JP2001030515A - Cleaner in ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clean the ink passage in a recording head and the ink passage communicating with the recording head effectively such that no ink is left on the pipe wall of the ink passage after cleaning. SOLUTION: A recording head 52 is coupled with a solenoid value 56 through a tube 53 and air, ink or cleaning liquid is supplied selectively to the tube 53 through the solenoid value 56. At the time of writing, the recording head 52 ejects a large number of ink drops controllably from nozzles to a writing medium within a writing range. At the time of internal cleaning of the recording head 52, air and cleaning liquid are pressure supplied alternately to the recording head 52 through the solenoid value 56 on the outside of the writing range. Consequently, residual ink in the tube 53 and the recording head 52 is discharged to a discharging outlet 110 from the nozzles of the recording head 52 along with air and cleaning liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a cleaning apparatus for cleaning the inside of a recording head and a tube connected to the recording head in an ink jet printer.

[0002]

2. Description of the Related Art In an ink-jet printer, when cleaning the inside of a recording head and the inside of a tube connected to the recording head, a cleaning liquid is fed to the tube under pressure, and the cleaning liquid passes through the inside of the recording head from an ink discharge hole of a nozzle to a purge box. Discharged to outlet.

[0003]

When the cleaning liquid flows through the tube, as shown in FIG. 5 (A), the cleaning liquid flows quickly at the center of the tube (4), and flows on the inner wall surface of the tube (4). The flow is slow in the near part. Therefore, a lump of the ink (6) remains on the inner wall surface of the tube (4) without flowing, and as shown in FIG. 5B, even if the cleaning liquid (8) is flown, the mass of the ink (6) increases, (4) There is a problem that the inside of the recording head is clogged. An object of the present invention is to solve the above problems.

[0004]

In order to achieve the above object, the present invention relates to an ink jet printer which performs controllable ejection of a large number of ink droplets from nozzles of a recording head onto an image forming medium to perform image formation on the image forming medium. The head is connected to an electromagnetic valve via a tube, so that air, ink, and a cleaning liquid are selectively supplied to the tube through the electromagnetic valve. The air and the cleaning liquid are alternately pumped through an electromagnetic valve. Further, in the present invention, the air and the cleaning liquid are alternately and repeatedly pumped for about 5 seconds for about 10 times.

[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 of the four rows of recording heads (52), which are arranged on the same plane, are elongated rectangles. On the bottom surface, nozzles having a large number of ink ejection holes opened in a row are provided so as to protrude slightly. ing.

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)
The three-way 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 control box attached to the substrate (26), and the pump (66) and the solenoid valves (68) (70) (72) (7) shown in FIG.
4) (76) (78) (80) (82) (84) (8)
6) (88) (90) (92) (94) (96) (9)
8) Built-in (100) and (101), and further provided with an electronic control circuit for controlling these electronic devices. A controller (not shown) for controlling the XY-axis driving device and the recording head (52) is attached to the substrate (26) of the printer (24).

Reference numeral (2) denotes a wiping device for cleaning the peripheral portion of the nozzle on the bottom surface of the recording head (52) and the discharge port of the nozzle, and is configured to be driven by a wiper motor (102) (see FIG. 4). ing. (106)
A rubber cap (108) for covering the discharge port of the nozzle (52a) of the recording head (52); and a liquid discharge port (11).
0) alternately with the substrate (2).
6), which is arranged on the side portion outside the drawing range and in the moving range of the recording head (52), and is configured to be able to move up and down by a motor (112) (see FIG. 4).

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) (see FIG. 4) 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.

The above components and devices are connected by tubes 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).

When the drawing operation is completed, the sub tank (5
In 4), it is determined based on the signal of the sensor whether or not there is ink, and when it is determined that there is no ink, the operation shifts to an ink supply operation. After ink replenishment, or when it is determined that there is ink, it is determined whether or not a predetermined time has elapsed since printing, and if affirmative, the process proceeds to the cleaning operation. After the cleaning or when the predetermined time has not elapsed after printing, it is determined whether or not the predetermined time has elapsed in the drawing end or in the standby state, and if the determination is negative, the process returns to the drawing operation. If the determination is affirmative, the operation sequentially proceeds to the ink recovery operation and the head cleaning operation.

Next, the head cleaning operation will be described with reference to the flowchart of FIG. First, it is determined whether there is a remaining amount in the cleaning liquid tank (62) based on a signal from the sensor (138). If there is no remaining amount, an error message is displayed by displaying that there is no remaining amount in the cleaning liquid tank on the display unit. .

If it is determined that there is a remaining amount, the recording head (52) is connected to the discharge port (11) of the purge box (106).
Move to just above 0). Next, the pump solenoid valve (68) (7
0) is switched to the pumping direction. Next, in the head cleaning operation, the cleaning liquid tank (62) is pressurized with air for 60 seconds so that the pressure of the cleaning liquid is instantaneously sent (step 1). This pressurizing operation is performed with the solenoid valve (72) between the pump and the main tank closed with the solenoid valve (78) closed.
(74) (76) is switched to the cleaning liquid tank direction, the pump (66) is driven, and air is fed into the cleaning liquid tank (62).

Next, the controller switches the head air solenoid valves (74) and (88) in the air feeding direction, switches the head solenoid valve (56) in the air feeding direction, drives the pump (66), and drives the recording head (52). ) Is supplied with air for 20 seconds. Thereby, the three-way solenoid valve (56)
Ink from the nozzle to the recording head (52) is extruded by air, and is discarded from the nozzle to the discharge port (110). Next, the controller switches the electromagnetic valves (74) and (76) toward the cleaning liquid tank, switches the cleaning liquid tank electromagnetic valves (78) and (88) and the head electromagnetic valve (56) toward the cleaning liquid tank, and drives the pump (66). Then, the cleaning liquid is pressure-fed to the recording head (52) for 20 seconds to wash the inside of the recording head (52) with the cleaning liquid (step 3).

Next, the controller operates the recording head (52).
Air for 30 seconds, and as shown in FIG. 1, a tube (53) between the three-way solenoid valve (56) and the nozzle of the recording head (52), a filter, and a lump of cleaning liquid in the recording head (52) ( Extrude 10) with a lump of air (12). Next, the controller moves the recording head (52) immediately above the wiping device (2) to perform wiping of the bottom of the recording head (52), that is, wiping operation (step 5). Next, the controller pumps the cleaning liquid to the recording head (52) for 20 seconds, and fills the recording head (52) with the cleaning liquid (step 6).

Next, the controller operates the waste liquid tank (11).
8) is set to a negative pressure for 5 seconds to collect the liquid accumulated in the collecting pipe (120) (Step 7). Next, the controller releases the cleaning liquid tank (62) to the atmosphere and sets the cleaning liquid tank (6).
Release the pressure in 2). In the above embodiment, as shown in FIG. 1, a lump of air (12) and a lump of cleaning liquid (10)
Are alternately sent to the ink passage between the three-way solenoid valve (56) and the recording head (52), and a mass of the cleaning liquid (10) flows at a high speed through the portion near the tube wall of the ink passage. The residual ink on the walls is effectively washed away by the cleaning liquid.

In the above embodiment, the air and the cleaning liquid are alternately pumped twice at intervals of 20 seconds or 30 seconds. However, in another embodiment, the air and the cleaning liquid are alternately pumped every 5 seconds. About 3 times
The residual ink in the ink passage between the one-way solenoid valve (56) 8 and the recording head (52) can be discharged more effectively.

[0031]

According to the present invention, the ink passage including the inside of the recording head can be effectively cleaned.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is a flowchart for explaining the operation of the present invention.

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 an explanatory diagram of a conventional technique.

[Explanation of symbols]

 2 Wiping device 4 Tube 6 Ink 8 Cleaning liquid 10 Cleaning liquid lump 12 Air lump 22 Legs 24 Inkjet printer 26 Substrate 28 Shaft holder 30 Drawing medium 30a Roll unit 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 53 tube 54 sub tank 56 electromagnetic valve 58 main tank case 60 main tank 62 cleaning liquid tank 64 supply controller 66 electromagnetic valve 68 electromagnetic valve 70 electromagnetic Valve 72 solenoid valve 74 solenoid valve 76 solenoid valve 78 solenoid valve 80 solenoid valve 82 solenoid valve 84 solenoid valve 86 solenoid valve 88 solenoid valve 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 discharge port 112 motor 114 motor 116 waste liquid tank case 118 waste liquid tank 120 collecting pipe 122 tube cable 134 sensor 136 sensor 138 sensor

Claims (2)

[Claims] 1. An ink jet printer for ejecting a large number of ink droplets from a nozzle of a recording head to an image forming medium in a controllable manner to form an image on the image forming medium, wherein the recording head is connected to an electromagnetic valve via a tube, and is connected through an electromagnetic valve. Air, ink and a cleaning liquid are selectively supplied to the tube, and when cleaning the inside of the recording head, the air and the cleaning liquid are alternately pressure-fed to the recording head through the electromagnetic valve. A washing device characterized by the above-mentioned. 2. The method according to claim 1, wherein the pressure of the air and the pressure of the cleaning liquid are 5
2. The cleaning apparatus according to claim 1, wherein the cleaning is performed alternately about ten times every second.