JPS63251243A - Ink jet recording head - Google Patents

Abstract

PURPOSE:To enable high speed printing to be carried out by supplying ink uniformly to all ink discharge openings, by a method wherein an ink supply groove is provided parallel to an array of heating elements in a thermal ink jet recording head, and ink is supplied from a side direction of a substrate. CONSTITUTION:Ink is supplied to a recording head 1 from an ink tank 5 through a pipe 12. The recording head 1 moves by being guided with a carriage guide 6, and carries out ink jet recording on a recording paper 3 which is intermittently line fed synchronizing with a platen 2 and a guide roller 4. For the recording head 1, substrates 13, 13b are connected to a base 14 so that arrays of heating elements 17 become parallel to each other across an ink supply groove 24 between both the substrates 13a, 13b, and a gap plate 15 and a nozzle plate 16 are connected thereto. Then, heating elements 17 are selectively energized by current via electrodes 19, the ink between the ink groove 25 and ink discharge openings 18 is quickly heated to generate bubbles and ink drops are jetted. Thus, since distances to all the ink discharge parts are identical with each other, passage resistance is equalized and high speed printing becomes possible.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an inkjet recording head (hereinafter referred to as a thermal inkjet recording head) that rapidly heats ink using a heating element to generate bubbles and ejects the ink to perform recording. .)
Regarding the structure of

[Conventional technology]

As a conventional example of a thermal inkjet recording head, the American He
Wlett-Packard Journal 1985 5
The structure of the print head is introduced in detail in the monthly issue, and it is an effective means for realizing an inkjet print head that has a simple structure and is capable of high-speed, high-density printing.

[Problem that the invention seeks to solve]

However, the thermal inkjet recording head introduced in the above-mentioned literature has only 12 ink ejection sections in one row at a pitch of 263 μm, and in order to perform high-density recording at a pitch of about 100 μm, multiple heads are required. Or the power required to arrange multiple ink ejection parts in multiple rows with a single head! be.

In the former case, there is a problem in that it is very difficult to align the individual heads with each other.

In the latter case, it is necessary to provide multiple rows of heating elements on a single board, and if the distances from the ink supply port to each heating element are different, when a high-speed response is achieved, the ink ejection unit far from the ink supply port will supply ink. There is a problem in that it is easy to run out and cause ejection failure, making it difficult to perform high-speed printing.

[Means for solving problems]

The present invention is intended to solve such problems, and is an inkjet recording head that performs recording by rapidly heating ink using a heating element to generate bubbles and ejecting the ink, the invention comprising a plurality of rows of heating elements. The invention is characterized by a structure in which a groove is provided in parallel with the ink supply groove, the groove is used as an ink supply groove, and ink is supplied from the side surface of the substrate having the heating element array.

[Effect]

According to the present invention, since the distances from the ink supply groove to all the ink discharge parts are equal, the flow path resistance is equalized,
Ink can be evenly supplied to all ink ejection units.

Furthermore, since it is easy to shorten the distance from the ink supply groove to the ink discharge section, flow path resistance can be reduced and high-speed printing is possible.

〔Example〕

FIG. 1 is a schematic diagram of the overall configuration of a recording apparatus having a thermal inkjet recording head 1 of the present invention.

In FIG. 1, a recording head 1 is supplied with ink from an ink tank 5 through an ink supply vibrator 12, and is guided by a carriage guide 6 and moves in the direction of an arrow I.
The recording paper 3 is fed with intermittent line feeds synchronized with the recording head 1 by the platen 2 and guide roller 4! - Record.

FIG. 2 is a perspective view showing the structure of the inkjet recording head 1 of the present invention, and FIG. 3 is a sectional view of FIG. 2.

The operation of each part will be briefly explained with reference to FIGS. 2 and 3. In FIG. 2, the substrates 13a and 13b have ink supply grooves 24
A gap plate 15 and a nozzle plate 16 are bonded to the substrates 13a and 13b on top of the substrates 13a and 13b.

Ink is supplied from the ink supply vibrator 12 shown in FIG. 3 through the ink chamber 21 to between the substrate 13a and the nozzle plate 16. Returning to FIG. 2, power is intermittently supplied to the heating element 17 by the switching element SW through the electrode 19.
The ink is rapidly heated by a heating element 17 to generate bubbles, and ink droplets 22 are ejected as shown in FIG.

4, 5, and 6 are perspective views showing the manufacturing process of the inkjet recording head 1 of the present invention.

A method of manufacturing the inkjet recording head 1 of the present invention will be explained with reference to FIGS. 4, 5, and 6. In FIG. 4, an ink supply vibrator 12 is attached to a base 14 provided with an ink chamber 21.
A substrate 13 on which a heating element 17 and an electrode 19 were formed as thin films was joined to this base 14.

Next, as shown in FIG. 5, the substrate 13 was cut with a dicing saw 23 to form ink supply grooves 24. Furthermore, as shown in FIG. 6, a gap plate 15 is bonded to the surface of the base 14 to which the cut substrates 13a and 13b are bonded, and a nozzle plate 16 is bonded to the surface of the gap plate 15. A thermal inkjet recording head of the present invention was manufactured by sealing the sealing portion 20 shown with a thermosetting adhesive or the like.

According to the above configuration, since the ink supply groove 24 can be processed by cutting, it is possible to perform processing by machining a large number of ink, making it possible to perform processing efficiently and improve the manufacturing yield of the recording head.

Furthermore, since the ink supply grooves 24 are located at equal distances from all the heat generating elements, ink can be supplied to all the ink ejection ports 18 under the same conditions. Also, since it becomes easier to shorten the distance between the ink supply groove 24 and the heating element 17,
The flow path resistance could be reduced. Therefore, it has become possible to perform stable high-speed printing.

A recording device having a thermal inkjet recording head of the present invention,
Then, an ink having a composition of 43 wt% water, 52 wt% diethylene glycol, and 5 wt% water-soluble dye (for example, C,1, Direct Black 154) is ejected by a recording device having a conventional thermal inkjet recording head, and the driving frequency is 1kHz, 2kHz, 3kHz2, 4kHz
When image evaluation was performed for z, 5 kHz, and 6 kHz, the results shown in Table 1 were obtained.

In Table 1, the image evaluation criteria are ■・・・・・・・・・・・・・・・・・・ Good quality image O・・・・・・・・・・・・・・・・・・・・・
・Image X for practical use・・・・・・・・・・・・・・・
......The image is not useful for practical use.

Table 1 also shows water 55wt%, triethylene glycol 20wt
%, diethylene glycol monobutyl ether 20wt
%, water-soluble dye (for example, C, 1, Direct Black 154) 5 wt % tissue ink was also subjected to image evaluation, and the same results as in Table 1 were obtained.

In both cases, the applied pulse voltage was 20 V and the applied pulse width was 6 μs.

The thermal ink jet recording head of the present invention may have a structure as shown in FIG. A method of manufacturing the recording head shown in FIG. 7 will be described. In order not to cut the substrate 13, the ink supply grooves 24 were formed using a dicing saw, and at the same time, the substrate 13 was cut for each head using a dicing saw. The substrate 13 on which the ink supply groove 21 was formed was joined to the base 14 on which the ink chamber 21 was provided. Next, the gap plate 15 is bonded to the surface of the base 14 to which the substrate 13 is bonded, the nozzle plate 16 is bonded to the surface of the gap plate 15, and the ink supply groove 2
The right end A of 1 was sealed with a thermosetting adhesive or the like.

According to the above configuration, the process of cutting the substrate for each head and the process of forming the ink supply groove can be performed in one process, thereby simplifying the manufacturing process.

When image evaluation was performed using a printing apparatus having a printing head having the configuration shown in FIG. 7, the same results as in Table 1 were obtained. In other words, the driving frequency is 1kHz, 2kHz, 3
In the case of kHz and 4kHz, images of good quality were obtained, and in the case of 5kHz and 6kHz, images suitable for practical use were obtained.

Further, the present invention is also applicable to color inkjet recording apparatuses. FIG. 8 shows an example of a recording head section when the present invention is applied to a color inkjet recording apparatus.

The manufacturing process is the same as shown in FIGS. 4 to 6. According to Figure 8, four-color heads, yellow, magenta, cyan, and black, can be manufactured from a single substrate, allowing for good color mixing, which was a problem with conventional Color In Fujiera I recording devices. It is possible to eliminate the need for positioning of the recording liquid ejecting sections for each color to obtain the recording liquid.

〔Effect of the invention〕

As described above, according to the present invention, grooves are provided in parallel with a plurality of heating element rows, the grooves are used as ink supply grooves, and by adopting a structure in which ink is supplied from the side surface of the substrate, all ink can be Ink can be evenly supplied to the ejection ports,
Furthermore, high-speed printing is easy and the recording head can be made thinner.

Furthermore, when applied to a color inkjet recording device, there is an effect that positioning of ink ejection ports for each hue pressure, which is a problem in conventional color inkjet recording devices, is not necessary.

[Brief explanation of the drawing]

FIG. 1 is a schematic overall configuration diagram of a recording apparatus having an inkjet recording head of the present invention. FIG. 2 is a perspective view showing the structure of the inkjet recording head of the present invention. Figure 3 shows the second
The sectional view, FIG. 4, FIG. 5, and FIG. 6 are perspective views showing the manufacturing process of the recording head of FIG. 2. FIG. 7 is a perspective view showing the structure of the inkjet recording head of the present invention. FIG. 8 is a perspective view showing the structure of a recording head section when the present invention is applied to a color inkjet recording apparatus. 1・・・・・・・・・・・・・・・・・・・・・ Recording head 12・・・・・・・・・・・・・・・・・・
Ink supply pipes 13.13a, 13b--One substrate 17...Heating element 24...・・・・・・・・・・・・
Ink supply groove and above Applicant Seiko Epson Corporation 1: tm-hemo 2 Nibraten 3: story charm 4 nigga) V roller 5: A/q) ri 7: frame 9: Tomu Sumo, -7- No. 2 Figure 12: s; y i ni heron 4 kari de 76: tyQ Shimeai 1
3a Michisaka 20: ■Ketome 14: Base 21: 4>7 temporary 75: f “￥
-/7・Uncle 22. Ishik Qing 3 Figure 12: 4 Nkui to shi 9 shi 1 to 13 = demon aim 74: base 17: 1/e: 伜 19, '4L 21: 4 nku non 74: base 17: 4 rash 24: I〉Gui length familiar name ↓ Figure 5 Figure 6 74, Base 77: M: Shadow Figure 7

Claims (1)

[Claims] In an inkjet recording head that performs recording by rapidly heating ink with a heating element to generate bubbles and ejecting the ink, grooves are provided in parallel with the plurality of heating element rows, the grooves are used as ink supply grooves, and the heating element row is An inkjet recording head characterized by a structure in which ink is supplied from a side surface of a substrate.