JPH05330075A - Ink jet recording head, method for inspecting ink supply device to the same head and inspection liquid - Google Patents

Abstract

PURPOSE:To well perform visual internal inspection through the part formed of a transparent material in the ink route from an ink tank to an ink jet recording head. CONSTITUTION:A part of the common liquid chamber 6 constituting the temporary ink storage chamber of an ink jet recording head is formed from a transparent plate 5 and, when visual inspection of the interior of the common liquid chamber 6 is performed in such a case that the processed surface of the transparent plate 5 has a relatively rough surface 8, for example, glycerine having a refractive index near to that of the plate 5 is injected into the common liquid chamber 6. By this constitution, the irregular reflection due to the rough surface 8 is eliminated and the common liquid chamber 6 can be well visually inspected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head, a method for inspecting an ink supply system for the head, and an inspection liquid.

[0002]

2. Description of the Related Art The applicant of the present invention discloses, for example, Japanese Patent Laid-Open No. 62-253.
In Japanese Patent Laid-Open No. 457, a method of manufacturing an inkjet recording head using two substrates, at least one of which is transparent to active energy rays, was proposed.

The substrate which is transparent to the active energy rays of the recording head has visibility (transparency), flatness, heat resistance, coefficient of thermal expansion, chemical stability, mechanical strength, etc. Glass is used. However, on this glass substrate,
In order to increase the volume of the common liquid chamber for temporarily storing the ink, a groove (recess) is provided at the common liquid chamber formation planned site.

[0004]

By the way, as a method of processing a groove in glass, mechanical processing such as ultrasonic processing and cutting processing is performed, so that the processed surface becomes a rough surface. As a result, the transparency of the substrate is impaired, and it is often difficult to visually observe the inside of the recording head manufactured using the glass substrate in which the groove is formed.

Also, when a transparent plastic molded product or the like is used as the substrate, a completely flat surface cannot be obtained even in the common liquid chamber concave portion and other flat portions, and the inside of the recording head cannot be obtained. Observation is very difficult.

On the other hand, as the number of ejection ports in an ink jet recording head is increased and the density is increased, dust and the like existing in the common liquid chamber, the ink supply path, and the like are relatively fine ink paths and ejection ports continuous therewith. It is becoming more likely that the ink will be blocked and ink ejection failure or ejection failure will occur. Therefore, it is important to inspect the dust in the ink supply path including the common liquid chamber.

Further, in order to reduce costs, it is desirable to omit the inspection during the manufacturing process of the recording head and to visually inspect the appearance of disconnection, scratches, residues, etc. collectively after the recording head is completed.

However, as described above, the surface of the processed surface such as the groove (recess) of the substrate is relatively rough, so that the substrate becomes opaque, which is a major obstacle to the above inspection.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object thereof is to eliminate irregular reflection due to a rough surface of a member for forming a common liquid chamber of a recording head. By doing so, it is an object of the present invention to provide an inkjet recording head that allows the inside to be visually observed, an inspection method of an ink supply system for the head, and the inspection liquid.

[0010]

Therefore, according to the present invention,
An ink jet recording head for ejecting ink, and an ink jet recording head in which at least a part of an ink supply system for the head is formed of a light transmissive material, and an inspection method of the ink supply system, wherein refraction of the light transmissive material is performed. A liquid having a refractive index approximately equal to the index,
The inside of the ink jet recording head or the ink supply system formed of the light transmissive material is filled, and the inside is inspected through the light transmissive material.

The ink jet recording head for ejecting ink and the ink jet recording head in which at least a part of an ink supply system for the head is formed of a light transmissive material, and the light transmissive material of the ink supply system. In the liquid used for the inspection of the inside through the inside of the ink jet recording head or the ink supply system, which has a refractive index substantially equal to the refractive index of the light transmissive material and is formed of the light transmissive material. It is characterized in that it has a part or all of the components of the ink that is filled and ejected by the recording head.

[0012]

With the above structure, the liquid filled in the inside formed of the light transmissive material and having substantially the same refractive index as the light transmissive material has a relatively rough surface such as a processed surface of the light transmissive material. Eliminates diffuse reflection from the surface. This enables a clear visual inspection of the inside.

Further, since the liquid that is almost the same as the component of the recording ink is used as the liquid, it does not adversely affect the ink ejection of the recording head after the inspection.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIGS. 1, 2 and 3 are a schematic perspective view of an ink jet recording head manufactured by a known method, a sectional view taken along the line AA 'and a sectional view taken along the line BB', respectively. An inspection method according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, on the first substrate 1 provided with the electrothermal converting element 2 as the ejection pressure generating element, the ink path 3 is formed by the substrate 1 and the recess forming layer 4. And a part of the common liquid chamber 6 is formed. Further, an ejection port 10 is formed at the tip of the ink path 3. Further, a second substrate 5 made of a transparent material such as glass is laminated on the layer 4. Grooves for forming a common liquid chamber are formed in advance on the glass substrate 5 by ultrasonic processing or cutting processing, so that the remaining portion of the common liquid chamber 6 is formed by stacking the substrates 5.

The processed surface of the groove is a relatively rough surface as indicated by reference numeral 8 in FIG. Therefore, in the empty state in which the ink is not stored in the common liquid chamber, the grooved surface of the completed recording head and the groove, that is, the portion of the substrate 1 corresponding to the common liquid chamber, is removed from the second substrate 5. It cannot be visually observed from the top.

On the other hand, in one embodiment of the present invention, glycerin having a refractive index close to that of the glass forming the second substrate 5 is provided in the common liquid chamber 6 and the ink passage 3 of the recording head as ink supply holes. By injecting with a syringe or the like through 7, the inside of the common liquid chamber or the like is filled with glycerin, and diffused reflection due to the rough surface 8 of the groove is eliminated. Thereby, for example, dust adhering to the grooved surface, defects such as electrode patterns provided on the first substrate 1, disconnections, etc. can be clearly observed with a metal microscope or the like. As a result,
Visual inspection inside the recording head is possible.

The liquid to be injected into the recording head for inspection is discharged from the recording head in place of the glycerin, and a part or all of the ink components used for recording except dyes or pigments, for example, polyethylene glycol. , Diethylene glycol, N-methyl-2-pyrrolidone or the like or a mixture thereof can be used to relatively reduce the influence on the recording head by mixing with the ink even if these injection liquids remain inside the recording head. it can.

Although not shown in FIGS. 1 to 3, the ink jet recording head is generally provided with an ink supply pipe and an ink tank connected to the ink supply hole 7 shown in the drawing. However, even when these are made of a transparent material, it is difficult to observe the inside from the outside due to the surface roughness of the processed surface. Therefore, the inspection method of the present invention can be applied to these members. That is, by injecting a liquid having a refractive index close to that of these materials, it is possible to inspect the internal state of the liquid, such as dust adhering to the inner wall surface.

Although glass is used as the material of the second substrate 5 in which the groove is formed in the above embodiment, a transparent material such as acrylic or epoxy can be used,
Also in this case, the inside of the recording head can be inspected by the same method. However, in the case of these resins, it is desirable to select, as the liquid to be injected, a liquid that has a close refractive index and does not dissolve or deteriorate these resins.

(Others) The present invention is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink even in the ink jet recording system. The present invention provides excellent effects in a recording head and a recording apparatus of the type in which the thermal energy causes a change in ink state. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal as a result
This is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection openings to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333, U.S. Pat. No. 44, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The configuration using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in Japanese Patent Laid-Open No. 59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the electrical connection to the main body of the apparatus and the ink from the main body of the apparatus by being attached to the main body of the apparatus. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping means, a cleaning means, a pressure or suction means for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be either integrally formed of the recording heads or a combination of a plurality of them. The present invention is also very effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet method, it is common to adjust the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. At times, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in a standing state. You may use the ink liquefied by. In any case, by applying heat energy such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP 54-56847 A or JP 60-7.
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the ink jet recording apparatus of the present invention may be used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. It may be in a form or the like.

[0031]

As is apparent from the above description, according to the present invention, a liquid filled in the inside formed of a light transmissive material and having a refractive index substantially equal to the refractive index of the light transmissive material transmits light. Diffuse reflection due to a relatively rough surface such as a machined surface of a flexible material is eliminated. This enables a clear visual inspection of the inside.

Further, since the liquid that is almost the same as the component of the recording ink is used as the liquid, it does not adversely affect the ink ejection of the recording head after the inspection.

As a result, the inside of the ink passage of the recording head can be visually inspected, and a highly reliable recording head with few failures in the market can be obtained.

Further, since the inspection of disconnection, loss or residue of the electrothermal conversion element, the electrodes and the like can be conducted collectively after the recording head is completed, the inspection can be omitted during the manufacturing process of the recording head, and the recording head can be manufactured at a low cost. Can be supplied.

Further, the liquid filling the ink passage is made to be a part or all of the components of the recording ink of the recording head, so that even if the liquid remains in the ink passage, the separation electric heat of the ink is generated. A highly reliable recording head can be obtained without changing the characteristics of the recording head due to adhesion of kogation or the like on the conversion element or change in wettability at the ejection port.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an inkjet recording head according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA ′ in FIG.

FIG. 3 is a sectional view taken along line BB ′ in FIG.

[Explanation of symbols]

 1 First Substrate 2 Electrothermal Conversion Element 3 Ink Path 4 Recess Formation Layer 5 Second Substrate 6 Common Liquid Chamber 7 Ink Supply Hole 8 Groove Processing Surface 10 Discharge Port

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 9012-2C B41J 3/04 103 B

Claims (3)

[Claims] 1. An ink jet recording head for ejecting ink, and an ink supply system for the head, wherein at least a part of an ink supply system is formed of a light-transmissive material. A liquid having a refractive index substantially equal to the refractive index of the transparent material is filled inside the ink jet recording head or the ink supply system formed of the light transparent material, and the liquid is filled through the light transparent material. A method for inspecting an inkjet recording head and an ink supply system for the head. 2. The ink jet recording head according to claim 1, wherein the ink jet recording head uses thermal energy to generate bubbles in the ink and ejects the ink based on the generation of the bubbles. A method for inspecting an ink supply system for the head. 3. An ink jet recording head for ejecting ink, and the ink jet recording head, wherein at least a part of an ink supply system for the head is formed of a light transmissive material, and the light transmissive material of the ink supply system. In the liquid used for the inspection of the inside through the inside of the ink jet recording head or the ink supply system, which has a refractive index substantially equal to that of the light transmissive material and is formed of the light transmissive material. A test liquid which is filled and has a part or all of the components of the ink ejected from the recording head.