JP2007261167A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make defects of an image by an ink hitting time difference hard to occur by reducing a distance between discharging port rows when ink feeding ports are arranged under a zigzag form. <P>SOLUTION: A distance L between the discharging port rows is made smaller by arranging discharging ports 102 along one edge on the internal side of an ink feeding port 110 of a two-row zigzag arrangement. Thus, the ink hitting time difference is made smaller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording head that discharges a desired liquid by applying energy to the liquid from the outside, and in particular, an ink jet recording head that discharges a liquid using kinetic energy generated by heating and foaming the liquid with thermal energy. It is about.

  With respect to this type of ink jet recording head, for example, the ink jet recording method described in Japanese Patent Laid-Open No. Sho 54-51837 is another ink jet recording method in that it provides thermal energy to a liquid to obtain droplet driving force. It has different characteristics. That is, in the recording method disclosed in the above publication, the liquid subjected to the action of thermal energy is heated to generate bubbles, and droplets are discharged from the orifice at the tip of the recording head by the action force based on the generation of bubbles. It is characterized in that information is recorded by forming the droplets on the recording member. A recording head applied to this recording method generally includes an orifice provided for ejecting a liquid, and a heat acting portion that is a portion where heat energy for ejecting droplets communicated with the orifice acts on the liquid. A liquid discharge section having a liquid flow path having a liquid crystal structure as a part, a heating resistance layer as a heat conversion body that is a means for generating thermal energy, an upper protective layer that protects it from ink, and a lower layer for storing heat It has.

  In recent years, in order to realize high-definition image recording at a higher speed, there has been a demand for a wider print width and a higher arrangement density of orifices. 10 to 12 will be described.

  FIG. 10 is an external perspective view showing an example of a conventional ink jet recording head, FIG. 11 is a schematic perspective view schematically showing the cross section of the main part, and FIG. 12 is a schematic view schematically showing the top surface thereof. FIG.

  In this ink jet recording head, a heater 111 is provided on a silicon substrate 101 and nozzles are formed by a nozzle material 113. Ink is supplied from the back surface of the silicon substrate 101 through an ink supply port 110 formed as a hole penetrating the silicon substrate 101. By applying electric energy to the heater 111 to heat and foam the ink, the ink is ejected from the ejection port 102 and recording is performed. Application of electric energy to the heater 111 is performed by a transistor circuit in the driving element 103 provided on the silicon substrate 101 through the electric circuit board 107 and the flexible circuit board 105 in accordance with a signal input from the outside through the electric connector 108. Is done by. The driving element 103 is provided with a sealing material 112 for preventing ink from entering the mounting portion. As methods for forming high-density, high-precision nozzles and ejection openings in such an ink jet recording head, methods disclosed in Japanese Patent Laid-Open Nos. 5-330066 and 6-286149 have been proposed. As for the formation of the ink supply port 110, there is known a method of forming a supply port etched perpendicularly to the Si (110) substrate as disclosed in JP-A-10-138478.

When the ink jet recording head having such a configuration is elongated, the ink supply ports formed by the above-described method are provided with a plurality of ink supply ports for one nozzle row as shown in FIG. 110 and a beam 115 for maintaining the mechanical strength of the silicon substrate 301 is provided. Further, a method for maintaining the mechanical strength of the silicon substrate 301 by increasing the thickness of the silicon substrate 301 as compared with a small-sized ink jet recording head is conventionally known.
JP 54-51837 A JP-A-5-330066 JP-A-6-286149 JP-A-10-138478

  However, the conventional ink jet recording head as described above has the following problems.

  By providing the beam 115, the nozzle 116 is generated on the beam. In this nozzle, the flow resistance to the ink discharge port 102 is particularly large, and the ink refill frequency is particularly low.

  Further, as the head becomes longer, the mechanical strength of the beam 115 part inevitably becomes lower than that of the ink jet recording head having a small ink supply port 110, and there are many damages in the manufacturing process of the ink jet recording head, and the yield. Has led to a decline.

  As one method for solving such a problem, the ink supply ports 110 are not formed in one line as shown in FIG. 12, but are arranged in a two-row staggered arrangement as shown in FIGS. Can be considered. By doing so, the mechanical strength of the head can be increased, and the nozzles applied to the beam portions are eliminated, so that the ink refill frequency is not lowered. However, as the ink supply ports are arranged in two rows, the ejection ports 102 are also arranged in two rows. Therefore, for example, when adjacent pixels are recorded by the discharge ports belonging to different columns, such as the discharge ports A and B, A ′ and B ′ shown in FIGS. A distance L between them and an ink placing time difference corresponding to the scanning speed in the X direction in the figure are generated. When ink is applied to adjacent pixels with a time lag, the ink that is applied later is affected by the adjacent ink that has been previously applied, and part of the ink moves to the adjacent pixel. There is. In this case, the same type and amount of ink is applied per pixel, but the optical density of the recorded material differs between adjacent pixels, resulting in defects such as so-called white stripes and black stripes. The effect of this ink driving time difference varies depending on the time difference, pixel density, ink type and amount, and type of recording material, but generally for recording materials suitable for higher image quality recording such as glossy paper. In any case, the difference is greater as the difference in the ink ejection time is larger.

  In the present invention, first, ink supply ports are arranged in a zigzag pattern in two rows, and a plurality of electrothermal conversion elements and nozzles and discharge ports corresponding thereto are arranged inside the plurality of supply ports arranged in a staggered pattern. It arrange | positions along one side located in this. By adopting such a configuration, the above-described conventional example eliminates the nozzles on the beam, improves the ink refill characteristics of all the nozzles, makes the inkjet recording head compatible with higher speed printing, and has a narrow width. By eliminating the beam-like structure, the mechanical strength of the ink jet can be improved, and the interval L between the ejection port arrays can be made sufficiently small. As a result, the time difference in which ink is ejected into the adjacent pixels is also small. An ink jet recording head suitable for higher quality recording is provided.

  As described above, according to the present invention, the plurality of ink supply ports are arranged in a staggered manner, so that the above-mentioned nozzles on the beam are eliminated, and the ink refill characteristics of all the nozzles are improved. By making the head compatible with higher-speed printing and eliminating the narrow beam-like structure, the mechanical strength of the ink jet is also improved, and the interval between the nozzle and discharge port arrays is reduced, so that adjacent pixels Therefore, it is possible to make it difficult to cause image defects due to the difference in the ink implantation time.

Example 1
1 to 9 are diagrams for explaining a first embodiment of the present invention. FIG. 1 is a schematic external perspective view of the embodiment of the present invention, FIG. 2 is a schematic sectional view, and FIG. FIG. 4 is a schematic plan view schematically showing the upper surface of the ink jet recording head of the present embodiment, FIGS. 4 and 5 are cross sectional views taken along the AA and BB sections of FIG. 3, respectively, and FIG. It is the perspective view which showed typically the structure of the inkjet recording device using a recording head.

  In the ink jet recording head of the present invention, a heater 111 is provided on a silicon substrate 101 and nozzles are formed by a nozzle material 113. Ink is supplied from the ink common liquid chamber 117 formed in the support member 106 through the base plate 104 to the heater 111 from the back surface of the silicon substrate 101 through the ink supply port 110 formed as a hole penetrating the silicon substrate 101. Is done.

  The ink supply port 110 was formed using a silicon substrate 101 having a plane orientation of (100) and using a silicon anisotropic etching method.

  Printing is performed by applying electric energy to the heater 111 to heat and foam the ink, thereby discharging the ink from the discharge port 102. Application of electric energy to the heater 111 is performed by a transistor circuit in the driving element 103 provided on the silicon substrate 101 through the electric circuit board 107 and the flexible circuit board 105 in accordance with a signal input from the outside through the electric connector 108. Is done by. The driving element 103 is provided with a sealing material 112 for preventing ink from entering the mounting portion.

  In the present invention, two nozzles 114 are provided, and the ink supply ports 110 are arranged in a staggered manner as shown in FIG. 3 corresponding to each of the nozzles 114. Since the ink supply ports are arranged in a staggered manner, the AA cross section and the BB cross section in FIG. 3 are shaped as shown in FIGS. For this reason, the mechanical strength of the silicon substrate 101 is also improved. In addition, since all the nozzles 114 are arranged at the edge of the ink supply port 110, the ink refill characteristics of each nozzle 114 are also improved uniformly.

  FIG. 9 schematically shows an ink jet recording apparatus using the ink jet recording head of the present invention. In FIG. 9, four inkjet recording heads 120 of the present invention are used, each of which is filled with yellow, magenta, cyan, and black colors. These ink jet recording heads are made long by adopting the above-described structure, and as shown in FIG. 9, the recording width of the recording paper 201 is full. Therefore, when printing, without moving the ink jet recording head 120, the recording paper 201 is attracted to the paper conveying belt 202 and passes under the ink jet recording head 120 once to complete the printing. It is.

  As described above, the present invention arranges a plurality of ink supply ports 110 in a staggered manner and arranges all the nozzles 114 adjacent to the ink supply ports 110, thereby improving the refill characteristics of the individual nozzles 114, The mechanical strength of the silicon substrate 101 is improved, and two nozzles are provided by disposing nozzles and discharge ports along one side located inside the plurality of supply ports arranged in a staggered pattern. An ink jet recording head suitable for high-quality recording, in which the gap L between the ejection port arrays is small and thereby the difference in ink ejection time between adjacent pixels is small and image defects such as black stripes and white stripes are unlikely to occur. is there.

(Example 2)
FIG. 6 is a schematic plan view schematically showing the upper surface of the ink jet recording head according to the second embodiment of the present invention, and FIGS. 7 and 8 are cross-sectional views taken along the AA and BB sections of FIG. 6, respectively. . In this case, a (110) -oriented Si single crystal substrate is used. As in the first embodiment, the ink supply port 110 is formed by anisotropic etching of Si. In this case, since the wall surface of the ink supply port 110 can be formed perpendicular to the substrate surface, the interval between the two rows of ink supply ports 110 arranged in a staggered manner is made closer than in the case of the first embodiment. be able to. For this reason, it is also possible to arrange the ejection port arrays arranged inside the supply port array in a single line, and in this case, there is no ink ejection time difference, and image defects caused by the ejection time difference can be prevented.

Schematic perspective view showing an embodiment of the ink jet recording head of the present invention. Schematic sectional view of the main part of the ink jet recording head of the present invention Schematic top view of the main part of the inkjet recording head of the present invention Sectional view in the AA section of FIG. Sectional view taken along the line BB in FIG. Schematic top view of the main part of the ink jet recording head of the second embodiment of the present invention Sectional view in the AA cross section of FIG. Sectional view in the BB cross section of FIG. Schematic perspective view of a recording apparatus using the inkjet recording head of the present invention Schematic perspective view of a conventional inkjet recording head Schematic sectional perspective view of the main part of a conventional ink jet recording head Schematic cross-sectional view of the main parts of a conventional inkjet recording head Schematic top view of the main parts of a conventional inkjet recording head Schematic top view of the main parts of a conventional inkjet recording head

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Silicon substrate 102 Ink discharge port 103 Drive element 104 Base plate 105 Flexible circuit board 106 Support member 107 Electrical circuit board 108 Electrical connector 109 Cap receiver 110 Ink supply port 111 Heater 112 Sealing material 113 Nozzle material 114 Nozzle 115 Beam 201 Recording paper 202 Paper conveyor belt

Claims (3)

  A plurality of electrothermal transducers disposed on the substrate and converting applied electrical energy into thermal energy in accordance with electrical signals input from the outside, and arranged in rows corresponding to the electrothermal transducers A plurality of nozzles arranged to foam and discharge ink with the thermal energy, and a plurality of ink supply ports formed as through holes in the thickness direction of the substrate and supplying ink to the plurality of nozzles; In the ink jet recording head, the plurality of ink supply ports are arranged in a staggered manner in two rows, and the electrothermal conversion elements and An ink jet recording head, wherein nozzles corresponding to the nozzles are arranged along one side of the plurality of supply ports located inside two rows formed by the supply ports.   The ink jet recording head according to claim 1, wherein the substrate is made of Si.   The substrate is a Si single crystal substrate, and the electrothermal conversion element and the nozzle corresponding thereto are disposed on the (100) plane or the (110) plane of the Si single crystal substrate, 2. The ink jet recording head according to claim 1, wherein a wall surface of an ink supply port formed as a through-hole in the thickness direction is formed by a (111) plane of the Si single crystal substrate.

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