JPH05238015A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To prevent formation of defective images arising from such malfunctions as slippage in positions of inking, defective ejection of ink drops, ejections in disordered directions and mixing of colors. CONSTITUTION:A cleaning means 100 is composed of ink absorption members 47a, 47b, 47c and 47d, corresponding respectively to recording heads 2a, 2b, 2c and 2d, and an ink absorption frame 48. Each of the ink absorption members 47a, 47b, 47c and 47d is fixed independently to the ink absorption frame 48. The ink absorption frame 48 is mounted to a shaft 49, fixed to a support plate 50, so that the frame can rotate round the shaft. A helical coil spring 51 is a device that energizes the ink absorption frame 48 to rotate in the direction A, and a bent part 50A of the support plate 50 and a projection 48A of the ink absorption frame 48 work as stoppers, and thereby positioning of the ink absorption frame 48 can be made.

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 such as a copying machine, a facsimile or a printer, which has a plurality of recording heads having ejection openings for ejecting ink.

[0002]

2. Description of the Related Art An ink jet recording apparatus ejects and ejects a small droplet of ink from an ejection port of a recording head.
It is configured to be attached to a recording medium (recording paper) such as paper or plastic for recording. Further, in the ink jet recording apparatus, since the ink is directly ejected from the ejection port of the recording head to perform the recording, a technique for constantly ejecting the ink normally is required.

For example, when the recording head is used to eject and fly the ink as described above to continue the recording operation, as shown in FIGS. 17 and 18, an ink droplet 81 is formed in each liquid path 10 of the recording head 90. When ejected from the, countless satellite-like minute ink mist (fog-like ink) 82,
Adheres and accumulates on the surface of the ejection port surface 91 of the recording head 90,
When the adhered amount further increases, it grows into a large ink droplet 83 and spreads to the ink ejection port of the ejection port surface 91 of the recording head 90, hinders the ejection of the ink liquid from each liquid path 10 of the recording head 90, or Recording paper 6 attached to paper 6
There was a problem such as soiling.

Therefore, as a conventional technique, in order to solve the problem caused by the minute ink mist 82 generated when the ink droplet 81 is ejected from the recording head 90, the ejection port surface 91 of the recording head 90 is solved. An air suction device (not shown) is provided in the vicinity to suck the minute ink mist 82, or a rubber blade (not shown) is periodically brought into pressure contact with the ejection port surface 91 of the recording head 90. For example, a method of scraping off the minute ink droplets 83 is used.

In addition, at present, an ink jet recording apparatus of a type that discharges ink from a recording head to perform recording is such that the recording head is reciprocally scanned (main scanning) on the recording sheet while intermittently conveying (step feeding) the recording sheet. The so-called serial type in which an image is formed by scanning) is the mainstream. In this method, the length of the nozzle array of the print head (print width of one scan) has a great influence on the print time, and the time can be shortened as the length of the head increases.

However, in making a recording head, the longer it is, the more difficult it is in terms of accuracy or performance. Even if such a recording head is formed, if nozzles are defective during operation, such as clogging, even if the number is small, all nozzles will be replaced at once. There is a point. Furthermore, the stability and reliability of the recording head are also major issues. On the other hand, a shorter recording head is easier to manufacture and has higher reliability. Further, there is an advantage that there is little waste when replacing the recording head, and the cost is easy for the user.

In view of the above, as a method for shortening the recording time while preventing the cost increase or the reliability deterioration of the recording head, a method of arranging a plurality of recording heads having short nozzle lengths in series is considered as shown in FIG. Be done. Specifically, for example, in FIG. 19, the recording head 101
Four A, 101B, 101C and 101D are arranged in the head holder 102 in a zigzag pattern. In this way, the recording areas of the recording heads 101A, 101B, 101C, and 101D can be connected without a gap, and can be regarded as a long head having a width four times as large as one head as a whole.

[0008]

Generally, a general ink jet recording apparatus performs the following operation in order to prevent deterioration of recording performance of the recording head.

(A) In order to prevent evaporation of ink from inside the nozzles when not in operation, the recording head is sealed by a capping device at the home position (capping operation).

(B) Before the image recording is started, a pressure is applied to the ink in the recording head by using a pump in order to discharge air bubbles and dust in the nozzle, and the ink is forcibly discharged from the nozzle (pressurization). Recovery operation).

(C) A part of the ink ejected during the recording operation becomes mist and adheres to the nozzle surface, and if it collects, it may adversely affect the subsequent ink ejection. Therefore, in order to prevent this, a rubber-like blade is arranged at a position facing the recording head immediately before the recording unit or immediately after the recording unit, and the nozzle surface is brought into contact with each nozzle for cleaning (wiping) (blade cleaning). motion).

Of these, especially (C) is an important operation for maintaining stable ejection of ink during the recording operation. In addition, it may be brought into contact with the surface of the recording head, which requires attention in many points such as the contact state of the blade and the blade material.

In general, the ink jet recording apparatus is a so-called non-impact system in which ink is ejected to record on recording paper. Therefore, its flight distance,
In other words, there is a large relationship between the distance between the recording head and the recording paper and the quality of the recorded image, and the shorter the recording, the higher the image quality (because the accuracy of the ink landing position on the recording paper increases). Therefore, it is necessary for the device to have a configuration in which the above distance is shortened as much as possible, and specifically, several mm or less, preferably 1 mm or less is required. However, on the other hand, if the distance is too short, the surface of the recording head and the paper are likely to come into contact with each other when the paper cannot keep a flat surface due to poor conveyance of the recording paper and waviness occurs. .. As a result, the surface of the recording head may be damaged, the ejection performance of the ink may be deteriorated, and in the worst case, ejection may not occur. Therefore, in order to prevent this, it is usual that the periphery of the nozzle of the recording head is covered with a head holder as much as possible, and the nozzle surface is designed to be retracted slightly inward from the surface of the head holder. Therefore, as shown in FIG. 19, when the cleaning operation is performed by one blade 701 in the configuration of a plurality of recording heads, there is a portion that rides on the holder portion. Therefore, as shown in FIG. There may be a region 104 (shaded portion) where wiping cannot be performed in the vicinity of the holder part.

If ink, dust, or the like remains on the nozzle in this way, the following problems occur. That is, a phenomenon is that the ink droplets ejected from the nozzles are obstructed by the adhered ink and dust to change the flight direction and shift the landing position, or in the worst case, the ejection is completely hindered (non-ejection). As a result, the image quality is remarkably deteriorated and the reliability of the apparatus is impaired.

When the air suction device is used as in the conventional example shown in FIGS. 17 and 18, not only the satellite-shaped minute ink mist 82 is sucked by the operation of the air suction device, but also the ink is discharged from the discharge port. Ink droplets 81 in flight
However, the influence of the air flow is exerted, and the landing position of the ink droplet 81 on the recording paper is deviated from the original position, so that there is a drawback that a high quality image cannot be obtained. In addition, the noise during operation is large, and the device configuration is complicated.

Next, even when the conventional rubber blade is used, since the rubber blade is pressed against the ejection port surface 91 of the recording head 90, the ejection port surface 91 is damaged and each liquid of the recording head 90 is damaged. The ejection failure (non-ejection) of the ink droplet 81 from the passage 10 or the disturbance of the ejection direction is generated, and the ink droplet 83 attached to the ejection opening surface 91 of the recording head 90 is changed to each liquid of the recording head of another color. The ink is mixed in the recording liquid passage of each recording head by filling the passage 10,
It has the drawback that high quality images cannot be obtained.

An object of the present invention is to absorb minute ink mist adhering to the ink ejection port surface of each recording head by the divided ink absorbing members corresponding to each recording head, and to shift the landing position of ejected ink droplets. An object of the present invention is to provide an inkjet recording apparatus capable of preventing defective ejection (discharging), irregularities in the ejection direction, and image defects such as color mixing.

[0018]

In an ink jet recording apparatus of the present invention, a multi-color recording means in which a plurality of recording heads having ejection openings for ejecting ink are arranged, and the ejection openings are arranged. An inkjet recording apparatus comprising: a cleaning unit that contacts the ejection port surface and cleans the ejection port surface, wherein the cleaning unit is divided corresponding to each recording head.

The cleaning means may be an ink absorbing member or a flexible member.

It is preferable that the cleaning means is supported so as to be movable back and forth toward the recording means.

The recording heads can be arranged in a direction parallel to the arrangement direction of the ejection openings, or can be arranged in a direction orthogonal to the arrangement direction of the ejection openings.

In the recording means, two or more recording heads constitute a plurality of sets of recording head rows, and the cleaning means is
The recording heads may be divided corresponding to each recording head, and a plurality of sets may be arranged corresponding to each recording head row.

The recording means may be mounted on a carriage movable over the maximum recording width of the recording medium, or may be a full line type in which the ejection openings are formed over the maximum recording width of the recording medium. It is possible.

The recording means is provided with an electrothermal converter for generating thermal energy for ejecting ink, and the thermal energy applied by the electrothermal converter utilizes film boiling generated in ink to eject the ink. It is preferable to eject more ink.

[0025]

According to the present invention, since the ejection port surfaces of a plurality of recording heads are cleaned well, the initial image quality does not deteriorate and a highly reliable apparatus can be provided. ..

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

[Embodiment 1] FIG. 1 shows a first embodiment of a serial type ink jet recording apparatus of the present invention.

In FIG. 1, the carriage 1 is equipped with color recording heads 2a, 2b, 2c and 2d corresponding to four colors of cyan, magenta, yellow and black.
The guide shaft 3 movably guides and supports the carriage 1. A part of the belt 4, which is an endless belt, is connected to the carriage 1, and the carriage 1 is
A drive motor 5 which is a pulse motor driven by a motor driver 23 drives the guide shaft 3 via a belt 4 so as to move along a recording surface of a recording paper 6 which is a recording medium such as paper. Further, a conveyance roller 7 that conveys the recording sheet 6 and a guide roller 8 that guides the recording sheet 6
A and 8B and a recording paper transport motor 9 are provided.

Further, the recording heads 2a, 2b, 2c, 2
A liquid path 10 for ejecting ink droplets toward the recording paper 6 is provided in d, and an ink tank 11a corresponding to each recording head 2a, 2b, 2c, 2d is provided for the liquid path 10. Ink is supplied from 11b, 11c, and 11d through supply tubes 12a, 12b, 12c, and 12d, and each head driver 24a is supplied to the ejection energy generating means (not shown) provided in each liquid passage 10.
Flexible cable 13 from 24b, 24c and 24d
Ink ejection signals are selectively supplied via a, 13b, 13c, and 13d.

Further, each recording head 2a, 2b, 2c,
2d includes head heaters 14a, 14b, 14 respectively.
c, 14d (14b, 14c, 14d are not shown) and temperature detecting means 15a, 15b, 15c, 15d are provided, and the temperature detecting means 15a, 15b, 15c, 15d.
A detection signal from the head heater 14a, 1 is input to the control circuit 16 having a CPU based on this signal via the driver 17 and the power supply 18.
Controls heating in 4b, 14c, 14d (14b, 14c, 14d not shown).

The capping means 20 is abutted against the ejection port surface of each of the recording heads 2a, 2b, 2c, 2d during non-recording, and during non-recording, the recording heads 2a, 2b,
2c and 2d move to a position facing the capping means 20. At that time, the capping means 20 is driven forward by the cap driver 25 to bring the elastic member 44 into pressure contact with the ejection port surface to perform capping. The capping means 20 accommodates the solution 46 containing the volatile component in the ink in the closed space 20A, and also incorporates the liquid holding member 45 in which the solution 46 is impregnated. This allows
The space 20A is filled with the volatile vapor of the solution 46 to prevent the volatile components of the ink from evaporating from the ejection ports of the liquid passage 10, and the composition ratio of the ink in the liquid passage 10 is not changed. There is.

The clogging prevention means 31 is used for the recording head 2
The inks a, 2b, 2c and 2d receive the ejected ink when performing the idle ejection operation. This clogging prevention means 31
Is a liquid receiving member 3 as a liquid receiving portion which faces the recording heads 2a, 2b, 2c and 2d and absorbs the ink that has been ejected by the idle.
2 and is arranged between the capping means 20 and the recording start position. As a material of the liquid receiving member 32 and the liquid holding member 45, a sponge-like porous member, a plastic sintered body, or the like is effective.

Further, as shown in the enlarged perspective view of the carriage portion of FIG. 2, the cleaning means 100 includes ink absorbing members 47a, 47b, 47c and 47d respectively corresponding to the recording heads 2a, 2b, 2c and 2d. An ink absorption frame 48 is provided. Ink absorbing members 47a, 47
b, 47c, and 47d are independently fixed to the ink absorbing frame 48. The ink absorption frame 48 is rotatably attached to a shaft 49 fixed to the support plate 50. Torsion coil spring 51
Is for rotating the ink absorbing frame 48 in the A direction, and the bent portion 50A of the support plate 50 and the protruding portion 48A of the ink absorbing frame 48 serve as stoppers to position the ink absorbing frame 48. Has become. Further, the support plate 50 is assembled to a frame (not shown) so as to be adjustable in the B and C directions. The cleaning unit 100 is arranged in the non-sheet passing portion at the print end position.

FIG. 3 is a plan view for explaining the operation of the recording head of this embodiment. The same elements as those shown in FIG. 1 are designated by the same reference numerals, and their explanations are omitted.

In FIG. 3, a recording start detecting sensor 34 and a capping means detecting sensor 36 detect that each of the recording heads 2a, 2b, 2c and 2d is at a predetermined capping position. Empty discharge position detection sensor 35
Detects the reference position of the idle ejection operation performed while the recording heads 2a, 2b, 2c, 2d move in the scanning direction.

Next, the operation of the ink jet recording apparatus will be described below. The cleaning means 100 will be described later.

First, during standby, the recording heads 2a, 2
b, 2c, and 2d are capped by the capping means 20, and when a print signal is input to the control circuit 16, the carriage 1 is driven through the motor driver 23. Next, the blank ejection position detection sensor 35 detects the blank ejection position of the ink for a predetermined time to the clogging prevention means 31,
While traveling in the direction of arrow D from the recording start position detected by the recording start detection sensor 34, the recording heads 2a, 2
The liquid paths 10b, 2c, and 2d are selectively driven. As a result, ink droplets are ejected, and image recording is performed on the recording width portion P of the recording paper 6 in a dot matrix pattern.

After that, as shown in FIG.
a, 2b, 2c and 2d are sent by P1 pulses from the recording start position by the drive motor 5 (FIG. 1), ink droplets are printed on the recording paper 6, and then the carriage 1 is moved to the position of P2 pulses for one scanning. Minute recording ends. After that, the carriage 1 is reversed, driven in the arrow E direction to return to the idle discharge position, the recording paper 6 is conveyed in the arrow F direction by the width of the recording width portion P, and the above-described operation is repeated again.

Next, the material of the ink absorbing members 47a, 47b, 47c and 47d constituting the cleaning means 100 and the operation of the cleaning means 100 will be described.

The ink absorbing members 47a, 47b, 47c,
As the material of 47d, a polymer porous body can be used. When a polymer porous body is used, the volume change due to the absorption of ink mist is not remarkable like a polymer foam, and the ink is A type that does not change in volume upon absorption is preferable, and for example, a foamed formal resin type is preferable.

The ink absorbing member 4 used here is also used.
As 7a, 47b, 47c and 47d, a heat-sintering type polymer porous body can also be used, and examples thereof include low density polyethylene, high density polyethylene, high molecular weight polyethylene, composite polyethylene, polypropylene, polymethylmethacrylate, Polystyrene, acrylonitrile copolymer, ethylene vinyl acetate copolymer, fluororesin,
A heat-sintered body such as a phenol resin can be used, and among them, those using low density polyethylene, high density polyethylene, high molecular weight polyethylene, or polypropylene are preferable from the viewpoint of ink mist absorption and ink resistance. Therefore, in this embodiment, the ink absorbing members 47a, 47b, 47 are used.
Foamed formal resin type was used for c and 47d.

In FIGS. 2, 3, 4, and 5, the carriage 1 is printed with the ink absorbing members 47a, 47b, 47c, 4c after the completion of printing by scanning in the D direction (hereinafter referred to as front scanning).
7d is pressed and driven to generate during printing, and recording head 2
a, 2b, 2c, 2d ejection port surfaces 22a, 22b, 22
The ink mist adhering to the recording member side surface of the head holder 19 is absorbed (FIG. 4). Next, as shown in FIG. 5, the carriage 1 is reversed and the scanning in the E direction (hereinafter, back scanning) is started. Also at this time, the ink absorbing member 4
7a, 47b, 47c, 47d are the recording heads 2a, 2
b, 2c, 2d discharge port surfaces 22a, 22b, 22c, 2
2d is pressed and driven to discharge surface 22a, 22b, 22c,
22d and the ink mist adhering to the head holder 19 are absorbed. In the cleaning operation described above, the support plate 50 can be adjusted and the ink absorbing members 47a, 47 can be adjusted.
b, 47c, and 47d are configured to be positioned (standby) at predetermined positions by the action of the stopper of the ink absorbing frame 48 and the torsion coil spring 51. Further, as shown in FIG. 4, the outer edge dimension J of the ink absorbing members 47a, 47b, 47c, 47d is substantially equal to the recording head interval N of the head holder 19, so that the cleaning operation is
The ink absorbing members 47a, 47b, 47c, 47d are always corresponding recording heads 2a, 2b, 2c, 2d.
Only the discharge port surfaces 22a, 22b, 22c and 22d are pressed and driven for cleaning. In addition, the ink absorbing member 47 at this time
a, 47b, 47c, 47d discharge port surfaces 22a, 22
The pressure contact depth δ (FIG. 5), which is the amount of penetration into b, 22c, and 22d, was set to about 2 mm by adjusting the support plate 50.

The chamfered portion 19A of the head holder 19
Has a shape (FIG. 4) that abuts the protrusion 48B of the ink absorbing frame 48, and the ink absorbing member 47a,
47b, 47c and 47d are the respective recording heads 2a,
The initial positioning is performed so as to be compatible with 2b, 2c, and 2d.

[Embodiment 2] FIGS. 6, 7, 8 and 9
The cleaning means of the second embodiment of the present invention will be described. The same elements as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

The ink absorbing members 60a, 60b, 60c,
60d designates the respective recording heads 2a, 2b, 2c, 2
This corresponds to d and each has a two-layer structure. The portion e has a higher porosity than the portion f and has improved water absorption characteristics, so that the ink absorbed in the portion f is absorbed and accumulated in the portion e.

The support plate 64 has a frame K (not shown),
It is attached so that it can be adjusted in the L direction. The shaft 63 is fixed to the support plate 64, and the ink absorbing members 60a, 6a
An ink absorption frame 61 to which 0b, 60c, and 60d are adhered is rotatably assembled. Tension spring 6
5 has one end attached to a frame (not shown) so that a force acts in the M direction, and the other end attached to the ink absorbing frame 61. During stand-by (non-operation), the bending and raising portion 64 of the support plate 64 is provided.
a serves as a stopper for the ink absorbing frame 61 and positions the ink absorbing frame 61 at a predetermined position.

The chamfered portion 19A of the head holder 19 is shaped so as to abut the protrusion 61A of the ink absorbing frame 61, and the ink absorbing members 60a, 60b, 60.
c and 60d are the respective recording heads 2a, 2b, 2c,
The initial positioning is made so as to be compatible with 2d.
The ink absorbing members 60a, 60b, 60c, 60d
The outer edge dimension J of the f portion is substantially equal to the recording head interval N of the head holder 19 (FIG. 7). Further, the arrangement position of the cleaning means and the configuration of the other ink jet recording apparatus are the same as those in the first embodiment.

Next, the cleaning operation will be described.

In the head holder 19, the chamfered portion 19A comes into contact with the protrusion 61A after printing is completed by front scanning,
The ink absorbing members 60a, 60b, 60c, and 60d are pressed and driven to absorb the ink mist adhering to the ejection port surfaces 22a, 22b, 22c, and 22d and the head holder 19, and the back scan is started after stopping at the position shown in FIG. However, the ink mist is absorbed as in the front scan. During the cleaning operation, the ink absorbing members 60a, 60b, 60c, 6
0d is always the discharge port surface 22a, 22
Only b, 22c and 22d are pressed and driven for cleaning. Further, the amount of penetration of the ink absorbing members 60a, 60b, 60c, 60d into the ejection port surfaces 22a, 22b, 22c, 22d is about 2 mm as in the first embodiment. In this embodiment, the ink absorbing members 60a, 60b, 60c, 60
The double structure of d made it possible to use it for a long period of time, and at the same time, made the ink absorbency in part f more stable.

[Embodiment 3] A third embodiment of the present invention will be described with reference to FIGS. The same elements as those in Embodiments 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

The ink absorbing members 70a, 70b, 70c,
70d is assembled to the ink absorbing frame 79, and the ink absorbing frame 79 can be divided into A, B, and C parts. The shaft 71 is attached to a support base 72 fixed to a table 73 movable in the B direction by rotating a ball screw 75 with a motor 76. The support base 72 is adjustable on the table 73 in the A direction, and an ink absorbing frame is rotatably attached to the shaft 71. The coupling 77 transmits the drive of the motor 76. A rotatable ball screw 75 and a guide shaft 74 that guides the table 73 are attached to the guide plate 78. The guide plate 78 and the motor 76 are fixed to a frame (not shown) with screws or the like. The arrangement position of the cleaning means and the configuration of the other inkjet recording devices are the same as those in the first and second embodiments.

Next, the cleaning operation will be described.

In this embodiment, the cleaning operation is performed when the recording heads 2a, 2b, 2c and 2d are stopped after the printing by the front scan is completed. The cleaning operation is performed by the motor 76
To drive the ink absorption members 70a, 70a.
It is carried out by moving b, 70c and 70d up and down in the order of C → D → C. At this time, the ink absorbing member 70
a, 70b, 70c, and 70d are arranged at positions facing the corresponding ejection opening surfaces 22a, 22b, 22c, and 22d, and the ejection opening surface 22 is moved during C → D → C movement.
a, 22b, 22c, 22d are pressed and driven to discharge face 2
2a, 22b, 22c, 22d and head holder 19
Absorb and clean the ink mist adhering to the.

Thereafter, the carriage 1 scans back and repeats the printing operation. Further, the invasion amount of the ink absorbing members 70a, 70b, 70c, 70d into the ejection port surfaces 22a, 22b, 22c, 22d in this embodiment is about 2 mm as in the first and second embodiments.

In this embodiment, the recording head 2
a, 2b, 2c, 2d, the ink absorbing member 70a,
Since 70b, 70c, and 70d move and rotate in the vertical direction and are pressed and driven, the ink absorbing member 70 at the start of cleaning
There is no need to align the a, 70b, 70c, 70d and the corresponding ejection opening faces 22a, 22b, 22c, 22d. Therefore, assembly and the like becomes easy.

[Fourth Embodiment] FIG. 13 is a sectional view of a fourth embodiment of the present invention. This embodiment is roughly classified into a recording system 10
0, recording system unit transport system 200, recording paper transport system 30
0, a control system (not shown) and the like.

The recording system 100 comprises four recording heads 101.
A, 101B, 101C, 101D (FIG. 12), the recording head unit 101 of the ink jet system and the ink tanks (not shown) to the recording heads 101A, 101
B, 101C, 101D, the ink supply tube 103, and the recording heads 101A, 101B, 1
A head driver (not shown) for controlling the driving of 01C and 101D. Here, each recording head 101A,
The ejection methods of 101B, 101C, and 101D are of a type in which electricity is applied to a nozzle heater (not shown) formed inside each nozzle (not shown) to generate heat, and the energy is used to eject ink (however, The present invention is not limited to this, and the same effect can be obtained even with a piezo type, for example).

The recording unit transport system 200 is equipped with recording heads 101A, 101B, 101C, 101D and a head driver, and moves along a guide rail 221 extending in a predetermined direction (here, a direction orthogonal to the drawing). By doing so, the recording heads 101A, 101B, 101C,
This is a system including a carriage 201 for scanning 101D with respect to the recording sheets RP and CS.

The recording sheet conveying system 300 includes a recording sheet RP,
CS conveyance paths P, PC, PR, PI and rollers 301, 311, 314, 315, 316, 324, 3 of each part.
25, 331, 341 and the like.

The control system includes a controller for controlling the operation sequence of the entire apparatus and an image processing section for performing various processes on the image signal of the output image.

Next, the details will be described.

The cut sheet-shaped recording paper CS is placed on the cassette 607. Roll-shaped recording paper RP
Is rotatable about the rotation axis RPA. The cut paper CS, the roll paper RP, and the conveyance paths PC, PR, and PI of the recording papers inserted in the manual feed port 609 join near the upstream side of the nipping position of the conveyance roller 301.

A pickup roller 31 is provided on the conveying path PC.
By the cooperation of 1 and a separating member (not shown), the cut sheet-shaped recording paper CS separated from the cassette 607 is introduced,
While being sandwiched by rollers 316, 315, and 314 provided on the path, they are guided on the conveyance path PC and guided to the conveyance roller 301. In addition to the set roller 324 for introducing the roll-shaped recording paper RP onto the path while pulling out the roll-shaped recording paper RP, the roller 325 for transporting on the path toward the transport roller 301, the transport path PR has a roll shape with a predetermined size. A cutter 326 for cutting the recording paper RP is provided. Further, the holder 321 holds the recording paper RP.

The recording papers RP and CS introduced into the conveying roller 301 through the respective paths are guided to the platen 401 via the registration rollers 331 and further pinched by the conveying rollers 341 on the downstream side of the platen 401 in the conveying path P. To be done. Then, the recording sheets RP and CS are attracted onto the platen 401 by a mechanism (not shown) such as air suction. After that, the carriage 201 reciprocates once on the guide rail 221, so that the recording heads 101A, 101B, 10
1C and 101D will scan the recording papers RP and CS. The recording heads 101A and 10A are synchronized with this scanning.
1B, 101C, 101D drive signals are sent from the control system, and ink is ejected accordingly. When an image for one line is formed on the recording papers RP and CS in this way, a predetermined amount of recording paper R is conveyed by the conveyance roller 341.
P and CS are conveyed, and the recording heads 101A and 101 are again provided.
B, 101C, and 101D scanning is performed. When the above operation is performed for a predetermined image length, the recording papers RP and CS are sent out by the conveyance roller 341 and ejected from the paper ejection port 611.

FIG. 14 shows the construction of a recording system and a recording system unit transport system.

The carriage 201 having the recording head section 101 and the ink carriage 203 containing the ink tank 120 are moved and scanned along the guide rails 221. A belt 219A installed between the pulleys 207A, 207B, and 207C is fixed to the carriage 201 and the ink carriage 203. The motor 210A is coupled to the pulley 207C, and the rotation causes the carriage 201 and the ink carriage 203 to scan. Recording heads 101A, 101B, 1
01C and 101D and the ink tank 120 are connected via an ink supply tube 103, and ink is supplied through this.

Recording heads 101A, 101B, 101
Output signals for driving C and 101D are applied to the recording head 1
One end of the signal cable 230 for transmitting to the 01A, 101B, 101C, and 101D sides is connected to a control system (not shown) fixed to the main body side. Here, the ink ejection performance of each of the recording heads 101A, 101B, 101C, 101D is the same as that of each of the recording heads 101A, 101B, 1
Since it largely depends on the temperature of 01C and 101D, it is necessary to provide a heater, a cooling fan, or the like in or around the recording heads 101A, 101B, 101C, and 101D. Included in cable 230. The signal cable 230 from the control system extends parallel to the guide rail 221, makes a U-turn, is guided to the opening of the carriage 201, and is connected to a head driver (not shown) inside the recording head unit 101.

Next, the structure around the recording head unit 101 and its operation will be described.

The structure is shown in FIG. Recording heads 101A, 101B, 101C, 10 having a recording width W1
Four IDs are arranged in a staggered manner in the head holder 102, and as a result, it can be regarded as a long head having a recording width W (= W1 × 4) as a whole. However, because of the zigzag shape, the positions of adjacent recording heads are displaced by a distance g in the main scanning direction. Therefore, the image signal is also divided into blocks so as to correspond to one recording head, and image processing is performed so that half of the data is shifted by an amount corresponding to the distance g.

Recording heads 101A, 101B, 101
A mechanism for maintaining the stability of C and 101D will be described.

In FIG. 14, the recovery unit 108 is
This is to remove or prevent increase in ink viscosity, ink adhesion to the nozzle surface, and residual air bubbles in the nozzle that cause unstable ink ejection, and to obtain reliable ejection stability. Have.

(A) Cap portion 108A: When the recording head is left in the air for a long time, the ink in the nozzle evaporates and the viscosity increases, and the ejection becomes unstable. In order to prevent this, during non-printing, the nozzle part is shut off from the outside air and sealed (capping). Inside the cap portion 108A, there is a liquid absorbing material (not shown) kept in a wet state by the ink.
The inside of the ink is kept at high humidity to minimize the thickening of the ink.

(B) Ink pressurization: When left for a long time, the ink in the nozzle evaporates and thickens even though capping is carried out although it is slow. In addition, bubbles may remain inside the nozzle to prevent stable ejection.
Therefore, at the start of printing, the pump provided in the ink tank 102 is driven to pressurize the ink, and the thickened ink inside the nozzle and residual bubbles are discharged to the outside of the nozzle. This has the effect of washing out dust and fluff even if dust or fluff is attached to the nozzle surface or if dust or the like has entered the nozzle to maintain stable ejection.

(C) Air flow: After pressurizing the ink, the ink discharged from the nozzle remains on the nozzle surface. If the ink remains attached, the ejected ink is adversely affected. For this reason, after pressurizing the ink, an air flow is blown from an air nozzle (not shown) in the upper part of the cap toward the nozzle surface to blow the ink to the lower part of the recording head. Each recording head 101
Liquid absorbing materials are in contact with the lower portions of A, 101B, 101C, and 101D, respectively, and the flowed ink is absorbed by the liquid absorbing materials.

(D) Idle ejection: When the print duty of a recorded image is low, some nozzles eject almost no ink during printing, which may cause ink thickening due to evaporation. In order to prevent this, a predetermined drive pulse is applied before the start of printing, and ink is ejected from all nozzles toward the cap portion 108A (aging operation). Capping may be performed to enhance the wet state of the atmosphere around the nozzle.

The ink absorbed by the absorbent by the recovery operations (c) and (d) travels through the tube and is recovered by the recovery unit 108.
Is sent to a waste ink bottle provided below.

(E) Blade unit 105: As described above, if ink mist generated by ink ejection adheres to the nozzle surface, ejection becomes unstable. In order to prevent this, a blade unit 105 having a rubber blade for wiping and cleaning the nozzle surface is provided immediately adjacent to the cap portion 108A. Silicon or urethane rubber is used as the material in terms of durability and ink resistance.

In the present embodiment, the blade unit 105 is connected to each recording head 10 as shown in FIG.
It was divided into 1A, 101B, 101C and 101D, and they were arranged in tandem. In practice, each recording head 101A,
Each blade 10 as well as 101B, 101C, 101D
5A, 105B, 105C and 105D are also arranged in a staggered pattern. The blade 105A corresponds to the recording head 101A, and in the same manner, the last 105D is 101D.
It corresponds to. Each blade 105A, 105B, 10
5C and 105D are respectively held by the blade holder 106 so that they can be easily exchanged, and they are supported by the frame of the blade unit 105. Each blade 105A, 105B,
The leading ends of 105C and 105D are the respective recording heads 101A and 1A.
0.5 for nozzle faces of 01B, 101C, 101D
The width is about 1.0 mm, and actually, the blades 105A, 105B, 105C, and 105D are respectively bent by that amount to perform wiping. The length of each of the blades 105A, 105B, 105C, and 105D is made slightly shorter than the length of the opening of the holder for exposing the nozzle surface. As a result, when wiping over the nozzle, the blades 105A, 105B,
Since 105C and 105D do not ride on the head holder 102, there is no unwiping left on the nozzle surface.

From the above, the factors that adversely affect the ejected ink are completely removed, and it is possible to always maintain good image quality. Furthermore, since each blade can be made to have the minimum length required for cleaning, its durability is improved. Moreover, even if the blade should be replaced due to deterioration, it is not necessary to replace all the blades, and the minimum replacement is required. This also has the advantage of reducing waste and lowering costs.

[Fifth Embodiment] In the fourth embodiment, one set of print heads has been described. However, a plurality of sets of print head rows are arranged in parallel and a color image is formed by ejecting inks of different colors from each set. The same effect can be obtained even with such a device. Hereinafter, such an application example will be described.

FIG. 15 shows the construction of the periphery of the recording head and the blade of the fifth embodiment of the present invention. Recording head 501
A, 501B, 501C, 501D are recording heads for black ink, while recording heads 502A, 50A
2B, 502C, and 502D are recording heads for another color, for example, red ink. Head holder 50
3 are arranged in a zigzag pattern with a distance G of each color.
Image signals of two colors are sent from the image processing system in parallel. More specifically, the data of each color is delayed depending on the position in consideration of the staggered arrangement as in the case of the previous embodiment. .. At the same time, the delay correction is performed for each color data by the amount G of the distance in which the recording heads are arranged in parallel.

Two sets of blade units 51 installed side by side
0 and 520 are four blades 510 on one side, respectively.
A, 510B, 510C, 510D and the other four blades 520A, 520B, 520C, 520D are staggeredly held by the blade holders 511, 521. Both blade units 510 and 520 are configured to be movable back and forth with respect to the recording head surface (only the blade unit 520 is shown in the figure, but the blade unit 510 is also the same). More specifically, a guide member 533 is connected to the blade holder 521 and has a guide groove 533A in a part thereof. On the other hand, the two guide pins 53 from the fixing plate 530 fixed to the main body side (not shown).
1A and 531B project and guide groove 533A of the guide member
Is plugged into. In addition, the linear actuator 5
32 is fixed to the fixed plate 530, and its moving pin 532A
Is fixed to one surface 533B of the guide member.
With the above configuration, when the linear actuator 532 operates, the guide member 533 moves along the guide pins 531A and 531B along with the movement of the moving pin 532A, which causes the blade units 510 and 520 to move.
The forward / backward movement is performed with respect to 1, 502.

The reason for having the advance / retreat function will be described. For example, when trying to wipe the black recording head 501A and the red recording head 502A with one blade 510A, the following problems may occur. In other words, first the red recording head 502A
When wiping is done, red ink adheres to the blade tip. In that state, the black recording head 501A continues.
When wiping is performed, the red ink attached to the blade at that time may be partially transferred onto the black head, and when it is worse, it is possible that the red ink may even enter the nozzle. Then, when the black ink is subsequently ejected from the nozzles, the red inks are mixed with each other, which causes a problem of so-called color mixing.

In order to prevent the above problem, the above-mentioned mechanism is provided and the following operation is performed. Figure 16 (1)
As shown in (5) to (5), (1) First, both blade units 510 and 520 are retracted at the start of scanning of the recording heads 501 and 502. (2) Next, the blade unit 510 is left as it is and the blade unit 520 is moved forward. (3) Recording head 502 by blade unit 520
Wipe. Further, the blade unit 510 is advanced. (4) Recording head 502 by blade unit 510
Wipe. Further, the blade unit 520 is retracted. (5) The blade unit 510 is retracted. After that, the recording heads 501 and 502 reciprocate to return to the state (1), and this is repeated thereafter. That is, the blade unit 510 wipes only the recording head 501, and the blade unit 520 wipes only the recording head 502. This makes it possible to form a good two-color image without causing the problem of color mixing (however, even if the main advancing / retreating mechanism is omitted due to problems such as cost and space, at least an uncleaned portion is generated. Since the image quality is not deteriorated by the above, the effect of the present invention is not lost.).

Up to this point, two color images have been described, but the present invention is not limited to this, and the same effect can be obtained by an apparatus that forms a full color image using three or more colors. The recording heads to be arranged are not limited to the same ones as described above, different ones may be arranged side by side, and the arrangement method is not limited to the staggered pattern, and the blades may be arranged in any arrangement. The recording head 1
Similar effects can be obtained by arranging them in correspondence with each other.

Further, although paper has been described as the recording medium so far, the present invention is not limited to this, and may be any plastic film or cloth material as long as it can be recorded by the ink jet system. Is also applicable.

The present invention brings excellent effects particularly in an ink jet type recording head and a recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording systems.

Regarding its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal transducer arranged corresponding to the sheet or liquid path in which is stored, a rapid temperature increase corresponding to the recorded information and exceeding nucleate boiling is applied. , It is effective because it generates heat energy in the electrothermal converter and causes film boiling on the heat-acting surface of the recording head, resulting in the formation of bubbles in the liquid (ink) corresponding to this drive signal one-to-one. Is. Liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The present invention also includes a configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region.

In addition, Japanese Patent Application Laid-Open No. 59-123670 discloses a structure in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which an opening corresponds to a discharge portion.

Further, as a full line type recording head having a length corresponding to the maximum recording medium width that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above-mentioned specification provides the length. The present invention can exert the above-mentioned effects more effectively, although it may have a configuration that satisfies the above requirements or a configuration as one recording head integrally formed.

In addition, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. The present invention is also effective when a cartridge-type recording head provided with an ink tank is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. If these are specifically mentioned,
Capping means, cleaning means, pressurizing or sucking means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and a preliminary ejection mode for performing ejection other than recording It is also effective to perform stable recording.

Further, as the recording mode of the recording apparatus, not only the mainstream color such as black is recorded but also the recording head may be integrally formed or a plurality of them may be combined. Alternatively, the present invention is extremely effective for an apparatus provided with at least one of full colors by color mixing.

In the embodiments of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens at room temperature, or is a liquid, or the above-mentioned liquid. In the inkjet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. Any liquid may be used.

In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in the standing state for the purpose of preventing evaporation of the ink. In some cases, whether ink is used, the ink is liquefied by application of thermal energy according to the recording signal and ejected as a liquid ink, or the one that has already started to solidify when it reaches the recording medium. The use of an ink having a property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or JP-A No. 60-71260, a mode in which it faces the electrothermal converter in a state of being held as a liquid or solid in the recess or through hole of the porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the recording apparatus according to the present invention, in addition to a recording apparatus integrally or separately provided as an image output terminal of information processing equipment such as a word processor or a computer, a copying apparatus combined with a reader or the like, May take the form of a facsimile machine having a transmission / reception function.

[0099]

As described above, according to the present invention, the divided ink absorbing member corresponding to each of the plurality of recording heads is used as the cleaning means (the ink ejection port surface of each recording head, the head holder, etc.). (Cleans and absorbs the ink mist adhering to the ink), the landing position deviation of ejected ink droplets, ejection failure (discharging), disturbance in the ejection direction, which is caused by ink adhering to the ejection port surface of the recording head, Prevents color mixing and obtains high quality images.

Particularly for color mixing, the effect is great because the divided ink absorbing members corresponding to the respective recording heads are used.

Since the ink absorbing member is used, the ejection port surface of the recording head is not damaged.

Further, in a serial type ink jet recording apparatus in which a plurality of recording heads are arranged on a carriage in the nozzle row direction and recording is performed while moving and scanning the carriage on the recording medium in a direction orthogonal to the nozzle rows. The following effects can be obtained by dividing the flexible member for contacting the nozzle surface of the recording head and cleaning the surface so as to correspond to each recording head.

It is possible to always maintain good image quality while shortening the recording time. In addition, the cost of the recording head is not increased and its reliability is not impaired.

The durability of the blade is improved.

There is also an advantage that the replacement work of the blade is facilitated and the waste is reduced to reduce the cost.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a first embodiment.

FIG. 2 is an enlarged perspective view of a carriage unit according to the first embodiment.

FIG. 3 is a schematic diagram showing a carriage operation of the first embodiment.

FIG. 4 is a plan view showing a cleaning state of the first embodiment.

FIG. 5 is a plan view showing a cleaning state of the first embodiment.

FIG. 6 is a plan view showing a cleaning state of the second embodiment.

FIG. 7 is a plan view showing a cleaning state of the second embodiment.

FIG. 8 is a plan view showing a cleaning state of the second embodiment.

9 is a sectional view taken along line ZZ of FIG.

FIG. 10 is a plan view showing a cleaning state of the third embodiment.

FIG. 11 is a side view showing a cleaning state of the third embodiment.

12A and 12B are configuration diagrams around a recording head in a fourth embodiment.

FIG. 13 is a sectional view of Example 4.

FIG. 14 is a configuration diagram of a recording system and a recording unit transport system according to a fourth embodiment.

FIG. 15 is a configuration diagram around a recording head in a fifth embodiment.

16 (A), (B), (C), (D), and (E) are explanatory views showing the operation of the blade unit of the fifth embodiment.

FIG. 17 is a sectional view of a recording head showing a discharge state of a conventional example.

FIG. 18 is a perspective view showing a state of a discharge port surface of a conventional example.

19A and 19B are explanatory views showing a blade unit of a conventional example.

[Explanation of symbols]

1 Carriage 2 Recording Head 22 Ejection Port Surfaces 47, 60, 70 Ink Absorbing Member 100 Cleaning Means 101A, 101B, 101C, 101D, 501A,
501B, 501C, 501D, 502A, 502B,
502C, 502D recording heads 102, 503 head holder 103 ink supply tube 201 carriage 105, 510, 520 blade unit 105A, 105B, 105C, 105D, 510A,
510B, 510C, 510D, 520A, 520B,
520C, 520D Blades 106, 511, 521 Blade Holder 532 Linear Actuator CS, RP Recording Paper W Total Nozzle Length W1 1 Recording Head Nozzle Length

Claims (11)

[Claims] 1. A multi-color recording unit in which a plurality of recording heads having ejection ports for ejecting ink are arrayed, and an ejection port surface in which the ejection ports are arrayed is brought into contact with the ejection port surface. An inkjet recording apparatus comprising: cleaning means for cleaning, wherein the cleaning means is divided corresponding to each recording head. 2. The ink jet recording apparatus according to claim 1, wherein the cleaning unit is an ink absorbing member. 3. The ink jet recording apparatus according to claim 1, wherein the cleaning unit is a flexible member. 4. The cleaning means is supported so as to be movable back and forth toward the recording means.
2. The inkjet recording device described in 2 or 3. 5. The inkjet recording apparatus according to claim 1, wherein the recording heads are arranged in a direction parallel to the arrangement direction of the ejection ports. 6. The inkjet recording apparatus according to claim 1, wherein the recording heads are arranged in a direction orthogonal to the arrangement direction of the ejection ports. 7. The recording means comprises two or more recording heads forming a plurality of recording head rows, and the cleaning means is divided corresponding to each recording head, and
7. The inkjet recording apparatus according to claim 1, wherein a plurality of sets are arranged corresponding to each set of recording head rows. 8. The recording means according to claim 1, wherein the recording means is mounted on a carriage movable over a maximum recording width of a recording medium. Inkjet recording device. 9. The recording medium is of a full line type in which the ejection openings are formed over the maximum recording width of a recording medium. The inkjet recording device described. 10. The recording means comprises an electrothermal converter for generating thermal energy for ejecting ink, in one of claims 1, 2, 3, 4, 5, 6, 7, 8
Or the inkjet recording device according to item 9. 11. The ink jetting apparatus according to claim 10, wherein the recording unit ejects the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter. Inkjet recording device.