JPH07314688A - Ink-jet head and ink-jet recording device - Google Patents

Abstract

PURPOSE:To provide an ink-jet head and ink-jet recording device wherein a temperature detecting performance of the head temperature detecting device is improved and a temperature rise of a head is controlled. CONSTITUTION:In an ink-jet head provided with an electricity heat converter possessing a heating resistor 1 generating heat energy to be used to discharge ink by imparting heat energy directly to the ink on a heat acting surface by electrification and possesses at least two liquid chambers (ink reservoirs) which are independent of each other, a temperature detecting part 5 of the head is provided except for an end part of the head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head and an ink jet recording apparatus, and more particularly to suppressing temperature rise in color printing and multi-valued heads.
It should be noted that the term "recording" as used herein includes ink application and the like (printing) to all ink supports that receive ink, such as cloth, thread, paper, and sheet material. It includes a printer as its output device, and the present invention can be applied to these.

[0002]

2. Description of the Related Art In recent years, the demand for non-impact printers has been increasing due to their quiet design, high printing quality and low running cost. Various printers are provided by various companies to meet this demand, but no product has completely met the demand. Therefore, it is necessary to sufficiently satisfy the above requirements.

The ink jet system described in US Pat. No. 4,723,129, US Pat. No. 4,740,796, etc., is capable of high-speed, high-density, high-definition and high-quality recording, and is suitable for colorization and compactness. In recent years, it has been attracting attention. In a typical example of an apparatus using this method, since ink (recording liquid or the like) is ejected by using thermal energy, there is a heat acting portion that applies heat to the ink. That is, a heating resistor having a heat acting portion is provided corresponding to the ink path, the thermal energy generated from the heating resistor is used to rapidly heat the ink to cause foaming, and the foaming ejects the ink. Is.

The heat acting portion applies heat to the object.
From the viewpoint, the conventional so-called thermal head
Although there are some parts that are similar to the configuration of
Ink directly at the points where it directly contacts the ink
Mechanical impact due to repeated (cavitation ero
John) and the heat acting part is 10 ^-1
10 in an extremely short time of the order of 10 μsec
Exposed to rising and falling temperatures close to 00 degrees
The fundamental technology differs greatly from the thermal head in some respects.
Become. Therefore, thermal head technology is used in bubble jet technology.
Needless to say, it cannot be applied directly to surgery
Absent. In other words, thermal head technology and inkjet
Technology cannot be discussed in the same line.

By the way, the heat acting portion of the ink jet head is exposed to the harsh environment as described above.
_An electrically insulating layer composed of ₂ , SiC, Si ₃ N _4, etc.,
Further, it is a general structure that a cavitation erosion layer made of Ta or the like is further provided thereon to protect the heat acting portion from the environment of use. Proposals have been made for thermal inkjet heads that use it, but for printers that support recent colors, inkjet printers that use multiple heads and multiple inks in one head can reduce the size of the printer. There is an inexpensive color inkjet printer. Since the printer uses a plurality of heads, the cost is high, and the technology is gradually shifting to a head integrated color printer described later. With this integrated head that has multiple colors in one head, the head temperature rises when you continue to hit a specific color, and when you try to hit a color that has not been used until now, the ink at the ejection port solidifies and printing is impossible. Was sometimes.

Further, when printing is performed in winter or cold regions, if the environmental temperature is too low, the viscosity of the ink is high and sufficient quality printing cannot be obtained. It is necessary to heat up.

The cause of the above-mentioned defects is mainly that the heat of printing raises the temperature of the entire head, so that the solvent and water in the ink evaporate.

In order to solve this problem, a temperature detecting means is provided in the head to control the pulse width and limit the number of pulses to prevent the head temperature from rising. However, in the conventional structure, the temperature detection unit is located at the end of the substrate, and the temperature of the entire head is detected by the average of the temperatures at both ends of the substrate. The liquid of the unused color ink adjacent to the head of the frequently used color may evaporate, and may not be ejected when actually used.

Further, when designing in consideration of printing life, the most frequently used color is designed so as to satisfy the above-mentioned life, and therefore the protective film is a protective film corresponding to the most frequently used color. Since it is adjusted to the film thickness of other films, it is unnecessary for other colors (printing life is proportional to the thickness of the protective film).

Therefore, the energy use efficiency is low when using a color that is printed infrequently, which results in an increase in the temperature of the substrate during printing.

On the contrary, when the temperature of the head is low, the viscosity of the ink is high and the ejection amount of the ink is small. To prevent this, a temperature control heater is provided in the head for maintaining the head at an appropriate temperature. Has been done. The above-mentioned temperature detecting means and the below-mentioned temperature adjusting heater are usually provided at positions close to each other on the same plane.

[0012]

The temperature control heater and the temperature detection means arranged as described above are located in the immediate vicinity before the entire head is warmed when the temperature control heater heats up due to the positional situation. Detects the temperature and stops heating. Therefore, there is a drawback that the temperature of the head cannot be controlled accurately.

Further, in the conventional temperature sensor using TCR (thermal resistance coefficient), it is necessary to take a large initial resistance value in order to use the change in resistance as the change in temperature. However, in the case where the temperature sensor of the inkjet head is placed in the same plane as the discharge heater for discharging ink and the temperature control heater, if the area of the sensor is increased to increase the resistance value, the board cost increases. , The substrate size cannot be increased. Therefore, the conventional heater in which the substrate heating heater (temperature control heater) and the temperature detecting means are disposed at substantially the same location has a drawback that the temperature detection sensitivity is low and accurate temperature control cannot be performed because the resistance value cannot be large. Have.

In view of such circumstances, an object of the present invention is to
An object of the present invention is to provide an inkjet head and an inkjet recording apparatus in which the temperature detection performance of the head temperature detection means is further improved and the temperature rise of the head is suppressed.

[0015]

The first ink jet head of the present invention which achieves the above object comprises a plurality of electrothermal converters having heating resistors which generate the thermal energy used for ejecting ink. An ink jet head having a group constituted by, wherein the temperature detecting means of the head is provided between the group on the same substrate as the substrate on which the plurality of electrothermal converter groups are provided. And

The second ink jet head of the present invention is
The first inkjet head is characterized in that a plurality of liquid chambers independent of each other are provided corresponding to the group of electrothermal converters.

The third ink jet head of the present invention is
In the second inkjet head, the temperature detecting means is provided in at least one or more liquid chambers of two or more liquid chambers independent of each other.

The fourth ink jet head of the present invention is
In the first inkjet head, the temperature detecting means is provided between a group of the electrothermal converters that is most frequently used and a group adjacent thereto.

The fifth ink jet head of the present invention is
In the second inkjet, the temperature detecting means is
Among the two or more liquid chambers independent of each other, at least the liquid chambers corresponding to the most frequently used group are provided.

The sixth ink jet head of the present invention is
In the first inkjet head, the temperature detecting means is provided in parallel with the short side of the substrate of the inkjet head, and the length of the temperature detecting range is longer than the length of the heating resistor.

The seventh ink jet head of the present invention is
Two or more independent electric heat converters, each having an exothermic resistor having a heating resistor for generating thermal energy by directly applying thermal energy to the ink on the heat acting surface to eject the ink. In the inkjet head having the liquid chamber, the means for detecting the temperature is provided in a portion over the length of the short side of the substrate of the inkjet head and excluding the external connection portion.

The eighth ink jet head of the present invention is
In the seventh inkjet head, the temperature detecting means is not on the same straight line parallel to the short side of the head temperature control heater and the substrate of the head.

The ninth ink jet head of the present invention is
In the seventh inkjet head, the temperature detecting means is provided at a position other than the end portion of the head.

A tenth ink jet head of the present invention is the seventh ink jet head, wherein the temperature detecting means is provided between at least one or more of two or more liquid chambers independent of each other. To do.

An eleventh ink jet head of the present invention is the seventh ink jet head, wherein the temperature detecting means is provided in at least one liquid chamber of two or more liquid chambers independent of each other. To do.

The twelfth ink-jet head of the present invention is the seventh ink-jet head, wherein the temperature detecting means is adjacent to the most frequently used color of the two or more liquid chambers independent of each other. It is characterized in that it is provided between a liquid chamber having a high frequency and a liquid chamber adjacent thereto.

A thirteenth ink-jet head of the present invention is the ink-jet head of the seventh invention, wherein the temperature detecting means is one of two or more liquid chamber colors independent of each other.
It is characterized in that it is provided in a liquid chamber of at least the most frequently used color.

The fourteenth ink-jet head of the present invention is an electric heater having a heat-generating resistor which is generated by energizing the heat energy used to eject the ink by directly applying the heat energy to the ink on the heat acting surface. In an ink jet head having a converter and having two or more liquid chambers independent of each other, the protective film of the heating resistor has at least one protective film of the heating heater in the liquid chamber, It is characterized in that it is different from the film thickness of the protective film of the heat generating heater in the liquid chamber.

A fifteenth ink jet head of the present invention is the ink jet head according to the fourteenth ink jet head, wherein the protective film has a two-layer structure, and a part of the protective film is formed by removing one layer of the two-layer protective film. It is characterized by changing.

A sixteenth ink jet head of the present invention is the ink jet head according to the fourteenth ink jet head, wherein the protective film has a structure of three or more layers, and a part of the structure changes the film thickness by removing the uppermost part of the three layers. It is characterized by

A seventeenth ink-jet head of the present invention is characterized in that, in the fourteenth ink-jet head, a part of the protective film is changed in thickness by etching with a liquid.

An eighteenth ink-jet head of the present invention is characterized in that, in the fourteenth ink-jet head, a part of the protective film has its film thickness changed by plasma etching using gas.

A nineteenth ink jet head of the present invention is characterized in that, in the sixteenth ink jet head, the intermediate second layer of the protective film is a material capable of being selectively etched with a material of the uppermost layer.

A twentieth ink jet head of the present invention is the ink jet head according to any one of the fourteenth to eighteenth ink jet heads, wherein the protective film is made of Si ₃ N ₄ and Ta. It is characterized by being etched.

A twenty-first ink jet head of the present invention is the ink jet head according to any one of the fourteenth to nineteenth aspects, wherein the protective film is made of Si ₃ N ₄ , Al and Ta, and the protective film is one layer. Is characterized by etching Ta.

[0036] 22 ink jet head of the present invention, in the fourteenth ink jet head, the protective layer is made of Si ₃ N ₄ and Al and Si ₃ N _4, a portion of the protective film, the uppermost Si ₃ It is characterized in that the film thickness is changed by etching N ₄ .

A twenty-third ink jet recording apparatus of the present invention is an ink jet recording apparatus having any one of the first to twenty second ink jet heads, wherein the ink jet head is detachable from the recording apparatus main body. Characterize.

[0038]

According to the present invention, by providing a temperature detecting means between a color most frequently used and a color adjacent thereto in a head having two or more independent liquid chambers in the head, the temperature of the head can be reduced. It is possible to accurately grasp the climbing condition.

Further, the head heating temperature can be grasped as the temperature of the entire head by making the position far from the head heating heater.

In addition, the area of the temperature sensor is made as large as possible in parallel with the short side of the head substrate to improve the temperature detecting ability.

Further, by increasing the thickness of the protective film of at least one of the two or more liquid chambers, which is the most frequently used head, and reducing the thickness of the protective films of other colors, the energy is reduced. The present invention provides an ink jet printer that maintains good print quality by improving the use efficiency of the whole head and suppressing the temperature rise of the whole head.

More specifically, according to the present invention, a large number of colors are used in a temperature detection area having a length substantially equal to the length of the short side of the substrate of the head and a sufficient width between the color frequently used and the color adjacent thereto. By providing a thin film resistor that has been diffracted back so that the resistance change is sufficient even for a minute temperature of the head, the temperature rise of the head during printing can be optimally controlled, and it can be unused for a long time. In addition to preventing non-ejection of colors, when the head is heated when the environmental temperature is low and the temperature is not appropriate, the temperature detection means described above is far away from the heater so that the heater can detect the temperature at which the head has been sufficiently warmed. This makes it possible to print at an optimum head temperature, which helps improve print quality.

Further, the protective film of the most frequently used color in the head is thicker than the other colors to satisfy the printing life, and otherwise, the optimum protective film thickness improves the printing efficiency. The temperature rise of the head can be suppressed to the minimum.

[0044]

EXAMPLES The present invention will be described below based on examples.

FIG. 1 shows an embodiment of the present invention, in which 1 and 2 are a heating resistor and a wiring conductor constituting an electrothermal converter, 3 is a head heater, 4 is a substrate, and 5 is a temperature. It is a detection unit.

The manufacturing method of this embodiment will be described with reference to the drawings.

HfB ₂ Ti was deposited on a Si wafer with a thermal oxide film.
Al is sequentially sputtered, a resist pattern is formed by a photolithography method, and Al is etched with a nitric acid / phosphoric acid-based etching solution. Next, after the Al resist is peeled off, HfB ₂ resist is formed. The HfB ₂ etching is dry etching using reactive ion etching (RIE). After removing the resist by ashing, Si ₃ N ₄ and Ta are sequentially sputtered as a film that protects the resistance from cavitation that occurs when the resistance oxidizes at high temperature and ink bubbles disappear. First, a resist pattern for etching the upper Ta film is formed. T of the part that requires cavitation
A is left and the others are removed by etching. Then
A resist pattern is formed to open a through hole for connecting the wiring under the protective film and the outside to the protective film.
Etch ₃ N ₄ . The formation of the ink flow path is performed by exposing and developing after welding the dry film in this wafer state,
Bond the top plate. This top plate has a hole for introducing ink, and a filter is adhered to the ink introducing hole in order to prevent dust from entering the ink discharge port. After that, a pipe for supplying ink from the ink cartridge is connected, and a cover for holding the whole is adhered to complete the ink jet head of this embodiment.
In the present embodiment, as shown in FIG. 1, an electrothermal converter group (book) provided for ejecting black (Bk), yellow (Y), magenta (M), and cyan (C) inks, respectively. In the embodiment, these are also referred to as black ink portion, yellow portion, magenta portion, and cyan portion), and A1 is used as a temperature sensor for detecting the temperature between the black ink portion Bk and the cyan portion C.
Is patterned in a meandering shape, and means for detecting the substrate temperature of the head is formed by utilizing the TCR (thermal temperature coefficient) of A1. The heater for increasing the temperature of the head is formed at the end portions (both sides) of the substrate.

FIG. 2 schematically shows a head substrate provided with temperature detecting means according to the present invention. Figure 3
It is a figure showing the head temperature rise at the time of black printing, (b) is temperature distribution in the AA 'cross section of (a), (c) is BB'.
4 is a temperature distribution along a line, FIG. 4 shows a temperature distribution when the head heater is driven, and (b) is A- of (a).
The temperature distribution on the A'section, (c) is the temperature distribution on the BB 'line.

On the other hand, FIGS. 5 and 6 show a background art head substrate provided with a temperature detecting means. FIG. 7 is a diagram showing how the head temperature rises when black is printed by using a head having a background art head substrate provided with a temperature detecting means, and FIG. 8 drives a head heating heater. It is the figure which represented typically the temperature distribution at the time of doing.

As can be seen from these figures, when the most frequently used black is printed, the head temperature rise is highest near the black liquid chamber, and the temperature gradually spreads from there. However, in the substrate having the structure of the background art, since the temperature detecting means 5 is provided at both ends of the head, the temperature detecting means closer to black shows a high temperature, but the other end still shows a low temperature. . Therefore, the temperature of the entire head is underestimated and the temperature of the color adjacent to black (cyan (blue) C in the present invention) is a value to be controlled (the temperature at which cyan ink evaporates).
However, the temperature control is not performed. For this reason, it is necessary to suck ink frequently, and the amount of ink consumption increases. On the other hand, in the structure according to the present invention, since the temperature detecting means is provided in the portion adjacent to the black which is frequently used, the temperature detecting means reaches the temperature control start value before the head becomes high during black printing, and the temperature control is performed. I do. Therefore, the ink of the color adjacent to black is less likely to evaporate, and good printing can always be performed.

FIG. 8 shows the situation when the temperature control (head heating) heater of the background art is driven, but when the head temperature is low because the heater and the temperature detecting means are adjacent to each other. Even if the heater is driven, the temperature detection means immediately determines that the temperature is the specified temperature and stops heating as it is.Therefore, it is necessary to heat the entire head more than necessary to reach the proper temperature. become. However, according to the present invention, the temperature in the vicinity of the heater becomes high, but since the temperature detection unit is separated from the heater, the heated heat is not immediately transmitted to the temperature detection unit, and the temperature is controlled so that the entire head has a uniform temperature. It becomes possible to control by the detection means.

FIG. 9 schematically shows an ink jet head substrate according to another embodiment of the present invention. The manufacturing method is similar to that of the embodiment shown in FIG. The present invention extends the size of the temperature detecting means in the short side direction of the head in comparison with the structure of the background art, increasing the temperature detecting area and increasing the resistance value of the thin film resistor used for temperature detection,
The amount of change in resistance with respect to temperature change is increased. FIG. 10 shows a comparison between the resistance value of the temperature detecting means according to the present invention and the resistance value according to the structure of the background art, and further schematically shows the amount of change in the resistance value with respect to temperature. Indicates that the amount of change in resistance with respect to temperature change is large.

The temperature detecting means of the present invention uses an Al thin film resistor. Since the TCR of Al is 4 × 10 ⁻³ / ° C., the rate of resistance change is the same in both the structure of the background art and the present invention.
Since the present invention can take a large initial resistance, the amount of resistance change with respect to temperature is larger according to the present invention. Therefore, it goes without saying that the detection sensitivity according to the present invention is higher.

By thus increasing the resistance of the temperature detecting means of the temperature detecting means, the amount of change in resistance value with respect to temperature can be increased and the temperature detection sensitivity can be increased.

FIG. 11 shows another embodiment of FIG. 1, in which black is frequently used and another color is used, and magenta M, cyan C and yellow Y which are not frequently used are used. Further, the temperature detecting section 5 is further provided to the sensor to correct the change in color tone due to the change in temperature. According to this, when black is used, a sensor between black and another color is used to prevent fixation of an unused color, and when a color other than black is used, a sensor between the colors is used. Can be used to compensate for changes in color tone with changes in head temperature.

FIG. 12 is a perspective view showing another embodiment of the present invention. In this embodiment, the protective films 6 and 7 are provided so as to cover the resistor 1 and the wiring 2 on the substrate 4, and only the protective film 6 is used in the portion of the color A which is not used frequently and the color which is used frequently. In the portion B, protective films 6 and 7 are provided. 13A and 13B show cross-sections of a color A having a low frequency of use and a color B having a high frequency of use.

Next, an example of this manufacturing method will be described.

HfB ₂ TiA was formed on a Si wafer with a thermal oxide film.
1 is sequentially sputtered, a resist pattern is formed by a photolithography method, and Al is etched with a nitric acid / phosphoric acid-based etching solution. Next, the Al resist is peeled off, and then HfB ₂ resist is formed. The HfB ₂ is etched by dry etching using RIE. After removing the resist by ashing, Si ₃ N ₄ and Ta are sequentially sputtered as a film that protects the resistance from cavitation that occurs when the resistance oxidizes at a high temperature and ink bubbles disappear. First, a resist pattern for etching the upper Ta film is formed. The Ta of the frequently used color is left, and the Ta of the other infrequently used color is removed by etching. At this time, the cavitation resistance of Ta and the cavitation resistance of Si ₃ N ₄ are almost equal, and the durability time is proportional to the film thickness. Therefore, T
Based on the above theory, the film thicknesses of a and Si ₃ N ₄ are designed so that the expected printing numbers of frequently used colors and low colors have the same life when Ta is provided and when it is removed. Then
A resist pattern is formed to open a through hole for connection between the wiring and the outside under the protective film in the protective film.
Etch i ₃ N ₄ . The formation of the ink flow path is performed by exposing and developing the dry film after welding in this wafer state,
Bond the top plate. This top plate has a hole for introducing the ink, and a filter is adhered to the introduction hole for preventing the entry of dust into the ink discharge port. After that, a pipe for supplying ink from the ink cartridge is connected, and a cover for holding the whole is adhered to complete the inkjet head according to the present invention.

FIG. 14 shows another embodiment of the present invention. In this embodiment, the first protective film 6, the second protective film 8 and the third protective film 9 are provided so as to cover the resistor 1 and the wiring 2 on the substrate 4. This cross-sectional view shows a portion of the color that is frequently used, and only the protective films 6 and 8 are provided in the portion of the color that is rarely used.

In this case, Si ₃ N ₄ is sputtered as the first protective film and Al is sputtered as the second protective film on the wafer on which the wiring pattern is formed as described above. For the third protective film, a material that can be etched by a relatively simple method such as Ta or Si ₃ N ₄ is used. As described above, the first to third protective films are left for the frequently used colors, and the first and second protective films are left for the other infrequently used colors. The second protective film functions as an etching stop film so that the first protective film is not etched when the third protective film is etched. The film thickness may be about 100 nm.

When printing was performed using the ink jet head manufactured by the above-mentioned forming method, in the first invention, the temperature detecting means is located in the vicinity of the head which is frequently used and the head heating heater is located away from the head. As a result, it is possible to obtain proper temperature characteristics and quickly control the temperature of the head. Note that FIG. 15 shows the relationship between the protective film thickness and the durable life of the head in the above-described embodiment.

By optimizing the film thickness of the protective film in this way, it is possible to suppress the rise in the head temperature as much as possible, reduce the evaporation of the ink of the unused color, and not eject the ink due to the influence of the head temperature. Can be prevented.

FIG. 16 is a schematic view of an example of an ink jet recording apparatus in which the ink jet cartridge IJC which employs the ink jet head configured as described above is mounted. This inkjet recording device IJRA is
It has a lead screw 2040 that rotates via driving force transmission gears 2020 and 2030 in association with forward and reverse rotations of the drive motor 2010. Inkjet cartridge I
The carriage HC on which the JC is placed is the carriage shaft 20.
50 and the lead screw 2040, and has a pin (not shown) that engages with the spiral groove 2041 of the lead screw 2040.
With the rotation of 40, it is reciprocated in the directions of arrows a and b. A paper pressing plate 2060 presses the paper P against the platen roller 2070 in the carriage movement direction. Reference numerals 2080 and 2090 denote photocouplers, which operate as home position detecting means for confirming the presence of the lever 2100 provided on the carriage HC in this area and switching the rotation direction of the motor 2010. Reference numeral 2110 denotes a cap member that caps the front surface of the recording head, and is supported by the support member 2120. A suction unit 2130 sucks the inside of the cap, and performs suction recovery of the recording head through the opening in the cap. The cleaning blade 2140 that cleans the end surface of the recording head is movable in the front-rear direction.
0, and these are supported by the main body support plate 2160. Needless to say, the blade 2140 is not limited to this form, and a known cleaning blade can be applied to this example. Reference numeral 2170 denotes a lever for starting suction for suction recovery, which is moved along with the movement of the cam 2180 engaged with the carriage HC, whereby the drive force from the drive motor 2010 is switched to the clutch. Movement is controlled by known transmission means such as.

The capping, cleaning, and suction recovery are configured so that the desired processing can be performed at their corresponding positions by the action of the lead screen 2040 when the carriage HC comes to the home position side area. Any of these can be applied to the present example as long as a desired operation is performed at a known timing. Each of the above-described configurations is an excellent invention, either alone or in combination, and shows a preferred configuration example for the present invention.

(Others) The present invention is provided with a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink, particularly in the ink jet recording system. The present invention brings about excellent effects in a recording head and a recording apparatus of the type in which the state of ink is changed by the heat energy. This is because such a system can achieve high density recording and high definition recording.

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 is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening 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 ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the ink from the main body of the apparatus can be electrically connected to the main body of the apparatus by mounting the recording head. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type or number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or below and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. 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 ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function It may be a form or the like.

[0073]

As described above, according to the present invention,
It is possible to optimize the installation position of the temperature detection means, take a large temperature detection sensitivity, and optimize the thickness of the protective film without increasing the cost, and control the head temperature rise during printing quickly. In addition, it is possible to provide an inkjet head and an inkjet recording apparatus, which can prevent non-ejection of ink, can perform appropriate temperature control for head heating at low temperature, and have an effect of improving energy efficiency of printing, at low cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a structure of an embodiment of an inkjet head of the present invention.

FIG. 2 is a schematic view showing a part of the structure of one embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a temperature distribution during black printing by the inkjet head according to the embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a temperature distribution when driving a head heater of an inkjet head according to an exemplary embodiment of the present invention.

FIG. 5 is a diagram illustrating a structure of an inkjet head having a conventional structure.

FIG. 6 is a diagram illustrating a structure of an inkjet head having a conventional structure.

FIG. 7 is a schematic diagram illustrating a temperature distribution during black printing of an inkjet head having a conventional structure.

FIG. 8 is a schematic diagram for explaining a temperature distribution when a head heater is driven by a conventional structure.

FIG. 9 is a schematic view showing an inkjet head according to another embodiment of the present invention.

FIG. 10 is a diagram illustrating a comparison of temperature detection amounts according to the present invention and a conventional structure.

FIG. 11 is a schematic view showing an inkjet head according to another embodiment of the present invention.

FIG. 12 is a perspective view showing another embodiment of the present invention.

13 is a cross-sectional view of FIG.

FIG. 14 is a sectional view showing another embodiment of the present invention.

FIG. 15 is a diagram showing a relationship between a protective film and a printing durability life.

FIG. 16 is a schematic view showing an example of an inkjet recording apparatus of the present invention.

[Explanation of symbols]

 1 Heating Resistor 2 Wiring Conductor 3 Head Heater 4 Substrate 5 Temperature Detector 6 First Protective Film 7 Third Protective Film 8 Second Protective Film

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B41J 3/04 104 K

Claims (23)

[Claims] 1. An ink jet head having a group composed of a plurality of electrothermal converters having a heating resistor for generating the thermal energy used for ejecting ink, wherein a temperature detecting means of the head is provided. An inkjet head, characterized in that it is provided between the groups on the same substrate as the substrate on which the plurality of electrothermal converter groups are provided. 2. The ink jet head according to claim 1, wherein a plurality of liquid chambers that are independent of each other are provided corresponding to the group of electrothermal converters. 3. The ink jet head according to claim 2, wherein the temperature detecting means is provided in at least one liquid chamber of two or more liquid chambers independent of each other. 4. The ink jet head according to claim 1, wherein the temperature detecting means is provided between a group having the highest frequency of use and a group adjacent thereto among the group of electrothermal converters. Characteristic inkjet head. 5. The ink jet head according to claim 2, wherein the temperature detecting means is provided in a liquid chamber corresponding to at least a group having the highest frequency of use among colors of two or more liquid chambers independent of each other. An inkjet head characterized in that. 6. The ink jet head according to claim 1, wherein the temperature detecting means is provided in parallel with the short side of the substrate of the ink jet head, and the length of the temperature detecting range is longer than the length of the heating resistor. Inkjet head characterized by. 7. An electrothermal converter having a heating resistor for generating heat energy by directly supplying the heat energy to the ink on the heat-acting surface to discharge the ink, and the two are mutually connected. In an inkjet head having two or more independent liquid chambers, the means for detecting the temperature is provided over the length of the short side of the substrate of the inkjet head and excluding the external connection portion. Inkjet head. 8. The ink jet head according to claim 7, wherein the temperature detecting means is not on the same straight line parallel to the short side of the head temperature control heater and the head substrate. 9. The ink jet head according to claim 7, wherein the temperature detecting means is provided at a position other than an end portion of the head. 10. The inkjet head according to claim 7, wherein the temperature detecting means is provided between at least one or more of two or more liquid chambers which are independent of each other. 11. The ink jet head according to claim 7, wherein the temperature detecting means is provided in at least one liquid chamber of two or more liquid chambers independent of each other. 12. The ink-jet head according to claim 7, wherein the temperature detecting means is adjacent to the most frequently used color among the two or more liquid chambers independent of each other, and the most frequently used liquid chamber. An ink jet head provided between a liquid chamber and a liquid chamber adjacent to the ink jet head. 13. The ink jet head according to claim 7, wherein the temperature detecting means is provided in a liquid chamber of at least the most frequently used color among two or more independent liquid chamber colors. Characteristic inkjet head. 14. An electrothermal converter having a heat-generating resistor, which is generated by energizing the thermal energy used to eject the ink by directly applying thermal energy to the ink on the heat acting surface, and each other. In an ink jet head having two or more independent liquid chambers, the protective film of the heating resistor has at least one protective film of a heating heater in a liquid chamber and a protective film of a heating heater in another liquid chamber. An inkjet head having a thickness different from that of. 15. The inkjet head according to claim 14, wherein the protective film has a two-layer structure, and a part of the protective film has a different thickness by removing one layer of the two-layer protective film. Characteristic inkjet head. 16. The ink jet head according to claim 14, wherein the protective film has a structure of three or more layers, and a part of the film has a different thickness by removing the uppermost part of the three layers. Inkjet head. 17. The inkjet head according to claim 14, wherein a part of the protective film is changed in thickness by etching with a liquid. 18. The inkjet head according to claim 14, wherein a part of the protective film has a different film thickness by plasma etching using a gas. 19. The inkjet head according to claim 16, wherein the intermediate second layer of the protective film is a material capable of being selectively etched with a material of the uppermost layer. 20. The ink jet head according to claim 14, wherein the protective film comprises Si ₃ N ₄ and T.
2. An ink jet head comprising a and Ta, wherein Ta is etched to form the protective film as one layer. 21. The ink jet head according to any one of claims 14 to 19, wherein the protective film is Si ₃ N ₄
And an Al and Ta, and Ta is etched to form the protective film as one layer. 22. The ink jet head according to claim 14, wherein the protective film is made of Si ₃ N ₄ , Al and Si ₃ N ₄ , and a part of the protective film is formed by etching the uppermost Si ₃ N _4. The ink jet head is characterized in that the film thickness is changed by. 23. An inkjet recording apparatus comprising the inkjet head according to claim 1, wherein the inkjet head is attachable to and detachable from a recording apparatus main body. .