JPS60206658A - Liquid recording head - Google Patents

Abstract

PURPOSE:To enable an accurate flight of ink droplets on a recording paper by providing protruded portions that can maintain a fixed distance between discharge plates and a recording paper where no discharge plates are provided on a surface. CONSTITUTION:In order to maintain a distance L between a recording paper 2 which is wound over a platen 1 and a discharge plate 20 on which plural number of orifices 19 are formed at a fixed extent, protruded portions 22 of bar shape or dot shape are provided. The above-mentioned protruded portions are formed on a ceramic substrate 12 and a glass paste is formed by screen process printing in two rows of protrusions, for instance, with 4mm. wide and 3cm long, and they are baked to become a glazed layer of 0.5mm. thick, and these shapes are made to be a circular arc and smooth to avoid scratches etc. on printed matters. Thus, the ink droplets that are discharged from the orifices 19 by the working of an electrothermal converters 14 can accurately shoot the recording paper 2 and an image of high quality may be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a liquid jet recording head that performs recording by jetting liquid and forming flying droplets.

[Prior Art] Non-impact recording methods have recently attracted particular attention because the noise generated during recording is so small that it can be ignored. Among these, the inkjet recording method (liquid jet recording method) is an extremely powerful recording method that enables high-speed recording and full-color recording without the need for special processing such as fixing on plain paper. Various methods have been proposed, some of which have already been commercialized, and studies are still ongoing.

In such a liquid jet recording method, recording is performed by causing droplets of a recording liquid called ink to fly and adhere to a recording material, and the formation of droplets of the recording liquid is There are several types of methods depending on the method and the method of controlling the flying direction of the formed droplets.

Among them, for example, U.S. Patent Nos. 3H3212 and 374
The liquid jet recording method disclosed in Japanese Patent No. 7120, No. 3E14B398, etc. is a method in which droplets are ejected from an ejection orifice in response to a recording signal, and the droplets are attached to the surface of a recording material to perform recording. This is the so-called drop-on-demand recording method. In this recording method, only the droplets necessary for recording are ejected, so there is no need to install special means for collecting or processing ejected liquid that is unnecessary for recording. , the device itself can be simplified and miniaturized, there is no need to control the flight direction of the droplets discharged from the discharge orifice, and multicolor recording can be easily performed. Recently, it has been attracting particular attention.

Furthermore, a liquid jet recording method that uses a completely different principle of formation of flying droplets from the above-mentioned liquid jet recording method is disclosed in Japanese Patent Application Laid-Open No. 54-51837. - Not only can it be applied extremely effectively to on-demand recording methods, it can also easily implement a high-density, multi-orifice recording head, so it has the characteristics of being able to obtain high-resolution, high-quality recorded images at high speed. have.

Liquid jet recording devices used in these drop-on-demand recording methods usually have an ejection opening (orifice) that ejects droplets, and an energy generating element that communicates with each orifice and forms flying droplets. A recording head consisting of a flow path and a liquid chamber that communicates with each liquid flow path and stores liquid to be supplied to these flow paths is fixed on a carriage that can relatively scan the recording material. This structure is common.

Figure 1 (A) shows the main parts of a conventional recording device.
In FIG. 1(A), reference numeral 1 denotes a platen, which feeds the recording paper 2 wound around it by rotation of the platen 1, and also serves as a printing stand. In front of this platen 1 is platen 1.
Two guide shafts 3 and 4 parallel to the axial direction are horizontally mounted, a carriage 5 is slidably attached to these guide shafts 3 and 4, and ink as a recording liquid is attached to the carriage 5. An ink tank 6 for storing .

11 is a recording head for ejecting liquid attached to the ink tank 6, and the recording head 11 has a substrate 12 as shown in FIGS. 1(B) and 1(C), and the substrate 12 has a recording liquid. An ink supply hole 13 is provided to allow ink to flow to the head. Furthermore, electrothermal converters 14 that generate thermal energy are arranged at predetermined intervals on the substrate 12, and three sides of these electrothermal converters 14 are shown in FIG. 1(A).
A liquid channel portion 16 having a predetermined depth and width is surrounded by a zigzag-shaped surrounding wall member 15 as shown in FIG. .

Reference numeral 18 denotes a liquid discharge port, or orifice, which is protruded at a position on the discharge plate 20 that is directly above the upper surface of the electrothermal converter 14, that is, the heat-effect surface 14A where the converter 14 maintains contact with the liquid. The electrothermal converter 1 is located in the portion of the liquid flow path 16 that is interposed between the
Thermal action area 1 [IA is configured in which bubbles are generated in the liquid that is supplied with generated heat energy from 4, and the volume of the liquid is rapidly expanded or contracted.

When the ejection plate 20 is scanned, in order for the ink droplets ejected from the ejection ports 19 to land on the recording paper 2 (not shown) with high accuracy, the ejection ports 19 disposed on the ejection plate 20 and the recording paper 2 are Regardless of the need to maintain a constant distance between
In order to prevent the discharge port 18 from being damaged, it is impossible to measure the distance by directly touching the discharge port 18, and a non-contact distance measurement method must be used naturally, making the assembly work much more efficient.

Furthermore, when the ejection plate 20 is scanned, air flow is generated near the ejection ports 18, which disturbs the ejection direction of ink droplets ejected from the ejection ports 18 and deteriorates the quality of printed characters, etc. This problem arises.

Furthermore, when the discharge plate 20 moves parallel to the surface of the recording paper 2, that is, while the discharge plate 20 is scanning, the recording paper 2 or part of the paper feeding mechanism such as the paper presser may directly collide with the discharge port 19. This also causes problems such as damaging the ejection port 18 and staining the recording paper 2 with ink.

In addition, when recording paper 2 of different thickness is used, the distance between the surface of the recording paper 2 and the ejection port 19 varies depending on the thickness of the recording paper 2, which not only causes differences in recording quality depending on the paper but also The recording paper 2 has a thickness less than the distance between the surface of the platen l and the ejection port 19 in the
cannot be recorded.

[Objective] In view of the above-mentioned problems, an object of the present invention is to make it possible to maintain a constant distance between the ejection opening of the recording head and the recording paper, so that liquid jet recording can deposit ink droplets on the recording paper with high precision. Let me shoot one shot,
An object of the present invention is to provide a liquid jet recording head that can provide excellent printing and image quality.

Another object of the present invention is to provide a liquid jet recording head that can accurately land ink droplets on recording paper I2 having different thicknesses to obtain high quality prints and images.

Still another object of the present invention is to have a discharge plate disposed parallel to the upper surface of the substrate, and to record liquid guided between the substrate and the discharge plate from discharge ports provided in the discharge plate. In a liquid jet recording head that performs recording by jetting toward the surface of paper,
An object of the present invention is to provide a liquid jet recording head in which a convex portion capable of maintaining a constant distance between the discharge plate and the recording paper is provided on a portion of the substrate where the discharge plate is not provided. .

[Example] Below, preferred examples of the present invention are shown in Figs. 2 (A) and (B).
This will be explained in detail using (C) and (C).

In FIG. 2(A), 31 is a recording head;
is a spring that biases the platen 1 toward the recording head 31.

Furthermore, in FIG. 2 CB), 22 is a bent member for keeping the distance between the recording paper 2 and the spatula 11 constant. By providing this bent member 22, the distance between the paper surface of the recording paper 2 and the ejection port 18 can be reduced as shown in FIG. 2(C).
The dimensions can be kept constant as shown in the figure.

Note that the position occupied by this bending member 22 is the same as that of the carriage 5.
When recording is made by moving the recording dot 31
Preferably, the position is not related to scanning.

Furthermore, it is desirable that the material forming the bent member 22 is one whose shape and material hardly change due to contact with ejected ink or paper 2, and furthermore, the material should have good adhesion to the substrate 12 to which it is attached. It is sufficient if it has a high value and can be easily processed.

Furthermore, it is desirable that the shape of the bent member 22 is such that it does not cause scratches or the like on the printed matter, for example, it is preferably in the shape of a gentle circular arc. It is also necessary that

Further, the four-tiered member 22 can be formed using a method such as screen printing or plating using photosensitive resin or photosensitive glass. Screen print the glass space I at the position of 4 mm wide and 3 cm long.
The curved member 22 was formed by molding two pieces into a convex shape of m and firing them to form a 0.5 mm thick glaze layer.

In this example, two bar-shaped bent members 22 are formed perpendicular to the direction in which the discharge ports 18 are arranged, but the bent members 22 are formed as shown in FIG. 3(A) or (B). Alternatively, the convex portion may have a dot shape. Furthermore, the number and position of the convex portions 23 may be determined as long as they are located at a position that does not interfere with scanning as described above and that the distance between sheets can be maintained. I don't mind.

Furthermore, in the above description, the case was described as a mechanism for biasing the platen 1 toward the head 31;
Even if the mechanism is to press the head 31 against the platen 1,
Further, it goes without saying that the present invention can be applied even to a printer mechanism designed to apply pressing pressure in advance when the head is attached, and sufficient effects of the present invention can be obtained by keeping the paper distance constant using the bending member 22. .

Further, as shown in FIG. 4, the curved member 22 according to the present invention is formed on the substrate 12 by first forming the periphery of the substrate 12 in a convex shape so that this region is higher than the discharge port 18. Ba,
Head 3! The effect of the present invention is further enhanced because the wind pressure generated during scanning by the paper 2 and when feeding the paper 2 is reduced, and the distance between the paper sheets can be selected more accurately and with a high degree of freedom. You can certainly do that.

[Effects] As explained below, according to the present invention, by forming a convex portion on the surface of the liquid ejection side of the recording head that can maintain a constant distance between sheets, it is possible to improve the distance between recording dots. Not only can the landing accuracy be dramatically improved compared to conventional methods, making it possible to obtain high-quality recorded images, but also to maintain the accuracy of the mounting position of the recording head using distance measurement during the manufacturing process. However, positional accuracy can now be easily maintained, there is no need for distance measurement, and high quality images can be automatically obtained regardless of paper thickness.

Furthermore, by forming this convex portion, it is possible to reduce the distance between the paper surfaces, and the impact can be made to land before satellites are generated, so that the effect of improving image quality can also be obtained from this aspect.

[Brief explanation of drawings]

FIG. 1(A) is a perspective view showing an example of the configuration of the main parts of a conventional liquid jet recording device. FIG. 1(B) is an exploded perspective view of the recording head. FIG. 1(C) FIG. 1(B) is a sectional view taken along the line X-X, FIG. 2(A) is a schematic perspective view of a recording apparatus equipped with the liquid jet recording head of the present invention, and FIG. 2(B) is a diagram of the recording. FIG. 2(C) is a sectional view taken along the Y-Y line in FIG. 2(B), FIG. 3(A), (B) and FIG. FIG. DESCRIPTION OF SYMBOLS 1... Pline, 2... Recording paper, 3.4... Guide shaft, 5... Carriage, 6... Ink tank, 11.31... Recording head, 12... Substrate, 13... Supply hole, 14... Electrothermal converter, 14A... Working surface, 15... Surrounding wall member, 16... Liquid channel, 17... Surrounding wall member, 18... Liquid Chamber, 19... Orifice, 20... Discharge plate, 21... Spring, 22... Convex stepped member, 23... Convex portion. Agent Patent Attorney Yoshi Tani − (

Claims (1)

[Claims] A discharge plate is provided on the substrate surface and is parallel to the substrate surface, and a liquid guided between the substrate and the discharge plate is jetted toward the paper surface of the recording paper from discharge ports provided on the discharge plate. In a liquid jet recording head that performs recording, a protruding portion capable of maintaining a constant distance between the ejection plate and the recording paper is provided on a portion of the substrate surface where the ejection plate is not provided. A liquid jet recording head characterized by: