JP3336312B2 - Color printing head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color printing head, and more particularly to a multi-nozzle type color ink jet recording head in which a plurality of color inks are ejected from a plurality of ejection orifices.

[0002]

2. Description of the Related Art Heretofore, non-impact recording apparatuses have attracted attention in that noise during recording is negligibly small. Among them, high-speed printing is possible, and special fixing to so-called plain paper has been performed. The ink jet recording (liquid jet recording) method, which can perform recording without performing any processing, is an extremely powerful recording apparatus. In recent years, various color printing methods using color inks have been proposed and improved. ing.

A conventional color printing system of this type performs printing by flying droplets of ink of a plurality of colors and attaching them to a recording member.
There is one such as described in Japanese Patent Publication No. 50, which is shown in FIG. In FIG. 16, a color inkjet head unit 1 includes a heating element substrate 2 having a heating resistor,
A grooved plate 3 in which a plurality of inks A, B, and C can be alternately supplied, and in which liquid supply grooves arranged on the same surface are formed; 4A, 4B, and 4C, supply pipes 5A, 5B, and 5C, and a printed circuit board 6 for applying image signals, and a discharge orifice 7 for multicolor ink.
Constitute a multi-orifice array arranged at high density.

In the color ink jet head unit 1 having such a configuration, the supply block 4A,
Ink A of three primary colors is supplied to the liquid supply groove through 4B and 4C,
B and C are supplied, and a small droplet of ink of a predetermined color is ejected from a discharge orifice 7 at a predetermined position by an electrothermal transducer selectively driven so that the ink adheres to the recording member. It has become.

[0005]

However, in the color ink jet head unit 1 described above,
The three colors of ink A, B, and C are discharged from the discharge orifice 7 from one end side to the other end side in the arrangement direction.
Since they are arranged so as to be ejected in the order of C, A, B, C, there is a problem that the structure is complicated and the manufacturing cost is high.

SUMMARY OF THE INVENTION An object of the present invention is to propose a multi-nozzle type color ink jet recording head capable of realizing compactness at low cost.

[0007]

According to the first aspect of the present invention,
In order to solve the above problems, an ink injection pressure application device which applies a jetting pressure to the ink, an electrode portion for inputting a signal to the ink ejection pressure applying means, the ink ejection pressure applying means
An ink flow path for supplying ink to the ink ejection pressure applying unit;
Independently forming an ink jet pressure applying block having
An ink ejection pressure applying unit integrating a plurality of independently formed ink ejection pressure applying blocks ;
And a multi-nozzle plate in which a discharge orifice communicating with each ink flow path of the dispensing unit is formed in one plate. The invention according to claim 2 is
In order to solve the above-mentioned problems, the ink jet pressure applying blow
The ink jet pressure applying means and the ink jet pressure;
A substrate having an electrode section for supplying a signal to the pressure applying means;
Ink flow path for supplying ink to the ink ejection pressure applying means
Is characterized in that it has a structure in which members constituting the above are combined . The invention according to claim 3 solves the above problem.
Therefore, the ink jet pressure applying unit has a plate-like structure.
A plurality of the ink ejection pressure applying blocks are laminated and integrated.
It is characterized by that. The invention according to claim 4 is the above-mentioned invention.
In order to solve the problem, the ink jetting pressure applying means includes a
It is characterized in that the piezo element is used as the driving force.

[0008]

According to the first aspect of the present invention, there is provided an ink jet pressure applying means for applying an ink jet pressure to ink, an electrode section for inputting a signal to the ink jet pressure applying means, and an ink jet pressure of the ink jet pressure applying means. Ink flow for supplying ink to the application section
Independently formed ink jet pressure applying block with path
A plurality of the independently formed ink ejection pressure applying blocks
An ink ejection pressure applying unit that integrates the ink
A multi-nozzle plate in which a discharge orifice communicating with each ink flow path of the ejection pressure applying unit is formed in one plate. Therefore, the color inkjet head can be compactly integrated and the manufacturing cost can be reduced. According to the second aspect of the invention, the application of the ink ejection pressure is performed.
The block comprises: the ink ejection pressure applying means;
Substrate having electrode portion for supplying signal to injection pressure applying means
And supplying ink to the ink jetting pressure applying means.
This is a structure formed by combining members constituting a flow channel. did
Therefore, the color inkjet head is compact
And can reduce manufacturing costs. Claim 3
In the invention, the ink jet pressure applying unit has a plate-like structure.
A plurality of the above-mentioned ink jet pressure applying blocks are laminated and integrated.
did. Therefore, color inkjet heads
It can be compactly integrated and can reduce manufacturing costs.
In the invention according to claim 4, the ink jetting pressure applying means is
The piezo element is used as the driving force. Therefore, semiconductor technology
Compared to thermal inkjet head manufactured using
Even if a piezo element that tends to be large due to
The ink jet head can be integrated compactly?
Production costs can be reduced.

[0009]

Embodiments of the present invention will be described below. First, an example of the inkjet head will be described with reference to FIGS. FIG. 5 is a view for explaining the operation of a bubble jet (registered trademark) head as an example of an ink jet head, FIG. 6 is a perspective view showing an example of a bubble jet head, and FIG. 7 is a view showing the bubble jet head shown in FIG. The lid substrate (FIG. 7A) and the heating element substrate (FIG. 7A)
7B is a perspective view of the lid substrate shown in FIG. 7A as viewed from the back side. In FIGS. 5 to 8, 21 is a lid substrate, and 22 is a heating element. Substrate, 23 is a selection (independent) electrode, 24 is a common electrode, 25 is a heating element (heater), 26 is an adjacent ink layer (ink), 27 is a bubble, 28 is a flying ink droplet, 29 is a recording liquid (ink) flow An inlet, 30 is a discharge orifice, 31 is a flow path, and 32 is a region for forming a liquid chamber.

First, the ink ejection by the bubble jet will be described with reference to FIG. (a) is a steady state, in which the surface tension of the ink 26 and the external pressure are in an equilibrium state at the orifice surface. 6B, the heater 25 is heated until the surface temperature of the heater 25 sharply rises and the adjacent ink layer 26 is heated until a boiling phenomenon occurs, and minute bubbles 27 are scattered.

FIG. 3C shows a state in which the adjacent ink layer 26, which is rapidly heated on the entire surface of the heater 25, is instantaneously vaporized to form a boiling film, and the bubbles 27 grow. At this time, the pressure in the nozzle rises by an amount corresponding to the growth of the bubble, the balance with the external pressure on the orifice surface is lost, and the ink column starts to grow from the orifice. (D) is a state in which the bubble 27 has grown to the maximum, and the ink 26 corresponding to the volume of the bubble is pushed out from the orifice surface. At this time, no current is flowing through the heater 25, and the surface temperature of the heater 25 is decreasing. The maximum value of the volume of the bubble 27 is slightly delayed from the timing of applying the electric pulse.

FIG. 3E shows a state in which the bubble 27 is cooled by ink or the like and starts to contract. At the front end of the ink column, the ink moves forward while maintaining the pushed speed, and at the rear end, the ink flows backward from the orifice surface into the nozzle due to a decrease in the nozzle internal pressure due to the contraction of the bubble, and the ink column is constricted. . In (f), the bubble 27 is further contracted, the adjacent ink layer 26 is in contact with the surface of the heater 25, and the surface of the heater 25 is cooled more rapidly. On the orifice surface, the external pressure is higher than the internal pressure of the nozzle, so that a large meniscus has entered the nozzle. The tip of the ink column becomes an ink drop 28 and flies at a speed of 5 to 10 m / sec toward the recording paper.

(G) In the process in which the ink 26 is supplied (refilled) to the orifice again by capillary action and returns to the state of (a), the bubbles 27 are completely eliminated. FIG. 9 is a view showing a typical example for explaining a main part configuration of the above-described bubble jet head. FIG. 9 (a) is a detailed front partial view from the orifice side of the bubble jet head, and FIG. 9 (b). FIG. 3 is a partial sectional view taken along the dashed-dotted line AA.

In the bubble jet head 41 shown in these figures, a predetermined number of grooves having a predetermined line density and a predetermined width and depth are formed on a substrate 43 provided with an electrothermal transducer 42 on the back surface thereof. An orifice for causing liquid to fly by joining a grooved plate 44 provided so as to cover the substrate 43
It has a structure in which a liquid ejection part 46 including 45 is formed.

The liquid discharge part 46 is a heat source in which thermal energy generated by the orifice 45 and the electrothermal transducer 42 acts on the liquid to generate bubbles, which cause a sudden state change due to expansion and contraction of the volume. And an action part 47. The heat acting portion 47 is located above the heat generating portion 48 of the electrothermal transducer 42 and has a heat acting surface 49 serving as a surface of the heat generating portion 48 that comes into contact with the liquid.
Is the low side.

The heat generating section 48 includes a lower layer 50 provided on the substrate 43, a heating resistor layer 51 provided on the lower layer 50, and an upper layer 52 provided on the heating resistor layer 51. Is done. The heating resistance device 51 is provided with electrodes 53 and 54 for supplying electricity to the layer 51 for generating heat on its surface, and a heat generation portion 48 is formed by the heating resistance layer between these electrodes. ing.

The electrode 53 is a common electrode for the heat generating section of each liquid discharging section, and the electrode 54 is a selection electrode for selecting the heat generating section of each liquid discharging section to generate heat. It is provided along the liquid flow path of the section. The protective layer 52 is a liquid that fills the liquid flow path of the heat generating resistance layer 51 and the liquid discharge unit 46 in order to chemically and physically protect the heat generating resistance layer 51 in the heat generating unit 48 from the liquid used. And prevents short circuit between the electrodes 53 and 54 through the liquid, and also prevents electric leakage between adjacent electrodes.

The liquid flow paths provided in the respective liquid discharge sections are communicated upstream of each discharge section via a common liquid chamber (not shown) constituting a part of the liquid flow paths. The electrodes 53 and 54 connected to the electrothermal converter 42 provided in each liquid discharge section are protected by the upper layer and pass under the common liquid chamber on the upstream side of the heat acting section due to the design convenience. It is provided to pass through.

FIG. 10 is a view for explaining the structure of a bubble generating means using a heating resistor. In the drawing, reference numeral 61 denotes a heating resistor;
62 is an electrode, 63 is a protective layer, 64 is a power supply device, and useful materials for forming the heating resistor 61 include, for example,
A mixture of tantalum-SiO2, tantalum nitride, nichrome, silver-palladium alloy, silicon semiconductor or boride of metal such as hafnium, lanthanum, zirconium, titanium, tantalum, tungsten, molybdenum, niobium, chromium, vanadium and the like can be mentioned.

Among the materials constituting the heating resistor 61, metal borides can be mentioned as being particularly excellent. Among them, hafnium boride has the most excellent characteristics, The order is zirconium boride, lanthanum boride, tantalum boride, vanadium boride, and niobium boride. The heating resistor 61 can be formed using the above-mentioned materials by using a technique such as electron beam evaporation or sputtering. The film thickness of the heating resistor 61 is determined according to its area, material, shape and size of the heat acting portion, and furthermore, power consumption in an actual plane, so that the amount of heat generated per unit time is as desired. But usually 0.
001 to 5 μm, preferably 0.01 to 1 μm.

As the material constituting the electrode 62, many of the commonly used electrode materials are effectively used, and specifically, for example, Al, Ag, Au, Pt, Cu and the like are mentioned. At a predetermined position by a method such as evaporation using
It is provided in a predetermined size, shape, and thickness. The characteristic required for the protective layer 63 is to protect the heating resistor 61 from the recording liquid without preventing the heat generated by the heating resistor 61 from being effectively transmitted to the recording liquid. Useful materials for forming the protective layer 63 include, for example, silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, tantalum oxide, zirconium oxide, and the like. Can be formed. The thickness of the protective layer 63 is usually
0.01-10 μm, preferably 0.1-5 μm, optimally 0.1-
Desirably, it is 3 μm.

FIGS. 11 and 12 show another example of the ink jet head applied to the present invention.
(b) is a principle diagram thereof, and FIG. 12 is an example of a multi-orifice head. 11 and 12, 71 is a piezo element, 72
Is an ink pressure chamber, 73 is a discharge orifice, 74 is a common ink chamber, 75 is a valve, 76 is an ink filter, 77 is an inkjet head, 78 is a print surface, and 79 is an ink droplet.

In this method, unlike the ink jet head of the above-described method, a piezo element 71 constituting an electrostrictive vibrator is provided as an energy actuating part in the middle of a discharge orifice 73 and an ink supply source (common ink chamber 74). A pulse-like signal voltage is applied to the piezo element 71 to distort the piezo element 71 to reduce the volume of the ink pressure chamber 72 and generate a pressure wave.
Is discharged. FIG. 12 forms a multi-orifice array by arranging a plurality of piezo elements 71 shown in FIG.

FIG. 1 is a view showing a first embodiment of a color ink jet recording apparatus according to the present invention, and shows a color ink jet head unit. FIG. 1 shows that four inks, specifically, black (B), cyan (C), magenta (M), and yellow (Y) are provided for each color by stacking four heads shown in FIG. A plurality of ejection orifices 81B, 82C, 83M and 84Y for ejection are arranged so as to be arranged on substantially the same plane, and a pair of lid substrates 85 provided with ejection orifices 81B, 82C, 83M and 84Y are provided. A bubble jet type color ink jet head unit 97 is shown in which recording heads 93 to 96 composed of elements 88 to 88 and heating element substrates 89 to 92 are integrated.

It should be noted that an ink jet head using a piezo element as shown in FIG. 11 can be applied to the head unit 97. FIG. 2 shows the head unit described above.
Reference numeral 97 denotes a main part of the color inkjet recording apparatus to which the color inkjet recording apparatus is attached. In the figure, reference numeral 97 denotes a color ink jet head unit shown in FIG. 1 mounted on a carriage 101, and a storage unit for storing ink supplied from an ink supply source, and a discharge orifice for ejecting the stored ink.
Recording heads 93 to 96 provided with 81B, 82C, 83M, 84Y,
Having.

FIG. 3 is a view showing a second embodiment of the color ink jet recording apparatus according to the present invention. In this embodiment, an example in which an orifice plate is provided for each discharge orifice is shown. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Since the configuration is common, the description will be made using the head 93.

The head 93 shown in the first embodiment has a flow path shown in FIG.
The orifice plate 121 having a plurality of holes 121a corresponding to the discharge orifices 81B is attached to the head 93 on the side of the discharge orifices 81, and the distal end of the discharge orifice 81B is directly formed through the holes 121a. The discharge orifices 81 (that is, corresponding to the tip of the flow path 31 in FIG. 8) communicate with each other, and the plate 121 is provided independently for each of the heads 93 to 96.

The plate 121 can be formed by, for example, a technique such as photoetching or photoelectroforming. For example, a method of manufacturing the orifice plate 121 by Ni photoelectroforming is described in Japanese Patent Application Laid-Open No. 54-87529. Such techniques can be used. Thus plate 121
Since the head 93 with the orifice plate is more excellent in the symmetry of the shape of the ejection orifice than the head without the orifice plate 121, it is possible to perform stable ink ejection (particularly, stability in the ejection direction). .

FIG. 4 is a view showing a third embodiment of the color ink jet recording apparatus according to the present invention.
An example in which one orifice plate is provided for the discharge orifices 81B, 82C, 83M, and 84Y is shown. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In this embodiment, the discharge orifices 81B, 82C, 83M, 84Y
One orifice plate 131 in which a plurality of holes 131a corresponding to 81B, 82C, 83M and 84Y are formed in the heads 93 to 96 on the side.
Sheets, and discharge orifices 81 to 8 through these holes 131a.
4 (that is, corresponding to the tip of the flow path 31 in FIG. 8).

In this embodiment, one orifice plate
Since the 131 is provided, the manufacturing cost of the color ink jet head unit 97 can be reduced as compared with the one described in the second embodiment.

[0031]

According to the present invention, color ink jet head can be integrated into the compact and can be reduced manufacturing cost. In addition, thermal technology manufactured using semiconductor technology
Tends to be large in structure compared to inkjet heads
Color inkjet head
Can be integrated compactly and production costs can be reduced
You.

[Brief description of the drawings]

FIG. 1 is a perspective view of a color inkjet head unit.

FIG. 2 is a diagram illustrating a main part of the inkjet printer.

FIG. 3 is a view showing a second embodiment of the color ink jet recording apparatus according to the present invention, wherein (a) is an exploded perspective view of a head and an orifice plate, and (b) is a head in which an orifice plate is attached to a discharge orifice. It is a perspective view of.

FIG. 4 is a view showing a third embodiment of the color ink jet recording apparatus according to the present invention, wherein (a) is an exploded perspective view of a head plate and a head unit, and (b) is a discharge orifice having an orifice plate attached thereto. FIG. 3 is a perspective view of a head unit.

FIG. 5 is a diagram illustrating the principle of ink ejection by a bubble jet.

FIG. 6 is a perspective view showing an example of a bubble jet head.

7 (a) is a perspective view of a lid substrate constituting the bubble jet head shown in FIG. 6, and FIG. 7 (b) is a perspective view of a heating element substrate shown in FIG.

FIG. 8 is a perspective view of the lid substrate shown in FIG.

9 (a) is a detailed partial front view of the bubble jet head viewed from the orifice side, and FIG. 9 (b) is a partial sectional view taken along a chain line AA.

FIG. 10 is a diagram showing a structure of a bubble generating means using a heating resistor.

FIG. 11 is a diagram illustrating another example of the inkjet head.

FIG. 12 is a view showing a multi-orifice head.

FIG. 13 is a configuration diagram of a conventional color inkjet head unit.

[Explanation of symbols]

 81B, 82C, 83M, 84Y Discharge orifice 97 Color inkjet head unit 101 Carriage 113 Blade (cleaning member) 121, 131 Orifice plate P Recording paper

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-10948 (JP, A) JP-A-2-8059 (JP, A) JP-A-1-238943 (JP, A) 80345 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/05 B41J 2/045 B41J 2/055

Claims (4)

(57) [Claims] An ink jetting means for applying an ink jetting pressure to the ink; an electrode unit for inputting a signal to the ink jetting pressure applying means ;
Ink jet having an ink flow path for supplying ink to the application section
The injection pressure applying block is formed independently, and formed independently.
Ink jet with an integrated ink jet pressure applying block more
An integrated color inkjet head, comprising: a pressure application unit ; and a multi-nozzle plate in which a discharge orifice communicating with each ink flow path of the ink ejection pressure application unit is formed in one plate. 2. The ink jet pressure applying block according to claim 1 , wherein
The ink jetting pressure applying means and the ink jetting pressure applying means.
A substrate having an electrode section for supplying a signal,
A member constituting an ink flow path for supplying ink to the applying means
2. The integrated color ink jet head according to claim 1, wherein the integrated color ink jet head has a structure formed by combining the following . 3. The ink jet pressure applying unit according to claim 1, wherein the ink jet pressure applying unit has a plate-like structure.
The above-mentioned ink jet pressure applying blocks are laminated and integrated.
The integrated collar according to claim 2, wherein the collar is formed as a single piece.
Ink jet head. 4. The ink jet pressure applying means includes a piezo element.
4. A driving force according to claim 1, wherein the driving force is a driving force.
Integrated color inkjet head.