JPH04250047A - Ink jet head, ink jet head cartridge and ink jet device - Google Patents

Abstract

PURPOSE:To open an ink supply orifice on a most remote ceiling from a flow path for a common liquid chamber, and at the same time, form a peripheral wall for the common liquid chamber by combination of continuous planes from the ink supply orifice to the flow path, and discharge bubbles from an ink discharge orifice without allowing the bubbles to be resident in the common liquid chamber or the flow path. CONSTITUTION:An ink jet head is formed with a common liquid chamber 1 having an ink supply orifice 5 and an ink discharge orifice 11 for discharging ink from each liquid path 12, as a single body, on a ceiling where liquid paths 12 to which ink is guided from the common liquid chamber 1. In the mentioned constitution, the ceiling 2 where the ink discharge orifice 11 is formed, with its rear defined by the ink supply orifice 5, is directly connected to a semi- cylindrical rear wall 3 from the ink supply orifice 5. Then a front wall 6, a lateral wall 7 and a top wall 8 are formed flat. Subsequentlym no spot where ink is stagnant, is any longer present in the common liquid chamber 1. In addition, each wall 6 to 8 and the flow path 12 are connected together without any stepped part and thereby ink is smoothly guided to each flow path 12 from the supply orifice 5.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet head, an inkjet head cartridge, and an inkjet device, and more particularly, the present invention relates to an inkjet head for recording, an inkjet head cartridge in which an inkjet head and an ink tank are integrated, and a recording device that performs recording by scanning. The present invention relates to an inkjet device.

0002

2. Description of the Related Art Conventionally, this type of inkjet apparatus has an inkjet head, an energy conversion means for generating ejection energy used to eject ink into a liquid path, and an inkjet apparatus that supplies ink from an ink supply port. The ink is guided to the above-mentioned liquid path via the liquid chamber, and the ink is ejected from the ejection port as a flying droplet by the ejection energy given to the ink by the energy conversion means, and is ejected toward the recording material, and the recording is performed by the landing of the ink. is configured to take place.

Among them, recording liquid (
An inkjet head that ejects ink (ink) can perform high-resolution recording because it has a high-density array of ink ejection ports that eject recording ink droplets to form flying droplets. It has been put into practical use because of its advantages, such as the ease of overall compactness.

By the way, in conventional recording, since ink is used, recording is performed by receiving ink supply from an ink tank that holds the ink, or the ink tank that holds the ink is integrated with the head. However, it is not preferable that air bubbles are formed in the ink channel or the liquid chamber to which only ink should be guided. In particular, if such bubbles increase after they are generated, the electrothermal converter that generates the thermal energy may lose its function due to recording failure or abnormal temperature rise due to the thermal energy, so recording failure may occur. When a recording defect occurs or when a recording defect is predicted, depending on the conditions, you can recover the defective state by suctioning ink from the ejection port side of the head, or pour pressurized ink or cleaning liquid into the liquid chamber and remove the ejection port side. Recovery measures have been proposed that attempt to remove the air bubbles along with the ink supplied from. Conventionally, such recovery means have been used to remove air bubbles by increasing the number of times, or by increasing the amount of suction or pressurization, which has resulted in an increase in recording interruption time. In addition, the interval between recovery processing for an incomplete recovery state becomes shorter.

[0005] Furthermore, as another means for removing air bubbles,
A configuration has also been proposed in which the generated air bubbles are collected in a chamber communicating with the atmosphere and removed naturally, but this increases the size of the device and cannot be used in closed liquid chambers or liquid channels.

In particular, in the recovery operation in which ink is forced to flow as described above, since the ink flows linearly through the ink channel, curved surfaces or curved parts in the liquid chamber adjacent to the ink channel may be affected. When air bubbles remain on the ink receiving side, the air bubbles not only are not removed, but also tend to increase over time.

[0007]

[Problems to be Solved by the Invention] According to research conducted by the present inventors, conventional inkjet heads have a
As a result of a durability test after being left unused for a long period of about a month, it was found that there were significant changes in the condition inside the common liquid chamber of the recording head. That is, bubbles as large as 400 μm were generated in the common liquid chamber. Although there are still many unknown factors behind this, when such large bubbles occur in an inkjet head with the conventional configuration as described above, the bubbles cannot be removed even if the recovery measures described above are taken, and the head must be replaced. I had no choice.

[0008]Furthermore, as a result of the research conducted by the present inventors regarding conventional normal recovery, it has been found that air bubbles that are generated inside the head, enter the common liquid chamber, and grow cannot be completely removed from the inside of the liquid chamber. It was found that bubbles of about 50 to 100 μm remained in a dispersed state.

[0009] The causes of such bubbles include evaporation of the ink in the ink tank, residual gas in the ink, residual air bubbles during bubbling during recording, and meniscus from the ejection port when the ejection port is capped. Although it is possible to prevent air bubbles that enter with the ink from the push-in/ink supply port, it is possible to prevent ink leakage from the guide path that guides the ink, but the configuration completely prevents air and gas from entering the liquid chamber and liquid path. is extremely difficult to achieve.

[0010] Therefore, the inventors of the present invention changed the idea to the opposite of the conventional method, and even if the growth of large bubbles as described above occurs, they can be easily removed, thereby shortening the recovery time. This may result in recording defects (unstable ink droplets landing, unstable ejected ink droplet volume, printing defects such as non-ejection of some nozzles, no ink in the common liquid chamber, etc.) or a state where there is no ink due to air bubbles. The main technical problem is to prevent the heat generation of the energy heating element from shortening its lifespan.

[0011] In other words, as a result of the research conducted by the present inventors, the reason why the above-mentioned conventional recovery means is not as successful as expected is that turbulent flow of ink occurs in the liquid chamber and liquid path. Therefore, the technical problem of the present invention is to attempt to solve the problem based on the clarification result that, on the contrary, the bubbles become dispersed and the factors that cause the bubbles to grow remain.

0012

[Means for Solving the Problems] In order to solve this problem, the present invention provides a common liquid chamber having an ink supply port and a plurality of liquid channels through which ink is guided from the common liquid chamber, which are formed as recesses. In an inkjet head, an ink ejection port for ejecting ink from each of the ink ejection ports is integrally formed in a top plate, and recording is performed using ink droplets ejected from the ink ejection ports. is opened at a ceiling or wall surface farthest from the plurality of liquid channels of the common liquid chamber, and the peripheral wall of the common liquid chamber is formed by a combination of planes that are continuous from the ink supply port to the plurality of liquid channels. It is characterized by this.

[0013]

[Operation] According to the present invention, in the inkjet head or inkjet head cartridge, the wall surfaces from the opening position of the ink supply port in the common liquid chamber to the plurality of liquid paths are all formed by a combination of continuous planes. Since the ink supply port is opened on the opposite side of the common liquid chamber from the multiple liquid paths, ink and air bubbles in the ink are prevented from accumulating on the wall of the common liquid chamber from the ink supply port to each liquid path. Therefore, no air bubbles are left in the common liquid chamber or liquid path without being removed during the suction recovery operation performed through the ink discharge ports.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be described in detail and specifically based on the drawings.

FIGS. 2 to 6 show an inkjet unit (IJU), an inkjet head (IJH), an ink tank (IT), an inkjet head cartridge (IJC), an inkjet apparatus main body (IJRA), and a carriage suitable for carrying out the present invention. (HC) and their relationships; FIG. The configuration of each part will be explained below using these drawings.

The inkjet head cartridge (IJC) 1000 in this example has a large ink storage capacity as shown in FIG. 3, and the IT formed in the cartridge IJC 1000 (see FIG. 4) The tip of the inkjet unit (IJU) protrudes slightly from the front surface of the inkjet unit (IJU). Also, this IJC1000
The carriage (HC) (Fig. 5) installed in the inkjet recording apparatus main body (IJRA) is fixedly supported by the positioning means and electrical contacts described later, and is a disposable type that can be attached to and detached from the HC. It is.

Furthermore, since FIGS. 2 to 6 show configurations to which a number of novel techniques developed at the stage of establishment of the present invention are applied, these configurations will be explained in sequence below.

(A) Inkjet unit (IJU)
The IJU is a bubble jet unit that performs recording using an electrothermal transducer that generates thermal energy to cause film boiling in ink in response to electrical signals.

In FIG. 2, reference numeral 100 denotes a heater board constituting the IJH, and the heater board 100 includes electrothermal converters (discharge heaters) arranged in a plurality of rows on a Si substrate.
and electrical wiring made of Al or the like for supplying power thereto are formed by film-forming technology. 200 is heater board 100
It is a wiring board for the heater board 100, and has a wiring corresponding to the wiring of the heater board 100 (for example, connected by wire bonding), and a pad 201 located at the end of this wiring and receiving an electric signal from the main device. .

A grooved top plate 1300 forms an IJH together with the ejection port forming member 400 and the heater board 100. A common liquid chamber or the like for storing ink is provided to supply ink to the ink flow path, and an ink receiving port (supply port) 1500 receives ink supplied from IT and introduces it into the above-mentioned common liquid chamber. , an ejection port forming member 400 having a plurality of ejection ports corresponding to each ink flow path are integrally molded with the top plate 1300. Although polysulfone is preferable as the material for integral molding, other resin materials for molding may also be used.

Reference numeral 300 is a support made of metal, for example, which supports the back surface of the wiring board 200 on a flat surface, and serves as a bottom plate of an inkjet head unit (IJU). 500 is a pressing spring, which is almost M-shaped, and has a central top plate 1 of the M-shape.
The vicinity of the common liquid chamber (not shown) of 300 is pressed with light pressure, and at the same time, a part of the liquid path, preferably a region near the discharge port, is concentratedly pressed with linear pressure using the front sagging portion 501. Thus, the leg of the pressing spring passes through the hole 3121 in the support 300
By engaging with the back side of the support body 300, the heater board 100 and the top plate 1300 can be engaged with each other while being sandwiched between them, and the concentrated biasing force of the pressing spring 500 and its front sagging portion 501 is reduced. The heater board 100 and the top plate 1300 are crimped and fixed.

[0022] The support body 300 also has an ink tank IT.
In addition to the two positioning protrusions 1012 and positioning holes 312, 1900, 2000 that engage with the protrusions 1800, 1801 (see FIG. 4) for positioning and heat fusion holding, there are It has protrusions 2500, 2600 on the back side. In addition, the support body 300 also has a hole 320 that allows an ink supply pipe 2200 (described later) to pass therethrough, which allows ink to be supplied from the ink tank IJ. Note that when attaching the wiring board 200 to such a support body 300, the wiring board 200 is attached using an adhesive or the like.

[0023] Furthermore, the recesses 2400, 24 of the support body 300
00 are provided near the positioning protrusions 2500 and 2600, respectively, and in the assembled inkjet head cartridge IJC (FIG. 3), parallel grooves 3000 and 30 are formed on three sides around the support body 300.
In the tip extension area of the head IJH defined by a plurality of projections 2500 and 01, unnecessary substances such as dust and ink are
I am trying to prevent it from reaching 2600.

As can be seen from FIGS. 3 and 5, the lid member 800 is attached to an inkjet head cartridge IJC.
In addition to forming an outer wall of the ink tank IT, a space portion for housing the inkjet unit IJU is formed between the ink tank IT and the ink tank IT. Further, the ink supply member 600 in which the parallel grooves 3001 described above are formed includes the ink supply pipe 22 described above.
The supply tube 2200 side of the ink conduit 1600 that is continuous with the ink conduit 1600 is formed as a fixed cantilever, and a sealing pin 602 is provided between the fixed side of the ink conduit 1600 and the ink supply tube 2200 to ensure capillary action. It has been inserted. Note that 601 is a packing that connects and seals between the ink tank IT and the supply pipe 2200, and 700 is the supply pipe 220.
This is a filter provided at the tank side end of the 0.

The ink supply member 600 is molded, is inexpensive, has high positional accuracy, eliminates deterioration in precision in formation, and has a cantilever structure for the conduit 1600, so it can be used in large quantities. Even during production, stable pressure contact between the conduit 1600 and the ink receptacle 1500 can be obtained. In this example, by simply pouring the sealing adhesive from the ink supply member 600 side under such a pressure-contact state, a more complete communication state can be reliably obtained. Note that the ink supply member 600 is fixed to the support body 300 by projecting pins (not shown) on the back surface of the ink supply member 600 through the holes 1901 and 1902 of the support body 300, and then fixing the ink supply member 600 to the back surface of the support body 300. This can be easily done by heat-sealing the parts that protrude to the sides. Note that the slight protruding area of the heat-sealed back surface is accommodated in a recess (not shown) in the side wall surface of the inkjet head unit IJU mounting surface of the ink tank IT, so the unit I
It is possible to accurately secure the positioning surface of the JU.

(B) Ink tank IT configuration description The ink tank IT consists of a cartridge main body 100 as shown in FIG.
0, an ink absorber group 900 to be described in detail later, and a lid member 1100 that seals the ink absorber group 900 after the ink absorber group 900 is inserted from the side opposite to the unit IJU mounting surface of the cartridge main body 1000. has been done.

Reference numeral 900 denotes an absorber for impregnating ink, and is disposed within the cartridge body 1000.

Reference numeral 1200 denotes a supply port for supplying ink to the unit IJU consisting of the above-mentioned parts 100 to 600, and ink is injected in a process before the unit IJU is placed inside the cartridge body 1000. It is also an injection port for impregnating the absorber 900 with ink.

In the ink tank IT of this example, the parts where ink can be supplied are the atmosphere communication port 1401 and the supply port 1.
200, but in order to improve ink supply from the ink absorber 900, there are ribs 230 inside the main body 1000.
0, and the lid member 1100 has partial ribs 2301 and 23.
02 is provided, and there is an air presence region in the tank formed by these, and this air presence region is continuously formed from the atmosphere communication port 1401 side to the corner region furthest from the ink supply port 1200. , absorber 9
This supply port 1 ensures a good and uniform supply of ink to 00.
This can be done from the 200 side.

This is extremely effective in practice; the ink tank IT has four ribs 2300 on the rear surface of the cartridge body 1000, which are parallel to the direction of carriage movement, to prevent the absorber 900 from coming into close contact with the rear surface. are doing. Further, the partial ribs 2301 and 2302 are the ribs 230
The rib 2300 is provided on the inner surface of the lid member 1100 in its extension corresponding to the rib 2300, but unlike the rib 2300, it is in a divided state, increasing the space in which air can exist. Note that the partial ribs 2301 and 2302 are distributed over a surface that is less than half of the total area of the lid member 1100,
Thus, these ribs make it possible to stabilize the ink in the region of the corner of the ink absorber 900 farthest from the tank supply port 1200, and moreover, to reliably guide it to the supply port 1200 side by capillary force. 1400 is atmospheric communication port 140
This is a liquid-repellent material disposed inside the air communication port 1401, thereby preventing ink from leaking from the atmosphere communication port 1401.

The ink storage space of the ink tank IT described above has a rectangular shape, and its long side is parallel to the cartridge main body 1.
000 sides, so the arrangement of the ribs described above is particularly effective. However, if the carriage has long sides in the direction of movement or if it is a cube, providing ribs all over the lid member 1100 will prevent the ink from entering. Ink supply from the absorber group 900 can be stabilized. A rectangular parallelepiped shape is suitable for storing as much ink as possible within a limited space, but
In order to use the stored ink for recording without wasting it, as described above, it is important to provide ribs that can perform the above-mentioned action in the two-sided areas close to the corner areas.

Furthermore, the ink tank IT in this embodiment
The inner ribs are arranged in a substantially uniform distribution in the thickness direction of the rectangular parallelepiped-shaped ink absorber 900, so this means that the atmospheric pressure distribution is uniform with respect to the ink consumption of the entire absorber 900. This is an important configuration because the remaining amount of ink can be reduced to almost nothing. Furthermore, to explain in detail the technical idea behind the arrangement of the ribs, when an arc is drawn with the long side as the radius on the top surface of the rectangular parallelepiped, centered on the projected position of the ink supply port 1200, It is important to arrange the ribs on the outer surface of the arc so that the absorber located at the absorber is exposed to atmospheric pressure quickly. In this case, the atmosphere communication port of the tank is of course not limited to the position of this example, as long as it is at a position where the atmosphere can be introduced into the region where the ribs are provided.

In addition, in this embodiment, the rear surface of the inkjet head cartridge IJC relative to the head IJH is flattened to minimize the space required when it is incorporated into an apparatus, and to maximize the amount of ink that can be accommodated. Due to this configuration, not only can the device be made smaller, but also the excellent advantage that the frequency of replacing the cartridge IJC can be reduced can be obtained. Then, by utilizing the rear part of the space for integrating the inkjet unit IJU, a protruding part for the atmosphere communication port 1401 is formed therein, and the inside of this protruding part is hollowed out, and the above-mentioned absorption Atmospheric pressure supply space 1 for the entire thickness of the body 900
402 is formed. With this configuration, it was possible to provide an excellent cartridge that has not been seen before.

Note that this atmospheric pressure supply space 1402 is a much larger space than the conventional one, and the atmospheric pressure supply space 1402 is much larger than the conventional one.
401 is located above, even if the ink is released from the absorber 900 due to some abnormality, the atmospheric pressure supply space 1402 temporarily retains the ink.
Ink can be reliably collected into the absorber 900 again.

FIG. 4 shows the ink tank IT in the unit I.
This is shown when viewed from the side on which the JU is attached, where L1 is a straight line that passes through approximately the center of the row of ejection ports of the ink ejection port forming member 400 and is parallel to the bottom surface of the tank IT or the mounting reference surface of the carriage surface. and the support 3 shown in FIG.
The two positioning protrusions 1012, 1012 that engage with the holes 312, 312 of 00 are located on this straight line L1, respectively. The height of this protrusion 1012 is slightly lower than the thickness of the support 300, and positions the support 300. In addition, on the extension of the straight line L1 in Fig. 4, there is a carriage HC shown in Fig. 5.
90° engagement surface 400 of the positioning hook 4001
A pawl 2100 that is engaged with the carriage HC is arranged so that the force acting on the carriage HC for positioning is applied in a plane region parallel to the reference plane that includes this straight line L1. As will be described later with reference to FIG. 5, this relationship provides the effect of increasing the positioning accuracy of the ink tank itself to the same level as the positioning accuracy of the ejection ports of the head IJH.

Further, the projections 1800 and 1801 of the ink tank corresponding to the fixing holes 1900 and 2000 on the side surface of the ink tank of the support body 300 are the projections 10 described above.
12, and is for fixing the support 300 to the side surface thereof by heat-sealing the portion that protrudes through the support 300. Therefore, this protrusion 1 is perpendicular to the line L1 mentioned above.
When the straight line passing through 800 is L3 and the straight line passing through protrusion 1801 is L2, the supply port 1200 is located on the straight line L3.
The approximately center of the supply port 1200 and the supply pipe 2200 is positioned approximately at the center thereof, which acts to stabilize the connection between the supply port 1200 and the supply pipe 2200, and to reduce the load on the connection due to drops or impacts. In addition, since the straight lines L2 and L3 do not match, and there are protrusions 1800 and 1801 around the protrusion 1012 on the discharge port side of the head IJH, the effect of reinforcing the positioning of the head IJH with respect to the tank can be obtained. . Note that the curve indicated by L4 is the outer wall position when the ink supply member 600 is attached. Protrusions 1800, 18
01 is along the curve L4, so the head IJH
It provides sufficient strength and positional accuracy even with the weight of the distal end configuration. Reference numeral 2700 denotes a tip collar of the ink tank IT, which is inserted into a slot in the front plate 4000 of the carriage HC as shown in FIG. 5, in preparation for an abnormal situation where the displacement of the ink tank IT becomes extremely poor. In addition, 2 shown in FIGS. 4 and 5
Reference numeral 101 denotes a retainer for the carriage HC, which is provided on a bar (not shown) of the carriage HC, and the cartridge IJC may enter below this bar at a position where it is rotated and mounted as described later, and it may be unnecessarily removed from the positioning position. This is a protective member that maintains the attached state even if an upward force is applied to cause it to detach. Ink tank IT is unit IJU
After the inkjet head cartridge IJC is installed, it is covered with the lid 800 to enclose the unit IJU except for the lower opening.
Since it is close to C, a four-way surrounding space is essentially formed here. Therefore, heat generated from the head IJH in this enclosed space accumulates in this space, and although it is effective as a heat-retaining space, when used continuously for a long period of time, the temperature increases slightly. For this purpose, in this example,
Cartridge I is used to assist the natural heat dissipation of the support 300.
A slit 1 with a width smaller than this space is placed on the upper surface of JC.
700 was installed to prevent temperature rise and to make the temperature distribution uniform throughout the unit IJU, so that it would not be influenced by the environment.

Now, when the inkjet head cartridge IJC is assembled, ink is supplied inside the cartridge through a supply port 1200, a hole 320 provided in the support 300, and an introduction port (not shown) provided on the inner back side of the ink tank IT. After being fed into the tank and passing through it,
The ink flows from the outlet into the common liquid chamber via an appropriate supply pipe and the ink inlet 1500 of the top plate 1300. A packing made of, for example, silicone rubber or butyl rubber is disposed at the above-mentioned connection portion for ink communication, and this seals the ink supply path to ensure an ink supply path.

[0038] In this embodiment, the top plate 1 of the IJH
A resin having excellent ink resistance such as polysulfone, polyethersulfone, polyphenylene oxide, polypropylene, etc. is used for the material 300, and is molded together with the ink discharge port forming member 400 in a mold.

As described above, the ink supply member 600, the member that integrates the top plate 300 and the ink discharge port forming member 400, and the inkjet head cartridge main body 10
Since each of 00 is made into an integrally molded part, not only is the assembly accuracy of a high level achieved, but it is also extremely effective in improving the quality of mass production. Furthermore, since the number of parts has been reduced compared to the prior art, excellent desired characteristics can be reliably exhibited.

Further, in this embodiment, in the above assembled shape, as shown in FIGS. 2 to 4, the ink supply member 600 has an upper surface portion 603 that is a roof portion provided with the slit 1700 of the ink tank IT. As shown in FIG. 3, a slit S is formed between the end 4008 of the member 600 and the head side end 4011 of the thin plate to which the bottom cover 800 is bonded. A slit (not shown) similar to slit S is formed. The slit thus formed between the ink tank IT and the ink supply member 600 substantially acts to further promote heat dissipation through the slit 1700, and
Even if there is unnecessary pressure applied to the inkjet unit IJT, this can be effectively prevented from being applied directly to the supply member, and ultimately to the inkjet unit IJT.

As described above, the above-mentioned configurations of this embodiment are unprecedented configurations, and each of them individually provides an effective effect, and in combination, various synergistic effects are achieved depending on each component. It can have a compositional effect.

(C) Explanation of Attachment of Inkjet Head Cartridge IJC to Carriage HC In FIG. 5, reference numeral 5000 is a platen roller that guides the recording medium P from the bottom to the top of the page. The carriage HC moves along the platen roller 5000, and the carriage HC has a front plate 40 located on the front side of the inkjet head cartridge (IJC) 1000 on the front platen side.
00 (thickness is, for example, 2 mm) and cartridge 1000.
The pad 20 corresponding to the pad 201 of the wiring board 200 of
11 and a support plate 4003 for an electrical connection part that holds a rubber pad sheet 4007 for generating elastic force to press the flexible sheet 4005 against each pad 2011 from the back side, and an inkjet cartridge 1000 at a recording position. A positioning hook 4001 for fixing is provided.

The front plate 4000 connects the positioning protrusion 4010 to the aforementioned positioning protrusion 2 of the cartridge support 300.
500 and 2600, respectively, and after the cartridge 1000 is installed, a force perpendicular to the protruding surface 4010 is applied. For this reason, a plurality of reinforcing ribs (not shown) are provided on the platen roller side of the front plate 4000 along the direction of force. Note that this rib is attached to the cartridge I.
Slightly (approximately 0.1
mm) is also formed with a head protection protrusion that protrudes toward the platen roller.

The electrical connection support plate 4003 has a plurality of reinforcing ribs 4004 in a direction perpendicular to the plane of the drawing, and the proportion of each side protrusion gradually decreases from the platen 5000 side to the hook 4001 side. This provides a function to tilt the position of the cartridge when it is installed as shown in the figure. In addition, in order to stabilize the electrical contact state, the support plate 4003 is used to position the hook side to apply an acting force to the cartridge 1000 in the opposite direction to the acting direction in which the two positioning protruding surfaces 4010 act on the cartridge 1000. It has two surfaces 4006 corresponding to the protruding surfaces 4010, forming a pad contact area between them and uniquely defining the deformation amount of the notch of the rubber sheet 4007 with a notch corresponding to the pad 2011. These positioning surfaces 4
006 is kept in contact with the surface of the wiring board 300 when the cartridge 1000 is fixed at a recordable position.

Furthermore, in this embodiment, the wiring board 30
Since the pads 201 of 0 are distributed symmetrically with respect to the above-mentioned line L1, the amount of deformation of each notch of the rubber sheet 4007 can be made uniform, and the contact pressure between the pads 2011 and 201 can be made more stable. can. The distribution of the pads 201 in this embodiment is two rows upward, two rows downward, and two columns vertically.

The hook 4001 has an elongated hole that engages with the fixed shaft 4009, and after rotating counterclockwise from the position shown in the figure using the movement space of this elongated hole, the hook 4001 moves to the platen roller 500.
The cartridge 1000 is positioned with respect to the carriage HC by moving to the left along the line 0. The hook 4001 may be moved in any way, but a configuration in which it can be moved using a lever or the like is preferable. In any case, when the hook 4001 rotates, the cartridge 1000 moves toward the platen roller 5000 and the positioning protrusions 2500, 2
600 moves to a position where it can come into contact with the positioning surface 4010 of the front plate, and as the hook 4001 moves to the left, the 90° hook surface 4002 contacts the claw 2100 of the cartridge 1000.
The cartridge 1000 is rotated in a horizontal plane around the contact area of the positioning surfaces 2500 and 4010 while in close contact with the 90° plane of the pads 201 and 2011, and finally the pads 201 and 2011 begin to come into contact with each other.

[0047] When the hook 4001 is thus held in a predetermined position, that is, a fixed position, the pads 201, 2011
Complete contact state between them and positioning protrusions 2500, 401
0 to each other, two-sided contact between the 90-degree surface 4002 and the 90-degree surface of its claw, and surface contact between the wiring board 300 and the positioning surface 4006 are simultaneously formed, and holding of the cartridge IJC to the carriage is completed. do.

(D) Description of inkjet device FIG. 6 shows an example of the configuration of an inkjet device according to the present invention. Here, 5003 is a guide shaft that guides the carriage HC in the directions of arrows a and b, and 5004 is a lead screw 50.
The carriage HC is a spiral groove formed in the guide shaft 5 according to the forward and reverse rotation of the lead screw 5005.
003 in the direction of arrow a or b. Then, while moving, recording is performed on the recording sheet P by the inkjet head IJH of the inkjet head cartridge IJC mounted on the carriage HC.

5013 is a carriage drive motor, 500
9, 5011 is a gear for transmitting the driving force of the drive motor 5013 to the lead screw 5005, and 5002 is a sheet pressing plate that presses the recording sheet P toward the platen 5000. Further, in this embodiment, the opening 5023
a cap member 5022 that covers the ejection surface forming member 400 (see FIG. 2) of the inkjet head IJH;
Suction means 50 is connected to this and sucks ink from the head IJH via the cap member 5022 during a recovery operation.
15, further includes a cleaning blade 5017 that is used before and after the recovery operation, and a support member 5016 that supports the cap member 5022. wipe away.

Reference numeral 5021 is a lever for driving the suction means 5015 via the gear 5010 and the cam 5020, and during the suction operation, the driving force is transmitted by the drive motor 5013 via the clutch switching means (not shown) and the above-mentioned transmission means. communicated. Further, 5007 and 5008 are photocouplers for detecting the home position of the carriage HC, and the home position is detected by blocking the optical path of the ejection lever 5006 provided on the carriage HC, and the forward and reverse rotation directions of the drive motor 5013 are detected. Switching etc. are performed.

In this embodiment, these capping, cleaning, and suction recovery are carried out by the lead screw 500 when the carriage HC comes to the home position side area.
Although the configuration is such that the desired processing can be performed at the corresponding positions by the action of 5, any configuration may be used as long as it is configured to perform the desired operation at a known timing. . However, this embodiment shows a preferred configuration example for the present invention.

Next, the configuration of the inkjet head IJH according to the present invention will be described in detail with reference to FIG. An overview of the configuration will be explained with reference to FIGS. 7 and 8.

FIG. 7 shows an outline of a conventional inkjet head. Here, 10 is a common liquid chamber formed in the top plate 1300, 11 is an ink discharge port formed in the ink discharge port forming member 400 integrally formed with the top plate 1300, and 12 is an ink discharge port formed in the common liquid chamber 10. This is a liquid path that guides ink to the outlet 11. Therefore, in the inkjet head configured in this way, the ink led from the ink tank IT to the common liquid chamber 10 via the ink supply port 15 is led from there to a plurality of liquid paths 12 arranged in parallel, and each By selectively driving an electrothermal converter (not shown) provided for each liquid path 12,
The ink is ejected from the ink ejection port 11.

FIG. 8 shows the top plate of the ink jet head taken out.

Conventionally, the peripheral wall of the common liquid chamber 10 formed on the side of the top plate 1300 is
Ceiling 19 where ink supply port 15 opens as shown in
a front wall 16 formed toward the arrangement of the liquid passages 12;
Side walls 1 on both sides curved as shown in (b)
7 and an upper wall 18 formed obliquely on the ceiling side between the side walls 17 and the front wall 16. Further, the ink supply port 15 was opened approximately at the center of the ceiling 19 of the common liquid chamber 10.

Therefore, as mentioned above, in the common liquid chamber 10 formed in this way, ink stagnation occurs near the left and right side walls 17 at the rear of the liquid chamber and near the rear ceiling of the ink supply port 15. Another problem is that the air bubbles generated or accumulated in these parts cannot be completely removed even if a suction recovery operation is performed.

In contrast to such a conventional inkjet head, in the present invention, the area around the common liquid chamber and the ink supply port are constructed as shown in FIG. 1. Here, 1
5 is the common liquid chamber, 5 is the ink supply port, and the ceiling 2 where the ink supply port 5 of this example is formed is shown in (a) of this figure.
, (b) and (c), the rear thereof is limited by the ink supply port 5, and the ink supply port 5 is directly connected to the semi-cylindrical rear wall 3. Further, since the front wall 6, side wall 7, and upper wall 8 are all formed in a flat plate shape, there is no place in the common liquid chamber 1 where ink may stagnate. Furthermore, as shown in (a), these walls 6, 7, and 8 and the liquid passages 12 are connected without any difference in level, so that the ink can be guided from the supply port 5 to each liquid passage 12 without stagnation. .

FIG. 9 shows the structure of an inkjet head IJH according to a second embodiment of the present invention. In this embodiment, in the top plate 1300 where the common liquid chamber 1 and the liquid path 12 are formed, the ink supply port 5 is opened directly into the rear wall of the common liquid chamber 1. In order to maintain continuity between each wall surface, the shape of the ink supply port 5 is square in this embodiment.
Further, its width is made to match the width of the ceiling 2 and the rear wall 3 to prevent the formation of corners where ink or air bubbles may accumulate. Thus, the peripheral walls forming the common liquid chamber 1, that is, the side wall 7, the upper wall 8, and the front wall 6, are all continuous with each other from the ceiling 2 or around the ink supply port 5 toward the liquid path 12. It is formed of a flat surface, and even if air bubbles enter or occur in the common liquid chamber 1,
The suction recovery operation guides these bubbles along the plane wall from the liquid path 12 to the ink discharge port 11, allowing them to be easily discharged.
Can be removed.

(Others) Note that the present invention is particularly applicable to an inkjet recording system, in which a means for generating thermal energy as the energy used to eject ink (
For example, the present invention provides an excellent effect in an inkjet head or an inkjet device that is equipped with an electrothermal converter, a laser beam, etc., and uses the thermal energy to cause a change in the state of the ink. This is because such a system can achieve higher recording density and higher definition.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, it is carried out using the basic principles disclosed in the '796 specification. This method is the so-called on-demand type.
It is applicable to both continuous types, but in particular, in the case of on-demand type, it is applicable to the electrothermal converter placed corresponding to the sheet holding the liquid (ink) or the liquid path. , by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise exceeding nucleate boiling, the electrothermal transducer generates thermal energy to produce film boiling on the thermally active surface of the recording head. liquid (ink) that corresponds one-to-one to this drive signal.
This is effective because it can form air bubbles inside. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject liquid (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in US Pat. No. 4,463,359 and US Pat.
345262 are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

[0061] The structure of the inkjet head includes a combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the heat acting portion is disposed in a bending region. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The effects of the present invention are also effective even with a configuration based on Japanese Patent Application Laid-open No. 138461/1985 which discloses a configuration corresponding to the discharge section. That is, regardless of the form of the inkjet head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type head having a length corresponding to the maximum width of a recording medium that can be recorded by an inkjet apparatus. Such an inkjet head may have a configuration in which the length is filled by a combination of a plurality of heads, or a configuration as a single head formed integrally. In addition, even with the serial type shown in the above example, the recording head fixed to the device body or installed in the device body can be electrically connected to the device body or from the device body as described in this example. The present invention is also effective when using a replaceable chip-type inkjet head that can supply ink of 100% or less, or a cartridge-type inkjet head in which an ink tank is integrally provided in the head itself.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. for the inkjet head, which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. . Specifically, these include a capping means for the inkjet head, a cleaning means, a pressurizing or suction means, a preheating means using an electrothermal converter or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

Regarding the type and number of inkjet heads to be mounted, for example, in addition to one installed for single-color ink, there are also options for multiple inkjet heads with different recording colors and densities. A plurality of them may be provided. That is, for example, the recording mode of the recording apparatus is not limited to a recording mode for only a mainstream color such as black, but may also be a recording mode in which the recording head is configured integrally or in a combination of multiple colors,
The present invention is also extremely effective for devices equipped with at least one full color by color mixture.

In addition, the inkjet apparatus of the present invention can be used as an image output terminal for information processing equipment such as a computer, a copying apparatus combined with a reader, etc., or a facsimile apparatus having a transmitting and receiving function. It may also be something that takes .

[0066]

As described above, according to the present invention, a top plate in which a common liquid chamber provided with an ink supply port and a plurality of liquid channels through which ink is guided from the common liquid chamber are formed as recesses. In an inkjet head in which ink ejection ports for ejecting ink from each of the liquid paths are integrally formed and recording is performed using ink droplets ejected from the ink ejection ports, the ink supply port is connected to the common liquid. The common liquid chamber is opened at the ceiling or wall surface farthest from the plurality of liquid paths of the chamber, and the peripheral wall of the common liquid chamber is formed by a combination of planes continuous from the ink supply port to the plurality of liquid paths. Even if air bubbles enter or occur in the chamber and grow large due to being left unattended, the suction recovery operation can easily remove the ink ejection port without causing these bubbles to remain in the common liquid chamber or liquid path. Even if the interval between recovery operations is maintained for a long time, there is no fear of recording failure due to obstruction by air bubbles, and normal recording is guaranteed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an example of the ceiling of an inkjet head of the present invention in a cross section (a), a plane (b), and a longitudinal section (c).

FIG. 2 is an exploded perspective view showing an example of the configuration of the inkjet head cartridge of the present invention.

FIG. 3 is a perspective view showing the inkjet head of the present invention in an assembled state.

FIG. 4 is a perspective view showing the inkjet head of the present invention with the inkjet head unit removed.

FIG. 5 is an explanatory diagram showing a state in which the inkjet head cartridge of the present invention is attached to a carriage.

FIG. 6 is a perspective view showing an example of the configuration of an inkjet apparatus of the present invention.

FIG. 7 is a cross-sectional view showing an outline of the configuration of a conventional inkjet head.

[Figure 8] Cross section of the ceiling of a conventional inkjet head (
FIG.

FIG. 9 shows a cross section (a), a plane (b), and a longitudinal section (c) of the ceiling of an inkjet head according to another embodiment of the present invention.
) is a configuration diagram shown by.

[Explanation of symbols]

1 Common liquid chamber 2 Ceiling 3 Rear wall 5 Ink common port 6 Front wall 7 Side wall 8 Upper wall 11 Ink discharge port 12 Liquid path IJH Inkjet head IJU Inkjet head unit 1000 (I
JC) Inkjet head cartridge IT Ink tank 100 Heater board 400 Ink discharge port forming member 900 Ink absorber 1300 Ceiling 1401 Atmospheric communication port

Claims (4)

[Claims] 1. A common liquid chamber provided with an ink supply port and a plurality of liquid paths through which ink is guided from the common liquid chamber are formed as recesses on a top plate, and ink is discharged from each of the liquid paths. In an inkjet head in which ink ejection ports are integrally formed and recording is performed using ink droplets ejected from the ink ejection ports, the ink supply port is connected to a ceiling or a wall farthest from the plurality of liquid channels of the common liquid chamber. An inkjet head characterized in that the peripheral wall of the common liquid chamber is formed by a combination of planes that are open in a wall surface and that are continuous from the ink supply port to the plurality of liquid channels. 2. The liquid path according to claim 1, further comprising an electrothermal transducer that generates thermal energy that causes film boiling in the ink as an element that generates energy for ejecting the ink. inkjet head. 3. The inkjet head according to claim 1 or 2 and an ink tank for accommodating ink supplied to the common liquid chamber are integrally configured and can be freely attached to and detached from a carriage. inkjet head cartridge. 4. Selectively converting the electrothermal transducer while moving a carriage carrying the inkjet head according to claim 1 or 2 or the inkjet head cartridge according to claim 3 along a recording material. An inkjet device that is driven to perform recording on the recording material.