JP2003103784A - Liquid discharge head, head cartridge and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that a liquid drop discharge failure or a liquid supply failure is brought about by heating of a Liquid jet head, and a printing time becomes redundant if printing work is carried out at not higher than a predetermined temperature range with a temperature sensor being incorporated in the liquid discharge head. SOLUTION: The liquid jet head 19 is provided with a head body 27 which has discharge openings from which liquid droplets are discharged, discharge energy generation parts for generating a discharge energy to discharge liquid droplets from the discharge openings, liquid chambers which are formed over the discharge energy generation parts and discharge openings and to which the liquid to be discharged from the discharge openings is supplied, and a supporting plate 28 having the head body 27 set thereto and having liquid supply paths 35 formed to communicate with liquid chambers of the head body 27. The liquid discharge head 19 is further provided with a heat radiation member 31 which has a flat part 38 joined to a face at the opposite side to a face of the supporting plate 28 where the head body 27 is set, and a heat radiation part 39 rising from the flat part 38 and meandering in a direction at right angles to the flat part 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a liquid discharge head having discharge ports for discharging liquid droplets, and a mounting portion for a liquid tank supplied to the liquid discharge head and the liquid discharge head. The present invention relates to a head cartridge and an image forming apparatus having the liquid ejection head or a mounting portion of the head cartridge, and particularly to cooling the liquid ejection head.

[0002] The "print" described in the present specification is not limited to the case of forming meaningful information such as characters and figures, but is also manifested so that it can be visually perceived by humans regardless of significant intent. It also includes the case where an image, a pattern, a pattern, or the like is widely formed on a print medium, or the print medium is processed by etching or the like regardless of whether it is a materialized product.

The "print medium" is not only a paper piece used in a general printing apparatus but also a liquid such as cloth, resin film, metal plate, glass, ceramics, wood, and leather, which can receive liquid. It also includes three-dimensional solids other than sheet-like objects, such as spheres and cylinders.

The term "liquid" is to be broadly interpreted in the same way as the definition of "print", and when applied to a print medium, it forms an image, a pattern, a pattern, etc., and a print medium such as etching. Or a treatment of ink, for example, a liquid that can be used for solidifying or insolubilizing a coloring material in the ink applied to the print medium, and includes all liquids used for printing.

[0005]

2. Description of the Related Art An ink jet printing apparatus for forming a desired image on a print medium by ejecting liquid droplets onto a print medium from an ejection port formed in an ink jet head is a so-called non-impact type printing apparatus. It is widely used as a printing mechanism for printers, word processors, facsimiles, copiers, etc. because it has the characteristics that it can perform high-speed printing on various print media and hardly generate noise during printing.

A device using an electromechanical converter such as a piezo element as a discharge energy generating portion provided for discharging a droplet from a discharge port of an ink jet head,
Known are those that irradiate electromagnetic waves such as lasers, and those that use electrothermal conversion elements. Further, due to the positional relationship between the ejection port and the ejection energy generation unit, an edge shooter type that ejects droplets substantially parallel to the surface of the substrate on which the ejection energy generation unit is provided and an ejection energy generation unit are provided. There is a side shooter type in which droplets are ejected perpendicularly to the surface of the formed substrate.

Such an ink jet head is roughly divided into two units, and an ejection port for ejecting droplets and an ejection energy generation for producing ejection energy for ejecting the droplets from the ejection port. Section, a head main body having a liquid chamber formed over the ejection energy generating section and the ejection port and supplied with liquid ejected from the ejection port, and a liquid chamber of the head main body to which the head main body is attached A head unit having a support plate in which a liquid supply path communicating with the head unit is formed, and a liquid for storing the liquid supplied to the liquid chamber of the head main body through the liquid supply path formed in the support plate of the head unit. A tank holding unit that holds a tank.

[0008]

As the printing speed of an ink jet printing apparatus is increased and the density of liquid droplets formed on a print medium is increased, that is, the integration of ejection ports is increased, the ejection energy generation unit is advanced. However, in the case of an inkjet head using an electrothermal converter, the adverse effect caused by heat generation of the head unit, particularly the head body, cannot be ignored. For example, when a printing operation with a high drive duty for the ejection energy generating section such as solid printing is performed or a high-speed printing operation is continuously performed, the temperature of the head main body rises violently and intervenes in the liquid chamber. The dissolved gas in the liquid is generated as bubbles, which accumulate in the liquid chamber and grow, resulting in defective ejection of liquid droplets from the ejection port or defective liquid supply to the liquid chamber, which forms on the print medium. Cause deterioration of the quality of the displayed image.

In the case of an ink jet head which may cause such a problem, a temperature sensor is incorporated in the head unit. For example, when the temperature of the head unit detected by the temperature sensor reaches 50 ° C., the printing work is temporarily performed. Although the printing operation is also restarted when the head unit temperature is stopped and the temperature of the head unit is lowered to 40 ° C., such a method causes the adverse effect that the printing time becomes redundant.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid ejection head capable of coping with high-speed printing work and high integration of ejection ports without causing a significant increase in cost.

Another object of the present invention is to provide a head cartridge having the liquid discharge head and a mounting portion for a liquid tank supplied to the liquid discharge head, and an image forming apparatus having the liquid discharging head or a mounting portion for the head cartridge. To provide.

[0012]

The first aspect of the present invention is as follows.
A discharge port for discharging the droplet, a discharge energy generating unit for generating discharge energy for discharging the droplet from the discharge port, and the discharge energy generating unit and the discharge port. A head main body having a liquid chamber to which the liquid discharged from the discharge port is supplied, and a support plate to which the head main body is attached and in which a liquid supply path communicating with the liquid chamber of the head main body is formed are provided. The liquid discharge head, further comprising a heat dissipation member joined to a surface of the support plate opposite to the mounting surface, the heat dissipation member comprising:
It has a flat portion joined to the surface of the support plate opposite to the mounting surface, and a heat radiating portion that rises from the flat portion and meanders in a direction perpendicular to the flat portion. is there.

According to the present invention, when the temperature of the head main body rises as the ejection energy generating section is driven, the heat generated thereby is transferred from the supporting plate to the flat section of the heat radiating member, and the flat section radiates the heat. Is mainly transmitted to the atmosphere from the heat radiating portion, so that the temperature rise of the head main body is suppressed.

A second aspect of the present invention comprises a liquid ejection head according to the first aspect of the present invention and a mounting portion of a liquid tank for storing the liquid supplied to the liquid ejection head. It is a characteristic head cartridge.

According to a third aspect of the present invention, a mounting portion of the liquid ejection head according to the first aspect of the present invention or a mounting portion of the head cartridge according to the second aspect of the present invention and the ejection portion of the liquid ejection head. An image forming apparatus comprising: a print medium conveying unit on which an image is formed by droplets discharged from an outlet.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the liquid discharge head according to the first aspect of the present invention, a pair of heat dissipation portions may be formed so as to rise from both side end portions of the flat portion.

The heat dissipation member may be formed by bending a plate material.

The discharge port and the discharge energy generating portion may be arranged so as to face each other across the liquid chamber.

The discharge energy generating section may have an electrothermal converter that applies heat energy to the liquid to cause film boiling.

In the head cartridge according to the second aspect of the present invention, the liquid tank may be removable from the mounting portion of the liquid tank.

The liquid may be a treatment liquid for ejecting ink and / or print medium to adjust the printability of the ink.

In the image forming apparatus according to the third aspect of the present invention, the carriage in which the mounting portion of the liquid ejection head or the head cartridge is capable of scanning and moving in a direction intersecting with the transport direction of the print medium on which liquid is ejected from the liquid ejection head. May be included. In this case, the liquid ejection head or the head cartridge may be detachably mounted on the carriage via the attaching / detaching means.

It is preferable that the folded portion of the heat radiating portion extends along the scanning movement direction of the carriage.

[0024]

EXAMPLES Examples in which the image forming apparatus according to the present invention is applied to a serial scan type ink jet printer will be described in detail with reference to FIGS. 1 to 11, but the present invention is not limited to these examples. , These can be further combined, and all changes and modifications included in the concept of the present invention described in the claims of the present specification can be made, and thus, of course, be applied to other techniques belonging to the spirit of the present invention. It can be applied.

FIG. 1 shows the appearance of the mechanical portion of the ink jet printer in this embodiment, and FIG. 2 shows the appearance of the head cartridge and ink tank used in this ink jet printer, which is the opposite of the head cartridge shown in FIG. The external appearance of the side is shown in FIG. That is, the chassis 10 of the inkjet printer according to the present embodiment.
Is composed of a plurality of plate-shaped metal members having a predetermined rigidity, and forms the framework of this inkjet printer. For the chassis 10, a medium feeding unit 11 that automatically feeds a sheet-shaped printing medium (not shown) into the interior of the inkjet printer, and a printing medium fed one by one from this medium feeding unit 11 are desired. To the print position and guides the print medium from the print position to the medium discharge unit 12, a print unit that performs a predetermined print operation on the print medium conveyed to the print position, and the discharge of the print unit. A head recovery unit 14 that performs recovery processing is assembled.

The printing section includes a carriage 16 supported so as to be capable of scanning along a carriage shaft 15, and a head cartridge 18 which is detachably mounted on the carriage 16 via a headset lever 17.

The carriage 16 on which the head cartridge 18 is mounted has a carriage cover 20 for positioning the print head 19 of the head cartridge 18 at a predetermined mounting position on the carriage 16, and a tank holder 21 of the head cartridge 18. The aforementioned head set lever 17 is provided which engages and presses the print head 19 so as to position it at a predetermined mounting position.
The headset lever 17 functions as a part of a means for attaching / detaching the head cartridge 18 to / from the carriage 16, is rotatably attached to a head set lever shaft (not shown) provided on the upper portion of the carriage 16, and is also a head cartridge. A not-illustrated headset plate that is spring-biased is provided at an engaging portion with 18, and the head cartridge 18 is mounted on the carriage 16 while pressing the print head 19 to a predetermined mounting position by the spring force of the headset plate. It is designed to be worn.
That is, the print head 19 in this embodiment employs a so-called cartridge system, which is detachably mounted on the carriage 16.

Carriage 1 for print head 19
One end of a contact flexible printed cable (hereinafter referred to as a contact FPC) 22 is connected to another engaging portion of 6, and a contact portion (not shown) formed at one end of the contact FPC 22 and the print head 1
Contact portion 2 which is an external signal input terminal provided at 9
3 and 3 are electrically contacted with each other so that various kinds of information for printing can be exchanged and power can be supplied to the print head 19.

An elastic member (not shown) such as rubber is provided between the contact portion of the contact FPC 22 and the carriage 16, and the contact FPC 22 is caused by the elastic force of this elastic member and the pressing force of the headset plate.
Contact part and contact part 2 of print head 19
It is possible to make a reliable contact with 3. The other end of the contact FPC 22 is connected to a wiring board (not shown) mounted on the back surface of the carriage 16.

The head cartridge 18 in this embodiment
4 shows the disassembled structure of FIG. 4, the plan shape of the print head 19 is shown in FIG. 5, and the cross-sectional structure taken along the line VI-VI is shown in FIG. That is, in the head cartridge 18 in this embodiment, the above-mentioned tank holder 21 to which the ink tank 24 that stores ink is detachably mounted, and the ink supplied from the ink tank 24 is stored in the print head 19 according to the print information. It has the above-mentioned print head 19 for ejecting from the ejection port 25.

In the present embodiment, in order to enable high-quality color printing having multi-level lightness, for example, black, light cyan, light magenta, cyan, magenta, and yellow inks are independent. Six ink tanks 24 can be used. Each ink tank 24 is provided with an elastically deformable removal lever 26 that can be locked to the tank holder 21 of the head cartridge 18. By operating this removal lever 26, as shown in FIG. In addition, the ink tank 24
Are removable. That is, the levers 26 for detachment function as a part of the means for attaching and detaching the ink tank 24 to and from the tank holder 21 of the head cartridge 18.

The print head 19 in this embodiment is
The head main body 27, the base plate 28, the electric wiring board 29, the spacers 30, the heat dissipation member 31, and the like are included, and the tank holder 21 is configured with the flow path forming member 32, the filter 33, the seal rubber 34, and the like.

The head main body 27 is adhesively fixed to the surface side of the base plate 28 together with the spacer 30, and the base plate 2
An ink supply passage 35 for supplying ink to the head main body 27 is formed at 8. The base plate 28 is made of, for example, alumina (Al ₂ O ₃ ) having a thickness of 0.5 to 10 mm.
The base plate 28 can be formed by using a material having a thermal expansion coefficient equal to or higher than that of the head main body 27 and a thermal conductivity equal to or higher than the thermal conductivity of the head body 27. The spacer 30 has an opening 3 that surrounds the head body 27.
6 is formed, and the electric wiring board 29 joined to the spacer 30 is electrically connected to the head main body 27. The spacer 30 provided so that the head body 27 and the electric wiring board 29 can be connected in a plane is
For example, it is made of alumina with a thickness of 0.5-1 mm,
As long as the material has a coefficient of linear expansion equivalent to that of the head body 27 and the base plate 28, it is naturally possible to use materials other than alumina. The electric wiring board 29 is the head body 27.
For applying an electric signal for ejecting ink to the head main body 27, and the above-mentioned contact located at the end of the electric wire for receiving the electric signal from the printer main body. The contact portion 23 is positioned and fixed on the back side of the tank holder 21. That is, the electric wiring board 2
9 is bent along the base plate 28 and the tank holder 21, and the contact portion 23 is fixed to the tank holder 21.

Base plate 28 having an ink supply passage 35 open
A heat dissipation member 31 as shown in FIG. 7 is filled and bonded to the back surface side of the via a filler 37 having a good thermal conductivity such as silver paste. The heat dissipation member 31 is formed at a low cost by pressing or drawing a metal plate having a plate thickness of about 1 to 3 mm, particularly aluminum or copper having good thermal conductivity, or an alloy of these, if necessary. Correspondingly, a surface treatment is performed to improve the corrosion resistance. The heat dissipating member 31 of the present embodiment rises from both sides of the flat portion 38 that is joined to the back surface of the base plate 28 in a substantially close contact state and the flat portion 38 that is orthogonal to the scanning movement direction of the carriage 16, and the carriage 16 And a pair of heat radiating portions 39 that are bent so as to meander along a direction orthogonal to the scanning movement direction. An opening 40 is formed in the central portion of the flat portion 38 for allowing the passage forming member 32 connected to the ink supply passage 35 of the base plate 28 to pass therethrough.
The pair of heat radiating portions 39 facing each other across the flow path forming member 32 of the tank holder 21 are arranged so as not to directly face the wind generated by the scanning movement of the carriage 16.
6 is preferably extended along the scanning movement direction,
An arbitrary shape that can obtain a sufficient heat dissipation area can be adopted. In the present embodiment, the filler 3 is also applied to a part of the heat dissipation portion 39, that is, the folded-back portion 41 that abuts the flat portion 38.
Since 7 is interposed, heat can be efficiently transferred from the flat portion 38 to the heat radiating portion 39.

By adopting such a structure, the heat generated when the print head 19 is driven is transmitted to the heat radiating member 31 via the base plate 28, and the wind generated by the scanning movement of the carriage 16, especially the heat radiating portion. Since the heat is efficiently radiated from 39 to the atmosphere, the temperature rise of the print head 19 can be suppressed. By the way, when the liquid droplets are ejected at the driving frequency of 30 kHz to the ejection ports 25 having the arrangement interval of 1200 dpi, a wind of 0.635 m / s is generated when the carriage 16 scans and moves. The heat is dissipated from the heat dissipating member 31 to the atmosphere by utilizing the heat radiation, and the print head 19 can be cooled efficiently.

In the tank holder 21 that detachably holds the ink tank 24, the ink supply passage 35 of the base plate 28 is provided.
The flow path forming member 32, which is connected to the flow path forming member 32 via the elastically deformable seal ring 42, is integrally fixed by, for example, ultrasonic welding to form an ink flow path from the ink tank 24 to the flow path forming member 32. . As the seal ring 42 that is required to have gas barrier properties and ink resistance, it is preferable to adopt an epoxy resin-based sealing material, chlorinated butyl rubber, EPDM rubber, or the like. The filter 33 provided at the end portion of the ink flow path on the ink tank 24 side can prevent dust from entering from the outside. Seal rubber 34 attached to the engaging portion with the ink tank 24
Is for preventing evaporation of ink from these engaging portions.

The tank holder 21 is integrally assembled with the flow path forming member 32, the filter 33, the seal rubber 34 and the like, the head body 27, the base plate 28, the electric wiring board 29, the spacer 30 and the heat dissipation member 31. The head cartridge 18 is configured by connecting the print head 19 with an adhesive or the like.

The appearance of the head body 27 in this embodiment is shown in FIG. 8 in a partially broken state. That is, the head body 27 in this embodiment has a thickness of 0.5 mm to 1.0 mm.
The ejection energy generating portion, the common ink chamber 44, the ejection port 25, etc. are formed on the silicon substrate 43 of mm by using the film forming technique. The passage 45 is formed by anisotropic etching or the like utilizing its crystal orientation. On both sides of the ink passage 45, a plurality of (128 in one side in this embodiment) electrothermal converters 46 arranged in two rows at predetermined intervals along the longitudinal direction of the ink passage 45 are shifted from each other by a half pitch. Are formed, and each constitutes a discharge energy generating portion. On the silicon substrate 43, in addition to these electrothermal converters 46, bump-shaped connecting terminals 47 formed of gold or the like for electrically connecting the electrothermal converters 46 and the electric wiring board 29 and aluminum are used. The electric wiring (not shown) to be formed is formed by a film forming technique, and a drive signal to the electrothermal converter 46 is given from a drive IC (not shown) through these connection terminals 47, and at the same time, drive power is supplied to the electrothermal conversion. Supplied to body 46.

An ink passage 45 is formed on the silicon substrate 43.
Through the common ink chamber 44 communicating with the electrothermal converter 46.
An upper plate member 48 having a plurality of discharge ports 25 facing each other is provided. That is, an ink path 49 communicating with each of the ejection ports 25 and the common ink chamber 44 is formed between the upper plate member 48 and the head body 27, and a partition wall 50 is provided between the adjacent ink paths 49. Is formed.
The common ink chamber 44, the ink passage 49, the partition wall 50, and the like are formed together with the upper plate member 48 by the photolithography technique like the ejection port 25.

The liquid supplied from the ink passages 45 into the respective ink passages 49 is supplied with a drive signal to the electrothermal converters 46 facing the corresponding ink passages 49, so that the electrothermal converters 46 generate heat. The liquid is boiled and discharged from the discharge port 25 by the pressure of bubbles generated thereby.

In the above-described embodiment, the folded back portion 41 of the heat radiating portion 39 of the heat radiating member 31 is spring-back generated immediately after the heat radiating member 31 is processed, so that the close contact with the flat portion 38 of the heat radiating member 31 is deteriorated. In some cases, heat transfer may not be performed well in the area. In order to prevent such a problem, it is also effective to mechanically connect the flat portion 38 of the heat dissipation member 31 and the folded portion 41 of the heat dissipation portion 39.

The print head 1 according to the present invention as described above.
9 shows a sectional structure of another embodiment of FIG. 9 and FIG. 10 shows the bottom shape thereof. However, elements having the same functions as those of the previous embodiment are denoted by the same reference numerals, and duplicate explanations are omitted. It shall be. That is, in this embodiment, the fitting holes 51 are formed at a predetermined interval in a part of the flat portion 38 that faces the folded-back portion 41 of the heat radiating portion 39, and the heat radiating portion 39 is fitted so as to fit into these fitting holes 51. By caulking a part of the folded-back portion 41, the fitting hole 51 and the protrusion 52 penetrating therethrough are formed.
And are joined together. Thereby, the heat dissipation member 3
The flat portion 38 of No. 1 and the folded-back portion 41 of the heat radiating portion 39 are surely coupled to each other, so that heat can be satisfactorily transferred from the flat portion 38 to the heat radiating portion 39. Also, if necessary, the protrusion 5
It is also possible to apply the filler 37 between the flat portion 38 and the folded portion 41 of the heat radiating portion 39 so as to surround 2.

In order to increase the heat radiation area of the heat radiation portion 39 of the heat radiation member 31, it is possible to fold the heat radiation portion 39 in a more complicated manner. For example, a diagram showing a sectional structure of another embodiment of the print head 19 according to the present invention. As shown in FIG. 11, complicated unevenness 53 can be formed in a part of the heat dissipation portion 39. Such complicated irregularities 53 contribute to increase the heat dissipation area of the heat dissipation unit 39 and also increase the rigidity of the heat dissipation unit 39 itself.

The present invention comprises means for generating thermal energy as the energy used for ejecting the liquid (for example, an electrothermal converter or laser light), and this thermal energy causes a change in the state of the liquid. The present invention has excellent effects in an inkjet liquid ejection head, a head cartridge, or an image forming apparatus. This is because according to such a method, high density and high definition printing can be achieved.

Regarding its typical structure and principle, for example, US Pat. No. 4,723,129 and US Pat.
What is done using the basic principles disclosed in 796 is preferred. This method is applicable to both the so-called on-demand type and the continuous type, but in the case of the on-demand type in particular, the electrical device arranged corresponding to the sheet or flow path holding the liquid. Thermal energy is generated by applying at least one drive signal that gives a rapid temperature rise exceeding nucleate boiling corresponding to print information to the heat conversion element, and causes film boiling on the heat-acting surface of the liquid ejection head. As a result, bubbles can be formed in the liquid in a one-to-one correspondence with this drive signal, which is effective. By the growth and contraction of the bubbles, the liquid is ejected through the ejection port 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 with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. No. 4,463,359 and US Pat. No. 4,345,262 are suitable.

By adopting the conditions described in US Pat. No. 4,313,124, which is an invention relating to the rate of temperature rise of the heat acting surface, more excellent printing can be performed.

As the constitution of the liquid discharge head, the combination constitution of the discharge port, the liquid passage and the electrothermal converter as disclosed in the above-mentioned specifications (the electrothermal converter is arranged along the liquid passage). U.S. Pat. No. 455, which discloses a configuration in which the heat-acting portion is arranged in a region in which the heat-acting portion is bent, in addition to the straight liquid passage or the electrothermal converter (a right-angled liquid passage that faces the discharge port with the liquid passage in between).
The present invention includes a configuration using the specification of 8333 and the specification of US Pat. No. 4,459,600. In addition, JP-A-59-59 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters.
Japanese Laid-Open Patent Publication No. 123670 and Japanese Patent Laid-open No. Sho 59-59, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge portion.
The effect of the present invention is effective even with a configuration based on Japanese Patent Laid-Open No. 138461. That is, according to the present invention, it is possible to perform printing reliably and efficiently regardless of the form of the liquid ejection head.

The present invention can be effectively applied to a full-line type liquid ejection head having a length corresponding to the maximum width of a print medium that can be printed by the image forming apparatus.
Such a liquid ejection head may have a configuration that fills the length by a combination of a plurality of liquid ejection heads or a configuration as one liquid ejection head integrally formed.

Even in the case of the serial type as in the above-described embodiment, the liquid ejection head fixed integrally to the carriage which moves in scanning and the electrical connection with the carriage by being exchangeably attached to the carriage. When using a replaceable chip-in type head cartridge that enables various connections and supply of liquid from the device body, or a head cartridge in which a liquid storage head itself is provided with a tank that stores liquid in an integrated or replaceable manner Also, the present invention is effective.

As the constitution of the image forming apparatus of the present invention, by adding a recovery means for making the ejection state of the liquid from the liquid ejection head proper, a preliminary auxiliary means and the like, the effect of the present invention is further stabilized. It is possible because it is possible.
Specific examples thereof include capping means for the liquid ejection head, cleaning means, pressurization or suction means, preheating means for heating using an electrothermal converter or a heating element other than this, or a combination thereof. Preliminary ejection means for ejecting separately from the printing work can be mentioned.

Regarding the type and number of liquid ejection heads to be mounted, for example, only one is provided corresponding to a single color ink, and a plurality of types of ink having different hues and densities (lightness) are also supported. And a plurality of them may be provided. That is, for example, the print mode of the image forming apparatus is not limited to the print mode of only the mainstream color such as black, and the liquid discharge head may be integrally configured or a plurality of combinations may be used. The present invention is also extremely effective for an image forming apparatus having at least one of full-color print modes of color color or mixed color. In this case, it is also effective to eject the treatment liquid (printability improving liquid) for adjusting the printability of the ink onto the print medium from a dedicated or common liquid ejection head in accordance with the type of print medium and the print mode.

In the embodiment of the present invention described above,
A liquid that solidifies at room temperature or lower and softens or liquefies at room temperature may be used, or in the inkjet method, the temperature of the liquid itself is adjusted within the range of 30 ° C to 70 ° C to stabilize the viscosity of the liquid in a stable discharge range. Since the temperature control is generally performed as described in (1), a liquid state may be used when the use print signal is applied. In addition, in order to positively prevent the temperature rise due to thermal energy as the energy of the state change from the solid state to the liquid state, or to prevent the liquid from evaporating, it is solidified in the standing state and liquefied by heating. You may use what does. In any case, it liquefies by applying heat energy according to the print signal, and liquefies only when heat energy is applied, such as those that eject liquid and those that already start to solidify when reaching the print medium. The present invention can be applied to the case of using a material having a property. In such a case, the liquid is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Then, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned liquids is to execute the above-mentioned film boiling method.

The form of the image forming apparatus according to the present invention is used as an image output terminal of information processing equipment such as a computer, a copying machine combined with a reader or the like, and a facsimile machine or a textile printing machine having a transmitting / receiving function. Alternatively, the print medium may be in the form of an etching device, and the print medium may be a sheet or a long paper or cloth, or a plate-like wood or leather,
In addition to stone materials, resins, glass, metals, etc., three-dimensional three-dimensional structures can be cited.

[0054]

According to the liquid discharge head of the present invention, the flat portion joined to the surface of the support plate opposite to the mounting surface of the head body, and the flat portion rising from the flat portion to the flat portion. Since the heat radiation member having the heat radiation portion meandering in the vertical direction is joined, the heat generated in the head body can be efficiently transmitted from the flat portion of the heat radiation member to the heat radiation portion, and can be radiated to the atmosphere. Therefore, it is possible to suppress the temperature rise of the head main body, and it is possible to increase the printing speed and increase the integration of the ejection ports without increasing the cost. As a result, 1
It is possible to realize six sets of liquid discharge head units having a set of liquid discharge heads, for example, 600 or 1200 discharge ports, and it is possible to print a color image having high lightness gradation at an ultrahigh speed.

When at least one folded portion of the heat radiating portion is brought into contact with or joined to the flat portion, the contact area between the flat portion and the heat radiating portion increases, and heat is efficiently transferred from the flat portion to the heat radiating portion. Therefore, the heat dissipation of the heat dissipation member can be further enhanced.

When a pair of heat radiating portions is formed by rising from both end portions of the flat portion, the contact area between the flat portion and the heat radiating portion is increased, so that heat can be efficiently transferred from the flat portion to the heat radiating portion. As a result, the heat dissipation property of the heat dissipation member can be further improved, and the assembling property at the time of manufacturing can be improved by making the heat dissipation member symmetrical.

When the heat dissipating member is formed by bending the plate material, the heat dissipating member can be manufactured at low cost.

In the head cartridge according to the present invention, when the liquid tank can be attached to and detached from the mounting portion, even if the liquid stored in the liquid tank is used up, it can be replaced by a new liquid tank. Head cartridge can be used.

When the folded portion of the heat radiating portion extends along the scanning movement direction of the carriage, the wind generated by the scanning movement of the carriage flows along the heat radiating portion.
The heat can be satisfactorily dissipated from the heat radiating portion to the atmosphere.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a main part of an embodiment in which an image forming apparatus according to the present invention is applied to a serial type inkjet printer.

FIG. 2 is an exploded perspective view of a head cartridge and an ink tank used in the embodiment shown in FIG.

FIG. 3 is a perspective view showing an appearance of the head cartridge shown in FIG.

FIG. 4 is an exploded perspective view of the head cartridge shown in FIG.

5 is a plan view of an inkjet head portion of the head cartridge shown in FIG.

6 is a sectional view taken along the line VI-VI in FIG.

FIG. 7 is an extracted enlarged perspective view of the heat dissipation member shown in FIG.

8 is a cutaway perspective view showing an appearance of a head main body portion of the inkjet head shown in FIG.

FIG. 9 is a cross-sectional view of another embodiment in which the liquid ejection head according to the present invention is applied to an inkjet head.

FIG. 10 is a bottom view of the inkjet head shown in FIG.

FIG. 11 is a cross-sectional view of another embodiment in which the liquid ejection head according to the present invention is applied to an inkjet head.

[Explanation of symbols]

10 Chassis 11 Medium Feeding Section 12 Medium Ejection Section 13 Medium Conveying Section 14 Head Recovery Section 15 Carriage Shaft 16 Carriage 17 Headset Lever 18 Head Cartridge 19 Printhead 20 Carriage Cover 21 Tank Holder 22 Contact Flexible Print Cable (Contact FPC) 23 Contact part 24 Ink tank 25 Ejection port 26 Removal lever 27 Head body 28 Base plate 29 Electric wiring board 30 Spacer 31 Radiating member 32 Flow path forming member 33 Filter 34 Seal rubber 35 Ink supply path 36 Opening 37 Filling material 38 Flat part 39 Heat dissipation part 40 Opening 41 Heatsink return part 42 Seal ring 43 Silicon substrate 44 Common ink chamber 45 Ink passage 46 Electrothermal converter 47 Connection terminal 48 Upper plate member 49 Ink passage 50 Rikabe 51 fitting hole 52 protrusion 53 uneven

Claims (13)

[Claims] 1. A discharge port for discharging a droplet, a discharge energy generating unit for generating discharge energy for discharging a droplet from the discharge port, and the discharge energy generating unit and the discharge port. And a head main body having a liquid chamber to which the liquid discharged from the discharge port is supplied, and a support to which the head main body is attached and a liquid supply path communicating with the liquid chamber of the head main body is formed. A liquid discharge head comprising a plate, further comprising a heat dissipation member bonded to a surface of the support plate opposite to the mounting surface,
The heat dissipation member has a flat portion joined to a surface of the support plate opposite to the mounting surface, and a heat dissipation portion rising from the flat portion and meandering in a direction perpendicular to the flat portion. Characteristic liquid ejection head. 2. The liquid ejection head according to claim 1, wherein at least one folded-back portion of the heat dissipation portion is in contact with or joined to the flat portion. 3. The liquid ejection head according to claim 1, wherein the heat radiation portion is formed in a pair so as to rise from both side end portions of the flat portion. 4. The liquid ejection head according to claim 1, wherein the heat dissipation member is formed by bending a plate material. 5. The liquid discharge according to claim 1, wherein the discharge port and the discharge energy generating section are arranged to face each other across the liquid chamber. head. 6. The liquid according to claim 1, wherein the discharge energy generating unit has an electrothermal converter that applies heat energy to the liquid to cause film boiling. Discharge head. 7. A liquid ejection head according to claim 1, and a mounting portion for a liquid tank for storing the liquid supplied to the liquid ejection head. A head cartridge that does. 8. The head cartridge according to claim 7, wherein the liquid tank is attachable to and detachable from a mounting portion of the liquid tank. 9. The head cartridge according to claim 7, wherein the liquid is a treatment liquid for adjusting the printability of the ink and / or the ink ejected onto the print medium. 10. A liquid ejection head mounting portion according to any one of claims 1 to 6, or a head cartridge mounting portion according to any one of claims 7 to 9; An image forming apparatus comprising: a print medium conveying unit on which an image is formed by droplets discharged from a discharge port of a head. 11. The liquid ejecting head or the mounting portion of the head cartridge has a carriage capable of scanning and moving in a direction intersecting a transport direction of a print medium on which liquid is ejected from the liquid ejecting head. The image forming apparatus according to claim 10. 12. The liquid ejecting head or the head cartridge is detachably mounted on the carriage via an attaching / detaching means.
The image forming apparatus according to item 1. 13. The image forming apparatus according to claim 11, wherein the folded-back portion of the heat dissipation portion extends along a scanning movement direction of the carriage.