JP2003182104A - Ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ink jet recorder in which ink can be supplied smoothly to a recording head while preventing leakage of ink therefrom. <P>SOLUTION: A Y-cursor is fixed movably to a Y-axis rail laid on the machine body and an ink jet type recording head is fixed to the Y-cursor. A subtank is fixed to the Y-cursor side at a position higher than the recording head and ink is supplied naturally from the subtank to the recording head through an ink supply path according to the level difference. The subtank is coupled with a main tank disposed on the machine body side through a pump. An imaging medium is fed in the X-axis direction while being pinched by means of a drive roller and a pinch roller. Imaging is effected by ejecting ink from the recording head to the imaging medium. Interior of the subtank is coupled with a negative pressure air pump and constantly kept at a negative pressure level suitable for blocking leakage of ink from the recording head. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus in which a sub head tank for ink is mounted on a recording head side and a main tank for ink is provided on a machine side.

[0002]

2. Description of the Related Art JP-A-10-6521 and JP-A-1
No. 0-86395 gazette, the subhead tank for ink is mounted on the recording head side, the main tank for ink is mounted on the machine side, ink is supplied from the main tank to the subtank, and the ink is supplied from the subtank to the recording head. There is disclosed an inkjet recording apparatus that supplies ink and ejects ink from a recording head to form an image on a sheet.

[0003]

If there is a sub-tank on the side of the Y cursor, that is, the recording head, ink can be charged in this sub-tank once, so that there is an advantage that ink supply control to the recording head becomes easy. However, in order for the ink to be smoothly supplied between the sub-tank and the recording head, there is a problem that the mounting positional relationship between them is required to be highly accurate, and the assembling work thereof is not easy. That is, if the position of the recording head is too high with respect to the liquid surface of the ink in the sub tank, the ink cannot be supplied to the recording head portion. Moreover, in order to attach the sub-tank to a position lower than the recording head, the degree of freedom in design is restricted. In addition to the Y-cursor for the recording head, a Y-carriage dedicated to the sub-tank is provided, or a Y-cursor for mounting the recording head is installed. , It is necessary to attach the sub-tank on the side opposite to the recording head attachment side so that it is lower than the recording head. In both cases, the mechanism becomes complicated and highly accurate adjustment of the height positional relationship between the recording head and the sub-tank is possible. There was a problem that it was necessary and costly. If the sub-tank can be arranged above the recording head, the above problem can be solved, but if the sub-tank is arranged above the recording head, the ink in the sub-tank will flow into the recording head by spontaneous fall and the ink will leak from the recording head. Dots occur. The present invention aims to solve the above problems.

[0004]

In order to achieve the above object, the present invention movably attaches a Y cursor (26) to a Y-axis rail (24) installed on an airframe and attaches it to the Y cursor (26). Inkjet type recording head (36)
The sub-tank (38) on the Y cursor (26) side at a position higher than the recording head (36), and ink is supplied from the sub-tank (38) to the recording head (36) via an ink supply path. A pump (48) for supplying ink to a main tank (46) which is configured to be supplied and has the sub-tank (38) disposed on the machine side.
The recording head (3) is connected to an image forming medium which is in communication with each other via a drive roller (30) and a pinch roller (34).
In an ink jet recording apparatus configured to discharge ink from 6) to perform drawing, the inside of the sub tank (38) is connected to a negative pressure air pump (62), and the inside of the sub tank (38) from the recording head (36). The negative pressure suitable for preventing the ink leakage is always maintained. Further, according to the present invention, the sub-tank (38) is provided with a remaining amount detection sensor (83), and when the amount of ink in the sub-tank (38) becomes a predetermined amount or less, the ink supply pump (48) is driven, The ink in the main tank (46) is supplied to the sub tank (38) while the sub tank (38) is kept at a negative pressure, and the ink is replenished in the sub tank (38) without stopping the image forming operation. Is done automatically. Further, the present invention is
An air chamber (64) is provided in the air suction path of the negative pressure air pump (62), and the air chamber (6
By the air buffer of 4), the negative pressure air pump (6
The pressure fluctuation of 2) is absorbed. The present invention also provides a pressure gauge (70) and a speed controller (72) in the air suction path of the negative pressure air pump (62).
When the negative pressure in the air suction path increases, the speed controller (72) responds to the increase in the negative pressure.
External air is introduced to maintain the negative pressure in the air suction path constant.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The structure of the present invention will be described in detail below with reference to the accompanying drawings. In FIG. 2, (2) is a platen composed of a metal plate, which is fixedly mounted on a machine body (not shown) supported by a leg body (not shown) of the inkjet recording apparatus. On the rear side of the lower part of the leg,
A pair of bearing members (6) in which both end shaft portions (4a) of the roll paper supply scroller (4) to which the roll portion of the roll paper (102) is mounted are rotatably arranged on the left and right of the leg respectively.
(8) Placed on top.

Further, on the lower front side of the leg body, a pair of bearing members (12) (wherein both end shaft portions (10a) of the roll paper winding scroller (10) are rotatably arranged on the left and right sides of the leg body, respectively. 14). The pair of bearing members (12) and (14) are rotatably supported by legs, respectively, and one bearing member (12) is connected to an output shaft of a roll paper winding motor (16) and the other bearing member. An input shaft of an encoder (18) for detecting the rotational movement of the bearing member (14) is connected to (14).

A paper guide (20) is arranged behind the platen (2), and a guide roller (22) extending in the direction perpendicular to the paper surface, that is, the Y-axis direction in FIG. 2 is arranged behind the paper guide (20). ) Is arranged and the guide roller (22)
Is rotatably supported by the airframe. Reference numeral (24) is a Y-axis rail, which is horizontally arranged above the platen (2) and has both ends fixed to the machine body via brackets. A Y cursor (26) is attached to the Y-axis rail (24).
A (carriage) is movably attached, and the Y cursor (26) is linked to a Y-axis drive device (28) arranged on the body via an endless steel belt connected to a Y-axis drive motor. ing.

The platen (2) and the paper guide (20)
A slit is formed along the Y-axis direction between and, and the drive roller (30) is arranged in the slit. Both ends of the drive roller (30) are linked via brackets to an X-axis drive device (32) arranged on the machine body. Said Y
A pinch roller shaft is attached to the shaft rail (24) so as to be able to move up and down via an elastic mechanism (not shown), and the pinch roller (34) is rotatably fitted to the pinch roller shaft.
Is configured so that it can be set to either a state in which it is separated from the surface of the drive roller (30) or a state in which it is in horizontal contact with the surface.

A head base is fixedly provided on one side of the Y cursor (26), and an ink jet recording head (36) having a large number of four nozzles prepared for each ink color is attached to the head base. Has been. In the drawings, only one recording head is shown and the other recording heads are omitted. A sub-tank (38) for solvent ink of four colors (black K, cyan C, magenta M, and yellow Y), which is the same number as the recording head (26), is attached above the Y cursor (26). In the drawing, only one sub tank is shown and other sub tanks are omitted.

As shown in FIG. 1, a manual valve (40) is attached to each sub-tank (38) on the substrate supporting the recording head (36). Each sub-tank (38) is connected to the corresponding recording head (36) by a tube (42), and the ink discharge port (44) of each sub-tank (38) is more than the ink receiving port of the corresponding recording head (36). It is set to the upper side, and due to this height difference, the sub-tank (3
The ink is supplied from 8) by free fall.

Reference numeral (46) denotes four ink main tanks containing four color solvent inks, which are removably arranged in a tank storage case provided on the leg side. still,
In the drawing, only one main ink tank is shown, and the other main ink tanks are omitted. Each ink main tank (46) is connected to a corresponding sub tank (38) by a tube via a diaphragm pump (48), a filter (50) and a manual valve (40).

(52) is a cleaning liquid (jet wash)
It is a main tank for cleaning in which is installed, and is detachably arranged in a tank storage case provided on the leg side.
The main cleaning tank (52) is connected to each sub tank (38) by a tube via a diaphragm pump (54), a filter (56), a branch tube, and a manual valve (40). The diaphragm pump (4
8) In the bypass passages of (54), the safety valve (5
8) (60) is provided. (62) is a negative pressure air pump, which is provided in the machine body. The negative pressure air pump (62) is connected to each sub tank (38) by a tube via an air chamber (64), a two-way solenoid valve (66), a manifold (68), a branch tube, and a three-way solenoid valve (69). is doing.

A pressure gauge (70) and a speed controller (7) are provided in the air suction path of the negative pressure air pump (62).
2) is attached. The pressure gauge (70) and the speed controller (speed control valve) (72) are provided to control the negative pressure in the sub tank (38) with high accuracy. When the negative pressure in the sub-tank (38) is held in a high state, there is a possibility that the high negative pressure state may be maintained as it is because the air suction path is closed to the outside air. . In order to prevent such a state, the speed controller (72) is used in this embodiment.
Is provided. This speed controller (72)
As a result, a mechanism in which air slightly flows into the air suction path from the outside is configured in the middle of the path, which enables highly accurate control of negative pressure.

Reference numeral (74) is a positive pressure air pump which is arranged in the machine body. The positive pressure air pump (74) includes a regulator (76), a filter (78), and a manifold (8).
0), a branch tube, and a three-way solenoid valve (69) to connect to the corresponding sub-tanks (38) by tubes. The sub-tank (38) is provided with a sensor (83) for detecting the remaining amount of ink. The winding motor (16) and the pumps (48) (58) (62) (7)
4) is a controller (82) via respective drivers
And a speed controller (72), solenoid valves (66) (69), XY drive devices (32) (28),
The recording head (36) and other various electronic devices and devices are
As shown in FIG. 3, it is configured to be connected to and controlled by the controller (82).

In the figure, (86) is a recording head heating heater, (84) is a sub tank heating heater, (88) is a tube heating heater, (90) is a platen heating heater, and (92) is each recording. A temperature sensor provided in the head (36) and a temperature sensor (94) provided in the sub tank (38). Next, the operation of this embodiment will be described. In order to set the feeding part of the roll paper (102) on the platen (2), the pinch roller (34) is raised and the roll paper of the roll paper set on the supply scroller (4) is rolled (102). Then, it is passed through the platen (2) and inserted between the drive roller (30) and the pinch roller (34), and then the pinch roller (34) is lowered to move the pinch roller (34) to the roll paper ( The drive roller (30) is elastically contacted from above the (102).
As a result, the drive roller (30) and the pinch roller (3
4) and the drawing medium is gripped, and the setting of the drawing medium is completed.

A first ink initial filling operation is performed by the controller (82). At the time of initial filling of this ink,
The recording head (36) returns to the home position, and the negative pressure air pump (62) is turned on. Since the main tank (46) is located lower than the sub tank (38), the ink in the main tank (46) is pumped (48).
Then, the sub tank (38) is filled through the filter (50). When the filter (50) is clogged, the safety valve (58) works when the inside of the tube on the downstream side of the diaphragm pump (48) reaches a predetermined pressure, and returns the ink to the main tank (46) when the pressure becomes constant. It has a structure that prevents liquid leakage.

When ink is supplied to the sub-tank (38), the pressure in the sub-tank (38) becomes high. Therefore, in order to release this pressure, the negative pressure air pump (62).
Is normally up. When the sub tank (38) is filled with the ink, the controller first starts the three-way solenoid valve (6
9) is switched from the negative pressure side to the positive pressure side, and the positive pressure air pump (74) is driven.

As a result, a positive pressure is supplied from the positive pressure air pump (74) to the sub tank (38), and the corresponding recording head (36) is filled with ink from the sub tank (38). When the recording head (36) is initially filled with ink, the positive pressure air pump (74) is stopped, the three-way solenoid valve (69) is switched to the negative pressure side, and the two-way solenoid valve (66) is opened. The air suction path of the negative pressure air pump (62) is opened, and the inside of each sub tank (38) is maintained at a negative pressure. As described above, in the normal state, the inside of the sub tank (38) is kept at a negative pressure by the negative pressure air pump (62), so that the ink does not drip, that is, does not leak from the recording head (36).

If the negative pressure in the sub-tank (38) is too high, the ink will not be supplied to the recording head (36), so that the negative pressure will flow from the sub-tank (38) to the recording head in the ink supply path (42). It is kept to the extent that ink is naturally supplied via the. Specifically, the negative pressure state is properly managed by the pressure gauge (70), and control is performed so that a constant negative pressure is obtained. Further, since the value of the negative pressure air pump (62) varies slightly, an air buffer portion is provided by the air chamber (64), and the buffer action of pressure fluctuation is performed here.

When the printer shifts to the drawing operation, the feeding portion of the roll paper (102) is conveyed in the X-axis direction on the platen (2) by the intermittent rotation of the drive roller (30) in one direction. The recording head (36) is driven based on the image information under the control of the controller, ejects ink, and also the Y-axis rail (2) of the Y cursor (26).
By the reciprocating movement along 4), the feeding part of the roll paper (102) is scanned along the Y axis, and the image information developed in the memory of the controller is visualized on the roll paper (102) surface.

When the piezo element of the recording head (36) ejects ink, the ink is automatically sucked from the sub tank (38) correspondingly. While the drawing operation is being performed, the ink in the sub tank (38) is running low. In this case, the pressure in the sub tank (38) becomes low. In such a state, the speed controller (72) works to prevent a slight amount of air from flowing into the ink suction path and prevent the pressure in the sub-tank (38) from lowering more than necessary. Ink is supplied to (36) smoothly.

During the image forming operation, when the remaining amount detection sensor (82) senses that the ink in the sub tank (38) has run out, the diaphragm pump (48) is driven and ink is ejected from the main tank (46) into the sub tank (38). ) Is filled through the filter (50). At this time, the pressure in the sub-tank (38) rises due to the supply of ink, but the negative pressure air pump (6) is placed in each sub-tank (38).
Since the negative pressure of 2) is acting, this pressure increase is immediately resolved and no problem occurs. Since the ink replenishing operation to the sub tank (38) can be performed during the printing operation, it is not necessary to interrupt the printing operation, and the printing operation can be efficiently performed.

When the printer device is not used for a while, the sub tank (38) and the recording head (36) are cleaned. In this case, the controller displays the Y cursor (2
6) is driven along the Y-axis rail (24) in a direction out of the drawing range to move the recording head (36) to a predetermined home position. Next, the controller turns off the negative pressure air pump (62), switches the three-way solenoid valve (69) to the positive pressure side, shuts off the air suction path, and then first drives the positive pressure air pump (74). The positive pressure air pressurizes the inside of the sub tank (38) to completely remove the ink in the sub tank (38) and the recording head (36).
Discharge by jet jet from the nozzle of 6).

At this time, the manual valve (40) is switched to the cleaning tank side. Next, the diaphragm pump (5
4) is driven to fill the sub tank (38) with the washing water in the washing main tank (52) through the filter (56), and the inside of the sub tank (38) is washed by the positive pressure air pump (74). Push the water to the recording head (36),
Cleaning water is discharged from the nozzle of the recording head (36) as a jet jet. Sub tank (38) and recording head (3
After draining wash water from 6), positive pressure air pump (74)
Then, air is sent into the sub tank (38) and the recording head (36), and the sub tank (38) and the recording head (3) are
6) Dry the inside.

As is apparent from the above description, in the present embodiment, the air pump (6) is constantly provided in the sub tank (38).
2) By applying a negative pressure from the sub tank (38)
The inside of the recording head (36) is set to be lower than the atmospheric pressure so that ink does not drop from the recording head (36). In addition, by constantly controlling the negative pressure to be slightly lower than the atmospheric pressure, it is possible to reliably supply and control the ink to the recording head (36). Moreover, since the speed controller (72) is arranged closer to the negative pressure air pump (62) than the two-way solenoid valve (66), the two-way solenoid valve (66) is provided even when the power of the device is turned off. By keeping the closed state,
There is no risk of air flowing into the sub tank (38),
The negative pressure in the sub tank (38) is maintained as it is, and ink does not drop from the recording head (36).

[0026]

As described above, according to the present invention, since the sub-tank is arranged above the recording head and the ink is supplied to the recording head by the head difference, the ink can be smoothly supplied to the recording head. In addition, since the negative pressure is constantly applied to the sub tank, it is possible to prevent the ink from dripping from the recording head.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a side view of the recording apparatus.

FIG. 3 is a functional block diagram of a recording device.

[Explanation of symbols]

2 Platen 4 Roll paper supply scroller 6 Bearing members 8 Bearing members 10 Roll paper winding scroller 12 Bearing member 14 Bearing member 16 winding motor 18 encoder 20 Paper guide 22 Guide roller 24 Y-axis rail 26 Y cursor 28 Y-axis drive 30 drive roller 32 X-axis drive 34 pinch roller 36 recording head 38 Sub tank 40 Manual valve 42 ink supply path 44 Ink outlet 46 Ink main tank 48 diaphragm pump 50 filters 52 Main tank for cleaning 54 Diaphragm pump 56 filters 58 Safety valve 60 safety valve 62 Negative pressure air pump 64 air chamber 66 two-way solenoid valve 68 manifold 70 Pressure gauge 72 Speed controller 74 Positive pressure air pump 76 regulator 78 filters 80 manifold 82 controller 83 Remaining amount detection sensor 84 heater 86 heater 88 heater 90 heater 92 Temperature sensor 94 Temperature sensor 102 roll paper

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C056 EA26 EB21 EB34 EB50 EC20                       EC32 FA04 KB04 KB10 KB37                       KB40 KC15 KC17 KD08

Claims (4)

[Claims] 1. A Y-axis rail (24) installed on the body of the aircraft
A cursor (26) is movably attached, an ink jet type recording head (36) is attached to the Y cursor (26), and a sub tank (3) is attached to the Y cursor (26) side.
8) is attached to a position higher than the recording head (36), and the recording head (3) is moved from the sub tank (38).
Ink is supplied to 6) via an ink supply path, and the sub-tank (38) communicates with a main tank (46) arranged on the machine side via an ink supply pump (48). , Drive roller (30) and pinch roller (3
4) In an ink jet recording apparatus in which ink is ejected from the recording head (36) to an image forming medium sandwiched between the sub tank (38) and a negative pressure air pump (62), Sub tank (38)
An ink jet recording apparatus characterized in that the inside is always kept at a negative pressure suitable for preventing ink leakage from the recording head (36). 2. A sub-tank (38) is provided with a remaining amount detection sensor (83), and when the amount of ink in the sub-tank (38) is below a predetermined amount, the ink supply pump (48).
The sub tank (38) is maintained at a negative pressure by supplying the ink in the main tank (46) to the sub tank (38), and the sub tank (38) is supplied without stopping the image forming operation. The ink jet recording apparatus according to claim 1, wherein ink is replenished automatically. 3. An air chamber (64) is provided in the air suction path of the negative pressure air pump (62), and the pressure fluctuation of the negative pressure air pump (62) is absorbed by buffering the air in the air chamber (64). The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is configured to do so. 4. A pressure gauge (70) and a speed controller (7) in the air suction path of the negative pressure air pump (62).
2) is provided, and when the negative pressure in the air suction path increases, the speed controller (7
2. The ink jet recording apparatus according to claim 1, wherein external air is introduced from 2) to keep the negative pressure in the air suction path constant.