JP2002052717A - Print head, its manufacturing method and its controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a frame member from being warped on the side applied with a nozzle forming member and to solve problems caused by warping. SOLUTION: In the inventive print head 100, a frame member 4 having a coefficient of linear expansion substantially equal to that of a substrate member 6 is stuck to a nozzle forming member 2 and an anti-warp member 101 having a coefficient of linear expansion substantially equal to that of the nozzle forming member is stuck to the side 4d of the frame member opposite to the side 4c applied with the nozzle forming member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel print head, a method for manufacturing the same, and a method for controlling the same. More specifically, in a print head in which a positional shift between an ink discharge nozzle of a nozzle forming member, a heating resistor of a substrate member, and ink pressure is eliminated by bonding a frame member to the nozzle forming member, the nozzle of the frame member The present invention relates to a technology for solving the problem of warping of a bonding surface on which forming members are bonded and the problem of warping.

[0002]

2. Description of the Related Art The front surface of an ink pressurizing chamber is covered with a nozzle forming member having fine ink discharge nozzles formed therein, and ink bubbles generated by rapid heating of a heating resistor provided in the ink pressurizing chamber are formed. There is a print head of a type in which ink droplets are ejected from an ink ejection nozzle by pressure.

A print head a of such a type is usually
It has a structure as shown in FIG. 12 and FIG.

[0004] The print head a has a substrate member d provided with a side wall of the ink pressurizing chamber b and a heating resistor c to limit one end face of the ink pressurizing chamber b. The substrate member d is formed by depositing a heating resistor c on one surface of a semiconductor substrate e made of silicon or the like, and limiting the side surface of the ink pressurizing chamber b to the surface of the semiconductor substrate e where the heating resistor c is formed. That is, the barrier layer f serving as a side wall is laminated. The barrier layer f is made of, for example, an exposure-curable dry film resist. After being laminated on the entire surface of the semiconductor substrate e on which the heating resistor c is formed, unnecessary portions are removed by a photolithography process. The substrate member d is formed.

[0005] Then, a nozzle forming member g is laminated on the barrier layer f of the substrate member d. Nozzle forming member g
Is formed by an electroforming technique using nickel, for example. An ink discharge nozzle h is formed on the nozzle forming member g, and the ink discharge nozzle h is aligned with the heating resistor c deposited on the substrate member d.

As described above, both ends are limited by the substrate member d and the nozzle forming member g, and the side surfaces are formed by the barrier layer f.
And an ink pressurizing chamber b having an ink discharge nozzle h which is communicated with the ink flow path i and faces the heating resistor c. The heating resistor c in the ink pressurizing chamber b is electrically connected to an external circuit via a conductor (not shown) deposited on the semiconductor substrate e.

Normally, one print head a is provided with a plurality of heating resistors c in units of 100 and an ink pressurizing chamber b provided with the heating resistors c, and in response to a command from a control unit of the printer. Ink can be ejected by uniquely selecting each of the heating resistors c.

That is, in the print head a, the ink pressurizing chamber b is filled with ink from an ink tank (not shown) connected to the print head a through the ink flow path i. Then, a short time, for example, 1
By passing a current pulse for ~ 3 microseconds, the heating resistor c is rapidly heated, and as a result, a gas-phase ink bubble is generated at a portion in contact with the heating resistor c, and the ink bubble expands. A certain volume of ink is displaced, whereby an ink having a volume equivalent to the displaced ink in a portion in contact with the ink discharge nozzle h is ejected from the ink discharge nozzle h as an ink droplet, and is printed on a print medium such as paper. Adhered (landed).

Generally, a heating step is included in the manufacturing process of the print head a. For example, after forming the barrier layer f on the semiconductor substrate e, the nozzle forming member g is laminated. In order to cure the barrier layer f and fix the nozzle forming member g, a heat curing process at a high temperature is performed. . Also, a barrier layer f made of a dry film resist
The curing step for obtaining the ink resistance is also performed at a high temperature.

As described above, a heating step is required in the manufacturing process of the print head. By the way, the linear expansion coefficient of silicon, which is usually the material of the semiconductor substrate e, and nickel, which is the material of the nozzle forming member g, are different by about one digit.

[0011] When such materials having greatly different coefficients of linear expansion are bonded in the heating step, a relative displacement occurs after bonding due to the difference in the respective expansion and contraction rates. Such a displacement depends on the difference in linear expansion coefficient between the members to be bonded, and the greater the difference, the greater the displacement.

That is, as shown in FIG. 14, with respect to one substrate member d, in a certain portion (a), even if the positions of the heating resistor c and the ink pressurizing chamber b and the ink discharge nozzle h coincide with each other, At a position (b) far from the position (a), a positional shift occurs between the heating resistor c and the ink pressurizing chamber b and the ink discharge nozzle h, and at a position further away (c), the ink discharge nozzle h is moved. A situation occurs in which the ink pressure chamber b is also displaced. Then, such a positional shift becomes larger as the members to be bonded become larger. In this manner, as the positional relationship between the heating resistor c and the ink pressurizing chamber b and the ink ejection nozzle h deviates from the predetermined positional relationship (see FIG. 14B), a displacement occurs in the ejection direction, and the displacement amount further decreases. When it becomes large (see FIG. 14 (c))
Ink ejection itself becomes impossible.

The demands of the printer market are in the direction of increasing the printing speed, and one of the means for achieving this is to increase the number of nozzles for discharging ink. When the number of nozzles increases at the same resolution, the size of the print head increases, and the positional deviation between the heating resistor c and the ink pressurizing chamber b and the ink discharge nozzle h caused by the difference in the linear expansion coefficient. The effect is greater. Further, in the case of a large print head such as a line head, the influence of the positional shift between the heating resistor c and the ink pressurizing chamber b and the ink discharge nozzle h becomes more remarkable, and becomes a very serious problem. .

[0014]

In order to prevent the displacement between the ink discharge nozzle h and the heating resistor c and the ink pressurizing chamber b, as shown in FIG.
It is conceivable to attach the frame member j to the nozzle forming member g.

That is, a frame-shaped frame member j made of a material having a linear expansion coefficient substantially equal to that of a semiconductor substrate e serving as a base of the substrate member d is bonded to the nozzle forming member g at a high temperature. Thereafter, at a temperature lower than the bonding temperature between the frame member j and the nozzle forming member g, the substrate member d
To the nozzle forming member g.

After the nozzle forming member g is bonded to the frame member j, the transition of the formation interval of the ink discharge nozzles h formed on the nozzle forming member g based on the temperature change is based on the frame member j. Since the coefficient of linear expansion of the substrate member d and the coefficient of linear expansion of the frame member j are substantially the same, the heating resistor c formed on the substrate member d and the ink pressure Since the formation interval of the chamber b and the formation interval of the ink discharge nozzle h formed in the nozzle forming member g expand and contract at the same rate with respect to a temperature change, the above-described heating resistor c and ink pressure The problem of misalignment between the chamber b and the ink discharge nozzle h is solved.

However, there is a problem that the frame member j is warped due to a difference in linear expansion coefficient between the frame member j and the nozzle forming member g. That is, the linear expansion coefficient of the nozzle forming member g is
Is larger than the linear expansion coefficient, the shrinkage rate of the nozzle forming member g is larger than the shrinkage rate of the frame member j as the temperature environment falls from the bonding temperature of the two, and as a result, the nozzle forming member g is bonded. Warpage occurs so that the side becomes concave (see FIG. 16).

When the frame member j is warped, as shown by an arrow in FIG. 16, the ejection direction of the ink droplet onto the printing medium k such as printing paper changes, and the ink droplet lands on the printing medium k. The distance m between points l, l,.
m become narrower from the center to the periphery. Landing point intervals m, m,.
The non-uniformity gives a print (character) as if it were a distortion such as a spherical aberration in a lens, and lowers the print (character) quality.

If the frame member j is warped,
The flight distances n, n,... Of the ink droplets to the print medium k become shorter from the center to the periphery. When the flight distances n, n,... Of the ink droplets differ, the ink droplets in the peripheral portion reach the print medium sooner. The (character) line is bent at the center so as to be located lower (position delayed) than the peripheral portion with respect to the paper feeding direction, and the print (character) quality is degraded.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problem of warpage of the attachment surface of the frame member to which the nozzle forming member is attached and the problem caused by the warpage.

[0021]

According to the present invention, there is provided a print head having a surface on which a nozzle forming member of a frame member is bonded so as not to warp the bonding surface of the frame member on which the nozzle forming member is bonded. A warp preventing member having a coefficient of linear expansion substantially equal to the coefficient of linear expansion of the nozzle forming member is attached to the surface on the side opposite to the above.

Therefore, in the print head of the present invention, the surface opposite to the bonding surface of the frame member is pulled by the warp preventing member with the same tension as the bonding surface.
Warpage due to the tension of the nozzle forming member can be prevented.

In the method of manufacturing a print head according to the present invention, the bonding surface of the frame member to which the nozzle forming member is bonded is formed in advance so that the bonding surface of the frame member to which the nozzle forming member is bonded does not warp. After forming on a curved surface, the nozzle forming member is bonded to the bonding surface at a high temperature,
The bonding surface is made flat by warping of the frame member at the operating temperature of the print head due to the difference between the linear expansion coefficient of the frame member and the linear expansion coefficient of the nozzle forming member.

Therefore, in the method for manufacturing a print head of the present invention, the bonding surface is flat at the operating temperature.

According to another print head of the present invention, the interval between the heat generating resistor, the ink pressurizing chamber, and the ink discharge nozzle is reduced in order to eliminate the problem caused by the warpage of the surface of the frame member to which the nozzle forming member is bonded. From the center to the periphery.

Therefore, in another print head of the present invention, the intervals between the impact points of the ink droplets are uniform from the center to the periphery, and as a result, the ink droplets between the center and the periphery are reduced. The print (character) quality is not degraded due to the non-uniformity of the landing point intervals of the image.

According to the print head control method of the present invention, in order to eliminate the problem caused by the warpage of the surface of the frame member to which the nozzle forming member is bonded, the energization timing for the heating resistor is located at the peripheral portion. The more centrally located, the faster it is.

Therefore, in the control method of the print head of the present invention, the energization timing to the heating resistor is advanced by an amount corresponding to the longer flying distance of the ink droplet at the center due to the warpage of the bonding surface of the frame member. As a whole, the landing timing of the ink droplets on the print medium can be matched.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a print head according to the present invention,
An embodiment of the manufacturing method and the control method will be described with reference to the accompanying drawings.

First, a description will be given of a pudding and a head in which a frame member (head frame) is bonded to a nozzle forming member in order to eliminate the positional deviation between the heating resistor, the ink pressurizing chamber, and the ink discharge nozzle. The print head 1 described in this specification is a print head for a full-color bubble inkjet type line printer.

The print head 1 has a nozzle forming member 2. A large number of ink discharge nozzles 3, 3,... Are formed on the nozzle forming member 2. The ink ejection nozzles 3, 3,... Are formed in a state where several hundred nozzles are arranged for each substrate member described later. Such a nozzle forming member 2 is formed by, for example, an electroforming technique, for example, is formed in a sheet shape having a thickness of 15 μm to 20 μm, and the ink ejection nozzles 3 having a diameter of about 20 μm there.
Is formed (see FIGS. 2 and 3).

The nozzle forming member 2 is bonded to a head frame 4 as a frame member. The head frame 4 is formed by integrally forming three cross members 4b, 4b, 4b at equal intervals between short sides of a rectangular outer frame 4a, thereby forming a rectangular shape. The four spaces 5, 5,... To be formed are formed in a state of being arranged in parallel (see FIG. 2). The length of these spaces 5, 5,... Is, for example, approximately 21 cm, which is equivalent to the width of A4 size when used in a line printer that prints vertically on A4 size paper.

The head frame 4 is made of a material having a coefficient of linear expansion substantially equal to the coefficient of linear expansion of a semiconductor substrate serving as a base of a substrate member described later. When a silicon substrate is used as the semiconductor substrate, for example, silicon nitride is used. In addition, in ceramics, alumina (A1
₂ O ₃ ), mullite, aluminum nitride, silicon carbide, etc., in the case of glass, quartz (SiO ₂ ) or the like, and in the case of metal, invar steel or the like.

The head frame 4 is, for example, 5 mm
When the head frame 4 and the nozzle forming member 2 are bonded at a high temperature, for example, 150 ° C., the nozzle is not heated at a temperature lower than the bonding temperature (150 ° C.). Since the forming member 2 tends to contract more than the head frame 4, the nozzle forming member 2
Are in tension, and as a result, the distance between the ink discharge nozzles 3, 3,... Formed on the nozzle forming member 2, that is, the distance between the nozzles changes according to the linear expansion coefficient of the head frame 4. . The head frame 4
The bonding between the nozzle and the nozzle forming member 2 is performed by, for example, a thermosetting sheet adhesive, for example, an epoxy-based sheet adhesive.

After the nozzle forming member 2 and the head frame 4 are bonded as described above, a number of substrate members 6, 6,... Are bonded to the nozzle forming member 2 (see FIG. 2). . The substrate member 6 has heating resistors 8, 8,... Deposited on one surface of a semiconductor substrate 7 made of silicon or the like, and the heating resistors 8, 8,.
Are limited to the side where the ink pressure chambers 9, 9,... Are formed, that is, the barrier layer 10 serving as the side wall is laminated (see FIGS. 3 and 4). The barrier layer 10 is made of, for example, an exposure-curable dry film resist,
After the heat generating resistors 8, 8,... Are formed on the entire surface of the semiconductor substrate 7, unnecessary portions are removed by a photolithography process to form the substrate member 6.

In the substrate member 6, the thickness of the barrier layer 10 is approximately 12 μm, and the side of the heating resistor 8 is approximately 18 μm.
m square. Further, the width of the ink pressurizing chamber 9 is approximately 25 μm.

As one example, for example, in the case of a line printer using A4 size paper in a vertical position, ink formed on the nozzle forming member 2 in a space surrounded by one space 5 of the head frame 4 Discharge nozzles 3, 3, ...
Are about 5,000, and the substrate members 6, 6,... (1) to be bonded to the nozzle forming member 2 in this range.
Are 16). Therefore, the number of ink ejection nozzles 3, 3,... Corresponding to one substrate member 6 is three.
It will be around 10. Therefore, it is impossible to accurately express these numbers and sizes in drawings having restrictions on the size and the like, and in each drawing, they are exaggerated or omitted for easy understanding. .

The above substrate members 6, 6,... Are attached to the nozzle forming member 2 at a temperature of about 105 ° C.
Since this sticking is performed by thermally curing the barrier layer 10, the sticking temperature largely depends on the properties of the barrier layer 10, and is not limited to 105 ° C. The temperature for attaching to the head frame 4 needs to be higher than the temperature for attaching to the substrate members 6, 6,... And the nozzle forming member 2. This will be described with reference to the graph of FIG.

FIG. 5 shows the formation intervals (inter-nozzle intervals) of the ink discharge nozzles 3, 3,... Formed on the nozzle forming member 2.
, And the transition of the formation interval (inter-heater interval) of the heating resistors 8, 8,... Formed on the substrate member 6 due to the temperature change. That is, the curve A
Shows the transition due to temperature change when the interval between nozzles at room temperature (RT) is L1, and the curve B shows the transition due to temperature change when the interval between heaters at room temperature is L2. It is a thing.

The curves A and B are respectively
When the linear expansion coefficient of the nozzle forming member 2 is α1, the linear expansion coefficient of the semiconductor substrate 7 is α2, and the temperature is T, A: L = L1 + L1α1T B: L = L2 + L2α2T (where L2> L1, α1> α2) expressed.

Therefore, the temperature T at which the curve A and the curve B intersect with each other is calculated.
In step 1, the head frame 4 and the nozzle forming member 2 are bonded together.

Thereafter, the substrate members 6, 6,... Are attached to the nozzle forming member 2 at a temperature T2 lower than the temperature T1.

As described above, first, the head frame 4 and the nozzle forming member 2 are bonded at the temperature T 1, so that the nozzle forming member 2 is lower than the head frame 4 at a temperature lower than the bonding temperature (T 1). The nozzle forming member 2 is in a tensioned state in order to largely contract, and as a result, the interval between the ink discharge nozzles 3, 3,... The transition will be in accordance with the coefficient of linear expansion of 4. Since the linear expansion coefficient of the head frame 4 is substantially the same as the linear expansion coefficient of the substrate member 6, the interval between the nozzles and the interval between the heaters are substantially the same at the same temperature. (The ink pressurizing chambers 9, 9,...) And the ink ejection nozzles 3, 3,.

Therefore, since the interval between nozzles when the print head is completed is determined by the definition required for the printer using the print head, L2 is determined as a design value. In this case, L1 required is the linear expansion coefficient α1 of the nozzle forming member 2 and the linear expansion coefficient of the semiconductor substrate 7 (the head frame 4).
Α2, the sticking temperature T1 between the nozzle forming member 2 and the head frame 4, the sticking temperature T1 and the room temperature R. T. From the difference ΔT from FIG. Alternatively, it can be obtained from the following equation: L1 = L2 (α2ΔT-1) / (α1ΔT-1)

It is desirable that the linear expansion coefficient of the head frame 4 is smaller than the linear expansion coefficient of the nozzle forming member 2. When the temperature returns to room temperature after the head frame 4 and the nozzle forming member 2 are pasted together at a high temperature, the nozzle forming member 2 is moved by the head frame 4 due to the magnitude relationship between the linear expansion coefficients of the head frame 4 and the nozzle forming member 2. (1) Either a force is applied in the pulling direction or (2) a force is applied in the contracting direction, but in the case of (2), irregularities (wrinkles) may occur in the nozzle forming member 2 It is more desirable that (1) be constantly pulled. For this purpose, the linear expansion coefficient of the head frame 4 is
It is desirable to select a material such that the coefficient of linear expansion is smaller than the coefficient of linear expansion. Further, preferably, the linear expansion coefficient of the head frame 4 is smaller than the linear expansion coefficient of the nozzle forming member 2 and is substantially the same as the linear expansion coefficient of the substrate member 6.

It is desirable that the bonding temperature T1 between the head frame 4 and the nozzle forming member 2 be higher than the temperature in any subsequent process. Thereby, during the process after the head frame 4 and the nozzle forming member 2 are bonded to each other, the nozzle forming member 2 is always in a tensioned state, and the generation of wrinkles in the nozzle forming member 2 is prevented. . In the above-described example, the head frame 4 and the nozzle forming member 2 are bonded to each other in a temperature environment of approximately 150 ° C., and then, the substrate members 6, 6,. They are stuck together.

The flow path plates 11, 11,... Are attached to the print head 1 formed as described above (see FIG. 1).

There are a total of four flow passage plates 11, 11,... Corresponding to each color of ink (see FIGS. 1 and 2), and they have rigidity and ink resistance which are not easily deformed. It is formed of a material. The flow path plate 11 is formed by integrally forming a chamber portion 12 fitted into the space 5 of the head frame 4 and a flange portion 13 continuous with one surface of the chamber portion 12. The flange portion 13 is formed larger than the planar shape of the space 5 of the head frame 4. The chamber portion 12 has a space 14 opened on the end face opposite to the side on which the flange portion 13 is formed, and the walls defining both sides of the space 14 have substrate members 6, 6,. Are formed so as to communicate with the space 14 (see FIGS. 3 and 4). Further, an ink supply pipe 16 protrudes from a surface of the flange portion 13 opposite to a surface where the chamber portion 12 is continuous, and the ink supply tube 16 communicates with the space 14 (FIG. 1). , FIG. 2, FIG. 4).

Then, the above-mentioned flow path plates 11, 11,...
Are fitted into the spaces 5, 5,... Of the head frame 4, and the flange portions 13, 13,. Are fixed to the head frame 4 while being in contact with the crosspieces 4b, 4b,. And the nozzle forming member 2
Are bonded to the chamber portions 12, 12,... Of the flow path plates 11, 11,.
Are located in the notched recesses 15, 15,... Formed and bonded to the chamber portions 12, 12,... (See FIGS. 3, 4).

As described above, the flow path plates 11, 11,...
Are connected to the print head 1 so that the chambers 12, 12,... Of the flow path plates 11, 11,.
And the nozzle forming member 2, a closed space is formed, and the closed space is communicated with the outside only through the ink supply pipes 16, 16,. Are located in the closed space, and when viewed with respect to one closed space, the board members 6, which are arranged alternately (so-called staggered) while partially overlapping, 6,
Are formed between the rows, and the ink pressurizing chambers 9, 9,... Are in communication with the ink flow paths 17 (see FIG. 3).

The flexible substrates 18, 18,... For electrically connecting the heating resistors 8, 8,... Formed on the substrate members 6, 6,. Each of the flexible boards 18, 18,... Is provided with a connection piece 18a, 18a,.
(See FIG. 4) formed between the head frame 4 and the flow path plates 11, 11,... (See FIG. 4) to the positions of the substrate members 6, 6,. Member 6,
Are connected to the not-shown contacts which are respectively formed on the heating resistors 8, 8,.

The ink supply pipes 16, 16,... Provided on the flow path plates 11, 11,... Are respectively connected to ink tanks (not shown) storing inks of different colors. .. And the ink pressurizing chambers 9, 9,.
・ ・ Is filled with ink.

By passing a current pulse for a short period of time, for example, 1 to 3 microseconds, through the heating resistors 8, 8,... Uniquely selected by a command from the control unit of the printer, Are rapidly heated, and as a result, gas-phase ink bubbles are generated at portions in contact with the heating resistors 8, 8,..., And a certain volume is generated by the expansion of the ink bubbles. Are ejected, whereby ink having the same volume as the displaced ink in the portion in contact with the ink ejection nozzles 3, 3,... Is ejected from the ink ejection nozzles 3, 3,. Then, the ink is attached (landed) on a printing medium such as paper. Then, the ink pressurizing chambers 9, 9,.
Are immediately replenished with the same amount of ink ejected through the ink flow paths 17, 17,....

As described above, by bonding the head frame 4 to the nozzle forming member 2, the positional deviation between the heating resistor 8 and the ink pressurizing chamber 9 and the ink discharge nozzle 3 can be eliminated. This time, the warping problem shown in FIG. 16 occurs.

Therefore, the print head 1 according to the present invention
00, as shown in FIG.
A warp preventing member 101 having the same linear expansion coefficient as the nozzle forming member 2 is bonded to a surface 4d opposite to the bonding surface 4c to which the nozzle forming member 2 is bonded. When the nozzle forming member 2 is formed of nickel as in the above example, the warpage preventing member 101 is also preferably formed of nickel.

The bonding between the warpage preventing member 101 and the head frame 4 is performed at the same temperature as the bonding temperature between the nozzle forming member 2 and the head frame 4 in the above example.
Made at 0 ° C.

In the print head 100, at the operating temperature, the two surfaces 4c and 4d located on the opposite sides of the head frame 4 receive the same tensile force, respectively. Does not occur.

FIGS. 7 and 8 show a first embodiment of a method for manufacturing a print head according to the present invention.

First, the bonding surface 201a of the head frame 201 to which the nozzle forming member 2 is bonded is formed in advance so as to have a convex curved surface, and the surface 201b opposite to the bonding surface is formed to be flat. The curvature of the bonding surface 201a is determined so as to cancel the warpage generated at the operating temperature by the difference between the linear expansion coefficient of the head frame 201 and the linear expansion coefficient of the nozzle forming member 2.

Then, at a temperature higher than the use temperature, that is, at a temperature of 150 ° C. in the above example, the nozzle forming member 2
To the bonding surface 201a of the head frame 201 (see FIG. 7).

In the print head 200 manufactured through the above-described steps, the bonding surface 201a of the head frame 201 is warped due to the contracting force of the nozzle forming member 2 at the operating temperature. Since the mating surface 201a is formed in advance as a convexly curved surface, the warpage occurs to be flat (see FIG. 8).

FIGS. 9 and 10 show a second embodiment of the method for manufacturing a print head according to the present invention.

First, the entire head frame 301 is curved so that the bonding surface 301a of the head frame 301 to which the nozzle forming member 2 is bonded is a convex curved surface.
Thereby, the bonding surface 301a of the head frame 301
The surface 301b on the opposite side is a concave curved surface (see FIG. 9). In this case, the curvature of the bonding surface 301a is
The difference between the coefficient of linear expansion of No. 01 and the coefficient of linear expansion of the nozzle forming member 2 is determined so as to cancel the warpage generated at the operating temperature.

Then, at a temperature higher than the use temperature, that is, at a temperature of 150 ° C. in the above example, the nozzle forming member 2
To the bonding surface 301a of the head frame 301 (see FIG. 9).

In the print head 300 manufactured through the above-described steps, the bonding surface 301a of the head frame 301 is warped due to the contraction force of the nozzle forming member 2 at the operating temperature. Since the mating surface 301a is formed in advance as a convexly curved surface, the warpage occurs to be flat (see FIG. 10).

FIG. 11 shows another embodiment of the print head of the present invention.

In the print head 400, the formation interval D of the heating resistor, the ink pressurizing chamber, and the ink discharge nozzle (the positions of these are indicated by black circles for the right half for convenience) is set from the center portion CP. It is made to become wider as it goes to the peripheral part PP. That is, D1 <D2 <D3 <D4 <D5.

As a result, the bonding surface 4c of the head frame 4 becomes a concave curved surface at the operating temperature lower than the bonding temperature between the nozzle forming member 2 and the head frame 4, and goes from the central portion CP to the peripheral portion PP. The ink droplet ejection direction (indicated by an arrow) is inclined toward the center in accordance with
As shown in the figure, the correction is made so that the distance between the landing points of the ink droplets on the print medium 401 becomes narrower from the center to the periphery, and the landing point distance d is changed from the center CP to the periphery.
Even up to the PP. That is, d1 ≒ d2 ≒ d3 ≒ d4 ≒ d5.

Therefore, according to the print head 400 of the present invention, the printing (character) quality does not deteriorate due to the uneven landing point intervals of the ink droplets between the central portion and the peripheral portion.

Further, in the method of controlling the print head of the present invention, the energization timing for the heating resistors 8, 8,... Is set earlier in the central portion than in the peripheral portion. is there.

As shown in FIG. 16, the head frame 4
Is generated, the ink ejection nozzles 3,
.. And the print medium are closer to the peripheral portion, and if the timing of energizing the heating resistors 8, 8,. The flight time of the droplet to the print medium becomes longer, and the timing of reaching the print medium is delayed. However, as described above, the energization timing for the heating resistors 8, 8,... Is set earlier in the central portion than in the peripheral portion, so that the closer to the central portion, that is, The longer the flight time to the print medium, the sooner the current is supplied, and therefore, the ink droplets start flying earlier, so that the print medium reaches the print medium at the same timing from the one located at the center to the one located at the periphery. In other words, when the present invention is applied to a line printer, the print (character) line is straight from the center to the periphery, and high print (character) quality can be maintained.

In the illustrated embodiment, the present invention is applied to a print head for a full-color bubble ink-jet printer. However, the print head according to the present invention is used as a print head for a mono-color printer. The present invention is also applicable to a print head for a full-color printer, and is not limited to the four-color integrated type described above, but may be configured as an independent print head for each color. Things.

The shape and structure of each part shown in each of the above-described embodiments are merely examples of the specific embodiments to be carried out when carrying out the present invention. The scope should not be construed as limiting.

[0074]

As is apparent from the above description, the print head of the present invention has a side wall portion and one end face of the ink pressurizing chamber, and a substrate member provided with a heating resistor and the ink pressurizing chamber. A print head comprising the other end surface of the chamber and an ink discharge nozzle corresponding to the ink pressurization chamber formed and bonded to a nozzle forming member having a linear expansion coefficient larger than a linear expansion coefficient of a substrate member, A frame member having a linear expansion coefficient substantially equal to a linear expansion coefficient of the substrate member is bonded to the nozzle forming member, and a line of the nozzle forming member is formed on a surface of the frame member opposite to a surface on which the nozzle forming member is bonded. It is characterized in that a warp preventing member having a linear expansion coefficient substantially equal to the expansion coefficient is bonded.

Therefore, in the print head of the present invention, the surface opposite to the bonding surface of the frame member is pulled by the warp preventing member with the same tension as the bonding surface.
Warpage due to the tension of the nozzle forming member can be prevented.

Further, according to the method of manufacturing a print head of the present invention, it is preferable that a side wall portion and one end face of the ink pressurizing chamber are formed and a substrate member provided with a heating resistor and the other end face of the ink pressurizing chamber are formed. A nozzle forming member having an ink ejection nozzle corresponding to the ink pressurizing chamber and having a linear expansion coefficient larger than a linear expansion coefficient of the substrate member; and a line supporting the nozzle forming member and substantially equal to the linear expansion coefficient of the substrate member. A method for manufacturing a print head comprising a frame member having an expansion coefficient, wherein a bonding surface for bonding a nozzle forming member of the frame member is formed in a curved surface in advance,
The nozzle forming member is bonded to the bonding surface at a high temperature, and the difference is caused by the difference between the linear expansion coefficient of the frame member and the linear expansion coefficient of the nozzle forming member. It is characterized in that the surface is flat.

Therefore, in the method for manufacturing a print head of the present invention, the bonding surface is flat at the operating temperature.

According to the third aspect of the present invention, the bonding surface of the frame member is formed as a curved surface, and the surface opposite to the bonding surface is formed as a flat surface. Then, the bonding surface becomes a flat surface.

According to the fourth aspect of the present invention, the bonding surface is made to be a curved surface by curving the entire frame member having the same thickness.
At the operating temperature, the bonding surface is flat.

Another print head of the present invention comprises a substrate member forming a side wall portion and one end face of an ink pressurizing chamber and having a heating resistor, and forming the other end face of the ink pressurizing chamber and forming an ink. A nozzle forming member in which an ink discharge nozzle corresponding to the pressurized chamber is formed and having a linear expansion coefficient larger than the linear expansion coefficient of the substrate member; and a linear expansion coefficient substantially equal to the linear expansion coefficient of the substrate member supporting the nozzle forming member. And a frame member having a heat generating resistor. The print head ejects ink from the ink discharge nozzles by energizing the heat generating resistors to generate heat. It is characterized in that it becomes larger from the part to the peripheral part.

Therefore, in another print head of the present invention, the intervals between the impact points of the ink droplets are uniform from the center to the periphery, and as a result, the ink droplets between the center and the periphery are different. The print (character) quality is not degraded due to the non-uniformity of the landing point intervals of the image.

The method of controlling a print head according to the present invention comprises forming a side wall portion and one end face of an ink pressurizing chamber and a substrate member provided with a heating resistor, and forming the other end face of the ink pressurizing chamber. A nozzle forming member formed with an ink discharge nozzle corresponding to the ink pressurizing chamber and having a linear expansion coefficient larger than the linear expansion coefficient of the substrate member; and a linear expansion coefficient supporting the nozzle forming member and substantially the same as the linear expansion coefficient of the substrate member And a frame member having the following configuration: a print head that discharges ink from ink discharge nozzles by energizing the heat generating resistor to generate heat, wherein the energizing timing for the heat generating resistor is set at a central portion rather than at a peripheral portion. It is characterized in that the faster one is located.

Therefore, according to the print head control method of the present invention, the energization timing to the heating resistor is increased by an amount corresponding to the longer flight distance of the ink droplet at the center due to the warpage of the bonding surface of the frame member. As a whole, the landing timing of the ink droplets on the print medium can be matched.

According to the seventh aspect of the present invention, the timing of energizing the heating resistor of the print head according to the fifth aspect of the present invention is located at the center of the print head relative to that at the periphery. The higher the speed, the more uniform the interval between the landing points of ink droplets from the center to the periphery, and the same landing timing, resulting in high print (character) quality. Can be.

[Brief description of the drawings]

FIG. 1 shows a print head in which a frame member is bonded to a nozzle forming member together with FIGS. 2 to 4,
This figure is a perspective view.

FIG. 2 is an exploded perspective view.

FIG. 3 is an enlarged sectional view of a main part.

FIG. 4 is an enlarged sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 shows the expansion / contraction curve and the heat generation of the substrate member based on the temperature change of the bonding temperature between the head frame and the nozzle forming member and the bonding temperature of the substrate member to the nozzle forming member based on the temperature change of the interval between the ink discharge nozzles of the nozzle forming member. FIG. 7 is a graph showing an expansion / contraction curve based on a temperature change of a resistor formation interval.

FIG. 6 is a schematic side view showing an embodiment of the print head of the present invention.

FIG. 7 shows a first embodiment of the method of manufacturing a print head of the present invention together with FIG. 8, and is a schematic side view showing a state before the nozzle forming member and the frame member are bonded to each other. .

FIG. 8 is a schematic perspective view showing a state after returning to room temperature.

9 shows a second embodiment of the method for manufacturing a print head of the present invention together with FIG. 10, and is a schematic side view showing a state before the nozzle forming member and the frame member are bonded to each other. .

FIG. 10 is a schematic perspective view showing a state after returning to room temperature.

FIG. 11 is a schematic side view showing another embodiment of the print head of the present invention.

FIG. 12 shows an example of a conventional print head together with FIGS. 13 and 14, and FIG. 12 is a perspective view.

FIG. 13 is an exploded perspective view.

FIG. 14 is a sectional view showing a problem.

FIG. 15 is a schematic side view showing an improvement of a conventional print head.

16 is a schematic side view showing a problem of the improvement plan shown in FIG.

[Explanation of symbols]

Reference numeral 2: nozzle forming member, 3: ink discharge nozzle, 4: head frame (frame member), 4c: bonding surface, 4d: surface opposite to the bonding surface, 100: print head, 101:
Warpage preventing member, 200: print head, 201: head frame (frame member), 201a: bonding surface, 20
1b: surface opposite to the bonding surface, 300: print head,
301 ... head frame (frame member), 301a ...
Bonding surface, 301b: Surface opposite to bonding surface, 400: Print head

Claims (7)

[Claims] 1. An ink pressurizing chamber, comprising a side wall and one end face, a substrate member provided with a heating resistor, and an ink pressurizing chamber, the other end face of which corresponds to the ink pressurizing chamber. What is claimed is: 1. A print head comprising: a discharge nozzle formed thereon; and a nozzle forming member having a linear expansion coefficient larger than a linear expansion coefficient of a substrate member bonded thereto, wherein the frame member has a linear expansion coefficient substantially equal to the linear expansion coefficient of the substrate member. Was bonded to the nozzle forming member, and a warpage preventing member having a linear expansion coefficient substantially equal to the linear expansion coefficient of the nozzle forming member was bonded to the surface of the frame member opposite to the surface to which the nozzle forming member was bonded. A print head, characterized in that: 2. A substrate member forming a side wall portion and one end face of an ink pressurizing chamber and having a heating resistor, and forming another end face of the ink pressurizing chamber and corresponding to the ink pressurizing chamber. A nozzle forming member in which an ink discharge nozzle is formed and has a linear expansion coefficient larger than a linear expansion coefficient of the substrate member,
A method of manufacturing a print head comprising: a frame member having a linear expansion coefficient substantially equal to a linear expansion coefficient of a substrate member, supporting the nozzle forming member, wherein a bonding surface of the frame member to which the nozzle forming member is bonded is previously formed. Formed on a curved surface, the nozzle forming member is bonded to the bonding surface at a high temperature, and the frame member warps at the print head operating temperature due to the difference between the linear expansion coefficient of the frame member and the linear expansion coefficient of the nozzle forming member. The method for manufacturing a print head, characterized in that the bonding surface is made flat by the occurrence of. 3. The bonding surface of the frame member is formed into a curved surface,
3. The method according to claim 2, wherein the surface opposite to the bonding surface is formed as a flat surface. 4. The method according to claim 2, wherein the bonding surface is curved by bending a frame member having the same thickness as a whole. 5. A substrate member forming a side wall portion and one end face of the ink pressurizing chamber and having a heating resistor, and forming the other end face of the ink pressurizing chamber and corresponding to the ink pressurizing chamber. A nozzle forming member in which an ink discharge nozzle is formed and has a linear expansion coefficient larger than a linear expansion coefficient of the substrate member,
A frame member that supports the nozzle forming member and has a linear expansion coefficient substantially equal to the linear expansion coefficient of the substrate member;
What is claimed is: 1. A print head which ejects ink from an ink discharge nozzle by energizing the heat generating resistor to generate heat. A print head characterized in that it is made larger. 6. A substrate member forming a side wall and one end face of the ink pressurizing chamber and having a heating resistor, and forming the other end face of the ink pressurizing chamber and corresponding to the ink pressurizing chamber. A nozzle forming member in which an ink discharge nozzle is formed and has a linear expansion coefficient larger than a linear expansion coefficient of the substrate member,
A frame member that supports the nozzle forming member and has a linear expansion coefficient substantially equal to the linear expansion coefficient of the substrate member;
In a print head in which ink is ejected from an ink discharge nozzle by energizing the heat generating resistor to generate heat, the energizing timing of the heat generating resistor is set to be earlier in a central portion than in a peripheral portion. A print head control method, comprising: 7. An energization timing for the heating resistor is defined by:
7. The method according to claim 6, wherein the speed of the print head is faster in the central portion than in the peripheral portion.