JPH11245399A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably supply an ink independently to a plurality of rows of pressure generating chambers formed on the same base plate without increasing a width direction size of a recording head by forming a channel communicating with a reservoir body at an ink introducing inlet periphery, and supporting two points of an outer periphery of an ink guide passage opening. SOLUTION: In the step of adhering a channel unit to a head holder, two points of a reservoir 3 of a peripheral edge of an ink guide passage opening 13, i.e., an area of a wall of a right side of a recess 18 and a wall 2a for forming an ink supply port and an area of an end 19a of a protrusion 19 are supported. A sealing plate at a periphery of the opening 13 of the ink guide passage is effectively adhered to the holder to obtain a liquid-sealing structure. When a drive signal is applied to the head, a piezoelectric vibrator is contracted, and a pressure generating chamber is expanded. Thus, an ink of the reservoir 3 flows from the ink supply port to the generating chamber. When a predetermined time is elapsed so that the vibrator is electrically discharged, the vibrator is elongated to be reset to its original state.

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 forming a recorded image by discharging ink droplets on a recording medium, and more particularly to a structure of a spacer for forming a flow path such as a pressure generating chamber.

[0002]

2. Description of the Related Art Ink jet recording is performed by laminating an elastically deformable sealing plate on a wall surface of a pressure generating chamber communicating with a nozzle, and discharging the ink droplets by pressing the sealing plate with a piezoelectric vibrator to record on a recording medium. Type recording head is disclosed in
No. 7,323,543, a nozzle plate having a nozzle, a spacer member in which a pressure generating chamber, a reservoir and an ink flow path are formed, and a sealing plate are laminated in a sandwich shape. Elastically deformed by a vibrator,
The pressure generating chamber is configured to expand and contract.

[0003] The reservoir is formed in a substantially U shape so as to surround the outer peripheries of the two rows of pressure generating chambers, and is configured such that an inlet is connected to a central portion. According to such a configuration, high-density printing can be performed using two rows of pressure generating chambers. However, in a recording head that uses a plurality of types of inks, such as color printing, the number of ink types is small. However, there is a problem that the size of the recording head in the width direction becomes very large. The present invention has been made in view of such a problem, and an object of the present invention is to provide a plurality of rows of pressure generating chambers formed on the same substrate without increasing the size of a recording head in the width direction. An object of the present invention is to provide an ink jet recording head capable of stably supplying ink independently to each row.

[0004]

According to the present invention, in order to solve such a problem, a plurality of pressure generating chambers are formed in a row and communicate with the pressure generating chambers in each row via ink supply ports. A flow formed by stacking a spacer having a reservoir formed therein, a nozzle plate provided with a nozzle opening communicating with the pressure generating chamber, a sealing plate for sealing the pressure generating chamber, and the reservoir. A path unit and a head holder that fixes the flow path unit and includes an ink guide path for injecting ink into the reservoir, wherein the spacer communicates with the main body of the reservoir around the ink introduction port. A connection flow path is formed, and has a region that supports at least two points on the outer periphery of the opening of the ink guide path in a direction across the reservoir.

[0005]

In the process of bonding to the head holder, a plurality of points on the outer periphery of the ink guide path of the head holder are brought into contact with the head holder due to the convex portion of the spacer formed near the ink introduction port. And a liquid-tight structure is secured. The ink that has flowed back from the ink supply port to the reservoir absorbs a pressure increase due to the elastic deformation of the sealing plate.
In addition, the ink that has flowed back from the pressure generating chamber in the area facing the ink inlet is also diverted to both sides from the recess formed in this area, and is absorbed by the large compliance on both sides.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of the present invention. FIG. 1 shows an embodiment of a recording head according to the present invention.
A flow path forming unit 5 that forms the ink supply port 2, the reservoir 3, and the pressure generating chamber 4 is fixed to one end of the head holder 6, and a piezoelectric vibration is provided at a position facing the pressure generating chambers 4 in each row of the unit 5. The piezoelectric vibrator unit 8 is fixed to the head holder 6 so that the tips of the elements 7, 7, 7,...

As shown in FIG. 2, the head holder 6 has a window 9 for exposing the piezoelectric vibrators 7, 7, 7 at a position facing the pressure generating chamber 4, and a region facing the reservoir 3,
A concave portion 11 is formed to make a later-described sealing plate 10 elastically deformable by the piezoelectric vibrator 7 elastically deformable. Further, an opening 13 is formed at a position facing the center of the reservoir at the tip of an ink guide path 12. It is configured.

The flow path unit 5 includes a nozzle plate 14 having a nozzle opening 1 communicating with the pressure generating chamber 2, a spacer 3 for forming the reservoir 3, the ink supply port 2, and the pressure generating chamber 4, and at least a reservoir 3. The ink supply port 2 and the pressure generating chamber 4 are sealed, and the opening 13 of the head holder 6 and the reservoir 3 are connected to the reservoir 3 and an elastic film which can be elastically deformed in the area of the pressure generating chamber 4. 16 and a sealing plate 10 formed by piercing the sealing plate 16 in a sandwich shape.

In this embodiment, in order to convert the displacement of the piezoelectric vibrator 7 into a change in the volume of the pressure generating chambers, the sealing plate 10 is formed with an island portion 17 having rigidity in the center line of each pressure generating chamber. ing.

FIG. 3 shows an embodiment of the spacer 15. Pressure generating chambers 4, 4, 4,... Are formed at a constant pitch in two rows so that the center line is a symmetrical line. The reservoirs 3, 3 are independently formed outside the ink supply ports 2, 2, 2,.
... and the reservoirs 3, 3 and the pressure generating chambers 4, 4,
4,... Are connected.

The reservoir 3 is formed in a wing shape so that both sides are slightly narrowed so that the center point is a symmetrical point, and a concave portion 18 connected to the ink guide path 12 of the head holder 6 is formed at the center portion. 19 are formed. The recess 18 is formed so as to be located inside the outermost side of the reservoir 3. This makes it possible to reduce the overall width of the recording head to achieve downsizing.

On both sides (vertical direction in the figure) of the protruding portion 19, a connecting flow path 20 composed of a step portion through which ink can flow through the main body portion of the reservoir 3 and the concave portion 18 is provided in FIG.
And as shown in FIG. 5, it is formed on the sealing plate 10 side.

The spacer 15 is made of a silicon single crystal substrate cut to a predetermined thickness as is well known, and the reservoir 3, the recess 18 and the like are formed with through holes by anisotropic full etching. The connection channel 20 can be formed by anisotropic half-etching.

Further, a plate material such as metal or glass which is etchable and has corrosion resistance to the ink is used, and a penetrating region and a concave portion are formed by etching in the plate material. Can be constituted by decomposing the film into a plurality of layers and laminating an etching film in which through holes corresponding to the through holes of each layer are formed.

In this embodiment, the nozzle plate 14 is provided on one surface of the spacer 15 and the sealing plate 1 is provided on the other surface.
0 is fixed in a liquid-tight manner with an adhesive or the like to form a flow path forming unit 5.
Is configured.

The ink inlet 1 of the channel forming unit 5
6 is aligned with the opening 13 of the ink guide path 12 of the head holder 6 and fixed to the head holder 6 with an adhesive or the like;
The tip of the piezoelectric vibrator 7 is located at the island 1 of the sealing plate 10.
When the piezoelectric vibrator unit 8 is fixed to the head holder 6 so as to be in contact with 7, the ink supply needle 21 and the filter 22 are attached to the other surface of the head holder 6, and the outside is fixed by the frame 23 also serving as a shield member. The recording head is completed.

By the way, in the process of adhesion between the flow path unit 5 and the head holder 6, at least two points in the width direction of the reservoir 3 in the periphery of the opening 13 of the ink introduction path 12, that is, the concave portion 18 in FIG. Middle right wall and ink supply port 2
Area of the wall 2a forming the tip and the tip 19a of the projection 19
, The sealing plate 10 around the opening 13 of the ink guide path is securely adhered to the head holder 6,
A liquid-tight structure is ensured.

When a drive signal is applied to the recording head thus configured, the piezoelectric vibrator 7 contracts and the pressure generating chamber 4
Expands. As a result, the ink in the reservoir 3 flows from the ink supply port 2 into the pressure generating chamber 4. When the piezoelectric vibrator 7 is discharged after a lapse of a predetermined time, the piezoelectric vibrator 7 expands and returns to the original state. In this process, the pressure generating chamber 4
Is compressed, a part of the ink in the pressure generating chamber 4 is discharged as an ink droplet from the nozzle opening 1, and the remaining part flows backward from the ink supply port 2 to the reservoir 3.

The ink flowing back into the reservoir 3 increases the pressure in the reservoir 3. One surface of the reservoir 3 is sealed by an elastically deformable sealing plate 10 such as a film, and the head holder 6 The sealing plate 10 is elastically deformed in response to pressure and absorbs an increase in pressure because the concave portion 11 is formed on the opposite surface of the sealing plate 10. The ink inlet 16
The ink flowing backward from the pressure generating chamber 4 in the area facing
The fluid is diverted to both sides from the connection flow path 20 formed in this region, and is absorbed by the large compliance of the main bodies of the reservoirs 3 on both sides.

When the ink in the reservoir 3 is consumed in this way, the ink in the ink cartridge (not shown) connected by the ink supply needle 21 passes from the ink introduction port 12 through the ink guide path 12 of the head holder 6. The fluid is divided and flows into both sides from the opening 18a of the concave portion 18 of the reservoir 3 and the connection flow path 20.

FIG. 6 shows a second embodiment of the present invention. In this embodiment, the above-mentioned protrusion 19 is provided.
A wall 19b is formed on the pressure generating chamber side (the left side in the figure) so as to surround the concave portion 18 and a connection flow path 24 is formed on the wall 19b.

According to this embodiment, it is possible to secure the contact area with the peripheral edge of the opening 13 of the ink guide path 12 as long as possible, and to secure the bonding structure more stably.

In the above embodiment, the wall portion 19b
The connection channel 24 is formed in the elongate area facing the reservoir on the pressure generating chamber side as shown in FIG.
When the branch 5 is formed and the branch 26 is formed so as to be connected to the wall 19b, the wall 19b can be reinforced while ensuring communication between the recess 18 and the reservoir 3.

Further, as shown in FIG. 8, the tip 26a of the branch 26 is slightly retracted from the recess to secure the opening area 27, and the tip 26a is formed to have the same thickness as the spacer 15. This may be used as a support area around the periphery of the opening 13 of the ink guide path 12 of the head holder 6.

In the above-described embodiment, the connection flow path between the opening 13 of the ink guide path 12 of the head holder 6 and the reservoir 3 is formed on the sealing plate 10 side.
It is apparent that the same effect can be obtained even if the connection flow path 20 'is formed on the nozzle plate side as shown in FIG. 9 or the connection flow path 20 "is formed on both sides as shown in FIG. It is.

In particular, when the connection flow path 20 ′ is formed on the nozzle plate side, the ink guide path 12
Since the projections 19 of the spacers 15 in the area in contact with the periphery of the openings 13 of the openings 13 remain in a large area on the sealing plate 10 side, the spacers 15 are bonded when the head holder 6 and the flow path unit 5 are bonded.
It is easy to apply pressure for bonding due to its rigidity. As a result, as shown in FIGS. 10 and 11, the tip 19a of the projection 19 in the embodiment shown in FIG. 4, the wall 19b in the embodiment shown in FIGS. 6 and 7, and furthermore, the embodiment shown in FIG. The concave portion can be formed so as to be enlarged so that the region corresponding to the distal end portion 26a in the example is used as the connection flow channel, and the flow resistance in the connection flow channel can be reduced.

Further, as shown in FIG. 12, a region corresponding to the periphery of the opening 13 of the ink guide path 12 of the head holder 6 can be a concave portion.

Further, in the above-described embodiment, the connection flow path between the opening 13 of the ink guide path 12 of the head holder 6 and the reservoir 3 is formed one by one in the direction in which the reservoir 3 extends. In addition, as shown in FIG. 13, the flow path 20 is formed so as to leave the island portion 19c around the opening 13, and the flow path resistance of the connection flow path is reduced while ensuring the adhesiveness of the flow path unit. Can be lowered.

Further, in the above-described embodiment, the piezoelectric vibrator which expands and contracts in the axial direction is used as the pressure generating means, but the piezoelectric vibrator which bends and vibrates is provided opposite each pressure generating chamber 4, The same effect can be obtained by applying a heating element capable of evaporating and vaporizing ink to a recording head provided in each pressure generating chamber 4.

[0030]

As described above, in the present invention,
The connection path is formed around the ink introduction port of the spacer so as to communicate with the main body of the reservoir, and the spacer has an area that supports at least two points on the outer periphery of the opening of the ink guide path in the direction across the reservoir. In the process of bonding the units, a plurality of points on the outer periphery of the ink guide path of the head holder can be brought into contact with the head holder by the convex portion of the spacer formed in the vicinity of the ink introduction port to ensure reliable bonding. In addition, the ink that has flowed back to the reservoir from the pressure generating chamber near the ink guide port can be diverted to both sides from the concave portion formed in this area and absorbed by the large compliance on both sides.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of an ink jet recording head of the present invention.

FIG. 2 is an assembled perspective view of the recording head.

FIG. 3 is a plan view showing one embodiment of a spacer.

FIG. 4 is an enlarged plan view of a region of the spacer facing the opening of the ink guide path of the head holder.

FIG. 5 is an enlarged sectional view showing the vicinity of an opening of an ink guide path of a head holder.

FIG. 6 is an enlarged plan view showing another embodiment of the present invention in the vicinity of an opening of an ink guide path of a head holder.

FIG. 7 is an enlarged plan view showing the vicinity of an opening of an ink guide path of a head holder according to another embodiment of the present invention.

FIG. 8 is a plan view showing another embodiment of the present invention in which the vicinity of the opening of the ink guide path of the head holder is enlarged.

FIGS. 9A and 9B are cross-sectional views showing another embodiment of the present invention, in which the vicinity of the opening of the ink guide path of the head holder is enlarged.

FIG. 10 is a plan view showing, in an enlarged scale, the vicinity of the opening of the ink guide path of the head holder in the embodiment in which a connection recess is formed on the nozzle plate side.

FIG. 11 is a plan view showing, in an enlarged manner, the vicinity of the opening of the ink guide path of the head holder in the embodiment in which a connection recess is formed on the nozzle plate side.

FIG. 12 is a plan view showing, in an enlarged manner, the vicinity of the opening of the ink guide path of the head holder in an embodiment in which a connection recess is formed on the nozzle plate side.

FIG. 13 is a plan view showing, in an enlarged manner, the vicinity of the opening of the ink guide path of the head holder in the embodiment in which a connection recess is formed on the nozzle plate side.

[Description of Reference Numerals] 3 reservoir 4 pressure generating chamber 5 flow path unit 6 head holder 7 piezoelectric vibrator 10 sealing plate 12 ink guide path 13 opening 14 nozzle plate 15 spacer 16 ink introduction port 18 concave section 19 projecting section 20 connection flow path

Claims (13)

[Claims] A spacer having a plurality of pressure generating chambers formed in a row and a reservoir formed to communicate with the pressure generating chambers of each row via an ink supply port, and a nozzle opening communicating with the pressure generating chambers. A flow path unit formed by laminating a perforated nozzle plate, the pressure generating chamber, and a sealing plate that seals the reservoir, and fixing the flow path unit, and applying ink to the reservoir. A head holder provided with an ink guide path for injecting, wherein the spacer has a connection flow path formed around the ink introduction port and communicating with the main body of the reservoir, and the ink guide path extends in a direction across the reservoir. An ink jet recording head having a region that supports at least two points on the outer periphery of the opening. 2. The ink jet recording head according to claim 1, wherein the connection flow path is formed as a recess on the nozzle plate side or the sealing plate side. 3. The ink jet recording head according to claim 1, wherein the connection flow path is formed as a recess on both sides of the nozzle plate side and the sealing plate side. 4. The ink jet recording head according to claim 1, wherein the connection flow path is formed so as to open to the nozzle plate side and substantially surround the outer circumference of the ink guide path. 5. The ink jet recording head according to claim 1, wherein the connection flow path is branched into a plurality of portions so as to be connected to an opening of the ink guide path. 6. The ink jet recording head according to claim 1, wherein the spacer is formed by anisotropically etching a silicon single crystal substrate, and the connection channel is formed by half-etching the silicon single crystal substrate. . 7. The ink jet recording head according to claim 1, wherein an outer boundary of the ink inlet substantially coincides with an outermost side of the reservoir. 8. The ink jet recording head according to claim 1, wherein the periphery of the opening of the ink guide path of the head holder is supported across a reservoir. 9. A part of a periphery of an opening of the ink guide path of the head holder is supported in a reservoir.
3. The ink jet recording head according to item 1. 10. The ink jet recording head according to claim 1, wherein a recess is formed in a region on the pressure generating chamber side facing the reservoir. 11. The ink jet recording according to claim 1, wherein the sealing plate is elastically deformable in a region facing the reservoir, and a concave portion is formed in the head holder to allow the elastic deformation. head. 12. The ink jet recording head according to claim 1, wherein the sealing plate is elastically deformable in a region facing the pressure generating chamber and receives a displacement of a piezoelectric vibrator. 13. The ink jet recording head according to claim 1, wherein a heating element for vaporizing ink is provided in the pressure generating chamber.