JP3653833B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet printer that performs printing by ejecting ink from a nozzle of an ink jet head onto a printing paper, and can discharge the printing paper so that the surface of the printing paper does not come into contact with the ink jet head.
[0002]
[Prior art]
Conventionally, the ink jet printer shown in FIG. 4 is known. In this apparatus, the inkjet head 51 is provided in a direction in which the printing surface (nozzle surface) 54 and the upper surface 78 of the stacker 72 are parallel, and the auxiliary stacker 72 is disposed below the printing surface 54. Then, the printing paper 12 loaded in the paper feeding cassette 14 is conveyed by the paper feeding roller 16, is sandwiched by the paper feeding roller 31 and the pressing roller 32, and is fed onto the printing guide 35. Subsequently, the paper feed roller 31 stops when the print paper 12 is fed to a predetermined printing position. Subsequently, the carriage 52 on which the inkjet head 51 is mounted is reciprocated along a guide shaft 53 by a carriage drive motor (not shown), and the inkjet head 51 performs printing by ejecting ink onto the printing paper 12 from the nozzle. Do.
[0003]
When printing with a predetermined width is completed, the paper feed roller is rotated and the printing paper 12 is fed to the next printing position. On the other hand, the front end 122 of the printed printing paper 12 is squeezed and discharged by the paper discharge roller 60 and the spur roller 61, and the printing is finished, and the rear end 121 of the printing paper 12 is discharged to the discharge roller 60 and the spur roller. When the holding state by 61 is released, the printing paper 12 is accommodated in the upper surface 78 of the auxiliary stacker 72.
[0004]
There is also known a printing apparatus in which a print head is provided such that its print surface and a surface for storing discharged print paper form a predetermined angle (Japanese Patent Laid-Open No. 57-17879). This drive guides the printing paper (printing paper) that is nipped and conveyed by the drive roller (paper feed roller) and follower roller (pressing roller) onto the flat platen (printing guide), and performs printing by the print head. It is configured to crawl and discharge by a roller (discharge roller) and a follower roller (pressing roller).
[0005]
[Problems to be solved by the invention]
FIG. 5 shows a state in which the printing paper is discharged by the above-mentioned conventional former. For easy understanding, the interval between the inkjet head 51 and the printing guide 35 is drawn larger than the actual distance.
As shown in FIG. 5, when the printing paper 12 is discharged by the discharge roller 60 and the spur roller 61, the force indicated by the arrow F <b> 1 acts due to its own weight, and the point where the print paper 12 is pinched by the discharge roller 60 and the spur roller 61. Attempts to bend into a convex shape as a fulcrum.
[0006]
When the printing paper 12 is released from the holding state by the paper feeding roller 31 and the pressing roller 32, the trailing edge 121 in the feeding direction of the printing paper 12 is applied by the rigid force to maintain the shape of the printing paper 12. Jumps up, and the rear end 121 in the feeding direction comes into contact with the printing surface 54 of the inkjet head 51.
Therefore, there is a problem that the rear end 121 of the printing paper 12 in the feeding direction is soiled by the ink attached to the printing surface of the inkjet head 51. In addition, there is a problem that the nozzles of the inkjet head 51 are clogged by dust or paper fibers adhering to the surface of the printing paper 12.
[0007]
Further, in the latter case of the prior art, if the configuration is applied to an ink jet printer, the pressing roller paired with the drive roller on the discharge side is not a spur roller but has a large contact area with the printing surface of the printing paper. Therefore, it is not suitable for picking up and discharging undried printing paper. In addition, the stacker is provided at a position where the front end of the print paper comes into contact with the print paper storage surface of the stacker when the rear end of the print paper in the feeding direction is removed from the drive roller and follower roller on the paper feed side. Therefore, it is not possible to prevent the trailing edge of the printing paper from feeding up toward the print head.
Further, a guide for guiding the printing paper is provided at a position facing the platen on the discharge side with respect to the print head, but it is not suitable because there is a possibility that an undried printing surface may come into contact.
Therefore, there is a problem that the above cannot be applied to an ink jet printer.
[0008]
Therefore, the present invention has been made to solve the above-described problems, and the object of the present invention is to prevent the rear end of the printing paper in the feeding direction from contacting the printing surface of the inkjet head when the printing paper is discharged. It is to provide an ink jet printer.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, in the invention described in claim 1, the sheet feeding / conveying means for picking up the printing paper and feeding it to the printing position is provided on the printing paper feeding side of the paper feeding / conveying means. An inkjet head that performs printing by ejecting ink from above onto the fed printing paper, and a feeding direction of the printing paper printed by the inkjet head. And a discharge conveying means for picking up and discharging by a discharge roller abutting from above and a spur roller abutting from above, and provided between the paper feed conveying means and the discharge conveying means so as to face the ink jet head. the printing paper has a printing guide for supporting and housing means for housing the printing paper discharged from said discharge conveying means, it is provided inkjet In the printer, the housing means, the dispensing direction trailing end of the printing paper, when deviated from said sheet feed conveying unit, the front end of the printing paper is brought into contact with the receiving surface of the printing paper of the housing means, said printing dispensing direction trailing end of the sheet is provided at a position that will be energized in the print guide direction, in the state where the discharge conveying means sandwiching the printing paper, the feed direction rear end of the printing paper to the printing guide, The storage surface is set in a predetermined direction with respect to the discharge direction of the print paper by the discharge conveyance means so that the front end of the print paper is brought into contact with the storage means to bend the print paper substantially in a concave shape toward the inkjet head. The technical means that the angle is set is adopted.
[0010]
According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the printing paper moves on the storage surface as it is discharged from the discharge direction of the discharge conveyance unit above the storage surface. The technical means is adopted that there is nothing in contact with the upper surface of the printing paper over a range where the angle is changed.
[0011]
According to a third aspect of the present invention, in the ink jet printer according to the first or second aspect, the accommodating means is located above a range in which the printing paper changes its angle while moving on the accommodating surface as it is discharged. The technical means that the wall means which covers the upper part of the accommodating means is provided is employ | adopted.
[0012]
According to a fourth aspect of the present invention, in the ink jet printer according to any one of the first to third aspects, a technical means that the predetermined angle is 17 ° to 60 ° is employed.
[0013]
According to a fifth aspect of the present invention, in the ink jet printer according to any one of the first to third aspects, a technical means that the predetermined angle is 43 ° to 47 ° is employed.
[0014]
[Action]
In the invention according to any one of claims 1 to 5, when the rear end in the feeding direction of the printing paper is removed from the paper feeding / conveying means, the storage means is configured such that the front edge of the printing paper is the printing paper of the storage means. receiving surface abuts, dispensing direction trailing end of the printing paper is provided at a position that will be energized in the printing guide direction. That is, when the trailing edge of the printing paper feeding direction is separated from the paper feeding / conveying means, the front edge of the printing paper comes into contact with the printing paper containing surface of the containing means, so that the printing paper is discharged by its own weight. Using the conveying means as a fulcrum, it can be prevented from being curved in a convex shape.
[0015]
In addition, in a state where the discharge conveyance unit holds the printing paper , the printing paper is almost directed toward the inkjet head by bringing the rear end of the printing paper in the feeding direction into contact with the printing guide and the front end of the printing paper in contact with the storage unit. Since the storage surface is set at a predetermined angle with the discharge direction of the print paper by the discharge conveyance means so as to be curved in a concave shape, the print paper after coming into contact with the storage surface is ink jetted by a force pressed in the discharge direction. Since it is discharged toward the head in a substantially concave curved state, it is possible to discharge the printing paper while urging the rear end in the feeding direction away from the inkjet head.
Therefore, it is possible to prevent the rear end of the printing paper from being fed out in the direction of the ink jet head and coming into contact with the printing surface to be contaminated with ink and the nozzles of the ink jet head are clogged.
[0016]
In particular, in the invention described in claim 2, an angle (degree of concave curvature) is formed above the storage surface while the printing paper moves on the storage surface as it is discharged from the discharge direction by the discharge conveyance unit. Since there is nothing in contact with the upper surface of the printing paper over the range where the change is made, it is possible to prevent the undried printing surface (upper surface) of the printing paper from being rubbed and soiled.
[0017]
According to a third aspect of the present invention, the accommodating means is located above the range in which the angle (the degree of concave curvature) changes while the printing paper moves on the accommodating surface as it is discharged. Since the wall means for covering the upper side of the printing paper is provided, the wall means can prevent the undried printing surface (upper surface) of the printing paper from being rubbed and soiled, and dust or the like can be found on the printing surface. Adhesion can be prevented.
[0018]
Furthermore, in the invention described in claim 4, the accommodation surface is arranged at 17 ° to 60 ° with respect to the discharge direction of the print paper by the discharge conveyance means so that the print paper is curved substantially concavely upward and downward. By setting the angle, the trailing edge of the printing paper in the feeding direction is prevented from jumping up, and the trailing edge of the printing paper in the feeding direction comes into contact with the printing surface of the inkjet head, or the nozzles of the inkjet head are not visible. It is possible to prevent clogging.
[0019]
In particular, in the invention described in claim 5, by setting the angle to 43 ° to 47 °, the rear end in the feeding direction of the printing paper is more effectively brought into contact with the printing surface of the inkjet head. It is possible to prevent contamination and clogging of the nozzles of the inkjet head.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view illustrating main internal mechanisms of an ink jet printer (hereinafter abbreviated as a printer) according to an embodiment of the present invention, and FIG. 2 illustrates paper feeding, printing, and printing of the printer shown in FIG. FIG. 5 is an enlarged explanatory view of a portion that performs paper discharge and storage. 1 and 2, the left side of the paper is the rear part of the printer, and the right side of the paper is the front part of the printer.
[0021]
As shown in FIG. 1, a paper feed cassette 14 that can store a plurality of printing papers 12 is provided at the rear of the printer 10. A paper feed roller 16 having a rotation axis along the width direction of the printing paper 12 is provided at a lower portion of the paper feeding cassette 14 and in contact with the uppermost printing paper 12. A tray 18 on which the printing paper 12 is placed is provided in the paper feed cassette 14, and this tray 18 is urged toward the paper feed roller 16 by a coil spring 20. That is, the printing paper 12 on the tray 18 is brought into contact with the surface of the paper feed roller 16 by the urging force of the coil spring 20 and is conveyed downward on the guide 21 by the paper feed roller 16 that rotates by driving the motor.
[0022]
Inside the cover frame 24 and in front of the lower part of the paper feed roller 16 is formed of a paper feed roller 31 that is rotated by a motor and a pressing roller 32 having a rotation axis parallel to the rotation axis of the paper feed roller 31. A paper feeding / conveying means is provided. The pressing roller 32 is rotatably supported by a roller holder 33. The roller holder 33 is rotatably supported by an attachment shaft 34 and is rotated by an urging means (not shown). (Clockwise in the drawing). That is, the surface of the pressing roller 32 is pressed against the surface of the paper feed roller 31 by the biasing force in the rotating direction.
As a result, the printing paper 12 conveyed on the guide 21 by the paper feeding roller 16 is sandwiched between the paper feeding roller 31 and the pressing roller 32, and the printing guide 35 provided obliquely in front of the lower side (printing position). Paper is fed up.
[0023]
In the cover frame 24, a printing unit 50 including an inkjet head 51 having a printing surface facing the upper surface of the printing guide 35 is provided. The printing guide 35 is provided at an angle of T ° (= 47 °) with respect to the storage surface 78 of the auxiliary stacker 72 described later. That is, the inkjet head 51 is also provided so that the printing surface 54 is at an angle of 47 ° with respect to the accommodation surface 78 of the auxiliary stacker 72. A plurality of ink chambers to which piezoelectric elements are attached are formed inside the ink jet head 51. By applying a voltage to the piezoelectric elements, the volume of the ink chamber is changed, and nozzles formed in the ink chambers. Ink is discharged onto the upper surface of the printing paper 12 on the printing guide 35.
[0024]
The inkjet head 51 is mounted on a carriage 52, and the carriage 52 is attached to a guide shaft 53 provided in the width direction in the printer. The carriage 52 is reciprocated along a guide shaft 53 by a carriage drive motor (not shown), and the inkjet head 51 performs printing in the width direction on the printing paper 12.
[0025]
Below the ink jet head 51, there is provided a discharge conveying means comprising a discharge roller 60 that rotates by driving a motor, and a spur roller 61 that sandwiches and discharges the printing paper 12 printed between the discharge roller 60. Yes. The spur roller 61 is made of a thin plate material having a number of sharp protrusions on the outer periphery. That is, the upper surface of the printed printing paper 12 is in an undried state, and a rubber roller having a large contact area cannot be used unlike other non-inkjet printers. Is used.
[0026]
The spur roller 61 is supported by a plate-shaped spur roller holder 62, and the spur roller holder 62 is attached to a frame 63 that supports the carriage 52. A bent portion 64 is formed at the tip of the frame 63, and a substantially continuous surface is formed by the bent portion 64 and the spur roller holder 62. A partition plate 65 is formed below the frame 63 so as to extend substantially in parallel with the frame 63 from the back surface of the cover frame 24, and the tip of the partition plate 65 is located near the tip of the bent portion 64. doing.
That is, the spur roller holder 62, the bent portion 64, and the partition plate 65 form a wall that covers the upper surface of the rear portion of the stacker 70, so that dust or the like can be prevented from falling on the upper surface of the printed printing paper 12. it can.
[0027]
The path of the printing paper formed by the paper feeding / conveying means 31 and 32 and the discharging / conveying means 60 and 61 is inclined downward toward the paper conveying direction. The angle is T °.
A storage means, that is, a stacker 70 is provided below the discharge conveyance means 60 and 61 with a step. The stacker 70 includes a spur roller holder 62, a bent portion 64, a stacker base 71 positioned below the partition plate 65, and an auxiliary stacker 72 extending forward.
The stacker base 71 is formed with a part of the base frame 73 with a slight downward slope in the discharge direction of the printing paper 12. The auxiliary stacker 72 is provided below the stacker base 71 and can be inserted into and removed from a stacker storage space 74 provided below the base frame 73. A plate-like contact member 75 is formed at the front end of the auxiliary stacker 72 so that the front end of the discharged printing paper 12 is brought into contact with the front end to accommodate the front end. 76 is provided, and the stopper 76 prevents the auxiliary stacker 72 from coming off when it is pulled out.
[0028]
Further, as shown in FIG. 1, the auxiliary stacker 72 is in a position in which the contact member 75 comes into contact with the front end of the base frame 73 (indicated by “A” in FIG. 1) when stored in the stacker storage space 74. It is in. That is, the entire auxiliary stacker 72 can be stored in the stacker storage space 74. In addition, B in the figure indicates the position of the contact member 75 when the auxiliary stacker 72 is fully pulled forward. Further, in the state of being drawn out to the position shown in B, the total length L1 of the surface (accommodating surface) of the upper surface 79 (accommodating surface) of the stacker base 71 and the upper surface 78 of the auxiliary stacker 72 is the maximum usable size. The total length of the printing paper 12 is almost equal.
[0029]
In this embodiment, when the rear end 121 of the printing paper 12 is released from the nipping state by the paper feed roller 31 and the pressing roller 32, the front end 122 of the printing paper 12 is already on the upper surface 79 of the stacker base 71. In order to make contact, the upper surface 78 of the stacker 70 passes from the contact point between the paper feed roller 31 and the pressing roller 32 (the gripping point of the printing paper 12) through the contact point between the discharge roller 60 and the spur roller 61. Is set to be equal to or less than the total length L4 of the printing paper 12 (L5 ≦ L4). L5 is determined to be a minimum usable size, for example, a short side of a postcard of 100 mm. The auxiliary stacker 72 is provided at a height at which the uppermost printing paper 12 does not come into contact with the tip of the partition plate 65 when the printing paper 12 is fully stacked. In the present embodiment, the thickness D1 of the printing paper at the time of full stack is about L4 / 10.
[0030]
Next, a state from the feeding of the printing paper 12 to the ejection after printing will be described by the printer 10 having the above configuration.
First, the printing paper 12 accommodated in the paper feed cassette 14 is fed to the paper feed roller 31 side along the guide 21 by the paper feed roller 16 that rotates counterclockwise. Subsequently, the printing paper 12 fed along the guide 21 is sandwiched between a paper feed roller 31 that rotates in the clockwise direction and a pressing roller 32 that rotates in the counterclockwise direction, and is placed on the printing guide 35. Along the print surface 54 side.
[0031]
Then, when the printing paper 12 reaches the printing surface 54, the rotation of the paper feed roller 31 is stopped, the inkjet head 51 is driven, and the inkjet head 51 performs printing by ejecting ink onto the upper surface of the printing paper 12. The carriage 52 moves as the carriage 52 moves. Subsequently, when printing for one line is completed, the paper feed roller 31 rotates, and the printing paper 12 is fed to the next printing position, and printing similar to the above is performed. Thereafter, the same printing and paper feeding are repeated, and the printing paper 12 is sandwiched between the discharge roller 60 and the spur roller 61 and discharged toward the auxiliary stacker 72.
[0032]
Here, when the rear end 121 of the printing paper 12 is released from the nipping state by the paper feed roller 31 and the pressing roller 32, the front end 122 of the printing paper 12 is still on the upper surface 79 of the stacker base 71 as in the prior art. Assuming that the printing paper 12 is in a suspended state without contacting, the printing paper 12 hangs downward due to its own weight and curves in a convex shape with the discharge roller 51 as a fulcrum. The head 51 is flipped up in the direction of the printing surface.
However, in the printer 10, when the trailing edge 121 of the printing paper 12 is released from the nipping state by the paper feeding roller 31 and the pressing roller 32, that is, when the printing paper 12 is removed from the paper feeding means, Since the front end 122 is already in contact with the upper surface 79 of the stacker base 71 at an angle of 47 °, it can be easily curved concavely upward as shown by P1 in FIG.
[0033]
Thereafter, as the paper feed proceeds, the printing paper 12 gradually moves in the accommodation surfaces 79 and 78 while gradually decreasing the degree of bending (angle) as indicated by P2 and P3 in FIG. And is released from the holding state by the discharge roller 60 and the spur roller 61 and accommodated in the upper surface 79 of the stacker base 71 and the upper surface 78 of the auxiliary stacker 72.
That is, the rear end 121 of the printing paper 12 is maintained in a state of being biased in the direction of the printing guide 35 even if the nipping by the paper feed roller 31 and the pressing roller 32 is released. No jump in the direction of 54.
Therefore, it is possible to prevent the rear end 121 of the printing paper 12 from coming into contact with the printing surface 54 and being stained with ink. Moreover, dust and paper fibers of the printing paper 12 do not adhere to the nozzles of the inkjet head 51 and the nozzles are not clogged.
Further, in the process in which the printing paper 12 is loosened as described above, the spur roller holder 62, the bent portion 64, and the partition plate 65 are separated sufficiently above the printing paper 12. And the undried ink on the printing paper 12 is prevented from being rubbed.
[0034]
Next, in the embodiment of the present invention, the case where the angle formed between the printing surface 54 of the inkjet head 51 and the upper surface 78 of the auxiliary stacker 72 is set to 47 ° is described. As shown in FIG. Even when the angle is set to T ° = 17 °, the trailing edge 121 of the printing paper 12 can be prevented from jumping up as in the case where the angle is set to 47 °. It is possible to prevent the undried ink from being rubbed.
However, in this case, when the rear end 121 of the printing paper 12 is removed from the paper feeding / conveying means, the stacker 70 is set so that the front edge 122 of the printing paper 12 is already in contact with the upper surface 79 of the stacker base 71. Is set closer to the discharge roller 60 than the 47 ° position. That is, the setting height of the auxiliary stacker 72 is changed so as to satisfy the above condition according to the angle.
[0035]
In the case of the conventional one shown in FIG. 4, the distance L2 from the center of the paper feed roller 31 to the center of the discharge roller 60 is a distance necessary for transporting the printing paper 12.
However, when the inkjet head 51 is installed at an inclination as in the printer according to each of the above embodiments, the distance L3 is L2 cosT (T = 47 ° or 17 °) as shown in FIG. . That is, it is shortened by (L2−L2cosT) = L2 (1−cosT).
Accordingly, since the position of the rear end 121 of the printing paper 12 to be accommodated can be set closer to the inkjet head, the area occupied by the printer 10 can be reduced.
[0036]
Further, according to the experiment by the present inventor, it has been clarified that if the angle is set within a range of 17 ° to 60 °, the above-described effect can be obtained. It was found that it is desirable to set the angle in the range of 43 ° to 47 ° in consideration of the bounce of the lens.
In the embodiment of the present invention, the paper feed roller 31 and the pressing roller 32 correspond to the sheet feeding / conveying means according to the present invention. However, a sheet guide may be provided between the pressing roller 32 and the inkjet head 51. it can. In this case, it is assumed that when the rear end of the printing paper 12 is removed from the paper guide, the printing paper 12 is removed from the paper feeding / conveying means. Further, the discharge roller 60 and the spur roller 61 correspond to a discharge conveyance unit, and the stacker base 71 and the auxiliary stacker 72 correspond to a storage unit.
[0037]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the trailing edge of the printing paper feed direction from jumping in the direction of the ink jet head when it is removed from the paper feeding / conveying means.
Therefore, it is possible to prevent the rear end of the printing paper in the feeding direction from coming into contact with the ink jet head and being stained with ink. In addition, it is possible to prevent clogging of the nozzles due to dust or paper fibers of the printing paper adhering to the nozzles of the inkjet head.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view illustrating main internal mechanisms of a printer according to an embodiment of the present invention.
FIG. 2 is an enlarged partial cross-sectional explanatory view showing a paper feeding and discharging mechanism of the printer shown in FIG. 1;
FIG. 3 is a partial explanatory view of a longitudinal section when the angle of the inkjet head of the printer shown in FIG. 2 is set to 17 °.
FIG. 4 is a longitudinal sectional view illustrating main internal mechanisms of a conventional printer.
FIG. 5 is an explanatory diagram showing an enlarged view of a printer paper feed and discharge mechanism of the printer shown in FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Printer 12 Printing paper 14 Paper feed cassette 16 Paper feed roller 31 Paper feed roller 32 Pressing roller 35 Printing guide 51 Inkjet head 60 Discharge roller 61 Spur roller 72 Auxiliary stacker

Claims (5)

Paper feeding and conveying means for picking up printing paper and feeding it to the printing position;
An inkjet head that is provided on the feeding side of the printing paper of the paper feeding / conveying means, and that performs printing by ejecting ink from above onto the fed printing paper;
Discharging and conveying means provided in the feeding direction of the printing paper printed by the inkjet head, and the printed printing paper is held by a discharging roller that contacts from below and a spur roller that contacts from above and discharged and conveying means;
A printing guide provided between the paper feed conveying means and the discharge conveying means so as to face the ink jet head, and supporting a sent printing paper;
A housing means for housing the printing paper discharged from said discharge conveying means,
In an inkjet printer equipped with
When the rear end of the printing paper in the feeding direction is disengaged from the paper feeding and conveying means, the front end of the printing paper comes into contact with the printing paper containing surface of the containing means, and the feeding means sends out the printing paper. provided at a position rearward end is Ru is biased to the printing guide direction,
In a state in which the discharge conveyance unit holds the printing paper, the printing paper is moved to the printing guide by bringing the rear end in the feeding direction of the printing paper into contact with the printing guide, and the front end of the printing paper is brought into contact with the storage unit. An ink jet printer , wherein the receiving surface is set at a predetermined angle with respect to the discharge direction of the printing paper by the discharge and transport means so as to be bent substantially concavely toward the ink jet head .   Above the receiving surface, there is nothing that contacts the upper surface of the printing paper over a range in which the printing paper changes its angle while moving on the receiving surface as it is discharged from the discharging direction by the discharging and conveying means. The inkjet printer according to claim 1.   The above-mentioned accommodation means is provided with wall means for covering the upper part of the accommodation means above the range in which the printing paper moves on the accommodation surface as it is discharged and changes its angle. The inkjet printer according to 1 or 2.   The inkjet printer according to claim 1, wherein the predetermined angle is 17 ° to 60 °.   The inkjet printer according to claim 1, wherein the predetermined angle is 43 ° to 47 °.

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