JPH0577997A - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to prevent the print quality from deteriorating at the time of switching the discharge path in a printer having a plurality of discharge positions. [Structure] The printing paper P is provided near the guide member 25 of the platen 2.
The platen 2 is provided with a suction hole 18 for sucking paper and a through hole 27 provided in the guide member 25 so as to be able to communicate with the suction hole 18, and when the paper is discharged to the paper discharge paths a and b. Either of the suction holes 18 or the through holes 27 of the guide member 25 sucks the printing paper P from the back side of the printing surface,
The printed surface was not touched with other members.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a printer having a plurality of paper discharge paths.

[0002]

2. Description of the Related Art Printing apparatuses, particularly printing apparatuses such as ink jet printers that perform printing using liquid ink, have a problem in that the printed surface of the printing paper comes into contact with something before the ink on the printing paper has dried. In order to prevent the print quality from degrading, it is necessary to secure a certain distance between the print head and the print paper. As one method of this, there is currently known a sheet suction type platen which stably holds a printing sheet during printing and after printing at a position separated from the print head by a predetermined distance. With regard to an ink jet printer using this paper suction type platen, as shown in Japanese Utility Model Laid-Open No. 2-40544, the print paper is supported at a position facing the print head at a predetermined distance from the print head. A platen is provided, and the platen is formed into a flat plate shape extending over the entire area facing the print head and upstream and downstream thereof, and a plurality of holes are formed at predetermined positions in the height direction substantially facing the print head over substantially the entire length of the platen. Each of them is formed in a line in the printing direction. Also, on the opposite side of the platen facing the print head,
That is, in the rear part of the platen, a chamber communicating with this hole and a suction fan at a predetermined position on the opposite side of the platen position of the chamber are provided. By operating this suction fan, the air in the chamber is sucked and The print sheet on the platen is adsorbed in the platen direction through the through plate to keep the distance between the print surface of the print sheet and the print head after printing constant.

Further, in such a printing apparatus, when the printed paper is collected at the discharged paper collecting position, when it is desired to change the discharged paper collecting position in order to distinguish the paper at the user's request, or a plurality of printed paper is collected. In order to change the order, if you want to eject or collect the printed surface of the printed paper upward or downward, select and guide multiple paper ejection paths that are located downstream of the printing position and lead to multiple paper ejection collection positions. A rotatable wedge-shaped guide member is provided for the purpose of switching to a desired sheet discharge path.

[0004]

However, the paper used for printing is not always an ideal flat surface, and is usually slightly curved to some extent. Therefore, in the case where the guide member moves in the plurality of paper discharge paths and the suction holes provided in the platen are blocked by the guide member, until the paper discharge collection position is reached, that is, , Until the printed ink is sufficiently dried and fixed on the printing paper, the paper guide surface on the side facing the printing surface of the printed paper and the printing surface of the printed paper are in contact with each other When it is conveyed to, the printed image is rubbed and disturbed.

This is because, particularly in a printing apparatus for forming an image with liquid ink, that is, an ink jet printer or the like, after printing, the ink on the printed paper is hard to dry, and the paper discharge path is formed before the ink is sufficiently dried. This is a serious problem when the paper is determined and guided, or when a paper on which the ink does not easily adhere to the print medium, that is, a paper for which the ink hardly penetrates into the paper such as OHP paper is used. The present invention has been made to solve the above-mentioned problems, and in a printing apparatus having a plurality of paper discharge paths, it is possible to quickly and without disturbing the image on the printed paper on the way of the selected paper discharge path. It is an object of the present invention to provide a printing device that can be transported to a discharged paper collection position.

[0006]

In order to achieve this object, the present invention performs printing on a recording medium in a printing apparatus having a plurality of paper discharge paths for guiding a recorded recording medium after printing to a paper discharge collecting position. A print head, and a platen which is provided to face the print head, holds the recording medium from the back side of the recording surface, and has a plurality of suction holes formed in the facing surface.
A chamber provided on the side opposite to the print head of the platen, and provided at a predetermined position of the chamber,
Suction means for sucking and holding the recording medium on the platen by sucking air through the suction hole, and provided at the branch point of the discharge path located in the sheet feeding direction with respect to the printing position of the platen, The guide member includes a guide member that is movable to select and switch the platen side and other sheet discharge paths, and a driving unit that drives the guide member, and the guide member has a sheet discharge path other than the platen side. When is selected, a through hole that communicates with the suction hole formed at a position facing the guide member of the platen and that sucks the recording medium from the back side of the recording surface is formed.

[0007]

According to the above construction, the guide member is moved by the drive of the drive means to select one of the paper discharge paths. The recorded recording medium recorded by the print head is guided to the paper discharge path selected by the guide member. At this time, when the recorded recording medium is guided to the sheet discharge path provided on the platen side, it is adsorbed to the platen from the back side of the recording surface of the recorded recording medium through the adsorption hole provided on the platen. The distance between the print surface of the recorded recording medium and the wall surface of the paper discharge path is kept constant. Further, when the recorded recording medium is guided to the paper discharge path provided on the side other than the platen side, the through hole provided in the guide member is provided in the suction hole provided at the position facing the guide member of the platen. The guide member is adsorbed from the back side of the recording surface of the recorded recording medium through the through holes and the suction holes, and the distance between the printed surface of the recorded recording medium and the wall surface of the paper discharge path is kept constant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A printer according to an embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are a cross-sectional view and a perspective view showing the configuration of the printing apparatus. At a predetermined position above the body frame 1, two paper discharge stackers a and b for collecting the print paper P discharged after printing are provided, and the printed paper P is collected in the paper discharge stacker a. When printing is performed, the printing surface is on the upper side, and the paper output stacker b
When the printed paper P is collected, the printed paper is collected so that the print surface is on the lower side, that is, the print surface of the printed paper P contacts the wall surface of the paper discharge stacker b.

A print head 24 for jetting a liquid ink onto a print sheet for printing and a position facing the print head 24 are provided at substantially the center of the main body frame 1, and the print position and a predetermined range extending upstream and downstream thereof. Print paper P that has a height
The platen 2 for supporting the flat sheet-shaped printing paper P having the left and right lengths corresponding to the width is provided in the vertical direction, that is, parallel to the paper feeding direction. This platen 2
Has a suction hole 3 for sucking the print sheet P from the back side of the printing surface to the platen 2 in order to maintain a predetermined distance from the print head 24 provided facing the platen 2. Is approximately in the middle of the platen 2, over the entire length,
The upper and lower rows are formed at predetermined intervals. Further, on the rear part of the platen 2, that is, on the side opposite to the print head 24 with respect to the platen 2, there is provided a chamber 14 made of a synthetic resin or the like having excellent airtightness, which communicates with the suction holes 3, and a rear end part of the chamber 14. That is, the suction fan 15 is attached to a predetermined position on the opposite side of the platen 2 side of the chamber 14.

When the suction fan 15 is operated by a drive motor (not shown), the air in the chamber 14 is sucked,
The printing paper P fed onto the platen 2 has a plurality of suction holes 3
It is adsorbed in the platen 2 direction via. A guide shaft 4 extending in a direction perpendicular to the paper feed direction and a guide bar 5 parallel to the guide shaft 4 and having a predetermined distance from the guide shaft 4 are provided on the side of the suction hole 3 supporting the print paper P. .. A carriage 6 is mounted on the guide shaft 4 and the guide bar 5 so that the print head 24 faces the platen 2. The carriage 6 is inserted through the guide shaft 4 and slidably mounted on the guide bar 5 from above. , Is supported so as to be capable of reciprocating parallel movement via a wire (not shown).

Further, two paper feed rollers 10 are provided at predetermined intervals at a predetermined position upstream and downstream of the position facing the print head 24 of the platen 2 and on the opposite side of the platen 2 facing the print head. And is rotatably supported by two roller shafts 8 extending in the left-right direction. Further, the front edge of the paper feed roller 10 has the platen 2
The platen 2 is provided with an opening window 11 so as to come into contact with the upper printing paper P, and the platen 2 is
The paper feed roller 10 slightly projects toward the print head. Further, in order to sandwich and convey the print paper P together with the paper feed roller 10, an auxiliary roller 13 paired with each paper feed roller 10 is provided on the print head 24 side of the platen 2, and each shaft 12 extending in the left-right direction is provided. It is provided and rotatably supports the auxiliary roller 13. Each auxiliary roller 13
In order to feed the print paper P in the paper feed direction by the rotation of the paper feed roller 10, a predetermined pressing force is applied to the corresponding paper feed roller 10. A paper storage case 21 for storing the print paper P is provided at a paper supply start position located upstream of these paper feed rollers 10.
A paper feed roller 23 for feeding the print paper P toward the paper feed roller 10 is provided.

At the downstream position of the platen 2, a guide surface 17 for guiding the print paper P to the paper discharge stacker a is provided.
The guide surface 17 has a suction hole 18 formed in the same manner as the suction hole 3 described above so that the printed paper P can be sucked from the back side of the printing surface. .. Further, at a position upstream of the guide surface 17, that is, at a branch position of the paper discharge path, a guide member 25 having a cross section of a home base shape for switching the paper discharge path to the paper discharge stacker a or b. It is provided. The guide member 25 is rotatably supported by a shaft 26 provided parallel to the platen 2, and two guide members 25 are installed at a predetermined interval. The shaft 26 is connected to a solenoid 29 via a lever 28 attached to the body frame 1 on the side opposite to the platen 2. Depending on whether or not the solenoid 29 is driven, the guide member 25 causes the printed sheet P to be printed. Output stacker a,
The sheet is guided to one of the sheet discharge stackers b. A spring 3 is provided between the solenoid 29 and the lever 28.
0 (shown in FIG. 4) is attached to this spring 30
Since the lever 28 exerts an urging force by the elastic action of the guide member 25, the guide member 25 is positioned so as to guide the printed paper P to the paper discharge tray a when the solenoid 29 is not driven.

Further, the guide member 25 is provided with a through hole 27 formed in a penetrating state at a position corresponding to the suction hole 18 provided in the platen 2, and the through hole 27 is sucked. It is adapted to communicate with the hole 18. As a result, when the guide member 25 moves to the guide surface 17 side and guides the printed paper P to the paper discharge path leading to the paper discharge tray b,
The printed sheet P is sucked from the back side through the through holes 27 and the suction holes 18 to prevent the printed surface of the printed sheet P from coming into contact with the wall surface of the sheet discharge path. Furthermore, facing the guide member 25,
When the printer is normal, the printing surface of the printed paper P does not come into contact with the upstream position of the paper discharge path that leads to the paper discharge collection unit b, and when the suction mechanism has an abnormality and the print paper is not sufficiently sucked. A guide portion 19 for preventing the print sheet P from colliding with the carriage 4 and the print head 24 is formed on an extension line of the main body frame 1.

Next, the block configuration of the control unit of the printer will be described with reference to FIG. The control unit 20 having a memory such as a ROM and a RAM receives code data from the main body device and various data relating to printing, and also has a paper feed motor 9 for operating the roller shaft 8 and a paper feed roller 23. The paper feed motor 22, the print head 24, the carriage drive motor 7, the suction fan 15, and the solenoid 29 for operation are connected. The control unit 20 is provided with a drive circuit for driving the motors 9, 22, 7 and the solenoid 29.

Next, the discharge path switching operation will be described with reference to FIGS. 4 (a) and 4 (b). First, when the sheet is discharged to the sheet discharge cassette a, as shown in FIG. 4A, since the solenoid 29 is in the OFF state and the spring 30 is in the uncompressed state, the guide member is inserted via the lever 28 and the shaft 26. 25
Is positioned so as to guide the print sheet P toward the sheet discharge stacker a along the sheet discharge path on the platen 2 side, that is, the guide surface 17. At this time, the printing paper P is attracted to the platen 2 from the back side of the printing surface by the suction holes 18 formed in the platen 2, and the wall surfaces 31 and 32 facing the printing surface of the guide member 25 do not touch the printing surface, The image is not disturbed. When the paper is discharged to the paper discharge cassette b, as shown in FIG.
As shown in, the solenoid 29 is turned on, the spring 30 is compressed, and the guide member 25 moves to a position where the print sheet P is guided toward the discharge stacker b. And at this time,
The through hole 27 of the guide member 25 communicates with the hole 18 of the platen 2, and the printing paper P is adsorbed from the back side of the printing surface via the through hole 27 of the guide member 25 and the suction hole 18, and the guide portion 19
The wall surface and the print surface of the are not touched, and the image is not disturbed. In addition, the embodiment is not limited to this, and when the hole 27 of the guide member 25 communicates with the suction hole of the platen 2, air is prevented from leaking from the gap between the guide member 25 and the platen 2 by the guide member 25. The material of the wall surface 31 may be a sealing member such as soft rubber.

[0016]

As is apparent from the above description, according to the present invention, at the switching position of the sheet discharge path, the through hole communicating with the suction hole in the guide member sucks and holds the recorded recording medium from the back side. It is possible to prevent the deterioration of the print quality caused by the contact of the member with the print surface of the recorded recording medium.

[Brief description of drawings]

FIG. 1 is a sectional view of a printer according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of the printing apparatus.

FIG. 3 is a block configuration diagram showing a control unit of the printing apparatus.

FIG. 4 is a cross-sectional view showing an operation of the printing apparatus when switching a paper discharge path.

[Explanation of symbols]

 2 platen 3 suction hole 14 chamber 15 suction fan (suction means) 18 suction hole 24 print head 25 guide member 27 through hole 29 solenoid P printing paper (recording medium)

Claims (1)

[Claims] 1. A printing apparatus having a plurality of discharge paths for guiding a recorded recording medium after printing to a discharge collecting position, a print head for printing on the recording medium, and a print head provided opposite to the print head. While holding the medium from the back side of the recording surface, a platen having a plurality of suction holes formed in the facing surface, a chamber provided on the opposite side of the platen from the print head, and a predetermined position of the chamber. Suction means provided for sucking and holding the recording medium on the platen by sucking air through the suction hole, and a branch point of the sheet discharge path located in the sheet feeding direction with respect to the printing position of the platen. The guide member is provided and is provided with a guide member that is movable for selecting and switching the sheet discharge path other than the platen side, and drive means for driving the guide member. , A through hole that communicates with a suction hole formed at a position facing the guide member of the platen when a paper discharge path other than the platen side is selected and that sucks the recording medium from the back side of the recording surface is formed. A printing device characterized by being provided.