JPH0671872A - Ink-jet printer - Google Patents

Abstract

PURPOSE:To smoothly and surely collect sheets of printed paper in a paper receiving tray even when they curl. CONSTITUTION:A paper receiving tray 21 is provided with a paper presser 30 which presses the printed faces of sheets of printed paper to keep them from curling with their printed faces up. The paper receiving tray 21 also has a recessed part 26 which allows the printed paper to warp in reverse against the curl, and guide rails 28 which are able to guide and correct the printed paper which are being discharged as they curl.

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 having a paper receiving portion capable of sequentially accumulating printed paper with the printing surface facing upward.

[0002]

2. Description of the Related Art FIG. 8 shows a schematic structure of a conventional ink jet printer. In the figure, 2 is a print head (inkjet head). The inkjet head 2 is
A carrier (not shown) is moved in a direction orthogonal to the paper surface in the drawing to eject ink droplets onto the paper P so that printing is possible. Further, 3 is a feed roller, which is configured so as to cooperate with the leaf plate 4 to feed the paper in the paper tray 6 or a manual paper (for example, an envelope) toward the printing section C. In the figure, 5 is a tension spring.

The paper P fed by the feed roller 3 to the printing section C and printed by the ink jet head 2 is ejected by the ejection roller 11 and the spur 12 which are rotated in the arrow direction (arrow E). Direction) and is stored in the paper receiving portion 21A with the printing surface facing upward.

[0004]

By the way, in the above-mentioned ink jet printer, the paper P printed by the ink jet head 2 is curled with its printed surface outside as shown in FIG. [Curling of the paper P is particularly noticeable when high-density printing is performed in an environment of low humidity (for example, 40% RH or less). ].

That is, when the curled printed paper P is ejected to the paper receiving portion 21A, the lower end of the paper P is pushed up by the paper P to be ejected next and dropped from the receiving portion 21A. I have something to do.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an ink jet printer capable of smoothly and surely accumulating in a paper receiving portion even in a situation where printed paper is curled.

[0007]

According to another aspect of the present invention, there is provided an ink jet printer having a paper receiving portion capable of sequentially accumulating printed paper sent from a printing portion with its printing surface facing upward. The paper receiving unit is provided with a paper pressing unit that presses the print surface of the printed paper to prevent the paper from curling with the print surface facing outward.

An ink jet printer according to a second aspect of the present invention is further characterized in that the paper sheet receiving portion is provided with a concave portion that allows the printed paper sheet to reversely warp against the curl.

An ink jet printer according to a third aspect of the invention is characterized in that the paper receiving portion is provided with a guide rail that can guide the printed paper that is being curled and discharged.

[0010]

According to the invention of claim 1, which has the above-described structure, the printed surface of the printed paper sent to the paper receiving portion is prevented from being pressed by the paper pressing means to curl with the printed surface facing outward. Therefore, it is possible to effectively prevent the printed sheets from interfering with each other in an unnatural state in the sheet receiving section. For example, the lower end of the printed sheet discharged to the sheet receiving section will not be pushed up by the printed sheet discharged to the receiving section next. Therefore, even if the printed paper is curled and discharged to the paper receiving portion, it can be smoothly and reliably accumulated in the paper receiving portion.

Further, according to the invention of claim 2 having the above-mentioned structure, the printing surface of the printed paper is pressed by the paper pressing means to cause the paper to warp in the concave portion of the paper receiving portion (that is, the printed paper is It can be stored in a state in which the printed surface is turned inside and is warped. Therefore, it is possible to more effectively prevent the printed sheets from interfering with each other in an unnatural state in the sheet receiving portion. As a result, even if the printed paper is curled and discharged to the paper receiving portion, it can be stored in the paper receiving portion more smoothly and reliably.

In addition, in the invention of claim 3 having the above-mentioned configuration, in addition, since the curled state of the printed sheet is guided by the guide rails while being corrected in the sheet receiving portion, the sheet can be made smoother and more reliable. Can be stored in the paper receiver.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 7, the present inkjet printer includes an inkjet head 2, a printing unit C, a feed roller 3, a paper transport surface 9, a paper tray 6, a spur 12, an eject arm 15, a paper receiving unit 21, and a printer. It is configured to include a sheet pressing unit 30 which is one characteristic part.
It should be noted that the same parts as those in FIG.
Detailed description thereof will be omitted.

In this ink jet printer, the paper (printed paper P) printed by the printing unit C is spur 1
2. The paper is conveyed to the paper receiving portion 21 by the paper conveying surface 9 and the eject arm 15. here,
The spur 12 is configured to be rotationally driven in the counterclockwise direction in FIG. 7 by a drive motor (not shown). The spur 12 frictionally comes into contact with the printed paper P sent between the spur 12 and the paper transport surface 9 and the discharge direction. It is provided so that it can be fed in the direction of arrow E.
Further, the eject arm 15 presses the trailing end of the printed paper P after the trailing end of the printed paper P reaches the spurs 12, and the printed paper P is then pressed.
Is provided so that it can be fed to the paper receiving portion 21 and can be returned to the standby position (the position shown in FIG. 7) outside the paper transport path after the feeding is completed. In this embodiment, the eject arm 15
Are provided at predetermined intervals on a support shaft 16 extending in a direction (direction orthogonal to the paper surface in the drawing) orthogonal to the paper discharge direction (E direction), and the support shaft 16 is synchronous with the support shaft 16 as a center. It is rotatably provided. This eject arm 15
It is configured to be driven and controlled in a predetermined procedure by a stepping motor, a control device, and the like. Then, after the rear end of the printed paper P reaches the spur 12, the eject arm 15 is driven and rotated from the standby position by a predetermined angle amount. As a result, the printed paper P is sent to the paper receiving portion 21 with its rear end pushed by the eject arm 15.

As shown in FIG. 1, the sheet receiving portion 21 is formed of a sheet supporting portion 22 and a backrest portion 25 which is detachably connected to the supporting portion 22.

The paper support portion 22 is formed so as to be able to support the lower end portion of the discharged printed paper P. On the other hand, the backrest portion 25 is provided with a concave portion 26 that allows the printed paper sheet P to warp (reverse warp) with the printing surface inside, and the printed paper sheet P can be guided while correcting curl. Guide rails 28, 28 are provided. In the present embodiment, the recess 26 is the sheet receiving surface 2 of the backrest 25.
The central portion of 5a is recessed by a predetermined depth to form a step.

More specifically, the recessed portion 26 is formed in an inverted C shape in the central portion of the paper receiving surface 25a so as to widen toward the paper feeding direction (direction of arrow F).
Further, the depth of the concave portion 26 is formed such that the front portion closest to the sheet supporting portion 22 is the shallowest (flush with the sheet receiving surface 25a) and continuously increases as it goes rearward. As a result, the printed sheet P gradually becomes more warped as it moves in the sheet receiving portion 21 in the sheet feeding direction (F direction).

Each of the guide rails 28 is formed on both sides of the recess 26 in an inverted V-shape with respect to the paper feeding direction (F direction) like the recess 26. Further, the height of each guide rail 28 is formed so that the front part is the highest and decreases continuously toward the rear. As a result, the printed paper P is guided in the paper feed direction (F direction) while the curled state is gradually corrected.

Further, the backrest 25 is provided with a cover 29 for covering the recess 26, the guide rails 28, 28 and the like. In this embodiment, the cover 29 is detachably attached for easy cleaning and is made semitransparent by using polycarbonate so that the internal state can be confirmed.

Further, the paper pressing means 30 includes the paper receiving portion 2
1 is means for preventing the printed paper (P) from being curled with the printing surface facing outward. In the present embodiment, the paper pressing means 30 has a star wheel 32 in the middle portion.
It is composed of a bar 31 to which is attached.

The bar 31 has a base end portion attached to the inner surface of the cover portion 29 and is formed of a conductive elastic member (eg, stainless steel, phosphor bronze plate, etc.) bent in a dogleg shape. There is. In the present embodiment, a phosphor bronze plate is selected as the elastic member in consideration of having appropriate elasticity, conductivity and workability. Further, in the middle portion of the bar 31, the paper feed direction (F
(Direction) A star wheel 32 that presses the central portion is rotatably mounted. As shown in FIG. 2, the star wheel 32 has an outer peripheral surface formed in a sawtooth shape having a small contact area with the paper P in order to prevent transfer of ink from the printed paper P. The star wheel 32 is made of a conductive material (stainless steel in this embodiment). In addition, in the middle part of the bar 31, the star wheel 32
The sponge rollers 33, 33 for removing the ink adhering to the outer peripheral surface of are attached so as to be rotatable in contact with the star wheel 32.

A ground plate 39 extending to the frame (not shown) of the ink jet printer is connected to the base end of the bar 31. As a result, the static electricity charged on the printed paper P is removed from the star wheel 32 and the bar 3.
1 and the earth plate 39 and the like, and can be released to the frame of the printer. In addition, earth plate 3
It is also possible to reduce the number of parts by integrally forming 9 and the bar 31 as shown in FIG.

Next, the operation will be described. The curled printed sheet P sent to the sheet receiving portion 21 by the spur 12 and the eject arm 15 is guided in the sheet feeding direction (F direction) while the curl is gradually corrected by the guide rails 28, 28, and the curled printed sheet P is guided by the bar 31. The print surface of the star wheel 32 is pressed toward the recess 26. Therefore, the printed paper P does not interfere with the printed paper (P) to be discharged next in an unnatural state, and does not come into contact with the printing surface of the previously discharged printed paper (P). Thus, it is accumulated in the recess 26 (see FIG. 6). Note that the printed paper P generally returns to the original state (non-curled state) when the ink on the printed surface is dried. As a result, the printed paper P that has been ejected to the paper receiving portion 21 is prevented from being pushed up at the lower end by the printed paper P that is ejected next and falling off from the receiving portion 21. . In addition, ink stains on the print surface due to curling of the printed paper P are prevented. At this time,
Star wheel 32, bar 31, and earth plate 3
Static electricity charged on the printed paper P via 9 or the like can be released to the frame.

However, according to this embodiment, the printing surface of the printed paper P is pressed against the paper receiving portion 21 to press the paper P.
Since the paper pressing means 30 is provided to prevent the paper from curling with the printing surface as the outer side, even if the printed paper P is curled and discharged to the paper receiving portion 21, the paper receiving portion 21 is smoothly and surely held in the receiving portion 21. Can be accumulated. In addition, ink stains on the print surface due to curling of the printed paper P are prevented.

In addition, since the paper receiving portion 21 is provided with the concave portion 26 for allowing the printed paper P to be warped backward by the paper pressing means 30, it cooperates with the paper pressing means 30. Thus, the printed paper P can be accumulated in the concave portion 26 in a state in which the paper P is reversed. As a result, even if the printed paper P is curled and discharged, it can be accumulated in the paper receiving portion 21 more smoothly and reliably, and ink stains on the printing surface of the paper P can be prevented. In particular, since the concave portion 26 is formed in the central portion of the backrest portion 25 of the paper receiving portion 21 so as to have an inverted V-shape with respect to the paper feeding direction (direction of arrow F) and become gradually deeper, the printed paper P is unreasonable. The printed sheet P that is about to be curled can be accumulated in the sheet receiving portion 21 more smoothly from this point.

Further, since the paper receiving portion 21 is provided with the guide rails 28, 28 which can guide the printed paper P while correcting the printed paper P, the printed paper P to be curled is smoother and more reliable. It can be accumulated in the paper receiving portion 21, and ink stain on the printing surface of the paper P can be prevented. In particular, the guide rails 28 are formed on both sides of the recess 26 in an inverted V shape with respect to the paper feeding direction (F direction) similarly to the recess 26, and the height gradually decreases toward the rear. Therefore, the curl of the printed paper P can be gradually corrected without difficulty, and from this point, the printed paper P to be curled can be stored in the paper receiving portion 21 more smoothly.

Further, the bar 3 forming the paper pressing means 30.
1 and the star wheel 32 are formed of a conductive member,
Moreover, since the ground plate 39 is connected to the bar 31, the static electricity charged on the printed paper P can be removed.

Further, since the cover 29 is detachably attached to the backrest portion 25 of the paper receiving portion 21, even if ink or the like adheres to the back surface of the cover portion 29, it can be easily wiped off. Furthermore, since the cover 29 is translucent, the internal state can be easily confirmed.

Furthermore, since the sheet supporting portion 22 forming the sheet receiving portion 21 and the backrest portion 25 are separable from each other, maintenance and the like can be easily performed.

In the above embodiment, the point that the paper receiving portion 21 receives the curled printed paper P has been explained. However, the uncurled printed paper is stored smoothly and surely in the receiving portion 21. can do. Further, even when both are mixed, they can be smoothly accumulated similarly.

Further, the paper pressing means 30 is formed by one bar 31 having a star wheel 32 attached to the middle portion thereof, but the printing surface of the printed paper P is pressed to press the paper P.
Any structure may be used as long as it can prevent curl from being printed with the printing surface as the outside. For example, a plurality of bars having the same structure as the above-mentioned bar 31 are provided in the paper feed direction (F direction).
The paper pressing means 30 are arranged in parallel in a direction orthogonal to
May be configured.

[0032]

According to the first aspect of the invention, the paper receiving portion is provided with the paper pressing means for pressing the printing surface of the printed paper to prevent the paper from curling with the printing surface as the outside. Therefore, even if the printed paper is curled and discharged to the paper receiving portion, the printed paper can be smoothly and reliably accumulated in the receiving portion.

According to the invention of claim 2, in addition,
Since the recessed portion is provided to allow the printed paper to reversely curl against curling, the printed paper is reversed to the concaved portion against the force to curl in cooperation with the paper pressing means. It can be stored in a stored state. As a result, the printed paper can be stored in the paper receiving portion more smoothly and reliably.

According to the invention of claim 3, in addition,
Since the guide rail that can guide the printed paper while correcting the curl is provided, the printed paper can be stored in the paper receiving portion more smoothly and reliably even if it is discharged while curled.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining a sheet receiving unit that is a main part of an embodiment of the present invention.

FIG. 2 is a perspective view for explaining a sheet pressing unit and an earth plate according to an embodiment.

FIG. 3 is a perspective view showing a state where a paper pressing unit and an earth plate of one embodiment are integrally formed.

FIG. 4 is a perspective view showing a state in which a paper support portion and a backrest portion of a paper receiving portion of one embodiment are separated.

FIG. 5 is a diagram illustrating a state in which a cover is removed from a backrest portion of a sheet receiving unit according to an embodiment.

FIG. 6 is a diagram showing a state in which printed paper has been discharged to a paper receiving unit according to an embodiment.

FIG. 7 is a diagram for explaining the overall configuration of an embodiment.

FIG. 8 is a diagram for explaining a schematic configuration of a conventional inkjet printer.

FIG. 9 is a diagram for explaining an inconvenience that occurs in a sheet receiving portion of a conventional inkjet printer.

[Explanation of symbols]

 21 paper receiving portion 26 concave portion 28 guide rail 30 paper pressing means

Claims (3)

[Claims] 1. A printed sheet sent from a printing unit,
In an ink jet printer having a paper receiving portion capable of accumulating sequentially with the printing surface as the upper side, a paper pressing for pressing the printing surface of the printed paper against the paper receiving portion to prevent the paper from curling with the printing surface as the outside. An inkjet printer provided with means. 2. The ink jet printer according to claim 1, wherein the paper sheet receiving portion is provided with a concave portion that allows the printed paper sheet to reversely warp against the curl. 3. The ink jet printer according to claim 1, wherein the paper receiving portion is provided with a guide rail that can guide the printed paper that is being curled and ejected while being corrected.