JP3248219B2 - Inkjet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head for an ink jet recording apparatus, and more particularly to an ink jet recording head provided with dummy nozzles.

[0002]

2. Description of the Related Art The ink jet recording system is capable of high-speed recording, and has almost no noise generated at the time of recording.
Since it can print directly on plain paper and does not require a fixing process or the like, attention has been paid to the fact that the size of the apparatus can be reduced.

Conventionally, as a known ink jet device,
JP-A-61-35966 and JP-A-61-2309.
No. 54, JP-A-63-54250, JP-A-1
Japanese Unexamined Patent Publication No. 148560/1990 is known.

However, in such an ink jet apparatus, the ejection characteristics of the nozzle arranged at the center in the nozzle arrangement direction and the nozzle arranged at the end are not uniform, and the ejection speed of the nozzle arranged at the end is not uniform. Decrease,
There has been a problem that a shortage of the drop amount occurs, and printing from nozzles near the end portions becomes blurred during high-speed solid printing.

In the present invention, as described later, an attempt is made to realize uniform printing characteristics using dummy nozzles. In the prior art, an ink jet recording head using dummy nozzles was examined.

The ink jet recording head described in Japanese Patent Application Laid-Open No. 61-35966 can be said to be the same as the present invention only from the point that dummy nozzles are provided. However, this is not for the purpose of improving the ejection characteristics, but for the purpose of providing a dummy nozzle to prevent defective fusion during bonding.

The ink jet recording head described in JP-A-63-54250 uses a piezo element, and improves the image quality by removing bubbles in the ink from the dummy nozzle.

The ink jet recording head described in JP-A-61-230954 and JP-A-1-148560 can be said to have the same manufacturing method and head configuration as the present invention, but is provided with a dummy nozzle. I did not mention that.

FIG. 7 is a schematic configuration diagram showing a channel structure between an ink reservoir and a nozzle in a conventional ink jet recording head having no dummy nozzle. In the figure, 1 is a nozzle, 2 is an ink reservoir, and 3 is a heater. As shown in the figure, in the head having no dummy nozzle, ink flows from both sides of the nozzle at the central nozzle A, whereas ink flows only from one side of the nozzle at the nozzle B at the end. Therefore, there is a difference in the ink supply property between the central nozzle A and the end nozzle B. In particular, the ejection becomes unstable at the end nozzle B, and it is difficult to follow a high printing frequency. is there.

FIG. 8 is a schematic diagram showing the flow path structure of an ink jet recording head in which an attempt has been made to equalize the supply of ink between a central nozzle A and an end nozzle B by increasing the width of an ink reservoir. FIG. In the figure, FIG.
The same reference numerals are given to the same parts as those described above, and the description is omitted. According to such a flow path structure, ink can flow from both sides of the nozzle in the end nozzle B, similarly to the nozzle A in the center. However,
The hatched corners of the ink reservoir become pocket-like portions for the ink flow, and ink stagnation occurs in these portions. The stagnation of the ink causes a change in the composition of the ink and the generation of a precipitate, so that the initial printing characteristics cannot be maintained for a long time.

Further, there is a problem in manufacturing the ink reservoir and the nozzle. Japanese Patent Application Laid-Open No. 61-230954 discloses a technique for manufacturing an ink jet recording head using anisotropic etching of an Si wafer (ODE: Orientati).
On-dependent etching) creates a nozzle for discharging ink and an ink reservoir for supplying ink from outside. This wafer is called a channel wafer, and is a perspective view in FIG.
(B) shows a plan view, and (C) shows a cross-sectional view. In the anisotropic etching, even if a square or rectangular pattern can be formed with high accuracy, if the shapes are connected, the accuracy of the connected portion is reduced. Therefore, the nozzle 1 and the ink reservoir 2
Then, in order to form a flow path connecting the two, a connection groove is formed in the hatched portion 14 to connect the nozzle 1 and the ink reservoir 2. Since this groove is formed by dicing, it is formed penetrating to the head end. Therefore, the portion of the connection groove formed on the side surface of the head must be filled, and a filling repair work is required. In addition, the connection groove formed by dicing has fluid resistance, and the liquid flow at the time of ink supply is different between the central nozzle and the end nozzle, which causes poor ink supply to the end nozzle. Becomes In particular, in solid printing by jetting all the nozzles, the non-uniformity of the liquid flow becomes more remarkable, and there is a disadvantage that the amount of ink in the nozzles at the end portions is insufficient and the image is blurred.

In the ink jet recording head described in Japanese Patent Application Laid-Open No. 1-148560, the work of filling and repairing the connecting groove by dicing has been improved, but the ink jet recording head and the nozzle at the center in the nozzle arrangement direction due to the difference in fluid resistance have been improved. There is no consideration of the difference in the ejection characteristics from the nozzle at the end, and similarly, the nozzles have the difference in the nozzle ejection characteristics.

On the other hand, the channel wafer has a restriction that the size of one head must be reduced since a large number of individual heads are simultaneously manufactured from the wafer.

The inventors of the present invention have conducted intensive studies on the nozzle ejection characteristics at the center and the end due to the difference in fluid resistance, and as a result, have found an ink flow path structure having uniform characteristics, and have reached the present invention.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a head having uniform ejection characteristics without greatly increasing the size of one head. It is the purpose.

[0016]

According to the present invention, there is provided an ink jet recording head which is constituted by bonding two substrates and has a plurality of nozzles provided with ink discharging means and a common ink reservoir communicating with the nozzles. A dummy nozzle provided with an ink ejection unit that ejects ink droplets driven by a maintenance ejection signal is arranged outside the nozzle, and the dimension of the ink reservoir in the nozzle arrangement direction is a dimension between dummy nozzle ends. And the dimension in the direction perpendicular to the nozzle array at the end is substantially the same as the dimension in the direction perpendicular to the nozzle array at the center.

The number of dummy nozzles can be one to four. As the two substrates, Si wafers can be used. The ink reservoir and the dummy nozzle are:
It can be manufactured by anisotropic etching.

[0018]

According to the present invention, the dummy nozzle is arranged outside the nozzle for ejecting ink, and the dimension in the direction perpendicular to the nozzle array at the end is substantially the same as the dimension in the direction perpendicular to the nozzle array at the center. As a result, the ink is supplied to the discharge nozzles from the ink supply port almost linearly, and the ink supply to the discharge nozzles in the head, particularly, the ink supply to the nozzles at the end when all the nozzles are ejected, is improved. be able to.

Increasing the number of dummy nozzles increases the size of the head and causes ink to stagnate at the end of the ink reservoir. Therefore, the number of dummy nozzles at the end is preferably about 1 to 4. The size and pitch of the dummy nozzle are preferably the same as those of the discharge nozzle. Although the ink reservoir is designed according to the number of dummy nozzles, the size of the head can be reduced by making the size of the ink reservoir in the nozzle arrangement direction substantially equal to the size between the ends of the dummy nozzles.

Further, since the ink discharge means provided in the dummy nozzle is driven by a discharge signal for maintenance, the increase in the viscosity of the ink in the dummy nozzle is always prevented by the discharge operation at the time of maintenance with little consumption of ink. it can. As a result, the dummy nozzles have the function of accelerating the recovery of the liquid level of the end nozzles, and can guarantee a stable discharge operation for all nozzles.

[0021]

FIG. 2 is a perspective view of a part of a print head chip separated from a wafer according to one embodiment of the present invention. In the figure, 1 is a nozzle, 2 is an ink reservoir,
3 is a heater, 4 is an electrode, 5 is a thick resin layer, 6 is a bubble,
7 is a heater substrate, 8 is a channel substrate, and 9 is an ink droplet. In this figure, illustration of the heater 3, the protective layer of the electrode 4, and the like is omitted. A plurality of heaters 3 are formed on a heater substrate 7, and nozzles 1 are formed on a channel substrate 8 corresponding to the heaters 3. Incremental reservoir 2
Is provided with an opening 2a. The opening 2a of the ink reservoir 2 is connected to a second ink reservoir (not shown) made of resin and having a connection to the ink tank. On the heater substrate, a thick resin layer 5 is formed so as to surround the heater 3 in order to allow the bubbles 6 to grow stably. The ink is held in each nozzle 1 and forms an ink orifice portion separated for each nozzle. When a print signal is applied to the heater 3 through the electrode 4, the ink near the heater 3 is heated, vaporized and rapidly expanded to form bubbles 6.
Is discharged. The heater substrate 7 and the channel substrate 8 are S
It is usually formed by an i-wafer.

FIG. 1 is a plan view of a channel substrate according to one embodiment of the present invention. In the figure, 1 is a nozzle, 2 is an ink reservoir, and 10 is a dummy nozzle. Four dummy nozzles 10 are provided on both sides where the nozzles 1 for ejecting ink droplets are arranged. In this embodiment, all the dummy nozzles 10 are connected to the ink reservoir 2 in the same manner as the nozzle 1. Note that a heater may not be provided in a portion of the heater substrate 7 corresponding to the dummy nozzle 10.
The dimensions of the ink reservoir in the direction perpendicular to the nozzle array were all the same, and the dimensions of the ink reservoir in the nozzle array direction were matched with the dummy nozzle ends.

FIG. 3 is a process chart for manufacturing a channel substrate using a Si wafer. In the figure, 1 is a nozzle, 2 is an ink reservoir, 11 is a silicon wafer, 12 is SiO
Reference numeral ₂ and 13 are Si ₃ N ₄ films.

An SiO ₂ film 12 is formed to a thickness of 5000 ° by thermal oxidation on a silicon wafer 11 having a (100) crystal surface on its surface, and the resist is photolithographically removed so as to remove portions where nozzles 1 and ink reservoirs 2 are formed. After forming a pattern by the process, the SiO ₂ film 12 is patterned by a dry etching method. Next, after the Si ₃ N ₄ film 13 is formed by the CVD method, patterning is performed such that only the portion where the ink reservoir 2 is formed is opened, and the state shown in FIG. The back surface of the substrate is in a state where an unpatterned SiO ₂ film and Si ₃ N ₄ film remain.

As described above, after two patterns are formed using different etching masks, the process proceeds to anisotropic etching. First, as shown in FIG. 3B, using the Si ₃ N ₄ film 13 as an etching mask, a first etching process for forming the ink reservoir 2 with an aqueous potassium hydroxide solution heated to 90 ° C. is performed. Next, using a phosphoric acid heated to 180 ° C., as shown in FIG. ₃ (C), Si 3
The N ₄ film 13 is removed, and this time, using the SiO ₂ film 12 as an etching mask, a potassium hydroxide aqueous solution heated to 90 ° C. is used to form the nozzle 1 as shown in FIG. A second etching process is performed.

Finally, the SiO ₂ film 12 is formed using hydrofluoric acid.
Then, as shown in FIG. 3E, a channel wafer in which the nozzle portion and the ink reservoir portion are formed is completed.

In the channel substrate having this structure, the nozzle portion and the ink reservoir portion are not connected to each other. However, in one embodiment, since the concave portion is formed in the corresponding portion of the pair of heater substrates, the print head is not provided. Is equivalent to a channel formed by a connecting groove.

FIG. 4 is a sectional view of a print head in which a concave portion is formed in a corresponding portion of a heater substrate. In the drawing, 1 is a nozzle, 2 is an ink reservoir, 5 is a thick resin layer, 7 is a heater substrate, and 8 is a channel substrate. In this example,
In the channel substrate 8 manufactured in the process shown in FIG. 3, the unetched protrusion at the boundary between the nozzle 1 and the ink reservoir 2 is left as it is. The openings 5a and 5b are formed in the thick resin layer 5 formed on the heater substrate 7 by patterning. The opening 5a is a recess called a pit, and a heater (not shown) is provided at the bottom. The opening 5b is formed at a position facing the above-mentioned convex portion of the channel substrate 8. As shown by the arrows, an ink flow path can be formed through the opening 5b of the thick film resin layer 5. Since the patterning of the opening 5b can be performed with high precision, there is an advantage that the flow resistance of the ink flow path can be accurately determined.

A description will be given of a prototype ink jet recording head. FIG. 5 is a plan view of the channel substrate. In the figure, 1 is a nozzle, 2 is an ink reservoir, and 10 is a dummy nozzle. Each of the four types of heads shown in FIGS. 7A to 7D has one dummy nozzle on each side. The dummy nozzle 10 does not have a heater corresponding to the nozzle, and the dimensions and arrangement pitch are the same as those of the nozzle 1 that ejects ink. (A) The figure is a type,
At the end of the dummy nozzle 10 and the nozzle 1, the dimension Y of the ink reservoir 2 in the direction perpendicular to the nozzle array is 600 μm, which is approximately 比 べ compared to the center. (B) In the type shown in the figure, the dimension Y of the ink reservoir 2 in the direction orthogonal to the nozzle array is equal to the central portion. (C) In the type shown in the figure, the dimension Y of the ink reservoir 2 in the direction perpendicular to the nozzle array is the same as that of the type, but the dimension of the ink reservoir 2 in the nozzle array direction is each X smaller than the dimension up to the end of the dummy nozzle. X is the nozzle pitch (8
4.5 μm). (D) In the type shown in the figure, X in the type is four times the nozzle pitch.

Comparing the goodness of blurring of the nozzles at the ends in the printing results using these four types of ink jet recording heads, the order of ≒≒> was as follows.

From this result, the dimension Y in the nozzle array orthogonal direction at the end of the ink reservoir is equal to the dimension in the nozzle array orthogonal direction at the center, and the dimension of the ink reservoir in the nozzle array direction is the dummy nozzle. From the viewpoint of the size of the end or more, that is, from the viewpoint of the discharge nozzle, it was found that the pitch from the end of the discharge nozzle needs to be larger by one or more.

However, when X is large, it is difficult for the ink in the portions near the left and right ends of the ink reservoir to be supplied to the nozzles. In other words, the end of the ink reservoir becomes a pocket-shaped portion for the flow of ink, and ink stays in this portion. Stagnation of the ink causes a change in the composition of the ink and generation of a precipitate. In addition, when X is large, the size of the head becomes large, so that there is a problem from this aspect. Therefore, in consideration of these conditions, it is desirable that X = 0, that is, the end of the ink reservoir in the nozzle array direction is located at the same position as the end of the dummy nozzle.

Next, when the dimension Y in the direction perpendicular to the nozzle array at the end of the ink reservoir is equal to the dimension perpendicular to the nozzle array at the center, the number of dummy nozzles at the end differs. Prototype the head. FIG. 6 is a plan view of the channel substrate. In the figure, the same parts as those in FIG. (A) The figure shows a type in which the number of dummy nozzles at the end is one,
(B) shows two types, (C) shows four types, and (D) shows eight types.

The results of printing using these four types of ink jet recording heads were compared in the order of ≒≒≒> when the goodness of the blur at the end nozzles was compared.

From these results, the number of dummy nozzles is
It was found that at least one ink reservoir had to be provided as long as it had the dimensions described in FIGS. 5B to 5D.

Comparing the ink outflow state of the dummy nozzles with respect to the ink pressure change in these prototype ink jet recording heads, it was observed that the ink outflow from the dummy nozzles occurred in the type. Increasing the number of dummy nozzles increases the size of the head, and causes the above-described ink stagnation in a portion of the ink reservoir corresponding to the dummy nozzle.

From these results, the dimension Y in the nozzle array orthogonal direction at the end of the ink reservoir is equal to the dimension in the nozzle array orthogonal direction at the center, and the number of dummy nozzles is one.
It was found that the printing quality was stable in the case of an ink jet recording head using a channel substrate having a structure and a shape of about 4 pieces and having the end of the ink reservoir in the nozzle arrangement direction at the same position.

FIG. 9 is a schematic diagram showing the structure of the flow path between the ink reservoir and the nozzles in the ink jet recording head of the embodiment described above. As shown in the figure, in the print head provided with the dummy nozzle C, the nozzle A
However, even at the nozzle B at the end, ink flows from both sides, and the supply of ink at the center and the nozzle at the end becomes equal by having the dummy nozzle.

In this ink jet recording head, the dummy nozzles are not provided with an ink discharge means. However, during maintenance, ink is retained from the dummy nozzles as described with reference to FIG. Can be eliminated.

The dummy nozzle plays a large role in the stability of ejection. That is, when an ink droplet is ejected from the nozzle, the ink surface temporarily retreats, the ink is resupplied into the nozzle, and the ink surface returns to the original position. The speed of recovery of the ink surface affects ejection stability when the printing frequency is increased. When re-supplying the ink, the rise and fall of the ink in the adjacent nozzle increases the speed of the recovery of the ink surface. If there are no dummy nozzles, ejection becomes unstable because the nozzles at both ends have only adjacent nozzles on one side that serve to increase the speed of ink surface recovery. Therefore, if a dummy nozzle is provided at the end, stable ejection at a high frequency can be realized even at the end nozzle.

As described above, the provision of the dummy nozzle improves the ejection characteristics in the above-described embodiment.
Here, consider the ink in the dummy nozzle. In the nozzles that perform printing, the ink in the nozzles is constantly replaced with new ink by discharging ink, but in the dummy nozzles, there is no change in the ink replacement, and the viscosity increases more easily than other nozzles However, in the above-described embodiment, there is no problem of viscosity increase or precipitation due to ink drying in the dummy nozzle.

Here, the increase in the viscosity of the ink in the nozzle will be considered. Thickening of the ink is likely to occur in the vicinity of the discharge port of a nozzle that has a narrow flow path and is in contact with the atmosphere. There are two possible methods for removing the thickened ink. The first is a method using an ink suction operation of covering a nozzle with a cap member and sucking ink from the nozzle, and the second is a preliminary discharge operation of discharging ink droplets toward a cap member before or after the start of a printing operation. It is.
The ink suction operation has a strong effect, but it consumes a lot of ink, so it is preferable that the frequency is not too high, and it is preferable to remove the ink thickened by the preliminary ejection operation.

When the viscosity of the ink in the dummy nozzle increases, the function of accelerating the recovery of the liquid level of the adjacent nozzle is lost, and the effect of stabilizing the discharge is reduced. In addition, when dust adheres to the atmosphere, it does not flow and solidifies on the spot, adversely affecting adjacent nozzles, causing a change in the ink composition in the dummy nozzles, or causing precipitates to grow and grow. May adversely affect adjacent nozzles, or may enter the interior of the head and enter other nozzles from the ink reservoir side.

However, in the above-mentioned embodiment, since the ink ejection means is not provided in the dummy nozzle, the thickening cannot be eliminated by the preliminary ejection operation. The ink suction operation must be performed. However, if the frequency of the ink suction operation is increased, the consumption of ink is increased, which leads to an increase in cost, and the frequency of maintenance work such as ink replacement and waste liquid treatment is also increased.

FIG. 10 is a schematic structural view of an ink jet recording head according to another embodiment of the present invention. In the figure, 1 is a nozzle, 2 is an ink reservoir, 3 is a heater, 4 is an electrode, 1
0 is a dummy nozzle, 15 is a first driver group, 16 is a second driver, 17 is a driver drive circuit, 18 is an input protection circuit, 19 is a connector, 20 is an image signal transmission clock, 21 is an image signal, 22 Denotes a printing pulse, 23 denotes a control signal, and 24 denotes a preliminary ejection pulse. This ink jet recording head is formed by joining two silicon substrates. On the heater substrate, a heater 3, an electrode 4, a first driver group 15 for driving the heater 3, a first
A driver driving circuit 17 for driving the driver group 15 according to an image signal is formed.

As described in FIG. 3, the channel substrate is
The nozzle 1, the dummy nozzle 10, and the ink reservoir 2 are formed by anisotropic etching of the Si wafer.
The outline of the ink jet recording head is the same as that described in FIG.

Returning to FIG. The ink jet recording head is filled with ink, and the first driver group 1 is set in accordance with an image signal input to the driver driving circuit 17.
By driving 5, a pulse voltage is applied to the heater 3. With this drive pulse, the ink on the heater 3 is rapidly heated to generate bubbles, which grow, and the ink is ejected as droplets from the nozzle 1 by the pressure. Regarding the dummy nozzles 10, the second driver 16 is also driven by the input preliminary ejection pulse.
Is driven to apply a pulse-like voltage to the heater 3,
Similarly, ink droplets are ejected.

The flow of ink in the ink jet head having such a configuration will be described with reference to FIG. As shown in the figure, there is no difference in ink supply between the nozzle B at the end and the other nozzles A. As described above, the reason why the ink supply to each nozzle can be made uniform is not only the presence of the dummy nozzle C, but also the size of the ink reservoir 2 in the direction perpendicular to the nozzle array is substantially the same as the size between the dummy nozzles at both ends. And the dimension in the direction perpendicular to the nozzle array at the end is substantially the same as the dimension in the direction perpendicular to the nozzle array at the center. Further, due to the presence of the dummy nozzle C, the nozzle B at the end also has adjacent nozzles on both sides, and improvement in the ink surface recovery speed due to the vertical movement of the ink surface of the adjacent nozzle can be expected for all nozzles. In addition, the dimension of the ink reservoir in the direction perpendicular to the nozzle array is substantially the same as the dimension between the dummy nozzles at both ends, and the dimension in the direction perpendicular to the nozzle array at the end is substantially the same as the dimension in the direction perpendicular to the nozzle array at the center. By the same, ink stagnation at the end of the ink reservoir is small, and even if ink is thickened at the corner of the ink reservoir due to stagnation of ink due to long-term storage, ink suction operation from all nozzles including dummy nozzles Can be eliminated promptly.

The thickening of the ink in the dummy nozzle, which is a problem here, is caused not only by the ink suction operation but also by the ink suction operation.
The problem can also be solved by performing a preliminary ejection operation in the following procedure.

During normal printing, in order to prevent the ink from increasing in viscosity, a maintenance operation is performed every predetermined time by a built-in timer, and a preliminary ejection operation is performed. First, in synchronization with the image signal transfer clock 20, an image signal 21 for setting all the printing nozzles to the ejection state is transferred to the driver drive circuit 17, and a predetermined number of printing pulses 22 for preliminary ejection are transferred. And the control signal 23 are inputted to drive the first driver group 15 corresponding to all the printing nozzles. At the same time, a predetermined number of pulses for preliminary ejection for preliminary ejection are input to the second driver 16 corresponding to the dummy nozzle. In response to these input signals, a predetermined number of droplets for preliminary ejection are ejected from all the nozzles, and the thickened ink in the nozzles is removed to start normal printing.

Experiments with a printer prototyped by the inventor of the present invention have revealed that when the time interval for performing preliminary ejection is 20 minutes, normal printing is guaranteed if at least 50 preliminary ejections are performed. However, if the same preliminary ejection is performed only with the nozzles other than the dummy nozzles, the printing position accuracy of the dots printed by the end nozzles deteriorates after 4 hours or more, and the dots printed by the same nozzles It was found that the variation in the diameter also increased at the end. In the embodiments described with reference to FIGS. 10 and 11, the case where the number of dummy nozzles is one has been described, but the same can be said for the case where the number of dummy nozzles is one or more.

[0052]

As is apparent from the above description, according to the present invention, it is possible to make the ejection characteristics of the nozzles at the end in the arrangement direction the same as those of the nozzle at the center, and to reduce image quality defects at the end of the head. There is an effect that it can be improved.

Further, since the ink discharge means provided in the dummy nozzle is driven by the preliminary discharge operation which consumes a small amount of ink, a stable discharge operation can be always guaranteed for all the nozzles. The ink in the dummy nozzle thickens and drifts through the atmosphere, dust adheres and solidifies in place without affecting the adjacent nozzles, or the ink itself in the dummy nozzle changes in composition or precipitates are generated and grown It is possible to prevent an unexpected situation in which the deposit adversely affects the adjacent nozzle or enters the inside of the head and enters another nozzle from the ink reservoir side.

A high-quality print with a uniform dot diameter and good directivity over all nozzles can be printed at high speed, and the image quality can be maintained for a long time by low-cost maintenance with low ink consumption. There is an effect that a highly reliable printer can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view of a channel substrate according to an embodiment of the present invention.

FIG. 2 is a perspective view of a part of a print head chip separated from a wafer according to an embodiment of the present invention.

FIG. 3 is a process chart for manufacturing a channel substrate according to one embodiment of the present invention.

FIG. 4 is a sectional view of a print head according to an embodiment of the present invention.

FIG. 5 is a plan view of a channel substrate of four prototype ink jet recording heads.

FIG. 6 is a plan view of channel substrates of other four types of experimentally manufactured ink jet recording heads.

FIG. 7 is a schematic configuration diagram illustrating a flow path structure of ink in a conventional inkjet recording head.

FIG. 8 is a schematic configuration diagram showing an ink flow path structure in an ink jet recording head in which the width of an ink reservoir is widened.

FIG. 9 is a schematic configuration diagram illustrating a flow path structure of ink in an ink jet recording head according to one embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of an ink jet recording head according to another embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing an ink flow path structure in an ink jet recording head according to another embodiment of the present invention.

FIG. 12 is an explanatory diagram of a conventional ink jet recording head.

[Explanation of symbols]

1 nozzle, 2 reservoirs, 3 heaters, 4
Electrodes, 5 thick resin layers, 6 bubbles, 7 heater substrate,
8 channel substrate, 9 ink droplets, 10 dummy nozzle, 15 first driver group, 16 second driver,
17 Driver drive circuit, 18 Input protection circuit, 19
Connector, 20 Image signal transmission clock, 21 Image signal, 22 Printing pulse, 23 Control signal, 24
Predischarge pulse.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yoshihiko Fujimura 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Masahiko Fujii 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. Institution (72) Inventor Shinji Tabata 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Masaki Kataoka 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Tohru Mihara 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Office (72) Inventor Koichi Saito 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd. Ichimoto 2274 Address Fuji Xerox Co., Ltd.Ebina Works (72) Inventor Koichi Naito 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Works (72) Inventor Jun Isozaki 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Shares (56) References JP-A-2-165962 (JP, A) JP-A-62-90254 (JP, A) JP-A-3-218841 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) B41J 2/05

Claims (1)

(57) [Claims] 1. An ink jet recording head which is formed by bonding two substrates and has a plurality of nozzles provided with ink discharging means, and a common ink reservoir communicating with the nozzles. A dummy nozzle provided with an ink ejection unit that ejects an ink droplet driven by an ejection signal is arranged, and
The dimension of the ink reservoir in the nozzle array direction was substantially the same as the dimension between the dummy nozzle ends, and the dimension in the nozzle array orthogonal direction at the end was substantially the same as the dimension in the nozzle array orthogonal direction at the center. An ink jet recording head, characterized in that: