JP3563968B2 - Liquid ejection recording head - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid discharge recording head that performs a recording operation by discharging a liquid to a recording surface of a recording medium.
[0002]
[Prior art]
An ink jet recording apparatus generally includes an ink jet recording head as a liquid discharge recording head. The ink jet recording head performs a recording operation by discharging ink onto a recording surface of a recording medium.
[0003]
For example, as shown in FIG. 6, there has been known an ink jet recording head having ink ejection portions 8A and 8B for ejecting inks having different densities, respectively, due to a demand for high image quality and high speed printing.
[0004]
In FIG. 6, the ink jet recording head includes a base 2 fixed to the bottom of an ink tank holder TKH connected to an ink tank (not shown) and a base 2 protruding from the bottom of the ink tank holder TKH. Ink ejection units 8A and 8B each formed integrally with the base unit 2 and having an ink ejection port formation unit 14 for ejecting ink, and a heater described later as each of the ink ejection unit 8A and the ink ejection unit 8B and an ejection pressure forming substrate The leaf spring members 6A and 6B as connecting members for connecting the board 4a and one end are electrically connected to the heater boat 4a, and the supplied drive control signal group is supplied to the heater boat 4a on the ink ejection unit 8A side. The printed wiring board 4A and one end thereof are electrically connected to the heater boat 4a, and the supplied drive control signals are supplied to the ink ejection unit. It is configured to include a printed circuit board 4B supplied to the heater boat 4a of B side.
[0005]
A so-called top plate of an ink jet recording head is formed by integrally molding the base portion 2 and the ink ejection portions 8A and 8B. A concave portion 10 is provided between the ink ejection portions 8A and 8B arranged substantially in parallel with each other so as to prevent the inks from being mixed during ink ejection. A plurality of ribs 12 are formed in the concave portion 10 so as to connect the ink discharge portions 8A and 8B.
[0006]
Since the ink discharge units 8A and 8B have the same structure, only the ink discharge unit 8A will be described, and the description of the ink discharge unit 8B will be omitted.
[0007]
In the ink ejection section 8A, an ink ejection port forming section 14 is formed on the upper surface along the longitudinal direction. In the ink discharge port forming section 14, a plurality of ink discharge ports 14a are formed at predetermined intervals, and each ink discharge port 14a of the ink discharge port forming section 14 is shown in FIG. So as to communicate with the plurality of ink branch channels 16a provided on the end face side facing the heater board 4a. Adjacent ink branch channels 16a are isolated by each partition 16b. Each ink branch channel 16a communicates with, for example, each of the common liquid chambers 18A and 18B in which ink is stored, respectively. The common liquid chamber 18A and the common liquid chamber 18B are separated by a partition wall 20. As shown in FIG. 7B, the common liquid chamber 18A and the common liquid chamber 18B communicate with the ink tank (not shown) through the respective ink supply paths 8a.
[0008]
On the surface of the heater board 4a facing each of the ink branch channels 16a, a heater as an electrothermal converter is provided correspondingly. Each heater is controlled based on a drive control signal group supplied through the printed wiring board 4A. By controlling the driving of each heater, the ink stored in each of the common liquid chambers 18A and 18B is supplied to each ink branch channel 16a in the direction indicated by the arrow in FIG. The ink introduced into the flow path 16a is heated and is ejected from the ink ejection port 14a as an ink droplet ID.
[0009]
At this time, as shown in FIG. 7B, each of the ink branch flow paths 16a and each of the common liquid chambers 18A and 18B are moved by the urging force of the pressing portion 6a of the leaf spring member 6A. By being pressed toward the flow path 16a and bringing the surfaces into close contact with each other, the hermetic seal is achieved.
[0010]
Therefore, the surfaces of the partition 16b and the partition wall 20 that are in contact with the heater board 4a require relatively high-precision flatness.
[0011]
[Problems to be solved by the invention]
However, when the ink ejection portions 8A and 8B are formed of a resin material by injection molding, the dimensional difference is different from the thickness of the portion where the common liquid chambers 18A and 18B are formed and the thickness of the portion where the partition wall 20 is formed. In the vicinity of the partition wall 20, warpage of about several μm may occur toward the heater board 4 a side due to the presence of the heater board 4 a.
[0012]
When the vicinity of the partition wall 20 is warped in this way, the adhesion between the partition wall 16b and the partition wall 20 and the heater board 4a is deteriorated, which causes printing unevenness.
[0013]
In such a case, it is conceivable to increase the urging force of the pressing portion 6a of the leaf spring member 6A to forcibly bring the partition 16b and the partition wall 20 into close contact with the heater board 4a. There is a possibility that the ink discharge units 8A and 8B may be bowed in a bow. That is, since the mutual interval between the ink ejection ports is different between the both end portions and the central portion, the position of the ink ejection ports is shifted from the predetermined reference position.
[0014]
In view of the above problems, the present invention is directed to a liquid ejection recording head that performs a recording operation by ejecting a liquid to a recording surface of a recording medium, and a portion of the liquid ejection section where a heater board is in close contact is warped. To provide a liquid discharge recording head that can maintain good adhesion between the liquid discharge portion and the discharge pressure forming substrate without increasing the urging force of the coupling member even when the liquid discharge recording head is formed in a state where the liquid discharge recording head is formed. And
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a liquid discharge recording head according to the present invention includes a liquid discharge port forming member having an arrangement of a plurality of liquid discharge ports, and the plurality of liquid discharge ports being in close contact with the liquid discharge port forming member. A discharge pressure forming substrate for forming a liquid flow path communicating with each of the liquid discharge ports and discharging the liquid supplied to the liquid flow path through the plurality of liquid discharge ports, and pressing the discharge pressure forming substrate against the liquid discharge port forming member. A joining member for joining the ejection pressure forming substrate to the liquid ejection port forming member, and a liquid ejection port forming member disposed opposite to the joining member with an arrangement of the plurality of liquid ejection ports of the liquid ejection port forming member interposed therebetween. And an elastic member biasing to the side.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 4 shows the appearance of an example of a liquid discharge recording head according to the present invention, together with an ink jet recording apparatus to which it is applied.
[0017]
The ink jet recording apparatus shown in FIG. 4 is capable of reciprocating on the bottom of the carriage member 32 which is supported on both ends of the housing 28 and the carriage member 32 which supports two ink tank holders 46 which are detachably mounted. The guide shaft 30 is supported by both ends of the housing 28 substantially in parallel with the guide shaft 30, and the guide shaft 31 supports the bottom of the carriage member 32 in a reciprocating manner, and is connected to the carriage member 32. A motor 40 for transmitting a driving force to the belt 36 via a pulley 38B; and a recovery processing device 42 disposed at one end inside the housing 28 and performing a recovery process for ink ejection units 52A and 52B described later. It is comprised including.
[0018]
The belt 36 is wound around pulleys 38A and 38B rotatably supported on the rear surface of the housing 28 at predetermined intervals. The pulley 38B is connected to an output shaft of the motor 40. The motor 40 is controlled based on a drive control signal from a control unit (not shown), and its output shaft is rotated in the forward or reverse direction. As a result, the carriage member 32 reciprocates within a predetermined distance from a position directly above the recovery processing device 42 while being guided by the guide shafts 30 and 31 at a predetermined timing with the two ink tank holders 46. I'm sullen.
[0019]
One end of a flexible cable 34 for supplying a drive control signal group to a recording head unit to be described later is electrically connected to a connector portion of the carriage member 32.
[0020]
Further, a paper transport path through which paper Pa as a recording medium is intermittently transported in a direction indicated by an arrow F in FIG. It is provided below.
[0021]
A color ink tank 44 and a black ink tank 48 are mounted on the two ink tank holders 46, respectively. The color ink tank 44 and the black ink tank 48 have the same structure except for the color of the stored ink. Therefore, the color ink tank 44 will be described, and the description of the black ink tank 48 will be omitted.
[0022]
The inside of the color ink tank 44 is a room where so-called dark yellow ink, dark magenta ink, and dark cyan ink each having a predetermined relatively high density are stored, and the density is compared with the density of the dark yellow ink. The light yellow ink, the light magenta ink, and the light cyan ink having extremely low densities are each divided into six rooms for storing therein. Each room is provided with urethane foam as an ink absorber. As shown in FIG. 5, ink supply ports 44Y, 44M, and 44C communicating with the respective rooms are formed corresponding to ink flow paths 46Y to 46C of an ink tank holder 46 to be described later.
[0023]
Each of the ink tank holders 46 formed of resin has a tank accommodating portion 46A for detachably accommodating the black ink tank 48 or the color ink tank 44, respectively. In the tank accommodating portion 46A, ink flow paths 46Y, 46M, and 46C for supplying each color ink or black ink to each ink supply passage 52ar in the ink ejection portions 52A and 52B described later are provided inside. . The ink flow paths 46Y to 46C communicate with the respective ink supply paths 52ar of the ink discharge unit 52A.
[0024]
Although not shown in FIG. 5, the ink flow paths communicating with the respective ink supply paths 52ar of the ink discharge unit 52B are formed similarly.
[0025]
The portion of the ink tank holder 46 where the ink flow paths 46Y to 46C are formed is made of a material having high transparency so that the ink flowing through the ink flow paths 46Y, 46M, and 46C can be viewed from the outside.
[0026]
As shown in FIG. 5, each of the two ink tank holders 46 is provided with ink ejection sections 52A and 52B on a base 50 at the bottom facing the paper Pa. When the paper Pa is stopped, the ink ejection units 52A and 52B eject ink to the recording surface of the paper Pa through the opening 28a of the housing 28 with the movement of the carriage member 32 to perform a recording operation.
[0027]
The recording head unit including the ink discharge units 52A and 52B is, for example, of a bubble jet type, and is fixed to the outer peripheral surface at the bottom of the ink tank holder 46 as shown in FIGS. And a base section 50 integrally formed of resin with the ink ejection sections 52A and 52B, and a common liquid chamber 52as and each ink flow path of the ink ejection sections 52A and 52B. The boards 66A and 66B, the printed wiring boards 54A and 54B having one end electrically connected to the heater boards 66A and 66B, respectively, and the heater boards 66A and 66B are respectively connected to the common liquid chambers 52as and 52as of the ink ejection sections 52A and 52B. The heater boards 66A and 66A are pressed against the respective ink flow paths. Spring members 56A and 56B as connecting members for connecting the ink ejecting portions 52A and 52B to each other, and urging members as pressing members which are press-fitted into concave portions 58 formed between the ink ejecting portions 52A and 52B. And a leaf spring member 60.
[0028]
The leaf spring members 56A and 56B respectively have a pair of engaging portions 56ak and 56bk which are respectively opposed to both side surfaces of the ink discharge portions 52A and 52B and are engaged with a pair of engaged portions 52a and 52b. Have.
[0029]
The engagement portion 56ak of the leaf spring member 56A is formed on a side surface portion bent in the left and right direction so as to be continuous with a base end surface portion 56as which is in contact with the outer peripheral edge portion of the ink ejection port forming portion 64A of the ink ejection portion 52A. . Further, as shown in FIG. 2, the pressing surface portion 56ap that presses the heater board 66A toward the ink ejection portion 52A is formed so as to be continuous with the base end surface portion 56as and curved toward the printed wiring board 54A.
[0030]
The engagement portion 56bk of the leaf spring member 56B is formed on a side surface portion bent in the left and right direction so as to be continuous with a base end surface portion 56bs abutting on the outer peripheral edge portion of the ink ejection port forming portion 64B of the ink ejection portion 52B. . Further, a pressing surface portion 56bp that presses the heater board 66B toward the ink ejection portion 52B is formed to be curved toward the printed wiring board 54B so as to be continuous with the base end surface portion 56bs.
[0031]
Each of the heater boards 66A and 66B has a plurality of heaters as electrothermal transducers arranged in a straight line at predetermined intervals.
[0032]
Printed wiring boards 54A and 54B, one ends of which are connected to heater boards 66A and 66B, respectively, are electrically connected to heater boards 66A and 66B by a tape carrier system (TAB), respectively.
[0033]
Thus, the drive control signal supplied through the connector of the carriage member 32 and the connector of the ink tank holder 46 is supplied to each heater of the heater boards 66A and 66B via the printed wiring boards 54A and 54B. .
[0034]
The base 50 and the ink discharge units 52A and 52B are integrally formed of, for example, polysulfone to form a so-called top plate of a recording head unit.
[0035]
When ink is ejected between the ink ejection units 52A and 52B, which are arranged so that the ink ejection unit 64A and the ink ejection unit 64B, which will be described later, are substantially parallel to each other, the respective inks are ejected. A recess 58 is provided to shut off mixing. A pair of ribs 62 are formed in the concave portion 58 so as to connect the ink ejection portion 52A and the ink ejection portion 52B.
[0036]
Since the ink discharge units 52A and 52B have the same structure, only the ink discharge unit 52A will be described, and the description of the ink discharge unit 52B will be omitted. The ink ejection section 52A ejects ink having a density lower than the density of the ink ejected from the ink ejection section 52B.
[0037]
As shown in FIG. 1, the ink ejection section 52A has an ink ejection port forming section 64A in which a plurality of ink ejection ports 64a are formed at predetermined intervals in the transport direction of the paper Pa. Part is formed. Each of the ink discharge ports 64a of the ink discharge port forming section 64A is connected to each of the ink branch flow paths provided on the end face side of the heater board 66A facing the respective heaters, similarly to the case shown in FIG. Communicating. Adjacent ink branch channels are separated by each partition. Each of the ink branch passages communicates with, for example, each of the common liquid chambers 52as in which each color of ink is stored. The common liquid chambers 52as are separated from each other by a partition wall. At this time, the heater board 66A is pressed toward each ink branch flow path by the urging force of the pressing surface portion 56ap of the leaf spring member 56A, and the surfaces of the ink branch flow paths and the common liquid chambers 50as are in close contact with each other. This results in hermetic sealing. The contact surface between the heater board 66A and the periphery of each common liquid chamber 52as and each partition is sealed by a sealing material not shown.
[0038]
As shown in FIG. 2, the common liquid chambers 52as communicate with the ink supply ports 44C to 44Y of the color ink tank 44 through the respective ink supply paths 52ar.
[0039]
Therefore, when the respective inks stored in the respective common liquid chambers 52as are supplied to the respective ink branch channels, when the heaters of the heater board 66A are driven and controlled, the ink introduced into the ink branch channels is heated. The ink is then ejected from the ink ejection port 64a as an ink droplet onto the recording surface of the paper Pa.
[0040]
Further, the leaf spring member 60 press-fitted into the concave portion 58 is formed by, for example, bending a relatively thin stainless steel plate so as to have a curved shape, for example, a V-shaped cross section toward the rib 62 side. I have. In the leaf spring member 60, both ends connected to the bent portion can be displaced in a direction substantially orthogonal to the direction in which the ink ejection ports 64 a are arranged, and are in contact with the inner peripheral surface of the recess 58. Therefore, the leaf spring member 60 is pressed into the recess 58 and is fixed by the elastic force. As a result, the urging force in the direction substantially perpendicular to the direction in which the ink ejection ports 64a are arranged in the leaf spring member 60 is applied in a direction to increase the distance between the ink ejection sections 52A and 52B.
[0041]
The order of assembling the leaf spring members 60 may be before or after the joining operation between the heater boards 66A and 66B and the partition walls of the ink ejection sections 52A and 52B.
[0042]
The length of the leaf spring member 60 in the longitudinal direction is set to be longer than, for example, the length of the ink discharge port forming portion 64A along the ink discharge port arrangement direction. If the undesired warpage of the partition wall between the common liquid chambers 52as is a limited part of the ink discharge port forming portion 64A, the longitudinal length of the leaf spring member 60 may be reduced. The length in the direction may be set to a length corresponding to a part of the region. Further, the cross-sectional shape of the leaf spring member 60 as the elastic member is not limited to the V-shape, and may be formed in a U-shape. Further, the material of the leaf spring member 60 having elasticity is not limited to a stainless steel plate, but may be, for example, an elastomer.
[0043]
Accordingly, the partition walls separating the ink branch flow paths of the ink ejection sections 52A and 52B and the peripheral edge of the common liquid chamber are pressed toward the heater board 66A by the urging force of the leaf spring member 60, so that each common liquid chamber 52as Even when an undesired warpage of the partition wall occurs between the partition walls and the peripheral edge of the common liquid chamber and the heater board without increasing the elastic coefficient of the leaf spring members 56A and 56B. Good adhesiveness with 66A is obtained.
[0044]
In the above-described example, the recording head unit ejects ink. However, the present invention is not limited to this example. For example, the recording head unit ejects a so-called processing liquid that insolubilizes a dye of a predetermined ink. There may be.
[0045]
【The invention's effect】
As is apparent from the above description, according to the liquid discharge recording head of the present invention, the elastic member is additionally provided while the discharge pressure forming substrate is connected to the liquid discharge port forming member by the connecting member . Since the liquid ejection port forming member is disposed to face the coupling member across the arrangement of the plurality of liquid ejection ports and biases the liquid ejection port forming member toward the coupling member, a portion of the liquid ejection section where the heater board is in close contact is provided. Even in the case of being formed in a warped state, it is possible to maintain good adhesion between the liquid discharge portion and the discharge pressure forming substrate without increasing the urging force of the connecting member.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a main part of an example of a liquid discharge recording head according to the present invention.
FIG. 2 is a partial sectional view of the example shown in FIG.
FIG. 3 is an exploded perspective view showing components of an example of a liquid discharge recording head according to the present invention in an exploded manner.
FIG. 4 is a perspective view schematically showing an external appearance of an example of a liquid ejection recording head according to the present invention, together with a recording apparatus to which the liquid ejection recording head is applied.
FIG. 5 is a perspective view showing an external appearance of an example of a liquid discharge recording head according to the present invention, together with an ink tank to which the head is applied.
FIG. 6 is a perspective view showing a main part of a conventional liquid discharge recording head.
7A is a partial perspective view showing each common liquid chamber in the example shown in FIG. 6, and FIG. 7B is a partial cross-sectional view in the example shown in FIG.
[Explanation of symbols]
44 color ink tank 46 black ink tanks 52A, 52B ink discharge sections 56A, 56B, 60 leaf spring member 58 recesses 64A, 64B ink discharge port forming section 66A heater board

Claims (9)

A liquid ejection port forming member having an arrangement of a plurality of liquid ejection ports,
A discharge pressure forming substrate that forms a liquid flow path in close contact with the liquid discharge port forming member and communicates with each of the plurality of liquid discharge ports, and discharges liquid supplied to the liquid flow path through the plurality of liquid discharge ports; ,
A coupling member that presses the discharge pressure forming substrate against the liquid discharge port forming member and couples the discharge pressure forming substrate to the liquid discharge port forming member;
An elastic member disposed to face the coupling member with an arrangement of a plurality of liquid ejection ports of the liquid ejection port forming member interposed therebetween and biasing the liquid ejection port forming member toward the coupling member;
A liquid discharge recording head comprising: A first liquid ejection port forming member having an arrangement of a plurality of liquid ejection ports,
A second liquid ejection port forming member that has an arrangement of a plurality of liquid ejection ports and is disposed to face the first liquid ejection port forming member;
The first liquid discharge port forming member and the second liquid discharge port forming member are in close contact with each other to form liquid flow paths respectively communicating with the plurality of liquid discharge ports, and the liquid supplied to the liquid flow paths is A discharge pressure forming substrate for discharging through a plurality of liquid discharge ports,
The discharge pressure forming substrate is pressed against the first liquid discharge port forming member and the second liquid discharge port forming member, and the discharge pressure forming substrate is pressed against the first liquid discharge port forming member and the second liquid discharge port forming member. A coupling member coupled to the liquid ejection port forming member of
The first liquid ejection port forming member disposed between the arrangement of the plurality of liquid ejection ports of the first liquid ejection port forming member and the arrangement of the plurality of liquid ejection ports of the second liquid ejection port forming member. And an elastic member for urging the second liquid ejection port forming member toward the coupling member,
A liquid discharge recording head comprising: 3. The liquid discharge recording head according to claim 1, wherein the coupling member is a leaf spring member. 3. The liquid discharge recording head according to claim 1 , wherein the elastic member has a curved cross-sectional shape. The liquid discharge recording head according to claim 1 , wherein a length of the elastic member is set to be longer than a length of an arrangement of the plurality of liquid discharge ports. 3. The liquid discharge recording head according to claim 1, wherein the discharge pressure forming substrate discharges the ink supplied to the ink flow path through the plurality of ink discharge ports. The liquid ejection recording head according to claim 1, wherein the liquid ejection port forming member is formed integrally with a liquid storage unit. The concentration of the liquid discharged from the plurality of liquid discharge ports of the first liquid discharge port forming member is different from the concentration of the liquid discharged from the plurality of liquid discharge ports of the second liquid discharge port forming member. 3. The liquid discharge recording head according to claim 2, wherein: The liquid discharge recording head according to claim 1, wherein the discharge pressure forming substrate has an electrothermal transducer corresponding to each of the plurality of liquid discharge ports.

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