JPS581569A - Liquid injecting recording head - Google Patents

Abstract

PURPOSE:To provide the titled head, of which continuous liquid droplet forming characteristics are stabilized over a long time and liquid droplet forming frequency is also enhanced, wherein the average pore cross area of an energy acting region is made smaller than the average zore cross area of a liquid introducing region. CONSTITUTION:A groove 202, which is formed so as to widen the groove width thereof toward an introducing port 205 from an emitting port 206, is adhered to a base plate 201 so as to cover the heat generator with the groove and the end surface thereof is polished. A glass plate is adhered to the side of the introducing port 205 with an adhesive to form a liquid chamber 204. The average pore cross area S1 of an energy acting region 212 and the average pore cross area S2 of a liquid introducing region 213 satisfy formula S2/S1>1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a liquid jet RC that performs recording by forming flying droplets.
Concerning recording heads applied to recording methods.

In VC, the non-impact 6-track recording method generates very little noise during recording, which is negligible.
It has been attracting a lot of attention recently. Among these, the so-called inkjet recording method (liquid jet recording method) is an extremely useful recording method that enables high-speed recording and does not require special processing such as fixing on RFI-open plain paper. Various methods have been devised so far, some of which have been improved and commercialized, and efforts are still being made to put them into practical use.

In this liquid jet recording method, recording is performed by causing droplets of a recording liquid called so-called ink to fly and adhere to a recording member. There are several types of methods depending on the generation method and the control force method used to control the flight direction of the generated droplets.

Among them, for example, USP 3683212, US
The liquid jet recording method, which is described in publications such as P 3946398, performs recording by ejecting and flying droplets from an ejection orifice in response to a recording signal, and causing the liquid M to adhere to the surface of the recording member. , Tokoro GF4 drop-on deman
d In the BQ recording method, only the droplets necessary for recording are ejected, so there is no need to provide special means for collecting or processing ejected liquid that is not necessary for recording, and the device itself can be simplified and miniaturized. In recent years, it has attracted particular attention because it is easy to perform multicolor recording, there is no need to control the flight direction of droplets ejected from an ejection orifice, and it is easy to perform multicolor recording.

Furthermore, a liquid jet recording method with a completely different principle of droplet formation from the above-mentioned liquid jet recording method is disclosed in Japanese Patent Application Laid-open No. 1 54-59.
It is disclosed in Japanese Patent No. 936.

This liquid jet recording method is based on the above-mentioned drop-an-dem recording method.
Not only is it extremely effectively applied to and recording methods (
, a full 1ine type recording head with high density multi-orifices can be easily realized, so high resolution,
It has the characteristic of being able to obtain high-quality images at high speed.

The structure of the recording head applied to these liquid jet recording methods is designed and the necessary means are provided so as to maximize the characteristics of each recording method. They have a common structure.

That is, the head applied to these recording methods has a liquid ejection area that has an orifice at its tip to eject liquid;
Equipped with a liquid ejection hole consisting of an energy action area where energy for forming flying droplets acts on the liquid, and a liquid introduction area having an inlet for introducing the liquid into the action area. ing.

In the energy action area, for example, USP 3,683,212
In the recording method disclosed in USP 3946398 etc.,
An electrical/mechanical transducer such as a piezo element is provided in a mechanically coupled relationship, and droplets are ejected and ejected using pressure energy (pressure waves) generated by manually applying a recording signal to the transducer. 69, JP-A-54-5
In one of the recording methods disclosed in Japanese Patent No. 9936, an electric/thermal converter is provided in the energy action area, and thermal energy generated by inputting a recording signal to the converter allows Record by ejecting and flying droplets. Alternatively, in another recording method disclosed in Japanese Patent Application Laid-open No. 54-59936, no special means is provided in the energy action area, and the energy action area is irradiated with electromagnetic waves such as a laser to record the information that exists there. It is absorbed into a liquid and generates heat, and the action of the generated heat causes droplets to be ejected and flown for recording.

In the recording method disclosed in JP-A-54-59936, thermal energy is applied to the liquid as described above,
To obtain the driving force for ejecting droplets, or to be more specific, the liquid subjected to the action of thermal energy undergoes a state change accompanied by a sharp increase in volume, and the liquid is ejected by the acting force based on this state change. , it flies and lands on the recording member, and recording is performed.

In this way, the liquid jet recording method described above applies mechanical pressure or thermal energy to the liquid in the energy action area to obtain the motive force for ejecting the liquid.
In this recording method, in order to improve the quality of recorded images and enable high-speed recording, the recording head used must eject droplets stably and repeatedly over a long period of time. Also, is it possible to improve the droplet formation frequency (the number of droplets formed per unit time/droplet formation frequency per unit time) of the recording head? & It is necessary to stabilize the droplet formation characteristics.

In the past 100 years, it was difficult to say that all of these problems could be satisfactorily solved.

The present invention has been made in view of these technical problems, and it is possible to stabilize the continuous droplet formation characteristics (over a long period of time),
It is an object of the present invention to provide a liquid jet recording head with an improved droplet formation frequency.

The liquid jet recording head of the present invention has an energy acting area that applies an ejecting force to the liquid, a liquid introducing area that extends from the liquid inlet to the area, and a liquid area that extends from the energy acting area to the liquid ejecting port. It has a liquid discharge hole consisting of a discharge area, where the average hole cross-sectional area in the energy action area is SI, and the average hole cross-sectional area in the liquid introduction area is 8. The liquid discharge hole is characterized in that the liquid discharge hole is configured so as to satisfy the relational expression S, /SI>1.

When the recording head is designed and manufactured in this manner, the continuous liquid W4 formation ability is stably maintained over a long period of time, and the droplet formation frequency is also significantly improved.

Hereinafter, the present invention will be explained according to examples using the drawings.

FIG. 2 shows one of the preferred embodiments of the present invention.

In advance, the thermal energy acting section installation board of the recording head was installed on the sixth
As shown in the figure, an 8IO layer 607 is formed to a thickness of 3 μm by sputtering on an alumina substrate 601 having a rectangular size of 10 ii + x 20 mm and a thickness of 1 mm.
HfB as, 100OA, A as electrode, ff as 5
After sputtering each of 00OA, selective etching was performed to form a heating element 603 with a width of 50 μm and a length of 300 μm.
After forming electrodes 608 and 609 of 0 μm,
, a layer of 5000 Å thick was formed by sputtering coating.

Next, cover the photosensitive glass with a thickness of 1.

A groove plate 202 with a constant depth of 75 μm, which is formed by cutting so that the dimensions of the discharge port 206 are 75 μm×75 μm and the groove width becomes wider toward the inlet 205, is attached to the substrate 20 as shown in the sixth figure.
1, the heating element 203 is glued so that the groove runs through it, and the end face is polished.Next, a glass plate is cut to an appropriate size, and it is pasted to the inlet 2054J41 with adhesive to form the liquid chamber 204. was formed.

In addition, in the figure, 211 is a liquid ejection area, 212 il''!,
The energy action chain acid 213 indicates a liquid introduction area, and together these three elements constitute a frame discharge hole.

Further, in the liquid chamber 204, as shown in the figure, an ink supply pipe 210 is provided.
is connected.

Further, FIG. 3 shows another example of the preferred embodiment of the present invention, in which the substrate and the common liquid chamber are formed by the same method as shown in FIG. 1mm deep using a diamond cutting whetstone on glass
After making a groove of 75 μm in diameter, the groove was polished at an angle so that the groove depth became shallower on the orifice side.
A groove plate 302 with a diameter of 5 μm is bonded to the substrate 301 so that the grooves enclose the heating element 303, and the end surface is polished.

FIG. 1 shows a pJ that can be manufactured in a manner similar to that described in the examples of FIGS. 2 and 3, which is necessary in the prior art.

The inventors refer to the record described above as an example.

Average pore F of energy acting chain acid about de! We designed and manufactured a large number of heads with a fT area of 10mm for each head.
When we measured the voltage margin that enabled stable droplet formation over pulses, we found that the larger S2 was, the wider the voltage margin was, but in the case of 5l = 82, 3 Discharge stopped at the throat.

In addition, the results show that the droplet formation frequency limit increases as S2 is larger than Sl.0 The table below shows that S2/Sl is l, 1.3, and 1.5, respectively
, 2°3, lK1″i
The voltage margin width at which liquid weave formation is stable up to 106 pulses at z and the frequency limit for liquid image formation are collectively shown.

As described above, the present invention has major advantages such as improved reliability of droplet ejection due to an increase in voltage margin, simplification and miniaturization of the energy acting part drive circuit design, and further improved frequency limit. The advantage is that high-speed recording is possible.

In the above investigation, the ink used was one that had been passed through an a-filter with the following composition vlJ all-mix filter.

In addition, the resistance value of the heating element is 150Ω, and 5μ
Droplets were ejected by applying 5 ec (45 rectangular pulses).

Figures 4 and 5 similarly show other examples of the embodiment of the present invention, and in the figures, when the last two digits are the same as in Figure 2, they mean the same structure "A". Improvements similar to those of the embodiments shown in FIGS. 2 and 3 were also observed.

In addition, when the recording head is configured in the embodiment shown in FIGS. 3 and 5, a high density of about 10$-/vrrtr is required when forming a large number of liquid ejection parts in the same head to form a multi-head. In addition, there are 10 very important points for downsizing the recording head, including the ability to record images that are distorted, and combined with the effect of improving the liquid cylinder formation frequency according to the present invention. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically depicting the structure of a conventional recording head with its main parts cut away, and FIGS. 2 to 5 show a preferred recording head of the present invention. FIG. 6 is a schematic perspective view of a main part thereof cut away to explain an example of the embodiment, and FIG. In the figure, 101, 201, 301, 401,
503. 601 is a thermal energy action unit installation board, 102, 202
゜302, 402, 502 are groove plates, 103, 20
3, 303. 403, 503, 603 are heating elements, 104, 20
4, 304. 404, 504 are liquid chambers, 105, 205, 305
, 405. 505 is an introduction port, 106 , 206 , 306 , 40
6, 506° is the discharge port, Ill, 211, 31
1, 411, 511 are liquid ejection areas, 112, 2
12, 312, 412, 512 are energy action areas, 113, 213, 313, 413°513
is the liquid introduction area. Patent applicant Canon Co., Ltd. ZVB ZTR

Claims (1)

[Claims] It has a liquid discharge hole consisting of an energy action region that imparts a discharge force to the liquid, a liquid introduction region extending from the liquid introduction port to the region, and a liquid discharge region extending from the energy action region to the liquid discharge port. , the average pore cross-sectional area in the energy action region is Sl, and the average pore cross-sectional area in the liquid introduction region is 8. When 8. A liquid jet recording head characterized in that the liquid ejection holes are configured to satisfy a relational expression: /S,>1.