JP2022116534A - Sheet carrier unit - Google Patents

Abstract

To provide a sheet carrier unit that can suppress scattering of a dust on a de-electrifying brush to be contacted with a conveyance belt where a sheet is electrostatically attracted.SOLUTION: A sheet carrier unit comprises: a conveyance belt 31 that can retract from a conveyance position for conveying an electrostatically attracted sheet P on a sheet-conveyance path, to an unjamming position separated away from the sheet-conveyance path; a de-electrifying brush 34 that contacts the conveyance belt 31 in the conveyance position to de-electrify the sheet P electrostatically attracted on the conveyance belt 21 and a portion of the conveyance belt 21 surrounding the same; and a brush-moving mechanism 35 that, in conjunction mechanically with retraction of the conveyance belt 31 to the unjamming position from the conveyance position, moves the de-electrifying brush 34 from a de-electrifying position for contacting the conveyance belt 21 in the conveyance position, to a retracted position spaced from the conveyance belt 21 in the conveyance position departed from a work space M formed around the conveyance belt 31 in the unjamming position.SELECTED DRAWING: Figure 3B

Description

The present invention relates to a paper transport unit.

2. Description of the Related Art In an image forming apparatus, an electrostatic adsorption type paper transport unit is known that transports a paper by electrostatically adsorbing it to the surface of a charged transport belt. An image is printed by the printer engine on the paper attracted to the conveying belt.

When the image forming apparatus stops operating due to a paper jam, it is necessary to remove the paper being conveyed from the image forming apparatus in order to restore the image forming apparatus. In the electrostatic attraction type paper conveying unit, it is necessary to remove the paper being conveyed that is attracted to the conveying belt. In order to take out the paper on the conveying belt, a working space that can be approached from outside the image forming apparatus is required between the printer engine and the conveying belt. In order to secure this work space, it is necessary to retract the transport belt from a position on the paper transport path near the printer engine.

Japanese Patent Application Laid-Open No. 2002-200002 describes an image forming apparatus that retracts a conveying belt on a conveying path to a position outside the conveying path under the control of a control unit when a paper jam occurs. In this image forming apparatus, retracting the conveying belt creates a work space between the printer engine and the conveying belt for taking out the paper on the conveying belt.

JP 2017-109811 A

The conveying belt that electrostatically attracts and conveys the paper is charged before electrostatically attracting the paper. When a sheet of paper approaches the charged conveying belt, the sheet is also electrified due to the bias of electrons, and is electrostatically attracted to the conveying belt. The surface of the paper attracted to the conveying belt is charged, and the attraction force between the paper and the belt remains weak. If the conveying belt conveys the paper as it is, it becomes a cause of paper jams and the like.

In addition, if the surface of the paper attracted to the conveyor belt, that is, the printed surface, is charged, when the printer engine prints an image on the paper, the electric charge remaining on the printed surface of the paper may cause the image to be distorted. There is

The occurrence of the above-mentioned phenomenon occurs when the static elimination brush is brought into contact with the conveying belt that electrostatically attracts the paper, and the portion of the conveying belt excluding the portion that electrostatically attracts the paper and the printed surface of the paper are neutralized. This can be suppressed by increasing the adsorption force of the paper to the sheet. When the static elimination brush is brought into contact with the transport belt that electrostatically attracts the paper, dust such as paper dust from the contacting paper may adhere to the static elimination brush.

For example, if the static elimination brush is exposed in the work space created by retracting the conveying belt, there is a possibility that other objects may come into contact with the static elimination brush when taking out the paper in the work space. When other objects come into contact with the static elimination brush, dust on the static elimination brush scatters in the work space and adheres to structures such as a printer engine around the work space. For example, dust on a printer engine can degrade the quality of the image that the printer engine prints on paper.

The image forming apparatus disclosed in Japanese Patent Laid-Open No. 2002-200000 has a neutralization brush that neutralizes the surface of the conveying belt that has been charged after an image is printed on the paper that is being conveyed. After the conveying belt is withdrawn from the conveying path under the control of the control unit, the neutralizing brush moves from a position in contact with the conveying belt to a position out of contact with the conveying belt under the control of the control unit.

When the static elimination brush that contacts the transport belt that electrostatically attracts the paper is moved under the control of the control unit after the transport belt is retracted, as in the static elimination brush of Patent Document 1, when a control abnormality occurs in the control unit. , the neutralizing brush remains positioned at the position where it contacts the conveying belt before retraction. If the static elimination brush at this position is exposed to the work space created by retracting the conveying belt, it may become impossible to prevent the scattering of dust adhering to the static elimination brush in the work space in the event of a control error in the control unit.

An object of the present invention is to prevent the dust adhering to the static elimination brush that contacts the conveying belt that electrostatically attracts the paper from scattering into the work space created around the conveying belt when the conveying belt is retracted from the paper conveying position. is suppressed.

In order to achieve the above object, a paper transport unit according to one aspect of the present invention includes:
a conveying belt that can be retracted from a conveying position where the electrostatically attracted paper is conveyed on the paper conveying path to a jam clearing position outside the paper conveying path;
a neutralizing brush that contacts the conveying belt at the conveying position and neutralizes the sheet electrostatically attracted to the conveying belt and the surrounding conveying belt portion;
Mechanically interlocking with the retraction of the conveying belt from the conveying position to the jam clearing position, the static eliminating brush moves from the static neutralizing position contacting the conveying belt at the conveying position to the conveying belt at the jam clearing position. A brush moving mechanism that moves to a retracted position away from the conveying belt at the conveying position out of the work space created around the
Prepare.

According to the present invention, dust adhering to the neutralizing brush that contacts the conveying belt that electrostatically attracts the paper does not scatter in the work space created around the conveying belt when the conveying belt is retracted from the conveying position of the paper. can be suppressed.

FIG. 1 is an explanatory diagram showing a schematic configuration of an inkjet printer including a sheet conveying unit according to one embodiment of the present invention. FIG. 2A is an explanatory diagram showing a schematic configuration of an inkjet printer including a paper transport unit of a comparative example in which a neutralizing brush remains on the paper transport path after the transport unit is retracted to the jam release position. FIG. 2B is an explanatory view of taking out the paper remaining in the vicinity of the inkjet head section after the conveying section is retracted in the paper conveying unit of FIG. 2A. FIG. 3A is an explanatory diagram specifically showing a movement mechanism of the neutralization brush in FIG. 1. FIG. FIG. 3B is an explanatory view showing a state in which the static elimination brush movement mechanism in FIG. 3A has moved the static elimination brush by retreating to the jam release position of the transport section.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent reference numerals are given to the same or equivalent parts and components throughout each drawing. However, it should be noted that the drawings are schematic and differ from reality. In addition, it is a matter of course that there are portions with different dimensional relationships and ratios between the drawings.

Further, the embodiments shown below are examples of apparatuses and the like for embodying the technical idea of the present invention. not specific to The technical idea of this invention can be modified in various ways within the scope of claims.

FIG. 1 is an explanatory diagram showing a schematic configuration of an inkjet printer provided with a sheet conveying unit according to one embodiment of the present invention.

As shown in FIG. 1, the inkjet printer 1 includes a paper feeding section 2, a conveying section 3, and a printing section 4. As shown in FIG.

The paper feed unit 2 feeds the paper P to the transport unit 3 . The paper feed unit 2 includes a paper feed table 21 , paper feed rollers 22 and registration rollers 23 .

The paper feed table 21 is for stacking paper P used for printing, and the paper feed roller 22 is arranged on the upper side thereof. The paper feed roller 22 feeds the paper P on the paper feed table 21 to the transport unit 3 one by one.

The registration rollers 23 temporarily stop the leading edge of the paper P sent from the 21st paper feed roller 22 to correct the skew, and then nip the leading edge of the paper P and send it to the conveying unit 3 .

The transport unit 3 includes a transport belt 31, a platen plate 32, a charging roller 33, a neutralizing brush 34, and a brush moving mechanism 35 (see FIG. 3A).

The conveying belt 31 can be constructed using an endless belt stretched between a pair of guide rollers 36 , 36 . A tension roller 37 applies tension to the conveying belt 31 . One of the guide rollers 36, 36 is a drive roller driven by a motor (not shown), and the other is a driven roller (free roller). The transport belt 31 rotates as the driving roller is rotated by a motor. A portion of the transport belt 31 between the guide rollers 36 and 36 is positioned on the transport path of the paper P. As shown in FIG.

The platen plate 32 supports the portion of the conveyor belt 31 between the guide rollers 36, 36 from the back side.

The charging roller 33 contacts the surface of the conveying belt 31 at a location near the registration roller 23 and nips the conveying belt 31 together with a guide roller 36 closer to the registration roller 23 . The charging roller 33 charges the surface of the nipped conveying belt 31 .

The neutralizing brush 34 contacts the conveying belt 21 electrostatically attracting the paper P conveyed by the registration roller 23, and neutralizes the paper P electrostatically attracted to the conveying belt 21 and the surrounding conveying belt 21 portion. .

The sheet P whose static electricity has been eliminated by the static elimination brush 34 is adsorbed and held on the upper surface of the portion between the guide rollers 36 of the transport belt 31 whose surface is charged. By bringing the neutralizing brush 34 into contact with the conveying belt 21 electrostatically attracting the paper P, the portion of the conveying belt 21 excluding the portion electrostatically attracting the paper P and the surface of the paper P exposed on the conveying belt 21 are removed. (printing surface) is neutralized. By removing static electricity from the portion of the transport belt 21 that does not electrostatically attract the paper P, it is possible to suppress the generation of unnecessary adsorption force from the transport belt 21 portion to the paper P being transported. By this suppression, it is possible to suppress the occurrence of a jam or the like of the paper P being transported due to deviation of the suction position of the paper P on the transport belt 21 .

In addition, since the surface (printed surface) of the paper P electrostatically attracted to the transport belt 21 is neutralized, the uncharged paper P can be transported to the printing unit 4 by the transport unit 3 .

The transport belt 31 sucking and holding the paper P transports the paper P in the transport direction A. As shown in FIG. The paper P conveyed by the conveying belt 31 passes directly below the printing section 4 .

The printing unit 4 prints on the paper P conveyed by the conveying belt 31 . The printing unit 4 includes an inkjet head unit 41 (printer engine).

The inkjet head section 41 is arranged above the conveying belt 31 . The inkjet head unit 41 has line heads for each color arranged at intervals in the transport direction A. As shown in FIG. The inkjet head unit 41 ejects ink from the nozzles of each head block in a pattern corresponding to the image to be printed on the paper P, thereby printing an image on the paper P transported by the transport belt 31 at the transport position. .

The paper P on which an image is to be printed is conveyed to the printing section 4 in a state in which the surface of the paper P is neutralized by contact with the neutralization brush 34 . Since the surface of the paper P is neutralized, the ink ejected from the inkjet head unit 41 is prevented from landing on the paper P in a position that deviates from its original position due to the influence of the charge remaining on the surface (printing surface) of the paper P. be. By suppressing the displacement of the ink landing position, it is possible to suppress the disturbance of the printed image.

The transport belt 31, the platen plate 32, and the charging roller 33 of the transport unit 3 are retracted together from the transport position shown in FIG. 1 to a jam release position (see FIG. 2A) below the transport position by a moving mechanism (not shown). be able to.

At the transport position, the portion of the transport belt 31 between the guide rollers 36, 36 is positioned on the transport path of the paper P, and the paper P transported by the registration rollers 23 can be attracted and held. At the jam release position, the portion of the transport belt 31 between the guide rollers 36 and 36 is retracted below the transport path of the paper P. As shown in FIG. At the jam clearing position, the conveying belt 31 is further away from the printing unit 4 than at the conveying position, and a work space is created above the conveying belt 31 . This working space can be used, for example, when removing the paper P adsorbed and held by the conveying belt 31 or the paper P nipped by the registration rollers 23 and left near the printing unit 4 .

As in the paper conveying unit of the comparative example shown in FIG. 2A , the neutralizing brush 34 remains in the static neutralizing position where it contacts the paper P conveyed by the registration roller 23 while the conveying belt 31 is retracted to the jam release position. When remaining, the static elimination brush 34 is exposed to the working space M.

Dust such as paper dust of the paper P may adhere to the static elimination brush 34 due to contact with the paper P at the static elimination position. When the static elimination brush 34 remains at the static elimination position shown in FIG. 2A and is exposed to the work space M, when the registration roller 23 pulls the sheet P on the way to the transport unit 3 toward the work space M to take it out, for example, as shown in FIG. , there is a possibility that the paper P or the like will come into contact with the static elimination brush 34 .

If the paper P or the like contacts the static elimination brush 34 remaining at the static elimination position, dust D adhering to the static elimination brush 34 may scatter in the work space M where the static elimination brush 34 is exposed. When the dust D scatters, it adheres to the inkjet head section 41 exposed in the work space M, and there is a possibility that the quality of the image printed on the paper P by the inkjet head section 41 is deteriorated.

In this embodiment, the brush moving mechanism 35 shown in FIG. is set in The brush moving mechanism 35 mechanically operates in conjunction with retraction of the transport belt 31 from the transport position to the jam release position, and moves the static elimination brush 34 from the static elimination position in FIG. 1 to the retracted position (see FIG. 3B). .

The brush movement mechanism 35 of FIG. 3A has a support arm 38. As shown in FIG. An intermediate portion of the support arm 38 is rotatably supported by a support shaft 38a. The rotation range of the support arm 38 may be restricted by a stopper mechanism (not shown). A neutralization brush 34 is attached to one end of the support arm 38 across the support shaft 38a. A contact portion 38b is formed at the other end of the support arm 38 with the support shaft 38a interposed therebetween. The support arm 38 is urged to rotate clockwise around the support shaft 38a by the urging force of a coil spring 38c connected to one side of the support arm 38. As shown in FIG.

When the transport belt 31 is at the transport position, the contact portion 38b of the support arm 38 contacts the platen plate 32 located outside the transport belt 31 in the width direction. This contact causes the support arm 38 to rotate counterclockwise around the support shaft 38a against the biasing force of the coil spring 38c. By this rotation, the static elimination brush 34 is arranged at the static elimination position. The rotation of the support arm 38 may be restricted by a stopper mechanism (not shown) at the angle at which the static elimination brush 34 is arranged at the static elimination position.

The static elimination brush 34 arranged at the static elimination position contacts the transport belt 21 that electrostatically attracts the paper P transported by the registration roller 23, and the paper P electrostatically attracted to the transport belt 21 and the surrounding transport belt. 21 portion can be discharged.

When the conveying belt 31 retreats from the conveying position to the jam clearing position, the contact portion 38b of the support arm 38 separates from the platen plate 32 as shown in FIG. 3B. Due to this separation, the support arm 38 rotates clockwise around the support shaft 38a by the biasing force of the coil spring 38c. By this rotation, the static elimination brush 34 is arranged at the retracted position shown in FIG. 3B. The rotation of the support arm 38 may be restricted by a stopper mechanism (not shown) at the angle at which the static elimination brush 34 is arranged at the retracted position.

The retracted position of the static elimination brush 34 is a position above the static elimination position of the static elimination brush 34 shown in FIG. 3A. The static elimination brush 34 at the static elimination position contacts the transport belt 31 at the transport position, and the transport belt 31 at the transport position is arranged on the transport path of the paper P. FIG. Therefore, the neutralization brush 34 at the retracted position is arranged at a position separated from the transport path of the paper P and spaced upward from the transport belt 31 at the transport position and the paper P on the transport belt 31 .

A work space M created by retracting the conveying belt 31 from the conveying position to the jam clearing position is developed below the conveying belt 31 at the conveying position. Therefore, the static elimination brush 34 at the retracted position is positioned above the work space M without being exposed to the work space M formed above the conveying belt 31 at the jam release position.

Since the static elimination brush 34 at the retracted position is positioned above the work space M, for example, when the registration rollers 23 pull the paper P on the way to the transport unit 3 toward the work space M to take it out, the paper P, etc. The possibility of contact with the static elimination brush 34 is suppressed.

In the inkjet printer 1 of the present embodiment, the static elimination brush 34 at the static elimination position mechanically interlocks with the retraction of the transport belt 31 from the transport position to the jam release position by the rotation of the support arm 38 of the brush moving mechanism 35. Moved to the retracted position. Therefore, even if a control abnormality occurs in the control system of the inkjet printer 1 when retracting the transport belt 31 at the transport position to the jam release position, the transport belt 31 is retracted without leaving the static elimination brush 34 at the static elimination position. can be moved to the retracted position in conjunction with

For this reason, the static elimination brush 34 is exposed in the work space M created by the retraction of the conveying belt 31, the sheet P or the like comes into contact with the static elimination brush 34, and the dust D adhering to the static elimination brush 34 exposes the static elimination brush 34. Scattering in the working space M can be suppressed. By suppressing the scattering of the dust D from the static elimination brush 34 in the working space M, the dust D adheres to the inkjet head portion 41 exposed in the working space M, and the quality of the image printed on the paper P by the inkjet head portion 41 is improved. can reduce the possibility of a decline in

Note that the present invention is not limited to the inkjet printer 1, and can be applied to an image forming apparatus such as an electrophotographic image forming apparatus, in which a conveying belt that electrostatically attracts and conveys paper is released from a conveying position on the conveying path of the paper. It can be widely applied to a paper transport unit that retracts to a position.

Moreover, the present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the present invention at the implementation stage. Furthermore, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be omitted from all components shown in the embodiments.

[Note]
The embodiments described above disclose the following aspects of the invention.

That is, as one aspect of the invention,
a conveying belt that can be retracted from a conveying position where the electrostatically attracted paper is conveyed on the paper conveying path to a jam clearing position outside the paper conveying path;
a neutralizing brush that contacts the conveying belt at the conveying position and neutralizes the sheet electrostatically attracted to the conveying belt and the surrounding conveying belt portion;
Mechanically interlocking with the retraction of the conveying belt from the conveying position to the jam clearing position, the static eliminating brush moves from the static neutralizing position contacting the conveying belt at the conveying position to the conveying belt at the jam clearing position. A brush moving mechanism that moves to a retracted position away from the conveying belt at the conveying position out of the work space created around the
A sheet transport unit is disclosed comprising:

According to the above aspect of the invention, dust adhering to the neutralizing brush that makes contact with the conveying belt that electrostatically attracts the paper creates a working space around the conveying belt when the conveying belt is retracted from the conveying position of the paper. can be suppressed.

Reference Signs List 1 inkjet printer 2 paper feed unit 3 transport unit 4 print unit 21 paper feed table 22 paper feed roller 23 registration roller 31 transport belt 32 plate template 33 charging roller 34 static elimination brush 35 brush movement mechanism 36 guide roller 37 tension roller 38 support arm 38a Support shaft 38b Contact portion 38c Coil spring 41 Inkjet head portion A Conveyance direction D Dust M Work space P Paper

Claims (1)

a conveying belt that can be retracted from a conveying position where the electrostatically attracted paper is conveyed on the paper conveying path to a jam clearing position outside the paper conveying path;
a neutralizing brush that contacts the conveying belt at the conveying position and neutralizes the sheet electrostatically attracted to the conveying belt and the surrounding conveying belt portion;
Mechanically interlocking with the retraction of the conveying belt from the conveying position to the jam clearing position, the static eliminating brush moves from the static neutralizing position contacting the conveying belt at the conveying position to the conveying belt at the jam clearing position. A brush moving mechanism that moves to a retracted position away from the conveying belt at the conveying position out of the work space created around the
A paper transport unit with a

Images