JP2006142504A - Ink jet print head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To interpolate a nozzle ink ejection of which is impeded through mixture of a foreign matter with another nozzle in an ink jet print head. <P>SOLUTION: Wiring of a pressure generating element corresponding to a nozzle choked with a foreign matter is cut selectively, and only the wiring portion is disconnected selectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet print head and a manufacturing method thereof.

  The present invention also provides a printer, a copying machine, a facsimile having a communication system, and a word processor having a printer section for recording on a recording medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. The present invention is applicable to an industrial recording apparatus combined with various processing apparatuses.

  [Recording] in the present invention means not only giving an image having a meaning such as a character or a figure to a recording medium but also giving an image having no meaning such as a pattern.

  The ink jet recording system is extremely small in noise generation during recording, can be recorded at high speed, can be fixed on so-called plain paper, and can be recorded without requiring special processing. In that respect, it has been spreading rapidly in recent years. A liquid discharge head in which ink droplets are discharged in a vertical direction with respect to a substrate on which an ink discharge energy generating element is formed is referred to as a “side shooter type recording head”. The present invention relates to a structure of a side shooter type recording head.

  To reduce the size and increase the density of the liquid discharge head, a method that incorporates an electrical control circuit (diode matrix circuit or shift register circuit) to drive the pressure generating element using semiconductor manufacturing technology in the substrate is proposed. Has been. The high-performance liquid discharge head described above has a structure in which the substrate is penetrated from the back side of the substrate as a method for supplying ink to a plurality of nozzles as shown in FIG. 2, and ink is supplied to each nozzle from a common ink supply port. It has become.

  With this structure, when ejecting fine ink droplets from fine nozzles, minute foreign matter mixed in the vicinity of the pressure generating element or in the nozzle portion, or abnormalities in the pressure generating element have a significant effect on ink ejection. , Which is a major factor in the decline in recording quality. When recording business documents, etc., due to the recent increase in the density of nozzles, it is rare that a small number of nozzles fail to be ejected. However, for high-quality recording such as photographic image quality, the print quality is greatly reduced. Invite. For this reason, the foreign matter mixed in the vicinity of the nozzles is detected in advance, or the part where ink ejection is abnormal is detected in advance, and the part is interpolated to prevent the deterioration of the recording quality. In the conventional technology, it is possible to detect an abnormality by ejecting ink from a foreign substance mixed in the vicinity of the nozzle. At this time, the foreign substance moves due to the pressure generated by the pressure generating element, and an abnormality is recognized in the discharge. The problem that the part to be changed changes has arisen. Conventionally, as a technique for preventing this movement, the nozzle portion and the foreign matter are forcibly adhered, or destroyed or dissolved by heat. When the nozzle is broken or dissolved, as shown in FIG. 3, when wiping the ink droplets near the discharge port with the wiping blade, the surface smoothness is lost and the ink droplets are left behind. Greatly affects ink ejection.

Further, as described in Japanese Patent Laid-Open No. 2000-15845, in a recording apparatus equipped with two heads, when an undischarge nozzle occurs in one head, recording should be performed with the undischarge nozzle by the corresponding nozzle in the other head. There is a method for recording image data. Even in this method, there is no effective method accompanying the movement of the undischarge nozzle during recording.
JP 2000-15845 A

  The conventional method has the following problems.

  (1) Since the nozzle part forcibly adhered to the foreign material by the sealing material / adhesive is closed at the discharge port, the suction balance is lost when recovering the suction, and the predetermined quality is maintained by the recovery of the suction. I can't.

  (2) The nozzle portion destroyed or melted by heat such as laser light loses its smoothness and cannot maintain a predetermined quality by the wiping blade.

  (3) In a system that does not interpolate ejection failure nozzles when recording business documents, etc., if the landing of ink enemies is significantly shifted due to ejection abnormalities even if ejection failure does not occur, the print quality deteriorates rather than ejection failure. .

  In order to solve the above-mentioned problems, the inkjet printing head of the present invention is characterized by the following shapes.

  First, a system that does not interpolate undischarge nozzles will be described.

  Even if ink droplet landing deviation or non-ejection occurs due to ejection failure of a small number of nozzles, it is not necessary to take measures if the effect is not recognized in a recorded matter such as a business document. However, even if the ejection abnormalities due to ink droplet adhesion and micro-scratches near the ejection opening are initially minute ejection abnormalities, the state changes due to repeated ejection, and sometimes a large landing deviation occurs. . Even if the initial minute abnormality cannot be recognized by the recorded matter, it will be easily recognized even by the recorded matter when the ink droplets are greatly displaced. In the present invention, even if an initial fine abnormality occurs, the abnormal phenomenon is made non-ejection by cutting the pressure generating element wiring so that it is difficult to be recognized by the recorded matter.

  Next, a system for interpolating undischarge nozzles will be described.

  In the present invention, the nozzles that are prevented from ejecting ink due to foreign matter are kept in the same shape as normal nozzles, only the pressure generating element wiring portion is destroyed, and the pressure is not transmitted to the corresponding nozzles. ing. Since the foreign matter mixing nozzle maintains the same shape as the normal nozzle, the discharge port is not completely blocked and the smoothness is not lost, so that the above problem can be solved.

  This is an ink jet recording head having an ink discharge port, a nozzle, a pressure generating element, and a pressure generating element wiring, and a pressure generating element corresponding to a nozzle mixed with foreign matter or a wiring of the pressure generating element that is selectively electrically cut.

  By utilizing the present invention, in a system that does not require interpolation, a form is realized in which all ejection abnormalities are regarded as non-ejection and are not recognized by a recorded matter such as a business document.

  In a system that performs non-discharge interpolation, the non-discharge nozzle that has been interpolated once does not move, and the non-discharge interpolation system can be greatly improved. Further, since the shape of the non-discharge nozzle is not different from that of a normal nozzle, it does not affect the ink wiping property and suction recovery property by the blade.

Example 1
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  Ink was injected into the completed inkjet head, an appropriate pulse was added, and ink was ejected from all nozzles to be recorded on the paper surface. In order to obtain proper recording, suction recovery operation and preliminary ejection before recording were performed in advance to completely fill the nozzle with ink.

  Thereafter, the nozzle that failed to discharge was detected from the recorded material on the paper surface, and the corresponding nozzle was observed. At this time, in the case where foreign matter was mixed into the undischarge nozzle or abnormality was found in the pressure generating element, the pressure generating element wiring of the corresponding nozzle was cut with a YAG laser. Laser light emission was performed from the ink ejection side of the nozzle part, and the nozzle part made of resin was transmitted to destroy only the pressure generating element wiring part. This succeeded in cutting the wiring without deforming or destroying the nozzle part. In order to verify the effect, a head not subjected to the laser cutting was also prepared in addition to the undischarge head due to foreign matter mixing.

  Thereafter, the ejection of ink by pulse application and the flow of ink by suction recovery were repeatedly performed on both heads, and the occurrence of movement of the undischarge nozzle was confirmed.

  As a result, no movement of the undischarge nozzle was observed in the four heads subjected to laser cutting (the undischarge nozzle did not generate pressure by cutting the pressure generating element wiring). On the other hand, undischarge nozzle movement occurred in 3 out of 4 heads that were not subjected to laser cutting. As a result, it is conceivable that the foreign matter mixed in the nozzle moves to the rear of the nozzle portion due to repeated application of the pressure generated by the pressure generating element, and is mixed into the nozzle again when ink is ejected. At this time, the nozzle into which the foreign substance enters is not necessarily the same as before. Further, it was confirmed that the foreign matter in the nozzle did not move in a simple ink flow due to suction recovery because the foreign matter did not move with the laser-cut head.

  FIG. 1 is a schematic diagram of the present invention, and FIG. 4 is a schematic diagram related to the movement of foreign matter in the nozzle.

a) Foreign matter mixed in the nozzle b) Foaming in the nozzle when the pressure generating element is driven (film boiling in the heater in this embodiment), and foreign matter is pushed out of the nozzle by this pressure c) Driving the pressure generating element Is stopped and foaming in the nozzle is eliminated. The foreign matter pushed out of the nozzle is moved by the negative pressure generated at this time.

  d) At this time, the mixed nozzle is not necessarily the same as the previous nozzle.

  When blade wiping was performed with a head cut from the pressure generating element wiring created in this example, no ink droplets were left to be wiped, and the same quality as a normal good head could be maintained. FIG. 5 shows a schematic diagram thereof.

  FIG. 6 shows a schematic diagram of this example.

(Example 2)
In Example 1, the effect on the movement of the foreign matter was sufficiently recognized, but this example was also performed for the purpose of improving the quality reliability. In the first embodiment, the pressure generating element wiring wired in the nozzle is cut. However, there is always ink in this portion, and there is a possibility that the ink may enter due to a fine crack of the protective film on the surface layer generated at the time of cutting the wiring. there were. There is a concern that the corrosion of the wiring portion may progress over time due to the ink entering, and as a result, the inkjet head may be destroyed. In this example, in order to solve this concern, the pressure generating element wiring is arranged outside the nozzle, and the contact with the ink is cut off. A method was adopted in which only the wiring portion was cut by transmitting the nozzle material made of resin with YAG or femtosecond laser.

  In this form, even when the printing durability was performed up to the guaranteed number of printing sheets, the corrosion of the wiring portion did not proceed.

  FIG. 7 shows a schematic diagram of this example.

The schematic diagram of this invention. The schematic diagram sectional drawing in a prior art example. FIG. 6 is a schematic view showing a harmful effect of wiping with a blade in a conventional example. The schematic diagram which shows the movement of the foreign material in a nozzle. The schematic diagram in the wiping by the blade in this invention. The schematic diagram of Example 1 of this invention. The schematic diagram of Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Common liquid chamber 2 Ejection port 3 Pressure chamber 4 Pressure generating element 5 Ink supply port 6 Ink droplet 7 Wiping blade 8 Uncleaned ink droplet after wiping 9 Destroyed non-discharge nozzle 10 Normal nozzle 11 Foreign matter mixed nozzle 12 Foreign matter in nozzle 13 Pressure generation element foaming at the time of activation 14 Pressure generation element wiring cutting part 15 Nozzle pressure generation element wiring disconnection part 16 Pressure generation element wiring arranged outside the nozzle 17 Pressure cutting element wiring cutting part arranged outside the nozzle

Claims (7)

  In an ink jet recording head having an ink discharge port, a nozzle (hereinafter referred to as a nozzle) consisting of a pressure generation chamber and a pressure generation element corresponding to each ink discharge port, an ink pressure generation element, and a wiring for driving the pressure generation element. An ink jet print head characterized in that a pressure generating element or wiring in a part where ejection is abnormal is selectively electrically disconnected.   In an ink jet recording head having an ink discharge port, a nozzle corresponding to each ink discharge port, an ink pressure generating element, and a wiring for driving the pressure generating element, the pressure generating element or wiring corresponding to the nozzle mixed with foreign matter is selected. An ink jet print head characterized by being electrically cut.   The ink jet print head according to claim 2, wherein the nozzle is made of a resin.   4. An ink jet print head according to claim 2, wherein the nozzle corresponding to the electrically generated pressure generating element or wiring is not deformed or broken.   In an ink jet recording head manufacturing method having an ink discharge port, a nozzle corresponding to each ink discharge port, a pressure generating element, and a wiring for driving the pressure generating element, the pressure generating element or wiring corresponding to the nozzle mixed with foreign matter Is a method of manufacturing an ink jet print head, wherein:   4. The method of manufacturing an ink jet print head according to claim 3, wherein the electrical cutting method is a (YAG / femtosecond) laser.   7. The method of manufacturing an ink jet print head according to claim 5, wherein the nozzle portion is not deformed or destroyed when electrically cut by a (YAG / femtosecond) laser.

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