JPH09301600A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent discharged sheet material from coming in sliding contact with already discharged sheet material with an image formed by providing a discharge part with guide means arranged at least partially at a narrower space than the width of the sheet material so as to dome in contact with the side edges of the discharged sheet material to bend the sheet material in the width direction. SOLUTION: Sheet material S3 in process of discharge is bent by coming in contact with suppot members A1, A2 serving as guide means provided at a discharge part H1. The support members A1, A2 are arranged at least partially at a narrower space than the width of the sheet material S3 so as to come in contact with the side edges of the sheet material A3. Specifically, the sheet material S3 is discharged while coming in contact with the support members A1, A2, so that the sheet material A3 is discharged on a specified discharge path without bending in a discharge direction. Sliding contact between already discharged sheet material and the sheet material S3 in process of discharge is thereby prevented so as to prevent the lowering of image quality caused by rubbing of formed images.

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, and more particularly to a discharging mechanism for a sheet material on which an image is formed by an inkjet method.

[0002]

2. Description of the Related Art Conventionally, in a printer that forms an image by an ink jet method, when printing is continuously performed on a plurality of sheet materials, the next sheet material is discharged before the ink on the printed sheet material dries. If the printed surface of the printed sheet material comes into sliding contact with the printed surface of the printed sheet material, the printed surface of the printed sheet material or the back surface of the discharged sheet material is contaminated.

As an attempt to solve such a problem, a paper discharge stacker disclosed in Japanese Patent Laid-Open No. 134865/1993 is known.

In this publication, the discharge tray 101 is formed in a concave shape as shown in FIG. 7, and the printed sheet material S101 is stacked in a concave shape as shown in FIG. Sheet material S with sheet material S102 printed
A technique is disclosed in which the time until sliding contact with 101 is delayed.

Further, as shown in FIG. 9, the sheet material S10
3 are spurs 102a, 102b, 1 having different outer diameters.
02c and rollers 103a and 103 facing them
There is a technique in which the sheet material S103 is ejected in a convex shape by b and 103c to delay the time until the sheet material S103 comes into sliding contact with the printed sheet material.

Further, as shown in FIG.
5 is provided with a contact flange having an outer diameter larger than the outer diameter of the roller 105 on both end surfaces of the sheet 5, and the sheet material S104 sandwiched between the roller 105 and the spur 104 has the contact flanges 105a, 1a.
There is disclosed a technique for delaying the time until it comes into slidable contact with a printed sheet material by corrugating and discharging by 05b.

In Japanese Patent Laid-Open No. 6-91861,
As shown in FIG. 11, both end portions of the discharged sheet material S105 are supported from below by the support members 106a and 106b, and the central portion is pushed downward by the spur 107, whereby the sheet material is discharged in a concave shape. A technique is disclosed in which even a stiff sheet material is bent to prevent stains on the printing surface and prevent the influence of the shape of the sheet material from affecting the printing portion.

[0008]

However, the above-mentioned conventional techniques have the following problems, respectively.

First, in the case of JP-A-3-134865, even if the sheet discharge tray 101 is formed in a concave shape, if the sheet material S101 is strong, it is not stacked in a concave shape, and therefore, , Sheet material S to be discharged next
There is a problem that the printing surface of the printed sheet material S101 may become dirty because the time until the sliding contact of the 102 with the printed sheet material S101 is not delayed. Further, since the paper discharge tray 101 is formed in a concave shape, there is also a problem that the space occupied by the paper discharge tray becomes large accordingly.

Further, in both of the techniques shown in FIGS. 9 and 10, the sheet material is directly sandwiched by a pair of spur rollers and a sheet discharge roller to make the sheet material into a convex shape or a corrugated shape. However, there is a problem that the print quality is adversely affected by the influence of the forced shape deformation due to the above.

Further, in the case of Japanese Patent Laid-Open No. 6-91861, there is proposed a method capable of preventing stains on the printing surface even with a strong sheet material and not affecting printing quality. When the spur 107 is pressed down by a mountain-shaped projection (gear roller) formed on the outer periphery, there is a problem that a mark is left on the printing surface of the sheet material. It was remarkable in the film for OHP, which has strong power. There is also a problem that the number of parts increases.

The present invention solves the above problems, and its object is to make a sheet material to be discharged next come into sliding contact with an image-formed sheet material that has already been discharged during discharging. To prevent the deterioration of the quality of the formed image or the stain of the sheet material by delaying the time until it makes sliding contact, and it does not leave an extra mark on the printing surface and is simple. An object of the present invention is to provide an inexpensive image forming apparatus having a small number of parts in the configuration.

[0013]

In order to achieve the above object, the present invention is provided with a conveying means for discharging a sheet material on which an image is formed by an image forming section from the discharging section to the outside of the apparatus. In the image forming apparatus, at least a part is arranged in the discharge portion at an interval narrower than the width of the sheet material, and a guide means for contacting a side end portion of the discharged sheet material to bend the sheet material in the width direction is provided. It is characterized by that.

According to this, the sheet material is bent and discharged in the width direction by the guide means, is not bent in the discharging direction, is discharged on a certain discharge path, and the already discharged sheet material and the sheet in the middle of discharging. Contact with the material is prevented.

The guide means is provided with an inclined surface which becomes narrower in the sheet material discharging direction.

According to this, the side end portion of the sheet material is ejected following the inclined surface, and the bending shape is gradually formed.

The guide means is provided with an inclined slit for bending the sheet material in the width direction with the side end portion of the conveyed sheet material being sandwiched therebetween.

According to this, since the inclined slit holds the side end portion of the sheet material and forcibly bends it, the bending direction and the bending amount can be set.

The guide means is provided with an end contact member that abuts both widthwise end portions of the conveyed sheet material on the image forming surface side, and an image formation of the sheet material conveyed by the end contact member. A central portion abutting member that abuts a substantially central portion in the width direction on the non-image forming surface side at a position where the surface side is convex.

In this structure, the abutting member does not abut on the image forming surface side of the sheet material except the both side end portions in the width direction, and does not affect the image forming surface in the central portion of the sheet material.

The carrying means is provided with a carrying section for holding the sheet material in a straight line in the width direction before the guide means.

With this configuration, the bending of the sheet material formed by the guide means in the width direction does not proceed to the image forming portion, the flatness of the sheet material in the image forming portion is maintained, and good image formation is achieved. Is done.

At least one of the guide means is integrally provided with an exterior member of the image forming apparatus.

With this structure, it is not necessary to newly provide the guide means as a member of another structure, and the member and its mounting process are unnecessary.

At least one of the guide means is interlocked with a guide member that moves in accordance with the width of the sheet material of the sheet material supply section.

In this structure, the position of the guide means of the discharge portion is determined by adjusting only the guide member that moves according to the width of the sheet material used, and the operator need not adjust the position of the guide means.

The image forming unit is characterized by including an ink jet recording head for forming an image by ejecting ink droplets onto the image forming surface of the sheet material.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a printer as an image forming apparatus in which an ink jet recording head is provided in an image forming section to which the present invention is applied, and ink droplets are ejected onto an image forming surface of a sheet material to form an image. It is a perspective view showing an embodiment.

The sheet materials S1 stacked in the sheet material supply section K1 of the printer body 11 are image-formed (printed) one by one.
Then, the sheet is discharged from the discharge section H1 onto the sheet discharge tray 13.

In the drawing, the sheet material S3 being discharged is bent by abutting on the supporting members A1 and A2 as guide means provided in the discharging portion. At least a part of the support members A1 and A2 is arranged at a distance narrower than the width of the sheet material S3 (the length of one side in the direction perpendicular to the transport direction), and abuts the side end portion of the sheet material A3.

In this example, A1 is integrally molded with an exterior mold which is an exterior member of the printer body 11, and A2 is connected to a guide member 12 that moves in accordance with the width of the sheet material of the sheet material supply section K1. It is configured to interlock with the movement of twelve.

FIG. 2 is a sectional explanatory view showing a specific arrangement of the present invention.

The sheet material S1 stacked in the sheet material supply section K1 is fed one by one by the pickup roller 21, conveyed by the feed roller 22 and the pressure roller 23, passes through the image forming section G1, and is ejected by the eject roller 24 and It is discharged to the discharge portion H1 by a spur 25 that faces the eject roller 24 and abuts against it.

At this time, since the position of the image forming portion G1 is between the feed roller 22 and the eject roller 24, the supporting members A1 and A located on the discharge side of the eject roller 24.
Even if the sheet material S3 discharged by 2 is bent, it does not affect the printing surface.

FIG. 3 shows the relationship between the supporting members A1 and A2 of FIG. 1 and the sheet material S3 to be discharged. As the sheet material S3 is discharged, the sheet material S3 is narrowed from both sides by the support members A1 and A2, and is bent concavely or convexly. The support members A1 and A2 may be integrally molded with the exterior member by molding, but may be provided separately from the exterior member by using a material having less friction such as POM.

Further, the sheet material S3 of the supporting members A1 and A2
The inclined surface A1 that narrows the surface that abuts against the discharge direction
a and A2a. Therefore, this inclined surface A1a, A
Since the end surface of the sheet material S3 is discharged following the sheet 2a, flexure is gradually formed, and problems such as bending are prevented.

When the sheet material is discharged while contacting the guide means, the sheet material is bent and discharged in the width direction by the guide means, and is discharged on a certain discharge path without being bent in the discharge direction. Sliding contact between the already discharged sheet material and the sheet material in the middle of discharging is prevented, or the time until sliding contact becomes long, so before the formed image dries, the sheet material discharged after The image quality is not rubbed and the image quality is not deteriorated, and the back surface of the sheet material discharged later is not soiled.

Further, since the guide means does not come into contact with the image forming surface of the sheet material, it does not deteriorate the image forming surface even slightly, and good image quality is maintained.

Further, the supporting member A as this guide means
1 and A2 have a simple structure and a small number of parts, and it is possible to provide an inexpensive image forming apparatus.

(Second Embodiment) FIGS. 4 and 5 are supporting members A3, A4 and A according to a second embodiment of the present invention.
5 shows the relationship between A5 and A6 and the discharged sheet material S3, and both sides of the sheet material S3 are sandwiched by inclined slits A3a, A4a and A5a, A6a provided in the respective supporting members. Thus, the bending stress is forcibly applied to bend the sheet material S3. The sheet material S3 is bent in a downward convex shape in FIG. 4 and is bent in an upward convex shape in FIG.

In FIG. 4, the entrance side of the sheet material S3 of the supporting members A3 and A4 is the leading end portion S3 of the sheet material S3.
Introducing portions A3b and A4b for smoothly guiding a are provided.

According to the second embodiment, since the bending direction and the bending amount can be set by the angle of the inclined slits A3a and A4a, the discharged sheet material is stably discharged on a constant discharge path. Can be made.

(Third Embodiment) FIG. 6 (a) is a perspective view of a third embodiment of the present invention, and FIG. 6 (b) is a sectional explanatory view thereof. In the drawing, the discharged sheet material S3 has an upper surface as an image forming surface and a central portion supported from below by a non-image forming surface by a supporting member 31 as a central portion abutting member and both ends as end abutting members. Spur 32a, 32
The sheet is pressed down from above with b, and the image forming surface side of the sheet material has a convex shape. The support member 31 may be a fixed member such as a mold, a rotating member such as a rubber roller, or the contact portion with the sheet material may be a curved surface according to the bending of the sheet material.

In this structure, the contact member does not contact except the both side ends in the width direction on the image forming surface side of the sheet material, and the image forming surface at the central portion of the sheet material is not affected by the guide member.

[0046]

The present invention has the above-described structure and operation, and the formed image is not rubbed by the sheet material discharged later, and the image quality is not deteriorated, and the image is discharged later. The back side of the sheet material does not get dirty.

Further, since the guide means does not come into contact with the image forming surface of the sheet material, it does not deteriorate the image forming surface even slightly, and good image quality is maintained.

Further, the guide means has a simple structure, has a small number of parts, and can provide an inexpensive image forming apparatus.

According to the guide means having the inclined surface which becomes narrower in the discharging direction of the sheet material, the side end portion of the sheet material is discharged following the inclined surface, and the bent shape is gradually formed so that the sheet material is discharged. No problems such as breakage of the sheet material occur.

The guide means provided with the inclined slit for bending the sheet material in the width direction with the side end portion of the conveyed sheet material sandwiched therebetween can set the bending direction and the bending amount of the sheet material, and is therefore discharged. The sheet material can be stably discharged on a certain discharge path, and the sliding contact of the sheet material can be reliably suppressed.

An end contact member that abuts both widthwise end portions of the conveyed sheet material on the image formation surface side, and the image formation surface side of the sheet material conveyed by the end contact member is convex. According to the guide means having the central portion abutting member that abuts the substantially central portion in the width direction on the non-image forming surface side, the abutting member is provided on the image forming surface side of the sheet material except for the both width direction end portions. It does not abut, and does not affect the image forming surface in the central portion of the sheet material.

In the constitution in which the conveying means is provided with a conveying section for sandwiching the sheet material in a straight line in the width direction in front of the guide means, the bending of the sheet material formed by the guide means in the width direction is The flatness of the sheet material in the image forming portion is maintained without advancing to the forming portion, and good image formation is performed.

In the structure of the guide means integrally provided with the exterior member of the image forming apparatus, it is not necessary to newly provide the guide means as a member having a different structure, and the member and its mounting process are unnecessary.

In the structure of the guide means interlocking with the guide member that moves in accordance with the width of the sheet material of the sheet material supply section,
By adjusting only the guide member that moves according to the width of the sheet material to be used, the position of the guide means of the discharge portion is determined, and the operator does not need to adjust the position of the guide means.

[Brief description of drawings]

FIG. 1 is a perspective view of an image forming apparatus to which the present invention is applied.

FIG. 2 is a diagram illustrating a cross-sectional configuration of a discharge unit of an image forming apparatus to which the present invention has been applied.

FIG. 3 is a diagram for explaining a state of the guide member and the sheet material bent by the guide member.

FIG. 4 is a diagram for explaining a state of a guide member and a sheet material bent by the guide member.

FIG. 5 is a diagram illustrating a state of a guide unit and a sheet material bent by the guide unit.

FIG. 6 is a diagram illustrating a guide unit according to a third embodiment.

FIG. 7 is a conventional image forming apparatus.

FIG. 8 is a diagram showing a discharge state of a sheet material by a conventional image forming apparatus.

FIG. 9 is a cross-sectional view of a discharge unit of a conventional image forming apparatus.

FIG. 10 is a cross-sectional view of a discharge unit of a conventional image forming apparatus.

FIG. 11 is a perspective view of a discharge unit of a conventional image forming apparatus.

[Explanation of symbols]

 11 Printer Main Body (Image Forming Apparatus) 12 Guide Member 13 Paper Ejection Tray 21 Pickup Roller 22 Feed Roller 23 Pressure Roller 24 Eject Roller 25 Spur A1, A2 Supporting Member (Guide Means) A1a, A2a Inclined Surface G1 Image Forming Section H1 Discharging Section K1 sheet material supply section S1 sheet material

Claims (8)

[Claims] 1. An image forming apparatus comprising a conveying means for discharging a sheet material on which an image has been formed by an image forming section from the discharging section to the outside of the apparatus, wherein at least a part of the discharging section is wider than the width of the sheet material. Also, the image forming apparatus is provided with a guide unit that is disposed at a narrow interval and that abuts against a side end portion of the discharged sheet material to bend the sheet material in the width direction. 2. The image forming apparatus according to claim 1, wherein the guide unit includes an inclined surface that narrows in a sheet material discharge direction. 3. The guide means is provided with an inclined slit for bending the sheet material in the width direction while sandwiching a side end portion of the sheet material to be conveyed, according to claim 1. The image forming apparatus according to item 1. 4. The guide means includes an end abutting member that abuts both widthwise end portions of the conveyed sheet material on the image forming surface side, and a sheet material conveyed by the end abutting member. The image forming apparatus according to claim 1, further comprising a central portion abutting member that abuts a substantially central portion in the width direction of the non-image forming surface side at a position where the image forming surface side is convex. 5. The transporting unit comprises a transporting unit that clamps the sheet material in a straight line in the width direction in front of the guide unit. The image forming apparatus according to item 1. 6. The image forming apparatus according to claim 1, wherein at least one of the guide units is integrally provided with an exterior member of the image forming apparatus. 7. The method according to claim 1, wherein at least one of the guide means is interlocked with a guide member that moves in accordance with the width of the sheet material of the sheet material supply section. Image forming apparatus. 8. The image forming unit includes an ink jet recording head that forms an image by ejecting ink droplets onto an image forming surface of a sheet material. 2. The image forming apparatus according to item 1.