JP2001080802A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly guide an image-formed recording medium in the discharge direction without being attracted to a discharge guide by providing the discharge guide for making wind flow in the carrying direction on this surface for guiding an image part in the carrying direction. SOLUTION: Air blown out of respective air blowing exhaust ports 40 flows in the arrow C direction on a surface 32 of a discharge guide plate 30. A recording paper carrying directional downstream side part 24b of a platen 24 is positioned in a slightly upper part of the respective air blowing exhaust ports 40. Thus, when blowing out wind from the air blowing exhaust ports 40 before a discharge part 22a of roll paper 22 reaches the air blowing exhaust ports 40, an air layer is formed between the discharge part 22a and the surface 32 of the discharge guide plate 30. Thus, the discharge part 22a is guided in the arrow C direction without contacting with the surface 32, so that static electricity caused by friction of the discharge part 22a and the surface 32 of the discharge guide plate 30 is not generated, and the discharge part 22a is not electrostatically attracted to the surface 32 of the discharge guide plate 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an image on a recording medium such as recording paper, and more particularly to an image forming apparatus suitable for an ink jet system for forming an image by discharging ink onto a recording medium. .

[0002]

2. Description of the Related Art As one of output devices of a computer or a workstation, an electrophotographic image forming apparatus for forming an image on a recording medium using a developer, and an ink jet for forming an image by discharging ink onto the recording medium. 2. Description of the Related Art A conventional image forming apparatus is known. Among these image forming apparatuses, for example, an inkjet type image forming apparatus usually includes a print head for discharging ink, a carriage mounted with the print head and reciprocating in a predetermined main scanning direction, and a carriage orthogonal to the main scanning direction. And a transport device that transports the recording paper in the sub-scanning direction (the transport direction of the recording medium). In such an inkjet type image forming apparatus, a platen on which a recording paper is placed is usually formed. The print head reciprocates above the platen, and the portion of the platen facing the print head is an image forming area where an image is formed.

When an image is formed on a recording sheet, the recording sheet being conveyed by the conveying device is temporarily stopped, and the carriage is reciprocated in the main scanning direction, based on an image signal carrying image information. Ink is ejected from the print head to form an image for one band on a portion (image forming portion) of the recording paper located in the image forming area. Thereafter, the paper is conveyed by the width of one band and stopped again, and while the carriage is reciprocated in the main scanning direction, ink is ejected from the print head based on the image signal, and the image newly positioned in the image forming area is formed. An image is formed on the formation portion. By repeating such an operation, an image is formed on the entire surface of the recording paper.

Some of the above-described ink jet type image forming apparatuses form an image on recording paper (roll paper) wound in a roll shape. In many cases, this type incorporates a cutter blade for cutting the roll paper on which an image is formed into a predetermined length. This cutter blade is generally arranged in a portion of the platen on the downstream side in the recording paper transport direction.

A discharge guide for guiding the roll paper in a predetermined discharge direction is arranged adjacent to the platen and downstream of the platen in the recording paper transport direction. The material of the discharge guide is generally a resin such as PC. The cross-sectional shape of the discharge guide is, for example, an arc shape, and the roll paper is smoothly guided and discharged without causing any trouble such as wrinkles or twists. After an image is formed on the roll paper, the portion on which the image is formed is guided while sliding on the surface of the discharge guide. When the portion is guided by a predetermined length, the roll paper is cut by a cutter blade.

[0006]

As described above, the portion of the roll paper on which the image is formed is guided while sliding on the surface of the discharge guide. For this reason, the roll paper is continuously rubbed against the surface of the discharge guide in a close contact state, and static electricity is generated on the surface of the discharge guide, and this surface may be gradually charged. When the surface of the discharge guide is charged in this way, the roll paper is electrostatically attracted to the surface of the discharge guide. In particular, the inkjet type image forming apparatus is set to a humidity of 2
When used in an environment of 0% or less, the surface potential of the roll paper positioned on the surface of the discharge guide becomes about 2 kV, and the experiment according to the present invention revealed that the roll paper was easily electrostatically attracted to the surface of the discharge guide. did.

Further, the roll paper often has a downward curl habit. In this case, the roll paper tends to be in close contact with the surface of the discharge guide having the arc-shaped cross section as described above. For this reason,
The roll paper is more likely to be electrostatically attracted to the surface of the discharge guide.

When the roll paper is electrostatically attracted to the surface of the discharge guide as described above, the roll paper does not fall naturally into the storage basket disposed below the discharge guide, and the roll paper is placed on the surface of the discharge guide. It remains adsorbed. Also, when an image is continuously formed on a roll paper and the roll paper is repeatedly cut with a cutter blade to form a plurality of recording papers, the plurality of recording papers are overlapped by electrostatic attraction on the surface of the discharge guide. May remain adsorbed.

When the roll paper remains adsorbed on the surface of the discharge guide as described above, the appearance is adversely affected during the image forming operation. Further, when a plurality of recording papers are overlapped and adsorbed, the image of the lower recording paper comes into contact with the upper recording paper and is rubbed, so that the image may be stained.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an image forming apparatus that smoothly guides a recording medium on which an image is formed in a discharge direction without adsorbing the recording medium on a discharge guide.

[0011]

In order to achieve the above object, an image forming apparatus according to the present invention forms an image on a recording medium on a platen on which the recording medium is placed, and forms an image portion on which the image is formed. An image forming apparatus which guides the image portion conveyed on its surface in the conveying direction, and has a discharge guide on which the air flows in the conveying direction on the surface. It is characterized by having.

Here, (2) the image forming apparatus may include a blower that blows air flowing in the transport direction to the surface of the discharge guide.

(3) The image forming apparatus further includes a suction unit disposed below the platen for sucking air to cause a recording medium to be attracted to the platen,
(4) The blowing means may blow air sucked by the suction means onto the surface of the discharge guide.

Further, (5) the blowing means discharges air sucked by the suction means, which is formed downstream of the platen in the conveyance direction and upstream of the discharge guide in the conveyance direction. (6) a plurality of air outlets arranged in a direction substantially perpendicular to the transport direction and formed in a region equal to or larger than the width of the maximum width of the recording medium placed on the platen; May be used.

Further, (7) the blower has a plurality of blower outlets formed in a region of the surface of the discharge guide that is equal to or larger than the width of a recording medium having a maximum width mounted on the platen. It may be.

[0016]

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

Referring to FIGS. 1 to 4, a plotter which is a first embodiment of the image forming apparatus of the present invention will be described.

FIG. 1 is a perspective view showing a schematic configuration of the plotter as viewed substantially from the front, and FIG. 2 is a side view schematically showing the structure of the plotter of FIG. FIG. 3 is an enlarged side view showing the vicinity of the discharge guide of FIG. FIG.
FIG. 5 is a perspective view of the discharge guide of FIG.

An operation unit 12 for operating the plotter 10 is disposed on the plotter 10. Various switches and the like provided on the operation unit 12 allow the user to select the paper size,
Online / offline, commands, etc. are instructed.
The roll paper (an example of a recording medium) 22 inserted into the recording paper insertion slot 14 from the direction of arrow A is conveyed to the inside of the plotter 10 based on an instruction from the operation unit 12, where a color image is printed. The recording paper is discharged from the recording paper discharge port 16 in the direction of arrow C.

The plotter 10 includes a print head 18 having a plurality of ink discharge ports (not shown) for discharging ink.
The print head 18 is mounted in the main scanning direction (FIG. 2).
A carriage 20 that reciprocates in a direction perpendicular to the paper surface of FIG.
A drive roller 25 and a paper transport roller 26 for intermittently transporting a recording medium such as a roll paper 22 are provided in a direction indicated by an arrow A perpendicular to the main scanning direction (a recording paper transport direction, which is referred to as a sub-scanning direction). I have.

The carriage 20 reciprocates in the main scanning direction while being guided by two guide rails 21 extending parallel to the main scanning direction. A cutter blade 23 for cutting the roll paper 22 at a predetermined timing is attached to a lower portion of the carriage 20. The paper transport roller 26 is held by a roller holder 27 and pressed against the drive roller 25.

The plotter 10 is provided with a platen 24 on which a portion from which the roll paper 22 has been pulled out is placed. The front (below) of the print head 18 is an image forming area where an image is formed. A portion of the roll paper 22 located in the image forming area (hereinafter, referred to as an image forming portion) is formed by a suction fan 29 (an example of a suction unit according to the present invention) disposed below the platen 24. Air is sucked from arrow 24a in the direction of arrow B to make close contact with platen 24.

When an image is formed on the roll paper 22, the roll paper 22 being transported by the drive roller 25 and the paper transport roller 26 is temporarily stopped, and the carriage 20 is reciprocated in the main scanning direction and sucked. While sucking the image forming portion with the fan 29 and bringing the image forming portion into close contact with the platen 24, ink is ejected from the print head 18 to the image forming portion to form (print) an image for one band, and thereafter, the roll paper has a predetermined length. 2
2 is repeated to form an image for the next band on the image forming portion newly located in the image forming area. The discharged portion 22 on which an image is formed and discharged in this way
a is guided in the direction of arrow C by a discharge guide plate 30 (which is an example of a discharge guide according to the present invention), and is accommodated in a basket (not shown) located below.

The discharge portion 22a is connected to the discharge guide plate 30.
Along the surface 32 in the direction of arrow C. When viewed from the side, the surface 32 is curved as shown in FIGS. Above the discharge guide plate 30, a plurality of ventilation outlets 4 are provided.
0 is formed. The plurality of air outlets 40
An opening is formed by forming a recess in the upper portion of the discharge guide plate 30 at a position where the downstream portion of the platen 24 in the recording paper conveyance direction and the upstream portion of the surface 32 of the discharge guide plate 30 in the recording paper conveyance direction overlap. . Therefore, the plurality of air outlets 40 are formed downstream of the platen 24 in the recording paper transport direction and upstream of the surface 32 of the discharge guide plate 30 in the recording paper transport direction.

The plurality of air outlets 40 are arranged in a direction substantially perpendicular to the arrow C direction. The area where the plurality of air outlets 40 are formed is equal to or larger than the width of the recording medium having the maximum width placed on the platen 24. Therefore, the plurality of ventilation outlets 40 are formed over a wider area than the recording medium of the maximum size that can be printed by the plotter 10.

A louver 34 for guiding the air sucked by the suction fan 29 to a plurality of air outlets 40 is formed on the back surface of the discharge guide plate 30 opposite to the front surface 32. The louver 34 has an angle and a size such that the air sucked by the suction fan 29 is substantially evenly distributed to the plurality of air outlets 40. The air sucked by the suction fan 29 passes through the exhaust port 42 and is collected by the louver 34, and substantially the same amount of air blows out from the plurality of air outlets 40. In this case, the blower means referred to in the present invention is formed by the blower outlet 40 and the louver 34.

[0027] The air blown out from each ventilation outlet 40 is
It flows on the surface 32 of the discharge guide plate 30 in the direction of arrow C. The downstream side portion 24b of the platen 24 in the recording paper conveyance direction is shown in FIG.
As shown in FIG. For this reason, if the air is blown out from the air outlet 40 before the discharge portion 22 a of the roll paper 22 reaches the air outlet 40, the discharge portion 22 a and the discharge guide plate 3
An air layer is formed between the surface and the zero surface 32. Therefore, the discharge portion 22a is guided in the arrow C direction without contacting the surface 32 of the discharge guide plate 30. As a result, the discharge portion 22
No static electricity is generated due to friction between the discharge guide plate 30 and the surface 32 of the discharge guide plate 30, and the discharge portion 22a is not electrostatically attracted to the surface 32 of the discharge guide plate 30. Therefore, the discharge portion 22a
Is smoothly guided in the direction of the arrow C on the surface 32 of the discharge guide plate 30, falls naturally, and falls into a storage basket (not shown).
It will be housed in.

With reference to FIGS. 5 and 6, another example of the discharge guide plate will be described.

FIG. 5 is a perspective view showing a discharge guide plate of another example, and FIG. 6 is a side view schematically showing the discharge guide of FIG. In these figures, the same components as those shown in FIGS. 1 to 4 are denoted by the same reference numerals.

A feature of the discharge guide plate 50 shown in FIGS. 5 and 6 is that a large number of ventilation openings 54 are formed on the surface 52 thereof. The ventilation outlet 54 has a size of about several mm.
In addition, a region where a large number of ventilation exhaust ports 54 are formed is:
It is equal to or larger than the width of the recording medium having the maximum width placed on the platen 24. Therefore, a large number of ventilation outlets 54 are provided over a wider area than the maximum size recording medium that can be printed by the plotter 10.
Is formed.

A louver 56 for guiding the air sucked by the suction fan 29 to a plurality of air outlets 54 is formed on the back surface of the discharge guide plate 50 opposite to the front surface 52. The louver 56 has an angle and a size such that the air sucked by the suction fan 29 is substantially evenly distributed to the large number of ventilation outlets 54. The air sucked by the suction fan 29 passes through the exhaust port 42 and is collected by the louver 56, and substantially the same amount of air is blown out from the large number of air outlets 54. In this case, the blower means referred to in the present invention is formed by the blower outlet 54 and the louver 56.

The air blown out from each ventilation outlet 54 is
It flows in the direction of arrow C on the surface 52 of the discharge guide plate 50. The downstream side portion 24b of the platen 24 in the recording paper conveyance direction is shown in FIG.
As shown in FIG. For this reason, if air is blown out from the blower exhaust port 54 before the discharge part 22 a of the roll paper 22 reaches the blower exhaust port 54, an air layer is formed between the discharge part 22 a and the surface 52 of the discharge guide plate 50. It is formed. Therefore, the discharge portion 22a is guided in the arrow C direction without contacting the surface 52 of the discharge guide plate 50. As a result, no static electricity is generated due to friction between the discharge portion 22a and the surface 52 of the discharge guide plate 50, and the discharge portion 22a is not electrostatically attracted to the surface 52 of the discharge guide plate 50. Therefore, the discharge portion 22a is smoothly guided on the surface 52 of the discharge guide plate 50 in the direction of arrow C, falls naturally, and is stored in the storage basket (not shown).

[0033]

As described above, in the image forming apparatus of the present invention, the surface of the discharge guide and the discharge portion conveyed on this surface (the portion of the recording medium on which the image is formed and discharged) are formed. An air layer is formed between the surfaces by the wind flowing on the surface in the transport direction. For this reason, the discharge portion is guided in the transport direction without contacting the surface of the discharge guide.
As a result, no static electricity is generated due to friction between the discharge portion and the surface of the discharge guide, and the discharge portion is not electrostatically attracted to the surface of the discharge guide. Therefore, the discharge portion is smoothly guided on the surface of the discharge guide in the transport direction.

Here, if the image forming apparatus has a blowing means for blowing the air flowing in the transport direction to the surface of the discharge guide, the blowing means blows the air in the transport direction. The wind surely flows. For this reason, the discharge portion is not reliably electrostatically attracted to the surface of the discharge guide, and the discharge portion is guided on the surface of the discharge guide more smoothly in the transport direction.

Further, the above-mentioned image forming apparatus makes the platen adsorb a recording medium by sucking air.
A suction unit disposed below the platen, wherein the air blowing unit blows the air sucked by the suction unit to the surface of the discharge guide when the air sucked by the suction unit is blown out. Since the blowing means blows out to the surface of the discharge guide, another suction device or the like is not required. Therefore, the image forming apparatus does not need to have a complicated configuration.

Further, the blower means is a blower outlet formed at a downstream side of the platen in the transfer direction and an upstream side of the discharge guide in the transfer direction, for discharging air sucked by the suction means. And this ventilation outlet is
In the case where a plurality of recording media are arranged in a region equal to or more than the width of the recording medium having the maximum width mounted on the platen and arranged in a direction substantially orthogonal to the transport direction, the maximum width of the recording medium mounted on the platen is Since the ventilation outlet is formed in an area larger than the width of the recording medium, even if the recording medium has the maximum width that can form an image with the image forming apparatus, air is blown so that the discharge portion does not contact the surface of the discharge guide. I can blow out. As a result,
Even with the recording medium having the maximum width, the discharge portion is not reliably electrostatically attracted to the surface of the discharge guide, and the discharge portion is smoothly guided on the surface of the discharge guide in the transport direction.

Further, the blower means has a plurality of blower outlets formed in a region of the surface of the discharge guide which is equal to or larger than a width of a recording medium having a maximum width mounted on the platen. Since the air outlet is formed in a region equal to or larger than the width of the maximum width recording medium placed on the platen, even if the maximum width of the recording medium that can form an image with the image Air can be blown out so as not to contact the surface of the discharge guide. As a result, even with a recording medium having the maximum width that can form an image with the image forming apparatus, the discharge portion is not reliably electrostatically attracted to the surface of the discharge guide,
The discharge portion is smoothly guided on the surface of the discharge guide in the transport direction.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a plotter viewed substantially from the front.

FIG. 2 is a side view schematically showing the structure of the plotter of FIG.

FIG. 3 is an enlarged side view showing the vicinity of a discharge guide of FIG. 2;

FIG. 4 is a perspective view of the discharge guide of FIG. 2 as viewed from the back side.

FIG. 5 is a perspective view showing another example of a discharge guide plate.

FIG. 6 is a side view schematically showing the discharge guide of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plotter 22 Roll paper 24 Platen 29 Suction fan 30, 50 Discharge guide plate 32, 52 Surface of discharge guide plate 34, 56 Louver 40, 54 Ventilation exhaust port

Claims (5)

[Claims] An image forming apparatus forms an image on a recording medium on a platen on which the recording medium is placed, and guides an image portion on which the image is formed in a predetermined conveying direction. An image forming apparatus, comprising: a discharge guide that guides the image portion that has come in the transport direction and that allows air to flow on the surface in the transport direction. 2. The image forming apparatus according to claim 1, further comprising a blower that blows air flowing in the transport direction to a surface of the discharge guide. 3. A suction means disposed below the platen for sucking air onto the platen to suck a recording medium, wherein the blower means blows the air sucked by the suction means into the discharge guide. The image forming apparatus according to claim 2, wherein the image is blown onto the surface. 4. The blower outlet, which is formed on the downstream side of the platen in the transport direction and on the upstream side of the discharge guide in the transport direction, and configured to discharge air sucked by the suction unit. Having a plurality of air outlets, which are arranged in an orthogonal direction substantially orthogonal to the transport direction and are formed in an area equal to or larger than the width of a recording medium having a maximum width mounted on the platen. Claim 3
An image forming apparatus according to claim 1. 5. The apparatus according to claim 5, wherein the blower has a plurality of blower outlets formed in a region of the surface of the discharge guide which is equal to or larger than a width of a recording medium having a maximum width mounted on the platen. Claim 3
An image forming apparatus according to claim 1.