JPH0761072A - Ink jet printer - Google Patents

Abstract

PURPOSE:To prevent ink blur of various printed papers and smoothly discharge the papers on a paper receive section by arranging paper delivery rollers so as to make the printed papers to be sent by the rollers in cooperation with pressing bodies curve as a whole in a direction rectangular to the sending direction. CONSTITUTION:A paper guide face 9 for guiding a paper P printed by a print head to a paper receive section, paper delivery rollers 11A-11C which have roller upper ends 11U arranged so as to protrude from the paper guide face 9 and can send the paper P to the paper receive section, and pressing bodies 15A-15C for pressing the paper P to the paper delivery rollers are provided. The paper delivery rollers 11A-11C are arranged so as to make the printed paper P, which is to be sent by the rollers in cooperation with the pressing bodies 15A-15C, curve as a whole in a direction rectangular to the sending direction (direction of paper width). That is, when the diameters of the rollers 11A-11C are made to be Da, Db, Dc respectively, the paper delivery rollers are arranged so as to have a relationship of Da>Db>Dc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer. More specifically, the present invention relates to an inkjet printer that nips and conveys printed paper by a paper ejection roller and a pressing body (for example, a spur) and ejects the paper to a paper receiving portion.

[0002]

2. Description of the Related Art A conventional structure of an ink jet printer is shown in FIGS. In these figures, 2 is a print head (inkjet head), 3 is a feed roller,
Reference numeral 4 is a leaf plate, 6 is a paper tray, and 9 is a paper guide surface. Further, 11 is a discharge roller, 15 is a pressing body, 1
9 is a paper receiving portion.

The print head 2 is reciprocally moved by a carriage (not shown) in a direction orthogonal to the paper surface in the drawing, and ink droplets are ejected from the nozzle portion 2a onto the paper P so that printing can be performed. The feed roller 3 is configured to cooperate with the leaf plate 4 so as to feed the paper P in the paper tray 6 or the manual paper to the print head 2. The paper guide surface 9 is formed so that the paper (printed paper) P printed by the print head 2 can be guided to the paper receiving portion 19.

Further, each paper discharge roller 11 is arranged via a common rotary shaft 12 so that its roller upper end 11u projects from the paper guide surface 9, and sends the printed paper P to the paper receiving portion 19. It is configured to be active. The paper discharge roller 11 is rotated clockwise in FIG. 4 by a drive mechanism 17 connected to the rotary shaft 12.

The pressing body 15 is formed so that the printed paper P can be pressed against the paper discharge roller 11. Usually, the pressing body 15 is formed of a spur having a serrated outer peripheral surface having a small contact area with the paper P in order to prevent ink transfer from the printed paper P. Paper discharge roller 11 described above
The printed sheet P is discharged to the sheet receiving portion 19 with the printing surface facing upward by the cooperation of the pressing body (spur) 15 with the sheet.

[0006]

By the way, in the above-mentioned ink jet printer, the printed paper P urged by the discharge roller 11 is printed on the previously printed paper P already stored in the paper receiving portion 19. Sliding on the surface and receiving part 1
The paper is discharged to 9. Therefore, when the ink is in a semi-dried state, there arises a problem that the printing surface of the previous printed paper P and the back surface of the next printed paper P are soiled. Nowadays, various kinds of inks are selectively switched and used with further increase in printing speed and diversification, and this problem becomes more prominent.

Therefore, a printer has been proposed in which the paper P can be discharged without coming into contact with the printing surface of the printed paper P (USP 4728963). As shown in FIGS. 7 and 8, the paper discharge mechanism of such a printer is provided with a paper guide 9A rotatably in the arrow direction and a printed surface of the printed paper P on the downstream side of the print head 2 in a horizontal state. Upper rail 19A of the paper receiving part that can be temporarily placed at
When the sheet is discharged, the sheet guide 9A is rotated in the direction of the arrow to store the sheet P from the upper rail 19A into the storage section (not shown) of the lower sheet receiving section by utilizing its own weight or the like. ing.

However, such a structure has a disadvantage that the proportion of the sheet receiving portion in the installation area of the printer is large, and the printer becomes large so that it cannot meet the current demand for downsizing.

In view of the above circumstances, an object of the present invention is to provide an ink jet printer which can prevent various kinds of printed paper from being stained with ink and can be smoothly discharged to a paper receiving portion.

[0010]

An ink jet printer according to the present invention is provided with a paper guide surface for guiding a paper printed by a print head to a paper receiving portion, and a roller upper end protruding from the paper guide surface. The discharge roller includes: a discharge roller capable of urging and feeding the sheet to the sheet receiving portion; and a pressing body that presses the sheet against the discharge roller.
It is characterized in that it is provided so that the printed sheet for urging the feeding in cooperation with the pressing body can be entirely curved in the direction orthogonal to the feeding direction.

[0011]

According to the present invention having the above-described structure, the paper (printed paper) printed by the print head is pressed against the paper discharge roller by the pressing body (for example, a spur) and sent to the paper receiving portion by the paper discharge roller. Energized.

At this time, the printed sheet is entirely curved in the direction (sheet width direction) orthogonal to the feeding direction. In this way, the printed paper is entirely curved in the paper width direction, so that the second moment of area of the paper is increased and the resistance to bending is significantly increased.

Therefore, even if the printed sheet is a vertically long sheet such as a legal sheet or a thin sheet on which high density printing has been performed, the printed sheet is ejected to the sheet receiving portion in a hanging state due to its own weight. This eliminates the problem, and the printed surface of the printed paper already stored in the paper receiving section can be discharged without sliding and with a long time until it comes into contact with the paper, and ink contamination can be prevented. .

[0014]

Embodiments of the present invention will be described with reference to the drawings. (First Embodiment) As shown in FIGS. 1 and 2, this ink jet printer has a basic configuration of a conventional example (FIGS. 5 and 6).
Is similar to the above, and a plurality of (6) paper discharge rollers (1
1A, 11B, 11C) to bend the printed paper P (width dimension w1) for feeding and urging in cooperation with the pressing body (spur) 15 in a direction (paper width direction) orthogonal to the feeding direction. (More specifically, the sheet P can be recessed upward as a whole). The same components as those of the conventional example (FIGS. 5 and 6) are designated by the same reference numerals, and the description thereof will be omitted or simplified.

Each of the discharge rollers (11A, 11B, 11C), which is a characteristic part of the present ink jet printer, is mounted on the common rotary shaft 12 at a predetermined distance in the paper width direction, and the roller upper end 11u is the paper width. The diameters of the rollers are formed so as to decrease toward the center of the direction, and decrease toward the center of the direction. That is, when the roller diameters of the paper discharge rollers (11A, 11B, 11C) are Da, Db, Dc, respectively, Da>Db> D
It is formed to be c.

As described above, each paper discharge roller (11A, 11
B, 11C), the peripheral velocities of the rollers (11A, etc.) are different when the rotary shaft 12 is rotated (that is, the peripheral velocities become slower in the order of the discharge rollers 11A, 11B, 11C). In order to smoothly feed and urge printed paper, it is necessary to absorb the difference in peripheral speed. Therefore, in the present embodiment, each paper discharge roller (11A, 11B, 11
By changing the friction coefficient of the outer peripheral surface in C), when the printed sheet is fed and urged, a slip is generated between the sheet and the sheet, and the difference in peripheral speed is absorbed.

That is, the outer peripheral surface of the paper discharging roller (11C, 11C) having the lowest peripheral speed is formed to have a high friction coefficient, and the paper discharging roller (1 having the highest peripheral speed is used.
1A, 11A) is formed so as to have a low friction coefficient. In addition, the discharge rollers (11B,
The outer peripheral surface of 11B) is formed so as to have an intermediate friction coefficient between the paper discharge rollers 11A and 11C. As a result, it is possible to feed and urge the printed paper with a uniform force by each paper discharge roller (11A, 11B, 11C). ◎ In addition,
Each paper discharge roller (11A, 11B, 11C) is made of ethylene propylene rubber (hardness 60 °).

Further, each paper discharge roller (11A, 11B, 1
1C) and the corresponding spurs (15A, 15B, 15C) are
The respective discharge rollers (11A, 11B, 11C) are arranged in a height difference so that the printed paper can be pressed with a predetermined pressure. Also,
The paper guide surface 9 is also formed in a curved shape so as to become lower toward the center of the paper width direction.

In FIG. 2, reference numeral 21 is a paper discharge arm, and the rear end of the printed paper P is a paper discharge roller (11A, 11B, 11).
After reaching C), the rear end is pressed to feed the printed paper P to the paper receiving portion 19, and after the feeding is completed, it can be returned to the waiting position below the paper guide surface 9.

More specifically, the paper discharge arm 21 is attached to a support shaft 25, and is positioned and held at a standby position by a spring 26. A drive mechanism (not shown) is connected to the support shaft 25, and when the drive mechanism is operated by an arm controller (not shown), the paper discharge arm 21
Is rotated by a predetermined angle amount from the standby position while resisting the urging force of the spring 26, and presses the trailing end of the printed paper P that has reached the paper discharge rollers (11A, 11B, 11C) to receive the paper P. It is configured to send to the section 19.

Next, the operation of this embodiment will be described. The paper (printed paper) P printed by the print head (2) is discharged by the spurs 15 to the paper discharge rollers (11A, 11A).
B, 11C) and the paper discharge rollers (11A, 11C)
B, 11C) and the paper discharge arm 21 for the paper receiving portion 1
It is urged to send to 9.

At this time, the discharge rollers (11A, 11B, 1
1C), the upper end 11u of the roller becomes lower as it goes to the center of the paper width direction, so the printed paper P pressed by the spur 15 against the paper discharge rollers (11A, 11B, 11C) is orthogonal to the feed direction (paper It is entirely curved in the width direction. As a result, the second moment of area of the printed sheet P is increased, and the resistance to bending is significantly increased. Therefore, the printed paper P does not hang down by its own weight, and the time until it touches the printing surface of the previous printed paper P already stored in the paper receiving portion 19 does not slide and is extended. You can let it be ejected.

However, according to this embodiment, the discharge rollers (11A, 11B, 11C) are connected to the upper end 11u of the rollers.
Is arranged so as to become lower toward the center of the paper width direction, so that even if the printed paper P is a vertically long paper or a thin paper on which high density printing has been performed, the printed paper P hangs down due to its own weight. Therefore, the sheet is not discharged to the sheet receiving section 19, and it is possible to prevent ink stains between the sheet and the printed sheet previously stored in the sheet receiving section 19.

Further, each paper discharge roller (11A, 11B, 1
By changing the friction coefficient of the outer peripheral surface of (1C) to absorb the difference in peripheral speed of the rollers (11A, 11B, 11C), the printed paper P is smoothly and reliably delivered to the paper receiving portion 19. It can be energized.

Further, the paper discharge rollers (11A, 11B, 11
Since only the difference in diameter of C) is provided, it does not become large and complicated.

In this ink jet printer, the discharge rollers (11A, 11B, 11C) have the same roller diameter D, and the rotary shafts (12A, 12B, 12C) of the discharge rollers (11A, 11B, 11C) are the same. The roller upper end 11u may be configured to be lowered toward the center in the same direction by disposing the step.

More specifically, each paper discharge roller (11A,
11B, 11C) rotating shaft (12A, 12B, 12C)
Are arranged with a height difference such that the upper end 11u of the roller becomes lower toward the center in the paper width direction.
That is, the rotating shafts 12A, 12B, and 12C are arranged so as to be lowered in this order. Further, a gear portion 13A is formed at one end portion inside the rotary shaft 12A, and gear portions 13B and 13C are formed at both end portions of the rotary shafts 12B and 12C.
Are formed. In addition, each gear part (13A, 13B,
13C) is connected via an odd number of idle gears (not shown).

Therefore, when the drive mechanism 17 rotationally drives the rotary shaft 12A (paper discharge roller 11A) on the right side in FIG. 3, the other rotary shaft 12A (paper discharge roller 11A) and rotary shaft 12B (paper discharge roller 11B) are driven. , The rotating shaft 12C (paper discharge roller 11C) also rotates in the same direction at the same speed.

Each paper discharge roller (11A, 11B, 1
1C) and the corresponding spurs (15A, 15B, 15C) are
Each of the sheet discharge rollers (11A, 11B, 11C) is arranged with a height difference so that the printed sheet P can be pressed with a predetermined pressure. Further, the paper guide surface 9 is also formed with a step so that it becomes lower toward the center of the paper width direction.

With this structure, the printed paper P is discharged onto the paper discharge rollers (11A, 11B, 11C) and the spur (15A, 1A).
5B, 15C) and the step-like paper guide surface 9 so that the paper is curved in the paper width direction as a whole, even if the printed paper P is a vertically long paper or a thin paper with high density printing, The paper is not discharged to the paper receiving portion 19 in a hanging state by its own weight, and it is possible to prevent ink stains between the paper and the printed paper previously accommodated in the paper receiving portion 19.

Further, the discharge rollers (11A, 11B, 11
Since the roller diameter D in C) is the same, component management, replacement, and the like can be performed more easily.

Although a plurality of paper discharge rollers are provided in the above embodiment, a single paper discharge roller may be used. In this case, the paper discharge roller is formed, for example, in a drum shape so that the upper end of the roller is lowered toward the center in the paper width direction.

(Second Embodiment) The second embodiment is shown in FIG. This inkjet printer is equipped with each paper ejection roller (1
The upper end 11u of the roller 1A, 11B, 11C) is configured to be higher toward the center in the paper width direction.
More specifically, each paper discharge roller (11A, 11B, 11
When the roller diameters of C) are Da, Db, and Dc, Da <Db <Dc.

With this configuration, the printed paper P is printed on the paper discharge rollers (11A, 11B, 11C) and the spur (15A,
15B, 15C), it is dented downward when it is nipped and conveyed. Therefore, even if the printed sheet P is a vertically long sheet or a thin sheet on which high-density printing is performed, it is hung down by its own weight. Therefore, the paper is not discharged to the paper receiving portion 19, and it is possible to prevent ink stains with the printed paper previously stored in the paper receiving portion 19.

In the second embodiment, the diameter of each paper discharge roller (11A, 11B, 11C) is changed so that the upper end 11u of the roller becomes higher toward the center of the paper width direction. Each discharge roller (11
A, 11B, 11C) rotating shafts (12A, 12B, 12)
C) is arranged with a step, and each rotary shaft (12
The upper end 11u of the roller may be configured to become higher as it goes in the width direction of the paper by connecting the ends of (A, 12B, 12C) via a gear part (not shown).

[0036]

As described above, according to the present invention, the paper discharge roller is provided so as to be able to bend the printed paper for urging the feeding in cooperation with the pressing body in the direction orthogonal to the feeding direction. The printed sheet can be discharged to the sheet receiving portion in a curved state. As a result, even if the printed paper is vertically long paper or thin paper with high density printing, it will not be discharged to the paper receiving part in the state of hanging down by its own weight. It is possible to prevent ink stains between the printed paper stored in the paper receiving portion.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an essential part of a first embodiment of the present invention.

FIG. 2 is likewise an exploded perspective view.

FIG. 3 is also a diagram for explaining a modified example of the paper discharge roller.

FIG. 4 is also a diagram for explaining a second embodiment of the present invention.

FIG. 5 is a diagram for explaining a conventional configuration of an inkjet printer.

FIG. 6 is also a diagram for explaining a disposition state of paper discharge rollers.

FIG. 7 is a diagram for explaining a conventional configuration of a printer having an ink stain prevention function.

FIG. 8 is a diagram for explaining a paper discharging operation, similarly.

[Explanation of symbols]

 2 Inkjet head (printing head) 11A, 11B, 11C Paper ejection roller 11u Roller upper end 15A, 15B, 15C Spur (pressing body) 19 Paper receiving portion

Claims (1)

[Claims] 1. A paper guide surface for guiding a paper printed by a print head to a paper receiving portion, and a roller upper end protruding from the paper guide surface so that the paper can be urged to be fed to the paper receiving portion. A discharge roller and a pressing body that presses the paper against the discharge roller are included. The discharge roller cooperates with the pressing body to urge and feed the printed paper as a whole in a direction orthogonal to the feeding direction. An inkjet printer characterized in that it is provided so that it can be curved.