JPS59138459A - Liquid jet recording apparatus - Google Patents

Abstract

PURPOSE:To make it possible to record an image having excellent faithfulness and certainly in the response to a recording signal and high in resolving power and quality at a high speed, by arranging a partition wall so as to satisfy a specific relation formula when the min. value of the distance between heat acting surfaces measured without piercing the partition wall is set to Lmi and the distance of each heat acting surface and the center of an emitting port corresponding thereto is set to Doh. CONSTITUTION:A current is supplied to a heat generating resistance layer 111 through a selection electrode 112 and a common electrode 114 and heat energy is mainly generated in the heat generating part 16 between the electrodes. Bubbles are generated in a liquid by the heat action in the heat acting surface 115 and the liquid is emitted from an orifice as liquid droplets in a scattered form by the pressure energy of said bubbles to perform recording. An electricity to heat converting element 102 is driven according to a recording signal and signal voltage is supplied in order to emit the liquid droplets from the predetermined orifice 108 through the selected selection electrode 112 and the common electrode 114. When the length of a partition wall 117 is short to such an extent that it does not reach the range shown by the formula, interference action of liquid emission is generated between adjacent orifices and, when the length of said partition wall 117 is long enough to exceed a specific range, following characteristics under high frequency becomes inferior.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid jet recording device that performs recording using flying droplets formed by discharging liquid from a discharge port, and particularly relates to a liquid jet recording device that uses thermal energy. .

There are various types of liquid jet recording devices, and among them, for example, the liquid jet recording device disclosed in OLS No. 21144005 is easy to perform high-speed color recording, and its output section is The recording head, which is the main part, can obtain high resolution because it has a dense array of ejection ports (orifices) for ejecting recording liquid and forming flying droplets. At the same time, the overall recording head can be made more compact, making it suitable for mass production, and furthermore, it takes full advantage of the advantages of IC technology and micro-processing technology, where technological advances and reliability improvements are remarkable in the semiconductor field. Recently, it has been attracting a lot of attention because it is easy to make it long and planar (two-dimensional) by using it.

However, in the case of a conventional recording head of the multi-orifice type, a liquid flow path is provided corresponding to each orifice, and thermal energy is applied to the liquid filling the liquid flow path for each liquid flow path to open the corresponding orifice. Discharge more liquid,
An electrothermal converter is provided as a means for forming flying liquid, and each liquid flow path is configured to be supplied with liquid from a common liquid chamber communicating with each liquid flow path. If the orifices are arranged in a high-density structure and have a long structure, each of the liquid flow paths described above will inevitably become narrower and the wall resistance of the liquid flow path will increase, making it impossible to keep up with the liquid refill during high-speed recording. A problem arose in that droplet formation became unstable, making it impossible to record high-quality images at high speed.

One way to solve this liquid supply problem when performing high-speed recording is to remove the liquid flow path walls between each liquid flow path and create a large space so that the liquid supply can be performed quickly and smoothly. Consideration has been given to designing a liquid supply path so that sufficient sewing liquid can be quickly and smoothly supplied to the liquid chamber. However, in this case, since there is no separation wall between adjacent electrothermal converters, interaction occurs in liquid discharge between adjacent orifices, making it impossible for liquid to be discharged independently from each orifice. It becomes difficult. That is, for example, when electrothermal converters corresponding to adjacent orifices are driven independently,
At the same time, liquid is discharged from the orifice corresponding to the electrothermal transducer that is turned on, and at the same time, liquid is discharged from the orifice corresponding to the adjacent electrothermal transducer that is in the OFF state, or the liquid is completely discharged. Even if this is not done, movement and vibration of the meniscus will occur, causing an interference effect that will adversely affect the stable liquid discharge from the adjacent orifice. Therefore, if such interference occurs, the ejection condition of the liquid ejected from each orifice will become unstable, and the flying speed, direction, diameter, etc. of the formed droplets will not be stable, and the quality will deteriorate. In many cases, it becomes impossible to record high-quality images.

This becomes an extremely serious problem when high-quality images are recorded at high speed by arranging orifices at high density, as the amount of thermal energy generated by the electrothermal converter increases. Become.

The present invention has been made in view of the following two points,
The main objective is to provide a liquid jet recording device that can easily perform high-density and high-speed recording.

Another object of the present invention is to provide a liquid jet recording device suitable for recording high quality images.

The liquid jet recording device of the present invention includes a plurality of ejection ports provided for ejecting liquid to form flying droplets by using thermal energy, and a plurality of ejection ports communicating with these ejection ports to form flying droplets. The means for generating the thermal energy is provided corresponding to a liquid chamber to which a liquid is supplied to form a liquid, a supply port for supplying the liquid to the liquid chamber, and a discharge port. a plurality of electrothermal converters, each of the electrothermal converters having a heat acting surface on the bottom surface of the liquid chamber as a surface on which generated thermal energy acts on the liquid; In a liquid jet recording device in which each of the outlets is provided opposite to each other on the bottom surface, a separation wall provided in the liquid chamber that isolates adjacent heat acting surfaces and discharge ports, respectively, is provided in the liquid jet recording device. La1n is the minimum value of the distance between the heat acting surfaces measured without penetrating the separation wall, and Do is the distance between the heat acting surface and the center of the corresponding discharge port.
When h, l≦L akin / D oh≦5
It is characterized by being installed so as to satisfy the relational expression 00.

The liquid jet recording apparatus of the present invention having the above configuration has excellent fidelity and reliability of response to recording signals, and can record high-resolution, high-quality images at high speed.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

1 to 3 are diagrams showing an outline of the liquid jet recording device according to the present invention, in which FIG. 1 is a schematic perspective view, and FIG. 2 is a diagram taken along the dashed line AB in FIG. 1. FIG. 3 is a schematic exploded view for explaining the internal structure.

The liquid jet recording apparatus 100 shown in FIGS. 1 to 3 includes a substrate 101, a substrate +01. n electrical converters 102 (in the figure, the first, second and nth electrical converters are shown) and a reservoir forming the liquid chamber 110. , front wall plate 103, rear wall plate 105
and two side wall plates +04-1 which are clamped at both ends of these wall plates 103 and +05.

104-2 (one side wall plate is not shown in Fig. 1, but the -- part is visible in Fig. 3) and a through hole 10 constituting an orifice 108 provided corresponding to each electric converter.
The orifice plate 107 provided with 8 and the side wall plate +04-
It is mainly composed of a supply pipe 106 provided for supplying liquid to a liquid chamber 110 provided on the rear side of the device.

The electric converter 102 includes a heating resistance layer 111 on the substrate 101 in order from the substrate side, and a selection electrode 112 provided in parallel on the heating resistance layer 111 except for a part of the heating resistance layer 111.
, a common electrode 114 , and a protective layer 113 provided at least in a portion that directly contacts the liquid in the liquid chamber 110 .

The heat generating resistive layer Ill is energized through the selection electrode 112 and the common electrode 114, and thereby mainly generates thermal energy in the heat generating portion 116 between these electrodes. The heat acting surface 115 is a place where the generated heat acts on the liquid, and has a close relationship with the heat generating part 116. This heat action surface 1
Bubbles are generated in the liquid due to the thermal action at 15, and the pressure energy of the bubbles causes the liquid to be ejected from the orifice 108 as flying droplets to perform recording.

In order to drive each of the electric transducers 102 in accordance with a recording signal to eject a droplet from a predetermined orifice 108, a signal voltage is supplied through a selected selection electrode 112 and a common electrode 114, as described in the embodiments above. In addition to the configuration of the conventional liquid jet recording device, the liquid jet recording device of the present invention is provided with a separating wall 117 having a specified configuration for isolating the adjacent heat acting surfaces 115 and orifices 108, respectively. .

This separation wall 117 has problems with the aforementioned individual liquid flow path method in which a liquid flow path is provided corresponding to each orifice, namely, poor follow-up characteristics under high frequencies due to slow liquid supply, and the large liquid chamber individual method. This is provided in order to simultaneously solve both problems, namely, the interference of liquid discharge occurring between adjacent orifices, and in order to do so, it is necessary to create a separation wall that satisfies the relational expression detailed below. There must be.

That is, when La1n is the minimum distance between the heat acting surfaces measured without penetrating the separation wall, and Dah is the distance between the heat acting surfaces and the center of the corresponding orifice, l≦Lmin/ There is peace of mind that it is installed so that the relational expression Doh≦500 is satisfied.

In order to clarify the meaning of the above relational expression of the present invention, FIGS. These will be explained in more detail using FIG. 5, which is a cutaway view taken along the dashed line XY.

The heat action surface 115 refers to a portion of the heat generating portion 11B projected perpendicularly I to the bottom surface of the liquid chamber, and the distance between the heat action surfaces is indicated by Lo, but the distance gii[11? The distance between the heat acting surfaces that is measured without penetrating is the distance that is determined by bypassing the separation wall 117 like Ll and L2, and the shortest value among these many measured distances is L min. On the other hand, the distance #Doh between the heat acting surface and the center of the corresponding orifice generally takes a constant value for each heat acting surface and orifice, as shown in Figure 5, but if that value is not constant, In this case, Doh is the shortest value among the measured distances.

Minimum distance between the heat-active surfaces measured without penetrating the separating wall 1@L for the distance 1Doh between the heat-active surfaces and the center of the orifice
If the length of the partition wall 117 is so short that a1n does not reach the range indicated by -F, interference effect of liquid discharge will occur between adjacent orifices, and conversely, the length of the partition wall 117 will exceed the range indicated by "-F". If it is too long, as in the case of the conventional individual liquid flow path method,
Tracking characteristics at high frequencies deteriorate. In order to further exhibit the effects of the present invention, it is preferable that l≦Lmin/Dab≦100, and 2≦L sin / D oh≦40.
More preferably, 4≦L+ain/
It is preferable to provide a separation wall so that Doh≦20.

The isolation wall 117 is provided in contact with the orifice plate 107 and the protective layer 113 that constitutes the bottom surface of the liquid chamber 110, but it may be in contact with the front wall plate 103 as in the case of FIG. They do not have to be in contact as in the case of FIG.

6 and 7 are schematic diagrams showing variations of the installation style of the separation walls 117 in the liquid jet recording device of the present invention, and FIG. In this example, La1n is the minimum value among L1 to L4. Further, FIG. 7 shows an example in which the liquid chamber is divided into two parts by a separating wall 117, and adjacent heat-acting surfaces alternately belong to one liquid chamber. In this case, the separating wall 117
The distance between heat-active surfaces measured without penetrating is not the distance between adjacent heat-active surfaces, but is measured as the distance between adjacent heat-active surfaces, which is the smaller of L and L2. The value on the other hand is defined as L win.

Hereinafter, the present invention will be explained in more detail according to Examples.

Example 1 An 81 substrate whose surface was thermally oxidized to form a SiO□ layer three times thicker was removed by etching to form a common liquid chamber portion of 100 μm. Next, a Ta layer with a thickness of 2000 as a heating resistance layer and an A1 layer with a thickness of 1 μm as an electrode were laminated, and then a heat generating part (heater) array with a shape of 4Q, X IOQμ was formed at 100 scale pitches by a photolithography process.

In addition, 8102 layer 0.5 mm thick, S
A protective layer was formed by sequentially laminating i0 layers with a thickness of 1 u by sputtering.

Next, on this board, a width of 50 mm as shown in Figs.
A liquid jet recording device was fabricated by installing a separation wall with a height of 80 μ, a front wall plate, a rear wall plate, two side wall plates, an orifice plate, and a supply pipe. The width of the liquid flow path partitioned by the separation wall 2 is 50 mm, the distance between the common liquid chamber (not including the liquid flow path section partitioned by the separation wall here) and the heat-active surface is 500 mm, and La1n was approximately 1050 μs. The orifice plate is made of 403% nichrome plate and is etched to form a 35 mm diameter orifice located directly above each heat working surface. Therefore, the distance Doh between the heat acting surface and the center of the orifice was 120μ in each case.

This liquid jet recording device was driven by applying a rectangular voltage of 8 IJ, sec. In this case, the highest frequency response fl1ax of droplet ejection was 7 KHz, and no interference effect of liquid ejection occurred between adjacent orifices.

Examples 2 to 7 and Comparative Example 1 A liquid jet recording device similar to that of Example 1 was manufactured except that the length of the separating wall to be installed was varied. These liquid jet recording devices were driven under the same conditions as in Example 1, and the highest frequency response fmax and the presence or absence of interference between adjacent orifices in liquid ejection were evaluated. The results are shown in Table 1.

From this result, it is clear that when L sin / Doh is 1 or more, the interference effect of liquid discharge between adjacent orifices is considerably suppressed, and when La1n / Doh is 2 or more, the interference effect is almost suppressed. did. Also, La1n/D
If oh exceeds 500, the highest frequency response fmax
was found to be significantly reduced.

Example 8 Same as Example 1 except that the height of the separating wall to be installed was 50μ, the distance between the common liquid chamber and the heat action surface was 3201AJ1, and the orifice plate was 30mm thick. A liquid jet recording device similar to the above was fabricated. That is, in this device, La1n is approximately 690 tiles, and Doh is 80-
With Te, Llln/Doh was 8.8, which was almost the same value as in Example 1. When this device was operated under the same conditions as in Example 1, the highest frequency response f11aw was 7 KHz, which was almost the same value as in Example 1, and of course there was no interference effect of liquid discharge between adjacent orifices. Examples 9 to 15 and Comparative Example 2.3 In Example 1, a shape of 80uX 100μ was formed on the substrate.
The heater array was formed with 100u+ pitch,
The use of a 20 μs thick orifice plate,
A liquid jet recording device similar to that of Example 1 was manufactured except that the length of the partition wall, which was 20 tiles wide and 20 tiles high, was installed with various lengths. That is, in this device, Doh is 40 tiles. These liquid jet recording devices were driven under the same conditions as in Example 1, and the highest frequency response f wax and the presence or absence of interference between adjacent orifices in liquid ejection were evaluated. The results are shown in Table 2.

[Brief explanation of the drawing]

1 to 3 are diagrams showing an outline of the liquid jet recording device according to the present invention, in which FIG. 1 is a schematic perspective view, and FIG. 2 is a diagram taken along the dashed line AB in FIG. 1. FIG. 3 is a schematic exploded view for explaining the internal structure. FIG. 4 is a partially enlarged plan view of an embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along the dashed line XY in FIG. 6 and 7 show the isolation wall 11 that can be placed in the liquid jet recording device of the present invention. It is a schematic diagram showing a modification of the installation state. 100: Liquid jet recording device 101: Substrate 102: Electric converter 103: Front wall plate 104: Side wall plate 105: Rear wall plate
10B=Supply pipe 107: Orifice i 108 Niorifice 108: Through hole 110: Liquid chamber 111: Heat generating resistance layer 112 Bi-selective electrode 113: Protective layer 114: Common electrode 115: Heat action surface
118: Heat generating part 7 117: Separation wall La1n: Minimum value of the distance between the heat action surfaces measured without penetrating the separation wall Doh: Distance between the heat action surface and the center of the corresponding orifice 8th 4 causes 5 Figure 2 Figure 6 2 Figure 7

Claims (1)

[Claims] 1. A plurality of ejection ports provided for ejecting liquid to form flying droplets by using thermal energy, and a plurality of ejection ports communicating with these ejection ports to form flying droplets. A means for generating the thermal energy is provided corresponding to a liquid chamber to which a liquid for forming is supplied, a supply port for supplying the liquid to the liquid chamber, and a discharge port. a plurality of electrothermal converters, each of the electrothermal converters having a heat acting surface on the bottom surface of the liquid chamber as a surface on which generated thermal energy acts on the liquid; In a liquid jet recording device which is provided facing each other on the bottom surface, a separation wall provided in the liquid chamber that separates adjacent heat acting surfaces and discharge ports, respectively, When the minimum value of the distance between the heat acting surfaces measured without penetrating the wall is Lln, and the distance between the heat acting surface and the center of the corresponding discharge port is Doh, l≦Lmin/Doh≦ A liquid jet recording device characterized in that it is installed so as to satisfy a relational expression: 500.