper discharge image formation by discharge roller 7.
As the recording method of the image forming apparatus, all kinds of methods such as an ink jet method, a wire dot method, a thermal method, and a laser beam method can be adopted.

In the image forming apparatus shown in FIG. 1, when a sheet taken out from a sheet feeding tray (not shown) and conveyed through a conveyance path comes into contact with a conveyance belt 1 that is stretched between a driving roller 2 and a driven roller 3, the conveyance belt. 1 is adsorbed by the electric charge charged by the charging roller 4, conveyed below the recording head 5, and a predetermined image is formed by the recording head 5 driven at that position based on image information. Paper after image formation is fed between the paper discharge roller 7 and the spur roller 8, are stacked on the discharge tray 11 through the upper discharge guide 9 and air collector sheet 10.

2 is a cross-sectional view taken along line XX in FIG. 1, and FIG. 3 is a cross-sectional view taken along line YY in FIG.
A plurality of paper discharge rollers 7 are supported at predetermined intervals over the entire width of the paper path P on a paper discharge roller shaft 6 driven by a driving device (not shown). Further, a spur roller 8 is provided so as to face the plurality of paper discharge rollers 7, and the paper after image formation is sandwiched between the paper discharge roller 7 and the spur roller 8 by driving the paper discharge roller shaft 6. Is discharged.

A paper discharge guide 9 is provided between the paper discharge rollers 7 adjacent to the paper discharge roller shaft 6 to guide the paper discharged from the paper discharge roller 7. The discharge guide 9 has an inverted L-shaped cross section as shown in FIG. 3, and guide ribs 9a and 9a are formed so as to protrude from both sides including the bent portion. Both guide ribs 9a, is adhered is divided conductive sheet 10 in the recesses between 9a, as a sheet guided by the discharge guide 9 and divided conductive sheet 10 are isolated by a predetermined distance, there is no direct contact It has become.

The divided conductive sheet 10, but not selected the material if the sheet-like material having conductivity, sufficient static elimination effect are achieved using a removal conductive fabric, also the handling at the time of attaching the sheet discharge guide 9 Easy.

Discharge rollers 7, the sheet discharge guide 9, the positional relationship between the divided conductive sheet 10 each other, the guide rib 9a of the upper side portion of the sheet discharge guide 9 as shown in FIG. 3 is protruded from the uppermost portion of the discharge roller 7 The guide rib 9 a at the bottom of the paper discharge guide 9 is set to a sufficient length in relation to the paper discharge tray 11.

According to the present invention, it divided conductive sheet 10 rib 9a of the discharge guide 9 so as not to contact with the paper after image formation, because it is affixed to the concave between 9a, divided conductive sheet 10 is paper dust and duplex printing without it contaminated with ink or the like when, removing electrostatic effect unchanging permanent is obtained, paper transport system path and already prevent the sticking of the sheet being stacked, good transportability is obtained.

1 is a schematic cross-sectional view illustrating an image forming apparatus according to an embodiment of the present invention. It is XX sectional drawing of FIG. It is YY sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Conveyance belt, 2 ... Drive roller, 3 ... Driven roller, 4 ... Charging roller, 5 ... Recording head, 6 ... Discharge roller shaft, 7 ... Discharge roller, 8 ... Spur roller, 9 ... Discharge guide, 9a ... guide rib, 10 ... dividing conductive sheet, 11 ... output tray.

Claims (3)

A conveying belt that adsorbs and conveys a recording medium with electric charge, a charging roller that applies electric charge to the conveying belt, a driving roller and a driven roller that span the conveying belt, and the recording medium after image formation are stacked. an image forming apparatus having a paper discharge tray, between the discharge tray and the conveyor belt, the conveyor belt side side surface and the reverse L-shaped of the sheet discharge tray and the conveyor belt contact surface of the recording medium An image forming apparatus comprising a static elimination member connected in a shape.   The image forming apparatus according to claim 1, wherein the charge removal member is disposed at a position away from a conveyance surface by a predetermined distance, and the recording medium can be discharged without contact with the charge removal member. .   3. The image forming apparatus according to claim 1, wherein the charge removal member is made of a charge removal cloth.

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