JP2001030514A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the drawing quality by keeping a nozzle cleanly. SOLUTION: A recording head 52 is moved in the Y axis direction with respect to a drawing medium during drawing for ejecting a large number of ink droplets from a nozzle 52a of the recording head 52 to the recording medium controllably. The drawing medium is conveyed in the X axis direction for drawing on the drawing medium. A wiping device 2 comprising a wiper 14 movably in the direction parallel to the longitudinal direction of a bottom surface of the recording head 52 is provided outside the drawing area of an ink-jet printer. The recording head 52 is moved to the area with the wiping device 2 disposed at a predetermined timing so that the wiper 14 is moved along the nozzle 52a of the recording head 14 for wiping substantially the entire area of the recording head 52 while blowing out air, a cleaning liquid or an ink from the nozzle 52a. Liquid scattering protection walls 83, 85 for receiving a liquid scattered by the contact with the wiper 14, such as an ink, are provided on the front and back, and both sides of the wiper 14 in the main scanning direction.

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, and more particularly, to an ink jet printer having a wiping device for wiping ink discharge nozzles of a recording head.

[0002]

2. Description of the Related Art An ink jet recording head scans an image forming medium in the Y axis direction within an image forming range, and ejects a large number of ink droplets from the nozzles of the recording head to the image forming medium in a controllable manner. 2. Description of the Related Art Inkjet printers that transport images in an axial direction to create images on an image forming medium are conventionally known. Further, Japanese Patent Application Laid-Open No. 8-112916 discloses an ink jet printing mechanism that performs idle printing to prevent clogging of ink discharge nozzles and cleans the inside of a print head.

[0003]

In this type of ink jet printer, dust or the like adhered to the surface of the image forming medium by static electricity or the like sometimes adheres to the bottom surface of the recording head during image formation. In particular, the drawing medium called tarpaulin has a structure in which a cloth is sandwiched between vinyl chlorides, and the thread of the cloth often comes out from the end of the drawing medium, and when the recording head passes through the end of the drawing medium. Thread debris adheres to the bottom surface of the recording head and nozzles protruding from the bottom surface.
If dirt or thread debris is attached to the bottom of the recording head or nozzles, the ink will gradually penetrate into the dirt or thread debris during the drawing operation, and this will fall onto the drawing media being drawn, There is a problem that the drawing medium is soiled.
In addition, if dust or thread debris adheres to the nozzle, the direction of the ink ejected from the nozzle is changed by the dust or thread debris, and the printing quality is degraded. By moving the recording head to a cleaning position outside the printing range and blowing out gas or liquid from the nozzles, dust and thread debris attached to the nozzles can be removed to some extent, but this alone may cause ink residue around the nozzles. Also, the ink ejection direction is changed, and the image quality deteriorates. An object of the present invention is to solve the above problems.

[0004]

In order to achieve the above object, the present invention provides an ink jet type recording head which scans an image forming medium in the Y-axis direction, and outputs a large number of ink droplets from the nozzles of the recording head onto the image forming medium. In an ink jet printer that controls and discharges the image forming medium to convey the image forming medium in the X-axis direction and prints the image on the image forming medium, a wiper wipes a substantially entire area of the nozzle of the recording head at a predetermined timing while discharging a fluid from the nozzle. It was made. In the present invention, the fluid is air. Further, in the present invention, the fluid is a cleaning liquid. In the present invention, the fluid is ink. The present invention also provides an inkjet recording head that scans an image forming medium in the Y-axis direction within an image forming range, and ejects a large number of ink droplets from the nozzles of the recording head to the image forming medium in a controllable manner. In an ink-jet printer that conveys images in an X-axis direction on an image forming medium, a wiping device having a wiper movable in a direction parallel to a longitudinal direction of a bottom surface of the recording head is provided outside an image forming area, At a predetermined timing, the print head is moved to the area where the wiping device is arranged, and the wiper is scanned along the nozzles of the print head to wipe out substantially the entire area of the nozzles while discharging fluid from the nozzles of the print head. In addition, a liquid splash protection wall for receiving liquid such as ink scattered from the wiper before and after in the scanning direction of the wiper is provided.
The present invention also provides an inkjet recording head that scans an image forming medium in the Y-axis direction within an image forming range, and ejects a large number of ink droplets from the nozzles of the recording head to the image forming medium in a controllable manner. In an ink jet printer that performs image formation on a printing medium by transporting in the X-axis direction, a wiping device including a wiper that is movable in a direction parallel to a longitudinal direction of a bottom surface of the recording head is provided outside an image forming area,
At a predetermined timing, the print head is moved to the area where the wiping device is arranged, and the wiper is scanned along the nozzles of the print head to wipe out substantially the entire area of the nozzles while discharging fluid from the nozzles of the print head. In addition, a liquid scattering protection wall for receiving a liquid such as ink scattered on the wiper is disposed on a side of the wiping portion of the wiper.

[0005]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In FIG.
(22) is a substrate (2) of the inkjet printer (24).
6) Legs (the other is not shown) arranged on the left and right sides, and a board (26) is fixed to the upper end of these legs. The legs (22) and the substrate (26) constitute the body of the inkjet printer (24).

A shaft holder (2) is provided on the upper part of the leg (22).
8) is fixed, and the shaft of the roll paper holder (32) is rotatably and detachably supported on the shaft holder (28). A roll portion (30a) of an image forming medium (30) wound in a roll shape is detachably held by the roll paper holder (32).

A platen (34) is provided on the substrate (26).
(Paper guide plate) is fixed, and near the upstream end of the platen (34), a guide roller (36) extending in the Y-axis direction and having substantially the same length as the width of the drawing medium (30) is arranged. .
The guide roller (36) is disposed above the roll portion (30a) of the roll paper (30), and both ends of the guide roller (36) are rotatably supported on the substrate (26) via a bracket. ing. (38) is a Y-axis rail, which is disposed horizontally above the platen (34),
Both ends are supported on the board (26) via brackets.

A Y-cursor (40) (carriage) is movably mounted on the Y-axis rail (38), and the Y-cursor (40) is a steel belt (42) endlessly stretched between pulleys. Through a Y-axis driving device (not shown) disposed on the substrate (26). A slit is formed in the platen (34) along the Y-axis direction, and a driving roller (44) is disposed in the slit.

Both ends of the driving roller (44) are rotatably supported on a substrate (26) via a bracket, and the driving roller (44) is connected to an X-axis driving device (shown in FIG. 1) provided on the substrate (26). (Omitted). The Y-axis rail (3
8), a pinch roller shaft (46) is attached to the pinch roller shaft (46) so as to be able to move up and down via an elastic mechanism (not shown), and is rotatably fitted to the pinch roller shaft (46).
8) is configured to be able to set one of a state of being separated from the surface of the drive roller (44) and a state of being in elastic contact with the surface horizontally.

A head base (50) is fixed to one side of the Y cursor (40), and four heads for four colors are provided on the head base (50).
Ink jet recording heads (52) each having a nozzle (52a) are attached. The bottom surfaces (52b) of the four rows of recording heads (52) arranged on the same plane are elongated rectangles.
In b), a nozzle (52a) in which a number of ink ejection holes are opened in a line is provided to slightly protrude.

Each of the four rows of recording heads (52) is arranged in parallel with each other at a predetermined interval, and the bottom surface (52b) of each of the recording heads (52) is perpendicular to the Y-axis rail (38). Are arranged at an angle α with respect to.
On the other side of the Y cursor (40), a recording head (5
Sub-tanks (54) for solvent inks of the same number as in 2) for four colors (black K, cyan C, magenta M, yellow Y)
, And a solenoid valve (56) is attached to the upper lid of the sub-tank (54).

Each sub-tank (54) is provided with a sensor for detecting the ink level. The liquid supply surface of the sub-tank (54) corresponds to the recording head (52) such that the ink supply path, that is, the tube (53) between the recording head (52) and the corresponding sub-tank (54) is maintained at a negative pressure. 52) is disposed below the ink discharge port.

Reference numeral (58) denotes a main tank case provided on the substrate (26). The same number of main tanks (60) for four-color solvent ink as the sub-tanks (54) are provided (three are not shown). And a cleaning liquid tank (62) are detachably stored. Each tank (60) (62) is supported by a spring and sensors (136) (138) consisting of limit switches located below each tank (60) (62).
(See FIG. 4) so that the remaining amount of ink is detected.

The main tank (60) and the sub tank (54) are connected via a solenoid valve to a tube cable (12).
It communicates by 2). Reference numeral (64) denotes a supply controller attached to the substrate (26), and the pump (66) and the solenoid valves (68) (70) (72) (74) shown in FIG.
(76) (78) (80) (82) (84) (86)
(88) (90) (92) (94) (96) (98)
(100) and (101), and further, an electronic control circuit for controlling these electronic devices. A controller (not shown) for controlling the XY-axis driving device and the ink ejection of the recording head (52) is attached to the substrate (26) of the printer (24).

(2) The bottom (52) of the recording head (52)
b) A wiping device for cleaning the peripheral portion of the nozzle and the discharge port of the nozzle (52a), wherein the device main body (4) is on a side portion outside the drawing range of the substrate (26) and the recording head (52) It is disposed below the range of movement along the Y-axis rail (38). An elongated rectangular wiper moving passage (6) is opened on the upper surface of the apparatus body (4).

The longitudinal direction of the wiper moving passage (6) has the same angle α with respect to the X-axis as the longitudinal direction of the recording head (52). A liquid storage container (8) is formed below the wiper moving passage (6). A feed screw (10) is rotatably supported in the apparatus main body (4) in parallel with the longitudinal direction of the wiper moving passage (6). One of the feed screws (10) is connected via a gear mechanism to an output shaft of a motor (102) fixed to the apparatus body (4).

The wiper moving passage (6) and the bottom surface (52b) of the recording head (52) are connected to the recording head (52).
Are moved parallel to each other directly above the wiper moving passage (6). As shown in FIG. 6, a wiper holder (12) is disposed in the wiper moving passage (6), and a wiper (14) is attached to the wiper holder (12).
The wiper holder (12) is connected to the carrier (67) via a connector (65). A side hole provided in the carrier (67) is parallel to the feed screw (10), and a pair of guide shafts (69) supported by the apparatus body (4).
(71) is slidably fitted.

The feed screw (10) has a nut member (7
The screw portion of 3) is screwed, and the carrier (67) is connected to the nut member (73). The wiper (14) is made of a rubber plate or other equivalent material, and its upper edge (14a) is slightly higher than the bottom surface (52b) of the recording head (52) and can be engaged with the bottom surface (52b). The longitudinal direction of the upper edge (14a) is set at right angles to the longitudinal direction of the nozzle (52a) of the recording head (52).

In the center of the upper edge portion (14a) of the wiper (14), a relief (75) formed of a triangular recess for avoiding the nozzle (52a) is formed. The escape (7
The shape of 5) is not particularly limited to a triangle, but may be a quadrangle or the like. As shown in FIG. 8, a bottom plate (87) made of a rubber plate is integrally formed on the wiper (14). The bottom plate (87) is located on both sides of the wiper (14) and has ink or the like. Protective walls (89) and (91) for preventing the liquid from scattering are integrally erected.

When the upper edge (14a) of the wiper (14) is in elastic contact with the nozzle (52a) of the recording head (52), the protective walls (89) and (91) are shown in FIG.
As shown in FIG. 2, the print head (52) is configured to surround both sides of the bottom of the print head (52), that is, the side in the scanning direction of the wiper (14). A mounting plate (77) is provided upright on the upper part of the apparatus main body (4) at a position near one end of the wiper moving passage (6), and a wiper cleaner (7) for wiping the wiper is mounted on the mounting plate (77).
9) A shaft body (81) fitted rotatably and detachably.
Is fixed.

In the apparatus main body (4), liquid scattering protection walls (83) (8) are located before and after the wiper moving passage (6).
5) is erected. (106) is a recording head (5)
2) A purge box having a rubber cap (108) for covering a discharge port of the nozzle (52a) and a liquid discharge port (110) alternately, and a side portion of the substrate (26) outside the drawing range. And is arranged in the movement range of the recording head (52), and is configured to be able to move up and down by a motor (112).

Each of the caps (108) and the discharge port (110) of the purge box (106) is connected to a collecting pipe (120) fixed to the substrate (26) via a tube and a solenoid valve.
Connected to (114) is a stirring motor for stirring the ink in the main tank (60), (116) is a waste liquid tank case attached to the leg (22), (1)
18) is a waste liquid tank.

The waste liquid tank (118) is provided with a case (1).
16) supported by a spring stored in the tank (11).
The ink amount is detected by a sensor (134) composed of a limit switch disposed between the bottom of 8) and the upper surface of the case (116).

At the bottom of each main tank (60),
A rotor made of a magnetic material is rotatably supported on a shaft, and the rotor is rotated by driving a motor (114) so that the ink in each main tank (60) is agitated.

Each of the above components and devices is connected by a tube as shown in FIG. The recording head (5
2) is configured so as to be able to move up to just above the purge box (112) outside the drawing range by moving the Y cursor (40) along the Y-axis rail (38).

Next, the operation of this embodiment will be described.
To set the drawing medium (30) on the platen (34), the pinch roller (48) is raised, and the roll (30) is set.
The drawing medium (30) is pulled out from a), inserted between the driving roller (44) and the pinch roller (48) via the guide roller (36), and then the pinch roller (48) is lowered, The pinch roller (48) is brought into elastic contact with the drive roller (44) from above the image forming medium (30).

Thus, the setting of the drawing medium is completed. When the setting of the drawing medium is completed and the printer enters the drawing mode, the controller performs an ink filling operation,
Thereafter, the operation proceeds to the drawing operation. When the drawing is started, the drawing portion of the drawing medium (30) is driven by the driving roller (4).
4) Due to the intermittent rotation in one direction, the sheet is conveyed on the platen (34) in the X-axis direction, that is, the arrow direction (C).

The recording head (52) is driven based on the image information under the control of the controller, and the nozzle (5) is driven.
2a), ink is ejected from the Y cursor (4
0) by reciprocating along the Y-axis rail (38),
The drawing medium (30) is scanned along the Y axis, and the image information developed in the memory of the controller is visualized on the drawing medium (30).

When the piezo element of the recording head (52) discharges ink, the piezo element automatically sucks the ink from the sub tank (54) accordingly. In this case, unless the sub tank (54) is set to a negative pressure, the recording head (52)
Means that ink is sucked too much and the ink flows out. In order to make the sub-tank (52) have a negative pressure, in the present embodiment, the level of the bottom surface of the sub-tank (54) is set lower than the ink ejection port of the recording head (52).

At the start of drawing and during drawing, the wiping operation of the bottom surface of the recording head is performed at a preset time interval. When the controller shifts to the head bottom wiping mode, the Y cursor (40) is moved along the Y-axis rail (38), and the bottom surface (52b) of the foremost recording head (52) in the four rows is moved to the wiper moving passage ( 6) Move directly above
The nozzle (52a) is connected to the upper edge (14a) of the wiper (14).
On the moving path of At this time, since the wiper (14) is previously positioned at one end of the wiper moving passage (6), the recording head (52) does not collide with the wiper (14) and does not collide with the wiper moving passage (6). Can be moved directly above.

Next, the controller drives the motor (102) to rotate the feed shaft (10). Feed screw (1
By the rotation of (0), the nut member (73) moves the feed screw (1
Move along 0). By the movement of the nut member (73), the carrier (67) and the connecting tool (65) move,
The wiper (14) moves from one standby position to the recording head (52) along the wiper moving path (6).

When the wiper (14) reaches the recording head (52), the upper edge (14a) of the wiper (14) collides with the nozzle (52a) of the recording head (52) and the wiper (1).
4) is bent by the elasticity, and the upper edge portion (14a) elastically contacts the nozzle (52a) of the recording head (52).

Further, the wiper (14) serves as a recording head (52).
And moves in the nozzle scanning direction while elastically contacting the nozzle (52a). At this time, the wiper (14) moves while rubbing the nozzle (52a). However, if nothing is blown out from the nozzle (52a), the deposit such as ink around the ink ejection hole of the nozzle (52a) may be removed. The ink is pushed into the ejection hole, and the ink ejection hole is clogged. Therefore, in the present embodiment, during the wiping of the nozzle (52a), air is discharged to the outside from the ink discharge hole of the nozzle (52a) to prevent the attached matter from being pushed into the ink discharge hole.

When injecting air from the nozzle (52a), the pump solenoid valves (68) and (70) are switched to the pressure feeding direction, and the solenoid valve (72) is switched to the air feeding direction. Further, the head air solenoid valves (74) and (88) and the solenoid valve (56) are switched in the air feeding direction. Next, when the pump (66) is driven, air is pressure-fed into the recording head (52), and air is ejected from the nozzle (52a) together with residual ink.

In this embodiment, the nozzle is wiped while jetting air from the nozzle (52a). However, the cleaning liquid may be blown out from the nozzle (52a). To blow out the cleaning liquid from the nozzle (52a),
The pump solenoid valves (68) and (70) are switched to the pumping direction,
The solenoid valves (72), (74) and (76) are switched to the direction of the cleaning liquid tank. Further, the cleaning liquid tank solenoid valve (78) (8
8) Switch the head solenoid valve (56) toward the cleaning liquid tank.

Next, when the pump (66) is driven, the cleaning liquid is pumped into the recording head (52), and the cleaning liquid blows out from the nozzle (52a) together with the ink remaining in the recording head. The nozzle (52a) of the recording head (52) may be wiped while performing idle ejection of ink from the nozzle (52a).

When the wiper (14) scans substantially the entire area of the nozzle (52a) in a state in which air is blown from the nozzle (52a), dust such as thread debris attached to the nozzle (52a) is removed and the wiper (14) is wiped. (14) comes off the recording head (52), moves to the other standby position of the wiper moving passage (6), and the blowing of air stops. At this time, the position of the coupler (65) is detected by the sensor, the motor (102) stops, and the movement of the wiper (14) stops.

The recording head (5) is moved by the wiper (14).
When wiping the nozzle (52a) of 2), the nozzle (52
The ink adhering to a) or the residual ink ejected from the nozzle (52a) scatters in the scanning movement direction of the wiper (14) and in the side of the wiper (14). The ink scattered in the scanning direction of (1) hits the liquid scattering protection wall (83) or (85), and the ink scattered to the side of the wiper (14) hits the protection wall (89) (91). This prevents the ink from being scattered and prevents the ink from being scattered to other parts of the apparatus main body (4) during wiping, and the apparatus main body (4) is not contaminated.

Next, the controller moves the Y cursor (4) along the Y-axis rail (38) by a predetermined amount, and moves the nozzles (52a) of the recording head (52) in the second row to the wiper moving passage (6). Move directly above. Next, the motor (102) is driven in the reverse rotation direction, and the wiper (14) moves in the direction of the original standby position along the wiper moving path (6), and the nozzles of the print head (52) in the second row. The entire area of (52a) is wiped with the upper edge (14a) of the wiper (14) while blowing air, cleaning liquid or ink from the nozzle (52a).

In the manner described above, the wiping of the nozzles (52a) of the recording heads (52) in the third and fourth rows is sequentially performed, and when the wiping operation is completed, the mode is again shifted to the drawing mode. The recording head (5) other than the nozzle (52a) portion
Since the wiping operation of the bottom surface (52b) of 2) is not the gist of the present invention, the description thereof is omitted.

[0041]

Since the present invention is constructed as described above, it is possible to clean the nozzles of the recording head and to improve the printing quality.

[Brief description of the drawings]

FIG. 1 is an external view of a wiping device.

FIG. 2 is an explanatory diagram illustrating a relationship between a recording head and a wiper.

FIG. 3 is an external view of the inkjet printer.

FIG. 4 is an explanatory diagram of piping showing an ink supply system of the ink jet printer.

FIG. 5 is a plan view of the wiping device.

FIG. 6 is a sectional view taken along line DD.

FIG. 7 is a side view of the wiping device.

FIG. 8 is an external view of a wiper.

[Explanation of symbols]

 Reference Signs List 2 Wiping device 4 Device main body 6 Wiper moving passage 8 Liquid storage container 10 Feed screw 12 Wiper holder 14 Wiper 14a Upper edge 22 Leg 24 Inkjet printer 26 Substrate 28 Shaft holder 30 Drawing medium 30a Roll portion 32 Roll paper holder 34 Platen 36 Guide roller 38 Y-axis rail 40 Y cursor 42 Steel belt 44 Drive roller 46 Pinch roller shaft 48 Pinch roller 50 Head base 52 Ink jet recording head 52a Nozzle 52b Bottom surface 53 Tube 54 Sub tank 56 Solenoid valve 58 Main tank case 60 Main tank 62 Cleaning liquid tank 64 Supply controller 65 Connector 66 Solenoid valve 67 Carrier 68 Solenoid valve 69 Guide shaft 70 Solenoid valve 71 Guide shaft 72 Solenoid valve 73 Nut member 74 Solenoid valve 75 relief 76 solenoid valve 77 mounting plate 78 solenoid valve 79 wiper cleaner 80 solenoid valve 81 shaft body 82 solenoid valve 83 liquid splash protection wall 84 solenoid valve 85 liquid splash protection wall 86 solenoid valve 87 bottom plate 88 solenoid valve 89 liquid splash protection wall 90 Solenoid valve 92 Solenoid valve 94 Solenoid valve 96 Solenoid valve 98 Solenoid valve 100 Solenoid valve 101 Solenoid valve 102 Wiper motor 106 Purge box 108 Cap 110 Ink outlet 112 Motor 114 Motor 116 Waste tank case 118 Waste tank 120 Collecting pipe 122 Tube cable 134 Sensor 136 sensor 138 sensor

Claims (6)

[Claims] 1. An ink jet recording head scans a drawing medium in a Y-axis direction, and a large number of ink droplets are controllably ejected from nozzles of the recording head to the drawing medium to convey the drawing medium in the X-axis direction. An ink-jet printer in which an image is formed on an image forming medium by wiping a substantially entire area of a nozzle of the recording head with a wiper at a predetermined timing while discharging fluid from the nozzle. 2. The ink jet printer according to claim 1, wherein the fluid is air. 3. The ink jet printer according to claim 1, wherein the fluid is a cleaning liquid. 4. The ink jet printer according to claim 1, wherein the fluid is ink. 5. An ink jet recording head scans a drawing medium in a drawing range in a Y-axis direction, and a large number of ink droplets are controllably ejected from nozzles of the recording head to the drawing medium. In an ink jet printer that performs printing on a printing medium by being transported in an axial direction, a wiping device having a wiper movable in a direction parallel to a longitudinal direction of a bottom surface of the recording head is provided outside a printing area, and At the timing of, moving the print head to the arrangement area of the wiping device, and while discharging the fluid from the nozzle of the print head, scanning the wiper along the nozzle of the print head to wipe substantially the entire area of the nozzle; An ink characterized in that a liquid splash protection wall for receiving a liquid such as ink scattered from the wiper before and after the scanning direction of the wiper is provided. Jet printer. 6. An ink jet recording head scans the image forming medium in the Y axis direction within the image forming range, and ejects a large number of ink droplets from the nozzles of the recording head to the image forming medium in a controllable manner. In an ink jet printer that performs printing on a printing medium by being transported in an axial direction, a wiping device having a wiper movable in a direction parallel to a longitudinal direction of a bottom surface of the recording head is provided outside a printing area, and At the timing of, moving the print head to the arrangement area of the wiping device, and while discharging the fluid from the nozzle of the print head, scanning the wiper along the nozzle of the print head to wipe substantially the entire area of the nozzle; It is characterized in that a liquid splash protection wall for receiving a liquid such as ink splashing on the wiper is disposed on a side of the wiper wiping work portion. Inkjet printer.