JPH08197723A - Ink-jet printer - Google Patents

Abstract

PURPOSE: To prevent paper which has been discharged first from being pushed out by the following paper. CONSTITUTION: Both end supporting parts 271 which guide a paper P which has been printed on its upper face by means of a printing part and is discharged while being energized by being supported in its both side parts in a manner that the paper P is made into a recessed shape with its printed face seen from its discharging direction and its rear end side being depressed more gently than the front end side, and a pushing-down part 272 for pushing downward the central part of the paper are provided.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to ink jet printers. More specifically, the printed paper is ejected while biasing it into a concave shape when viewed from the ejection direction, so that the paper is conveyed in a floating state and printed on the paper that is printed and ejected first and then stacked. The present invention relates to an improvement in a paper discharge structure in which a time until sliding contact with a surface is delayed to secure a time for ink of printed paper to dry.

[0002]

2. Description of the Related Art In general, an ink jet printer is designed to eject ink onto a sheet for printing.
When printing on multiple sheets of paper continuously, if the next paper is ejected before the ink on the printed paper dries and comes into sliding contact with the printed surface of the printed paper, the printed surface of the printed paper becomes dirty. There is a problem that it will end up.

As an attempt to solve such a problem, an ink jet printer described in JP-A-6-91861 is known.

FIG. 4 is a perspective view showing the discharge portion of this printer.

The discharging section 90 includes both side supporting sections 91, 91 for guiding both side portions of the sheet P printed and discharged on the upper surface by a printing section (not shown) so as to support the sheet P from below.
Push-down section 92 that pushes down the center of the paper
And have.

The both-sides support portion 91 is composed of a fixed rib integrally formed with the frame 70, and its upper surface 91a.
Is inclined upward in accordance with the paper discharge direction.

The pushing-down portion 92 is composed of a serrated roller, and is rotatably supported by an arm 93 rotatably attached to a frame (not shown).

The paper discharge operation in the printer as described above is as follows.

(I) When printing is performed on the paper P and the paper P enters the discharge section 90, both sides of the paper P are supported by the both side support sections 91.
Is gradually guided upward by the upper surface 91a.
At the same time, the central portion of the paper gradually pushes up the push-down portion 92 while rotating the arm 93 upward, but conversely, the central portion of the paper gradually enters below the push-down portion 92 and pushes down the push-down portion 92 and the arm 93. It will be pushed down compared to both sides due to the weight of.

In this way, the paper P is gradually discharged from the leading end thereof while being forcibly biased into a concave shape in which the printing surface is depressed when viewed from the discharge direction.

(Ii) When the paper P is forcibly urged to have a concave shape when viewed from the discharge direction, the rigidity of the paper P becomes strong and the paper P is conveyed in a floating state. For this reason, as shown in FIG. 5, the ejected paper P is printed and ejected first, and the printing surface P of the paper P1 that is ejected and stacked on the ejection tray 60.
The time until sliding contact with 1f is delayed, and the printed paper P
The time for the ink of No. 1 to dry is secured.

(Iii) The paper P is further conveyed, and as shown in FIG.
As shown in FIG. 7, when the trailing edge Pb passes through the transport unit 80, the transporting force is lost, and the trailing edge portion Pc of the sheet is retained in the concave shape by the discharging unit 90.

(Iv) The succeeding paper P2 is printed, and as shown in FIG. 6, the leading end P2a passes through the transport section 80 and hits the trailing end Pb of the preceding paper P so that the preceding paper P is discharged. The holding by the portion 90 is released (the released state is shown in FIG. 7). When the preceding paper P is pushed by the succeeding paper P2, its holding is released and it is stacked on the previous printed paper (P1 in FIG. 5). Time is further delayed.

[0014]

The shape of the both side support portions 91 in the above-described conventional ink jet printer is a concave shape of the discharged paper P parallel to the discharging direction (the shape is schematically shown in FIG. 8). The shape is such that it is intended to bend.

For this reason, the trailing edge Pb of the sheet of paper P may be kept concave even after the trailing edge Pb of the trailing edge Pb of the trailing edge Pb of the trailing sheet of paper P2.
There is a problem that it may be pushed out of the discharge tray 60 by coming into contact with the sheet 2a.

An object of the present invention is to solve the above problems and to provide an ink jet printer in which a discharged sheet is not pushed out by a succeeding sheet.

[0017]

In order to achieve the above object, an ink jet printer of the present invention has a printing section having an ink jet head and both side portions of a sheet printed on the upper surface and discharged by the printing section. By supporting the paper from the discharge direction, the printing surface is concave and the trailing edge side is gentler than the leading edge side. It is characterized by comprising a support portion and a push-down portion for pushing down the central portion of the sheet.

[0018]

Since the present invention has the above-mentioned structure, it operates as follows.

That is, both side portions of the paper which is printed on the upper surface by the printing portion having the ink jet head and is discharged are supported from below by the both side supporting portions, and the central portion of the paper is pushed downward by the pushing-down portion. The paper is discharged while being forcibly urged into a concave shape in which the printing surface is depressed when viewed from the discharge direction.

Then, the sheet is ejected while being urged by the both-sided supporting portions so that the rear end side has a gentle concave shape rather than the front end side. Therefore, the sheet is ejected after the rear end. The concave shape is gentle or almost flat.

Therefore, the trailing edge is less likely to come into contact with the leading edge of the succeeding sheet, and the discharged sheet is less likely to be pushed out by the succeeding sheet.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially omitted side view showing an embodiment of an ink jet printer according to the present invention.

In the figure, 100 is a paper feeding device, and 200 is
Is the main body of the inkjet printer.

The paper feeding device 100 includes a paper support 11
0, a pair of hoppers 120, and a pair of paper feed rollers 130
It has and.

On the upper surface of the paper support 110, there is formed a rear support surface 112 for supporting the rear portion of the paper (not shown) to be fed. The rear support surface 112 is provided with a trailing edge presser 113 that comes into contact with the trailing edge of the sheet and prevents the sheet from moving rearward.

A pair of hoppers 120 are provided so as to be able to support both sides of the paper, and are slidably inserted in the support rod 140. The upper surface of the hopper 120 forms a front support surface 121 that supports the front of the paper.

The hopper 120 is provided with an edge guide 150 for guiding the side edge of the paper, and the hopper 120 and the edge guide 150 together can slide in the direction orthogonal to the paper surface of FIG. There is. Edge guide 1
The reference numeral 50 is slidably supported by the support rod 141.
Note that reference numeral 133 denotes a paper feed roller holder, and the paper feed roller holder 133 and the edge guide 150 are engaged with each other, and the paper feed roller 130 also slides together.

The lower surface of the hopper 120 and the edge guide 15
A hopper spring (compression spring) not shown is provided between the bottom plate 152 and the bottom plate 152. The hopper 120 is biased upward by this hopper spring, but a cam (not shown) for pushing down the hopper 120 against the spring force of the hopper spring as shown by an imaginary line is applied to both ends of the support rod 140. A pressing mechanism such as a mechanism is provided.

The hopper 120 is released by the pressing mechanism when the paper is fed, and is pushed up by the hopper spring so as to press the leading end of the paper toward the paper feeding roller 130 and presses it against the paper feeding roller 130. It is pushed down by the button to release the contact of the sheet with the sheet feeding roller 130 at the position separated from the sheet feeding roller 130 (the position indicated by the phantom line in FIG. 1).

The paper feed roller 130 is composed of a D-shaped roller having a rubber layer on its surface, and is fixed to a grooved paper feed roller shaft 131. The paper feed roller shaft 131 is rotatably supported by a side frame of the main body via a bearing, and is rotationally driven at the time of paper feeding by a drive mechanism of the main body. The paper feed roller 130 is provided at the front of the edge guide 150.
A separation pad 132 is provided that is biased toward. The pressing mechanism of the hopper described above is driven in conjunction with the driving of the paper feed roller 130.

According to the paper feeding device 100 as described above, when the paper is set, the rear end of the paper is in contact with the rear end pressing member 113 of the paper support, and the rear part of the paper support is the rear support surface 112 of the paper support. Supported by the front support surface 121 of the hopper 120.

When the paper feed roller 130 is not rotated, the hopper 120 is located apart from the paper feed roller 130, and is relatively positioned between the front support surface 121 and the rear support surface 112 of the paper support. A large first step G1 is formed, and at the time of paper feeding, the hopper 120 is biased in a direction in which the leading end of the paper is brought into contact with the paper feeding roller 130, so that the front support surface 121 of the hopper 120 and the paper are supported. A second step G2 smaller than the first step G1 is formed between the rear support surface 112 of the support. As a result, a tension force is generated on the paper, and the leading edge bites the paper feed roller 130 to reliably feed the paper. It should be noted that only the uppermost paper sheet pressed against the paper feed roller 130 is separated from other paper sheets by the separation pad 132,
The sheet is fed to the main body 200 in the direction of arrow b in FIG.

The fed sheet is wound around the sheet feed roller 230 and conveyed to the printing section A, where it is printed by the ink jet head 240, and then the conveying roller pair 251, 25.
The sheet is conveyed by the sheet No. 2 and is further driven by the pair of discharge rollers 261 and 262, and is discharged onto the discharge tray 280 above the hopper 120 through the discharge unit 270.

The discharging section 270 has a pair of both side supporting sections 271, 271 (see FIG. 3) for supporting both side portions of the sheet printed and discharged on the upper surface by the printing section A from below and a central portion of the sheet. And a push-down portion 272 that pushes down toward.

Both side support portions 271 are the subframe 2 of the main body.
Slider 2 slidably attached to 21
It is fixed to 73.

As shown in FIG. 2, the both side supporting portions 271 are
The triangular piece 271a and the triangular portion 271b integrally formed on the upper surface of the triangular piece 271a are provided.
71a of slanted side 271c and triangular portion 271b of slanted surface 271d
And form a guide portion for ejected paper. The inclined surface of the triangular portion 271b is not parallel to the paper discharge direction but is inclined inward and upward. As a result, as shown in FIG. 3, the discharged paper P is
The rear end Pb side is discharged while being biased in a gentle concave shape rather than the front end Pa side. The pair of both side support portions 271, 271 are symmetrically configured.

The push-down portion 272 has the same structure as that of the conventional serrated roller (see FIG. 4), and the sub-frame 22
It is rotatably supported by an arm attached so as to be rotatable with respect to 1.

According to the paper discharge unit 270 as described above, basically the same paper discharge operation as that of the conventional printer described above can be obtained.

As shown in FIG. 3, the characteristic feature of the paper discharge operation in this embodiment is that the two side support parts 271, 271,
The sheet P is discharged while being biased in a state where the rear end Pb side has a gentle concave shape rather than the front end Pa side.

When discharged in such a state, the concave shape of the rear end Pb of the paper P after falling on the paper discharge tray 280 becomes gentle or nearly flat, so that the rear end Pb follows. It becomes difficult for the ejected paper to come into contact with the leading edge of the ejected paper, and the ejected paper is unlikely to be pushed out of the paper ejection tray 280 by the following paper.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be appropriately modified and implemented within the scope of the gist of the present invention.

For example, the shape of the both-side support portion is not limited to the above-described shape, and the sheet P may be discharged while urging the sheet P toward the rear end Pb side to have a gentle concave shape rather than toward the front end Pa side. It is arbitrary as long as it can be shaped.

[0044]

According to the present invention, it is possible to obtain the effect that the discharged sheet is less likely to be pushed out by the succeeding sheet.

[0045]

[Brief description of drawings]

FIG. 1 is a partially omitted side view showing an embodiment of an inkjet printer according to the present invention.

FIG. 2A is a plan view showing one of the both side supporting portions, FIG.
(B) is a front view.

FIG. 3 is a perspective view for explaining the operation.

FIG. 4 is an explanatory diagram of a conventional technique.

FIG. 5 is an explanatory diagram of a conventional technique.

FIG. 6 is an explanatory diagram of a conventional technique.

FIG. 7 is an explanatory diagram of a conventional technique.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 A printing section P paper 240 inkjet head 271 both side support section 272 push-down section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutoshi Kashihara 3-3-5 Yamato, Suwa, Nagano Seiko Epson Corporation (72) Inventor Takuya Yasue 3-3-5 Yamato, Suwa, Nagano Prefecture Seiko -In Epson Corporation

Claims (1)

[Claims] 1. A printing unit having an ink jet head, and both side portions of a sheet printed on the upper surface and discharged by the printing unit are supported from below, so that the printing surface is dented when the sheet is viewed from the discharging direction. A both-sided supporting portion that guides while urging the concave shape that is concave and the rear end side is gentler than the front end side, and the pushing down portion that pushes down the central portion of the sheet downward. An inkjet printer characterized in that it is provided.