JP2002137392A - Recording head, production method for recording head and image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording head, a production method for a recording head and an image recorder capable of providing an effective preventive measure for mutual interference, to be produced easily. SOLUTION: In this recording head, a plurality of pressure buffer members (15) for absorbing the pressure wave generated in a pressure liquid chamber are provided on at least one of the wall surfaces comprising a common liquid chamber. Thereby, influence of the mutual interference to adjacent ink ejection bits can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head, a method of manufacturing the recording head, and an image recording apparatus, and more particularly, to a recording head of an ink jet recording apparatus for preventing mutual interference between adjacent ink ejection bits.

[0002]

2. Description of the Related Art A recording head having a drive system in which a liquid recording medium is ejected from an ejection port by a pressure applied to a pressurized liquid chamber by a vibration plate has a simple structure, and a plurality of ejection ports are easily integrated with high density. Since it can be formed in an array, it is widely applied as an inkjet recording head. However, if the intervals between the discharge ports are reduced for higher output, mutual interference between adjacent pressurized liquid chambers becomes a problem. This mutual interference occurs because the pressure applied by the diaphragm to the pressurized liquid chamber of the drive bit is transmitted to the adjacent non-drive bit via the common liquid chamber or the side wall between the pressurized liquid chambers, and the pressure fluctuation occurs in the bit that does not operate originally. This is caused by causing As conventional techniques for preventing this, there have been proposed several methods of forcibly suppressing vibration on the non-driving side and a method of providing a buffer region to absorb pressure.

One of them is disclosed in Japanese Patent Application Laid-Open No. 6-143562.
Japanese Patent Application Publication (hereinafter referred to as Conventional Example 1) discloses an ink jet recording head that suppresses the occurrence of diaphragm displacement of a non-drive bit by applying a voltage to the diaphragm of the non-drive bit to suppress vibration. Have been. That is, a voltage is also applied to the non-drive side, and the vibration due to the pressure wave from the drive side is canceled to suppress the vibration. Also, Japanese Patent Laid-Open No. 6-191
No. 030 (hereinafter referred to as Conventional Example 2) discloses that by providing a damper chamber through an opening in a flow path connecting a pressurized liquid chamber and a common liquid chamber, the pressure wave generated by the diaphragm driving can be reduced by the common liquid chamber. An ink jet recording head is disclosed in which a pressure wave is absorbed by a damper chamber before heading to a chamber, a pressure wave is hardly transmitted to a non-drive bit via a common liquid chamber, and a pressure fluctuation on a non-drive side is suppressed. Further, Japanese Patent Application Laid-Open No. Hei 9-141864 (hereinafter referred to as Conventional Example 3) discloses that a pressure absorber is provided in a common liquid chamber to absorb pressure waves transmitted from a pressurized liquid chamber and to cause pressure fluctuation in the common liquid chamber. There is disclosed an ink jet head which suppresses the ink jetting. Japanese Patent Application Laid-Open No. H11-192699 (hereinafter referred to as Conventional Example 4) discloses an ink jet recording head that uses an ink tank as a buffer area and absorbs a rise in pressure.

[0004]

However, according to the above prior art 1, it is extremely difficult to control the voltage on the non-driving side, and since the voltage is also applied to the non-driving side, the consumption of the entire apparatus is reduced. There is a problem that power increases. Also, in the above-described conventional example 2, when the damper chamber is provided, it is necessary to incorporate the formation of the damper chamber into the manufacturing process, but there is a problem that the number of steps is relatively complicated. In addition, although a damper using air filling is effective in absorbing bubbles, it is necessary to provide a considerably large damper chamber in order to suppress a high pressure propagating through the ink itself, which leads to an increase in the size of the head. Further, according to the conventional example 4, the pressure absorber is provided in the entire ink tank. In this case, however, there is a problem that the deformation accompanying the pressure absorption of the absorber occurs over the entire ink tank depending on the driving conditions. is there. For example, when only the center bit in the bit string direction is not driven and all other bits are driven, the vibration of the pressure absorber has a maximum amplitude near the center of the non-driven bit, and the pressure fluctuation due to this vibration is reduced to the non-driven bit. There is a problem of having an adverse effect. In addition, it is necessary to install a low-rigidity pressure absorber over a wide area, and there is a problem that the strength is insufficient and breakage easily occurs. For example, 192 at 150 dpi
In the case of a bit inkjet head, the width of the common liquid chamber in the longitudinal direction is 25.4 / 150 × 192 = 32.5 mm. It becomes difficult and becomes difficult. In the future, if the number of bits increases for speeding up, this tendency will become more remarkable. According to the above-described conventional example 3, although the problem seen in the conventional example 4 is improved, the pressure absorber is not stuck on the free vibration surface, but is stuck on the wall surface as it is, and the pressure absorber only by the contraction of the surface is used. Due to the absorption, the effect of reducing the pressure is limited.

The present invention has been made to solve these problems, and provides a recording head, a method of manufacturing a recording head, and an image recording apparatus capable of providing an effective measure against mutual interference and easy prevention. The purpose is to do.

[0006]

In order to solve the above-mentioned problems, a diaphragm is arranged on at least one surface of a wall constituting a pressurized liquid chamber, and the pressure in the pressurized liquid chamber is increased by a displacement operation of the diaphragm. Then, a plurality of ink discharge bits for discharging the ink in the pressurized liquid chamber from the end discharge port of the jet flow path communicating with the pressurized liquid chamber are arranged, and each ink discharge bit is added via the fluid resistance section. The recording head of the present invention, which is configured so as to communicate with a common liquid chamber that supplies ink to the pressure liquid chamber, absorbs a pressure wave generated in the pressurized liquid chamber on at least one surface of the wall constituting the common liquid chamber. It is characterized in that a plurality of pressure buffers are provided. Further, by providing the pressure buffer for each ink ejection bit, it is possible to particularly suppress the influence of mutual interference on adjacent ink ejection bits.

Furthermore, the elastic modulus of the pressure buffer is 1 × 10
⁹ (N / m ² ) or less, so that the size of the pressure buffer can be reduced and the size of the recording head can be reduced.

The longitudinal length of the pressure buffer is represented by L
(M), the thickness is T (m), the elastic modulus is Y (N / m ² ), and when A = L × T ⁻³ × Y ⁻¹ , 3000 <A <
By setting the length, thickness, and elastic modulus of the pressure buffer in the longitudinal direction so as to be 8000, the influence of mutual interference can be further suppressed.

Further, by using a dry film resist for the pressure buffer, the processing is easy and easy to use, and the material itself is inexpensive and the production cost can be minimized.

Further, by forming the housing of the recording head from silicon, fine processing can be performed very easily.

Further, as another invention, a diaphragm is disposed on at least one surface of a wall surface constituting a pressurized liquid chamber, and the pressure in the pressurized liquid chamber is increased by a displacement operation of the diaphragm to cause the ink in the pressurized liquid chamber to rise. And a plurality of ink ejection bits for ejecting ink from an end ejection port of an ejection passage communicating with the pressurized liquid chamber, and each ink discharge bit supplies ink to the pressurized liquid chamber via the fluid resistance portion. According to the method of manufacturing a print head for manufacturing a print head configured to communicate with the common liquid chamber, a plurality of openings are provided on at least one surface of a wall forming the common liquid chamber, and a pressure buffer material is provided on all of the openings. It is characterized in that a plurality of pressure buffers are formed by attaching a film, for example, one pressure buffer material film. Therefore, an increase in the number of manufacturing steps can be minimized. Further, by forming the housing of the recording head from silicon, fine processing can be performed extremely easily, and thus the cost of the manufacturing process can be minimized.

Further, by mounting the above-mentioned recording head or mounting the recording head manufactured by the above-described method of manufacturing a recording head, it is possible to provide a high-quality image recording apparatus with less mutual interference.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a recording head according to the present invention, a plurality of pressure buffers for absorbing pressure waves generated in a pressurized liquid chamber are provided on at least one surface of a wall constituting a common liquid chamber. Therefore,
The effect of mutual interference on adjacent ink ejection bits can be suppressed.

[0014]

FIG. 1A is a sectional view showing the structure of a recording head according to an embodiment of the present invention, and FIG.
3A is a plan view of a cross section taken along line AA ′ of FIG. In FIG. 1, a recording head 1 according to the present embodiment includes an ejection flow path 11, a pressurized liquid chamber 12, a fluid resistance path 13, a common liquid chamber 14, a pressure buffer 15, a vibration plate 16, The body 17 is included. A plurality of pressure buffers 15 are provided on at least one wall surface of the common liquid chamber 14, for example, provided on the bottom of the common liquid chamber 14 as shown in FIG. It is in contact with the ink in the common liquid chamber 14. Further, the pressure buffer 15 is provided intermittently in the bit row direction in which discharge ports (not shown) are arranged. According to the recording head 1 of the present embodiment having such a configuration, since each of the pressure buffers 15 vibrates in each region, the vibration is large at a portion where the pressure rise is large, and conversely, it is not so much vibrated at a small portion. . For this reason, it is possible to efficiently absorb the pressure in accordance with the pressure increase in each region, and also to suppress the influence on adjacent bits due to vibration. In terms of structure, the number of locations for supporting the pressure buffer 15 increases, so that the pressure buffer 15 is less likely to break. The pressure buffer 15 is a bit buffer.
It is desirable that there be a number of them and that they be arranged near the fluid resistance path of each bit. In other words, by completely setting the pressurized liquid chamber and the pressure buffer in a one-to-one correspondence, the influence on adjacent bits is suppressed, and the pressure wave is diffused into the common liquid chamber by being arranged near the fluid resistance path. Pressure can be reduced before doing so.

However, in the case of the configuration of this embodiment, each pressure buffer
Since the size of the vibration surface of the body becomes smaller,
It may not be possible to obtain a sufficient pressure relief effect compared to surgery
It is. Therefore, pressure buffers of various materials were studied.
The result is shown in FIG. The characteristics shown in FIG.
The dimension of the length L in the longitudinal direction of the pressure buffer 15 (375 to 3
000 μm) and the elastic modulus of the pressure buffer 15 (3 × 10
⁸~ 3 × 10⁹(N / m ^TwoMutual interference when changing))
It is a comparison of the production amount. Mutual interference here means
Maximum value of diaphragm displacement in dynamic bit and non-drive bit
To the maximum value of the diaphragm displacement at
Displacement / drive bit maximum displacement x 100)
You. The recording head is 150 dpi and the height of the common liquid chamber is high.
600μm, height of pressurized liquid chamber 400μm, pressure buffer
Has a thickness of 10 μm. The length of the common liquid chamber is
L is set to 1.33 times.

According to FIG. 2, the elastic modulus is 1 × 10 ⁹ (N /
m ² ) or less, the mutual interference is at a level where there is no practical problem by optimizing the size of the pressure buffer.
It can be suppressed to less than 0%. If the modulus is higher than this,
The mutual interference does not decrease to a sufficient value, or even if the mutual interference decreases, it is necessary to take L to be extremely large, and it is difficult to apply the printer head to a printer that requires miniaturization. Therefore, the elastic modulus of the pressure buffer is desirably 1 × 10 ⁹ (N / m ² ) or less.

Further, in order to examine a strictly applicable configuration, the amount of mutual interference generated in various configurations was examined. As a parameter considered to affect the pressure relaxation effect, as shown in FIG. 1, the length L in the longitudinal direction of the pressure buffer (375 to 3)
000 μm), thickness T of the pressure buffer (5 to 10 μm),
And the elastic modulus Y of the pressure buffer (3 × 10 ^{8 to} 3 × 10 ⁹ (N
/ M ² )), the amount of mutual interference was investigated.
The dimensions other than L, T, and Y are the same as those of the head studied previously shown in FIG. Here, the study parameter A is
Suppose ^{A = L x × T y ×} Y z, went x, y, a fitting z. As a result, x = 1, y = -3, z = -1
In this case, the change characteristic of A became U-shaped as shown in FIG. As can be seen from FIG.
When the value is 00 or less or 8000 or more, the amount of mutual interference increases rapidly, and 10% within the range of 3000 to 8000.
It can be suppressed below. From now on, 3000 <A <80
It is desirable to set the length L in the longitudinal direction of the pressure buffer, the thickness T of the pressure buffer, and the elastic modulus of the pressure buffer so that 3000 <A <8000.

It is desirable to use a dry film resist as the pressure buffer. Because the processing is easy and easy to use and the material itself is inexpensive, the production cost can be minimized. The elastic modulus of the dry film resist is also about 0.5 to 1 × 10 ⁹ (N / m ² ), and it is easy to apply particularly to the above-mentioned conditions.

Further, as an actual method of forming the pressure buffer, first, an opening is provided in the wall surface of the common liquid chamber in which the pressure buffer is disposed, and the pressure buffer is attached as a single film to the entire wall surface. It is desirable to attach. Thereby, the increase in the number of steps can be minimized.

Further, in this case, the processing of this opening is
Although unit accuracy is required, it is desirable that the wall surface be made of silicon. This is because silicon can be easily microprocessed by etching, and there are a number of necessary processing devices. In terms of material,
The elastic modulus is as high as 1 × 10 ¹¹ (N / m ² ) or more, and vibration hardly occurs even when used as a housing of a recording head in which the internal pressure fluctuates greatly. In addition, because processing can be performed easily,
The entire head can be formed of silicon, which also simplifies the process.

FIG. 4 is a schematic sectional view showing the structure of an image recording apparatus equipped with the above recording head. The image recording apparatus shown in the figure is an example of an ink jet recording apparatus. As shown in FIG. 1, the ink jet recording apparatus 101 includes four ink cartridges 1 each containing ink of each color of cyan C, magenta M, yellow Y, and black BK.
02, four recording heads 103 having a plurality of nozzles and supplied with ink from each ink cartridge 2, a carriage 104 on which the ink cartridge 102 and the ink jet head 103 are mounted, and a paper feed tray 105a storing recording paper. , 105b and a manual feed table 106, a transport roller 108 for transporting the recording paper to the printing unit 107, and a discharge roller 110 for discharging the printed recording paper to a discharge tray 109. When printing image data sent from the host device on recording paper, the carriage 10
While scanning the carriage 4 along the carriage roller 111, ink is ejected from the nozzles of the recording head 103 onto recording paper sent to the printing unit 107 by the transport roller 108 in accordance with image data to record characters and images. By mounting the recording head in such an image recording apparatus, it is possible to obtain a high-quality recording apparatus with little mutual interference.

The present invention is not limited to the above embodiment, and needless to say, various modifications and substitutions can be made within the scope of the claims.

[0023]

As described above, the diaphragm is disposed on at least one surface of the wall constituting the pressurized liquid chamber, and the pressure in the pressurized liquid chamber is increased by the displacement operation of the diaphragm to thereby increase the pressure in the pressurized liquid chamber. A plurality of ink ejection bits for discharging the ink from the end ejection port of the ejection channel communicating with the pressurized liquid chamber are arranged, and each ink ejection bit supplies ink to the pressurized liquid chamber via the fluid resistance part. To communicate with the common liquid chamber to perform
The recording head according to the present invention is characterized in that a plurality of pressure buffers for absorbing pressure waves generated in the pressurized liquid chamber are provided on at least one surface of a wall constituting the common liquid chamber. Further, by providing the pressure buffer for each ink ejection bit, it is possible to particularly suppress the influence of mutual interference on adjacent ink ejection bits.

Further, the elastic modulus of the pressure buffer is 1 × 10
⁹ (N / m ² ) or less, so that the size of the pressure buffer can be reduced and the size of the recording head can be reduced.

The length of the pressure buffer in the longitudinal direction is represented by L
(M), the thickness is T (m), the elastic modulus is Y (N / m ² ), and when A = L × T ⁻³ × Y ⁻¹ , 3000 <A <
By setting the length, thickness, and elastic modulus of the pressure buffer in the longitudinal direction so as to be 8000, the influence of mutual interference can be further suppressed.

Further, by using a dry film resist for the pressure buffer, the processing is easy and easy to use, the material itself is inexpensive, and the production cost can be minimized.

Further, by forming the entire housing of the recording head from silicon, fine processing can be performed very easily.

Further, as another invention, a vibrating plate is arranged on at least one surface of a wall surface constituting the pressurized liquid chamber, and the pressure in the pressurized liquid chamber is increased by the displacement operation of the vibrating plate to thereby increase the ink in the pressurized liquid chamber. And a plurality of ink ejection bits for ejecting ink from an end ejection port of an ejection passage communicating with the pressurized liquid chamber, and each ink discharge bit supplies ink to the pressurized liquid chamber via the fluid resistance portion. According to the method of manufacturing a print head for manufacturing a print head configured to communicate with the common liquid chamber, a plurality of openings are provided on at least one surface of a wall forming the common liquid chamber, and a pressure buffer material is provided on all of the openings. It is characterized in that a plurality of pressure buffers are formed by attaching one pressure buffer material film to the membrane, for example. Therefore, an increase in the number of manufacturing steps can be minimized. Further, by forming the entire housing of the recording head from silicon, fine processing can be performed extremely easily, and therefore, the cost of the manufacturing process can be minimized.

Further, by mounting the above-described recording head or mounting the recording head manufactured by the above-described method of manufacturing a recording head, it is possible to provide a high-quality image recording apparatus with less mutual interference.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a recording head according to one embodiment of the present invention.

FIG. 2 is a diagram showing a characteristic of a length L in the longitudinal direction of a pressure buffer in this embodiment and mutual interference.

FIG. 3 is a diagram illustrating characteristics of a study parameter A and mutual interference in the present embodiment.

FIG. 4 is a schematic sectional view illustrating a configuration of an image recording apparatus equipped with a recording head.

[Explanation of symbols]

1; recording head, 11; ejection flow path, 12; pressurized liquid chamber, 1
3; fluid resistance path, 14; common liquid chamber, 15; pressure buffer,
16; diaphragm, 17; housing.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yasuyuki Okada 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2C057 AF40 AF93 AG75 AP02 AP11 AP47 AQ02 BA05 BA14

Claims (11)

[Claims] 1. A vibrating plate is disposed on at least one surface of a wall constituting a pressurized liquid chamber, and the pressure in the pressurized liquid chamber is increased by a displacement operation of the vibrating plate to pressurize ink in the pressurized liquid chamber. A common liquid chamber configured by arranging a plurality of ink discharge bits to be discharged from the end discharge port of the discharge flow path communicating with the liquid chamber, and each ink discharge bit supplies ink to the pressurized liquid chamber via the fluid resistance part. A recording head comprising a plurality of pressure buffers for absorbing a pressure wave generated in a pressurized liquid chamber on at least one surface of a wall constituting a common liquid chamber. 2. The recording head according to claim 1, wherein said pressure buffer is provided for each of said ink ejection bits. 3. An elastic modulus of the pressure buffer is 1 × 10.
3. The recording head according to claim 1, wherein the recording head is ⁹ (N / m ² ) or less. 4. The length of the pressure buffer in the longitudinal direction is L.
(M), the thickness is T (m), the elastic modulus is Y (N / m ² ), and when A = L × T ⁻³ × Y ⁻¹ , 3000 <A <
The recording head according to claim 1, wherein a length, a thickness, and an elastic modulus of the pressure buffer in the longitudinal direction are set to 8000. 5. 5. The recording head according to claim 1, wherein a dry film resist is used for the pressure buffer. 6. The recording head according to claim 1, wherein a housing of the recording head is formed of silicon. 7. A vibrating plate is arranged on at least one surface of a wall surface forming the pressurized liquid chamber, and the displacement of the vibrating plate increases the pressure in the pressurized liquid chamber to pressurize the ink in the pressurized liquid chamber. A common liquid chamber configured by arranging a plurality of ink discharge bits to be discharged from the end discharge port of the discharge flow path communicating with the liquid chamber, and each ink discharge bit supplies ink to the pressurized liquid chamber via the fluid resistance part. In a method for manufacturing a recording head for producing a recording head configured to communicate with a part, a plurality of openings are provided on at least one surface of a wall constituting a common liquid chamber, and a plurality of pressure buffer films are attached to the openings. A method for manufacturing a recording head, comprising forming a pressure buffer. 8. The method of manufacturing a recording head according to claim 7, wherein all of the openings are adhered by the pressure buffer film formed as one sheet. 9. The method according to claim 7, wherein the housing of the recording head is formed of silicon. 10. An image recording apparatus comprising the recording head according to claim 1. 11. An image recording apparatus comprising a recording head manufactured by the method for manufacturing a recording head according to claim 7.